WO2005109395A1 - Driving method of deplay device having main display and sub display - Google Patents

Driving method of deplay device having main display and sub display Download PDF

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Publication number
WO2005109395A1
WO2005109395A1 PCT/JP2005/009019 JP2005009019W WO2005109395A1 WO 2005109395 A1 WO2005109395 A1 WO 2005109395A1 JP 2005009019 W JP2005009019 W JP 2005009019W WO 2005109395 A1 WO2005109395 A1 WO 2005109395A1
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WO
WIPO (PCT)
Prior art keywords
display
display panel
common
signal
scanning lines
Prior art date
Application number
PCT/JP2005/009019
Other languages
French (fr)
Inventor
Tomomi Kamio
Original Assignee
Casio Computer Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Casio Computer Co., Ltd. filed Critical Casio Computer Co., Ltd.
Priority to EP05741329A priority Critical patent/EP1634271A1/en
Priority to CN2005800005324A priority patent/CN1806274B/en
Publication of WO2005109395A1 publication Critical patent/WO2005109395A1/en
Priority to HK07100219.8A priority patent/HK1093255A1/en

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Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3614—Control of polarity reversal in general
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3648—Control of matrices with row and column drivers using an active matrix
    • G09G3/3666—Control of matrices with row and column drivers using an active matrix with the matrix divided into sections
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3674—Details of drivers for scan electrodes
    • G09G3/3677—Details of drivers for scan electrodes suitable for active matrices only
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02—Details of power systems and of start or stop of display operation
    • G09G2330/021—Power management, e.g. power saving
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M2250/00—Details of telephonic subscriber devices
    • H04M2250/16—Details of telephonic subscriber devices including more than one display unit

Definitions

  • the present invention relates to a display device and an electronic apparatus comprising the display device and drive control method for the display devices. More particularly, the present invention relates to an electronic apparatus , for example a cellular telephone (cell-phone), portable telephone, etc. comprising a display device and associated display device comprising two or more display panels and a drive control method thereof.
  • an electronic apparatus for example a cellular telephone (cell-phone), portable telephone, etc. comprising a display device and associated display device comprising two or more display panels and a drive control method thereof.
  • FIG.7 is an outline configuration diagram showing an example of a conventional prior art display device comprised with two display panels . As seen in FIG. 7 and like the above-mentioned cellular telephone, this configuration is comprised with a relatively largemain displayandacomparatively smaller sub-display.
  • the configuration illustrates two display panels in which the displaypixels are arranged in a two-dimensional arrayandapplied to a liquid crystal display panel corresponding to an active-matrix driving method.
  • the conventional prior art display device for example as shown in FIG. 7, has a configuration comprised with at least two varieties of display panels PNL1, PNL2 arranged in parallel with a different number of scanning lines; a gate driver GDR (scanning driver) which sequentially applies a scanning signal to each scanning line group SLm, SLs arranged in the row direction of each displaypanel PNL1, PNL2; a source driver SDR (data driver) which applies a display signal (for example, display signal voltage corresponding to a luminance signal) to the data line group DLm arranged in the column direction of the display panel PNL1; and common voltage generation sections COM1, COM2 (common electrode driver section) which apply a common signal voltage Vcoml , Vcom2 to a common electrode (omittedfrom diagram) provided in each display panel PNL1, PNL2.
  • GDR scanning driver
  • the two display panels PNL1, PNL2 are different in panel size.
  • a portion of the data line group DLs passes through the display panel PNL1 and leads to the display panel PNL2.
  • the data line group DLs is shared by the two display panels PNL1, PNL2.
  • FIG. 7 an example is shown in FIG. 7.
  • the number of scanning lines is 240 and the number of data lines is 528 (176 x 3 (RGB)).
  • the number of scanning lines is 64 and the number of data lines is 264 (88 x RGB) .
  • the data line group DL1-DL528 which extend from the source driver SDR
  • the data line group DL1-DL264 has a configuration shared by the two display panels PNL1, PNL2.
  • the display device shown in FIG. 7 for example even though a configuration in the case of two different panel sizes (the number of scanning lines) is illustrated, the display device may also be comprised of two display panels of the same panel size.
  • the gate driver GDR has a single driver chip structure, but it can also have a distinct driver chip structure corresponding to each scanning line group
  • the structure has to be able to apply a sequential scanning signal to all of the scanning lines in plural stages by way of the shift signal generation component provided in the gate driver GDR.
  • the common voltage generation sections COM1, COM2 apply common signal voltages Vcoml , Vcom2 to the common electrode of each display panel PNL1, PNL2 and as seen in FIG. 7 may have a configuration formed separately so as to correspond to each of the display panels PNL1, PNL2.
  • separate common signal voltages Vcoml, Vcom2 may also be applied to each display panel PNL1, PNL2 from a single common voltage generation section.
  • FIG. 8 is a timing chart showing an example of the display drive control method in a conventional prior art display device.
  • the display drive control method in the above-mentioned display device for example as shown in FIG. 8 exemplifies 1 vertical scanning period of 1 frame period.
  • scanning drive for the scanning signals S1-S64 is sequentially applied from the gate driver GDR to the scanning line group SLs (SL1-SL64) of the display panel PNL2 used for the smaller panel size.
  • SLs scanning line group SLs (SL1-SL64) of the display panel PNL2 used for the smaller panel size.
  • this timing synchronizes and after supplying the display signals D1-D264 from the source driver SDR to the data.line group DLs
  • the desired image information is displayed on each of the display panels PNL1 and PNL2.
  • a series of display drive control operations is sequentially performed which writes the display signal to the display panel PNL1 in 1 frame period as 1 cycle. Accordingly, within a 1 frame period, separate operation periods (individual display periods) perform the display drive of each display panel PNL1, PNL2 in chronological order (serial) .
  • the display signal is sequentially written to the display panels PNL2 and PNL1 in a 1 frame period of 1 cycle.
  • This case example is implemented with a frame reversal drive method (also commonly known as a frame-inversion drive method) which performs reversal control of the signal polarity (polarity reversal) in the common signal voltage Vcom (Vcoml, Vcom2) for every 1 frame period.
  • Vcom common signal voltage
  • Vcoml common signal voltage
  • the voltage polarity applied to the liquid crystal molecules (pixel capacitance) of the display pixel configuration readily produces degeneration of the liquid crystals or seizing, the display image quality tends to deteriorate by flickering, etc.
  • FIG.9 is a timing chart showing a case of performing display drivewithaconventionalpriorart displaydevicebylinereversal drive method and frame reversal drive method.
  • the PNL2 display available period from the 1 st row thru the 160 th row is scanned in the display panel PNL2.
  • the display signal is simultaneously supplied via the data lines by way of the source driver SDR and synchronizing with the scan timing Tl, T2, • • • , T480 (horizontal scanning period) of each row (scanning lines) , reversal control of the signal polarity for the common signal voltages Vcoml,
  • the reversal drive performed in the display panels during driving cycles (frequency rate of repetition) is equivalent to the cases of line reversal drive and frame reversal drive.
  • BP back portion
  • MP middle portion
  • FP front portion
  • FP front portion
  • each display panel is set to a line reversal drive and a frame reversal drive method even though one of the display panels is actuated in a display state and the display panel on the opposite side is shifted to a non-display state.
  • the reversal drive of the common signal voltage applied to the common electrode of the display panel in a non-display state cannot be discontinued.
  • the present invention of an electronic apparatus comprises a plurality of display panels and comprises display devices which display an image corresponding to a display signal.
  • the present invention has the advantage of being able to achieve a reduction in the power consumption related to reversal drive in each display panel.
  • the display device in the present invention for acquiring the above-mentioned advantage comprises at least a plurality of display panels which comprise a plurality of scanning lines and a plurality of signal lines with display pixels situated near each intersecting point of each scanning line and signal line besides a common electrode situated in common with each of the display pixels; the display panels having a predetermined numbers of the scanning lines respectively; a scan driver section which sequentially applies a scanning signal to each of the plurality of scanning lines in each of the plurality of display panels and sequentially set the display pixels corresponding to the appropriate scanning lines as a selective state; and a control section which controls operation for sequentially selecting a number of the scanning lines of each of the plurality of display panels corresponding to the ratio of the numbers of the scanning lines in each of the plurality of display panels at every predetermined scan timing by the scan driver section and for repeating uniform sequences between each of the display panels in a display period at a plurality of times within a one frame period.
  • the display period comprises a vertical scanning period required for shifting the number of scanning lines of each display panel entirely to a selective state.
  • the display device further comprises a common electrode driver section to a common electrode for each display panel which applies a common signal voltage for setting a voltage level in respective common electrodes; and the control section at least performs reversal control of the signal polarity relative to each of the display panels for each of the common signal voltages applied to the common electrode in each of the display panels by the common electrode driver section so that reversal drive for every scanning line and every frame period corresponds to a selection operation for each of the scanning lines by the scan driver section.
  • control section is set to a period which selects the scanning lines of anyone of the displaypanels in the plurality of display panels by the scan driver section, the signal polarity of the common signal voltage applied to the common electrode of whichever other of the display panels selected next by the common electrode driver section is set as the same polarity as the signal polarity of the common signal voltage applied to the common electrode of the relevant display panel when the scanning lines of the next relevant display panel are selected; performs reversal control of the signal polarity for each of the common signal voltages so that a sum total applied time period for each signal polarity of the common signal voltage applied to the common electrode in each of the display panels becomes equal in the display period; and the reversal frequency in a display period within a one frame period of the signal polarity for the common signal voltage applied to the common electrode of each of the display panels is set to the same total as the number of scanning lines of each these display panels .
  • the displaydevice further comprises one signal driver section which applies a display signal voltage corresponding to the display signal to the plurality of signal lines .
  • the scan driver section is separately provided corresponding to each of the plurality of display panels .
  • the plurality of the display panels in the case of having a 1 st display panel and a 2 nd display panel in which the ratio of the numbers of the scanning lines is defined as i: j (i, j are random 1-digit positive integers) comprises a 1 st common electrode driver section and a 2 nd common electrode driver section for each common electrode of the 1 st display panel and the 2 nd display panel which apply a 1 st common signal voltage and a 2 nd common signal voltage that sets a voltage level in each of these common electrodes.
  • the control section contro.ls to repeat alternately an operation which sequentially selects the scanning lines of i-th rows in the 1 st display panel and an operation which sequentially selects the scanning lines of j-th rows in the 2 nd display panel by the scan driver section in the display period; and in a period which scans the display pixels of the 1 st display panel, the signal polarity of the 2 nd common signalvoltage applied to the common electrode of the 2 nd display panel by the 2 nd common electrode driver section is set as the same polarity as the signal polarity of the 2 nd common signal voltage when the scanning lines of the 2 nd display panel are selected next; and in a period which selects the scanning lines of the 2 nd display panel, the signal polarity of the 1 st common signal voltage applied to the 1 st common electrode of the 1 st display panel by the 1 st common electrode driver section is set as the same polarity as the signal polarity of the 2 nd common signal voltage.
  • the control section comprises adummyperiod for applied time period adjustment of the common signal voltage which regulates the sum total applied time period for each signal polarity of the common signal voltage to become equal in arelevant display period which is applied to the common electrode of each display panel in the display period.
  • the electronic apparatus in the present invention for acquiring the above-mentioned advantage is an electronic apparatus comprising a display device which displays an image corresponding to a display signal, the display device comprises at least two displaypanels which comprise a plurality of scanning lines and a plurality of signal lines with display pixels situated near each intersecting point of each scanning line and signal line besides a common electrode situated in common with each of the display pixels; the two display panels having first and second numbers of the scanning lines respectively; a scan driver section which sequentially applies a scanning signal to each of the plurality of scanning lines in each of the plurality of display panels and sequentially sets the display pixels corresponding to the appropriate scanning lines as a selective state; a common electrode driver section which applies a common signal voltage for setting this common electrode voltage level in the common electrode in each of the display panels;
  • the electronic apparatus is a cellular telephone.
  • the display period comprises a vertical scanning period required for shifting the number of scanning lines of each display panel entirely to a selective state.
  • the control section in a period which selects the scanning lines of one direction of the display panels of the two display panels by a scan driver section, the signal polarity of the common signal voltage applied to the common electrode of other direction display panel by the common electrode driver section is set as the same polarity as the signal polarity of the common signal voltage which is applied to the common electrode of the relevant other direction display panel when the scanning lines of the other direction display panel are selected next; and in a period which selects the scanning lines of the other direction display panel by the scanning driver section, the signal polarity of the common signal voltage applied to the common electrode of the one direction display panel by the common electrode driver section is set as the same polarity as the signal polarity of the common signal voltage applied to the common electrode of the relevant other direction display panel; performs reversal control of the signal polarity for each of the common signal voltages so that a
  • j (i, j are random 1-digit positive integers ) comprises a 1 st common electrode driver section and a 2 nd common electrode driver section for each common electrode of the 1 st display panel and the 2 nd display panel which apply a 1 st common signal voltage and a 2 nd common signal voltage that sets a voltage level in each of these common electrodes.
  • the control section controls to repeat alternately an operationwhich sequentially selects the scanning lines of i-th rows in the 1 st display panel and an operation which sequentially selects the scanning lines of j-th rows in the 2 nd display panel by the scan driver section in the display period; and in a period which scans the display pixels of the 1 st display panel, the signal polarity of the 2 nd common signal voltage applied to the common electrode of the 2 nd display panel by the 2 nd common electrode driver section is set as the same polarity as the signal polarity of the 2 nd common signal voltage when the scanning lines of the 2 nd display panel are selectednext; and in aperiodwhich selects the scanning lines of the 2 nd display panel, the signal polarity of the 1 st common signal voltage applied to the 1 st common electrode of the 1 st display panel by the 1 st common electrode driver section is set as the same polarity as the signal polarity of the 2 nd common signal voltage.
  • the control section comprises a dummy period for applied time period adjustment of the common signal voltage which regulates the sum total applied time period for each signal polarity of the common signal voltage to become equal in a relevant display period and controls to repeat alternately an operation which sequentially selects the scanning lines of i-throws in the 1 st displaypanel andan operation which sequentially selects the scanning lines of j-th rows in the 2 nd display panel by the scan driver section.
  • FIG.1 is an entire configuration view showing one embodiment of the display device related to the present invention
  • FIGS. 2A and 2B are entire configuration views showing one embodiment of the electronic apparatus (cellular telephone) related to the present invention
  • FIG. 3 is a timing chart showing the first embodiment of the drive control method in the liquid crystal display related to the present invention
  • FIG. 4 is a timing chart showing the second embodiment of the drive control method in the liquid crystal display related to the present invention
  • FIG. 5 is a timing chart showing the third embodiment of the drive control method in the liquid crystal display related to the present invention
  • FIG. 6 is a timing chart showing the fourth embodiment of the drive control method in the liquid crystal display related to the present invention
  • FIG.7 is an outline configuration diagram showing an example of a conventional prior art display device comprised with two display panels
  • FIG. 8 is a timing chart showing an example of the display drive control method in a conventional prior art display device
  • FIG.9 is a timing chart showing a case of performing display drivewithaconventionalprior art displaydevicebylinereversal drive method and frame reversal drive method.
  • FIG.1 is an entire configuration view showing one embodiment of the display device related to the present invention.
  • the display device related to the present invention is divided roughly into a configuration comprising a main display panel 10m, a sub-display panel 10s, a data line group Ld, a data driver 20, scanning line groups Lsm and Lss, a main scan driver 30m, a sub-scan driver 30s, a display signal generation circuit 40, a main common electrode driver circuit
  • the main display panel 10m (1 st display panel) and the sub-display panel 10s (2 nd display panel) display pixels are arranged in a two-dimensional array and have predetermined panel sizes, respectively.
  • the data line group Ld is arranged so as to extend in the column direction and shared with the main display panel 10m and the sub-display panel 10s .
  • the single data driver 20 (source driver; signal driver section) is connected to the data line group Ld.
  • the scanning line groups Lsm, Lss are arranged so as to extend in the row direction of the main display panel 10m and the sub-display panel 10s.
  • the main scan driver 30m (described as the "main driver” for convenience in the diagram; scan driver section) is connected to the scanning line group Lsm of the main display panel 10m.
  • the sub-scan driver 30s (describedas the "sub-driver” for convenience in the diagram; scan driver section) is connected to the scanning line group Lss of the sub-display panel 10s.
  • the display signal generation circuit 40 is constituted with an RGB decoder 41 and a reversal amplifier 42.
  • the main common electrode driver circuit 60m (common electrode driver section) applies a main common signal voltage Vcomm (1 st common signal voltage) to a common electrode
  • the sub-common electrode driver circuit 60s applies a sub-common signal voltage Vcoms (2 nd common signal voltage) to a common electrode of the sub-display panel 10s.
  • the LCD controller 50 (control section) supplies a predetermined control signal to at least the above-mentioned data driver 20, the main scan driver 30m, the sub-scan driver 30s , the main common electrode driver circuit 60m and the sub-common electrode driver circuit 60s .
  • the backlight provided consists of, for example, a light source such as a cold cathode-raytube, etc. andalight-guiding sheet suchas an acrylic sheet, etc. in the main display panel 10m and reverse side sub-display panel 10s.
  • a light source such as a cold cathode-raytube, etc.
  • alight-guiding sheet suchas an acrylic sheet, etc.
  • the main display panel 10m and the sub-display panel 10s are liquidcrystal displaypanelswhichbothhave apanel structure corresponding to awell-known active-matrix drivingmethod.
  • the main display panel 10m and the sub-display panel 10s comprise the data line group Ld and scanning line groups Ls which are arranged in mutually intersecting directions between opposing transparent substrates , respectively.
  • a plurality of displaypixels (pictureelement transistors, pixel capacitance and auxiliary capacitance) are arranged near each intersecting point of the data line group Ld and the scanning line groups
  • the data driver 20, the main scan driver 30m and the sub-scan driver 30s may also have a configuration which is mounted on the above-mentioned flexible printed circuit board.
  • the data driver 20 is connected to the data line group Ld and situated in common with the above-described main display panel 10m and the sub-display panel 10s. Based on a horizontal control signal provided from the LCD controller 50, the data driver 20 is supplied from the display signal generation circuit 40. For example, each color of the luminance signal (display signal) of R (red), G (green) and B (blue) is taken in for 1 row units and held. Subsequently, display signal voltage correspondingto this luminance signal is simultaneouslysupplied to the data line group Ld.
  • the main scan driver 30m and the sub-scan driver 30s are connected respectively to each of the scanning line groups Lsm,
  • a predetermined scanning signal (selection signal) is sequentially applied to each scanning line of the main display panel 10m and the sub-display panel 10s which sets a selective state. Accordingly, while synchronizing with this selection timing, display signal voltage is written to the display pixels corresponding to the scanning lines set as a selective state by applying display signal voltage corresponding to the luminance signal from the data driver 20 to the display pixel positions which intersect with the above-mentioned data line group Ld.
  • the panel sizes of the main display panel 10m and the sub-display panel 10s are different and the panel size ratio (number of scanning lines) of the main display panel 10m and sub-display panel 10s is approximated (i: j; i, j are random 1-digit positive integers).
  • the main scan driver 30m and the sub-scan driver 30s related to the embodiment function at timing corresponding to this panel size ratio. After sequentially applying a scanning signal to the scanning lines of the i-th row segment in the main display panel 10m and accomplishing scanning drive, an operation sequentially applies a scanning signal to the scanning lines of the j-th row segment in the sub-display panel 10s and accomplishes scanning drive.
  • Operational control is performed so as to repeat alternately between. the main display panel 10m and the sub-display panel
  • display signal voltage corresponding to the luminance signal is sequentially written to the display pixels for each row in the main display panel 10m and the sub-display panel 10s .
  • FIG. 1 shows a functional block diagram of an outline configuration for the display device related to the present invention.
  • the main scan driver 30m and the sub-scan driver 30s provided corresponding to each of the display panels are shown as a separate configuration, specifically as seen in FIG. 7 for example, the device may have a configuration in which these scan drivers are formed in one component using a single driver chip or may have a configuration provided with separate driver chips as shown in FIG. 1.
  • the RGB decoder 41 constituted in the display signal generation circuit 40 for example, extracts each chrominance signal (RGB signal) of R, G, B from an image input signal supplied from the exterior of the display device and outputs to the reversal amplifier 42.
  • the reversal amplifier 42 performs reversal processing of the RGB signal polarity extracted by the RGB decoder 41 basedon apolarityreversal signalFRPp(frame/line reversal signal) supplied from the LCD controller 50.
  • a RGB reversal signal (also referred to as an inversion signal) is generated and outputted to the data driver 20 as the luminance signal (analog signal).
  • the LCD controller 50 generates the above-mentionedpolarity reversal signal FRPp and polarity reversal signals FRPm, FRPs based on a horizontal synchronizing signal H and a vertical synchronizing signal V supplied from the exterior of the display device (or extracted from an image input signal by the RGB decoder
  • display signal voltage corresponding to the luminance signal is applied to each display pixel (pixel electrode side) at predetermined timing by generating a horizontal control signal and a vertical control signal and supplying the data driver 20, the main scan driver 30m and the sub-scan driver 30s, respectively, and control is effected to display the predetermined image information based on the image input signal to the main display panel 10m and the sub-display panel 10s.
  • the drive control operation distinctive to the embodiment is performed by controlling the polarity reversal signals FRPp, FRPm, FRPs supplied to the reversal amplifier 42, the main common electrode driver circuit 60m and the sub-common electrode driver circuit 60s together with the horizontal control signal and the vertical control signal which are supplied to the data driver 20, the main scan driver 30m and the sub-scan driver 30s.
  • the operation which scans (scanning signal applied to the scanning lines) each row of the main display panel 10m and the sub-display panel 10s is switched between the main scan driver 30m and the sub-scan driver 30s for every row of a predetermined number and a vertical control signal setting is alternately repeated.
  • the main common electrode driver circuit 60m and the sub-common electrode driver circuit 60s are connected to the common electrode provided in the above-mentioned main display panel 10m and the sub-display panel 10s, respectively.
  • Themain common signalvoltageVcommandthe sub-common signal voltage Vcoms applied to each common electrode are set in order for the signal polarity to reverse relative to the display signal voltage which is applied to each display pixel (pixel electrode) of the main display panel 10m and the sub-display panel 10s based on the polarity reversal signals FRPm, FRPs outputted from the LCD controller 50.
  • FIGS. 2A and 2B are entire configuration views showing one embodiment of the electronic apparatus (cellular telephone) related to the present invention.
  • FIG.2A is a drawing showing the primary operation functions surface (inner surface) side of the electronic apparatus
  • FIG. 2B is a drawing showing the reverse (outer surface) side of an electronic apparatus.
  • the apparatus illustrated has a foldable case structure, this shape is just one of various types employed in cellular telephones . Therefore, it is stressed that the electronic apparatus canhave another style of case structure, such as a bar type, a revolving (rotatable) type, a slide (swivel) type, etc.
  • the cellular telephone 100 related to the embodiments has a configurationwhich is foldable and constructedwith a lower section casing 115 next to a centrally placed hinge joint 114, manual operation buttons 113 (keypad), etc; and an upper section display casing 116 with a main display 111 (corresponds to the above-mentioned main display panel 10m) and a sub-display 112 (corresponds to the above-mentioned sub-display panel 10s) installed back to back.
  • the manual operation buttons 113 are provided on the primary operation surface (case lower inner surface) side with an assortment of buttons for performing selection and execution of specific functions, such as entering a telephone number for placing a phone call, buttons usedforinputtingalphanumericcharacters , atelephonedirectory or other,various applications .
  • the main display 111 which displays the alphanumeric characters and symbols input by manipulating the above-mentioned manual operation buttons 113 or an executed application, etc. and is situated opposing (facing inwards) the above-mentioned manual operation buttons 113 when the foldable cellular telephone 100 is closed.
  • the sub-display 112 displays , for example, the current time and date, the incoming status of E-mail and telephone calls, etc. when the cellular telephone 100 is folded and situated on the reverse side (facing outwards) of the out of view main display 111.
  • the main display 111 for example, employs a relatively high definition display panel consisting of a reasonably large screen with a diagonal dimension of about two inches (2").
  • the sub-display 112 employs arelative lowimage quality display panel consisting of a comparatively smaller screen with a diagonal dimension of about one inch (1").
  • FIG. 3 is a timing chart showing the first embodiment of the drive control method in the liquid crystal display related to the present invention.
  • the number of scanning lines allocated in the main display panel 10m is 320.
  • the number of scanning lines allocated in the sub-display panel 10s is 160.
  • the panel size ratio (number of scanning lines) of themain display panel 10m and the sub-display panel 10s that will be explained is precisely 2:1. Also, the number of data lines in the main display panel 10m and the sub-display panel 10s can be the same number or may be a different number.
  • the drive control method of the display device related to the embodiment depicts 1 vertical scanning period (display period) within a 1 frame period. Initially, at scan timing Tl (horizontal scanning period) , the main scan driver 30m applies a high-level scanning signal Sim relative to the 1 st row (line) scanning line in the main display panel 10m based on a vertical control signal supplied from the LCD controller 50.
  • ahigh-level scanning signal S2m is sequentially applied relative to the 2 nd row scanning line .
  • a predetermined luminance signal is sequentiallywritten relative to the 1 st and 2 nd rows of the display pixels in the main display panel 10m by simultaneously applying display signal voltage relative to the 1 st row of the display pixels in the main display panel 10m from the data driver 20 at scan timing Tl and display signal voltage relative to the
  • the display signal voltage applied at scan timing Tl is set as a signal voltage which constitutes positive polarity relative to apredetermineddisplaycentervoltage and the display signal voltage applied at scan timing T2 is set as a signal voltage which constitutes negative polarity relative to the proper display center voltage.
  • the main common signal voltage Vcomm applied from the main common electrode driver circuit 60m to the common electrode of the main display panel 10m is set as signal voltage (low-level) which constitutes negative polarity relative to a common signal center voltage Vcomc at the above-mentioned scan timing Tl and is set as signal voltage (high-level) relative to the proper common signal center voltage Vcomc at scan timing T2.
  • the sub-common signal voltage Vcoms which has any one of the high or low signal levels is applied from the sub-common electrode driver circuit 60s to the common electrode of the sub-display panel 10s and further controlled so that the same signal level (low-level in
  • FIG. 3 of the sub-common signal voltage Vcoms is applied, for example, during the periods of consecutive scan timing Tl, T2, based on the polarity reversal signal FRPs supplied from the LCD controller 50. Subsequently, at scan timing T3, the sub-scan driver 30s applies a high-level scanning signal Sis relative to the 1 st row scanning line in the sub-display panel 10s based on a vertical control signal supplied from the LCD controller 50.
  • a predetermined luminance signal is written relative to the 1 st row of the display pixels in the sub-display panel 10s by simultaneously applying display signal voltage of positive polarity relative to the 1 st row of the display pixels in the sub-display panel 10s via each data line from the data driver 20.
  • a low-level sub-common signal voltage Vcoms is applied from the sub-common electrode driver circuit 60s to the common electrode of the sub-display panel 10s. Accordingly, at periods of scan timing T1-T3, sub-common signal voltage Vcoms having the same signal level (low-level) is applied continuously.
  • a display data writing operation of the display data is not performed during scan timing T3 in main display panel 10m side, while low-level scanning signals
  • the main scan driver 30m sequentially applies high-level scanning signals S3m, S4m relative to the 3 rd and 4 th rows in the main display panel 10m based on a vertical control signal.
  • a predetermined luminance signal is sequentially written relative to the 3 rd and 4 th rows of the display pixels in the main display panel 10m by simultaneously applying display signal voltage of positive polarity relative to the 3 rd row of the display pixels in the main display panel 10m from the data driver 20 at scan timing T4 and display signal voltage of negative polarity relative to the 4 th row of the display pixels in the main display panel 10m at scan timing T5 via each data line.
  • the main common signal voltage Vcomm which becomes low-level at scan timing T4 and high-level at scan timing T5 is sequentially applied from the main common electrode driver circuit 60m to the common electrode of the main display panel
  • the sub-common signal voltage Vcoms which has any one of the high or low signal levels (high-level in FIG.3) is applied continuously from the sub-common electrode driver circuit 60s to the common electrode based on the polarity reversal signal FRPs.
  • the sub-scan driver 30s applies a high-level scanning signal S2s relative to the 2 nd row scanning line in the sub-display panel 10s based on a vertical control signal.
  • a predetermined luminance signal is written relative to the 2 nd row of the display pixels in the sub-display panel 10s by simultaneously applying display signal voltage of negative polarity relative to the 2 nd row of the display pixels in the sub-display panel 10s via each data line from the data driver 20.
  • a high-level sub-common signal voltage Vcoms is applied from the sub-common electrode driver circuit 60s to the common electrode of the sub-display panel 10s. Accordingly, at periods of scan timing T4-T6, sub-common signal voltage Vcoms having the same signal level
  • the main common signal voltage Vcomm whichhas anyone of thehighor low signal levels (high-level in FIG.3) is applied continuously from the main common electrode driver circuit 60m to the common electrode based on the polarity reversal signal FRPm.
  • the desired luminance signal (display signal voltage) is written and displayed as image information in both the main display panel 10m which has 320 scanning lines andthe sub-displaypanel 10swhichhas 160 scanning lines in 1 vertical scanning period (display period) within a
  • a vertical retrace line period is set after conclusion of 1 vertical scanning period within a 1 frame period regarding the display signalvoltage togetherwith themain common signal voltage Vcomm and sub-common signal voltage Vcoms applied to each row of the display pixels (pixel electrodes and common electrode) in the main display panel 10m and the sub-display panel 10s in the above-mentioned 1 vertical scanning period.
  • the period (for example, period of 3 phase segments in FIG. 3) of duration allocated for odd-numbered segments is identical for each scan timing T1-T480 in the above-mentioned vertical scanning period.
  • the odd-numbered reversals of the main common signal voltage Vcomm and sub-common signal voltage Vcoms are performed.
  • the main common signal voltage Vcomm is reversed 3 times and the sub-common signal voltage Vcoms is reversed 1 time.
  • the signal polarity of each signal voltage in the next 1 frame period is reversed and frame reversal drive is performed in the main display panel 10m and the sub-display panel 10s.
  • the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s for the following scanning drive occurrence.
  • line (row) reversal drive is performed regarding the main display panel 10m and the sub-display panel 10s, respectively, and set in each display panel so as to become the same sum total time between each signal polarity (namely, the periods when the signal polarity constitutes positive polarity and the periods which constitute negative polarity are equal) of each common signal voltage Vcomm, Vcoms.
  • the reversal drive frequency of the main common signal voltage Vcomm applied to the main display panel 10m is the same total as the number of scanning lines in the main display panel 10m.
  • the reversal drive frequency of the sub-common signal voltage Vcoms applied to the sub-display panel 10s is the same total as the number of scanning lines in the sub-display panel 10s. Additionally, when one display is performing scanning drive in one display panel, the signal polarity of the common signal voltage is applied to the common electrode in the second display panel. However, the present invention is not limited to that which is set to the same polarity as the signal polarity of the common signal voltage applied to the common electrode of one display panel as mentioned above. For example, the apparatus may be set to reversed polarity or to reversed polarity only one time for every predetermined frequency randomly.
  • FIG. 4 is a timing chart showing the second embodiment of the drive control method in the liquid crystal display related to the present invention.
  • explanation is simplified or omitted in regard to control operations equivalent to the first embodiment mentioned above.
  • the number of scanning lines allocated in the main display panel 10m is
  • the number of scanning lines allocated in the sub-display panel 10s is 107.
  • the panel size ratio (number of scanning lines) of the main display panel 10m and the sub-display panel 10s will be explained as a case approximated 3:1 instead of a simpler integer ratio.
  • the number of data lines in the main display panel 10m and the sub-display panel 10s can be the same number or may be a different number.
  • high-level scanning signals Slm ⁇ S3m are sequentially applied relative to the 1 st thru 3 rd rows of the scanning lines in the main display panel 10m from the main scan driver 30m.
  • a predetermined luminance signal is sequentially written relative to the 1 st thru 3 rd rows of the display pixels in the main display panel 10m by sequentially applying display signal voltage relative to each of the display pixels for the 1 st thru 3 rows in the main display panel 10m via each data line from the data driver 20.
  • the display signal voltage applied from the data driver 20 at scan timing T1-T3, for example is set to a. signal voltage consisting of each polarity of positive, negative, positive, respectively, relative to a predetermined display center voltage.
  • the main common signal voltage consisting of each polarity of positive, negative, positive, respectively, relative to a predetermined display center voltage.
  • Vcomm applied from the main common electrode driver circuit 60m to the common electrode of the main display panel 10m is set to a signal voltage consisting of each polarity of positive, negative, positive, respectively, relative to predetermined common signal center voltage Vcomc.
  • the operation executes control so that the sub-common signal voltage Vcoms which has any one of the high or low signal levels (low-level in FIG.
  • a predetermined luminance signal is sequentially written relative to the 4 th thru 6 th rows of the display pixels in the main display panel 10m by sequentially applying display signal voltage relative to each of the display pixels for the 4 th thru 6 th rows in the main display panel 10m via each data line from the data driver 20.
  • the display signal voltage applied from the data driver 20 at scan timing T5-T7 is set to signal voltage consisting of each polarity of positive, negative, positive, respectively, relative to a predetermined display center voltage.
  • the main common signal voltage Vcomm applied from the main common electrode driver circuit 60m to the common electrode of the main display panel 10m is set to signal voltage consisting of each polarityof positive, negative, positive, respectively, relative to predetermined common signal center voltage Vcomc. More specifically focused on each scan timing T1-T3, T5-T7,
  • the sub-common signal voltage Vcoms which has any one of the high orlowsignal levels (high-level inFIG.4) is appliedcontinuously from the sub-common electrode driver circuit 60s to the common electrode based on the polarity reversal signal FRPs.
  • the sub-scan driver 30s applies a high-level scanning signal S2s relative to the 2 nd row scanning line in the sub-display panel 10s .
  • apredeterminedluminance signal iswritten relative to the 2 nd row of the display pixels in the sub-display panel 10s by simultaneously applying display signal voltage of negative polarity relative to the 2 nd row of the display pixels in the sub-display panel 10s via each data line from the data driver 20.
  • a high-level sub-common signal voltage Vcoms is applied from the sub-common electrode driver circuit 60s to the common electrode of the sub-display panel 10s . Accordingly, at periods of scan timing T5-T8, sub-common signal voltage Vcoms having the same signal level (high-level) is applied continuously.
  • the main common electrode driver circuit 60m is applied continuously from the main common electrode driver circuit 60m to the common electrode. Accordingly, at periods of scan timing T7-T8 , themain common signal voltage Vcommhaving the same signal level (high-level) is applied continuously.
  • the desired luminance signal is alternately repeating execution of similar control operations until scan timing T428 which perform scanning drive for 1 row segments of the scanning lines in the sub-display panel 10s after performing scanning drive for 3 row segments of the main display panel 10m.
  • display signal voltage is written and displayed as image information in both the main display panel 10m which has 320 scanninglines andthe sub-displaypanel 10swhichhas 107 scanning lines in 1 vertical scanning period (display period) within a
  • scanning drive of the scanning lines of each display panel is not performed for the purpose of regulating the sum total time for each signal polarity of each common signal voltage so as to be the same.
  • a dummy scanning interval is provided for adjusting the applied time period of each common signal voltage.
  • the scan timing T427 has a period equivalent to 1 scan timing set within 1 vertical scanning period. Accordingly, sum total time for each signal polarity of each common signal voltage Vcomm, Vcomms can be made the same (equalized) .
  • each signal polarity of the sub-common signal voltage Vcoms will be reversed in the following frame period and frame reversal drive is performed in the main display panel 10m and the sub-display panel 10s
  • the signal polarity of the main common signal voltage Vcomm on the main display panel 10m side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s.
  • the signal polarity of the sub-common signal voltage Vcoms on the sub-display panel 10s side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s for the following scanning drive occurrence. Accordingly, in 1 vertical scanning period, while being able to establish the reversal drive frequency of the main common signal voltage Vcomm applied to the main display panel
  • the reversal drive frequency of the sub-common signal voltage Vcoms applied to the sub-display panel 10s is the same total as the number of scanning lines in the sub-display panel
  • FIG. 5 is a timing chart showing the third embodiment of the drive control method in the liquid crystal display related to the present invention.
  • the number of scanning lines allocated in the main display panel 10m is 320.
  • the number of scanning lines allocated in the sub-display panel 10s is 80.
  • the panel size ratio (number of scanning lines) of the main display panel 10m and the sub-display panel 10s that will be explained is precisely 4:1.
  • the drive control method of the display device related to the embodiment, as seen in FIG. 5, depicts 1 vertical scanning period within a 1 frame period.
  • high-level scanning signals Slm ⁇ S4m are sequentially applied relative to the 1 st thru 4 th rows of the scanning lines in the main display panel 10m.
  • a predetermined luminance signal is sequentially written relative to the 1 st thru 4 th rows of the displaypixels in themain displaypanel 10mby sequentially applyingdisplay signalvoltage relative to eachof displaypixels of the appropriate 1 st thru 4 th rows via each data line from the data driver 20.
  • ahigh-level.scanning signal a high-level.scanning signal
  • Sis is applied relative to the 1 st row scanning line of the sub-display panel 10s from the sub-scan driver 30s .
  • a predetermined luminance signal is written relative to the 1 st row of the display pixels in the sub-display panel
  • the desired luminance signal (display signal voltage) is written and displayed as image information in both the main display panel 10m which has 320 scanning lines and the sub-display panel 10s which has 80 scanning lines in 1 vertical scanning period (display period) within a 1 frame period.
  • T10 • • • , as display signal voltage of positive polarity andnegative polarity is alternately applied to the pixel electrodes for each row of display pixels in the sub-displaypanel 10s, low-levelandhigh-level sub-common signal voltage Vcoms is alternately applied to the common electrode of the sub-display panel 10s and line (row) reversal drive is performed in the sub-display panel 10s.
  • a vertical retrace line period (non-display period) is set after conclusion of 1 vertical scanning period within a 1 frame period regarding the display signal voltage together with the main common signal voltage Vcomm and sub-common signal voltage Vcoms applied to each row of the display pixels (pixel electrodes and common electrode) in the main display panel 10mandthe sub-displaypanel 10s in the above-mentioned 1vertical scanning period.
  • the period (for example, period of 5 phase segments in FIG. 5) of duration allocated for odd-numbered segments is identical for each of the above mentioned scan timing T1-T400. In thesevertical retrace lineperiods the odd-numbered reversals of the main common signal voltage Vcomm and sub-common signal voltage Vcoms are performed.
  • the main common signal voltage Vcomm is reversed 5 times and the sub-common signal voltage Vcoms is reversed 1 time. Accordingly, the signal polarity of each signal voltage in the next 1 frame period is reversed and frame reversal drive is performed in the main display panel 10m and the sub-display panel 10s. Moreover, for example as shown in FIG. 5, when performing scanning drive in the sub-display panel 10s, the signal polarity of the main common signal voltage Vcomm in the main display panel
  • Vcoms in the sub-display panel 10s side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s for the following scanning drive occurrence. Accordingly, in 1 vertical scanning period, the reversal drive frequency of the main common signal voltage Vcomm applied to the main display panel 10m is the same total as the number of scanning lines in the main display panel 10m. The reversal drive frequency of the sub-common signal voltage Vcoms applied to the sub-display panel 10s is the same total as the number of scanning lines in the sub-display panel 10s.
  • FIG. 6 is a timing chart showing the fourth embodiment of the drive control method in the liquid crystal display related to the present invention.
  • explanation is simplified or omitted in regard to control operations equivalent to the first thru third embodiments mentioned above.
  • the display device (refer to FIG. 1) which contains the configuration mentioned above, the number of scanning lines allocated in the main display panel 10m is 160.
  • the number of scanning lines allocated in the sub-display panel 10s is 160.
  • the panel size ratio (number of scanning lines) of the main display panel 10m and the sub-display panel 10s will be explained is precisely 1:1.
  • the drive control method of the display device related to the embodiment, as seen in FIG. 6, depicts 1 vertical scanning period within a 1 frame period.
  • scan timing Tl, T3, T5, • • • , high-level scanning signals Sim, S2m, S3m, • • • are sequentially applied relative to the 1 st , 2 nd , 3 rd , • • • rows of each scanning line in the main display panel 10m from the main scan driver
  • a predetermined luminance signal is sequentiallywritten relative to eachrowof the sub-displaypanel 10s bysimultaneously applying display signal voltage relative to each of the display pixels for the 1 st , 2 nd , 3 rd ,••• rows in the sub-display panel 10s via each data line from the data driver 20.
  • the desired luminance signal (display signal voltage) is sequentially written and displayed as image information in both themain displaypanel 10mand the sub-display panel 10s which have 160 scanning lines, respectively, in 1 vertical scanningperiod (displayperiod) within a 1 frame period.
  • a vertical retrace line period (non-display period) is set after conclusion of 1 vertical scanning period within a 1 frame period regarding the display signal voltage together with the main common signal voltage Vcomm and sub-common signal voltage Vcoms applied to each row of the display pixels (pixel electrodes and common electrode) in the main display panel 10mandthe sub-displaypanel 10s in the above-mentioned 1vertical scanning period.
  • the period (for example, period of 3 phase segments in FIG. 6) of duration allocated for odd-numbered segments is identical for each of the above mentioned scan timing T1-T320.
  • the odd-numbered reversals of the main common signal voltage Vcomm and sub-common signal voltage Vcoms are performed. For example, as seen in FIG. 6, both the main common signal voltage Vcomm and the sub-common signal voltage Vcoms are reversed 3 times.
  • the signal polarity of the main common signal voltage Vcomm in the main display panel 10m side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s.
  • the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s for the following scanning drive occurrence.
  • the reversal drive frequency of the main common signal voltage Vcomm applied to the main display panel 10m is the same total as the number of scanning lines in the main display panel 10m.
  • the reversal drive frequency of the sub-common signal voltage Vcoms applied to the sub-display panel 10s is the same total as the number of scanning lines in the sub-display panel 10s.
  • the panel size ratio (number of scanning lines) of the main display panel 10m and the sub-display panel 10s is set as 1:1, as shown in FIG.
  • the reversal drive of the main common voltage Vcomm applied to the main display panel 10m and sub-common signal voltage Vcoms applied to the sub-display panel 10s is performed in the same cycle.
  • a configuration which interchanges the main common electrode driver circuit 60m and the sub-common driver circuit 60s with a single common electrode driver circuit is applicable. Accordingly, the circuit configuration of the display device can be simplified and miniaturized.
  • the panel size (number of scanning lines) of the main display panel and sub-display panel is set as 1:1, as described in each of the above-described embodiments, because reversal drive of the common signal voltage is applied to the main display panel and the sub-display panel and performed for only the number of scanning lines allocated in the main display panel or the sub-display panel, the reversal drive of the common signal voltage can be applied to the main displaypanel andthe sub-displaypanel.
  • the drivingcycles (frequency rate of repetition) related to the reversal drive can be decreased and a reduction in power consumption can be achieved.
  • the present invention is not restricted to this.
  • the present invention is anapparatuswhichapplies ascanning signalrelative to ascanning line group situated in each of two display panels at timing corresponding to the panel size ratio (number of scanning lines) of each display panel.
  • the panel sizeratio of the two displaypanels constitutes arelational quantity of i:j (i, j > 1, 1-digit positive integers)
  • this proportion is favorably applicable as well.
  • the reversal drive frequency (rate of repetition) of the common signal voltage applied to each display panel is the same total as the number of scanning lines in each display panel. While being able to reduce the driving cycles (frequency) related to the reversal drive to achieve a reduction in power consumption, line reversal drive and frame reversal drive can be accomplished. In addition, mentioned above is a case in which the panel size ratio of the two display panels does not constitute a simpler integer ratio.
  • operation timing is regulated with a 1 frame period. Specifically, a dummy scanning interval is provided which adjusts timing so that the sum total time for each signal polarity becomes the same for each common signal voltage in each display panel and an approximated integer ratio i: j proportionate to the panel size ratio is employed.
  • the operation then alternately repeats scanning drive between each of the display panels by the number of scanning lines relative to the panel size ratio of both display panels .
  • line reversal drive and frame reversal drive can be accomplished.
  • the display device comprises a main display panelwhich includes arelativelylargepanel size (greaternumber of scanning lines) and a sub-display panel with a comparatively smaller panel size (lesser number of scanning lines) .
  • the electronic apparatus may perform operational control so that i-th row scanning drive in the main display panel is performed after j-th row scanning drive in the sub-display panel.
  • the present invention may be a display device which is not limited to this and comprised with a greater number of display panels of 3 or more than 3.
  • the technical concept of the present invention can be applied by sequentially repeating scanning drive between each of the display panels by the number of scanning lines relative to the panel size ratio of each display panel.
  • line reversal drive and frame reversal drive can be accomplished.

Abstract

Two display panels (10m, 10s) each have a plurality of scanning lines and a plurality of signal lines with display pixels situated near each intersection point of each scanning line and signal line. A common electrode is situated in common with each of the display pixels and the display panels have a predetermined numbers of the scanning lines respectively. While repeating alternately between each of the display panels (10m, 10s) in a display period within a one frame period, an operation sequentially selects a number of the scanning lines of each of these display panel in turn in each display period corresponding to the ratio of the numbers of the scanning lines in each of these display panels at predetermined scan timing. Reversal control of the signal polarity of each common signal voltage is applied to the common electrode of each display panel (10m, 10s) in order that reversal drive of each display panel is performed for every scanning line and every frame period.

Description

DESCRIPTION DRIVING METHOD OF DISPLAY DEVICE HAVING MAIN DISPLAY AND SUB DISPLAY
CROSS-REFERENCE TO RELATED APPLICATION This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2004-142201, filed May 12, 2004, the entire contents of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device and an electronic apparatus comprising the display device and drive control method for the display devices. More particularly, the present invention relates to an electronic apparatus , for example a cellular telephone (cell-phone), portable telephone, etc. comprising a display device and associated display device comprising two or more display panels and a drive control method thereof. 2. Description of the Related Art During the last decade, proliferation of digital information equipment , such as personal computers , digital cameras , cellular telephones, DVD recorders , etc. has been unprecedented. In such digital information equipment, a display device is supplied for displaying various kinds of image information, the current operational state, etc. For instance, at present the majority of cellular telephones have evolved into a foldable type case structure (clamshell-type) . Also, many mainstream cellular telephone handsets of this style comprise two display panels installed back to back in the upper portion of the telephone: a relatively large main display formed in the primary operation functions surface side facing inwards (case inner surface) and a comparatively smaller sub-display that faces outwards (case outer surface). Here, a conventional prior art display device comprised with two display panels will be explained. FIG.7 is an outline configuration diagram showing an example of a conventional prior art display device comprised with two display panels . As seen in FIG. 7 and like the above-mentioned cellular telephone, this configuration is comprised with a relatively largemain displayandacomparatively smaller sub-display. Also, the configuration illustrates two display panels in which the displaypixels are arranged in a two-dimensional arrayandapplied to a liquid crystal display panel corresponding to an active-matrix driving method. The conventional prior art display device, for example as shown in FIG. 7, has a configuration comprised with at least two varieties of display panels PNL1, PNL2 arranged in parallel with a different number of scanning lines; a gate driver GDR (scanning driver) which sequentially applies a scanning signal to each scanning line group SLm, SLs arranged in the row direction of each displaypanel PNL1, PNL2; a source driver SDR (data driver) which applies a display signal (for example, display signal voltage corresponding to a luminance signal) to the data line group DLm arranged in the column direction of the display panel PNL1; and common voltage generation sections COM1, COM2 (common electrode driver section) which apply a common signal voltage Vcoml , Vcom2 to a common electrode (omittedfrom diagram) provided in each display panel PNL1, PNL2. Here, for example, the two display panels PNL1, PNL2 are different in panel size. In the configuration among the data line group DLm which extends from the source driver SDR in the display panel PNL1, a portion of the data line group DLs passes through the display panel PNL1 and leads to the display panel PNL2. Basically, in this arrangement the data line group DLs is shared by the two display panels PNL1, PNL2. For instance, an example is shown in FIG. 7. In the display panel PNL1 the number of scanning lines is 240 and the number of data lines is 528 (176 x 3 (RGB)). In the display panel PNL2 the number of scanning lines is 64 and the number of data lines is 264 (88 x RGB) . Among the data line group DL1-DL528 which extend from the source driver SDR, the data line group DL1-DL264 has a configuration shared by the two display panels PNL1, PNL2. Also, in the display device shown in FIG. 7 for example even though a configuration in the case of two different panel sizes (the number of scanning lines) is illustrated, the display device may also be comprised of two display panels of the same panel size. Furthermore, as seen in FIG. 7, the gate driver GDR has a single driver chip structure, but it can also have a distinct driver chip structure corresponding to each scanning line group
SLm, SLs arrangedin the displaypanels PNL1, PNL2. Specifically, the structure has to be able to apply a sequential scanning signal to all of the scanning lines in plural stages by way of the shift signal generation component provided in the gate driver GDR. Moreover, the common voltage generation sections COM1, COM2 apply common signal voltages Vcoml , Vcom2 to the common electrode of each display panel PNL1, PNL2 and as seen in FIG. 7 may have a configuration formed separately so as to correspond to each of the display panels PNL1, PNL2. On the other hand, separate common signal voltages Vcoml, Vcom2 may also be applied to each display panel PNL1, PNL2 from a single common voltage generation section. FIG. 8 is a timing chart showing an example of the display drive control method in a conventional prior art display device. The display drive control method in the above-mentioned display device, for example as shown in FIG. 8 exemplifies 1 vertical scanning period of 1 frame period. Initially, scanning drive for the scanning signals S1-S64 is sequentially applied from the gate driver GDR to the scanning line group SLs (SL1-SL64) of the display panel PNL2 used for the smaller panel size. As this timing synchronizes and after supplying the display signals D1-D264 from the source driver SDR to the data.line group DLs
(DL1-DL264) corresponding to each row of the display panel PNL2 and writing the display pixels of each row, subsequent scanning drive for the scanning signals S65-S304 is sequentially applied to the scanning line group SLm (SL65-SL304) of the display panel
PNL1 used for the larger panel size. As this timing synchronizes and by supplying the display signals D1-D528 from the source driver SDR to the data line group DLm (DL1 DL528) corresponding to each row of the display panel PNL1 and writing the display pixels of each row, the desired image information is displayed on each of the display panels PNL1 and PNL2. Specifically, in the display drive control method shown in FIG. 8, after writing the display data to the display panel PNL2, a series of display drive control operations is sequentially performed which writes the display signal to the display panel PNL1 in 1 frame period as 1 cycle. Accordingly, within a 1 frame period, separate operation periods (individual display periods) perform the display drive of each display panel PNL1, PNL2 in chronological order (serial) . Furthermore, in the display drive control method shown in FIG.8 the display signal is sequentially written to the display panels PNL2 and PNL1 in a 1 frame period of 1 cycle. This case example is implemented with a frame reversal drive method (also commonly known as a frame-inversion drive method) which performs reversal control of the signal polarity (polarity reversal) in the common signal voltage Vcom (Vcoml, Vcom2) for every 1 frame period. As is generally known in such a frame reversal drive method, the voltage polarity applied to the liquid crystal molecules (pixel capacitance) of the display pixel configuration readily produces degeneration of the liquid crystals or seizing, the display image quality tends to deteriorate by flickering, etc. as a result of being maintained at a specific polarity for a relatively lengthy interval of a 1 frame period. Therefore, as a display drive control method for controlling such phenomena in addition to the frame reversal drive method, a line (row) reversal drivemethod (also commonlyknown as row-inversion drive method) is applied in many cases which reverses (inverts) the signal polarity of the common signal voltage for each scanning line. FIG.9 is a timing chart showing a case of performing display drivewithaconventionalpriorart displaydevicebylinereversal drive method and frame reversal drive method. Here, with regard to the above comparative relationship with the embodiments of the present invention described later, a case will be explained in which after the display signal is written to the display panel PNL1, the display signal is written to the display panel PNL2 in a 1 frame period of the display device shown in FIG. 7. Also, while having 320 scanning lines for the display panel PNL1 and 160 scanning lines for the display panel PNL2 , this instance consists of the same number of data lines . Specifically, as shown in FIG. 9 for example, first in the PNL1 display available period within a 1 frame period and by way of the gate driver GDR, after scanning from the 1st row thru the 320th row in the display panel PNL1 , the PNL2 display available period from the 1st row thru the 160th row is scanned in the display panel PNL2. Also, while the display signal is simultaneously supplied via the data lines by way of the source driver SDR and synchronizing with the scan timing Tl, T2, • • • , T480 (horizontal scanning period) of each row (scanning lines) , reversal control of the signal polarity for the common signal voltages Vcoml,
Vcom2 is carriedout for each scan timing of eachrow. Furthermore, reversal control of the signal polarity (polarity reversal) in the relevant common signal voltages Vcoml , Vcom2 is performed for every 1 frame period. Accordingly, the number of scanning lines in the common signal voltages Vcoml, Vcom2 together constitute substantially 480 lines (= 320 lines + 160 lines) which represent the total number of scanning lines in each display panel PNL1, PNL2. The reversal drive performed in the display panels during driving cycles (frequency rate of repetition) is equivalent to the cases of line reversal drive and frame reversal drive. In addition as seen in FIG. 9, BP (back portion) is a non-display period from vertical synchronization timing (start timing of a 1 frame period) to a display available period of the display panel PNL1. MP (middle portion) is a non-display period from a display available period of the display panel PNL1 to a displayavailable periodof the displaypanel PNL2. FP (front portion) is a non-display period from a display available period of the display panel PNL2 to the next vertical synchronization timing and indicates what is known as a vertical retrace line period. Parenthetically, in a cellular telephone which has two display panels , an image can only be viewed on one of the display panels (for example, the main display) at a time and nothing can be viewed on the other side display panel (for example, the sub-display) because the opposite side display panel is shifted to a non-display state. In this case, each display panel is set to a line reversal drive and a frame reversal drive method even though one of the display panels is actuated in a display state and the display panel on the opposite side is shifted to a non-display state. The reversal drive of the common signal voltage applied to the common electrode of the display panel in a non-display state cannot be discontinued. Thus, it is essential to maintain the reversal drive of the common signal voltage appliedconstantly to the common electrode of bothdisplay panels . In order to lower power consumption in the display panel of the opposite direction in a non-display state, when reversal drive of the common signalvoltage suppliedto the common electrode of the relevant displaypanel is discontinued, the electric charge stored in the display pixels in the previous display state leaks gradually via an electrostatic protection device. As a result, streak-like "noise" may be generated in the display screen in proportion to the amount of variation of this leak and the display state becomes distorted (smeared) • Also, based on the electric charge stored in the display pixels, the liquid crystals tend to deterioratebycontinuouslyapplyingconstant polarityvoltage to the liquid crystal molecules for a relatively lengthy period. Thus , in a display device which has two display panels , even if the display panel of one direction is actuated in a display state and the display panel of the opposite direction is shifted to a non-display state, common signal voltage is always applied to both displaypanels . Since it is necessary to performreversal drive by predetermined cycles for reversal drive control of the common signal voltage, there is a drawback in that power consumption increases .
SUMMARY OF THE INVENTION The present invention of an electronic apparatus comprises a plurality of display panels and comprises display devices which display an image corresponding to a display signal. The present invention has the advantage of being able to achieve a reduction in the power consumption related to reversal drive in each display panel. The display device in the present invention for acquiring the above-mentioned advantage comprises at least a plurality of display panels which comprise a plurality of scanning lines and a plurality of signal lines with display pixels situated near each intersecting point of each scanning line and signal line besides a common electrode situated in common with each of the display pixels; the display panels having a predetermined numbers of the scanning lines respectively; a scan driver section which sequentially applies a scanning signal to each of the plurality of scanning lines in each of the plurality of display panels and sequentially set the display pixels corresponding to the appropriate scanning lines as a selective state; and a control section which controls operation for sequentially selecting a number of the scanning lines of each of the plurality of display panels corresponding to the ratio of the numbers of the scanning lines in each of the plurality of display panels at every predetermined scan timing by the scan driver section and for repeating uniform sequences between each of the display panels in a display period at a plurality of times within a one frame period. The display period comprises a vertical scanning period required for shifting the number of scanning lines of each display panel entirely to a selective state. The display device further comprises a common electrode driver section to a common electrode for each display panel which applies a common signal voltage for setting a voltage level in respective common electrodes; and the control section at least performs reversal control of the signal polarity relative to each of the display panels for each of the common signal voltages applied to the common electrode in each of the display panels by the common electrode driver section so that reversal drive for every scanning line and every frame period corresponds to a selection operation for each of the scanning lines by the scan driver section. Also, the control section is set to a period which selects the scanning lines of anyone of the displaypanels in the plurality of display panels by the scan driver section, the signal polarity of the common signal voltage applied to the common electrode of whichever other of the display panels selected next by the common electrode driver section is set as the same polarity as the signal polarity of the common signal voltage applied to the common electrode of the relevant display panel when the scanning lines of the next relevant display panel are selected; performs reversal control of the signal polarity for each of the common signal voltages so that a sum total applied time period for each signal polarity of the common signal voltage applied to the common electrode in each of the display panels becomes equal in the display period; and the reversal frequency in a display period within a one frame period of the signal polarity for the common signal voltage applied to the common electrode of each of the display panels is set to the same total as the number of scanning lines of each these display panels . At least some of the plurality of signal lines in each of the display panels is connected in common to each of these display panels ; andthe displaydevice further comprises one signal driver section which applies a display signal voltage corresponding to the display signal to the plurality of signal lines . The scan driver section is separately provided corresponding to each of the plurality of display panels . The plurality of the display panels in the case of having a 1st display panel and a 2nd display panel in which the ratio of the numbers of the scanning lines is defined as i: j (i, j are random 1-digit positive integers) comprises a 1st common electrode driver section and a 2nd common electrode driver section for each common electrode of the 1st display panel and the 2nd display panel which apply a 1st common signal voltage and a 2nd common signal voltage that sets a voltage level in each of these common electrodes. The control section contro.ls to repeat alternately an operation which sequentially selects the scanning lines of i-th rows in the 1st display panel and an operation which sequentially selects the scanning lines of j-th rows in the 2nd display panel by the scan driver section in the display period; and in a period which scans the display pixels of the 1st display panel, the signal polarity of the 2nd common signalvoltage applied to the common electrode of the 2nd display panel by the 2nd common electrode driver section is set as the same polarity as the signal polarity of the 2nd common signal voltage when the scanning lines of the 2nd display panel are selected next; and in a period which selects the scanning lines of the 2nd display panel, the signal polarity of the 1st common signal voltage applied to the 1st common electrode of the 1st display panel by the 1st common electrode driver section is set as the same polarity as the signal polarity of the 2nd common signal voltage. Additionally, as for the above-mentioned plurality of display panels, in the case of having a 1st display panel and a 2nd displaypanel inwhich the ratio of the numbers of the scanning lines is defined as approximated i:j (i, j are random 1-digit positive integers) , the control section comprises adummyperiod for applied time period adjustment of the common signal voltage which regulates the sum total applied time period for each signal polarity of the common signal voltage to become equal in arelevant display period which is applied to the common electrode of each display panel in the display period. An operation controls to repeat alternately which sequentially selects the scanning lines of i-th rows in the 1st display panel and an operation which sequentially selects the scanning lines of j-th rows in the 2nd display panel by the scan driver section. The electronic apparatus in the present invention for acquiring the above-mentioned advantage is an electronic apparatus comprising a display device which displays an image corresponding to a display signal, the display device comprises at least two displaypanels which comprise a plurality of scanning lines and a plurality of signal lines with display pixels situated near each intersecting point of each scanning line and signal line besides a common electrode situated in common with each of the display pixels; the two display panels having first and second numbers of the scanning lines respectively; a scan driver section which sequentially applies a scanning signal to each of the plurality of scanning lines in each of the plurality of display panels and sequentially sets the display pixels corresponding to the appropriate scanning lines as a selective state; a common electrode driver section which applies a common signal voltage for setting this common electrode voltage level in the common electrode in each of the display panels; and a control section which controls so as to repeat alternately an operation that sequentially selects a number of scanning lines corresponding to the ratio of the first and second numbers of the scanning lines by the scan driver section for every predetermined scan timing between each of the display panels in a display period at a plurality of times within a one frame period; and for each of the display panels performs reversal control of the signal polarity for each of the common signal voltages applied to the common electrode in each of the display panels by the common electrode driver section so that reversal drive of each of the displaypanels is performed for every scanning line and for every frame period corresponding to a selection operation for each of the scanning lines of each of the display panels by the scan driver section. For example, the electronic apparatus is a cellular telephone. The display period comprises a vertical scanning period required for shifting the number of scanning lines of each display panel entirely to a selective state. The control section in a period which selects the scanning lines of one direction of the display panels of the two display panels by a scan driver section, the signal polarity of the common signal voltage applied to the common electrode of other direction display panel by the common electrode driver section is set as the same polarity as the signal polarity of the common signal voltage which is applied to the common electrode of the relevant other direction display panel when the scanning lines of the other direction display panel are selected next; and in a period which selects the scanning lines of the other direction display panel by the scanning driver section, the signal polarity of the common signal voltage applied to the common electrode of the one direction display panel by the common electrode driver section is set as the same polarity as the signal polarity of the common signal voltage applied to the common electrode of the relevant other direction display panel; performs reversal control of the signal polarity for each of the common signal voltages so that a sum total applied time period for each signal polarity of the common signal voltage applied to the common electrode in each of the display panels becomes equal in the display period; and reversal frequency in a display periodwithin a one frame period of the signal polarity for the common signal voltage applied to the common electrode of each of the display panels is set to the same total as the number of scanning lines of each these display panels. As for two display panels in the case of having a 1st display panel and a 2nd display panel in which the ratio of the numbers of the scanning lines is defined as i: j (i, j are random 1-digit positive integers ) comprises a 1st common electrode driver section and a 2nd common electrode driver section for each common electrode of the 1st display panel and the 2nd display panel which apply a 1st common signal voltage and a 2nd common signal voltage that sets a voltage level in each of these common electrodes. The control section controls to repeat alternately an operationwhich sequentially selects the scanning lines of i-th rows in the 1st display panel and an operation which sequentially selects the scanning lines of j-th rows in the 2nd display panel by the scan driver section in the display period; and in a period which scans the display pixels of the 1st display panel, the signal polarity of the 2nd common signal voltage applied to the common electrode of the 2nd display panel by the 2nd common electrode driver section is set as the same polarity as the signal polarity of the 2nd common signal voltage when the scanning lines of the 2nd display panel are selectednext; and in aperiodwhich selects the scanning lines of the 2nd display panel, the signal polarity of the 1st common signal voltage applied to the 1st common electrode of the 1st display panel by the 1st common electrode driver section is set as the same polarity as the signal polarity of the 2nd common signal voltage. Furthermore, in the case of two display panels having a 1st display panel and a 2nd display panel in which the ratio of the numbers of the scanning lines is defined as approximated i:j (i, j are random 1-digit positive integers) , the control section comprises a dummy period for applied time period adjustment of the common signal voltage which regulates the sum total applied time period for each signal polarity of the common signal voltage to become equal in a relevant display period and controls to repeat alternately an operation which sequentially selects the scanning lines of i-throws in the 1stdisplaypanel andan operation which sequentially selects the scanning lines of j-th rows in the 2nd display panel by the scan driver section. Theabove andfurtherobjects andnovelfeatures of thepresent invention will more fully appear from the following detailed description when the same is read in conjunction with the accompanying drawings . It is to be expresslyunderstood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS FIG.1 is an entire configuration view showing one embodiment of the display device related to the present invention; FIGS. 2A and 2B are entire configuration views showing one embodiment of the electronic apparatus (cellular telephone) related to the present invention; FIG. 3 is a timing chart showing the first embodiment of the drive control method in the liquid crystal display related to the present invention; FIG. 4 is a timing chart showing the second embodiment of the drive control method in the liquid crystal display related to the present invention; FIG. 5 is a timing chart showing the third embodiment of the drive control method in the liquid crystal display related to the present invention; FIG. 6 is a timing chart showing the fourth embodiment of the drive control method in the liquid crystal display related to the present invention; FIG.7 is an outline configuration diagram showing an example of a conventional prior art display device comprised with two display panels; FIG. 8 is a timing chart showing an example of the display drive control method in a conventional prior art display device; and FIG.9 is a timing chart showing a case of performing display drivewithaconventionalprior art displaydevicebylinereversal drive method and frame reversal drive method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of the present invention electronic apparatus comprising a display device and associated display device along with a complementary drive control method for the display devices will be explained based on the embodiments shown in the drawings.
<Entire configuration Initially, the entire configuration of the electronic apparatus comprising the display device related to the present invention will be explained. FIG.1 is an entire configuration view showing one embodiment of the display device related to the present invention. As seen in FIG.1, the display device related to the present invention is divided roughly into a configuration comprising a main display panel 10m, a sub-display panel 10s, a data line group Ld, a data driver 20, scanning line groups Lsm and Lss, a main scan driver 30m, a sub-scan driver 30s, a display signal generation circuit 40, a main common electrode driver circuit
60m, a sub-common electrode driver circuit 60s and an LCD controller 50. The main display panel 10m (1st display panel) and the sub-display panel 10s (2nd display panel) display pixels are arranged in a two-dimensional array and have predetermined panel sizes, respectively. The data line group Ld is arranged so as to extend in the column direction and shared with the main display panel 10m and the sub-display panel 10s . The single data driver 20 (source driver; signal driver section) is connected to the data line group Ld. The scanning line groups Lsm, Lss are arranged so as to extend in the row direction of the main display panel 10m and the sub-display panel 10s. The main scan driver 30m (described as the "main driver" for convenience in the diagram; scan driver section) is connected to the scanning line group Lsm of the main display panel 10m. The sub-scan driver 30s (describedas the "sub-driver" for convenience in the diagram; scan driver section) is connected to the scanning line group Lss of the sub-display panel 10s. The display signal generation circuit 40 is constituted with an RGB decoder 41 and a reversal amplifier 42. The main common electrode driver circuit 60m (common electrode driver section) applies a main common signal voltage Vcomm (1st common signal voltage) to a common electrode
(counterelectrode) of themaindisplaypanel 10m. The sub-common electrode driver circuit 60s (common electrode driver section) applies a sub-common signal voltage Vcoms (2nd common signal voltage) to a common electrode of the sub-display panel 10s.
The LCD controller 50 (control section) supplies a predetermined control signal to at least the above-mentioned data driver 20, the main scan driver 30m, the sub-scan driver 30s , the main common electrode driver circuit 60m and the sub-common electrode driver circuit 60s . In addition, when the above-mentioned main display panel 10m and the sub-display panel 10s are constituted with a transmission type liquid crystal display panel, the backlight provided consists of, for example, a light source such as a cold cathode-raytube, etc. andalight-guiding sheet suchas an acrylic sheet, etc. in the main display panel 10m and reverse side sub-display panel 10s. Hereinafter, each component will be explained in detail. The main display panel 10m and the sub-display panel 10s are liquidcrystal displaypanelswhichbothhave apanel structure corresponding to awell-known active-matrix drivingmethod. The main display panel 10m and the sub-display panel 10s comprise the data line group Ld and scanning line groups Ls which are arranged in mutually intersecting directions between opposing transparent substrates , respectively. In addition, a plurality of displaypixels (pictureelement transistors, pixel capacitance and auxiliary capacitance) are arranged near each intersecting point of the data line group Ld and the scanning line groups
Ls, which are respectively connected to the data line group Ld and the scanning line groups Ls. Here, referring to FIG. 1, a case is shown in which the number of data lines situated in the main display panel 10m and the sub-display panel 10s are the same. However, as shown in the conventional prior art (refer to FIG. 7, it is possible to reduce the number of data lines allocated in the sub-display panel 10s in comparison to the main display panel 10m. Also, the above-mentioned main display panel 10m, the sub-display panel 10s, the data line group Ld and the scanning line groups Ls, for example, may have a configuration installed (mounted) on a single flexible printed circuit board. Furthermore, as described later, the data driver 20, the main scan driver 30m and the sub-scan driver 30s may also have a configuration which is mounted on the above-mentioned flexible printed circuit board. The data driver 20 is connected to the data line group Ld and situated in common with the above-described main display panel 10m and the sub-display panel 10s. Based on a horizontal control signal provided from the LCD controller 50, the data driver 20 is supplied from the display signal generation circuit 40. For example, each color of the luminance signal (display signal) of R (red), G (green) and B (blue) is taken in for 1 row units and held. Subsequently, display signal voltage correspondingto this luminance signal is simultaneouslysupplied to the data line group Ld. The main scan driver 30m and the sub-scan driver 30s are connected respectively to each of the scanning line groups Lsm,
Lss situated by the above-mentioned main display panel 10m and sub-display panel 10s. Based on a vertical control signal outputted from the LCD controller 50, a predetermined scanning signal (selection signal) is sequentially applied to each scanning line of the main display panel 10m and the sub-display panel 10s which sets a selective state. Accordingly, while synchronizing with this selection timing, display signal voltage is written to the display pixels corresponding to the scanning lines set as a selective state by applying display signal voltage corresponding to the luminance signal from the data driver 20 to the display pixel positions which intersect with the above-mentioned data line group Ld. Here, the panel sizes of the main display panel 10m and the sub-display panel 10s, namely, the number of scanning lines, are different and the panel size ratio (number of scanning lines) of the main display panel 10m and sub-display panel 10s is approximated (i: j; i, j are random 1-digit positive integers). Briefly, the main scan driver 30m and the sub-scan driver 30s related to the embodiment function at timing corresponding to this panel size ratio. After sequentially applying a scanning signal to the scanning lines of the i-th row segment in the main display panel 10m and accomplishing scanning drive, an operation sequentially applies a scanning signal to the scanning lines of the j-th row segment in the sub-display panel 10s and accomplishes scanning drive.
Operational control is performed so as to repeat alternately between. the main display panel 10m and the sub-display panel
10s. Accordingly, display signal voltage corresponding to the luminance signal is sequentially written to the display pixels for each row in the main display panel 10m and the sub-display panel 10s . The functions and operation of the main scan driver
30m and the sub-scan driver 30s will be further explained in the drive control method. Also, FIG. 1 shows a functional block diagram of an outline configuration for the display device related to the present invention. Although the main scan driver 30m and the sub-scan driver 30s provided corresponding to each of the display panels are shown as a separate configuration, specifically as seen in FIG. 7 for example, the device may have a configuration in which these scan drivers are formed in one component using a single driver chip or may have a configuration provided with separate driver chips as shown in FIG. 1. The RGB decoder 41 constituted in the display signal generation circuit 40, for example, extracts each chrominance signal (RGB signal) of R, G, B from an image input signal supplied from the exterior of the display device and outputs to the reversal amplifier 42. In addition, the reversal amplifier 42 performs reversal processing of the RGB signal polarity extracted by the RGB decoder 41 basedon apolarityreversal signalFRPp(frame/line reversal signal) supplied from the LCD controller 50. A RGB reversal signal (also referred to as an inversion signal) is generated and outputted to the data driver 20 as the luminance signal (analog signal). The LCD controller 50 generates the above-mentionedpolarity reversal signal FRPp and polarity reversal signals FRPm, FRPs based on a horizontal synchronizing signal H and a vertical synchronizing signal V supplied from the exterior of the display device (or extracted from an image input signal by the RGB decoder
41) . While individually supplying the reversal amplifier 42 as well as the main common electrode driver circuit 60m and the sub-common electrode driver circuit 60s described later, display signal voltage corresponding to the luminance signal is applied to each display pixel (pixel electrode side) at predetermined timing by generating a horizontal control signal and a vertical control signal and supplying the data driver 20, the main scan driver 30m and the sub-scan driver 30s, respectively, and control is effected to display the predetermined image information based on the image input signal to the main display panel 10m and the sub-display panel 10s. Here, in the LCD controller 50 relating to the embodiment, the drive control operation distinctive to the embodiment (described later) is performed by controlling the polarity reversal signals FRPp, FRPm, FRPs supplied to the reversal amplifier 42, the main common electrode driver circuit 60m and the sub-common electrode driver circuit 60s together with the horizontal control signal and the vertical control signal which are supplied to the data driver 20, the main scan driver 30m and the sub-scan driver 30s. Particularly, in the scanning interval which writes display signal voltage in the main display panel 10m and the sub-display panel 10s, the operation which scans (scanning signal applied to the scanning lines) each row of the main display panel 10m and the sub-display panel 10s is switched between the main scan driver 30m and the sub-scan driver 30s for every row of a predetermined number and a vertical control signal setting is alternately repeated. The main common electrode driver circuit 60m and the sub-common electrode driver circuit 60s are connected to the common electrode provided in the above-mentioned main display panel 10m and the sub-display panel 10s, respectively. Themain common signalvoltageVcommandthe sub-common signal voltage Vcoms applied to each common electrode are set in order for the signal polarity to reverse relative to the display signal voltage which is applied to each display pixel (pixel electrode) of the main display panel 10m and the sub-display panel 10s based on the polarity reversal signals FRPm, FRPs outputted from the LCD controller 50.
Next , the electronic apparatus in connectionwith the present invention will be explained. A cellular telephone comprising two display panels is an electronic apparatus which can ideally apply the display device relating to the present invention. FIGS. 2A and 2B are entire configuration views showing one embodiment of the electronic apparatus (cellular telephone) related to the present invention. FIG.2A is a drawing showing the primary operation functions surface (inner surface) side of the electronic apparatus
(cellular telephone) related to the embodiment. FIG. 2B is a drawing showing the reverse (outer surface) side of an electronic apparatus. Here, although the apparatus illustrated has a foldable case structure, this shape is just one of various types employed in cellular telephones . Therefore, it is stressed that the electronic apparatus canhave another style of case structure, such as a bar type, a revolving (rotatable) type, a slide (swivel) type, etc. \ As seen in FIGS.2A and 2B, the cellular telephone 100 related to the embodiments , briefly, has a configurationwhich is foldable and constructedwith a lower section casing 115 next to a centrally placed hinge joint 114, manual operation buttons 113 (keypad), etc; and an upper section display casing 116 with a main display 111 (corresponds to the above-mentioned main display panel 10m) and a sub-display 112 (corresponds to the above-mentioned sub-display panel 10s) installed back to back. Namely, in the lower section casing 115 , the manual operation buttons 113 are provided on the primary operation surface (case lower inner surface) side with an assortment of buttons for performing selection and execution of specific functions, such as entering a telephone number for placing a phone call, buttons usedforinputtingalphanumericcharacters , atelephonedirectory or other,various applications . The upper section display casing
116 is provided with, for example, the main display 111 which displays the alphanumeric characters and symbols input by manipulating the above-mentioned manual operation buttons 113 or an executed application, etc. and is situated opposing (facing inwards) the above-mentioned manual operation buttons 113 when the foldable cellular telephone 100 is closed. Also, the sub-display 112 displays , for example, the current time and date, the incoming status of E-mail and telephone calls, etc. when the cellular telephone 100 is folded and situated on the reverse side (facing outwards) of the out of view main display 111. The main display 111, for example, employs a relatively high definition display panel consisting of a reasonably large screen with a diagonal dimension of about two inches (2"). The sub-display 112, forexample, employs arelative lowimage quality display panel consisting of a comparatively smaller screen with a diagonal dimension of about one inch (1").
Next , the drive control operation of the display device which has such the configuration mentioned above will be explained withreference to the drawings . Here, the drive controloperation (display drive control method) illustrated below is performed based on various types of control signals supplied from the LCD controller 50 stated above. <lst embodiment> FIG. 3 is a timing chart showing the first embodiment of the drive control method in the liquid crystal display related to the present invention. Here, a case of the drive control method will be explained in relation to the display device (refer to FIG. 1) comprising the configuration explained previously. The number of scanning lines allocated in the main display panel 10m is 320. The number of scanning lines allocated in the sub-display panel 10s is 160. The panel size ratio (number of scanning lines) of themain display panel 10m and the sub-display panel 10s that will be explained is precisely 2:1. Also, the number of data lines in the main display panel 10m and the sub-display panel 10s can be the same number or may be a different number. The drive control method of the display device related to the embodiment, as seen in FIG. 3, depicts 1 vertical scanning period (display period) within a 1 frame period. Initially, at scan timing Tl (horizontal scanning period) , the main scan driver 30m applies a high-level scanning signal Sim relative to the 1st row (line) scanning line in the main display panel 10m based on a vertical control signal supplied from the LCD controller 50. Subsequently, at scan timingT2, ahigh-level scanning signal S2m is sequentially applied relative to the 2nd row scanning line . While synchronizing to the applied timing of the scanning signal for each of these rows, a predetermined luminance signal is sequentiallywritten relative to the 1st and 2nd rows of the display pixels in the main display panel 10m by simultaneously applying display signal voltage relative to the 1st row of the display pixels in the main display panel 10m from the data driver 20 at scan timing Tl and display signal voltage relative to the
2nd row of the display pixels in the main display panel 10m at scan timing T2 via each data line. Here, the display signal voltage applied at scan timing Tl is set as a signal voltage which constitutes positive polarity relative to apredetermineddisplaycentervoltage and the display signal voltage applied at scan timing T2 is set as a signal voltage which constitutes negative polarity relative to the proper display center voltage. Furthermore, the main common signal voltage Vcomm applied from the main common electrode driver circuit 60m to the common electrode of the main display panel 10m is set as signal voltage (low-level) which constitutes negative polarity relative to a common signal center voltage Vcomc at the above-mentioned scan timing Tl and is set as signal voltage (high-level) relative to the proper common signal center voltage Vcomc at scan timing T2. On the other hand, since a display data writing operation of the display data is not performed during scan timing Tl, T2 in the sub-display panel 10s side, while low-level scanning signals Sls~S160s are applied from the sub-scan driver 30s to each scanning line in the sub-displaypanel 10s based on avertical control signal suppliedfrom the LCD controller 50 , the sub-common signal voltage Vcoms which has any one of the high or low signal levels is applied from the sub-common electrode driver circuit 60s to the common electrode of the sub-display panel 10s and further controlled so that the same signal level (low-level in
FIG. 3) of the sub-common signal voltage Vcoms is applied, for example, during the periods of consecutive scan timing Tl, T2, based on the polarity reversal signal FRPs supplied from the LCD controller 50. Subsequently, at scan timing T3, the sub-scan driver 30s applies a high-level scanning signal Sis relative to the 1st row scanning line in the sub-display panel 10s based on a vertical control signal supplied from the LCD controller 50. While synchronizing to scan timing T3, a predetermined luminance signal is written relative to the 1st row of the display pixels in the sub-display panel 10s by simultaneously applying display signal voltage of positive polarity relative to the 1st row of the display pixels in the sub-display panel 10s via each data line from the data driver 20. Here, a low-level sub-common signal voltage Vcoms is applied from the sub-common electrode driver circuit 60s to the common electrode of the sub-display panel 10s. Accordingly, at periods of scan timing T1-T3, sub-common signal voltage Vcoms having the same signal level (low-level) is applied continuously. On the other hand, since a display data writing operation of the display data is not performed during scan timing T3 in main display panel 10m side, while low-level scanning signals
Slm~S320mareappliedfromthemain scandriver 30mto eachscanning line in the main display panel 10m based on a vertical control signal supplied from the LCD controller 50, the common signal voltage Vcomm which has any one of the high or low signal levels
(low-level in FIG. 3) is applied from the main common electrode driver circuit 60m to the common electrode of the main display panel 10m based on the polarity reversal signal FRPm supplied from the LCD controller 50. Subsequently, at scan timing T4, T5, the main scan driver 30m sequentially applies high-level scanning signals S3m, S4m relative to the 3rd and 4th rows in the main display panel 10m based on a vertical control signal. While synchronizing to this scan timing, a predetermined luminance signal is sequentially written relative to the 3rd and 4th rows of the display pixels in the main display panel 10m by simultaneously applying display signal voltage of positive polarity relative to the 3rd row of the display pixels in the main display panel 10m from the data driver 20 at scan timing T4 and display signal voltage of negative polarity relative to the 4th row of the display pixels in the main display panel 10m at scan timing T5 via each data line. Here, the main common signal voltage Vcomm which becomes low-level at scan timing T4 and high-level at scan timing T5 is sequentially applied from the main common electrode driver circuit 60m to the common electrode of the main display panel
10m. Accordingly, at scan timing T3, T4, the main common signal voltage Vcomm having the same signal level (low-level) is applied continuously. More specifically focused on each scan timing Tl, T2, T4,
T5, T7, T8, • • • , as display signal voltage of positive polarity and negative polarity is alternately applied to the pixel electrodes for each row of display pixels in the main display panel 10m, low-level and high-level main common signal voltage Vcomm is alternately applied to the common electrode of the main display panel 10m and line (row) reversal drive is performed in the main display panel 10m. On the other hand, in scan timing T4, T5 on the sub-display panel 10s side while low-level scanning signals Sls~S160s are applied to each scanning line from the sub-scan driver 30s based on a vertical control signal, the sub-common signal voltage Vcoms which has any one of the high or low signal levels (high-level in FIG.3) is applied continuously from the sub-common electrode driver circuit 60s to the common electrode based on the polarity reversal signal FRPs. Subsequently, at scan timing T6, the sub-scan driver 30s applies a high-level scanning signal S2s relative to the 2nd row scanning line in the sub-display panel 10s based on a vertical control signal. While synchronizing to this scan timing T6, a predetermined luminance signal is written relative to the 2nd row of the display pixels in the sub-display panel 10s by simultaneously applying display signal voltage of negative polarity relative to the 2nd row of the display pixels in the sub-display panel 10s via each data line from the data driver 20. Here, a high-level sub-common signal voltage Vcoms is applied from the sub-common electrode driver circuit 60s to the common electrode of the sub-display panel 10s. Accordingly, at periods of scan timing T4-T6, sub-common signal voltage Vcoms having the same signal level
(high-level) is applied continuously. More specifically focused on each scan timing T3, T6, T9, • • • , as display signal voltage of positive polarity and negative polarity is alternately applied to the pixel electrodes for each row of display pixels in the sub-display panel 10s, low-level and high-level sub-common signal voltage Vcoms is alternately applied to the common electrode of the sub-display panel 10s and line (row) reversal drive is performed in the sub-display panel 10s. On the other hand, in this scan timing T6 on the main display panel 10m side while low-level scanning signals Slm~S320m are applied to each scanning line from the main scan driver 30m based on a vertical control signal, the main common signal voltage Vcommwhichhas anyone of thehighor low signal levels (high-level in FIG.3) is applied continuously from the main common electrode driver circuit 60m to the common electrode based on the polarity reversal signal FRPm. Hereinafter, by alternately repeating execution of similar control operations until scan timing T480 which performs scanning drive for 1 row segments of the scanning lines in the sub-display panel 10s after performing scanning drive for 2 row segments of the main display panel 10m, the desired luminance signal (display signal voltage) is written and displayed as image information in both the main display panel 10m which has 320 scanning lines andthe sub-displaypanel 10swhichhas 160 scanning lines in 1 vertical scanning period (display period) within a
1 frame period. Furthermore, a vertical retrace line period is set after conclusion of 1 vertical scanning period within a 1 frame period regarding the display signalvoltage togetherwith themain common signal voltage Vcomm and sub-common signal voltage Vcoms applied to each row of the display pixels (pixel electrodes and common electrode) in the main display panel 10m and the sub-display panel 10s in the above-mentioned 1 vertical scanning period. The period (for example, period of 3 phase segments in FIG. 3) of duration allocated for odd-numbered segments is identical for each scan timing T1-T480 in the above-mentioned vertical scanning period. In these vertical retrace line periods (non-display periods), the odd-numbered reversals of the main common signal voltage Vcomm and sub-common signal voltage Vcoms are performed. For example, as seen in FIG. 3, the main common signal voltage Vcomm is reversed 3 times and the sub-common signal voltage Vcoms is reversed 1 time. Accordingly, the signal polarity of each signal voltage in the next 1 frame period is reversed and frame reversal drive is performed in the main display panel 10m and the sub-display panel 10s. Moreover, for example as shown in FIG. 3, when performing scanning drive in the sub-display panel 10s, the signal polarity of the main common signal voltage Vcomm in the main display panel
10m side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel
10s. Also, when performing scanning drive in the main display panel 10m, the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s for the following scanning drive occurrence. Accordingly, in 1 vertical scanning period (displayperiod) , line (row) reversal drive is performed regarding the main display panel 10m and the sub-display panel 10s, respectively, and set in each display panel so as to become the same sum total time between each signal polarity (namely, the periods when the signal polarity constitutes positive polarity and the periods which constitute negative polarity are equal) of each common signal voltage Vcomm, Vcoms. The reversal drive frequency of the main common signal voltage Vcomm applied to the main display panel 10m is the same total as the number of scanning lines in the main display panel 10m. The reversal drive frequency of the sub-common signal voltage Vcoms applied to the sub-display panel 10s is the same total as the number of scanning lines in the sub-display panel 10s. Additionally, when one display is performing scanning drive in one display panel, the signal polarity of the common signal voltage is applied to the common electrode in the second display panel. However, the present invention is not limited to that which is set to the same polarity as the signal polarity of the common signal voltage applied to the common electrode of one display panel as mentioned above. For example, the apparatus may be set to reversed polarity or to reversed polarity only one time for every predetermined frequency randomly. In summation, other techniquesmaybeapplied so longas the apparatus is set so that a variation does not occur between the sum total time of the signal polarities for each common signal voltage during the write-in period (1 vertical scanning period) of the luminance signal of 1 screen page in the main display panel and sub-display panel. Consequently, in the conventional prior art display device comprised with two display panels implemented with a line reverse drive method and a frame reversal drive method, when performing sequential scanning drive of each display panel and writing in the luminance signal of either of the common signal voltages individually applied to the common electrode of each display panel, what is accomplished is to perform reversal drive only for the frequency (rate of repetition) corresponding to the overall number of the scanning lines allocated in two display panels. However, according to the display device related to the embodiment, what is accomplished is just to perform reversal drive for the common signal voltage on the main display panel sideonlyforthefrequencycorrespondingto thenumberof scanning lines allocated in the main display panel in 1 vertical scanning period (display period). Furthermore, because reversal drive of the common signal voltage on the sub-display side is performed only for the frequency corresponding to the number of scanning lines allocated in the sub-display panel, the driving cycles
(frequency rate of repetition) related to the reversal drive can be decreased. In this manner, while a reduction in power consumption can be achieved, line reversal drive and frame reversal drive in the main display panel and the sub-display panel can be accomplished. Thus, degeneration and seizing of the liquid crystal molecules in the display pixel configuration which results in deterioration of the display image quality by a flickering problem, device malfunction, etc. can be more precisely controlled.
<2nd embodiment> Next, the second embodiment of the drive control operation of the display device which has the configuration mentioned above will be explained with reference to the drawings . FIG. 4 is a timing chart showing the second embodiment of the drive control method in the liquid crystal display related to the present invention. In addition, explanation is simplified or omitted in regard to control operations equivalent to the first embodiment mentioned above. In this embodiment of the display device (refer to FIG. 1) which contains the configuration mentioned above, the number of scanning lines allocated in the main display panel 10m is
320. The number of scanning lines allocated in the sub-display panel 10s is 107. The panel size ratio (number of scanning lines) of the main display panel 10m and the sub-display panel 10s will be explained as a case approximated 3:1 instead of a simpler integer ratio. Also, the number of data lines in the main display panel 10m and the sub-display panel 10s can be the same number or may be a different number. The drive control method of the display device related to the embodiment, as seen in FIG. 4, depicts 1 vertical scanning period within a 1 frame period. Initially, at scan timing T1-T3 (horizontal scanning period) , high-level scanning signals Slm~S3m are sequentially applied relative to the 1st thru 3rd rows of the scanning lines in the main display panel 10m from the main scan driver 30m. While synchronizing to this scan timing T1-T3, a predetermined luminance signal is sequentially written relative to the 1st thru 3rd rows of the display pixels in the main display panel 10m by sequentially applying display signal voltage relative to each of the display pixels for the 1st thru 3 rows in the main display panel 10m via each data line from the data driver 20. Here, as seen in FIG. 4, the display signal voltage applied from the data driver 20 at scan timing T1-T3, for example, is set to a. signal voltage consisting of each polarity of positive, negative, positive, respectively, relative to a predetermined display center voltage. Also, the main common signal voltage
Vcomm applied from the main common electrode driver circuit 60m to the common electrode of the main display panel 10m is set to a signal voltage consisting of each polarity of positive, negative, positive, respectively, relative to predetermined common signal center voltage Vcomc. On the other hand, since a writing operation of the display data is not performed during scan timing T1-T3 in the sub-display panel 10s side, while low-level scanning signals Sls~S107s are applied from the sub-scan driver 30s to each scanning line in the sub-display panel 10s, the operation executes control so that the sub-common signal voltage Vcoms which has any one of the high or low signal levels (low-level in FIG. 4) is applied continuously from the sub-common electrode driver circuit 60s to the common electrode of the sub-display panel 10s. Subsequently, at scan timing T4, ahigh-level scanning signal Sis is applied relative to the 1st row scanning line of the sub-display panel 10s from the sub-scan driver 30s. Here, low-level sub-common signal voltage Vcoms is applied from the sub-common electrode driver circuit 60s to the common electrode of the sub-display 10s. Accordingly, during scan timing T1~T4, the sub-common signal voltage Vcoms having the same signal level (low-level) is applied continuously. On the other hand, since a display data writing operation is not performed during scan timing T4 in the main display panel
10m side, while low-level scanning signals Slm~S320m are applied from the main scan driver 30m to each scanning line in the main display panel 10m, the main common signal voltage Vcomm which has any one of the high or low signal levels (low-level in FIG.
4) is applied from the main common electrode driver circuit 60m to the common electrode of the main display panel 10m. Accordingly, at scan timing T3 , T4 , the main common signal voltage Vcomm having the same signal level (low-level) is applied continuously. Subsequently, at scan timing T5-T7, high-level scanning signals S4m~S6m are sequentially applied relative to the 4th thru 6th rows of the scanning lines in the main display panel 10m from the main scan driver 30m. While synchronizing to this scan timing T5-T7, a predetermined luminance signal is sequentially written relative to the 4th thru 6th rows of the display pixels in the main display panel 10m by sequentially applying display signal voltage relative to each of the display pixels for the 4th thru 6th rows in the main display panel 10m via each data line from the data driver 20. Here, the display signal voltage applied from the data driver 20 at scan timing T5-T7 is set to signal voltage consisting of each polarity of positive, negative, positive, respectively, relative to a predetermined display center voltage. Also, the main common signal voltage Vcomm applied from the main common electrode driver circuit 60m to the common electrode of the main display panel 10m is set to signal voltage consisting of each polarityof positive, negative, positive, respectively, relative to predetermined common signal center voltage Vcomc. More specifically focused on each scan timing T1-T3, T5-T7,
T9~, •••, as the display signal voltage of positive polarity and negative polarity is alternately applied to the pixel electrodes for each row of display pixels in the main display panel 10m, low-level and high-level main common signal voltage Vcomm is alternately applied to the common electrode of the main display panel 10m and line (row) reversal drive is performed in the main display panel 10m. On the other hand, in scan timing T5-T7 on the sub-display panel 10s side while low-level scanning signals Sls~S107s are applied to each scanning line from the sub-scan driver 30s, the sub-common signal voltage Vcoms which has any one of the high orlowsignal levels (high-level inFIG.4) is appliedcontinuously from the sub-common electrode driver circuit 60s to the common electrode based on the polarity reversal signal FRPs. Subsequently, at scan timing T8, the sub-scan driver 30s applies a high-level scanning signal S2s relative to the 2nd row scanning line in the sub-display panel 10s . While synchronizing to this scan timingT8 , apredeterminedluminance signal iswritten relative to the 2nd row of the display pixels in the sub-display panel 10s by simultaneously applying display signal voltage of negative polarity relative to the 2nd row of the display pixels in the sub-display panel 10s via each data line from the data driver 20. Here, a high-level sub-common signal voltage Vcoms is applied from the sub-common electrode driver circuit 60s to the common electrode of the sub-display panel 10s . Accordingly, at periods of scan timing T5-T8, sub-common signal voltage Vcoms having the same signal level (high-level) is applied continuously. More specifically focused on scan timing T4, T8,-'*, as display signal voltage of positive polarity andnegative polarity is alternately applied to the pixel electrodes for each row of display pixels in the sub-display panel 10s, low-level and high-level sub-common signalvoltageVcoms is alternatelyapplied to the common electrode of the sub-display panel 10s and line (row) reversal drive is performed in the sub-display panel 10s. On the other hand, in this scan timing T8 on the main display panel 10m side while low-level scanning signals Slm~S320m are applied to each scanning line from the main scan driver 30m, the main common signal voltage Vcomm which has any one of the high or low signal levels (high-level in FIG. 4) is applied continuously from the main common electrode driver circuit 60m to the common electrode. Accordingly, at periods of scan timing T7-T8 , themain common signal voltage Vcommhaving the same signal level (high-level) is applied continuously. Hereinafter, by alternately repeating execution of similar control operations until scan timing T428 which perform scanning drive for 1 row segments of the scanning lines in the sub-display panel 10s after performing scanning drive for 3 row segments of the main display panel 10m, the desired luminance signal
(display signal voltage) is written and displayed as image information in both the main display panel 10m which has 320 scanninglines andthe sub-displaypanel 10swhichhas 107 scanning lines in 1 vertical scanning period (display period) within a
1 frame period. Here, in this embodiment , because thepanel size ratio (number of scanninglines) of themaindisplaypanel 10mandthe sub-display panel 10s are not precisely 3:1, when signal polarity reversal timing of each common signal voltage Vcomm, Vcoms is implemented to timing corresponding only to the scanning lines in each display panel, the timing generated in the alternating scanning drive for the number of scanning lines in each display panel will not be constant. For example as illustrated in FIG. 4, preceding scan timing T425, although scanning drive for 3 row segments of the scanning lines in the main display panel 10m is performed continuously, scanning drive is performed for only 2 row segments of the scanning lines following scan timing T425. Therefore, in this embodiment during 1 vertical scanning period, scanning drive of the scanning lines of each display panel is not performed for the purpose of regulating the sum total time for each signal polarity of each common signal voltage so as to be the same. Instead a dummy scanning interval is provided for adjusting the applied time period of each common signal voltage. As for this dummy scanning interval in FIG. 4, the scan timing T427 has a period equivalent to 1 scan timing set within 1 vertical scanning period. Accordingly, sum total time for each signal polarity of each common signal voltage Vcomm, Vcomms can be made the same (equalized) . Furthermore, based on the above-mentioned drive control method of 1 frame period ( 1 vertical scanning period) , the display signal voltage and main common signal voltage Vcomm which are applied to each row of the display pixels (pixel electrodes and commonelectrode) in themaindisplaypanel 10mandthe sub-display panel 10s, each signal polarity of the sub-common signal voltage Vcoms will be reversed in the following frame period and frame reversal drive is performed in the main display panel 10m and the sub-display panel 10s Also, for example as seen in FIG.4, when performing scanning drive of the sub-display panel 10s, the signal polarity of the main common signal voltage Vcomm on the main display panel 10m side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s. Besides , when performing scanning drive of the main display panel 10m, the signal polarity of the sub-common signal voltage Vcoms on the sub-display panel 10s side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s for the following scanning drive occurrence. Accordingly, in 1 vertical scanning period, while being able to establish the reversal drive frequency of the main common signal voltage Vcomm applied to the main display panel
10m equal to the number of scanning lines in the main display panel 10m, the reversal drive frequency of the sub-common signal voltage Vcoms applied to the sub-display panel 10s is the same total as the number of scanning lines in the sub-display panel
10s. Consequently, even in the case where the panel size ratio
(number of scanning lines) of the main display panel and the sub-display panel is established as 3:1 in general, similar to the first embodiment mentioned above in which the common signal voltage is individually applied to the main display panel and the sub-display panel, this method simply necessitates reversal drive for only the frequency corresponding to the number of scanning lines allocated in the main display panel or the sub-display panel, respectively. In this manner, while being able to reduce the driving cycles (frequency) related to the reversal drive to achieve a reduction in power consumption, line reversal drive and frame reversal drive in the main display and the sub-display can be accomplished. Therefore, degeneration and seizing of the liquid crystal molecules in the display pixel configurationwhichresults in deterioration of the display image quality by a flickering problem, device malfunction, etc. can be more precisely controlled.
<3rd embodiment> Next, the third embodiment of the drive control operation of the display device which has the configuration mentioned above will be briefly explained with reference to the drawings. FIG. 5 is a timing chart showing the third embodiment of the drive control method in the liquid crystal display related to the present invention. In addition, explanation is simplified or omitted in regard to control operations equivalent to the first and second embodiments mentioned above. In this embodiment of the display device (refer to FIG. 1) which contains the configuration mentioned above, the number of scanning lines allocated in the main display panel 10m is 320. The number of scanning lines allocated in the sub-display panel 10s is 80. The panel size ratio (number of scanning lines) of the main display panel 10m and the sub-display panel 10s that will be explained is precisely 4:1. The drive control method of the display device related to the embodiment, as seen in FIG. 5, depicts 1 vertical scanning period within a 1 frame period. At scan timing T1-T4 , high-level scanning signals Slm~S4m are sequentially applied relative to the 1st thru 4th rows of the scanning lines in the main display panel 10m. At this scan timing T1~T4, a predetermined luminance signal is sequentially written relative to the 1st thru 4th rows of the displaypixels in themain displaypanel 10mby sequentially applyingdisplay signalvoltage relative to eachof displaypixels of the appropriate 1st thru 4th rows via each data line from the data driver 20. Subsequently, at scan timing T5, ahigh-level.scanning signal
Sis is applied relative to the 1st row scanning line of the sub-display panel 10s from the sub-scan driver 30s . At this scan timing T5 , a predetermined luminance signal is written relative to the 1st row of the display pixels in the sub-display panel
10s by simultaneously applying display signal voltage relative to the appropriate 1st row of the display pixels via each data line from the data driver 20. Hereinafter, after performing scanning drive for the 4th row of the scanning lines in themain displaypanel 10m, by alternately repeating execution of similar control operations until scan timing T400 which perform scanning drive for 1 row segments of the scanning lines in the sub-display panel 10s, the desired luminance signal (display signal voltage) is written and displayed as image information in both the main display panel 10m which has 320 scanning lines and the sub-display panel 10s which has 80 scanning lines in 1 vertical scanning period (display period) within a 1 frame period. Also, in the drive control method mentioned above and as seen in FIG.5, at scan timing T1-T4, T6-T9, Tll~, • • • , as display signal voltage of positive polarity and negative polarity is alternatelyappliedto thepixelelectrodes foreachrowofdisplay pixels in the main display panel 10m, low-level and high-level main common signal voltage Vcomm is alternately applied to the common electrode of the main display panel 10m and line (row) reversal drive is performed in the main display panel 10m. Also, at scan timing T5, T10, • • • , as display signal voltage of positive polarity andnegative polarity is alternately applied to the pixel electrodes for each row of display pixels in the sub-displaypanel 10s, low-levelandhigh-level sub-common signal voltage Vcoms is alternately applied to the common electrode of the sub-display panel 10s and line (row) reversal drive is performed in the sub-display panel 10s. Furthermore, a vertical retrace line period (non-display period) is set after conclusion of 1 vertical scanning period within a 1 frame period regarding the display signal voltage together with the main common signal voltage Vcomm and sub-common signal voltage Vcoms applied to each row of the display pixels (pixel electrodes and common electrode) in the main display panel 10mandthe sub-displaypanel 10s in the above-mentioned 1vertical scanning period. The period (for example, period of 5 phase segments in FIG. 5) of duration allocated for odd-numbered segments is identical for each of the above mentioned scan timing T1-T400. In thesevertical retrace lineperiods the odd-numbered reversals of the main common signal voltage Vcomm and sub-common signal voltage Vcoms are performed. For example, as seen in FIG. 5, the main common signal voltage Vcomm is reversed 5 times and the sub-common signal voltage Vcoms is reversed 1 time. Accordingly, the signal polarity of each signal voltage in the next 1 frame period is reversed and frame reversal drive is performed in the main display panel 10m and the sub-display panel 10s. Moreover, for example as shown in FIG. 5, when performing scanning drive in the sub-display panel 10s, the signal polarity of the main common signal voltage Vcomm in the main display panel
10m side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel
10s. Also, when performing scanning drive in the main display panel 10m, the signal polarity of the sub-common signal voltage
Vcoms in the sub-display panel 10s side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s for the following scanning drive occurrence. Accordingly, in 1 vertical scanning period, the reversal drive frequency of the main common signal voltage Vcomm applied to the main display panel 10m is the same total as the number of scanning lines in the main display panel 10m. The reversal drive frequency of the sub-common signal voltage Vcoms applied to the sub-display panel 10s is the same total as the number of scanning lines in the sub-display panel 10s. Consequently, even in the case where the panel size ratio (number of scanning lines) of the main display panel and the sub-display panel is established as 4:1, similar to the first and second embodiments mentioned above in which the common signal voltage is individually applied to the main display panel and the sub-display panel, this method simply necessitates reversal drive for only the frequency corresponding to the number of scanning lines allocated in the main display panel or the sub-display panel, respectively. In this manner, while being able to reduce the driving cycles (frequency rate of repetition) related to the reversal drive to achieve a reduction in power consumption, line reversal drive and frame reversal drive in the main display and the sub-display can be accomplished. Therefore, degeneration and seizing of the liquid crystal molecules in the display pixel configuration which results in deterioration of the displayimage qualitybya flickeringproblem, device malfunction, etc. can be more precisely controlled.
<4th embodiment> Next, the fourth embodiment of the drive control operation of the display device which has the configuration mentioned above will be briefly explained with reference to the drawings . FIG. 6 is a timing chart showing the fourth embodiment of the drive control method in the liquid crystal display related to the present invention. In addition, explanation is simplified or omitted in regard to control operations equivalent to the first thru third embodiments mentioned above. In this embodiment of the display device (refer to FIG. 1) which contains the configuration mentioned above, the number of scanning lines allocated in the main display panel 10m is 160. The number of scanning lines allocated in the sub-display panel 10s is 160. The panel size ratio (number of scanning lines) of the main display panel 10m and the sub-display panel 10s will be explained is precisely 1:1. The drive control method of the display device related to the embodiment, as seen in FIG. 6, depicts 1 vertical scanning period within a 1 frame period. At scan timing Tl, T3, T5, • • • , high-level scanning signals Sim, S2m, S3m, • • • are sequentially applied relative to the 1st, 2nd, 3rd , • • • rows of each scanning line in the main display panel 10m from the main scan driver
30m. Also, at scan timing T2, T4, T6,--*, high-level scanning signals Sis, S2s, S3s, • • • are sequentially applied relative to the 1st, 2nd , 3rd, • • • rows of each scanning line in the sub-display panel 10s from the sub-scan driver 30s. Here, during scan timing Tl, T3, T5,*-«, a predetermined luminance signal is sequentially written relative to each row of the main display panel 10m by simultaneously applying display signal voltage relative to each of the display pixels for the 1st, 2nd, 3rd , • • • rows in the main display panel 10m via each data line from the data driver 20. During scan timing T2, T4, T6, • • • , a predetermined luminance signal is sequentiallywritten relative to eachrowof the sub-displaypanel 10s bysimultaneously applying display signal voltage relative to each of the display pixels for the 1st, 2nd, 3rd ,••• rows in the sub-display panel 10s via each data line from the data driver 20. Accordingly, the desired luminance signal (display signal voltage) is sequentially written and displayed as image information in both themain displaypanel 10mand the sub-display panel 10s which have 160 scanning lines, respectively, in 1 vertical scanningperiod (displayperiod) within a 1 frame period. Additionally, as seen inFIG.6, in thedrive control operation described above, at scan timing Tl, T3, T5, • • • , as display signal voltage of positive polarity and negative polarity is alternately applied to the pixel electrodes for each row of display pixels in the main display panel 10m, low-level and high-level main common signal voltage Vcomm is alternately applied to the common electrode of the main display panel 10m and line (row) reversal drive is performed. Also, at scan timing T2, T4, T6,---, as display signal voltage of positive polarity and negative polarity is alternately applied to the pixel electrodes for each row of display pixels in the sub-display panel 10s, low-level and high-level sub-common signalvoltageVcoms is alternatelyapplied to the common electrode of the sub-display panel 10s and line (row) reversal drive is performed. Furthermore, a vertical retrace line period (non-display period) is set after conclusion of 1 vertical scanning period within a 1 frame period regarding the display signal voltage together with the main common signal voltage Vcomm and sub-common signal voltage Vcoms applied to each row of the display pixels (pixel electrodes and common electrode) in the main display panel 10mandthe sub-displaypanel 10s in the above-mentioned 1vertical scanning period. The period (for example, period of 3 phase segments in FIG. 6) of duration allocated for odd-numbered segments is identical for each of the above mentioned scan timing T1-T320. In these vertical retrace line periods, the odd-numbered reversals of the main common signal voltage Vcomm and sub-common signal voltage Vcoms are performed. For example, as seen in FIG. 6, both the main common signal voltage Vcomm and the sub-common signal voltage Vcoms are reversed 3 times.
Accordingly, the signal polarity of each signal voltage in the next 1 frame period is reversed and frame reversal drive is performed in the main display panel 10m and the sub-display panel
10s. Moreover, for example as shown in FIG. 6, when performing scanning drive in the sub-display panel 10s, the signal polarity of the main common signal voltage Vcomm in the main display panel 10m side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s. Also, when performing scanning drive in the main display panel 10m, the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s side is set to the same polarity as the signal polarity of the sub-common signal voltage Vcoms in the sub-display panel 10s for the following scanning drive occurrence. Accordingly, in 1 vertical scanning period, the reversal drive frequency of the main common signal voltage Vcomm applied to the main display panel 10m is the same total as the number of scanning lines in the main display panel 10m. The reversal drive frequency of the sub-common signal voltage Vcoms applied to the sub-display panel 10s is the same total as the number of scanning lines in the sub-display panel 10s. Particularly, such as this embodiment when the panel size ratio (number of scanning lines) of the main display panel 10m and the sub-display panel 10s is set as 1:1, as shown in FIG.
6, the reversal drive of the main common voltage Vcomm applied to the main display panel 10m and sub-common signal voltage Vcoms applied to the sub-display panel 10s is performed in the same cycle. As a result, for example, a configuration which interchanges the main common electrode driver circuit 60m and the sub-common driver circuit 60s with a single common electrode driver circuit is applicable. Accordingly, the circuit configuration of the display device can be simplified and miniaturized. Additionally, even if it is a casewhere the panel size (number of scanning lines) of the main display panel and sub-display panel is set as 1:1, as described in each of the above-described embodiments, because reversal drive of the common signal voltage is applied to the main display panel and the sub-display panel and performed for only the number of scanning lines allocated in the main display panel or the sub-display panel, the reversal drive of the common signal voltage can be applied to the main displaypanel andthe sub-displaypanel. Thus , the drivingcycles (frequency rate of repetition) related to the reversal drive can be decreased and a reduction in power consumption can be achieved.
In each of the embodiments above, although explained that the panel size ratio (number of scanning lines) of the two display panels is defined as n:l (n = 1-4), the present invention is not restricted to this. Specifically, the present invention is anapparatuswhichapplies ascanning signalrelative to ascanning line group situated in each of two display panels at timing corresponding to the panel size ratio (number of scanning lines) of each display panel. For example, even in the case where the panel sizeratio of the two displaypanels constitutes arelational quantity of i:j (i, j > 1, 1-digit positive integers), this proportion is favorably applicable as well. For example, when the panel size ratio (number of scanning lines) of two display panels has the relation of 3:2 in the drive control method described above, after sequentially applying a scanning signal and performing scanning drive relative to 3 row segments (for example, main display panel 10m for the 1st thru
3rd rows; i-th rows) of the scanning lines in one display panel at consecutive scan timing (3 scan timing), a scanning signal is sequentially applied and scanning drive performed relative to 2 row segments (for example, sub-display panel 10s for the
1st and 2nd rows; j-th rows) of the scanning lines in the second display panel by the following consecutive scan timing (2 scan timing) . This control operation which executes scanning drive is alternately repeated between both display panels . As in the case of each embodiment explained above, the reversal drive frequency (rate of repetition) of the common signal voltage applied to each display panel is the same total as the number of scanning lines in each display panel. While being able to reduce the driving cycles (frequency) related to the reversal drive to achieve a reduction in power consumption, line reversal drive and frame reversal drive can be accomplished. In addition, mentioned above is a case in which the panel size ratio of the two display panels does not constitute a simpler integer ratio. In this instance, operation timing is regulated with a 1 frame period. Specifically, a dummy scanning interval is provided which adjusts timing so that the sum total time for each signal polarity becomes the same for each common signal voltage in each display panel and an approximated integer ratio i: j proportionate to the panel size ratio is employed. As stated above, the operation then alternately repeats scanning drive between each of the display panels by the number of scanning lines relative to the panel size ratio of both display panels . Like the drive control method mentioned above, while being able to reduce the driving cycles (frequency) related to the reversal drive achieves a reduction in power consumption, line reversal drive and frame reversal drive can be accomplished. Furthermore, as for the first through third embodiments mentioned above, the display device comprises a main display panelwhich includes arelativelylargepanel size (greaternumber of scanning lines) and a sub-display panel with a comparatively smaller panel size (lesser number of scanning lines) . Besides, although a case is explained in which j-th row scanning drive in the sub-display panel is performed after i-th row scanning drive in the main display panel, the possibility is stressed that the electronic apparatus may perform operational control so that i-th row scanning drive in the main display panel is performed after j-th row scanning drive in the sub-display panel. Finally, although the embodiments mentioned above only described cases comprising two display panels, the present invention may be a display device which is not limited to this and comprised with a greater number of display panels of 3 or more than 3. Also, in this case the technical concept of the present invention can be applied by sequentially repeating scanning drive between each of the display panels by the number of scanning lines relative to the panel size ratio of each display panel. Again, like the drive control method mentioned above, while being able to reduce the driving cycles (frequency) related to the reversal drive to achieve a reduction in power consumption, line reversal drive and frame reversal drive can be accomplished. While the present inventionhas been describedwithreference to the preferred embodiments, it is intended that the invention be not limited by any of the details of the description therein but includes all the embodiments which fall within the scope of the appended claims.

Claims

1. A display device which displays an image corresponding to a display signal comprising at least: a plurality of display panels (10m, 10s) which comprise a plurality of scanning lines and a plurality of signal lines with display pixels situated near each intersecting point of each scanning line and signal line besides a common electrode situated in common with each of the display pixels; the display panels having a predetermined numbers of the scanning lines respectively; a scan driver section (30m, 30s) which sequentially applies a scanning signal to each of the plurality of scanning lines in each of the plurality of display panels and sequentially set the display pixels corresponding to the appropriate scanning lines as a selective state; and a control section (50) which controls operation for sequentially selecting a number of the scanning lines of each of the plurality of display panels corresponding to the ratio of the numbers of the scanning lines in each of the plurality of display panels at every predetermined scan timing by the scan driver section (30m, 30s) and for repeating uniform sequences between each of the display panels in a display period at a plurality of times within a one frame period.
2. The display device according to claim 1 , wherein the display periodcomprises avertical scanningperiodrequiredforshifting the number of scanning lines of each display panel entirely to a selective state.
3. The display device according to claim 1 , further comprises acommonelectrodedriver section (60m, 60s) to acommon electrode for each display panel which applies a common signal voltage for setting a voltage level in respective common electrodes; and the control section (50) at least performs reversal control of the signal polarity relative to each of the display panels for each of the common signal voltages applied to the common electrode in each of the display panels by the common electrode driver section (60m, 60S) so that reversal drive for every scanning line corresponds to a selection operation for each of the scanning lines by the scan driver section (30m, 30s).
4. The display device according to claim 3 , wherein the control section (50) of a period which selects the scanning lines of any one of the display panels in the plurality of display panels by the scan driver section (30m, 30s), the signal polarity of the common signal voltage applied to the common electrode of whichever other of the displaypanels selectednext by the common electrode driver section (60m, 60s) is set as the same polarity as the signal polarity of the common signal voltage applied to the common electrode of the relevant display panel when the scanning lines of the next relevant display panel are selected.
5. The display device according to claim 3 , wherein the control section. (50) further performs reversal control of the signal polarity for each of the common signal voltages in each of the frame periods .
6. The display device according to claim 5 , wherein during the one frame period comprises a non-display period for timing adjustment in order to reverse the signal polarity for each of the common signal voltages in each of the one frame periods.
7. The display device according to claim 3 , wherein the control section (50) performs reversal control of the signal polarity for each of the common signal voltages so that a sum total applied time period for each signal polarity of the common signal voltage applied to the common electrode in each of the display panels becomes equal in the display period.
8. The display device according to claim 7 , wherein the display period comprises a dummy period for applied time period adjustment of the common signal voltage which regulates the sum total applied time period for each signal polarity of the common signal voltage to become equal in a relevant display period.
9. The display device according to claim 3, wherein reversal controlperformedbythe control section (50) , reversal frequency inadisplayperiodwithinaoneframeperiodof the signalpolarity for the common signal voltage applied to the common electrode of each of the display panels is set to the same total as the number of scanning lines of each these display panels.
10. The display device according to claim 1, at least some of the plurality of signal lines in each of the display panels are connected in common to each of these display panels (10m, 10s) ; and the display device further comprises one signal driver section ( 20 ) whichapplies adisplaysignalvoltage corresponding to the display signal to the plurality of signal lines .
11. The display device according to claim 1, wherein the scan driver section (30m, 30s) is separately provided corresponding to each of the plurality of display panels.
12. The display device according to claim 1, wherein the plurality of the display panels comprise a 1st display panel (10m) and a 2nd display panel (10s) in which the ratio of the numbers of the scanning lines is defined as i: j (i, j are random 1-digit positive integers); and the control section (50) controls to repeat alternately an operation which sequentially selects the scanning lines of i-th rows in the 1st display panel and an operation which sequentially selects the scanning lines of j-th rows in the 2nd displaypanel by the scan driver section (30m, 30s) in the display period.
13. The display device according to claim 12, comprises a 1st common electrode driver section (60m) and a 2nd common electrode driver section (60s) for each common electrode of the 1st display panel (10m) and the 2nd display panel (10s) which apply a 1st common signal voltage and a 2nd common signal voltage that sets a voltage level in each of these common electrodes; and the control section ( 50 ) in a period which scans the display pixels of the 1st display panel (10m), the signal polarity of the 2nd common signal voltage applied to the common electrode of the 2nd display panel (10s) by the 2nd common electrode driver section (60s) is set as the same polarity as the signal polarity of the 2nd common signal voltage when the scanning lines of the 2nd display panel (10s) are selected next; and in a period which selects the scanning lines of the 2nd display panel (10s), the signal polarity of the 1st common signal voltage applied to the 1st common electrode of the 1st display panel (10m) by the 1st common electrode driver section (60m) is set as the same polarity as the signal polarity of the 2n common signal voltage.
14. The display device according to claim 1, wherein the plurality of display panels comprise a 1st display panel (10m) and a 2nd display panel (10s) in which the ratio of the numbers of the scanning lines is defined as approximated i: j (i, j are random 1-digit positive integers); and the control section (50) controls to repeat alternately an operation which sequentially selects the scanning lines of i-th rows in the 1st display panel (10m) and an operation which sequentially selects the scanning lines of j-th rows in the 2nd display panel (10s) by the scan driver section (30m, 30s) in the display period.
15. The displaydeviceaccording toclaim14, wherein thedisplay period comprises a dummy period for applied time period adjustment of the common signal voltage which regulates the sum total applied time period for each signal polarity of the common signal voltage to become equal in a relevant display period.
16. An electronic apparatus comprising a display device which displays an image corresponding to a display signal, the display device comprises at least : two display panels (10m, 10s) which comprise a plurality of scanning lines and a plurality of signal lines with display pixels situated near each intersecting point of each scanning line andsignal linebesides acommon electrode situatedin common with each of the display pixels; the two display panels having first and second numbers of the scanning lines respectively; a scan driver section(30m, 30s) which sequentially applies a scanning signal to each of the plurality of scanning lines in each of the plurality of display panels and sequentially sets the display pixels corresponding to the appropriate scanning lines as a selective state; a common electrode driver section (60m, 60s) which applies a common signalvoltage for setting this common electrodevoltage level in the common electrode in each of the display panels (10m, 10s); and a control section (50) which controls so as to repeat alternately an operation that sequentially selects a number of scanning lines of each of the display panels corresponding to the ratio of the first and second numbers of the scanning lines in each of the display panels by the scan driver section (30m, 30s) for every predetermined scan timing between each of the display panels in a display period at a plurality of times within a one frame period; and which at least performs reversal control of the signal polarity for each of the common signal voltages applied to the common electrode in each of the display panels (10m, 10s) by the common electrode driver section (60m, 60S) so that reversal drive of each of the display panels (10m, 10s) is performed for every scanning line corresponding to a selection operation for each of the scanning lines of each of the display panels (10m, 10s) by the scan driver section (30m, 30s).
17. The electronic apparatus according to claim 16 comprises a cellular telephone.
18. The electronic apparatus according to claim 16, wherein the displayperiod comprises a vertical scanning period required for shifting the number of scanning lines of each display panel entirely to a selective state.
19. The electronic apparatus according to claim 16, wherein the control section (50) in a period which selects the scanning lines of one direction of the display panels (10m) of the two display panels (10m, 10s) by a scan driver section (30m, 30s), the signal polarity of the common signal voltage applied to the common electrode of other direction display panel (10s) by the common electrode driver section (60s) is set as the same polarity as the signal polarity of the common signal voltage which is applied to the common electrode of the relevant other direction displaypanel ( 10s ) when the scanning lines of the other direction display panel (10s) are selected next; and in a period which selects the scanning lines of the other direction display panel (10s) by the scanning driver section, the signal polarity of the common signal voltage applied to the common electrode of the one direction display panel (10m) by the common electrode driver section (60m) is set as the same polarity as the signal polarity of the common signal voltage applied to the common electrode of the relevant other direction display panel (10s) .
20. The electronic apparatus according to claim 16, wherein the control section (50) further performs reversal control of the signal polarity for each of the common signal voltages in each of the frame periods.
21. The electronic apparatus according to claim 20, wherein during the one frame period comprises a non-display period for timing adjustment in order to reverse the signal polarity for eachof thecommon signalvoltages ineachof theoneframeperiods .
22. The electronic apparatus according to claim 16, wherein the control section (50) performs reversal control of the signal polarity for each of the common signal voltages so that a sum total applied time period for each signal polarity of the common signal voltage applied to the common electrode in each of the display panels becomes equal in the display period.
23. The electronic apparatus according to claim 22, wherein the display period comprises a dummy period for applied time period adjustment of the common signal voltage which regulates the sum total applied time period for each signal polarity of the common signal voltage to become equal in a relevant display period.
24. The electronic apparatus according to claim 16, wherein reversal control performed by the control section ( 50 ) , reversal frequency in a display period within a one frame period of the signal polarity for the common signal voltage applied to the common electrode of each of the display panels is set to the same total as the number of scanning lines of each these display panels .
25. The electronic apparatus according to claim 16, at least some of the plurality of signal lines in each of the display panels are connected in common to each of these display panels; and the display device further comprises one signal driver section ( 20) whichapplies adisplaysignalvoltagecorresponding to the display signal to the plurality of signal lines.
26. The electronic apparatus according to claim 16, wherein the scan driver section (30m, 30s) is separately provided corresponding to each of the plurality of display panels.
27. The electronic apparatus according to claim 16, wherein the two display panels comprise a 1st display panel (10m) and a 2nd display panel (10s) in which the ratio of the numbers of the first and second scanning lines is defined as i: j (i, j are random 1-digit positive integers); and the control section (50) controls to repeat alternately an operation which sequentially selects the scanning lines of i-th rows in the 1st display panel and an operation which sequentially selects the scanning lines of j-th rows in the 2nd displaypanel by the scan driver section (30m, 30s) in the display period.
28. The electronic apparatus according to claim 27 comprises a 1st common electrode driver section (60m) and a 2nd common electrode driver section (60s) for each common electrode of the 1st display panel (10m) and the 2nd display panel (10s) which apply a 1st common signal voltage and a 2nd common signal voltage that sets a voltage level in each of these common electrodes; and the control section (50) in a period which scans the display pixels of the 1st display panel (10m), the signal polarity of the 2nd common signal voltage applied to the common electrode of the 2nd display panel (10s) by the 2nd common electrode driver section (60s) is set as the same polarity as the signal polarity of the 2nd common signal voltage when the scanning lines of the 2nd display panel (10s) are selected next; and in a period which selects the scanning lines of the 2nd display panel (10s), the signal polarity of the 1st common signal voltage applied to the 1st common electrode of the 1st display panel (10m) by the 1st common electrode driver section ( 60m) is set as the same polarity as the signal polarity of the 2nd common signal voltage.
29. The electronic apparatus according to claim 16, wherein the two display panels comprise a 1st display panel (10m) and a 2nd display panel (10s) in which the ratio of the numbers of the first and second scanning lines is defined as approximated i:j (i# j are random 1-digit positive integers); and the control section (50) controls to repeat alternately an operation which sequentially selects the scanning lines of i-th rows in the 1st display panel (10m) and an operation which sequentially selects the scanning lines of j-th rows in the 2nd display panel (10s) by the scan driver section (30m, 30s) in the display period.
30. The electronic apparatus according to claim 29, wherein the display period comprises a dummy period for applied time period adjustment of the common signal voltage which regulates the sum total applied time period for each signal polarity of the common signal voltage to become equal in a relevant display period.
31. A drive control method of the display device comprising a plurality of display panels (10m, 10s); comprising a plurality of scanning lines and a plurality of signal lines with display pixels situated near each intersecting point of each of the scanning lines and signal lines besides a common electrode situated in common with each of the display pixels includes : the display panels having a predetermined numbers of the scanning lines respectively; a process which repeats a control operation for sequentially scanning a number of the scanning lines of each of the display panels at every predetermined scan timing corresponding to the ratio of the numbers of the scanning lines in each of the plurality of display panels and for repeating uniform sequences between each of the display panels in a display period at a plurality of times within a one frame period; and a process which at least performs reversal of the signal polarity of the common voltage signal relative to each of the displaypanels for settingavoltage level of the common electrode of eachof thedisplaypanels (10m, 10s) correspondingto acontrol operation of the scanning lines so that reversal drive is performed for every scanning line.
32. The drive control method according to claim 31, wherein the display period comprises a vertical scanning period required for shiftingthenumberof scanninglines of apluralityof display panels entirely to a selective state.
33. The drive control method according to claim 32, wherein the process which reverses the signal polarity of the common signal voltage further comprises a process which reverses the signal polarity for each of the common signal voltages in each of the one frame periods .
34. The drive control method according to claim 31, wherein the process which reverses the signal polarity of the common signal voltage sets so that a sum total applied time period for each signal polarity of the common signal voltage applied to the common electrode in each of the display panels (10m, 10s) becomes equal in the display period.
35. The drive control method according to claim 31, wherein the process which reverses the signal polarity of the common signal voltage in a period which selects the scanning lines of any one of the display panels in the plurality of display panels (10m, 10s), the signal polarity of the common signal voltage applied to the common electrode of whichever other of the display panels selected next is set as the same polarity as the signal polarity of the common signal voltage applied to the common electrode of the relevant display panel when the scanning lines of the next relevant display panel are selected.
36. The drive control method according to claim 31, wherein reversal frequency in a display period within a one frame period of the signal polarity for the common signal voltage applied to the common electrode of each of the display panels (10m, 10s) is set to the same total as the number of scanning lines of each these display panels.
37. The drive control method according to claim 31, wherein the plurality of the display panels comprise a 1st display panel (10m) and a 2nd display panel (10s) in which the ratio of the numbers of the scanning lines is defined as i: j (i, j are random 1-digit positive integers); and the process which repeats a control operation for sequentially scanning the scanning lines of each of the display panels includes a process which controls to repeat alternately an operation which sequentially selects the scanning lines of i-th rows in the 1st display panel (10m) and an operation which sequentially selects the scanning lines of j-th rows in the 2nd display panel (10s) in the display period.
38. The drive control method according to claim 37, wherein the process which reverses the signal polarity of the common signal voltage includes a process which scans the display pixels of the 1st display panel (10m) in a period, the signal polarity of the 2nd common signal voltage applied to the common electrode of the 2nd display panel (10s) by the 2nd common electrode driver section (60s) is set as the same polarity as the signal polarity of the 2nd common signal voltage when the scanning lines of the 2nd display panel (10s) are selected next; and which selects the scanning lines of the 2nd display panel (10s) in a period, the signal polarity of the 1st common signal voltage applied to the 1st common electrode of the 1st display panel (10m) by the 1st common electrode driver section (60m) is set as the same polarity as the signal polarity of the 2nd common signal voltage.
39. The drive control method according to claim 31, wherein the plurality of display panels comprise a 1st display panel (10m) and a 2nd display panel (10s) in which the ratio of the numbers of the scanning lines is defined as approximated i:j (i, j are random 1-digit positive integers); and the process which repeats a control operation for sequentially scanning the scanning lines in each of the display panels includes a process which repeats alternately an operation which sequentially selects the scanning lines of i-th rows in the 1st display panel (10m) and an operation which sequentially selects the scanning lines of j-th rows in the 2nd display panel
(10s) in a display period.
40. The drive control method according to claim 39, wherein the process which repeats a control operation for sequentially scanning the scanning lines in each of the display panels (10m, 10s) includes a process which provides a dummy period within a relevant display period and adjusts the applied time period of the common signal voltage in order to regulate the sum total applied time period for each signal polarity of the common signal voltage to become equal in the display period.
PCT/JP2005/009019 2004-05-12 2005-05-11 Driving method of deplay device having main display and sub display WO2005109395A1 (en)

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Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3541891B2 (en) * 2002-03-15 2004-07-14 日本電気株式会社 Connector with dustproof mechanism
JP4501525B2 (en) * 2004-05-12 2010-07-14 カシオ計算機株式会社 Display device and drive control method thereof
EP1717782B1 (en) * 2005-04-27 2008-10-22 LG Display Co., Ltd. Dual panel apparatus and method of driving the same
JP4561557B2 (en) * 2005-09-22 2010-10-13 株式会社デンソー Liquid crystal display device and vehicle periphery monitoring device
KR100635511B1 (en) * 2005-09-30 2006-10-17 삼성에스디아이 주식회사 Organic electroluminescent display device
CN101322170B (en) * 2005-12-02 2012-10-10 株式会社半导体能源研究所 Display module and electronic device using the same
US20070152955A1 (en) * 2005-12-29 2007-07-05 Nokia Corporation Reduced power consumption display panel
US7439679B2 (en) * 2006-03-16 2008-10-21 Motorola, Inc. Method and apparatus for illuminating light sources within an electronic device
WO2007142190A1 (en) * 2006-06-09 2007-12-13 Sharp Kabushiki Kaisha Display drive circuit and display
US20080036720A1 (en) * 2006-08-09 2008-02-14 Foo Ken K System and method for driving a liquid crystal display to reduce audible noise levels
KR20080037754A (en) * 2006-10-27 2008-05-02 삼성전자주식회사 Liquid crystal display device and driving mathod thereof
KR20090054836A (en) * 2007-11-27 2009-06-01 삼성전자주식회사 The apparatus for displaying image and the method thereof
JP4737562B2 (en) * 2008-06-19 2011-08-03 ソニー株式会社 Information processing apparatus and method, and program
KR101751352B1 (en) * 2010-10-29 2017-06-28 삼성디스플레이 주식회사 Method of driving display panel and display apparatus for performing the method
TWI451393B (en) * 2011-10-14 2014-09-01 Sitronix Technology Corp A driving method of a liquid crystal display device and a driving circuit thereof
KR20140052454A (en) * 2012-10-24 2014-05-07 삼성디스플레이 주식회사 Scan driver and display device comprising the same
WO2015173954A1 (en) * 2014-05-16 2015-11-19 富士通株式会社 Drawing device, drawing method, and computer program for drawing
KR102398677B1 (en) * 2015-04-06 2022-05-16 삼성디스플레이 주식회사 Display device
JP6830765B2 (en) * 2015-06-08 2021-02-17 株式会社半導体エネルギー研究所 Semiconductor device
KR102412456B1 (en) * 2015-08-26 2022-06-27 엘지디스플레이 주식회사 Display Device
JP6146594B1 (en) * 2015-12-22 2017-06-14 カシオ計算機株式会社 Display device, control method therefor, and control program
KR102541709B1 (en) * 2016-04-04 2023-06-13 삼성디스플레이 주식회사 Method of driving display panel and display apparatus for performing the method
US10354569B2 (en) * 2017-02-08 2019-07-16 Microsoft Technology Licensing, Llc Multi-display system
JP2019109353A (en) * 2017-12-18 2019-07-04 シャープ株式会社 Display control device and liquid crystal display device provided with the display control device
US11462189B2 (en) 2019-09-11 2022-10-04 Sitronix Technology Corp. Driving circuit and driving method for display panel and display module

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5748165A (en) * 1993-12-24 1998-05-05 Sharp Kabushiki Kaisha Image display device with plural data driving circuits for driving the display at different voltage magnitudes and polarity
US5907314A (en) * 1995-10-31 1999-05-25 Victor Company Of Japan, Ltd. Liquid-crystal display apparatus
US20030080932A1 (en) * 2001-10-30 2003-05-01 Akitoyo Konno Liquid crystal display apparatus
US20040021616A1 (en) * 2002-07-30 2004-02-05 Mitsuru Goto Liquid crystal display device
EP1389775A2 (en) * 2002-08-09 2004-02-18 Sanyo Electric Co., Ltd. Display including a plurality of display panels
EP1406240A2 (en) * 2002-10-03 2004-04-07 NEC Electronics Corporation Apparatus for driving a plurality of display units using common driving circuits
US20040140947A1 (en) * 2002-11-15 2004-07-22 Takashi Tsuyuki Display device

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07504997A (en) * 1992-03-20 1995-06-01 ブイ　エル　エス　アイ　テクノロジー，インコーポレイテッド VGA controller and driving method using address conversion for driving dual scan LCD panel
JP3476241B2 (en) * 1994-02-25 2003-12-10 株式会社半導体エネルギー研究所 Display method of active matrix type display device
TW515924B (en) * 1997-04-02 2003-01-01 Toshiba Corp Flat-panel display device and display method
JP2003323164A (en) * 2002-05-08 2003-11-14 Hitachi Displays Ltd Liquid crystal display device and its driving method
JP4297662B2 (en) * 2002-08-09 2009-07-15 三洋電機株式会社 Display device
JP4297660B2 (en) * 2002-08-09 2009-07-15 三洋電機株式会社 Display device
JP4145637B2 (en) * 2002-11-25 2008-09-03 シャープ株式会社 Active matrix substrate and display device
KR100957574B1 (en) * 2003-09-17 2010-05-11 삼성전자주식회사 Display apparatus
JP4501525B2 (en) * 2004-05-12 2010-07-14 カシオ計算機株式会社 Display device and drive control method thereof

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5748165A (en) * 1993-12-24 1998-05-05 Sharp Kabushiki Kaisha Image display device with plural data driving circuits for driving the display at different voltage magnitudes and polarity
US5907314A (en) * 1995-10-31 1999-05-25 Victor Company Of Japan, Ltd. Liquid-crystal display apparatus
US20030080932A1 (en) * 2001-10-30 2003-05-01 Akitoyo Konno Liquid crystal display apparatus
US20040021616A1 (en) * 2002-07-30 2004-02-05 Mitsuru Goto Liquid crystal display device
EP1389775A2 (en) * 2002-08-09 2004-02-18 Sanyo Electric Co., Ltd. Display including a plurality of display panels
EP1406240A2 (en) * 2002-10-03 2004-04-07 NEC Electronics Corporation Apparatus for driving a plurality of display units using common driving circuits
US20040140947A1 (en) * 2002-11-15 2004-07-22 Takashi Tsuyuki Display device

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