CN101533609B - Electro-optic displays and methods for controlling the same - Google Patents
Electro-optic displays and methods for controlling the same Download PDFInfo
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- CN101533609B CN101533609B CN200910128714XA CN200910128714A CN101533609B CN 101533609 B CN101533609 B CN 101533609B CN 200910128714X A CN200910128714X A CN 200910128714XA CN 200910128714 A CN200910128714 A CN 200910128714A CN 101533609 B CN101533609 B CN 101533609B
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Abstract
The invention relates to electro-optic display and method for controlling the same. The electro-optic display comprises a bistable electro-optic medium, a plurality of pixel electrodes, with associated non-linear elements, and a common electrode, disposed on opposed sides of the electro-optic medium. The display has a writing mode, in which at least two different voltages are applied to different pixel electrodes, and a non-writing mode in which the voltages applied to the pixel electrodes are controlled so that any image previously written on the electro-optic medium is substantially maintained. The display is arranged to apply to the common electrode a first voltage when the display is in its writing mode and a second voltage, different from the first voltage, when the display is in its non-writing mode.
Description
The application is that application number is 200480023730.8, the applying date is on August 19th, 2004, denomination of invention is divided an application for the application for a patent for invention of " method of control electro-optic displays ".
Technical field
The present invention relates to control the method for electro-optic displays.In one aspect; The present invention relates in electro-optic displays, provide the reduction power rating; More particularly; Relate to a kind of active matrix electro-optic displays that utilizes the bistable electro-optical medium, said display is equipped with the device that is used for controlling in the non-write state process of display the current potential of common electrode.On the other hand, the present invention relates to be used for controlling the method for electro-optic displays electrode voltage, more particularly, relate to the voltage method that is used to control the public preceding electrode that is applied to the active matrix electro-optic displays that utilizes the bistable electro-optical medium.
Background technology
Electro-optic displays comprises electro-optical material layer; Refer to have the material of first and second different at least a optical characteristics show states with it at this term that uses on the traditional sense of imaging technique among this paper, said material is through applying electric field and change into its second show state from its first show state to said material.Although said optical characteristics generally is appreciable to the human eye color; But it can be another kind of optical characteristics; Such as light transmission, reflectance, luminous; Or under the situation of the display that designs for the machine reading, change the pseudo-colours on the meaning in the electromagnetic wavelength reflectance that exceeds visible-range.
The term that in imaging technique, uses on its traditional sense among this paper " bistable " is meant that with " bistable state " display comprises the display element with first and second different at least a optical characteristics show states; And after making that any given element has driven by means of the addressing pulse of a limited duration; Just take its first or second show state; After said addressing pulse finishes; Said state will continue to change the several times at least of the minimum duration of the required addressing pulse of said status display module, for example, and at least four times.U.S. Patent No. application No.2002/0180687 shows; Some electrophoretic display device (EPD) based on particle that can carry out the gray scale demonstration is stable at their extreme black and white state not only; And also be stable in their gray states of centre, the electro-optic displays situation of some other type also is like this.The display of said type should be called " multistable " rather than bistable state, although for simplicity, can use term " bistable " to come not only to cover bistable but also cover the multistable display here.
The electro-optic displays that several types are arranged is known.For example, as in United States Patent(USP) No. 5,808,783; 5,777,782; 5,760,761; 6,054,071; 6,055,091; 6,097,531; 6,128,124; 6,137,467; With 6; 147; Described in 791; One type electro-optic displays is (although the display of said type often is called " Rotating Double chromosphere " display, it is a kind of appellation more accurately that term " rotates double-colored member ", because be not sphere at rotating member described in some above-mentioned patents) of the double-colored member type of rotation.A kind of display like this uses a large amount of wisps (spherical in shape or cylindrical), and they have two or more cross sections, has different optical characteristic and internal dipole.These objects are suspended in the cavity of the full of liquid in the matrix, and said cavity filling liquid makes said object to rotate freely.Apply electric field above that, thereby said object rotates to different positions and change object towards the cross section of watching the surface, the outward appearance of said display is changed.
The electro-optic displays of another kind of type uses electrochromic media; For example; Take the electrochromic media of nanometer variable color film (nanochromic film) form to comprise the electrode that at least a portion ground is formed by semiconduction metal oxide and a plurality of dye molecule; Reversible change color can take place in dye molecule, is attached on the said electrode; For example, see people such as O ' Regan B., Nature1991,353,737; And Wood D., Information Display, 18 (3), the article of 24 (March2002).Other sees Bach, people Adv.Mater. such as U., 2002,14 (11), 845 article.The nanometer variable color film of said type is also for example being described in United States Patent(USP) No. 6,301,038, the open No.WO 01/27690 of international patent application and the U.S. Patent application 2003/0214695.The medium of said type generally also is bistable.
The electro-optic displays of another kind of type that has become the problem of broad research and exploitation for many years is based on the electrophoretic display device (EPD) of particle, and wherein a plurality of charged particles move through suspending liquid under electric field effects.Compare with LCD, electrophoretic display device (EPD) can have good attribute in brightness and contrast, wide wide viewing angle, bistable state and low-power consumption.Yet the long-term image quality problem of these displays has hindered their extensive employing.For example, the particle that constitutes electrophoretic display device (EPD) often precipitates, and causes these displays to fall short of serviceable life.
The patent and the application of recently disclosed many name applications with Massachusetts Institute of Technology (MIT) (MIT) and E Ink company, the description encapsulated electrophoretic medium.Such sealing medium comprises many Caplets, and wherein each itself comprises a kind of inner phase again, comprise movably particle of the electrophoresis that is suspended in the liquid suspension medium, and capsule wall surrounds said inner phase.Generally, they itself are maintained at said capsule in the polymeric binder, form a relevant layer that is positioned between two electrodes.The sealing medium of said type is for example, United States Patent(USP) No. 5,930,026; 5,961,804; 6,017,584; 6,067,185; 6,118,426; 6,120,588; 6,120,839; 6,124,851; 6,130,773; 6,130,774; 6,172,798; 6,177,921; 6,232,950; 6,249,721; 6,252,564; 6,262,706; 6,262,833; 6,300,932; 6,312,304; 6,312,971; 6,323,989; 6,327,072; 6,376,828; 6,377,387; 6,392,785; 6,392,786; 6,413,790; 6,422,687; 6,445,374; 6,445,489; 6,459,418; 6,473,072; 6,480,182; 6,498,114; 6,504,524; 6,506,438; 6,512,354; 6,515,649; 6,518,949; 6,521,489; 6,531,997; 6,535,197; 6,538,801; 6,545,291; 6,580,545; 6,639,578; 6,652,075; 6,657,772; 6,664,944; 6,680,725; 6,683,333; 6,704,133; 6,710,540; 6,721,083; 6,724,519; 6,727,881; 6,750,473; And 6,753, and 999; With the open No.2002/0019081 of U.S. Patent application; 2002/0021270; 2002/0053900; 2002/0060321; 2002/0063661; 2002/0063677; 2002/0090980; 2002/0106847; 2002/0113770; 2002/0130832; 2002/0131147; 2002/0145792; 2002/0171910; 2002/0180687; 2002/0180688; 2002/0185378; 2003/0011560; 2003/0020844; 2003/0025855; 2003/0034949; 2003/0038755; 2003/0053189; 2003/0102858; 2003/0132908; 2003/0137521; 2003/0137717; 2003/0151702; 2003/0189749; 2003/0214695; 2003/0214697; 2003/0222315; 2004/0008398; 2004/0012839; 2004/0014265; 2004/0027327; 2004/0075634; 2004/0094422; 2004/0105036; With 2004/0112750; And the open No.WO 99/67678 of international patent application; WO 00/05704; WO 00/38000; WO 00/38001; WO 00/36560; WO 00/67110; WO 00/67327; WO 01/07961; WO 01/08241; WO 03/092077; WO 03/107315; With describe among the WO2004/049045.
Above-mentioned many patents and application are recognized; The wall portion that in encapsulated electrophoretic medium, surrounds discrete micro-capsule can replace with external phase; Thereby, producing a kind of what is called " polymer-dispersed electrophoretic display ", wherein said electrophoretic medium comprises a plurality of discrete electrophoresis droplets and the external phase of polymeric material; And the discrete electrophoresis droplet in such polymer-dispersed electrophoretic display can be regarded as capsule or micro-capsule, although the discrete capsule film that is not associated with each independent drop; For example, see above-mentioned 2002/0131147.Correspondingly, for the application's purpose, such polymer-dispersed electrophoretic media is counted as the subclass of encapsulated electrophoretic medium.
Encapsulated electrophoretic display does not generally have traditional electrophoresis device to assemble and the problem of deposition failure mode, and in addition, it also has such as can or being coated on the advantage on the substrate of various flexibilities and rigidity the display printing.Want to comprise whole forms of printing and coating when using " printing " speech, include, but is not limited to: scheduled volume (pre-metered) coating is coated with, shelters coating such as repairing punch die coating, slit or extrusion coated, slip or lamination; Print roll coating is such as knife over roll coating, two-way print roll coating; The intaglio plate coating; Dip-coating; Spraying; Meniscus (meniscus) coating; Spin coating; Brush; The air knife coating; Serigraphy is handled; Xeroprinting is handled; The hot stamping brush is handled; Ink jet printing is handled; And other similar techniques.Thereby the display of gained can be flexible.In addition, because display medium can print (utilizing various methods), so display itself can be with less cost production.
Above-mentioned some patent of E Ink and MIT has been described the electrophoretic medium that has two above type electrophoresis particles in the single capsule with application.For current purpose, so many granule mediums are counted as the subclass of two granule mediums.
A kind of electrophoretic display device (EPD) of correlation type is so-called " micro element electrophoretic display device (EPD) ".In the micro element electrophoretic display device (EPD), charged particle and suspending liquid are not sealed in the capsule, but maintain in the mounting medium, generally are in a plurality of holes that form in the thin polymer film.For example, see open No.WO 02/01281 of international patent application and the open No.2002/0075556 of U.S. Patent application, both all transfer Sipix Imaging, Inc. (company).
Although electrophoretic medium is opaque often (for example; Because in many electrophoretic mediums; Particle block visible light basically sees through said display), and operate under the reflection mode, many electrophoretic display device (EPD)s may operate under the what is called " optical gate mode "; One of them show state is opaque basically, and one is printing opacity.For example, see above-mentioned United States Patent(USP) No. 6,130,774 and 6,172,798 and United States Patent(USP) No. 5,872,552; 6,144,361; 6,271,823; 6,225,971; And 6,184,856.Be similar to electrophoretic display device (EPD), but depend on electric field intensity change dielectrophoretic displays, may operate under the similar mode; See United States Patent(USP) No. 4,418,346.The electro-optic displays of other type perhaps also can operate under the optical gate mode.
In order to obtain the high resolving power electro-optic displays, each pixel of said display must be able to be addressed, and don't disturbs neighbor.An approach that reaches this purpose is the array that non-linear element is set, and it can be transistor or diode, has the nonlinear element that at least one is associated with each pixel of said display.The pixel on related pixel next door or addressing electrode are connected to the driving circuit that is used to control said display operation through nonlinear element." active matrix " display that is equipped with the display of such nonlinear element to be called.
Generally, such Active Matrix Display adopts two dimension (" XY ") addressing scheme, has many data lines and many selection wires, and each pixel is defined by the intersection point of a data line and a selection wire uniquely.Through applying voltage to a particular selecting line, and just selected delegation (supposition here, said selection wire defines the row of said matrix; And said data line definition row; This is arbitrarily, can do opposite appointment in case of necessity but obviously); Voltage on adjustment data line or the alignment is so that make the pixel in the said select row that required optic response is provided.Thereby the pixel electrode voltage in the select row rises to and approaches, but the voltage on (owing to the reason of following explanation) inaccurate data line that is associated that equals them.Through applying voltage to next bar selection wire, selected next line pixel is so that write whole display line by line then.
When said nonlinear element is transistor (generally being thin film transistor (TFT) (TFT)); Traditional way is a side that is arranged on data and selection wire and transistor electro-optical medium, and is arranged on an opposite side of electro-optical medium to the single common electrode of the extension of crossing over many pixels and general whole display.For example, see above-mentioned WO 00/67327, it describes a such structure; Wherein data line is connected to the source electrode of tft array; Pixel electrode is connected to the drain electrode of said TFT, and selection wire is connected to the grid of said TFT, and single common electrode is arranged on the opposite side of electro-optical medium.Said common electrode operated by rotary motion is watched face (that is, the surface of the display that the observer watches) said display.In writing the display process, common electrode remains under the fixing voltage, is called " common electrode voltage " or " common plane voltage ", and generally is abbreviated as " V
COM".Common plane voltage can have any value easily, because it is the difference between common plane voltage and the voltage that is applied to the optical states that influences the electro-optical medium pixels with different on the pixels with different electrode.The electro-optical medium of most of type is to the polarity and the magnitude of the electric field that applied, thereby, must be driven into voltage to pixel electrode above and below common plane voltage.For example, common plane voltage can be 0, and pixel electrode changes from-V to+V, and wherein V is any maximum voltage arbitrarily.As another program, common practices be remain on common plane voltage+V/2 is last, and lets pixel electrode change from 0 to+V.
Important use of bistable electro-optical medium is on portable electron device, and such as PDA(Personal Digital Assistant) and cellular telephone, wherein the electric battery life-span is an important consideration, thereby hope reduces the power consumption of display as far as possible.LCD is not bistable, so image writes such display, if want said image still visible, must constantly refresh.The power that like this constantly consumes in the refresh process at figure is the main leakage point of electric battery.Otherwise bistable electro-optic displays only need write once, and after this bistable medium will be kept one period considerable time of image, and needn't anyly refresh, thereby, reduce the power consumption of display widely.For example, the electrophoretic display device (EPD) based on particle shows that image energy was adhered to several hours even several days.
Thereby, between image update, stop to scan the active matrix bistable electro-optic displays, help saving electric power.In some cases, cut off fully and be used for driving the driver of said display and the power supply of common plane circuit, even can save more electric power.
But, must realize non-writing mode (, being called " non-scanning " or " zero energy " mode as another program) and remarkable.The said display of design and running in such a way, that is, said electro-optical medium does not experience great voltage amplitude transition when switching between (scanning) mode that writes and its non-writing mode of display at it.
At first sight; Appear if to row driver pack into mid-point voltage (that is; The voltage of the mid point of these driver usable range), and under the situation that does not have the grid circuit to be chosen, stopping the gate drivers clock, can be the way that an acceptable is realized said non-writing mode.But this can cause stable state DC bias current to be applied on the electro-optical medium in practice.The problem that any Active Matrix Display all has and be called as " the grid feedthrough is logical " or " flyback " to cause, the voltage that wherein pixel electrode reached is from some quantity of corresponding row (data) voltage input skew (general 0.5-2V).Said grid feedthrough effect is that the scanning by grid (selection) circuit causes, works through the coupling electrical network between gate line and the source electrode line/pixel electrode.Thereby the voltage that in fact is applied on the pixel electrode moves to negative direction from said row driver voltage because of the grid feedthrough in scanning process.Generally, common plane voltage from its nominal value to the fixing quantity of negative direction skew, so that allow the grid feedthrough to squint being applied on the voltage of said pixel electrode.When stopping to scan, because the skew that the grid feedthrough causes can not occur, said then row driver mid-point voltage is higher than the required value of generation zero-voltage difference between said common plane and pixel electrode.TFT will under the said bias voltage between said alignment and said pixel electrode the disconnection off-state characteristic according to them correspondingly produce leakage current, and said electric current will flow to common electrode through electro-optical medium from said pixel electrode.Said flow of current itself will produce the voltage across electro-optical medium again; And said voltage is undesirable; Because it maybe be at the said optical states of upsetting electro-optical medium non-write cycle in the process like this; And also possibly cause material lifetime shorten with electro-optical medium in the gathering of electric charge, this will negatively influence the optical states that scanning recovers afterwards image subsequently.(show that if be not long-term DC balance through its electric current, some electro-optical medium receives passive influence at least, and such DC is unbalance possibly cause shortening mission life and other undesirable influences).
In addition; Although at first sight; As if when preparing, break off the power supply of driving circuit, only need to break off the circuit that bias voltage is provided, or break off power circuit from such circuit to said driver for non-writing mode; But in practice, any one in these two measures all provides undesirable voltage transient to said electro-optical medium probably; Such voltage transient, except that other factor, possibly be by existing stray capacitance caused in the traditional active matrix driving circuit.
Summary of the invention
In one aspect, the present invention makes every effort in electro-optic displays, provide realization non-writing mode, and switches entering and withdraw from equipment and the method that on said electro-optical medium, does not cause undesirable voltage transient in the non-writing mode process at said display.The present invention also makes every effort to be provided at the non-writing mode of realization in the electro-optic displays, and on said electro-optical medium, does not cause undesirable equipment and the method that the voltage deviation of negative influence possibly arranged said medium.
Others of the present invention relate to the method for measuring and revising voltage deviation.The source of grid feed-trough voltage has been described above.It is desirable to, the two ends that said grid feed-trough voltage is crossed over all pixels in array and can balance out through said common electrode voltage is applied side-play amount about equally.But, be difficult to apply the bias voltage of almost just offsetting said feed-trough voltage to common electrode.In order to do like this, a kind of device must to be set to confirm whether said bias voltage matees said feed-trough voltage exactly, and produce, be provided with and adjust said bias voltage.It is desirable to, said feed-trough voltage is known in advance, and can be when making the display electronic circuit for good and all with said bias voltage is set with low costly.In practice, said electronic circuit and display require bias voltage is done some adjustment after being assembled into last device.
In traditional LCD (LCD), the adjustment of bias voltage can be carried out through vision; When applying incorrect bias voltage, eyes will be discovered the flicker of display.By operator's adjustment, change the simulation potentiometer till flicker disappears then.
But in based on the electrophoretic display device (EPD) of particle and in the bistable electro-optic displays of most of other type, incorrect bias voltage can not cause any to the visible influence of human eye, only if said bias voltage error is very big.Thereby sizable error can continue and visually invisible on the bias voltage, and these sizable errors do not carry over if do not proofread and correct, and then these sizable errors possibly have injurious effects to display.Therefore, the method that is desirable to provide very much beyond some visual observation detects the error in the said bias voltage.In addition, the error of even now in case detect and survey, just can be revised on the same ground with LCD by hand, and so manual correction inconvenience preferably provides some automatically to adjust the way of bias voltage.
The present invention makes every effort to be provided for measuring and revising the equipment and the method for bias voltage.The present invention extends to manual and automatic bearing calibration.
Therefore, in one aspect, the present invention provides a kind of electro-optic displays, and it comprises:
The bistable electro-optical dielectric layer;
A plurality of pixel electrodes, they are arranged on a side of said electro-optical medium layer,
The nonlinear element that at least one is associated with each pixel electrode;
Pixel driving device, it is arranged to apply voltage through said nonlinear element to said pixel electrode;
Common electrode, it is in a side opposite with pixel electrode on the electro-optical medium layer; And
The common electrode control device, it is arranged to apply voltage to common electrode,
Said display has: writing mode, and wherein said pixel driving device is added to two different voltages with different in said each pixel electrode on the pixels with different electrode at least, thereby writes electro-optical medium to image; And non-writing mode, wherein said pixel driving device control is applied to the voltage on the said pixel electrode, and any image that writes said electro-optical medium before making is all preserved basically.
Said common electrode control device is arranged to when said display is in its writing mode, applies first voltage to common electrode, and when said display is in its non-writing mode, apply second voltage that is different from first voltage.
For simplicity, display of the present invention can be called " variable common plane voltage display " hereinafter.Such display has two main modification.In two modification, said common electrode all remains on the predetermined voltage in said write mode process.(this does not get rid of the possibility that said display can have an above writing mode, is applied on the said common electrode at different voltages under the different writing modes.) for example,, possibly preferably use what is called " top plan switching " sometimes like what in above-mentioned 2003/0137521, discuss; Wherein said common electrode (for example) 0 and+switch between the V, and the voltage that is applied to said pixel electrode simultaneously changes to+V from 0, when said common electrode is in 0; Processed pixels transformation in one direction, and when said common electrode be in+during V, handle the transformation on other direction; For example, if supposition is a black/white display, according to the characteristic of said electro-optical medium; When said common electrode is in 0, can handle the transformation that bleaches (that is, the transformation that the last state of wherein said pixel is brighter than initial state); And when said common electrode be in+during V, can handle the transformation (that is, the transformation that the last state of wherein said pixel is darker than initial state) of blackening.But; In the first main transformer type; When the non-writing mode of said display, the voltage on the said common electrode is through being connected to said common electrode on voltage supply line or other circuit, remains on " fixing " value (adjustment of the method that this possibly stand to describe below).In the second main transformer type, when non-writing mode that said display is in, said utility voltage and external voltage source break off, and are allowed to " floating ".When distinguishing between must these two modification of discussion below, the former is called " two common plane voltage display ", and the latter will be called " the common electrode display floats ".
Two common plane voltage displays can comprise:
First voltage supply line, it is arranged to supply with first voltage;
Second voltage supply line, it is arranged to supply with second voltage;
Output line;
Switching device shifter, one that is used for said first and second voltage supply lines is connected to said output line; And
Control line, it is connected to said switching device shifter and is configured to receive the control signal with first or second value,
Said switching device shifter is arranged to when said control signal has first value, be connected to first voltage supply line to output line, and when control signal has second value, be connected to second voltage supply line to output line.
In two common plane voltage displays of said form, said output line can be to be connected to said common electrode.In this case; Said display possibly also comprise at least one sensor pixel; The latter has the sensor associated pixel electrode, and said sensor pixel electrode is configured to receive second voltage, and said at least one sensor pixel is connected to second voltage supply line.Said display can also comprise differential amplifier, and its positive input terminal is connected at least one sensor pixel; And its output is connected to its negative input end and second voltage supply line.
As another program, said output line can be arranged to control the mid point of pixel driving device voltage range.If as described at above-mentioned WO 00/67327, capacitor is associated with each pixel electrode, an electrode of each capacitor is configured to receive the voltage same with said common electrode.
The common electrode display that floats can comprise:
Voltage supply line, it is arranged to supply first voltage;
Output line is connected to said common electrode;
Switching device shifter is used for being connected to output line to said voltage supply line; Or be used for breaking off said output line and said voltage supply line.
Control line is connected to said switching device shifter, and is configured to receive the control signal with first or second value,
Switching device shifter is arranged to when control signal has first value, be connected to voltage supply line to output line, and when control signal has second value, output line and voltage supply line is broken off.
Of the present invention pair of common plane voltage display generally comprises the bias voltage supply circuit; The latter is arranged to supply first and second voltages; And said display can be equipped with when said display is in its non-writing mode, is used to break off the device of said bias voltage supply circuit.Said pixel electrode can be arranged in said bias voltage supply circuit break off with power up in the reception voltage identical with said common electrode.
Variable common plane voltage display of the present invention can utilize the above-mentioned electro-optical medium of any kind.Thereby; In said display; Said electrooptic layer can comprise rotation double-colored member or electrochromism display medium or a kind of electrophoresis material based on particle, comprises suspending liquid and a plurality of charged particle that is suspended in the suspending liquid and when said electrophoresis material applies electric field, can moves through it.Such electrophoretic medium can be the sealing electrophoresis material, and wherein suspending liquid and charged particle are sealed in a plurality of capsules, and each capsule has capsule wall; Perhaps can be the micro element type, wherein suspending liquid and charged particle maintain in a plurality of unit that form in the substrate.
The present invention also provides a kind of method of operating electro-optic displays, and said electro-optic displays comprises: the bistable electro-optical dielectric layer; A plurality of pixel electrodes, they are arranged on a side of said electro-optical medium layer, and each pixel electrode has at least one nonlinear element that is associated with it; And common electrode, it is in a side opposite with said pixel electrode on the said electro-optical medium layer.Said method comprises:
Apply first voltage to said common electrode, and be added at least two different voltages with different in said each pixel electrode on the pixels with different electrode simultaneously, thereby write said electro-optical medium to image; And
Apply second voltage that is different from said first voltage to said common electrode, and control simultaneously is applied to the voltage on the said pixel electrode, makes any any image that writes said electro-optical medium in the past all be able to basically preserve.
The present invention also provides a kind of operation electro-optic displays method, and said electro-optic displays comprises: the bistable electro-optical dielectric layer; A plurality of pixel electrodes, they are arranged on a side of said electro-optical medium layer, and each pixel electrode has at least one nonlinear element that is associated with it; Common electrode, it is in a side opposite with said pixel electrode on the said electro-optical medium layer; And voltage supply line, be used for voltage being provided to said common electrode.Said method comprises:
Apply first voltage to said common electrode, and be added at least two different voltages with different in said each pixel electrode on the pixels with different electrode simultaneously, thereby write on image on the said electro-optical medium; And
Control is applied to the voltage of said pixel electrode, and any image that writes said electro-optical medium before making all is able to preserve basically, and breaks off said common electrode from said voltage supply line simultaneously, thereby allows the voltage on the said common electrode to float.
As pointed out, others of the present invention relate to and are used to measure and revise equipment and the method that bias voltage is used.Thereby in yet another aspect, the present invention provides a kind of electro-optic displays, and it comprises:
The bistable electro-optical dielectric layer;
A plurality of pixel electrodes, they are arranged on a side of said electro-optical medium layer, and at least one pixel electrode is the sensor pixel electrode;
The nonlinear element that at least one is associated with each pixel electrode;
Pixel driving device, it is arranged to apply voltage through said nonlinear element to said pixel electrode, and said pixel driving device is arranged to apply predetermined voltage at least one sensor pixel electrode;
Common electrode, it is in a side opposite with said pixel electrode on the said electro-optical medium layer; And
Measurement mechanism, it is configured to receive said predetermined voltage and the voltage on said at least one sensor pixel, and confirms the difference between them.
The present invention also provides a kind of electro-optic displays, it comprises:
The bistable electro-optical dielectric layer;
A plurality of pixel electrodes, they are arranged on a side of said electro-optical medium layer;
The nonlinear element that at least one is associated with each pixel electrode;
Pixel driving device, it is arranged to apply voltage through said nonlinear element to said pixel electrode;
Common electrode, it is in a side opposite with said pixel electrode on the said electro-optical medium layer;
The common electrode voltage feed lines, it is arranged to supply at least one voltage;
Switching device shifter, it is connected to said common electrode to said voltage supply line, and said switching device shifter has: mode of operation, wherein said voltage supply line is connected to said common electrode; And test mode, wherein said voltage source and said common electrode break off, thereby allow the voltage on the said common electrode to float,
Said pixel driving device is arranged to when said switching device shifter is in its test mode, supply single predetermined voltage through said nonlinear element to whole pixel electrodes,
Said display also comprises measurement mechanism, and it is arranged to when said switching device shifter is in its test mode, receive said single predetermined voltage and the voltage on said common electrode, so that confirm the difference between them.
The present invention also provides a kind of electro-optic displays, and it comprises:
The bistable electro-optical dielectric layer;
A plurality of pixel electrodes, they are arranged on a side of said electro-optical medium layer, and at least one pixel electrode is the sensor pixel electrode;
The nonlinear element that at least one is associated with each pixel electrode;
Pixel driving device, it is arranged to apply voltage through said nonlinear element to said pixel electrode, and said pixel driving device is arranged to apply predetermined voltage to said at least one sensor pixel electrode;
Common electrode, it is in a said electro-optical medium layer side opposite with said pixel electrode; And
The common electrode voltage control device, it is configured to receive the signal of the voltage on said at least one the sensor pixel electrode of representative, and is applied to the voltage on the said common electrode according to said signal change.
At last, the present invention provides a kind of method of operating electro-optic displays, and said electro-optic displays comprises: the bistable electro-optical dielectric layer; A plurality of pixel electrodes, they are arranged on a side of said electro-optical medium layer; The nonlinear element that at least one is associated with each pixel electrode; Pixel driving device, it is arranged to apply voltage through said nonlinear element to said pixel electrode; Common electrode, it is in a side opposite with said pixel electrode on the said electro-optical medium layer.Said method comprises:
Apply predetermined voltage by means of said pixel driving device to whole pixel electrodes of said display;
The said predetermined voltage of storage representative and in the value that applies the difference between the voltage that appears at common electrode in the said predetermined voltage process to pixel electrode; And
After this value according to said storage applies voltage to said common electrode, and applies pixel electrode voltage simultaneously, and said pixel electrode voltage causes writing said electro-optical medium to image.
Description of drawings
Fig. 1 is the partial circuit figure of of the present invention pair of common plane voltage display;
Fig. 2 is the partial circuit figure of unsteady common electrode display of the present invention;
Fig. 3 is the partial circuit figure that is used for realizing at large-scale Active Matrix Display the prototype circuit of Fig. 1 basic circuit and some others of the present invention;
Fig. 4 is the partial circuit figure of revision of two common plane voltage displays of the use sensor pixel of Fig. 1;
Fig. 5 is the partial circuit figure that is equipped with the display of the device that is used to measure feed-trough voltage;
Fig. 6 is the partial circuit figure of revision of the display of being equipped with of Fig. 2 device that is used to measure feed-trough voltage;
Fig. 7 utilizes external unit to adjust so that the partial circuit figure of a kind of display of the present invention of compensating feed through voltage;
Fig. 8 is the partial circuit figure of a kind of display of the present invention, wherein the compensation of feed-trough voltage is carried out at the inner utilization sensor pixel;
Fig. 9 is the partial circuit figure of the display revision of Fig. 1, is equipped with the device that is used for compensating feed through voltage;
Figure 10 is the partial circuit figure of a kind of display of the present invention, wherein the compensation of feed-trough voltage is carried out with digital form.
Embodiment
As shown that the present invention has several different aspects, relate to display and in such display, be used for the method controlling the electro-optic displays electrode voltage and be used to measure and revise feed-trough voltage.Usually describe different aspect of the present invention below respectively, but will appreciate that single kind of display possibly utilize the more than one aspect of the present invention; For example, the display of Fig. 6 uses unsteady common electrode display of the present invention and feed-trough voltage measurement aspect simultaneously.
As discussed above; The subject matter that the present invention makes every effort to handle is: by the grid feedthrough cause each voltage that driving circuit applies to the nonlinear element of electro-optic displays (possibly be called hereinafter " the row driving voltage "; Because as shown; Although in that to select the Active Matrix Display one-row pixels to write constantly at any one traditionally be arbitrarily basically) between difference; Be applied on the said pixel electrode to row (data) electrode then and produce the required different voltages with different of different voltages (these voltages can be called " pixel electrode voltage " hereinafter), said pixel electrode voltage is that on the pixel of said select row, to produce required transformation required.
Fig. 1 is the partial circuit figure of two common plane voltage displays of recommendation of the present invention, and illustrates common electrode control device (usually being denoted as 100).Control device 100 comprises first voltage supply line 102, second voltage supply line 104 and output line 106.Control device 100 also comprises the switching device shifter of following form: be arranged on first switch S 1 between first voltage supply line 102 and the output line 106 and be arranged on the second switch S2 between second voltage supply line 102 and the output line 106.As shown in Figure 1, switch S 1 is connected to control line 108 with S2, and switch S 2 is directly connected to control line 108 through line 110, and switch S 1 is connected to control line 108 through phase inverter 112 simultaneously.Output line 106 is connected to the common electrode (not shown) of bistable electro-optic displays.
As pointed out, the output line 106 of Fig. 1 circuit is connected to the common electrode of the display that is associated.But as another program, output line 106 can be connected to the circuit of the mid point that is used for controlling the voltage range that row driver uses.When output line connects with this substitute mode, control signal will make that when display is in its writing mode output line 106 receives voltage V from top with reference to the described state counter-rotating of Fig. 1
SM, and when display was in its non-writing mode, output line 106 received voltage V
COM(certainly, as another program, through keep same control signal overturn from control line 108 to switch S 1 with being connected of S2, make S1 be directly connected to line 108, and S2 is connected to line 108 through phase inverter 112.) in this case, common electrode all will receive V any time
COM
The circuit that is connected to common electrode with output line 106 or is connected to the mid point that is used for controlling the voltage range that row driver uses is irrelevant; If pixel electrode is equipped with the memory capacitor that is associated; Described like above-mentioned WO 00/67327; Preferably present and be fed to the same voltage of voltage of common electrode to the counter electrode of pixel capacitor (that is, be not in the electrode for capacitors of same voltage) with their pixel electrode that is associated.
Its output line 106 is connected to the circuit shown in Figure 1 of the common electrode of display, maybe display write and non-writing mode between in the transforming process, make electro-optical medium experience some little, undesirable voltage transient.For example, in recommending operation method, when scanning the last time, display changes over to before its non-writing mode, and all row driver all is set to voltage V
SMBecause former explanation, actual pixel voltage will be different from V slightly
SM, because display still stands the grid feedthrough this moment, and pixel voltage in fact equals V
COM, with the identical voltage that in scanning process, is applied on the common electrode.Then, if said common electrode switches to voltage V through circuit 100 immediately
SM, then electro-optical medium equals experience to the transition that the grid feed-trough voltage is present in pixel electrode, and along with the leakage through pixel transistor and electro-optical medium, pixel electrode is charged to voltage V
SM, said transition decays gradually.Obviously, preferably eliminate said voltage transient, or reduce it as far as possible.Similarly, when display when its non-writing mode switches to its writing mode, with producing little voltage transient.When circuit shown in Figure 1 is used for controlling the mid point of the voltage range of being used by row driver, can switch to its non-writing mode or produce voltage transient mutually on the contrary along with the writing mode of display from it.
Fig. 2 is the partial circuit figure of the unsteady common electrode display of recommendation of the present invention, and illustrates common electrode control device (usually being denoted as 200).Control device 200 usually is similar to control device shown in Figure 1 100 and comprises: voltage supply line 202, it provides voltage V through the bias control circuit (not shown)
COM Output line 206, it is connected to the common electrode (not shown) of display; Switch S 3, it these two lines be used for the control line 208 of operation of CS S3 and link together.Be present in control device 100 phase inverters 112 because from the control device 200 of Fig. 2, saved; So the control signal on the lead 208 need be reversed from the state on the lead 108; Make that switch S 3 is connected in the writing mode process of display, and common electrode receives V through switch S 3 and output line 206 from voltage supply line 202
COM
When display was in its non-writing mode, switch S 3 was broken off, and common electrode and bias voltage supply circuit break off, thereby permission " floating ".In the process that common electrode floats like this, like what described, all the row electrode all remains on V
SM, leak and all to be charged to voltage V to pixel electrode and common electrode at last through pixel transistor and the electric current through electro-optical medium
SM, thereby, stay zero electric field at the electro-optical medium two ends.Will find out; Be similar to drive unit 100; When switching between writing mode and the non-writing mode of display at it; Drive unit shown in Figure 2 200 produces little voltage transient, and said transition lasts till that always voltage on pixel electrode and the common electrode is with till the aforesaid way equilibrium or resetting.
Fig. 3 is the partial circuit figure of prototype circuit (usually being denoted as 300) that is used for realizing at large-scale Active Matrix Display basic circuit and some other side of the present invention of Fig. 1.Now, only describe those parts that Fig. 3 is similar to the circuit of Fig. 1, the remainder of Fig. 3 will be described with reference to the aspect of the present invention of implementing them below.
Fig. 3 also illustrates and is used for producing the input voltage V that common electrode control device of the present invention uses
COMAnd V
SMThe part of bias control circuit.Shown in the lower right of Fig. 3, as the signal V of the ceiling voltage that is used for driving row driver
SHBe fed to voltage divider, the latter comprises resistance R 5 and the R6 that resistance equates, and is V
SHThe pin 10 (positive input terminal) of the IC 330 that half the R5 and the voltage between the R6 are fed to operational amplifier OPA 4243.Be fed back to the negative input end on its pin 9 in the 8 resulting amplifier outputs of IC 330 pins; Also be fed to the circuit that comprises resistance R 4 and capacitor C3; Said RC circuit between resistance R 4 and capacitor C3 by tap, so that as the voltage V of other local usefulness that circuit 300 is provided of following description
SMCapacitor C3 is in a conventional manner as accumulator, so that burning voltage V
SM
The voltage V that produces like this
SMBe fed to the pin 11 (S3) of IC 320; High voltage enables the control corresponding pin 9 (C3) that (HVEN) signal (be used for control Driver Circuit powering on or down) is fed to IC 320, and the result on the pin 10 (D3) export be connected to output line 106 '.Voltage V
SMAlso be fed to the variable voltage divider that comprises potentiometer R9 and resistance R 10, this voltage that is present between R9 and the RIO is denoted as V through pin 3 (positive input terminal) conduct that resistance R 1 is fed to IC 330
COM_REFSignal.Corresponding output feeds back on its pin 2 on IC 330 pins 1 negative input end and conduct are denoted as V
COMThe signal of _ DRIVE is fed to the pin 6 (S4) of IC 320.
Lead 106 ' on signal (, can be V like what described
COMOr V
SM, depend on line 108 ' on the value of control signal) be fed to the pin 5 (positive input terminal) of IC 330.Corresponding output on IC 330 pins 7 feeds back to the negative input end on its pin 6, also as being denoted as V
COMThe signal of _ PANEL_BUF3 is fed to the pin 2 (S1) of IC 320.As pointed out, the pin 1 (C1) of IC 320 through lead 110 ' reception from control line 108 ' signal.Corresponding output on the pin 2 (D1) of IC320 is fed to the circuit that comprises resistance R 2 and capacitor C1, and the voltage that exists between resistance R 2 and the capacitor C1 is as above-mentioned signal V
COM_REFBe fed to the pin 3 of IC 330.Capacitor C1 is in a conventional manner as accumulator, so that burning voltage V
COM_REF(therefore circuit shown in Figure 3 is arranged for different modes for test objective rather than large-scale production design.The said circuit of design makes generally only to have one of R1 and R2 constantly at any one like this.R1 does not exist if R2 exists, and then said circuit can be basically to work with the identical mode of following Fig. 9 circuit; When R1 exists and R2 when not existing, said circuit is to work with the mode identical with the circuit of following Fig. 7 basically.)
Common electrode control device shown in Fig. 4 (usually being denoted as 400) is the modification of control device 100 shown in Figure 1, but is to use one or more " sensor " pixel that is arranged on display itself.Control device 400 comprises lead 402,406,408 and 410, phase inverter 412 and switch S 1 and S2, all with basically with control device 100 shown in Figure 1 in corresponding part (integers) identical mode work.But, second voltage input end 404 of control device 400 ' not voltage V to be provided simply by said bias control circuit
SMOn the contrary, the voltage supply on the sensor pixel 414 is to the positive input terminal of differential amplifier 416, and the output of amplifier be fed to simultaneously its negative input end and line 404 '.
The row of the part outside that sensor pixel 414 is generally seen with the user of display easily or the mode of row are arranged on the zone of display.For example, the extra row that sensor pixel 414 can be used as pixel is provided with, and is generally hidden by the bezel of display.The control circuit of display is set like this, so that utilize voltage V
SMConstantly write the pixel electrode of sensor pixel, like what described, voltage V
SMBe returned be transported to second voltage supply line 404 '.
As conspicuous for the technician who drives electro-optic displays, control device 400 is operated with the mode that is quite analogous to control device shown in Figure 1 100.Differential amplifier 416 is used for cushioning the voltage from sensor pixel 414.When display is in its writing mode, control device 100 as shown in Figure 1, switch S 1 is connected and switch S 2 disconnections, makes common electrode receive voltage V
COMWhen display when its writing mode converts its non-writing mode into, during the last end of scan of display, control signal uprises, and makes switch S 1 break off and switch S 2 is connected.This moment, the voltage on the sensor pixel 414 equals V
COM, make it not produce voltage transient, because common electrode is connected to the output of amplifier 416.After this, the pixel electrode (comprising sensor pixel 414) when display little by little is charged to voltage V by the leakage through pixel transistor with the mode of having described
SMThe time, the connection between sensor pixel 414 and the common electrode guarantees the lucky voltage that is present in said pixel electrode of following the tracks of of the voltage on the common electrode, making does not have electric field to exist at the electro-optical medium two ends.But, when display when its non-writing mode switches to its writing mode, with producing a little voltage transient.
Can revise control device 400 like this, make common electrode always be connected to sensor pixel 414, suppose that sensor pixel is set like this to make always with voltage V
SMThey are write.This configuration has the additional benefit that allows the automatic fine tuning of common plane voltage.If only use the voltage on a sensor pixel and the said pixel only to send to common electrode when (as at control device 400) when display is in its non-writing mode; So; Said sensor pixel can be said array common pixel (that is; Rather than the sensor special pixel image pixel).
Embodiments of the invention shown in Fig. 1 to 4 depend on analog line.But, can also carry out with digital form the control of the required common plane voltage of variable common plane voltage display of the present invention.For example, common electrode can be connected to digital/analog converter (DAC), makes output controlled by display controller.Like this, display writing mode and non-writing in both processes, can be set to any required value by common plane voltage.But the hardware that digital embodiment needs is generally than the needed costliness of above-mentioned simulation embodiment, and in driver power down process, makes common electrode follow the difficult more difficulty of process that the driver mid-point voltage descends and occur error easily.
In other embodiments of the invention, common plane voltage or the voltage that is applied to pixel electrode can be set up through software design in the non-writing mode process of display, thereby, the analog line of describing before removing from; Instead, in said non-writing mode process, select common plane voltage or be applied to the voltage of pixel electrode, make the electric field at electro-optical medium two ends reduce to minimum.Generally, when utilizing the modern digital driving circuit, there is one to compare V
SMMore near V
COMDigital voltage can use, especially if the digital resolution of said driver is high.For example, investigate a display, wherein row driver uses 0 to 30 volt scope, makes V
SMBe 15 volts, and supposition V
COMBe 14 volts (15 volts deduct by caused 1 volt of grid feedthrough), and driver provide six voltage resolution and linear fully Control of Voltage.If the output of row driver rests on V in non-writing mode process
SM(15 volts), then electro-optical medium will stand by 1 volt of electric field that difference causes between pixel electrode and the common electrode.But row driver can provide 14.063 volts voltage (descending from VSM two digits ladder), and if voltage puts on pixel electrode in non-writing mode process, then electro-optical medium only stands the electric field that the 63mV difference between pixel and the common electrode causes.This electric field that reduces widely at the electro-optical medium two ends will be acceptable under most of situation.
In other words; Can select digital addressable voltage for row driver in many cases; Through under non-writing mode, selecting, can reduce the electric field at electro-optical medium two ends during the non-writing mode of display greatly near the digital addressable voltage of common plane voltage
As shown; Variable common plane voltage display of the present invention can be equipped with and be used for device that the non-writing mode process at display breaks the bias voltage supply circuit (as above-described; Use referring to signal HVEN among Fig. 3); Thereby, additional power save is provided on sizable degree.But,, hope very then to guarantee that common plane voltage can not be different from the voltage of pixel electrode in disconnection of bias voltage supply circuit and the power up significantly if break off the bias voltage supply circuit.This can through break off at the bias voltage supply circuit and power up in still by row driver with V
SMThe driven pixel electrode realize.When doing like this, common electrode should be directly connected to V
SMVoltage or be arranged to follow V
SMVoltage is so that change along with the change of said voltage.This can utilize any one circuit shown in Fig. 1 and 2 to reach.Utilize the circuit of Fig. 1, common electrode can switch to voltage V simply
SMUtilize the circuit of Fig. 2, in power up at voltage V
SMDuring change, common electrode will be allowed to float.In these circuit any one all can reduce to minimum to the voltage transient that electro-optical medium experienced, but circuit shown in Figure 4 is eliminated such transition fully.In a kind of like this layout, it possibly be difficult using digital to analog converter (DAC) to control common plane voltage.
In case the power supply of bias voltage supply circuit breaks off, the power supply of logical circuit also possibly break off, and after this possibly cut off the power supply of operational amplifier, and analog switch generally is used as the part of control circuit.Realize that the operations necessary sequence requires the electronic circuit of said display to comprise suitable power supply order hardware, and will appropriate software be set at display controller.
The technician of display actuation techniques will appreciate that; When display powers on after bias voltage supply circuit and the following electricity of driver; Before electro-optical medium can begin update image, system requirements considerable time (perhaps 10-100 millisecond) encouraged again.In some application (for example, when display is used as information symbol in airport, station or similar position), said time delay as a result is not horrible.But in other is used (for example, when display is used as e-book), if often repeat, then said time delay as a result maybe be horrible.In a kind of application in back; Rational trading off is between the response (wherein bias voltage supply circuit and driver are still supplied power) that can obtain from the non-basically writing mode of display and the additional power save (wherein under bias voltage supply circuit and/or the driver) that can obtain from " dormancy " mode; In case no longer require image update; Just must let display get into non-basically writing mode; But only after non-basically writing mode continues one period considerable time, just let display get into sleep mode.For example; If display is as the books of electronics; Then can select to get into the time delay before the sleep mode, make display not get into sleep mode, and the user read the single page (moment carries out basically to make the renewal that obtains down one page) by image setting simultaneously; But when reading a few minutes that the user breaks off him for example so that when handling call, display just can get into sleep mode.As another program, if display is under the control of host computer system (for example, if display is just as portable computer or cellular telephone auxiliary screen), then the following electricity of bias voltage supply circuit and driver can be controlled by host computer system; Note that in this case host computer system need allow when display powers on, send new image to display and occurred time delay in the past.
Can find out by above-mentioned; The embodiment of the recommendation of variable common plane voltage display of the present invention can provide the power consumption that reduces electro-optic displays greatly and don't influence the image that has write display, and electro-optical medium is exposed to maybe be to the method and apparatus of the harmful voltage transient of medium.
In case above-mentioned discussion concentrates on equipment and method that known grid feed-trough voltage of the present invention just is used to compensate the influence of said voltage.For example, for the description of control device shown in Figure 1 100 operations, supposed grid feed-trough voltage (V in the past
COMAnd V
SMBetween difference) known, therefore give V
COMSuitable value known, and have suitable circuit can be used for formation voltage V on first voltage supply line
COMExisting notice is turned to is used to measure the grid feed-trough voltage and adjusts display circuit so that assurance has suitable voltage to can be used to compensate the method for grid feed-trough voltage.
First challenge will be any specific combined to panel, driver, sweep speed and other correlative factors, accurately measure the size of feed-trough voltage.Although the present invention does not get rid of other method of use, the measuring method of two type of recommendation is sensor pixel and unsteady common electrode.
Said sensor pixel method is used the one or more sensor pixels on the display, and the sole purpose of these pixels provides the indication of required feed-trough voltage.For example, discussed with reference to Fig. 4 as top, can be at the pel array edge, exceed the edge in the active pixel zone (that is, the zone that is used for display image of display) of design, increase one or more pixels.These sensor pixels are identical with active pixel, and just conductive path is connected to said panel edges to sensor pixel along a bit, is connected to measuring system here.All sensors pixel on the said panel can link together with lead, and in the panel scanning process, is upgraded by the controller that has same magnitude of voltage.Be used for upgrading the required value of pixel and, obtain representative value through measurement about feed-trough voltage from the difference between the measured value of sensor pixel.
Fig. 5 representes to be used for a simple circuit (usually being denoted as 500) of this purpose.Relatively will find out Fig. 5 and Fig. 4; The circuit of Fig. 5 is substantially similar to the part of the control device 400 of Fig. 4, except the destination of last output signal and for fear of repetition be each several part (integers) among Fig. 5 provide with Fig. 4 in identical label.Fig. 5 circuit comprises a plurality of sensor pixels 414 and differential amplifier 416.But the output of amplifier 416 " sends to metering circuit through lead 404.Relation between given control device 400 and the circuit 500; Just will appreciate that; The sensor pixel measuring method can be through temporarily the lead 404 of control device 400 ' being connected to metering circuit carries out; Measure (because switch S 1 is broken off in measuring process, this moment, lead 402 needn't connect) and implement the grid feed-trough voltage simultaneously, the voltage V that after this is provided with on the measured value adjustment lead 402 according to the grid feed-trough voltage
COM
As another program; Can measure the grid feed-trough voltage through following method: allow common electrode float (that is; It and all conductor disconnections); And upgrade one period sufficiently long cycle of whole pixel electrode array with single voltage, so that let electric current be charged to the voltage that equals pixel electrode voltage to common electrode through the leakage of electro-optical medium layer.Then, metering circuit can be measured the difference between the output voltage of the row driving voltage voltage of drive source polar curve (scan period be used for) and unsteady public electrode, and thereby the area weighted mean value of definite grid feed-trough voltage.
Fig. 6 representes to be used to implement the simple circuit (usually being denoted as 600) of said process of measurement.More just can find out Fig. 6 and Fig. 2 and 5; Circuit 600 is the control device 200 of Fig. 2 basically; Its modification is: add differential amplifier 416 ' the same with counterpart among Fig. 5 be directed to the lead 404 of metering circuit from amplifier "; amplifier 416 ', lead 404 " and the operation method of metering circuit, and correspondingly the different piece among Fig. 5 is numbered.Might comprise differential amplifier and metering circuit through temporarily being connected to suitable test cell to the output line 206 of control device shown in Figure 2 200, carry out process of measurement.In the process of measurement process, should be arranged to cut-off switch S3 to the control signal on the lead 208, thereby common electrode is broken off from its driving circuit.Similarly, S3 also can be used to provide a display " dormancy " state, as above-described.
Adopt or the sensor pixel or the common electrode measuring method of floating,, need a kind of low-down method of measuring from the output voltage of sensor pixel or common electrode of leakage current for fear of in the measured value of grid feed-trough voltage, producing error.The voltage measurement method of such recommendation will be connected the high impedance voltage follower circuit between sensor pixel or common electrode and the said metering circuit.
Use description to adjust the voltage input so that the method for adjustment actual measurement grid feed-trough voltage at present.The most directly way of compensating feed through voltage (and measuring such voltage really) is, in case display fully and its driver be assembled together, just be connected to external unit to display.Fig. 7 representes to be applicable to the circuit (usually being denoted as 700) of this purpose; It is included in the basic controlling device of type shown in Figure 2; And comprising voltage supply line 202, control line 208, switch S 3 and output line 206, they are all with part is identical accordingly among Fig. 2.For suitable V is provided on lead 202
COMValue, handle electrokinetic potential device P1 is connected between voltage V1 and the V2, makes the output of said potentiometer sliding contact on lead 720 can cover the V corresponding with possible feed-trough voltage gamut
COMThe scope of value.Lead 720 is connected to the positive input terminal of voltage follower, and said voltage follower comprises differential amplifier 722, and the latter's output terminal is connected to lead 202 and negative input end thereof simultaneously.The output 202 of amplifier also is connected to external measurement devices 726 through lead 724, and the latter also receives common electrode voltage through lead 728 from lead 206.
In order suitable V to be set for the voltage input lead 202 in the circuit 700
COMValue; Can be set under the situation of their mid-point voltage (often being 0V) type scanner continuously at whole pixel electrodes; And be arranged to the control signal on the lead 208 make switch S 3 to keep breaking off, and display and the driving circuit disconnection that forms by potentiometer P1 and amplifier 722.The output voltage of amplifier 722 on the common electrode voltage that exists on external unit 726 measurements and the comparison lead 206 and 728 and lead 202 and 724.The operator rotates the sliding contact of P1, up to the difference between external test facility 726 indication (through green glow, ring sound or other signal) these two voltages be in can accept within the scope till.
As shown, the circuit 300 of Fig. 3 comprises the circuit of type shown in Figure 7 really, the combination of potentiometer R9 and resistance R 10 replaces potentiometer P1, and pin 1/2/3 part of IC 330 replaces amplifier 722.
Potentiometer P1 among Fig. 7 can replace with digital regulation resistance.The interface that testing apparatus can be through special use then or automatically adjust the value of potentiometer through controller, up to measure difference in the difference of regulation till.Potentiometer can or have nonvolatile memory or be stored in the controller and be used for when display powers at every turn the said potentiometer of initialization to last setting value.No matter under any situation, said potentiometer can be arranged on the display module printed circuit board (PCB), rather than on controller board, because feed-trough voltage becomes with display, rather than become with controller; Thereby, said potentiometer is set like this allows exchange control unit in the middle of each display.
Can replace potentiometer P1 with dissimilar circuit.For example, can parallel connection be provided with resistive trace or resistor and to its optionally cut, perforation or laser ablation adjust said voltage setting value.As another program, digital-to-analog mechanism can be used for this purpose such as R-2R stairing circuit, the pulse-modulator that is coupled to low-pass filter or real D/A.Said external unit can be accomplished measurement and compare, and the while control unit interface, so that adjustment digital-to-analog device.In case confirm last setting, it just can be stored in the controller or be installed among the little EEPROM or other nonvolatile memory on the display module printed circuit board (PCB).
But, it is desirable to, display need not carried out the adjustment program when being connected to external unit; But have a kind of adjustment capability of inside, adjust its common electrode voltage and (or more precisely, adjust the side-play amount of said voltage from the mid point of said drive voltage range; So that reserve the grid feedthrough); Thereby, save time and eliminate the potential error when making, and allow repeatedly adjustment again.Provide the simple circuit (usually being denoted as 800) of such " inner adjustment " to be illustrated in Fig. 8.Circuit 800 is the remodeling of circuit 700 shown in Figure 7 basically; Wherein lead 724 and 728, external measurement devices 726 and potentiometer P1 all save; And replace in order to the lower part: a plurality of sensor pixels 414 (described above being equal to) and signal adjustment unit 830 with reference to Fig. 4; The input end of signal adjustment unit 830 is arranged to receive voltages from sensor pixel 414, and its output through lead 720 ' be fed to amplifier 722 '.
Fig. 9 illustrates another " inner adjustment " method, and it does not require the existence of sensor pixel.Circuit shown in Figure 9 (usually being denoted as 900) can be regarded as from the circuit 800 of Fig. 8 through saving sensor pixel 414 and signal adjustment unit 830, and to be connected amplifier 722 " positive input terminal and ground between and replace deriving through the capacitor C1 that switch S 4 is connected to output line 206.Switch S 4 receives control signal through lead 932 from lead 208, and between control line 208 and switch S 3, inserts phase inverter 912 simultaneously.(because the existence of phase inverter 912 is compared with circuit 800, the control signal on the lead 208 need be reversed on circuit 900.Certainly, as another program, phase inverter can insert in the lead 932, and control signal still remains unchanged.)
As shown; Circuit 300 shown in Figure 3 is to prepare for proofreading and correct the grid feedthrough with a kind of mode that is similar to circuit shown in Figure 9 900; Capacitor C1 in the circuit play a part with circuit 900 in capacitor C1 identical; And in circuit 300, switch said HVEN signal, replace the switch S 4 in the circuit 900.
Form contrast with analog sampling of using in the circuit 900 and maintenance method, digitial controller can play its digital-to-analog mechanism effect, makes voltage deviation at V
SMAnd V
COMBetween, the said feed-trough voltage of close match.The circuit of said type (usually being denoted as 1000) is illustrated among Figure 10.Can be regarded as circuit 1000 remodeling of circuit shown in Figure 7 700, potentiometer P1 is replaced by digital to analog converter 934, and its slave controller 936 receives the numeral input.In addition, external measurement devices 726 is replaced by comparer 938, the output that its positive input terminal receives from amplifier 722 through lead 924, and the negative input end of comparer 938 is connected to output line 206 through lead 928 simultaneously.The output of comparer 938 is fed to controller 936.
Confirm suitable voltage V
COMSo that be arranged on the lead 202 and 206 in the circuit 1000, this is to carry out with a kind of circuit 900 used modes that usually are similar to.Control signal on the controller 936 adjustment leads 208 is so that cut-off switch S3, and is set to V at whole row drivers
SMSituation under display is carried out one or many scanning.The controller 936 at first output of digital to analog converter 934 is set to the ultimate value of its scope; Then or sequentially step is through the whole possible output valve of digital to analog converter 934; Perhaps (perhaps preferably) uses approximation technique one by one; Obtain two output valves of digital to analog converter 934, the single position output of comparer 938 changes between said two output valves.Then, the output of controller 936 digital to analog converters 934 is set in these two values, and switch S 3 is connected, and the renewal of beginning display epigraph.According to the accuracy and the resolution of said circuit, in fact said program minimizing is arranged on the value V on the output line 206
COMRequire in V in theory
SMValue between difference, and be reduced to the grid feed-trough voltage low to acceptable level.
In circuit 1000, comparer 938 can be replaced by total weighted-voltage D/A converter, but sees the analog comparator 938 of recommending use single from cost.
From the above, will find out that the present invention is provided for measuring and compensate the equipment and the method for the feed-trough voltage of electro-optic displays, thereby, avoid at the issuable injurious effects of such display if said feed-trough voltage can not get accurate compensation.
Claims (15)
1. electro-optic displays comprises:
The bistable electro-optical dielectric layer;
Be arranged on a plurality of pixel electrodes of a side of said electro-optical medium layer;
At least one nonlinear element that is associated with each pixel electrode;
Pixel driving device is arranged to apply voltage through said nonlinear element to said pixel electrode;
Common electrode is in the side opposite with said pixel electrode of said electro-optical medium layer;
Common electrode voltage feed lines (202) is arranged to supply at least one voltage;
Switching device shifter (S3) is connected to said common electrode to said voltage supply line (202), and said switching device shifter (S3) has: running status, and wherein said voltage supply line (202) is connected to said common electrode; And test mode, wherein said voltage supply line (202) breaks off with said common electrode, thereby allows the voltage on the said common electrode to float,
Said pixel driving device is arranged to when said switching device shifter is in its test mode, supplies single predetermined voltage through said nonlinear element to whole said pixel electrodes,
Said display also comprises: measurement mechanism (726), be arranged to when said switching device shifter (S3) is in its test mode, and receive said single predetermined voltage and the voltage on the said common electrode, and confirm the difference between them.
2. electro-optic displays as claimed in claim 1, wherein said electrooptic layer comprise double-colored member of rotation or electrochromism display medium.
3. electro-optic displays as claimed in claim 1; Wherein said electrooptic layer comprises the electrophoresis material based on particle, and said electrophoresis material based on particle comprises suspending liquid and is suspended in the said suspending liquid and at a plurality of charged particles that when said electrophoresis material applies electric field, can move through said suspending liquid.
4. electro-optic displays as claimed in claim 3, wherein said electrophoresis material are the sealing electrophoresis materials, and wherein said suspending liquid and said charged particle are sealed in a plurality of capsules, and each in the said capsule has capsule wall.
5. electro-optic displays as claimed in claim 3, wherein said suspending liquid and said charged particle are maintained in a plurality of unit that are formed in the substrate.
6. method of operating electro-optic displays, said electro-optic displays comprises:
The bistable electro-optical dielectric layer;
Be arranged on a plurality of pixel electrodes of a side of said electro-optical medium layer;
At least one nonlinear element that is associated with each pixel electrode;
Pixel driving device is arranged to apply voltage through said nonlinear element to said pixel electrode;
Common electrode is in the side opposite with said pixel electrode of said electro-optical medium layer;
Said method comprises:
Be applied to predetermined voltage on the whole said pixel electrode of said display by means of said pixel driving device;
Storage is represented said predetermined voltage and is being applied the value that appears at difference between the voltage on the said common electrode in the said predetermined voltage process to said pixel electrode; And
The voltage of the value of after this storing depending on is added on the said common electrode, makes image be written into the voltage of said electro-optical medium and apply to said pixel electrode simultaneously.
7. method as claimed in claim 6, wherein said electrooptic layer comprise double-colored member of rotation or electrochromism display medium.
8. method as claimed in claim 6; Wherein said electrooptic layer comprises the electrophoresis material based on particle, and said electrophoresis material based on particle comprises suspending liquid and is suspended in the said suspending liquid and at a plurality of charged particles that when said electrophoresis material applies electric field, can move through said suspending liquid.
9. method as claimed in claim 8, wherein said electrophoresis material are the sealing electrophoresis materials, and wherein said suspending liquid and said charged particle are sealed in a plurality of capsules, and each in the said capsule has capsule wall.
10. method as claimed in claim 8, wherein said suspending liquid and said charged particle are maintained in a plurality of unit that are formed in the substrate.
11. an electro-optic displays comprises:
The bistable electro-optical dielectric layer;
A plurality of pixel electrodes are arranged on a side of said electro-optical medium layer, and at least one in the said pixel electrode is sensor pixel electrode (414);
At least one nonlinear element that is associated with each pixel electrode;
Pixel driving device is arranged to apply voltage through said nonlinear element to said pixel electrode, and said pixel driving device is arranged to apply predetermined voltage at least one sensor pixel electrode;
Common electrode is in the side opposite with said pixel electrode of said electro-optical medium layer; And
Measurement mechanism is configured to receive said predetermined voltage and the actual measurement voltage on said at least one sensor pixel, and confirms the difference between them.
12. electro-optic displays as claimed in claim 11, wherein said electrooptic layer comprise double-colored member of rotation or electrochromism display medium.
13. electro-optic displays as claimed in claim 11; Wherein said electrooptic layer comprises the electrophoresis material based on particle, and said electrophoresis material based on particle comprises suspending liquid and is suspended in the said suspending liquid and at a plurality of charged particles that when said electrophoresis material applies electric field, can move through said suspending liquid.
14. electro-optic displays as claimed in claim 13, wherein said electrophoresis material are the sealing electrophoresis materials, wherein said suspending liquid and said charged particle are sealed in a plurality of capsules, and each in the said capsule has capsule wall.
15. electro-optic displays as claimed in claim 13, wherein said suspending liquid and said charged particle are maintained in a plurality of unit that are formed in the substrate.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US48126203P | 2003-08-19 | 2003-08-19 | |
| US48125803P | 2003-08-19 | 2003-08-19 | |
| US60/481262 | 2003-08-19 | ||
| US60/481258 | 2003-08-19 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNB2004800237308A Division CN100483499C (en) | 2003-08-19 | 2004-08-19 | Methods for controlling electro-optic displays |
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| CN101533609A CN101533609A (en) | 2009-09-16 |
| CN101533609B true CN101533609B (en) | 2012-07-04 |
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| CN200910128714XA Expired - Fee Related CN101533609B (en) | 2003-08-19 | 2004-08-19 | Electro-optic displays and methods for controlling the same |
| CNB2004800237308A Active CN100483499C (en) | 2003-08-19 | 2004-08-19 | Methods for controlling electro-optic displays |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP5320757B2 (en) * | 2008-02-01 | 2013-10-23 | セイコーエプソン株式会社 | Electrophoretic display device driving method, electrophoretic display device, and electronic apparatus |
| JP5504567B2 (en) * | 2008-03-14 | 2014-05-28 | セイコーエプソン株式会社 | Electrophoretic display device driving method, electrophoretic display device, and electronic apparatus |
| JP5790968B2 (en) * | 2008-08-18 | 2015-10-07 | Ｎｌｔテクノロジー株式会社 | Display device and manufacturing method thereof |
| TWI505246B (en) | 2009-09-08 | 2015-10-21 | Prime View Int Co Ltd | Driver circuit for bistable display device and control method thereof |
| CN102110417B (en) * | 2009-12-25 | 2014-03-05 | 元太科技工业股份有限公司 | Bistable display driving circuit and control method thereof |
| CN102479441A (en) * | 2010-11-23 | 2012-05-30 | 汉王科技股份有限公司 | E-reader and method for controlling common voltage (VCOM) of e-paper screen |
| GB201106350D0 (en) * | 2011-04-14 | 2011-06-01 | Plastic Logic Ltd | Display systems |
| TWI545551B (en) * | 2014-11-19 | 2016-08-11 | Electrochromic device control apparatus and control method | |
| CN106205548B (en) | 2015-05-25 | 2019-05-03 | 株式会社理光 | Electroluminescent colored display dimming device and electroluminescent colored display drive apparatus |
| KR102250640B1 (en) * | 2015-11-18 | 2021-05-10 | 이 잉크 코포레이션 | Electro-optical displays |
| CN113823232B (en) * | 2016-03-09 | 2024-01-19 | 伊英克公司 | Method for driving electro-optic display |
| CN108320715A (en) * | 2018-01-03 | 2018-07-24 | 惠科股份有限公司 | Liquid crystal display device and its driving method |
| US20190266956A1 (en) * | 2018-02-26 | 2019-08-29 | E Ink Corporation | Electro-optic displays, and methods for driving same |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5539546A (en) * | 1993-10-29 | 1996-07-23 | Sharp Kabushiki Kaisha | Ferroelectric liquid crystal display device in which partition walls formed on an electrode create differently sized partition areas for gray scale |
| US5706023A (en) * | 1988-03-11 | 1998-01-06 | Matsushita Electric Industrial Co., Ltd. | Method of driving an image display device by driving display materials with alternating current |
| CN1274454A (en) * | 1998-08-04 | 2000-11-22 | 精工爱普生株式会社 | Electrooptic device and electronic device |
| US6531997B1 (en) * | 1999-04-30 | 2003-03-11 | E Ink Corporation | Methods for addressing electrophoretic displays |
-
2004
- 2004-08-19 CN CN200910128714XA patent/CN101533609B/en not_active Expired - Fee Related
- 2004-08-19 CN CNB2004800237308A patent/CN100483499C/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5706023A (en) * | 1988-03-11 | 1998-01-06 | Matsushita Electric Industrial Co., Ltd. | Method of driving an image display device by driving display materials with alternating current |
| US5539546A (en) * | 1993-10-29 | 1996-07-23 | Sharp Kabushiki Kaisha | Ferroelectric liquid crystal display device in which partition walls formed on an electrode create differently sized partition areas for gray scale |
| CN1274454A (en) * | 1998-08-04 | 2000-11-22 | 精工爱普生株式会社 | Electrooptic device and electronic device |
| US6531997B1 (en) * | 1999-04-30 | 2003-03-11 | E Ink Corporation | Methods for addressing electrophoretic displays |
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| CN101533609A (en) | 2009-09-16 |
| CN100483499C (en) | 2009-04-29 |
| CN1839419A (en) | 2006-09-27 |
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