-
Continuation Application Of U.S. Ser. No. 09/112,743 filed on Jul. 10, 1998[0001]
CROSS REFERENCES TO RELATED APPLICATIONS
-
The following patent applications are hereby incorporated by cross-reference. For the purposes of location and identification, US patent applications identified by their US patent application serial numbers (USSN) and US patents identified by their Patent Numbers are listed with Australian applications from which the US patents or patent applications claim the right of priority and the Applicant's Docket No.
[0002] |
|
CROSS-REFERENCED | U.S. PATENT/ | |
AUSTRALIAN | PATENT APPLICATION |
PROVISIONAL | (CLAIMING RIGHT OF |
PATENT | PRIORITY FROM AUSTRALIAN | DOCKET |
APPLICATION NO. | PROVISIONAL APPLICATION) | NO. |
|
PO7991 | 09/113,060 | ART01 |
PO8505 | 09/113,070 | ART02 |
PO7988 | 09/113,073 | ART03 |
PO9395 | 6,322,181 | ART04 |
PO8017 | 09/112,747 | ART06 |
PO8014 | 09/112,776 | ART07 |
PO8025 | 09/112,750 | ART08 |
PO8032 | 09/112,746 | ART09 |
PO7999 | 09/112,743 | ART10 |
PO7998 | 09/112,742 | ART11 |
PO8031 | 09/112,741 | ART12 |
PO8030 | 6,196,541 | ART13 |
PO7997 | 6,195,150 | ART15 |
PO7979 | 09/113,053 | ART16 |
PO8015 | 09/112,738 | ART17 |
PO7978 | 09/113,067 | ART18 |
PO7982 | 09/113,063 | ART19 |
PO7989 | 09/113,069 | ART20 |
PO8019 | 09/112,744 | ART21 |
PO7980 | 6,356,715 | ART22 |
PO8018 | 09/112,777 | ART24 |
PO7938 | 09/113,224 | ART25 |
PO8016 | 6,366,693 | ART26 |
PO8024 | 09/112,805 | ART27 |
PO7940 | 09/113,072 | ART28 |
PO7939 | 09/112,785 | ART29 |
PO8501 | 6,137,500 | ART30 |
PO8500 | 09/112,796 | ART31 |
PO7987 | 09/113,071 | ART32 |
PO8022 | 09/112,824 | ART33 |
PO8497 | 09/113,090 | ART34 |
PO8020 | 09/112,823 | ART38 |
PO8023 | 09/113,222 | ART39 |
PO8504 | 09/112,786 | ART42 |
PO8000 | 09/113,051 | ART43 |
PO7977 | 09/112,782 | ART44 |
PO7934 | 09/113,056 | ART45 |
PO7990 | 09/113,059 | ART46 |
PO8499 | 09/113,091 | ART47 |
PO8502 | 09/112,753 | ART48 |
PO7981 | 6,317,192 | ART50 |
PO7986 | 09/113,057 | ART51 |
PO7983 | 09/113,054 | ART52 |
PO8026 | 09/112,752 | ART53 |
PO8027 | 09/112,759 | ART54 |
PO8028 | 09/112,757 | ART56 |
PO9394 | 09/112,758 | ART57 |
PO9396 | 09/113,107 | ART58 |
PO9397 | 6,271,931 | ART59 |
PO9398 | 6,353,772 | ART60 |
PO9399 | 6,106,147 | ART61 |
PO9400 | 09/112,790 | ART62 |
PO9401 | 6,304,291 | ART63 |
PO9402 | 09/112,788 | ART64 |
PO9403 | 6,305,770 | ART65 |
PO9405 | 6,289,262 | ART66 |
PP0959 | 6,315,200 | ART68 |
PP1397 | 6,217,165 | ART69 |
PP2370 | 09/112,781 | DOT01 |
PP2371 | 09/113,052 | DOT02 |
PO8003 | 09/112,834 | Fluid01 |
PO8005 | 09/113,103 | Fluid02 |
PO9404 | 09/113,101 | Fluid03 |
PO8066 | 6,227,652 | IJ01 |
PO8072 | 6,213,588 | IJ02 |
PO8040 | 6,213,589 | IJ03 |
PO8071 | 6,231,163 | IJ04 |
PO8047 | 6,247,795 | IJ05 |
PO8035 | 09/113,099 | IJ06 |
PO8044 | 6,244,691 | IJ07 |
PO8063 | 6,257,704 | IJ08 |
PO8057 | 09/112,778 | IJ09 |
PO8056 | 6,220,694 | IJ10 |
PO8069 | 6,257,705 | IJ11 |
PO8049 | 6,247,794 | IJ12 |
PO8036 | 6,234,610 | IJ13 |
PO8048 | 6,247,793 | IJ14 |
PO8070 | 6,264,306 | IJ15 |
PO8067 | 6,241,342 | IJ16 |
PO8001 | 6,247,792 | IJ17 |
PO8038 | 6,264,307 | IJ18 |
PO8033 | 6,254,220 | IJ19 |
PO8002 | 6,234,611 | IJ20 |
PO8068 | 09/112,808 | IJ21 |
PO8062 | 6,283,582 | IJ22 |
PO8034 | 6,239,821 | IJ23 |
PO8039 | 09/113,083 | IJ24 |
PO8041 | 6,247,796 | IJ25 |
PO8004 | 09/113,122 | IJ26 |
PO8037 | 09/112,793 | IJ27 |
PO8043 | 09/112,794 | IJ28 |
PO8042 | 09/113,128 | IJ29 |
PO8064 | 09/113,127 | IJ30 |
PO9389 | 6,227,653 | IJ31 |
PO9391 | 6,234,609 | IJ32 |
PP0888 | 6,238,040 | IJ33 |
PP0891 | 6,188,415 | IJ34 |
PP0890 | 6,227,654 | IJ35 |
PP0873 | 6,209,989 | IJ36 |
PP0993 | 6,247,791 | IJ37 |
PP0890 | 09/112,764 | IJ38 |
PP1398 | 6,217,153 | IJ39 |
PP2592 | 09/112,767 | IJ40 |
PP2593 | 6,243,113 | IJ41 |
PP3991 | 6,283,581 | IJ42 |
PP3987 | 6,247,790 | IJ43 |
PP3985 | 6,260,953 | IJ44 |
PP3983 | 6,267,469 | IJ45 |
PO7935 | 6,224,780 | IJM01 |
PO7936 | 6,235,212 | IJM02 |
PO7937 | 6,280,643 | IJM03 |
PO8061 | 6,284,147 | IJM04 |
PO8054 | 6,214,244 | IJM05 |
PO8065 | 6,071,750 | IJM06 |
PO8055 | 6,267,905 | IJM07 |
PO8053 | 6,251,298 | IJM08 |
PO8078 | 6,258,285 | IJM09 |
PO7933 | 6,225,138 | IJM10 |
PO7950 | 6,241,904 | IJM11 |
PO7949 | 09/113,129 | IJM12 |
PO8060 | 09/113,124 | IJM13 |
PO8059 | 6,231,773 | IJML4 |
PO8073 | 6,190,931 | IJM1S |
PO8076 | 6,248,249 | IJM16 |
PO8075 | 09/113,120 | IJM17 |
PO8079 | 6,241,906 | IJM18 |
PO8050 | 09/113,116 | IJM19 |
PO8052 | 6,241,905 | IJM20 |
PO7948 | 09/113,117 | IJM21 |
PO7951 | 6,231,772 | IJM22 |
PO8074 | 6,274,056 | IJM23 |
PO7941 | 09/113,110 | IJM24 |
PO8077 | 6,248,248 | IJM25 |
PO8058 | 09/113,087 | IJM26 |
PO8051 | 09/113,074 | IJM27 |
PO8045 | 6,110,754 | IJM28 |
PO7952 | 09/113,088 | IJM29 |
PO8046 | 09/112,771 | IJM30 |
PO9390 | 6,264,849 | IJM31 |
PO9392 | 6,254,793 | IJM32 |
PP0889 | 6,235,211 | IJM35 |
PP0887 | 09/112,801 | IJM36 |
PP0882 | 6,264,850 | IJM37 |
PP0874 | 6,258,284 | IJM38 |
PP1396 | 09/113,098 | IJM39 |
PP3989 | 6,228,668 | IJM40 |
PP2591 | 6,180,427 | IJM41 |
PP3990 | 6,171,875 | IJM42 |
PP3986 | 6,267,904 | IJM43 |
PP3984 | 6,245,247 | IJM44 |
PP3982 | 09/112,835 | IJM45 |
PP0895 | 6,231,148 | IR01 |
PP0870 | 09/113,106 | IR02 |
PP0869 | 09/113,105 | IR04 |
PP0887 | 09/113,104 | IR05 |
PP0885 | 6,238,033 | IR06 |
PP0884 | 09/112,766 | IR10 |
PP0886 | 6,238,111 | IR12 |
PP0871 | 09/113,086 | IR13 |
PP0876 | 09/113,094 | IR14 |
PP0877 | 09/112,760 | IR16 |
PP0878 | 6,196,739 | IR17 |
PP0879 | 09/112,774 | IR18 |
PP0883 | 6,270,182 | IR19 |
PP0880 | 6,152,619 | IR20 |
PP0881 | 09/113,092 | IR21 |
PO8006 | 6,087,638 | MEMS02 |
PO8007 | 09/113,093 | MEMS03 |
PO8008 | 09/113,062 | MEMS04 |
PO8010 | 6,041,600 | MEMS05 |
PO8011 | 09/113,082 | MEMS06 |
PO7947 | 6,067,797 | MEMS07 |
PO7944 | 09/113,080 | MEMS09 |
PO7946 | 6,044,646 | MEMS10 |
PO9393 | 09/113,065 | MEMS11 |
PP0875 | 09/113,078 | MEMS12 |
PP0894 | 09/113,075 | MEMS13 |
|
FIELD OF THE INVENTION
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The present invention relates to a method of enhancement image and, in particular, discloses a process for Utilising Exposure Information in a Digital Image Camera. [0003]
-
The present invention further relates to the field of digital image processing and in particular, the field of processing of images taken with a digital camera. [0004]
BACKGROUND OF THE INVENTION
-
Recently, digital cameras have become increasingly popular. These cameras normally operate by means of imaging a desired image utilising a charge coupled device (CCD) array and storing the imaged scene on an electronic storage medium for later down loading onto a computer system for subsequent manipulation and printing out. Normally, when utilising a computer system to print out an image, sophisticated software may be available to manipulate the image in accordance with requirements. [0005]
-
Unfortunately such systems require significant post processing of a captured image and normally present the image in an orientation in which it was taken, relying on a post processing process to perform any necessary or required modifications of the captured image. Further, much of the environmental information available when the picture was taken is lost. [0006]
SUMMARY OF THE INVENTION
-
It is an object of the present invention to provide for the utilisation of exposure information in an image specific manner. [0007]
-
In accordance with a first aspect of the invention there is provided a method of image enhancement of a sensed image taken with a digital camera, said digital camera being hand held and including an area image sensor, internal page width ink jet printer, processor means for processing an output of said area image sensor in accordance with processing rules, and a print roll including print media and printing ink for printing out a processed image on said print media, said digital camera further including an auto exposure setting means, said method comprising the step of utilising exposure setting information from said auto exposure setting means to process said sensed image in accordance with said processing rules. [0008]
-
In accordance with a second aspect of the invention there is provided a method of image enhancement of a sensed image taken with a digital camera, including an auto exposure setting means, said method comprising the step of utilising the auto exposure setting from said auto exposure setting means to process said sensed image to add exposure specific graphics to said image. [0009]
-
The utilising step can comprise utilising the auto exposure setting to determine a re-mapping of colours within the image so as to produce an amended image having colours within an image transformed to take account of the auto exposure setting. The processing can comprise re-mapping image colours so they appear deeper and richer when the exposure setting indicates low light conditions and re-mapping image colours to be brighter and more saturated when the auto exposure setting indicates bright light conditions. [0010]
-
The utilising step includes adding exposure specific graphics to the image. [0011]
BRIEF DESCRIPTION OF DRAWINGS
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Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: [0012]
-
FIG. 1 illustrates the method of operation of the preferred embodiment.[0013]
DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS
-
The preferred embodiment is preferably implemented through suitable programming of a hand held camera device such as that described in the concurrently filed application U.S. Ser. No 09/113,060, entitled “A Digital Instant Printing Camera with Image Processing Capability” filed concurrently herewith by the present applicant the content of which is hereby specifically incorporated by cross reference and the details of which, and other related applications are set out in the tables included herein. [0014]
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The aforementioned patent specification discloses a camera system, hereinafter known as an “Artcam” type camera, wherein sensed images can be directly printed out by an Artcam portable camera unit. Further, the aforementioned specification discloses means and methods for performing various manipulations on images captured by the camera sensing device leading to the production of various effects in any output image. The manipulations are disclosed to be highly flexible in nature and can be implemented through the insertion into the Artcam of cards having encoded thereon various instructions for the manipulation of images, the cards hereinafter being known as Artcards. The Artcam further has significant onboard processing power provided by an Artcam Central Processor unit (ACP) which is interconnected to a memory device for the storage of important data and image. [0015]
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The invention disclosed in U.S. Ser. No. 09/113,060, relates to providing an alternative form of camera system which includes a digital camera with an integral color printer. Additionally, the camera provides hardware and software for the increasing of the apparent resolution of the image sensing system and the conversion of the image to a wide range of “artistic styles” and a graphic enhancement. [0016]
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In accordance with the invention, disclosed in U.S. Ser. No. 09/113,060, there is provided a camera system comprising at least one area image sensor for imaging a scene, a camera processor means for processing said imaged scene in accordance with a predetermined scene transformation requirement, a printer for printing out said processed image scene on print media, print media and printing ink stored in a single detachable module inside said camera system, said camera system comprising a portable hand held unit for the imaging of scenes by said area image sensor and printing said scenes directly out of said camera system via said printer. [0017]
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Preferably the camera system includes a print roll for the storage of print media and printing ink for utilization by the printer, the print roll being detachable from the camera system. Further, the print roll can include an authentication chip containing authentication information and the camera processing means is adapted to interrogate the authentication chip so as to determine the authenticity of said print roll when inserted within said camera system. [0018]
-
Further, the printer can include a drop on demand ink printer and guillotine means for the separation of printed photographs. [0019]
-
In the preferred embodiment, the Artcam has an auto exposure sensor for determining the light level associated with the captured image. This auto exposure sensor is utilised to process the image in accordance with the set light value so as to enhance portions of the image. [0020]
-
Preferably, the area image sensor includes a means for determining the light conditions when capturing an image. The area image sensor adjusts the dynamic range of values captured by the CCD in accordance with the detected level sensor. The captured image is transferred to the Artcam central processor and stored in the memory store. Intensity information, as determined by the area image sensor, is also forwarded to the ACP. This information is utilised by the Artcam central processor to manipulate the stored image to enhance certain effects. [0021]
-
Turning now to FIG. 1, the auto exposure setting information [0022] 1 is utilised in conjunction with the stored image 2 to process the image by utilising the ACP. The processed image is returned to the memory store for later printing out 4 on the output printer.
-
A number of processing steps can be undertaken in accordance with the determined light conditions. Where the auto exposure setting [0023] 1 indicates that the image was taken in a low light condition, the image pixel colours are selectively re-mapped so as to make the image colours stronger, deeper and richer.
-
Where the auto exposure information indicates that highlight conditions were present when the image was taken, the image colours can be processed to make them brighter and more saturated. The re-colouring of the image can be undertaken by conversion of the image to a hue-saturation-value (HSV) format and an alteration of pixel values in accordance with requirements. The pixel values can then be output converted to the required output colour format of printing. [0024]
-
Of course, many different re-colouring techniques may be utilised. Preferably, the techniques are clearly illustrated on the pre-requisite artcard inserted into the reader. Alternatively, the image processing algorithms can be automatically applied and hard-wired into the camera for utilization in certain conditions. [0025]
-
Alternatively, the Artcard inserted could have a number of manipulations applied to the image which are specific to the auto-exposure setting. For example, clip arts containing candles etc could be inserted in a dark image and large suns inserted in bright images. [0026]
-
It would be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the specific embodiment without departing from the spirit or scope of the invention as broadly described. The present embodiment is, therefore, to be considered in all respects to be illustrative and not restrictive. [0027]
-
The present invention is best utilized in the Artcam device, the details of which are set out in the following paragraphs. [0028]
-
Ink Jet Technologies [0029]
-
The embodiments of the invention use an ink jet printer type device. Of course many different devices could be used. However presently popular ink jet printing technologies are unlikely to be suitable. [0030]
-
The most significant problem with thermal ink jet is power consumption. This is approximately 100 times that required for high speed, and stems from the energy-inefficient means of drop ejection. This involves the rapid boiling of water to produce a vapor bubble which expels the ink. Water has a very high heat capacity, and must be superheated in thermal ink jet applications. This leads to an efficiency of around 0.02%, from electricity input to drop momentum (and increased surface area) out. [0031]
-
The most significant problem with piezoelectric ink jet is size and cost. Piezoelectric crystals have a very small deflection at reasonable drive voltages, and therefore require a large area for each nozzle. Also, each piezoelectric actuator must be connected to its drive circuit on a separate substrate. This is not a significant problem at the current limit of around 300 nozzles per print head, but is a major impediment to the fabrication of pagewidth print heads with 19,200 nozzles. [0032]
-
Ideally, the ink jet technologies used meet the stringent requirements of in-camera digital color printing and other high quality, high speed, low cost printing applications. To meet the requirements of digital photography, new ink jet technologies have been created. The target features include: [0033]
-
low power (less than 10 Watts) [0034]
-
high resolution capability (1,600 dpi or more) [0035]
-
photographic quality output [0036]
-
low manufacturing cost [0037]
-
small size (pagewidth times minimum cross section) [0038]
-
high speed (<2 seconds per page). [0039]
-
All of these features can be met or exceeded by the ink jet systems described below with differing levels of difficulty. Forty-five different ink jet technologies have been developed by the Assignee to give a wide range of choices for high volume manufacture. These technologies form part of separate applications assigned to the present Assignee as set out in the table under the heading Cross References to Related Applications. [0040]
-
The ink jet designs shown here are suitable for a wide range of digital printing systems, from battery powered one-time use digital cameras, through to desktop and network printers, and through to commercial printing systems [0041]
-
For ease of manufacture using standard process equipment, the print head is designed to be a monolithic 0.5 micron CMOS chip with MEMS post processing. For color photographic applications, the print head is 100 mm long, with a width which depends upon the ink jet type. The smallest print head designed is IJ38, which is 0.35 mm wide, giving a chip area of 35 square mm. The print heads each contain 19,200 nozzles plus data and control circuitry. [0042]
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Ink is supplied to the back of the print head by injection molded plastic ink channels. The molding requires 50 micron features, which can be created using a lithographically micromachined insert in a standard injection molding tool. Ink flows through holes etched through the wafer to the nozzle chambers fabricated on the front surface of the wafer. The print head is connected to the camera circuitry by tape automated bonding. [0043]
-
Tables of Drop-on-Demand Ink Jets [0044]
-
Eleven important characteristics of the fundamental operation of individual ink jet nozzles have been identified. These characteristics are largely orthogonal, and so can be elucidated as an eleven dimensional matrix. Most of the eleven axes of this matrix include entries developed by the present assignee. [0045]
-
The following tables form the axes of an eleven dimensional table of ink jet types. [0046]
-
Actuator mechanism (18 types) [0047]
-
Basic operation mode (7 types) [0048]
-
Auxiliary mechanism (8 types) [0049]
-
Actuator amplification or modification method (17 types) [0050]
-
Actuator motion (19 types) [0051]
-
Nozzle refill method (4 types) [0052]
-
Method of restricting back-flow through inlet (10 types) [0053]
-
Nozzle clearing method (9 types) [0054]
-
Nozzle plate construction (9 types) [0055]
-
Drop ejection direction (5 types) [0056]
-
Ink type (7 types) [0057]
-
The complete eleven dimensional table represented by these axes contains 36.9 billion possible configurations of ink jet nozzle. While not all of the possible combinations result in a viable ink jet technology, many million configurations are viable. It is clearly impractical to elucidate all of the possible configurations. Instead, certain ink jet types have been investigated in detail. These are designated IJ01 to IJ45 which match the docket numbers in the table under the heading Cross References to Related Applications. [0058]
-
Other ink jet configurations can readily be derived from these forty-five examples by substituting alternative configurations along one or more of the 11 axes. Most of the IJ01 to IJ45 examples can be made into ink jet print heads with characteristics superior to any currently available ink jet technology. [0059]
-
Where there are prior art examples known to the inventor, one or more of these examples are listed in the examples column of the tables below. The IJ01 to IJ45 series are also listed in the examples column. In some cases, a print technology may be listed more than once in a table, where it shares characteristics with more than one entry. [0060]
-
Suitable applications for the ink jet technologies include: Home printers, Office network printers, Short run digital printers, Commercial print systems, Fabric printers, Pocket printers, Internet WWW printers, Video printers, Medical imaging, Wide format printers, Notebook PC printers, Fax machines, Industrial printing systems, Photocopiers, Photographic minilabs etc. [0061]
-
The information associated with the aforementioned 11 dimensional matrix are set out in the following tables.
[0062] | |
| |
| | | Dis- | |
| Description | Advantages | advantages | Examples |
| |
|
ACTUATOR MECHANISM |
(APPLIED ONLY TO SELECTED INK DROPS) |
Thermal | An electrothermal | Large force | High power | Canon |
bubble | heater heats the | generated | Ink carrier | Bubblejet |
| ink to above | Simple | limited to | 1979 Endo |
| boiling point, | construction | water | et al GB |
| transferring | No moving | Low | patent |
| significant heat to | parts | efficiency | 2,007,162 |
| the aqueous ink. | Fast | High | Xerox |
| A bubble | operation | temperatures | heater-in-pit |
| nucleates and | Small chip | required | 1990 |
| quickly forms, | area required | High | Hawkins et |
| expelling the ink. | for actuator | mechamcal | al USP |
| The efficiency of | | stress | 4,899,181 |
| the process is | | Unusual | Hewlett- |
| low, with | | materials | Packard TIJ |
| typically less | | required | 1982 Vaught |
| than 0.05% of the | | Large drive | et al USP |
| electrical energy | | transistors | 4,490,728 |
| being transformed | | Cavitation |
| into kinetic | | causes |
| energy of the | | actuator |
| drop. | | failure |
| | | Kogation |
| | | reduces |
| | | bubble |
| | | formation |
| | | Large print |
| | | heads are |
| | | difficult to |
| | | fabricate |
Piezo- | A piezoelectric | Low power | Very large | Kyser et al |
electric | crystal such as | consumption | area required | USP |
| lead lanthanum | Many ink | for actuator | 3,946,398 |
| zirconate (PZT) is | types can be | Difficult to | Zoltan USP |
| electrically | used | integrate | 3,683,212 |
| activated, and | Fast | with | 1973 |
| either expands, | operation | electronics | Stemme USP |
| shears, or bends | High | High | 3,747,120 |
| to apply pressure | efficiency | voltage drive | Epson |
| to the ink, | required | transistors | Stylus |
| ejecting drops. | | Full page- | Tektronix |
| | | width print | IJ04 |
| | | heads |
| | | impractical |
| | | due to |
| | | actuator size |
| | | Requires |
| | | electrical |
| | | poling in |
| | | high field |
| | | strengths |
| | | during |
| | | manufacture |
Electro- | An electric field | Low power | Low | Seiko Epson, |
strictive | is used to activate | consumption | maximum | Usui et all JP |
| electrostriction in | Many ink | strain | 253401/96 |
| relaxor materials | types can | (approx. | IJ04 |
| such as lead | be used | 0.01%) |
| lanthanum | Low | Large area |
| zirconate titanate | thermal | required for |
| (PLZT) or lead | expansion | actuator due |
| magnesium | Electric | to low strain |
| niobate (PMN). | field strength | Response |
| | required | speed is |
| | (approx. 3.5 | marginal |
| | V/μm) can | (˜10 μs) |
| | be generated | High voltage |
| | without | drive |
| | difficulty | transistors |
| | Does not | required |
| | require | Full |
| | electrical | pagewidth |
| | poling | print heads |
| | | impractical |
| | | due to |
| | | actuator size |
Ferro- | An electric field | Low power | Difficult to | IJ04 |
electric | is used to induce | consumption | integrate |
| a phase transition | Many ink | with |
| between the | types can | electronics |
| antiferroelectric | be used | Unusual |
| (AFE) and | Fast | materials |
| ferroelectric (FE) | operation | such as |
| phase. Perovskite | (<1 μs) | PLZSnT are |
| materials such as | Relatively | required |
| tin modified lead | high | Actuators |
| lanthanum | longitudinal | require a |
| zirconate titanate | strain | large |
| (PLZSnT) exhibit | High | area |
| large strains of up | efficiency |
| to 1% associated | Electric |
| with the AFE to | field strength |
| FE phase | of around |
| transition. | 3 V/μm can |
| | be readily |
| | provided |
Electro- | Conductive plates | Low power | Difficult to | IJ02, IJ04 |
static | are separated by a | consumption | operate |
plates | compressible or | Many ink | electrostatic |
| fluid dielectric | types can | devices in |
| (usually air). | be used | an aqueous |
| Upon application | Fast | environment |
| of a voltage, the | operation | The |
| plates attract each | | electrostatic |
| other and displace | | actuator will |
| ink, causing drop | | normally |
| ejection. The | | need to be |
| conductive plates | | separated |
| maybe in a comb | | from the ink |
| or honeycomb | | Very large |
| structure, or | | area required |
| stacked to | | to achieve |
| increase the | | high forces |
| surface area | | High |
| and therefore the | | voltage drive |
| force. | | transistors |
| | | may be |
| | | required |
| | | Full page- |
| | | width print |
| | | heads are not |
| | | competitive |
| | | due to |
| | | actuator size |
Electro- | A strong electric | Low current | High voltage | 1989 Saito |
static | field is applied to | consumption | required | et al, USP |
pull on | the ink, where- | Low | May be | 4,799,068 |
ink | upon electrostatic | temperature | damaged by | 1989 Miura |
| attraction | | sparks due | et al, USP |
| accelerates the | | to air | 4,810,954 |
| ink towards the | | breakdown | Tone-jet |
| print medium. | | Required |
| | | field strength |
| | | increases as |
| | | the drop size |
| | | decreases |
| | | High |
| | | voltage drive |
| | | transistors |
| | | required |
| | | Electrostatic |
| | | field attracts |
| | | dust |
Permanent | An electromagnet | Low power | Complex | IJ07, IJ10 |
magnet | directly attracts | consumption | fabrication |
electro- | a permanent | Many ink | Permanent |
magnetic | magnet, | types can | magnetic |
| displacing ink and | be used | material |
| causing drop | Fast | such as |
| ejection. Rare | operation | Neodymium |
| earth magnets | High | Iron Boron |
| with a field | efficiency | (NdFeB) |
| strength around 1 | Easy | required. |
| Tesla can be | extension | High local |
| used. Examples | from single | currents |
| are: Samarium | nozzles to | required |
| Cobalt (SaCo) | pagewidth | Copper |
| and magnetic | print heads | metalization |
| materials in the | | should be |
| neodymium iron | | used for long |
| boron family | | electro- |
| (NdFeB, | | migration |
| NdDyFeBNb, | | lifetime |
| NdDyFeB, etc) | | and low |
| | | resistivity |
| | | Pigmented |
| | | inks are |
| | | usually |
| | | infeasible |
| | | Operating |
| | | temperature |
| | | limited to |
| | | the Curie |
| | | temperature |
| | | (around |
| | | 540 K) |
Soft | A solenoid | Low power | Complex | IJ01, IJ05, |
magnetic | induced a | consumption | fabrication | IJ08, IJ10, |
core | magnetic field in | Many ink | Materials | IJ12, IJ14, |
electro- | a soft magnetic | types can | not usually | IJ15, IJ17 |
magnetic | core or yoke | be used | present in |
| fabricated from a | Fast | a CMOS fab |
| ferrous material | operation | such as |
| such as electro- | High | NiFe, |
| plated iron alloys | efficiency | CoNiFe, or |
| such as CoNiFe | Easy | CoFe are |
| [1], CoFe, or | extension | required |
| NiFe alloys. | from single | High local |
| Typically, the soft | nozzles to | currents |
| magnetic material | pagewidth | required |
| is in two parts, | print heads | Copper |
| which are | | metalization |
| normally held | | should be |
| apart by a spring. | | used for long |
| When the | | electro- |
| solenoid is | | migration |
| actuated, the two | | lifetime |
| parts attract, | | and low |
| displacing the | | resistivity |
| ink. | | Electro- |
| | | plating is |
| | | required |
| | | High |
| | | saturation |
| | | flux density |
| | | is required |
| | | (2.0-2.1 T is |
| | | achievable |
| | | with CoNiFe |
| | | [1]) |
Lorenz | The Lorenz force | Low power | Force acts | IJ06, IJ11, |
force | acting on a | consumption | as a twisting | IJ13, IJ16 |
| current carrying | Many ink | motion |
| wire in a | types can | Typically, |
| magnetic field is | be used | only a |
| utilized. | Fast | quarter of |
| This allows the | operation | the solenoid |
| magnetic field to | High | length |
| be supplied | efficiency | provides |
| externally to the | Easy | force in a |
| pnnt head, for | extension | useful |
| example with rare | from single | direction |
| earth permanent | nozzles to | High local |
| magnets. | pagewidth | currents |
| Only the current | print heads | required |
| carrying wire | | Copper |
| need be fabricated | | metalization |
| on the print-head, | | should be |
| simplifying | | used for |
| materials | | long electro- |
| requirements. | | migration |
| | | lifetime |
| | | and low |
| | | resistivity |
| | | Pigmented |
| | | inks are |
| | | usually |
| | | infeasible |
Magneto- | The actuator uses | Many ink | Force acts | Fisehenbeck, |
striction | the giant | types can | as a twisting | USP |
| magnetostrictive | be used | motion | 4,032,929 |
| effect of materials | Fast | Unusual | IJ25 |
| such as | operation | materials |
| Terfenol-D (an | Easy | such as |
| alloy of terbium, | extension | Terfenol-D |
| dysprosium and | from single | are required |
| iron developed at | nozzles to | High local |
| the Naval | pagewidth | currents |
| Ordnance | print heads | required |
| Laboratory, hence | High force | Copper |
| Ter-Fe-NOL). For | is available | metalization |
| best efficiency, | | should be |
| the actuator | | used for long |
| should be pre- | | electro- |
| stressed to | | migration |
| approx. 8 MPa. | | lifetime |
| | | and low |
| | | resistivity |
| | | Pre-stressing |
| | | may be |
| | | required |
Surface | Ink under positive | Low power | Requires | Silverbrook, |
tension | pressure is held in | consumption | supple- | EP 0771 |
reduction | a nozzle by | Simple | mentary | 658 A2 |
| surface tension. | construction | force to | and related |
| The surface | No unusual | effect | patent |
| tension of | materials | drop | applications |
| the ink is reduced | required in | separation |
| below the bubble | fabrication | Requires |
| threshold, causing | High | special ink |
| the ink to egress | efficiency | surfactants |
| from the nozzle. | Easy | Speed may |
| | extension | be limited by |
| | from single | surfactant |
| | nozzles to | properties |
| | pagewidth |
| | print heads |
Viscosity | The ink viscosity | Simple | Requires | Silverbrook, |
reduction | is locally reduced | construction | supple- | EP 0771 |
| to select which | No unusual | mentary | 658 A2 |
| drops are to be | materials | force to | and related |
| ejected. A vis- | required in | effect drop | patent |
| cosity reduction | fabrication | separation | applications |
| can be achieved | Easy | Requires |
| electrothermally | extension | special ink |
| with most inks, | from single | viscosity |
| but special inks | nozzles to | properties |
| can be engineered | pagewidth | High speed |
| for a 100:1 | print heads | is difficult |
| viscosity | | to achieve |
| reduction. | | Requires |
| | | oscillating |
| | | ink pressure |
| | | A high |
| | | temperature |
| | | difference |
| | | (typically 80 |
| | | degrees) is |
| | | required |
Acoustic | An acoustic wave | Can operate | Complex | 1993 |
| is generated and | without a | drive | Hadimioglu |
| focussed upon the | nozzle plate | circuitry | et al, EUP |
| drop ejection | | Complex | 550,192 |
| region. | | fabrication | 1993 Elrod |
| | | Low | et al, EUP |
| | | efficiency | 572,220 |
| | | Poor control |
| | | of drop |
| | | position |
| | | Poor control |
| | | of drop |
| | | volume |
Thermo- | An actuator | Low power | Efficient | IJ03, IJ09, |
elastic | which relies upon | consumption | aqueous | IJ17, IJ18, |
bend | differential | Many ink | operation | IJ19, IJ20, |
actuator | thermal expansion | types can | requires a | IJ21, IJ22, |
| upon Joule | be used | thermal | IJ23, IJ24, |
| heating is used. | Simple | insulator on | IJ27, IJ28, |
| | planar | the hot side | IJ29, IJ30, |
| | fabrication | Corrosion | IJ31, IJ32, |
| | Small chip | prevention | IJ33, IJ34, |
| | area required | can be | IJ35, IJ36, |
| | for each | difficult | IJ37, IJ38, |
| | actuator | Pigmented | IJ39, IJ40, |
| | Fast | inks may be | IJ41 |
| | operation | infeasible, |
| | High | as pigment |
| | efficiency | particles may |
| | CMOS | jam the bend |
| | compatible | actuator |
| | voltages and |
| | currents |
| | Standard |
| | MEMS |
| | processes |
| | can be used |
| | Easy |
| | extension |
| | from single |
| | nozzles to |
| | pagewidth |
| | print heads |
High CTE | A material with a | High force | Requires | IJ09, IJ17, |
thermo- | very high | can be | special | IJ18, IJ20, |
elastic | coefficient of | generated | material | IJ21, IJ22, |
actuator | thermal expansion | Three | (e.g. PTFE) | IJ23, IJ24, |
| (CTE) such as | methods of | Requires a | IJ27, IJ28, |
| polytetrafluoro- | PTFE | PTFE | IJ29, IJ30, |
| ethylene (PTFE) | deposition | deposition | IJ31, IJ42, |
| is used. As high | are under | process, | IJ43, IJ44 |
| GTE materials are | develop- | which is not |
| usually non- | ment: | yet standard |
| conductive, a | chemical | in ULSI fabs |
| heater fabricated | vapor | PTFE |
| from a conductive | deposition | deposition |
| material is | (CVD), spin | cannot be |
| incorporated. A | coating, and | followed |
| 50 μm long PTFE | evaporation | with high |
| bend actuator | PTFE is a | temperature |
| with polysilicon | candidate | (above |
| heater and 15 | for low | 350° C.) |
| mW power input | dielectric | processing |
| can provide 180 | constant | Pigmented |
| μN force and 10 | insulation | inks may be |
| μm deflection. | in ULSI | infeasible, |
| Actuator motions | Very low | as pigment |
| include: | power | particles may |
| Bend | consumption | jam the bend |
| Push | Many ink | actuator |
| Buckle | types can |
| Rotate | be used |
| | Simple |
| | planar |
| | fabrication |
| | Small chip |
| | area required |
| | for each |
| | actuator |
| | Fast |
| | operation |
| | High |
| | efficiency |
| | CMOS |
| | compatible |
| | voltages and |
| | currents |
| | Easy |
| | extension |
| | from single |
| | nozzles to |
| | pagewidth |
| | print heads |
Con- | A polymer with a | High force | Requires | IJ24 |
ductive | high coefficient | can be | special |
polymer | of thermal | generated | materials |
thermo- | expansion (such | Very low | development |
elastic | as PTFE) is | power | (High CTE |
actuator | doped with | consumption | conductive |
| conducting | Many ink | polymer) |
| substances to | types can | Requires a |
| increase its | be used | PTFE |
| conductivity to | Simple | deposition |
| about 3 orders of | planar | process, |
| magnitude below | fabrication | which |
| that of copper. | Small chip | is not yet |
| The conducting | area required | standard in |
| polymer expands | for each | ULSI fabs |
| when resistively | actuator | PTFE |
| heated. | Fast | deposition |
| Examples of | operation | cannot be |
| conducting | High | followed |
| dopants include: | efficiency | with high |
| Carbon nanotubes | CMOS | temperature |
| Metal fibers | compatible | (above |
| Conductive | voltages and | 350° C.) |
| polymers such as | currents | processing |
| doped | Easy | Evaporation |
| polythiophene | extension | and CVD |
| Carbon granules | from single | deposition |
| | nozzles to | techniques |
| | pagewidth | cannot |
| | print heads | be used |
| | | Pigmented |
| | | inks may be |
| | | infeasible, |
| | | as pigment |
| | | particles |
| | | may jam |
| | | the bend |
| | | actuator |
Shape | A shape memory | High force | Fatigue | IJ26 |
memory | alloy such as TiNi | is available | limits |
alloy | (also known as | (stresses of | maximum |
| Nitinol-Nickel | hundreds of | number of |
| Titanium alloy | MPa) | cycles |
| developed at the | Large strain | Low strain |
| Naval Ordnance | is available | (1%) is |
| Laboratory) is | (more than | required to |
| thermally | 3%) | extend |
| switched between | High | fatigue |
| its weak | corrosion | resistance |
| martensitic state | resistance | Cycle rate |
| and its high | Simple | limited by |
| stiffness austenic | construction | heat removal |
| state. The shape | Easy | Requires |
| of the actuator in | extension | unusual |
| its martensitic | from single | materials |
| state is deformed | nozzles to | (TiNi) |
| relative to the | pagewidth | The latent |
| austenic shape. | print heads | heat of |
| The shape change | Low voltage | trans- |
| causes ejection of | operation | formation |
| a drop. | | must be |
| | | provided |
| | | High current |
| | | operation |
| | | Requires |
| | | pre-stressing |
| | | to distort |
| | | the |
| | | martensitic |
| | | state |
Linear | Linear magnetic | Linear | Requires | IJ12 |
Magnetic | actuators include | Magnetic | unusual |
Actuator | the Linear In- | actuators | semi- |
| duction Actuator | can be | conductor |
| (LIA), Linear | constructed | materials |
| Permanent | with high | such |
| Magnet | thrust, long | as soft |
| Synchronous | travel, and | magnetic |
| Actuator | high | alloys |
| (LPMSA), Linear | efficiency | (e.g. |
| Reluctance | using planar | CoNiFe) |
| Synchronous | semi- | Some |
| Actuator (LRSA), | conductor | varieties |
| Linear Switched | fabrication | also require |
| Reluctance | techniques | permanent |
| Actuator (LSRA), | Long | magnetic |
| and the Linear | actuator | materials |
| Stepper Actuator | travel is | such as |
| (LSA). | available | Neodymium |
| | Medium | iron boron |
| | force is | (NdFeB) |
| | available | Requires |
| | Low voltage | complex |
| | operation | multi-phase |
| | | drive |
| | | circuitry |
| | | High current |
| | | operation |
Actuator | This is the | Simple | Drop | Thermal |
directly | simplest mode of | operation | repetition | ink jet |
pushes | operation: the | No external | rate is | Piezoelectric |
ink | actuator directly | fields | usually | ink jet |
| supplies sufficient | required | limited to | IJ01, IJ02, |
| kinetic energy to | Satellite | around | IJ03, IJ04, |
| expel the drop. | drops can | 10 kHz. | IJ05, IJ06, |
| The drop must | be avoided | However, | IJ07, IJ09, |
| have a sufficient | if drop | this is not | IJ11, IJ12, |
| velocity to | velocity is | the method, | IJ14, IJ16, |
| overcome the | less than | but | IJ20, IJ22, |
| surface tension. | 4 m/s | fundamental | IJ23, IJ24, |
| | Can be | to is related | IJ25, IJ26, |
| | efficient, | to the refill | IJ27, IJ28, |
| | depending | method | IJ29, IJ30, |
| | upon the | normally | IJ31, IJ32, |
| | actuator | used | IJ33, IJ34, |
| | used | All of the | IJ35, IJ36, |
| | | drop kinetic | IJ37, IJ38, |
| | | energy must | IJ39, IJ40, |
| | | be provided | IJ41, IJ42, |
| | | by the | IJ43, IJ44 |
| | | actuator |
| | | Satellite |
| | | drops usually |
| | | form if drop |
| | | velocity |
| | | is greater |
| | | than 4.5 m/s |
Proximity | The drops to be | Very simple | Requires | Silverbrook, |
| printed are | print head | close | EP 0771 |
| selected by some | fabrication | proximity | 658 A2 |
| manner (e.g. | can be used | between the | and related |
| thermally induced | The drop | print head | patent |
| surface tension | selection | and the | applications |
| reduction of | means does | print media |
| pressurized ink). | not need to | or transfer |
| Selected drops are | provide the | roller |
| separated from | energy | May require |
| the ink in the | required to | two print |
| nozzle by contact | separate the | heads |
| with the print | drop from | printing |
| medium or a | the nozzle | alternate |
| transfer roller. | | rows of |
| | | the image |
| | | Monolithic |
| | | color print |
| | | heads are |
| | | difficult |
Electra- | The drops to be | Very simple | Requires | Silverbrook, |
static | printed are | print head | very high | EP 0771 |
pull on | selected by some | fabrication | electrostatic | 658 A2 |
ink | manner (e.g. | can be used | field | and related |
| thermally induced | The drop | Electrostatic | patent |
| surface tension | selection | field for | applications |
| reduction of | means does | small | Tone-Jet |
| pressurized ink). | not need to | nozzle sizes |
| Selected drops are | provide the | is above air |
| separated from | energy | breakdown |
| the ink in the | required to | Electrostatic |
| nozzle by a strong | separate the | field may |
| electric field. | drop from | attract dust |
| | the nozzle |
Magnetic | The drops to be | Very simple | Requires | Silverbrook, |
pull on | printed are | print head | magnetic ink | EP 0771 |
ink | selected by some | fabrication | Ink colors | 658 A2 |
| manner (e.g. | can be used | other than | and related |
| thermally induced | The drop | black are | patent |
| surface tension | selection | difficult | applications |
| reduction of | means does | Requires |
| pressurized ink), | not need to | very high |
| Selected drops are | provide the | magnetic |
| separated from | energy | fields |
| the ink in the | required to |
| nozzle by a strong | separate the |
| magnetic field | drop from |
| acting on the | the nozzle |
| magnetic ink. |
Shutter | The actuator | High speed | Moving parts | IJ13, IJ17, |
| moves a shutter to | (>50 kHz) | are required | IJ21 |
| block ink flow to | operation | Requires ink |
| the nozzle. The | can be | pressure |
| ink pressure is | achieved due | modulator |
| pulsed at a | to reduced | Friction and |
| multiple of the | refill time | wear must be |
| drop ejection | Drop timing | considered |
| frequency. | can be very | Stiction is |
| | accurate | possible |
| | The actuator |
| | energy can |
| | be very low |
Shuttered | The actuator | Actuators | Moving parts | IJ08, IJ15, |
grill | moves a shutter to | with small | are required | IJ18, IJ19 |
| block ink flow | travel can | Requires ink |
| through a grill to | be used | pressure |
| the nozzle. The | Actuators | modulator |
| shutter movement | with small | Friction and |
| need only be | force can | wear must be |
| equal to the width | be used | considered |
| of the grill holes. | High speed | Stiction is |
| | (>50 kHz) | possible |
| | operation |
| | can be |
| | achieved |
Pulsed | A pulsed | Extremely | Requires an | IJ10 |
magnetic | magnetic field | low energy | external |
pull on | attracts an ‘ink | operation is | pulsed |
ink | pusher’ at the | possible | magnetic |
pusher | drop ejection | No heat | field |
| frequency. An | dissipation | Requires |
| actuator controls | problems | special |
| a catch, which | | materials |
| prevents the ink | | for both the |
| pusher from | | actuator |
| moving when a | | and the |
| drop is not | | ink pusher |
| to be ejected. | | Complex |
| | | construction |
AUXILIARY MECHANISM (APPLIED TO ALL NOZZLES) |
None | The actuator | Simplicity of | Drop | Most ink |
| directly fires the | construction | ejection | jets, |
| ink drop, and | Simplicity of | energy | including |
| there is no | operation | must be | piezoelectric |
| external field or | Small | supplied by | and thermal |
| other mechanism | physical size | individual | bubble. |
| required. | | nozzle | IJ01, IJ02, |
| | | actuator | IJ03, IJ04, |
| | | | IJ05, IJ07, |
| | | | IJ09, IJ11, |
| | | | IJ12, IJ14, |
| | | | IJ20, IJ22, |
| | | | IJ23, IJ24, |
| | | | IJ25, IJ26, |
| | | | IJ27, IJ28, |
| | | | IJ29, IJ30, |
| | | | IJ31, IJ32, |
| | | | IJ33, IJ34, |
| | | | IJ35, IJ36, |
| | | | IJ37, IJ38, |
| | | | IJ39, IJ40, |
| | | | IJ41, IJ42, |
| | | | IJ43, IJ44 |
Oscillating | The ink pressure | Oscillating | Requires | Silverbrook, |
ink | oscillates, | ink pressure | external ink | EP 0771 |
pressure | providing much | can provide | pressure | 658 A2 |
(including | of the drop | a refill | oscillator | and related |
acoustic | ejection energy. | pulse, | Ink pressure | patent |
stimu- | The actuator | allowing | phase and | applications |
lation) | selects which | higher | amplitude | IJ08, IJ13, |
| drops are to be | operating | must be | IJ15, IJ17, |
| fired by | speed | carefully | IJ18, IJ19, |
| selectively | The | controlled | IJ21 |
| blocking or | actuators | Acoustic |
| enabling nozzles. | may operate | reflections |
| The ink pressure | with much | in the ink |
| oscillation may be | lower energy | chamber |
| achieved by | Acoustic | must be |
| vibrating the print | lenses can be | designed for |
| head, or | used to focus |
| preferably by | the sound on |
| an actuator in | the nozzles |
| the ink supply. |
Media | The print head is | Low power | Precision | Silverbrook, |
proximity | placed in close | High | assembly | EP 0771 |
| proximity to the | accuracy | required | 658 A2 |
| print medium. | Simple print | Paper fibers | and related |
| Selected drops | head | may cause | patent |
| protrude from the | construction | problems | applications |
| print head further | | Cannot print |
| than unselected | | on rough |
| drops, and contact | | substrates |
| the print medium. |
| The drop soaks |
| into the medium |
| fast enough to |
| cause drop |
| separation. |
Transfer | Drops are printed | High | Bulky | Silverbrook, |
roller | to a transfer roller | accuracy | Expensive | EP 0771 |
| instead of straight | Wide range | Complex | 658 A2 |
| to the print | of print | construction | and related |
| medium. A | substrates | | patent |
| transfer roller can | can be used | | applications |
| also be used for | Ink can be | | Tektronix |
| proximity drop | dried on the | | hot melt |
| separation. | transfer | | piezoelectric |
| | roller | | ink jet |
| | | | Any of the |
| | | | IJ series |
Electro- | An electric field | Low power | Field | Silverbrook, |
static | is used to | Simple | strength | EP 0771 |
| accelerate | print head | required for | 658 A2 |
| selected drops | construction | separation | and related |
| towards the print | | of small | patent |
| medium. | | drops is | applications |
| | | near or | Tone-Jet |
| | | above air |
| | | breakdown |
Direct | A magnetic field | Low power | Requires | Silverbrook, |
magnetic | is used to | Simple | magnetic ink | EP 0771 |
field | accelerate | print head | Requires | 658 A2 |
| selected drops of | construction | strong | and related |
| magnetic ink | | magnetic | patent |
| towards the print | | field | applications |
| medium. |
Cross | The print head is | Does not | Requires | IJ06, IJ16 |
magnetic | placed in a | require | external |
field | constant magnetic | magnetic | magnet |
| field. The Lorenz | materials | Current |
| force in a current | to be | densities |
| canying wire is | integrated | may be high, |
| used to move the | in the | resulting in |
| actuator. | print head | electro- |
| | manu- | migration |
| | facturing | problems |
| | process |
Pulsed | A pulsed | Very low | Complex | IJ10 |
magnetic | magnetic field is | power | print head |
field | used to cyclically | operation | construction |
| attract a paddle, | is possible | Magnetic |
| which pushes on | Small print | materials |
| the ink. A small | head size | required in |
| actuator moves a | | print head |
| catch, which |
| selectively |
| prevents the |
| paddle from |
| moving. |
ACTUATOR AMPLIFICATION OR MODIFICATION METHOD |
None | No actuator | Operational | Many | Thermal |
| mechanical | simplicity | actuator | Bubble |
| amplification | | mechanisms | Ink jet |
| is used. The | | have | IJ01, IJ02, |
| actuator directly | | insufficient | IJ06, IJ07, |
| drives the drop | | travel, or | IJ16, IJ25, |
| ejection process. | | insufficient | IJ26 |
| | | force, to |
| | | efficiently |
| | | drive the |
| | | drop |
| | | ejection |
| | | process |
Differ- | An actuator | Provides | High stresses | Piezoelectric |
ential | material expands | greater | are involved | IJ03, IJ09, |
expansion | more on one side | travel in a | Care must be | IJ17, IJ18, |
bend | than on the other. | reduced print | taken that | IJ19, IJ20, |
actuator | The expansion | head area | the materials | IJ21, IJ22, |
| may be thermal, | | do not | IJ23, IJ24, |
| piezoelectric, | | delaminate | IJ27, IJ29, |
| magnetostrictive, | | Residual | IJ30, IJ31, |
| or other | | bend | IJ32, IJ33, |
| mechanism. The | | resulting | IJ34, IJ35, |
| bend actuator | | from high | IJ36, IJ37, |
| converts a high | | temperature | IJ38, IJ39, |
| force low travel | | or high | IJ42, IJ43, |
| actuator | | stress | IJ44 |
| mechanism to | | during |
| high travel, | | formation |
| lower force |
| mechanism. |
Transient | A trilayer bend | Very good | High stresses | IJ40, IJ41 |
bend | actuator where | temperature | are involved |
actuator | the two outside | stability | Care must be |
| layers are | High speed, | taken that |
| identical. This | as a new | the materials |
| cancels bend due | drop can be | do not |
| to ambient | fired before | delaminate |
| temperature and | heat |
| residual stress. | dissipates |
| The actuator only | Cancels |
| responds to | residual |
| transient heating | stress of |
| of one side | formation |
| or the other. |
Reverse | The actuator | Better | Fabrication | IJ05, IJ11 |
spring | loads a spring. | coupling to | complexity |
| When the actuator | the ink | High stress |
| is turned off, the | | in the spring |
| spring releases. |
| This can reverse |
| the force/distance |
| curve of the |
| actuator to make |
| it compatible with |
| the force/time |
| requirements of |
| the drop ejection. |
Actuator | A series of thin | Increased | Increased | Some |
stack | actuators are | travel | fabrication | piezoelectric |
| stacked. This can | Reduced | complexity | ink jets |
| be appropriate | drive | Increased | IJ04 |
| where actuators | voltage | possibility |
| require high | | of short |
| electric field | | circuits |
| strength, such as | | due to |
| electrostatic and | | pinholes |
| piezoelectric |
| actuators. |
Multiple | Multiple smaller | Increases | Actuator | IJ12, IJ13, |
actuators | actuators are used | the force | forces | IJ18, IJ20, |
| simultaneously to | available | may not add | IJ22, IJ28, |
| move the ink. | from an | linearly, | IJ42, IJ43 |
| Each actuator | actuator | reducing |
| need provide only | Multiple | efficiency |
| a portion of the | actuators |
| force required. | can be |
| | positioned |
| | to control |
| | ink flow |
| | accurately |
Linear | A linear spring is | Matches | Requires | IJ15 |
Spring | used to transform | low travel | print head |
| a motion with | actuator | area for |
| small travel and | with higher | the spring |
| high force into a | travel |
| longer travel, | requirements |
| lower force | Non-contact |
| motion. | method of |
| | motion trans- |
| | formation |
Coiled | A bend actuator is | Increases | Generally | IJ17, IJ21, |
actuator | coiled to provide | travel | restricted | IJ34, IJ35 |
| greater travel in a | Reduces | to planar |
| reduced chip area. | chip area | imple- |
| | Planar | mentations |
| | imple- | due to |
| | mentations | extreme |
| | are relatively | fabrication |
| | easy to | difficulty |
| | fabricate. | in other |
| | | orientations. |
Flexure | A bend actuator | Simple | Care must be | IJ10, IJ19, |
bend | has a small region | means of | taken not to | IJ33 |
actuator | near the fixture | increasing | exceed the |
| point, which | travel of | elastic limit |
| flexes much more | a bend | in the flexure |
| readily than the | actuator | area |
| remainder of the | | Stress |
| actuator. The | | distribution |
| actuator flexing | | is very |
| is effectively | | uneven |
| converted from an | | Difficult to |
| even coiling to an | | accurately |
| angular bend, | | model with |
| resulting in | | finite |
| greater travel of | | element |
| the actuator tip. | | analysis |
Catch | The actuator | Very low | Complex | IJ10 |
| controls a small | actuator | construction |
| catch. The catch | energy | Requires |
| either enables | Very small | external |
| or disables | actuator size | force |
| movement | Unsuitable |
| of an ink pusher | | for |
| that is controlled | | pigmented |
| in a bulk manner. | | inks |
Gears | Gears can be used | Low force, | Moving parts | IJ13 |
| to increase travel | low travel | are required |
| at the expense of | actuators | Several |
| duration. Circular | can be used | actuator |
| gears, rack and | Can be | cycles |
| pinion, ratchets, | fabricated | are required |
| and other gearing | using | More |
| methods can be | standard | complex |
| used. | surface | drive |
| | MEMS | electronics |
| | processes | Complex |
| | | construction |
| | | Friction, |
| | | friction, and |
| | | wear are |
| | | possible |
Buckle | A buckle plate | Very fast | Must stay | S. Hirata |
plate | can be used to | movement | within | et al, “An |
| change a slow | achievable | elastic limits | Ink-jet Head |
| actuator into a | | of the | Using |
| fast motion. It can | | materials for | Diaphragm |
| also convert a | | long device | Micro- |
| high force, low | | life | actuator”, |
| travel actuator | | High stresses | Proc. IEEE |
| into a high | | involved | MEMS, Feb. |
| travel, medium | | Generally | 1996, |
| force motion. | | high power | pp 418-423. |
| | | requirement | IJ18, IJ27 |
Tapered | A tapered | Linearizes | Complex | IJ14 |
magnetic | magnetic pole | the magnetic | construction |
pole | can increase | force/ |
| travel at the | distance |
| expense of force. | curve |
Lever | A lever and | Matches | High | IJ32, IJ36, |
| fulcrum is used | low travel | stress | IJ37 |
| to transform a | actuator with | around the |
| motion with small | higher travel | fulcrum |
| travel and high | requirements |
| force into a | Fulcrum |
| motion with | area has no |
| longer travel and | linear |
| lower force. The | movement, |
| lever can also | and can be |
| reverse the | used for a |
| direction of | fluid seal |
| travel. |
Rotary | The actuator is | High | Complex | IJ28 |
impeller | connected to a | mechanical | construction |
| rotary impeller. A | advantage | Unsuitable |
| small angular | The ratio of | for |
| deflection of the | force to | pigmented |
| actuator results in | travel of the | inks |
| a rotation of the | actuator |
| impeller vanes, | can be |
| which push the | matched to |
| ink against | the nozzle |
| stationary vanes | requirements |
| and out of the | by varying |
| nozzle. | the number |
| | of impeller |
| | vanes |
Acoustic | A refractive or | No moving | Large area | 1993 |
lens | diffractive (e.g. | parts | required | Hadimioglu |
| zone plate) | | Only | et al, EUP |
| acoustic lens | | relevant | 550,192 |
| is used to | | for acoustic | 1993 Elrod |
| concentrate sound | | ink jets | et al, EUP |
| waves. | | | 572,220 |
Sharp | A sharp point is | Simple | Difficult to | Tone-jet |
conductive | used to con- | construction | fabricate |
point | centrate an | | using |
| electrostatic | | standard |
| field. | | VLSI |
| | | processes |
| | | for a |
| | | surface |
| | | ejecting |
| | | ink-jet |
| | | Only |
| | | relevant for |
| | | electrostatic |
| | | ink jets |
Volume | The volume of | Simple | High energy | Hewlett- |
expansion | the actuator | construction | is typically | Packard |
| changes, pushing | in the case | required to | Thermal |
| the ink in all | of thermal | achieve | Ink jet |
| directions. | ink jet | volume | Canon |
| | | expansion. | Bubblejet |
| | | This leads |
| | | to thermal |
| | | stress, |
| | | cavitation, |
| | | and kogation |
| | | in thermal |
| | | ink jet |
| | | imple- |
| | | mentations |
Linear, | The actuator | Efficient | High | IJ01, IJ02, |
normal | moves in a | coupling to | fabrication | IJ04, IJ07, |
to chip | direction normal | ink drops | complexity | IJ11, IJ14 |
surface | to the print head | ejected | may be |
| surface. The | normal to | required to |
| nozzle is typically | | achieve the |
| in the line of | | surface per- |
| movement. | | pendicular |
| | | motion |
Parallel | The actuator | Suitable for | Fabrication | IJ12, IJ13, |
to chip | moves parallel to | planar | complexity | IJ15, IJ33, |
surface | the print head | fabrication | Friction | IJ34, IJ35, |
| surface. Drop | | Stiction | IJ36 |
| ejection may still |
| be normal to the |
| surface. |
Membrane | An actuator with | The effective | Fabrication | 1982 |
push | a high force but | area of the | complexity | Howkins |
| small area is used | actuator | Actuator size | USP |
| to push a stiff | becomes the | Difficulty of | 4,459,601 |
| membrane that is | membrane | integration |
| in contact with | area | in a VLSI |
| the ink. | | process |
Rotary | The actuator | Rotary | Device | IJ05, IJ08, |
| causes the | levers may | complexity | IJ13, IJ28 |
| rotation of some | be used to | May have |
| element, such a | increase | friction |
| grill or impeller | travel | at a pivot |
| | Small chip | point |
| | area |
| | requirements |
Bend | The actuator | A very | Requires the | 1970 Kyser |
| bends when | small | actuator to | et al USP |
| energized. This | change in | be made | 3,946,398 |
| may be due to | dimensions | from at | 1973 |
| differential | can be | least two | Stemme |
| thermal | converted | distinct | USP |
| expansion, | to a large | layers, or | 3,747,120 |
| piezoelectric | motion. | to have a | IJ03, IJ09, |
| expansion, | | thermal | IJ10, IJ19, |
| magnetostriction, | | difference | IJ23, IJ24, |
| or other form of | | across the | IJ25, IJ29, |
| relative | | actuator | IJ30, IJ31, |
| dimensional | | | IJ33, IJ34, |
| change. | | | IJ35 |
Swivel | The actuator | Allows | Inefficient | IJ06 |
| swivels around a | operation | coupling to |
| central pivot. This | where the | the ink |
| motion is suitable | net linear | motion |
| where there are | force on |
| opposite forces | the paddle |
| applied to | is zero |
| opposite sides of | Small chip |
| the paddle, e.g. | area |
| Lorenz force. | requirements |
Straighten | The actuator is | Can be used | Requires | IJ26, IJ32 |
| normally bent, | with shape | careful |
| and straightens | memory | balance of |
| when energized. | alloys where | stresses to |
| | the austenic | ensure that |
| | phase is | the quiescent |
| | planar | bend is |
| | | accurate |
Double | The actuator | One | Difficult | IJ36, IJ37, |
bend | bends in one | actuator can | to make | IJ38 |
| direction when | be used to | the drops |
| one element is | power two | ejected by |
| energized, and | nozzles. | both bend |
| bends the other | Reduced | directions |
| way when another | chip size. | identical. |
| element is | Not | A small |
| energized. | sensitive | efficiency |
| | to ambient | loss |
| | temperature | compared to |
| | | equivalent |
| | | single bend |
| | | actuators. |
Shear | Energizing the | Can increase | Not readily | 1985 |
| actuator causes a | the effective | applicable | Fishbeck |
| shear motion in | travel of | to other | USP |
| the actuator | piezoelectric | actuator | 4,584,590 |
| material. | actuators | mechanisms |
Radial | The actuator | Relatively | High force | 1970 |
con- | squeezes an ink | easy to | required | Zoltan |
striction | reservoir, forcing | fabricate | Inefficient | USP |
| ink from a | single | Difficult to | 3,683,212 |
| constricted | nozzles | integrate |
| nozzle. | from glass | with VLSI |
| | tubing as | processes |
| | macroscopic |
| | structures |
Coil/ | A coiled actuator | Easy to | Difficult to | IJ17, IJ21, |
uncoil | uncoils or coils | fabricate | fabricate for | IJ34, IJ35 |
| more tightly. The | as a planar | non-planar |
| motion of the free | VLSI | devices |
| end of the | process | Poor out-of- |
| actuator ejects | Small area | plane |
| the ink. | required, | stiffness |
| | therefore |
| | low cost |
Bow | The actuator | Can increase | Maximum | IJ16, IJ18, |
| bows (or buckles) | the speed | travel is | IJ27 |
| in the middle | of travel | constrained |
| when energized. | Mechanic- | High force |
| | ally rigid | required |
Push-Pull | Two actuators | The | Not readily | IJ18 |
| control a shutter. | structure is | suitable for |
| One actuator pulls | pinned at | ink jets |
| the shutter, and | both ends, | which |
| the other pushes | so has a | directly |
| it. | high out-of- | push |
| | plane rigidity | the ink |
Curl | A set of actuators | Good fluid | Design | IJ20, IJ42 |
inwards | curl inwards to | flow to | complexity |
| reduce the | the region |
| volume of ink | behind the |
| that they enclose. | actuator |
| | increases |
| | efficiency |
Curl | A set of actuators | Relatively | Relatively | IJ43 |
outwards | curl outwards, | simple | large chip |
| pressurizing ink | construction | area |
| in a chamber |
| surrounding the |
| actuators, and |
| expelling ink |
| from a nozzle in |
| the chamber. |
Iris | Multiple vanes | High | High | IJ22 |
| enclose a volume | efficiency | fabrication |
| of ink. These | Small chip | complexity |
| simultaneously | area | Not suitable |
| rotate, reducing | | for |
| the volume | | pigmented |
| between the | | inks |
| vanes. |
Acoustic | The actuator | The | Large area | 1993 |
vibration | vibrates at a high | actuator | required for | Hadimioglu |
| frequency. | can be | efficient | et al, EUP |
| | physically | operation at | 550,192 |
| | distant from | useful | 1993 Elrod |
| | the ink | frequencies | et al, EUP |
| | | Acoustic | 572,220 |
| | | coupling and |
| | | crosstalk |
| | | Complex |
| | | drive |
| | | circuitry |
| | | Poor control |
| | | of drop |
| | | volume |
| | | and position |
None | In various ink jet | No moving | Various | Silverbrook, |
| designs the | parts | other | EP 0771 |
| actuator does | | tradeoffs are | 658 A2 |
| not move. | | required to | and related |
| | | eliminate | patent |
| | | moving parts | applications |
| | | | Tone-jet |
Surface | This is the normal | Fabrication | Low speed | Thermal |
tension | way that ink jets | simplicity | Surface | ink jet |
| are refilled. After | Operational | tension force | Piezoelectric |
| the actuator is | simplicity | relatively | ink jet |
| energized, it | | small | IJ01-IJ07, |
| typically returns | | compared to | IJ10-IJ14, |
| rapidly to its | | actuator | IJ16, IJ20, |
| normal position. | | force | IJ22-IJ45 |
| This rapid return | | Long refill |
| sucks in air | | time usually |
| through the | | dominates |
| nozzle opening. | | the total |
| The ink surface | | repetition |
| tension at the | | rate |
| nozzle then exerts |
| a small force |
| restoring the |
| meniscus to a |
| minimum area. |
| This force refills |
| the nozzle. |
Shuttered | Ink to the nozzle | High speed | Requires | IJ08, IJ13, |
oscillating | chamber is | Low actuator | common ink | IJ15, IJ17, |
ink | provided at a | energy, as | pressure | IJ18, IJ19, |
pressure | pressure that | the actuator | oscillator | IJ21 |
| oscillates at twice | need only | May not be |
| the drop ejection | open or | suitable for |
| frequency. When | close the | pigmented |
| a drop is to be | shutter, | inks |
| ejected, the | instead |
| shutter is opened | of ejecting |
| for 3 half cycles: | the ink |
| drop ejection, | drop |
| actuator return, |
| and refill. The |
| shutter is then |
| closed to prevent |
| the nozzle |
| chamber |
| emptying during |
| the next negative |
| pressure cycle. |
Refill | After the main | High speed, | Requires two | IJ09 |
actuator | actuator has | as the | independent |
| ejected a drop a | nozzle is | actuators |
| second (refill) | actively | per nozzle |
| actuator is | refilled |
| energized. The |
| refill actuator |
| pushes ink into |
| the nozzle |
| chamber. The |
| refill actuator |
| returns slowly, to |
| prevent its return |
| from emptying |
| the chamber |
| again. |
Positive | The ink is held a | High refill | Surface spill | Silverbrook, |
ink | slight positive | rate, | must be | EP 0771 |
pressure | pressure. After | therefore a | prevented | 658 A2 |
| the ink drop is | high drop | Highly | and related |
| ejected, the | repetition | hydrophobic | patent |
| nozzle chamber | rate is | print head | applications |
| fills quickly as | possible | surfaces are | Alternative |
| surface tension | | required | for:, |
| and ink pressure | | | IJ01-IJ07, |
| both operate to | | | IJ10-IJ14, |
| refill the nozzle. | | | IJ16, IJ20, |
| | | | IJ22-IJ45 |
METHOD OF RESTRICTING BACK-FLOW THROUGH INLET |
Long inlet | The ink inlet | Design | Restricts | Thermal |
channel | channel to the | simplicity | refill rate | ink jet |
| nozzle chamber is | Operational | May result | Piezoelectric |
| made long and | simplicity | in a | ink jet |
| relatively narrow, | Reduces | relatively | IJ42, IJ43 |
| relying on viscous | crosstalk | large chip |
| drag to reduce | | area |
| inlet back-flow. | | Only |
| | | partially |
| | | effective |
Positive | The ink is under a | Drop | Requires a | Silverbrook, |
ink | positive pressure, | selection and | method | EP 0771 |
pressure | so that in the | separation | (such as a | 658 A2 |
| quiescent state | can forces | nozzle rim | and related |
| some of the ink | be reduced | or effective | patent |
| drop already | Fast refill | hydro- | applications |
| protrudes from | time | phobizing, | Possible |
| the nozzle. | | or both) to | operation |
| This reduces the | | prevent | of the |
| pressure in the | | flooding | following: |
| nozzle chamber | | of the | IJ01-IJ07, |
| which is required | | ejection | IJ09-IJ12, |
| to eject a certain | | surface of | IJ14, IJ16, |
| volume of ink. | | the print | IJ20, IJ22, |
| The reduction in | | head. | IJ23-IJ34, |
| chamber pressure | | | IJ36-IJ41, |
| results in a | | | IJ44 |
| reduction in ink |
| pushed out |
| through the inlet. |
Baffle | One or more | The refill | Design | HP Thermal |
| baffles are placed | rate is not | complexity | Ink Jet |
| in the inlet ink | as restricted | May increase | Tektronix |
| flow. When the | as the long | fabrication | piezoelectric |
| actuator is | inlet method. | complexity | ink jet |
| energized, the | Reduces | (e.g. |
| rapid ink | crosstalk | Tektronix |
| movement creates | | hot melt |
| eddies which | | Piezoelectric |
| restrict the flow | | print heads). |
| through the |
| inlet. The slower |
| refill process is |
| unrestricted, and |
| does not result in |
| eddies. |
Flexible | In this method | Significantly | Not | Canon |
flap | recently disclosed | reduces | applicable |
restricts | by Canon, the | backflow | to most ink |
inlet | expanding | for edge- | jet con- |
| actuator (bubble) | shooter | figurations |
| pushes on a | thermal | Increased |
| flexible flap that | ink jet | fabrication |
| restricts the inlet. | devices | complexity |
| | | Inelastic |
| | | deformation |
| | | of polymer |
| | | flap results |
| | | in creep over |
| | | extended |
| | | use |
| | |
| | |
| | |
Inlet | A filter is located | Additional | Restricts | IJ04, IJ12, |
filter | between the ink | advantage | refill rate | IJ24, IJ27, |
| inlet and the | of ink | May result | IJ29, IJ30 |
| nozzle chamber. | filtration | in complex |
| The filter has a | Ink filter | construction |
| multitude of small | may be |
| holes or slots, | fabricated |
| restricting ink | with no |
| flow. The filter | additional |
| also removes | process |
| particles which | steps |
| may block the |
| nozzle. |
Small | The ink inlet | Design | Restricts | IJ02, IJ37, |
inlet | channel to the | simplicity | refill rate | IJ44 |
compared | nozzle chamber | | May result |
to nozzle | has a substantially | | in a |
| smaller cross | | relatively |
| section than that | | large chip |
| of the nozzle, | | area |
| resulting in easier | | Only |
| ink egress out of | | partially |
| the nozzle than | | effective |
| out of the inlet. |
Inlet | A secondary | Increases | Requires | IJ09 |
shutter | actuator controls | speed of | separate |
| the position of a | the inkjet | refill |
| shutter, closing | print head | actuator |
| off the ink inlet | operation | and drive |
| when the main | | circuit |
| actuator is | |
| energized. |
The inlet | The method | Back-flow | Requires | IJ01, IJ03, |
is located | avoids the | problem is | careful | IJ05, IJ06, |
behind | problem of inlet | eliminated | design to | IJ07, IJ10, |
the ink- | back-flow by | | minimize the | IJ11, IJ14, |
pushing | arranging the ink- | | negative | IJ16, IJ22, |
surface | pushing surface | | pressure | IJ23, IJ25, |
| of the actuator | | behind | IJ28, IJ31, |
| between the inlet | | the paddle | IJ32, IJ33, |
| and the nozzle. | | | IJ34, IJ35, |
| | | | IJ36, IJ39, |
| | | | IJ40, IJ41 |
Part of | The actuator and | Significant | Small | IJ07, IJ20, |
the | a wall of the ink | reductions in | increase in | IJ26, IJ38 |
actuator | chamber are | back-flow | fabrication |
moves to | arranged so that | can be | complexity |
shut off | the motion of the | achieved |
the inlet | actuator closes off | Compact |
| the inlet. | designs |
| | possible |
Nozzle | In some | Ink back- | None related | Silverbrook, |
actuator | configurations of | flow | to ink | EP 0771 |
does not | ink jet, there is | problem is | back-flow | 658 A2 |
result in | no expansion or | eliminated | on actuation | and related |
ink back- | movement of an | | | patent |
flow | actuator which | | | applications |
| may cause ink | | | Valve-jet |
| back-flow | | | Tone-jet |
| through the inlet. |
Normal | All of the nozzles | No added | May not be | Most ink jet |
nozzle | are fired | complexity | sufficient | systems |
firing | periodically, | on the | to displace | IJ01, IJ02, |
| before the ink has | print head | dried | IJ03, IJ04, |
| a chance to dry. | | ink | IJ05, IJ06, |
| When not in use | | | IJ07, IJ09, |
| the nozzles are | | | IJ10, IJ11, |
| sealed (capped) | | | IJ12, IJ14, |
| against air. | | | IJ16, IJ20, |
| The nozzle firing | | | IJ22, IJ23, |
| is usually | | | IJ24, IJ25, |
| performed during | | | IJ26, IJ27, |
| a special clearing | | | IJ28, IJ29, |
| cycle, after first | | | IJ30, IJ31, |
| moving the print | | | IJ32, IJ33, |
| head to a cleaning | | | IJ34, IJ36, |
| station. | | | IJ37, IJ38, |
| | | | IJ39, IJ40, |
| | | | IJ41, IJ42, |
| | | | IJ43, IJ44, |
| | | | IJ45 |
Extra | In systems which | Can be | Requires | Silverbrook, |
power to | heat the ink, but | highly | higher drive | EP 0771 |
ink heater | do not boil it | effective | voltage for | 658 A2 |
| under normal | if the | clearing | and related |
| situations, nozzle | heater is | May require | patent |
| clearing can be | adjacent to | larger drive | applications |
| achieved by over- | the nozzle | transistors |
| powering the |
| heater and boiling |
| ink at the nozzle. |
Rapid | The actuator is | Does not | Effectiveness | May be used |
succession | fired in rapid | require | depends | with: IJ01, |
of actuator | succession. | extra drive | substantially | IJ02, IJ03, |
pulses | In some | circuits | upon the | IJ04, IJ05, |
| configurations, | on the | configuration | IJ06, IJ07, |
| this may cause | print head | of the ink | IJ09, IJ10, |
| heat build-up at | Can be | jet nozzle | IJ11, IJ14, |
| the nozzle which | readily | | IJ16, IJ20, |
| boils the ink, | controlled | | IJ22, IJ23, |
| clearing the | and initiated | | IJ24, IJ25, |
| nozzle. In other | by digital | | IJ27, IJ28, |
| situations, it may | logic | | IJ29, IJ30, |
| cause sufficient | | | IJ31, IJ32, |
| vibrations to | | | IJ33, IJ34, |
| dislodge clogged | | | IJ36, IJ37, |
| nozzles. | | | IJ38, IJ39, |
| | | | IJ40, IJ41, |
| | | | IJ42, IJ43, |
| | | | IJ44, IJ45 |
Extra | Where an actuator | A simple | Not suitable | May be used |
power to | is not normally | solution | where there | with: IJ03, |
ink | driven to the limit | where | is a hard | IJ09, IJ16, |
pushing | of its motion, | applicable | limit to | IJ20, IJ23, |
actuator | nozzle clearing | | actuator | IJ24, IJ25, |
| may be assisted | | movement | IJ27, IJ29, |
| by providing an | | | IJ30, IJ31, |
| enhanced drive | | | IJ32, IJ39, |
| signal to the | | | IJ40, IJ41, |
| actuator. | | | IJ42, IJ43, |
| | | | IJ44, IJ45 |
Acoustic | An ultrasonic | A high | High | IJ08, IJ13, |
resonance | wave is applied to | nozzle | implement- | IJ15, IJ17, |
| the ink chamber. | clearing | ation | IJ18, IJ19, |
| This wave is of | capability | cost if | IJ21 |
| an appropriate | can be | system |
| amplitude and | achieved | does not |
| frequency to | May be | already |
| cause sufficient | implemented | include |
| force at the | at very low | an acoustic |
| nozzle to clear | cost in | actuator |
| blockages. This is | systems |
| easiest to achieve | which |
| if the ultrasonic | already |
| wave is at a | include |
| resonant | acoustic |
| frequency of the | actuators |
| ink cavity. |
Nozzle | A microfabricated | Can clear | Accurate | Silverbrook, |
clearing | plate is pushed | severely | mechanical | EP 0771 |
plate | against the | clogged | alignment | 658 A2 |
| nozzles. The plate | nozzles | is required | and related |
| has a post for | | Moving | patent |
| every nozzle. A | | parts are | applications |
| post moves | | required |
| through each | | There is |
| nozzle, displacing | | risk of |
| dried ink. | | damage to |
| | | the nozzles |
| | | Accurate |
| | | fabrication |
| | | is required |
Ink | The pressure of | May be | Requires | May be used |
pressure | the ink is | effective | pressure | with all |
pulse | temporarily | where | pump | IJ series |
| increased so that | other | or other | ink jets |
| ink streams from | methods | pressure |
| all of the nozzles. | cannot | actuator |
| This may be used | be used | Expensive |
| in conjunction | | Wasteful |
| with actuator | | of ink |
| energizing. |
Print | A flexible ‘blade’ | Effective | Difficult | Many ink jet |
head | is wiped across | for planar | to use if | systems |
wiper | the print head | print head | print head |
| surface. The | surfaces | surface is |
| blade is usually | Low cost | non-planar |
| fabricated from a | | or very |
| flexible polymer, | | fragile |
| e.g. rubber or | | Requires |
| synthetic | | mechanical |
| elastomer. | | parts |
| | | Blade can |
| | | wear out |
| | | in high |
| | | volume |
| | | print |
| | | systems |
Separate | A separate heater | Can be | Fabrication | Can be used |
ink | is provided at the | effective | complexity | with many IJ |
boiling | nozzle although | where other | series ink |
heater | the normal drop | nozzle | jets |
| e-ection | clearing |
| mechanism does | methods |
| not require it. | cannot |
| The heaters do | be used |
| not require | Can be |
| individual | implemented |
| drive circuits, as | at no |
| many nozzles can | additional |
| be cleared | cost in some |
| simultaneously, | ink jet con- |
| and no imaging is | figurations |
| required. |
Electro- | A nozzle plate is | Fabrication | High | Hewlett |
formed | separately | simplicity | temperatures | Packard |
nickel | fabricated from | | and | Thermal |
| electroformed | | pressures | Ink jet |
| nickel, and | | are required |
| bonded to the | | to bond |
| print head chip. | | nozzle plate |
| | | Minimum |
| | | thickness |
| | | constraints |
| | | Differential |
| | | thermal |
| | | expansion |
Laser | Individual nozzle | No masks | Each hole | Canon |
ablated or | holes are ablated | required | must be | Bubblejet |
drilled | by an intense UV | Can be | individually | 1988 Sercel |
polymer | laser in a nozzle | quite fast | formed | et al., SPIE, |
| plate, which is | Some | Special | Vol. 998 |
| typically a | control over | equipment | Excimer |
| polymer such as | nozzle | required | Beam |
| polyimide or | profile is | Slow where | Applications, |
| polysulphone | possible | there | pp. 76-83 |
| | Equipment | are many | 1993 |
| | required is | thousands of | Watanabe |
| | relatively | nozzles per | et al., USP |
| | low cost | print head | 5,208,604 |
| | | May produce |
| | | thin burrs at |
| | | exit holes |
Silicon | A separate nozzle | High | Two part | K. Bean, |
micro- | plate is | accuracy is | construction | IEEE |
machined | micromachined | attainable | High cost | Transactions |
| from single | | Requires | on Electron |
| crystal silicon, | | precision | Devices, |
| and bonded to the | | alignment | Vol. ED-25, |
| print head wafer. | | Nozzles | No. 10, |
| | | may be | 1978, pp |
| | | clogged | 1185-1195 |
| | | by adhesive | Xerox 1990 |
| | | | Hawkins |
| | | | et al., USP |
| | | | 4,899,181 |
Glass | Fine glass | No | Very small | 1970 Zoltan |
capillaries | capillaries are | expensive | nozzle sizes | USP |
| drawn from glass | equipment | are difficult | 3,683,212 |
| tubing. This | required | to form |
| method has been | Simple to | Not suited |
| used for making | make single | for mass |
| individual | nozzles | production |
| nozzles, but is |
| difficult to |
| use for bulk |
| manufacturing of |
| print heads with |
| thousands of |
| nozzles. |
Mono- | The nozzle plate | High | Requires | Silverbrook, |
lithic, | is deposited as a | accuracy | sacrificial | EP 0771 |
surface | layer using | (<1 μm) | layer | 658 A2 |
micro- | standard VLSI | Monolithic | under the | and related |
machined | deposition | Low cost | nozzle plate | patent |
using | techniques. | Existing | to form | applications |
VLSI | Nozzles are | processes | the nozzle | IJ01, IJ02, |
litho- | etched in the | can be | chamber | IJ04, IJ11, |
graphic | nozzle plate using | used | Surface | IJ12, IJ17, |
processes | VLSI lithography | | may be | IJ18, IJ20, |
| and etching. | | fragile | IJ22, IJ24, |
| | | to the | IJ27, IJ28, |
| | | touch | IJ29, IJ30, |
| | | | IJ31, IJ32, |
| | | | IJ33, IJ34, |
| | | | IJ36, IJ37, |
| | | | IJ38, IJ39, |
| | | | IJ40, IJ41, |
| | | | IJ42, IJ43, |
| | | | IJ44 |
Mono- | The nozzle plate | High | Requires | IJ03, IJ05, |
lithic, | is a buried etch | accuracy | long etch | IJ06, IJ07, |
etched | stop in the wafer. | (<1 μm) | times | IJ08, IJ09, |
through | Nozzle chambers | Monolithic | Requires | IJ10, IJ13, |
substrate | are etched in the | Low cost | a support | IJ14, IJ15, |
| front of the wafer, | No | wafer | IJ16, IJ19, |
| and the wafer is | differential | | IJ21, IJ23, |
| thinned from the | expansion | | IJ25, IJ26 |
| back side. |
| Nozzles are then |
| etched in the etch |
| stop layer. |
No nozzle | Various methods | No nozzles | Difficult to | Ricoh 1995 |
plate | have been tried to | to become | control drop | Sekiya |
| eliminate the | clogged | position | et al USP |
| nozzles entirely, | | accurately | 5,412,413 |
| to prevent nozzle | | Crosstalk | 1993 |
| clogging. These | | problems | Hadimioglu |
| include thermal | | | et al EUP |
| bubble | | | 550,192 |
| mechanisms and | | | 1993 Elrod |
| acoustic lens | | | et al EUP |
| mechanisms | | | 572,220 |
Trough | Each drop ejector | Reduced | Drop firing | IJ35 |
| has a trough | manu- | direction is |
| through which a | facturing | sensitive to |
| paddle moves. | complexity | wicking. |
| There is no | Monolithic |
| nozzle plate. |
Nozzle slit | The elimination | No nozzles | Difficult to | 1989 Saito |
instead of | of nozzle holes | to become | control drop | et al USP |
individual | and replacement | clogged | position | 4,799,068 |
nozzles | by a slit | | accurately |
| encompassing | | Crosstalk |
| many actuator | | problems |
| positions reduces |
| nozzle clogging, |
| but increases |
| crosstalk due to |
| ink surface waves |
Edge | Ink flow is along | Simple | Nozzles | Canon |
(‘edge | the surface of the | construction | limited to | Bubblejet |
shooter’) | chip, and ink | No silicon | edge | 1979 |
| drops are ejected | etching | High | Endo et al |
| from the chip | required | resolution is | GB patent |
| edge. | Good heat | difficult | 2,007,162 |
| | sinking via | Fast color | Xerox |
| | substrate | printing | heater-in-pit |
| | Mech- | requires one | 1990 |
| | anically | print head | Hawkins |
| | strong | per color | et al USP |
| | Ease of chip | | 4,899,181 |
| | handing | | Tone-jet |
Surface | Ink flow is along | No bulk | Maximum | Hewlett- |
(‘roof | the surface of the | silicon | ink flow is | Packard TIJ |
shooter’) | chip, and ink | etching | severely | 1982 Vaught |
| drops are ejected | required | restricted | et al USP |
| from the chip | Silicon can | | 4,490,728 |
| surface, normal to | make an | | IJ02, IJ11, |
| the plane of the | effective | | IJ12, IJ20, |
| chip. | heat sink | | IJ22 |
| | Mechanical |
| | strength |
Through | Ink flow is | High ink | Requires | Silverbrook, |
chip, | through the chip, | flow | bulk silicon | EP 0771 |
forward | and ink drops are | Suitable | etching | 658 A2 |
(‘up | ejected from the | for | | and related |
shooter’) | front surface of | pagewidth | | patent |
| the chip. | print heads | | applications |
| | High nozzle | | IJ04, IJ17, |
| | packing | | IJ18, IJ24, |
| | density | | IJ27-IJ45 |
| | therefore |
| | low manu- |
| | facturing |
| | cost |
Through | Ink flow is | High ink | Requires | IJ01, IJ03, |
chip, | through the chip, | flow | wafer | IJ05, IJ06, |
reverse | and ink drops are | Suitable for | thinning | IJ07, IJ08, |
(‘down | ejected from the | pagewidth | Requires | IJ09, IJ10, |
shooter’) | rear surface of | print heads | special | IJ13, IJ14, |
| the chip. | High nozzle | handling | IJ15, IJ16, |
| | packing | during | IJ19, IJ21, |
| | density | manufacture | IJ23, IJ25, |
| | therefore | | IJ26 |
| | low manu- |
| | facturing |
| | cost |
Through | Ink flow is | Suitable for | Pagewidth | Epson |
actuator | through the | piezoelectric | print heads | Stylus |
| actuator, which is | print heads | require | Tektronix |
| not fabricated as | | several | hot melt |
| part of the same | | thousand | piezoelectric |
| substrate as the | | connections | ink jets |
| drive transistors. | | to drive |
| | | circuits |
| | | Cannot be |
| | | manu- |
| | | factured |
| | | in standard |
| | | CMOS fabs |
| | | Complex |
| | | assembly |
| | | required |
Aqueous, | Water based ink | Environ- | Slow drying | Most |
dye | which typically | mentally | Corrosive | existing |
| contains: water, | friendly | Bleeds on | ink jets |
| dye, surfactant, | No odor | paper | All IJ series |
| humectant, and | | May | ink jets |
| biocide. | | strikethrough | Silverbrook, |
| Modem ink dyes | | Cockles | EP 0771 |
| have high water- | | paper | 658 A2 |
| fastness, light | | | and related |
| fastness | | | patent |
| | | | applications |
Aqueous, | Water based ink | Environ- | Slow drying | IJ02, IJ04, |
pigment | which typically | mentally | Corrosive | IJ21, IJ26, |
| contains: water, | friendly | Pigment | IJ27, IJ30 |
| pigment, | No odor | may clog | Silverbrook, |
| surfactant, | Reduced | nozzles | EP 0771 |
| humectant, and | bleed | Pigment | 658 A2 |
| biocide. | Reduced | may clog | and related |
| Pigments have an | wicking | actuator | patent |
| advantage in | Reduced | mechanisms | applications |
| reduced bleed, | strike- | Cockles | Piezoelectric |
| wicking and | through | paper | ink-jets |
| strikethrough. | | | Thermal ink |
| | | | jets (with |
| | | | significant |
| | | | restrictions) |
Methyl | MEK is a highly | Very fast | Odorous | All IJ |
Ethyl | volatile solvent | drying | Flammable | series |
Ketone | used for industrial | Prints on | | ink jets |
(MEK) | printing on | various |
| difficult surfaces | substrates |
| such as aluminum | such as |
| cans. | metals and |
| | plastics |
Alcohol | Alcohol based | Fast drying | Slight odor | All IJ |
(ethanol, | inks can be used | Operates at | Flammable | series |
2-butanol, | where the printer | sub-freezing | | ink jets |
and | must operate at | temperatures |
others) | temperatures | Reduced |
| below the | paper cockle |
| freezing point | Low cost |
| of water. An |
| example of this |
| is in-camera |
| consumer |
| photographic |
| printing. |
Phase | The ink is solid | No drying | High | Tektronix |
change | at room | time—ink | viscosity | hot melt |
(hot melt) | temperature, | instantly | Printed ink | piezoelectric |
| and is melted in | freezes on | typically has | ink jets |
| the print head | the print | a ‘waxy’ feel | 1989 Nowak |
| before jetting. | medium | Printed | USP |
| Hot melt inks are | Almost any | pages may | 4,820,346 |
| usually wax | print | ‘block’ | All IJ series |
| based, with a | medium can | Ink | ink jets |
| melting point | be used | temperature |
| around 80° C. | No paper | may be |
| After jetting | cockle | above the |
| the ink freezes | occurs | curie point |
| almost instantly | No wicking | of permanent |
| upon contacting | occurs | magnets |
| the print medium | No bleed | Ink heaters |
| or a transfer | occurs | consume |
| roller. | No | power |
| | strikethrough | Long warm |
| | occurs | up time |
Oil | Oil based inks are | High | High | All IJ |
| extensively used | solubility | viscosity: | series |
| in offset printing, | medium for | this is a | ink jets |
| They have | some dyes | significant |
| advantages in | Does not | limitation |
| improved | cockle | for use in |
| characteristics on | paper | ink jets, |
| paper (especially | Does not | which |
| no wicking or | wick through | usually |
| cockle). Oil | paper | require |
| soluble dies and | | a low |
| pigments are | | viscosity. |
| required. | | Some short |
| | | chain and |
| | | multi- |
| | | branched |
| | | oils have a |
| | | sufficiently |
| | | low |
| | | viscosity. |
| | | Slow drying |
| | | |
Micro- | A microemulsion | Stops ink | Viscosity | All IJ |
emulsion | is a stable, self | bleed | higher than | series |
| forming emulsion | High dye | water | ink jets |
| of oil, water, and | solubility | Cost is |
| surfactant. The | Water, | slightly |
| characteristic | oil, and | higher than |
| drop size is less | amphiphilic | water |
| than 100 nm, and | soluble | based ink |
| is determined by | dies can | High |
| the preferred | be used | surfactant |
| curvature of the | Can stabilize | con- |
| surfactant. | pigment | centration |
| | suspensions | required |
| | | (around 5%) |
|