# Patent

## Title
Refillable ink supply cartridge for a postcard printing camera system

## Abstract

The invention relates to a refillable ink supply cartridge for a postcard printing camera system. The cartridge includes a pagewidth printhead having a series of holes etched on a back surface thereof for the supply of ink to a front surface of the printhead for subsequent ejection via a micro-electromechanical system. The cartridge also includes an elongate top molding piece and an elongate bottom molding piece configured to operatively receive the top molding piece to define a plurality of elongate ink reservoirs, said bottom molding piece supporting the printhead and having guide walls and block portions for arranging the ink reservoirs in fluid communication with the series of holes.

## Background
CROSS REFERENCE TO RELATED APPLICATION
The present application is a Continuation of U.S. application Ser. No. 10/846,647 filed on May 17, 2004, now issued U.S. Pat. No. 7,334,855, which is a Continuation of U.S. application Ser. No. 09/663,153 filed on Sep. 15, 2000, now issued U.S. Pat. No. 6,738,096, which is a divisional of and claims the benefit of U.S. application Ser. No. 09/113,086 filed on Jul. 10, 1998 now abandoned, the entire contents of which are herein incorporated by reference.


FIELD OF THE INVENTION
The present invention relates substantially to the concept of a disposable camera having instant printing capabilities and in particular, discloses a method integrating the electronic components of a camera system.
BACKGROUND OF THE INVENTION
Recently, the concept of a “single use” disposable camera has become an increasingly popular consumer item. Disposable camera systems presently on the market normally include an internal film roll and a simplified gearing mechanism for traversing the film roll across an imaging system including a shutter and lensing system. The user, after utilizing a single film roll returns the camera system to a film development center for processing. The film roll is taken out of the camera system and processed and the prints returned to the user. The camera system is then able to be re-manufactured through the insertion of a new film roll into the camera system, the replacement of any worn or wearable parts and the re-packaging of the camera system in accordance with requirements. In this way, the concept of a single use “disposable” camera is provided to the consumer.
Recently, a camera system has been proposed by the present applicant which provides for a handheld camera device having an internal print head, image sensor and processing means such that images sense by the image sensing means, are processed by the processing means and adapted to be instantly printed out by the printing means on demand. The proposed camera system further discloses a system of internal “print rolls” carrying print media such as film on to which images are to be printed in addition to ink for supplying to the printing means for the printing process. The print roll is further disclosed to be detachable and replaceable within the camera system.
Unfortunately, such a system is likely to only be constructed at a substantial cost and it would be desirable to provide for a more inexpensive form of instant camera system which maintains a substantial number of the quality aspects of the aforementioned arrangement.
It would be further advantageous to provide for the effective interconnection of the sub components of a camera system.
SUMMARY OF THE INVENTION
According to the invention, there is provided a recyclable, one-time use, print on demand, digital camera comprising:
an image sensor device for sensing an image;
a processing means for processing said sensed image;
a pagewidth print head for printing said sensed image;
an ink supply means for supplying ink to the print head; and
a supply of print media on to which said image is printed, the supply of print media being pre-marked with tokens designating that postage has been paid so that each image printed out on the print media has one such token associated with it.
Preferably, the supply of print media is in the form of a roll, the tokens being pre-printed at regularly spaced intervals on one surface of the print media.
Each token may have an address zone and a blank zone for writing associated with it on said one surface to provide a postcard effect.
Each image may be printed on an opposed surface of the print media.
The token may be in the form of a postage stamp which is in a currency of a country in which the camera is bought, with a notice to that effect being carried on an exterior of that camera. Preferably, the camera has a sleeve placed about a casing of the camera. The notice may then be carried on the sleeve of the camera.



BRIEF DESCRIPTION OF THE DRAWINGS
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:
FIG. 1 illustrates a front perspective view of the assembled camera of the preferred embodiment;
FIG. 2 illustrates a rear perspective view, partly exploded, of the preferred embodiment;
FIG. 3 is a perspective view of the chassis of the preferred embodiment;
FIG. 4 is a perspective view of the chassis illustrating mounting of electric motors;
FIG. 5 is an exploded perspective view of the ink supply mechanism of the preferred embodiment;
FIG. 6 is a rear perspective view of the assembled form of the ink supply mechanism of the preferred embodiment;
FIG. 7 is a front perspective view of the assembled form of the ink supply mechanism of the preferred embodiment;
FIG. 8 is an exploded perspective view of the platten unit of the preferred embodiment;
FIG. 9 is a perspective view of the assembled form of the platten unit;
FIG. 10 is also a perspective view of the assembled form of the platten unit;
FIG. 11 is an exploded perspective view of the printhead recapping mechanism of the preferred embodiment;
FIG. 12 is a close up, exploded perspective view of the recapping mechanism of the preferred embodiment;
FIG. 13 is an exploded perspective view of the ink supply cartridge of the preferred embodiment;
FIG. 14 is a close up, perspective view, partly in section, of the internal portions of the ink supply cartridge in an assembled form;
FIG. 15 is a schematic block diagram of one form of chip layer of the image capture and processing chip of the preferred embodiment;
FIG. 16 is an exploded perspective view illustrating the assembly process of the preferred embodiment;
FIG. 17 illustrates a front exploded perspective view of the assembly process of the preferred embodiment;
FIG. 18 illustrates a perspective view of the assembly process of the preferred embodiment;
FIG. 19 illustrates a perspective view of the assembly process of the preferred embodiment;
FIG. 20 is a perspective view illustrating the insertion of the platten unit in the preferred embodiment;
FIG. 21 illustrates the interconnection of the electrical components of the preferred embodiment;
FIG. 22 illustrates the process of assembling the preferred embodiment; and
FIG. 23 is a perspective view further illustrating the assembly process of the preferred embodiment.



DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS
Turning initially simultaneously to FIG. 1 and FIG. 2 there are illustrated perspective views of an assembled camera constructed in accordance with the preferred embodiment with FIG. 1 showing a front perspective view and FIG. 2 showing a rear perspective view. The camera 1 includes a paper or plastic film jacket 2 which can include simplified instructions 3 for the operation of the camera system 1. The camera system 1 includes a first “take” button 4 which is depressed to capture an image. The captured image is output via output slot 6. A further copy of the image can be obtained through depressing a second “printer copy” button 7 whilst an LED light 5 is illuminated. The camera system also provides the usual viewfinder 8 in addition to a CCD image capture/lensing system 9.
The camera system 1 provides for a standard number of output prints after which the camera system 1 ceases to function. A prints left indicator slot 10 is provided to indicate the number of remaining prints. A refund scheme at the point of purchase is assumed to be operational for the return of used camera systems for recycling.
Turning now to FIG. 3, the assembly of the camera system is based around an internal chassis 12 which can be a plastic injection molded part. A pair of paper pinch rollers 28, 29 utilized for de-curling are snap fitted into corresponding frame holes eg. 26, 27.
As shown in FIG. 4, the chassis 12 includes a series of mutually opposed prongs e.g. 13, 14 into which is snapped fitted a series of electric motors 16, 17. The electric motors 16, 17 can be entirely standard with the motor 16 being of a stepper motor type. The motors 16,17 include cogs 19, 20 for driving a series of gear wheels. A first set of gear wheels is provided for controlling a paper cutter mechanism and a second set is provided for controlling print roll movement.
Turning next to FIGS. 5 to 7, there is illustrated an ink supply mechanism 40 utilized in the camera system. FIG. 5 illustrates a rear exploded perspective view, FIG. 6 illustrates a rear assembled perspective view and FIG. 7 illustrates a front assembled view. The ink supply mechanism 40 is based around an ink supply cartridge 42 which contains printer ink and a print head mechanism for printing out pictures on demand. The ink supply cartridge 42 includes a side aluminum strip 43 which is provided as a shear strip to assist in cutting images from a paper roll.
A dial mechanism 44 is provided for indicating the number of “prints left”. The dial mechanism 44 is snap fitted through a corresponding mating portion 46 so as to be freely rotatable.
As shown in FIG. 6, the mechanism 40 includes a flexible PCB strip 47 which interconnects with the print head and provides for control of the print head. The interconnection between the Flex PCB strip and an image sensor and print head chip can be via Tape Automated Bonding (TAB) strips 51, 58. A molded aspherical lens and aperture shim 50 (FIG. 5) is also provided for imaging an image onto the surface of the image sensor chip normally located within cavity 53 and a light box module or hood 52 is provided for snap fitting over the cavity 53 so as to provide for proper light control. A series of decoupling capacitors e.g. 34 can also be provided. Further a plug 45 (FIG. 7) is provided for re-plugging ink holes after refilling. A series of guide prongs e.g. 55-57 are further provided for guiding the flexible PCB strip 47.
The ink supply mechanism 40 interacts with a platten unit 60 which guides print media under a printhead located in the ink supply mechanism. FIG. 8 shows an exploded view of the platten unit 60, while FIGS. 9 and 10 show assembled views of the platten unit. The platten unit 60 includes a first pinch roller 61 which is snap fitted to one side of a platten base 62. Attached to a second side of the platten base 62 is a cutting mechanism 63 which traverses the platen unit 60 by means of a rod 64 having a screw thread which is rotated by means of cogged wheel 65 which is also fitted to the platten base 62. The screw threaded rod 64 mounts a block 67 which includes a cutting wheel 68 fastened via a fastener 69. Also mounted to the block 67 is a counter actuator which includes a pawl. The pawl 71 acts to rotate the dial mechanism 44 of FIG. 6 upon the return traversal of the cutting wheel. As shown previously in FIG. 6, the dial mechanism 44 includes a cogged surface which interacts with pawl 71 thereby maintaining a count of the number of photographs by means of numbers embossed on the surface of dial mechanism 44. The cutting mechanism 63 is inserted into the platten base 62 by means of a snap fit via clips e.g. 74.
The platen unit 60 includes an internal recapping mechanism 80 for recapping the printhead when not in use. The recapping mechanism 80 includes a sponge portion 81 and is operated via a solenoid coil so as to provide for recapping of the print head. In the preferred embodiment, there is provided an inexpensive form of printhead re-capping mechanism provided for incorporation into a handheld camera system so as to provide for printhead re-capping of an inkjet printhead.
FIG. 11 illustrates an exploded view of the recapping mechanism whilst FIG. 12 illustrates a close up of the end portion thereof. The re-capping mechanism 80 is structured around a solenoid including a 16 turn coil 75 which can comprise insulated wire. The coil 75 is turned around a first stationery solenoid arm 76 which is mounted on a bottom surface of the platen base 62 (FIG. 8) and includes a post portion 77 to magnify effectiveness of operation. The arm 76 can comprise a ferrous material.
A second moveable arm 78 of the solenoid actuator is also provided. The arm 78 is moveable and is also made of ferrous material. Mounted on the arm is a sponge portion surrounded by an elastomer strip 79. The elastomer strip 79 is of a generally arcuate cross-section and acts as a leaf spring against the surface of the printhead ink supply cartridge 42 (FIG. 5) so as to provide for a seal against the surface of the printhead ink supply cartridge 42. In the quiescent position an elastomer spring unit 87, 88 acts to resiliently deform the elastomer seal 79 against the surface of the ink supply unit 42.
When it is desired to operate the printhead unit, upon the insertion of paper, the solenoid coil 75 is activated so as to cause the arm 78 to move down to be adjacent to the end plate 76. The arm 78 is held against end plate 76 while the printhead is printing by means of a small “keeper current” in coil 75. Simulation results indicate that the keeper current can be significantly less than the actuation current. Subsequently, after photo printing, the paper is guillotined by the cutting mechanism 63 of FIG. 8 acting against aluminum strip 43, and rewound so as to clear the area of the re-capping mechanism 80. Subsequently, the current is turned off and springs 87, 88 return the arm 78 so that the elastomer seal is again resting against the printhead ink supply cartridge.
It can be seen that the preferred embodiment provides for a simple and inexpensive means of re-capping a printhead through the utilization of a solenoid type device having a long rectangular form. Further, the preferred embodiment utilizes minimal power in that currents are only required whilst the device is operational and additionally, only a low keeper current is required whilst the printhead is printing.
Turning next to FIGS. 13 and 14, FIG. 13 illustrates an exploded perspective of the ink supply cartridge 42 whilst FIG. 14 illustrates a close up sectional view of a bottom of the ink supply cartridge with the printhead unit in place. The ink supply cartridge 42 is based around a pagewidth printhead 102 which comprises a long slither of silicon having a series of holes etched on the back surface for the supply of ink to a front surface of the silicon wafer for subsequent ejection via a micro electromechanical system. The form of ejection can be many different forms such as those set out in the tables below.
Of course, many other inkjet technologies, as referred to the attached tables below, can also be utilized when constructing a printhead unit 102. The fundamental requirement of the ink supply cartridge 42 is the supply of ink to a series of color channels etched through the back surface of the printhead 102. In the description of the preferred embodiment, it is assumed that a three color printing process is to be utilized so as to provide full color picture output. Hence, the print supply unit includes three ink supply reservoirs being a cyan reservoir 104, a magenta reservoir 105 and a yellow reservoir 106. Each of these reservoirs is required to store ink and includes a corresponding sponge type material 107-109 which assists in stabilizing ink within the corresponding ink channel and inhibiting the ink from sloshing back and forth when the printhead is utilized in a handheld camera system. The reservoirs 104, 105, 106 are formed through the mating of first exterior plastic piece 110 and a second base piece 111.
At a first end 118 of the base piece 111 a series of air inlet 113-115 are provided. Each air inlet leads to a corresponding winding channel which is hydrophobically treated so as to act as an ink repellent and therefore repel any ink that may flow along the air inlet channel. The air inlet channel further takes a convoluted path assisting in resisting any ink flow out of the chambers 104-106. An adhesive tape portion 117 is provided for sealing the channels within end portion 118.
At the top end, there is included a series of refill holes (not shown) for refilling corresponding ink supply chambers 104, 105, 106. A plug 121 is provided for sealing the refill holes.
Turning now to FIG. 14, there is illustrated a close up perspective view, partly in section through the ink supply cartridge 42 of FIG. 13 when formed as a unit. The ink supply cartridge includes the three color ink reservoirs 104, 105, 106 which supply ink to different portions of the back surface of printhead 102 which includes a series of apertures 128 defined therein for carriage of the ink to the front surface.
The ink supply cartridge 42 includes two guide walls 124, 125 which separate the various ink chambers and are tapered into an end portion abutting the surface of the printhead 102. The guide walls 124, 125 are further mechanically supported by block portions e.g. 126 which are placed at regular intervals along the length of the ink supply unit. The block portions 126 have space at portions close to the back of printhead 102 for the flow of ink around the back surface thereof.
The ink supply unit is preferably formed from a multi-part plastic injection mold and the mold pieces e.g. 110, 111 (FIG. 13) snap together around the sponge pieces 107, 109. Subsequently, a syringe type device can be inserted in the ink refill holes and the ink reservoirs filled with ink with the air flowing out of the air outlets 113-115. Subsequently, the adhesive tape portion 117 and plug 121 are attached and the printhead tested for operation capabilities. Subsequently, the ink supply cartridge 42 can be readily removed for refilling by means of removing the ink supply cartridge, performing a washing cycle, and then utilizing the holes for the insertion of a refill syringe filled with ink for refilling the ink chamber before returning the ink supply cartridge 42 to a camera.
Turning now to FIG. 15, there is shown an example layout of the Image Capture and Processing Chip (ICP) 48.
The Image Capture and Processing Chip 48 provides most of the electronic functionality of the camera with the exception of the print head chip. The chip 48 is a highly integrated system. It combines CMOS image sensing, analog to digital conversion, digital image processing, DRAM storage, ROM, and miscellaneous control functions in a single chip.
The chip is estimated to be around 32 mm2 using a leading edge 0.18 micron CMOS/DRAM/APS process. The chip size and cost can scale somewhat with Moore's law, but is dominated by a CMOS active pixel sensor array 201, so scaling is limited as the sensor pixels approach the diffraction limit.
The ICP 48 includes CMOS logic, a CMOS image sensor, DRAM, and analog circuitry. A very small amount of flash memory or other non-volatile memory is also preferably included for protection against reverse engineering.
Alternatively, the ICP can readily be divided into two chips: one for the CMOS imaging array, and the other for the remaining circuitry. The cost of this two chip solution should not be significantly different than the single chip ICP, as the extra cost of packaging and bond-pad area is somewhat cancelled by the reduced total wafer area requiring the color filter fabrication steps.
The ICP preferably contains the following functions:










Function

















1.5 megapixel image sensor



Analog Signal Processors



Image sensor column decoders



Image sensor row decoders



Analogue to Digital Conversion (ADC)



Column ADC's



Auto exposure



12 Mbits of DRAM



DRAM Address Generator



Color interpolator



Convolver



Color ALU



Halftone matrix ROM



Digital halftoning



Print head interface



8 bit CPU core



Program ROM



Flash memory



Scratchpad SRAM



Parallel interface (8 bit)



Motor drive transistors (5)



Clock PLL



JTAG test interface



Test circuits



Busses



Bond pads










The CPU, DRAM, Image sensor, ROM, Flash memory, Parallel interface, JTAG interface and ADC can be vendor supplied cores. The ICP is intended to run on 1.5V to minimize power consumption and allow convenient operation from two AA type battery cells.
FIG. 15 illustrates a layout of the ICP 48. The ICP 48 is dominated by the imaging array 201, which consumes around 80% of the chip area. The imaging array is a CMOS 4 transistor active pixel design with a resolution of 1,500×1,000. The array can be divided into the conventional configuration, with two green pixels, one red pixel, and one blue pixel in each pixel group. There are 750×500 pixel groups in the imaging array.
The latest advances in the field of image sensing and CMOS image sensing in particular can be found in the October, 1997 issue of IEEE Transactions on Electron Devices and, in particular, pages 1689 to 1968. Further, a specific implementation similar to that disclosed in the present application is disclosed in Wong et al., “CMOS Active Pixel Image Sensors Fabricated Using a 1.8V, 0.25 μm CMOS Technology”, IEDM 1996, page 915
The imaging array uses a 4 transistor active pixel design of a standard configuration. To minimize chip area and therefore cost, the image sensor pixels should be as small as feasible with the technology available. With a four transistor cell, the typical pixel size scales as 20 times the lithographic feature size. This allows a minimum pixel area of around 3.6 μm×3.6 μm. However, the photosite must be substantially above the diffraction limit of the lens. It is also advantageous to have a square photosite, to maximize the margin over the diffraction limit in both horizontal and vertical directions. In this case, the photosite can be specified as 2.5 μm×2.5 μm. The photosite can be a photogate, pinned photodiode, charge modulation device, or other sensor.
The four transistors are packed as an ‘L’ shape, rather than a rectangular region, to allow both the pixel and the photosite to be square. This reduces the transistor packing density slightly, increasing pixel size. However, the advantage in avoiding the diffraction limit is greater than the small decrease in packing density.
The transistors also have a gate length which is longer than the minimum for the process technology. These have been increased from a drawn length of 0.18 micron to a drawn length of 0.36 micron. This is to improve the transistor matching by making the variations in gate length represent a smaller proportion of the total gate length.
The extra gate length, and the ‘L’ shaped packing, mean that the transistors use more area than the minimum for the technology. Normally, around 8 μm2 would be required for rectangular packing. Preferably, 9.75 μm2 has been allowed for the transistors.
The total area for each pixel is 16 μm2, resulting from a pixel size of 4 μm×4 μm. With a resolution of 1,500×1,000, the area of the imaging array 101 is 6,000 μm×4,000 μm, or 24 mm2.
The presence of a color image sensor on the chip affects the process required in two major ways:

    
    
        The CMOS fabrication process should be optimised to minimize dark current
    
    


Color filters are required. These can be fabricated using dyed photosensitive polyimides, resulting in an added process complexity of three spin coatings, three photolithographic steps, three development steps, and three hardbakes.
There are 15,000 analog signal processors (ASPs) 205, one for each of the columns of the sensor. The ASPs amplify the signal, provide a dark current reference, sample and hold the signal, and suppress the fixed pattern noise (FPN).
There are 375 analog to digital converters 206, one for each four columns of the sensor array. These may be delta-sigma or successive approximation type ADC's. A row of low column ADC's are used to reduce the conversion speed required, and the amount of analog signal degradation incurred before the signal is converted to digital. This also eliminates the hot spot (affecting local dark current) and the substrate coupled noise that would occur if a single high speed ADC was used. Each ADC also has two four bit DAC's which trim the offset and scale of the ADC to further reduce FPN variations between columns. These DAC's are controlled by data stored in flash memory during chip testing.
The column select logic 204 is a 1:1500 decoder which enables the appropriate digital output of the ADCs onto the output bus. As each ADC is shared by four columns, the least significant two bits of the row select control 4 input analog multiplexors.
A row decoder 207 is a 1:1000 decoder which enables the appropriate row of the active pixel sensor array. This selects which of the 1000 rows of the imaging array is connected to analog signal processors. As the rows are always accessed in sequence, the row select logic can be implemented as a shift register.
An auto exposure system 208 adjusts the reference voltage of the ADC 205 in response to the maximum intensity sensed during the previous frame period. Data from the green pixels is passed through a digital peak detector. The peak value of the image frame period before capture (the reference frame) is provided to a digital to analogue converter (DAC), which generates the global reference voltage for the column ADCs. The peak detector is reset at the beginning of the reference frame. The minimum and maximum values of the three RGB color components are also collected for color correction.
The second largest section of the chip is consumed by a DRAM 210 used to hold the image. To store the 1,500×1,000 image from the sensor without compression, 1.5 Mbytes of DRAM 210 are required. This equals 12 Mbits, or slightly less than 5% of a 256 Mbit DRAM. The DRAM technology assumed is of the 256 Mbit generation implemented using 0.18 μm CMOS.
Using a standard 8F cell, the area taken by the memory array is 3.11 mm2. When row decoders, column sensors, redundancy, and other factors are taken into account, the DRAM requires around 4 mm2.
This DRAM 210 can be mostly eliminated if analog storage of the image signal can be accurately maintained in the CMOS imaging array for the two seconds required to print the photo. However, digital storage of the image is preferable as it is maintained without degradation, is insensitive to noise, and allows copies of the photo to be printed considerably later.
A DRAM address generator 211 provides the write and read addresses to the DRAM 210. Under normal operation, the write address is determined by the order of the data read from the CMOS image sensor 201. This will typically be a simple raster format. However, the data can be read from the sensor 201 in any order, if matching write addresses to the DRAM are generated. The read order from the DRAM 210 will normally simply match the requirements of a color interpolator and the print head. As the cyan, magenta, and yellow rows of the print head are necessarily offset by a few pixels to allow space for nozzle actuators, the colors are not read from the DRAM simultaneously. However, there is plenty of time to read all of the data from the DRAM many times during the printing process. This capability is used to eliminate the need for FIFOs in the print head interface, thereby saving chip area. All three RGB image components can be read from the DRAM each time color data is required. This allows a color space converter to provide a more sophisticated conversion than a simple linear RGB to CMY conversion.
Also, to allow two dimensional filtering of the image data without requiring line buffers, data is re-read from the DRAM array.
The address generator may also implement image effects in certain models of camera. For example, passport photos are generated by a manipulation of the read addresses to the DRAM. Also, image framing effects (where the central image is reduced), image warps, and kaleidoscopic effects can all be generated by manipulating the read addresses of the DRAM.
While the address generator 211 may be implemented with substantial complexity if effects are built into the standard chip, the chip area required for the address generator is small, as it consists only of address counters and a moderate amount of random logic.
A color interpolator 214 converts the interleaved pattern of red, 2× green, and blue pixels into RGB pixels. It consists of three 8 bit adders and associated registers. The divisions are by either 2 (for green) or 4 (for red and blue) so they can be implemented as fixed shifts in the output connections of the adders.
A convolver 215 is provided as a sharpening filter which applies a small convolution kernel (5×5) to the red, green, and blue planes of the image. The convolution kernel for the green plane is different from that of the red and blue planes, as green has twice as many samples. The sharpening filter has five functions:

    
    
        to improve the color interpolation from the linear interpolation provided by the color interpolator, to a close approximation of a sinc interpolation;
        to compensate for the image ‘softening’ which occurs during digitisation;
        to adjust the image sharpness to match average consumer preferences, which are typically for the image to be slightly sharper than reality. As the single use camera is intended as a consumer product, and not a professional photographic products, the processing can match the most popular settings, rather than the most accurate;
        to suppress the sharpening of high frequency (individual pixel) noise. The function is similar to the ‘unsharp mask’ process; and
        to antialias Image Warping.
    
    


These functions are all combined into a single convolution matrix. As the pixel rate is low (less than 1 Mpixel per second) the total number of multiplies required for the three color channels is 56 million multiplies per second. This can be provided by a single multiplier. Fifty bytes of coefficient ROM are also required.
A color ALU 113 combines the functions of color compensation and color space conversion into the one matrix multiplication, which is applied to every pixel of the frame. As with sharpening, the color correction should match the most popular settings, rather than the most accurate.
A color compensation circuit of the color ALU provides compensation for the lighting of the photo. The vast majority of photographs are substantially improved by a simple color compensation, which independently normalizes the contrast and brightness of the three color components.
A color look-up table (CLUT) 212 is provided for each color component. These are three separate 256×8 SRAMs, requiring a total of 6,144 bits. The CLUTs are used as part of the color correction process. They are also used for color special effects, such as stochastically selected “wild color” effects.
A color space conversion system of the color ALU converts from the RGB color space of the image sensor to the CMY color space of the printer. The simplest conversion is a 1's complement of the RGB data. However, this simple conversion assumes perfect linearity of both color spaces, and perfect dye spectra for both the color filters of the image sensor, and the ink dyes. At the other extreme is a tri-linear interpolation of a sampled three dimensional arbitrary transform table. This can effectively match any non-linearity or differences in either color space. Such a system is usually necessary to obtain good color space conversion when the print engine is a color electrophotographic
However, since the non-linearity of a halftoned ink jet output is very small, a simpler system can be used. A simple matrix multiply can provide excellent results. This requires nine multiplies and six additions per contone pixel. However, since the contone pixel rate is low (less than 1 Mpixel/sec) these operations can share a single multiplier and adder. The multiplier and adder are used in a color ALU which is shared with the color compensation function.
Digital halftoning can be performed as a dispersed dot ordered dither using a stochastic optimized dither cell. A halftone matrix ROM 216 is provided for storing dither cell coefficients. A dither cell size of 32×32 is adequate to ensure that the cell repeat cycle is not visible. The three colors—cyan, magenta, and yellow—are all dithered using the same cell, to ensure maximum co-positioning of the ink dots. This minimizes ‘muddying’ of the mid-tones which results from bleed of dyes from one dot to adjacent dots while still wet. The total ROM size required is 1 KByte, as the one ROM is shared by the halftoning units for each of the three colors.
The digital halftoning used is dispersed dot ordered dither with stochastic optimized dither matrix. While dithering does not produce an image quite as ‘sharp’ as error diffusion, it does produce a more accurate image with fewer artifacts. The image sharpening produced by error diffusion is artificial, and less controllable and accurate than ‘unsharp mask’ filtering performed in the contone domain. The high print resolution (1,600 dpi×1,600 dpi) results in excellent quality when using a well formed stochastic dither matrix.
Digital halftoning is performed by a digital halftoning unit 217 using a simple comparison between the contone information from the DRAM 210 and the contents of the dither matrix 216. During the halftone process, the resolution of the image is changed from the 250 dpi of the captured contone image to the 1,600 dpi of the printed image. Each contone pixel is converted to an average of 40.96 halftone dots.
The ICP incorporates a 16 bit microcontroller CPU core 219 to run the miscellaneous camera functions, such as reading the buttons, controlling the motor and solenoids, setting up the hardware, and authenticating the refill station. The processing power required by the CPU is very modest, and a wide variety of processor cores can be used. As the entire CPU program is run from a small ROM 220 program compatibility between camera versions is not important, as no external programs are run. A 2 Mbit (256 Kbyte) program and data ROM 220 is included on chip. Most of this ROM space is allocated to data for outline graphics and fonts for specialty cameras. The program requirements are minor. The single most complex task is the encrypted authentication of the refill station. The ROM requires a single transistor per bit.
A Flash memory 221 may be used to store a 128 bit authentication code. This provides higher security than storage of the authentication code in ROM, as reverse engineering can be made essentially impossible. The Flash memory is completely covered by third level metal, making the data impossible to extract using scanning probe microscopes or electron beams. The authentication code is stored in the chip when manufactured. At least two other Flash bits are required for the authentication process: a bit which locks out reprogramming of the authentication code, and a bit which indicates that the camera has been refilled by an authenticated refill station. The flash memory can also be used to store FPN correction data for the imaging array. Additionally, a phase locked loop resealing parameter is stored for scaling the clocking cycle to an appropriate correct time. The clock frequency does not require crystal accuracy since no date functions are provided. To eliminate the cost of a crystal, an on chip oscillator with a phase locked loop 224 is used. As the frequency of an on-chip oscillator is highly variable from chip to chip, the frequency ratio of the oscillator to the PLL is digitally trimmed during initial testing. The value is stored in Flash memory 221. This allows the clock PLL to control the ink-jet heater pulse width with sufficient accuracy.
A scratchpad SRAM is a small static RAM 222 with a 6T cell. The scratchpad provided temporary memory for the 16 bit CPU. 1024 bytes is adequate.
A print head interface 223 formats the data correctly for the print head. The print head interface also provides all of the timing signals required by the print head. These timing signals may vary depending upon temperature, the number of dots printed simultaneously, the print medium in the print roll, and the dye density of the ink in the print roll.
The following is a table of external connections to the print head interface:












Connection
Function
Pins

















DataBits[0-7]
Independent serial data to the eight segments of
8



the printhead


BitClock
Main data clock for the print head
1


ColorEnable[0-2]
Independent enable signals for the CMY
3



actuators, allowing different pulse times



for each color.


BankEnable[0-1]
Allows either simultaneous or interleaved
2



actuation of two banks of nozzles. This allows



two different print speed/power consumption



tradeoffs


NozzleSelect[0-4]
Selects one of 32 banks of nozzles for
5



simultaneous actuation


ParallelXferClock
Loads the parallel transfer register with the
1



data from the shift registers



Total

20









The printhead utilized is composed of eight identical segments, each 1.25 cm long. There is no connection between the segments on the print head chip. Any connections required are made in the external TAB bonding film, which is double sided. The division into eight identical segments is to simplify lithography using wafer steppers. The segment width of 1.25 cm fits easily into a stepper field. As the printhead chip is long and narrow (10 cm×0.3 mm), the stepper field contains a single segment of 32 print head chips. The stepper field is therefore 1.25 cm×1.6 cm. An average of four complete print heads are patterned in each wafer step.
A single BitClock output line connects to all 8 segments on the printhead. The 8 DataBits lines lead one to each segment, and are clocked into the 8 segments on the print head simultaneously (on a BitClock pulse). For example, dot 0 is transferred to segment0, dot 750 is transferred to segment1, dot 1500 to segment2 etc simultaneously.
The ParallelXferClock is connected to each of the 8 segments on the printhead, so that on a single pulse, all segments transfer their bits at the same time.
The NozzleSelect, BankEnable and ColorEnable lines are connected to each of the 8 segments, allowing the print head interface to independently control the duration of the cyan, magenta, and yellow nozzle energizing pulses. Registers in the Print Head Interface allow the accurate specification of the pulse duration between 0 and 6 ms, with a typical duration of 2 ms to 3 ms.
A parallel interface 125 connects the ICP to individual static electrical signals. The CPU is able to control each of these connections as memory mapped I/O via a low speed bus.
The following is a table of connections to the parallel interface:















Connection
Direction
Pins









Paper transport stepper motor
Output
4



Capping solenoid
Output
1



Copy LED
Output
1



Photo button
Input
1



Copy button
Input
1



Total

8










Seven high current drive transistors e.g. 227 are required. Four are for the four phases of the main stepper motor two are for the guillotine motor, and the remaining transistor is to drive the capping solenoid. These transistors are allocated 20,000 square microns (600,000 F) each. As the transistors are driving highly inductive loads, they must either be turned off slowly, or be provided with a high level of back EMF protection. If adequate back EMF protection cannot be provided using the chip process chosen, then external discrete transistors should be used. The transistors are never driven at the same time as the image sensor is used. This is to avoid voltage fluctuations and hot spots affecting the image quality. Further, the transistors are located as far away from the sensor as possible.
A standard JTAG (Joint Test Action Group) interface 228 is included in the ICP for testing purposes and for interrogation by the refill station. Due to the complexity of the chip, a variety of testing techniques are required, including BIST (Built In Self Test) and functional block isolation. An overhead of 10% in chip area is assumed for chip testing circuitry for the random logic portions. The overhead for the large arrays the image sensor and the DRAM is smaller.
The JTAG interface is also used for authentication of the refill station. This is included to ensure that the cameras are only refilled with quality paper and ink at a properly constructed refill station, thus preventing inferior quality refills from occurring. The camera must authenticate the refill station, rather than vice versa. The secure protocol is communicated to the refill station during the automated test procedure. Contact is made to four gold plated spots on the ICP/print head TAB by the refill station as the new ink is injected into the print head.
FIG. 16 illustrates a rear view of the next step in the construction process whilst FIG. 17 illustrates a front view.
Turning now to FIG. 16, the assembly of the camera system proceeds via first assembling the ink supply mechanism 40. The flex PCB is interconnected with batteries 84, only one of which is shown, which are inserted in the middle portion of a print roll 85 which is wrapped around a plastic former 86. An end cap 89 is provided at the other end of the print roll 85 so as to fasten the print roll and batteries firmly to the ink supply mechanism.
The solenoid coil is interconnected (not shown) to interconnects 97, 98 (FIG. 8) which include leaf spring ends for interconnection with electrical contacts on the Flex PCB so as to provide for electrical control of the solenoid.
Turning now to FIGS. 17-19 the next step in the construction process is the insertion of the relevant gear trains into the side of the camera chassis. FIG. 17 illustrates a front view, FIG. 18 illustrates a rear view and FIG. 19 also illustrates a rear view. The first gear train comprising gear wheels 22, 23 is utilized for driving the guillotine blade with the gear wheel 23 engaging the gear wheel 65 of FIG. 8. The second gear train comprising gear wheels 24, 25 and 26 engage one end of the print roller 61 of FIG. 8. As best indicated in FIG. 18, the gear wheels mate with corresponding pins on the surface of the chassis with the gear wheel 26 being snap fitted into corresponding mating hole 27.
Next, as illustrated in FIG. 20, the assembled platten unit 60 is then inserted between the print roll 85 and aluminum cutting blade 43.
Turning now to FIG. 21, by way of illumination, there is illustrated the electrically interactive components of the camera system. As noted previously, the components are based around a Flex PCB board and include a TAB film 58 which interconnects the printhead 102 with the image sensor and processing chip 48. Power is supplied by two AA type batteries 83, 84 and a paper drive stepper motor 16 is provided in addition to a rotary guillotine motor 17.
An optical element 31 is provided for snapping into a top portion of the chassis 12. The optical element 31 includes portions defining an optical view finder 32, 33 which are slotted into mating portions 35, 36 in view finder channel 37. Also provided in the optical element 31 is a lensing system 38 for magnification of the prints left number in addition to an optical pipe element 39 for piping light from the LED 5 for external display.
Turning next to FIG. 22, the assembled unit 90 is then inserted into a front outer case 91 which includes button 4 for activation of printouts.
Turning now to FIG. 23, next, the unit 90 is provided with a snap-on back cover 93 which includes a slot 6 and copy print button 7. A wrapper label containing instructions and advertising (not shown) is then wrapped around the outer surface of the camera system and pinch clamped to the cover by means of clamp strip 96 which can comprise a flexible plastic or rubber strip.
Subsequently, the preferred embodiment is ready for use as a one time use camera system that provides for instant output images on demand. It will be evident that the preferred embodiment further provides for a refillable camera system. A used camera can be collected and its outer plastic cases removed and recycled. A new paper roll and batteries can be added and the ink cartridge refilled. A series of automatic test routines can then be carried out to ensure that the printer is properly operational. Further, in order to ensure only authorized refills are conducted so as to enhance quality, routines in the on-chip program ROM can be executed such that the camera authenticates the refilling station using a secure protocol. Upon authentication, the camera can reset an internal paper count and an external case can be fitted on the camera system with a new outer label. Subsequent packing and shipping can then take place.
It will be further readily evident to those skilled in the art that the program ROM can be modified so as to allow for a variety of digital processing routines. In addition to the digitally enhanced photographs optimized for mainstream consumer preferences, various other models can readily be provided through mere re-programming of the program ROM. For example, a sepia classic old fashion style output can be provided through a remapping of the color mapping function. A further alternative is to provide for black and white outputs again through a suitable color remapping algorithm. Minimum color can also be provided to add a touch of color to black and white prints to produce the effect that was traditionally used to colorize black and white photos. Further, passport photo output can be provided through suitable address remappings within the address generators. Further, edge filters can be utilized as is known in the field of image processing to produce sketched art styles. Further, classic wedding borders and designs can be placed around an output image in addition to the provision of relevant clip arts. For example, a wedding style camera might be provided. Further, a panoramic mode can be provided so as to output the well known panoramic format of images. Further, a postcard style output can be provided through the printing of postcards including postage on the back of a print roll surface. Further, cliparts can be provided for special events such as Halloween, Christmas etc. Further, kaleidoscopic effects can be provided through address remappings and wild color effects can be provided through remapping of the color lookup table. Many other forms of special event cameras can be provided for example, cameras dedicated to the Olympics, movie tie-ins, advertising and other special events.
The operational mode of the camera can be programmed so that upon the depressing of the take photo a first image is sampled by the sensor array to determine irrelevant parameters. Next a second image is again captured which is utilized for the output. The captured image is then manipulated in accordance with any special requirements before being initially output on the paper roll. The LED light is then activated for a predetermined time during which the DRAM is refreshed so as to retain the image. If the print copy button is depressed during this predetermined time interval, a further copy of the photo is output. After the predetermined time interval where no use of the camera has occurred, the onboard CPU shuts down all power to the camera system until such time as the take button is again activated. In this way, substantial power savings can be realized.
Ink Jet Technologies
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.
The most significant problem with thermal inkjet 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 inkjet applications. This leads to an efficiency of around 0.02%, from electricity input to drop momentum (and increased surface area) out.
The most significant problem with piezoelectric inkjet 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.
Ideally, the inkjet 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 inkjet technologies have been created. The target features include:
low power (less than 10 Watts)
high resolution capability (1,600 dpi or more)
photographic quality output
low manufacturing cost
small size (pagewidth times minimum cross section)
high speed (<2 seconds per page).
All of these features can be met or exceeded by the inkjet systems described below with differing levels of difficulty. forty-five different inkjet 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 below.
The inkjet 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
For ease of manufacture using standard process equipment, the printhead 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 inkjet 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.
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.
CROSS-REFERENCED APPLICATIONS
The following table is a guide to cross-referenced patent applications filed concurrently herewith and discussed hereinafter with the reference being utilized in subsequent tables when referring to a particular case:












Docket No.
Reference
Title







IJ01US
6227652
Radiant Plunger Ink Jet Printer


IJ02US
6213588
Electrostatic Ink Jet Printer


IJ03US
6213589
Planar Thermoelastic Bend Actuator Ink




Jet


IJ04US
6231163
Stacked Electrostatic Ink Jet Printer


IJ05US
6247795
Reverse Spring Lever Ink Jet Printer


IJ06US
6394581
Paddle Type Ink Jet Printer


IJ07US
6244691
Permanent Magnet Electromagnetic Ink




Jet Printer


IJ08US
6257704
Planar Swing Grill Electromagnetic Ink




Jet Printer


IJ09US
6416168
Pump Action Refill Ink Jet Printer


IJ10US
6220694
Pulsed Magnetic Field Ink Jet Printer


IJ11US
6257705
Two Plate Reverse Firing




Electromagnetic Ink Jet Printer


IJ12US
6247794
Linear Stepper Actuator Ink Jet Printer


IJ13US
6234610
Gear Driven Shutter Ink Jet Printer


IJ14US
6247793
Tapered Magnetic Pole Electromagnetic




Ink Jet Printer


IJ15US
6264306
Linear Spring Electromagnetic Grill Ink




Jet Printer


IJ16US
6241342
Lorenz Diaphragm Electromagnetic Ink




Jet Printer


IJ17US
6247792
PTFE Surface Shooting Shuttered




Oscillating Pressure Ink Jet Printer


IJ18US
6264307
Buckle Grip Oscillating Pressure Ink Jet




Printer


IJ19US
6254220
Shutter Based Ink Jet Printer


IJ20US
6234611
Curling Calyx Thermoelastic Ink Jet




Printer


IJ21US
6302528
Thermal Actuated Ink Jet Printer


IJ22US
6283582
Iris Motion Ink Jet Printer


IJ23US
6239821
Direct Firing Thermal Bend Actuator Ink




Jet Printer


IJ24US
6338547
Conductive PTFE Ben Activator Vented




Ink Jet Printer


IJ25US
6247796
Magnetostrictive Ink Jet Printer


IJ26US
6557977
Shape Memory Alloy Ink Jet Printer


IJ27US
6390603
Buckle Plate Ink Jet Printer


IJ28US
6362843
Thermal Elastic Rotary Impeller Ink Jet




Printer


IJ29US
6293653
Thermoelastic Bend Actuator Ink Jet




Printer


IJ30US
6312107
Thermoelastic Bend Actuator Using




PTFE and Corrugated Copper Ink Jet




Printer


IJ31US
6227653
Bend Actuator Direct Ink Supply Ink Jet




Printer


IJ32US
6234609
A High Young's Modulus Thermoelastic




Ink Jet Printer


IJ33US
6238040
Thermally actuated slotted chamber wall




ink jet printer


IJ34US
6188415
Ink Jet Printer having a thermal actuator




comprising an external coiled spring


IJ35US
6227654
Trough Container Ink Jet Printer


IJ36US
6209989
Dual Chamber Single Vertical Actuator




Ink Jet


IJ37US
6247791
Dual Nozzle Single Horizontal Fulcrum




Actuator Ink Jet


IJ38US
6336710
Dual Nozzle Single Horizontal Actuator




Ink Jet


IJ39US
6217153
A single bend actuator cupped paddle




ink jet printing device


IJ40US
6416167
A thermally actuated ink jet printer




having a series of thermal actuator units


IJ41US
6243113
A thermally actuated ink jet printer




including a tapered heater element


IJ42US
6283581
Radial Back-Curling Thermoelastic Ink




Jet


IJ43US
6247790
Inverted Radial Back-Curling




Thermoelastic Ink Jet


IJ44US
6260953
Surface bend actuator vented ink supply




ink jet printer


IJ45US
6267469
Coil Acutuated Magnetic Plate Ink Jet




Printer









Tables of Drop-on-Demand Inkjets

Eleven important characteristics of the fundamental operation of individual inkjet 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.
The following tables form the axes of an eleven dimensional table of inkjet types.
Actuator mechanism (18 types)
Basic operation mode (7 types)
Auxiliary mechanism (8 types)
Actuator amplification or modification method (17 types)
Actuator motion (19 types)
Nozzle refill method (4 types)
Method of restricting back-flow through inlet (10 types)
Nozzle clearing method (9 types)
Nozzle plate construction (9 types)
Drop ejection direction (5 types)
Ink type (7 types)
The complete eleven dimensional table represented by these axes contains 36.9 billion possible configurations of inkjet nozzle. While not all of the possible combinations result in a viable inkjet technology, many million configurations are viable. It is clearly impractical to elucidate all of the possible configurations. Instead, certain inkjet types have been investigated in detail. These are designated IJ01 to IJ45 above.
Other inkjet configurations can readily be derived from these forty-five examples by substituting alternative configurations along one or more of the eleven axes. Most of the IJ01 to IJ45 examples can be made into inkjet print heads with characteristics superior to any currently available inkjet technology.
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 printer may be listed more than once in a table, where it shares characteristics with more than one entry.
Suitable applications 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.
The information associated with the aforementioned eleven dimensional matrix are set out in the following tables.










ACTUATOR MECHANISM (APPLIED ONLY TO SELECTED INK DROPS)











Actuator






Mechanism
Description
Advantages
Disadvantages
Examples





Thermal
An electrothermal heater heats the
Large force generated
High power
Canon Bubblejet


bubble
ink to above boiling point,
Simple construction
Ink carrier limited to water
1979 Endo et al GB



transferring significant heat to the
No moving parts
Low efficiency
patent 2,007,162



aqueous ink. A bubble nucleates
Fast operation
High temperatures required
Xerox heater-in-pit



and quickly forms, expelling the
Small chip area required
High mechanical stress
1990 Hawkins et al



ink.
for actuator
Unusual materials required
U.S. Pat. No. 4,899,181



The efficiency of the process is

Large drive transistors
Hewlett-Packard



low, with typically less than

Cavitation causes actuator failure
TIJ 1982 Vaught et



0.05% of the electrical energy

Kogation reduces bubble formation
al U.S. Pat. No.



being transformed into kinetic

Large print heads are difficult to
4,490,728



energy of the drop.

fabricate


Piezoelectric
A piezoelectric crystal such as
Low power consumption
Very large area required for actuator
Kyser et al U.S. Pat. No.



lead lanthanum zirconate (PZT) is
Many ink types can be
Difficult to integrate with electronics
3,946,398



electrically activated, and either
used
High voltage drive transistors
Zoltan U.S. Pat. No.



expands, shears, or bends to apply
Fast operation
required
3,683,212



pressure to the ink, ejecting drops.
High efficiency
Full pagewidth print heads
1973 Stemme





impractical due to actuator size
U.S. Pat. No. 3,747,120





Requires electrical poling in high field
Epson Stylus





strengths during manufacture
Tektronix






IJ04


Electro-
An electric field is used to
Low power consumption
Low maximum strain (approx. 0.01%)
Seiko Epson, Usui


strictive
activate electrostriction in relaxor
Many ink types can be
Large area required for actuator due
et all JP 253401/96



materials such as lead lanthanum
used
to low strain
IJ04



zirconate titanate (PLZT) or lead
Low thermal expansion
Response speed is marginal (~10 μs)



magnesium niobate (PMN).
Electric field strength
High voltage drive transistors




required (approx. 3.5 V/μm)
required




can be generated
Full pagewidth print heads




without difficulty
impractical due to actuator size




Does not require electrical




poling


Ferroelectric
An electric field is used to induce
Low power consumption
Difficult to integrate with electronics
IJ04



a phase transition between the
Many ink types can be
Unusual materials such as PLZSnT



antiferroelectric (AFE) and
used
are required



ferroelectric (FE) phase.
Fast operation (<1 μs)
Actuators require a large area



Perovskite materials such as tin
Relatively high



modified lead lanthanum
longitudinal strain



zirconate titanate (PLZSnT)
High efficiency



exhibit large strains of up to 1%
Electric field strength of



associated with the AFE to FE
around 3 V/μm can be



phase transition.
readily provided


Electrostatic
Conductive plates are separated
Low power consumption
Difficult to operate electrostatic
IJ02, IJ04


plates
by a compressible or fluid
Many ink types can be
devices in an aqueous environment



dielectric (usually air). Upon
used
The electrostatic actuator will



application of a voltage, the plates
Fast operation
normally need to be separated from



attract each other and displace

the ink



ink, causing drop ejection. The

Very large area required to achieve



conductive plates may be in a

high forces



comb or honeycomb structure, or

High voltage drive transistors may be



stacked to increase the surface

required



area and therefore the force.

Full pagewidth print heads are not





competitive due to actuator size


Electrostatic
A strong electric field is applied
Low current consumption
High voltage required
1989 Saito et al,


pull on ink
to the ink, whereupon electrostatic
Low temperature
May be damaged by sparks due to air
U.S. Pat. No. 4,799,068



attraction accelerates the ink

breakdown
1989 Miura et al,



towards the print medium.

Required field strength increases as
U.S. Pat. No. 4,810,954





the drop size decreases
Tone-jet





High voltage drive transistors





required





Electrostatic field attracts dust


Permanent
An electromagnet directly attracts
Low power consumption
Complex fabrication
IJ07, IJ10


magnet
a permanent magnet, displacing
Many ink types can be
Permanent magnetic material such as


electromagnetic
ink and causing drop ejection.
used
Neodymium Iron Boron (NdFeB)



Rare earth magnets with a field
Fast operation
required.



strength around 1 Tesla can be
High efficiency
High local currents required



used. Examples are: Samarium
Easy extension from single
Copper metalization should be used



Cobalt (SaCo) and magnetic
nozzles to pagewidth print
for long electromigration lifetime and



materials in the neodymium iron
heads
low resistivity



boron family (NdFeB,

Pigmented inks are usually infeasible



NdDyFeBNb, NdDyFeB, etc)

Operating temperature limited to the





Curie temperature (around 540 K)


Soft magnetic
A solenoid induced a magnetic
Low power consumption
Complex fabrication
IJ01, IJ05, IJ08,


core
field in a soft magnetic core or
Many ink types can be
Materials not usually present in a
IJ10


electromagnetic
yoke fabricated from a ferrous
used
CMOS fab such as NiFe, CoNiFe, or
IJ12, IJ14, IJ15,



material such as electroplated iron
Fast operation
CoFe are required
IJ17



alloys such as CoNiFe [1], CoFe,
High efficiency
High local currents required



or NiFe alloys. Typically, the soft
Easy extension from single
Copper metalization should be used



magnetic material is in two parts,
nozzles to pagewidth print
for long electromigration lifetime and



which are normally held apart by
heads
low resistivity



a spring. When the solenoid is

Electroplating is required



actuated, the two parts attract,

High saturation flux density is



displacing the ink,

required (2.0-2.1 T is achievable with





CoNiFe [1])


Magnetic
The Lorenz force acting on a
Low power consumption
Force acts as a twisting motion
IJ06, IJ11, IJ13,


Lorenz force
current carrying wire in a
Many ink types can be
Typically, only a quarter of the
IJ16



magnetic field is utilized.
used
solenoid length provides force in a



This allows the magnetic field to
Fast operation
useful direction



be supplied externally to the print
High efficiency
High local currents required



head, for example with rare earth
Easy extension from single
Copper metalization should be used



permanent magnets.
nozzles to pagewidth print
for long electromigration lifetime and



Only the current carrying wire
heads
low resistivity



need be fabricated on the print-

Pigmented inks are usually infeasible



head, simplifying materials



requirements.


Magneto-
The actuator uses the giant
Many ink types can be
Force acts as a twisting motion
Fischenbeck,


striction
magnetostrictive effect of
used
Unusual materials such as Terfenol-D
U.S. Pat. No. 4,032,929



materials such as Terfenol-D (an
Fast operation
are required
IJ25



alloy of terbium, dysprosium and
Easy extension from single
High local currents required



iron developed at the Naval
nozzles to pagewidth print
Copper metalization should be used



Ordnance Laboratory, hence Ter-
heads
for long electromigration lifetime and



Fe-NOL). For best efficiency, the
High force is available
low resistivity



actuator should be pre-stressed to

Pre-stressing may be required



approx. 8 MPa.


Surface
Ink under positive pressure is held
Low power consumption
Requires supplementary force to
Silverbrook, EP


tension
in a nozzle by surface tension.
Simple construction
effect drop separation
0771 658 A2 and


reduction
The surface tension of the ink is
No unusual materials
Requires special ink surfactants
related patent



reduced below the bubble
required in fabrication
Speed may be limited by surfactant
applications



threshold, causing the ink to
High efficiency
properties



egress from the nozzle.
Easy extension from single




nozzles to pagewidth print




heads


Viscosity
The ink viscosity is locally
Simple construction
Requires supplementary force to
Silverbrook, EP


reduction
reduced to select which drops are
No unusual materials
effect drop separation
0771 658 A2 and



to be ejected. A viscosity
required in fabrication
Requires special ink viscosity
related patent



reduction can be achieved
Easy extension from single
properties
applications



electrothermally with most inks,
nozzles to pagewidth print
High speed is difficult to achieve



but special inks can be engineered
heads
Requires oscillating ink pressure



for a 100:1 viscosity reduction.

A high temperature difference





(typically 80 degrees) is required


Acoustic
An acoustic wave is generated and
Can operate without a
Complex drive circuitry
1993 Hadimioglu et



focussed upon the drop ejection
nozzle plate
Complex fabrication
al, EUP 550,192



region.

Low efficiency
1993 Elrod et al,





Poor control of drop position
EUP 572,220





Poor control of drop volume


Thermoelastic
An actuator which relies upon
Low power consumption
Efficient aqueous operation requires a
IJ03, IJ09, IJ17,


bend actuator
differential thermal expansion
Many ink types can be
thermal insulator on the hot side
IJ18



upon Joule heating is used.
used
Corrosion prevention can be difficult
IJ19, IJ20, IJ21,




Simple planar fabrication
Pigmented inks may be infeasible, as
IJ22




Small chip area required
pigment particles may jam the bend
IJ23, IJ24, IJ27,




for each actuator
actuator
IJ28




Fast operation

IJ29, IJ30, IJ31,




High efficiency

IJ32




CMOS compatible

IJ33, IJ34, IJ35,




voltages and currents

IJ36




Standard MEMS processes

IJ37, IJ38, IJ39,




can be used

IJ40




Easy extension from single

IJ41




nozzles to pagewidth print




heads


High CTE
A material with a very high
High force can be
Requires special material (e.g. PTFE)
IJ09, IJ17, IJ18,


thermoelastic
coefficient of thermal expansion
generated
Requires a PTFE deposition process,
IJ20


actuator
(CTE) such as
PTFE is a candidate for
which is not yet standard in ULSI fabs
IJ21, IJ22, IJ23,



polytetrafluoroethylene (PTFE) is
low dielectric constant
PTFE deposition cannot be followed
IJ24



used. As high CTE materials are
insulation in ULSI
with high temperature (above 350° C.)
IJ27, IJ28, IJ29,



usually non-conductive, a heater
Very low power
processing
IJ30



fabricated from a conductive
consumption
Pigmented inks may be infeasible, as
IJ31, IJ42, IJ43,



material is incorporated. A 50 μm
Many ink types can be
pigment particles may jam the bend
IJ44



long PTFE bend actuator with
used
actuator



polysilicon heater and 15 mW
Simple planar fabrication



power input can provide 180 μN
Small chip area required



force and 10 μm deflection.
for each actuator



Actuator motions include:
Fast operation



Bend
High efficiency



Push
CMOS compatible



Buckle
voltages and currents



Rotate
Easy extension from single




nozzles to pagewidth print




heads


Conductive
A polymer with a high coefficient
High force can be
Requires special materials
IJ24


polymer
of thermal expansion (such as
generated
development (High CTE conductive


thermoelastic
PTFE) is doped with conducting
Very low power
polymer)


actuator
substances to increase its
consumption
Requires a PTFE deposition process,



conductivity to about 3 orders of
Many ink types can be
which is not yet standard in ULSI fabs



magnitude below that of copper.
used
PTFE deposition cannot be followed



The conducting polymer expands
Simple planar fabrication
with high temperature (above 350° C.)



when resistively heated.
Small chip area required
processing



Examples of conducting dopants
for each actuator
Evaporation and CVD deposition



include:
Fast operation
techniques cannot be used



Carbon nanotubes
High efficiency
Pigmented inks may be infeasible, as



Metal fibers
CMOS compatible
pigment particles may jam the bend



Conductive polymers such as
voltages and currents
actuator



doped polythiophene
Easy extension from single



Carbon granules
nozzles to pagewidth print




heads


Shape memory
A shape memory alloy such as
High force is available
Fatigue limits maximum number of
IJ26


alloy
TiNi (also known as Nitinol -
(stresses of hundreds of
cycles



Nickel Titanium alloy developed
MPa)
Low strain (1%) is required to extend



at the Naval Ordnance
Large strain is available
fatigue resistance



Laboratory) is thermally switched
(more than 3%)
Cycle rate limited by heat removal



between its weak martensitic state
High corrosion resistance
Requires unusual materials (TiNi)



and its high stiffness austenic
Simple construction
The latent heat of transformation must



state. The shape of the actuator in
Easy extension from single
be provided



its martensitic state is deformed
nozzles to pagewidth print
High current operation



relative to the austenic shape. The
heads
Requires pre-stressing to distort the



shape change causes ejection of a
Low voltage operation
martensitic state



drop.


Linear
Linear magnetic actuators include
Linear Magnetic actuators
Requires unusual semiconductor
IJ12


Magnetic
the Linear Induction Actuator
can be constructed with
materials such as soft magnetic alloys


Actuator
(LIA), Linear Permanent Magnet
high thrust, long travel,
(e.g. CoNiFe [1])



Synchronous Actuator (LPMSA),
and high efficiency using
Some varieties also require permanent



Linear Reluctance Synchronous
planar semiconductor
magnetic materials such as



Actuator (LRSA), Linear
fabrication techniques
Neodymium iron boron (NdFeB)



Switched Reluctance Actuator
Long actuator travel is
Requires complex multi-phase drive



(LSRA), and the Linear Stepper
available
circuitry



Actuator (LSA).
Medium force is available
High current operation




Low voltage operation



















BASIC OPERATION MODE











Operational






mode
Description
Advantages
Disadvantages
Examples





Actuator
This is the simplest mode of
Simple operation
Drop repetition rate is usually limited
Thermal inkjet


directly
operation: the actuator directly
No external fields required
to less than 10 KHz. However, this is
Piezoelectric inkjet


pushes ink
supplies sufficient kinetic energy
Satellite drops can be
not fundamental to the method, but is
IJ01, IJ02, IJ03,



to expel the drop. The drop must
avoided if drop velocity is
related to the refill method normally
IJ04



have a sufficient velocity to
less than 4 m/s
used
IJ05, IJ06, IJ07,



overcome the surface tension.
Can be efficient,
All of the drop kinetic energy must
IJ09




depending upon the
be provided by the actuator
IJ11, IJ12, IJ14,




actuator used
Satellite drops usually form if drop
IJ16





velocity is greater than 4.5 m/s
IJ20, IJ22, IJ23,






IJ24






IJ25, IJ26, IJ27,






IJ28






IJ29, IJ30, IJ31,






IJ32






IJ33, IJ34, IJ35,






IJ36






IJ37, IJ38, IJ39,






IJ40






IJ41, IJ42, IJ43,






IJ44


Proximity
The drops to be printed are
Very simple print head
Requires close proximity between the
Silverbrook, EP



selected by some manner (e.g.
fabrication can be used
print head and the print media or
0771 658 A2 and



thermally induced surface tension
The drop selection means
transfer roller
related patent



reduction of pressurized ink).
does not need to provide
May require two print heads printing
applications



Selected drops are separated from
the energy required to
alternate rows of the image



the ink in the nozzle by contact
separate the drop from the
Monolithic color print heads are



with the print medium or a
nozzle
difficult



transfer roller.


Electrostatic
The drops to be printed are
Very simple print head
Requires very high electrostatic field
Silverbrook, EP


pull on ink
selected by some manner (e.g.
fabrication can be used
Electrostatic field for small nozzle
0771 658 A2 and



thermally induced surface tension
The drop selection means
sizes is above air breakdown
related patent



reduction of pressurized ink).
does not need to provide
Electrostatic field may attract dust
applications



Selected drops are separated from
the energy required to

Tone-Jet



the ink in the nozzle by a strong
separate the drop from the



electric field.
nozzle


Magnetic
The drops to be printed are
Very simple print head
Requires magnetic ink
Silverbrook, EP


pull
selected by some manner (e.g.
fabrication can be used
Ink colors other than black are
0771 658 A2 and


on ink
thermally induced surface tension
The drop selection means
difficult
related patent



reduction of pressurized ink).
does not need to provide
Requires very high magnetic fields
applications



Selected drops are separated from
the energy required to



the ink in the nozzle by a strong
separate the drop from the



magnetic field acting on the
nozzle



magnetic ink.


Shutter
The actuator moves a shutter to
High speed (>50 KHz)
Moving parts are required
IJ13, IJ17, IJ21



block ink flow to the nozzle. The
operation can be achieved
Requires ink pressure modulator



ink pressure is pulsed at a
due to reduced refill time
Friction and wear must be considered



multiple of the drop ejection
Drop timing can be very
Stiction is possible



frequency.
accurate




The actuator energy can be




very low


Shuttered
The actuator moves a shutter to
Actuators with small travel
Moving parts are required
IJ08, IJ15, IJ18,


grill
block ink flow through a grill to
can be used
Requires ink pressure modulator
IJ19



the nozzle. The shutter movement
Actuators with small force
Friction and wear must be considered



need only be equal to the width of
can be used
Stiction is possible



the grill holes.
High speed (>50 KHz)




operation can be achieved


Pulsed
A pulsed magnetic field attracts
Extremely low energy
Requires an external pulsed magnetic
IJ10


magnetic
an ‘ink pusher’ at the drop
operation is possible
field


pull
ejection frequency. An actuator
No heat dissipation
Requires special materials for both


on ink
controls a catch, which prevents
problems
the actuator and the ink pusher


pusher
the ink pusher from moving when

Complex construction



a drop is not to be ejected.



















AUXILIARY MECHANISM (APPLIED TO ALL NOZZLES)











Auxiliary






Mechanism
Description
Advantages
Disadvantages
Examples





None
The actuator directly fires the ink
Simplicity of construction
Drop ejection energy must be
Most inkjets,



drop, and there is no external field
Simplicity of operation
supplied by individual nozzle actuator
including



or other mechanism required.
Small physical size

piezoelectric and






thermal bubble.






IJ01-IJ07, IJ09,






IJ11






IJ12, IJ14, IJ20,






IJ22






IJ23-IJ45


Oscillating
The ink pressure oscillates,
Oscillating ink pressure
Requires external ink pressure
Silverbrook, EP


ink
providing much of the drop
can provide a refill pulse,
oscillator
0771 658 A2 and


pressure
ejection energy. The actuator
allowing higher operating
Ink pressure phase and amplitude
related patent


(including
selects which drops are to be fired
speed
must be carefully controlled
applications


acoustic
by selectively blocking or
The actuators may operate
Acoustic reflections in the ink
IJ08, IJ13, IJ15,


stimulation)
enabling nozzles. The ink pressure
with much lower energy
chamber must be designed for
IJ17



oscillation may be achieved by
Acoustic lenses can be

IJ18, IJ19, IJ21



vibrating the print head, or
used to focus the sound on



preferably by an actuator in the
the nozzles



ink supply.


Media
The print head is placed in close
Low power
Precision assembly required
Silverbrook, EP


proximity
proximity to the print medium.
High accuracy
Paper fibers may cause problems
0771 658 A2 and



Selected drops protrude from the
Simple print head
Cannot print on rough substrates
related patent



print head further than unselected
construction

applications



drops, and contact the print



medium. The drop soaks into the



medium fast enough to cause drop



separation.


Transfer
Drops are printed to a transfer
High accuracy
Bulky
Silverbrook, EP


roller
roller instead of straight to the
Wide range of print
Expensive
0771 658 A2 and



print medium. A transfer roller
substrates can be used
Complex construction
related patent



can also be used for proximity
Ink can be dried on the

applications



drop separation.
transfer roller

Tektronix hot melt






piezoelectric inkjet






Any of the IJ series


Electrostatic
An electric field is used to
Low power
Field strength required for separation
Silverbrook, EP



accelerate selected drops towards
Simple print head
of small drops is near or above air
0771 658 A2 and



the print medium.
construction
breakdown
related patent






applications






Tone-Jet


Direct
A magnetic field is used to
Low power
Requires magnetic ink
Silverbrook, EP


magnetic
accelerate selected drops of
Simple print head
Requires strong magnetic field
0771 658 A2 and


field
magnetic ink towards the print
construction

related patent



medium.


applications


Cross
The print head is placed in a
Does not require magnetic
Requires external magnet
IJ06, IJ16


magnetic
constant magnetic field. The
materials to be integrated
Current densities may be high,


field
Lorenz force in a current carrying
in the print head
resulting in electromigration



wire is used to move the actuator.
manufacturing process
problems


Pulsed
A pulsed magnetic field is used to
Very low power operation
Complex print head construction
IJ10


magnetic
cyclically attract a paddle, which
is possible
Magnetic materials required in print


field
pushes on the ink. A small
Small print head size
head



actuator moves a catch, which



selectively prevents the paddle



from moving.



















ACTUATOR AMPLIFICATION OR MODIFICATION METHOD











Actuator






amplification
Description
Advantages
Disadvantages
Examples





None
No actuator mechanical
Operational simplicity
Many actuator mechanisms have
Thermal Bubble



amplification is used. The actuator

insufficient travel, or insufficient
Inkjet



directly drives the drop ejection

force, to efficiently drive the drop
IJ01, IJ02, IJ06



process.

ejection process
IJ07






IJ16, IJ25, IJ26


Differential
An actuator material expands
Provides greater travel in a
High stresses are involved
Piezoelectric


expansion
more on one side than on the
reduced print head area
Care must be taken that the materials
IJ03, IJ09, IJ17-IJ24


bend actuator
other. The expansion may be
The bend actuator converts
do not delaminate
IJ27, IJ29-IJ39,



thermal, piezoelectric,
a high force low travel
Residual bend resulting from high
IJ42,



magnetostrictive, or other
actuator mechanism to
temperature or high stress during
IJ43, IJ44



mechanism.
high travel, lower force
formation




mechanism.


Transient bend
A trilayer bend actuator where the
Very good temperature
High stresses are involved
IJ40, IJ41


actuator
two outside layers are identical.
stability
Care must be taken that the materials



This cancels bend due to ambient
High speed, as a new drop
do not delaminate



temperature and residual stress.
can be fired before heat



The actuator only responds to
dissipates



transient heating of one side or the
Cancels residual stress of



other.
formation


Actuator stack
A series of thin actuators are
Increased travel
Increased fabrication complexity
Some piezoelectric



stacked. This can be appropriate
Reduced drive voltage
Increased possibility of short circuits
ink jets



where actuators require high

due to pinholes
IJ04



electric field strength, such as



electrostatic and piezoelectric



actuators.


Multiple
Multiple smaller actuators are
Increases the force
Actuator forces may not add linearly,
IJ12, IJ13, IJ18,


actuators
used simultaneously to move the
available from an actuator
reducing efficiency
IJ20



ink. Each actuator need provide
Multiple actuators can be

IJ22, IJ28, IJ42,



only a portion of the force
positioned to control ink

IJ43



required.
flow accurately


Linear Spring
A linear spring is used to
Matches low travel
Requires print head area for the spring
IJ15



transform a motion with small
actuator with higher travel



travel and high force into a longer
requirements



travel, lower force motion.
Non-contact method of




motion transformation


Reverse spring
The actuator loads a spring. When
Better coupling to the ink
Fabrication complexity
IJ05, IJ11



the actuator is turned off, the

High stress 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.


Coiled
A bend actuator is coiled to
Increases travel
Generally restricted to planar
IJ17, IJ21, IJ34,


actuator
provide greater travel in a reduced
Reduces chip area
implementations due to extreme
IJ35



chip area.
Planar implementations
fabrication difficulty in other




are relatively easy to
orientations.




fabricate.


Flexure bend
A bend actuator has a small
Simple means of
Care must be taken not to exceed the
IJ10, IJ19, IJ33


actuator
region near the fixture point,
increasing travel of a bend
elastic limit in the flexure area



which flexes much more readily
actuator
Stress distribution is very uneven



than the remainder of the actuator.

Difficult to accurately model with



The actuator flexing is effectively

finite element analysis



converted from an even coiling to



an angular bend, resulting in



greater travel of the actuator tip.


Gears
Gears can be used to increase
Low force, low travel
Moving parts are required
IJ13



travel at the expense of duration.
actuators can be used
Several actuator cycles are required



Circular gears, rack and pinion,
Can be fabricated using
More complex drive electronics



ratchets, and other gearing
standard surface MEMS
Complex construction



methods can be used.
processes
Friction, friction, and wear are





possible


Catch
The actuator controls a small
Very low actuator energy
Complex construction
IJ10



catch. The catch either enables or
Very small actuator size
Requires external force



disables movement of an ink

Unsuitable for pigmented inks



pusher that is controlled in a bulk



manner.


Buckle plate
A buckle plate can be used to
Very fast movement
Must stay within elastic limits of the
S. Hirata et al, “An



change a slow actuator into a fast
achievable
materials for long device life
Ink-jet Head . . . ”,



motion. It can also convert a high

High stresses involved
Proc. IEEE MEMS,



force, low travel actuator into a

Generally high power requirement
February 1996, pp 418-423.



high travel, medium force motion.


IJ18, IJ27


Tapered
A tapered magnetic pole can
Linearizes the magnetic
Complex construction
IJ14


magnetic pole
increase travel at the expense of
force/distance curve



force.


Lever
A lever and fulcrum is used to
Matches low travel
High stress around the fulcrum
IJ32, IJ36, IJ37



transform a motion with small
actuator with higher travel



travel and high force into a
requirements



motion with longer travel and
Fulcrum area has no linear



lower force. The lever can also
movement, and can be



reverse the direction of travel.
used for a fluid seal


Rotary
The actuator is connected to a
High mechanical
Complex construction
IJ28


impeller
rotary impeller. A small angular
advantage
Unsuitable for pigmented inks



deflection of the actuator results
The ratio of force to travel



in a rotation of the impeller vanes,
of the actuator can be



which push the ink against
matched to the nozzle



stationary vanes and out of the
requirements by varying



nozzle.
the number of impeller




vanes


Acoustic lens
A refractive or diffractive (e.g.
No moving parts
Large area required
1993 Hadimioglu et



zone plate) acoustic lens is used to

Only relevant for acoustic ink jets
al, EUP 550,192



concentrate sound waves.


1993 Elrod et al,






EUP 572,220


Sharp
A sharp point is used to
Simple construction
Difficult to fabricate using standard
Tone-jet


conductive
concentrate an electrostatic field.

VLSI processes for a surface ejecting


point


ink-jet





Only relevant for electrostatic ink jets



















ACTUATOR MOTION











Actuator






motion
Description
Advantages
Disadvantages
Examples





Volume
The volume of the actuator
Simple construction in the
High energy is typically required to
Hewlett-Packard


expansion
changes, pushing the ink in all
case of thermal ink jet
achieve volume expansion. This leads
Thermal Inkjet



directions.

to thermal stress, cavitation, and
Canon Bubblejet





kogation in thermal ink jet





implementations


Linear, normal
The actuator moves in a direction
Efficient coupling to ink
High fabrication complexity may be
IJ01, IJ02, IJ04,


to chip surface
normal to the print head surface.
drops ejected normal to the
required to achieve perpendicular
IJ07



The nozzle is typically in the line
surface
motion
IJ11, IJ14



of movement.


Linear, parallel
The actuator moves parallel to the
Suitable for planar
Fabrication complexity
IJ12, IJ13, IJ15,


to chip surface
print head surface. Drop ejection
fabrication
Friction
IJ33,



may still be normal to the surface.

Stiction
IJ34, IJ35, IJ36


Membrane
An actuator with a high force but
The effective area of the
Fabrication complexity
1982 Howkins


push
small area is used to push a stiff
actuator becomes the
Actuator size
U.S. Pat. No. 4,459,601



membrane that is in contact with
membrane area
Difficulty of integration in a VLSI



the ink.

process


Rotary
The actuator causes the rotation of
Rotary levers may be used
Device complexity
IJ05, IJ08, IJ13,



some element, such a grill or
to increase travel
May have friction at a pivot point
IJ28



impeller
Small chip area




requirements


Bend
The actuator bends when
A very small change in
Requires the actuator to be made from
1970 Kyser et al



energized. This may be due to
dimensions can be
at least two distinct layers, or to have
U.S. Pat. No. 3,946,398



differential thermal expansion,
converted to a large
a thermal difference across the
1973 Stemme U.S. Pat. No.



piezoelectric expansion,
motion.
actuator
3,747,120



magnetostriction, or other form of


IJ03, IJ09, IJ10,



relative dimensional change.


IJ19






IJ23, IJ24, IJ25,






IJ29






IJ30, IJ31, IJ33,






IJ34






IJ35


Swivel
The actuator swivels around a
Allows operation where
Inefficient coupling to the ink motion
IJ06



central pivot. This motion is
the net linear force on the



suitable where there are opposite
paddle is zero



forces applied to opposite sides of
Small chip area



the paddle, e.g. Lorenz force.
requirements


Straighten
The actuator is normally bent, and
Can be used with shape
Requires careful balance of stresses to
IJ26, IJ32



straightens when energized.
memory alloys where the
ensure that the quiescent bend is




austenic phase is planar
accurate


Double bend
The actuator bends in one
One actuator can be
Difficult to make the drops
IJ36, IJ37, IJ38



direction when one element is
used to power two
ejected by both bend directions



energized, and bends the other
nozzles.
identical.



way when another element is
Reduced chip size.
A small efficiency loss compared



energized.
Not sensitive to
to equivalent single bend




ambient temperature
actuators.


Shear
Energizing the actuator causes a
Can increase the
Not readily applicable to other
1985 Fishbeck



shear motion in the actuator
effective travel of
actuator mechanisms
U.S. Pat. No. 4,584,590



material.
piezoelectric actuators


Radial
The actuator squeezes an ink
Relatively easy to
High force required
1970 Zoltan


constriction
reservoir, forcing ink from a
fabricate single
Inefficient
U.S. Pat. No. 3,683,212



constricted nozzle.
nozzles from glass
Difficult to integrate with VLSI




tubing as macroscopic
processes




structures


Coil/uncoil
A coiled actuator uncoils or coils
Easy to fabricate as a
Difficult to fabricate for non-
IJ17, IJ21, IJ34,



more tightly. The motion of the
planar VLSI process
planar devices
IJ35



free end of the actuator ejects the
Small area required,
Poor out-of-plane stiffness



ink.
therefore low cost


Bow
The actuator bows (or buckles) in
Can increase the speed
Maximum travel is constrained
IJ16, IJ18, IJ27



the middle when energized.
of travel
High force required




Mechanically rigid


Push-Pull
Two actuators control a shutter.
The structure is pinned
Not readily suitable for inkjets
IJ18



One actuator pulls the shutter, and
at both ends, so has a
which directly push the ink



the other pushes it.
high out-of-plane




rigidity


Curl inwards
A set of actuators curl inwards to
Good fluid flow to the
Design complexity
IJ20, IJ42



reduce the volume of ink that they
region behind the



enclose.
actuator increases




efficiency


Curl outwards
A set of actuators curl outwards,
Relatively simple
Relatively large chip area
IJ43



pressurizing ink in a chamber
construction



surrounding the actuators, and



expelling ink from a nozzle in the



chamber.


Iris
Multiple vanes enclose a volume
High efficiency
High fabrication complexity
IJ22



of ink. These simultaneously
Small chip area
Not suitable for pigmented inks



rotate, reducing the volume



between the vanes.


Acoustic
The actuator vibrates at a high
The actuator can be
Large area required for efficient
1993


vibration
frequency.
physically distant from
operation at useful frequencies
Hadimioglu et




the ink
Acoustic coupling and crosstalk
al, EUP 550,192





Complex drive circuitry
1993 Elrod et al,





Poor control of drop volume and
EUP 572,220





position


None
In various ink jet designs the
No moving parts
Various other tradeoffs are required to
Silverbrook, EP



actuator does not move.

eliminate moving parts
0771 658 A2 and






related patent






applications






Tone-jet



















NOZZLE REFILL METHOD











Nozzle






refill


method
Description
Advantages
Disadvantages
Examples





Surface
After the actuator is energized, it
Fabrication simplicity
Low speed
Thermal inkjet


tension
typically returns rapidly to its
Operational simplicity
Surface tension force relatively small
Piezoelectric inkjet



normal position. This rapid return

compared to actuator force
IJ01-IJ07, IJ10-IJ14



sucks in air through the nozzle

Long refill time usually dominates the
IJ16, IJ20, IJ22-IJ45



opening. The ink surface tension

total repetition rate



at the nozzle then exerts a small



force restoring the meniscus to a



minimum area.


Shuttered
Ink to the nozzle chamber is
High speed
Requires common ink pressure
IJ08, IJ13, IJ15,


oscillating
provided at a pressure that
Low actuator energy, as
oscillator
IJ17


ink
oscillates at twice the drop
the actuator need only
May not be suitable for pigmented
IJ18, IJ19, IJ21


pressure
ejection frequency. When a drop
open or close the shutter,
inks



is to be ejected, the shutter is
instead of ejecting the ink



opened for 3 half cycles: drop
drop



ejection, actuator return, and



refill.


Refill
After the main actuator has
High speed, as the nozzle
Requires two independent actuators
IJ09


actuator
ejected a drop a second (refill)
is actively refilled
per nozzle



actuator is 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 slight positive
High refill rate, therefore a
Surface spill must be prevented
Silverbrook, EP


ink
pressure. After the ink drop is
high drop repetition rate is
Highly hydrophobic print head
0771 658 A2 and


pressure
ejected, the nozzle chamber fills
possible
surfaces are required
related patent



quickly as surface tension and ink


applications



pressure both operate to refill the


Alternative for:



nozzle.


IJ01-IJ07, IJ10-IJ14






IJ16, IJ20, IJ22-IJ45



















METHOD OF RESTRICTING BACK-FLOW THROUGH INLET











Inlet back-flow






restriction method
Description
Advantages
Disadvantages
Examples





Long inlet
The ink inlet channel to the nozzle
Design simplicity
Restricts refill rate
Thermal inkjet


channel
chamber is made long and
Operational simplicity
May result in a relatively large chip
Piezoelectric inkjet



relatively narrow, relying on
Reduces crosstalk
area
IJ42, IJ43



viscous drag to reduce inlet back-flow.

Only partially effective


Positive ink pressure
The ink is under a positive
Drop selection and
Requires a method (such as a
Silverbrook, EP



pressure, so that in the quiescent
separation forces can
nozzle rim or effective
0771 658 A2



state some of the ink drop already
be reduced
hydrophobizing, or both) to
and related



protrudes from the nozzle.
Fast refill time
prevent flooding of the ejection
patent



This reduces the pressure in the

surface of the print head.
applications



nozzle chamber which is required


Possible



to eject a certain volume of ink.


operation of the



The reduction in chamber


following:



pressure results in a reduction in


IJ01-IJ07, IJ09-IJ12



ink pushed out through the inlet.


IJ14, IJ16, IJ20,






IJ22,






IJ23-IJ34, IJ36-IJ41






IJ44


Baffle
One or more baffles are placed in
The refill rate is not as
Design complexity
HP Thermal Ink



the inlet ink flow. When the
restricted as the long
May increase fabrication
Jet



actuator is energized, the rapid ink
inlet method.
complexity (e.g. Tektronix hot
Tektronix



movement creates eddies which
Reduces crosstalk
melt Piezoelectric print heads).
piezoelectric ink



restrict the flow through the inlet.


jet



The slower refill process is



unrestricted, and does not result in



eddies.


Flexible flap
In this method recently disclosed
Significantly reduces
Not applicable to most inkjet
Canon


restricts inlet
by Canon, the expanding actuator
back-flow for edge-
configurations



(bubble) pushes on a flexible flap
shooter thermal ink jet
Increased fabrication complexity



that restricts the inlet,
devices
Inelastic deformation of polymer





flap results in creep over extended





use


Inlet filter
A filter is located between the ink
Additional advantage
Restricts refill rate
IJ04, IJ12, IJ24,



inlet and the nozzle chamber. The
of ink filtration
May result in complex
IJ27



filter has a multitude of small
Ink filter may be
construction
IJ29, IJ30



holes or slots, restricting ink flow.
fabricated with no



The filter also removes particles
additional process



which may block the nozzle.
steps


Small inlet
The ink inlet channel to the nozzle
Design simplicity
Restricts refill rate
IJ02, IJ37, IJ44


compared to
chamber has a substantially

May result in a relatively large


nozzle
smaller cross section than that of

chip area



the nozzle, resulting in easier ink

Only partially effective



egress out of the nozzle than out



of the inlet.


Inlet shutter
A secondary actuator controls the
Increases speed of the ink-
Requires separate refill actuator and
IJ09



position of a shutter, closing off
jet print head operation
drive circuit



the ink inlet when the main



actuator is energized.


The inlet is
The method avoids the problem of
Back-flow problem is
Requires careful design to minimize
IJ01, IJ03, IJ05,


located behind
inlet back-flow by arranging the
eliminated
the negative pressure behind the
IJ06


the ink-
ink-pushing surface of the

paddle
IJ07, IJ10, IJ11,


pushing
actuator between the inlet and the


IJ14


surface
nozzle.


IJ16, IJ22, IJ23,






IJ25






IJ28, IJ31, IJ32,






IJ33






IJ34, IJ35, IJ36,






IJ39






IJ40, IJ41


Part of the
The actuator and a wall of the ink
Significant reductions in
Small increase in fabrication
IJ07, IJ20, IJ26,


actuator
chamber are arranged so that the
back-flow can be achieved
complexity
IJ38


moves to shut
motion of the actuator closes off
Compact designs possible


off the inlet
the inlet.


Nozzle
In some configurations of ink jet,
Ink back-flow problem is
None related to ink back-flow on
Silverbrook, EP


actuator does
there is no expansion or
eliminated
actuation
0771 658 A2 and


not result in
movement of an actuator which


related patent


ink back-flow
may cause ink back-flow through


applications



the inlet.


Valve-jet






Tone-jet






IJ08, IJ13, IJ15,






IJ17






IJ18, IJ19, IJ21



















NOZZLE CLEARING METHOD











Nozzle






Clearing


method
Description
Advantages
Disadvantages
Examples





Normal nozzle firing
All of the nozzles are fired
No added complexity on
May not be sufficient to displace
Most ink jet systems



periodically, before the ink has a
the print head
dried ink
IJ01-IJ07, IJ09-IJ12



chance to dry. When not in use


IJ14, IJ16, IJ20,



the nozzles are sealed (capped)


IJ22



against air.


IJ23-IJ34, IJ36-IJ45



The nozzle firing is usually



performed during a special



clearing cycle, after first moving



the print head to a cleaning



station.


Extra power to
In systems which heat the ink, but
Can be highly effective if
Requires higher drive voltage for
Silverbrook, EP


ink heater
do not boil it under normal
the heater is adjacent to
clearing
0771 658 A2 and



situations, nozzle clearing can be
the nozzle
May require larger drive transistors
related patent



achieved by over-powering the


applications



heater and boiling ink at the



nozzle.


Rapid
The actuator is fired in rapid
Does not require extra
Effectiveness depends substantially
May be used with:


succession of
succession. In some
drive circuits on the print
upon the configuration of the inkjet
IJ01-IJ07, IJ09-IJ11


actuator
configurations, this may cause
head
nozzle
IJ14, IJ16, IJ20,


pulses
heat build-up at the nozzle which
Can be readily controlled

IJ22



boils the ink, clearing the nozzle.
and initiated by digital

IJ23-IJ25, IJ27-IJ34



In other situations, it may cause
logic

IJ36-IJ45



sufficient vibrations to dislodge



clogged nozzles.


Extra power to
Where an actuator is not normally
A simple solution where
Not suitable where there is a hard
May be used with:


ink pushing
driven to the limit of its motion,
applicable
limit to actuator movement
IJ03, IJ09, IJ16,


actuator
nozzle clearing may be assisted by


IJ20



providing an enhanced drive


IJ23, IJ24, IJ25,



signal to the actuator.


IJ27






IJ29, IJ30, IJ31,






IJ32






IJ39, IJ40, IJ41,






IJ42






IJ43, IJ44, IJ45


Acoustic
An ultrasonic wave is applied to
A high nozzle clearing
High implementation cost if system
IJ08, IJ13, IJ15,


resonance
the ink chamber. This wave is of
capability can be achieved
does not already include an acoustic
IJ17



an appropriate amplitude and
May be implemented at
actuator
IJ18, IJ19, IJ21



frequency to cause sufficient force
very low cost in systems



at the nozzle to clear blockages.
which already include



This is easiest to achieve if the
acoustic actuators



ultrasonic wave is at a resonant



frequency of the ink cavity.


Nozzle
A microfabricated plate is pushed
Can clear severely clogged
Accurate mechanical alignment is
Silverbrook, EP


clearing plate
against the nozzles. The plate has
nozzles
required
0771 658 A2 and



a post for every nozzle. The array

Moving parts are required
related patent



of posts

There is risk of damage to the nozzles
applications





Accurate fabrication is required


Ink pressure
The pressure of the ink is
May be effective where
Requires pressure pump or other
May be used with


pulse
temporarily increased so that ink
other methods cannot be
pressure actuator
all IJ series ink jets



streams from all of the nozzles.
used
Expensive



This may be used in conjunction

Wasteful of ink



with actuator energizing.


Print head
A flexible ‘blade’ is wiped across
Effective for planar print
Difficult to use if print head surface is
Many ink jet


wiper
the print head surface. The blade
head surfaces
non-planar or very fragile
systems



is usually fabricated from a
Low cost
Requires mechanical parts



flexible polymer, e.g. rubber or

Blade can wear out in high volume



synthetic elastomer.

print systems


Separate ink
A separate heater is provided at
Can be effective where
Fabrication complexity
Can be used with


boiling heater
the nozzle although the normal
other nozzle clearing

many IJ series ink



drop e-ection mechanism does
methods cannot be used

jets



not require it. The heaters do not
Can be implemented at no



require individual drive circuits,
additional cost in some



as many nozzles can be cleared
inkjet configurations



simultaneously, and no imaging is



required.



















NOZZLE PLATE CONSTRUCTION











Nozzle plate






construction
Description
Advantages
Disadvantages
Examples





Electroformed
A nozzle plate is separately
Fabrication simplicity
High temperatures and pressures are
Hewlett Packard


nickel
fabricated from electroformed

required to bond nozzle plate
Thermal Inkjet



nickel, and bonded to the print

Minimum thickness constraints



head chip.

Differential thermal expansion


Laser ablated
Individual nozzle holes are
No masks required
Each hole must be individually
Canon Bubblejet


or drilled
ablated by an intense UV laser in
Can be quite fast
formed
1988 Sercel et al.,


polymer
a nozzle plate, which is typically a
Some control over nozzle
Special equipment required
SPIE, Vol. 998



polymer such as polyimide or
profile is possible
Slow where there are many thousands
Excimer Beam



polysulphone
Equipment required is
of nozzles per print head
Applications, pp.




relatively low cost
May produce thin burrs at exit holes
76-83






1993 Watanabe et






al., U.S. Pat. No.






5,208,604


Silicon micromachined
A separate nozzle plate is
High accuracy is attainable
Two part construction
K. Bean, IEEE



micromachined from single

High cost
Transactions on



crystal silicon, and bonded to the

Requires precision alignment
Electron Devices,



print head wafer.

Nozzles may be clogged by adhesive
Vol. ED-25, No. 10,






1978, pp 1185-1195






Xerox 1990






Hawkins et al.,






U.S. Pat. No.






4,899,181


Glass
Fine glass capillaries are drawn
No expensive equipment
Very small nozzle sizes are difficult
1970 Zoltan U.S.


capillaries
from glass tubing. This method
required
to form
Pat. No. 3,683,212



has been used for making
Simple to make single
Not suited for mass production



individual nozzles, but is difficult
nozzles



to use for bulk manufacturing of



print heads with thousands of



nozzles.


Monolithic,
The nozzle plate is deposited as a
High accuracy (<1 μm)
Requires sacrificial layer under the
Silverbrook, EP


surface micromachined
layer using standard VLSI
Monolithic
nozzle plate to form the nozzle
0771 658 A2 and


using VLSI
deposition techniques. Nozzles
Low cost
chamber
related patent


lithographic
are etched in the nozzle plate
Existing processes can be
Surface may be fragile to the touch
applications


processes
using VLSI lithography and
used

IJ01, IJ02, IJ04,



etching.


IJ11






IJ12, IJ17, IJ18,






IJ20






IJ22, IJ24, IJ27,






IJ28






IJ29, IJ30, IJ31,






IJ32






IJ33, IJ34, IJ36,






IJ37






IJ38, IJ39, IJ40,






IJ41






IJ42, IJ43, IJ44


Monolithic,
The nozzle plate is a buried etch
High accuracy (<1 μm)
Requires long etch times
IJ03, IJ05, IJ06,


etched
stop in the wafer. Nozzle
Monolithic
Requires a support wafer
IJ07


through
chambers are etched in the front
Low cost

IJ08, IJ09, IJ10,


substrate
of the wafer, and the wafer is
No differential expansion

IJ13



thinned from the back side.


IJ14, IJ15, IJ16,



Nozzles are then etched in the


IJ19



etch stop layer.


IJ21, IJ23, IJ25,






IJ26


No nozzle
Various methods have been tried
No nozzles to become
Difficult to control drop position
Ricoh 1995 Sekiya


plate
to eliminate the nozzles entirely,
clogged
accurately
et al U.S. Pat. No.



to prevent nozzle clogging. These

Crosstalk problems
5,412,413



include thermal bubble


1993 Hadimioglu et al



mechanisms and acoustic lens


EUP 550,192



mechanisms


1993 Elrod et al






EUP 572,220


Trough
Each drop ejector has a trough
Reduced manufacturing
Drop firing direction is sensitive to
IJ35



through which a paddle moves.
complexity
wicking.



There is no nozzle plate.
Monolithic


Nozzle slit
The elimination of nozzle holes
No nozzles to become
Difficult to control drop position
1989 Saito et al U.S.


instead of
and replacement by a slit
clogged
accurately
Pat. No. 4,799,068


individual
encompassing many actuator

Crosstalk problems


nozzles
positions reduces nozzle clogging,



but increases crosstalk due to ink



surface waves



















DROP EJECTION DIRECTION











Ejection






direction
Description
Advantages
Disadvantages
Examples





Edge
Ink flow is along the surface of
Simple construction
Nozzles limited to edge
Canon


(‘edge
the chip, and ink drops are ejected
No silicon etching
High resolution is difficult
Bubblejet 1979


shooter’)
from the chip edge.
required
Fast color printing requires one
Endo et al GB




Good heat sinking via
print head per color
patent 2,007,162




substrate

Xerox heater-in-




Mechanically strong

pit 1990




Ease of chip handing

Hawkins et al






U.S. Pat. No.






4,899,181






Tone-jet


Surface
Ink flow is along the surface of
No bulk silicon
Maximum ink flow is severely
Hewlett-


(‘roof shooter’)
the chip, and ink drops are ejected
etching required
restricted
Packard TIJ



from the chip surface, normal to
Silicon can make an

1982 Vaught et



the plane of the chip.
effective heat sink

al U.S. Pat. No.




Mechanical strength

4,490,728






IJ02, IJ11, IJ12,






IJ20






IJ22


Through chip,
Ink flow is through the chip, and
High ink flow
Requires bulk silicon etching
Silverbrook, EP


forward
ink drops are ejected from the
Suitable for pagewidth

0771 658 A2


(‘up shooter’)
front surface of the chip.
print

and related




High nozzle packing

patent




density therefore low

applications




manufacturing cost

IJ04, IJ17, IJ18,






IJ24






IJ27-IJ45


Through chip,
Ink flow is through the chip, and
High ink flow
Requires wafer thinning
IJ01, IJ03, IJ05,


reverse
ink drops are ejected from the rear
Suitable for pagewidth
Requires special handling during
IJ06


(‘down
surface of the chip.
print
manufacture
IJ07, IJ08, IJ09,


shooter’)

High nozzle packing

IJ10




density therefore low

IJ13, IJ14, IJ15,




manufacturing cost

IJ16






IJ19, IJ21, IJ23,






IJ25






IJ26


Through
Ink flow is through the actuator,
Suitable for
Pagewidth print heads require
Epson Stylus


actuator
which is not fabricated as part of
piezoelectric print
several thousand connections to
Tektronix hot



the same substrate as the drive
heads
drive circuits
melt



transistors.

Cannot be manufactured in
piezoelectric ink





standard CMOS fabs
jets





Complex assembly required



















INK TYPE











Ink type
Description
Advantages
Disadvantages
Examples





Aqueous,
Water based ink which typically
Environmentally friendly
Slow drying
Most existing


dye
contains: water, dye, surfactant,
No odor
Corrosive
inkjets



humectant, and biocide.

Bleeds on paper
All IJ series ink jets



Modern ink dyes have high water-

May strikethrough
Silverbrook, EP



fastness, light fastness

Cockles paper
0771 658 A2 and






related patent






applications


Aqueous,
Water based ink which typically
Environmentally friendly
Slow drying
IJ02, IJ04, IJ21,


pigment
contains: water, pigment,
No odor
Corrosive
IJ26



surfactant, humectant, and
Reduced bleed
Pigment may clog nozzles
IJ27, IJ30



biocide.
Reduced wicking
Pigment may clog actuator
Silverbrook, EP



Pigments have an advantage in
Reduced strikethrough
mechanisms
0771 658 A2 and



reduced bleed, wicking and

Cockles paper
related patent



strikethrough.


applications






Piezoelectric ink-






jets






Thermal ink jets






(with significant






restrictions)


Methyl Ethyl
MEK is a highly volatile solvent
Very fast drying
Odorous
All IJ series ink jets


Ketone
used for industrial printing on
Prints on various
Flammable


(MEK)
difficult surfaces such as
substrates such as metals



aluminum cans.
and plastics


Alcohol
Alcohol based inks can be used
Fast drying
Slight odor
All IJ series ink jets


(ethanol, 2-
where the printer must operate at
Operates at sub-freezing
Flammable


butanol, and
temperatures below the freezing
temperatures


others)
point of water. An example of this
Reduced paper cockle



is in-camera consumer
Low cost



photographic printing.


Phase
The ink is solid at room
No drying time-ink
High viscosity
Tektronix hot melt


change
temperature, and is melted in the
instantly freezes on the
Printed ink typically has a ‘waxy’ feel
piezoelectric ink jets


(hot melt)
print head before jetting. Hot melt
print medium
Printed pages may ‘block’
1989 Nowak U.S.



inks are usually wax based, with a
Almost any print medium
Ink temperature may be above the
Pat. No. 4,820,346



melting point around 80° C. After
can be used
curie point of permanent magnets
All IJ series ink jets



jetting the ink freezes almost
No paper cockle occurs
Ink heaters consume power



instantly upon contacting the print
No wicking occurs
Long warm-up time



medium or a transfer roller.
No bleed occurs




No strikethrough occurs


Oil
Oil based inks are extensively
High solubility medium
High viscosity: this is a significant
All IJ series ink jets



used in offset printing. They have
for some dyes
limitation for use in inkjets, which



advantages in improved
Does not cockle paper
usually require a low viscosity. Some



characteristics on paper
Does not wick through
short chain and multi-branched oils



(especially no wicking or cockle).
paper
have a sufficiently low viscosity.



Oil soluble dies and pigments are

Slow drying



required.


Micro-
A microemulsion is a stable, self
Stops ink bleed
Viscosity higher than water
All IJ series ink jets


emulsion
forming emulsion of oil, water,
High dye solubility
Cost is slightly higher than water



and surfactant. The characteristic
Water, oil, and
based ink



drop size is less than 100 nm, and
amphiphilic soluble dies
High surfactant concentration



is determined by the preferred
can be used
required (around 5%)



curvature of the surfactant.
Can stabilize pigment




suspensions









Ink Jet Printing

A large number of new forms of ink jet printers have been developed to facilitate alternative ink jet technologies for the image processing and data distribution system. Various combinations of ink jet devices can be included in printer devices incorporated as part of the present invention. Australian Provisional Patent Applications relating to these ink jets which are specifically incorporated by cross reference include:












Australian




Pro-


visional
Filing


Number
Date
Title







PO8066
Jul. 15, 1997
Image Creation Method and Apparatus (IJ01)


PO8072
Jul. 15, 1997
Image Creation Method and Apparatus (IJ02)


PO8040
Jul. 15, 1997
Image Creation Method and Apparatus (IJ03)


PO8071
Jul. 15, 1997
Image Creation Method and Apparatus (IJ04)


PO8047
Jul. 15, 1997
Image Creation Method and Apparatus (IJ05)


PO8035
Jul. 15, 1997
Image Creation Method and Apparatus (IJ06)


PO8044
Jul. 15, 1997
Image Creation Method and Apparatus (IJ07)


PO8063
Jul. 15, 1997
Image Creation Method and Apparatus (IJ08)


PO8057
Jul. 15, 1997
Image Creation Method and Apparatus (IJ09)


PO8056
Jul. 15, 1997
Image Creation Method and Apparatus (IJ10)


PO8069
Jul. 15, 1997
Image Creation Method and Apparatus (IJ11)


PO8049
Jul. 15, 1997
Image Creation Method and Apparatus (IJ12)


PO8036
Jul. 15, 1997
Image Creation Method and Apparatus (IJ13)


PO8048
Jul. 15, 1997
Image Creation Method and Apparatus (IJ14)


PO8070
Jul. 15, 1997
Image Creation Method and Apparatus (IJ15)


PO8067
Jul. 15, 1997
Image Creation Method and Apparatus (IJ16)


PO8001
Jul. 15, 1997
Image Creation Method and Apparatus (IJ17)


PO8038
Jul. 15, 1997
Image Creation Method and Apparatus (IJ18)


PO8033
Jul. 15, 1997
Image Creation Method and Apparatus (IJ19)


PO8002
Jul. 15, 1997
Image Creation Method and Apparatus (IJ20)


PO8068
Jul. 15, 1997
Image Creation Method and Apparatus (IJ21)


PO8062
Jul. 15, 1997
Image Creation Method and Apparatus (IJ22)


PO8034
Jul. 15, 1997
Image Creation Method and Apparatus (IJ23)


PO8039
Jul. 15, 1997
Image Creation Method and Apparatus (IJ24)


PO8041
Jul. 15, 1997
Image Creation Method and Apparatus (IJ25)


PO8004
Jul. 15, 1997
Image Creation Method and Apparatus (IJ26)


PO8037
Jul. 15, 1997
Image Creation Method and Apparatus (IJ27)


PO8043
Jul. 15, 1997
Image Creation Method and Apparatus (IJ28)


PO8042
Jul. 15, 1997
Image Creation Method and Apparatus (IJ29)


PO8064
Jul. 15, 1997
Image Creation Method and Apparatus (IJ30)


PO9389
Sep. 23, 1997
Image Creation Method and Apparatus (IJ31)


PO9391
Sep. 23, 1997
Image Creation Method and Apparatus (IJ32)


PP0888
Dec. 12, 1997
Image Creation Method and Apparatus (IJ33)


PP0891
Dec. 12, 1997
Image Creation Method and Apparatus (IJ34)


PP0890
Dec. 12, 1997
Image Creation Method and Apparatus (IJ35)


PP0873
Dec. 12, 1997
Image Creation Method and Apparatus (IJ36)


PP0993
Dec. 12, 1997
Image Creation Method and Apparatus (IJ37)


PP0890
Dec. 12, 1997
Image Creation Method and Apparatus (IJ38)


PP1398
Jan. 19, 1998
An Image Creation Method and Apparatus




(IJ39)


PP2592
Mar. 25, 1998
An Image Creation Method and Apparatus




(IJ40)


PP2593
Mar. 25, 1998
Image Creation Method and Apparatus (IJ41)


PP3991
Jun. 9, 1998
Image Creation Method and Apparatus (IJ42)


PP3987
Jun. 9, 1998
Image Creation Method and Apparatus (IJ43)


PP3985
Jun. 9, 1998
Image Creation Method and Apparatus (IJ44)


PP3983
Jun. 9, 1998
Image Creation Method and Apparatus (IJ45)









Ink Jet Manufacturing

Further, the present application may utilize advanced semiconductor fabrication techniques in the construction of large arrays of ink jet printers. Suitable manufacturing techniques are described in the following Australian provisional patent specifications incorporated here by cross-reference:












Australian




Provisional



Number
Filing Date
Title







PO7935
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM01)


PO7936
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM02)


PO7937
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM03)


PO8061
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM04)


PO8054
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM05)


PO8065
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM06)


PO8055
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM07)


PO8053
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM08)


PO8078
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM09)


PO7933
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM10)


PO7950
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM11)


PO7949
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM12)


PO8060
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM13)


PO8059
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM14)


PO8073
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM15)


PO8076
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM16)


PO8075
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM17)


PO8079
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM18)


PO8050
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM19)


PO8052
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM20)


PO7948
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM21)


PO7951
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM22)


PO8074
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM23)


PO7941
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM24)


PO8077
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM25)


PO8058
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM26)


PO8051
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM27)


PO8045
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM28)


PO7952
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM29)


PO8046
Jul. 15, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM30)


PO8503
Aug. 11, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM30a)


PO9390
Sep. 23, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM31)


PO9392
Sep. 23, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM32)


PP0889
Dec. 12, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM35)


PP0887
Dec. 12, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM36)


PP0882
Dec. 12, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM37)


PP0874
Dec. 12, 1997
A Method of Manufacture of an Image Creation Apparatus




(IJM38)


PP1396
Jan. 19, 1998
A Method of Manufacture of an Image Creation Apparatus




(IJM39)


PP2591
Mar. 25, 1998
A Method of Manufacture of an Image Creation Apparatus




(IJM41)


PP3989
Jun. 9, 1998
A Method of Manufacture of an Image Creation Apparatus




(IJM40)


PP3990
Jun. 9, 1998
A Method of Manufacture of an Image Creation Apparatus




(IJM42)


PP3986
Jun. 9, 1998
A Method of Manufacture of an Image Creation Apparatus




(IJM43)


PP3984
Jun. 9, 1998
A Method of Manufacture of an Image Creation Apparatus




(IJM44)


PP3982
Jun. 9, 1998
A Method of Manufacture of an Image Creation Apparatus




(IJM45)









Fluid Supply

Further, the present application may utilize an ink delivery system to the ink jet head. Delivery systems relating to the supply of ink to a series of ink jet nozzles are described in the following Australian provisional patent specifications, the disclosure of which are hereby incorporated by cross-reference:












Australian




Provisional


Number
Filing Date
Title







PO8003
Jul. 15, 1997
Supply Method and Apparatus (F1)


PO8005
Jul. 15, 1997
Supply Method and Apparatus (F2)


PO9404
Sep. 23, 1997
A Device and Method (F3)









MEMS Technology

Further, the present application may utilize advanced semiconductor microelectromechanical techniques in the construction of large arrays of ink jet printers. Suitable microelectromechanical techniques are described in the following Australian provisional patent specifications incorporated here by cross-reference:












Australian




Provisional


Number
Filing Date
Title







PO7943
Jul. 15, 1997
A device (MEMS01)


PO8006
Jul. 15, 1997
A device (MEMS02)


PO8007
Jul. 15, 1997
A device (MEMS03)


PO8008
Jul. 15, 1997
A device (MEMS04)


PO8010
Jul. 15, 1997
A device (MEMS05)


PO8011
Jul. 15, 1997
A device (MEMS06)


PO7947
Jul. 15, 1997
A device (MEMS07)


PO7945
Jul. 15, 1997
A device (MEMS08)


PO7944
Jul. 15, 1997
A device (MEMS09)


PO7946
Jul. 15, 1997
A device (MEMS10)


PO9393
Sep. 23, 1997
A Device and Method (MEMS11)


PP0875
Dec. 12, 1997
A Device (MEMS12)


PP0894
Dec. 12, 1997
A Device and Method (MEMS13)









IR Technologies

Further, the present application may include the utilization of a disposable camera system such as those described in the following Australian provisional patent specifications incorporated here by cross-reference:












Australian




Provisional
Filing


Number
Date
Title







PP0895
Dec. 12, 1997
An Image Creation Method and Apparatus




(IR01)


PP0870
Dec. 12, 1997
A Device and Method (IR02)


PP0869
Dec. 12, 1997
A Device and Method (IR04)


PP0887
Dec. 12, 1997
Image Creation Method and Apparatus




(IR05)


PP0885
Dec. 12, 1997
An Image Production System (IR06)


PP0884
Dec. 12, 1997
Image Creation Method and Apparatus




(IR10)


PP0886
Dec. 12, 1997
Image Creation Method and Apparatus




(IR12)


PP0871
Dec. 12, 1997
A Device and Method (IR13)


PP0876
Dec. 12, 1997
An Image Processing Method and




Apparatus (IR14)


PP0877
Dec. 12, 1997
A Device and Method (IR16)


PP0878
Dec. 12, 1997
A Device and Method (IR17)


PP0879
Dec. 12, 1997
A Device and Method (IR18)


PP0883
Dec. 12, 1997
A Device and Method (IR19)


PP0880
Dec. 12, 1997
A Device and Method (IR20)


PP0881
Dec. 12, 1997
A Device and Method (IR21)









DotCard Technologies

Further, the present application may include the utilization of a data distribution system such as that described in the following Australian provisional patent specifications incorporated here by cross-reference:












Australian




Provisional


Number
Filing Date
Title







PP2370
Mar. 16, 1998
Data Processing Method and Apparatus




(Dot01)


PP2371
Mar. 16, 1998
Data Processing Method and Apparatus




(Dot02)









Artcam Technologies

Further, the present application may include the utilization of camera and data processing techniques such as an Artcam type device as described in the following Australian provisional patent specifications incorporated here by cross-reference:












Australian




Provisional
Filing


Number
Date
Title







PO7991
Jul. 15, 1997
Image Processing Method and Apparatus




(ART01)


PO8505
Aug. 11, 1997
Image Processing Method and Apparatus




(ART01a)


PO7988
Jul. 15, 1997
Image Processing Method and Apparatus




(ART02)


PO7993
Jul. 15, 1997
Image Processing Method and Apparatus




(ART03)


PO8012
Jul. 15, 1997
Image Processing Method and Apparatus




(ART05)


PO8017
Jul. 15, 1997
Image Processing Method and Apparatus




(ART06)


PO8014
Jul. 15, 1997
Media Device (ART07)


PO8025
Jul. 15, 1997
Image Processing Method and Apparatus




(ART08)


PO8032
Jul. 15, 1997
Image Processing Method and Apparatus




(ART09)


PO7999
Jul. 15, 1997
Image Processing Method and Apparatus




(ART10)


PO7998
Jul. 15, 1997
Image Processing Method and Apparatus




(ART11)


PO8031
Jul. 15, 1997
Image Processing Method and Apparatus




(ART12)


PO8030
Jul. 15, 1997
Media Device (ART13)


PO8498
Aug. 11, 1997
Image Processing Method and Apparatus




(ART14)


PO7997
Jul. 15, 1997
Media Device (ART15)


PO7979
Jul. 15, 1997
Media Device (ART16)


PO8015
Jul. 15, 1997
Media Device (ART17)


PO7978
Jul. 15, 1997
Media Device (ART18)


PO7982
Jul. 15, 1997
Data Processing Method and Apparatus




(ART19)


PO7989
Jul. 15, 1997
Data Processing Method and Apparatus




(ART20)


PO8019
Jul. 15, 1997
Media Processing Method and Apparatus




(ART21)


PO7980
Jul. 15, 1997
Image Processing Method and Apparatus




(ART22)


PO7942
Jul. 15, 1997
Image Processing Method and Apparatus




(ART23)


PO8018
Jul. 15, 1997
Image Processing Method and Apparatus




(ART24)


PO7938
Jul. 15, 1997
Image Processing Method and Apparatus




(ART25)


PO8016
Jul. 15, 1997
Image Processing Method and Apparatus




(ART26)


PO8024
Jul. 15, 1997
Image Processing Method and Apparatus




(ART27)


PO7940
Jul. 15, 1997
Data Processing Method and Apparatus




(ART28)


PO7939
Jul. 15, 1997
Data Processing Method and Apparatus




(ART29)


PO8501
Aug. 11, 1997
Image Processing Method and Apparatus




(ART30)


PO8500
Aug. 11, 1997
Image Processing Method and Apparatus




(ART31)


PO7987
Jul. 15, 1997
Data Processing Method and Apparatus




(ART32)


PO8022
Jul. 15, 1997
Image Processing Method and Apparatus




(ART33)


PO8497
Aug. 11, 1997
Image Processing Method and Apparatus




(ART30)


PO8029
Jul. 15, 1997
Sensor Creation Method and Apparatus




(ART36)


PO7985
Jul. 15, 1997
Data Processing Method and Apparatus




(ART37)


PO8020
Jul. 15, 1997
Data Processing Method and Apparatus




(ART38)


PO8023
Jul. 15, 1997
Data Processing Method and Apparatus




(ART39)


PO9395
Sep. 23, 1997
Data Processing Method and Apparatus




(ART4)


PO8021
Jul. 15, 1997
Data Processing Method and Apparatus




(ART40)


PO8504
Aug. 11, 1997
Image Processing Method and Apparatus




(ART42)


PO8000
Jul. 15, 1997
Data Processing Method and Apparatus




(ART43)


PO7977
Jul. 15, 1997
Data Processing Method and Apparatus




(ART44)


PO7934
Jul. 15, 1997
Data Processing Method and Apparatus




(ART45)


PO7990
Jul. 15, 1997
Data Processing Method and Apparatus




(ART46)


PO8499
Aug. 11, 1997
Image Processing Method and Apparatus




(ART47)


PO8502
Aug. 11, 1997
Image Processing Method and Apparatus




(ART48)


PO7981
Jul. 15, 1997
Data Processing Method and Apparatus




(ART50)


PO7986
Jul. 15, 1997
Data Processing Method and Apparatus




(ART51)


PO7983
Jul. 15, 1997
Data Processing Method and Apparatus




(ART52)


PO8026
Jul. 15, 1997
Image Processing Method and Apparatus




(ART53)


PO8027
Jul. 15, 1997
Image Processing Method and Apparatus




(ART54)


PO8028
Jul. 15, 1997
Image Processing Method and Apparatus




(ART56)


PO9394
Sep. 23, 1997
Image Processing Method and Apparatus




(ART57)


PO9396
Sep. 23, 1997
Data Processing Method and Apparatus




(ART58)


PO9397
Sep. 23, 1997
Data Processing Method and Apparatus




(ART59)


PO9398
Sep. 23, 1997
Data Processing Method and Apparatus




(ART60)


PO9399
Sep. 23, 1997
Data Processing Method and Apparatus




(ART61)


PO9400
Sep. 23, 1997
Data Processing Method and Apparatus




(ART62)


PO9401
Sep. 23, 1997
Data Processing Method and Apparatus




(ART63)


PO9402
Sep. 23, 1997
Data Processing Method and Apparatus




(ART64)


PO9403
Sep. 23, 1997
Data Processing Method and Apparatus




(ART65)


PO9405
Sep. 23, 1997
Data Processing Method and Apparatus




(ART66)


PP0959
Dec. 16, 1997
A Data Processing Method and Apparatus




(ART68)


PP1397
Jan. 19, 1998
A Media Device (ART69)

## Claims

1. A refillable ink supply cartridge for a postcard printing camera system, the cartridge comprising:
a pagewidth printhead having a series of holes etched on a back surface thereof for the supply of ink to a front surface of the printhead for subsequent ejection via a micro-electromechanical system;
an elongate top molding piece; and
an elongate bottom molding piece configured to operatively receive the top molding piece to define a plurality of elongate ink reservoirs, said bottom moulding piece supporting the printhead and having guide walls and block portions for arranging the ink reservoirs in fluid communication with the series of holes.

2. The cartridge of claim 1, wherein the ink reservoirs each include an elongate sponge to stabilize ink in that respective reservoir.

3. The cartridge of claim 1, wherein a series of air inlets are provided at a first end of the bottom molding piece, each air inlet leading to a corresponding winding channel which is hydrophobically treated so as to act as an ink repellent and therefore repel any ink that may flow along the air inlet channel.

4. The cartridge of claim 3, wherein each air inlet channel takes a convoluted path to assist in resisting any ink flow out of the ink reservoirs.

5. The cartridge of claim 3, wherein an adhesive tape portion seals the series of air inlets at the first end of the bottom moulding.

6. The cartridge of claim 1, wherein a series of refill holes are provided in the top moulding for refilling the ink reservoirs with ink, the cartridge including plugs for sealing the refill holes.

7. The cartridge of claim 1, wherein the guide walls separate the ink reservoirs, said walls being tapered into an end portion abutting the back surface of the printhead, the guide walls mechanically supported by the block portions which are placed at regular intervals along a length of the bottom moulding piece, said block portions having space at portions close to the back surface of the printhead for the flow of ink around the back surface.