# Patent

## Title
Postcard printing camera printing postage paid tokens

## Abstract

A recyclable, one-time use, print on demand, digital camera is provided which has an image sensor device for sensing an image. A processor processes the sensed image. A pagewidth printhead prints the sensed image. An ink supply arrangement supplies ink to the print head and the image is printed on print media from a supply of print media. The printer prints tokens designating that postage has been paid so that each image printed out on the print media has one such token associated with it.

## Background
CROSS REFERENCE TO RELATED APPLICATION
This is a Continuation Application 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 mm 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 rescaling 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
8



segments of the printhead


BitClock
Main data clock for the print head
1


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



CMY actuators, allowing different



pulse times for each color.


BankEnable[0-1]
Allows either simultaneous or
2



interleaved 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
5



for simultaneous actuation


ParallelXferClock
Loads the parallel transfer register
1



with the 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 segments, 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:











Reference
Title







6227652
Radiant Plunger Ink Jet Printer


6213588
Electrostatic Ink Jet Printer


6213589
Planar Thermoelastic Bend Actuator Ink



Jet


6231163
Stacked Electrostatic Ink Jet Printer


6247795
Reverse Spring Lever Ink Jet Printer


6394581
Paddle Type Ink Jet Printer


6244691
Permanent Magnet Electromagnetic Ink



Jet Printer


6257704
Planar Swing Grill Electromagnetic Ink



Jet Printer


6416168
Pump Action Refill Ink Jet Printer


6220694
Pulsed Magnetic Field Ink Jet Printer


6257705
Two Plate Reverse Firing



Electromagnetic Ink Jet Printer


6247794
Linear Stepper Actuator Ink Jet Printer


6234610
Gear Driven Shutter Ink Jet Printer


6247793
Tapered Magnetic Pole Electromagnetic



Ink Jet Printer


6264306
Linear Spring Electromagnetic Grill Ink



Jet Printer


6241342
Lorenz Diaphragm Electromagnetic Ink



Jet Printer


6247792
PTFE Surface Shooting Shuttered



Oscillating Pressure Ink Jet Printer


6264307
Buckle Grip Oscillating Pressure Ink Jet



Printer


6254220
Shutter Based Ink Jet Printer


6234611
Curling Calyx Thermoelastic Ink Jet



Printer


6302528
Thermal Actuated Ink Jet Printer


6283582
Iris Motion Ink Jet Printer


6239821
Direct Firing Thermal Bend Actuator Ink



Jet Printer


6338547
Conductive PTFE Ben Activator Vented



Ink Jet Printer


6247796
Magnetostrictive Ink Jet Printer


6557977
Shape Memory Alloy Ink Jet Printer


6390603
Buckle Plate Ink Jet Printer


6362843
Thermal Elastic Rotary Impeller Ink Jet



Printer


6293653
Thermoelastic Bend Actuator Ink Jet



Printer


6312107
Thermoelastic Bend Actuator Using



PTFE and Corrugated Copper Ink Jet



Printer


6227653
Bend Actuator Direct Ink Supply Ink Jet



Printer


6234609
A High Young's Modulus Thermoelastic



Ink Jet Printer


6238040
Thermally actuated slotted chamber wall



ink jet printer


6188415
Ink Jet Printer having a thermal actuator



comprising an external coiled spring


6227654
Trough Container Ink Jet Printer


6209989
Dual Chamber Single Vertical Actuator



Ink Jet


6247791
Dual Nozzle Single Horizontal Fulcrum



Actuator Ink Jet


6336710
Dual Nozzle Single Horizontal Actuator



Ink Jet


6217153
A single bend actuator cupped paddle ink



jet printing device


6416167
A thermally actuated ink jet printer



having a series of thermal actuator units


6243113
A thermally actuated ink jet printer



including a tapered heater element


6283581
Radial Back-Curling Thermoelastic Ink



Jet


6247790
Inverted Radial Back-Curling



Thermoelastic Ink Jet


6260953
Surface bend actuator vented ink supply



ink jet printer


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 ink-jet 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 bubble
An electrothermal heater
Large force generated
High power
Canon Bubblejet 1979



heats the ink to
Simple construction
Ink carrier limited
Endo et al GB patent



above boiling point,
No moving parts
to water
2,007,162



transferring significant
Fast operation
Low efficiency
Xerox heater-in-pit 1990



heat to the aqueous ink.
Small chip area required for
High temperatures
Hawkins et al U.S. Pat. No.



A bubble nucleates and
actuator
required
4,899,181



quickly forms, expelling

High mechanical
Hewlett-Packard TIJ



the ink. The efficiency

stress
1982 Vaught et al



of the process is low,

Unusual materials
U.S. Pat. No. 4,490,728



with typically less than

required



0.05% of the electrical

Large drive



energy being transformed

transistors



into kinetic energy of

Cavitation causes



the drop.

actuator failure





Kogation reduces





bubble formation





Large print heads





are difficult to





fabricate


Piezoelectric
A piezoelectric
Low power consumption
Very large area
Kyser et al U.S. Pat. No.



crystal such as lead
Many ink types can be used
required for
3,946,398



lanthanum zirconate
Fast operation
actuator
Zoltan U.S. Pat. No. 3,683,212



(PZT) is electrically
High efficiency
Difficult to
1973 Stemme U.S. Pat. No.



activated, and either

integrate with
3,747,120



expands, shears, or

electronics
Epson Stylus



bends to apply pressure

High voltage drive
Tektronix



to the ink, ejecting

transistors required
IJ04



drops.

Full pagewidth print





heads impractical due





to actuator size





Requires electrical





poling in high field





strengths during





manufacture


Electro-strictive
An electric field is
Low power consumption
Low maximum strain
Seiko Epson, Usui et all



used to activate
Many ink types can be used
(approx. 0.01%)
JP 253401/96



electrostriction in
Low thermal expansion
Large area required
IJ04



relaxor materials such
Electric field strength required
for actuator due to



as lead lanthanum
(approx. 3.5 V/μm) can be
low strain



zirconate titanate
generated without difficulty
Response speed is



(PLZT) or lead
Does not require electrical
marginal (~10 μs)



magnesium niobate
poling
High voltage drive



(PMN).

transistors required





Full pagewidth print





heads impractical due





to actuator size


Ferroelectric
An electric field is
Low power consumption
Difficult to
IJ04



used to induce a
Many ink types can be used
integrate with



phase transition
Fast operation (<1 μs)
electronics



between the
Relatively high longitudinal
Unusual materials



antiferroelectric
strain
such as PLZSnT are



(AFE) and ferroelectric
High efficiency
required



(FE) phase. Perovskite
Electric field strength of around
Actuators require



materials such as
3 V/μm can be readily
a large area



tin modified lead
provided



lanthanum zirconate



titanate (PLZSnT)



exhibit large strains



of up to 1% associated



with the AFE to FE



phase transition.


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


plates
separated by a
Many ink types can be used
electrostatic devices



compressible or fluid
Fast operation
in an aqueous



dielectric (usually

environment



air). Upon application

The electrostatic



of a voltage, the

actuator will normally



plates attract each

need to be separated



other and displace ink,

from the ink



causing drop ejection.

Very large area



The conductive plates

required to achieve



may be in a comb or

high forces



honeycomb structure, or

High voltage drive



stacked to increase the

transistors may be



surface area and

required



therefore the force.

Full pagewidth print





heads are not





competitive due to





actuator size


Electrostatic pull
A strong electric field
Low current consumption
High voltage required
1989 Saito et al, U.S. Pat. No.


on ink
is applied to the
Low temperature
May be damaged by
4,799,068



ink, whereupon

sparks due to air
1989 Miura et al, U.S. Pat. No.



electrostatic attraction

breakdown
4,810,954



accelerates the ink

Required field
Tone-jet



towards the print

strength increases



medium.

as the drop





size decreases





High voltage drive





transistors required





Electrostatic field





attracts dust


Permanent
An electromagnet
Low power consumption
Complex fabrication
IJ07, IJ10


magnet electro-
directly attracts a
Many ink types can be used
Permanent magnetic


magnetic
permanent magnet,
Fast operation
material such as



displacing ink and
High efficiency
Neodymium Iron Boron



causing drop ejection.
Easy extension from single
(NdFeB) required.



Rare earth magnets
nozzles to pagewidth print
High local currents



with a field strength
heads
required



around 1 Tesla can be

Copper metalization



used. Examples are:

should be used for



Samarium Cobalt

long electromigration



(SaCo) and magnetic

lifetime and low



materials in the

resistivity



neodymium iron boron

Pigmented inks are



family (NdFeB,

usually infeasible



NdDyFeBNb, NdDyFeB, etc)

Operating temperature





limited to the Curie





temperature (around





540 K)


Soft magnetic core
A solenoid induced a
Low power consumption
Complex fabrication
IJ01, IJ05, IJ08, IJ10


electro-magnetic
magnetic field in a
Many ink types can be used
Materials not usually
IJ12, IJ14, IJ15, IJ17



soft magnetic core or
Fast operation
present in a CMOS fab



yoke fabricated from a
High efficiency
such as NiFe, CoNiFe,



ferrous material such as
Easy extension from single
or CoFe are



electroplated iron
nozzles to pagewidth print
required



alloys such as CoNiFe
heads
High local currents



[1], CoFe, or NiFe

required



alloys. Typically, the

Copper metalization



soft magnetic material

should be used for



is in two parts,

long electromigration



which are normally held

lifetime and low



apart by a spring. When

resistivity



the solenoid is actuated,

Electroplating is



the two parts attract,

required



displacing the ink.

High saturation flux





density is required





(2.0-2.1 T is





achievable with





CoNiFe [1])


Magnetic
The Lorenz force acting
Low power consumption
Force acts as a
IJ06, IJ11, IJ13, IJ16


Lorenz force
on a current carrying
Many ink types can be used
twisting motion



wire in a magnetic field
Fast operation
Typically, only a



is utilized.
High efficiency
quarter of the sole-



This allows the
Easy extension from single
noid length provides



magnetic field to be
nozzles to pagewidth print
force in a useful



supplied externally to
heads
direction



the print head, for

High local currents



example with rare earth

required



permanent magnets.

Copper metalization



Only the current

should be used for



carrying wire need be

long electromigration



fabricated on the print-

lifetime and low



head, simplifying

resistivity



materials requirements.

Pigmented inks are





usually infeasible


Magneto-striction
The actuator uses the
Many ink types can be used
Force acts as a
Fischenbeck, U.S. Pat. No.



giant magnetostrictive
Fast operation
twisting motion
4,032,929



effect of materials such
Easy extension from single
Unusual materials
IJ25



as Terfenol-D (an
nozzles to pagewidth print
such as Terfenol-D



alloy of terbium,
heads
are required



dysprosium and iron
High force is available
High local currents



developed at the

required



Naval Ordnance

Copper metalization



Laboratory, hence Ter-

should be used for



Fe-NOL). For best

long electromigration



efficiency, the

lifetime and low



actuator should be

resistivity



pre-stressed to

Pre-stressing may



approx. 8 MPa.

be required


Surface tension
Ink under positive
Low power consumption
Requires supplementary
Silverbrook, EP 0771


reduction
pressure is held in
Simple construction
force to effect drop
658 A2 and related



a nozzle by surface
No unusual materials required
separation
patent applications



tension. The surface
in fabrication
Requires special ink



tension of the ink is
High efficiency
surfactants



reduced below the
Easy extension from single
Speed may be limited



bubble threshold,
nozzles to pagewidth print
by surfactant



causing the ink to
heads
properties



egress from the nozzle.


Viscosity
The ink viscosity is
Simple construction
Requires supplementary
Silverbrook, EP 0771


reduction
locally reduced to
No unusual materials required
force to effect drop
658 A2 and related



select which drops
in fabrication
separation
patent applications



are to be ejected. A
Easy extension from single
Requires special ink



viscosity reduction
nozzles to pagewidth print
viscosity properties



can be achieved
heads
High speed is



electrothermally with

difficult to achieve



most inks, but

Requires oscillating



special inks can be

ink pressure



engineered for a 100:1

A high temperature



viscosity reduction.

difference (typically





80 degrees) is required


Acoustic
An acoustic wave is
Can operate without a nozzle
Complex drive circuitry
1993 Hadimioglu et al,



generated and
plate
Complex fabrication
EUP 550,192



focussed upon the

Low efficiency
1993 Elrod et al, EUP



drop ejection region.

Poor control of drop
572,220





position





Poor control of drop





volume


Thermoelastic
An actuator which
Low power consumption
Efficient aqueous
IJ03, IJ09, IJ17, IJ18


bend actuator
relies upon
Many ink types can be used
operation requires
IJ19, IJ20, IJ21, IJ22



differential thermal
Simple planar fabrication
a thermal insulator
IJ23, IJ24, IJ27, IJ28



expansion upon
Small chip area required for
on the hot side
IJ29, IJ30, IJ31, IJ32



Joule heating is used.
each actuator
Corrosion prevention
IJ33, IJ34, IJ35, IJ36




Fast operation
can be difficult
IJ37, IJ38, IJ39, IJ40




High efficiency
Pigmented inks may
IJ41




CMOS compatible voltages and
be infeasible, as




currents
pigment particles




Standard MEMS processes can
may jam the bend




be used
actuator




Easy extension from single




nozzles to pagewidth print




heads


High CTE
A material with a very
High force can be generated
Requires special
IJ09, IJ17, IJ18, IJ20


thermoelastic
high coefficient of
PTFE is a candidate for low
material (e.g. PTFE)
IJ21, IJ22, IJ23, IJ24


actuator
thermal expansion (CTE)
dielectric constant insulation
Requires a PTFE
IJ27, IJ28, IJ29, IJ30



such as
in ULSI
deposition process,
IJ31, IJ42, IJ43, IJ44



polytetrafluoroethylene
Very low power consumption
which is not yet



(PTFE) is used.
Many ink types can be used
standard in ULSI fabs



As high CTE materials
Simple planar fabrication
PTFE deposition



are usually non-
Small chip area required for
cannot be followed



conductive, a heater
each actuator
with high temperature



fabricated from a
Fast operation
(above 350 °C.)



conductive material
High efficiency
processing



is incorporated. A 50
CMOS compatible voltages and
Pigmented inks may



μm long PTFE bend
currents
be infeasible, as



actuator with
Easy extension from single
pigment particles



polysilicon heater
nozzles to pagewidth print
may jam the bend



and 15 mW power
heads
actuator



input can provide 180



μN force and 10



μm deflection.



Actuator motions include:



Bend



Push



Buckle



Rotate


Conductive
A polymer with a
High force can be generated
Requires special
IJ24


polymer
high coefficient of
Very low power consumption
materials development


thermoelastic
thermal expansion
Many ink types can be used
(High CTE conductive


actuator
(such as PTFE) is
Simple planar fabrication
polymer)



doped with conducting
Small chip area required for
Requires a PTFE



substances to
each actuator
deposition process,



increase its
Fast operation
which is not yet



conductivity to about
High efficiency
standard in ULSI fabs



3 orders of magnitude
CMOS compatible voltages and
PTFE deposition cannot



below that of
currents
be followed with high



copper. The conducting
Easy extension from single
temperature (above



polymer expands
nozzles to pagewidth print
350 °C.) processing



when resistively heated.
heads
Evaporation and CVD



Examples of conducting

deposition techniques



dopants include:

cannot be used



Carbon nanotubes

Pigmented inks may



Metal fibers

be infeasible, as



Conductive polymers

pigment particles



such as doped

may jam the bend



polythiophene

actuator



Carbon granules


Shape memory
A shape memory alloy
High force is available (stresses
Fatigue limits
IJ26


alloy
such as TiNi (also
of hundreds of MPa)
maximum number of



known as Nitinol -
Large strain is available (more
cycles



Nickel Titanium alloy
than 3%)
Low strain (1%) is



developed at the
High corrosion resistance
required to extend



Naval Ordnance
Simple construction
fatigue resistance



Laboratory) is
Easy extension from single
Cycle rate limited



thermally switched
nozzles to pagewidth print
by heat removal



between its weak
heads
Requires unusual



martensitic state and
Low voltage operation
materials (TiNi)



its high stiffness

The latent heat of



austenic state. The

transformation must



shape of the actuator

be provided



in its martensitic

High current operation



state is deformed

Requires pre-stressing



relative to the

to distort the



austenic shape.

martensitic state



The shape change



causes ejection



of a drop.


Linear Magnetic
Linear magnetic
Linear Magnetic actuators can
Requires unusual semi-
IJ12


Actuator
actuators include the
be constructed with high
conductor materials



Linear Induction
thrust, long travel, and high
such as soft magnetic



Actuator (LIA), Linear
efficiency using planar
alloys (e.g. CoNiFe



Permanent Magnet
semiconductor fabrication
[1])



Synchronous Actuator
techniques
Some varieties also



(LPMSA), Linear
Long actuator travel is available
require permanent



Reluctance Synchronous
Medium force is available
magnetic materials



Actuator (LRSA), Linear
Low voltage operation
such as Neodymium



Switched Reluctance

iron boron (NdFeB)



Actuator (LSRA),

Requires complex



and the Linear Stepper

multi-phase drive



Actuator (LSA).

circuitry





High current operation



















BASIC OPERATION MODE











Operational mode
Description
Advantages
Disadvantages
Examples





Actuator directly
This is the simplest
Simple operation
Drop repetition rate is usually limited to less
Thermal inkjet


pushes ink
mode of operation:
No external fields required
than 10 KHz. However, this is not
Piezoelectric inkjet



the actuator directly
Satellite drops can be avoided if
fundamental to the method, but is related
IJ01, IJ02, IJ03, IJ04



supplies sufficient
drop velocity is less than 4
to the refill method normally used
IJ05, IJ06, IJ07, IJ09



kinetic energy to
m/s
All of the drop kinetic energy must be
IJ11, IJ12, IJ14, IJ16



expel the drop. The
Can be efficient, depending
provided by the actuator
IJ20, IJ22, IJ23, IJ24



drop must have a
upon the actuator used
Satellite drops usually form if drop velocity
IJ25, IJ26, IJ27, IJ28



sufficient velocity

is greater than 4.5 m/s
IJ29, IJ30, IJ31, IJ32



to overcome the


IJ33, IJ34, IJ35, IJ36



surface tension.


IJ37, IJ38, IJ39, IJ40






IJ41, IJ42, IJ43, IJ44


Proximity
The drops to be
Very simple print head
Requires close proximity between the print
Silverbrook, EP 0771



printed are selected
fabrication can be used
head and the print media or transfer roller
658 A2 and related



by some manner (e.g.
The drop selection means does
May require two print heads printing
patent applications



thermally induced
not need to provide the
alternate rows of the image



surface tension
energy required to separate
Monolithic color print heads are difficult



reduction of pressur-
the drop from the nozzle



ized ink). Selected



drops are separated



from the ink in the



nozzle by contact with



the print medium or



a transfer roller.


Electrostatic pull
The drops to be printed
Very simple print head
Requires very high electrostatic field
Silverbrook, EP 0771


on ink
are selected by
fabrication can be used
Electrostatic field for small nozzle sizes is
658 A2 and related



some manner (e.g.
The drop selection means does
above air breakdown
patent applications



thermally induced
not need to provide the
Electrostatic field may attract dust
Tone-Jet



surface tension
energy required to separate



reduction of pressur-
the drop from the nozzle



ized ink). Selected



drops are separated



from the ink in the



nozzle by a strong



electric field.


Magnetic pull on
The drops to be
Very simple print head
Requires magnetic ink
Silverbrook, EP 0771


ink
printed are selected
fabrication can be used
Ink colors other than black are difficult
658 A2 and related



by some manner (e.g.
The drop selection means does
Requires very high magnetic fields
patent applications



thermally induced
not need to provide the



surface tension
energy required to separate



reduction of pressur-
the drop from the nozzle



ized ink). Selected



drops are separated



from the ink in the



nozzle by a strong



magnetic field acting



on the magnetic ink.


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



shutter to block ink
operation can be achieved
Requires ink pressure modulator



flow to the nozzle.
due to reduced refill time
Friction and wear must be considered



The ink pressure is
Drop timing can be very
Stiction is possible



pulsed at a multiple
accurate



of the drop ejection
The actuator energy can be



frequency.
very low


Shuttered grill
The actuator moves a
Actuators with small travel can
Moving parts are required
IJ08, IJ15, IJ18, IJ19



shutter to block ink
be used
Requires ink pressure modulator



flow through a grill
Actuators with small force can
Friction and wear must be considered



to the nozzle. The
be used
Stiction is possible



shutter movement need
High speed (>50 KHz)



only be equal to
operation can be achieved



the width of the



grill holes.


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


pull on ink pusher
field attracts an ‘ink
is possible
Requires special materials for both the



pusher’ at the drop
No heat dissipation problems
actuator and the ink pusher



ejection frequency.

Complex construction



An actuator controls



a catch, which



prevents the ink



pusher from moving



when a drop is not



to be ejected.



















AUXILIARY MECHANISM (APPLIED TO ALL NOZZLES)











Auxiliary






Mechanism
Description
Advantages
Disadvantages
Examples





None
The actuator directly
Simplicity of construction
Drop ejection energy must be supplied
Most inkjets, including



fires the ink drop,
Simplicity of operation
by individual nozzle actuator
piezoelectric and



and there is no
Small physical size

thermal bubble.



external field or other


IJ01-IJ07, IJ09, IJ11



mechanism required.


IJ12, IJ14, IJ20, IJ22






IJ23-IJ45


Oscillating ink
The ink pressure
Oscillating ink pressure can
Requires external ink pressure oscillator
Silverbrook, EP 0771


pressure
oscillates, providing
provide a refill pulse,
Ink pressure phase and amplitude must
658 A2 and related


(including
much of the drop
allowing higher operating
be carefully controlled
patent applications


acoustic
ejection energy. The
speed
Acoustic reflections in the ink chamber
IJ08, IJ13, IJ15, IJ17


stimulation)
actuator selects
The actuators may operate with
must be designed for
IJ18, IJ19, IJ21



which drops are to be
much lower energy



fired by selectively
Acoustic lenses can be used to



blocking or enabling
focus the sound on the



nozzles. The ink
nozzles



pressure oscillation



may be achieved by



vibrating the print



head, or preferably



by an actuator in



the ink supply.


Media proximity
The print head is
Low power
Precision assembly required
Silverbrook, EP 0771



placed in close
High accuracy
Paper fibers may cause problems
658 A2 and related



proximity to the
Simple print head construction
Cannot print on rough substrates
patent applications



print medium. Selected



drops protrude from



the print head further



than unselected drops,



and contact the print



medium. The drop soaks



into the medium fast



enough to cause



drop separation.


Transfer roller
Drops are printed to
High accuracy
Bulky
Silverbrook, EP 0771



a transfer roller
Wide range of print substrates
Expensive
658 A2 and related



instead of straight
can be used
Complex construction
patent applications



to the print medium.
Ink can be dried on the transfer

Tektronix hot melt



A transfer roller
roller

piezoelectric inkjet



can also be used for


Any of the IJ series



proximity drop



separation.


Electrostatic
An electric field is
Low power
Field strength required for separation
Silverbrook, EP 0771



used to accelerate
Simple print head construction
of small drops is near or above air
658 A2 and related



selected drops towards

breakdown
patent applications



the print medium.


Tone-Jet


Direct magnetic
A magnetic field is
Low power
Requires magnetic ink
Silverbrook, EP 0771


field
used to accelerate
Simple print head construction
Requires strong magnetic field
658 A2 and related



selected drops of


patent applications



magnetic ink towards



the print medium.


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


field
placed in a constant
materials to be integrated in
Current densities may be high, resulting



magnetic field. The
the print head manufacturing
in electromigration problems



Lorenz force in a
process



current carrying wire



is used to move the



actuator.


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


field
field is used to
possible
Magnetic materials required in print head



cyclically attract a
Small print head size



paddle, which pushes



on the ink. A small



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 insuf-
Thermal Bubble InkJet



amplification is

ficient travel, or insufficient force,
IJ01, IJ02, IJ06, IJ07



used. The actuator

to efficiently drive the drop ejection
IJ16, IJ25, IJ26



directly drives the

process



drop ejection process.


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


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


actuator
one side than on
The bend actuator converts a
do not delaminate
IJ27 IJ29-IJ39, IJ42,



the other. The
high force low travel actuator
Residual bend resulting from high
IJ43, IJ44



expansion may be
mechanism to high travel,
temperature or high stress during



thermal, piezoelectric,
lower force mechanism.
formation



magnetostrictive, or



other mechanism.


Transient bend
A trilayer bend
Very good temperature stability
High stresses are involved
IJ40, IJ41


actuator
actuator where the two
High speed, as a new drop can
Care must be taken that the materials



outside layers are
be fired before heat dissipates
do not delaminate



identical. This cancels
Cancels residual stress of



bend due to ambient
formation



temperature and



residual stress.



The actuator only



responds to transient



heating of one side



or the other.


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



actuators are stacked.
Reduced drive voltage
Increased possibility of short circuits
jets



This can be

due to pinholes
IJ04



appropriate where



actuators require high



electric field



strength, such as



electrostatic and



piezoelectric



actuators.


Multiple actuators
Multiple smaller
Increases the force available
Actuator forces may not add linearly,
IJ12, IJ13, IJ18, IJ20



actuators are used
from an actuator
reducing efficiency
IJ22, IJ28, IJ42, IJ43



simultaneously to
Multiple actuators can be



move the ink. Each
positioned to control ink flow



actuator need
accurately



provide only a portion



of the force required.


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



used to transform a
with higher travel



motion with small
requirements



travel and high force
Non-contact method of motion



into a longer travel,
transformation



lower force motion.


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



spring. When the

High stress in the spring



actuator is turned off,



the 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 actuator
A bend actuator is
Increases travel
Generally restricted to planar
IJ17, IJ21, IJ34, IJ35



coiled to provide
Reduces chip area
implementations due to extreme



greater travel in a
Planar implementations are
fabrication difficulty in other



reduced chip area.
relatively easy to fabricate.
orientations.


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


actuator
a small region near
travel of a bend actuator
elastic limit in the flexure area



the fixture point,

Stress distribution is very uneven



which flexes much

Difficult to accurately model with finite



more readily than

element analysis



the remainder of the



actuator. The



actuator flexing is



effectively converted



from an even



coiling to an angular



bend, resulting in



greater travel of



the actuator tip.


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



increase travel at
can be used
Several actuator cycles are required



the expense of
Can be fabricated using
More complex drive electronics



duration. Circular
standard surface MEMS
Complex construction



gears, rack and pinion,
processes
Friction, friction, and wear are possible



ratchets, and other



gearing methods can



be used.


Catch
The actuator controls
Very low actuator energy
Complex construction
IJ10



a small catch. The
Very small actuator size
Requires external force



catch either enables

Unsuitable for pigmented inks



or disables movement of



an ink pusher that is



controlled in a bulk



manner.


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



used to change a

materials for long device life
jet Head . . . ”, Proc.



slow actuator into a

High stresses involved
IEEE MEMS, February



fast motion. It can

Generally high power requirement
1996, pp 418-423.



also convert a high


IJ18, IJ27



force, low travel



actuator into a high



travel, medium force



motion.


Tapered magnetic
A tapered magnetic
Linearizes the magnetic
Complex construction
IJ14


pole
pole can increase
force/distance curve



travel at the expense



of force.


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



is used to transform
with higher travel



a motion with small
requirements



travel and high force
Fulcrum area has no linear



into a motion with
movement, and can be used



longer travel and
for a fluid seal



lower force. The



lever can also



reverse the direction



of travel.


Rotary impeller
The actuator is
High mechanical advantage
Complex construction
IJ28



connected to a rotary
The ratio of force to travel of
Unsuitable for pigmented inks



impeller. A small
the actuator can be matched



angular deflection of
to the nozzle requirements by



the actuator results
varying the number of



in a rotation of the
impeller vanes



impeller vanes, which



push the ink against



stationary vanes and



out of the nozzle.


Acoustic lens
A refractive or
No moving parts
Large area required
1993 Hadimioglu et al,



diffractive (e.g. zone

Only relevant for acoustic ink jets
EUP 550,192



plate) acoustic lens


1993 Elrod et al, EUP



is used to concentrate


572,220



sound waves.


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


point
to concentrate an

VLSI processes for a surface ejecting



electrostatic field.

ink-jet





Only relevant for electrostatic ink





jets



















ACTUATOR MOTION











Actuator






motion
Description
Advantages
Disadvantages
Examples





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


expansion
actuator changes,
in the case
achieve volume expansion. This leads to
Thermal InkJet



pushing the ink in
of thermal ink jet
thermal stress, cavitation, and kogation
Canon Bubblejet



all directions.

in thermal ink jet implementations


Linear,
The actuator moves in
Efficient coupling
High fabrication complexity may be
IJ01, IJ02, IJ04, IJ07


normal to
a direction normal
to ink drops
required to achieve perpendicular motion
IJ11, IJ14


chip surface
to the print head
ejected normal to



surface. The nozzle
the surface



is typically in the



line of movement.


Linear,
The actuator moves
Suitable for planar
Fabrication complexity
IJ12, IJ13, IJ15, IJ33,


parallel to
parallel to the print
fabrication
Friction
IJ34, IJ35, IJ36


chip surface
head surface. Drop

Stiction



ejection may still be



normal to the surface.


Membrane push
An actuator with a
The effective
Fabrication complexity
1982 Howkins U.S. Pat. No.



high force but small
area of the
Actuator size
4,459,601



area is used to push
actuator becomes
Difficulty of integration in a VLSI



a stiff membrane that
the membrane area
process



is in contact with



the ink.


Rotary
The actuator causes
Rotary levers may
Device complexity
IJ05, IJ08, IJ13, IJ28



the rotation of some
be used to
May have friction at a pivot point



element, such a grill
increase travel



or impeller
Small chip area




requirements


Bend
The actuator bends
A very small
Requires the actuator to be made from
1970 Kyser et al U.S. Pat. No.



when energized. This
change in
at least two distinct layers, or to
3,946,398



may be due to
dimensions can
have a thermal difference across the
1973 Stemme U.S. Pat. No.



differential thermal
be converted
actuator
3,747,120



expansion, piezo-
to a large

IJ03, IJ09, IJ10, IJ19



electric expansion,
motion.

IJ23, IJ24, IJ25, IJ29



magnetostriction,


IJ30, IJ31, IJ33, IJ34



or other form of


IJ35



relative dimensional



change.


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



around a central
where the net



pivot. This motion is
linear force on



suitable where there
the paddle is



are opposite forces
zero



applied to opposite
Small chip area



sides of the paddle,
requirements



e.g. Lorenz force.


Straighten
The actuator is
Can be used
Requires careful balance of stresses to
IJ26, IJ32



normally bent, and
with shape
ensure that the quiescent bend is



straightens when
memory alloys
accurate



energized.
where the




austenic phase




is planar


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



one direction when one
be used to power
both bend directions identical.



element is energized,
two nozzles.
A small efficiency loss compared to



and bends the other way
Reduced chip size.
equivalent single bend actuators.



when another element is
Not sensitive to



energized.
ambient temperature


Shear
Energizing the actuator
Can increase the
Not readily applicable to other actuator
1985 Fishbeck U.S. Pat. No.



causes a shear motion in
effective travel
mechanisms
4,584,590



the actuator material.
of piezoelectric




actuators


Radial
The actuator squeezes
Relatively easy
High force required
1970 Zoltan U.S. Pat. No.


constriction
an ink reservoir,
to fabricate
Inefficient
3,683,212



forcing ink from a
single nozzles
Difficult to integrate with VLSI



constricted nozzle.
from glass
processes




tubing as




macroscopic




structures


Coil/uncoil
A coiled actuator
Easy to fabricate
Difficult to fabricate for non-planar
IJ17, IJ21, IJ34, IJ35



uncoils or coils more
as a planar
devices



tightly. The motion of
VLSI process
Poor out-of-plane stiffness



the free end of the
Small area



actuator ejects the ink.
required, therefore




low cost


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



buckles) in the
speed of travel
High force required



middle when energized.
Mechanically rigid


Push-Pull
Two actuators control
The structure is
Not readily suitable for inkjets which
IJ18



a shutter. One
pinned at both
directly push the ink



actuator pulls the
ends, so has a



shutter, and the other
high out-of-



pushes it.
plane rigidity


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



inwards to reduce
to the region



the volume of ink that
behind the



they enclose.
actuator increases




efficiency


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



curl outwards,
construction



pressurizing ink in



a chamber surrounding



the actuators, and



expelling ink from a



nozzle in the chamber.


Iris
Multiple vanes enclose
High efficiency
High fabrication complexity
IJ22



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



simultaneously rotate,



reducing the volume



between the vanes.


Acoustic vibration
The actuator vibrates
The actuator can
Large area required for efficient
1993 Hadimioglu et al,



at a high frequency.
be physically
operation at useful frequencies
EUP 550,192




distant from the
Acoustic coupling and crosstalk
1993 Elrod et al, EUP




ink
Complex drive circuitry
572,220





Poor control of drop volume and





position


None
In various ink jet
No moving parts
Various other tradeoffs are required
Silverbrook, EP 0771



designs the actuator

to eliminate moving parts
658 A2 and related



does not move.


patent applications






Tone-jet



















NOZZLE REFILL METHOD











Nozzle refill






method
Description
Advantages
Disadvantages
Examples





Surface tension
After the actuator
Fabrication simplicity
Low speed
Thermal ink jet



is energized, it
Operational simplicity
Surface tension force relatively small
Piezoelectric inkjet



typically returns

compared to actuator force
IJ01-IJ07, IJ10-IJ14



rapidly to its normal

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



position. This rapid

total repetition rate



return sucks in air



through the nozzle



opening. The ink



surface tension at



the nozzle then



exerts a small force



restoring the meniscus



to a minimum area.


Shuttered
Ink to the nozzle
High speed
Requires common ink pressure oscillator
IJ08, IJ13, IJ15, IJ17


oscillating ink
chamber is provided
Low actuator energy, as the
May not be suitable for pigmented inks
IJ18, IJ19, IJ21


pressure
at a pressure that
actuator need only open or



oscillates at twice
close the shutter, instead of



the drop ejection
ejecting the ink drop



frequency. When a drop



is to be ejected, the



shutter is opened for



3 half cycles: drop



ejection, actuator



return, and refill.


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



has ejected a drop a
actively refilled
nozzle



second (refill) 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 ink
The ink is held a slight
High refill rate, therefore a
Surface spill must be prevented
Silverbrook, EP 0771


pressure
positive pressure. After
high drop repetition rate is
Highly hydrophobic print head surfaces
658 A2 and related



the ink drop is ejected,
possible
are required
patent applications



the nozzle chamber fills


Alternative for:



quickly as surface


IJ01-IJ07, IJ10-IJ14



tension and ink pressure


IJ16, IJ20, IJ22-IJ45



both operate to refill



the nozzle.



















METHOD OF RESTRICTING BACK-FLOW THROUGH INLET











Inlet






back-flow


restriction


method
Description
Advantages
Disadvantages
Examples





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


channel
to the nozzle chamber
Operational simplicity
May result in a relatively large chip
Piezoelectric inkjet



is made long and
Reduces crosstalk
area
IJ42, IJ43



relatively narrow,

Only partially effective



relying on viscous



drag to reduce



inlet back-flow.


Positive ink
The ink is under a
Drop selection and separation
Requires a method (such as a nozzle rim
Silverbrook, EP 0771


pressure
positive pressure,
forces can be reduced
or effective hydrophobizing, or both) to
658 A2 and related



so that in the
Fast refill time
prevent flooding of the ejection surface
patent applications



quiescent state some

of the print head.
Possible operation of the



of the ink drop already


following:



protrudes from the


IJ01-IJ07, IJ09-IJ12



nozzle. This reduces


IJ14, IJ16, IJ20, IJ22,



the pressure in the


IJ23-IJ34, IJ36-IJ41



nozzle chamber which


IJ44



is required to eject



a certain volume of



ink. The reduction in



chamber pressure



results in a



reduction in ink



pushed out through



the inlet.


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



are placed in the
restricted as the long
May increase fabrication complexity
Tektronix piezoelectric



inlet ink flow. When
inlet method.
(e.g. Tektronix hot melt Piezoelectric
inkjet



the actuator is
Reduces crosstalk
print heads).



energized, the rapid



ink movement



creates eddies which



restrict the flow



through the inlet.



The slower refill



process is unre-



stricted, and does



not result in eddies.


Flexible flap
In this method
Significantly reduces back-flow
Not applicable to most inkjet config-
Canon


restricts inlet
recently disclosed by
for edge-shooter thermal ink
urations



Canon, the expanding
jet devices
Increased fabrication complexity



actuator (bubble)

Inelastic deformation of polymer flap



pushes on a flexible

results in creep over extended use



flap that restricts



the inlet.


Inlet filter
A filter is located
Additional advantage of ink
Restricts refill rate
IJ04, IJ12, IJ24, IJ27



between the ink inlet
filtration
May result in complex construction
IJ29, IJ30



and the nozzle chamber.
Ink filter may be fabricated



The filter has a
with no additional process



multitude of small
steps



holes or slots,



restricting ink flow.



The filter also



removes particles



which may block the



nozzle.


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


compared to
to the nozzle chamber

May result in a relatively large chip


nozzle
has a substantially

area



smaller cross section

Only partially effective



than that of the nozzle,



resulting in easier ink



egress out of the nozzle



than out of the inlet.


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



controls the position
jet print head operation
drive circuit



of a shutter, closing



off the ink inlet when



the main actuator is



energized.


The inlet is
The method avoids
Back-flow problem is
Requires careful design to minimize the
IJ01, IJ03, IJ05, IJ06


located behind
the problem of inlet
eliminated
negative pressure behind the paddle
IJ07, IJ10, IJ11, IJ14


the ink-pushing
back-flow by arrang-


IJ16, IJ22, IJ23, IJ25


surface
ing the ink-pushing


IJ28, IJ31, IJ32, IJ33



surface of the


IJ34, IJ35, IJ36, IJ39



actuator between the


IJ40, IJ41



inlet and the nozzle.


Part of the
The actuator and a
Significant reductions in back-
Small increase in fabrication complexity
IJ07, IJ20, IJ26, IJ38


actuator moves
wall of the ink
flow can be achieved


to shut off
chamber are arranged
Compact designs possible


the inlet
so that the motion



of the actuator



closes off the inlet.


Nozzle actuator
In some configura-
Ink back-flow problem is
None related to ink back-flow on
Silverbrook, EP 0771


does not result
tions of ink jet,
eliminated
actuation
658 A2 and related


in ink back-flow
there is no expan-


patent applications



sion or movement of


Valve-jet



an actuator which may


Tone-jet



cause ink back-flow


IJ08, IJ13, IJ15, IJ17



through the inlet.


IJ18, IJ19, IJ21



















NOZZLE CLEARING METHOD











Nozzle Clearing






method
Description
Advantages
Disadvantages
Examples





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


firing
fired periodically,
print head
ink
IJ01-IJ07, IJ09-IJ12



before the ink has a


IJ14, IJ16, IJ20, IJ22



chance to dry. When


IJ23-IJ34, IJ36-IJ45



not in use the nozzles



are sealed (capped)



against air.



The nozzle firing is



usually performed



during a special clear-



ing cycle, after first



moving the print head



to a cleaning station.


Extra power to
In systems which heat
Can be highly effective if the
Requires higher drive voltage for
Silverbrook, EP 0771


ink heater
the ink, but do not
heater is adjacent to the
clearing
658 A2 and related



boil it under normal
nozzle
May require larger drive transistors
patent applications



situations, nozzle



clearing can be



achieved by over-



powering the heater



and boiling ink at



the nozzle.


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


of actuator pulses
in rapid succession.
circuits on the print head
upon the configuration of the inkjet
IJ01-IJ07, IJ09-IJ11



In some configurations,
Can be readily controlled and
nozzle
IJ14, IJ16, IJ20, IJ22



this may cause heat
initiated by digital logic

IJ23-IJ25, IJ27-IJ34



build-up at the nozzle


IJ36-IJ45



which boils the ink,



clearing the nozzle.



In other situations,



it may cause sufficient



vibrations to dislodge



clogged nozzles.


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


ink pushing
not normally driven
applicable
to actuator movement
IJ03, IJ09, IJ16, IJ20


actuator
to the limit of its


IJ23, IJ24, IJ25, IJ27



motion, nozzle clearing


IJ29, IJ30, IJ31, IJ32



may be assisted by


IJ39, IJ40, IJ41, IJ42



providing an enhanced


IJ43, IJ44, IJ45



drive signal to the



actuator.


Acoustic
An ultrasonic wave is
A high nozzle clearing
High implementation cost if system does
IJ08, IJ13, IJ15, IJ17


resonance
applied to the ink
capability can be achieved
not already include an acoustic actuator
IJ18, IJ19, IJ21



chamber. This wave is
May be implemented at very



of an appropriate
low cost in systems which



amplitude and fre-
already include acoustic



quency to cause
actuators



sufficient force at



the nozzle to clear



blockages. This is



easiest to achieve if



the ultrasonic wave



is at a resonant



frequency of the ink



cavity.


Nozzle clearing
A microfabricated plate
Can clear severely clogged
Accurate mechanical alignment is re-
Silverbrook, EP 0771


plate
is pushed against the
nozzles
quired
658 A2 and related



nozzles. The plate has

Moving parts are required
patent applications



a post for every nozzle.

There is risk of damage to the nozzles



The array of posts

Accurate fabrication is required


Ink pressure pulse
The pressure of the
May be effective where other
Requires pressure pump or other
May be used with all IJ



ink is temporarily
methods cannot be used
pressure actuator
series ink jets



increased so that ink

Expensive



streams from all of

Wasteful of ink



the nozzles. This may



be used in con-



junction with actuator



energizing.


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



is wiped across the
surfaces
non-planar or very fragile



print head surface.
Low cost
Requires mechanical parts



The blade is usually

Blade can wear out in high volume print



fabricated from a

systems



flexible polymer, e.g.



rubber or synthetic



elastomer.


Separate ink
A separate heater is
Can be effective where other
Fabrication complexity
Can be used with many


boiling heater
provided at the
nozzle clearing methods

IJ series ink jets



nozzle although the
cannot be used



normal drop e-ection
Can be implemented at no



mechanism does not
additional cost in some inkjet



require it. The
configurations



heaters do not require



individual drive



circuits, as many



nozzles can be cleared



simultaneously, and



no imaging is required.



















NOZZLE PLATE CONSTRUCTION











Nozzle plate






construction
Description
Advantages
Disadvantages
Examples





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


nickel
separately fabricated

required to bond nozzle plate
Thermal Inkjet



from electroformed

Minimum thickness constraints



nickel, and bonded

Differential thermal expansion



to the print head chip.


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


drilled polymer
are ablated by an
Can be quite fast
Special equipment required
1988 Sercel et al.,



intense UV laser in a
Some control over nozzle
Slow where there are many thousands
SPIE, Vol. 998 Excimer



nozzle plate, which
profile is possible
of nozzles per print head
Beam Applications,



is typically a polymer
Equipment required is
May produce thin burrs at exit holes
pp. 76-83



such as polyimide or
relatively low cost

1993 Watanabe et al.,



polysulphone


U.S. Pat. No.






5,208,604


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


machined
plate is micromachined

High cost
Transactions on



from single crystal

Requires precision alignment
Electron Devices, Vol.



silicon, and bonded

Nozzles may be clogged by adhesive
ED-25, Nov. 10, 1978,



to the print head


pp 1185-1195



wafer.


Xerox 1990 Hawkins et






al., U.S. Pat. No.






4,899,181


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


capillaries
are drawn from glass
required
form
Pat. No. 3,683,212



tubing. This method
Simple to make single nozzles
Not suited for mass production



has been used for



making individual



nozzles, but is



difficult to use for



bulk manufacturing of



print heads with



thousands of nozzles.


Monolithic,
The nozzle plate is
High accuracy (<1 μm)
Requires sacrificial layer under the
Silverbrook, EP 0771


surface micro-
deposited as a layer
Monolithic
nozzle plate to form the nozzle chamber
658 A2 and related


machined using
using standard VLSI
Low cost
Surface may be fragile to the touch
patent applications


VLSI litho-
deposition techniques.
Existing processes can be

IJ01, IJ02, IJ04, IJ11


graphic
Nozzles are etched in
used

IJ12, IJ17, IJ18, IJ20


processes
the nozzle plate using


IJ22, IJ24, IJ27, IJ28



VLSI lithography and


IJ29, IJ30, IJ31, IJ32



etching.


IJ33, IJ34, IJ36, IJ37






IJ38, IJ39, IJ40, IJ41






IJ42, IJ43, IJ44


Monolithic,
The nozzle plate is a
High accuracy (<1 μm)
Requires long etch times
IJ03, IJ05, IJ06, IJ07


etched through
buried etch stop in
Monolithic
Requires a support wafer
IJ08, IJ09, IJ10, IJ13


substrate
the wafer. Nozzle
Low cost

IJ14, IJ15, IJ16, IJ19



chambers are etched in
No differential expansion

IJ21, IJ23, IJ25, IJ26



the front of the



wafer, and the wafer



is thinned from the



back side. Nozzles are



then etched in the



etch stop layer.


No nozzle plate
Various methods have
No nozzles to become clogged
Difficult to control drop position accu-
Ricoh 1995 Sekiya et al



been tried to eliminate

rately
U.S. Pat. No. 5,412,413



the nozzles entirely,

Crosstalk problems
1993 Hadimioglu et al



to prevent nozzle


EUP 550,192



clogging. These include


1993 Elrod et al EUP



thermal bubble mecha-


572,220



nisms and acoustic lens



mechanisms


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



a trough through
complexity
wicking.



which a paddle moves.
Monolithic



There is no nozzle



plate.


Nozzle slit
The elimination of
No nozzles to become clogged
Difficult to control drop position accu-
1989 Saito et al


instead of
nozzle holes and

rately
U.S. Pat. No.


individual
replacement by a

Crosstalk problems
4,799,068


nozzles
slit encompassing



many actuator posi-



tions reduces nozzle



clogging, but in-



creases crosstalk due



to ink surface waves



















DROP EJECTION DIRECTION











Ejection






direction
Description
Advantages
Disadvantages
Examples





Edge
Ink flow is along the
Simple construction
Nozzles limited to edge
Canon Bubblejet 1979


(‘edge shooter’)
surface of the chip,
No silicon etching required
High resolution is difficult
Endo et al GB patent



and ink drops are
Good heat sinking via sub-
Fast color printing requires one print
2,007,162



ejected from the chip
strate
head per color
Xerox heater-in-pit 1990



edge.
Mechanically strong

Hawkins et al U.S.




Ease of chip handing

Pat. No. 4,899,181






Tone-jet


Surface
Ink flow is along the
No bulk silicon etching
Maximum ink flow is severely restricted
Hewlett-Packard TIJ


(‘roof shooter’)
surface of the chip,
required

1982 Vaught et al



and ink drops are
Silicon can make an effective

U.S. Pat. No.



ejected from the chip
heat sink

4,490,728



surface, normal to
Mechanical strength

IJ02, IJ11, IJ12, IJ20



the plane of the chip.


IJ22


Through chip,
Ink flow is through
High ink flow
Requires bulk silicon etching
Silverbrook, EP 0771


forward
the chip, and ink
Suitable for pagewidth print

658 A2 and related


(‘up shooter’)
drops are ejected
High nozzle packing density

patent applications



from the front sur-
therefore low manufacturing

IJ04, IJ17, IJ18, IJ24



face of the chip.
cost

IJ27-IJ45


Through chip,
Ink flow is through
High ink flow
Requires wafer thinning
IJ01, IJ03, IJ05, IJ06


reverse
the chip, and ink
Suitable for pagewidth print
Requires special handling during
IJ07, IJ08, IJ09, IJ10


(‘down shooter’)
drops are ejected
High nozzle packing density
manufacture
IJ13, IJ14, IJ15, IJ16



from the rear surface
therefore low manufacturing

IJ19, IJ21, IJ23, IJ25



of the chip.
cost

IJ26


Through actuator
Ink flow is through
Suitable for piezoelectric
Pagewidth print heads require several
Epson Stylus



the actuator, which
print heads
thousand connections to drive circuits
Tektronix hot melt



is not fabricated as

Cannot be manufactured in standard
piezoelectric ink jets



part of the same

CMOS fabs



substrate as the

Complex assembly required



drive transistors.



















INK TYPE











Ink type
Description
Advantages
Disadvantages
Examples





Aqueous, dye
Water based ink
Environmentally friendly
Slow drying
Most existing inkjets



which typically
No odor
Corrosive
All IJ series ink jets



contains: water,

Bleeds on paper
Silverbrook, EP 0771



dye, surfactant,

May strikethrough
658 A2 and related



humectant, and

Cockles paper
patent applications



biocide.



Modern ink dyes



have high water-



fastness, light



fastness


Aqueous, pigment
Water based ink
Environmentally friendly
Slow drying
IJ02, IJ04, IJ21, IJ26



which typically
No odor
Corrosive
IJ27, IJ30



contains: water,
Reduced bleed
Pigment may clog nozzles
Silverbrook, EP 0771



pigment, surfactant,
Reduced wicking
Pigment may clog actuator mechanisms
658 A2 and related



humectant, and
Reduced strikethrough
Cockles paper
patent applications



biocide.


Piezoelectric ink-jets



Pigments have an


Thermal ink jets (with



advantage in reduced


significant



bleed, wicking


restrictions)



and strikethrough.


Methyl Ethyl
MEK is a highly vola-
Very fast drying
Odorous
All IJ series ink jets


Ketone (MEK)
tile solvent used for
Prints on various substrates
Flammable



industrial printing
such as metals and plastics



on difficult surfaces



such as aluminum cans.


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


(ethanol, 2-
can be used where
Operates at sub-freezing
Flammable


butanol, and
the printer must
temperatures


others)
operate at tempera-
Reduced paper cockle



tures below the
Low cost



freezing point of



water. An example of



this is in-camera



consumer photographic



printing.


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


(hot melt)
room temperature, and
freezes on the print medium
Printed ink typically has a ‘waxy’ feel
piezoelectric ink jets



is melted in the
Almost any print medium can
Printed pages may ‘block’
1989 Nowak U.S. Pat.



print head before jet-
be used
Ink temperature may be above the curie
No. 4,820,346



ting. Hot melt inks
No paper cockle occurs
point of permanent magnets
All IJ series ink jets



are usually wax based,
No wicking occurs
Ink heaters consume power



with a melting point
No bleed occurs
Long warm-up time



around 80° C. After
No strikethrough occurs



jetting the ink freezes



almost instantly upon



contacting the print



medium or a transfer



roller.


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



extensively used in
some dyes
limitation for use in inkjets, which



offset printing. They
Does not cockle paper
usually require a low viscosity. Some



have advantages in
Does not wick through paper
short chain and multi-branched oils



improved characteris-

have a sufficiently low viscosity.



tics on paper (especi-

Slow drying



ally no wicking or



cockle). Oil soluble



dies and pigments are



required.


Microemulsion
A microemulsion is a
Stops ink bleed
Viscosity higher than water
All IJ series ink jets



stable, self forming
High dye solubility
Cost is slightly higher than water based



emulsion of oil, water,
Water, oil, and amphiphilic
ink



and surfactant. The
soluble dies can be used
High surfactant concentration required



characteristic drop
Can stabilize pigment
(around 5%)



size is less than
suspensions



100 nm, and is deter-



mined by the preferred



curvature of the



surfactant.









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




Provisional


Number
Filing Date
Title







PO8066
15 Jul. 1997
Image Creation Method and




Apparatus (IJ01)


PO8072
15 Jul. 1997
Image Creation Method and




Apparatus (IJ02)


PO8040
15 Jul. 1997
Image Creation Method and




Apparatus (IJ03)


PO8071
15 Jul. 1997
Image Creation Method and




Apparatus (IJ04)


PO8047
15 Jul. 1997
Image Creation Method and




Apparatus (IJ05)


PO8035
15 Jul. 1997
Image Creation Method and




Apparatus (IJ06)


PO8044
15 Jul. 1997
Image Creation Method and




Apparatus (IJ07)


PO8063
15 Jul. 1997
Image Creation Method and




Apparatus (IJ08)


PO8057
15 Jul. 1997
Image Creation Method and




Apparatus (IJ09)


PO8056
15 Jul. 1997
Image Creation Method and




Apparatus (IJ10)


PO8069
15 Jul. 1997
Image Creation Method and




Apparatus (IJ11)


PO8049
15 Jul. 1997
Image Creation Method and




Apparatus (IJ12)


PO8036
15 Jul. 1997
Image Creation Method and




Apparatus (IJ13)


PO8048
15 Jul. 1997
Image Creation Method and




Apparatus (IJ14)


PO8070
15 Jul. 1997
Image Creation Method and




Apparatus (IJ15)


PO8067
15 Jul. 1997
Image Creation Method and




Apparatus (IJ16)


PO8001
15 Jul. 1997
Image Creation Method and




Apparatus (IJ17)


PO8038
15 Jul. 1997
Image Creation Method and




Apparatus (IJ18)


PO8033
15 Jul. 1997
Image Creation Method and




Apparatus (IJ19)


PO8002
15 Jul. 1997
Image Creation Method and




Apparatus (IJ20)


PO8068
15 Jul. 1997
Image Creation Method and




Apparatus (IJ21)


PO8062
15 Jul. 1997
Image Creation Method and




Apparatus (IJ22)


PO8034
15 Jul. 1997
Image Creation Method and




Apparatus (IJ23)


PO8039
15 Jul. 1997
Image Creation Method and




Apparatus (IJ24)


PO8041
15 Jul. 1997
Image Creation Method and




Apparatus (IJ25)


PO8004
15 Jul. 1997
Image Creation Method and




Apparatus (IJ26)


PO8037
15 Jul. 1997
Image Creation Method and




Apparatus (IJ27)


PO8043
15 Jul. 1997
Image Creation Method and




Apparatus (IJ28)


PO8042
15 Jul. 1997
Image Creation Method and




Apparatus (IJ29)


PO8064
15 Jul. 1997
Image Creation Method and




Apparatus (IJ30)


PO9389
23 Sep. 1997
Image Creation Method and




Apparatus (IJ31)


PO9391
23 Sep. 1997
Image Creation Method and




Apparatus (IJ32)


PP0888
12 Dec. 1997
Image Creation Method and




Apparatus (IJ33)


PP0891
12 Dec. 1997
Image Creation Method and




Apparatus (IJ34)


PP0890
12 Dec. 1997
Image Creation Method and




Apparatus (IJ35)


PP0873
12 Dec. 1997
Image Creation Method and




Apparatus (IJ36)


PP0993
12 Dec. 1997
Image Creation Method and




Apparatus (IJ37)


PP0890
12 Dec. 1997
Image Creation Method and




Apparatus (IJ38)


PP1398
19 Jan. 1998
An Image Creation Method and




Apparatus (IJ39)


PP2592
25 Mar. 1998
An Image Creation Method and




Apparatus (IJ40)


PP2593
25 Mar. 1998
Image Creation Method and




Apparatus (IJ41)


PP3991
9 Jun. 1998
Image Creation Method and




Apparatus (IJ42)


PP3987
9 Jun. 1998
Image Creation Method and




Apparatus (IJ43)


PP3985
9 Jun. 1998
Image Creation Method and




Apparatus (IJ44)


PP3983
9 Jun. 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
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM01)


PO7936
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM02)


PO7937
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM03)


PO8061
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM04)


PO8054
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM05)


PO8065
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM06)


PO8055
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM07)


PO8053
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM08)


PO8078
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM09)


PO7933
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM10)


PO7950
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM11)


PO7949
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM12)


PO8060
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM13)


PO8059
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM14)


PO8073
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM15)


PO8076
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM16)


PO8075
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM17)


PO8079
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM18)


PO8050
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM19)


PO8052
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM20)


PO7948
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM21)


PO7951
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM22)


PO8074
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM23)


PO7941
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM24)


PO8077
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM25)


PO8058
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM26)


PO8051
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM27)


PO8045
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM28)


PO7952
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM29)


PO8046
15 Jul. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM30)


PO8503
11 Aug. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM30a)


PO9390
23 Sep. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM31)


PO9392
23 Sep. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM32)


PP0889
12 Dec. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM35)


PP0887
12 Dec. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM36)


PP0882
12 Dec. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM37)


PP0874
12 Dec. 1997
A Method of Manufacture




of an Image Creation Apparatus (IJM38)


PP1396
19 Jan. 1998
A Method of Manufacture




of an Image Creation Apparatus (IJM39)


PP2591
25 Mar. 1998
A Method of Manufacture




of an Image Creation Apparatus (IJM41)


PP3989
9 Jun. 1998
A Method of Manufacture




of an Image Creation Apparatus (IJM40)


PP3990
9 Jun. 1998
A Method of Manufacture




of an Image Creation Apparatus (IJM42)


PP3986
9 Jun. 1998
A Method of Manufacture




of an Image Creation Apparatus (IJM43)


PP3984
9 Jun. 1998
A Method of Manufacture




of an Image Creation Apparatus (IJM44)


PP3982
9 Jun. 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
15 Jul. 1997
Supply Method and Apparatus (F1)


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


PO9404
23 Sep. 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
15 Jul. 1997
A device (MEMS01)


PO8006
15 Jul. 1997
A device (MEMS02)


PO8007
15 Jul. 1997
A device (MEMS03)


PO8008
15 Jul. 1997
A device (MEMS04)


PO8010
15 Jul. 1997
A device (MEMS05)


PO8011
15 Jul. 1997
A device (MEMS06)


PO7947
15 Jul. 1997
A device (MEMS07)


PO7945
15 Jul. 1997
A device (MEMS08)


PO7944
15 Jul. 1997
A device (MEMS09)


PO7946
15 Jul. 1997
A device (MEMS10)


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


PP0875
12 Dec. 1997
A device (MEMS12)


PP0894
12 Dec. 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



Number
Filing Date
Title









PP0895
12 Dec. 1997
An Image Creation





Method and Apparatus (IR01)



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



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



PP0887
12 Dec. 1997
Image Creation





Method and Apparatus (IR05)



PP0885
12 Dec. 1997
An Image Production





System (IR06)



PP0884
12 Dec. 1997
Image Creation





Method and Apparatus (IR10)



PP0886
12 Dec. 1997
Image Creation





Method and Apparatus (IR12)



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



PP0876
12 Dec. 1997
An Image Processing





Method and Apparatus (IR14)



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



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



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



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



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



PP0881
12 Dec. 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
16 Mar. 1998
Data Processing Method and





Apparatus (Dot01)



PP2371
16 Mar. 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


Number
Filing Date
Title







PO7991
15 Jul. 1997
Image Processing Method and




Apparatus (ART01)


PO8505
11 Aug. 1997
Image Processing Method and




Apparatus (ART01a)


PO7988
15 Jul. 1997
Image Processing Method and




Apparatus (ART02)


PO7993
15 Jul. 1997
Image Processing Method and




Apparatus (ART03)


PO8012
15 Jul. 1997
Image Processing Method and




Apparatus (ART05)


PO8017
15 Jul. 1997
Image Processing Method and




Apparatus (ART06)


PO8014
15 Jul. 1997
Media Device (ART07)


PO8025
15 Jul. 1997
Image Processing Method and




Apparatus (ART08)


PO8032
15 Jul. 1997
Image Processing Method and




Apparatus (ART09)


PO7999
15 Jul. 1997
Image Processing Method and




Apparatus (ART10)


PO7998
15 Jul. 1997
Image Processing Method and




Apparatus (ART11)


PO8031
15 Jul. 1997
Image Processing Method and




Apparatus (ART12)


PO8030
15 Jul. 1997
Media Device (ART13)


PO8498
11 Aug. 1997
Image Processing Method and




Apparatus (ART14)


PO7997
15 Jul. 1997
Media Device (ART15)


PO7979
15 Jul. 1997
Media Device (ART16)


PO8015
15 Jul. 1997
Media Device (ART17)


PO7978
15 Jul. 1997
Media Device (ART18)


PO7982
15 Jul 1997
Data Processing Method and




Apparatus (ART 19)


PO7989
15 Jul. 1997
Data Processing Method and




Apparatus (ART20)


PO8019
15 Jul. 1997
Media Processing Method and




Apparatus (ART21)


PO7980
15 Jul. 1997
Image Processing Method and




Apparatus (ART22)


PO7942
15 Jul. 1997
Image Processing Method and




Apparatus (ART23)


PO8018
15 Jul. 1997
Image Processing Method and




Apparatus (ART24)


PO7938
15 Jul. 1997
Image Processing Method and




Apparatus (ART25)


PO8016
15 Jul. 1997
Image Processing Method and




Apparatus (ART26)


PO8024
15 Jul. 1997
Image Processing Method and




Apparatus (ART27)


PO7940
15 Jul. 1997
Data Processing Method and




Apparatus (ART28)


PO7939
15 Jul. 1997
Data Processing Method and




Apparatus (ART29)


PO8501
11 Aug. 1997
Image Processing Method and




Apparatus (ART30)


PO8500
11 Aug. 1997
Image Processing Method and




Apparatus (ART31)


PO7987
15 Jul. 1997
Data Processing Method and




Apparatus (ART32)


PO8022
15 Jul. 1997
Image Processing Method and




Apparatus (ART33)


PO8497
11 Aug. 1997
Image Processing Method and




Apparatus (ART30)


PO8029
15 Jul. 1997
Sensor Creation Method and




Apparatus (ART36)


PO7985
15 Jul. 1997
Data Processing Method and




Apparatus (ART37)


PO8020
15 Jul. 1997
Data Processing Method and




Apparatus (ART38)


PO8023
15 Jul. 1997
Data Processing Method and




Apparatus (ART39)


PO9395
23 Sep. 1997
Data Processing Method and




Apparatus (ART4)


PO8021
15 Jul. 1997
Data Processing Method and




Apparatus (ART40)


PO8504
11 Aug. 1997
Image Processing Method and




Apparatus (ART42)


PO8000
15 Jul. 1997
Data Processing Method and




Apparatus (ART43)


PO7977
15 Jul. 1997
Data Processing Method and




Apparatus (ART44)


PO7934
15 Jul. 1997
Data Processing Method and




Apparatus (ART45)


PO7990
15 Jul. 1997
Data Processing Method and




Apparatus (ART46)


PO8499
11 Aug. 1997
Image Processing Method and




Apparatus (ART47)


PO8502
11 Aug. 1997
Image Processing Method and




Apparatus (ART48)


PO7981
15 Jul. 1997
Data Processing Method and




Apparatus (ART50)


PO7986
15 Jul. 1997
Data Processing Method and




Apparatus (ART51)


PO7983
15 Jul. 1997
Data Processing Method and




Apparatus (ART52)


PO8026
15 Jul. 1997
Image Processing Method and




Apparatus (ART53)


PO8027
15 Jul. 1997
Image Processing Method and




Apparatus (ART54)


PO8028
15 Jul. 1997
Image Processing Method and




Apparatus (ART56)


PO9394
23 Sep. 1997
Image Processing Method and




Apparatus (ART57)


PO9396
23 Sep. 1997
Data Processing Method and




Apparatus (ART58)


PO9397
23 Sep. 1997
Data Processing Method and




Apparatus (ART59)


PO9398
23 Sep. 1997
Data Processing Method and




Apparatus (ART60)


PO9399
23 Sep. 1997
Data Processing Method and




Apparatus (ART61)


PO9400
23 Sep. 1997
Data Processing Method and




Apparatus (ART62)


PO9401
23 Sep. 1997
Data Processing Method and




Apparatus (ART63)


PO9402
23 Sep. 1997
Data Processing Method and




Apparatus (ART64)


PO9403
23 Sep. 1997
Data Processing Method and




Apparatus (ART65)


PO9405
23 Sep. 1997
Data Processing Method and




Apparatus (ART66)


PP0959
16 Dec. 1997
A Data Processing Method and




Apparatus (ART68)


PP1397
19 Jan. 1998
A Media Device (ART69)

## Claims

1. 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, wherein the printer is adapted to print tokens at regularly spaced intervals on one surface of the print media designating that postage has been paid so that each image printed out on the print media has one such token associated with it.

2. The camera of claim 1 in which the supply of print media is in the form of a roll.

3. The camera of claim 2 in which each token has an address zone and a blank zone for writing associated with it on said one surface to provide a postcard effect.

4. The camera of claim 2 in which each image is printed on an opposed surface of the print media.

5. The camera of claim 1 in which the token 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 the camera.