# Patent

## Title
Printhead re-capping assembly for a print and demand digital camera system

## Abstract

A printhead re-capping assembly for a printer having a chassis, a platen assembly and a pagewidth printhead operatively mounted on the chassis to carry out a printing operation on print media passing over the platen assembly includes a base structure that is mounted on the chassis. At least one static solenoid is mounted on the base structure and is connected to an electrical power supply of the printer. A support member is actuable by the solenoid to be movable with respect to the chassis between an operative position and an inoperative position. A printhead capping member is mounted on the support member such that when the support member is in the operative position, the capping member engages the printhead to cap the printhead and when the support member is in the inoperative position, the capping member is disengaged from the printhead.

## Background
CROSS REFERENCE TO RELATED APPLICATION
The present application is a continuation of U.S. application Ser. No. 09/112,774 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 printhead re-capping assembly for a digital 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 can then 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 to supplying 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 a first aspect of the invention, there is provided a printhead re-capping assembly for a printer having a chassis, a platen assembly and a pagewidth printhead operatively mounted on the chassis to carry out a printing operation on print media passing over the platen assembly, the re-capping assembly comprising
a base structure that is mounted on the chassis;
at least one static solenoid that is mounted on the base structure and that is connected to an electrical power supply of the printer;
a support member that is actuable by the solenoid to be movable with respect to the chassis between an operative position and an inoperative position; and
a printhead capping member that is mounted on the support member such that when the support member is in the operative position, the capping member engages the printhead to cap the printhead and when the support member is in the inoperative position, the capping member is disengaged from the printhead.
The support member may be configured to be normally in the operative position and to move into the inoperative position when the solenoid is energized by the electrical power supply.
A biasing mechanism may be engaged with the support member to bias the support member into the operative position when the solenoid is de-energized.
The base structure and the solenoid may both be elongate to correspond with a length of the printhead.
The support member may also be elongate and may correspond generally with the printhead.
The capping member may include a length of sponge that is dimensioned to cover the printhead when the support member is displaced into its operative position.
A sealing member may be positioned on the support member to bound the length of sponge such that, when the length of sponge caps the printhead, the sealing member serves to seal a region about the printhead.
In accordance with a second aspect of the present invention, there is provided in a camera system comprising: an image sensor device for sensing an image; a processing means for processing the sensed image; a print media supply means for the supply of print media to a print head; a print head for printing the sensed image on the print media stored internally to the camera system; a portable power supply interconnected to the print head, the sensor and the processing means; and a guillotine mechanism located between the print media supply means and the print head and adapted to cut the print media into sheets of a predetermined size.
Further, preferably, the guillotine mechanism is detachable from the camera system. The guillotine mechanism can be attached to the print media supply means and is detachable from the camera system with the print media supply means. The guillotine mechanism can be mounted on a platen unit below the print head.



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 of the ink supply mechanism of the preferred embodiment;
FIG. 6 is rear perspective 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 platen unit of the preferred embodiment;
FIG. 9 is a perspective view of the assembled form of the platen unit;
FIG. 10 is also a perspective view of the assembled form of the platen 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 of the recapping mechanism of the preferred embodiment;
FIG. 13 is an exploded perspective 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 integrated circuit layer of the image capture and processing integrated circuit of the preferred embodiment;
FIG. 16 is an exploded view perspective 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 platen 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 4 whilst an LED light 5 is illuminated. The camera system also provides the usual view finder 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 decurling 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 eg. 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 motor 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 back exploded perspective view, FIG. 6 illustrates a back assembled 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 aluminium 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 integrated circuit can be via Tape Automated Bonding (TAB) Strips 51, 58. A moulded aspherical lens and aperture shim 50 (FIG. 5) is also provided for imaging an image onto the surface of the image sensor integrated circuit 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 eg. 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 eg. 55-57 are further provided for guiding the flexible PCB strip 47.
The ink supply mechanism 40 interacts with a platen unit 60 which guides print media under a printhead located in the ink supply mechanism. FIG. 8 shows an exploded view of the platen unit 60, while FIGS. 9 and 10 show assembled views of the platen unit. The platen unit 60 includes a first pinch roller 61 which is snap fitted to one side of a platen base 62. Attached to a second side of the platen 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 platen 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 71. 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 platen base 62 by means of a snap fit via clips 74.
The platen unit 60 includes an internal recapping mechanism 80 for recapping the print head 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 act 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 Aluminium 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 utilisation of a solenoid type device having a long rectangular form. Further, the preferred embodiment utilises 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 electro mechanical 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 utilised when constructing a printhead unit 102. The fundamental requirement of the ink supply cartridge 42 is the supply of ink to a series of colour channels etched through the back surface of the printhead 102. In the description of the preferred embodiment, it is assumed that a three colour printing process is to be utilised so as to provide full colour 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 stabilising ink within the corresponding ink channel and inhibiting the ink from sloshing back and forth when the printhead is utilised 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 colour 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 eg. 126 which are placed at regular intervals along the length of the ink supply unit. The block portions 126 leave 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 mould and the mould pieces eg. 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 utilising 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 integrated circuit (ICP) 48. The Image Capture and Processing integrated circuit 48 provides most of the electronic functionality of the camera with the exception of the print head integrated circuit. The integrated circuit 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 integrated circuit.
The integrated circuit is estimated to be around 32 mm2 using a leading edge 0.18 micron CMOS/DRAM/APS process. The integrated circuit 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 integrated circuits: one for the CMOS imaging array, and the other for the remaining circuitry. The cost of this two integrated circuit solution should not be significantly different than the single integrated circuit 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 integrated circuit 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 integrated circuit 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 integrated circuit affects the process required in two major ways:
The CMOS fabrication process should be optimized 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 integrated circuit 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 integrated circuit 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 integrated circuit 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 integrated circuit, the integrated circuit 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 digitization.
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.
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 integrated circuit 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 integrated circuit 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 integrated circuit oscillator with a phase locked loop 224 is used. As the frequency of an on-integrated circuit oscillator is highly variable from integrated circuit to integrated circuit, 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 inkjet heater pulse width with sufficient accuracy.
A scratchpad SRAM is a small static RAM 222 with a 6T cell. The scratchpad provided temporary memory for the 16 bit CPU. 1024 bytes is adequate.
A print head interface 223 formats the data correctly for the print head. The print head interface also provides all of the timing signals required by the print head. These timing signals may vary depending upon temperature, the number of dots printed simultaneously, the print medium in the print roll, and the dye density of the ink in the print roll.
The following is a table of external connections to the print head interface:












Connection
Function
Pins







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



of the print head


BitClock
Main data clock for the print head
1


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



actuators, allowing different pulse times for



each color.


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



actuation of two banks of nozzles. This



allows two different print speed/power



consumption tradeoffs


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



simultaneous actuation


ParallelXferClock
Loads the parallel transfer register with the
1



data from the shift registers



Total

20 









The print head utilized is composed of eight identical segments, each 1.25 cm long. There is no connection between the segments on the print head integrated circuit. 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 print head integrated circuit is long and narrow (10 cm×0.3 mm), the stepper field contains a single segment of 32 print head integrated circuits. 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 print head. 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 segments0, dot 750 is transferred to segment1, dot 1500 to segment2 etc simultaneously.
The ParallelXferClock is connected to each of the 8 segments on the print head, 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 eg. 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 integrated circuit 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 integrated circuit, a variety of testing techniques are required, including BIST (Built In Self Test) and functional block isolation. An overhead of 10% in integrated circuit area is assumed for integrated circuit 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 utilised 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 platen unit 60 is then inserted between the print roll 85 and aluminium 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 integrated circuit 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 authorised refills are conducted so as to enhance quality, routines in the on-integrated circuit 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 optimised 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 colour mapping function. A further alternative is to provide for black and white outputs again through a suitable colour remapping algorithm. Minimum colour can also be provided to add a touch of colour to black and white prints to produce the effect that was traditionally used to colourize black and white photos. Further, passport photo output can be provided through suitable address remappings within the address generators. Further, edge filters can be utilised 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 colour effects can be provided through remapping of the colour 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 utilised 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 pagewide 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. 45 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 print head is designed to be a monolithic 0.5 micron CMOS integrated circuit 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 integrated circuit area of 35 square mm. The print heads each contain 19,200 nozzles plus data and control circuitry.
Ink is supplied to the back of the print head by injection molded plastic ink channels. The molding requires 50 micron features, which can be created using a lithographically micromachined insert in a standard injection molding tool. Ink flows through holes etched through the wafer to the nozzle chambers fabricated on the front surface of the wafer. The print head is connected to the camera circuitry by tape automated bonding.
Cross-Referenced Applications
The following table is a guide to cross-referenced patent applications filed concurrently herewith and discussed hereinafter with the reference being utilized in subsequent tables when referring to a particular case:












Docket
Ref-



No.
erence
Title







IJ01US
IJ01
Radiant Plunger Ink Jet Printer


IJ02US
IJ02
Electrostatic Ink Jet Printer


IJ03US
IJ03
Planar Thermoelastic Bend Actuator Ink Jet


IJ04US
IJ04
Stacked Electrostatic Ink Jet Printer


IJ05US
IJ05
Reverse Spring Lever Ink Jet Printer


IJ06US
IJ06
Paddle Type Ink Jet Printer


IJ07US
IJ07
Permanent Magnet Electromagnetic Ink Jet Printer


IJ08US
IJ08
Planar Swing Grill Electromagnetic Ink Jet Printer


IJ09US
IJ09
Pump Action Refill Ink Jet Printer


IJ10US
IJ10
Pulsed Magnetic Field Ink Jet Printer


IJ11US
IJ11
Two Plate Reverse Firing Electromagnetic Ink Jet




Printer


IJ12US
IJ12
Linear Stepper Actuator Ink Jet Printer


IJ13US
IJ13
Gear Driven Shutter Ink Jet Printer


IJ14US
IJ14
Tapered Magnetic Pole Electromagnetic Ink Jet Printer


IJ15US
IJ15
Linear Spring Electromagnetic Grill Ink Jet Printer


IJ16US
IJ16
Lorenz Diaphragm Electromagnetic Ink Jet Printer


IJ17US
IJ17
PTFE Surface Shooting Shuttered Oscillating




Pressure Ink Jet Printer


IJ18US
IJ18
Buckle Grip Oscillating Pressure Ink Jet Printer


IJ19US
IJ19
Shutter Based Ink Jet Printer


IJ20US
IJ20
Curling Calyx Thermoelastic Ink Jet Printer


IJ21US
IJ21
Thermal Actuated Ink Jet Printer


IJ22US
IJ22
Iris Motion Ink Jet Printer


IJ23US
IJ23
Direct Firing Thermal Bend Actuator Ink Jet Printer


IJ24US
IJ24
Conductive PTFE Ben Activator Vented Ink Jet Printer


IJ25US
IJ25
Magnetostrictive Ink Jet Printer


IJ26US
IJ26
Shape Memory Alloy Ink Jet Printer


IJ27US
IJ27
Buckle Plate Ink Jet Printer


IJ28US
IJ28
Thermal Elastic Rotary Impeller Ink Jet Printer


IJ29US
IJ29
Thermoelastic Bend Actuator Ink Jet Printer


IJ30US
IJ30
Thermoelastic Bend Actuator Using PTFE and




Corrugated Copper Ink Jet Printer


IJ31US
IJ31
Bend Actuator Direct Ink Supply Ink Jet Printer


IJ32US
IJ32
A High Young's Modulus Thermoelastic Ink Jet




Printer


IJ33US
IJ33
Thermally actuated slotted chamber wall ink jet printer


IJ34US
IJ34
Ink Jet Printer having a thermal actuator comprising




an external coiled spring


IJ35US
IJ35
Trough Container Ink Jet Printer


IJ36US
IJ36
Dual Chamber Single Vertical Actuator Ink Jet


IJ37US
IJ37
Dual Nozzle Single Horizontal Fulcrum Actuator




Ink Jet


IJ38US
IJ38
Dual Nozzle Single Horizontal Actuator Ink Jet


IJ39US
IJ39
A single bend actuator cupped paddle ink jet printing




device


IJ40US
IJ40
A thermally actuated ink jet printer having a




series of thermal actuator units


IJ41US
IJ41
A thermally actuated ink jet printer including a




tapered heater element


IJ42US
IJ42
Radial Back-Curling Thermoelastic Ink Jet


IJ43US
IJ43
Inverted Radial Back-Curling Thermoelastic Ink Jet


IJ44US
IJ44
Surface bend actuator vented ink supply ink jet printer


IJ45US
IJ45
Coil Acutuated Magnetic Plate Ink Jet Printer









Tables of Drop-on-Demand Inkjets

Eleven important characteristics of the fundamental operation of individual inkjet nozzles have been identified. These characteristics are largely orthogonal, and so can be elucidated as an eleven dimensional matrix. Most of the eleven axes of this matrix include entries developed by the present assignee.
The following tables form the axes of an eleven dimensional table of inkjet types.
Actuator mechanism (18 types)
Basic operation mode (7 types)
Auxiliary mechanism (8 types)
Actuator amplification or modification method (17 types)
Actuator motion (19 types)
Nozzle refill method (4 types)
Method of restricting back-flow through inlet (10 types)
Nozzle clearing method (9 types)
Nozzle plate construction (9 types)
Drop ejection direction (5 types)
Ink type (7 types)
The complete eleven dimensional table represented by these axes contains 36.9 billion possible configurations of inkjet nozzle. While not all of the possible combinations result in a viable inkjet technology, many million configurations are viable. It is clearly impractical to elucidate all of the possible configurations. Instead, certain inkjet types have been investigated in detail. These are designated IJ01 to IJ45 above.
Other inkjet configurations can readily be derived from these 45 examples by substituting alternative configurations along one or more of the 11 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 11 dimensional matrix are set out in the following tables.












ACTUATOR MECHANISM (APPLIED ONLY TO SELECTED INK DROPS)











Actu-






ator


Mech-


anism
Description
Advantages
Disadvantages
Examples





Thermal
An electrothermal heater heats the
1) Large force generated
6) High power
16) Canon


bubble
ink to above boiling point,
2) Simple construction
7) Ink carrier limited to water
Bubblejet 1979 Endo



transferring significant heat to the
3) No moving parts
8) Low efficiency
et al GB patent



aqueous ink. A bubble nucleates and
4) Fast operation
9) High temperatures required
2,007,162



quickly forms, expelling the ink.
5) Small integrated circuit area
10) High mechanical stress
17) Xerox heater-in-



The efficiency of the process is low,
required for actuator
11) Unusual materials required
pit 1990 Hawkins et



with typically less than 0.05% of the

12) Large drive transistors
al U.S. Pat. No.



electrical energy being transformed

13) Cavitation causes actuator failure
4,899,181



into kinetic energy of the drop.

14) Kogation reduces bubble
18) Hewlett-Packard TIJ





formation
1982 Vaught et al 





15) Large print heads are difficult to
U.S. Pat. No. 4,490,728





fabricate


Piezo-
A piezoelectric crystal such as lead
19) Low power
23) Very large area required for
28) Kyser et al


electric
lanthanum zirconate (PZT) is
consumption
actuator
U.S. Pat. No. 3,946,398



electrically activated, and either
20) Many ink types can be
24) Difficult to integrate with
29) Zoltan U.S. Pat. No.



expands, shears, or bends to apply
used
electronics
3,683,212



pressure to the ink, ejecting drops.
21) Fast operation
25) High voltage drive transistors
30) 1973 Stemme




22) High efficiency
required
U.S. Pat. No. 3,747,120





26) Full pagewidth print heads
31) Epson Stylus





impractical due to actuator size
32) Tektronix





27) Requires electrical poling in high
33) IJ04





field strengths during manufacture


Electro-
An electric field is used to activate
34) Low power
39) Low maximum strain (approx.
44) Seiko Epson,


strictive
electrostriction in relaxor materials
consumption
0.01%)
Usui et all JP



such as lead lanthanum zirconate
35) Many ink types can be
40) Large area required for actuator
253401/96



titanate (PLZT) or lead magnesium
used
due to low strain
45) IJ04



niobate (PMN).
36) Low thermal
41) Response speed is marginal ( ̃10 μs)




expansion
42) High voltage drive transistors




37) Electric field strength
required




required (approx. 3.5 V/μm)
43) Full pagewidth print heads




can be generated without
impractical due to actuator size




difficulty




38) Does not require




electrical poling


Ferro-
An electric field is used to induce a
46) Low power
52) Difficult to integrate with
55) IJ04


electric
phase transition between the
consumption
electronics



antiferroelectric (AFE) and
47) Many ink types can be
53) Unusual materials such as



ferroelectric (FE) phase. Perovskite
used
PLZSnT are required



materials such as tin modified lead
48) Fast operation (<1 μs)
54) Actuators require a large area



lanthanum zirconate titanate
49) Relatively high



(PLZSnT) exhibit large strains of up
longitudinal strain



to 1% associated with the AFE to FE
50) High efficiency



phase transition.
51) Electric field strength




of around 3 V/μm can be




readily provided


Electro-
Conductive plates are separated by a
56) Low power
59) Difficult to operate electrostatic
64) IJ02, IJ04


static
compressible or fluid dielectric
consumption
devices in an aqueous environment


plates
(usually air). Upon application of a
57) Many ink types can be
60) The electrostatic actuator will



voltage, the plates attract each other
used
normally need to be separated from the



and displace ink, causing drop
58) Fast operation
ink



ejection. The conductive plates may

61) Very large area required to



be in a comb or honeycomb

achieve high forces



structure, or stacked to increase the

62) High voltage drive transistors



surface area and therefore the force.

may be required





63) Full pagewidth print heads are not





competitive due to actuator size


Electro-
A strong electric field is applied to
65) Low current
67) High voltage required
72) 1989 Saito et al,


static
the ink, whereupon electrostatic
consumption
68) May be damaged by sparks due to
U.S. Pat. No. 4,799,068


pull on
attraction accelerates the ink towards
66) Low temperature
air breakdown
73) 1989 Miura et


ink
the print medium.

69) Required field strength increases
al, U.S. Pat. No.





as the drop size decreases
4,810,954





70) High voltage drive transistors
74) Tone-jet





required





71) Electrostatic field attracts dust


Perma-
An electromagnet directly attracts a
75) Low power
80) Complex fabrication
86) IJ07, IJ10


nent
permanent magnet, displacing ink
consumption
81) Permanent magnetic material


magnet
and causing drop ejection. Rare earth
76) Many ink types can be
such as Neodymium Iron Boron


electro-
magnets with a field strength around
used
(NdFeB) required.


mag-
1 Tesla can be used. Examples are:
77) Fast operation
82) High local currents required


netic
Samarium Cobalt (SaCo) and
78) High efficiency
83) Copper metalization should be



magnetic materials in the neodymium
79) Easy extension from
used for long electromigration lifetime



iron boron family (NdFeB,
single nozzles to pagewidth
and low resistivity



NdDyFeBNb, NdDyFeB, etc)
print heads
84) Pigmented inks are usually





infeasible





85) Operating temperature limited to





the Curie temperature (around 540 K)


Soft
A solenoid induced a magnetic field
87) Low power
92) Complex fabrication
98) IJ01, IJ05, IJ08,


mag-
in a soft magnetic core or yoke
consumption
93) Materials not usually present in a
IJ10


netic
fabricated from a ferrous material
88) Many ink types can be
CMOS fab such as NiFe, CoNiFe, or
99) IJ12, IJ14, IJ15,


core
such as electroplated iron alloys such
used
CoFe are required
IJ17


electro-
as CoNiFe [1], CoFe, or NiFe alloys.
89) Fast operation
94) High local currents required


mag-
Typically, the soft magnetic material
90) High efficiency
95) Copper metalization should be


netic
is in two parts, which are normally
91) Easy extension from
used for long electromigration lifetime



held apart by a spring. When the
single nozzles to pagewidth
and low resistivity



solenoid is actuated, the two parts
print heads
96) Electroplating is required



attract, displacing the ink.

97) High saturation flux density is





required (2.0-2.1 T is achievable with





CoNiFe [1])


Mag-
The Lorenz force acting on a current
100) Low power
105) Force acts as a twisting motion
110) IJ06, IJ11, IJ13,


netic
carrying wire in a magnetic field is
consumption
106) Typically, only a quarter of the
IJ16


Lorenz
utilized.
101) Many ink types can be
solenoid length provides force in a


force
This allows the magnetic field to be
used
useful direction



supplied externally to the print head,
102) Fast operation
107) High local currents required



for example with rare earth
103) High efficiency
108) Copper metalization should be



permanent magnets.
104) Easy extension from
used for long electromigration lifetime



Only the current carrying wire need
single nozzles to pagewidth
and low resistivity



be fabricated on the print-head,
print heads
109) Pigmented inks are usually



simplifying materials requirements.

infeasible


Mag-
The actuator uses the giant
111) Many ink types can be
115) Force acts as a twisting motion
120) Fischenbeck,


neto-
magnetostrictive effect of materials
used
116) Unusual materials such as
U.S. Pat. No. 4,032,929


striction
such as Terfenol-D (an alloy of
112) Fast operation
Terfenol-D are required
121) IJ25



terbium, dysprosium and iron
113) Easy extension from
117) High local currents required



developed at the Naval Ordnance
single nozzles to pagewidth
118) Copper metalization should be



Laboratory, hence Ter-Fe-NOL). For
print heads
used for long electromigration lifetime



best efficiency, the actuator should
114) High force is available
and low resistivity



be pre-stressed to approx. 8 MPa.

119) Pre-stressing may be required


Surface
Ink under positive pressure is held in
122) Low power
127) Requires supplementary force to
130) Silverbrook, EP


tension
a nozzle by surface tension. The
consumption
effect drop separation
0771 658 A2 and


reduc-
surface tension of the ink is reduced
123) Simple construction
128) Requires special ink surfactants
related patent


tion
below the bubble threshold, causing
124) No unusual materials
129) Speed may be limited by
applications



the ink to egress from the nozzle.
required in fabrication
surfactant properties




125) High efficiency




126) Easy extension from




single nozzles to pagewidth




print heads


Vis-
The ink viscosity is locally reduced
131) Simple construction
134) Requires supplementary force to
139) Silverbrook, EP


cosity
to select which drops are to be
132) No unusual materials
effect drop separation
0771 658 A2 and


reduc-
ejected. A viscosity reduction can be
required in fabrication
135) Requires special ink viscosity
related patent


tion
achieved electrothermally with most
133) Easy extension from
properties
applications



inks, but special inks can be
single nozzles to pagewidth
136) High speed is difficult to achieve



engineered for a 100:1 viscosity
print heads
137) Requires oscillating ink pressure



reduction.

138) A high temperature difference





(typically 80 degrees) is required


Acous-
An acoustic wave is generated and
140) Can operate without a
141) Complex drive circuitry
146) 1993


tic
focussed upon the drop ejection
nozzle plate
142) Complex fabrication
Hadimioglu et al,



region.

143) Low efficiency
EUP 550,192





144) Poor control of drop position
147) 1993 Elrod et al,





145) Poor control of drop volume
EUP 572,220


Ther-
An actuator which relies upon
148) Low power
157) Efficient aqueous operation
160) IJ03, IJ09, IJ17,


mo-
differential thermal expansion upon
consumption
requires a thermal insulator on the hot
IJ18


elastic
Joule heating is used.
149) Many ink types can be
side
161) IJ19, IJ20, IJ21,


actuator

used
158) Corrosion prevention can be
IJ22




150) Simple planar
difficult
162) IJ23, IJ24, IJ27,




fabrication
159) Pigmented inks may be infeasible,
IJ28




151) Small integrated
as pigment particles may jam the bend
163) IJ29, IJ30, IJ31,




circuit area required for
actuator
IJ32




each actuator

164) IJ33, IJ34, IJ35,




152) Fast operation

IJ36




153) High efficiency

165) IJ37, IJ38, IJ39,




154) CMOS compatible

IJ40




voltages and currents

166) IJ41




155) Standard MEMS




processes can be used




156) Easy extension from




single nozzles to pagewidth




print heads


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


CTE
coefficient of thermal expansion
generated
PTFE)
IJ20


thermo-
(CTE) such as
168) PTFE is a candidate
178) Requires a PTFE deposition
182) IJ21, IJ22, IJ23,


elastic
polytetrafluoroethylene (PTFE) is
for low dielectric constant
process, which is not yet standard in
IJ24


actuator
used. As high CTE materials are
insulation in ULSI
ULSI fabs
183) IJ27, IJ28, IJ29,



usually non-conductive, a heater
169) Very low power
179) PTFE deposition cannot be
IJ30



fabricated from a conductive material
consumption
followed with high temperature (above
184) IJ31, IJ42, IJ43,



is incorporated. A 50 μm long PTFE
170) Many ink types can be
350° C.) processing
IJ44



bend actuator with polysilicon heater
used
180) Pigmented inks may be infeasible,



and 15 mW power input can provide
171) Simple planar
as pigment particles may jam the bend



180 μN force and 10 μm deflection.
fabrication
actuator



Actuator motions include:
172) Small integrated



Bend
circuit area required for



Push
each actuator



Buckle
173) Fast operation



Rotate
174) High efficiency




175) CMOS compatible




voltages and currents




176) Easy extension from




single nozzles to pagewidth




print heads


Con-
A polymer with a high coefficient of
185) High force can be
194) Requires special materials
199) IJ24


ductive
thermal expansion (such as PTFE) is
generated
development (High CTE conductive


polymer
doped with conducting substances to
186) Very low power
polymer)


thermo-
increase its conductivity to about 3
consumption
195) Requires a PTFE deposition


elastic
orders of magnitude below that of
187) Many ink types can be
process, which is not yet standard in


actuator
copper. The conducting polymer
used
ULSI fabs



expands when resistively heated.
188) Simple planar
196) PTFE deposition cannot be



Examples of conducting dopants
fabrication
followed with high temperature (above



include:
189) Small integrated
350° C.) processing



Carbon nanotubes
circuit area required for
197) Evaporation and CVD deposition



Metal fibers
each actuator
techniques cannot be used



Conductive polymers such as doped
190) Fast operation
198) Pigmented inks may be infeasible,



polythiophene
191) High efficiency
as pigment particles may jam the bend



Carbon granules
192) CMOS compatible
actuator




voltages and currents




193) Easy extension from




single nozzles to pagewidth




print heads


Shape
A shape memory alloy such as TiNi
200) High force is available
206) Fatigue limits maximum number
213) IJ26


memory
(also known as Nitinol —Nickel
(stresses of hundreds of
of cycles


alloy
Titanium alloy developed at the
MPa)
207) Low strain (1%) is required to



Naval Ordnance Laboratory) is
201) Large strain is
extend fatigue resistance



thermally switched between its weak
available (more than 3%)
208) Cycle rate limited by heat



martensitic state and its high stiffness
202) High corrosion
removal



austenic state. The shape of the
resistance
209) Requires unusual materials (TiNi)



actuator in its martensitic state is
203) Simple construction
210) The latent heat of transformation



deformed relative to the austenic
204) Easy extension from
must be provided



shape. The shape change causes
single nozzles to pagewidth
211) High current operation



ejection of a drop.
print heads
212) Requires pre-stressing to distort




205) Low voltage operation
the martensitic state


Linear
Linear magnetic actuators include the
214) Linear Magnetic
218) Requires unusual semiconductor
222) IJ12


Mag-
Linear Induction Actuator (LIA),
actuators can be constructed
materials such as soft magnetic alloys


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


Actu-
Synchronous Actuator (LPMSA),
and high efficiency using
219) Some varieties also require


ator
Linear Reluctance Synchronous
planar semiconductor
permanent magnetic materials such as



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



Reluctance Actuator (LSRA), and the
215) Long actuator travel is
220) Requires complex multi-phase



Linear Stepper Actuator (LSA).
available
drive circuitry




216) Medium force is
221) High current operation




available




217) Low voltage operation










BASIC OPERATION MODE











Operational






mode
Description
Advantages
Disadvantages
Examples





Actuator
This is the simplest mode of
223) Simple operation
227) Drop repetition rate is usually
230) Thermal inkjet


directly pushes
operation: the actuator directly
224) No external fields
limited to less than 10 KHz. However,
231) Piezoelectric


ink
supplies sufficient kinetic energy to
required
this is not fundamental to the method,
inkjet



expel the drop. The drop must have a
225) Satellite drops can be
but is related to the refill method
232) IJ01, IJ02, IJ03,



sufficient velocity to overcome the
avoided if drop velocity is
normally used
IJ04



surface tension.
less than 4 m/s
228) All of the drop kinetic energy
233) IJ05, IJ06, IJ07,




226) Can be efficient,
must be provided by the actuator
IJ09




depending upon the actuator
229) Satellite drops usually form if
234) IJ11, IJ12, IJ14,




used
drop velocity is greater than 4.5 m/s
IJ16






235) IJ20, IJ22, IJ23,






IJ24






236) IJ25, IJ26, IJ27,






IJ28






237) IJ29, IJ30, IJ31,






IJ32






238) IJ33, IJ34, IJ35,






IJ36






239) IJ37, IJ38, IJ39,






IJ40






240) IJ41, IJ42, IJ43,






IJ44


Proximity
The drops to be printed are selected
241) Very simple print head
243) Requires close proximity between
246) Silverbrook, EP



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



induced surface tension reduction of
242) The drop selection
transfer roller
related patent



pressurized ink). Selected drops are
means does not need to
244) May require two print heads
applications



separated from the ink in the nozzle
provide the energy required
printing alternate rows of the image



by contact with the print medium or a
to separate the drop from
245) Monolithic color print heads are



transfer roller.
the nozzle
difficult


Electrostatic
The drops to be printed are selected
247) Very simple print head
249) Requires very high electrostatic
252) Silverbrook, EP


pull on ink
by some manner (e.g. thermally
fabrication can be used
field
0771 658 A2 and



induced surface tension reduction of
248) The drop selection
250) Electrostatic field for small nozzle
related patent



pressurized ink). Selected drops are
means does not need to
sizes is above air breakdown
applications



separated from the ink in the nozzle
provide the energy required
251) Electrostatic field may attract dust
253) Tone-Jet



by a strong electric field.
to separate the drop from




the nozzle


Magnetic pull
The drops to be printed are selected
254) Very simple print head
256) Requires magnetic ink
259) Silverbrook, EP


on ink
by some manner (e.g. thermally
fabrication can be used
257) Ink colors other than black are
0771 658 A2 and



induced surface tension reduction of
255) The drop selection
difficult
related patent



pressurized ink). Selected drops are
means does not need to
258) Requires very high magnetic
applications



separated from the ink in the nozzle
provide the energy required
fields



by a strong magnetic field acting on
to separate the drop from



the magnetic ink.
the nozzle


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



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



pressure is pulsed at a multiple of the
due to reduced refill time
265) Friction and wear must be



drop ejection frequency.
261) Drop timing can be
considered




very accurate
266) Stiction is possible




262) The actuator energy




can be very low


Shuttered grill
The actuator moves a shutter to block
268) Actuators with small
271) Moving parts are required
275) IJ08, IJ15, IJ18,



ink flow through a grill to the nozzle.
travel can be used
272) Requires ink pressure modulator
IJ19



The shutter movement need only be
269) Actuators with small
273) Friction and wear must be



equal to the width of the grill holes.
force can be used
considered




270) High speed (>50 KHz)
274) Stiction is possible




operation can be achieved


Pulsed
A pulsed magnetic field attracts an
276) Extremely low energy
278) Requires an external pulsed
281) IJ10


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


on ink
frequency. An actuator controls a
277) No heat dissipation
279) Requires special materials for


pusher
catch, which prevents the ink pusher
problems
both the actuator and the ink pusher



from moving when a drop is not to be

280) Complex construction



ejected.










AUXILIARY MECHANISM (APPLIED TO ALL NOZZLES)











Auxiliary






Mechanism
Description
Advantages
Disadvantages
Examples





None
The actuator directly fires the ink
282) Simplicity of
285) Drop ejection energy must be
286) Most inkjets,



drop, and there is no external field or
construction
supplied by individual nozzle actuator
including



other mechanism required.
283) Simplicity of operation

piezoelectric and




284) Small physical size

thermal bubble.






287) IJ01-IJ07, IJ09,






IJ11






288) IJ12, IJ14, IJ20,






IJ22






289) IJ23-IJ45


Oscillating ink
The ink pressure oscillates, providing
290) Oscillating ink
293) Requires external ink pressure
296) Silverbrook, EP


pressure
much of the drop ejection energy.
pressure can provide a refill
oscillator
0771 658 A2 and


(including
The actuator selects which drops are
pulse, allowing higher
294) Ink pressure phase and amplitude
related patent


acoustic
to be fired by selectively blocking or
operating speed
must be carefully controlled
applications


stimulation)
enabling nozzles. The ink pressure
291) The actuators may
295) Acoustic reflections in the ink
297) IJ08, IJ13, IJ15,



oscillation may be achieved by
operate with much lower
chamber must be designed for
IJ17



vibrating the print head, or preferably
energy

298) IJ18, IJ19, IJ21



by an actuator in the ink supply.
292) Acoustic lenses can be




used to focus the sound on




the nozzles


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


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



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



print head further than unselected
construction

applications



drops, and contact the print medium.



The drop soaks into the medium fast



enough to cause drop separation.


Transfer roller
Drops are printed to a transfer roller
306) High accuracy
309) Bulky
312) Silverbrook, EP



instead of straight to the print
307) Wide range of print
310) Expensive
0771 658 A2 and



medium. A transfer roller can also be
substrates can be used
311) Complex construction
related patent



used for proximity drop separation.
308) Ink can be dried on the

applications




transfer roller

313) Tektronix hot






melt piezoelectric






inkjet






314) Any of the IJ






series


Electrostatic
An electric field is used to accelerate
315) Low power
317) Field strength required for
318) Silverbrook, EP



selected drops towards the print
316) Simple print head
separation of small drops is near or
0771 658 A2 and



medium.
construction
above air breakdown
related patent






applications






319) Tone-Jet


Direct
A magnetic field is used to accelerate
320) Low power
322) Requires magnetic ink
324) Silverbrook, EP


magnetic field
selected drops of magnetic ink
321) Simple print head
323) Requires strong magnetic field
0771 658 A2 and



towards the print medium.
construction

related patent






applications


Cross magnetic
The print head is placed in a constant
325) Does not require
326) Requires external magnet
328) IJ06, IJ16


field
magnetic field. The Lorenz force in a
magnetic materials to be
327) Current densities may be high,



current carrying wire is used to move
integrated in the print head
resulting in electromigration problems



the actuator.
manufacturing process


Pulsed
A pulsed magnetic field is used to
329) Very low power
331) Complex print head construction
333) IJ10


magnetic field
cyclically attract a paddle, which
operation is possible
332) Magnetic materials required in



pushes on the ink. A small actuator
330) Small print head size
print head



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 amplification
334) Operational simplicity
335) Many actuator mechanisms have
336) Thermal Bubble



is used. The actuator directly drives

insufficient travel, or insufficient force,
Inkjet



the drop ejection process.

to efficiently drive the drop ejection
337) IJ01, IJ02, IJ06,





process
IJ07






338) IJ16, IJ25, IJ26


Differential
An actuator material expands more
339) Provides greater travel
341) High stresses are involved
344) Piezoelectric


expansion bend
on one side than on the other. The
in a reduced print head area
342) Care must be taken that the
345) IJ03, IJ09,


actuator
expansion may be thermal,
340) The bend actuator
materials do not delaminate
IJ17-IJ24



piezoelectric, magnetostrictive, or
converts a high force low
343) Residual bend resulting from high
346) IJ27, IJ29-IJ39,



other mechanism.
travel actuator mechanism
temperature or high stress during
IJ42,




to high travel, lower force
formation
347) IJ43, IJ44




mechanism.


Transient bend
A trilayer bend actuator where the
348) Very good
351) High stresses are involved
353) IJ40, IJ41


actuator
two outside layers are identical. This
temperature stability
352) Care must be taken that the



cancels bend due to ambient
349) High speed, as a new
materials do not delaminate



temperature and residual stress. The
drop can be fired before



actuator only responds to transient
heat dissipates



heating of one side or the other.
350) Cancels residual stress




of formation


Actuator stack
A series of thin actuators are stacked.
354) Increased travel
356) Increased fabrication complexity
358) Some



This can be appropriate where
355) Reduced drive voltage
357) Increased possibility of short
piezoelectric ink jets



actuators require high electric field

circuits due to pinholes
359) IJ04



strength, such as electrostatic and



piezoelectric actuators.


Multiple
Multiple smaller actuators are used
360) Increases the force
362) Actuator forces may not add
363) IJ12, IJ13, IJ18,


actuators
simultaneously to move the ink. Each
available from an actuator
linearly, reducing efficiency
IJ20



actuator need provide only a portion
361) Multiple actuators can

364) IJ22, IJ28, IJ42,



of the force required.
be positioned to control ink

IJ43




flow accurately


Linear Spring
A linear spring is used to transform a
365) Matches low travel
367) Requires print head area for the
368) IJ15



motion with small travel and high
actuator with higher travel
spring



force into a longer travel, lower force
requirements



motion.
366) Non-contact method




of motion transformation


Reverse spring
The actuator loads a spring. When
369) Better coupling to the
370) Fabrication complexity
372) IJ05, IJ11



the actuator is turned off, the spring
ink
371) High stress in 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 coiled to provide
373) Increases travel
376) Generally restricted to planar
377) IJ17, IJ21, IJ34,



greater travel in a reduced integrated
374) Reduces integrated
implementations due to extreme
IJ35



circuit area.
circuit area
fabrication difficulty in other




375) Planar
orientations.




implementations are




relatively easy to fabricate.


Flexure bend
A bend actuator has a small region
378) Simple means of
379) Care must be taken not to exceed
382) IJ10, IJ19, IJ33


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



much more readily than the
actuator
380) Stress distribution is very uneven



remainder of the actuator. The

381) Difficult to accurately model with



actuator flexing is effectively

finite element analysis



converted from an even coiling to an



angular bend, resulting in greater



travel of the actuator tip.


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



at the expense of duration. Circular
actuators can be used
386) Several actuator cycles are



gears, rack and pinion, ratchets, and
384) Can be fabricated
required



other gearing methods can be used.
using standard surface
387) More complex drive electronics




MEMS processes
388) Complex construction





389) Friction, friction, and wear are





possible


Catch
The actuator controls a small catch.
391) Very low actuator
393) Complex construction
396) IJ10



The catch either enables or disables
energy
394) Requires external force



movement of an ink pusher that is
392) Very small actuator
395) Unsuitable for pigmented inks



controlled in a bulk manner.
size


Buckle plate
A buckle plate can be used to change
397) Very fast movement
398) Must stay within elastic limits of
401) S. Hirata et al,



a slow actuator into a fast motion. It
achievable
the materials for long device life
“An Ink-jet Head ... ”,



can also convert a high force, low

399) High stresses involved
Proc. IEEE MEMS,



travel actuator into a high travel,

400) Generally high power
Feb. 1996, pp 418-423.



medium force motion.

requirement
402) IJ18, IJ27


Tapered
A tapered magnetic pole can increase
403) Linearizes the
404) Complex construction
405) IJ14


magnetic pole
travel at the expense of force.
magnetic force/distance




curve


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



transform a motion with small travel
actuator with higher travel



and high force into a motion with
requirements



longer travel and lower force. The
407) Fulcrum area has no



lever can also reverse the direction of
linear movement, and can



travel.
be used for a fluid seal


Rotary impeller
The actuator is connected to a rotary
410) High mechanical
412) Complex construction
414) IJ28



impeller. A small angular deflection
advantage
413) Unsuitable for pigmented inks



of the actuator results in a rotation of
411) The ratio of force to



the impeller vanes, which push the
travel of the actuator can be



ink against stationary vanes and out
matched to the nozzle



of the nozzle.
requirements by varying the




number of impeller vanes


Acoustic lens
A refractive or diffractive (e.g. zone
415) No moving parts
416) Large area required
418) 1993



plate) acoustic lens is used to

417) Only relevant for acoustic ink jets
Hadimioglu et al,



concentrate sound waves.


EUP 550,192






419) 1993 Elrod et al,






EUP 572,220


Sharp
A sharp point is used to concentrate
420) Simple construction
421) Difficult to fabricate using
423) Tone-jet


conductive
an electrostatic field.

standard VLSI processes for a surface


point


ejecting ink-jet





422) Only relevant for electrostatic ink





jets










ACTUATOR MOTION











Actuator






motion
Description
Advantages
Disadvantages
Examples





Volume
The volume of the actuator changes,
424) Simple construction in
425) High energy is typically required
426) Hewlett-


expansion
pushing the ink in all directions.
the case of thermal ink jet
to achieve volume expansion. This
Packard Thermal





leads to thermal stress, cavitation, and
Inkjet





kogation in thermal ink jet
427) Canon





implementations
Bubblejet


Linear, normal
The actuator moves in a direction
428) Efficient coupling to
429) High fabrication complexity may
430) IJ01, IJ02, IJ04,


to integrated
normal to the print head surface. The
ink drops ejected normal to
be required to achieve perpendicular
IJ07


circuit surface
nozzle is typically in the line of
the surface
motion
431) IJ11, IJ14



movement.


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


to integrated
print head surface. Drop ejection may
fabrication
434) Friction
IJ33,


circuit surface
still be normal to the surface.

435) Stiction
437) IJ34, IJ35, IJ36


Membrane
An actuator with a high force but
438) The effective area of
439) Fabrication complexity
442) 1982 Howkins


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



membrane that is in contact with the
membrane area
441) Difficulty of integration in a



ink.

VLSI process


Rotary
The actuator causes the rotation of
443) Rotary levers may be
445) Device complexity
447) IJ05, IJ08, IJ13,



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



impeller
444) Small integrated




circuit area requirements


Bend
The actuator bends when energized.
448) A very small change
449) Requires the actuator to be made
450) 1970 Kyser et al



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



thermal expansion, piezoelectric
converted to a large motion.
have a thermal difference across the
451) 1973 Stemme



expansion, magnetostriction, or other

actuator
U.S. Pat. No. 3,747,120



form of relative dimensional change.


452) IJ03, IJ09, IJ10,






IJ19






453) IJ23, IJ24, IJ25,






IJ29






454) IJ30, IJ31, IJ33,






IJ34






455) IJ35


Swivel
The actuator swivels around a central
456) Allows operation
458) Inefficient coupling to the ink
459) IJ06



pivot. This motion is suitable where
where the net linear force
motion



there are opposite forces applied to
on the paddle is zero



opposite sides of the paddle, e.g.
457) Small integrated



Lorenz force.
circuit area requirements


Straighten
The actuator is normally bent, and
460) Can be used with
461) Requires careful balance of
462) IJ26, IJ32



straightens when energized.
shape memory alloys where
stresses to ensure that the quiescent




the austenic phase is planar
bend is accurate


Double bend
The actuator bends in one direction
463) One actuator can be
466) Difficult to make the drops
468) IJ36, IJ37, IJ38



when one element is energized, and
used to power two nozzles.
ejected by both bend directions



bends the other way when another
464) Reduced integrated
identical.



element is energized.
circuit size.
467) A small efficiency loss compared




465) Not sensitive to
to equivalent single bend actuators.




ambient temperature


Shear
Energizing the actuator causes a
469) Can increase the
470) Not readily applicable to other
471) 1985 Fishbeck



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




piezoelectric actuators


Radial
The actuator squeezes an ink
472) Relatively easy to
473) High force required
476) 1970 Zoltan


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



constricted nozzle.
from glass tubing as
475) Difficult to integrate with VLSI




macroscopic structures
processes


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



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



end of the actuator ejects the ink.
478) Small area required,
480) Poor out-of-plane stiffness




therefore low cost


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



middle when energized.
of travel
485) High force required




483) Mechanically rigid


Push-Pull
Two actuators control a shutter. One
487) The structure is pinned
488) Not readily suitable for inkjets
489) IJ18



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



other pushes it.
out-of-plane rigidity


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



reduce the volume of ink that they
region behind the actuator



enclose.
increases efficiency


Curl outwards
A set of actuators curl outwards,
493) Relatively simple
494) Relatively large integrated circuit
495) IJ43



pressurizing ink in a chamber
construction
area



surrounding the actuators, and



expelling ink from a nozzle in the



chamber.


Iris
Multiple vanes enclose a volume of
496) High efficiency
498) High fabrication complexity
500) IJ22



ink. These simultaneously rotate,
497) Small integrated
499) Not suitable for pigmented inks



reducing the volume between the
circuit area



vanes.


Acoustic
The actuator vibrates at a high
501) The actuator can be
502) Large area required for efficient
506) 1993


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




ink
503) Acoustic coupling and crosstalk
EUP 550,192





504) Complex drive circuitry
507) 1993 Elrod et al,





505) Poor control of drop volume and
EUP 572,220





position


None
In various ink jet designs the actuator
508) No moving parts
509) Various other tradeoffs are
510) Silverbrook, EP



does not move.

required to eliminate moving parts
0771 658 A2 and






related patent






applications






511) Tone-jet










NOZZLE REFILL METHOD











Nozzle refill






method
Description
Advantages
Disadvantages
Examples





Surface tension
After the actuator is energized, it
512) Fabrication simplicity
514) Low speed
517) Thermal inkjet



typically returns rapidly to its normal
513) Operational simplicity
515) Surface tension force relatively
518) Piezoelectric



position. This rapid return sucks in

small compared to actuator force
inkjet



air through the nozzle opening. The

516) Long refill time usually
519) IJ01-IJ07, IJ10-IJ14



ink surface tension at the nozzle then

dominates the total repetition rate
520) IJ16, IJ20, IJ22-IJ45



exerts a small force restoring the



meniscus to a minimum area.


Shuttered
Ink to the nozzle chamber is provided
521) High speed
523) Requires common ink pressure
525) IJ08, IJ13, IJ15,


oscillating ink
at a pressure that oscillates at twice
522) Low actuator energy,
oscillator
IJ17


pressure
the drop ejection frequency. When a
as the actuator need only
524) May not be suitable for
526) IJ18, IJ19, IJ21



drop is to be ejected, the shutter is
open or close the shutter,
pigmented inks



opened for 3 half cycles: drop
instead of ejecting the ink



ejection, actuator return, and refill.
drop


Refill actuator
After the main actuator has ejected a
527) High speed, as the
528) Requires two independent
529) IJ09



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



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 positive
530) High refill rate,
531) Surface spill must be prevented
533) Silverbrook, EP


pressure
pressure. After the ink drop is
therefore a high drop
532) Highly hydrophobic print head
0771 658 A2 and



ejected, the nozzle chamber fills
repetition rate is possible
surfaces are required
related patent



quickly as surface tension and ink


applications



pressure both operate to refill the


534) Alternative for:



nozzle.


535) IJ01-IJ07, IJ10-IJ14






536) IJ16, IJ20, IJ22-IJ45










METHOD OF RESTRICTING BACK-FLOW THROUGH INLET











Inlet back-






flow


restriction


method
Description
Advantages
Disadvantages
Examples





Long inlet
The ink inlet channel to the nozzle
537) Design simplicity
540) Restricts refill rate
543) Thermal inkjet


channel
chamber is made long and relatively
538) Operational simplicity
541) May result in a relatively large
544) Piezoelectric



narrow, relying on viscous drag to
539) Reduces crosstalk
integrated circuit area
inkjet



reduce inlet back-flow.

542) Only partially effective
545) IJ42, IJ43


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


pressure
so that in the quiescent state some of
separation forces can be
nozzle rim or effective hydrophobizing,
0771 658 A2 and



the ink drop already protrudes from
reduced
or both) to prevent flooding of the
related patent



the nozzle.
547) Fast refill time
ejection surface of the print head.
applications



This reduces the pressure in the


550) Possible



nozzle chamber which is required to


operation of the



eject a certain volume of ink. The


following:



reduction in chamber pressure results


551) IJ01-IJ07, IJ09-IJ12



in a reduction in ink pushed out


552) IJ14, IJ16, IJ20,



through the inlet.


IJ22,






553) IJ23-IJ34, IJ36-IJ41






554) IJ44


Baffle
One or more baffles are placed in the
555) The refill rate is not as
557) Design complexity
559) HP Thermal Ink



inlet ink flow. When the actuator is
restricted as the long inlet
558) May increase fabrication
Jet



energized, the rapid ink movement
method.
complexity (e.g. Tektronix hot melt
560) Tektronix



creates eddies which restrict the flow
556) Reduces crosstalk
Piezoelectric print heads).
piezoelectric ink jet



through the inlet. The slower refill



process is unrestricted, and does not



result in eddies.


Flexible flap
In this method recently disclosed by
561) Significantly reduces
562) Not applicable to most inkjet
565) Canon


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



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



that restricts the inlet.

564) Inelastic deformation of polymer





flap results in creep over extended use


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



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



filter has a multitude of small holes
567) Ink filter may be
construction
571) IJ29, IJ30



or slots, restricting ink flow. The
fabricated with no



filter also removes particles which
additional process steps



may block the nozzle.


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


compared to
chamber has a substantially smaller

574) May result in a relatively large


nozzle
cross section than that of the nozzle,

integrated circuit area



resulting in easier ink egress out of

575) Only partially effective



the nozzle than out of the inlet.


Inlet shutter
A secondary actuator controls the
577) Increases speed of the
578) Requires separate refill actuator
579) IJ09



position of a shutter, closing off the
ink-jet print head operation
and drive circuit



ink inlet when the main actuator is



energized.


The inlet is
The method avoids the problem of
580) Back-flow problem is
581) Requires careful design to
582) IJ01, IJ03, IJ05,


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


behind
pushing surface of the actuator

the paddle
583) IJ07, IJ10, IJ11,


the ink-
between the inlet and the nozzle.


IJ14


pushing



584) IJ16, IJ22, IJ23,


surface



IJ25






585) IJ28, IJ31, IJ32,






IJ33






586) IJ34, IJ35, IJ36,






IJ39






587) IJ40, IJ41


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


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


moves
motion of the actuator closes off the
achieved


to shut off
inlet.
589) Compact designs


the inlet

possible


Nozzle
In some configurations of ink jet,
592) Ink back-flow problem
593) None related to ink back-flow on
594) Silverbrook, EP


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


does not
an actuator which may cause ink


related patent


result in
back-flow through the inlet.


applications


ink back-



595) Valve-jet


flow



596) Tone-jet






597) IJ08, IJ13, IJ15,






IJ17






598) IJ18, IJ19, IJ21










NOZZLE CLEARING METHOD











Nozzle






Clearing


method
Description
Advantages
Disadvantages
Examples





Normal
All of the nozzles are fired
599) No added complexity
600) May not be sufficient to displace
601) Most ink jet


nozzle
periodically, before the ink has a
on the print head
dried ink
systems


firing
chance to dry. When not in use the


602) IJ01-IJ07, IJ09-IJ12



nozzles are sealed (capped) against


603) IJ14, IJ16, IJ20,



air.


IJ22



The nozzle firing is usually


604) IJ23-IJ34, IJ36-IJ45



performed during a special clearing



cycle, after first moving the print



head to a cleaning station.


Extra
In systems which heat the ink, but do
605) Can be highly
606) Requires higher drive voltage for
608) Silverbrook, EP


power
not boil it under normal situations,
effective if the heater is
clearing
0771 658 A2 and


to ink
nozzle clearing can be achieved by
adjacent to the nozzle
607) May require larger drive
related patent


heater
over-powering the heater and boiling

transistors
applications



ink at the nozzle.


Rapid
The actuator is fired in rapid
609) Does not require extra
611) Effectiveness depends
612) May be used


succession
succession. In some configurations,
drive circuits on the print
substantially upon the configuration of
with:


of
this may cause heat build-up at the
head
the inkjet nozzle
613) IJ01-IJ07, IJ09-IJ11


actuator
nozzle which boils the ink, clearing
610) Can be readily

614) IJ14, IJ16, IJ20,


pulses
the nozzle. In other situations, it may
controlled and initiated by

IJ22



cause sufficient vibrations to
digital logic

615) IJ23-IJ25, IJ27-IJ34



dislodge clogged nozzles.


616) IJ36-IJ45


Extra
Where an actuator is not normally
617) A simple solution
618) Not suitable where there is a hard
619) May be used


power
driven to the limit of its motion,
where applicable
limit to actuator movement
with:


to ink
nozzle clearing may be assisted by


620) IJ03, IJ09, IJ16,


pushing
providing an enhanced drive signal to


IJ20


actuator
the actuator.


621) IJ23, IJ24, IJ25,






IJ27






622) IJ29, IJ30, IJ31,






IJ32






623) IJ39, IJ40, IJ41,






IJ42






624) IJ43, IJ44, IJ45


Acoustic
An ultrasonic wave is applied to the
625) A high nozzle clearing
627) High implementation cost if
628) IJ08, IJ13, IJ15,


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



appropriate amplitude and frequency
626) May be implemented
acoustic actuator
629) IJ18, IJ19, IJ21



to cause sufficient force at the nozzle
at very low cost in systems



to clear blockages. This is easiest to
which already include



achieve if the ultrasonic wave is at a
acoustic actuators



resonant frequency of the ink cavity.


Nozzle
A microfabricated plate is pushed
630) Can clear severely
631) Accurate mechanical alignment is
635) Silverbrook, EP


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


plate
post for every nozzle. The array of

632) Moving parts are required
related patent



posts

633) There is risk of damage to the
applications





nozzles





634) Accurate fabrication is required


Ink
The pressure of the ink is temporarily
636) May be effective
637) Requires pressure pump or other
640) May be used


pressure
increased so that ink streams from all
where other methods cannot
pressure actuator
with all IJ series ink


pulse
of the nozzles. This may be used in
be used
638) Expensive
jets



conjunction with actuator energizing.

639) Wasteful of ink


Print
A flexible ‘blade’ is wiped across the
641) Effective for planar
643) Difficult to use if print head
646) Many ink jet


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


wiper
usually fabricated from a flexible
642) Low cost
644) Requires mechanical parts



polymer, e.g. rubber or synthetic

645) Blade can wear out in high



elastomer.

volume print systems


Separate
A separate heater is provided at the
647) Can be effective where
649) Fabrication complexity
650) Can be used


ink
nozzle although the normal drop e-
other nozzle clearing

with many IJ series


boiling
ection mechanism does not require it.
methods cannot be used

ink jets


heater
The heaters do not require individual
648) Can be implemented at



drive circuits, as many nozzles can
no additional cost in some



be cleared simultaneously, and no
inkjet configurations



imaging is required.










NOZZLE PLATE CONSTRUCTION











Nozzle






plate


construc-


tion
Description
Advantages
Disadvantages
Examples





Electro-
A nozzle plate is separately
651) Fabrication simplicity
652) High temperatures and pressures
655) Hewlett Packard


formed
fabricated from electroformed nickel,

are required to bond nozzle plate
Thermal Inkjet


nickel
and bonded to the print head

653) Minimum thickness constraints



integrated circuit.

654) Differential thermal expansion


Laser
Individual nozzle holes are ablated
656) No masks required
660) Each hole must be individually
664) Canon


ablated
by an intense UV laser in a nozzle
657) Can be quite fast
formed
Bubblejet


or
plate, which is typically a polymer
658) Some control over
661) Special equipment required
665) 1988 Sercel et


drilled
such as polyimide or polysulphone
nozzle profile is possible
662) Slow where there are many
al., SPIE, Vol. 998


polymer

659) Equipment required is
thousands of nozzles per print head
Excimer Beam




relatively low cost
663) May produce thin burrs at exit
Applications, pp. 76-83





holes
666) 1993 Watanabe






et al., U.S. Pat. No.






5,208,604


Silicon
A separate nozzle plate is
667) High accuracy is
668) Two part construction
672) K. Bean, IEEE


micro-
micromachined from single crystal
attainable
669) High cost
Transactions on


machined
silicon, and bonded to the print head

670) Requires precision alignment
Electron Devices,



wafer.

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





adhesive
1978, pp 1185-1195






673) Xerox 1990






Hawkins et al., U.S. Pat.






No. 4,899,181


Glass
Fine glass capillaries are drawn from
674) No expensive
676) Very small nozzle sizes are
678) 1970 Zoltan


capillaries
glass tubing. This method has been
equipment required
difficult to form
U.S. Pat. No. 3,683,212



used for making individual nozzles,
675) Simple to make single
677) Not suited for mass production



but is difficult to use for bulk
nozzles



manufacturing of print heads with



thousands of nozzles.


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


surface
layer using standard VLSI deposition
680) Monolithic
the nozzle plate to form the nozzle
0771 658 A2 and


micro-
techniques. Nozzles are etched in the
681) Low cost
chamber
related patent


machined
nozzle plate using VLSI lithography
682) Existing processes can
684) Surface may be fragile to the
applications


using
and etching.
be used
touch
686) IJ01, IJ02, IJ04,


VLSI



IJ11


litho-



687) IJ12, IJ17, IJ18,


graphic



IJ20


processes



688) IJ22, IJ24, IJ27,






IJ28






689) IJ29, IJ30, IJ31,






IJ32






690) IJ33, IJ34, IJ36,






IJ37






691) IJ38, IJ39, IJ40,






IJ41






692) IJ42, IJ43, IJ44


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


etched
in the wafer. Nozzle chambers are
694) Monolithic
698) Requires a support wafer
IJ07


through
etched in the front of the wafer, and
695) Low cost

700) IJ08, IJ09, IJ10,


substrate
the wafer is thinned from the back
696) No differential

IJ13



side. Nozzles are then etched in the
expansion

701) IJ14, IJ15, IJ16,



etch stop layer.


IJ19






702) IJ21, IJ23, IJ25,






IJ26


No
Various methods have been tried to
703) No nozzles to become
704) Difficult to control drop position
706) Ricoh 1995


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


plate
prevent nozzle clogging. These

705) Crosstalk problems
5,412,413



include thermal bubble mechanisms


707) 1993



and acoustic lens mechanisms


Hadimioglu et al EUP






550,192






708) 1993 Elrod et al






EUP 572,220


Trough
Each drop ejector has a trough
709) Reduced
711) Drop firing direction is sensitive
712) IJ35



through which a paddle moves. There
manufacturing complexity
to wicking.



is no nozzle plate.
710) Monolithic


Nozzle
The elimination of nozzle holes and
713) No nozzles to become
714) Difficult to control drop position
716) 1989 Saito et al


slit
replacement by a slit encompassing
clogged
accurately
U.S. Pat. No. 4,799,068


instead
many actuator positions reduces

715) Crosstalk problems


of
nozzle clogging, but increases


indi-
crosstalk due to ink surface waves


vidual


nozzles










DROP EJECTION DIRECTION











Ejection






direction
Description
Advantages
Disadvantages
Examples





Edge
Ink flow is along the surface of the
717) Simple construction
722) Nozzles limited to edge
725) Canon


(‘edge
integrated circuit, and ink drops are
718) No silicon etching
723) High resolution is difficult
Bubblejet 1979 Endo


shooter’)
ejected from the integrated circuit
required
724) Fast color printing requires one
et al GB patent



edge.
719) Good heat sinking via
print head per color
2,007,162




substrate

726) Xerox heater-in-




720) Mechanically strong

pit 1990 Hawkins et




721) Ease of integrated

al U.S. Pat. No. 4,899,181




circuit handing

727) Tone-jet


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


(‘roof shooter’)
integrated circuit, and ink drops are
etching required
restricted
Packard TIJ 1982



ejected from the integrated circuit
729) Silicon can make an

Vaught et al U.S. Pat. No.



surface, normal to the plane of the
effective heat sink

4,490,728



integrated circuit.
730) Mechanical strength

733) IJ02, IJ11, IJ12,






IJ20






734) IJ22


Through
Ink flow is through the integrated
735) High ink flow
738) Requires bulk silicon etching
739) Silverbrook, EP


integrated
circuit, and ink drops are ejected
736) Suitable for pagewidth

0771 658 A2 and


circuit, forward
from the front surface of the
print

related patent


(‘up shooter’)
integrated circuit.
737) High nozzle packing

applications




density therefore low

740) IJ04, IJ17, IJ18,




manufacturing cost

IJ24






741) IJ27-IJ45


Through
Ink flow is through the integrated
742) High ink flow
745) Requires wafer thinning
747) IJ01, IJ03, IJ05,


integrated
circuit, and ink drops are ejected
743) Suitable for pagewidth
746) Requires special handling during
IJ06


circuit, reverse
from the rear surface of the
print
manufacture
748) IJ07, IJ08, IJ09,


(‘down
integrated circuit.
744) High nozzle packing

IJ10


shooter’)

density therefore low

749) IJ13, IJ14, IJ15,




manufacturing cost

IJ16






750) IJ19, IJ21, IJ23,






IJ25






751) IJ26


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


actuator
which is not fabricated as part of the
piezoelectric print heads
several thousand connections to drive
757) Tektronix hot



same substrate as the drive

circuits
melt piezoelectric ink



transistors.

754) Cannot be manufactured in
jets





standard CMOS fabs





755) Complex assembly required










INK TYPE











Ink type
Description
Advantages
Disadvantages
Examples





Aqueous, dye
Water based ink which typically
758) Environmentally
760) Slow drying
765) Most existing



contains: water, dye, surfactant,
friendly
761) Corrosive
inkjets



humectant, and biocide.
759) No odor
762) Bleeds on paper
766) All IJ series ink



Modern ink dyes have high water-

763) May strikethrough
jets



fastness, light fastness

764) Cockles paper
767) Silverbrook, EP






0771 658 A2 and






related patent






applications


Aqueous,
Water based ink which typically
768) Environmentally
773) Slow drying
778) IJ02, IJ04, IJ21,


pigment
contains: water, pigment, surfactant,
friendly
774) Corrosive
IJ26



humectant, and biocide.
769) No odor
775) Pigment may clog nozzles
779) IJ27, IJ30



Pigments have an advantage in
770) Reduced bleed
776) Pigment may clog actuator
780) Silverbrook, EP



reduced bleed, wicking and
771) Reduced wicking
mechanisms
0771 658 A2 and



strikethrough.
772) Reduced strikethrough
777) Cockles paper
related patent






applications






781) Piezoelectric






ink-jets






782) Thermal ink jets






(with significant






restrictions)


Methyl Ethyl
MEK is a highly volatile solvent used
783) Very fast drying
785) Odorous
787) All IJ series ink


Ketone (MEK)
for industrial printing on difficult
784) Prints on various
786) Flammable
jets



surfaces such as aluminum cans.
substrates such as metals




and plastics


Alcohol
Alcohol based inks can be used
788) Fast drying
792) Slight odor
794) All IJ series ink


(ethanol, 2-
where the printer must operate at
789) Operates at sub-
793) Flammable
jets


butanol, and
temperatures below the freezing
freezing temperatures


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



in-camera consumer photographic
791) Low cost



printing.


Phase change
The ink is solid at room temperature,
795) No drying time-ink
801) High viscosity
807) Tektronix hot


(hot melt)
and is melted in the print head before
instantly freezes on the
802) Printed ink typically has a ‘waxy’
melt piezoelectric ink



jetting. Hot melt inks are usually wax
print medium
feel
jets



based, with a melting point around
796) Almost any print
803) Printed pages may ‘block’
808) 1989 Nowak



80° C. After jetting the ink freezes
medium can be used
804) Ink temperature may be above the
U.S. Pat. No. 4,820,346



almost instantly upon contacting the
797) No paper cockle
curie point of permanent magnets
809) All IJ series ink



print medium or a transfer roller.
occurs
805) Ink heaters consume power
jets




798) No wicking occurs
806) Long warm-up time




799) No bleed occurs




800) No strikethrough




occurs


Oil
Oil based inks are extensively used in
810) High solubility
813) High viscosity: this is a
815) All IJ series ink



offset printing. They have advantages
medium for some dyes
significant limitation for use in inkjets,
jets



in improved characteristics on paper
811) Does not cockle paper
which usually require a low viscosity.



(especially no wicking or cockle). Oil
812) Does not wick through
Some short chain and multi-branched



soluble dies and pigments are
paper
oils have a sufficiently low viscosity.



required.

814) Slow drying


Microemulsion
A microemulsion is a stable, self
816) Stops ink bleed
820) Viscosity higher than water
823) All IJ series ink



forming emulsion of oil, water, and
817) High dye solubility
821) Cost is slightly higher than water
jets



surfactant. The characteristic drop
818) Water, oil, and
based ink



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



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



curvature of the surfactant.
819) Can stabilize pigment




suspensions









Ink Jet Printing

A laze 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. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience.













Australian





Provisional


U.S. Pat. No./Patent Application


Number
Filing Date
Title
and Filing Date







PO8066
Jul. 15, 1997
Image Creation Method and Apparatus (IJ01)
6,227,652





(Jul. 10, 1998)


PO8072
Jul. 15, 1997
Image Creation Method and Apparatus (IJ02)
6,213,588





(Jul. 10, 1998)


PO8040
Jul. 15, 1997
Image Creation Method and Apparatus (IJ03)
6,213,589





(Jul. 10, 1998)


PO8071
Jul. 15, 1997
Image Creation Method and Apparatus (IJ04)
6,231,163





(Jul. 10, 1998)


PO8047
Jul. 15, 1997
Image Creation Method and Apparatus (IJ05)
6,247,795





(Jul. 10, 1998)


PO8035
Jul. 15, 1997
Image Creation Method and Apparatus (IJ06)
6,394,581





(Jul. 10, 1998)


PO8044
Jul. 15, 1997
Image Creation Method and Apparatus (IJ07)
6,244,691





(Jul. 10, 1998)


PO8063
Jul. 15, 1997
Image Creation Method and Apparatus (IJ08)
6,257,704





(Jul. 10, 1998)


PO8057
Jul. 15, 1997
Image Creation Method and Apparatus (IJ09)
6,416,168





(Jul. 10, 1998)


PO8056
Jul. 15, 1997
Image Creation Method and Apparatus (IJ10)
6,220,694





(Jul. 10, 1998)


PO8069
Jul. 15, 1997
Image Creation Method and Apparatus (IJ11)
6,257,705





(Jul. 10, 1998)


PO8049
Jul. 15, 1997
Image Creation Method and Apparatus (IJ12)
6,247,794





(Jul. 10, 1998)


PO8036
Jul. 15, 1997
Image Creation Method and Apparatus (IJ13)
6,234,610





(Jul. 10, 1998)


PO8048
Jul. 15, 1997
Image Creation Method and Apparatus (IJ14)
6,247,793





(Jul. 10, 1998)


PO8070
Jul. 15, 1997
Image Creation Method and Apparatus (IJ15)
6,264,306





(Jul 10 1998)


PO8067
Jul. 15, 1997
Image Creation Method and Apparatus (IJ16)
6,241,342





(Jul. 10, 1998)


PO8001
Jul. 15, 1997
Image Creation Method and Apparatus (IJ17)
6,247,792





(Jul. 10, 1998)


PO8038
Jul. 15, 1997
Image Creation Method and Apparatus (IJ18)
6,264,307





(Jul. 10, 1998)


PO8033
Jul. 15, 1997
Image Creation Method and Apparatus (IJ19)
6,254,220





(Jul. 10, 1998)


PO8002
Jul. 15, 1997
Image Creation Method and Apparatus (IJ20)
6,234,611





(Jul. 10, 1998)


PO8068
Jul. 15, 1997
Image Creation Method and Apparatus (IJ21)
6,302,528





(Jul. 10, 1998)


PO8062
Jul. 15, 1997
Image Creation Method and Apparatus (IJ22)
6,283,582





(Jul. 10, 1998)


PO8034
Jul. 15, 1997
Image Creation Method and Apparatus (IJ23)
6,239,821





(Jul. 10, 1998)


PO8039
Jul. 15, 1997
Image Creation Method and Apparatus (IJ24)
6,338,547





(Jul. 10, 1998)


PO8041
Jul. 15, 1997
Image Creation Method and Apparatus (IJ25)
6,247,796





(Jul. 10, 1998)


PO8004
Jul. 15, 1997
Image Creation Method and Apparatus (IJ26)
09/113,122





(Jul. 10, 1998)


PO8037
Jul. 15, 1997
Image Creation Method and Apparatus (IJ27)
6,390,603





(Jul. 10, 1998)


PO8043
Jul. 15, 1997
Image Creation Method and Apparatus (IJ28)
6,362,843





(Jul. 10, 1998)


PO8042
Jul. 15, 1997
Image Creation Method and Apparatus (IJ29)
6,293,653





(Jul. 10, 1998)


PO8064
Jul. 15, 1997
Image Creation Method and Apparatus (IJ30)
6,312,107





(Jul. 10, 1998)


PO9389
Sep. 23, 1997
Image Creation Method and Apparatus (IJ31)
6,227,653





(Jul. 10, 1998)


PO9391
Sep. 23, 1997
Image Creation Method and Apparatus (IJ32)
6,234,609





(Jul. 10, 1998)


PP0888
Dec. 12, 1997
Image Creation Method and Apparatus (IJ33)
6,238,040





(Jul. 10, 1998)


PP0891
Dec. 12, 1997
Image Creation Method and Apparatus (IJ34)
6,188,415





(Jul. 10, 1998)


PP0890
Dec. 12, 1997
Image Creation Method and Apparatus (IJ35)
6,227,654





(Jul. 10, 1998)


PP0873
Dec. 12, 1997
Image Creation Method and Apparatus (IJ36)
6,209,989





(Jul. 10, 1998)


PP0993
Dec. 12, 1997
Image Creation Method and Apparatus (IJ37)
6,247,791





(Jul. 10, 1998)


PP0890
Dec. 12, 1997
Image Creation Method and Apparatus (IJ38)
6,336,710





(Jul. 10, 1998)


PP1398
Jan. 19, 1998
An Image Creation Method and Apparatus
6,217,153




(IJ39)
(Jul. 10, 1998)


PP2592
Mar. 25, 1998
An Image Creation Method and Apparatus
6,416,167




(IJ40)
(Jul. 10, 1998)


PP2593
Mar. 25, 1998
Image Creation Method and Apparatus (IJ41)
6,243,113





(Jul. 10, 1998)


PP3991
Jun. 9, 1998
Image Creation Method and Apparatus (IJ42)
6,283,581





(Jul. 10, 1998)


PP3987
Jun. 9, 1998
Image Creation Method and Apparatus (IJ43)
6,247,790





(Jul. 10, 1998)


PP3985
Jun. 9, 1998
Image Creation Method and Apparatus (IJ44)
6,260,953





(Jul. 10, 1998)


PP3983
Jun. 9, 1998
Image Creation Method and Apparatus (IJ45)
6,267,469





(Jul. 10, 1998)









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. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience.













Australian





Provisional


U.S. Pat. No./Patent Application


Number
Filing Date
Title
and Filing Date







PO7935
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,224,780




Apparatus (IJM01)
(Jul. 10, 1998)


PO7936
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,235,212




Apparatus (IJM02)
(Jul. 10, 1998)


PO7937
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,280,643




Apparatus (IJM03)
(Jul. 10, 1998)


PO8061
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,284,147




Apparatus (IJM04)
(Jul. 10, 1998)


PO8054
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,214,244




Apparatus (IJM05)
(Jul. 10, 1998)


PO8065
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,071,750




Apparatus (IJM06)
(Jul. 10, 1998)


PO8055
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,267,905




Apparatus (IJM07)
(Jul. 10, 1998)


PO8053
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,251,298




Apparatus (IJM08)
(Jul. 10, 1998)


PO8078
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,258,285




Apparatus (IJM09)
(Jul. 10, 1998)


PO7933
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,225,138




Apparatus (IJM10)
(Jul. 10, 1998)


PO7950
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,241,904




Apparatus (IJM11)
(Jul. 10, 1998)


PO7949
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,299,786




Apparatus (IJM12)
(Jul. 10, 1998)


PO8060
Jul. 15, 1997
A Method of Manufacture of an Image Creation
09/113,124




Apparatus (IJM13)
(Jul. 10, 1998)


PO8059
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,231,773




Apparatus (IJM14)
(Jul. 10, 1998)


PO8073
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,190,931




Apparatus (IJM15)
(Jul. 10, 1998)


PO8076
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,248,249




Apparatus (IJM16)
(Jul. 10, 1998)


PO8075
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,290,862




Apparatus (IJM17)
(Jul. 10, 1998)


PO8079
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,241,906




Apparatus (IJM18)
(Jul. 10, 1998)


PO8050
Jul. 15, 1997
A Method of Manufacture of an Image Creation
09/113,116




Apparatus (IJM19)
(Jul. 10, 1998)


PO8052
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,241,905




Apparatus (IJM20)
(Jul. 10, 1998)


PO7948
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,451,216




Apparatus (IJM21)
(Jul. 10, 1998)


PO7951
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,231,772




Apparatus (IJM22)
(Jul. 10, 1998)


PO8074
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,274,056




Apparatus (IJM23)
(Jul. 10, 1998)


PO7941
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,290,861




Apparatus (IJM24)
(Jul. 10, 1998)


PO8077
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,248,248




Apparatus (IJM25)
(Jul. 10, 1998)


PO8058
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,306,671




Apparatus (IJM26)
(Jul. 10, 1998)


PO8051
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,331,258




Apparatus (IJM27)
(Jul. 10, 1998)


PO8045
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,110,754




Apparatus (IJM28)
(Jul. 10, 1998)


PO7952
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,294,101




Apparatus (IJM29)
(Jul. 10, 1998)


PO8046
Jul. 15, 1997
A Method of Manufacture of an Image Creation
6,416,679




Apparatus (IJM30)
(Jul. 10, 1998)


PO8503
Aug. 11, 1997
A Method of Manufacture of an Image Creation
6,264,849




Apparatus (IJM30a)
(Jul. 10, 1998)


PO9390
Sep. 23, 1997
A Method of Manufacture of an Image Creation
6,254,793




Apparatus (IJM31)
(Jul. 10, 1998)


PO9392
Sep. 23, 1997
A Method of Manufacture of an Image Creation
6,235,211




Apparatus (IJM32)
(Jul. 10, 1998)


PP0889
Dec. 12, 1997
A Method of Manufacture of an Image Creation
6,235,211




Apparatus (IJM35)
(Jul. 10, 1998)


PP0887
Dec. 12, 1997
A Method of Manufacture of an Image Creation
6,264,850




Apparatus (IJM36)
(Jul. 10, 1998)


PP0882
Dec. 12, 1997
A Method of Manufacture of an Image Creation
6,258,284




Apparatus (IJM37)
(Jul. 10, 1998)


PP0874
Dec. 12, 1997
A Method of Manufacture of an Image Creation
6,258,284




Apparatus (IJM38)
(Jul. 10, 1998)


PP1396
Jan. 19, 1998
A Method of Manufacture of an Image Creation
6,228,668




Apparatus (IJM39)
(Jul. 10, 1998)


PP2591
Mar. 25, 1998
A Method of Manufacture of an Image Creation
6,180,427




Apparatus (IJM41)
(Jul. 10, 1998)


PP3989
Jun. 9, 1998
A Method of Manufacture of an Image Creation
6,171,875




Apparatus (IJM40)
(Jul. 10, 1998)


PP3990
Jun. 9, 1998
A Method of Manufacture of an Image Creation
6,267,904




Apparatus (IJM42)
(Jul. 10, 1998)


PP3986
Jun. 9, 1998
A Method of Manufacture of an Image Creation
6,245,247




Apparatus (IJM43)
(Jul. 10, 1998)


PP3984
Jun. 9, 1998
A Method of Manufacture of an Image Creation
6,245,247




Apparatus (IJM44)
(Jul. 10, 1998)


PP3982
Jun. 9, 1998
A Method of Manufacture of an Image Creation
6,231,148




Apparatus (IJM45)
(Jul. 10, 1998)









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. The serial numbers of respective corresponding U.S. patent applications are also provided for the sake of convenience.













Australian


U.S. Pat. No./


Provisional


Patent Application and


Number
Filing Date
Title
Filing Date







PO8003
Jul. 15, 1997
Supply Method
6,350,023




and Apparatus
(Jul. 10, 1998)




(F1)


PO8005
Jul. 15, 1997
Supply Method
6,318,849




and Apparatus
(Jul. 10, 1998)




(F2)


PO9404
Sep. 23, 1997
A Device and
09/113,101




Method (F3)
(Jul. 10, 1998)









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. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience.













Australian


U.S. Pat. No./


Provisional


Patent Application and


Number
Filing Date
Title
Filing Date







PO7943
Jul. 15, 1997
A device





(MEMS01)


PO8006
Jul. 15, 1997
A device
6,087,638




(MEMS02)
(Jul. 10, 1998)


PO8007
Jul. 15, 1997
A device
09/113,093




(MEMS03)
(Jul. 10, 1998)


PO8008
Jul. 15, 1997
A device
6,340,222




(MEMS04)
(Jul. 10, 1998)


PO8010
Jul. 15, 1997
A device
6,041,600




(MEMS05)
(Jul. 10, 1998)


PO8011
Jul. 15, 1997
A device
6,299,300




(MEMS06)
(Jul. 10, 1998)


PO7947
Jul. 15, 1997
A device
6,067,797




(MEMS07)
(Jul. 10, 1998)


PO7945
Jul. 15, 1997
A device
09/113,081




(MEMS08)
(Jul. 10, 1998)


PO7944
Jul. 15, 1997
A device
6,286,935




(MEMS09)
(Jul. 10, 1998)


PO7946
Jul. 15, 1997
A device
6,044,646




(MEMS10)
(Jul. 10, 1998)


PO9393
Sep. 23, 1997
A Device and
09/113,065




Method
(Jul. 10, 1998)




(MEMS11)


PP0875
Dec. 12, 1997
A Device
09/113,078




(MEMS12)
(Jul. 10, 1998)


PP0894
Dec. 12, 1997
A Device and
09/113,075




Method
(Jul. 10, 1998)




(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. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience.













Australian





Provisional


U.S. Pat. No./Patent Application and


Number
Filing Date
Title
Filing Date







PP0895
Dec. 12, 1997
An Image Creation Method and Apparatus
6,231,148




(IR01)
(Jul. 10, 1998)


PP0870
Dec. 12, 1997
A Device and Method (IR02)
09/113,106





(Jul. 10, 1998)


PP0869
Dec. 12, 1997
A Device and Method (IR04)
6,293,658





(Jul. 10, 1998)


PP0887
Dec. 12, 1997
Image Creation Method and Apparatus
09/113,104




(IR05)
(Jul. 10, 1998)


PP0885
Dec. 12, 1997
An Image Production System (IR06)
6,238,033





(Jul. 10, 1998)


PP0884
Dec. 12, 1997
Image Creation Method and Apparatus
6,312,070




(IR10)
(Jul. 10, 1998)


PP0886
Dec. 12, 1997
Image Creation Method and Apparatus
6,238,111




(IR12)
(Jul. 10, 1998)


PP0871
Dec. 12, 1997
A Device and Method (IR13)
09/113,086





(Jul. 10, 1998)


PP0876
Dec. 12, 1997
An Image Processing Method and Apparatus
09/113,094




(IR14)
(Jul. 10, 1998)


PP0877
Dec. 12, 1997
A Device and Method (IR16)
6,378,970





(Jul. 10, 1998)


PP0878
Dec. 12, 1997
A Device and Method (IR17)
6,196,739





(Jul. 10, 1998)


PP0879
Dec. 12, 1997
A Device and Method (IR18)
09/112,774





(Jul. 10, 1998)


PP0883
Dec. 12, 1997
A Device and Method (IR19)
6,270,182





(Jul. 10, 1998)


PP0880
Dec. 12, 1997
A Device and Method (IR20)
6,152,619





(Jul. 10, 1998)


PP0881
Dec. 12, 1997
A Device and Method (IR21)
09/113,092





(Jul. 10, 1998)









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. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience.













Australian


U.S. Pat. No./Patent


Provisional


Application and


Number
Filing Date
Title
Filing Date







PP2370
Mar. 16, 1998
Data Processing
09/112,781




Method and
(Jul. 10, 1998)




Apparatus




(Dot01)


PP2371
Mar. 16, 1998
Data Processing
09/113,052




Method and
(Jul. 10, 1998




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. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience.













Australian





Provisional


U.S. Pat. No./Patent Application and


Number
Filing Date
Title
Filing Date







PO7991
Jul. 15, 1997
Image Processing Method and Apparatus
09/113,060




(ART01)
(Jul. 10, 1998)


PO7988
Jul. 15, 1997
Image Processing Method and Apparatus
6,476,863




(ART02)
(Jul. 10, 1998)


PO7993
Jul. 15, 1997
Image Processing Method and Apparatus
09/113,073




(ART03)
(Jul. 10, 1998)


PO9395
Sep. 23, 1997
Data Processing Method and Apparatus
6,322,181




(ART04)
(Jul. 10, 1998)


PO8017
Jul. 15, 1997
Image Processing Method and Apparatus
09/112,747




(ART06)
(Jul. 10, 1998)


PO8014
Jul. 15, 1997
Media Device (ART07)
6,227,648





(Jul. 10, 1998)


PO8025
Jul. 15, 1997
Image Processing Method and Apparatus
09/112,750




(ART08)
(Jul. 10, 1998)


PO8032
Jul. 15, 1997
Image Processing Method and Apparatus
09/112,746




(ART09)
(Jul. 10, 1998)


PO7999
Jul. 15, 1997
Image Processing Method and Apparatus
09/112,743




(ART10)
(Jul. 10, 1998)


PO7998
Jul. 15, 1997
Image Processing Method and Apparatus
09/112,742




(ART11)
(Jul. 10, 1998)


PO8031
Jul. 15, 1997
Image Processing Method and Apparatus
09/112,741




(ART12)
(Jul. 10, 1998)


PO8030
Jul. 15, 1997
Media Device (ART13)
6,196,541





(Jul. 10, 1998)


PO7997
Jul. 15, 1997
Media Device (ART15)
6,195,150





(Jul. 10, 1998)


PO7979
Jul. 15, 1997
Media Device (ART16)
6,362,868





(Jul. 10, 1998)


PO8015
Jul. 15, 1997
Media Device (ART17)
09/112,738





(Jul. 10, 1998)


PO7978
Jul. 15, 1997
Media Device (ART18)
09/113,067





(Jul. 10, 1998)


PO7982
Jul. 15, 1997
Data Processing Method and Apparatus
6,431,669




(ART19)
(Jul. 10, 1998


PO7989
Jul. 15, 1997
Data Processing Method and Apparatus
6,362,869




(ART20)
(Jul. 10, 1998


PO8019
Jul. 15, 1997
Media Processing Method and Apparatus
6,472,052




(ART21)
(Jul. 10, 1998


PO7980
Jul. 15, 1997
Image Processing Method and Apparatus
6,356,715




(ART22)
(Jul. 10, 1998)


PO8018
Jul. 15, 1997
Image Processing Method and Apparatus
09/112,777




(ART24)
(Jul. 10, 1998)


PO7938
Jul. 15, 1997
Image Processing Method and Apparatus
09/113,224




(ART25)
(Jul. 10, 1998)


PO8016
Jul. 15, 1997
Image Processing Method and Apparatus
6,366,693




(ART26)
(Jul. 10, 1998)


PO8024
Jul. 15, 1997
Image Processing Method and Apparatus
6,329,990




(ART27)
(Jul. 10, 1998)


PO7940
Jul. 15, 1997
Data Processing Method and Apparatus
09/113,072




(ART28)
(Jul. 10, 1998)


PO7939
Jul. 15, 1997
Data Processing Method and Apparatus
09/112,785




(ART29)
(Jul. 10, 1998)


PO8501
Aug. 11, 1997
Image Processing Method and Apparatus
6,137,500




(ART30)
(Jul. 10, 1998)


PO8500
Aug. 11, 1997
Image Processing Method and Apparatus
09/112,796




(ART31)
(Jul. 10, 1998)


PO7987
Jul. 15, 1997
Data Processing Method and Apparatus
09/113,071




(ART32)
(Jul. 10, 1998)


PO8022
Jul. 15, 1997
Image Processing Method and Apparatus
6,398,328




(ART33)
(Jul. 10, 1998


PO8497
Aug. 11, 1997
Image Processing Method and Apparatus
09/113,090




(ART34)
(Jul. 10, 1998)


PO8020
Jul. 15, 1997
Data Processing Method and Apparatus
6,431,704




(ART38)
(Jul. 10, 1998


PO8023
Jul. 15, 1997
Data Processing Method and Apparatus
09/113,222




(ART39)
(Jul. 10, 1998)


PO8504
Aug. 11, 1997
Image Processing Method and Apparatus
09/112,786




(ART42)
(Jul. 10, 1998)


PO8000
Jul. 15, 1997
Data Processing Method and Apparatus
6,415,054




(ART43)
(Jul. 10, 1998)


PO7977
Jul. 15, 1997
Data Processing Method and Apparatus
09/112,782




(ART44)
(Jul. 10, 1998)


PO7934
Jul. 15, 1997
Data Processing Method and Apparatus
09/113,056




(ART45)
(Jul. 10, 1998)


PO7990
Jul. 15, 1997
Data Processing Method and Apparatus
09/113,059




(ART46)
(Jul. 10, 1998)


PO8499
Aug. 11, 1997
Image Processing Method and Apparatus
6,486,886




(ART47)
(Jul. 10, 1998)


PO8502
Aug. 11, 1997
Image Processing Method and Apparatus
6,381,361




(ART48)
(Jul. 10, 1998)


PO7981
Jul. 15, 1997
Data Processing Method and Apparatus
6,317,192




(ART50)
(Jul. 10, 1998


PO7986
Jul. 15, 1997
Data Processing Method and Apparatus
09/113,057




(ART51)
(Jul. 10, 1998)


PO7983
Jul. 15, 1997
Data Processing Method and Apparatus
09/113,054




(ART52)
(Jul. 10, 1998)


PO8026
Jul. 15, 1997
Image Processing Method and Apparatus
09/112,752




(ART53)
(Jul 10, 1998)


PO8027
Jul. 15, 1997
Image Processing Method and Apparatus
09/112,759




(ART54)
(Jul. 10, 1998)


PO8028
Jul. 15, 1997
Image Processing Method and Apparatus
09/112,757




(ART56)
(Jul. 10, 1998)


PO9394
Sep. 23, 1997
Image Processing Method and Apparatus
6,357,135




(ART57)
(Jul. 10, 1998


PO9396
Sep. 23, 1997
Data Processing Method and Apparatus
09/113,107




(ART58)
(Jul. 10, 1998)


PO9397
Sep. 23, 1997
Data Processing Method and Apparatus
6,271,931




(ART59)
(Jul. 10, 1998)


PO9398
Sep. 23, 1997
Data Processing Method and Apparatus
6,353,772




(ART60)
(Jul. 10, 1998)


PO9399
Sep. 23, 1997
Data Processing Method and Apparatus
6,106,147




(ART61)
(Jul. 10, 1998)


PO9400
Sep. 23, 1997
Data Processing Method and Apparatus
09/112,790




(ART62)
(Jul. 10, 1998)


PO9401
Sep. 23, 1997
Data Processing Method and Apparatus
6,304,291




(ART63)
(Jul. 10, 1998)


PO9402
Sep. 23, 1997
Data Processing Method and Apparatus
09/112,788




(ART64)
(Jul. 10, 1998)


PO9403
Sep. 23, 1997
Data Processing Method and Apparatus
6,305,770




(ART65)
(Jul. 10, 1998)


PO9405
Sep. 23, 1997
Data Processing Method and Apparatus
6,289,262




(ART66)
(Jul. 10, 1998)


PP0959
Dec. 16 1997
A Data Processing Method and Apparatus
6,315,200




(ART68)
(Jul. 10, 1998)


PP1397
Jan. 19, 1998
A Media Device (ART69)
6,217,165





(Jul. 10, 1998)

## Claims

1. A printhead re-capping assembly for a printer having a chassis, a platen assembly and a pagewidth printhead operatively mounted on the chassis to carry out a printing operation on print media passing over the platen assembly, the re-capping assembly comprising
a base structure that is mounted on the chassis; 
at least one static solenoid that is mounted on the base structure and that is connected to an electrical power supply of the printer; 
a support member that is actuable by the solenoid to be movable with respect to the chassis between an operative position and an inoperative position; and 
a printhead capping member that is mounted directly on the support member such that when the support member is in the operative position, the capping member engages the printhead to cap the printhead and when the support member is in the inoperative position, the capping member is disengaged from the printhead, and wherein the base structure and the at least one static solenoid are both elongate to correspond with a length of the printhead.

2. A printhead re-capping assembly as claimed in claim 1, in which the support member is configured to be normally in the operative position and to move into the inoperative position when the solenoid is energized by the electrical power supply.

3. A printhead re-capping assembly as claimed in claim 2, in which a biasing mechanism is engaged with the support member to bias the support member into the operative position when the solenoid is de-energized.

4. A printhead re-capping assembly as claimed in claim 3, in which the support member is elongate and corresponds generally with the printhead.

5. A printhead re-capping assembly as claimed in claim 4, in which the capping member includes a length of sponge that is dimensioned to cover the printhead when the support member is displaced into its operative position.

6. A printhead re-capping assembly as claimed in claim 5, which includes a sealing member that is positioned on the support member to bound the length of sponge such that, when the length of sponge caps the printhead, the sealing member serves to seal a region about the printhead.

7. A printhead re-capping assembly on claimed in claim 6, which includes an elastomer strip, for sealing against the surface of the printhead ink supply cartridge.

8. A printhead re-capping assembly on claimed in claim 7, which includes an elastomer spring unit to deform the elastomer seal.