Abstract: A method and apparatus for checkerboard printing by a liquid ink printing apparatus. A liquid ink printing apparatus, such as a thermal ink jet printer, includes circuitry for reducing video data clocking in checkerboard printing by controlling the odd and even vertical print strokes of a reciprocating printhead mounted to a scanning carriage. The amount of bitmapped imaged data, also known as video data, is reduced by one half or more and sent to the printhead for printing checkerboard patterns. Reduction of the bitmapped image data is accomplished by a data packer circuit which selects certain bits of the bitmapped image data for printing by the printhead in a checkerboard pattern. At the printhead, the bitmapped image is reconstructed by a data unpacker circuit to cause selective ejection of ink from the appropriate nozzles of the printhead. Two or more passes information are printed to complete printing of the bitmapped image data.

Abstract: A valve for selecting an ink from a plurality of different types of inks having no dead spaces to prevent ink of one type from contaminating ink of a second type. The valve includes a selecting member with a channel and a housing having first, second and third passages. The housing defines with the valve a cleaning chamber in communicating relation with the channel and the first, second, and third passages. The cleaning chamber receives a solvent between changing from one ink to another ink which cleans the selecting member and chamber thereby preventing mixing of inks of different types.

Abstract: An apparatus for drying ink deposited upon cut sheet of paper. The apparatus includes a microwave generating member to generate microwave energy for the ink and an applying member connected to said microwave generating member to apply resonating traveling microwaves to the paper. The applicator member includes a serpentine applicator for drying the ink and includes input slots and output slots for moving cut sheet of paper through the serpentine applicator. A transport member transports ink printed cut sheet paper stock from the input slot to the output slot by a belt running through the center of the applicator.

Abstract: A method for fabricating a liquid ink printhead orifice plate for use in a liquid ink printhead and printer. The liquid ink orifice plate is formed of a thermal plastic resin which is stamped between an orifice plate mandrel which includes the ink carrying features and a flat mandrel. Once the orifice plate has been stamped, excess material is removed from the orifice plate to reveal ink carrying features of the stamped orifice plate. The orifice plate mandrel is formed by electroforming a mandrel on an etched silicon wafer which defines a plurality of ink carrying channels and ink reservoirs. The electroform mandrel can be made of any number of metals which includes nickel.

Abstract: A maintenance apparatus for maintaining an ink jet printhead. The maintenance apparatus includes a maintenance station having a first member, a translation apparatus connected to the maintenance station which generates a translation force to translate the maintenance station along a path, and a displacement apparatus connected to the translation apparatus and operatively coupled to the first member for displacing the first member with respect to the translation apparatus. The maintenance apparatus minimizes system complexity by using the energy which translates the maintenance station for extending and retracting the capping member which seals the area around the front nozzle face of an ink jet printhead during periods of non-use. A lead screw and a motor move the maintenance station in a direction towards an ink jet printhead for maintenance operations and a actuating lever and camming system move the capping member into contact with the front face of the ink jet printhead.

Abstract: A method and apparatus for controlling curl in a liquid ink printer. The liquid ink printer deposits an anticurl material on the side of a printed sheet opposite the one having printing deposited thereon. The anticurl material is a fluid which counteracts the steady state curl in the direction of the printed image resulting from active drying of the printed sheet. The back side of a printed sheet has deposited thereon an anticurl fluid which can contain water, a penetrant, and a humectant like material such as diethylene glycol, ethylene glycol, sulfolane and glycerin. The anticurl material is deposited with a roller made of a foam material for absorbing the anticurl fluid or a roller having dimples disposed on the surface thereof. In addition, the anticurl fluid can be deposited by a spray device or a thermal ink jet printhead ejecting anticurl fluid.

Abstract: A smart direct memory access controller for data space transformation. The smart direct memory access controller can be used in computer systems to read and/or write data in a non-linear fashion in order to alter the organization of data stored within the computer system. The direct memory access controller has particular application in the electronic subsystem of a non-raster format electronic printer, such as a partial width array or full width array thermal ink jet printer. The smart direct memory access controller enables a non-raster format printer to access image organized in raster format, by viewing the data space as a non-linear or multi-dimensional memory. Memory addresses of the non-linear or multi-dimensional address space are a catenation of several data fields. Each field is one of the coordinates that defines the location of data within memory.

Abstract: A priming element for priming or maintaining the nozzles or orifices of an ink jet printhead in an ink jet printer. The priming element applies a vacuum or negative pressure generated by a suction device to the nozzles. The priming element includes a first wall and a second wall spaced from the first wall to define a passageway between the first wall and the second wall. One or more support members connect the first wall to the second wall and span the passageway to prevent the walls of the priming element from collapsing from the applied vacuum or negative pressure.

Abstract: A large array or pagewidth printhead fabricated from printhead elements or subunits having adhesive-free butting edges. Each of the printhead elements includes a heater element and a channel element bonded together by an adhesive such as an epoxy. A space or adhesive-receiving aperture is formed between the channel element and the heater element before mating so that any adhesive forced from between the channel element and heater element by the pressure of mating does not flow onto the butting surfaces, but instead overflows into the space thereby maintaining an adhesive free butting edge. The channel element includes an etch trough which forms the space. The printhead elements are butted together to form a large array printhead. The absence of adhesive on the butting edges improves manufacturability of the large array printhead.

Abstract: A programmable encoder having an addressable display device to display an encoder pattern of fiducial marks. The programmable encoder can be programmed to display an encoder pattern on a liquid crystal display. A sensor senses the marks on the pattern and generates sensor signals indicative of the sensed pattern. A controller connected to the sensor receives the sensor signals and outputs control signals which control the movement of a machine, such as an ink jet printer. The programmable encoder can be programmed to display any number of patterns on the addressable display device, and consequently, is highly adaptable to any number of applications requiring position, speed, or acceleration control.

Abstract: An apparatus and method for bonding wafer pairs. The apparatus includes a heated platen surrounded by a pressurization vessel. The heated platen includes channels connected to a hole which runs through the heated platen. Wafer pairs are placed on the top surface of the platen, a rubber mat is placed over the top of the wafer pairs, and a vacuum is drawn through the hole and the channels. The rubber mat compresses the wafer pairs. The platen is heated for the bonding process. The pressurization chamber is pressurized supplying additional bonding pressure to the wafer pair. Once sufficiently heated, the heated platen is liquid cooled completing the bonding process.

Abstract: A recording medium holddown apparatus for holding down a recording medium traversing along a path on a platen in a post-printing area of a printer. The recording medium holddown apparatus includes a first and second holddown member located above the platen to force a recording medium having any curl flat against the platen to thereby prevent problems associated with curl such as contamination of the printhead nozzles, ink smear, paper misregistration, and carriage hangup. In addition to the holddown members, a first and second runner are disposed on a carriage carrying the printhead across the recording medium for printing. The first and second runners have upturned ends to intercept any curl of the recording medium to further avoid problems associated with recording medium curl.

Abstract: A method and apparatus for automatically adjusting the quality of printing made by a scanning type printhead or printbar upon a recording medium advanced perpendicularly to the scanning direction. The scanning printbar includes sequentially printed segments in which the dots or pixels in a segment are printed simultaneously. A source of illumination is passed across a test pattern having features indicative of printhead alignment and discernible under the illumination. The source of illumination is connected to circuitry with determines the variation in light intensity of the test pattern. A value indicative of the misalignment is calculated and used to correct the timing of firing signals between the sequentially fired banks of nozzles of a printbar.

Abstract: An integral seal for priming or maintaining the nozzles or orifices of an ink jet printhead in an ink jet printer. The ink jet printhead includes a plurality of ink ejecting orifices arranged on a surface of the printhead and includes a seal integral with the surface which surrounds the ink ejecting orifices. The seal member is located within a recess formed in the surface and has a contacting surface which can be recessed from the ink ejecting orifices so that cleaning operations of the surface which, for instance, use a wiping blade, are not impeded. A capping member on a maintenance station contacts and slightly compresses the seal member to provide an airtight seal during priming/maintenance operations.

Abstract: A cleaning apparatus for cleaning a transport belt in a printing machine of the type in which liquid ink is deposited on a recording medium moved along a path by the transport belt. The cleaning apparatus located next to the transport belt cleans a first surface and a second surface of the transport belt when ink and/or other contaminants collect on the belt. A sensor senses when the belt needs cleaning. Interior side walls of apertures within the belt which enable vacuum transport of the recording medium through the printing machine are also cleaned. The cleaning apparatus includes a first cleaning device having a flexible web for cleaning the first surface of the transport belt and a second cleaning device having a flexible web for cleaning the second surface of the transport belt. The sensor includes a length sufficient to sense contaminants along the width of the transport belt.

Abstract: An ink filling apparatus for filling ink cartridges with a quantity of ink. The ink filling apparatus includes ink injecting members or needles to inject ink into an ink saturating material or wicking medium contained in the ink cartridges. A compression member compresses the ink saturating medium while ink is injected into the saturating medium. A vent cover covers a vent tube in the ink cartridge and directs the flow of pressurized air or gas through the vent tube to prevent ink from entering the vent tube during the ink filling operation. A piston pump delivers a specific quantity of ink to the ink filling apparatus to accurately fill each ink cartridge.

Abstract: A matched or dummy load for a microwave dryer having a microwave generator and a microwave applicator. The matched load includes a waveguide having opposed broad walls, opposed narrow walls, and an end wall defining a waveguide chamber. A power absorbing body made of sintered silicon carbide, casted silicon carbide, or other materials is disposed in the waveguide chamber. One or more of the walls includes means for transferring heat from the power absorbing body. A housing or shroud having an inlet and an outlet surrounds the waveguide. The means for removing heat is disposed between the inlet and outlet of the housing so that a cooling medium passed through the housing removes heat from the power absorbing body. A tuning stub is placed in front of the power absorbing body to reduce microwave reflections.

Abstract: A phase shifter for shifting the phase angle of microwaves traveling in a waveguide of a microwave circuit. The phase shifter includes a dielectric plate which has first and second parallel surfaces, a distal edge, a proximate edge, a leading edge, and a trailing edge where each of the edges defines the outer bounds of the first and second parallel surfaces. The dielectric plate is shaped like a parallelogram lacking any right angles and is made of a microwave low loss dielectric material such as polystyrene or polytetrafluoroethylene. The height of the dielectric plate is less than one half the height of the waveguide side wall and the length is less than one guide wavelength long. The phase shifter fine tunes a resonating microwave circuit and provides approximately three-quarters of an inch adjustment of microwave circuit length.

Abstract: An ink jet printhead having off center or offset heaters or thermal transducers to reduce heater damage. The printhead has heaters located beneath channels to eject ink from the channel through a nozzle to a substrate for printing. Edge heaters are spaced away from the dicing edges of the heater plate to avoid damage resulting from dicing for assembly or from thermal expansion due to adjacent printheads if used to form a page width or large array printhead. The spacing distance between the edge heaters to adjacent equally spaced heaters on the same printhead is less than the distance between adjacent equally spaced heaters. Edge heaters are also offset from the centerline of respective channels in the printhead.