Abstract: A maintenance station for an ink jet printer of the type having a printhead movable between an operating position and a maintenance position provides the capability of priming the printhead as well as maintaining a humid environment to prevent ink from drying out in the printhead orifices. The maintenance station is located adjacent the printhead maintenance position periodically occupied by the printhead and is positionable towards and away from the printhead. The maintenance station comprises a movable chamber having a rigid wall confronting the printhead and the chamber wall has an aperture. A seal means comprises a resilient floating bed base with a opening similar in size to the chamber wall aperture and resilient lips extending from the periphery of the base opening, the outer edge of which is larger than the base opening, so that the lips of the seal means have a predetermined slope.

Abstract: An ink jet printhead having an integral silicon filter over the printhead ink inlet is disclosed. The filter is produced by orientation dependent etching during printhead fabrication. The individual printheads are obtained by a sectioning operation which cuts aligned and bonded channel and heater wafers into a plurality of printheads. The channel wafer is orientation dependent etched from one side of a (100) silicon wafer through a patterned etch resistant mask layer to produce the plurality of reservoir recesses, each having a predetermined depth and floor thickness, and a plurailty of sets of parallel ink channel grooves, one set of channel grooves for each reservoir recess. The etch resistant mask layer on both sides of the channel wafer are removed and a second etch resistant mask layer is deposited thereon.

Abstract: A precision etched, three dimensional device is fabricated from a silicon wafer by etching from one side of the wafer. A chemical masking layer, such as silicon nitride, is first deposited on all sides of the wafer, followed by the deposition of a robust mechanical layer, such as polycrystalline silicon, over the masking layer on all sides of the wafer. The two layers are sequentially patterned on one side of the wafer and then the wafer is placed into an etchant bath which etches the exposed surface of the wafer and concurrently removes the protective layer, leaving a defect-free masking layer that prevents unintentional etching that would reduce yields of fabricated devices.

Abstract: A fabricating process for pagewidth reading and/or writing bars assembled from subunits, such as ink jet printhead subunits, is disclosed. At least two lengths of subunits are cut and placed on corresponding flat containers. An assembly robot places the subunits in a butted array on an alignment fixture and checks the accumulated positional error of the subunits as they are being assembled. When the robot detects an error exceeding some preset limits, it chooses a subunit of a known size to compensate for the detected error.

Abstract: In the present invention, a drive means for use in a printer or copier is described which will transport a recording medium, such as paper, having liquid images on one surface thereof without inadvertently causing the recording liquid to be pushed from the still wet image areas into non-image areas, thereby reducing print quality. This transportation of a recording medium with wet images without degradation of print quality is accomplished by a drive means comprising a drive roller having a high friction surface which is rotatably mounted beneath and tangent to a planar path of movement for the recording medium and a toothed idler roller having spaced teeth with rounded distal ends which extend from a hub to form a nip with the drive roller through which the recording medium is transported. The teeth have a predetermined height from the hub and a predetermined spacing between teeth. The distal ends of the teeth have a surface which is of a material that is not wetted by a recording liquid.

Abstract: A pagewidth thermal ink jet printhead for an ink jet printer is disclosed. The printhead is the type assembled from fully functional roofshooter type printhead subunits fixedly mounted on the surface of one side of a structural bar. A passageway is formed adjacent the bar side surface containing the printhead subunits with openings provided between the passageway and the ink inlets of the printhead subunits, mounted thereon so that ink supplied to the passageway in the bar will maintain the individual subunits full of ink. The size of the printing zone for color printing is minimized because the roofshooter printhead subunits are mounted on one edge of the structural bar and may be stacked one on top of the other without need to provide space for the printhead subunits and/or ink supply lines. In addition, the structural bar thickness enables the bar to be massive enough to prevent warping because of printhead operating temperatures.

Abstract: In an ink jet printer, a printhead assembly comprising a printhead and an ink reservoir is mounted on a scanning carriage for movement across a recording medium. During printing, droplets of ink are expelled from ink channels within the printhead and the channels are replenished with ink which is drawn in from the reservoir. The reservoir is connected by supply and return lines to an ink source, and a pump is provided to deliver ink from the source along the supply line to prime the printhead and reservoir. To ensure that the reservoir is filled with ink during the priming operation, the outlet from the reservoir to the return line incorporates a flow restriction equal to, or greater than, that of the printhead.

Abstract: A method and apparatus is disclosed for an improved liquid development system for a high speed reproducing machine having a movable image retention belt. The liquid development system comprising a moving belt applicator mounted on a drive assembly containing at least one drive roll and a low lateral force roll with a position guide. The belt applicator is located in alignment with the image retention belt and spaced therefrom to form a development zone having a uniform gap with an extended length. The applicator drive roll and a low lateral force roll are positoned to transport the belt applicator in the same or opposite direction as the image retention belt, but at a much faster speed to facilitate an evenly distributed flow of liquid developer and to avoid depletion of toner particles from the liquid developer moved through the development zone.

Abstract: An integral filter is fabricated by patterning a layer of etch resistant material on one side of a (100) silicon wafer to produce an array of equally spaced, uniformly sized posts or shapes and doping the exposed surface of the wafer by boron ion implant. The dopant is diffused into the wafer while the array of posts of etch resistant material masks the diffusion under them. The size of the posts or shapes determines the undoped areas of the wafer and, thus, the mesh size of the eventually produced integral filter. The wafer is recoated with a layer of etch resistant material and the other side, which was not doped, is patterned to form a plurality of sets of elongated channel vias and reservoir vias, one reservoir via for each set of channel vias.

Abstract: In an ink jet printer, an arrangement is provided for cleaning the face of the printhead in which the ink ejecting orifices are located. The arrangement includes a suction chamber directed towards, but spaced apart from, the printhead face to draw air over the printhead face and thereby remove any contamination such as ink residue and paper fibers. Advantageously, the suction chamber is formed in the cap member that is conventionally provided to engage the printhead and cap the ink ejecting orifices when the printhead is not in use. In that case, suction may also be applied to the cap member when it is in engagement with the printhead, to prime the printhead and/or to clear the ink ejecting orifices. Suction may then be maintained while the cap member is moved away from the printhead, so that air will be drawn over the printhead face.

Abstract: In an ink jet printer, a printhead assembly comprising a printhead and an ink reservoir is mounted on a scanning carriage for movement across a recording medium. During printing, droplets of ink are expelled from ink channels within the printhead and the channels are replenished with ink which is drawn in from the reservoir. The reservoir is connected to an ink source from which ink is supplied during printing and when the printhead assembly is being primed. A partition within the reservoir ensures that, during priming, air can be expelled from the reservoir through the ink channels, thereby avoiding the need for an air vent from the reservoir.

Abstract: A carriage type ink printer having a replenishable ink cartridge and ink jet printhead mounted on the carriage for translation across a printing region of an ink jet printer. The replenishable ink cartridge having means to keep the necessary negative pressure at the printhead by way of a foam-like material contains an ink supply monitoring means which uses a thermistor and constant current circuitry to indicate when it should be resupplied with ink. The printer controller moves the replenishable cartridge to a predetermined side of the printer beyond the printing region and into position to receive ink from a fixed ink supply container. The ink supply monitoring means indicating when the replenishable cartridge is filled in order to prevent over filling the cartridge.

Abstract: A thermal ink jet printhead having an array of coplanar nozzles in a nozzle face that are entirely surrounded by an insulative polymeric material is disclosed, together with a method of fabrication thereof. The ink channels, nozzles, and reservoir are produced by sequentially depositing and patterning two layers of thick film material, such as Vacrel.RTM., on one substrate containing an array of heating elements and addressing electrodes, so that the heating elements are placed in a pit in the first thick film layer and the channels and reservoir recesses are produced in the overlaying second thick film layer. A second substrate having a third layer of the same thick layer and having a hole processed therethrough to serve as an ink inlet is aligned and bonded to the first substrate to form the printhead, with the second and third film layers bonded together in order to produce the nozzle which are surrounded by the thick film material.

Abstract: In a printhead assembly for a thermal ink jet printer there are a plurality of printheads mounted on a common heat sink, together with a heater and temperature controller for maintaining temperature of the printheads at an appropriate operating level. To prevent overheating of a printhead during periods of heavy use, the ink supply paths carrying ink to the printheads pass through, and receive heat from, the heat sink. The ink in each supply path then passes to the respective printhead via a tank, the position of which relative to the printhead establishes the ink pressure at the printhead discharge orifices. The tank is vented so that any air separating out from the ink can be removed. Capping means is provided to cap the ink discharge orifices when the printhead is idle and to prime/clean the printhead when required.

Abstract: A device to cap a thermal ink jet printhead, without the need of moving the printhead or the paper transport is described. The capping device has a resilient gasket which contains magnetic material and is attached to the printhead by a relatively thin flexible boot or sleeve. A steel bar is disposed in sliding contact beneath a paper transport belt. The belt is adjacently spaced parallel to the printhead. The paper transport belt is flat and smooth and has a hole-free surface. During operation of the printer, an electromagnet disposed on the printhead is energized and attracts the magnetic gasket, resulting in the attraction of the gasket above the printhead nozzles to enable printing. When the printhead is not in operation, the electromagnet is de-energized, allowing the steel bar to attract the magnetic gasket and seal the gasket to the belt, capping the printhead. The capping device eliminates the need for movement of the printhead or moving the paper transport.

Abstract: A thermal ink jet printer is disclosed which has a printhead that is maintained at a substantially constant operating temperature during printing. Printing on demand is accomplished by the ejection of ink droplets from the printhead nozzles in response to energy pulses selectively applied to heating elements located in ink channels upstream from the nozzles which pulses vaporize the ink to form temporary bubbles. To prevent printhead temperature fluctuations during printing, especially in translatable carriage printers, the heating elements not being used to eject droplets are selectively energized with energy pulses having insufficient magnitude to vaporize the ink.

Abstract: An ink jet printer is disclosed having a rotatable intermediate drum having a thermally conductive surface on which the ink droplets are printed from the printhead. The drum surface material is a suitable film forming silicone polymer having a high surface energy and surface roughness to prevent movement of the droplets after impact thereon. The printhead is located relative to the intermediate drum surface so that the ink droplets impact the drum surface with a large contact angle and the ink droplet image is transferred at a second location spaced from the printhead to minimize contaminating particles from the recording medium from reaching the printhead nozzles. The intermediate drum surface is heated to dehydrate the ink droplets prior to transfer from the intermediate drum to the recording medium.

Abstract: A cleaning device for removal of ink and other debris from the nozzle face of an ink jet printhead is disclosed. The cleaning device is located at a cleaning and priming station within the printer, and comprises a rotatable drum having at least one slot in which an absorbent material covered with a polymeric mesh material is manually inserted. When the printhead is located in the cleaning and priming station, the drum is rotated and the covered absorbent material wipes the nozzle face. In one embodiment, the printer is a carriage type with the cleaning station on one side of the printing region. The drum is surrounded by a housing with an opening so that the covered absorbent material is rotated therepast and into contact with the nozzle face of the printhead. The absorbent material is moistened to assist in cleaning the nozzle face in preventing ink removed from the nozzle face from drying on the mesh material.

Abstract: A plurality of thermal ink jet printheads, each with nozzles in a pre-diced nozzle face, obtained from sectioning of an etched channel wafer aligned and mated with a heating element containing wafer that have a patterned thick film layer sandwiched therebetween. The printhead nozzles and pre-diced nozzle face are produced in the channel wafer prior to the alignment and mating of the wafers by the combination of dicing a notch in the channel wafer through one end of a plurality of sets of etched channel grooves, forming the nozzles and the nozzle face in the channel wafer and photodelineating the thick film layer on the heating element wafer, so that when the wfaers are mated, the delineated edge of the thick film layer becomes part of the nozzles without requiring the cutting of the thick film layer by a dicing blade. In one embodiment, the heating element wafer has a similar notch diced therein adjacent the delineated edge of the thick film layer prior to mating with the channel wafer.

Abstract: A thermal ink jet printhead and method of batch production thereof is disclosed. Each printhead has a plurality of nozzles in a stepped nozzle face that are obtained by a two step dicing operation. The printheads being formed by aligning and bonding an anisotropically etched silicon wafer containing a plurality of sets of channel grooves to a silicon wafer containing a plurality of linear arrays of heating elements and addressing electrodes over which a thick film layer is deposited and photopatterned to expose the heating elements and electrode terminals and to remove the areas parallel to and a predetermined distanace from the heating element arrays, thus photodelineating the portion of the thick film layer between the heating elements and the nozzles. The mated wafer sandwiches the thick film layer, and first dicing cutting severs the etch wafer and notches the wafer with the heating elements, forming a nozzle face containing the nozzle.