Abstract: An electrographic liquid applicator head is inexpensively but precisely fabricated by adhering a flat base member, in which grooves are molded or cast, to a thin, photofabricated cover member. The adhesive isolates the supply gutters of the base and supply slits of the cover from adjacent drain slits and gutters. In a preferred embodiment the surface of the cover member is held in a suitably planar position by a planar surface on a magnetic chuck.

Abstract: In a method and apparatus for transmitting a digital image over a limited bandwidth communication channel, an image is block transformed to produce blocks of transform coefficients; the transform coefficients are quantized in accordance with a model of the visibility of quantization error in the presence of image detail; the quantized coefficients are encoded with a minimum redundancy code; and the coded, quantized transform coefficients are transmitted.

Abstract: An improved light valve device of the kind having: (i) an electro-optic modulator panel with a plurality of electrodes defining a linear array of selectively activatable modulation zones in the panel and (ii) a pair of polarizer elements sandwiching such panel and oriented with their polarization directions at 90.degree. relative to one another. The polarization directions of the polarizers are respectively parallel and perpendicular to the linear direction of the modulation zones array and the electrodes are constructed to provide electric fields across the modulation zones in directions approximately 45.degree. to the linear direction of the modulation zones array.

Abstract: Printer apparatus of the kind having a housing, a print zone and a serial printing device for printing along line sectors of print media that are successively advanced into and out of the print zone includes an integral subsystem for handling discrete sheets of print media. This subsystem includes (a) transport member having a peripheral surface that is movable around an endless path past a sheet ingress zone, the print zone and a sheet agress zone; (b) a drive for moving the transport member surface around the endless path; (c) a sheet supply station formed within the housing and including a device for positioning the face of a sheet-stack adjacent the path of the transport member at a position upstream of the sheet ingress zone; and (d) engagement device for effecting periodic feeding engagements between the transport means and successive face sheets of a positioned stack.

Abstract: A print output station for compact printer having a cut-sheet supply station located in the lower rear of the print housing and a transport platen for feeding successive sheets from the supply station, along a print path extending through a print zone and out a print path egress, includes: (a) a first wall having an inlet edge located proximate the print path egress for defining an inlet to a cut-sheet hopper zone; and (b) a lid forming an exterior housing portion overlying the first wall and mounted to pivot about an axis spaced from the leading edge to an open position so that the lid interior forms a rearward extension of the first wall means. The movable lid is constructed to function in the closed-lid position to prevent continuous print media from refeeding.

Abstract: A high-speed ink jet printing apparatus adapted for use with a plurality of insertable print/cartridges and having a platen for transporting successive line portions of a print medium through a linear print zone, includes a carriage with a plurality of nests for supporting, positioning and electrically coupling respective print/cartridges in the printer, the nests being spaced along the transverse dimension of the linear print zone in a manner dividing it into a plurality of discrete transverse subportions of equal length. A traversing device reciprocates the carriage in forward and return directions parallel to the linear print zone. The movement of the traverse is approximately equal to the length of the print zone divided by the number of nest means of the carriage.

Abstract: Printer apparatus of the kind having: (i) print/cartridges for printing on successive line sectors of print media that are advanced into and out of the print zone; (ii) a platen means including a feed/transport periphery that is movable around an endless path past a sheet ingress zone, the print zone and a sheet egress zone; (iii) a sheet supply station for positioning a stack of sheet print media at a position upstream of the sheet ingress zone; and (iv) structure for effecting periodic feeding engagements between the platen and successive face sheets of a positioned stack, features a pressure roller, located proximate the sheet ingress zone at a position upstream of the print path, for biasing a sheet moving therepast into drive transmission relation with the platen. The printer can also comprise a downstream guide, located proximate the sheet egress zone at a position downstream of the print zone printing means.

Abstract: A portion of print medium transport system of an electrically operable printer is constructed to house battery power sources. This construction enables size reduction of the printer. Disclosed embodiments include housing cylindrical batteries in a printer platen and housing batteries of other configurations in sheet guide structure of the printer.

Abstract: A hand held device for spraying liquid utilizes insertable drop-on-demand ink jet cartridges. The disclosed device is simple and inexpensive in design and facilitates interchangeable use of different inks without intervening cleaning.

Abstract: A selective drive transmission system for continuous ink jet printing apparatus of the type having a plurality of discrete ink circulation subsystems, each including an ink supply, a print head for directing droplet streams toward a print medium and pump means for pumping ink from its respective supply to its respective print head. The transmission system discretely couples and decouples the plurality of pump means discretely vis-a-vis a common motor source of the rotary drive.

Abstract: A gerotor pump construction having a magnetic female gerotor member which is magnetically coupled to a drive source through a non-magnetic cap. The female gerotor element is configured with top and side wall portions which define the pump chamber so that friction is reduced at the top interface with the male gerotor.

Abstract: A self-contained non-contact writing device is disclosed that employs a thermal ink jet to transfer ink to a writing substrate. The problems associated with conventional direct contact writing devices are avoided by preventing direct contact of the ink transfer mechanism and the writing substrate.

Abstract: Ink jet printing apparatus of the type having feed means for advancing successive line portions of a print medium past a linear print zone includes a plurality of carriages constructed to traverse the print zone in a predetermined direction and removably support a plurality of print/cartridges. Each of the carriages includes referencing edges that are substantially parallel to the direction of the carriages traverse and indexing means for moving supported print/cartridges into a precise detent relation with respective referencing surfaces of their carriage unit.

Abstract: For use in ink jet printing apparatus, an insertable print/cartridge having an ink reservoir, at least two linear arrays of drop generating elements located in a parrallel relation, a support for coupling the ink reservoir and driver arrays and an orifice plate comprising a plurality of linear orifice arrays aligned in spaced relation over respective drop generating arrays. The orifice plate is an integral photofabricated element wherein the linear patterns formed by the orifice arrays are precisely parallel and have a precise predetermined spacing therebetween.

Abstract: A regulation system controls the print head pressures of a plurality of discrete ink jet printers of the continuous type to the same nominal pressure, while the printers use a common drive source to their own ink pumps. The regulation system includes bypass pressure detection passages extending from a tap in each printer's circulation system to a detection reservoir. Each bypass passage includes a bladder/valve portion whose exterior is in fluid communication with a detection fluid enclosed within the common reservoir. A transducer detects the pressure of the common reservoir and signals control of the common pump drive so as to regulate all print head pressures to the same nominal operating pressure.

Abstract: A printer/feeder apparatus of the type having: (i) a feed/transport platen rotatable so that its peripheral surface moves past a sheet supply zone, a print path ingress, a print zone and a print path egress; (ii) frictional feed surface located on a peripheral sector of the platen surface and (iii) means for selectively effecting feeding engagement between the face sheet(s) of a stack of sheet media and the feed surface features a detection/control system that includes (a) a first detector for sensing and signalling when and when not a forward edge of the feed surface is at a predetermined start position; (b) a second detector means for sensing and signalling when and when not engagement condition exists; (c) a third detector means for sensing and signalling when and when not a sheet is located along a predetermined portion(s) of the print path; and (d) a control system for receiving signals from the detectors and enabling printing cycles and signalling error conditions.

Abstract: A print media handling system for a compact printer having a cut-sheet supply station formed in the lower portion of the printer housing and a rotatable print platen constructed and located to feed top sheets from the supply station through a print path ingress past a print zone and out a print path egress formed in the upper portion of the housing, includes (a) structure which mounts the supply station for movement to and from a sheet engaging relation with respect to the print platen and (b) a movable selection member that operates such movements of the supply station. The printer includes a supplemental inlet passage to the print path egress and the selection member includes structure for selectively blocking the supplemental inlet passage. The printer also includes a guide that is selectively positionable to alternatively direct egressing print media to either a sheet output zone or a continuous media output zone.

Abstract: Ink jet printer for printing along a linear print zone with a plurality of insertable print/cartridges employs a carriage for traversing the print zone and supporting the print/cartridges with their orifice arrays mutually indexed to a carriage reference that is parallel to the direction of carriage traverse; detecting and storing the relative transverse locations of the indexed orifice arrays; and controlling the actuations of the supported print/cartridges in accordance with their detected transverse locations. A detecting and storing sub-system detects and stores inter-array spacings in the form of encoder mark-count plus intra-mark phase information. A control sub-system: (1) outputs printing information signals for the print/cartridges on the basis of the stored mark-count information; and (2) enables print/cartridge actuations in sequential orders based on the stored intra-mark phase information. These orders differ in forward and retrace printing.

Abstract: Ink jet printing apparatus of the type having a carriage that traverses a printing zone with a plurality of insertable print/cartridges includes a system for use in coordinating the transverse printing of such print/cartridges to compensate for variable transverse print/cartridge locations. The system employs an electrooptical scanner located along the transverse path of the carriage for signalling the passage of a print/cartridge feature(s) that are indicative precisely of an instantaneous horizontal position, vis-a-vis the scanner, of the orifice array of a passing print/cartridge; a carriage detector for periodically sensing and signalling the successive instantaneous positions of the carriage during its traversing movement; and means, responsive to signal inputs from the scanner and the carriage detector, for computing and storing horizontal location data for each print/cartridge orifice array.

Abstract: Ink jet printing apparatus, for cooperative printing along a common linear print zone with a plurality of disposable print/cartridges having linear orifice arrays, utilizes a carriage which traverses adjacent and parallel to the print zone and includes positioning structure for insertably receiving and releasably constraining a plurality of print/cartridges in transversely spaced relation with the line of their orifice arrays precisely perpendicular to the direction of carriage traverse and vertically indexed to the direction of carriage traverse. The printer has a detector for sensing and storing the relative-transverse locations of the orifice arrays of the positioned print/cartridges. A printing controller regulates actuation of each positioned print/cartridge in accordance with its detected relative-transverse location to achieve proper horizontal drop placements.