Abstract: An ionographic marking apparatus capable of multifunction operation for use as an input printer, a document copier or a document scanner. The apparatus includes a writing head comprising thin film elements including ion modulating electrodes, data and address lines, and self-biasing amplification circuits including thin film transistors, resistors and photosensors integrally fabricated upon a large area substrate.

Abstract: A sheet feed device for sequentially selecting and feeding sheets of paper from one or more trays or magazines mounted upon a printer and delivering them to the platen of the printer. The device includes one or more selector latch mechanisms, one associated with each tray, whose movement is controlled by the platen rotation and which, in turn, controls the rotation of sheet feed rollers associated with the trays, in response to a specific sequence of forward and reverse angular platen movements.

Abstract: An improved short-channel field effect transistor including a standard tip implant type of source and drain each disposed in the surface of a semiconductor substrate and a gate electrode positioned upon the substrate between the source and drain and control plugs disposed in the substrate and associated with and contiguous to the source and drain for eliminating substrate punch-through currents without substantially increasing the device junction capacitance.

Abstract: A ribbon cartridge having a pair of movable arms extending outwardly from the body, over which the ribbon passes on its transit from an internal ribbon supply to an internal used ribbon storage. Each of the arms is supported for movement about an oblique axis which moves the active marking portion of the ribbon so that the path traversed by one edge is equal in length to the path traversed by the opposite edge.

Abstract: An improved modulation structure for the marking head of an ionographic marking aparatus for increasing the effective lifetime of the modulation electrodes in the highly corrosive atmosphere of such a device. A relative bias on the order of about 10% of the ion output cut-off bias is imposed across the ion modulation region in order to inhibit the deterioration effects of the ions on the modulation electrodes.

Abstract: A thin film writing head for recording information upon a record medium by means of a continuous writing process. The writing head comprises thin film elements including marking elements, high and low voltage bus lines, driver circuitry, and switching elements, integrally fabricated upon a large area substrate. A latching circuit, including at least one of the switching elements is located between the pair of bus lines for connecting the marking elements directly to one of the bus lines, so as to insure that the marking elements are always connected to a source of reference potential.

Abstract: A method of doping selected areas of semiconductor material in the fabrication of integrated circuit devices, including placing a semiconductor substrate in a glow discharge reactor, introducing reactant gases into the reactor, subjecting the reactant gases to a plasma discharge, depositing, upon the substrate, a dopant carrier layer comprising an amorphous semiconductor material having a predetermined dopant concentration, controlling the thickness of the dopant carrier layer, and driving the dopant atoms out of the amorphous semiconductor dopant carrier layer into the selected areas of the semiconductor substrate by means of a controlled elevated temperature anneal.

Abstract: A serial impact printer including a novel hammer mechanism for applying a printing force against a character element to drive it in sequence against a marking medium, a mark receiving support, such as a sheet of paper, and the print line on a platen. The hammer mechanism delivers its impact force against a character element along a line forming an angle with a line normal to the surface of the platen at the point of contact of the character element with the platen. This arrangement enhances the ink release of single strike ribbons and multi-part carbon forms. By urging the hammer mechanism against the character element for an extended dwell time of at least 1 millisecond, which is substantially greater than that in conventional printers, the ink release of multi-strike ribbons, fabric ribbons and correctable ribbonsd may also be enhanced. By incorporating both the oblique impact and the extended dwell, the ink release characteristics of all conventional ribbons and multi-part forms will be enhanced.

Abstract: A thermal transfer printing system in which a print scanning head is provided with a series of thermal heating elements. The elements are aligned in a column perpendicular to the line of printing. A sensor is provided to determine where the scanning head is aligned perpendicularly relative to the line of printing. More heating elements are provided on the head than are required for printing. Only those heating elements properly aligned with the line of printing are activated.

Abstract: An impacting element for an impact printer having a platen, selectable character elements and means for driving the impacting element to impart a printing force to a selected character element, to drive it against said platen for a contact period, the impacting element including a sensor thereon for generating a signal indicative of the initiation of the contact period.

Abstract: A printwheel, for use in a serial printer, in which the spokes pass in contact with a printwheel alignment member, which contact is a noise generation and wear inducing source. The printwheel is designed to include a noise and wear reducing element. The printwheel spokes terminate in character pads bearing type faces on one side thereof and are hammered on their opposite side. A wiping element is secured to the printwheel hub and lies adjacent to the spokes on the hammered side. The wiping element includes a ring of continuous, low mass, flexible material, having a wear resistant surface. The ring is located immediately radially inwardly of the character pads.

Abstract: An improved serial impact printer designed to substantially reduce impact noise generation during the printing operation. The printer includes a print tip relatively movable with respect to a deformable platen, with a print element, a marking ribbon and an image receptor sheet interposed between the print tip and the platen which are urged together during a controlled contact period. Movement is subject to control by a kinetic drive mechanism which applies a first force for moving the print tip relative to the platen, prior to the initiation of the contact period, for closing the gap therebetween and then applies a second force for accelerating the print tip relative to the platen, subsequent to the initiation of the contact period, for causing the print tip to deform the platen.

Abstract: An anti-backlash tractor assembly for the accurate registration of bi-directionally transported endless paper to the printing mechanism of a printer. When mounted upon the printer in an operative position, a resilient biasing device will urge the printer driving gear and the tractor assembly driven gear together for dynamically eliminating backlash therebetween and for dynamically compensating for gear eccentricities and other drive train variations. Also, in the operative position, a manual adjustment lever is provided for establishing nominal paper tension.

Abstract: A ribbon take-up drive mechanism for a universal ribbon cartridge. The cartridge is adapted to engage the ribbon drive shafts of printers of two different designs. The drive shaft positions are different, and the direction of drive shaft rotation is opposite for the two designs. The take-up mechanism is designed such that the ribbon is pinched between the teeth of a direct drive gear and a biased idler gear. The printer of one design drives the ribbon through the direct drive gear. The printer of the second design drives the ribbon through an alternate drive gear, an idler gear and the biased idler gear. In either case, the ribbon is advanced in the same direction.

Abstract: A fluid jet assisted ion projection copier including a marking head incorporating an array of thin film ion modulating electrodes and photosensors integrated upon a single substrate. An optical projection system places incremental images of light and dark areas from an original to be copied onto the photosensor array. The marking head is mounted upon the ion projection housing, adjacent an outlet channel thereof for controlling the passage of ions out of the housing in accordance with the projected pattern of light and dark areas.

Abstract: An improved fluid assisted ion projection printing head comprising a one-piece body having design features therein, including a generally U-shaped cavity, to which is mated a generally featureless, planar, conductive member which forms a closure for the major portion of the cavity opening and defines an ion generation chamber and a cavity exit region therewith. At least the one wall of the cavity adjacent the exit region is electrically conductive. A conductive wire supported on the body, extends in the direction of the cavity and is located closer to the one wall and to the conductive member than to any of the other walls of the cavity.

Abstract: A writing, erasing and readout system for a magneto-optic recording medium capable of achieving switching rates approaching the laser pulse rate, including plural diode lasers operating through a single optical path and cooperating with bi-polar magnetic field producing means located adjacent to and on the opposite side of the magneto-optic medium.

Abstract: An ionographic copier based upon the fluid jet assisted ion projection electrographic marking process. A light sensitive ion modulation assembly is used for controlling the flow of ions in accordance with dark and light patterns of raster line optical information projected from an original to be copied.

Abstract: An electrographic writing head capable of placing continuous marks upon a record medium in response to the application of a high voltage to selected writing styluses. The writing head includes a substrate upon which stylus electrodes, multiplexed driver circuitry and active devices are integrally fabricated by thin film deposition techniques. For each stylus, there is provided a high voltage thin film transistor and a latching circuit for holding the state of the high voltage transistor for substantially an entire line writing time.

Abstract: An envelope feeder for mounting on a computer printer, electronic typewriter, word processor or other programmable printer. The envelope feeder uses a centrally located drive separator roller and separating tongue to effect envelope separation.