Abstract: An electrode array forms a latent image by generating an electrical breakdown region and extracting an imagewise distribution of charge carriers which are accelerated toward a separate surface. Different control mechanisms, environments and ranges of operating parameters provide controlled amounts of charge delivered by electrons or ions for improved latent image production. High speed, high resolution and high uniformity of charge deposition are accomplished by different structures within the scope of the invention.

Abstract: A transport member moves in a cyclic path to carry material from a first location to a second location at a different temperature, and a thermal shunt connects portions of the transport member. Counter-moving portions of the member are positioned to exchange heat with each other along an intermediate portion of the path, so that minimum energy is lost to the environment. In one embodiment as a printing apparatus, a belt transports a heat-fusible toner to a heater location where it is transferred and fused, i.e., transfused, as a print image to a sheet. Effective powder pick up and release is obtained in the printing apparatus with a transport member having an elastomeric layer of a softness which conforms to a receiving member of characteristic surface roughness, and a non-tacky outer coating which is harder than the elastomeric layer. The outer coating is thin enough to conform to the surface roughness, but hard enough to prevent entrainment of toner particles.

Abstract: The invention provides an electrostatic print cartridge for use in placing electrostatically charged dots on a charge receiving surface to build a latent image for subsequent toning. The cartridge includes a rigid spine to prevent the cartridge from bending during construction; a dielectric substrate attached to the spine with driver electrodes arranged in parallel lines between the spine and the dielectric substrate; and finger electrodes arranged on the opposite side of the substrate intersecting the driver electrodes and defining a matrix of apertures aligned with the intersection points of the driver and finger electrodes. The apertures in each finger electrode cover a segment of a complete image and are arranged so that the sequence of creating dots is such that primary dots are laid down separated from one another in each segment and subsequently secondary or intermediate dots are placed in spaces between the primary dots as the segment is filled with dots.

Abstract: A printer autocontrast system measures the current passing from a toner reservoir to a charged dielectric member which receives toner from the reservoir. The charge delivered to the drum in this way is scaled and compared to an estimate of the intended image charge to develop an error signal. The error signal corrects a control parameter to adjust the operation of an electrographic printhead which forms a latent image on the dielectric member.

Abstract: A print cartridge is described for charged particle deposition of latent images on a receptor surface adapted to move longitudinally. The cartridge has driver electrodes extending transversely with respect to the movement of the receptor surface and a dielectric covers the driver electrodes. Finger electrodes on the dielectric extend angularly with respect to the driver electrodes with the dielectric separating the finger and driver electrodes. The finger electrodes define primary and secondary apertures where the driver and finger electrodes intersect for depositing latent images of discrete dots spaced transversely on the receptor surface upon selective activation of the driver and finger electrodes.

Abstract: An electrographic printhead assembly comprises first and second sets of electrodes which define an array of crossing regions for generating packets of electric charge. An RF electrode burst actuates a first electrode to generate charge carriers while a varying extraction potential is developed. A second electrode is then activated with one or more control pulses which are synchronized with the RF burst and with selected portions of the varying extraction potential to gate charge carriers from the printhead. This deposits the desired charge level for each dot on an imaging member. The assembly forms a gray scale latent image for printing, and provides enhanced range without requiring higher frequency or longer duration RF bursts.

Abstract: An improved controller for a printhead having crossed first and second sets of electrodes determines whether any electrode of the second set is to be activated, and disables an electrode of the first set if it determines that no second electrode is active. By reducing the number of times the first electrodes are actuated printhead life and print quality are improved. In one embodiment, the controller ORs the second electrode control signals to develop an output which enables the first electrodes.

Abstract: A charge transfer imaging cartridge features driver electrodes extending in a first direction and finger electrodes extending in a second direction and defining edge structure straddling the driver electrodes. The driver and finger electrodes are separated by a flexible dielectric layer, preferably a silicone modified polymer.

Abstract: There is described a cartridge mounting for locating a cartridge in a printer adjacent a print drum for receiving a charge image from the cartridge. The cartridge includes a spine and has a longitudinal axis substantially parallel to the axis of rotation of the print drum and an inner face adjacent the image receiving portion of the drum surface. The mounting has provision for locating the cartridge radially in relation to the axis of rotation of the drum and for biasing the cartridge towards the drum surface. Further provision is made for locating the cartridge tangentially in opposition to the direction of travel of the drum surface. Spacers extend from the inner face of the cartridge to abut the drum surface at a sliding contact, thus spacing the cartridge a predetermined distance from the surface.

Abstract: There is disclosed a print cartridge for use in charge transfer imaging comprising first and second electrodes on opposite sides of a layer of dielectric material. The first electrodes extend in a first direction and the second electrodes extend in a second direction, and edge structures are provided in the second electrodes at the locations where the electrodes cross. Various structures are described designed to improve the pattern of charge transfer to a receptor to enhance the accuracy of the image and the efficiency of the transfer.

Abstract: There is disclosed a print cartridge for use in charge transfer imaging comprising a dielectric substrate, driver electrodes extending in a first direction along the substrate, a dielectric layer covering the electrodes, and finger electrodes extending in a second direction across the dielectric layer and defining apertures having edge structures straddling the driver electrodes. A dielectric spacer covers the finger electrodes and defines apertures corresponding to the apertures of the finger electrodes. The dielectric spacer itself is covered by a screen electrode which also defines apertures corresponding to the apertures of the dielectric spacer and the finger electrodes. The apertures of the finger electrodes, the dielectric spacer, and the screen electrode collectively define a plurality of blind holes.

Abstract: The invention provides apparatus for coupling a pair of imaging units to receive paper along a first path from a first unit, and to invert and transfer the paper along a second path entering the second unit. Embodiments include one which in addition to inverting the paper provides an alternative path for paper so that the paper passes through one imaging unit only, and one which allows paper to pass through one or the other of the imaging units selectively.

Abstract: There is disclosed a multiple source charged particle generator having first electrodes and second electrodes separated by a dielectric. The second electrodes define independent discharge locations and each of the discharge locations comprises a plurality of discharge sites. The generator is particularly for use in charge transfer imaging of the type used in preparing a latent image on a dielectric, toning the image and transferring the toned image onto a receptor such as paper.

Abstract: Sheet turnover apparatus of particular utility in the document-delivery system of a high speed printer, copier, or the like. Documents are serially routed through an infeed nip of a three-roller assembly, and received by a narrow, angularly-profiled chute. The chute includes a recoil assembly at its far end, which causes the document to reverse its travel within the chute to be directed toward the outfeed nip of the roller assembly. A paddle or flipper assembly mounted to the central roller of the roller triad directs the trailing edge of the document from infeed nip to outfeed nip, where it becomes the document's leading edge.

Abstract: An RF drive network provides RF drive power to a device such as an ion deposition print cartridge synchronized with the natural resonance of the driver/device system. A voltage to current amplifier is fed by a power one-shot which triggers on a zero crossing feedback signal from the drive line, resulting in precise drive pulse synchronization and controlled drive power. A second feedback signal biases the amplifier to achieve uniformity in drive voltage and timing despite variations in component characteristics. A fault detector is connected to plural drive lines, and upon detection of an open line condition inhibits the drivers for all lines. A resonance shifting circuit shifts the resonance of each driver in its off state to damp oscillations and eliminate crosstalk between drivers.

Abstract: Ionographic raster scan printing apparatus capable of printing with selectable print density utilizes an imaging drum having a surface movable in a process direction, a connector assembly for receiving an imaging module having a characteristic dot density determined by a set of control electrodes individually driven by clocked driver elements, a sensor module for generating density signals representative of the characteristic dot density, and a position encoder for generating position signals representative of the instantaneous position of the imaging drum surface. A scan clock synthesizer module generates activation signals for clocking the driver elements, the signals having a clock frequency proportional to an algebraic combination of the density signals and the position signals.

Abstract: The present invention relates to non-impact printing apparatus and more particularly to apparatus which converts originating image data in ASCII, EPCDIC or equivalent form into output image data in raster scan arrangement suitable for presentation to a printing subsystem.

Abstract: The invention provides a method of making an ionographic cartridge for use with a dielectric coated drum to lay electrostatic images on the drum for subsequent toning. The method includes the steps of making a printed circuit board carrying on one of its faces a plurality of driver electrodes; attaching to the face of the board a dielectric layer sufficient to cover the driver electrodes; providing finger electrodes supported individually between parallel strips of dielectric tapes; and adhering the finger electrodes to the dielectric layer with the finger electrodes straddling the driver electrodes and the tapes spaced to either side of the printed circuit board.

Abstract: An ion generator for use with an electrostatic printer or the like to modify the electrostatic charge on a dielectric receptor surface is described. The generator includes a plurality of corona wires supported on a rod attached and to the rod. The wires are spaced angularly about the rod and a protector extends longitudinally around the rod and spaced radially from the wires. The protector has an axially extending window and an end piece is fixed to an outer end of the rod and journalled with an end of the protector to allow relative angular movement so that selected ones of the wires can be aligned with the window near the receptor surface. The window has an annular extent less than the spacing between adjacent wires so that for transportation the rod can be turned in the protector to place the wires to the sides of the window to minimize the risk of damage.The ion generator can be combined with a housing mounted on the printer and the generator is designed for rotational engagement in the housing.

Abstract: The invention provides a sheet stacker for receiving paper from a printer, copier and the like. The stacker includes a base, and an elevator mechanism contained in the base. A hopper sits on the base and includes a floor moveable within the hopper and supported by the elevator mechanism. As paper enters the hopper a sensor is used in conjunction with an activator to maintain the floor of the hopper at a level to ensure that each sheet slides essentially horizontally onto the stack to avoid curling of the sheet on the stack. The stacker also includes a paper positioning device above the stacker and operable by a controller to engage selected sheets as they enter the stacker. This engagement deflects the sheets to one side so that these sheets are staggered with respect to the other sheets in the pile for ease of identification in the finished pile.