Abstract: The present invention provides an electrophotographic (EP) image-forming machine and related method having activation of a charger cleaner in a corona charger after an arcing fault. The corona charger has corona wires connected to a high voltage potential supply, preferably providing a voltage in the range of about 5 to 11 kva or in the range of about 13,000 to 22,000 volts peak-to-peak. A corona voltage detection circuit is connected to measure current changes in the high voltage potential supply. A grid has a preselected electric potential to control the charge. The grid may be grounded, but preferably is connected to a power supply providing a voltage in the range of about 300 to 900 volts. A grid voltage detection circuit is connected to measure current changes in the power supply. The voltage detection circuits provide a voltage signal to a microprocessor. When arcing occurs, the microprocessor cycles the EP image-forming machine into a standby mode.

Abstract: A mechanism for automatically cleaning the surface of a corona wire within a corona charger is described, wherein the a cleaning assembly includes a cleaning pad mounted within a pad holder, the cleaning pad wrapped around a substantial portion of a circumference of the corona wire for wiping the surface of the corona wire. The cleaning mechanism also includes means for holding the cleaning assembly within the corona charger in association with the corona wire, means, associated with the holding means, for moving the holding means linearly along the length of the corona wire, and means for automatically selectively activating the moving means to move the holding means such that the cleaning assembly is moved to clean the corona wire. In one embodiment, the cleaning assembly includes at least one finishing stone mounted to a stone holder, wherein the finishing stone engages the surface of the corona wire.

Abstract: A high speed copier 10 has a transfer roller 42 and a cleaning brush 52. The cleaning performance is improved when the engagement of the two rollers exceeds a first threshold T1. Their engagement is maintained below a stall threshold T2.

Abstract: Disclosed herein are polyurethane elastomers and shaped articles prepared therefrom comprising charge-control agents to provide electrical conductivity to the elastomers, thereby allowing for their use in electrophotographic processes. The elastomers comprise a polyisocyanate prepolymer, a polyether prepolymer, and a hardener mixture comprised of at least one additional polyol and a charge-control agent. When used in an electrophotographic process, the elastomers are capable of exhibiting resistivities of less than 6×109 ohm-cm for 600,000 images or more.

Abstract: A grid electrode for attachment to a corona charger includes a series of substantially parallel grid wires extending in a longitudinal direction of the wires. A flat metallic plate member is formed integral with the wires at one of the longitudinal ends of the wires. A cap member is connected to the plate member. The cap member includes a cover segment having a surface that overlies and is in planar contact engagement with a substantial portion of a respective plate member with a thickness of at least 0.5 millimeters and the cover segment being formed of a material that is substantially electrically more resistive than the flat metallic plate member.

Abstract: A mechanism for mounting a transfer assembly in a reproduction apparatus, the reproduction apparatus having a transfer assembly including an electrically biased transfer roller for effecting transfer of pigmented marking particle images from a dielectric member to receiver members. The transfer assembly mounting mechanism includes a tie bar weldment for supporting the transfer assembly within the reproduction apparatus. A bracket, coupled to the transfer assembly, connects the tie bar weldment to the transfer assembly such that the transfer roller of the transfer assembly is castered and gimbaled.

Abstract: A corona charger and method and apparatus for corona charging features an insulative shield and an electrically biased grid electrode spaced from the shield. One or more substantially bare corona wires are located between the grid electrode and the shield. The corona wires are electrically biased with an AC voltage. An electrically biased highly conductive buried floor electrode forms a part of the charger and has a surface located between the one or more corona wires and the shield. An insulating layer is located between the corona wires and the surface of the buried floor electrode so that there is no exposure of the buried floor electrode in a direct line of sight from a corona wire.

Abstract: An electrostatographic reproduction apparatus having a transfer assembly, including an electrically biased transfer roller in nip relation with a dielectric support member, for effecting transfer of a pigmented marking particle image from an image area of a dielectric support member to a receiver member in transfer relation with the dielectric support member in the transfer nip, a mechanism for cleaning the transfer roller including a control for the electrical bias on the transfer roller. The electrical bias control has a power supply generating an electrical output, of a settable polarity, connected to the transfer roller for applying an electrical bias of a set polarity thereto. A timing signal generator produces signals respectively corresponding to the location of a receiver member relative to the transfer nip.

Abstract: An electrostatographic recording apparatus and method includes a primary charger that establishes a uniform electrostatic charge on the image recording member in accordance with a first operating parameter. A recording device that imagewise modulates the charge on the image recording member to form electrostatic images in accordance with a second operating parameter and additionally forms a developable process control patch. A development station develops the electrostatic images and the control patch on the image recording member with toner in accordance with a third operating parameter. A transfer station transfers developed images from the image recording member. The transfer station includes a transfer member and power supply providing to the transfer member a transfer current used for transferring developed images. In one embodiment a sensor senses density of the developed control patch.

Abstract: A setup method for a corona charger device used in an electrophotographic recording apparatus. The setup method includes operating the corona charger device in a calibration mode so that charge of a first polarity is output by the device and deposited upon a photoconductive recording member. The level of charge deposited upon the member is sensed and a position of the charger device relative to the member is adjusted so that the level of charge deposited upon the member is at a target level. The charge of the first polarity output for setup is opposite to that of charge output during the production run.

Abstract: A vacuum conveyor system for transporting sheets between two process stations in an image producing apparatus, such as copiers and printers. The system includes a plurality of interleaved belts which extend between the process stations and around rollers to convey the sheet without image disruption or sheet damage between the processing stations.

Abstract: An electrostatographic copier/printer has an image member with at least one portion which can selectively be imaged to receive an electrostatic image to be toned. A toning station is operable to bring the developer into contact with the image member portion so as to produce a toner image according to the electrostatic image if the portion has been imaged and to leave a small amount of background toner uniformly deposited if the image member portion has not been imaged. The background toner on the non-imaged portion serves to assist subsequent detack operation. A plurality of different color toning stations may be provided, and, if so, the black toner toning station is preferably used to leave the background toner.

Abstract: A device for assuring separation between a receiver member and a dielectric member in an electrostatographic reproduction apparatus. The electrostatographic reproduction apparatus includes a dielectric member adapted to carry a developed image, the dielectric member being movable along a travel path in which at some point the direction of travel is changed. Upstream of the change of direction of travel of the dielectric member, a mechanism is provided for electrostatically transferring a developed image from the dielectric member to a receiver member movable into register with the dielectric member. The separation device comprises an electrically conductive member of sharp edge configuration.

Abstract: A corona charger can be programmed without physical adjustment to the charger, to give a plurality of desired characteristic plate current-to-potential curves so that one charger design can be used for a number of different charger formulations. The corona charger includes a conductive electrode and a corona wire between the electrode and the receiver. A variable duty cycle, pulsing voltage is applied to the electrode of same sign as the voltage applied to the corona wire, such that the corona charge produced by the wire is periodically accelerated by the electrode to the receiver.

Abstract: A corona charger includes a conductive electrode and a corona wire between the electrode and a receiver. A non-conductive shell about the wire is open toward the receiver. A voltage is periodically applied to the wire, whereby a corona charge is produced in the shell and the shell charges with the wire such that the corona charge is directed toward the receiver. A voltage is applied to the electrode of same sign but lagging the voltage applied to the wire such that the corona charge is accelerated by the electrode to the receiver when the voltage on the electrode approximates the voltage on the wire.

Abstract: Apparatus is disclosed for driving from a single AC power supply a plurality of corona chargers and includes a substantially constant-potential power supply and a circuit interconnecting said power supply to the plurality of corona chargers such that a substantially constant average current input is delivered to each of the corona chargers. The circuit includes a capacitor associated with each corona charger between the power supply and the corona charger such that the capacitors charge upon transition of the AC power source, and thereupon discharge through the chargers until the corona onset potential is reached. Upon reaching the onset potential, the corona current is quenched. The capacitors are selected such that quenching occurs after the transition within a time interval less than half the period of the AC power supply so that each capacitor regulates the current output of the associated corona charger.