Abstract: A charging system for uniformly charging an imaging surface moving in a predefined path including a dicorotron for charging the imaging surface; a discorotron, adjacent to and downstream from said dicortron, for charging the imaging surface; the discorotron including a coronode, a grid and a shield a first power supply for biasing the grid and the shield; a second power supply for energizing each of the coronode; means for determining a voltage level of the imaging surface and generating a feedback signal of the voltage level; and a controller, responsive to the feedback signal and in communication with the first power supply, for controlling the energiziation of the grid and the shield.

Abstract: A sheet feeding device for an electrophotographic printing machine that minimizes trail edge flip when delivering a sheet to a photoreceptor at a desired tangential position. The sheet feeding device includes a baffle member which has two control points, one of which is an idler roller. The baffle further includes a ramp member which controls the trail edge of a sheet to maximize the beam length to reduce the bending energy which results in trail edge flip.

Abstract: A sheet feeding device for an electrophotographic printing machine that minimizes trail edge flip when delivering a sheet to a photoreceptor at a desired tangential position. The sheet feeding device includes a baffle member which has two control points, one of which is an idler roller. The baffle further includes a ramp member which controls the trail edge of a sheet to maximize the beam length to reduce the bending energy which results in trail edge flip.

Abstract: A charging device comprises a housing defining a charging chamber. Two tensioning shafts are mounted on opposite ends of the housing. The charging device comprises a control grid attached to the grid tensioning shafts, thus substantially covering the chamber opening. The control grid is comprised of a conductive material capable of being stretched along its length. As a result, the grid becomes flat when opposing rotating forces are applied to the two tensioning shafts.

Abstract: A charging device includes a housing defining a chamber, the chamber having a floor, the floor having disposed therein an elongated slot pressure port and a plurality of circular hole vacuum ports. Four air flow conduits are disposed under the chamber floor to provide separate pressure air flows and vacuum air flows through the chamber. These four air flow conduits comprise two pressure conduits and two vacuum conduits. The two pressure conduits and two vacuum conduits are respectively connected at one of their ends by two turn-around connectors. Separate pressure air supply connections and vacuum air supply connections are applied to the respective other ends of the two pressure conduits and two vacuum conduits. As a result, pressure air is applied at both ends of the pressure conduit adjacent to the floor, thus causing pressure air flow through the pressure port and into the chamber.

Abstract: A multiple port rotary indexing vacuum valve in a liquid ink printer including a selecting member and a multiple port member. The selecting member, defines an aperture therethrough and a first axis, including a first oscillatory surface. The multiple port member defines a plurality of ports and a second axis, including a second oscillatory surface wherein the second oscillatory surface is matable with the first oscillatory surface so that relative movement therebetween aligns the aperture of the selecting member with one of the plurality of ports of the multiple port member.

Abstract: A maintenance device includes a shuttle which is adapted to travel on a track through a fixed path generally parallel to the array. Mounted on the shuttle are an application, which includes a wicking member, for applying a cleaning liquid to the nozzle openings and a vacuum device for applying suction to the nozzle openings. A spacing member on the shuttle spaces the shuttle from the head to form a meniscus of the cleaning liquid against the nozzle openings of the printhead. The maintenance device is used in a cleaning method wherein a vacuum force is applied to the nozzle openings while moving the shuttle in a first direction, the surface is wetted by the cleaning liquid while moving the shuttle in a second direction, and the a vacuum force is again applied to the nozzle openings after the wetting while moving the shuttle in the second direction.

Abstract: A maintenance system for an ink jet printer of the type having a full width array printhead has a movable carriage with a droplet sensor and a nozzle recovery device. As the carriage moves along the length of the printhead, each nozzle checked, one at a time, by the droplet sensor for the presence or absence of an ejected droplet and if the droplet has the correct directionality. Any problem nozzle is identified during a single traversal of the carriage across the printhead, and during a second traversal, the identified problem nozzles have a recovery operation performed on them such as being cleaned to remove any dried ink or other contaminating particles or being primed in the case of a clogged nozzle. The problem nozzles which have had a recovery operation performed on them and checked again by the droplet sensor is required for the entire array of nozzles, and ink is conserved since only predetermined nozzles are printed.

Abstract: A maintenance apparatus for maintaining an ink jet printhead. The maintenance apparatus includes a maintenance station having a first member, a translation apparatus connected to the maintenance station which generates a translation force to translate the maintenance station along a path, and a displacement apparatus connected to the translation apparatus and operatively coupled to the first member for displacing the first member with respect to the translation apparatus. The maintenance apparatus minimizes system complexity by using the energy which translates the maintenance station for extending and retracting the capping member which seals the area around the front nozzle face of an ink jet printhead during periods of non-use. A lead screw and a motor move the maintenance station in a direction towards an ink jet printhead for maintenance operations and a actuating lever and camming system move the capping member into contact with the front face of the ink jet printhead.

Abstract: An ultrasonic liquid wiper for an ink jet printer maintenance station has a cleaning nozzle confrontingly aligned but spaced from printhead nozzles suspected of having viscous plugs of partially dried ink. A cleaning solution is held within the cleaning nozzle by surface tension to form a meniscus and is caused to bulge toward into contact with the printhead nozzle face and form a bridge of cleaning solution therewith. In addition to dissolving ink, the cleaning solution is ultrasonically excited by a piezoelectric material immediately upstream of the cleaning nozzle to provide a high frequency energized liquid wiper to facilitate viscous plug removal without having physical contact with the printhead nozzle face, thereby preventing wear of any hydrophobic coating on the nozzle face. A vacuum nozzle is positioned on each side of the cleaning nozzle to remove the cleaning solution deposited on the nozzle face, together with any ink dissolved therein.

Abstract: An ink jet maintenance system having a translatable maintenance station carriage assembly including priming nozzles, wipers and drop detection hardware for translating across the width of the front nozzle face of one or more full-width array (FWA) printbars. The system includes an FWA printbar that is pivotally articulated between a print position and a maintenance position. An articulating cap assembly facilitates capping of ink jet printbar nozzles when the maintenance station carriage assembly moves to a home position outside the edge of the printbar and provides a free space area that allows translation of the maintenance station assembly when spaced away from the printbar.