Abstract: There is provided a calibration system for a deskewing and registering device for an electrophotographic printing machine. The method includes a.) moving a sheet from a first position to a second position along a paper path; b.) sensing the position of the sheet at the first position and the second position; c.) choosing a correction value to cause the sheet to change a lateral position from the first position to the second position; d.) repeating the moving, sensing, and choosing steps until a predetermined adjustment is made when moving the sheet from the first position to the second position to determine a proper calibration value.

Abstract: An apparatus and method for registering and deskewing a sheet along a paper path. A pair of independently driven selectively actuable nips are used to drive a sheet transverse to a paper path direction until the edge of a sheet is registered laterally and in skew. The transverse nips are then deactivated and a drive nip moves the sheet in a process direction along the paper path. A first transport sensor senses the lead edge of a sheet, a second sensor is used to also detect the lead edge of a sheet within a certain distance from the detection by the first sensor. The transport drive nip can then be adjusted based on the transport time between the first transport sensor and the second transport sensor so that the sheet arrives at a registration sensor at the prescribed time. This apparatus and method allows the use of simple point type sensors as opposed to more complex and expensive sensor arrays.

Abstract: A registering device for an electrophotographic printing machine. A steerable pair of drive nips is located in the paper path. A lead edge sensor detects when a sheet is within the steerable drive nips. The steerable nips are turned so that the sheet is transported toward a side registration sensor located in the paper path. When the side registration sensor detects the edge of the sheet the actuator causes the steerable nips to be straightened. The sheet may be forwarded to a second, higher accuracy registration device for final registration. The steerable nip device provides a course preregistration device which may utilize inexpensive and non complex components. This device also enables the use of less expensive components in the fine registration device as the range of correction required by the fine registration device can be much narrower due to the preregistration device.

Abstract: A deskewing and registering device for an electrophotographic printing machine. A single set of sensors determine the position and skew of a sheet in a paper path and generate signals indicative thereof. A pair of independently driven nips forward the sheet to a registration position in skew and at the proper time based on signals from a controller which interprets the position signals and generates the motor control signals. An additional set of sensors can be used at the registration position to provide feedback for updating the control signals as rolls wear or different substrates having different coefficients of friction are used.

Abstract: A method and apparatus for simultaneously developing and transferring a liquid toner image. The method includes the steps of moving a photoreceptor including a charge bearing surface having a first electrical potential, applying a uniform layer of charge having a second electrical potential onto the charge bearing surface, and imagewise dissipating charge from selected portions on the charge bearing surface to form a latent image electrostatically, such that the charge-dissipated portions of the charge bearing surface have the first electrical potential of the charge bearing surface. The method also includes the steps of moving an intermediate transfer member biased to a third electrical potential that lies between said first and said second potentials, into a nip forming relationship with the moving imaging member to form a process nip.

Abstract: A method and apparatus is provided for controlling the transverse registration of an image area to be exposed on a longitudinally moving belt by providing belt edge profile data, detecting a lateral position of the belt during movement of the belt by measuring the lateral position of the belt edge, and adjusting the transverse location of the image on the belt to compensate for a difference between the detected lateral belt edge position and the belt edge profile data. In addition, a method and apparatus is provided for controlling the lateral position of a longitudinally moving endless belt by generating a steering command signal by calculating a difference between the detected first lateral position of the belt edge and the belt edge profile data corresponding to the first longitudinal position, and adjusting the lateral position of the belt by steering the belt in response to the steering command.

Abstract: A method and apparatus for controlling speed match between a photoreceptor and an intermediate transfer member to prevent image degradation by creating a deliberate speed mismatch. It has been found that slight variations in speed match between a photoreceptor and transfer member will maintain acceptable image quality, however, should the relative velocity between the members change sign, unacceptable image error results. The method herein comprises slewing the velocity of a photoreceptive member over a range of speeds while monitoring the output control signal current of a drive motor. The resulting control signal current has a large oscillation at the velocity at which the speed of the photoreceptor matches that of the intermediate transfer member. A controller is then used to maintain the motor velocity at a speed slightly less than or slightly greater than the intermediate transfer member speed so as to prevent a change in sign of the relative velocity between the two moving surfaces.

Abstract: An inductive-type rotary encoder includes a stator having at least one conductive pattern on one side thereof, and a rotor having another conductive pattern on one side thereof which faces the at least one conductive pattern of the stator. The conductive patterns are inductively coupled to one another so as to generate an output signal indicative of the angular position of the rotor relative to the stator. In order to reduce the overall size and number of parts required, the circuitry for energizing the stator conductive pattern(s) and for generating the output signal can be provided on a printed circuit board, the opposite side of which contains the at least one stator conductive pattern.

Abstract: The method and apparatus for measuring the particle concentration in a fluid that is passed between a reciprocally movable window and a single photodetector. A collimated beam of light is directed through the window and fluid to the photodetector. The window is moved from a first predetermined location to a second predetermined location to vary the light beam path length, thus enabling at least two different photodetector output signals. The ratio of the two signals provides the data needed to determine the particle concentration in the fluid.

Abstract: An end effector for use with a robotic mechanism is disclosed which is capable of grasping cylindrical workpieces having a varying diameter off center and holding it with six degrees of freedom. The end effector has a plurality of sets of fingers, each set having three fingers which radially approach and retract from the workpiece with a spacing of 120 degrees between the movement direction of the fingers. The movement of each of the fingers in a set are coplanar, and the planar movement of each set of fingers are parallel with each other. Each finger is actuated by its own hydraulic cylinder which causes it to independently engage the workpiece. The cylinders are hydraulically operated by a hydraulic system having a pressurizing pump for flowing fluid from a tank through a bidirectional valve to a series of pilot operated check valves and then to the cylinders. The setting of the bidirectional valve determines whether the fingers grasp the workpiece or release it.