Abstract: The disclosed document feeder apparatus includes a document drive that comprises only a single line of feed rollers with a simple skew adjustment system. This drive is shown incorporated in a cassette-loaded automatic document feeder ("ADF") that is attachable to an existing independent engineering document copier in a non-intrusive manner. The cassette can be loaded, either when positioned in the ADF or at a location remote from the ADF, with a stack of large engineering documents of mixed media and varying sizes; and it is even possible for the cassette to carry a document several yards (meters) long. Documents are fed serially from the top of the stack through the ADF's document flow path by the document drive which is centered for alignment along a line positioned parallel to the document flow path.

Abstract: A variable magnification copier apparatus includes an optical system which incorporates two pairs of moving mirror assemblies which are moved to maintain object and image conjugate requirements following magnification changes. Also included is a constant focal length lens movable between two segments of a folded optical path. The optical system provides a magnification range of between 0.45X and 2.0X, while positioning the optical elements in a compact design. The lens does not move along the optical path, but rather remains fixed in position along one path segment so long as magnification values are selected within a certain range. When the magnification value is selected outside the predetermined range, the lens moves to an adjacent segment of the optical path and remains in a second, fixed position so long as further magnification values are selected within a second range. When a range is selected outside the second range, the lens is moved back to the first position.

Abstract: An apparatus for registering successive toner images to a sheet includes a rotatable photoreceptor drum having a transfer zone on its circumferential surface at which toner images are transferred to the sheet, a generally cylindrical member having a circumferential surface adjacent the photoreceptor drum at the transfer zone, the cylindrical member having a radius which is an integer multiple of the radius of the photoreceptor drum, and a belt for moving the sheet around the circumferential surface of the cylindrical member in a recirculating path. A sensor detects when a lead edge of the sheet is a first predetermined distance from the transfer zone, and a polygon raster output scanner responsive to the sensor forms a latent image on the photoreceptor drum when the sensor detects the lead edge of the sheet, at an imaging point which is a second predetermined distance from the transfer zone, the second predetermined distance not exceeding the first predetermined distance.

Abstract: An apparatus in which successive toner images are transferred from a photoconductive drum to a sheet at a transfer zone. The sheet is transported by a perforated belt entrained about a stationary sleeve through a recirculating path. The sleeve has a plurality of spaced ports extending in and through the periphery thereof and connected to a vacuum source. In this way, the sheet is vacuum tacked to the belt to move in unison therewith in synchronism with the photoconductive drum. At the transfer zone, the sheet separates the belt and is interposed between the photoconductive member and a corona generator. The corona generator applies an electrostatic charge to the sheet to attract successive toner images thereto. The sheet moves with the belt in a recirculating path so that successive different color toner images are transferred thereto in registration with one another.

Abstract: An apparatus in which successive developer units are moved to a development zone to develop with different color toner successive latent images recorded on a photoconductive member. Developer units remote from the development zone are sealed to prevent the escape of toner therefrom and the contamination of the developer unit.

Abstract: With the advent of low volume, low cost desk top copiers, a low cost transfer system is needed. The present invention uses a brush having conductive bristles, and a low voltage source, the brush being mounted adjacent to, but not in contact with a photoreceptor. A copy sheet is directed toward the bristles to deflect the bristles so that the bristles are in contact with the back side of the copy sheet as it contacts the toner image on the photoreceptor. Immediately before the trailing edge of the copy sheet moves out of contact with the photoreceptor, the brush is returned to its original position without contacting the photoreceptor.

Abstract: An improved cleaning apparatus for cleaning a photoreceptor in a xerographic reproduction machine includes a rotatably mounted circular cleaning brush and a flicker member within a housing. A portion of the flicker member is in contact with the brush to produce a primary flicking of the brush bristles as the brush rotates out of contact with this portion. Formed in this portion of the flicker member is an aperture in the form of a slot to produce a secondary flicking of the brush bristles as the brush rotates over this portion. The flicker member is contoured so that the angle between the tangents to the flicker member and brush roll surface at the point of initial contact is very small, approximately 5.degree., but gradually increases to a maximum of approximately 45.degree. before the brush rotates out of contact with the flicker member.

Abstract: In an electrostatographic copier in which imaging material is transferred from an image support surface to an overlying copy sheet in a transfer station, by electrical transfer charges, the variable leakage conduction of these transfer charges by the copy sheet away from the transfer area (to contacting conductive members) changes the available transfer field strength, thus affecting transfer efficiency and quality. Here the conductive members contacting the copy sheet while it is in the transfer station are electrically isolated from ground and connected to feed back the sheet leakage currents to circuitry providing a compensatory change in the applied transfer charges.

Abstract: In an electrostatographic copier in which imaging material is transferred from an image support surface to an overlying copy sheet in a transfer station by electrical transfer charges, the variable leakage conduction of these transfer charges by the copy sheet away from the transfer area (to contacting conductive members) changes the available transfer field strength, thus affecting transfer efficiency and quality. Here the conductive members contacting the copy sheet while it is in the transfer station are electrically connected to ground only through a high resistance whereby the transfer leakage currents through the paper provide a compensatory self-biasing floating voltage on the conductive surfaces which opposes these leakage currents.