Abstract: A modulator for modifying a scanning beam to project a halftone image onto a photosensitive surface including a sensor providing sensor signals in relation to the speed of the photosensitive surface, a converter responsive to the speed of the photosensitive surface to provide a signal representing an image quality factor for altering the modulation of the beam of the scanning system to adjust the projected image in relation to the speed of the photosensitive surface, the projected image including banding errors, and a random signal generator responsive to the sensor signals for generating random signals, the random signals altering the modulation of the beam of the scanning system to counter the banding errors on the projected image.

Abstract: A thin scraper blade member is arranged in interference with, and at a low angle of attack with respect to the photoreceptor so that a maximum shearing force can be applied by the blade to the spot-causing agglomerate particles for removal thereof. A slit extends laterally from one side of the blade and parallel to the edge of the blade, so that blade tuck occurrence is minimized. The slits serve to reduce the load and eliminate forces on the ends of the blade that cause the blade to tuck under. The slit also improves the range of tolerance of interference of the blade surface with respect to the photoreceptor surface before blade tuck occurs. A relatively low load is applied to the blade, so that the problems associated with the frictional sealing contact that must occur in the normal cleaning engagement of blades with a charge retentive surface are avoided.

Abstract: Sheet stacking utilizing an orbital nip system by initially orbiting the nip with the sheet in the nip until the nip angle is aimed well up on the registration stacking wall above the stacking tray and adjacent the desired maximum stack height even if the tray is empty; feeding the sheet in this initial nip position out towards the wall at a preset nip feeding velocity without substantially orbiting the nip; then, when the edge of the sheet is within approximately 10 millimeters of the registration stacking wall, starting to orbit the nip with the sheet in the nip, away from the wall and downwardly at an orbiting angular velocity which is substantially slower (0.4 to 0.

Abstract: A system for compensating for motion errors that degrade image quality by modifying the modulation of a scanning beam across a photosensitive surface in response to changes in speed of the photosensitive surface by use of a shaft encoder mounted adjacent to the photosensitive surface to determine the speed of the photosensitive surface, a comparator electrically connected to the sensor for determining the change of speed of the photosensitive surface in relation to a standard speed, a converter connected to the comparator and responsive to the change in speed to provide a signal representing an image quality factor, and for altering the modulation of the beam of the scanning system in relation to the speed of the photosensitive surface.

Abstract: A plural mode system of transporting sheets in an output path of a copier or printer to a sheet stacking area, with selectable sheet inversion provided by opposing first and second sheet feeding rollers forming a sheet transporting nip engaging the leading edge of a sheet, by a relative orbital motion of the opposing rollers to progressively pivot the nip and thereby change the angular direction of motion of the leading edge of the sheet. A selection between faceup and facedown stacking of the sheets is provided by selectable orbital motion of the nip. The sheet is inverted for stacking by orbital motions pivoting the nip by greater than 90 degrees with the sheet's leading edge held in the nip, so that subsequently the leading edge of the sheet is moving in a direction substantially different from the direction of motion of the leading edge when the leading edge first entered the nip.

Abstract: A sheet feeder for feeding sheets from a support platform comprising a sheet support platform, a rotatable sheet feed roll reciprocally movable between a sheet feeding position wherein it is in feeding engagement with the top sheet when at least one sheet is on said support platform and a retracted standby position wherein it is retracted from feeding engagement with said the top sheet and a movable sheet restrictor member positioned by gravity to maintain the top sheet spaced from the rotatable feed roll when the feed roll is in the retracted standby position. In a preferred embodiment the sheet feeder prints for a second pass through a printing machine.