Abstract: In a xerographic image transfer device, copy sheets are sequentially aligned and position sensed before introduction to the image transfer zone. The position sensing is used to compare the copy sheet location with the position of the image panel on a moving photoconductor. The timing and velocity profile of the copy sheet drive after the position sensing is arranged so that the copy sheet arrives in registry with the image panel and at the same velocity.

Abstract: First side copying is produced on a sequence of copy sheets equivalent to the number required to fill a closed-loop duplex path that returns the sheets to the imaging station. An identical number of second images are transferred to the opposite sides as they are reintroduced from the closed-loop duplex path through the imaging station. The sheet reintroduction is timed so that the next image transfer cycle is used for the first reintroduced sheet. The copy sheets are passed through a fuser station either prior to exit from the machine or as an element of the closed-loop duplex return path.

Abstract: A xerographic reproduction device with a reusable, closed-loop, belt photoconductor, having the photoconductor supported by at least one roller whose surface is axially grooved. These grooves are dimensioned to accept and hold carrier beads at or below the surface of the roller. As carrier beads accumulate in a groove, they move longitudinally of the roller, to accept more beads. The beads thereby move to the end of the roller and are discharged, preferably to a bead-capturing device.

Abstract: A continuously variable reduction optical system for document copiers including various embodiments. A scanning optical system embodiment is disclosed for corner referenced documents. Full-exposure optical system embodiments are disclosed for both single-edge referenced and corner referenced documents. The systems can make use of single focus lens or variable focus lens. Specific mechanisms are disclosed for continuously variable adjustments to magnification, to total conjugate length, to image position, to scan speed and scan length and to leading edge registration. All adjustments are tied together under the control of the machine operator.

Abstract: A continuously variable reduction optical system for document copiers wherein a plurality of sets of reduction indicators are provided, each set corresponding to a particular size copy paper. Each set of indicators can be moved by the operator to frame the document to be copied and simultaneously the reduction optical system is set to provide proper adjustment for all system parameters. The indicators are continuously viewable by the operator. An embodiment is disclosed wherein each indicator is positioned so that reduction ratio is maintained whatever the copy paper size.

Abstract: A xerographic copier having a plurality of copy sheet supply bins wherein the bin paper stacks not currently in use are lowered to an intermediate position until such later time whereat a different stack is selected for use. A sensing switch senses the top of each non-used stack and bidirectionally maintains the stack at its intermediate level. Swelling of the paper stack, due to humidity and the like, causes the stack's elevator platform to lower under the control of the sensing switch. This sensing switch also senses the top of the stack when the stack is in use, and bidirectionally maintains the top of this stack at a higher sheet feed position. These two sensing functions are provided by a single pivoted member which engages the top sheet of the stack. This pivoted member controls a switch means. The selection of a stack causes a change in the physical position of the pivot and the switch means for this stack.