Sheet binding where the printing medium itself is the sheet binder. In a xerographic process, high density areas of xerographic toner are provided at desired binding areas. Sufficiently high density toner areas are provided by inserting a finely apertured optical mask adapted to provide edge development effects to maximize overall toner density over the selected binding area, yet which is compatible with solid area coverage machines. These toner binding areas may then be subsequently refused between adjacent overlaying sheets to provide bound stacks, without requiring any additional binding material.

Electrophotographic sheet binding process

Electrophotographic copying apparatus, such as electrophotographic duplicators, electrophotographic plate making machines and the like, in which an image of an original is formed on a photosensitive sheet, said apparatus provided with means for erasing undesirable images formed on selected marginal areas of the photosensitive sheet. Eraser light sources are provided for illuminating the marginal areas of a photosensitive sheet for the purpose of preventing the formation of undesirable images on said marginal areas. Manually adjustable intercepting plates are interposed between the eraser light sources and the photosensitive sheet for the purpose of selecting the particular marginal portions of the photosensitive sheet which are to be illuminated by the eraser light sources. The photosensitive sheet is transported to an exposing position by means of conveyer belts and is held against said conveyer belts by means of a suction box. A plurality of concentric frames may be drawn on the suction box, and the conveyer belts may be made of transparent material, such that an operator looking through a viewing window before a photosensitive sheet is transported to the exposing position may adjust the intercepting plates to allow illumination of the marginal area outside a selected frame by said eraser light sources, and may adjust the position of the original to make sure its image falls within a selected frame on the suction box.

Electrophotographic copying apparatus with means for erasing marginal images

A shutter arrangement is disclosed which at pre-selected intervals opens and closes to either permit light to illuminate a document plane or reflect light to the photoconductor of an electrostatic copying machine having the capability of half tone development, thus preventing the toning of unexposed areas of the photoconductor which bear no relation to the document being copied. The control arrangement opens the shutter during the normal scanning portion when a document is exposed to the illumination light and closes the shutter at a point corresponding approximately to the end of the document scan thus reflecting light to the photoconductor as if the photoconductor was receiving light from a white document, to discharge the unused portion of the photoconductor. This prevents excessive toning and the associated cleaning problems since this portion of the photoconductor will not have the toner transferred from it to a copy sheet.

Photoconductor discharge shutter assembly

VARIABLE EDGE FADEOUT APPARATUS FOR ELECTROSTATIC REPRODUCTION MACHINES ABSTRACT OF THE DISCLOSURE An imaging lens system for electrostatic type reproduction machine or copiers utilizing a zoom lens effective to provide, within the magnification limits of the lens, infinitely variable image sizes. A control is provided to pre-set the lens to auto-matically give, upon actuation, at least one preselected image size, with an override control to enable the lens to be set to provide any image size regardless of pre-set conditions. Further controls are provided for the machine non-image erase mechanism to automatically compensate for changes in the image borders brought about by changes in image size due to resetting of the zoom lens. For this purpose, an infinitely variable edge fadeout apparatus is provided incorporating movable shutters to vary the effective size of the edge erasure slots in correspondence with image size together with timing controls for changing the operational timing of the pitch fadeout lamp in response to changes in image size upon resetting of the zoom lens. Further controls enable the critical positioning of the image produced by the zoom lens on the photosensitive member to be adjusted to assure that the image, whatever the size, is optimally positioned on the copy produced with other controls to enable the image, whatever the size produced by the zoom lens, to be physically moved or offset on the copy.

Variable edge fadeout apparatus for electrostatic reproduction machines

Apparatus suitable for use in an automatic xerographic reproducing device for erasing a portion of the electrostatic charge recorded upon an imaged xerographic plate prior to the plate''s development in order to prevent development from occuring in at least one margin (unimaged) region thereon. Further means are provided to adjust the size of the area erased in response to the size of the copy produced.

Xerographic erase mechanism

AN AUTOMATIC COPYING MACHINE OPERABLE BETWEEN A REDUCED COPYING MODE AND A FULL SIZE COPYING MODE. IT HAS A TURRET LENS ASSEMBLY MOVABLE BETWEEN DIFFERENT POSITIONS FOR PROJECTING A FULL SIZE OR A REDUCED SIZE IMAGE OF AN ORIGINAL ONTO A COPY SHEET, AND A DRIVE SYSTEM FOR MOVING THE ORIGINAL AND COPY SHEET RESPECTIVELY PAST ILLUMINATING AND EXPOSURE STATIONS AT EQUAL OR UNEQUAL SPEEDS. A RESILIENT OVERTRAVEL OPERATING ASSEMBLY MOVES THE LENS ASSEMBLY BETWEEN POSITIONS AND FIRMLY HOLDS IT IN PLACE. IN THE FULL SIZE COPYING MODE THE COPY SHEET AND ORIGINAL MOVE AT THE SAME SPEED, IN THE REDUCED COPYING MODE THE ORIGINAL MOVES FASTER THAN THE COPY SHEET AND IN PROPORTION TO THE SIZE OF THE REDUCED LIGHT IMAGE. A SINGLE SWITCH CONTROLS THE COPYING MODE. DURING THE REDUCED COPYING MODE, IT TURNS ON EDGE EXPOSURE LAMPS WHICH DISCHARGE UNEXPOSED MARGINAL AREAS WHICH WOULD OTHERWISE FORM DIRTY COPY SHEET EDGES.

Photoelectrostatic copying machine

A photoelectrostatic copying machine selectively makes full size or reduced size copies of an original sheet. Movement of a size selection switch to the reduced size position adjusts an optics assembly to project a reduced size light image of an illuminated original sheet onto a copy sheet at an exposure station, and alters the speed of movement of the copy sheet relative to the original sheet. In order to prevent non-exposure of marginal areas of the copy sheet, edge exposure lamps, masked to expose only edge portions of the sheet, are energized automatically when the machine is conditioned for reduced size copymaking operation.

George K Lux

Papers

Photoelectrostatic copying machine

Photoelectrostatic copying machine having lamps for exposing copy margins