POSITIVE DEVELOPMENT XEROGRAPHIC OVERLAY SYSTEM
Original Publication Date: 1976-Mar-31
Included in the Prior Art Database: 2004-Mar-27
Xerox Disclosure Journal
This idea concerns the use a positive form for a form over~ lay with a positive development system. A form is placed on a platen and imaged by a light source onto a photocon-' ductor. The light source is selected to only discharge one half the photoconductor potential. If a photoconductor is initially charged to +1000 volts, then background areas will be reduced to +500 volts and the imaged areas will be at about +950 volts. A second exposure by laser imaging is effected. The laser is selected to only discharge +500 volts on the photoconductor. Laser exposure of the back-' ground areas of the image to be printed thereby will reduce the image areas and background areas from the form by +500 volts leaving the form image at +450 volts, Similarly, the image areas left by turning off the laser at the desired image areas will leave the image charged at +450 to +500 volts. Therefore, the image formed by exposing the form and created by laser imaging will be at about the same potential above background potential. The image may then be developed by the normal negative charged toner.