MULTIFUNCTION EXTERNAL ERASE LIGHT
Original Publication Date: 1987-Oct-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
U.S. Patent 4,265,990 describes multilayered electroconductive imaging photoreceptors which comprise at least two electrically operative layers, a photo generating or charge generating layer and a charged transport layer which would typically apply to the conductive layer. One of the properties of such photoreceptors is that they are semi-transparent. The Figure illustrates a machine geometry wherein a single lamp may be used to provide both a precharge erase function to the photoreceptor as well as pretransfer discharge function. The Figure schematically illustrates a portion of an electrostatographic printing machine wherein the photoreceptor 10 is in the form of a belt having a top run and a bottom run driven around two support rolls (not shown). The photoreceptor is comprised of generator layer 12 on a ground plane layer 14 according to the structure described in U.S. Patent No. 4,265,990. Light from the precharge erase lamp 18 is initially used to provide a precharge erase function to the top run of the photoreceptor belt after it has been cleaned of residual toner. Since a portion of the light generated by preckarge erase lamp 18 is transmitted by the photoreceptor belt, it can pass through aperture 20 to the backside of the bottom run of the photoreceptor belt thereby providing a pretransfer discharge of the photoreceptor belt. It should be noted that this aperture is positioned between the development zone and the transfer zone on the lower run of the belt. This multifunction capability is enabled by the fact that the light energy required to perform the precharge erase and the pretransfer discharge are different. For example, the recharge erase function may require about 500 ergdcm2 at the generator Payer and the pretransfer function require only 5 ergslcm2.