The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 28, 1981
Filed:
Nov. 13, 1978
Harold M Stahl, Ridgefield, CT (US);
Pitney Bowes Inc., Stamford, CT (US);
Abstract
In an electrostatic xerographic copying process and apparatus in which a photoconductive insulating master is sensitized by application of a uniform electrostatic charge to the photoresponsive surface thereof, the charge is removed in non-image areas by exposure to a light image corresponding to the non-image areas of an illuminated original to leave charged latent image areas capable of development with coloring material. The sensitized photoreceptive surface is pre-exposed to an electroluminescent element of sufficient intensity to completely or partially remove the charge from all areas or some areas of the surface prior to the exposure to the light image. Complete removal of the charge is advantageous in spaced transverse portions of a continuous master which are not to be exposed to the illuminated original sheet, thereby desensitizing such areas. Partial removal of the charge is advantageous in the case of masters having slow photoresponse, which can be overcome by reducing the surface potential thereof.