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:
Nov. 08, 1983
Filed:
Jan. 29, 1981
Shuichi Karasawa, Kokubunji, JP;
Fuyuhiko Matsumoto, Wako, JP;
Shuichi Tsushima, Tokyo, JP;
Masatoshi Saitou, Machida, JP;
Tsutomu Ishida, Machida, JP;
Kunihiko Ikeda, Kodaira, JP;
Masao Yoshikawa, Machida, JP;
Tsutomu Sato, Kawasaki, JP;
Ricoh Company, Ltd., , JP;
Abstract
A copying method for producing duplicates of an original of at least two colors by using a composite photosensitive member including more than two photosensitive layers, wherein the photosensitive member is subjected to charging more than twice and exposed to an optical image of the original more than once by changing charging and exposing conditions, to vary charge carried on the surface and in the interior of the photosensitive member. This causes two types of electrostatic image to be formed on the surface of the photosensitive member; one type includes image regions having a positive surface potential, a negative surface potential and a substantially zero surface potential respectively and the other type includes two image regions having different surface potentials of same polarity respectively, and one image regions of substantially zero surface potential, depending on differences in color between image regions of the original corresponding to the image regions on the photosensitive member. By suitably selecting charging and exposing conditions, it is possible to selectively carry out, by using a single copying apparatus, a copying mode in which duplicates are produced in several colors, a copying mode in which duplicates are produced in one color and a copying mode in which image regions of one color are erased.