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:
Mar. 09, 1999
Filed:
Sep. 19, 1996
Eisaku Murakami, Hiratsuka, JP;
Kazuhiro Yuasa, Zama, JP;
Shuichi Endoh, Isehara, JP;
Iwao Matsumae, Tokyo, JP;
Yoshiaki Tanaka, Kawasaki, JP;
Hiroshi Hosokawa, Yokohama, JP;
Mugijiroh Uno, Isehara, JP;
Hiroshi Saitoh, Ayase, JP;
Eiji Takenaka, Atsugi, JP;
Toshihiro Sugiyama, Tokyo, JP;
Tetsuo Yamanaka, Tokyo, JP;
Satoru Komatsubara, Atsugi, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
In an electrophotographic image forming apparatus of the type using single-ingredient type high resistance toner, a developing roller or similar toner conveyor roller is covered with a dielectric layer which is comparatively thick at opposite end portions than at an intermediate portion. A conductive or semiconductive elastic layer underlies the dielectric layer. With the above configuration, the dielectric layer is prevented from coming off the roller. This, coupled with the fact that the elastic layer does not contact a photoconductive element, eliminates current leaks and thereby extends the life of the roller and photoconductive element.