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:
Sep. 05, 1989
Filed:
Feb. 23, 1988
Takao Kumasaka, Takahagi, JP;
Teruaki Mitsuya, Hitachi, JP;
Isamu Komatsu, Takahagi, JP;
Shigetaka Fujiwara, Yokohama, JP;
Yuzuru Shimazaki, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Koki Co., Ltd., Tokyo, JP;
Abstract
Non-contact type developing device and method for electrophotographic recording system. The pitch of magnetic poles on a developing sleeve carrying a developer is selected to fall within a predetermined range or is varied such that the pitch increases as the circumferential distance from the point where the gap between the developer carrier member and a photosensitive member is minimum. The bias voltage applied to the developing sleeve is controlled in accordance with a change in the size of the gap between the surface of the photosensitive member and the layer of the developer on the developer carrying member. Alternatively, the bias voltage is applied throughout a period in which the charged region on the photosensitive member is opposed by the developing sleeve.