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:
Jul. 13, 1999
Filed:
Feb. 13, 1998
Masayasu Anzai, Hitachi, JP;
Tsuneaki Kawanishi, Toukai-mura, JP;
Yoshitaka Fujinuma, Hitachinaka, JP;
Hiroyoshi Matsumoto, Hitachinaka, JP;
Yasuo Takuma, Hitachi, JP;
Hisao Okada, Hitachi, JP;
Masayuki Ainoya, Mito, JP;
Takashi Suzuki, Hitachinaka, JP;
Yuichiro Suzuki, Toukai-mura, JP;
Tomonari Hokkyo, Hitachinaka, JP;
Koji Kato, Hitachinaka, JP;
Katsuya Kawai, Hitachinaka, JP;
Tsutomu Nakagawa, Hitachinaka, JP;
Hitachi Koki Co., Ltd., Tokyo, JP;
Abstract
A uniform image is obtained by matching the sliding friction force, the moving speed and the developing agent in a developing region of two developing rollers and an electric characteristic of a photosensitive body used for image development. Two developing rollers rotating in directions opposite to each other are used, the moving direction of the first developing roller being opposite to the moving direction of the photosensitive body, and a circumferential speed ratio of a circumferential speed of the first developing roller to a circumferential speed of the photosensitive body is within a rage of 0.5 to 2.5; and the moving direction of the second developing roller is equal to the moving direction of the photosensitive body, and a circumferential speed ratio of a circumferential speed of the second developing roller to a circumferential speed of the photosensitive body is within a range of 1.5 to 3.5. A ratio of the sliding friction force between a magnetic brush for developing agent and the photosensitive body formed in the first developing roller and the sliding friction force between a magnetic brush for developing agent and the photosensitive body formed in the second developing roller is within a range of 0.9 to 2.1.