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:
Jun. 19, 2001
Filed:
May. 13, 1999
Noboru Sawayama, Tokyo, JP;
Akio Kosuge, Kanagawa, JP;
Atsushi Takehara, Kanagawa, JP;
Hiroshi Yoshimura, Tokyo, JP;
Katsuhiko Maeda, Kanagawa, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
The present invention is aimed at carrying out high-precision and stable image formation using a gray-level image forming technique. In carrying out image formation by a gray-level electrophotographic process, the relationship between the layer thickness Tp of the photosensitive layer on the photosensitive member and the exposure diameter Db of a light beam emitted onto the photosensitive member is defined as 2Tp <Db, so that the charge diffusion and electric field in the photosensitive layer on the photosensitive member can be small. The maximum exposure within the exposure diameter Db is set at a value that can sufficiently reduce the differential sensitivity of the photosensitive layer, where the exposure diameter Db of the light beam is the minimum diameter at 1/e,with respect to the peak value of the exposure distribution obtained by integrating the energy distribution of the light beam with the exposure time. In this manner, excellent gray-level image presentation can be obtained, and high-precision and stable image formation can be carried out by using a region of damping characteristics on the photosensitive member.