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. 14, 1999
Filed:
Apr. 17, 1998
Takatsugu Fujishiro, Tokyo, JP;
Nobuhiko Umezawa, Kanagawa, JP;
Hajime Oyama, Chiba, JP;
Motonori Hanada, Kanagawa, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A developing unit of the present invention includes a developing roller facing a photoconductive element and formed with a magnetic layer on its circumference. The magnetic layer has a plurality of magnetic poles of opposite polarities alternating with each other and each extending in the axial direction of the developing roller. A developer consisting of magnetic particles an toner are deposited on the developing roller by the magnetic poles and conveyed by the roller to the photoconductive element carrying a latent image thereon, thereby developing the latent image. An agitator for agitating the magnetic particles and toner is positioned relative to the developing roller such that a blade thereof has an agitation range overlapping with the magnetic force range of the magnet layer. With this configuration, it is possible to insure high quality images free from background contamination and toner scattering while extending the service life of the developing unit.