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. 15, 2016
Filed:
Jan. 28, 2015
Keinosuke Kondoh, Kanagawa, JP;
Kiyonori Tsuda, Kanagawa, JP;
Yutaka Takahashi, Kanagawa, JP;
Kentaro Mikuniya, Tokyo, JP;
Toshio Koike, Tokyo, JP;
Emiko Shiraishi, Tokyo, JP;
Keinosuke Kondoh, Kanagawa, JP;
Kiyonori Tsuda, Kanagawa, JP;
Yutaka Takahashi, Kanagawa, JP;
Kentaro Mikuniya, Tokyo, JP;
Toshio Koike, Tokyo, JP;
Emiko Shiraishi, Tokyo, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A developing device includes a developer bearer to carry, by rotation, developer including toner and magnetic carrier to a development range facing a latent image bearer to bear a latent image. The developer bearer includes a magnetic field generator having multiple magnetic poles and a cylindrical developing sleeve to rotate and bear developer on an outer circumferential surface thereof with magnetic force of the magnetic field generator disposed inside the developing sleeve. The developing sleeve receives development voltage including an AC component having a frequency of 2.0 kHz or lower, and a duty ratio of a component having a polarity opposite a toner normal charge polarity of the AC component is within a range from 4% to 20%.