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:
Jan. 07, 2014
Filed:
Sep. 29, 2011
Katsuhiro Aoki, Kanagawa, JP;
Akira Azami, Kanagawa, JP;
Daichi Yamaguchi, Kanagawa, JP;
Akihiro Kawakami, Tokyo, JP;
Katsuhiro Aoki, Kanagawa, JP;
Akira Azami, Kanagawa, JP;
Daichi Yamaguchi, Kanagawa, JP;
Akihiro Kawakami, Tokyo, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A developing device includes a non-magnetic rotatable sleeve of a developer bearer to bear developer and a development electric field generator to generate a development electric field between the image bearer and the developer bearer by applying a development bias to the developer bearer. The developing bias is an AC bias generating an AC electric field therebetween. The magnetic carrier includes a plurality of fine particles each covered by a covering layer made of prescribed material having a volume resistivity equal to or more than 10[Ω·cm] having a prescribed particle diameter equal to or less than 100 [nm]. Each of the a plurality of fine particles has a total volume resistivity equal to or less than 10[Ω·cm]. The magnetic carrier has a total volume resistivity equal to or more than 10[Ω·cm].