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:
Dec. 23, 2008
Filed:
Sep. 12, 2005
Masashi Nagayama, Numadu, JP;
Kimitoshi Yamaguchi, Numadu, JP;
Naoki Imahashi, Mishima, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
Electro-photographic images having high picture quality and low carrier adhesion can be obtained using a two-component developer containing a carrier containing (A) a carrier containing a core containing a magnetic material, the core being coated with at least one resin layer; and (B) a toner; wherein the carrier has a weight average particle diameter Dw of 22-32 μm; wherein a content of carrier particles having a diameter smaller than 20 μm is 0-7% by weight based on the weight of the carrier; wherein a content of carrier particles having a diameter smaller than 36 μm is 90-100% by weight based on the weight of the carrier; wherein a weight average particle diameter Dw of the toner is 2-7 μm; and wherein a ratio Dw/Dn of the weight average particle diameter of the toner to the number average particle diameter of the toner is 1.00-1.25.