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:
Aug. 31, 2021
Filed:
Nov. 14, 2019
Ricoh Company, Ltd., Tokyo, JP;
Masashi Nagayama, Shizuoka, JP;
Hiroyuki Kishida, Shizuoka, JP;
Masahiro Seki, Nara, JP;
Yoshimichi Ishikawa, Hyogo, JP;
Saori Yamada, Shizuoka, JP;
RICOH COMPANY, LTD., Tokyo, JP;
Abstract
A carrier for forming an electrophotographic image is provided. The carrier includes a core particle comprising a manganese-based ferrite particle having an apparent density of from 2.0 to 2.2 g/cmand a magnetization of from 44 to 52 emu/g in a magnetic field of 500 Oe; and a coating layer coating a surface of the core particle. The coating layer contains a carbon black, an inorganic particle A, and an inorganic particle B. The inorganic particle A and the carbon black each have a concentration gradient in a thickness direction of the coating layer. A concentration of the inorganic particle A increases toward a surface of the coating layer, and a concentration of the carbon black decreases toward the surface of the coating layer.