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:
Mar. 16, 2012
Tomohiro Fukao, Osaka, JP;
Takuya Kadota, Hyogo, JP;
Yoshihiro Mikuriya, Hyogo, JP;
Tsuyoshi Nozaki, Osaka, JP;
Yoshimichi Ishikawa, Hyogo, JP;
Kazuoki Fuwa, Hyogo, JP;
Tomoharu Miki, Osaka, JP;
Tomohiro Fukao, Osaka, JP;
Takuya Kadota, Hyogo, JP;
Yoshihiro Mikuriya, Hyogo, JP;
Tsuyoshi Nozaki, Osaka, JP;
Yoshimichi Ishikawa, Hyogo, JP;
Kazuoki Fuwa, Hyogo, JP;
Tomoharu Miki, Osaka, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An electrostatic image developing toner including: toner particles each containing binder resin and colorant; and an external additive supported on the toner particles, wherein the toner particles each have protrusions on surface thereof, average of lengths of long sides of the protrusions is 0.10 μm or more but less than 0.50 μm, standard deviation of the lengths of the long sides of the protrusions is 0.20 or less, coverage rate of the protrusions on the surface of each toner particle is 30% to 90%, the external additive includes at least two different particles including external additive (A) and one or more external additives (B), external additive (A) has longest average primary particle diameter among the external additives and charged to have the opposite polarity to the toner particles, and at least one of the external additives (B) is charged to have the same polarity as the toner particles.