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:
May. 03, 2011
Filed:
Mar. 14, 2008
Takahiro Honda, Fujinomiya, JP;
Hiroyuki Fushimi, Numazu, JP;
Fumihiro Sasaki, Fuji, JP;
Hisashi Nakajima, Numazu, JP;
Yasuo Asahina, Numazu, JP;
Takahiro Honda, Fujinomiya, JP;
Hiroyuki Fushimi, Numazu, JP;
Fumihiro Sasaki, Fuji, JP;
Hisashi Nakajima, Numazu, JP;
Yasuo Asahina, Numazu, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
Disclosed is a developer containing toner and carrier, the toner containing as a binder resin a polyol resin having a plurality of OH groups in a molecule chain having an EX/OH ratio between epoxy groups (EX) and OH groups (OH) of 0.990 to 1.010. The rotational speed α, pitch β and conveyance path length γ of an stirring and conveying unit satisfies 1.0×10≦α×β×γ≦16.0×10. Toner base particles having an electrostatic property satisfies 1.5<[Q/M]/[Q/M]<2.5, toner having an electrostatic property satisfies 0.7<[Q/M]/[Q/M]<1.3, the external additive comprises two types of fine inorganic particles having different resistance values, wherein the particle size distribution Y and added amount X of the fine inorganic particles with smaller resistance satisfy 0.1≦x≦2.0, and Y≦2.6×10X+0.0048.