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:
Oct. 28, 2014
Filed:
Nov. 08, 2013
Canon Kabushiki Kaisha, Tokyo, JP;
Kunimasa Kawamura, Mishima, JP;
Minoru Nakamura, Mishima, JP;
Shohei Urushihara, Suntou-gun, JP;
Masaki Yamada, Mishima, JP;
Yasushi Katsuta, Susono, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
Provided are a developing unit alleviating fogging occurrence and an electrophotographic image forming apparatus providing images over long periods. The developing unit includes at least a toner of () and a developing roller of (). () When a displacement amount when a load is applied at Y° C. and 9.8×10N/sec to 2.94×10N is X, a displacement amount when the toner is left to stand for 0.1 second is X, a displacement amount when the load is reduced at 9.8×10N/sec to 0N is X, and percentage of (X−X) to Xis Z(Y), 40≦Z(25)≦80 and 10≦Z(50)≦55 are satisfied; when a gradient from the origin to the maximum load in the load-displacement curve at 25° C. is R(25), 0.49×10≦R(25)≦1.70×10is satisfied; the toner has glass transition temperature TgA (40° C.-60° C.) and maximum endothermic peak temperature P1 (70° C.-110° C.), 15° C.≦(P1−TgA)≦70° C. is satisfied. () The developing roller includes a surface layer containing a urethane resin having structure (a), and one or both structures (b)-(c).