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. 25, 2009
Filed:
Oct. 09, 2008
Tadashi Sato, Suntou-gun, JP;
Yosuke Ata, Suntou-gun, JP;
Saki Tominaga, Suntou-gun, JP;
Momosuke Takaichi, Nagareyama, JP;
Tadashi Sato, Suntou-gun, JP;
Yosuke Ata, Suntou-gun, JP;
Saki Tominaga, Suntou-gun, JP;
Momosuke Takaichi, Nagareyama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A developing roller has a conductive shaft member, a conductive elastic layer formed around the shaft member in a thickness of 0.5 mm to 6.0 mm, and a surface layer. The elastic layer contains carbon black and silicone rubber. The carbon black is in a content of 7% to 17% by mass and has at least two peaks in its particle size number distribution. The minimum diameter peak center in the particle size number distribution is within the range of 10 nm to 40 nm. The elastic layer has density within the range of 1.01 g/cmto 1.07 g/cm. Where the ratios of carbon atoms to silicon atoms (C/Si), in the vicinity of the surface of the elastic layer, at depths of 100 μm and 200 μm from the surface of the elastic layer are represented by X, Y and Z, respectively, the X, Y and Z satisfy a specific relationship.