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:
Jun. 23, 2015
Filed:
Sep. 30, 2013
Fuji Xerox Co., Ltd., Minato-ku, Tokyo, JP;
Takuro Hagiwara, Kanagawa, JP;
Yoshiki Shimodaira, Kanagawa, JP;
Yuko Kawase, Kanagawa, JP;
Satoru Tsuto, Kanagawa, JP;
Minoru Rokutan, Kanagawa, JP;
Satoya Sugiura, Kanagawa, JP;
FUJI XEROX CO., LTD., Tokyo, JP;
Abstract
An image forming apparatus includes a charging roller including elastic and surface layers and a photoconductor drum. Initially, the surface layer has a surface roughness Rz of 3-6 μm, and the layers have an impedance ratio of 0.81 or less in absolute value at a frequency of 800-3000 Hz. After a predetermined time, the surface roughness Rz is reduced by a decrement ΔRz of 0.1-4 μm. The drum has a film thickness D initially ranging from 20-40 μm and reduced by a decrement ΔD of 5-25 μm after the predetermined time. Herein, 0.005≦ΔRz/ΔD≦0.8 holds. The impedance ratio is represented as ZE/(ZE+ZS) wherein ZE and ZS represent the respective impedances of the elastic layer and the surface layer, and 100k A4-size recording media recorded with images with an area coverage of 7% are printed in the predetermined time.