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:
Nov. 02, 2010
Filed:
Dec. 12, 2008
Hiroo Naoi, Nara, JP;
Kohichi Takenouchi, Tenri, JP;
Mitsuru Tokuyama, Kizugawa, JP;
Kiyofumi Morimoto, Tenri, JP;
Kazuma Hinoue, Yamatokoriyama, JP;
Tomoki Minamikawa, Yamatokoriyama, JP;
Hiroo Naoi, Nara, JP;
Kohichi Takenouchi, Tenri, JP;
Mitsuru Tokuyama, Kizugawa, JP;
Kiyofumi Morimoto, Tenri, JP;
Kazuma Hinoue, Yamatokoriyama, JP;
Tomoki Minamikawa, Yamatokoriyama, JP;
Sharp Kabushiki Kaisha, Osaka-shi, JP;
Abstract
An image forming apparatus capable of performing monochrome printing and color printing in which all the developing units share a single development transformer is constructed such that at the time of monochrome printing the photoreceptor drums for colors are stopped rotating while all the developing units are constantly applied with a high voltage. Further, the cumulative operation time in which the black photoreceptor drum has been operated for monochrome printing is calculated so that the color-printing photoreceptor drums which are stopped during monochrome printing are rotationally driven by a predetermined angle when the cumulative operation time exceeds predetermined fixed time. Thus, the surface of each color-printing photoreceptor drum that is being worn is restored by making the fresh surface of the drum oppose the associated color developing unit, whereby it is possible to prevent occurrence of defects on the surface of each photoreceptor drum.