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. 27, 2014
Filed:
Sep. 27, 2010
Hikaru Uchidate, Yokohama, JP;
Tomoyuki Saiki, Suntou-gun, JP;
Tae Matsumoto, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A plurality of test patches each including a dark and light image which has density unevenness of a predetermined period in which the plurality of test patches are differentiated in phase difference relative to a phase of density unevenness induced by rotational unevenness occurring at a predetermined period in the motor for driving a photosensitive drum is formed. Then, density information of the plurality of test patches with is detected by a density sensor, and the phase of the density unevenness is obtained based on detection results (density information) of the plurality of test patches as well as based on a phase difference corresponding to a test patch whose density unevenness is a predetermined value in amplitude.