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:
Dec. 11, 2012
Filed:
Mar. 02, 2011
Kazuhiko Kobayashi, Tokyo, JP;
Joh Ebara, Kamakura, JP;
Yasuhisa Ehara, Kamakura, JP;
Kouji Amanai, Yokohama, JP;
Seiichi Handa, Tokyo, JP;
Yuji Matsuda, Tokyo, JP;
Toshiyuki Uchida, Kawasaki, JP;
Noriaki Funamoto, Tokyo, JP;
Keisuke Sugiyama, Yokohama, JP;
Kazuhiko Kobayashi, Tokyo, JP;
Joh Ebara, Kamakura, JP;
Yasuhisa Ehara, Kamakura, JP;
Kouji Amanai, Yokohama, JP;
Seiichi Handa, Tokyo, JP;
Yuji Matsuda, Tokyo, JP;
Toshiyuki Uchida, Kawasaki, JP;
Noriaki Funamoto, Tokyo, JP;
Keisuke Sugiyama, Yokohama, JP;
Ricoh Co., Ltd., Tokyo, JP;
Abstract
An image forming apparatus includes a plurality of image bearing members, each of which is configured to bear a portion of a pattern image including a plurality of reference images in a given form, an endless moving member facing the plurality of image bearing members and configured to receive the pattern image, an image detecting unit configured to detect the plurality of reference images, a rotational angle detecting unit configured to separately detect each image bearing member at a given rotational angle, and a controller configured to detect a speed deviation pattern for each revolution of each image bearing member. The controller is configured to detect the speed deviation pattern based on a result obtained from a phase component and a quadrature component of a frequency signal generated from the detection result obtained by the rotational angle detecting unit and a result of detecting the plurality of reference images in the pattern image transferred onto the endless moving member.