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:
Jul. 09, 2002
Filed:
Feb. 22, 2000
Applicant:
Inventor:
Makoto Ohki, Mishima, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03G 1/500 ;
U.S. Cl.
CPC ...
G03G 1/500 ;
Abstract
High precision image density characteristics are stable maintained over extended periods of time. For this purpose, a first calibration operation is preformed in which a predetermined grayscale pattern is formed on a recording paper and this pattern is read by a reading device to produce a LUT for controlling the laser output in accordance with the image signal (gamma correction). A second calibration operation is performed after the first calibration operation wherein a patch is formed on an image carrier by the laser output controlled by the above LUT, its density is detected by a detector and a correction LUT is generated in accordance with the detected density.