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:
Feb. 08, 2005
Filed:
Sep. 06, 2002
Hiroki Tezuka, Kanagawa, JP;
Yoichiro Maebashi, Shizuoka, JP;
Hiroki Tezuka, Kanagawa, JP;
Yoichiro Maebashi, Shizuoka, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In a color image forming apparatus, a color toner patch for controlling density or chromaticity may be detected by a color sensor and fed back to process conditions so as to control density or chromaticity of a final output image. However, a white reference board for proofreading sensor output is expensive, and may have paper powder, toner or ink scattered thereon to become no longer usable as a reference board. The present invention provides a color identification method and a color image forming apparatus exploitable for density or chromaticity control by using a color sensor without using the reference board. In the present invention, a gray patch of black and a process gray patch of yellow, magenta and cyan are formed on a transfer medium, the chromaticity is detected without using a criterion for sensor output proofreading, and relative comparison is made between the chromaticities detected from the above two types of gray patches by using as a standard the gray patch of black which is almost achromatic, and if the chromaticities are consistent with each other, the process gray patch is judged to be achromatic.