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:
Sep. 05, 2000
Filed:
Jul. 18, 1997
Satoru Fukushima, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
The present invention corrects and controls both short-term changes in the density and gradation of the obtained image due to changes in the environment and the like, and long-term changes in the density and gradation of the obtained image due to changes in the properties of the photosensitive member and the developer during a long use period using two kinds of density control operations. In first density control, a predetermined pattern is formed on a recording material via a visual-image forming process, and a contrast potential and an LUT (look-up table) for gamma conversion are set based on the value of density of the formed pattern and in a second density control, control is performed by controlling an amount of replenishment of a toner according to a first reference value, which is corrected based on the difference between the value of density of a pattern formed on a photosensitive drum and a second reference value, thereafter a pattern is formed on the photosensitive drum by driving the visual-image forming process with a parameter set in the first density control, and the first and second reference values are corrected based on the value of density of the formed pattern.