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. 09, 2000
Filed:
Oct. 15, 1996
Mitsuru Mamizuka, Tokyo-to, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A color copying apparatus includes a function for correcting image density when an image development system is deteriorated after a relatively long time of usage. A reference image including a number of color gray scales is stored in a memory, and is recorded on a recording medium. Each color gray scale corresponds to each of a yellow, a magenta, a cyan, and a black color for a letter image and each of a yellow, a magenta, a cyan, and a black color for a halftone image. When the image development system is deteriorated, the reference image recorded on the recording medium represents image density which is different from the reference image stored in the memory. This difference is detected by comparing the image density of two reference images, one stored in the memory and the other recorded on the recording medium. In accordance with a result of the comparison, a suitable data table of gamma data for each color element for a letter image and for each color element for a halftone image is selected from among a number of data tables of gamma data stored in the memory, so that the image density is corrected for each color element and for each image type and such that the image development system of the color copying apparatus is set again in a condition in which an image can be reproduced in a superior quality.