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, 2006
Filed:
May. 14, 2002
Katsuki Tamamura, Tokyo, JP;
Katsuki Tamamura, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An image reading apparatus comprises a correction coefficient determining circuitfor determining a correction coefficient per each bit of white reference data in a main scanning direction which are read immediately before reading an original image, a correction coefficient modifying circuitfor producing a modified correction coefficient, and a correction coefficient predicting circuitfor producing a predicted correction coefficient with reference to the modified correction coefficient. If an absolute value of a difference between the correction coefficient and the predicted correction coefficient is smaller than and not smaller than a predetermined threshold value, the correction coefficient modifying circuitproduces the correction coefficient and the predicted correction coefficient as the modified correction coefficient respectively. A correction coefficient memorizing circuitmemorizes the modified correction coefficient as shading correction coefficient data. The correction coefficient predicting circuitproduces the predicted correction coefficient for a particular bit of the white reference data in the main scanning direction with reference to at least a preceding adjacent bit preceding the particular bit in the main scanning direction.