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:
Nov. 09, 2004
Filed:
Jun. 10, 1999
Hidekazu Maruta, Yokohama, JP;
Kensaku Kusaka, Moriya-machi, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An image reading apparatus including a light source for illuminating an original, a white member which is illuminated by the light emitted from the light source, a photoelectric converting element for receiving the reflection light from the original and the reflection light from the white member, a memory for storing a reference output of the photoelectric converting element which is obtained by receiving the reflection light from the white member, a shading compensation device for compensating an output of the photoelectric converting element which is obtained by receiving the reflection light from the original in accordance with the reference output, and a rewriting device for rewriting the reference output to be stored in the memory, wherein the rewriting device rewrites the reference output at a timing according to a fluctuation in light amount of the light source.