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:
Mar. 24, 1998
Filed:
Mar. 16, 1995
Akio Suzuki, Kawasaki, JP;
Yoshio Tabata, Kawasaki, JP;
Yukako Murai, Kawasaki, JP;
Keiichi Saito, Kawasaki, JP;
Tamio Amagai, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
The invention provides a white level information correction apparatus for an image reading apparatus suitably used as an image scanner, which is improved in that analog to digital conversion can be performed effectively for originals of different ground colors with a high degree of accuracy. In the image reading apparatus, image information of a paper sheet being transported along a paper transport path is optically read at a fixed location of the paper transport path using an optical image reading unit and analog data obtained by the optical image reading unit are converted into digital data using white level information of the image information as an index to a conversion reference. The white level information correction apparatus comprises a plurality of storage apparatus for storing a plurality of pieces of white level information to be used as indices to the conversion reference, a data magnification variation apparatus for multiplying white level information from a storage apparatus by a coefficient to vary the magnification of the data, and a data write control apparatus for storing white level information varied in magnification by the data magnification variation apparatus into a storage apparatus to update the stored data.