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:
Aug. 29, 1989
Filed:
Nov. 12, 1987
Applicant:
Inventors:
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04N / ; H04N / ;
U.S. Cl.
CPC ...
358494 ; 358 75 ; 35821316 ;
Abstract
An image reading apparatus includes a plurality of linear sensors for reading an image of a document. Each linear sensor reads a different portion of a line of the document in a divided manner. A plurality of clamp circuits control black levels of signals generated by the plurality of linear sensors to be a black reference level. A plurality of multipliers control white levels of signals generated by the plurality of linear sensor means which are level-controlled by the clamp circuits so as to be a white reference level.