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:
Jan. 13, 2009
Filed:
May. 20, 2005
Tsuyoshi Higuchi, Kawasaki, JP;
Jun Funakoshi, Kawasaki, JP;
Seiji Yamagata, Kawasaki, JP;
Toshitaka Mizuguchi, Kawasaki, JP;
Katsuyoshi Yamamoto, Kawasaki, JP;
Tsuyoshi Higuchi, Kawasaki, JP;
Jun Funakoshi, Kawasaki, JP;
Seiji Yamagata, Kawasaki, JP;
Toshitaka Mizuguchi, Kawasaki, JP;
Katsuyoshi Yamamoto, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A second source follower circuit of a reference voltage generator includes a transistor having the same characteristics as a first source follower circuit of a pixel. Accordingly, the second source follower circuit can generate a second reference voltage according to the change in characteristics of the first source follower circuit. A noise voltage switching circuit outputs a first voltage as a noise voltage to a pixel signal generator when the noise voltage is equal to or lower than the second reference voltage. In a reset state, the noise voltage and the second reference voltage always have a predetermined voltage difference. Therefore, deterioration in image quality can be prevented even when capturing a subject having high brightness. Since a trimming circuit or the like selecting any one of a plurality of reference voltages according to characteristics of a formed transistor becomes unnecessary, the cost of an imaging device can be reduced.