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. 05, 2013
Filed:
Sep. 22, 2008
Somei Kawasaki, Saitama, JP;
Kouji Ikeda, Yokohama, JP;
Somei Kawasaki, Saitama, JP;
Kouji Ikeda, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A driving circuit for a light-emitting device outputs a drive current from an output terminal to the light-emitting device in accordance with a signal current input from an input terminal. The driving circuit includes a drive transistor, a capacitor connected between a gate and a source of the driving transistor, and a resistance device and a first switch arranged in series between a drain of the drive transistor and the input terminal. In addition, a second switch is configured to connect the gate and the drain of the drive transistor through the resistance device when the first switch is closed, and a third switch is disposed in a path through which a drain current of the drive transistor flows from the output terminal to the light-emitting device. The resistance device increases its resistance in accordance with a cumulative amount of a passing current.