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. 08, 2011
Filed:
Dec. 20, 2007
Hiroyuki Nakamura, Atsugi, JP;
Hiroyuki Nakamura, Atsugi, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A light-emitting device driving circuit capable of reliably performing emission control on a light-emitting device of a low emission threshold (about 10 mA or less) and capable of correcting a distortion due to the Early effect of a transistor in the drive current supplied to the light emitting device. The light limiting device driving circuit includes a current control unit () which controls the value of a main current based on a control voltage, a bias current source (CC) for subtracting a bias current from the main current, and a switching unit () which controls emission of light from the light-emitting device by switching, based on the drive signal, a current obtained by subtracting the bias current from the main current or a current based on the current obtained by the subtraction.