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. 16, 2010
Filed:
Jun. 07, 2007
Applicants:
Hiroaki Asazu, Kyoto, JP;
Kunihiro Komiya, Kyoto, JP;
Inventors:
Hiroaki Asazu, Kyoto, JP;
Kunihiro Komiya, Kyoto, JP;
Assignee:
Rohm Co., Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G05F 1/40 (2006.01);
U.S. Cl.
CPC ...
Abstract
A voltage generation unit generates a driving voltage for driving an LED. A first feedback path feeds back a voltage according to a voltage at one end of the LED. A second feedback path feeds back a voltage according to a voltage at the other end of the LED. A current driving circuit is provided on a path on which the voltage generation unit drives the LED. A control circuit controls the voltage generation unit so that one of first and second feedback voltages fed back by the first and second feedback paths, respectively is closer to a predetermined reference voltage.