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:
Feb. 14, 2012
Filed:
Apr. 02, 2009
Applicant:
Osamu Sasaki, Chiba, JP;
Inventor:
Osamu Sasaki, Chiba, JP;
Assignee:
Seiko Instruments Inc., Chiba, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 37/02 (2006.01);
U.S. Cl.
CPC ...
Abstract
Provided is an LED drive circuit capable of using a switching regulator IC having low breakdown voltage even when a power supply voltage is high. The LED drive circuit includes a voltage clamp circuit for clamping the power supply voltage to an operating voltage of the switching regulator IC, converts an output voltage of a current detecting circuit for detecting a current flowing through an LED into the operating voltage of the switching regulator IC, and outputs the operating voltage.