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:
Oct. 16, 2018
Filed:
Nov. 17, 2016
Applicant:
Renesas Electronics Corporation, Tokyo, JP;
Inventors:
Makoto Nakamura, Tokyo, JP;
Motoaki Suzuki, Tokyo, JP;
Mamoru Kitamura, Tokyo, JP;
Keisuke Fukuda, Tokyo, JP;
Assignee:
RENESAS ELECTRONICS CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B 33/08 (2006.01);
U.S. Cl.
CPC ...
H05B 33/0845 (2013.01); H05B 33/0815 (2013.01); H05B 33/0818 (2013.01); H05B 33/0851 (2013.01); H05B 33/0884 (2013.01);
Abstract
An LED drive method drives an LED by a drive current. The LED drive method uses a voltage conversion unit, which includes a coil and a first switch, and converts an external voltage into a first voltage, which is a DC voltage, by controlling the first switch to be on in an on-pulse period of a first drive signal. A constant current drive unit is provided with the first voltage and generates a drive current based on a second drive signal.