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:
Nov. 14, 2017
Filed:
Oct. 05, 2016
Applicant:
Rohm Co., Ltd., Kyoto, JP;
Inventors:
Assignee:
Rohm Co., Ltd., Kyoto, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 37/02 (2006.01); B60Q 3/04 (2006.01); H05B 33/08 (2006.01);
U.S. Cl.
CPC ...
B60Q 3/044 (2013.01); H05B 33/0815 (2013.01); H05B 33/0839 (2013.01);
Abstract
An apparatus for driving a light emitting device includes a constant current control circuit configured to control a current flowing through the light emitting device to be constant, and an extension circuit configured to generate a post-extending PWM signal obtained by extending a period of an input PWM signal having a first level. The constant current control circuit is turned on during the period of the post-extending PWM signal having the first level, and the constant current control circuit is turned off during a period of the post-extending PWM signal having a second level.