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. 27, 2007
Filed:
Feb. 17, 2004
Applicants:
Chung-che Yu, Taipei, TW;
Bor-yuh Chang, Taipei, TW;
Shih-chung Huang, Taipei, TW;
Inventors:
Assignee:
Beyond Innovation Technology Co., Ltd., Taipei, TW;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 41/16 (2006.01);
U.S. Cl.
CPC ...
Abstract
A pulse width modulation (PWM) illumination control circuit with a low visual noise for driving a light-emitting diode (LED) is provided. An illumination control pulse-generating unit is used to generate an illumination control pulse signal according to an illumination-adjusting signal. A duty cycle, a phase shift or a frequency of the illumination control pulse signal varies with time within a predetermined scope for controlling a DC/DC converter to drive the light-emitting diode so that the overall visual noise level of the PWM illumination control circuit is improved.