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:
Aug. 13, 2013
Filed:
Feb. 20, 2012
Yung Lin Lin, Palo Alto, CA (US);
Sheng-tai Lee, Taipei, TW;
Yung Lin Lin, Palo Alto, CA (US);
Sheng-Tai Lee, Taipei, TW;
O2Micro Inc., Santa Clara, CA (US);
Abstract
A portable lighting device includes a controller, a power source that provides a voltage, and a load that includes a light emitting diode (LED) light source. The controller receives the voltage and regulates a current of the LED light source based on a sensing signal indicating the voltage of the power source. The controller regulates the current of the LED light source to a first current level if the voltage of the power source is greater than a first voltage level, and to a second current level if the voltage of the power source is less than a second voltage level. The second voltage level is less than the first voltage level. The controller regulates the current of the LED light source to vary according to the sensing signal if the voltage of the power source is between the first voltage level and the second voltage level.