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:
Sep. 04, 2007
Filed:
May. 31, 2005
Sheng-feng Chen, Taipei Shien, TW;
Sheng-Feng Chen, Taipei Shien, TW;
Quanta Computer Inc., Tao Yuan Shien, TW;
Abstract
A driving apparatus includes a DC-to-DC converter, a first LED series, a second LED series, a first constant-current circuit, a second constant-current circuit, and a feedback circuit. The DC-to-DC converter respectively outputs a direct-current voltage to one terminal of the first and the second LED series to generate a first potential and a second potential at the other terminal of the first and the second LED series according to a feedback voltage. The first and the second constant-current circuits are respectively coupled to the other terminal of the first and the second LED series and output a first current and a second current for driving the first and the second LED series according to a first and a second control signals. The feedback circuit uses the lower one of the first potential and the second potential as a feedback voltage.