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. 26, 2010
Filed:
May. 02, 2008
Shinichi Tanaka, Tokyo, JP;
Shinichi Tanaka, Tokyo, JP;
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A backlight device that is not affected by offset voltage. Driving transistor () operates such that current flows in LED circuit (), and the detection voltage generated by current detector () and the reference voltage are input alternately to first input transistor () and second input transistor () of amplifier (). Brightness adjusting switch () operates such that when driving transistor () is turned OFF during the OFF period of LED circuit (), for example, during the horizontal blanking interval or vertical blanking interval, the detection voltage and the reference voltage are swapped, so that the average voltage generated in current detector () is equal to the reference voltage, and the effect of the offset voltage can be eliminated.