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:
Jun. 20, 2006
Filed:
Oct. 10, 2003
Khosrow Vijeh, Sunnyvale, CA (US);
Khosrow Vijeh, Sunnyvale, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
Control circuitry is used to control the backlighting of electronic displays. A light sensor (such as a phototransistor) is used to continuously measure ambient light conditions that are associated with an electronic display. A linear, continuous light-level signal is produced in response to the continuous measuring by the light sensor. The light-level signal is applied to a first input pin of an operational amplifier. The operational amplifier produces an output signal that is linear with respect to the light-level signal. The output signal is coupled to a second input pin, which provides feedback for the amplifier. The output signal is further coupled to an LED driver for driving backlighting LEDs.