Patent ID: 8106879
Filing Date: 2012-01-31
Classification: H05B

Abstract:
1. A backlight control circuit for changing a brightness of a light source comprising: a coarse adjusting circuit configured to coarsely adjust a DC voltage according to a received coarse adjusting signal and generate a corresponding coarse PWM signal; a fine adjusting circuit configured to finely adjust the DC voltage according to a received fine adjusting signal and generate a corresponding fine PWM signal; a coarse adjusting button configured for generating the coarse adjusting signal and providing the coarse adjusting signal to the coarse adjusting circuit; a fine adjusting button configured for generating the fine adjusting signal and providing the fine adjusting signal to the fine adjusting circuit; a modulation circuit configured to modulate the fine PWM signal and the coarse PWM signal into a mixed PWM signal; and a backlight driving circuit for receiving the mixed PWM signal and driving the light source according to the mixed PWM signal.