Patent ID: 9207458
Filing Date: 2015-12-08
Classification: H05B

Abstract:
1. A backlight driving board for driving a backlight source, comprising: a microprocessor for receiving a display mode switching signal and a synchronization signal from a liquid crystal driving board, and generating a first pulse width modulation signal corresponding to the backlight source according to the display mode switching signal and the synchronization signal, and the backlight driving board and the liquid crystal driving board are connected to a common ground; and a constant current driver chip for controlling a duty ratio of a current flowing through the backlight source according to the first pulse width modulation signal; wherein, the display mode switching signal is a 2D/3D switching signal; wherein, the constant current driver chip further receives the display mode switching signal and controls a magnitude of the current flowing through the backlight source, wherein the constant current driver chip and the display mode switching signal are connected; and wherein, the constant current driver chip comprises a comparator and a first controlled switch corresponding to the backlight source, wherein, the first controlled switch is connected in series with the backlight source, a positive input terminal of the comparator is connected to the display mode switching signal, and a negative input terminal of the comparator is directly connected to a first terminal of the first controlled switch and is grounded through a resistor, an output terminal of the comparator is directly connected to a control terminal of the first controlled switch, a second terminal of the first controlled switch is directly connected to a second end of the backlight source, and the control terminal of the first controlled switch is connected to the first pulse width modulation signal, the display mode switching signal generates different voltage values in different display modes at the positive input terminal of the comparator to control the magnitude of the current flowing through the backlight source.