| 摘要 |
A backlight driving device and a driving method thereof are provided to control brightness of the whole backlight screen uniformly and control characteristics of luminance and color of each part of the whole screen of the backlight minutely. A backlight unit(31) comprises plural light emitting zones(1A,1B,2A,2B) electrically separated from each other. A variable voltage power unit(32) receives power and voltage control signals, and individually outputs controlled voltage to each light emitting zone. A constant current driving unit includes plural constant current circuits(331~334) for receiving a PWM(Pulse Width Modulation) control signal to control amplitude and duty of currents individually which are outputted to each light emitting zone. A terminal voltage measuring unit(34) measures terminal voltage of the constant current circuits. Based on the terminal voltage measured in the terminal voltage measuring unit, a control unit(35) outputs the voltage control signal to the variable voltage power unit and outputs the PWM controls signal to the constant current driving unit. |
