Patent ID: 9119235
Filing Date: 2015-08-25
Classification: G09G,H05B

Abstract:
1. An LED backlight source, applicable to liquid crystal display device, which comprises: a boost converter, for boosting an input DC voltage and outputting boosted DC voltage; N LED strings connected in parallel, wherein each LED string comprising a plurality of LEDs strung in series and receiving the boosted DC voltage from the boost converter, N being a natural number; a backlight driving IC, for controlling the connection/disconnection of the boost converter, and determining whether to shut down the LED strings other than a specific LED string based on the voltage at the negative terminal of the specific LED string; and N control circuits, wherein each control circuit controlling the voltage at negative terminal of a corresponding LED stringy not to become zero so that the backlight driving IC unable to shut down LED strings other than the corresponding LED string; wherein the control circuit further comprises: an open detection unit, for detecting whether a corresponding LED string being open; and an open trigger protection unit, for controlling the negative terminal of a corresponding LED string not to become zero when the open detection unit detecting the corresponding LED string being open.