Patent ID: 9418623
Filing Date: 2016-08-16
CPC Classification: G09G,H05B

Claim Text:
1. A backlight unit comprising: a power converter configured to generate a light source driving voltage in response to a voltage control signal; a plurality of light emitting diode strings, wherein each of the light emitting diode strings receives the light source driving voltage through a first terminal thereof; a plurality of transistors corresponding to the light emitting diode strings, wherein each of the transistors comprises: a first electrode connected to a second terminal of a corresponding light emitting diode string; a second electrode; and a control electrode; and a controller connected to the control electrode and the second electrode of each of the transistors comprising an over-current detection circuit and a plurality of current controllers corresponding to the light emitting diode strings respectively and a voltage control signal generator, wherein the current controller outputs a plurality of current control signals to the control electrodes of the transistors and wherein the voltage control signal generator generates the voltage control signal in response to the current control signals, wherein the over-current detector generates an over-current detection signal when any one of the current control signals has a pulse width narrower than a predetermined reference width, wherein the over-current detection circuit comprises: a plurality of diodes corresponding to the transistors, wherein each of the diodes comprises a first terminal directly connected to the control electrode of a corresponding transistor thereof.