Patent ID: 7969406

Claim:
A backlight driving system for driving a backlight unit for a liquid crystal display device using a field sequential driving scheme, the back light unit including a plurality of first color, second color, and third color organic light emitting diodes (OLEDs), the backlight driving system comprising: a first switch unit including a first color switch, a second color switch, and a third color switch, the first switch unit adapted to selectively supply each of a first voltage and a ground voltage to cathodes of respective first color, second color, and third color OLEDs; and a light source controller adapted to supply independent second voltages, including a first color second voltage, a second color second voltage, and a third color second voltage, to anodes of respective first color, second color, and third color OLEDs, wherein: the light source controller comprises a DC/DC converter, the DC/DC converter comprises: a power source voltage booster adapted to boost an input voltage; a controller adapted to set and store the boosted input voltage as a reference voltage; a voltage divider adapted to divide the reference voltage into a plurality of output voltages; a first output stage adapted to supply the divided output voltages to the anode of an OLED; and a second output stage adapted to supply the divided output voltages to the first switch unit connected with the cathode of the OLED, and the voltage divider comprises: a first resistor provided between a first node and a second node, the first node being connected with the first and second output stages, and the second node being connected with a feedback terminal of the controller; and a second resistor, a third resistor, and a fourth resistor provided between the first resistor and a ground power source, the second, third, and fourth resistors being connected in parallel with each other.