Patent ID: 8350492

Claim:
A driver for a backlight unit comprising: a first and a second lamps connected parallel to each other; a DC/AC inversion portion inverting a DC voltage into an AC voltage to apply the AC voltage to the lamps; a frequency controller controlling the DC/AC inversion portion to stably output the AC voltage of a fixed frequency; a transformer transforming the AC voltage from the DC/AC inversion portion; a positive polarity AC signal compensator compensating a positive electric current difference between the first and the second lamps using positive polarity AC signals from the first and the second lamps; and a negative polarity AC signal compensator compensating a negative electric current difference between the first and the second lamps using negative polarity AC signals from the first and the second lamps, wherein the positive polarity AC signal compensator includes: a first and a second diodes connected to one end of the first and the second lamps and being shorted by a positive polarity AC signal, a first transistor including a first collector connected to the first diode and a first base directly connected to the first collector, a second transistor including a second collector connected to the second diode and a second base connected to the first base of the first transistor, a first and a second resistors each connected between a first and a second emitters of the first and the second transistors, respectively, and a ground electric current source.