| 摘要 |
PURPOSE: A backlight converter of a liquid crystal display device is provided to generate dead-time to FET drive signals for restraining the heating problem of FET elements in the case of full-bridge type backlight inverter. CONSTITUTION: A backlight converter of a liquid crystal display device includes switches(FET1,FET2) to be turned on/off according to switching control signals for forming a current conducting path for a primary coil of a rear part transformer by a predetermined period, thereby applying a driving power(Vcc) to the primary coil. The transformer is driven according to the turning on/off of the switches, and the power converted to an AC high voltage is applied to a lamp at a rear part. The power passing through the lamp is input to an inverse(-) terminal of an error amplifier(ERR1) as a feedback signal(F/B). The ERR1 compares the feedback signal with a reference voltage input to a non-inversion(+) terminal. A time difference generator(21) compares an output signal from the ERR1 with a pyramidal wave input to a non-inversion input terminal. A driving part(22) controls the turning on/off of the switches according to output signals from second and third comparators of the time difference generator. |
