Patent ID: 8344993

Claim:
A backlight device for a liquid crystal display (LCD), said backlight device comprising: a power supply generating device configured to generate a high frequency power supply; and a light-emitting source that includes at least one of a cold-cathode and a hot-cathode fluorescent tube that utilizes the high-frequency power supply from the power supply generating device; wherein the power supply generating device includes, a pulse width modulation (PWM) controller configured to generate a PWM control signal; and a modulating device configured to receive the PWM control signal to generate a PWM-modulated high frequency voltage to adjust a brightness of the light-emitting source, the modulating device including a frequency hopping data generator configured to generate a pseudo-randomly changed voltage, and an oscillator configured to generate a high frequency voltage having frequencies pseudo-randomly changed by the pseudo-randomly changed voltage from the frequency hopping data generator to light at least one of the cold-cathode and the hot-cathode fluorescent tube.