Patent ID: 8416180

Claim:
A backlight modulation circuit comprising: an illumination control signal generating circuit configured for receiving a modulation signal and generating an illumination control signal according to the modulation signal; an illumination control signal separating circuit configured for separating the illumination control signal into a first modulation signal and a second modulation signal; and an illumination modulation circuit configured for modulating illumination of a backlight module according to the first and second modulation signals; wherein the illumination control signal separating circuit comprises a square wave amplitude separating circuit, an integrating and smoothing circuit, an amplifying circuit, a duty ratio separating circuit, and a fine modulation signal processing circuit, wherein the first modulation signal is separated by the square wave amplitude separating circuit, the integrating and smoothing circuit, and the amplifying circuit, and wherein the second modulation signal is separated by the duty ratio separating circuit and the fine modulation signal processing circuit.