Patent ID: 8907885

Claim:
A backlight control apparatus, for controlling a backlight module of a liquid crystal display, the backlight control apparatus comprising: an image update progress detector, configured for detecting an update progress of an image signal and generating an update progress signal comprising a count value, said image update progress detector comprising: a counter circuit, configured for performing a count operation of counting a number of updated pixel rows according to a horizontal synchronous signal of the image signal to generate said count value, and resetting the count operation according to a vertical synchronous signal of the image signal; a backlight control signal generator, configured for generating a first backlight control signal and a second backlight control signal according to the update progress signal, wherein the backlight module comprises a first backlight area and a second backlight area; wherein the backlight control signal generator generates the first backlight control signal when the count value is equal to a first predetermined value, the first backlight control signal turns on backlights of the first backlight area, and the backlights of the first backlight area stay on until end of a frame period of the image signal; and wherein the backlight control signal generator generates the second backlight control signal when the count value is equal to a second predetermined value, the second backlight control signal turns on backlights of the second backlight area, and the backlights of the second backlight area stay on until end of the frame period of the image signal; wherein the first backlight control signal sets the first backlight area to an illumination intensity W( 1 ) and an illumination duration T( 1 ); wherein the second backlight control signal sets the second backlight area to an illumination intensity W( 2 ) and an illumination duration T( 2 ); and wherein W( 1 ) is different from W( 2 ), and T( 1 ) is different from T( 2 ).