Patent ID: 7973758

Claim:
An apparatus for controlling display backlight, comprising: an image analyzer, for receiving an input image data and finding out a statistic characteristic of the pixel color values of the image data; a look-up table device of color value and its corresponding brightness, established according to the statistic characteristic, for outputting a Gamma value according to the statistic characteristic; a calculator, for receiving a user setting value of backlight intensity and the Gamma value and calculating out an appropriate setting range of backlight according to the user setting value of backlight intensity and the Gamma value; a backlight adjustor for receiving the setting range of backlight and the user setting value of backlight intensity, wherein the backlight adjustor is used, first determine to decrease or increase backlight adjustment value, initially starting from the user setting value of backlight intensity and in a predetermined time, to subtract or add a predetermined value from a present backlight adjustment value accordingly, wherein the resulted value serving as an next backlight adjustment value is output to control a backlight module, and when the backlight adjustment value exceeds a boundary value of the setting range of backlight, the boundary value is used as the backlight adjustment value; and an image compensator, for receiving the backlight adjustment value, the user setting value of backlight intensity and the input image data, in order to output a compensated image data, wherein the image compensator comprises: an image compensation calculator, for receiving the backlight adjustment value and the user setting value of backlight intensity to output an image compensation value of each primary color by referring to an image compensation table according to the pulse width adjustment value and the pixel color values; and a multiplier, for receiving the image compensation value and all the pixel color values in the image data, multiplying all the pixel color values of the input image data by the image compensation value and outputting the results serving as the compensated pixel color values.