Patent ID: 8120569
Filing Date: 2012-02-21
Classification: G09G

Abstract:
1. An apparatus of adaptively adjusting backlight for use in a liquid crystal display, the apparatus comprising: an intensity-pair distribution device for receiving a plurality of image frames to correspondingly generate a plurality of intensity-pair distribution values of the image frames, wherein each of the image frames is composed of a plurality of pixel data; a brightness compensation module, electrically coupled to the intensity-pair distribution device, for computing a dark-state ratio of the pixel data in a current image frame in response to the intensity-pair distribution values of the current image frame, and for computing a brightness index of the current image frame in response to the dark-state ratio for generating a brightness compensating signal based on the dark-state ratio and the brightness index of the current image frame, wherein the dark-state ratio of the brightness compensation module is the ratio between the amount of the gray pixel data in one image frame and the total amount of the pixel data in the image frame, and the gray levels of the gray pixel data are lower than a predetermined value, and wherein the brightness index of the current image frames is the sum of the largest gray level multiplying a first weighting value and the dark-state ratio multiplying a second weighting value for each image frame; a frame-adjusting device, electrically coupled to the brightness compensation module, for adjusting the brightness of the pixel data of the current image frame in response to the brightness compensating signal; a backlight control device, electrically coupled to the intensity-pair distribution device and the brightness compensation module, for updating the brightness index of the current image frame in response to the brightness index of a previous image frame and the intensity-pair distribution values of the current image frame for generating a backlight control signal of the current image frame; and a backlight module, electrically coupled to the backlight control device, for adjusting the backlight luminance of the backlight module in response to the backlight control signal from the backlight control device for adaptively matching the brightness of the current image frame with the luminance profile of the backlight module.