Patent ID: 7446746

Claim:
A method for detecting whether or not a display mode has to be switched and for detecting a frame of a liquid crystal display panel, the frame being displayed under a first display mode and having M vertical blocks, each of which comprising K display lines, each of which having N horizontal blocks, each of which being composed of a plurality of display units, each of the horizontal blocks corresponding to a horizontal block energy value and a horizontal block flag value, each of the display lines corresponding to a display line energy value and a display line flag value, each of the vertical blocks corresponding to a vertical block energy value and a vertical block flag value, M, K, and N being positive integers, and the method comprising the steps of: (a) obtaining the horizontal block energy value of each of the horizontal blocks according to a sum of energy levels of all of the display units in each of the horizontal blocks; (b) obtaining the horizontal block flag value of each of the horizontal blocks by comparing the horizontal block energy value of each of the horizontal blocks to a horizontal block threshold value, respectively, wherein each of the horizontal block flag values is used to identify a polarity of the corresponding horizontal block; (c) obtaining the display line energy value of each of the display lines according to a sum of the horizontal block flag values of all of the horizontal blocks in each of the display lines; (d) obtaining the display line flag value of each of the display lines by comparing the display line energy value of each of the display lines to a display line threshold value, respectively; (e) obtaining the M vertical block energy values according to the display line flag values of all of the display lines in each of the vertical blocks; (f) obtaining the M vertical block flag values by comparing the vertical block energy value of each of the vertical blocks to a vertical block threshold value; and (g) calculating a sum of the M vertical block flag values and comparing the sum of the M vertical block flag values to a frame threshold value to determine whether or not the first display mode has to be switched to a second display mode.