Patent ID: 7764256

Claim:
An overdrive computation apparatus for generating a desired overdrive gray-level value, the apparatus comprising: a first addition/subtraction device for receiving a first overdrive gray-level value OD 1 and a second overdrive gray-level value OD 2 , and outputting a difference value indicating a difference between the first overdrive gray-level value OD 1 and the second overdrive gray-level value OD 2 , wherein the first overdrive gray-level value OD 1 corresponds to an ith first gray-level index value X(i) and a second gray-level index value Y 1 in an overdrive lookup table, the second overdrive gray-level value OD 2 corresponds to an (i+1)th first gray-level index value X(i+1) and the second gray-level index value Y 1 in the overdrive lookup table, the overdrive lookup table includes M first gray-level index values from X( 1 ) to X(M), the ith first gray-level index value X(i) and the (i+1)th first gray-level index value X(i+1) are included in the M first gray-level index values, where i is smaller than M, and i and M are integers, the difference value lies in one of a plurality of intervals, and each of the intervals has a respective corresponding computation for an overdrive gray-level value; a priority encoder for generating a first decision signal according to the one of the intervals in which the difference value lies; a computation device for receiving first gray-level data and converting the first gray-level data to operated gray-level data by at least one of a bit-shifting operation and a first adding/subtracting operation, by the respective corresponding computation according to the first decision signal, wherein the first gray-level data indicates a value lying between the ith first gray-level index value X(i) and the (i+1)th first gray-level index value X(i+1); and a second addition/subtraction device, for receiving the operated gray-level data and the first overdrive gray-level value OD 1 and for generating the desired overdrive gray-level value by a second adding/subtracting operation on the operated gray-level data and the first overdrive gray-level value OD 1 .