Patent ID: 8203572

Claim:
An organic light emitting display device comprising: a display panel including a plurality of pixels displaying a first color, a second color, a third color, and a white color; and a signal processor receiving a plurality of input image signals respectively corresponding to the pixels, and converting the input image signals of at least two dots respectively representing the first color to the third color among the input image signals according to a first extension coefficient to generate a plurality of four-color image signals of at least two dots respectively representing the first color, the second color, the third color, and the white color, to respectively sum a distortion amount of a color impression of the four-color image signals of at least two dots, to calculate a partial extension coefficient corresponding to the sum result, and to extension-convert the input image signals of at least two dots according to the partial extension coefficient to thereby generate the four-color output image signals of at least two dots, wherein the signal processor includes: an RGBW converter extension-converting the input image signals of at least two dots according to the first extension coefficient to generate the four-color image signal of at least two dots, calculating an excess value by comparing grays respectively corresponding to the four-color image signal of at least two dots with a maximum gray, and extension-converting the input image signal of at least two dots according to the partial extension coefficient to generate the four-color output image signals of at least two dots; a distortion adder calculating and summing the distortion of the color impression by using the calculated excess value to calculate the distortion amount of the color impression of a first region of the display panel corresponding to the input image signals of at least two dots; and a partial extension coefficient determiner calculating the partial extension coefficient according to the distortion amount of the color impression of the first region, estimating the partial extension coefficient as the partial extension coefficient of the first region, and transmitting the partial extension coefficient to the RGBW converter.