Patent ID: 8013880
Filing Date: 2011-09-06
Classification: G09G,H01L

Abstract:
1. An apparatus for driving a display device including a plurality of four-color (a first color, a second color, a third color and a fourth color) pixels, the apparatus comprising: an input unit receiving input three-color (a first color, a second color and a third color) image signals; an image signal modifier converting the three-color image signals into output four-color image signals such that a maximum gray among an input first color image signal, an input second color image signal, and an input third color image signal of the input three-color image signals is equal to a maximum gray among an output first color image signal, an output second color image signal, and an output third color image signal of the output four-color image signals; and an output unit outputting the output four-color image signals, wherein the image signal modifier compares grays of the input three-color image signals, determines a maximum input gray, a middle input gray, and a minimum input gray, and assigns order indices based thereon, gamma and reverse gamma converts the maximum input gray, the middle input gray, and the minimum input gray to obtain a maximum output gray (Max′), a middle output gray (Mid′), a minimum output gray (Min′), and an output fourth color image gray (W) of the output four-color image signals, and generates the output four-color image signals based on the order indices, wherein the maximum input gray (Max), the middle input gray (Mid), and the minimum input gray (Min) have relations with the maximum output gray (Max′), the middle output gray (Mid′), the minimum output gray (Min′), and the output fourth color image gray (W) as follows: wherein Γ is a gamma conversion function, Γ