Patent ID: 8373818

Claim:
A multiple primary color display device comprising a pixel defined by a plurality of sub pixels, wherein: the plurality of sub pixels include a first sub pixel to display a first color having a first hue, a second sub pixel to display a second color having a second hue, a third sub pixel to display a third color having a third hue, and a fourth sub pixel to display a fourth color having a fourth hue; in the case where gray scale levels of two colors among three colors of red, green and blue of an input signal are increased at an equal rate to one another to a maximum gray scale level and then a gray scale level of the remaining color is increased to the maximum gray scale level, so that a color represented by the input signal is changed from black to white via a color of a prescribed hue; where the prescribed hue is different from any of the first hue, the second hue, the third hue and the fourth hue; and where in a chromaticity diagram of an L*a*b* colorimetric system, the prescribed hue is closest to the first hue among the hues of the plurality of sub pixels, the second hue is closest to the prescribed hue on an opposite side to the first hue with respect to the prescribed hue, and the third hue is closest to the prescribed hue next to the first hue on the same side as the first hue with respect to the prescribed hue; luminance levels of the plurality of sub pixels are set such that the luminance level of each of the first sub pixel, the second sub pixel and the third sub pixel is started to be increased without increasing the luminance level of the fourth sub pixel and such that the luminance level of the third sub pixel is increased at a lower rate than that of the luminance level of each of the first sub pixel and the second sub pixel.