Patent ID: 8314761

Claim:
A display device, comprising: a display panel having a number of data lines and a number of scanning lines which cross the data lines, wherein color pixels containing red (R), green (G), blue (B) and white (W) sub-pixels corresponding to intersections between said data lines and said scanning lines are aligned in a matrix; and a backlight which illuminates said display panel, characterized in that the display device has: a scanning driver which applies a horizontal scanning signal to said scanning lines; a data driver which outputs gradation voltages for the grades of said scanning lines to said data lines; and a processing apparatus which transmits RGB data to said data driver, said data driver has a conversion circuit which converts RGB data for one color pixel containing R sub-pixel data, G sub-pixel data and B sub-pixel data to RGBW data for one color pixel containing R sub-pixel data, G sub-pixel data, B sub-pixel data and W sub-pixel data, said conversion circuit has a W intensity setting circuit which is configured to change a ratio of the W intensity to a grade number of one RGB pixel, and the W intensity setting value for said W intensity setting circuit is determined in accordance with a ratio of the number of saturation pixels in the RGB data for each frame, said saturation pixels comprise pixels where the difference between the maximum value and the minimum value of the sub-pixel data for each piece of RGB data is greater than the set saturation threshold value (integer of 0 or greater), and the ratio of said number of saturation pixels is a ratio of the number of saturation pixels to the number of pixels within one frame from which black pixels where the maximum grade of the sub-pixels in each piece of RGB data is greater than the black threshold value (integer of 0 or greater) are excluded.