Embodiments relate to an organic EL panel comprising a panel driving circuit for converting R′G′B′W data into driving signals which is supplied to a pixel circuit. At a RGB→R′G′B′W converting section, the bit width of input RGB data is greater than the bit width of converted R′G′B′W, and the characteristic curve of the amount of luminescent of W sub pixel for the input data of W in the said panel driving circuit is different from the R′G′B′curve normalized at a luminance ratio necessary for a reproduction of white color with sub pixels of RGB. An appropriate process is carried out by the RGB→R′G′B′W converting section in accordance with the curve of input data from the panel driving circuit verses amount of luminescent to minimize an error which may be generated when a conversion is made.
