In a self-luminous type display in which one pixel includes four unit pixels of RGBW, a signal processing circuit includes first, second and third parts. The first part subtracts a minimum value in RGB input signals from each input signal of RGB. The second part calculates an RGBW signal corresponding to the case in which all the RGB input signals are the minimum value, based on an RGB signal value for realizing target white when all the RGB input signals are a maximum value. The third part determines the RGBW signal by adding a signal corresponding to each RGB subtraction result to the RGBW signal calculated by the second part. Each RGB subtraction result is calculated by the first part.