Disclosed herein is a display device having an insulating substrate, an effective pixel area formed on the insulating substrate and having at least pixels arranged in the form of a matrix, and a peripheral circuit formed on the insulating substrate so as to surround the effective pixel area, the pixels being driven by the peripheral circuit to display a desired image in the effective pixel area, the display device including an extraneous light sensor provided in the effective pixel area for detecting extraneous light to output an extraneous light quantity detection result for use in controlling the luminance of the image.