A display device includes a first processing circuit mounted on a substrate separate from a translucent substrate constituting a display panel, and a second processing circuit mounted on the translucent substrate. The first and the second processing circuits receive the same image data. The first processing circuit includes a determination unit that uses color values of a plurality of pixels constituting an image based on the image data to determine an expansion coefficient value serving as a value for improving luminance of the image, and outputs the expansion coefficient value to the second processing circuit. The second processing circuit includes an expansion processing unit that uses the expansion coefficient value to provide expansion processing for improving the luminance of the image for the image based on the image data.