A display device including: an optical image sensor; a pinhole array mask layer on the optical image sensor; a display layer disposed on the pinhole array mask layer and including a plurality of pixels; and a transparent cover layer disposed on the display layer, wherein a finger placement surface is provided on the transparent cover layer, wherein each of the pixels is one of a red pixel, a green pixel, and a blue pixel, and at least one of the green pixel and the blue pixel emits light and the red pixel does not emit light when a finger is adjacent to the finger placement surface.