Patent attributes
An image forming device includes a display panel for exposing a photosensitive recording medium to light. The display panel includes a light transmissive substrate, and a plurality of light emitting elements provided on the substrate. The substrate includes a first surface for facing the photosensitive recording medium, a second surface which is opposite from the first surface, and thickness T defined as spacing distance between the first surface and the second surface. The plurality of light emitting elements is provided on the second surface to be spaced from each other. When refractive index of the substrate is expressed by n and minimum spacing distance between the plurality of light emitting elements is expressed by S, the thickness T satisfies the following inequality:
