A flat panel display device. The device includes a plurality of self-luminant devices, each of which includes at least a light emitting layer, formed on every pixel, and a lens sheet having a plurality of condensing lenses that correspond to the self-luminant devices and direct the light emitted from the self-luminant devices toward a predetermined direction. A distance between the light emitting layer and an exterior portion of the condensing lens in the direction of propagation of the light is between 50 and 500 microns so as not to overlap images of neighboring sub-pixels, that are expanded by the condensing lenses. Therefore, a lowering of image sharpness that is caused by the condensing lenses can be prevented, while a light coupling efficiency and a brightness are improved.