Disclosed is a display device at a low cost which enhances the color purity of light to be projected, and which resists deterioration due to ambient light such as infrared ray. This display device includes an LED, an optical member for selectively outputting light components, of which wavelength is a predetermined minimum-limit wavelength or longer, from incident light, and a mirror for selectively reflecting light components, of which wavelength is a predetermined maximum-limit wavelength or shorter, from irradiated light. One of the optical member or the mirror receives light directly from the LED, and outputs it to the other. Subsequently, the other receives the light from one of the optical member and the mirror, and outputs it.