A display device is provided including an optical waveguide, and a light source, and also a louver, a transparent/scattering state switching element, and a transmissive liquid crystal display panel, provided in order on the side of a light-emitting surface of the optical waveguide. The transparent/scattering state switching element switches between a state for scattering the incident light and a state for transmitting the light without scattering. The light source drive circuit causes the transparent/scattering state switching element to transfer from the transparent state to the scattering state, and when the viewing angle range of the display is switched from narrow to wide, the intensity of the light source is gradually increased in conjunction with the transition state of the transparent/scattering state switching element.