An image display device includes a light source which emits laser light; an optical element which is operable to switch between a first state for reducing a coherence of the laser light and a second state for substantially maintaining the coherence of the laser light; a switching control circuit which controls the optical element; an imager which modulates the laser light transmitted through the optical element; and a modulation control circuit which controls the imager based on an image signal. The modulation control circuit causes the imager to render an image pattern for generating an image by changing alight amount at each pixel position when the optical element is in the first state, and causes the imager to render a hologram pattern for generating an image by diffraction when the optical element is in the second state.