An image information detecting apparatus is disclosed that comprises: a semiconductor laser that emits a laser light beam; a light receiving unit that receives a reflected light beam of the laser light beam applied to a color changing layer of an optical disc, the color changing layer being formed from a photo-sensitive material of a heat-sensitive material, and that outputs an electrical signal corresponding to the level of the reflected light beam; and a detecting unit that detects image information based on the electric signal, wherein the image information detecting apparatus detects the image information indicating an image from the color changing layer after the image has been formed therein.