A display device for illuminating non-opaque materials and non-opaque mediums upon their surface while simultaneously illuminating a three-dimensional object. By making current blocking layer 19 at the light-emission end large enough that carriers flowing from a current injection region do not reach the light-emission end surface, the light intensity distribution in the near field at the light-emission end surface is strongly concentrated, allowing the horizontal divergence angle of an emerging laser beam to be enlarged. A receiving structure is located between the immovable portion and the movable portion for receiving the heat pipe therein. The image processing means extracts the actual solder regions of solder on the printed board K from image data imaged by the CCD camera and generates \u201cactual solder position information\u201d from the actual solder regions.