A lamp unit for an image projector comprises: a cable fixing portion comprising two posts and provided to stand inside a lamp box; and a cover plate mounted to contact upper ends of the posts and of the cable fixing portion. A cable for supplying electric power to a lamp body is inserted into the space between the posts, and wound around the posts. Thereby, even when a connector at an end of the cable is pulled, the cable is fixed and does not move, with the pulling force being not transferred to the lamp body. The cover plate mounted to contact the upper ends of the posts furthermore prevents the cable from slipping off the posts. Thus, with simple cable fixing structure, the lamp body can be prevented from slipping in position without increasing cost.
A projector includes a resin-made lamp case in which a light source lamp is fitted and a metal-made optical part holder in which an optical part is fitted. Preferably, the lamp case includes a positioning boss, the optical part holder includes a resin-made lamp case holder which accommodates the lamp case, a tubular light tunnel which shapes a form of light, a cylindrically shaped portion having a guide hole into which the positioning boss is inserted, and a resiliently deformable detent member, a metal-made light-tunnel fixing member, the detent member is substantially U-shaped and is provided integrally on the light-tunnel fixing member, the cylindrically shaped portion has a slot portion into which the detent member is inserted and which extends from an outer peripheral surface to the guide hole, and the positioning boss has a concave engaging portion which is engaged with the detent member.
