At least part of a reflector surface covering a rod-shaped light source is a continuous body having such a shape that in a plane perpendicular to the central axis of the rod-shaped light source, a ray emitted from a light emitting point on the surface of the rod-shaped light source in the tangential direction going away from a light conducting plate is reflected back to the vicinity of the light emitting point. According to another aspect, at least part of a reflector surface covering a rod-shaped light source located between the rod-shaped light source and the light conducting plate is part of a parabola whose focus is substantially located on the side face of the light conducting plate in a plane perpendicular to the central axis of the rod-shaped light source.