Although the structure of a base 101 in a comparative example shown in the figure (7b) is simple, the upper portion of the lens becomes dark since a light-emitting diodes (102,103) are far from the lens (107), while the lower portion of the lens becomes brighter since the light-emitting diodes (105,106) are close to the lens (107). The brightness over the surface of the lens (107) is apt to be non-uniform. The figure (7a) shows the present invention, which is adapted to provide a uniform brightness over a lens (51) by disposing light-emitting diodes (54-58) in substantially parallel with the inclined lens (51). In order to do so, the base for supporting the light-emitting diodes (54-58) is formed into a stepped base (52), and a reflecting surface is provided on the rear surface of the stepped base (52).