A bar-shaped light guide is provided to allow its emitting surface to be
exposed from a white casing and is provided with a pattern for scattering
and reflecting the light on a bottom surface opposite to the emitting
surface. This pattern is formed by a white paint or minute
irregularities. Further, an end face of the bar-shaped light guide
opposite to the incident side is made cube-corner shaped. In other words,
the end face is made chevroned by mirror-finished flat surfaces. These
flat surfaces are tilted at such an angle that an incident angle .theta.
of the rays of light traveling through the bar-shaped light guide
parallel to the longitudinal direction of the bar-shaped light guide is
smaller than a critical angle.