"FIGS. 14A and 14B show a scuff plate illumination device 101 equivalent to one embodiment of the invention, FIG. 14A is a plan view from the side of an emission observation surface and FIG. 14B is a sectional view viewed along a line III???III in FIG. 14A. FIG. 15 is an enlarged view showing a part of FIG. 14A and a state of grooves formed on the backside 113 of a light guide member 110 is shown." . . . .