A light guide plate includes a light exit surface, a light guide plate bottom surface, and at least one light incidence surface. The light exit surface and the light guide plate bottom surface are opposite to each other. The light incidence surface is connected to the light exit surface and the light guide plate bottom surface. The light guide plate is of a wedge configuration and has an end that is close to the light incidence surface and has a thickness greater than a thickness of an end thereof distant from the light incidence surface. The light guide plate includes a hollow wedge cavity that includes a hollow wedge cavity bottom surface adjacent to the light guide plate bottom surface. The hollow wedge cavity receives therein a reflector plate laminated on the hollow wedge cavity bottom surface and having a surface facing the light exit surface and including reflection projections.