Patent ID: 7371001

Claim:
A light guide plate comprising: a top surface serving as a light-emitting surface; a bottom surface serving as a reflecting surface; and a periphery having a first side surface serving as an incident surface and a second side surface opposite the first side surface, wherein the bottom surface is provided with a plurality of reflecting prisms successively arranged in a direction from the first side surface to the second side surface; each reflecting prism has a first slant surface inclined so as to extend toward the top surface in a direction from the first side surface toward the second side surface, and a second slant surface succeeding to the first slant surface and inclined so as to extend away from the top surface in the direction from the first side surface toward the second side surface; and the second slant surfaces of reflecting prisms are designed to reflect a large part of light reflected back from the second side surface toward the first side surface so that the large part of light is emitted from an area of the top surface located near the first side surface; wherein inclination angles of the second slant surfaces of the reflecting prisms positioned near the first side surface are larger than those of the second slant surfaces of other reflecting prisms so that the large part of light reflected back from the second side surface toward the first side surface is emitted from the area of the top surface located near the first side surface.