| 摘要 |
An end surface (26) of a light guide plate (24) has a flat surface (48) and a protruding surface (50) which protrudes with respect to the flat surface (48). Light traveling from a light source (22) in a direction perpendicular to the flat surface (48) enters the light guide plate (24) in an expanded manner due to refraction at the protruding surface (54). The protruding surface (50) has a shape in which cylindrical surfaces (54) are integrated, the respective cylindrical surfaces (54) being formed about central axes (58) which are orthogonal to the front surface (28) from which the light exits. A pair of cylindrical surfaces (54), which is positioned at both end portions of the protruding surface (50) in an arraying direction of the cylindrical surfaces (54), is each adjacent to the flat surface (48). Adjacent cylindrical surfaces (54) are connected to each other at a position shifted in a protruding direction of the protruding surface (50) with respect to the flat surface (48). |
