Light guide plate and surface illumination device

A light guide plate for introducing light from a light incident surface to output the light to an outside from a light exit surface, the light guide plate comprising:

• a light introduction unit configured to confine the light incident from the light incident surface;
• and
• a light guide plate body having a thickness smaller than a maximum thickness of the light introduction unit, the light guide plate body being provided so as to be continuously connected to the light introduction unit, the confined light being output to the outside from the light exit surface by a light exit part,
• wherein
• the light introduction unit includes an inclined surface in at least one of a surface on a light exit side of the light guide plate and an opposite surface thereof, the inclined surface being inclined toward an end of a surface of the light guide plate body from a surface in a portion having a thickness greater than that of the light guide plate body,
• the light guide plate body includes a directivity conversion pattern in a region located between the light introduction unit and an effective illumination region of the light guide plate body in at least one of the surface on the light exit side of the light guide plate and the opposite surface thereof, and
• the directivity conversion pattern converts a directivity direction of the light passing through the effective illumination region from the light introduction unit such that an angle formed by the directivity direction of the light and a direction perpendicular to the light incident surface increases when viewed from a direction perpendicular to the light exit surface.