Light guide plate, surface light source device, and display device

A light guide plate comprising:

• a light exit surface;
• a back surface opposed to the light exit surface;
• at least one light entrance surface consisting of part of a side surface between the light exit surface and the back surface;
• and
• a counter surface consisting of part of the side surface and opposed to the one light entrance surface in a first direction,
• said light guide plate comprising:
• a body portion;
• and
• unit shaped elements defining the light exit surface, the unit shaped elements being arranged on one-side surface of the body portion in an arrangement direction intersecting the first direction,
• wherein each unit shaped element extends in a direction intersecting the arrangement direction,
• wherein in a main cross-section parallel to both the arrangement direction and a normal direction of the one-side surface of the body portion, a light exit surface angle, which is an angle of a contour of each unit shaped element with respect to the one-side surface of the body portion, is more than 10° and not more than 30° in a zone of the contour of each unit shaped element, a width of the zone along the arrangement direction is not less than 35% and not more than 70% of a full width of the unit shaped element, and the light exit surface angle is more than 30° or not more than 10° in the other zone of the contour of each unit shaped element.