Light guide plate, surface light source device of side light type and liquid crystal display

A surface light source device comprising:

• a primary light source;
• and
• a light guide plate, said light guide plate comprising:
• minor faces to provide an incidence face and flank faces adjacent to opposite ends of said incidence face,
• major faces comprising a back face and an emission face,
• wherein said light guide plate is arranged to be supplied with light from said primary light source through said incidence face,
• one of said major faces being provided with a great number of projection rows running in a direction approximately perpendicular to said incidence face, thereby providing a great number of valleys,
• each of said valleys comprising, in a vicinity of said incidence face, a first curled-surface bottom portion comprised of a connected pair of approximately cylindrically surfaced slopes provided by a pair of the projection rows located at opposite sides of each of each of said valleys.

A liquid crystal display including a liquid crystal display panel and a surface light source device, said surface light source device comprising:

• a primary light source;
• and
• a light guide plate, said light guide plate comprising:
• minor faces to provide an incidence face and flank faces adjacent to opposite ends of said incidence face;
• major fades to provide an emission face and back face,
• wherein said light guide plate is arranged to be supplied with light from said primary light source through said incidence face,
• one of said major faces being provided with a great number of projection rows running in a direction approximately perpendicular to said incidence face, thereby providing a great number of valleys,
• each of said valleys comprising, at least in the vicinity of said incidence face, a curled-surface bottom portion composed of a connected pair of approximately cylindrically surfaced slopes provided by a pair of projection rows located at both sides of each of said valleys.

A light guide plate comprising:

• a first face to receive light;
• second and third faces adjacent to opposite ends of the first face;
• a fourth face to emit the received light, the fourth face comprising a plurality of projection rows forming a plurality of valleys and running in a direction approximately perpendicular to said first face,
• each of the valleys comprising a curled-surface bottom portion.