Light guide plate, surface-emitting apparatus, liquid crystal display apparatus, and method of producing a light guide plate
View Patent ↗A light guide plate includes a light-emitting surface, a light-reflecting surface opposed to the light-emitting surface, and a light-incident surface including a protrusion formed continuously along an edge portion of the light-emitting surface. Accordingly, light that has entered the protrusion is transmitted through the protrusion and totally reflected on an inner surface of the light-emitting surface to thus propagate inside the light guide plate. As described above, since incident light components emitted toward an upper portion of the light-incident surface can be effectively blocked by the protrusion, luminance distribution characteristics as well as a light use efficiency can be improved. The light guide plate is produced by a punching press process.
1. A light guide plate comprising:
a light-emitting surface;
a light-reflecting surface opposed to the light-emitting surface; and
a light-incident surface including a side surface portion formed in a thickness direction and a protrusion whose protrusion amount gradually decreases from the light-emitting surface side toward the light-reflecting surface side, the protrusion being formed at an end portion of the side surface portion only on the light-emitting surface side,
wherein the protrusion is formed continuously on the light-incident surface along an edge portion of the light-emitting surface, and
wherein the light guide plate has a thickness of 0.30 mm or less.
2. The light guide plate according to claim 1 ,
wherein the light-incident surface includes a large number of streaky concave portions extending from the light-reflecting surface side toward the light-emitting surface side.
3. The light guide plate according to claim 1 ,
wherein the light-incident surface has a roughness degree distribution along a longitudinal direction of the light-incident surface.
4. The light guide plate according to claim 1 ,
wherein the light-incident surface is a prism surface including of a plurality of rows of prisms arranged along a longitudinal direction of the light-incident surface.
5. The light guide plate according to claim 4 ,
wherein the prism surface includes a large number of streaky concave portions extending from the light-reflecting surface side toward the light-emitting surface side.
6. The light guide plate according to claim 1 ,
wherein the protrusion includes a tapered surface that tilts from the light-emitting surface side toward the light-reflecting surface side.
7. The light guide plate according to claim 1 ,
wherein the light-reflecting surface includes curved dot patterns that are formed with a higher density as a distance thereof from the light-incident surface increases.
8. The light guide plate according to claim 1 ,
wherein the light-emitting surface includes prism patterns arranged in a direction parallel to the light-incident surface.
9. A light guide plate comprising:
a light-emitting surface;
a light-reflecting surface opposed to the light-emitting surface; and
four side surfaces including a light-incident surface, that each include a side surface portion formed in a thickness direction and a protrusion whose protrusion amount gradually decreases from the light-emitting surface side toward the light-reflecting surface side, each of the protrusions being formed at an end portion of the side surface portion only on the light-emitting surface side,
wherein the protrusions are formed continuously on the light-incident surface on the side surfaces along an edge portion of the light-emitting surface, and
wherein the light guide plate has a thickness of 0.30 mm or less.
10. The light guide plate according to claim 9 ,
wherein the four side surfaces include a large number of streaky concave portions extending from the light-reflecting surface side toward the light-emitting surface side.