| 摘要 |
PROBLEM TO BE SOLVED: To provide a light guide plate 14 capable of stable mass production and realizing high front-face luminance and uniform luminance distribution, and a backlight unit using the light guide plate 14 as well as a display device.SOLUTION: The light guide plate 14 has a thickness of 0.5 to 4 mm, and a three-layered structure of a first layer 14e containing an optical path change element, a second layer 14f not containing the optical path change element and a third layer 14g not containing the optical path change element. On the surface of the third layer 14g positioned opposite to the first layer 14e, a plurality of grooves 14c extended linearly in parallel to a light-incident surface 14d and structured of curved surfaces are arranged. When a distance from the center in a thickness direction of the light guide plate 14 to the surface on the second layer 14f side of the first layer 14e is to be D1, and a distance to the surface on the third layer 14g side of the first layer 14e is to be D2, the D1 as well as the D2 is 0.2 to 1.5 mm. A cross-section shape of the groove 14c cut on a surface perpendicular to the light-incident surface 14d and a light emission surface 14a is to be of bilateral symmetry. |
