| 摘要 |
PROBLEM TO BE SOLVED: To provide a fine light guide plate capable of sharply improving moire and having high in-plane uniformity of brightness, a surface light source device including the light guide plate and a transmission type display device including the surface light source device.SOLUTION: A plurality of rear side unit optical shapes 133 each of which has an approximately quadrangular prism shape projected to the rear side are arrayed adjacently to each other on a rear surface 13d of a light guide plate 13 in an array direction approximately in parallel with a light guide direction of light. Each rear side unit optical shape 133 has a top surface part 133c and a first slope part 133a and a second slope part 133b which are side faces, a plurality of pitch fixed areas R2-R7 in which a dimension Wc of the top surface part 133c in the array direction is fixed and an array pitch P1 of the rear side unit optical shape 133 is fixed in an area separated from a light incident surface 13a at least in the array direction are adjacently formed, and the array pitch P1 of the rear side unit optical shape 133 is gradually increased in each of the pitch fixed areas R2-R7 in proportion to separation from the light incident surface 13a in the array direction. |
