| 摘要 |
A surface light source device includes a lamp post, a number of light sources distributed in rows on the side surfaces of the lamp post, and a number of first prism sheets and second prism sheets arranged around the lamp post in that order. Each of the first prism sheets and the second prism sheets includes a light incident surface and a light exit surface opposite to the light incident surface. Each of the light exit surfaces includes a number of substantially parallel elongated protrusions, and the longitudinal directions of the elongated protrusions of the first prism sheet and the second prism sheet are substantially perpendicular to each other. The first prism sheets and the lamp post are approximately spaced by a first predefined distance, and the second prism sheets and the first prism sheets are approximately spaced by a second predefined distance. |
