| 摘要 |
The invention provides a light control plate which can stably restrain uneven brightness better, a surface light source device comprising the light control plate, and a transmission type image display device. The light control plate is the light control plate which causes the incident light from a first surface to exit from a second surface. The second surface is provided with a plurality of convex parts which extend along a first direction and are parallel to a second direction orthogonal to the first direction. When on an orthogonal cross section of the first direction of the convex part, an axis passing through two ends of the convex part in the second direction is considered to be axis X, an axis passing through the center of two ends on the axis X and orthogonal to the axis X is considered to be axis Z, and the length of the convex part in the direction of axis X is set as wa, the outline shape of the convex part on the cross section is in the range that x is more than or equal to -0.475wa and less than or equal to 0.475wa and expressed by z(x)=(z0(x)xr)+/-0.01 wa (r is the number between 0.95 and 1.05); z0(x) can be expressed by the formula, wherein ha is a constant number more than or equal to 0.27wa and less than or equal to 1.02wa, and ka is the constant number more than or equal to -0.38 and less than or equal to 0.00. |
