| 摘要 |
PURPOSE:To easily obtain a directive property as desired, by forming the 1-pitch section of a lenticular lens with a linear part and a circular part and setting the angle formed by the linear part and the surface vertical to the incident direction from a projection tube at a value smaller than the full reflection angle. CONSTITUTION:The base material 5 of transparent polymethyl methacrylate has the 1.492 refractive index plus a lenticular surface 6 formed with a linear and round parts in terms of its section and on a single surface and contains 3.0wt% silicon oxide 7 having 1.544 refractive index and 8.7 mean grain size. The angle of inclination at the linear part is set at the value smaller than the full reflection angle caused by the refractive index of the material 5. As a result, a high-contrast image can be obtained without lowering the quality of image. |
