| 摘要 |
PURPOSE:To reduce the reflection factor of the external light to make it possible that the screen is seen from a wide range, by the constitution where many screen elements, which have prisms and convex lenses and are provided with small-diameter holes or slits at their focuses, are arranged closely on the screen board. CONSTITUTION:Convex lens 6 and prism 7 are stored in cylindrical case 9 having pinhole part 8 at the tip to constitute a screen element, and screen board 10 where many screen elements are arranged closely is painted black, and the focal length of convex lens 6 is set to a short value to widen the visible range of the screen. By this constitution, transmittivity for the light of projector 3 is improved, and the reflection factor of the external light is reduced, so that the screen is seen from a wide range under the condition of an intensive external light. |
