| 摘要 |
PURPOSE:To make it possible to see one side from the other side through the titled sheet by making use of a reed screen effect, by forming plural small flat parts at equal intervals on a surface where projections consisting of small prisms are formed. CONSTITUTION:A Fresnel prism sheet 10 is formed like a thin plate consisting of a transparent body such as plastics and glass. Plural small prisms 12 are formed on the surface of said prism in multiple stages and ridgelines including vertexes 14 are paralleled to each other at prescribed intervals so as to make a right angle with the surface of paper. Each small prism 12 has an easy sloop 16 and a steep sloop 18 on one and the other sides of its vertex 14. Small flat parts 20 are formed between respective small prisms so as to be paralleled to the rear surface of the prism sheet 10 as slender parts expanded in the longitudinal direction of the small prisms. The sunlight projected from the outside of a room is totally reflected by the prism sheet when the height of the sun is high and penetrated into the room through the prism sheet when the height is low and, in addition, the outside of the room can be seen through the flat parts. |
