| 摘要 |
PROBLEM TO BE SOLVED: To obtain a light diffusion sheet of which luminance distribution of light emission surface can be made uniform since the parallel light-beam transmissivity is small and the total light-beam transmissivity is high, and is thin, light in weight, and is flexible and can easily be installed on a curved surface by providing the light diffusion sheet which is made of woven fabric having a specific difference between total light-beam transmissivity and parallel light-beam trasmissivity specified. SOLUTION: The light diffusion sheet is formed of a woven fabric having a >=40 difference between total light-beam transmissivity and parallel-light light beam transmissivity. So that the woven fabric has this light-beam transmissivity difference, the diameter of the fiber is preferably 1μm-5mm, specially, 10μm-1mm. When the fiber diameter is <1μm, the woven fabric easily diffuses and reflect light, but when the diameter of the fiber exceeds 5mm, the flexibility of the woven fiber is spoiled and its use for a curved surface is disabled, so that its use range narrows down. This woven fabric is formed substantially of monofilament fiber, but multifilament fiber may be used at need and there is no problem in this case as long as the total fineness is within this range.
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