| 摘要 |
A Fresnel lens sheet which is bright due to a small light quantity loss, is restricted in speckles and ghosts, does not produce moires, and can be used in an inexpensive transmitting screen, wherein the sheet satisfies the diffusion characteristics of the following expressions (1) and (2), or the following expressions (3), (4) and (5). gamma/alpha<=2.8 (1) zeta/alpha<=6 (2), where alpha is viewing half value angle, gamma viewing 1/10 value angle, and zeta viewing 1/100 value angle. 2.0°<=alpha<=5.5° (3), where alpha is viewing half value angle, gamma<=12° (4), where gamma is viewing 1/10 value angle, zeta<=18° (5), where zeta is viewing 1/100 value angle.
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