| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that image disturbance called a speckle is caused when the effective screen size of an image source is small and the diameter D of a projection lens is small. SOLUTION: A lenticular lens sheet has two layers of diffusing materials, and the absolute value of the difference in refractive index between the diffusing material on an image observation side (on the opposite side from the Fresnel lens sheet) and a base material is≤0.03 and the mean particle size of the diffusing material is≤10μm. Or the lenticular lens sheet has two layers of diffusing materials, and the absolute value of the difference of the refractive index of the diffusing material on the Fresnel lens sheet side from that of a base material is≥0.08 and the mean particle size of the diffusing material is≤10μm. Consequently, an image display device which hardly causes the speckle is obtained even when an image modulating element such as a reflection or a transmission liquid crystal panel and a display element equipped with a plurality of fine mirrors is used for an image source instead of a projection cathode-ray tube. COPYRIGHT: (C)2004,JPO&NCIPI
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