FRESNEL LENS SHEET, TRANSMISSION TYPE SCREEN AND REAR PROJECTION DISPLAY DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a Fresnel lens sheet, transmission type screen and rear projection display device, capable of substantially reducing display defects, such as a ghost and displaying an excellent image.SOLUTION: A Fresnel lens sheet 20 has a unit convex part 22d having a first inclined surface part 22e and a second inclined surface part 22f and arranged on a non lens surface 22c. A lens layer 22 satisfiesγ≥θ-90+α+θwhen a distance between a light source and an optical center F is W; a distance between the optical center F and an incident position of image light in the lens layer 22 is R; an angle of the light outgoing surface of a base material 21 at the incident position isθ; refractive indexes of light of the lens layer 22 in the air are nand n; an angle of a lens surface 22b isα; an angle of the second inclined surface part 22f isγ;θ=arctan(R/W);θ'=θ-θ;θ=arcsin(n/n×sinθ');θ=α-θ; andθ=arcsin(n/n).