Fresnel lens sheet, rear projection screen, and rear-projection-type display

Abstract

The present invention provides a Fresnel lens sheet that scarcely makes the projected image distorted, and others. The Fresnel lens sheet has a plurality of unit total reflection Fresnel lenses arranged on the light-entering side, each unit lens having a light-entering surface and a total reflection surface that totally reflects a part of or all of the imaging light that has passed through the light-entering surface to deflect the light in the desired direction. This Fresnel lens sheet is formed so that it fulfills the relationship H1×H1/(10×E1×T1×T1)≦3L/2000, where H1 represents the length (cm) in the vertical direction of the Fresnel lens sheet; L1, the length (cm) in the horizontal direction of the Fresnel lens sheet; T1, the thickness (cm) of the Fresnel lens sheet; and E1, the modulus of elasticity (kgf/cm2) of the Fresnel lens sheet. Further, by using, to make up the Fresnel lens sheet, a Fresnel-lens-molded sheet having unit total reflection Fresnel lenses and a backing sheet laminated to the light-emerging surface of the Fresnel-lens-molded sheet, improvement in the efficiency of mold releasing operation that is conducted in the production of the Fresnel lens sheet is achieved.

Dependencies are inferred from the claim text.