US 6,785,048 B2 · Rear-projection screen and rear-projection image display

Abstract

A rear-projection screen 3, including at least a lenticular lens sheet 32 and a Fresnel lens sheet 31, is configured so that the lenticular lens sheet 32 contains, in a base material thereof made of a resin, light diffusing microparticles made of a resin having a refractive index different from a refractive index of the base material, and the light diffusing microparticles satisfy 0.5 μm≦ΔN1×d1≦0.9 μm, where ΔN1 represents a difference between a refractive index of the light diffusing microparticles and a refractive index of the base material of the lenticular lens sheet, and d1 represents an average particle diameter of the light diffusing microparticles. With this, a rear-projection screen with small wavelength dependency of diffusion characteristics can be provided utilizing only resins with general properties.

Claims12

Dependent claims

A rear-projection display comprising a spatial modulation element, and a rear-projection screen on whose surface on a light-projected side an image formed by the spatial modulation element is projected so that the image is observed from an image-observed side opposite to the light-projected side,

wherein the rear-projection screen includes a first screen element for converting projected light from the spatial modulation element into substantially parallel light, and a second screen element for diffusing the substantially parallel light,
wherein the second screen element includes a lenticular lens array that is provided on the surface on the light-projected side and whose lengthwise direction is directed in a vertical direction, a diffusing layer provided at the image-observed side of the lenticular lens array, and a transparent layer provided between the lenticular lens array and the diffusing layer,
wherein a distance t1 between a light-projected-side surface of the diffusing layer and a focal plane of the lenticular lens array satisfies Formula II-1 below, and a distance t2 between an image-observed-side surface of the diffusing layer and the focal plane of the lenticular lens array satisfies Formula II-2 below:
Formula II-1:
t1 ≧ f1 Formula II-2:
t2 ≦ f1 × Pg/Pl
where f1 represents a distance between a valley of the lenticular lens array and the focal plane, Pg represents a pixel pitch on the screen, and P1 represents an array pitch of the lenticular lens array.

4 more elements

wherein the rear-projection screen includes a first screen element for converting projected light from the spatial modulation element into substantially parallel light, and a second screen element for diffusing the substantially parallel light,
wherein the second screen element includes a lenticular lens array that is provided on the surface on the light-projected side and whose length-wise direction is directed in a vertical direction, a diffusing layer provided at the image-observed side of the lenticular lens array, and a transparent layer provided between the lenticular lens array and the diffusing layer,
wherein a distance t1 between a light-projected-side surface of the diffusing layer and a focal plane of the lenticular lens array satisfies Formula II-1 below, and a distance t2 between an image-observed-side surface of the diffusing layer and the focal plane of the lenticular lens array satisfies Formula II-3 below:
Formula II-1:
t1 ≧ f1 Formula II-3:
t2 ≦ Pg/2/tan(γi)
where f1 represents a distance between a valley of the lenticular lens array and the focal plane, Pg represents a pixel pitch on the screen, and γi represents an in-layer equivalent angle in the transparent layer that is obtained by converting an observation angle γ at which a luminance of {fraction (1/10)} of that in a normal direction is obtained due to diffusion caused by the diffusing layer, and is expressed as Formula II-4 below:
Formula II-4:
γi = asin(sin(γ)/n)
where n represents a refractive index n of the transparent layer.

7 more elements

A rear-projection screen on whose surface on a light-projected side an image formed by a spatial modulation element is projected so that the image is observed from an image-observed side opposite to the light-projected side,

the rear-projection screen comprising:
a first screen element for converting projected light from the spatial modulation element into substantially parallel light;
and
a second screen element for diffusing the substantially parallel light,
wherein the second screen element includes a lenticular lens array that is provided on the surface on the light-projected side and whose length-wise direction is directed in a vertical direction, a diffusing layer provided at the image-observed side of the lenticular lens array;
and a transparent layer provided between the lenticular lens array and the diffusing layer,
wherein a distance t1 between a light-projected-side surface of the diffusing layer and a focal plane of the lenticular lens array satisfies Formula II-1 below, and a distance t2 between an image-observed-side surface of the diffusing layer and the focal plane of the lenticular lens array satisfies Formula II-6 below:
Formula II-1:
t1 ≧ f1 FormuLa II-6:
t2 ≦ 0.35/tan(γi)
where:
f1 represents a distance between a valley of the lenticular lens array and the focal plane, and γi represents an in-layer equivalent angle in the transparent layer that is obtained by converting an observation angle γ at which a luminance of {fraction (1/10)} of that in a normal direction is obtained due to diffusion caused by the diffusing layer, and is expressed as Formula II-7 below:
Formula 11-7:
γi = asin(sin(γ)/n)
where:
n represents a refractive index n of the transparent layer;
and
a unit of t1 is according to that of F1, and a unit of t2 is millimeters.

15 more elements

Dependencies are inferred from the claim text.

Rear-projection screen and rear-projection image display

Life of this patent

Rear-projection screen and rear-projection image display

Life of this patent

Abstract

Claims12