US 5,400,114 A · Rear-projection screen and a rear projection image display employing the rear-projection screen

Abstract

A rear-projection screen for a rear-projection image display comprising a Fresnel lens sheet (2) and a lenticular lens sheet (3), or a Fresnel lens sheet (2), a lenticular lens sheet (3) and a light absorbing sheet (4). The entrance surface (21) of the Fresnel lens sheet (2) or the entrance surface (41) of the light absorbing sheet (4) is formed by contiguously and vertically arranging a plurality of horizontally elongate lenticular lenses. The thickness of the Fresnel lens sheet (2) is approximately equal to that of the lenticular lens sheet (3). The entrance surface (31) and the exit surface (32) of the lenticular lens sheet (3) are formed by contiguously and horizontally arranging a plurality of vertically elongate lenticular lenses. Particles of a light diffusing material, which is essential to the prior art rear-projection screen, are not necessarily dispersed in the base sheet (30) of the lenticular lens sheet (3). The rear-projection image display provided with this rear-projection screen has satisfactory focusing characteristics and enhanced vertical directional characteristics and is capable of displaying an image in high brightness and high contrast.

Claims37

Dependent claims

A rear-projection screen for a rear-projection image display having a video source, comprising:

a Fresnel lens sheet disposed on the side of the video source;
and a lenticular lens sheet disposed on the viewing side:
wherein the Fresnel lens sheet has a first entrance surface formed by contiguously and vertically arranging a plurality of horizontally elongate lenticular lenses having a convex, vertical cross section convex toward the video source, and an exit surface having the shape of a convex Fresnel lens, and the lenticular lens sheet has a second entrance surface formed by contiguously and horizontally arranging a plurality of first vertically elongate lenticular lenses;
each of the horizontally elongate lenticular lenses forming the entrance surface of said Fresnel lens sheet having a convex, vertical cross section convex toward the video source, and meeting an inequality:
l.sub.0 .gtoreq.2l.sub.1
where l.sub.0 is the distance between the vertex of the convex, vertical cross section and a focal point on the optical axis where light rays are focused by a portion of the horizontally elongate lenticular lens around the optical axis, and l.sub.1 is the distance between the vertex of the convex, vertical cross section and a focal point on the optical axis where light rays are focused by a portion of the horizontally elongate lenticular lens remote from the optical axis.

3 more elements

A rear-projection screen for a rear-projection image display having a video source, comprising:

a Fresnel lens sheet disposed on the side of the video source;
and a lenticular lens sheet disposed on the viewing side;
wherein the Fresnel lens sheet has an entrance surface having the shape of a convex Fresnel lens, and an exit surface formed by vertically and contiguously arranging a plurality of horizontally elongate lenticular lenses, and the lenticular lens sheet has an entrance surface formed by horizontally and contiguously arranging a plurality of first vertically elongate lenticular lenses.

A rear-projection screen for a rear-projection image display having a video source, comprising:

a Fresnel lens sheet disposed nearest to the video source;
a lenticular lens sheet disposed next to the Fresnel lens sheet on the viewing side;
and a light absorbing sheet disposed next to the lenticular lens sheet on the viewing side;
wherein at least either the entrance surface or the exit surface has the shape of a Fresnel lens, the lenticular lens sheet has an entrance surface formed by contiguously and horizontally arranging a plurality of first vertically elongate lenticular lenses, and the light absorbing sheet has an entrance surface formed by contiguously and vertically arranging a plurality of horizontally elongate lenticular lenses.

1 more element

Dependencies are inferred from the claim text.

Rear-projection screen and a rear projection image display employing the rear-projection screen

Life of this patent

Rear-projection screen and a rear projection image display employing the rear-projection screen

Life of this patent

Abstract

Claims37