Projection screen and system

Claim 2

A projection screen comprising: a plate of transparent material having a generally upright reference plane, a front face facing the viewer, and a back face on the opposite side therefrom, a plurality of generally horizontal optical wedges forming said front face, each of said wedges comprising a transmission surface and an offset surface, the transmission surfaces constituting bent surfaces having a substantially horizontal line disposed vertically from the mid-elevation of the respective transmission surface, and between the top and bottom edges of the respective wedge, on both sides of which line the distance of the transmission surface from the reference plane continuously changes, the direction of change being the same on both sides thereof, and each of the offset surfaces extending between the top and bottom edges of its two adjacent transmission surfaces, the optical wedges being parallel to each other and to the reference plane, and a plurality of axially extending curved surfaces forming said back face, the curved surfaces extending parallel to each other and to the reference plane and each comprising an axial segment of a circular cylinder and being generally normal in plan view to the wedges, whereby the optical wedges refractively direct an incident light beam away from the normal to the reference axis in a generally vertical pattern, and the back face causes an angular fanning out of the beam emergent from the front face as viewed in a generally horizontal plane.

Claim 3

A projection screen according to claim 1 in which a reflective coating is formed on the back face whereby the fanning out is caused by reflection on the back face, the curved surfaces being concave as they face toward the front face.

Claim 4

A projection screen according to claim 2 in which the front face is frosted to a diffusive but primarily transmissive condition.

Claim 5

A projection screen according to claim 2 in which the reflective coating is metallic and adherent to the back face.

Claim 6

A projection screen according to claim 2 in which the reflective coating comprises a flexible metallized adhesive body adherent to the back face.

Claim 7

A projection screen according to claim 5 in which the front face is frosted to a diffusive but primarily transmissive condition.

Claim 8

A projection screen according to claim 2 in which the region of each of the optical wedges at and near the members of that set of intersections of the transmission surface and offset surfaces which is the farther of the sets of said intersections from the reference axis, is diffusely reflecting, and the remainder of each of the transmission surfaces is smooth and clear.

Claim 9

A projection screen according to claim 1 in which the curved surfaces are convex as they face toward the front face and the rear face is nonopaque, whereby the fanning out is caused by refraction at the back face.

Claim 10

A projection screen according to claim 8 in which the front face is frosted to a diffusive but primarily transmissive condition.

Claim 11

A projection screen according to claim 8 in which the region of each of the optical wedges at and near the members of that set of intersections of the transmission surfaces and offset surfaces which is the farther of the sets of said intersections from the reference axis, is diffusely reflecting, and the remainder of each of the transmission surfaces is smooth and clear.

Claim 12

A projection screen according to claim 1 in which the transmission surfaces are cylindrically arcUate.

Claim 13

A projection screen according to claim 1 in which the transmission surfaces are convex.

Claim 14

A projection screen according to claim 1 in which the transmission surfaces are concave.

Claim 15

A projection screen according to claim 1 in which each of the transmission surfaces is cylindrically arcuate, with the respective center of curvature at an elevation other than that of said midelevation of the respective wedge, and between the elevation of said top and bottom edges of the respective wedge.

Claim 16

A projection screen according to claim 14 in which a reflective coating is formed on the back face whereby the fanning out is caused by reflection at the back face, the curved surfaces being concave as they face toward the front face.

Claim 17

A projection screen according to claim 15 in which the transmission surfaces are frosted to a diffusive but primarily transmissive condition.

Claim 18

A projection installation comprising: a projector having a projection axis generally aligned with an audience direction, and a screen comprising: a plate of transparent material having a generally upright reference plane, a front face facing the viewer, and a back face on the opposite side therefrom, a plurality of generally horizontal optical wedges forming said front face, each of said wedges comprising a transmission surface and an offset surface, the transmission surfaces constituting bent surfaces having a substantially horizontal line disposed vertically from the midelevation of the respective transmission surface, and between the top and bottom edges of the respective wedge, on both sides of which line the distance of the transmission surface from the reference plane continuously changes, the direction of change being the same on both sides thereof, and each of the offset surfaces extending between the top and bottom edges of its two adjacent transmission surfaces, the optical wedges being parallel to each other and to the reference plane, and a plurality of axially extending curved surfaces forming said back face, the curved surfaces extending parallel to each other and to the reference plane and each comprising an axial segment of a circular cylinder and being generally normal in plan view to the wedges, whereby the principal property of the optical wedges is to refractively direct a light beam away from the normal to the reference axis in a generally vertical pattern, and the principal property of the back face is to cause an angular fanning out of the beam emergent from the front face as viewed in a generally horizontal plane.

Claim 19

A projection installation comprising: a projector having a projection axis generally aligned with an audience direction, and a screen comprising: a plate of transparent material having a generally upright reference plane, a front face facing the viewer, and a back face on the opposite side therefrom, a plurality of generally horizontal optical wedges forming said front face, each of said wedges comprising a transmission surface and an offset surface, the transmission surfaces constituting bent surfaces having a substantially horizontal line disposed vertically from the midelevation of the respective transmission surface, and between the top and bottom edges of the respective wedge, on both sides of which line the distance of the transmission surface from the reference plane continuously changes, the direction of change being the same on both sides thereof, and each of the offset surfaces extending between the top and bottom edges of its two adjacent transmission surfaces, the optical wedges being parallel to each other and to the reference plane, and a plurality of axially extending curved surfaces forming said back face, the curved surfaces extending parallel to each other and to the reference plane and each comprising an axial segment of a circular cylinder and being generally normal in plan view to the wedges, whereby the principal property of the optical wedges is to refractively direct a light beam away from the normal to the reference axis in a generally vertical pattern, and the principal property of the back face is to cause an angular fanning out of the beam emergent from the front face as viewed in a generally horizontal plane.

Claim 20

A projection installation according to claim 17 in which the projector and the audience are on the same side of the screen, and in which a reflective coating is formed on the back face whereby the fanning out is caused by reflection at the back face, the curved surfaces being concave as they face toward the front face.

Claim 21

A projection installation according to claim 18 in which the front face is frosted to a diffusive but primarily transmissive condition.

Claim 22

A projection installation according to claim 18 in which the transmission surfaces are concave and cylindrically arcuate.

Claim 23

A projection installation according to claim 17 in which the projector and the audience are on opposite sides of the screen and in which the curved surfaces are convex as they face toward the front face and the rear face is nonopaque, whereby the fanning out is caused by refraction at the back face.

Claim 24

A projection installation according to claim 21 in which the front face is frosted to a diffusive but primarily transmissive condition.

Claim 25

A projection installation according to claim 21 in which the transmission surfaces are concave and cylindrically arcuate.

Claim 26

A projection installation according to claim 17 in which each of the transmission surfaces is cylindrically arcuate, with the respective center of curvature at an elevation other than that of the said midelevation of the respective wedge, and between the elevation of said top and bottom edges of the respective wedge.

Claim 27

A projection screen comprising: a plate of transparent material having a generally upright reference axis, a front face facing the viewer, and a back face on the opposite side therefrom, a plurality of generally horizontal optical wedges forming said front face, each of said wedges comprising a flat planar transmission surface and an offset surface, the transmission surfaces forming acute angles with the reference axis, and each of the offset surfaces extending between the top and bottom edges of its two adjacent transmission surfaces, the optical wedges being parallel to each other, and a plurality of axially extending curved surfaces forming said back face, the curved surfaces extending parallel to each other and each comprising an axial segment of a circular cylinder and being generally normal in plan view to the wedges, whereby the principal property of the optical wedges is to refractively direct a light beam away from the normal to the reference axis, and the principal property of the back face is to cause an angular fanning out of the beam emergent from the front face as viewed in a generally horizontal plane.

Claim 28

A projection screen comprising: a plate of transparent material having a generally upright reference axis, a front face facing the viewer, and a back face on the opposite side therefrom, a plurality of generally horizontal optical wedges forming said front face, each of said wedges comprising a flat planar transmission surface and an offset surface, the transmission surfaces forming acute angles with the reference axis, and each of the offset surfaces extending between the top and bottom edges of its two adjacent transmission surfaces, the optical wedges being parallel to each other, and a plurality of axially extending curved surfaces forming said back face, the curved surfaces extending parallel to each other and each comprising an axial segment of a circular cylinder and being generally normal in plan view to the wedges, whereby the principal property of the optical wedges is to refractively direct a light beam away from the normal to the reference axis, and the principal property of the back face is to cause an angular fanning out of the beam emergent from the front face as viewed in a generally horizontal plane.

Claim 29

A projection screen according to claim 25 in which a reflective coating is formed on the back face whereby the fanning out is caused by reflection at the back face, the curved surfaces being concave as they face toward the front face.

Claim 30

A projection screen according to claim 26 in which the front face is frosted to a diffusive but primarily transmissive condition.

Claim 31

A projection screen according to claim 26 in which the reflective coating is metallic and adherent to the back face.

Claim 32

A projection screen according to claim 26 in which the reflective coating comprises a flexible metallized adhesive body adherent to the back face.

Claim 33

A projection screen according to claim 29 in which the front face is frosted to a diffusive but primarily transmissive condition.

Claim 34

A projection screen according to claim 26 in which the region of each of the optical wedges at and near the members of that set of intersections of the transmission surfaces and offset surfaces which is the farther of the sets of said intersections from the reference axis, is diffusely reflecting, and the remainder of each of the transmission surfaces is smooth and clear.

Claim 35

A projection screen according to claim 25 in which the curved surfaces are convex as they face toward the front face and the rear face is nonopaque, whereby the fanning out is caused by refraction at the back face.

Claim 36

A projection screen according to claim 32 in which the front face is frosted to a diffusive but primarily transmissive condition.

Claim 37

A projection screen according to claim 32 in which the region of each of the optical wedges at and near the members of that set of intersections of the transmission surfaces and offset surfaces which is the farther of the sets of said intersections from the reference axis, is diffusely reflecting, and the remainder of each of the transmission surfaces is smooth and clear.

Claim 38

A projection installation comprising: a projector having a projection axis generally aligned with an audience direction, and a screen comprising: a plate of transparent material having a generally upright reference axis, a front face facing the viewer, and a back face on the opposite side therefrom, a plurality of generally horizontal optical wedges forming said front face, each of said wedges comprising a flat planar transmission surface and an offset surface, the transmission surfaces forming acute angles with the reference axis, and each of the offset surfaces extending between the edges of its two adjacent transmission surfaces, the optical wedges being parallel to each other, and a plurality of axially extending curved surfaces forming said back face, the curved surfaces extending parallel to each other and each comprising an axial segment of a circular cylinder and being generally normal in plan view to the wedges, whereby the principal Property of the optical wedges is to refractively direct a light beam away from the normal to the reference axis, and the principal property of the back face is to cause an angular fanning out of the beam emergent from the front face as viewed in a generally horizontal plane.

Claim 39

A projection installation comprising: a projector having a projection axis generally aligned with an audience direction, and a screen comprising: a plate of transparent material having a generally upright reference axis, a front face facing the viewer, and a back face on the opposite side therefrom, a plurality of generally horizontal optical wedges forming said front face, each of said wedges comprising a flat planar transmission surface and an offset surface, the transmission surfaces forming acute angles with the reference axis, and each of the offset surfaces extending between the edges of its two adjacent transmission surfaces, the optical wedges being parallel to each other, and a plurality of axially extending curved surfaces forming said back face, the curved surfaces extending parallel to each other and each comprising an axial segment of a circular cylinder and being generally normal in plan view to the wedges, whereby the principal Property of the optical wedges is to refractively direct a light beam away from the normal to the reference axis, and the principal property of the back face is to cause an angular fanning out of the beam emergent from the front face as viewed in a generally horizontal plane.

Claim 40

A projection installation according to claim 35 in which the projector and the audience are on the same side of the screen, and in which a reflective coating is formed on the back face whereby the fanning out is caused by reflection at the back face, the curved surfaces being concave as they face toward the front face.

Claim 41

A projection installation according to claim 36 in which the front face is frosted to a diffusive but primarily transmissive condition.

Claim 42

A projection installation according to claim 35 in which the projector and the audience are on opposite sides of the screen and in which the curved surfaces are convex as they face toward the front face and the rear face is nonopaque, whereby the fanning out is caused by refraction at the back face. 39 A projection installation according to claim 38 in which the front face is frosted to a diffusive but primarily transmissive condition.