Rear projection screen for high ambient light environments having a pinhole area substantially equal to luminous area of the light source

Claim 2

A rear projection display system, comprising: a light source; means for directing light generated by said light source toward a display screen; said display screen comprising a matrix of small cells, each cell representing a display pixel which is selectively illuminated, each cell comprising: an electrically activated cell light scattering element, said element when a first operating mode for scattering light incident thereon from the light source, said element passing light therethrough without scattering when in a second operating mode; a cell lens element for focussing non-scattered light passing through said light scattering element at a focus point within a focal plane; a cell opaque screen portion having a pinhole aperture located at said focus point of said lens element; each cell having individual ones of said cell light scattering elements, cell lens elements and cell opaque screen portions; and wherein said pinhole aperture covers a pinhole area, said lamp defines a luminous area, and wherein said pinhole area is substantially equal to said luminous area of said lamp; and a driver system for selectively electrically activating said light scattering elements of said matrix of cells to selectively operate the respective cells in said first or second operating mode to modulate the intensity of light passing through said cells, wherein light passing through light scattering elements operating in said first mode is scattered in many directions and very little light passes through the pinhole to a viewer, and light passing through light scattering elements operating in said second operating mode is not scattered and focused through the pinhole, so as to form a desired image defined by said display pixels represented by the cells of the matrix.

Claim 3

The display system of claim 1 wherein said light scattering elements of said cells each comprise a polymer dispersed liquid crystal (PDLC) element.

Claim 4

The display system of claim 2 wherein said driver system selectively electrically activates said cells to modulate said light intensity at video rates.

Claim 5

The display system of claim 2 wherein said driver system selectively electrically activates said cells to modulate said light intensity at video rates.

Claim 6

The display system of claim 1 wherein said light source comprises a lamp element, and said means for directing light from said light source onto said screen includes a light reflector element.

Claim 7

The display system of claim 1 wherein said means for directing light from said light source onto said screen includes a light collimator for collimating light from the light source into a collimated beam to be directed onto said screen.

Claim 8

The display system of claim 6 wherein all of said cells comprising said matrix are identical.

Claim 9

The display system of claim 1 wherein said light source is a single lamp.

Claim 10

The display system of claim 8 wherein said lamp has a spherical luminous area.

Claim 11

The display system of claim 1 wherein each cell of said display screen covers a cell area, said pinhole covers a pinhole area comprising said cell area, and wherein said pinhole area is no more than 1% of said cell area.

Claim 12

The display system of claim 1 wherein said opaque screen includes an external screen surface facing a viewer, and said screen surface is black to minimize reflection of ambient light back to the viewer.

Claim 13

The display system of claim 1 wherein said pinhole aperture covers a pinhole area which is small in relation to a display screen cell area to minimize reflection of ambient light from said lens element back to a viewer.

Claim 14

The display system of claim 1 wherein the light directed toward the display screen is uncollimated, and wherein an inter-cell spacing of said cell lens elements across said display screen is constant, and an inter-cell spacing of said cell pinhole apertures is varied across said display screen.

Claim 15

The display system of claim 1 wherein the light directed toward the display screen is uncollimated, and wherein an inter-cell spacing of said cell pinhole apertures is constant, and an inter-cell spacing of said cell lens elements is varied across said screen.

Claim 16

A rear projection display system, comprising: a lamp for generating display illumination light; a reflector for directing light generated by said light source toward a light collimator; said light collimator for collimating incident light from said lamp and directing the collimated light onto a display screen; said display screen comprising a matrix of small cells, each cell representing a display pixel which is selectively illuminated, each cell comprising: an electrically activated cell light scattering element, said element when in a first operating mode for scattering light incident thereon from the light source, said element passing light therethrough without scattering when in a second operating mode; a cell lens element for focussing non-scattered light passing through said light scattering element at a focus point within a focal plane; a cell opaque screen portion having a pinhole aperture located at said focus point of said lens element, wherein said opaque screen portion includes an external screen surface facing a viewer, and said screen surface is black to minimize reflection of ambient light back to the viewer; each cell having individual ones of said cell light scattering elements, cell lens elements and cell opaque screen portions; and a driver system for selectively electrically activating said light scattering elements of said matrix of cells to selectively operate the respective cells in said first or second operating mode to modulate the intensity of light passing through said cells, wherein light passing through light scattering elements operating in said first mode is scattered in many directions and very little light passes through the pinhole to a viewer, and light passing through light scattering elements operating in said second operating mode is not scattered and focused through the pinhole, so as to form a desired image defined by said display pixels represented by the cells of the matrix.

Claim 17

A rear projection display system, comprising: a lamp for generating display illumination light; a reflector for directing light generated by said light source toward a light collimator; said light collimator for collimating incident light from said lamp and directing the collimated light onto a display screen; said display screen comprising a matrix of small cells, each cell representing a display pixel which is selectively illuminated, each cell comprising: an electrically activated cell light scattering element, said element when in a first operating mode for scattering light incident thereon from the light source, said element passing light therethrough without scattering when in a second operating mode; a cell lens element for focussing non-scattered light passing through said light scattering element at a focus point within a focal plane; a cell opaque screen portion having a pinhole aperture located at said focus point of said lens element, wherein said opaque screen portion includes an external screen surface facing a viewer, and said screen surface is black to minimize reflection of ambient light back to the viewer; each cell having individual ones of said cell light scattering elements, cell lens elements and cell opaque screen portions; and a driver system for selectively electrically activating said light scattering elements of said matrix of cells to selectively operate the respective cells in said first or second operating mode to modulate the intensity of light passing through said cells, wherein light passing through light scattering elements operating in said first mode is scattered in many directions and very little light passes through the pinhole to a viewer, and light passing through light scattering elements operating in said second operating mode is not scattered and focused through the pinhole, so as to form a desired image defined by said display pixels represented by the cells of the matrix.

Claim 18

The display system of claim 15 wherein said light scattering elements of said cells each comprise a polymer dispersed liquid crystal (PDLC) element.

Claim 19

The display system of claim 15 wherein all of said cells comprising said matrix are identical.

Claim 20

The display system of claim 15 wherein said lamp has a small spherical luminous area.

Claim 21

The display system of claim 15 wherein said lamp is a high intensity lamp and said projection system is suited for high ambient light environments.

Claim 22

The display system of claim 15 wherein said pinhole aperture covers a pinhole area, said lamp defines a luminous area, and wherein said pinhole area is substantially equal to said luminous area of said lamp.

Claim 23

The display system of claim 15 wherein each cell of said display screen covers a cell area, said pinhole covers a pinhole area comprising said cell area, and wherein said pinhole area is no more than 1% of said cell area.

Claim 24

The display system of claim 15 wherein said pinhole aperture covers a pinhole area which is small in relation to a display screen cell area to minimize reflection of ambient light from said lens element back to a viewer.

Claim 25

A rear projection display system, comprising: a light source; means for directing light generated by said light source toward a display screen; said display screen comprising a matrix of small cells, each cell representing a display pixel which is selectively illuminated, each cell comprising: an electrically activated cell light scattering element, said element when a first operating mode for scattering light incident thereon from the light source, said element passing light therethrough without scattering when in a second operating mode; a cell lens element for focussing non-scattered light passing through said light scattering element at a focus point within a focal plane; a cell opaque screen portion having a pinhole aperture located at said focus point of said lens element, said opaque screen portion including an external screen surface facing a viewer, and wherein said screen surface is black to minimize reflection of ambient light back to the viewer; each cell having individual ones of said cell light scattering elements, cell lens elements and cell opaque screen portions; and a driver system for selectively electrically activating said light scattering elements of said matrix of cells to selectively operate the respective cells in said first or second operating mode to modulate the intensity of light passing through said cells, wherein light passing through light scattering elements operating in said first mode is scattered in many directions and very little light passes through the pinhole to a viewer, and light passing through light scattering elements operating in said second operating mode is not scattered and focused through the pinhole, so as to form a desired image defined by said display pixels represented by the cells of the matrix.

Claim 26

A rear projection display system, comprising: a light source; means for directing light generated by said light source toward a display screen; said display screen comprising a matrix of small cells, each cell representing a display pixel which is selectively illuminated, each cell comprising: an electrically activated cell light scattering element, said element when a first operating mode for scattering light incident thereon from the light source, said element passing light therethrough without scattering when in a second operating mode; a cell lens element for focussing non-scattered light passing through said light scattering element at a focus point within a focal plane; a cell opaque screen portion having a pinhole aperture located at said focus point of said lens element, said opaque screen portion including an external screen surface facing a viewer, and wherein said screen surface is black to minimize reflection of ambient light back to the viewer; each cell having individual ones of said cell light scattering elements, cell lens elements and cell opaque screen portions; and a driver system for selectively electrically activating said light scattering elements of said matrix of cells to selectively operate the respective cells in said first or second operating mode to modulate the intensity of light passing through said cells, wherein light passing through light scattering elements operating in said first mode is scattered in many directions and very little light passes through the pinhole to a viewer, and light passing through light scattering elements operating in said second operating mode is not scattered and focused through the pinhole, so as to form a desired image defined by said display pixels represented by the cells of the matrix.

Claim 27

A rear projection display system, comprising: a light source; means for directing light generated by said light source toward a display screen, wherein the light directed toward the display screen is uncollimated; said display screen comprising a matrix of small cells, each cell representing a display pixel which is selectively illuminated, each cell comprising: an electrically activated cell light scattering element, said element when a first operating mode for scattering light incident thereon from the light source, said element passing light therethrough without scattering when in a second operating mode; a cell lens element for focussing non-scattered light passing through said light scattering element at a focus point within a focal plane; a cell opaque screen portion having a pinhole aperture located at said focus point of said lens element; each cell having individual ones of said cell light scattering elements, cell lens elements and cell opaque screen portions; and wherein an inter-cell spacing of said cell lens elements across said display screen is constant, and an inter-cell spacing of said cell pinhole apertures is varied across said display screen; and a driver system for selectively electrically activating said light scattering elements of said matrix of cells to selectively operate the respective cells in said first or second operating mode to modulate the intensity of light passing through said cells, wherein light passing through light scattering elements operating in said first mode is scattered in many directions and very little light passes through the pinhole to a viewer, and light passing through light scattering elements operating in said second operating mode is not scattered and focused through the pinhole, so as to form a desired image defined by said display pixels represented by the cells of the matrix.

Claim 28

A rear projection display system, comprising: a light source; means for directing light generated by said light source toward a display screen, wherein the light directed toward the display screen is uncollimated; said display screen comprising a matrix of small cells, each cell representing a display pixel which is selectively illuminated, each cell comprising: an electrically activated cell light scattering element, said element when a first operating mode for scattering light incident thereon from the light source, said element passing light therethrough without scattering when in a second operating mode; a cell lens element for focussing non-scattered light passing through said light scattering element at a focus point within a focal plane; a cell opaque screen portion having a pinhole aperture located at said focus point of said lens element; each cell having individual ones of said cell light scattering elements, cell lens elements and cell opaque screen portions; and wherein an inter-cell spacing of said cell lens elements across said display screen is constant, and an inter-cell spacing of said cell pinhole apertures is varied across said display screen; and a driver system for selectively electrically activating said light scattering elements of said matrix of cells to selectively operate the respective cells in said first or second operating mode to modulate the intensity of light passing through said cells, wherein light passing through light scattering elements operating in said first mode is scattered in many directions and very little light passes through the pinhole to a viewer, and light passing through light scattering elements operating in said second operating mode is not scattered and focused through the pinhole, so as to form a desired image defined by said display pixels represented by the cells of the matrix.

Claim 29

A rear projection display system, comprising: a light source; means for directing light generated by said light source toward a display screen, wherein the light directed toward the display screen is uncollimated; said display screen comprising a matrix of small cells, each cell representing a display pixel which is selectively illuminated, each cell comprising: an electrically activated cell light scattering element, said element when a first operating mode for scattering light incident thereon from the light source, said element passing light therethrough without scattering when in a second operating mode; a cell lens element for focussing non-scattered light passing through said light scattering element at a focus point within a focal plane; a cell opaque screen portion having a pinhole aperture located at said focus point of said lens element; each cell having individual ones of said cell light scattering elements, cell lens elements and cell opaque screen portions; and wherein an inter-cell spacing of said cell pinhole apertures is constant, and an inter-cell spacing of said cell lens elements is varied across said screen; and a driver system for selectively electrically activating said light scattering elements of said matrix of cells to selectively operate the respective cells in said first or second operating mode to modulate the intensity of light passing through said cells, wherein light passing through light scattering elements operating in said first mode is scattered in many directions and very little light passes through the pinhole to a viewer, and light passing through light scattering elements operating in said second operating mode is not scattered and focused through the pinhole, so as to form a desired image defined by said display pixels represented by the cells of the matrix.

Claim 30

A rear projection display system, comprising: a light source; means for directing light generated by said light source toward a display screen, wherein the light directed toward the display screen is uncollimated; said display screen comprising a matrix of small cells, each cell representing a display pixel which is selectively illuminated, each cell comprising: an electrically activated cell light scattering element, said element when a first operating mode for scattering light incident thereon from the light source, said element passing light therethrough without scattering when in a second operating mode; a cell lens element for focussing non-scattered light passing through said light scattering element at a focus point within a focal plane; a cell opaque screen portion having a pinhole aperture located at said focus point of said lens element; each cell having individual ones of said cell light scattering elements, cell lens elements and cell opaque screen portions; and wherein an inter-cell spacing of said cell pinhole apertures is constant, and an inter-cell spacing of said cell lens elements is varied across said screen; and a driver system for selectively electrically activating said light scattering elements of said matrix of cells to selectively operate the respective cells in said first or second operating mode to modulate the intensity of light passing through said cells, wherein light passing through light scattering elements operating in said first mode is scattered in many directions and very little light passes through the pinhole to a viewer, and light passing through light scattering elements operating in said second operating mode is not scattered and focused through the pinhole, so as to form a desired image defined by said display pixels represented by the cells of the matrix.

Claim 31

A rear projection display system, comprising: a lamp for generating display illumination light; a reflector for directing light generated by said light source toward a light collimator; said light collimator for collimating incident light from said lamp and directing the collimated light onto a display screen; said display screen comprising a matrix of small cells, each cell representing a display pixel which is selectively illuminated, each cell comprising: an electrically activated cell light scattering element, said element when in a first operating mode for scattering light incident thereon from the light source, said element passing light therethrough without scattering when in a second operating mode; a cell lens element for focussing non-scattered light passing through said light scattering element at a focus point within a focal plane; a cell opaque screen portion having a pinhole aperture located at said focus point of said lens element; each cell having individual ones of said cell light scattering elements, cell lens elements and cell opaque screen portions; and wherein said pinhole aperture covers a pinhole area, said lamp defines a luminous area, and wherein said pinhole area is substantially equal to said luminous area of said lamp; and a driver system for selectively electrically activating said light scattering elements of said matrix of cells to selectively operate the respective cells in said first or second operating mode to modulate the intensity of light passing through said cells, wherein light passing through light scattering elements operating in said first mode is scattered in many directions and very little light passes through the pinhole to a viewer, and light passing through light scattering elements operating in said second operating mode is not scattered and focused through the pinhole, so as to form a desired image defined by said display pixels represented by the cells of the matrix.

Claim 32

A rear projection display system, comprising: a lamp for generating display illumination light; a reflector for directing light generated by said light source toward a light collimator; said light collimator for collimating incident light from said lamp and directing the collimated light onto a display screen; said display screen comprising a matrix of small cells, each cell representing a display pixel which is selectively illuminated, each cell comprising: an electrically activated cell light scattering element, said element when in a first operating mode for scattering light incident thereon from the light source, said element passing light therethrough without scattering when in a second operating mode; a cell lens element for focussing non-scattered light passing through said light scattering element at a focus point within a focal plane; a cell opaque screen portion having a pinhole aperture located at said focus point of said lens element; each cell having individual ones of said cell light scattering elements, cell lens elements and cell opaque screen portions; and wherein said pinhole aperture covers a pinhole area, said lamp defines a luminous area, and wherein said pinhole area is substantially equal to said luminous area of said lamp; and a driver system for selectively electrically activating said light scattering elements of said matrix of cells to selectively operate the respective cells in said first or second operating mode to modulate the intensity of light passing through said cells, wherein light passing through light scattering elements operating in said first mode is scattered in many directions and very little light passes through the pinhole to a viewer, and light passing through light scattering elements operating in said second operating mode is not scattered and focused through the pinhole, so as to form a desired image defined by said display pixels represented by the cells of the matrix.