Luminaire device

• US 5,594,830 A
• Filed: 06/07/1995
• Issued: 01/14/1997
• Est. Priority Date: 03/23/1992
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Company
• Inventors: Emmons, Robert M., Holman, Robert L., Winston, Roland, Jacobson, Benjamin A.
• Primary Examiner(s): Bovernick, Rodney B.
• Assistant Examiner(s): Palmer, Phan T. H.
• Application Number:
  US08/486,784
• Time in Patent Office: 587 Days
• Field of Search: 385/146, 385/147, 385/140, 385/129, 385/130, 385/131, 385/43, 385/901, 359/48, 359/50, 359/599, 359/833, 359/834, 362/19, 362/31, 362/32
• US Class Current: 385/146
• CPC Class Codes: F21V 5/02 of prismatic shape F21V5/04 takes precedence
• CPC Class Codes: G02B 6/0001 specially adapted for lighting devices or systems lighting or signalling on vehicles using light guides B60Q1/00; lighting devices for vehicle dashboards B60Q3/10; lighting devices for vehicle interior using light guides B60Q3/62; lighting devices mounted on the vehicle rear part using light guides F21S43/235; measuring arrangements having light conducting pointers G01D13/265; illumination of liquid crystal displays G02F1/1336; illuminated signs G09F13/00
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02B 6/4298 coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/13355 Polarising beam splitters [PBS]
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: G09F 13/00 Illuminated signs; Luminous advertising G09F9/00, G09F11/00 take precedence; control of displays in general using static means to present variable information G09G
• CPC Class Codes: G09F 13/0409 Arrangements for homogeneous illumination of the display surface, e.g. using a layer having a non-uniform transparency arrangements of reflectors G09F13/14
• CPC Class Codes: G09F 2013/05 indicating exit way or orientation
• CPC Class Codes: G09F 2013/1827 Prismatic window
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

An optical device for collecting light and selectively outputting or concentrating the light. A wedge layer has an optical index of refraction n₁, and top, bottom and side surfaces intersecting to define an angle of inclination φ. A back surface spans the top, bottom and side surface. A first layer is coupled to the bottom surface of the layer and has an index of refraction n₂. The first layer index n₂ causes light input through the back surface of the layer to be preferentially output into the first layer. A second layer is coupled to the bottom of the first layer and selectively causes output of light into ambient. Additional layers, such as a light polarization layer, a polarization converting layer and a post LCD diffuser layer can be used to make preferential use of polarized light or diffuse light having passed through the LCD layer to enhance viewing of the output light.

Claims

1. An optical device for operating on light from a source and for selectively outputting light to a viewer, comprising:

a wedge-shaped base layer having an optical index of refraction n₁ and a first and a second surface, said base layer further including a back surface spanning said first and second surfaces, and the light exiting said base layer when the light being reflected therein decreases its angle relative to a normal to said second surface at a point of incidence and achieves an angle of incidence less than. a critical angle θ

_c relative to the normal at the point of incidence on said second surface;

first layer means including a layer having index n₂ less than n₁ disposed beyond said second surface relative to said base layer and for enabling light to enter into and pass across said first layer means after output from said base layer when the light in said base layer achieves the angle of incidence less than the critical angle θ

_c characteristic of an interface between the base layer and said first layer means of index n₂ ;

second layer means for preferably outputting light of a first polarization state compared to a second polarization state, said second layer means being disposed beyond said second surface relative to said base layer and said second layer means further able to reflect at least part of the light having the second polarization state; and

light redirecting means at least one of overlying and underlying said first layer means, said redirecting means allowing transmission of light thereacross its thickness and for redirecting light output from said first layer means.

2. The optical device as defined in claim 1 further including a liquid crystal display layer and light diffuser means for diffusing light output from said liquid crystal layer.

3. The optical device as defined in claim 1 wherein said light redirecting means includes at least one of a faceted layer, isotropic multi-planar layers and a multi-layer dielectric coating.

4. The optical device as defined in claim 1 wherein said light redirecting means acts to collimate the light over a controlled angular range.

5. The optical device as defined in claim 1 where said second layer means for preferably outputting light is disposed at least one of (a) between said liquid crystal layer and said base layer and (b) further from said base layer then said liquid crystal display layer.

6. The optical device as defined in claim 1 further including converting means for changing light of the second polarization state to the first polarization state.

7. An optical device for operating on light from a source and for selectively outputting light to a viewer, comprising:

a base layer having an optical index of refraction n₁ and a first and a second surface, said base layer further including a back surface spanning said first and second surfaces, and the light exiting said base layer when the light contained therein decreases its angle relative to a normal to said second surface at the point of light incidence and achieves an angle of incidence less than a critical angle θ

_c relative to the normal at the point of light incidence on said second surface;

first layer means including a layer having index n₂ less than n₁ disposed beyond said second surface relative to said base layer and for enabling light to enter into and pass across said first layer means after output from said base layer when the light in said base layer achieves the angle of incidence less than the critical angle θ

_c characteristic of an interface between the base layer and said first layer means of index n₂ ;

first light redirecting means for operating on light having passed through said base layer and for redirecting the light through said base with the light also traversing said first redirecting means;

second light redirecting means for operating on light having passed through said base layer and said first redirecting means and for controlling the angular range of the light output from said optical device; and

means for preferably outputting light of a first polarization state compared to a second polarization state and said means for preferably outputting light reflects at least part of the light having the second polarization state.

8. The optical device as defined in claim 7 further including converting means for changing light of the second polarization state to light of the first polarization state.

9. The optical device as defined in claim 8 wherein said converting means reflects at least part of the light having the second polarization state and is disposed at least one of (a) between said liquid crystal layer and said base layer and (b) further from said first surface than said second surface with said liquid crystal layer disposed nearer said base layer first surface.

10. The optical device as defined in claim 8 wherein said converting means comprises a matching layer providing a preferred polarization state for said liquid crystal layer.

11. The optical device as defined in claim 9 wherein said converting means comprises a birefringent layer.

12. The optical device as defined in claim 7 further including light diffuser means for diffusing light output from said base layer and broadening the light over an angular range for the viewer.

13. The optical device as defined in claim 12 wherein said light diffuser means comprises at least on of (a) a transverse diffuser and (b) a parallel diffuser.

14. The optical device as defined in claim 7 wherein said first light redirecting means comprises at least one of a faceted layer, isotropic multi-planar layers, a multi-layer dielective coating, a lens and a curved reflector.

15. The optical device as defined in claim 7 wherein said base layer comprises at least one of a wedge-shaped layer, a disk, an oblate shape, a parallelpiped and a cylinder.

16. The optical device as defined in claim 7 wherein at least one of said second light redirecting means and said first layer means include an air gap.

17. An optical device for operating on light from a source and for selectively outputting light to a viewer, comprising:

a base layer having an optical index of refraction n₁ and a first and a second surface, said base layer further including a back surface spanning said first and second surfaces, and the light exiting said base layer when the light being reflected therein decreases its angle relative to a normal to said second surface at the point of light incidence and achieves an angle of incidence less than a critical angle θ

_c relative to the nominal at the point of light incidence on said second surface;

first layer means including a layer having index n₂ less than n₁ disposed beyond said second surface relative to said base layer and for enabling light to enter and pass across said first layer means after output from said base layer when the light in said base layer achieves the angle of incidence less than the critical angle θ

_c characteristic of an interface between the base layer and said first layer means of index n₂ ;

light redirecting means for operating on light having passed through said base layer and said first layer means and for controlling the angular range of the light output from said optical device;

means for preferably outputting light of a first polarization state compared to a second polarization state and reflecting at least part of the light having the second polarization state; and

a liquid crystal display layer positioned to receive the light output from said light redirecting means.

18. The optical device as defined in claim 17 further including converting means for changing light of the second polarization state to light of the first polarization state.

19. The optical device as defined in claim 18 wherein said converting means reflects at least part of the light having the second polarization state and is disposed at least one of (a) between said liquid crystal layer and said base layer and (b) further from said first surface than said second surface with said liquid crystal layer disposed nearer said base layer first surface than said second surface.

20. The optical device as defined in claim 19 wherein said convening means comprises a matching layer providing a preferred polarization state for said liquid crystal layer.

21. The optical device as defined in claim 20 wherein said matching layer is disposed between said base layer and said liquid crystal layer and both of said layers are disposed nearer said second surface than said first surface.

22. The optical device as defined in claim 21 further including means for preferably outputting light of a first polarization state compared to a second polarization state, said means for preferably outputting light being disposed nearer said first surface than said second surface.

23. The optical device as defined in claim 19 wherein said converting means comprises a birefringent layer.

24. The optical device as defined in claim 17 wherein said light redirecting means is disposed nearer said first surface then said second surface and further from said base layer than said means for preferably outputting light.

25. The optical device as defined in claim 17 wherein said light redirecting means comprises at least one of (a) a reflective layer able to reflect light and (b) a transmissive layer able to modify the angular distribution of light passing therethrough.

26. The optical device as defined in claim 17 further including light diffuser means for diffusing light output from said liquid crystal display layer and broadening the light over an angular range for the viewer.

27. The optical device as defined in claim 17 wherein said means for preferably outputting light is disposed at least one of (a) between said liquid crystal display layer and said base layer and (b) further from said base layer than said liquid crystal display layer.

28. The optical device as defined in claim 17 wherein said base layer comprises at least one of a wedge-shaped layer, a disk, an oblate shape, a parallelpiped and a cylinder.

29. The optical device as defined in claim 17 wherein said light diffuser means comprises at least one of (a) a transverse diffuser and (b) a parallel diffuser.

30. An optical device for operating on light from a source and for selectively outputting light to a viewer, comprising:

a base layer having an optical index of refraction n₁ and a first and a second surface, said base layer further including a back surface spanning said first and second surfaces, and the light exiting said base layer when the light being reflected therein decreases its angle relative to a normal to said second surface at the point of incidence and achieves an angle of incidence less than a critical angle θ

_c relative to the normal at the point of incidence on said second surface;

first layer means including a layer having index n₂ less than n₁ disposed beyond said second surface relative to said base layer and for enabling light to enter and pass across said first layer means after output from said base layer when the light in said base layer achieves the angle of incidence less than the critical angle θ

_c characteristic of an interface between the base layer and said first layer means of index n₂ ;

second layer means for preferably outputting light of a first polarization state compared to a second polarization state, said second layer means being disposed beyond said second surface relative to said base layer and said second layer means further able to reflect at least part of the light having the second polarization state; and

a liquid crystal display layer positioned to receive the light of first polarization state and output the light to the viewer.

31. The optical device as defined in claim 30 further including light redirecting means for operating on light having passed through said base layer and said first layer means and also for controlling the angular range of the light output from said optical device.

32. The optical device as defined in claim 31 wherein said light redirecting means comprises at least one of (a) a reflective layer able to reflect light and (b) a transmissive layer able to modify the angular distribution of light passing therethrough.

33. The optical device as defined in claim 30 further including light diffuser means for diffusing light output from said liquid crystal layer.

34. The optical device as defined in claim 30 where said second layer means for preferably outputting light is disposed at least one of (a) between said liquid crystal layer and said base layer and (b) further from said base layer then said liquid crystal display layer.

35. The optical device as defined in claim 30 further including converting means for changing light of the second polarization state to the first polarization state.

36. An optical device for collecting light from a source and outputting the light, comprising:

a first layer having an optical index of refraction n₁ said layer having a back surface and first and second surfaces spanning said back surface;

at least one second layer with an optical index of refraction n₂ and light being input through said back surface of said first layer entering and crossing through said second layer when the light being reflected in said first layer achieves an angle of reflection less than the critical angle of incidence θ

_c relative to a normal with said second surface at the point of incidence, the θ

_c being characteristic of the interface between said first layer and said second layer;

third layer means disposed adjacent said at least one second layer acting cooperatively with said first layer and said at least one second layer to control angular distribution of the light of said optical device and for outputting the light from said optical device after passing across said third layer means; and

a diffuser layer at least one of (a) disposed between said first layer and a source of light for said optical device, (b) beyond said first layer relative to said base layer and (c) beyond said third layer means relative to said second layer with said diffuser layer providing broadened light within an angular distribution.

37. The optical device as defined in claim 36 further including means for preferably outputting light of first polarization state relative to a second polarization state, said means for preferably outputting light able to reflect at least part of the light having the second polarization state.

38. The optical device as defined in claim 37 further including converting means for changing light of the second polarization to the first polarization state.

39. The optical device as defined in claim 36 further including a display layer disposed between said base layer and said diffuser layer.

40. The optical device as defined in claim 36 wherein said base layer comprises at least one of a wedge-shaped layer, a disk, an oblate shape, a parallelpiped and a cylinder.

41. An optical device for operating on light from a source and for selectively outputting light to a viewer, comprising:

a base layer having an optical index of refraction n₁ and a first and second surface, said base layer further including a back surface spanning said first and second surfaces, and the light exiting said base layer when the light being reflected therein decreases its angle relative to a normal to at least one of said first and second surfaces at the point of light incidence and achieves an angle of incidence less than a critical angle θ

_c relative to the normal at the point of light incidence on said surfaces;

first layer means of index of refraction n₂ disposed beyond at least one of said first and second surfaces relative to said base layer and for enabling light to enter and pass across said first layer means after output from said base layer when the light in said base layer achieves the angle of incidence less than the critical angle θ

_c characteristic of an interface between said base layer and said first layer;

second layer means for preferably outputting light of a first polarization state compared to a second polarization state, said second layer means disposed beyond at least one of said first and second surfaces relative to said base layer and said second layer means further enabling reflection of at least part of the light having the second polarization state;

light control layer means for at least one of redirecting and diffusing light output from said first layer means, thereby providing light of controlled angular distribution; and

imaging layer means for forming an image from the light of the first polarization state for display to the viewer.

42. The optical device as defined in claim 41 further including converting means for changing light of the second polarization state to the first polarization state.

43. The optical device as defined in claim 42 wherein said convening means is disposed at least one of (a) between said liquid crystal layer and said base layer and (b) further from said second surface relative to said first surface with said liquid crystal layer disposed further said first surface relative to said second surface.

44. The optical device as defined in claim 41 wherein said light control layer means for redirecting light comprises a faceted layer for controlling the angular distribution of light output from said optical device.

45. The optical device as defined in claim 41 wherein said light control layer means for diffusing light is disposed at least one of (a) between said base layer and said imaging layer and (b) between the viewer and said imaging layer.

46. The optical device as defined in claim 41 wherein said base layer comprises at least one of a wedge-shaped layer, a disk, an oblate shape, a parallelpiped and a cylinder.

47. The optical device as defined in claim 41 wherein said imaging layer comprises at least one of a transparent display, a holographic image, a liquid crystal layer and a CCD layer.

48. The optical device as defined in claim 41 further including antireflection layers to reduce scattering.

49. The optical device as defined in claim 41 wherein said light control layer means includes a faceted layer of variable facet angles.

50. The optical device as defined in claim 41 wherein said second layer means is selected from the group consisting of an optical interference layer, a Brewster stack, a combination of the interference coating and the Brewster stack, a roughened surface, specular reflection layer, a dichroic layer, and a birefringent layer.

51. An optical device for operating on light from a source and for selectively outputting light to a viewer, comprising;

a base layer having an optical index of refraction n₁ and a first and a second surface with said base layer further including a back surface spanning said first and second surfaces, and the light exiting said base layer when the light achieves an angle of incidence less than a critical angle θ

_c relative to a normal at the point of light incidence on one of said first and second surfaces;

first layer means at least one of disposed above said first surface and below said second surface relative to said base layer and having an optical index of refraction n₂ for allowing transmission of light received from said base layer, the light being output from said base layer upon achieving the θ

_c characteristic of the interface between said base layer and said first layer means;

second layer means for preferably outputting light of a first polarization state compared to a second polarization state, said second layer means disposed beyond said second surface relative to said base layer and said second layer means further enabling reflection of at least part of the light having the second polarization state;

a liquid crystal display layer positioned to receive the light of first polarization state; and

light diffuser means for diffusing light output from said first layer means and said liquid crystal display layer to broaden the light in a controlled angular distribution thereby outputting light to the viewer without distorting image quality.

52. The optical device as defined in claim 51 further including converting means for changing light of the second polarization state to light of the first polarization state.

53. The optical device as defined in claim 52 wherein said converting means is disposed at least one of (a) between said liquid crystal display layer and said base layer and (b) further from said first surface than said second surface with said liquid crystal display layer disposed further from said second surface than said first surface.

54. The optical device as defined in claim 51 further including light redirecting means for operating on light output from said base layer for providing angular control of light output to the viewer.

55. The optical device as defined in claim 54 wherein said light redirecting means comprises at least one of (a) a reflective layer able to reflect light and (b) a transmissive layer able to modify the angular distribution of light passing therethrough.

56. The optical device as defined in claim 51 wherein said means for preferably outputting light is disposed at least one of (a) between said liquid crystal display layer and said base layer and (b) further from said base layer then said liquid crystal display layer.

57. The optical device as defined in claim 51 wherein said base layer comprises at least one of a wedge-shaped layer, a disk, an oblate shape, a parallelpiped and a cylinder.

58. An optical device for operating on light from a source and for selectively outputting light to a viewer, comprising:

a base layer having an optical index of refraction n₁ and a first and a second surface, said base layer further including a back surface spanning said first and second surfaces and the light exiting said base layer when the light achieves an angle of incidence less than a critical angle θ

_c relative to a nominal at the point of incidence on said second surface;

first layer means at least one of disposed beyond said first surface relative to said base layer and beyond said second layer surface relative to said base layer and having an optical index of refraction n₂ for allowing transmission of light received from said base layer, the light being output from said base layer upon achieving the θ

_c characteristic of the interface between said base and said first layer means;

second layer means for preferably transmitting light of a first polarization state relative to a second polarization state and reflects at least a portion of the light of second polarization state, said second layer means disposed at least one of (a) further from said first surface than said first layer means;

(b) nearer said first surface than said second surface and said first layer means relative to said base layer;

(c) nearer said second surface than said first surface but further from said base layer than said first layer means; and

(d) nearer said second surface than said first layer means;

light redirecting means at least one of overlying and underlying said first layer means for operating on the light reflected by said second layer means and redirecting it back toward said second layer means;

third layer means for convening at least part of the light of the second polarization state to light of the first polarization state; and

a display layer positioned to receive the light of first polarization state output from said third layer means.

59. The optical device as defined in claim 58 wherein said means for preferably transmitting light is disposed at least one of (a) between said liquid crystal display layer and said base layer and (b) further from said base layer then said liquid crystal display layer.

60. The optical device as defined in claim 58 wherein said third layer means for converting light is disposed at least one of (a) between said liquid crystal layer and said base layer and (b) nearer said second surface than said first surface with said liquid crystal layer disposed nearer said first surface than said second surface.

61. The optical device as defined in claim 58 wherein said third layer means for converting comprises a matching layer providing a preferred polarization state for said liquid crystal layer.

62. The optical device as defined in claim 58 wherein said light redirecting means comprises at least one of (a) a reflective layer able to reflect light, (b) a transmissive layer able to modify the angular distribution of light passing therethrough, and (c) a faceted layer having a variable facet angle.

63. The optical device as defined in claim 58 wherein said display layer comprises at least one of (a) a liquid crystal layer, (b) a transparent display, (c) a hologram image embedded in a medium and (d) a CCD layer.

64. The optical device as defined in claim 58 further including light diffuser means for diffusing light output from said display layer and broadening the light in a controlled angular range to provide light to the viewer over a range of viewing angle.

65. The optical device as defined in claim 58 wherein said base layer comprises at least one of a wedge-shaped layer, a disk, an oblate shape, a parallelpiped and a cylinder.

66. An optical device for operating on light from a source and for selectively outputting light to a viewer, comprising:

a base layer having an optical index of refraction n₁, and a first and a second surface, said base layer further including a back surface spanning said first and second surfaces;

means for incrementally changing an angle of light propagation in said base layer of said optical device, the light achieving an angle of incidence less than a critical angle θ

_c relative to a normal to at least one of said first and second surfaces at the point of incidence, the light thereby exiting said base layer;

layer means for receiving the light from said base layer and preferably outputting light of a first polarization state compared to a second polarization state, said layer means including means for preferably passing said light of first polarization state and reflecting at least part of the light of second polarization state and said layer means further including converting means for changing said light of second polarization state to said light of first polarization state; and

a liquid crystal display layer positioned to receive said light of first polarization state.

67. The optical device as defined in claim 66 wherein the reflected light of second polarization state follows a collimated path.

68. The optical device as defined in claim 66 wherein said means for incrementally changing light angle comprises a changing index of refraction in said base layer.

69. The optical device as defined in claim 66 wherein said means for incrementally changing the angle of light comprises a nonlinear shape of said base layer.

70. The optical device as defined in claim 66 further including light diffuser means for diffusing light output from said layer means and said liquid crystal display layer to broaden the light in a controlled angular distribution in a plane thereby outputting light to a viewer over a range of viewing angle without distorting image quality.

71. The optical device as defined in claim 66 wherein said means for incrementally changing angle includes means for causing an angular change of light per reflection cycle of less than (4×

(arc sin(h/L)) where h is thickness of the base layer wherein the light is input and L is length of the base layer.

72. The optical device as defined in claim 66 wherein said converting means includes a birefringent layer.

73. The optical device as defined in claim 66 wherein said base layer comprises at least one of a wedge-shaped layer, a disk, an oblate shape, a parallelpiped and a cylinder.

74. An optical device for collecting light from a source and outputting the light, comprising:

a first layer having an optical index of refraction n₁ said layer having a back surface and first and second surfaces spanning said back surface;

at least one second layer with an optical index of refraction n₂ and light being input through said back surface of said first layer entering and crossing through said second layer when the light being reflected in said first layer achieves an angle of reflection less than the critical angle of incidence θ

_c relative to a normal with said second surface at the point of incidence, the θ

_c being characteristic of the interface between said first layer and said second layer;

third layer means disposed adjacent said at least one second layer acting cooperatively with said first layer and said at least one second layer to control angular distribution of the light of said optical device and for outputting the light from said optical device after passing across said third layer means;

converting means for changing light of the second polarization to the first polarization state; and

means for preferably outputting light of first polarization state relative to a second polarization state, said means for preferably outputting light able to reflect at least part of the light having the second polarization state.

75. The optical device as defined in claim 74 further including an imaging layer.

76. The optical device as defined in claim 75 wherein said imaging layer comprises at least one of a transparent display, a holographic image, an LCD layer and a CCD layer.

77. The optical device as defined in claim 74 wherein said converting means comprises a matching layer providing a light of a preferred polarization state.

78. The optical device as defined in claim 74 further including light diffuser means for diffusing light output from said base layer and broadening the light over an angular range for the viewer.

79. An optical device for operating on light from a source and for selectively outputting light to a viewer, comprising:

a base layer having an optical index of refraction n₁ and a first and second surface, said base layer further including a back surface spanning said first and second surfaces, and the light exiting said base layer when the light being reflected therein decreases its angle relative to a normal to at least one of said first and second surfaces at the point of light incidence and achieves an angle of incidence less than a critical angle θ

_c relative to the normal at the point of light incidence on said surfaces;

first layer means of index of refraction n₂ disposed beyond at least one of said first and second surfaces relative to said base layer and for enabling light to enter and pass across said first layer means after output from said base layer when the light in said base layer achieves the angle of incidence less than the critical angle θ

_c characteristic of an interface between said base layer and said first layer, said first layer means outputting substantially collimated light;

a light redirecting layer disposed adjacent said first layer means receiving said collimated light output from said base layer with said light redirecting layer having facets with faceted face portions, each of said faceted portions being at least partly illuminated by the light and being oriented spatially to redirect the light along a selected direction in cooperation with said first layer means and said base layer;

second layer means for preferably outputting light of a first polarization state compared to a second polarization state, said second layer means disposed beyond at least one of said first and second surfaces relative to said base layer and said second layer means further enabling reflection of at least part of the light having the second polarization state; and

light control layer means for at least one of redirecting and diffusing light toward a viewer wherein the light has been output from said base layer and said light redirecting layer thereby providing light of controlled angular distribution to the viewer.

80. The optical device as defined in claim 79 further including converting means for changing light of the second polarization state to light of the first polarization state.

81. The optical device as defined in claim 80 wherein said converting means comprises a matching layer providing light of a preferred polarization state.

82. The optical device as defined in claim 79 further including an imaging layer.