Luminaire device

• US 6,002,829 A
• Filed: 01/13/1997
• Issued: 12/14/1999
• Est. Priority Date: 03/23/1992
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Company
• Inventors: Winston, Roland, Emmons, Robert M., Gleckman, Philip, Holman, Robert L., Jacobson, Benjamin A.
• Primary Examiner(s): PALMER, PHAN T H
• Application Number:
  US08/783,212
• Time in Patent Office: 1,065 Days
• Field of Search: 385/146, 385/147, 385/140, 385/129, 385/130, 385/131, 385/43, 385/901, 359/559, 359/833, 359/834, 359/869, 362/19, 362/31, 362/32, 362/554, 362/556, 362/560, 349/61, 349/70, 349/159, 349/164, 349/56, 349/121, 349/117
• 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 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• CPC Class Codes: G02B 6/002 by shaping at least a portion of the light guide, e.g. with collimating, focussing or diverging surfaces
• CPC Class Codes: G02B 6/0021 for housing at least a part of the light source, e.g. by forming holes or recesses
• CPC Class Codes: G02B 6/0023 provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
• CPC Class Codes: G02B 6/0025 Diffusing sheet or layer; Prismatic sheet or layer
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0055 Reflecting 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 1/13362 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 layer has an optical index of referaction n₁, and top, bottom and side surfaces defining an angel 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 alight polarization layer, a polarization converting layer and a post LCD diffuser layer can be used to make preferential use of polarized light of 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 base layer having at least 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 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.

2. 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.

3. The optical device as defined in claim 2 wherein said converting means is disposed at least one of (a) between said imaging layer means and said base layer and (b) further from said second surface relative to said first surface with said imaging layer means disposed further said first surface relative to said second surface.

4. The optical device as defined in claim 1 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.

5. The optical device as defined in claim 1 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.

6. The optical device as defined in claim 1 wherein said base layer comprises at least one of a wedge-shaped layer, a disk, an oblate shape, a parallelpiped and a cylinder.

7. The optical device as defined in claim 1 wherein said imaging layer means comprises at least one of a transparent display, a holographic image, a liquid crystal layer and a CCD layer.

8. The optical device as defined in claim 1 further including antireflection layers to reduce scattering.

9. The optical device as defined in claim 1 wherein said light control layer means includes a faceted layer of variable facet angles.

10. The optical device as defined in claim 1 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.

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

a base layer having at least 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 normal 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 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 converting 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.

12. The optical device as defined in claim 11 wherein said means for preferably transmitting light is disposed at least one of (a) between said display layer and said base layer and (b) further from said base layer then said display layer.

13. The optical device as defined in claim 11 wherein said third layer means for converting light is disposed at least one of (a) between said display layer and said base layer and (b) nearer said second surface than said first surface with said display layer disposed nearer said first surface than said second surface.

14. The optical device as defined in claim 11 wherein said third layer means for converting comprises a matching layer providing a preferred polarization state for said display layer.

15. The optical device as defined in claim 11 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.

16. The optical device as defined in claim 11 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.

17. The optical device as defined in claim 11 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.

18. The optical device as defined in claim 11 wherein said base layer comprises at least one of a wedge-shaped layer, a disk, an oblate shape, a parallelpiped and a cylinder.

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

a base layer having 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.

20. The optical device as defined in claim 19 wherein said means for incrementally changing light angle comprises a changing index of refraction in said base layer.