Light emitting panel assemblies

• US 5,618,096 A
• Filed: 11/20/1995
• Issued: 04/08/1997
• Est. Priority Date: 06/27/1995
• Status: Expired due to Term

• Current Assignee: Rambus Delaware LLC (Rambus Inc.)
• Original Assignee: Lumitex Incorporated
• Inventors: Kelsch, Daniel N., Parker, Jeffery R., Miller, Mark D.
• Primary Examiner(s): Lazarus, Ian S.
• Assistant Examiner(s): Basichas, Alfred
• Application Number:
  US08/560,582
• Time in Patent Office: 505 Days
• Field of Search: 362/26, 362/27, 362/31, 362/235, 362/249, 362/297, 362/299, 362/300, 362/308, 362/329, 362/330, 362/346, 362/800
• US Class Current: 362/629
• CPC Class Codes: A61B 2090/309 using white LEDs
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• 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 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• 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 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: H01H 2219/062 Light conductor
• CPC Class Codes: H01H 2221/07 transparent
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

Light emitting panel assemblies include light emitting panel members and one or more light sources positioned/embedded in a light transition area, which increases the efficiency of light entering the panel members along the light input area to be emitted from one or more light emitting surfaces along the length of the panel members. Light may be reflected or refracted by a surface which changes the path of a portion of light such that it enters the input area of the panel member at a more acceptable angle. A uniform light output distribution may be produced by utilizing a pattern of light extracting deformities.

Claims

1. A method of planar illumination comprising the steps of:

generating light via a light source;

directing generated light, defined by a directional component in each of first and second relatively unique axes of a cross-sectional area of an optical conductor, generally perpendicularly to the cross-sectional area such that a component of generated light along the first axis is distributed to a greater extent therealong than a component of generated light along the second axis;

receiving generated light into a generally planar optical conductor having at least one pair of generally parallel, opposed walls, the light being received at an angle relative to the opposed walls such that a significant portion thereof is reflected between the opposed walls via internal reflection; and

communicating received light through the optical conductor to a preselected pattern of irregularities associated with the optical conductor to cause light to be emitted outward therefrom.

2. The method of claim 1 further comprising the step of directing light generated by the light source to a transition area between a first refractive index of an optically conductive medium disposed between the light source and the optical conductor having a second refractive index distinct from the first.

3. The method of claim 2 further comprising the step of concentrating light of the light source prior to the step of directing light to the transition area.

4. The method of claim 3 further comprising the step of communicating light emanating from the irregularities to an associated display secured to the optical conductor so as to illuminate indicia disposed on the associated display.

5. The method of claim 4 wherein the step of communicating received light includes the step of communicating the received light through the optical conductor inclusive of a dye disposed therein.

6. The method of claim 4 wherein the step of communicating received light includes the step of communicating the received light through the optical conductor inclusive of a dispersion material disposed therein.

7. The method of claim 4 wherein the step of communicating received light includes the step of communicating the received light through the optical conductor inclusive of a plurality of generally translucent subareas disposed therein.

8. A method of planar illumination comprising the steps of:

directing light from a light source into an optical conductor at an angle relative to the opposed walls such that a significant portion thereof is reflected between the opposed walls via internal reflection;

directing light from the light source, defined by a directional component in each of a first and second mutually distinct axis of a generally planar cross-section of the optical conductor, generally perpendicular to light emanating from the light source;

directing a component of light from the light source along the second axis to a greater extent than a component of light directed along the first axis; and

a preselected pattern of irregularities associated along the optical conductor to cause light to be emitted outward therefrom.

9. A method of planar illumination comprising the steps of:

generating light via a light source;

selectively directing generated light, defined as having a directional component in each of first and second axes of a generally planar cross-section of a generally planar optical conductor, such that a second component of generated light is distributed along the second selected axis generally to a greater extent than a first component distributed along the first axis;

receiving generated light that has been selectively generated along the selected axis into a generally planar optical conductor having at least one pair of generally parallel, opposed walls, the light being received at an angle relative to the opposed walls such that a significant portion thereof is reflected between the opposed walls via internal reflection; and

communicating received light through the optical conductor to a preselected pattern of irregularities associated therewith.

10. The method of claim 9 further comprising the step of directing light generated by the light source a transition area between a first refractive index of an optically conductive medium disposed between the light source and the optical conductor having a second refractive index distinct from the first so as to accomplish the step of selectively spreading generated light along a selected axis.

11. The method of claim 10 further comprising the step of communicating light reflected from the irregularities to an associated display secured to the optical conductor so as to illuminate indicia disposed on the associated display.

12. The method of claim 11 wherein the step of communicating received light includes the step of communicating the received light through the optical conductor inclusive of a dye disposed therein.

13. A planar illumination system comprising:

a generally planar optical conductor having at least one pair of generally parallel, opposed walls and defining first and second mutually distinct axes of a cross-sectional area thereof generally perpendicular to a direction of light propagation;

directing means for directing light defined by a directional component in each of the first and second axes so as to be distributed over a greater extent along the first axis relative to light distribution along the second axis;

receiving means for receiving directed light from the directing means into the optical conductor at an angle relative to the opposed walls such that a significant portion thereof is reflected between the opposed walls via internal reflection; and

a preselected pattern of irregularities associated with the optical conductor to cause light to be emitted outward therefrom.

14. The planar illumination system of claim 13 wherein the preselected pattern of light scattering irregularities includes a dye interspersed within the optical conductor.

15. The planar illumination system of claim 13 wherein the preselected pattern of light scattering irregularities includes a dispersion material disposed within the optical conductor.

16. The planar illumination system of claim 13 wherein the preselected pattern of light scattering irregularities includes a plurality of generally opaque subareas.

17. The planar illumination system of claim 13 wherein the preselected pattern of light scattering irregularities includes a plurality of generally translucent subareas.

18. The planar illumination system of claim 13 further comprising:

a light source adapted to generate light to the directing means; and

wherein

at least one of the directing means and the receiving means is comprised of a light reflector.

19. The planar illumination system of claim 13 wherein the at least one pair of generally parallel, opposed walls are curved.

20. The planar illumination system of claim 13 further comprising:

a light source adapted to generate light to the directing means; and

wherein

at least one of the directing means and the receiving means includes a transition area between a first refractive index of an optically conductive medium disposed between the light source and the optical conductor having a second refractive index distinct from the first.

21. The planar illumination system of claim 20 further comprising means adapted for securing an associated display to the optical conductor so as to illuminate indicia disposed on the associated display via light emanating from the preselected pattern.

22. A planar illumination system comprising:

a generally planar optical conductor having at least one pair of generally parallel, opposed walls;

a light source;

directing means for directing light from the light source into the optical conductor at an angle relative to the opposed walls such that a significant portion thereof is reflected between the opposed walls via internal reflection, the directing means including,

means for directing light, defined by a directional component in each of first and second mutually distinct axes of a generally planar cross-section of the optical conductor, from the light source to the generally planar cross-sectional area generally perpendicular to a direction of propagation of light from the light source, and

means for directing light from the light source such that light thereof is distributed along the second axis to a greater extent than a distribution of light along the first axis; and

a preselected pattern of irregularities associated along the optical conductor to cause light to be emitted therefrom.

23. The planar illumination system of claim 22 wherein

the direction means is formed by a transition area between a first refractive index of an optically conductive medium disposed between the light source and the optical conductor having a second refractive index distinct from the first.

24. An illumination system comprising:

a light source;

a semi-transparent visual display having an indicia set of at least one of text or character indica disposed thereon;

a generally planar optical conductor having at least one pair of generally parallel, opposed walls;

directing means for directing light, defined by a directional component in each of first and second mutually distinct axes of a generally planar cross-section of the optical conductor, such that a light component is distributed along the second axis to a greater extent than a light component distributed along the first axis;

receiving means for receiving directed light from the directing means into the optical conductor at an angle relative to the opposed walls such that a significant portion thereof is reflected between the opposed walls via internal reflection; and

a preselected pattern of irregularities associated the optical conductor and ordered to correspond with the indica set such that the indicia is illuminated from light emitted from the irregularities.

25. The illumination system of claim 24 wherein the indicia set is comprised of a flat-panel video display terminal.

26. The illumination system of claim 25 wherein the indicia set is comprised of an instrument panel display.