Light redirecting films and film systems

• US 8,092,068 B2
• Filed: 02/03/2009
• Issued: 01/10/2012
• Est. Priority Date: 02/23/1999
• Status: Expired due to Fees

• Current Assignee: Rambus Delaware LLC (Rambus Inc.)
• Original Assignee: Rambus International Ltd (Rambus Inc.)
• Inventors: Parker, Jeffery R., McCollum, Timothy A., Ezell, Robert M.
• Primary Examiner(s): Negron, Ismael
• Application Number:
  US12/364,554
• Publication Number:
  US 20090135626A1
• Time in Patent Office: 1,071 Days
• Field of Search: 362/606, 362/607, 362/615, 362617-627, 362/330, 362/339, 359/599, 359/615, 385/130
• US Class Current: 362/620
• CPC Class Codes: A61B 2090/309 using white LEDs
• CPC Class Codes: A61M 2021/0044 by the sight sense
• CPC Class Codes: A61M 21/02 for inducing sleep or relaxation, e.g. by direct nerve stimulation, hypnosis, analgesia for massage A61H; electrotherapy A61N, e.g. applying alternating or intermittent electric currents for producing anaesthesia A61N1/36021
• CPC Class Codes: A61N 2005/063 comprising light transmitting means, e.g. optical fibres
• CPC Class Codes: A61N 2005/0652 Arrays of diodes
• CPC Class Codes: A61N 5/0621 Hyperbilirubinemia, jaundice treatment
• CPC Class Codes: F21V 11/00 Screens not covered by groups F21V1/00, F21V3/00, F21V7/00 or F21V9/00 characterised by cooling arrangements F21V29/502
• CPC Class Codes: F21V 5/10 comprising photoluminescent material
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• 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 6/0028 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 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/006 to produce indicia, symbols, texts or the like
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• 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

Abstract

Optical assembly includes a generally planar light output surface located on a first major plane, and a generally planar second surface located on a second major plane approximately parallel to the first major plane and superimposed thereon. Both the light output surface and the second surface have respective first and second patterns of well defined optical elements that are quite small in relation to the length and width of the optical assembly. The optical elements of the first pattern have an apex angle formed by a first sloped surface that is larger in an area closer to at least one light input edge of the optical assembly and smaller in another area further away from the light input edge.

Claims

1. An optical assembly comprising:

at least one light input edge;

at least one light source positioned adjacent to the at least one light input edge;

a generally planar light output surface located on a first major plane and having a first pattern of well defined optical elements that are projections or depressions on or in the light output surface, each optical element of the first pattern being quite small in relation to a length and width of the optical assembly, each optical element of the first pattern having at least a first sloped surface, with an apex angle being formed by said at least first sloped surface;

wherein the apex angle varies at various locations of the optical assembly such that the apex angle is larger in an area closer to the light input edge and smaller in another area further away from the light input edge;

a generally planar second surface located on a second major plane and having a second pattern of well defined optical elements that are projections or depressions on or in the second surface, each optical element of the second pattern being quite small in relation to the length and width of the optical assembly, the second major plane being approximately parallel to the first major plane and superimposed thereon; and

a reflector layer in close proximity to the second surface.

2. The optical assembly of claim 1, wherein the at least one light source is a light emitting diode.

3. The optical assembly of claim 1, wherein at least some of the optical elements of the first pattern intersect other optical elements of the first pattern.

4. The optical assembly of claim 1, wherein at least some of the optical elements of the second pattern intersect other optical elements of the second pattern.

5. The optical assembly of claim 1, wherein the optical elements of the first pattern have an area density that increases as distance away from the at least one light source increases.

6. The optical assembly of claim 1, wherein the optical elements of the second pattern have an area density that increases as distance away from the at least one light source increases.

7. The optical assembly of claim 1, comprising a light guide substrate and an optical sheet or film, wherein the light guide substrate includes the at least one light input edge and the second surface and the optical sheet or film includes the light output surface.

8. The optical assembly of claim 1, comprising a light guide substrate that includes the at least one light input edge.

9. The optical assembly of claim 8, wherein the light guide substrate includes a transition region that is in close proximity to the at least one light input edge and configured to spread the light from the at least one light source.

10. The optical assembly of claim 8, wherein the light guide substrate includes the light output surface.

11. The optical assembly of claim 8, wherein the light guide substrate includes the second surface.

12. The optical assembly of claim 8, wherein the light guide substrate includes the reflector layer.

13. The optical assembly of claim 8, wherein the light guide substrate is a multi-layer structure including the light output surface and the second surface.

14. The optical assembly of claim 1, wherein the at least one light source has a total width that is quite small in relation to the length and width of the optical assembly.

15. The optical assembly of claim 14, wherein the at least one light source is configured to generate light having an output distribution defined by a greater width component than height component.

16. The optical assembly of claim 14, wherein at least some of the optical elements of the first pattern additionally have a second sloped surface, the first sloped surface and the second sloped surface form the apex angle, the first sloped surface and the second sloped surface form a ridge, the ridges of at least some of the optical elements being arranged in generally radial patterns that are pointed towards the at least one light source.

17. The optical assembly of claim 14, wherein at least some of the optical elements of the first pattern additionally have a second sloped surface, the first sloped surface and the second sloped surface form the apex angle, the first sloped surface and the second sloped surface form a non-linear ridge, the non-linear ridges of at least some of the optical elements being curved towards the at least one light source.

18. The optical assembly of claim 14, wherein at least some of the optical elements of the first pattern additionally have a second sloped surface, the first sloped surface and the second sloped surface of at least some of the optical elements of the first pattern form a non-linear ridge, the non-linear ridges of at least some of the optical elements being curved away from the at least one light source.

19. The optical assembly of claim 1, wherein at least some of the optical elements of the first pattern additionally have a second sloped surface, and the first and second sloped surfaces form the apex angle.

20. The optical assembly of claim 19, wherein the first sloped surface and the second sloped surface of at least some of the optical elements of the first pattern form a ridge, the ridge of at least some of the optical elements being approximately parallel to the length direction of at least some of the optical elements.

21. The optical assembly of claim 19, wherein the first sloped surface and the second sloped surface of at least some of the optical elements of the first pattern form a ridge, the ridge of at least some of the optical elements being arranged in approximately the same direction.

22. The optical assembly of claim 21, wherein the direction of the ridge of at least some of the optical elements is approximately parallel to the at least one light input edge.