Lenticular illumination system

• US 5,949,933 A
• Filed: 03/03/1998
• Issued: 09/07/1999
• Est. Priority Date: 03/03/1998
• Status: Expired due to Term

• Current Assignee: Alliedsignal Inc. (Honeywell International Inc.)
• Original Assignee: Alliedsignal Inc. (Honeywell International Inc.)
• Inventors: Steiner, Ivan B., Beeson, Karl W.
• Primary Examiner(s): Ullah, Akm E.
• Application Number:
  US09/033,772
• Time in Patent Office: 553 Days
• Field of Search: 385/31, 385/36, 385/39, 362/559-560, 362/561, 362/551, 359/15, 359/1, 359/487, 359/494, 359/385, 359/709, 349/65, 349/64, 349/70
• US Class Current: 385/36
• 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

Abstract

An optical illumination system comprising a waveguide that accepts light and transmits the light via total internal reflection. Attached on one face of the waveguide is an array of lenticular microprisms, with each microprism having an light input surface optically coupled to the waveguide and a light output surface. The light input surface is defined by a number of tapered grooves which prevent light from escaping from the waveguide and further redirect light within the microprism. Light that escapes from the waveguide, reflects off the tilted sidewalls of the tapered grooves and emerges from the microprism as a spatially directed light source. An array of lenticular microlenses may be positioned to accept the output of the microprisms so that the light exiting from the microlenses is a substantially collimated light source.

Claims

1. An illumination assembly comprising a means for transmitting light, having a refractive index n₁, in optical cooperation with a light input surface of a means for removing light from the light transmitting means and reflecting the light to an output surface and having a refractive index equal to n₂, wherein the continuity of the light input surface is interrupted by regions having a refractive index n₃, where n₃ <

n₁ and n₂.

2. The illumination assembly of claim 1 wherein said means for removing light is lenticular.

3. The illumination assembly of claim 1 wherein the regions having a refractive index n₃ define a tapered volume.

4. The illumination assembly of claim 3 wherein the interface between indices n₂ and n₃ reflect light within the light removing means.

5. The illumination assembly of claim 3 wherein the tapered volume is V-shaped.

7. The illumination assembly of claim 5 wherein said output surface is parallel to said light input surface.

8. The illumination assembly of claim 5 wherein said output surface is a curved.

6. An illumination assembly for providing a spatially directed light source comprising:

a means for transmitting light having a refractive index n₁ and a first light accepting surface for accepting a light input; and

an array of lenticular microprisms comprising

i) a light input surface for receiving light from said means for transmitting light, said light input surface having selected interstitial regions of a refractive index n₂ where n₂ <

n₁ ; and

ii) a light output surface having a surface area greater than the surface area of said light input surface.

9. An illumination assembly for providing a spatially directed light source comprising:

a) a means for transmitting light having a refractive index n₁ and a first light accepting surface for accepting a light input; and

b) an array of lenticular microprisms comprising a length and a width, a light input surface for receiving light from said light transmitting means, said light input surface having selected interstitial regions of a refractive index n₂ where n₂ <

n₁ and a light output surface having a surface area greater than the surface area of said light input surface; and

the length of each microprism is aligned in the general direction of the travel of the light through the means for transmitting light, and the interstitial regions are aligned in the general direction perpendicular to the direction of the travel of light.

10. The illumination assembly of claim 9 wherein said output surface is a curved.