Lightguide device with outcoupling structures

• US 9,423,552 B2
• Filed: 02/24/2014
• Issued: 08/23/2016
• Est. Priority Date: 02/24/2014
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Richards, Evan M., Gupta, Anurag, Cakmakci, Ozan
• Primary Examiner(s): Mai, Anh
• Assistant Examiner(s): ZIMMERMAN, GLENN D
• Application Number:
  US14/188,411
• Publication Number:
  US 20150241619A1
• Time in Patent Office: 911 Days
• Field of Search: 362/601, 362/606, 362/607, 362/616, 362/627, 362/628
• US Class Current: 1/1
• CPC Class Codes: B32B 37/00 Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
• CPC Class Codes: B32B 38/14 Printing or colouring
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 27/0081 with means for altering, e.g. enlarging, the entrance or exit pupil
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/1073 characterized by manufacturing or alignment methods
• CPC Class Codes: G02B 27/141 using dichroic mirrors
• CPC Class Codes: G02B 5/09 Multifaceted or polygonal mirrors , e.g. polygonal scanning mirrors; Fresnel mirrors
• CPC Class Codes: G02B 6/0015 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/0026 Wavelength selective element, sheet or layer, e.g. filter or grating
• CPC Class Codes: G02B 6/0035 provided on the surface of the light guide or in the bulk of it
• 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 6/0045 by shaping at least a portion of the light guide
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: Y10T 29/49885 with coating before or during assembling

Abstract

A lightguide assembly including structures to provide for outcoupling of light from an internal reflection structure. In an embodiment, a lightguide assembly includes light transmissive bodies forming respective corrugations which are coupled to one another. Optical coatings are variously disposed between the respective corrugations, wherein the optical coatings provide for redirection of light from the lightguide assembly. In another embodiment, optical coatings are each applied to a respective one of alternate facets of a corrugation. Polymer film portions provide mechanical support for the optical coatings during application to the corrugation.

Claims

1. A lightguide assembly comprising:

a first body including a first light transmissive material which forms a first corrugation comprising a first plurality of facets;

a second body including a second light transmissive material which forms a second corrugation coupled to the first corrugation;

a plurality of optical coatings disposed between the first corrugation and the second corrugation, wherein for each optical coating of the plurality of optical coatings;

the optical coating extends across a surface of a respective one of the first plurality of facets, wherein, within a cross-section of the lightguide assembly, the optical coating is separated from another of the plurality of optical coatings; and

a plurality of polymer coatings disposed between the first body and the second body, wherein for each polymer coating of the plurality of polymer coatings;

the polymer coating extends across a surface of a respective one of the first plurality of facets, wherein, within a cross-section of the lightguide assembly, the polymer coating is separated from another of the plurality of polymer coatings;

wherein the lightguide assembly includes a first surface and a second surface opposing the first surface, the lightguide assembly to receive first light, wherein the first light propagates along a first optical path disposed at least partially between the first surface and the second surface, wherein the first surface to receive and reflect the first light to the second surface, wherein the plurality of optical coatings to pass the first light out of the lightguide assembly through the second surface.

2. The lightguide assembly of claim 1, wherein the first corrugation includes a second plurality of facets alternating with the first plurality of facets along a length of the first corrugation.

3. The lightguide assembly of claim 1, wherein an index of refraction of the polymer coatings is equal to an index of refraction of the first light transmissive material.

4. The lightguide assembly of claim 1, wherein the first body comprises a plurality of component blocks each forming a respective portion of the first corrugation, the plurality of component blocks each coupled to one another with an optical adhesive.

5. The lightguide assembly of claim 1, wherein the first plurality of facets include flat facets.

6. The lightguide assembly of claim 1, wherein a portion of the first corrugation is directly coupled to a portion of the second corrugation.

7. The lightguide assembly of claim 2, wherein the first plurality of facets are each of a first length and the second plurality of facets are each of a second length other than the first length.

8. An optical system comprising:

an image source to generate first light; and

a lightguide assembly including;

a first body including a first light transmissive material which forms a first corrugation comprising a first plurality of facets;

a second body including a second light transmissive material which forms a second corrugation coupled to the first corrugation; and

a plurality of optical coatings disposed between the first corrugation and the second corrugation, wherein for each optical coating of the plurality of optical coatings;

the optical coating extends across a surface of a respective one of the first plurality of facets, wherein, within a cross-section of the lightguide assembly, the optical coating is separated from another of the plurality of optical coatings;

wherein the lightguide assembly includes a first surface and a second surface opposing the first surface, the lightguide assembly to receive the first light, wherein the first light propagates along a first optical path disposed at least partially between the first surface and the second surface, wherein the first surface to receive and reflect the first light to the second surface, wherein the plurality of optical coatings to pass the first light out of the lightguide assembly through the second surface.

9. The optical system of claim 8, wherein the first corrugation includes a second plurality of facets alternating with the first plurality of facets along a length of the first corrugation.

10. The optical system of claim 8, further comprising:

a plurality of polymer coatings disposed between the first body and the second body, wherein for each polymer coating of the plurality of polymer coatings;

the polymer coating extends across a surface of a respective one of the first plurality of facets, wherein, within a cross-section of the lightguide assembly, the polymer coating is separated from another of the plurality of polymer coatings.

11. The optical system of claim 8, wherein the first body comprises a plurality of component blocks each forming a respective portion of the first corrugation, the plurality of component blocks each coupled to one another with an optical adhesive.

12. The optical system of claim 9, wherein the first plurality of facets are each of a first length and the second plurality of facets are each of a second length other than the first length.

13. The optical system of claim 10, wherein an index of refraction of the polymer coatings is equal to an index of refraction of the first light transmissive material.