Light-Guiding Structures

• US 20130088780A1
• Filed: 03/12/2010
• Published: 04/11/2013
• Est. Priority Date: 03/12/2010
• Status: Active Grant

• Current Assignee: Magic Leap, Inc.
• Original Assignee: Nokia Technologies Oy (Nokia Corporation)
• Inventors: Jarvenpaa, Toni J., Saarikko, Pasi Riso Olavi
• Granted Patent: US 9,766,381 B2
• Time in Patent Office: Days
• US Class Current: 359/566
• CPC Class Codes: G02B 2027/0134 of stereoscopic type
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 5/18 Diffraction gratings holographic optical elements G02B5/32, G03H; integrally combined with optical fibres G02B6/02057; for coupling light guides G02B6/34; integrally combined with optical integrated light guides G02B6/12; grating systems G02B27/44
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings

Abstract

A method and an apparatus for providing a first light-guiding structure and a second light-guiding structure to receive an input optical beam and output an output optical beam to be viewed by a user. At least one of the first or the second light-guiding structure has a non-flat shape. The first and the second light-guiding structures are configured to produce virtual images at different viewing distances.

Claims

1. An apparatus comprising:

a first light-guiding structure configured to guide optical waves, having a first surface and a second surface which is opposite to the first surface;

a second light-guiding structure configured to guide optical waves, having a first surface and a second surface which is opposite to the first surface;

an in-coupling element disposed on the first or the second surface of the first or the second light-guiding structure and configured to receive an input optical beam;

an out-coupling element disposed on the first or the second surface of the first or the second light-guiding structure and being offset from the said in-coupling element and configured to output an output optical beam out of the first or the second light-guiding structure to be viewed by a user;

wherein at least one of the first or the second light-guiding structure has a non-flat shape, and

the first and the second light-guiding structures are respectively configured to produce virtual images at different viewing distances.

2. The apparatus of claim 1, wherein a curvature radius of the non-flat shape defines a focal distance.

3. The apparatus of claim 1, wherein at least one of the light-guiding structures is an exit-pupil expander.

4. The apparatus of claim 1, wherein the input optical beam is generated from a virtual image of a display.

5. The apparatus of claim 1, wherein a curvature radius of the non-flat shape of the first light-guiding structure is different to the curvature of the non-flat shape of the second light-guiding structure.

6. The apparatus of claim 1, wherein a curvature radius of the non-flat shape of at least one of the light-guiding structures is changeable.

7. The apparatus of claim 1, wherein a curvature radius is the same for the opposite surfaces of at least one of the light-guiding structures.

8. The apparatus of claim 1, wherein at least one of the in-coupling element and the out-coupling element is a diffractive element.

9. The apparatus of claim 1, wherein the first light-guiding structure has a flat shape and the second light-guiding structure has a non-flat shape.

10. The apparatus of claim 1 comprising a third light-guiding structure configured to guide optical waves, having a first surface and a second surface which is opposite to the first surface, wherein the third light-guiding structure and the second light-guiding structure have different curvature radii.

11. The apparatus of claim 10, wherein the first light-guiding structure, the second light-guiding structure and the third light-guiding structure present different two-dimensional content of different focal distance to the user.

12. The apparatus of claim 4, wherein the display is a field-sequential display with directional properties.

13. The apparatus of claim 1, wherein the input optical beams are configured to be controlled by an optical engine comprising a lens.

14. The apparatus of claim 13, wherein the optical engine comprises multiple lenses.

15. The apparatus of claim 13, wherein the optical engine is configured to provide adjustable optical power.

16. The apparatus of claim 13, wherein the optical engine comprises a shutter.

17. The apparatus of claim 16, comprising a set of shutters placed and aligned with the in-coupling elements.

18. A method comprising:

receiving an input optical beam by at least one of a first light-guiding structure and a second light-guiding structure;

outputting an output optical beam to be viewed by a user, wherein at least one of the first or the second light-guiding structure has a non-flat shape; and

configuring the first and the second light-guiding structures to produce virtual images at different viewing distances.

19. The method of claim 18, wherein a curvature radius of the non-flat shape defines a focal distance.

20. The method of claim 18, wherein at least one of the light-guiding structures is an exit-pupil expander.

21. The method of claim 18, wherein the input optical beam is generated from a virtual image of a display.

22. The method of claim 18, wherein a curvature radius of the non-flat shape of the first light-guiding structure is different to the curvature of the non-flat shape of the second light-guiding structure.

23. The method of claim 18, wherein the first light-guiding structure is configured to have a flat shape and the second light-guiding structure is configured to have a non-flat shape.

24. The method of claim 18, comprising a third light-guiding structure configured to guide optical waves, having a first surface and a second surface which is opposite to the first surface, wherein the third light-guiding structure and the second light-guiding structure have different curvature radii.

25. The method of claim 24, wherein the first light-guiding structure, the second light-guiding structure and the third light-guiding structure present different two-dimensional content of different focal distance to the user.