Architectures and methods for outputting different wavelength light out of waveguides

• US 10,156,725 B2
• Filed: 07/21/2017
• Issued: 12/18/2018
• Est. Priority Date: 09/29/2014
• Status: Active Grant

• Current Assignee: Magic Leap, Inc.
• Original Assignee: Magic Leap, Inc.
• Inventors: TeKolste, Robert Dale, Klug, Michael Anthony, Schowengerdt, Brian T.
• Primary Examiner(s): Kianni, Kaveh C
• Application Number:
  US15/656,283
• Publication Number:
  US 20170322419A1
• Time in Patent Office: 515 Days
• Field of Search: 385 36
• CPC Class Codes: G02B 2027/0112 comprising device for genereting colour display
• CPC Class Codes: G02B 2027/0114 comprising dichroic elements
• CPC Class Codes: G02B 2027/0127 comprising devices increasing the depth of field
• CPC Class Codes: G02B 2027/0134 of stereoscopic type
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0194 with combiner of laminated type, for optical or mechanical aspects
• 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 27/4205 having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant
• CPC Class Codes: G02B 6/0025 Diffusing sheet or layer; Prismatic sheet or layer
• CPC Class Codes: G02B 6/0026 Wavelength selective element, sheet or layer, e.g. filter or grating
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0076 Stacked arrangements of multiple light guides of the same or different cross-sectional area

Abstract

Architectures are provided for selectively outputting light for forming images, the light having different wavelengths and being outputted with low levels of crosstalk. In some embodiments, light is incoupled into a waveguide and deflected to propagate in different directions, depending on wavelength. The incoupled light then outcoupled by outcoupling optical elements that outcouple light based on the direction of propagation of the light. In some other embodiments, color filters are between a waveguide and outcoupling elements. The color filters limit the wavelengths of light that interact with and are outcoupled by the outcoupling elements. In yet other embodiments, a different waveguide is provided for each range of wavelengths to be outputted. Incoupling optical elements selectively incouple light of the appropriate range of wavelengths into a corresponding waveguide, from which the light is outcoupled.

Claims

1. A display system comprising:

a display comprising a plurality of stacked waveguides, each waveguide comprising a first major surface and a second major surface, wherein the plurality of stacked waveguides comprises;

a first waveguide;

a first incoupling optical element configured to incouple incident light into the first waveguide;

a first wavelength selective filter on the first major surface of the first waveguide;

a first outcoupling optical element comprising diffractive elements disposed on the first wavelength selective filter, the first outcoupling optical element configured to outcouple the incoupled light at a first plurality of wavelengths transmitted through the first wavelength selective filter;

a second waveguide over the first outcoupling optical element;

a second incoupling optical element configured to incouple incident light into the second waveguide;

a second wavelength selective filter on the first major surface of the second waveguide; and

a second outcoupling optical element comprising diffractive elements disposed on the second wavelength selective filter, the second outcoupling optical element configured to outcouple the incoupled light at a second plurality of wavelengths transmitted through the second wavelength selective filter.

2. The display system of claim 1, wherein the first waveguide further comprises:

a third wavelength selective filter on the second major surface; and

a third outcoupling optical element comprising diffractive elements disposed on the third wavelength selective filter, the third outcoupling optical element configured to outcouple the incoupled light at one or more third wavelengths transmitted through the third wavelength selective filter.

3. The display system of claim 2, wherein the additional wavelength selective filter is configured to transmit incoupled light at the one or more third wavelengths and reflect incoupled light at wavelengths other than the one or more third wavelengths.

4. The optical system of claim 2, wherein the first waveguide further comprises a light redistributing element configured to:

receive a portion of light at the first plurality of wavelengths and the one or more third wavelengths transmitted through the first and the third wavelength selective filters; and

distribute the light of the first plurality of wavelengths and the one or more third wavelengths to the first and the third outcoupling optical elements.

5. The display system of claim 2, wherein the first and the third wavelength selective filters comprise dichroic filters.

6. The display system of claim 2, wherein the first and the third wavelength selective filters are configured to transmit light of the first plurality of wavelengths and the one or more third wavelengths incident at angles between 0 degrees and 20 degrees with respect to a normal to the corresponding first or the second major surface of the first waveguide.

7. The display system of claim 2, wherein the first waveguide comprises:

light distributing elements configured to;

receive incoupled light of the first plurality of wavelengths and the one or more third wavelengths from the incoupling optical element; and

distribute the light of the first plurality of wavelengths and the one or more third wavelengths to the first, second and the third outcoupling optical elements.

8. The display system of claim 7, wherein the light distributing elements comprise one or more diffractive optical elements.

9. The display system of claim 2, wherein the diffractive elements of the third outcoupling optical element comprises one or more of a surface relief grating, a hologram, or a switchable diffractive optical element.

10. The display system of claim 9, wherein the switchable diffractive optical element comprises a switchable Polymer Dispersed Liquid Crystal (PDLC) grating.

11. The display system of claim 7, wherein the light distributing elements are orthogonal pupil expanders.

12. The display system of claim 2, wherein the third outcoupling element is configured to receive incoupled light at the one or more third wavelengths at one or more angles that support propagation of light in the first waveguide by total internal reflection.

13. The display system of claim 1, wherein each waveguide has an associated depth plane, wherein each waveguide is configured to produce an image appearing to originate from that waveguide'"'"'s associated depth plane.

14. The display system of claim 1, wherein different waveguides of the plurality of stacked waveguides have different associated depth planes.

15. The display system of claim 14, wherein the outcoupling optical elements for different depth planes have different optical power so as to provide different divergence of exiting light for each depth plane.

16. The display system of claim 1, wherein the first wavelength selective filter is configured to transmit incoupled light at a first plurality of wavelengths and reflect incoupled light at wavelengths other than the first plurality of wavelengths.

17. The display system of claim 1, wherein the diffractive elements of one or both of the first outcoupling optical element and the second outcoupling optical element comprises a surface relief grating, a hologram, or a switchable diffractive optical element.

18. The display system of claim 17, wherein the switchable diffractive optical element comprises a switchable Polymer Dispersed Liquid Crystal (PDLC) grating.

19. The display system of claim 17, wherein the surface relief grating comprises one or more of an analog surface relief grating (ASR) or a binary surface relief structure (BSR).

20. The display system of claim 1, wherein one or both of the first and the second incoupling optical elements includes one or more diffractive optical elements.

21. The display system of claim 20, wherein the one or more diffractive optical elements comprises a surface relief grating or a hologram.

22. The display system of claim 20, wherein the one or more diffractive optical elements comprises a switchable diffractive optical element, the switchable diffractive optical element being a switchable Polymer Dispersed Liquid Crystal (PDLC) grating.

23. The display system of claim 22, wherein the surface relief grating comprises one or more of an analog surface relief grating (ASR) or a binary surface relief structure (BSR).

24. The display system of claim 1, wherein the first outcoupling element is configured to receive incoupled light of the first plurality of wavelengths at one or more angles that support propagation of light in the first waveguide by total internal reflection.