Superluminous LED array for waveguide display

• US 10,690,919 B1
• Filed: 02/14/2018
• Issued: 06/23/2020
• Est. Priority Date: 02/17/2017
• Status: Active Grant

• Current Assignee: META Platforms Technologies LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Original Assignee: Facebook Technologies, LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Inventors: Fu, Yijing, Chi, Wanli, Saarikko, Pasi, Liu, Xinqiao, Lee, Hee Yoon, Parsons, Maxwell
• Primary Examiner(s): Lubit, Ryan A
• Application Number:
  US15/896,392
• Time in Patent Office: 860 Days
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129
• 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 6/0035 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/34 utilising prism or grating G02B6/293 takes precedence

Abstract

A waveguide display includes a light source, a scanning mirror assembly, an output waveguide, and a controller. The light source emits image light. The scanning mirror assembly scans the image light as scanned image light to particular locations in accordance with scanning instructions. The output waveguide includes an input area and an output area. The output waveguide receives the scanned image light emitted from the scanning mirror assembly at the input area, and output expanded image light from a portion of the output area, the location of the portion of the output area based in part on a direction of the scanned image light output from the scanning mirror assembly. The controller generates the scanning instructions and provides the scanning instructions to the scanning mirror assembly.

Claims

1. A waveguide display, comprising:

a light source including an array of superluminous LEDs (SLEDs) that are configured to emit image light, and each SLED has a first end and second end that is opposite the first end, the second end configured to emit a respective portion of the image light, and respective distances between adjacent first ends are smaller than respective distances between adjacent second ends such that the array of SLEDs has a fanned out structure;

a scanning mirror assembly configured to scan the image light to particular locations as scanned image light in accordance with scanning instructions;

an output waveguide including an input area and an output area, the output waveguide coupled to receive the scanned image light emitted from the scanning mirror assembly at the input area, and output expanded image light from a portion of the output area, and a location of the portion of the output area is based in part on a direction of the scanned image light output from the scanning mirror assembly; and

a controller configured to generate the scanning instructions and provide the scanning instructions to the scanning mirror assembly.

2. The waveguide display of claim 1, wherein the array is a one-dimensional array of superluminous LEDs (SLEDs).

3. The waveguide display of claim 2, wherein each SLED of the one-dimensional array of SLEDs comprises a ridge waveguide structure providing an optical confinement of the image light.

4. The waveguide display of claim 1, wherein the scanning mirror assembly performs at least one of:

a raster scan, a biresonant scan, or a combination thereof.

5. The waveguide display of claim 1, wherein the image light comprises at least a first band of wavelengths, and a second band of wavelengths different from the first band of wavelengths.

6. The waveguide display of claim 5, wherein the first band of wavelengths is in the range of 700 nm to 1400 nm.

7. The waveguide display of claim 1, further comprising:

a conditioning assembly configured to condition the image light from the light source, the conditioning assembly directing a conditioned image light toward the scanning mirror assembly.

8. The waveguide display of claim 1, wherein the array of SLEDs includes a pixel pitch of at least 30 microns.

9. The waveguide display of claim 1, wherein the scanning mirror assembly includes a Micro-Electro Mechanical System (MEMS) mirror configured to scan along two dimensions.

10. The waveguide display of claim 1, wherein the scanning mirror assembly performs a translation of at least one of the SLEDs in accordance with the image light emitted by the light source.

11. The waveguide display of claim 1, wherein the light source further comprises:

a two-dimensional array of vertical cavity surface emitters; and

an addressing circuit configured to address each of the vertical cavity surface emitters.

12. The waveguide display of claim 1, wherein

the light source performs a temporal modulation of the image light to emit a temporally modulated image light, and

the scanning mirror assembly performs a scanning of the temporally modulated image light in accordance with a target frame rate of the expanded image light.

13. A waveguide display, comprising:

a light source including an array of superluminous LEDs (SLEDs) that are configured to emit image light, the image light comprising at least a first band of wavelengths and a second band of wavelengths, and each SLED has a first end and second end that is opposite the first end, the second end configured to emit a respective portion of the image light, and respective distances between adjacent first ends are smaller than respective distances between adjacent second ends such that the array of SLEDs has a fanned out structure;

a combining assembly configured to combine the image light emitted by the light source and output a colored image light comprising a third band of wavelengths different from the first band and the second band;

a scanning mirror assembly configured to scan the colored image light to particular locations in accordance with scanning instructions; and

a controller configured to generate the scanning instructions and provide the scanning instructions to the scanning mirror assembly.

14. The waveguide display of claim 13, wherein the scanning mirror assembly performs at least one of:

a raster scan, a biresonant scan, or a combination thereof.

15. The waveguide display of claim 13, wherein the image light comprises at least a first band of wavelengths, and a second band of wavelengths different from the first band of wavelengths.

16. The waveguide display of claim 13, wherein the light source further comprises:

a two-dimensional array of vertical cavity surface emitters; and

an addressing circuit configured to address each of the vertical cavity surface emitters.

17. The waveguide display of claim 13, wherein

the light source performs a temporal modulation of the image light to emit a temporally modulated image light, and

the scanning mirror assembly performs a scanning of the temporally modulated image light in accordance with a target frame rate of the expanded image light.

18. The waveguide display of claim 13, wherein the array of SLEDs includes a pixel pitch of at least 30 microns.

19. The waveguide display of claim 13, wherein the scanning mirror assembly includes a Micro-Electro Mechanical System (MEMS) mirror configured to scan along two dimensions.

20. A near-eye display (NED), comprising:

a frame configured to be worn by a user;

a waveguide display that is integrated into the display, the waveguide display comprising;

a light source including an array of superluminous LEDs (SLEDs) that are configured to emit image light, and each SLED has a first end and second end that is opposite the first end, the second end configured to emit a respective portion of the image light, and respective distances between adjacent first ends are smaller than respective distances between adjacent second ends such that the array of SLEDs has a fanned out structure;

a scanning mirror assembly configured to scan the image light to particular locations as scanned image light in accordance with scanning instructions;

an output waveguide including an input area and an output area, the output waveguide coupled to receive the scanned image light emitted from the scanning mirror assembly at the input area, and output expanded image light from a portion of the output area, and a location of the portion of the output area is based in part on a direction of the scanned image light output from the scanning mirror assembly; and

a controller configured to generate the scanning instructions and provide the scanning instructions to the scanning mirror assembly.