Multiple laser light source sets for scanning display systems

Patent metadata

Field	Value
Publication number	US-12276790-B2
Application number	US-202217580749-A
Country	US
Kind code	B2
Filing date	Jan 21, 2022
Priority date	Jan 22, 2021
Publication date	Apr 15, 2025
Grant date	Apr 15, 2025

Abstract

Systems, devices, and methods for accommodating multiple sets of laser light sources in an optical engine of a display system such as a laser projection system are described. Laser light beams may be combined via wavelength-, polarization-, and/or angular-separation-based techniques. First and second sets of laser light beams may be angularly separated such that different sets of partially overlapping pixels are projected by the system, thereby increasing the display pixel density and/or an expanding the field of view of the display. One or more laser die may be mounted to each submount of the optical engine. For embodiments with two laser dies on each submount, collimating lenses may introduce angular separation between laser light beams output by each pair of commonly mounted laser dies. A retroreflector prism may be disposed at a beam combiner to provide a compact extension of the optical path through the beam combiner.

First claim

What is claimed is:

1. A display system comprising:
an optical engine comprising:
a first set of laser light sources that includes at least three laser light sources, the first set of laser light sources having a first threshold excitation level; and
a second set of laser light sources that includes at least one laser light source, the second set of laser light sources having a second threshold excitation level that is lower than the first threshold excitation level; and

a beam combiner configured to combine a plurality of laser light beams output by the first set of laser light sources and the second set of laser light sources.

2. The display system of claim 1 , wherein the first set of laser light sources outputs laser light beams having a first intensity and a first set of wavelengths, wherein the second set of laser light sources outputs second laser light beams having a second intensity and a second set of wavelengths that is substantially identical to the first set of wavelengths, and wherein the first intensity is higher than the second intensity.

3. The display system of claim 1 , wherein the first set of laser light sources outputs laser light beams having a first set of wavelengths, and wherein the second set of laser light sources outputs second laser light beams having a second set of wavelengths that is different from the first set of wavelengths.

4. The display system of claim 3 , wherein the first set of wavelengths includes first red, green, and blue (R 1 G 1 B 1 ) nominal wavelengths, and wherein the second set of wavelengths includes second red, green, and blue (R 2 G 2 B 2 ) nominal wavelengths that are different than the R 1 G 1 B 1 nominal wavelengths.

5. The display system of claim 3 , wherein the first set of wavelengths includes red, green, and blue (RGB) nominal wavelengths, and wherein the second set of wavelengths includes cyan, yellow, and maroon (CYM) nominal wavelengths.

6. The display system of claim 1 , wherein the first set of laser light sources comprises a first type of laser light source, and wherein the second set of laser light sources comprises a second type of laser light source.

7. The display system of claim 6 , wherein the first type of laser light source is selected from a group that includes double heterojunction laser diodes, quantum dot lasers, vertical-cavity surface-emitting lasers (VCSELs), internal cavity lasers, and external cavity lasers.

8. The display system of claim 1 , wherein the second set of laser light sources includes multiple laser light sources, and wherein the beam combiner comprises:
a first set of dichroic beam splitters configured to combine a first subset of the plurality of laser light beams output by the first set of laser light sources into a first combined laser light beam; and
a second set of dichroic beam splitters configured to combine a second subset of the plurality of laser light beams output by the second set of laser light sources into a second combined laser light beam; and
wherein the first combined laser light beam is angularly separated from the second combined laser light beam.

9. The display system of claim 8 , further comprising:
an optical scanner configured to receive the first combined laser light beam and the second combined laser light beam and to scan the first combined laser light beam and the second combined laser light beam along an incoupler of a waveguide that is configured to project the first combined laser light beam and the second combined laser light beam to form respective first and second sets of pixels.

10. The display system of claim 1 , wherein the at least one laser light source of the second set of laser light sources includes multiple laser light sources, wherein the optical engine further comprises a plurality of submounts, and wherein each of a plurality of pairs of laser light sources of the first and second sets of laser light sources is disposed on a respectively different submount of the plurality of submounts.

11. The display system of claim 10 , wherein each laser light source of the first and second sets of laser light sources comprises a laser die.

12. The display system of claim 10 , further comprising a plurality of collimating lenses disposed between the optical engine and the beam combiner, wherein the collimating lenses are configured to angularly separate pairs of laser light beams of the plurality of laser light beams, each of the pairs of laser light beams corresponding to a different pair of the plurality of pairs of laser light sources.

13. The display system of claim 1 , wherein at least one of the laser light sources outputs a laser light beam having a noncircular profile.

14. An optical engine comprising:
a first set of laser light sources that includes at least three laser light sources, wherein the laser light sources of the first set of laser light sources have a first threshold excitation level; and
a second set of laser light sources that includes at least one laser light source, wherein the laser light sources of the second set of laser light sources have a second threshold excitation level that is lower than the first threshold excitation level.

15. The optical engine of claim 14 , wherein the first set of laser light sources outputs laser light beams having a first intensity and a first set of wavelengths, wherein the second set of laser light sources outputs second laser light beams having a second intensity and a second set of wavelengths that is substantially identical to the first set of wavelengths, and wherein the first intensity is higher than the second intensity.

16. The optical engine of claim 14 , wherein the first set of laser light sources outputs laser light beams having a first set of wavelengths, and wherein the second set of laser light sources outputs second laser light beams having a second set of wavelengths that is different from the first set of wavelengths.

17. The optical engine of claim 16 , wherein the first set of wavelengths includes first red, green, and blue (R 1 G 1 B 1 ) nominal wavelengths, and wherein the second set of wavelengths includes second red, green, and blue (R 2 G 2 B 2 ) nominal wavelengths that are different than the R 1 G 1 B 1 nominal wavelengths.

18. The optical engine of claim 16 , wherein the first set of wavelengths includes red, green, and blue (RGB) nominal wavelengths, and wherein the second set of wavelengths includes cyan, yellow, and maroon (CYM) nominal wavelengths.

19. The optical engine of claim 14 , wherein the first set of laser light sources comprises a first type of laser light source, and wherein the second set of laser light sources comprises a second type of laser light source.

20. A wearable heads-up display (WHUD) comprising:
a first set of laser light sources comprising at least three laser light sources;
a second set of laser light sources comprising at least one laser light source; and
a beam combiner configured to combine a plurality of laser light beams output by the first set of laser light sources and the second set of laser light sources into a first combined laser light beam and a second combined laser light beam, wherein the first combined laser light beam is angularly separated from the second combined laser light beam.

21. The WHUD of claim 20 , wherein:
the second set of laser light sources includes multiple laser light sources; and
the beam combiner comprises a plurality of dichroic beam splitters configured to combine a first subset of the plurality of laser light

Assignees

• Google Llc

Inventors

• Adema Daniel
• Nicholson Stuart James Myron

Classifications

• G02B27/283

  used for beam splitting or combining · CPC title

• G02B27/141

  using dichroic mirrors · CPC title

• G02B2027/0114

  comprising dichroic elements · CPC title

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title