Beam combining architectures for scanning display systems

Patent metadata

Field	Value
Publication number	US-12292569-B2
Application number	US-202217580745-A
Country	US
Kind code	B2
Filing date	Jan 21, 2022
Priority date	Jan 22, 2021
Publication date	May 6, 2025
Grant date	May 6, 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 plurality of laser light sources;
a beam combiner configured to:
combine a first subset of a plurality of laser light beams output by the plurality of laser light sources into a first combined laser light beam; and
combine a second subset of the plurality of laser light beams into a second combined laser light beam that is different from the first combined laser light beam; and

an optical scanner configured to form a first set of pixels using the first combined laser light beam and to form a second set of pixels using the second combined laser light beam, wherein the first set of pixels at least partially overlaps the second set of pixels within a field of view of the display system.

2. The display system of claim 1 , wherein the beam combiner comprises a plurality of dichroic beam splitters that each receive one or more laser light beams of the plurality of laser light beams.

3. The display system of claim 2 , wherein the plurality of dichroic beam splitters is arranged within the beam combiner in an ascending order with respect to a wavelength of light respectively associated with each of the plurality of dichroic beam splitters.

4. The display system of claim 1 , wherein the beam combiner comprises at least one polarization beam splitter configured to combine a first subset of the plurality of laser light beams having a first polarization with a second subset of the plurality of laser light beams having a second polarization.

5. The display system of claim 1 , wherein the beam combiner comprises a first set of dichroic beam splitters to combine the first subset of laser light beams and comprises a second set of dichroic beam splitters to combine the second subset of laser light beams.

6. The display system of claim 1 , wherein the first combined laser light beam is angularly separated from the second combined laser light beam.

7. The display system of claim 1 , further comprising a waveguide, wherein the optical scanner is 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 the waveguide, and wherein the waveguide is configured to project the first combined laser light beam and the second combined laser light beam to form the respective first and second sets of pixels.

8. The display system of claim 1 , wherein a first region of the field of view includes only pixels of the first set of pixels, and a second region of the field of view includes only pixels of the second set of pixels.

9. The display system of claim 8 , wherein a third region of the field of view includes pixels of the first set of pixels superimposed with at least some of the second set of pixels.

10. A display system comprising:
an optical engine comprising a plurality of laser light sources;
a beam combiner configured to combine a plurality of laser light beams output by the plurality of laser light sources;
a plurality of collimating lenses that are disposed between the optical engine and the beam combiner, and that are configured to angularly separate pairs of laser light beams of the plurality of laser light beams; and
a retroreflector prism disposed at a first side of the beam combiner, wherein the optical engine and the collimating lenses are disposed at a second side of the beam combiner that is opposite the first side, wherein the retroreflector prism is configured to provide an extended optical path length to one or more laser light beams of the plurality of laser light beams.

11. The display system of claim 10 , further comprising:
a wedge prism coupled to the beam combiner to adjust an angular separation between the laser light beams of each pair of laser light beams output by the beam combiner toward the retroreflector prism.

12. A beam combiner operable to be optically coupled to a plurality of laser light sources, the beam combiner comprising:
a plurality of dichroic beam splitters configured to combine a first subset of the plurality of laser light beams into a first combined laser light beam, and to combine a second subset of the plurality of laser light beams into a second combined laser light beam that is distinct and separate from the first combined laser light beam; and
a retroreflector prism configured to provide an extended optical path length to one or more laser light beams of the plurality of laser light beams.

13. The beam combiner of claim 12 , wherein the plurality of dichroic beam splitters is arranged within the beam combiner in an ascending order with respect to a wavelength of light respectively associated with each of the plurality of dichroic beam splitters.

14. The beam combiner of claim 12 , further comprising at least one polarization beam splitter configured to combine a first subset of the plurality of laser light beams having a first polarization with a second subset of the plurality of laser light beams having a second polarization.

15. The beam combiner of claim 12 , wherein the beam combiner comprises a first set of dichroic beam splitters to combine the first subset of laser light beams, and comprises a second set of dichroic beam splitters to combine the second subset of laser light beams.

16. The beam combiner of claim 12 , wherein the first combined laser light beam is angularly separated with respect to the second laser light beam.

17. The beam combiner of claim 12 , further comprising:
a wedge prism configured to adjust an angular separation between the laser light beams of each of multiple pairs of laser light beams output by the beam combiner toward the retroreflector prism.

18. A method, comprising:
combining a first subset of a plurality of laser light beams into a first combined laser light beam;
combining a second subset of the plurality of laser light beams into a second combined laser light beam that is angularly separated from the first combined laser light beam; and
based at least in part on an angular separation of the first combined laser light beam and the second combined laser light beam, scanning the first combined laser light beam and the second combined laser light beam across an incoupler of a waveguide to form respective first and second sets of pixels, the first set of pixels at least partially overlapping the second set of pixels.

19. The display system of claim 18 , wherein a first region of the field of view includes only pixels of the first set of pixels, and a second region of the field of view includes only pixels of the second set of pixels.

20. The display system of claim 19 , wherein a third region of the field of view includes pixels of the first set of pixels superimposed with at least some of the second set of pixels.

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