Scanning projector display with multiple light engines

Patent metadata

Field	Value
Publication number	US-11366309-B2
Application number	US-201916443644-A
Country	US
Kind code	B2
Filing date	Jun 17, 2019
Priority date	Mar 29, 2019
Publication date	Jun 21, 2022
Grant date	Jun 21, 2022

Abstract

A scanning projector display includes a plurality of light engines coupled to a MEMS scanner. Each light engine includes a light source subassembly for providing a diverging light beam optically coupled to a collimator for collimating the diverging light beam. In operation, the collimated light beams of the plurality of light engines impinge onto the tiltable reflector at different angles of incidence. A controller may be operably coupled to the light source subassembly of each light engine of the plurality of light engines and the MEMS scanner for tilting the tiltable reflector of the MEMS scanner. The controller is configured to energize the light source of each light engine in coordination with tilting the tiltable reflector for displaying the image.

First claim

What is claimed is:

1. A scanning projector display comprising:
a plurality of light engines, each light engine comprising a light source subassembly for providing a diverging light beam optically coupled to a collimator for collimating the diverging light beam to provide a collimated light beam, the collimator comprising a folded-beam optical element comprising at least one reflective surface having optical power; and
a MEMS scanner comprising a tiltable reflector configured to receive and scan the collimated light beam from each light engine of the plurality of light engines to form an image in angular domain;
wherein in operation, the collimated light beams provided by different ones of the plurality of light engines impinge onto the tiltable reflector at different angles of incidence.

2. The scanning projector display of claim 1 , wherein the tiltable reflector comprises a 2D tiltable reflector.

3. The scanning projector display of claim 1 , wherein the light source subassembly comprises a solid-state light source.

4. The scanning projector display of claim 3 , wherein the solid-state light source comprises a plurality of light-emitting semiconductor chips supported by a substrate.

5. The scanning projector display of claim 4 , wherein the collimator is supported by the substrate of the corresponding solid-state light source.

6. The scanning projector display of claim 4 , wherein at least one of the plurality of light-emitting semiconductor chips comprises a plurality of emitters.

7. The scanning projector display of claim 4 , wherein the plurality of light-emitting semiconductor chips comprises a plurality of superluminescent light-emitting diodes (SLEDs).

8. The scanning projector display of claim 4 , wherein the plurality of light-emitting semiconductor chips comprises red, green, and blue color channel light-emitting semiconductor chips for emitting light beams of red, green, and blue color channels, respectively, of the image to be displayed.

9. The scanning projector display of claim 8 , wherein the red, green, and blue color channel light-emitting semiconductor chips are side-emitting chips for emitting the light beams at respective end facets of the red, green, and blue color channel light-emitting semiconductor chips.

10. The scanning projector display of claim 9 , wherein the end facets of the red, green, and blue color channel light-emitting semiconductor chips are disposed at different distances from the corresponding collimator to offset chromatic aberration of the collimator.

11. The scanning projector display of claim 8 , wherein the red, green, and blue color channel light-emitting semiconductor chips are oriented at different angles w.r.t the corresponding collimator to direct their light beams to a clear aperture of the collimator.

12. The scanning projector display of claim 1 , wherein the tiltable reflector has a range of tilt angles, wherein in operation, a difference between angles of incidence of the collimated light beams provided by two of the plurality of light engines at the tiltable reflector is no greater than the range of tilt angles of the tiltable reflector, such that an overlap exists between fields of view provided by each one of the two of the plurality of light engines.

13. The scanning projector display of claim 12 , wherein the overlap is at least 10% of the field of view provided by each one of the two of the plurality of light engines.

14. The scanning projector display of claim 12 , further comprising a controller operably coupled to the light source subassembly of each light engine of the plurality of light engines and the MEMS scanner for tilting the tiltable reflector of the MEMS scanner and configured to energize the light source of each light engine in coordination with tilting the tiltable reflector for displaying the image.

15. The scanning projector display of claim 14 , wherein the controller is further configured to energize the light source of each light engine with a delay corresponding to a difference of the angles of incidence of the corresponding collimated light beams onto the tiltable reflector.

16. A method for displaying an image, the method comprising:
energizing a plurality of light engines for providing a plurality of collimated light beams;
directing the plurality of collimated light beams onto a tiltable reflector of a MEMS scanner, wherein different ones of the collimated light beams impinge onto the tiltable reflector of the MEMS scanner at different angles of incidence; and
tilting the tiltable reflector of the MEMS scanner in coordination with the energizing the plurality of light engines to display the image;
wherein each collimated light beam of the plurality of collimated light beams is obtained using a collimator comprising a folded-beam optical element comprising at least one reflective surface having optical power.

17. The method of claim 16 , wherein the light engines are energized with a delay corresponding to a difference of the angles of incidence of the corresponding collimated light beams onto the tiltable reflector.

18. A scanning projector display comprising:
a first light engine comprising a first light source subassembly for providing a first diverging light beam optically coupled to a first collimator for collimating the first diverging light beam to provide a first collimated light beam having a first polarization;
a second light engine comprising a second light source subassembly for providing a second diverging light beam optically coupled to a second collimator for collimating the second diverging light beam to provide a second collimated light beam having a second polarization orthogonal to the first polarization;
a polarization beam combiner configured for receiving the first and second collimated light beams and combining the first and second collimated light beams into an output beam; and
a MEMS scanner comprising a tiltable reflector configured to receive and scan the output beam to form an image in angular domain;
wherein the first collimator and the second collimator comprise a folded-beam optical element comprising at least one reflective surface having optical power; and
wherein in operation, the collimated light beam provided by the first light engine impinges onto the tiltable reflector at a different angle of incidence than the collimated light beam provided by the second light engine.

19. The scanning projector display of claim 18 , further comprising a controller operably coupled to the first and second light source subassemblies and the MEMS scanner for tilting the tiltable reflector of the MEMS scanner and configured to energize the first and second light source subassemblies in coordination with tilting the tiltable reflector for displaying the image.

Assignees

• Facebook Tech Llc

Inventors

• Mcnally Stephen James
• Martin Chadwick Brian

Classifications

• H04N9/3152

  for shaping the light beam (beam shaping per se G02B27/09) · CPC title

• G02B26/101 Primary

  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 title

• G02B2027/0123

  comprising devices increasing the field of view · CPC title

• G02B2027/0112

  comprising device for genereting colour display · CPC title

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title