Systems and methods to minimize double-bounce in waveguides

Patent metadata

Field	Value
Publication number	US-12270997-B2
Application number	US-202117464240-A
Country	US
Kind code	B2
Filing date	Sep 1, 2021
Priority date	Sep 1, 2021
Publication date	Apr 8, 2025
Grant date	Apr 8, 2025

Abstract

Systems and methods to reduce diffraction-angle effects, such as instances of double-bounces and bounce separation spacing effects in a laser projection system including an optical engine with laser diodes configured to emit light beams of different wavelengths and a beam combiner having a reflective surfaces each configured to receive one of the light beams from one of the laser diodes and to reflect the received light beam such that an edge of the reflected light beam lies on a tangent common to the other light beams reflected from the other reflective surfaces. The laser projection system may be implemented in head-mounted display (HMD) including a waveguide having an incoupler to receive the combined light beam, where an edge of the incoupler corresponds to the tangent on which the edges of the plurality of light beams are aligned.

First claim

What is claimed is:

1. A laser projection system comprising:
an optical engine comprising a plurality of laser diodes configured to emit a plurality of light beams; and
a beam combiner having a plurality of reflective surfaces each configured to receive a light beam of the plurality of light beams from one of the plurality of laser diodes and to reflect the received light beam such that an edge of the reflected light beam lies on a tangent common to the plurality of light beams reflected from other of the plurality of reflective surfaces, wherein at least one light beam of the plurality of light beams has a different perimeter relative to at least one other light beam of the plurality of light beams upon exiting the beam combiner.

2. The laser projection system of claim 1 , wherein each of the plurality of laser diodes emits light over a unique range of wavelengths relative to the other plurality of laser diodes.

3. The laser projection system of claim 1 , wherein the plurality of reflective surfaces are disposed at parallel planes intersecting an optical path within the beam combiner.

4. The laser projection system of claim 3 , wherein a position of each of the plurality of reflective surfaces within the beam combiner is based on aligning an edge of each the plurality of light beams on a tangent.

5. The laser projection system of claim 3 , wherein spacing between each of the plurality of reflective surfaces within the beam combiner is based on aligning an edge of each the plurality of light beams on a tangent.

6. The laser projection system claim 3 , wherein the tangent corresponds to an edge of an incoupler of a waveguide associated with the laser projection system, wherein each light beam of the plurality of light beams has a perimeter that is proportional to a diffraction angle to be imparted on the respective light beam when incident on the incoupler.

7. A method comprising:
at a laser projection system comprising a plurality of laser diodes and a beam combiner having a plurality of reflective surfaces disposed therein, wherein each of the plurality of reflective surfaces is positioned to receive a light beam projected from one of the plurality of laser diodes:
projecting a plurality of light beams from the plurality of laser diodes; and
generating a combined light beam by reflecting the plurality of light beams from the plurality of reflective surfaces such that an edge of each of the plurality of light beams is aligned on a tangent, wherein at least one light beam of the plurality of light beams has a different perimeter relative to at least one other light beam of the plurality of light beams within the combined light beam.

8. The method of claim 7 , wherein each of the plurality of laser diodes emits light over a unique range of wavelengths relative to the other plurality of laser diodes.

9. The method of claim 8 , wherein each of the plurality of laser diodes emits light over a unique range of wavelengths relative to the other plurality of laser diodes.

10. The method of claim 7 , wherein the plurality of reflective surfaces are disposed at parallel planes intersecting an optical path within the beam combiner.

11. The method of claim 10 , wherein:
each of the plurality of reflective surfaces within the beam combiner is positioned such that an edge of each of the light beams reflected by each of the plurality of reflective surfaces is aligned on a tangent common to an edge of one of the other plurality of light beams reflected from a different one of the plurality of reflective surfaces.

12. The method of claim 10 , further comprising:
spacing each of the plurality of reflective surfaces within the beam combiner such that an edge of each of the light beams reflected by each of the plurality of reflective surfaces is aligned on a tangent common to an edge of one of the other plurality of light beams reflected from a different one of the plurality of reflective surfaces.

13. The method of claim 7 , wherein the tangent corresponds to an edge of an incoupler of a waveguide associated with the laser projection system.

14. A head-mounted display (HMD) comprising:
a laser projection system comprising:
an optical engine comprising a plurality of laser diodes configured to emit a plurality of light beams; and
a beam combiner having a plurality of reflective surfaces configured to generate a combined light beam by reflecting the plurality of light beams from the plurality of reflective surfaces such that an edge of each of the plurality of light beams is aligned on a tangent, wherein at least one light beam of the plurality of light beams has a different perimeter relative to at least one other light beam of the plurality of light beams within the combined light beam; and

a waveguide having an incoupler to receive the combined light beam, wherein an edge of the incoupler corresponds to the tangent on which the edges of the plurality of light beams are aligned.

15. The HMD of claim 14 , wherein each of the plurality of laser diodes emits light over a unique range of wavelengths relative to the other plurality of laser diodes.

16. The HMD of claim 14 , wherein the plurality of reflective surfaces are disposed at parallel planes intersecting an optical path within the beam combiner.

17. The HMD of claim 14 , wherein a position of each of the plurality of reflective surfaces and a spacing between each of the plurality of reflective surfaces within the beam combiner is based on aligning an edge of each the plurality of light beams on a tangent.

Assignees

• Google Llc

Inventors

• Adema Daniel

Classifications

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02B6/0023

  provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source · CPC title

• G02B27/0081

  with means for altering, e.g. enlarging, the entrance or exit pupil · CPC title

• G02B2027/0123

  comprising devices increasing the field of view · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title