Method and system for projection display with polarization selective reflectors

Patent metadata

Field	Value
Publication number	US-11982818-B2
Application number	US-202017114122-A
Country	US
Kind code	B2
Filing date	Dec 7, 2020
Priority date	Jun 8, 2018
Publication date	May 14, 2024
Grant date	May 14, 2024

Abstract

Augmented reality glasses can include a first laser, a second laser, and a scanning mirror. The augmented reality glasses can also include a first polarization selective reflector and a second polarization selective reflector. The first polarization selective reflector is arranged to receive light from the first laser and reflect light received from the first laser at a first angle to the scanning mirror, and the second polarization selective reflector is arranged to receive light from the second laser and reflect light received from the second laser at a second angle to the scanning mirror. The augmented reality glasses can also have an eyepiece having an input coupling port arranged to receive light reflected by the scanning mirror.

First claim

What is claimed is:

1. Augmented reality glasses comprising:
a first laser;
a second laser;
a scanning mirror;
a first polarization selective reflector arranged to receive light from the first laser and reflect light received from the first laser at a first angle to the scanning mirror;
a second polarization selective reflector arranged to receive light from the second laser and reflect light received from the second laser at a second angle to the scanning mirror; and
an eyepiece having an input coupling port arranged to receive light reflected by the scanning mirror.

2. The augmented reality glasses of claim 1 wherein:
the first laser is configured to emit light having a first polarization state that is either p-polarization or s-polarization;
the second laser is configured to emit light having the first polarization state;
the first polarization selective reflector is configured to reflect light of the first polarization state; and
the second polarization selective reflector is configured to reflect light of the first polarization state.

3. The augmented reality glasses of claim 1 wherein:
the first laser is configured to emit light having a first polarization state;
the second laser is configured to emit light having a second polarization state;
the first polarization selective reflector is configured to reflect light of the first polarization state; and
the second polarization selective reflector is configured to reflect light of the second polarization state.

4. The augmented reality glasses of claim 3 further comprising:
a third laser; and
a fourth laser.

5. The augmented reality glasses of claim 4 further comprising:
a third polarization selective reflector arranged to receive light from the third laser and reflect light received from the third laser at a third angle to the scanning mirror; and
a fourth polarization selective reflector arranged to receive light from the fourth laser and reflect light received from the fourth laser at a fourth angle to the scanning mirror.

6. The augmented reality glasses of claim 5 wherein:
the third laser is configured to emit light having the first polarization state;
the fourth laser is configured to emit light having the first polarization state;
the third polarization selective reflector is configured to reflect light of the first polarization state; and
the fourth polarization selective reflector is configured to reflect light of the first polarization state.

7. The augmented reality glasses of claim 5 wherein:
the third laser is configured to emit light having the first polarization state;
the fourth laser is configured to emit light having the second polarization state;
the third polarization selective reflector is configured to reflect light of the first polarization state; and
the fourth polarization selective reflector is configured to reflect light of the second polarization state.

8. The augmented reality glasses of claim 1 wherein the scanning mirror comprises a two axis scanning mirror.

9. The augmented reality glasses of claim 1 further comprising a first wave plate positioned along a first optical path between the first polarization selective reflector and the second polarization selective reflector.

10. The augmented reality glasses of claim 9 wherein the first wave plate comprises a half wave plate.

11. The augmented reality glasses of claim 9 wherein the first optical path includes the scanning mirror.

12. The augmented reality glasses of claim 9 wherein the first optical path does not include the scanning mirror.

13. The augmented reality glasses of claim 9 comprising a prism wherein the first polarization selective reflector, the second polarization selective reflector and the first wave plate are embedded in the prism.

14. The augmented reality glasses of claim 9 further comprising a second wave plate positioned along a second optical path between the first polarization selective reflector and the second polarization selective reflector.

15. The augmented reality glasses of claim 14 wherein the second optical path includes the scanning mirror.

16. The augmented reality glasses of claim 1 wherein the first laser is arranged to emit light in a first direction and the second laser is arranged to emit light in a second direction.

17. The augmented reality glasses of claim 1 comprising a prism, wherein the first polarization selective reflector and the second polarization selective reflector are embedded in the prism.

18. The augmented reality glasses of claim 1 wherein:
the eyepiece further comprises an orthogonal pupil expander and an exit pupil expander; and
the input coupling port is configured to direct light to the orthogonal pupil expander and the orthogonal pupil expander is configured to direct light toward the exit pupil expander.

19. The augmented reality glasses of claim 1 wherein the first laser comprises a first red laser, the augmented reality glasses further comprising:
a first RGB beam combiner and a second RGB beam combiner; and
a first blue laser and a first green laser, wherein the first red laser, the first blue laser, and the first green laser are coupled through the first RGB beam combiner to the first polarization selective reflector.

20. The augmented reality glasses of claim 1 wherein the first polarization selective reflector and the second polarization selective reflector are located at least partly overlying the input coupling port.

Assignees

• Magic Leap Inc

Inventors

• Freedman Barak
• Pellman Asaf
• Weinstein Ori

Classifications

• G02B27/28 Primary

  for polarising (used in stereoscopes G02B30/25) · CPC title

• G02B27/0172

  characterised by optical features · CPC title

• G02B27/0176

  characterised by mechanical features · CPC title

• G02B30/25

  using polarisation techniques · CPC title

• G02B30/60

  involving reflecting prisms and mirrors only · CPC title