Waveguide display system with wide field of view

Patent metadata

Field	Value
Publication number	US-2024210612-A1
Application number	US-202117913816-A
Country	US
Kind code	A1
Filing date	Mar 22, 2021
Priority date	Mar 23, 2020
Publication date	Jun 27, 2024
Grant date	—

Abstract

Embodiments include an optical system that may be included in a waveguide display. An example optical system includes a first waveguide having a first transmissive diffractive in-coupler (DG1) and a first diffractive out-coupler (DG6) and a second waveguide having a second transmissive diffractive in-coupler (DG2), a reflective diffractive in-coupler (DG3), a second diffractive out-coupler (DG4), and a third diffractive out-coupler (DG5). The second transmissive diffractive in-coupler (DG2) is arranged between the first transmissive diffractive in-coupler (DG1) and the reflective diffractive in-coupler (DG3) in an input region.

First claim

1 . An optical system comprising:
a first waveguide having a first transmissive diffractive in-coupler (DG1); and a second waveguide having a second transmissive diffractive in-coupler (DG2) and a reflective diffractive in-coupler (DG3); wherein the second transmissive diffractive in-coupler (DG2) is arranged between the first transmissive diffractive in-coupler (DG1) and the reflective diffractive in-coupler (DG3) in an input region.

2 . The optical system of claim 1 , wherein:
the first waveguide further comprises a first diffractive out-coupler (DG6); and the second waveguide further comprises a second diffractive out-coupler (DG4) and a third diffractive out-coupler (DG5).

3 . The optical system of claim 2 , further comprising an image generator operative to provide an image at the input region, wherein the optical system is configured to substantially replicate the image at an output pupil region, the output pupil region including the first diffractive out-coupler (DG6), the second diffractive out-coupler (DG4), and the third diffractive out-coupler (DG5).

4 . The optical system of claim 3 , wherein the system is configured to substantially replicate an image spanning a field of view of at least 100°.

5 . The optical system of claim 3 , wherein the system is configured to replicate a full-color image.

6 . The optical system of claim 1 , wherein the first diffractive in-coupler has a first grating pitch, the second diffractive in-coupler has a second grating pitch greater than the first grating pitch, and the reflective diffractive in-coupler has a third grating pitch greater than the second grating pitch.

7 . The optical system of claim 1 , wherein

d
1

=

M
1

⁢
λ

n
2

⁢

sin
⁢

Φ

WG
⁢
1

G

+

sin
⁢

Θ

WG
⁢
1

G

where d 1 is a grating pitch the of first transmissive diffractive in-coupler (DG1), M 1 is a non-zero integer, n 2 is a refractive index of the first waveguide, λ is a wavelength between 450 nm and 700 nm, Φ WG1 G is an angle between 55 and 90 degrees, and Θ GW1 G is substantially equal to an angle that diffracts into a critical angle of the second waveguide, where the critical angle of the second waveguide is arcsin(1/n 3 ), where n 3 is a refractive index of the first waveguide.

8 . The optical system of claim 7 , wherein

d
2

=

M
2

⁢
λ

n
3

⁢

sin
⁢

Φ

WG
⁢
2

G

+

sin
⁢

Θ

WG
⁢
2

G

where d 2 is a grating pitch of the second transmissive diffractive in-coupler (DG2), M 2 is a non-zero integer, n 3 is a refractive index of the second waveguide, λ is a wavelength between 450 nm and 700 nm, Φ WG2 G is an angle between 55 and 90 degrees, and Θ WG2 G is an angle within ±5 degrees of normal incidence.

9 . The optical system of claim 1 , wherein the system is configured (i) to couple at least some incident light having a first incident angle to travel in a first direction in at least one of the first and second waveguide, and (ii) to couple at least some incident light having a second incident angle substantially opposite the first incident angle to travel in a second direction substantially opposite the first direction in at least one of the first and second waveguide.

10 . The optical system of claim 1 , wherein:
a first grating pitch (d 1 ) of the first transmissive diffractive in-coupler is between 420 nm and 520 nm; a second grating pitch (d 2 ) of the second transmissive diffractive in-coupler is between 600 nm and 700 nm; and a third grating pitch (d 3 ) of the reflective diffractive in-coupler is between 720 nm and 820 nm.

11 . The optical system of claim 1 , wherein:
a first grating pitch (d 1 ) of the first transmissive diffractive in-coupler is between 460 nm and 480 nm; a second grating pitch (d 2 ) of the second transmissive diffractive in-coupler is between 640 nm and 660 nm; and a third grating pitch (d 3 ) of the reflective diffractive in-coupler is between 760 nm and 780 nm.

12 . The optical system of claim 1 , wherein:
a second grating pitch (d 2 ) of the second transmissive diffractive in-coupler is between 30% and 50% greater than a first grating pitch (d 1 ) of the first transmissive diffractive in-coupler; and a third grating pitch (d 3 ) of the reflective diffractive in-coupler is between 10% and 30% greater than the second grating pitch.

13 . A method of operating an optical system, the method comprising:
directing input light representing an image onto a first transmissive diffractive in-coupler (DG1) of a first waveguide; using the first transmissive diffractive in-coupler (DG1) to couple into the first waveguide a first portion of the input light; using a second transmissive diffractive in-coupler (DG2) of a second waveguide to couple into the second waveguide a second portion of the input light; and using a reflective diffractive in-coupler (DG3) of the second waveguide to couple into the second waveguide a third portion of the input light.

14 . The method of claim 13 , wherein

d
1

=

M
1

⁢
λ

Assignees

• Interdigital Ce Patent Holdings Sas

Inventors

• Shramkova Oksana
• Drazic Valter
• Allie Valerie

Classifications

• G02B2027/0174

  holographic · CPC title

• G02B2027/0123

  comprising devices increasing the field of view · CPC title

• G02B2027/0112

  comprising device for genereting colour display · CPC title

• G02B6/0088 Primary

  of the light guide or other optical sheets in the package · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title