Anamorphic directional illumination device

Patent metadata

Field	Value
Publication number	US-12585094-B2
Application number	US-202318211704-A
Country	US
Kind code	B2
Filing date	Jun 20, 2023
Priority date	Jun 22, 2022
Publication date	Mar 24, 2026
Grant date	Mar 24, 2026

Abstract

An anamorphic near-eye display apparatus comprises a spatial light modulator with asymmetric pixels; an input transverse anamorphic lens; and an extraction waveguide that passes input light in a first direction to a lateral anamorphic reflector arranged to reflect the light back through the waveguide. Partially reflective extraction elements are arranged between the rear and front guide surfaces of the waveguide to extract the reflected light towards the pupil of an observer, maintaining the directionality of the fan of light rays from the spatial light modulator and anamorphic imaging system. A thin, transparent and efficient anamorphic display apparatus for Augmented Reality and Virtual Reality displays is provided.

First claim

The invention claimed is:

1 . An anamorphic near-eye display apparatus comprising:
an illumination system comprising a spatial light modulator, the illumination system being arranged to output light; and an optical system arranged to direct light from the illumination system to a viewer's eye, wherein the optical system has an optical axis and has anamorphic properties in a lateral direction and a transverse direction that are perpendicular to each other and perpendicular to the optical axis, wherein the spatial light modulator comprises pixels distributed in the lateral direction, and the optical system comprises: a transverse anamorphic component having positive optical power in the transverse direction, wherein the transverse anamorphic component is arranged to receive light from the spatial light modulator and the illumination system is arranged so that light output from the transverse anamorphic component is directed in directions that are distributed in the transverse direction; an extraction waveguide arranged to receive light from the transverse anamorphic component; a lateral anamorphic component having positive optical power in the lateral direction, the extraction waveguide being arranged to guide light from the transverse anamorphic component to the lateral anamorphic component along the extraction waveguide in a first direction; and a light reversing reflector that is arranged to reflect light that has been guided along the extraction waveguide in the first direction so that the reflected light is guided along the extraction waveguide in a second direction opposite to the first direction, wherein the extraction waveguide comprises an array of reflective extraction features disposed internally within the extraction waveguide, the reflective extraction features being arranged to transmit light guided along the extraction waveguide in the first direction and to extract light guided along the extraction waveguide in the second direction towards an eye of a viewer, the array of reflective extraction features being distributed along the extraction waveguide so as to provide exit pupil expansion.

2 . An anamorphic near-eye display apparatus according to claim 1 , wherein the reflective extraction features comprise extraction reflectors extending across at least part of the extraction waveguide between front and rear guide surfaces of the extraction waveguide.

3 . An anamorphic near-eye display apparatus according to claim 2 ,
wherein the array of reflective extraction reflectors have reflectivities defined across their overall area that increase with increasing distance along the second direction.

4 . An anamorphic near-eye display apparatus according to claim 2 , wherein the extraction reflectors comprise extraction surfaces spaced apart by a partially reflective coating.

5 . An anamorphic near-eye display apparatus according to claim 4 , wherein the partially reflective coating comprises at least one dielectric layer.

6 . An anamorphic near-eye display apparatus according to claim 5 , wherein the at least one dielectric layer comprises a stack of dielectric layers.

7 . An anamorphic near-eye display apparatus according to claim 4 , wherein the partially reflective coating is metallic.

8 . An anamorphic near-eye display apparatus according to claim 2 , wherein the extraction reflectors comprise extraction surfaces spaced apart by a gap.

9 . An anamorphic near-eye display apparatus according to claim 8 , wherein the extraction surfaces have an anti-reflection coating.

10 . An anamorphic near-eye display apparatus according to claim 2 , wherein the extraction reflectors extend partially across the extraction waveguide between the front and rear guide surfaces of the extraction waveguide with successively shifted positions.

11 . An anamorphic near-eye display apparatus according to claim 10 , wherein the extraction reflectors extend to the front and rear guide surfaces of the extraction waveguide.

12 . An anamorphic near-eye display apparatus according to claim 11 , wherein the extraction reflectors do not extend to the front and rear guide surfaces of the extraction waveguide.

13 . An anamorphic near-eye display apparatus according to claim 10 , further comprising intermediate reflectors extending along the extraction waveguide between adjacent pairs of extraction reflectors.

14 . An anamorphic near-eye display apparatus according to claim 13 , wherein the intermediate reflectors comprise intermediate surfaces spaced apart by a partially reflective coating.

15 . An anamorphic near-eye display apparatus according to claim 14 , wherein the partially reflective coating comprises at least one dielectric layer.

16 . An anamorphic near-eye display apparatus according to claim 15 , wherein the at least one dielectric layer comprises a stack of dielectric layers.

17 . An anamorphic near-eye display apparatus according to claim 14 , wherein the partially reflective coating is metallic.

18 . An anamorphic near-eye display apparatus according to claim 13 , wherein the intermediate reflectors comprise intermediate surfaces spaced apart by a gap.

19 . An anamorphic near-eye display apparatus according to claim 18 , wherein the intermediate surfaces have an anti-reflection coating.

20 . An anamorphic near-eye display apparatus according to claim 10 , wherein the extraction waveguide comprises plural constituent parts having facing stepped surfaces attached together, the stepped surfaces being shaped with alternating extraction surfaces extending in the transverse direction and intermediate surfaces extending along the extraction waveguide, wherein the extraction reflectors comprise the facing extraction surfaces.

21 . An anamorphic near-eye display apparatus according to claim 20 , wherein the intermediate surfaces are optically coupled together.

22 . An anamorphic near-eye display apparatus according to claim 10 , wherein the extraction reflectors comprise plural sets of extraction reflectors, wherein, within each set of extraction reflectors, in the transverse direction the extraction reflectors extend partially across the extraction waveguide with successively shifted positions, the extraction reflectors of different sets overlapping in extent in the transverse direction.

23 . An anamorphic near-eye display apparatus according to claim 2 , wherein at least part of the extraction waveguide comprises plural constituent plates optically coupled together, wherein the extraction reflectors are formed between the plural constituent plates.

24 . An anamorphic near-eye display apparatus according to claim 2 , wherein the extraction reflectors extend between the front and rear guide surfaces of the extraction waveguide.

25 . An anamorphic near-eye display apparatus according to claim 2 , wherein the extraction reflectors have the same reflective area.

26 . An anamorphic near-eye display apparatus according to claim 2 , wherein the extraction reflectors are patterned to have different reflective areas providing reflectivities defined across their overall area that increase with increasing distance along the optical axis.

27 . An anamorphic near-eye display apparatus according to claim 2 , wherein the extraction reflectors have a surface normal direction that is inclined with respect to the direction along the extraction waveguide by an angle in

Assignees

• Reald Spark Llc

Inventors

• Woodgate Graham J
• Robinson Michael G
• Harrold Jonathan

Classifications

• G02B27/0172 Primary

  characterised by optical features · CPC title

• G02B27/0081

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

• G02B13/08 Primary

  Anamorphotic objectives · CPC title