Optical System

Patent metadata

Field	Value
Publication number	US-2024288826-A1
Application number	US-202318502256-A
Country	US
Kind code	A1
Filing date	Nov 6, 2023
Priority date	Feb 28, 2023
Publication date	Aug 29, 2024
Grant date	—

Abstract

There is provided an optical system having a viewing window. The optical system comprises a display device arranged to spatially modulated light in accordance with a hologram displayed thereon to form a holographic wavefront. The holographic wavefront forms a holographic reconstruction of an image downstream of the display device. The optical system further comprises a waveguide arranged to receive the holographic wavefront and waveguide the holographic wavefront between a pair of reflective surfaces thereof. One surface of the pair of reflective surfaces is partially transmissive such that a plurality of replicas of the holographic wavefront are emitted therefrom. The optical system further comprises an optical component between the holographic reconstruction and the waveguide, wherein the optical component is arranged to (a) form a virtual image of the holographic reconstruction upstream of the display device and (b) form an image of the displayed hologram at infinity or downstream of the waveguide.

First claim

What is claimed is:

1 . An optical system comprising a viewing window, wherein the optical system further comprises:
a display device arranged to spatially modulate light in accordance with a hologram displayed thereon to form a holographic wavefront, wherein the holographic wavefront forms a holographic reconstruction of an image downstream of the display device; a waveguide arranged to receive the holographic wavefront and waveguide the holographic wavefront between a pair of reflective surfaces thereof, wherein one surface of the pair of reflective surfaces is partially transmissive such that a plurality of replicas of the holographic wavefront are emitted therefrom; and an optical component between the holographic reconstruction and the waveguide, wherein the optical component is arranged to (a) form a virtual image of the holographic reconstruction upstream of the display device and (b) form an image of the displayed hologram at one of infinity or downstream of the waveguide.

2 . The optical system of claim 1 , wherein the optical component is arranged such that the wavefront coupled into the waveguide comprises a transform of a holographic wavefront encoding a picture.

3 . The optical system of claim 1 , wherein the optical component is arranged such that the wavefront coupled into the waveguide comprises a Fourier transform of the holographic wavefront.

4 . The optical system of claim 1 , wherein the optical system further comprises:
an optical relay between the display device and the waveguide, wherein the optical relay comprises two lenses arranged in cooperation to form a relayed hologram and a relayed holographic reconstruction, wherein the relayed hologram is an image of the hologram displayed on the display device and the relayed holographic reconstruction is an image of the holographic reconstruction formed by the hologram displayed on the display device; and wherein the optical component is between the relayed holographic reconstruction and the waveguide and: (a) a distance between the relayed holographic reconstruction and the optical component is less than a focal length of the optical component such that the virtual image of the holographic reconstruction formed by the optical component is a virtual image of the relayed holographic reconstruction; and (b) a distance between the relayed hologram and the optical component is equal to a focal length of the optical component such that the image of the hologram formed by the optical component is a virtual image formed at infinity.

5 . The optical system of claim 1 , wherein the optical system further comprises:
an optical relay between the display device and waveguide, wherein the optical relay comprises two lenses arranged in cooperation to form a relayed hologram and a relayed holographic reconstruction, wherein the relayed hologram is an image of the hologram displayed on the display device and the relayed holographic reconstruction is an image of the holographic reconstruction formed by the hologram displayed on the display device; and wherein the optical component is between the relayed holographic reconstruction and the waveguide and: (a) a distance between the relayed holographic reconstruction and the optical component is less than a focal length of the optical component such that the virtual image of the holographic reconstruction formed by the optical component is a virtual image of the relayed holographic reconstruction; and (b) a distance between the relayed hologram and the optical component is greater than a focal length of the optical component such that the image of the hologram formed by the optical component is a real image formed downstream of the waveguide.

6 . The optical system of claim 5 , wherein at least one of the image of the hologram or relayed hologram formed by the optical component is a real image formed downstream of a viewing window of the optical system.

7 . The optical system of claim 1 , wherein (i) a distance between the holographic reconstruction and the optical component is less than a focal length of the optical component such that the image of the holographic reconstruction is a virtual image formed upstream of the display device and (ii) a distance between the display device and the waveguide is equal to a focal length of the optical component such that an image of the hologram is formed upstream of the hologram.

8 . The optical system of claim 1 , wherein (i) a distance between the holographic reconstruction and the optical component is less than a focal length of the optical component such that the image of the holographic reconstruction is a virtual image formed upstream of the display device and (ii) a distance between the display device and the waveguide is greater than a focal length of the optical component such that an image of the hologram is formed downstream of the waveguide.

9 . The optical system of claim 8 , wherein the image of the hologram or relayed hologram formed by the optical component is a real image formed downstream of a viewing window of the optical system.

10 . The optical system of claim 1 , wherein a distance between the virtual image of the holographic reconstruction and the image of the displayed hologram formed by the optical component is one of (i) greater than 1 meter, (ii) greater than 2 meters, or (iii) greater than 5 meters.

11 . The optical system of claim 1 , wherein the optical component is arranged such that a distance from the optical component to the virtual image of the holographic reconstruction is in a range of between about 0.5 to 10 meters.

12 . The optical system of claim 1 , wherein a focal length of the optical component is one of (i) less than 150 mm, (ii) less than 120 mm, or (iii) less than 100 mm.

13 . The optical system of claim 1 , wherein the holographic wavefront received by the waveguide comprises non-collimated light.

14 . The optical system of claim 13 , wherein the non-collimated light comprises diverging light.

15 . The optical system of claim 1 , wherein each diffractive pattern is representative of a lens.

16 . The optical system of claim 1 , wherein each diffractive pattern brings light to a focal point.

17 . A method of holographic image formation, the method comprising:
spatially modulating light in accordance with a hologram displayed on a display device to form a holographic wavefront; forming a holographic reconstruction of an image downstream of the display device; forming a virtual image of the holographic reconstruction upstream of the display device using an optical component; forming an image of the displayed hologram at infinity or downstream of a waveguide using the optical component; and receiving the holographic wavefront at a waveguide and waveguiding the holographic wavefront between a pair of reflective surfaces thereof, wherein one surface of the pair of reflective surfaces is partially transmissive such that a plurality of replicas of the holographic wavefront are emitted therefrom; wherein the optical component is between the holographic reconstruction and the waveguide.

18 . The method of claim 17 , wherein (i) a distance between the holographic reconstruction and the optical component is less than a focal length of the optical component such that the image of the holographic reconstruction is a virtual image formed upstream of the display device and (ii) a distance between the display device and the waveguide is greater than a focal length of the optical component such that an image of the hologram is formed downstream of the wave

Assignees

• Envisics Ltd

Inventors

• Christmas Jamieson

Classifications

• G03H1/265

  Angle multiplexing; Multichannel holograms (G03H1/268 takes precedence) · CPC title

• G03H1/2294

  Addressing the hologram to an active spatial light modulator · CPC title

• G03H1/2249

  Holobject properties · CPC title

• G03H1/2202

  Reconstruction geometries or arrangements · CPC title

• G03H1/22

  Processes or apparatus for obtaining an optical image from holograms (G03H1/26 - G03H1/34 take precedence) · CPC title