MULTI-FOCAL DISPLAY SYSTEM AND METHOD

• US 20150222884A1
• Filed: 01/30/2015
• Published: 08/06/2015
• Est. Priority Date: 01/31/2014
• Status: Active Grant

• Current Assignee: Magic Leap, Inc.
• Original Assignee: Magic Leap, Inc.
• Inventors: Cheng, Hui-Chuan
• Granted Patent: US 10,317,690 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 26/103 having movable or deformable optical fibres, light guides or waveguides as scanning elements light guides per se G02B6/00
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 30/52 the 3D volume being constructed from a stack or sequence of 2D planes, e.g. depth sampling systems
• CPC Class Codes: H04N 13/344 with head-mounted left-right displays
• CPC Class Codes: H04N 13/395 with depth sampling, i.e. the volume being constructed from a stack or sequence of 2D image planes

Abstract

Configurations are disclosed for presenting virtual reality and augmented reality experiences to users. The system may comprise a scanning device for scanning one or more frames of image data. The scanning device may be communicatively coupled to an image source to receive the image data. The system may further comprise a variable focus element (VFE) operatively coupled to the scanning device for focusing the one or more frames of image data on an intermediate image plane, wherein the intermediate image plane is aligned to one of a plurality of switchable screens. The plurality of switchable screens may spread light associated with the intermediate image plane to specific viewing distances. The system may also comprise viewing optics operatively coupled to the plurality of switchable screens to relay the one or more frames of image data.

Claims

1. An augmented reality display system, comprising:

a scanning device for scanning one or more frames of image data, wherein the scanning device is communicatively coupled to an image source to receive the image data;

a variable focus element (VFE) operatively coupled to the scanning device for focusing the one or more frames of image data on an intermediate image plane, wherein the intermediate image plane is aligned to one of a plurality of switchable screens, and the plurality of switchable screens spreads light associated with the intermediate image plane to specific viewing distances; and

viewing optics operatively coupled to the plurality of switchable screens to relay the one or more frames of image data.

2. The augmented reality display system of claim 1, wherein the plurality of switchable screens comprise switchable polymer dispersed liquid crystal (PDLC) diffusers.

3. The augmented reality display system of claim 1, wherein the scanning device is a fiber scanned device (FSD).

4. The augmented reality display system of claim 1, wherein the plurality of switchable screens switch between a diffusive state and a transparent state.

5. The augmented reality display system of claim 4, wherein one screen of the plurality of switchable screens is switched into the diffusive state and a remaining number of screens are switched into the transparent state.

6. The augmented reality display system of claim 4, wherein the plurality of switchable screens can be switched between the diffusive and transparent state on a frame-by-frame basis.

7. The augmented reality display system of claim 1, wherein the scanning device scans the one or more frames of image data in a scanning pattern.

8. The augmented reality display system of claim 1, wherein the VFE is associated with a small aperture.

9. The augmented reality display system of claim 7, wherein a drive signal of the VFE is varied as a function of the scanning pattern of the light modulator.

10. The augmented reality display system of claim 9, wherein the VFE flattens a field curvature of the one or more frames of image data.

11. The augmented reality display system of claim 9, wherein an optical power of the VFE is varied as a function of a position of a scanned spot within a scan field of the scanning device.

12. The augmented reality display system of claim 9, wherein a first portion of an image is focused differently than a periphery of the image.

22. The method of claim 12, wherein a first portion of an image is focused differently than a periphery of the image.

13. A method of displaying augmented reality, comprising:

providing one or more frames of image data;

scanning light associated with the one or more frames of image data in a scanning pattern;

varying the focus of the scanned light, through a variable focus element (VFE), such that the one or more frames of image data is brought into focus on one of plurality of switchable screens; and

spreading the focused light, through the one of the plurality of switchable screens, wherein the switchable screens correspond to different viewing distances.

14. The method of claim 13, wherein the focus is varied on a frame-by-frame basis.

15. The method of claim 13, wherein the one or more frames of image data is presented in a time-sequential manner.

16. The method of claim 13, wherein the plurality of switchable screens comprise switchable polymer dispersed liquid crystal (PDLC) diffusers.

17. The method of claim 13, wherein the plurality of switchable screens switch between a diffusive state and a transparent state.

18. The method of claim 17, wherein the plurality of switchable screens can be switched between the diffusive and transparent state on a frame-by-frame basis.

19. The method of claim 13, wherein the VFE is associated with a small aperture.

20. The method of claim 13, further comprising varying an optical power of the VFE as a function of a position of a scanned spot within a scan field of the scanned light.

21. The method of claim 13, further comprising driving a signal of the VFE to match the scan pattern of the scanned light

23. The method of claim 13, further comprising adjusting a drive signal of the VFE to match the scan pattern of the light modulator, thereby producing a flat image field.

24. An augmented reality display system, comprising;

a scanning device operatively coupled to an image source for scanning an image in a scanning pattern;

a variable focus element (VFE) operatively coupled to the scanning light display to variably focus the image; and

a processor coupled to the VFE to vary a drive signal of the VFE as a function of the scanning pattern of the display in order to produce a substantially flat image field to correct a field curvature of the image.

25. The augmented reality display system of claim 24, wherein the VFE varies the focus of a center of an image different than a periphery of the image.

26. The augmented reality display system of claim 24, further comprising a plurality of switchable screens having a range of numerical apertures to spread a light associated with the image, wherein the VFE focuses the scanned light on one of the switchable screens of the plurality of switchable screens.

27. The augmented reality display system of claim 24, wherein the one or more frames of image data is provided in a time-sequential manner.

28. The augmented reality display system of claim 24, wherein the VFE varies the focus of the scanned light on a frame-by-frame basis.

29. The augmented reality display system of claim 24, wherein the processor adjusts the drive signal of the VFE in correspondence to the scan pattern of the scanning device.

30. The augmented reality display system of claim 24, wherein a first frame of image data is swept through a first focus range, and wherein a second frame of image data is swept through a second focus range, wherein the first focus range is different from the second focus range.

31. The augmented reality display system of claim 24, wherein the drive signal of the VFE is a sinusoidal wave.

32. The augmented reality display system of claim 24, wherein the drive signal of the VFE is a triangular wave.

33. A method of displaying augmented reality, comprising;

providing one or more frames of image data;

scanning light associated with the one or more frames of image data in a scanning pattern; and

adjusting a drive signal of a variable focus element (VFE) in accordance to the scanning pattern to correct for a field curvature of the one or more frames of image data, producing a substantially flat image field.

34. The method of claim 33, wherein the drive signal is adjusted such that a first portion of an image is focused differently than a second portion of the image.

35. The method of claim 33, wherein the VFE switches focus on a frame-by-frame basis.

36. The method of claim 33, further comprising driving a frame of image data through a focus range.

37. The method of claim 33, wherein a first frame of image data is swept through a first focus range, and wherein a second frame of image data is swept through a second focus range, wherein the first focus range is different from the second focus range.

38. The method of claim 33, wherein the drive signal of the VFE is adjusted in accordance to a sinusoidal wave.

39. The method of claim 33, wherein the drive signal of the VFE is adjusted in accordance to a triangular wave.