Variable-depth stereoscopic display

• US 10,082,669 B2
• Filed: 02/19/2016
• Issued: 09/25/2018
• Est. Priority Date: 07/27/2011
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Large, Timothy Andrew
• Primary Examiner(s): Chang, Audrey Y
• Application Number:
  US15/047,859
• Publication Number:
  US 20160161739A1
• Time in Patent Office: 949 Days
• Field of Search: 359462, 359464, 345102, 363278, 349 65
• CPC Class Codes: G02B 27/0075 with means for altering, e.g. increasing, the depth of field or depth of focus
• CPC Class Codes: G02B 30/27 involving lenticular arrays
• CPC Class Codes: G02B 30/28 involving active lenticular arrays
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336

Abstract

This document describes various techniques for implementing a variable-depth stereoscopic display. A first distance at which a viewer is disposed relative to a stereoscopic display is received. Once received, a second distance by which to change a front focal distance of a lens structure of the stereoscopic display is determined based on the first distance. The front focal distance of the lens structure is then caused to change by the second distance effective to display a stereoscopic image at the first distance.

Claims

1. An optical system comprising:

a spatial light modulator configured to modulate diffuse light with frames of visual information to provide stereoscopic imagery to a viewer;

a liquid crystal lens configured to focus the diffuse light to enable viewing of the stereoscopic imagery over different respective ranges of distance;

a diffusion panel configured to provide the diffuse light by diffusing collimated light in a first direction and direct the diffuse light through the spatial light modulator;

an optical wedge having a viewing surface configured to emit the collimated light into the diffusion panel and a thin end configured to receive light for collimation;

two or more light source arrays individually selectable to inject the light for collimation into the thin end of the optical wedge, each of the two or more light source arrays being disposed at a different distance from the thin end of the optical wedge than others of the two or more light source arrays and configured to generate the light at different locations along the thin end of the optical wedge effective to scan, in a second direction that is substantially perpendicular to the first direction, the collimated light emitted by the optical wedge to direct different frames of the visual information to each eye of the viewer; and

a controller configured to;

determine a viewing distance at which the viewer is disposed relative the optical system; and

manipulate, based on the viewing distance and the different respective ranges of distance over which the liquid crystal lens enables viewing of the stereoscopic imagery, the liquid crystal lens by applying an excitation voltage to the liquid crystal lens such that the stereoscopic imagery is visible to the viewer disposed at the determined viewing distance.

2. The optical system as recited in claim 1, wherein the optical wedge further comprises a thick end disposed opposite the thin end, the thick end being configured to reflect at least some of the light within the optical wedge prior to emission from the viewing surface into the diffusion panel.

3. The optical system as recited in claim 1, further comprising light guides associated with the two or more light source arrays are configured to not occlude light patterns generated by the selected light source array.

4. The optical system as recited in claim 1, wherein the controller is further configured to receive, from a sensor, viewer positional data based on which the controller is configured to determine the viewing distance.

5. The optical system as recited in claim 1, wherein the controller is further configured to detect movement of the viewer in response to which the controller is configured to determine the viewing distance.

6. The optical system as recited in claim 1, wherein the optical system is configured as a non-projective flat panel display.

7. The optical system as recited in claim 1, wherein the visual information with which the spatial light modulator modulates the light includes parallax information associated with the stereoscopic imagery.

8. The optical system as recited in claim 1, the liquid crystal lens further comprising electrodes capable of applying the excitation voltage to the liquid crystal lens to re-align the liquid crystal molecules effective to re-focus the liquid crystal lens at various distances.

9. A system comprising:

a first light source and a second light source, the first and second light sources being disposed at different distances from a lens structure and individually selectable to scan light for displaying stereoscopic imagery, each of the first and the second light sources including an array of light generating elements configured to provide the scanned light by emitting light at different locations along the array such that the light is scanned in a first direction;

a first light guide configured to receive the scanned light emitted from the first light source and emit light to the lens structure and a second light guide, configured to receive the scanned light emitted from the second light source and emit light to the lens structure;

the lens structure configured to receive the light from the first and second light guides and emit collimated light to a diffusion panel, based on the patterns of scanned light generated by the first or the second light source;

the diffusion panel configured to receive the scanned collimated light from the lens structure and diffuse the scanned collimated light in a second direction that is substantially perpendicular to the first direction to provide diffuse light;

a liquid crystal lens configured to focus the diffuse light to enable viewing of the stereoscopic imagery over different respective ranges of distance;

a spatial light modulator configured to modulate the focused diffuse light with frames of the stereoscopic imagery; and

a controller configured to;

manipulate the liquid crystal lens by applying an excitation voltage to the liquid crystal lens, based on a distance at which a viewer is located with respect to the lens structure; and

synchronize the scanning of the light and the modulation of the scanned diffuse light such that different frames of the stereoscopic imagery are directed to each eye of the viewer at the viewing distance.

10. The system as recited in claim 9, wherein the lens structure is an optical wedge.

11. The system as recited in claim 9, wherein the lens structure is configured to collimate, via internal reflection, the scanned light to provide the scanned collimated light to the diffusion panel.

12. The system as recited in claim 9, wherein the different respective ranges of distance overlap such that the system is capable of providing stereoscopic imagery that is continuously viewable while the viewer transitions between the different respective ranges of distance.

13. The system as recited in claim 9, wherein the array of light generating elements includes light-emitting diodes (LEDs) that are individually selectable to emit the light at different locations along the array.

14. A computer-implemented method comprising:

determining a viewing distance at which a viewer is disposed relative to a lens structure of a stereoscopic display;

selecting a light source from multiple light sources of the stereoscopic display, based on the viewing distance and on a back focal length of the light source, to emit light into a receiving surface of the lens structure, each of the multiple light sources being disposed at a different distance from the lens structure than others of the multiple light sources and including a respective array of light emitting elements and being associated with a respective light guide;

injecting, via a subset of light emitting elements of the selected light source, the light into a location along the receiving surface the lens structure effective to direct the light emitted from a viewing surface of the lens structure toward the viewer'"'"'s eye;

injecting, via another subset of light emitting elements of the selected light source, other light into another location along the receiving surface of the lens structure effective to direct the other light emitted from the viewing surface of the lens structure toward viewer′

other eye, the location and other location being proximate opposite ends of the lens structure'"'"'s receiving surface;

modulating the light directed towards the viewer'"'"'s eye and the other light directed toward the viewer'"'"'s other eye with different frames of visual information; and

focusing, via a liquid crystal lens, the light and the other light such that the stereoscopic imagery is visible to the viewer disposed at the viewing distance.

15. The method as recited in claim 14, wherein the lens structure is an optical wedge comprising a thin end configured as the receiving surface and a thick end disposed opposite the thin end, the thick end being configured to reflect at least some of the light within the optical wedge prior to emission from the viewing surface.

16. The method as recited in claim 14, wherein the act of modulating is performed via a spatial light modulator disposed between the viewing surface of the lens structure and the viewer.

17. The method as recited in claim 14, wherein the different frames of visual information with which the light and other light are modulated includes parallax information associated with the stereographic imagery.

18. The method as recited in claim 14, wherein the array of light emitting elements comprises an array of light emitting diodes (LEDs) that are individually selectable to emit the light into the receiving surface of the lens structure.

19. The method as recited in claim 14 further comprising, prior to determining the viewing distance, detecting movement of the viewer via a sensor, and wherein determining the viewing distance is in response to detecting the movement of the viewer.

20. The method as recited in claim 14 further comprising, prior to the act of modulating, diffusing the light and the other light emitted from the viewing surface in one dimension via a diffusion panel having a prismatic surface.