Multiview display, system, and method having shiftable convergence plane

1. A multiview display comprising:

a multiview backlight configured to emit light as directional light beams having different principal angular directions corresponding to respective different view directions of a multiview image, the directional light beams being configured to converge at points within a convergence plane corresponding to locations of different views of the multiview image; and

an array of light valves configured to modulate the directional light beams as the different views of the multiview image at the convergence plane,

wherein a distance between the multiview backlight and the light valve array is configured to be adjustable to shift a corresponding location of the convergence plane relative to the multiview display.

2. The multiview display of claim 1 , wherein an inter-view spacing between the different views of the multiview image is configured to be constant as function of the adjustable distance between the multiview backlight and the light valves array and the corresponding location of the convergence plane.

3. The multiview display of claim 2 , wherein the inter-view spacing at the convergence plane is commensurate with an inter-ocular distance for a user of the multiview display.

4. The multiview display of claim 1 , wherein an adjustment of the distance between the multiview backlight and the light valve array comprises a mechanical motion of the multiview backlight relative to the light valve array.

5. The multiview display of claim 1 , wherein the multiview backlight is a first multiview backlight and the convergence plane is a first convergence plane of the multiview display, the multiview display further comprising a second multiview backlight configured to provide directional light beams that converge within a second convergence plane at points corresponding locations of the different views of the multiview image at the second convergence plane, a location of the second convergence plane relative to the multiview display being different from a location of the first convergence plane.

6. The multiview display of claim 5 , wherein the first multiview backlight is located between the second multiview backlight and the light valve array, the first multiview backlight being transparent to the directional light beams provided by the second multiview backlight, and wherein an adjustment of the distance between the multiview backlight and the light valve array comprises a selectively activated one of the first multiview backlight and the second multiview backlight to provide the multiview image within a respective one of the first and second convergence planes.

7. The multiview display of claim 1 , wherein the multiview backlight comprises:

a light guide configured to guide light in a propagation direction along a length of the light guide; and

a plurality of multibeam elements spaced apart from one another along the light guide length, a multibeam element of the multibeam element plurality having a size comparable to a size of a light valve of the light valve array and being configured to scatter out from the light guide a portion of the guided light as the directional light beams.

8. The multiview display of claim 7 , wherein the multibeam element comprises one or more of a diffraction grating, a micro-reflective element, and a micro-refractive element optically connected to the light guide, the diffraction grating being configured to diffractively scatter out the portion of the guided light, the micro-reflective element being configured to reflectively scatter out the portion of the guided light, and the micro-refractive element being configured to refractively scatter out the portion of the guided light.

9. A multiview display system comprising the multiview display of claim 1 , the multiview display system further comprising a head tracker configured to determine a distance between the multiview display and a user, wherein distance between the multiview backlight and the light valve array is configured to be adjusted according to the determined distance between the multiview display and the user to shift the convergence plane location to correspond to a location of the user relative to the multiview display.

10. A multiview display system comprising:

a multiview backlight configured to provide directional light beams having different principal angular directions corresponding to respective different view directions of different views of a multiview image;

an array of light valves configured to modulate the directional light beams to provide the multiview image at a convergence plane of the multiview display system; and

a head tracker configured to determine a distance of a user from the multiview display system,

wherein a distance between the multiview backlight and the light valve array is configured to be adjustable according to the determined user distance to shift a location of the convergence plane to correspond to the determined user distance.

11. The multiview display system of claim 10 , wherein an inter-view spacing of the different views at the convergence plane is configured to remain constant as the convergence plane is shifted, and wherein the inter-view spacing within the convergence plane is commensurate with an inter-ocular distance for the user.

12. The multiview display system of claim 10 , wherein the multiview backlight is a first multiview backlight of the multiview display system at a first distance from the light valve array, the multiview display system further comprising a second multiview backlight at a second distance from the light valve array, the first distance being different from the second distance, and wherein the convergence plane location is configured to be shifted by selectively activating one of the first multiview backlight and the second multiview backlight.

13. The multiview display system of claim 10 , wherein the multiview backlight further comprises:

a light guide configured to guide light in a propagation direction along a length of the light guide; and

a plurality of multibeam elements spaced apart from one another along the light guide length, a multibeam element of the multibeam element plurality having a size comparable to a size of a light valve of the light valve array and being configured to scatter out from the light guide a portion of the guided light as the directional light beams.

14. The multiview display system of claim 10 , wherein the head tracker comprises one or more of a plurality of cameras configured to determine user distance using disparity estimation and a time-of-flight sensor configured to determine user distance using a propagation time of a signal reflected by the user.

15. A method of multiview display operation, the method comprising:

emitting light using a multiview backlight as directional light beams having different principal angular directions corresponding to respective different view directions of a multiview image, the directional light beams converging at points within a convergence plane corresponding to locations of different views of the multiview image;

modulating the directional light beams using an array of light valves to provide the different views of the multiview image at the convergence plane; and

adjusting a distance between the multiview backlight and the light valve array to shift a location of the convergence plane relative to the multiview display.

16. The method of multiview display operation of claim 15 , wherein emitting light using a multiview backlight comprises:

guiding light in a light guide as guided light; and

scattering a portion of the guided light out of the light guide as the directional light beams using an array of multibeam elements, a size of a multibeam element of the multibeam element array being comparable to a size of a light valve of the light valve array.

17. The method of multiview display operation of claim 16 , wherein the multibeam element comprises one or more of a diffraction grating, a micro-reflective element, and a micro-refractive element optically connected to the light guide, the diffraction grating diffractively scattering out the portion of the guided light, the micro-reflective element reflectively scattering out the portion of the guided light, and the micro-refractive element refractively scattering out the portion of the guided light.

18. The method of multiview display operation of claim 15 , wherein adjusting the distance between the multiview backlight and the light valve array comprises mechanically moving the multiview backlight relative to the light valve array.

19. The method of multiview display operation of claim 15 , further comprises determining a distance of a user from the multiview display using a head tracker and adjusting the distance between the multiview backlight and the light valve array to shift the convergence plane location to correspond to the determined user distance.

20. The method of multiview display operation of claim 19 , wherein determining the distance of the user from the multiview display using a head tracker comprises one or more of:

capturing an image of the user using a plurality of cameras and employing disparity estimation to determine the distance of the user from the multiview display; and

employing a time-of-flight sensor to determine the distance of the user from the multiview display from a propagation time of a signal emitted by the time-of-flight sensor and reflected by the user.