Near-eye light field display

1. A near-eye light field display device for displaying a light field to at least one eye of a viewer, the device comprising an array of light field display elements, each display element having a discrete position on the display device, and adapted to display a plurality of directional beams corresponding to a time-varying light field view image, each beam having a discrete angular direction within a two-dimensional angular field associated with the display element, a time-varying radiance associated with the angular direction within the light field view image, and a time-varying focus, the display device configured to modulate the focus of each directional beam according to a time-varying fixation depth of the at least one eye.

2. The device of claim 1 , further comprising a gaze tracking system for tracking a gaze of at least one of the viewer's eyes, thereby to estimate the fixation depth of the at least one eye of the viewer.

3. The device of claim 2 , wherein the gaze tracking system comprises at least one camera.

4. The device of claim 2 , wherein the gaze tracking system is configured to track the gaze of the at least one eye based on at least one of the group comprising: a position of the eye; a position of the sclera of the eye; a position of the limbus of the eye; and a position of the pupil of the eye.

5. The device of claim 1 , wherein each display element further comprises a focus modulator for modulating the focus of each directional beam.

6. The device of claim 5 , wherein the focus modulator comprises at least one element selected from the group comprising: a lens; a liquid crystal lens; a liquid lens; a deformable membrane mirror; a deformable-membrane liquid-filled lens; an addressable lens stack; and an electro-optic lens.

7. The device of claim 1 , wherein each display element further comprises:

(a) a beam generator for generating an output beam of light;

(b) a scanner for scanning the output beam across the two-dimensional angular field to generate the plurality of directional beams; and

(c) a radiance modulator for modulating the radiance of the output beam according to a radiance value associated with the position of the display element and each discrete angular direction within the angular field.

8. The device of claim 7 , wherein the beam generator comprises at least one light emitter selected from the group comprising: a laser; a laser diode; a light-emitting diode; a fluorescent lamp; and an incandescent lamp.

9. The device of claim 7 , wherein the beam generator comprises multiple light emitters with different emission spectra, the light emitters selected from the group comprising: a laser; a laser diode; a light-emitting diode; a fluorescent lamp; and an incandescent lamp.

10. The device of claim 7 , wherein the radiance modulator is intrinsic to the beam generator.

11. The device of claim 7 , wherein the radiance modulator is selected from the group comprising: an acousto-optic modulator; an absorptive electro-optic modulator; and a refractive electro-optic modulator.

12. The device of claim 7 , wherein the scanner is selected from the group comprising: an electromechanical scanning mirror; an addressable deflector stack; an acousto-optic scanner; and an electro-optic scanner.

13. The device of claim 7 , wherein the scanner comprises a biaxial electromechanical scanning mirror with at least one drive mechanism selected from the group comprising: an electrostatic drive mechanism; a magnetic drive mechanism; and a capacitive drive mechanism.

14. The device of claim 7 , wherein the scanner comprises a first scanner for scanning the beam in a first direction and a second scanner for simultaneously scanning the beam in a second direction, the second direction substantially orthogonal to the first.

15. The device of claim 14 , wherein the first and second scanners are selected from the group comprising: an electromechanical scanning mirror; an addressable deflector stack; an acousto-optic scanner; and an electro-optic scanner.

16. The device of claim 1 , further comprising at least one actuator for oscillating the display elements between at least two positions, each display element adapted to display a different set of beams at each of the at least two positions.

17. The device of claim 16 , wherein the oscillation is resonant.

18. The device of claim 1 , wherein each display element comprises a two-dimensional array of light emitters, each light emitter adapted to generate one of the directional beams.

19. The device of claim 18 , wherein each light emitter comprises at least one organic light emitting diode (OLED).

20. The device of claim 18 , wherein each display element further comprises a focus modulator for modulating the focus of each directional beam.