Holographic video display system

• US 8,149,265 B2
• Filed: 08/11/2007
• Issued: 04/03/2012
• Est. Priority Date: 08/11/2007
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Smalley, Daniel E., Smithwick, Quinn Y. J., Bove, V. Michael Jr.
• Primary Examiner(s): ENG, DAVID Y
• Application Number:
  US11/837,517
• Publication Number:
  US 20090040294A1
• Time in Patent Office: 1,697 Days
• Field of Search: 348/40, 359/1, 359/9, 359/22, 382/232
• US Class Current: 348/40
• CPC Class Codes: G03H 1/02 Details of features involved during the holographic process; Replication of holograms without interference recording
• CPC Class Codes: G03H 1/2294 Addressing the hologram to an active spatial light modulator
• CPC Class Codes: G03H 2001/0224 Active addressable light modulator, i.e. Spatial Light Modulator [SLM] corresponding details, see subgroups of G03H2225/00
• CPC Class Codes: G03H 2001/2292 Using scanning means
• CPC Class Codes: G03H 2223/17 Element having optical power
• CPC Class Codes: G03H 2225/21 Acousto-optic SLM [AO-SLM]

Abstract

A holographic video display comprises a monochromatic light source, a video signal generator, guided-wave acousto-optic modulators for diffracting light according to signals received from the video signal generator, a vertical scanning subsystem, and an optical path between the acousto-optic modulator and the vertical scanning subsystem. The optical path preferably comprises a Bravais lens system, first and second Fourier transform lens systems, and at least one holographic optical element or stationary mirror of continuous helical shape. In a method for generating a holographic image, monochromatic light is provided to at least one guided-wave acousto-optic modulator, the received light is diffracted according to a video signal, the guided-wave modulator aperture is scanned to produce a holo-line, the motion of the diffraction pattern is undone to render the holo-line stationary, the guided-wave modulator aperture is demagnified to create a wide field of view, and the holo-lines are tiled vertically to create the image.

Claims

1. A holographic video display system comprising:

at least one monochromatic light source;

a video signal generator;

at least one guided-wave acousto-optic modulator for diffracting light received from the light source according to at least one video signal received from the video signal generator;

a vertical scanning subsystem for rendering a holographic image; and

an optical path for passing the diffracted light from the acousto-optic modulator to the vertical scanning subsystem, the optical path comprising;

a Bravais lens system;

a first Fourier transform lens system;

at least one holographic optical element or at least one stationary mirror of continuous helical shape; and

a second Fourier transform lens system.

2. The holographic video display system of claim 1, wherein the guided-wave acousto-optic modulator is a two-dimensional device.

3. The holographic video display system of claim 1, wherein the vertical scanning subsystem further comprises a galvanometric scanner.

4. The holographic video display system of claim 1, wherein the vertical scanning subsystem further comprises a motor.

5. The holographic video display system of claim 1, wherein the vertical scanning subsystem further comprises a micro-electromechanical scanner.

6. The holographic video display system of claim 1, further comprising a polarizer that blocks undiffracted light from exiting the guided-wave mosulator.

7. The holographic video display system of claim 1, wherein the first Fourier transform lens system is a telephoto lens system.

8. The holographic video display system of claim 1, wherein the second Fourier transform lens system performs demagnification.

9. The holographic video display system of claim 1, wherein the guided-wave acousto-optic modulator further comprises video signal inputs for multiple frequency bands.

10. The holographic video display system of claim 1, wherein the color of the monochromatic light source changes with time in order to create a time-sequential full-color display.

11. The holographic video display system of claim 1, wherein there are three monochromatic light sources, one light source each being red, blue, and green, and three guided-wave modulators, each guided-wave modulator receiving light from one of the three monochromatic light sources.

12. The holographic video display system of claim 1, wherein there are three monochromatic light sources, one light source each being red, blue, and green, and the guided-wave modulator sequentially cycles through receiving light from each of the three monochromatic light sources.

13. A holographic video image produced using the display of claim 1.

14. A method for generating a holographic image, comprising:

providing monochromatic light to at least one guided-wave acousto-optic modulator;

diffracting the received light according to at least one video signal;

scanning the aperture of the guided-wave acousto-optic modulator to produce a holo-line;

undoing the motion of the diffraction pattern to render the holo-line stationary;

demagnifying the guided-wave acousto-optic modulator aperture to create a wide field of view; and

tiling the holo-lines vertically to create the holographic image.

15. The method of claim 14, wherein the guided-wave acousto-optic modulator is a two-dimensional device.

16. The method of claim 14, wherein the step of tiling the holo-lines vertically is performed via a galvanometric scanner, motor, or micro-electromechanical scanner.

17. The method of claim 14, further comprising the step of using a polarizer to block undiffracted light exiting the guided-wave modulator.

18. The method of claim 14, wherein the step of demagnifying is performed via a Fourier transform lens system.

19. The method of claim 14, wherein the guided-wave acousto-optic modulator receives video signal inputs for multiple frequency bands.

20. The method of claim 14, further comprising the step of changing the color of the monochromatic light source with time in order to create a time-sequential full-color display.

21. The method of claim 14, wherein there are three monochromatic light sources, one light source each being red, blue, and green, and three guided-wave modulators, each guided-wave modulator receiving light from one of the three monochromatic light sources.

22. The method of claim 14, wherein there are three monochromatic light sources, one light source each being red, blue, and green, and further comprising the step of sequentially cycling the guided-wave modulator through receiving light from each of the three monochromatic light sources.

23. A holographic video display that employs the method of claim 14.