Radiation conditioning system

• US 20030151821A1
• Filed: 12/19/2002
• Published: 08/14/2003
• Est. Priority Date: 12/19/2001
• Status: Active Grant

• Current Assignee: Parellel Consulting Limited Liability Company (Intellectual Ventures LLC)
• Original Assignee: Actuality Systems, Inc. (Ellis Amalgamated LLC)
• Inventors: Favalora, Gregg E., Napoli, Joshua, Oliver, David-Henry
• Granted Patent: US 6,940,653 B2
• Time in Patent Office: Days
• US Class Current: 359/619
• CPC Class Codes: G02B 26/106 having diffraction gratings as scanning elements, e.g. holographic scanners holographic optical elements G02B5/32, holography G03H
• CPC Class Codes: G02B 30/27 involving lenticular arrays
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G03H 1/268 Holographic stereogram
• CPC Class Codes: G03H 2001/2292 Using scanning means
• CPC Class Codes: G03H 2210/454 into planes
• CPC Class Codes: G03H 2225/31 Amplitude only
• CPC Class Codes: H04N 13/302 for viewing without the aid of special glasses, i.e. using autostereoscopic displays

Abstract

A holographic imaging system and method includes a radiation source for generating radiation. A data base has a set of elements, each element is indicative of a trajectory of a light ray exiting a point in a recorded scene. A spatial light modulator is receptive of the radiation from the radiation source and the elements of the data base mapped to the spatial light modulator, thereby projecting from the spatial light modulator an optical signal in the nature of a two dimensional bitmap of the recorded scene. A diffractive optical element includes a set of basis fringes receptive of the projected optical signal from the spatial light modulator for diffracting the optical signal in a specified direction. A multiplexer is receptive of the elements of the data base for multiplexing the elements of the data base to the spatial light modulator. A timing device synchronizes multiplexing the elements of the data base to the spatial light modulator and diffracting the optical signal in a specified direction.

Claims

1. A holographic imaging system comprising:

a radiation source for generating radiation;

a data base comprising a set of elements, each element indicative of a trajectory of a light ray exiting a point in a recorded scene;

a spatial light modulator receptive of the radiation from the radiation source and the elements of the data base mapped to the spatial light modulator, thereby projecting from the spatial light modulator an optical signal in the nature of a two dimensional bitmap of the recorded scene; and

a beam steering device receptive of the projected optical signal from the spatial light modulator for directing the optical signal in a specified direction.

2. The imaging system as set forth in claim 1 further comprising a beam expanding device receptive of the radiation from the radiation source for expanding the radiation.

3. The imaging system as set forth in claim 1 further comprising a collimating device receptive of the radiation from the radiation source for collimating the radiation.

4. The imaging system as set forth in claim 1 wherein the beam steering device comprises a diffractive optical element.

5. The imaging system as set forth in claim 4 wherein the diffractive optical element comprises a diffraction grating.

6. The imaging system as set forth in claim 5 wherein the diffraction grating comprises a grating pattern having a spatial frequency defined by the mathematical equation:

f=A sin(x)+B

wherein f is the spatial frequency of the grating pattern, A is scaling factor that determines the ratio of maximum to minimum diffraction grating frequencies, x is a spatial dimension and B is a carrier frequency offset factor.

7. The imaging system as set forth in claim 6 wherein x is linear dimension.

8. The imaging system as set forth in claim 6 wherein x is an angular dimension.

9. The imaging system as set forth in claim 1 further comprising a beam magnifier receptive of light from the beam steering device.

10. The imaging system as set forth in claim 1 further comprising a diffuser receptive of light from the beam steering device for diffusing the light.

11. The imaging system as set forth in claim 1 wherein the data base comprises a set of elements derived from a record of the scene from at least one view point.

12. The imaging system as set forth in claim 1 wherein the data base comprises a set of elements derived from a ray trace of a light ray exiting a point in the scene to a plane.

13. The imaging system as set forth in claim 1 further comprising:

a multiplexer receptive of the elements of the data base for multiplexing the elements of the data base to the spatial light modulator; and

a timing device for synchronizing the multiplexing of the elements of the data base to the spatial light modulator and the directing of the optical signal in a specified direction.

14. The imaging system as set forth in claim 1 wherein the diffraction grating comprises a grating pattern defined by a set of basis fringes.

15. The imaging system as set forth in claim 1 wherein the data base is connected to remote spatial light modulator by way of a computer or communications network.

16. A holographic imaging system comprising:

a radiation source for generating radiation;

a data base comprising a set of elements, each element indicative of a trajectory of a light ray exiting a point in a recorded scene;

a spatial light modulator receptive of the radiation from the radiation source and the elements of the data base mapped to the spatial light modulator, thereby projecting from the spatial light modulator an optical signal in the nature of a two dimensional bitmap of the recorded scene;

a diffractive optical element including a set of basis fringes receptive of the projected optical signal from the spatial light modulator for diffracting the optical signal in a specified direction;

a multiplexer receptive of the elements of the data base for multiplexing the elements of the data base to the spatial light modulator; and

a timing device for synchronizing multiplexing the elements of the data base to the spatial light modulator and diffracting the optical signal in a specified direction.

17. A holographic imaging method comprising:

establishing a data base comprising a set elements, each element indicative of a trajectory and an origin of a light ray exiting a point in a recorded scene;

mapping each element of the data base onto a spatial light modulator;

directing radiation onto the spatial light modulator;

projecting an optical signal from the spatial light modulator in the nature of a two dimensional bitmap of the recorded scene;

diffracting the optical signal projected from the spatial light modulator with a set of basis fringes.

18. The method as set forth in claim 17 wherein establishing a data base comprises:

recording the scene from at least one view point; and

assigning a unique time designation to each of the view points of the recorded scene.

19. The method as set forth in claim 17 wherein establishing a data base comprises:

examining the light field of the recorded scene; and

ray-tracing the trajectory and origin of a light ray exiting a point in the scene to a plane.

20. The method as set forth in claim 17 wherein diffracting the optical signal comprises scanning the optical signal from the spatial light modulator with a diffraction grating having a grating pattern with a spatial frequency defined by the mathematical equation:

f=A sin(x)+B

wherein f is the spatial frequency of the grating pattern, A is scaling factor that determines the ratio of maximum to minimum diffraction grating frequencies, x is a spatial dimension and B is an offset carrier frequency.

21. The method as set forth in claim 20 further comprising diffusing the scanned optical signal.

22. The method as set forth in claim 17 wherein diffracting the optical signal comprises scanning the optical signal emanating from the spatial light modulator with a diffraction grating having a set of basis fringes.

23. The method as set forth in claim 22 wherein scanning the optical signal from the spatial light modulator comprises scanning the optical signal at a rotational rate of approximately one twentieth of a second per basis fringe.

24. The method as set forth in claim 17 wherein projecting an optical signal from the spatial light modulator in the nature of a two dimensional bitmap of the recorded scene comprises projecting the bitmap at a rate of approximately 4,000 to 10,000 frames per second.

25. The method as set forth in claim 17 wherein mapping each element of the data base onto a spatial light modulator comprises multiplexing the elements of the data base to the spatial light modulator.

26. The method as set forth in claim 17 further comprising synchronizing multiplexing the elements of the data base to the spatial light modulator and diffracting the optical signal projected from the spatial light modulator.

28. The display device as set forth in claim 26 wherein the radiation conditioning device comprises a diffractive optical element.

29. The display device as set forth in claim 28 wherein the diffractive optical element comprises a diffraction grating.

30. The display device as set forth in claim 29 wherein the diffraction grating comprises a set of basis fringes.

31. The display device as set forth in claim 29 wherein the diffraction grating comprises grating pattern having a spatial frequency defined by the mathematical equation:

f=A sin(θ

)+B

wherein f is the spatial frequency of the grating pattern, A is scaling factor that determines the ratio of maximum to minimum diffraction grating frequencies, θ

is a spatial dimension and B is a carrier frequency offset factor.

32. The display device as set forth in claim 30 wherein the diffractive optical element comprises a disc.

33. The display device as set forth in claim 28 wherein the diffractive optical element comprises an acousto-optic modulator.

27. A radiation conditioning system comprising:

a radiation source for generating radiation;

a spatial light modulator receptive of the radiation from the radiation source and a control signal for addressing the spatial light modulator, thereby projecting a radiation field from the spatial light modulator; and

a radiation conditioning device receptive of the radiation field from the spatial light modulator for conditioning the radiation field;

wherein the radiation conditioning device includes a plurality of radiation conditioning regions.

34. The display device as set forth in claim 27 wherein the radiation conditioning device comprises a set of lenslets.

35. The display device as set forth in claim 27 wherein the set of lenslets comprise an array.

36. The display device as set forth in claim 27 wherein the set of lenslets are arranged in a rectangular host.

37. The display device as set forth in claim 27 wherein the rectangular host is in reciprocating motion.

38. The display device as set forth in claim 27 wherein the radiation conditioning device comprises a spatial light modulator.

39. The display device as set forth in claim 38 wherein the spatial light modulator comprises an optically addressable spatial light modulator.

40. The display device as set forth in claim 39 wherein the optically addressable spatial light modulator includes a material having properties depending upon a first illumination frequency and is read out at a second frequency.

41. A radiation conditioning device comprising:

a diffractive optical element including a diffraction grating comprising a set of basis fringes.

42. The radiation conditioning device as set forth in claim 41 wherein the diffraction grating comprises grating pattern having a spatial frequency defined by the mathematical equation:

f=A sin(θ

)+B

wherein f is the spatial frequency of the grating pattern, A is scaling factor that determines the ratio of maximum to minimum diffraction grating frequencies, θ

is a spatial dimension and B is a carrier frequency offset factor.

43. A method of conditioning a radiation field, the method comprising:

conditioning the radiation field by scanning the radiation field with a radiation conditioning device comprising a set of basis fringes.

44. The method as set forth in claim 43 further comprising decomposing the radiation field into a set of components.

45. The method as set forth in claim 43 wherein the radiation conditioning device comprises a diffractive optical element.

46. The method as set forth in claim 43 wherein conditioning the radiation field comprises scanning the radiation field with a diffraction grating having a grating pattern defined by the mathematical equation:

f=A sin (θ

)+B

wherein f is the spatial frequency of the grating pattern, A is scaling factor that determines the ratio of maximum to minimum diffraction grating frequencies, θ

is a spatial dimension and B is a carrier frequency offset factor.

47. The method as set forth in claim 45 wherein scanning the radiation field comprises rotating the radiation conditioning device through a prescribed angular distance.

48. The method as set forth in claim 45 wherein scanning the radiation field comprises rotating the diffraction grating through a prescribed angular distance.

49. A method of conditioning a radiation field, the method comprising:

conditioning the radiation field by scanning the radiation field with a radiation conditioning device having time varying properties.

50. A radiation conditioning system comprising:

a radiation projector for projecting a radiation field; and

a radiation conditioning device receptive of the radiation field from the radiation projector for conditioning the radiation field;

wherein the radiation conditioning device includes a plurality of radiation conditioning regions.

51. The system as set forth in claim 50 wherein the radiation conditioning device comprises a set of basis fringes.