HOLOGRAPHIC PROJECTION METHOD AND HOLOGRAPHIC PROJECTION DEVICE

• US 20090109405A1
• Filed: 12/22/2008
• Published: 04/30/2009
• Est. Priority Date: 03/02/2007
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: HORIKAWA, Yoshiaki
• Granted Patent: US 7,976,170 B2
• Time in Patent Office: Days
• US Class Current: 353/31
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 27/46 Systems using spatial filters
• CPC Class Codes: G03B 21/28 Reflectors in projection beam in illumination beam G03B21/2066
• CPC Class Codes: G03B 33/06 by additive-colour projection apparatus
• CPC Class Codes: G03H 1/2249 Holobject properties
• CPC Class Codes: G03H 1/2286 Particular reconstruction light G03H1/24 takes precedence; Beam properties
• CPC Class Codes: G03H 1/2294 Addressing the hologram to an active spatial light modulator
• CPC Class Codes: G03H 2001/2218 being perpendicular to optical axis
• CPC Class Codes: G03H 2210/20 2D object
• CPC Class Codes: G03H 2222/18 RGB trichrome light
• CPC Class Codes: G03H 2222/34 Multiple light sources
• CPC Class Codes: G03H 2222/54 Convergent beam
• CPC Class Codes: G03H 2225/24 Having movable pixels, e.g. microelectromechanical systems [MEMS]
• CPC Class Codes: G03H 2225/32 Phase only
• CPC Class Codes: G03H 2225/52 Reflective modulator
• CPC Class Codes: G03H 2225/61 for multicolour processing

Abstract

According to the present invention, a plurality of video image data are converted into individual spatial frequency information using Fourier transformation. The individual spatial frequency information is provided to a plurality of information display unit corresponding to the individual spatial frequency information. The spatial frequency information corresponding to the plurality of video image data is displayed on the plurality of information display unit, light is irradiated onto the plurality of information display unit using a plurality of light sources corresponding to the plurality of information display unit. The spatial frequency information that is displayed by the plurality of information display unit is projected by using diffraction light, and a plurality of video images are synthesized on projection surfaces.

Claims

1. A holographic projection method comprising:

a Fourier transformation step of converting a plurality of video image data into individual spatial frequency information using Fourier transformation;

an information provision step of providing the individual spatial frequency information to a plurality of information display unit corresponding to the individual spatial frequency information;

a display step of displaying the spatial frequency information corresponding to the plurality of video image data on the plurality of information display unit;

an irradiation step of irradiating light onto the plurality of information display unit using a plurality of light sources corresponding to the plurality of information display unit; and

a projection step of projecting the spatial frequency information displayed by the plurality of information display unit using diffraction light and synthesizing a plurality of video images onto projection surfaces.

2. The holographic projection method according to claim 1,

wherein the plurality of light sources include a red light source, a green light source, and a blue light source, and

the plurality of video image data include red video image data, green video image data, and blue video image data.

3. The holographic projection method according to claim 2,

wherein the information display unit each are composed of a spatial light phase modulator.

4. The holographic projection method according to claim 3,

wherein the plurality of spatial light phase modulators are disposed on the same plane.

5. The holographic projection method according to claim 4,

wherein the plurality of spatial light phase modulators each are composed of a reflecting spatial light phase modulator.

6. The holographic projection method according to claim 5,

wherein the plurality of spatial light phase modulators each include a mirror.

7. The holographic projection method according to claim 6, further comprising:

a light amount adjustment step of adjusting the amount of light that is irradiated by the red light source, the green light source, and the blue light source based on the video image data.

8. The holographic projection method according to claim 7,

wherein the amount of light that is incident from the red light source, the green light source, and the blue light source is set to zero, while the spatial frequency information is altered in the information display unit.

9. The holographic projection method according to claim 8,

wherein the adjustment of the light amount in the light amount adjustment step is performed by controlling the red light source, the green light source, and the blue light source.

10. The holographic projection method according to claim 1,

wherein, in the Fourier transformation step, the Fourier transformation is performed after a random phase is added to the video image data.

11. The holographic projection method according to claim 10,

wherein, in the Fourier transformation step, a correction process based on phase information depending on the optical system is executed on the spatial frequency information including spatial light phase information obtained by performing the Fourier transformation.

12. The holographic projection method according to claim 11,

wherein, in the Fourier transformation step, the correction process is executed based on a distance between the spatial light phase modulator and projection unit.

13. A holographic projection device comprising:

a plurality of light sources to irradiate light;

data processing unit for converting a plurality of video image data into individual spatial frequency information using Fourier transformation; and

a plurality of information display unit which are provided to correspond to the plurality of light sources and display the spatial frequency information,

wherein the plurality of information display unit are disposed such that diffraction light, which is irradiated by the plurality of light sources and modulated as the spatial phase information by the plurality of information display unit, is synthesized as a projection video image on projection surfaces.

14. The holographic projection device according to claim 13,

wherein the information display unit each are composed of a spatial light phase modulator.

15. The holographic projection device according to claim 14,

wherein the plurality of spatial light phase modulators are disposed on the same plane.

16. The holographic projection device according to claim 15,

wherein the plurality of spatial light phase modulators each are composed of a reflecting spatial light phase modulator.

17. The holographic projection device according to claim 16,

wherein the plurality of spatial light phase modulators each include a mirror.

18. The holographic projection device according to claim 17,

wherein the plurality of light sources include at least a red light source, a green light source, and a blue light source, and

the plurality of video image data include at least red data, green data, and blue data.

19. The holographic projection device according to claim 18,

wherein the data processing unit handles the spatial frequency information as spatial phase information by subjecting the video image data to the Fourier transformation, after adding random phases to the video image data.

20. The holographic projection device according to claim 19, further comprising:

control unit for controlling the amount of light that is irradiated by the red light source, the green light source, and the blue light source based on the plurality of video image data.

21. The holographic projection device according to claim 13,

wherein the amount of light that is incident from the light sources is set to zero, while the spatial frequency information is altered in the information display unit.

22. The holographic projection device according to claim 13,

wherein the control unit controls the amount of light by controlling the light sources.

23. The holographic projection device according to claim 22, further comprising:

unit for restricting illumination light from the light sources, such that the illumination light is not irradiated onto an area beyond an effective display range in the spatial light phase modulators.

24. The holographic projection device according to claim 13 or 23, further comprising:

unit for trapping zero-order light reflected on the spatial light phase modulators.

25. The holographic projection device according to claim 13, further comprising:

zero-order light traps, each of which has an optical sensor function capable of measuring intensity of light and traps zero-order light reflected on the spatial light phase modulators,

wherein the control unit controls the amount of light that is irradiated by the light sources based on output information of the zero-order light traps.

26. The holographic projection device according to claim 13, further comprising:

zero-order light traps, each of which has an optical sensor function capable of measuring intensity of light,

wherein the control unit controls the amount of light that is irradiated by the light sources based on output information of the zero-order light traps and the video image data.

27. The holographic projection device according to claim 25,

wherein the control unit controls the amount of light irradiated by the light sources based on a total light amount value of the amount of light in each scene of a video image by the video image data.

28. The holographic projection device according to claim 27,

wherein, when T is defined as the number of bits of a gradation, M and N are defined as the number of pixels vertically and the number of pixels horizontally in each information display unit, respectively, and brightness of each pixel is defined as represented by the following Equation 1, the control unit calculates the total light amount value using the following Equation 2:

$\begin{array}{cc}B<br><br>\left(x,y\right)=2^T& \left(\mathrm{Equation}<br><br><br><br>1\right)\\ H=\underset{y=1}{\overset{M}{\sum <br><br>}}<br><br>\underset{x=1}{\overset{N}{\sum <br><br>}}<br><br>B<br><br>\left(x,y\right)& \left(\mathrm{Equation}<br><br><br><br>2\right)\end{array}$

29. The holographic projection device according to claim 28,

wherein, when H is defined as a total light amount value of a projected video image, S is defined as a light amount of zero-order light, and K is defined as a proportionality coefficient, the control unit controls the amount of light irradiated by the light sources based on a value calculated using the following Equation 3:

$\begin{array}{cc}F=\frac{H}{K}+S& \left(\mathrm{Equation}<br><br><br><br>3\right)\end{array}$

30. The holographic projection device according to claim 13,

wherein a calculation precision of the data processing unit is at least 12 bits or more.

31. The holographic projection device according to claim 13,

wherein the data processing unit converts video image data into spatial frequency information after added different random phases to the video image data in a subframe unit.

32. A holographic projection method comprising:

a Fourier transformation step of converting video image data into spatial phase information using Fourier transformation after added different random phases to the video image data in a subframe unit;

an information provision step of providing the spatial phase information to information display unit;

a display step of displaying spatial phase information corresponding to the video image data as a phase distribution on the information display unit;

an irradiation step of irradiating light onto the information display unit using light sources;

a light amount adjustment step of controlling drivers of the light sources to adjust the amount of light irradiated by the light sources based on the video image data; and

a projection step of projecting diffraction light, which is irradiated by the light sources and modulated as the spatial phase information by the information display unit, onto projection unit.