Holographic projection screen for displaying a three-dimensional color images and optical display system using the holographic screen

US 20010006426A1
Filed: 01/25/2001
Published: 07/05/2001
Est. Priority Date: 07/18/1996
Status: Abandoned Application

First Claim

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1. An optical display system for displaying stereoscopic or multi-view color images comprising:

a holographic screen; and

two or more image projectors which project the stereoscopic or multi-view color images on said holographic screen, a distance between exit pupils of the two or more image projectors being decided depending on a viewer'"'"'s inter-eye distance, wherein said holographic screen is formed by a method including the steps of;

(a) placing a photoplate on an x-y plane of a three dimensional space, wherein the center of the photoplate is disposed in the origin of the three dimensional space;

(b) splitting the laser beam into two beams;

reference beam and object beam, both beams being used to illuminate the photoplate surface;

(c) shaping the reference beam as a sperical wave diverging from a point on a z-axis which is located a distance R₁from the photoplate center;

(d) shaping the object beam so as to illuminate the photoplate through an elongated narrow slit-shaped diffuser inclined to the photoplate surface; and

(e) recording an interference pattern, which is arising as a result of the superposition of the reference wave with an object wave from the diffuser on the photoplate, whereby the stereoscopic or multiview three dimensional color images is displayed on a recorded screen by the projectors disposed at a distance R₃from the screen, if a viewer'"'"'s eyes are placed at viewing zones which are located behind the screen at a distance R₄the viewing zones being composed of superposed diffuser'"'"'s real images of the different colors, wherein the coordinates of the diffuser point, which is responsible for the contribution of a light with a wavelength X₂in the viewing zone, are calculated from the following equations;

$\begin{matrix} k_{2} r_{3} + k_{1} (r_{1} - r_{2}) = - k_{2} r_{4} + const & (1) \\ α = \sin^{- 1} [\frac{k_{2}}{k_{1}} \sin β] = \sin^{- 1} [\frac{λ_{1}}{λ_{2}} \sin β] & (2) \\ R_{2} = \frac{R_{1}}{1 + \frac{2 λ_{1} R_{1}}{λ_{2} R_{4}}} & (3) \end{matrix}$ where r₁is the distance between an arbitrary point (x,y) on the photoplate and a position of the source of the reference beam;

r₂and R₂are the distances between a point (x,y) on the photoplate and a point on the diffuser and between the coordinate origin and the same diffuser point;

α

is the angle between R₂straight line and the z-axis;

r₃is the distance between a point (x,y) on the photoplate and a point source of the projection beam;

r₄is the distance between a point (x,y) on the photoplate and a viewing zone;

R₄is the distance between an origin and a viewing zone;

β

is the angle between R₄straight line and the z-axis;

λ

₁and λ

₂represent wavelengths of the recording and projecting waves, respectively;

k₁and k₂are wave numbers of the recording and projecting waves, respectively, wherein the diffuser'"'"'s length and position are calculated using equations (2) and (3) for covering an entire spectral range of a projected image.

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Abstract

A method is proposed, how to produce a holographic screen for projection of the three-dimensional color images, where a narrow and elongate slit-shaped diffuser is recorded on a hologram as an object to ensure the well defined viewing zone forming in the course of the image projection. Further to the back side of the holographic screen a mirror is attached to transform it into reflection mode of operation. Further, the holographic screen is rotated under a control of an eye-tracking system to provide viewing zone movement together with a viewer'"'"'s eye. Also, a diffuser with vertical light scattering is attached to a surface of the holographic screen to increase a vertical size of a viewing zone of the holographic screen. In addition, two or more holographic screens manufactured by this method are combined in a mosaic manner to form a big size holographic screen.

81 Citations

9 Claims

1. An optical display system for displaying stereoscopic or multi-view color images comprising:
- a holographic screen; and
  
  two or more image projectors which project the stereoscopic or multi-view color images on said holographic screen, a distance between exit pupils of the two or more image projectors being decided depending on a viewer'"'"'s inter-eye distance, wherein said holographic screen is formed by a method including the steps of;
  
  (a) placing a photoplate on an x-y plane of a three dimensional space, wherein the center of the photoplate is disposed in the origin of the three dimensional space;
  
  (b) splitting the laser beam into two beams;
  
  reference beam and object beam, both beams being used to illuminate the photoplate surface;
  
  (c) shaping the reference beam as a sperical wave diverging from a point on a z-axis which is located a distance R₁from the photoplate center;
  
  (d) shaping the object beam so as to illuminate the photoplate through an elongated narrow slit-shaped diffuser inclined to the photoplate surface; and
  
  (e) recording an interference pattern, which is arising as a result of the superposition of the reference wave with an object wave from the diffuser on the photoplate, whereby the stereoscopic or multiview three dimensional color images is displayed on a recorded screen by the projectors disposed at a distance R₃from the screen, if a viewer'"'"'s eyes are placed at viewing zones which are located behind the screen at a distance R₄the viewing zones being composed of superposed diffuser'"'"'s real images of the different colors, wherein the coordinates of the diffuser point, which is responsible for the contribution of a light with a wavelength X₂in the viewing zone, are calculated from the following equations;
  
  $\begin{matrix} k_{2} r_{3} + k_{1} (r_{1} - r_{2}) = - k_{2} r_{4} + const & (1) \\ α = \sin^{- 1} [\frac{k_{2}}{k_{1}} \sin β] = \sin^{- 1} [\frac{λ_{1}}{λ_{2}} \sin β] & (2) \\ R_{2} = \frac{R_{1}}{1 + \frac{2 λ_{1} R_{1}}{λ_{2} R_{4}}} & (3) \end{matrix}$ where r₁is the distance between an arbitrary point (x,y) on the photoplate and a position of the source of the reference beam;
  
  r₂and R₂are the distances between a point (x,y) on the photoplate and a point on the diffuser and between the coordinate origin and the same diffuser point;
  
  α
  
  is the angle between R₂straight line and the z-axis;
  
  r₃is the distance between a point (x,y) on the photoplate and a point source of the projection beam;
  
  r₄is the distance between a point (x,y) on the photoplate and a viewing zone;
  
  R₄is the distance between an origin and a viewing zone;
  
  β
  
  is the angle between R₄straight line and the z-axis;
  
  λ
  
  ₁and λ
  
  ₂represent wavelengths of the recording and projecting waves, respectively;
  
  k₁and k₂are wave numbers of the recording and projecting waves, respectively, wherein the diffuser'"'"'s length and position are calculated using equations (2) and (3) for covering an entire spectral range of a projected image.
- View Dependent Claims (2, 3, 4, 5, 6)
- - 2. The optical display system according to claim 1, further comprising a reflecting means attached to the back side of said holographic screen for allowing said holographic screen to operate in a reflection mode.
  - 3. The optical display system according to claim 2, further comprising:
    - means for rotating said holographic screen; and
      
      an eye-tracking system for tracking a viewer'"'"'s eye movement to control an operation of said rotating means, whereby said holographic screen is rotated in accordance with the viewer'"'"'s eye movement.
  - 4. The optical display system according to claim 1, further comprising a vertical diffusing means attached to a surface of said holographic screen, wherein said vertical diffusing means generates vertical light scattering on the surface of said holographic screen to increase a vertical size of the viewing zone to be formed by said holographic screen.
  - 5. The optical display system according to claim 4, wherein said diffusing means is formed as a bleached photograph of a speckle pattern, said speckle pattern being obtained by scattering a thin line of laser light to a ground glass.
  - 6. The optical display system according to claim 4, wherein said diffusing means is formed as a diffraction grating with vertical direction of dispersion, said diffraction grating having such a grating period that neighboring diffraction orders are separated at the viewer position by a distance equal to an diameter of the viewing zone.

7. An optical display system for displaying a large stereoscopic or multi-view color image comprising:
- two or more holographic screens;
  
  means for combining said two or more holographic screens in such a manner that their viewing zones coincide in a viewer'"'"'s position to form a large holographic screen, to thereby provide the large stereoscopic or multi-view image; and
  
  two or more image projectors which project the large stereoscopic or multi-view color image on said two or more holographic screens, a distance between exit pupils of the two or more image projectors being decided depending on a viewer'"'"'s inter-eye distance, wherein each of said two or more holographic screens is formed by a method including the steps of;
  
  (a) placing a photoplate on an x-y plane of a three dimensional space, wherein the center of the photoplate is disposed in the origin of the three dimensional space;
  
  (b) splitting the laser beam into two beams;
  
  reference beam and object beam, both beams being used to illuminate the photoplate surface;
  
  (c) shaping the reference beam as a sperical wave diverging from a point on a z-axis which is located a distance R₁from the photoplate center;
  
  (d) shaping the object beam so as to illuminate the photoplate through an elongated narrow slit-shaped diffuser inclined to the photoplate surface; and
  
  (e) recording an interference pattern, which is arising as a result of the superposition of the reference wave with an object wave from the diffuser on the photoplate, whereby the large stereoscopic or multiview color image is displayed on a recorded screen by the two or more projectors disposed at a distance R₃from said two or more holographic screens, if a viewer'"'"'s eyes are placed at viewing zones which are located behind the screen at a distance R₄, the viewing zones being composed of superposed diffuser'"'"'s real images of the different colors, wherein the coordinates of the diffuser point, which is responsible for the contribution of a light with a wavelength λ
  
  ₂in the viewing zone, are calculated from the following equations;
  
  $\begin{matrix} k_{2} r_{3} + k_{1} (r_{1} - r_{2}) = - k_{2} r_{4} + const & (1) \\ α = \sin^{- 1} [\frac{k_{2}}{k_{1}} \sin β] = \sin^{- 1} [\frac{λ_{1}}{λ_{2}} \sin β] & (2) \\ R_{2} = \frac{R_{1}}{1 + \frac{2 λ_{1} R_{1}}{λ_{2} R_{4}}} & (3) \end{matrix}$ where r₁is the distance between an arbitrary point (x,y) on the photoplate and a position of the source of the reference beam;
  
  r₂and R₂are the distances between a point (x,y) on the photoplate and a point on the diffuser and between the coordinate origin and the same diffuser point;
  
  α
  
  is the angle between R₂straight line and the z-axis;
  
  r₃is the distance between a point (x,y) on the photoplate and a point source of the projection beam;
  
  r₄is the distance between a point (x,y) on the photoplate and a viewing zone;
  
  R₄is the distance between an origin and a viewing zone;
  
  β
  
  is the angle between R₄straight line and the z-axis;
  
  λ
  
  ₁, and λ
  
  ₂represent wavelengths of the recording and projecting waves, respectively;
  
  k₁and k₂are wave numbers of the recording and projecting waves, respectively, wherein the diffuser'"'"'s length and position are calculated using equations (2) and (3) for covering an entire spectral range of a projected image.

8. A holographic screen being formed by a method including the steps of:
- (a) placing a photoplate on an x-y plane of a three dimensional space, wherein the center of the photoplate is disposed in the origin of the three dimensional space;
  
  (b) splitting the laser beam into two beams;
  
  reference beam and object beam, both beams being used to illuminate the photoplate surface;
  
  (c) shaping the reference beam as a sperical wave diverging from a point on a z-axis which is located a distance R₁from the photoplate center;
  
  (d) shaping the object beam so as to illuminate the photoplate through an elongated narrow slit-shaped diffuser inclined to the photoplate surface; and
  
  (e) recording an interference pattern, which is arising as a result of the superposition of the reference wave with an object wave from the diffuser on the photoplate, whereby the stereoscopic or multiview three dimensional color images is displayed on a recorded screen by the projectors disposed at a distance R₃from the screen, if a viewer'"'"'s eyes are placed at viewing zones which are located behind the screen at a distance R₄, the viewing zones being composed of superposed diffuser'"'"'s real images of the different colors, wherein the coordinates of the diffuser point, which is responsible for the contribution of a light with a wavelength λ
  
  ₂in the viewing zone, are calculated from the following equations;
  
  $\begin{matrix} k_{2} r_{3} + k_{1} (r_{1} - r_{2}) = - k_{2} r_{4} + const & (1) \\ α = \sin^{- 1} [\frac{k_{2}}{k_{1}} \sin β] = \sin^{- 1} [\frac{λ_{1}}{λ_{2}} \sin β] & (2) \\ R_{2} = \frac{R_{1}}{1 + \frac{2 λ_{1} R_{1}}{λ_{2} R_{4}}} & (3) \end{matrix}$ where r₁is the distance between an arbitrary point (x,y) on the photoplate and a position of the source of the reference beam;
  
  r₂and R₂are the distances between a point (x,y) on the photoplate and a point on the diffuser and between the coordinate origin and the same diffuser point;
  
  α
  
  is the angle between R₂straight line and the z-axis;
  
  r₃is the distance between a point (x,y) on the photoplate and a point source of the projection beam;
  
  r₄is the distance between a point (x,y) on the photoplate and a viewing zone;
  
  R₄is the distance between an origin and a viewing zone;
  
  β
  
  is the angle between R₄straight line and the z-axis;
  
  λ
  
  ₁and λ
  
  ₂represent wavelengths of the recording and projecting waves, respectively;
  
  k₁and k₂are wave numbers of the recording and projecting waves, respectively, wherein the diffuser'"'"'s length and position are calculated using equations (2) and (3) for covering an entire spectral range of a projected image.

9. A large holographic screen comprising:
- two or more holographic screens; and
  
  means for combining said two or more holographic screens in such a manner that their viewing zones coincide in a viewer'"'"'s position to form the large holographic screen, to thereby provide a large stereoscopic or multi-view image, wherein each of said two or more holographic screens is formed by a method including the steps of;
  
  (a) placing a photoplate on an x-y plane of a three dimensional space, wherein the center of the photoplate is disposed in the origin of the three dimensional space;
  
  (b) splitting the laser beam into two beams;
  
  reference beam and object beam, both beams being used to illuminate the photoplate surface;
  
  (c) shaping the reference beam as a sperical wave diverging from a point on a z-axis which is located a distance R₁from the photoplate center;
  
  (d) shaping the object beam so as to illuminate the photoplate through an elongated narrow slit-shaped diffuser inclined to the photoplate surface; and
  
  (e) recording an interference pattern, which is arising as a result of the superposition of the reference wave with an object wave from the diffuser on the photoplate, whereby the stereoscopic or multiview three dimensional color images is displayed on a recorded screen by the projectors disposed at a distance R₃from the screen, if a viewer'"'"'s eyes are placed at viewing zones which are located behind the screen at a distance R₄, the viewing zones being composed of superposed diffuser'"'"'s real images of the different colors, wherein the coordinates of the diffuser point, which is responsible for the contribution of a light with a wavelength λ
  
  ₂in the viewing zone, are calculated from the following equations;
  
  $\begin{matrix} k_{2} r_{3} + k_{1} (r_{1} - r_{2}) = - k_{2} r_{4} + const & (1) \\ α = \sin^{- 1} [\frac{k_{2}}{k_{1}} \sin β] = \sin^{- 1} [\frac{λ_{1}}{λ_{2}} \sin β] & (2) \\ R_{2} = \frac{R_{1}}{1 + \frac{2 λ_{1} R_{1}}{λ_{2} R_{4}}} & (3) \end{matrix}$ where r₁is the distance between an arbitrary point (x,y) on the photoplate and a position of the source of the reference beam;
  
  r₂and R₂are the distances between a point (x,y) on the photoplate and a point on the diffuser and between the coordinate origin and the same diffuser point;
  
  cc is the angle between R₂straight line and the z-axis;
  
  r₃is the distance between a point (x,y) on the photoplate and a point source of the projection beam;
  
  r₄is the distance between a point (x,y) on the photoplate and a viewing zone;
  
  R₄is the distance between an origin and a viewing zone;
  
  β
  
  is the angle between R₄straight line and the z-axis;
  
  λ
  
  ₁and λ
  
  ₂represent wavelengths of the recording and projecting waves, respectively;
  
  k₁and k₂are wave numbers of the recording and projecting waves, respectively, wherein the diffuser'"'"'s length and position are calculated using equations (2) and (3) for covering an entire spectral range of a projected image.

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Current Assignee
Hanger Solutions, LLC (IP Investments Group LLC)
Original Assignee
Korea Advanced Institute of Science and Technology
Inventors
Son, Jung Young, Bobrinev, Vladimir Ivanovich

Application Number

US09/768,624
Publication Number

US 20010006426A1
Time in Patent Office

Days
Field of Search
US Class Current

359/15
CPC Class Codes

G02B 5/32 Holograms used as optical e...

G03B 21/606 for relief projection

Holographic projection screen for displaying a three-dimensional color images and optical display system using the holographic screen

First Claim

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Abstract

81 Citations

9 Claims

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Holographic projection screen for displaying a three-dimensional color images and optical display system using the holographic screen

First Claim

4 Assignments

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Accused Products

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Abstract

81 Citations

9 Claims

Specification

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