Full-color hologram

• US 4,421,380 A
• Filed: 10/06/1980
• Issued: 12/20/1983
• Est. Priority Date: 10/06/1980
• Status: Expired due to Term

• Current Assignee: McGrew, Stephen P.
• Original Assignee: McGrew, Stephen P.
• Inventors: McGrew, Stephen P.
• Primary Examiner(s): Arnold, Bruce Y.
• Application Number:
  US06/194,438
• Time in Patent Office: 1,170 Days
• Field of Search: 350/3.76, 350/3.69, 350/3.75, 350/3.77, 350/3.6, 350/3.86, 350/3.78
• US Class Current: 359/23
• CPC Class Codes: G03H 1/0256 having specific functional layer
• CPC Class Codes: G03H 1/24 using white light , e.g. rainbow holograms
• CPC Class Codes: G03H 1/26 Processes or apparatus specially adapted to produce multiple sub- holograms or to obtain images from them, e.g. multicolour technique
• CPC Class Codes: G03H 2001/2239 Enlarging the viewing window
• CPC Class Codes: G03H 2001/2263 Multicoloured holobject
• CPC Class Codes: G03H 2001/2265 Achromatic holobject
• CPC Class Codes: G03H 2001/2268 Rainbow hologram
• CPC Class Codes: G03H 2001/269 Two and more than two steps recording process
• CPC Class Codes: G03H 2001/303 Interleaved sub-holograms, e.g. three RGB sub-holograms having interleaved pixels for reconstructing coloured holobject
• CPC Class Codes: G03H 2210/13 Coloured object
• CPC Class Codes: G03H 2210/30 3D object
• CPC Class Codes: G03H 2210/454 into planes
• CPC Class Codes: G03H 2222/18 RGB trichrome light
• CPC Class Codes: G03H 2223/14 Diffuser, e.g. lens array, random phase mask
• CPC Class Codes: G03H 2223/23 Diffractive element
• CPC Class Codes: G03H 2250/34 Colour layer
• CPC Class Codes: G03H 2270/23 Ribbon shaped, e.g. holographic foil

Abstract

A new class of holograms, having the properties of full-color reconstruction from a single white light source, an extended vertical viewing aperture, and extended scene depth is disclosed. These advantageous properties are provided by a hologram composed of three intermeshed holograms, each of which reconstructs only one of the three color components of the scene. Each color component hologram consists of an array of noncontiguous small dots or thin stripes so that the three-color component holograms may be intermeshed without overlap of the dots or stripes. Associated with each color component hologram is a similar array of dot or stripe color filters which allow only the appropriate color of light to reconstruct each color component hologram. The component holograms themselves are vertically focused so that the composite hologram is white light viewable.

Claims

1. A multicolor hologram comprising:

a first group of small areas of a recording medium, said group bearing diffractive patterns substantially corresponding to a spatially sampled, first hologram recorded in a first color and bearing an image having horizontal parallax, substantially no vertical parallax, and a finite degree of vertical diffuseness;

first color filter means proximate said first group of small areas to limit reconstruction of an image from said first group of areas to a predetermined first color;

a second group of small areas of said recording medium non-overlapping with said first group of small areas and distributed on said surface, said second group bearing diffractive patterns substantially corresponding to a spatially sampled, second hologram recorded in a color different from that of said first hologram and bearing an image with horizontal parallax, substantially no vertical parallax, and a finite degree of vertical diffuseness; and

second color filter means located proximate said second group of small areas to limit reconstruction of the image from said second group of areas to a predetermined second color.

2. The multicolor hologram of claim 1 wherein the images in said recited first and second holograms are vertically focused substantially upon said recording medium but are horizontally focused elsewhere than substantially open said medium.

3. The multicolor hologram of claim 1 wherein said diffractive patterns are surface relief holograms and said color filter means are zero-order diffraction color filters.

4. The multicolor hologram of claim 1 wherein at least one of said recited first and second holograms is a multiplexed hologram composed from a range of perspective views of a three-dimensional scene.

5. A system for making color matrix holograms, comprising:

means for generating upon a high-resolution recording medium a first light-diffractive pattern reconstructing an object scene when said diffractive pattern is illuminated by a first color of light, said light-diffractive pattern substantially corresponding to a hologram bearing an image vertically focused substantially upon said medium and horizontally focused elsewhere than substantially upon said medium;

means for limiting the generation of said diffractive pattern on said medium to a first group of small areas distributed on said medium;

means for generating upon said medium a second light-diffractive pattern reconstructing an object scene when said second diffractive pattern is illuminated by a second color of light, said second light diffractive pattern substantially corresponding to a hologram bearing an image vertically focused substantially upon said medium and horizontally focused elsewhere than substantially upon said medium; and

means for limiting the generation of said second diffractive pattern on said medium to a second group of small areas distributed on said medium.

6. The system of claim 5 wherein said means for generating said diffractive patterns is a strip multiplexed hologram printer.

7. The system of claim 5 wherein said means for generating a light-diffractive pattern comprises at least one master hologram containing a representation of said object scene, means for reconstructing said master hologram with a plurality of colors of coherent light, and means for recording said light-diffractive pattern as a hologram of said reconstruction of said object scene such that said hologram of said reconstruction is a color matrix hologram.

8. A method for producing multicolor holograms, comprising:

creating an original color matrix hologram comprising at least a first group and a second group of small areas of a recording medium, each of said groups bearing diffractive patterns substantially corresponding to a spatially sampled hologram recorded in a predetermined color and bearing an image with horizontal parallax, substantially no vertical parallax, and a finite degree of vertical diffuseness;

wherein said second group of small areas of said recording medium is substantially non-overlapping with said first group of small areas and is distributed on said surface; and

replicating said original color matrix hologram onto a substrate in registration with matched color-selective means imposed upon the same substrate such that said matched color-selective means substantially prevents color cross-talk among color components of the hologram during reconstruction while permitting reconstruction of each of said groups in the corresponding colors.

9. A method of making a multicolor hologram, comprising:

recording a series of incoherent perspective views of a scene, said views being located along a horizontal line in a predetermined position relative to said scene;

constructing a first hologram on a first recording medium from said series of views by projecting with coherent light said views sequentially into an optical system which vertically disperses said coherent light from a focal plane, said first hologram being further constructed by recording downstream from said optical system the interference between said coherent light and a reference beam which is coherent with respect to said coherent light, said first hologram constructed such that, upon illumination with a reconstruction beam, said views are reconstructed in superposition to constitute a three-dimensional image of said scene;

limiting the recording of said first hologram such that groups of small, substantially non-overlapping areas on said first recording medium bear interference patterns corresponding primarily to predetermined color components of said scene;

reconstructing a three-dimensional image of said scene by illuminating said first hologram with a reconstruction beam of coherent light and providing means to limit the reconstruction of each of said groups of said small areas primarily to the corresponding colors of said reconstruction beam;

constructing a second hologram on a second recording medium by recording the interference beween the reconstruction of said scene and a second reference beam coherent with respect to said reconstruction beam; and

limiting the recording of said second hologram such that groups of small areas on said second medium bear interference patterns corresponding primarily to the predetermined color components of said scene.

10. The method of claim 9, further comprising:

limiting the recording of said first hologram such that groups of small, substantially non-overlapping areas on said first recording medium bear interference patterns corresponding primarily to predetermined color components of said scene; and

limiting the reconstruction of each of said groups to said small areas on said first medium primarily to the corresponding colors of said reconstruction beam.