US3877776A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speckle reduction in holography
Assignee: Panasonic Holdings Corp
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Filing: 1974-04-25
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Granted: 1975-04-15
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Expires: 1994-04-25
Abstract
Abstract Interference dot patterns that would be inevitably introduced in the holographic recording using diffused light have undesirable visual effects. Such undesirable effects can be greatly reduced by utilizing characteristics peculiar to the hologram.
Inventors
- 👤 Yoshihiro Okino
- 👤 Toshiro Kamogawa
- 👤 Makoto Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:30
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/32
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
215 words
A method of recording and reproducing a holographic image, comprising the steps of: recording a holographic image by: illuminating an object, the image of which is to be recorded, with a first coherent beam of light; projeCting a Fraunhofer diffraction pattern of said object onto a recording medium; projecting at least two reference beams of coherent light onto said recording medium in superposition with the projected image of said object, said reference beams impinging on said recording medium at angles of incidence theta 1 and theta 2 with respect to the angle of incidence of projection of said illuminated image onto said recording medium; and reconstructing the recorded holographic image by: illuminating the image on said recording medium with two coherent beams of light projected onto said recording medium with angles of incidence which correspond to the angles theta 1 and theta 2 of said reference beams, said two coherent beams reproducing two corresponding superimposed images; and displacing said recording medium in a generally rotational manner in the plane of the image face thereof to produce an out-of-focus component, the rotational displacement being sufficiently small so as to keep said out-of-focus component from visually obscuring the reproduced holographic image, thereby causing speckle patterns individually contained in the respective reproduced superimposed images to overlap each other.
Claim 2
Independent Claim
215 words
A method of recording and reproducing a holographic image, comprising the steps of: recording a holographic image by: illuminating an object, the image of which is to be recorded, with a first coherent beam of light; projeCting a Fraunhofer diffraction pattern of said object onto a recording medium; projecting at least two reference beams of coherent light onto said recording medium in superposition with the projected image of said object, said reference beams impinging on said recording medium at angles of incidence theta 1 and theta 2 with respect to the angle of incidence of projection of said illuminated image onto said recording medium; and reconstructing the recorded holographic image by: illuminating the image on said recording medium with two coherent beams of light projected onto said recording medium with angles of incidence which correspond to the angles theta 1 and theta 2 of said reference beams, said two coherent beams reproducing two corresponding superimposed images; and displacing said recording medium in a generally rotational manner in the plane of the image face thereof to produce an out-of-focus component, the rotational displacement being sufficiently small so as to keep said out-of-focus component from visually obscuring the reproduced holographic image, thereby causing speckle patterns individually contained in the respective reproduced superimposed images to overlap each other.
Claim 3
Dependent Claim
24 words
The method according to claim 1, comprising the further step of projecting said first coherent beam through an optical diffuser before illuminating said object.
Claim 4
Dependent Claim
38 words
The method according to claim 1, further comprising projecting said first coherent beam through a beam splitter located between the source of said first coherent beam and said object to thereby produce said at least two reference beams.
Claim 5
Independent Claim
115 words
A method for reconstructing a holographic image, comprising the steps of: illuminating a hologram having an image recorded thereon with a first beam of coherent light to reconstruct and project said image; illuminating a translucent diffuser with a second beam of light coherent with said first coherent light beam and laterally displaced therefrom, said translucent diffuser upon illumination producing only a speckle pattern which is finer than the speckle pattern inherently produced when reconstructing the image from said hologram; and superimposing said speckle pattern of said translucent diffuser and said projected image onto each other in coherent relation to produce an apparent visually finer speckle pattern and the speckle pattern of said reconstructed image along.
Claim 6
Independent Claim
115 words
A method for reconstructing a holographic image, comprising the steps of: illuminating a hologram having an image recorded thereon with a first beam of coherent light to reconstruct and project said image; illuminating a translucent diffuser with a second beam of light coherent with said first coherent light beam and laterally displaced therefrom, said translucent diffuser upon illumination producing only a speckle pattern which is finer than the speckle pattern inherently produced when reconstructing the image from said hologram; and superimposing said speckle pattern of said translucent diffuser and said projected image onto each other in coherent relation to produce an apparent visually finer speckle pattern and the speckle pattern of said reconstructed image along.
Claim 7
Dependent Claim
33 words
The method according to claim 4, further comprising the step of displacing said hologram and translucent diffuser relative to each other to produce relative movement between said superimposed speckle pattern and reconstructed image.
Claim 8
Dependent Claim
120 words
Apparatus for reconstruction holographic images, comprising: a hologram having an image recorded thereon; a stationary translucent diffuser having a fixed pattern; means for illuninating said hologram and said translucent diffuser with coherent light to reconstruct said image from said hologram and to produce only a speckle pattern from said translucent diffuser which is finer than the speckle pattern inherently produced when reconstructing said image from said hologram; said illuminating means illuminating said hologram and said translucent diffuser in a manner to superimpose the projected reconstructed image from said hologram and the projected speckle pattern from said translucent diffuser onto each other in coherent relation to produce a visually apparent finer speckle pattern than is produced by said projected image alone.
Claim 9
Dependent Claim
120 words
Apparatus for reconstruction holographic images, comprising: a hologram having an image recorded thereon; a stationary translucent diffuser having a fixed pattern; means for illuninating said hologram and said translucent diffuser with coherent light to reconstruct said image from said hologram and to produce only a speckle pattern from said translucent diffuser which is finer than the speckle pattern inherently produced when reconstructing said image from said hologram; said illuminating means illuminating said hologram and said translucent diffuser in a manner to superimpose the projected reconstructed image from said hologram and the projected speckle pattern from said translucent diffuser onto each other in coherent relation to produce a visually apparent finer speckle pattern than is produced by said projected image alone.
Claim 10
Dependent Claim
40 words
The apparatus according to claim 6, wherein said translucent diffuser comprises a hologram having said diffuser recorded thereon, and said illuminating means comprises a first beam illuminating said image recorded hologram and a second beam illuminating said diffuser record hologram.
Claim 11
Dependent Claim
38 words
The apparatus according to claim 6, wherein said hologram comprises a matrix of a plurality of individual holograms on a single plate and said diffuser comprises the spaces on Said plate between adjacent ones of said individual holograms.
Claim 12
Dependent Claim
55 words
The apparatus according to claim 8, wherein said illuninating means comprises a composite beam having a diameter at the plane of said plate which is greater than the width of an individual hologram and less than the distance from the center of one individual hologram to the outer edge of a next adjacent individual hologram.
Claim 13
Independent Claim
197 words
A method for reconstructing a holographic image from a hologram plate, comprising a matrix of a plurality of individual holograms on a single plate and a translucent diffuser comprising the spaces on said plate between said individual holograms, with a coherent light beam having a diameter at the plane of said plate which is greater than the width of an individual hologram and less than twice the distance from the center of one individual hologram to the outer edge of a next adjacent individual hologram, said method comprising the steps of: illuminating said hologram plate with said coherent light beam to construct and project an image recorded thereon, whereby said translucent diffuser is illumninated with said coherent light beam, said translucent diffuser upon illumination producing only a speckle pattern which is finer then the speckle pattern inherently produced when reconstructing the image from said hologram; superimposing said speckle pattern of said translucent diffuser and said projected image onto each other in coherent relation to produce an apparent visually finer speckle pattern than the speckle pattern of said reconstructed image alone; and displacing said coherent beam and said plate relative to each other to produce relative movement therebetween.
Claim 14
Independent Claim
197 words
A method for reconstructing a holographic image from a hologram plate, comprising a matrix of a plurality of individual holograms on a single plate and a translucent diffuser comprising the spaces on said plate between said individual holograms, with a coherent light beam having a diameter at the plane of said plate which is greater than the width of an individual hologram and less than twice the distance from the center of one individual hologram to the outer edge of a next adjacent individual hologram, said method comprising the steps of: illuminating said hologram plate with said coherent light beam to construct and project an image recorded thereon, whereby said translucent diffuser is illumninated with said coherent light beam, said translucent diffuser upon illumination producing only a speckle pattern which is finer then the speckle pattern inherently produced when reconstructing the image from said hologram; superimposing said speckle pattern of said translucent diffuser and said projected image onto each other in coherent relation to produce an apparent visually finer speckle pattern than the speckle pattern of said reconstructed image alone; and displacing said coherent beam and said plate relative to each other to produce relative movement therebetween.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |