US3635539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wide-angle holographic apparatus
Assignee: Unisys Corp
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Filing: 1969-08-18
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Granted: 1972-01-18
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Expires: 1989-08-18
Abstract
Abstract A method and apparatus for constructing wide angle holograms. The construction apparatus comprises propagating onto a Ronchi ruling and photographic plate serially disposed in the path of the beam. An object of which a holographic recording is to be obtained is positioned on the side of the plate remote from the light source and ruling. The ruling precludes the direct light beam from impinging on various regions of the plate which is canted with respect to the propagational axis of the direct beam so that the light propagating through the plate is partially reflected from its rear surface thereby forming a reference beam which is directed onto regions of the emulsion devoid of direct light. The light transmitted through the plate onto the object is scattered therefrom whereupon that part of the scattered light directed back onto the plate interferes with the reflected reference beam to form the hologram.
Inventors
- 👤 Donald H Mcmahon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:24
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/02; G03H1/024; G03H1/0248
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
12 words
The apparatus of claim 1 wherein the light source is a laser.
Claim 2
Dependent Claim
60 words
The apparatus of claim 1 wherein the holographic recording medium is canted relative to the propagational axis of the beam emitted from said source so that the reflecting means is provided by the refractive index mismatch between the ambient medium and the surface of said recording medium opposite from the surface of incidence of the beam emitted from the source.
Claim 3
Dependent Claim
23 words
The apparatus of claim 1 wherein the holographic recording medium is a photographic plate having the photosensitive emulsified surface thereof proximate the mask.
Claim 4
Dependent Claim
58 words
The apparatus of claim 4 wherein the photographic plate is canted relative to the propagational axis of the beam emitted from the source so that the reflecting means is provided by the refractive index mismatch between the ambient medium and the surface of the plate opposite from the surface of incidence of the beam emitted from the source.
Claim 5
Dependent Claim
29 words
The apparatus of claim 5 wherein the mask is a Ronchi ruling having alternate transparent and opaque lines with a resolution in the range of 2-5 lines per millimeter.
Claim 6
Dependent Claim
25 words
The apparatus of claim 5 wherein the emulsion on the photographic plate includes a swelling agent to minimize shrinkage attendant to development of the plate.
Claim 7
Dependent Claim
11 words
The apparatus of claim 5 wherein the source is a laser.
Claim 8
Dependent Claim
15 words
The apparatus of claim 8 wherein the beam provided by the laser is slightly convergent.
Claim 9
Dependent Claim
31 words
The apparatus of claim 1 wherein the spacing between adjacent transparent regions of said mask is sufficiently small so that the spacing of said spatially separated regions is not normally discernible.
Claim 10
Dependent Claim
60 words
The apparatus of claim 10 wherein tHe holographic recording medium is canted relative to the propagational axis of the bean emitted from said source so that the reflecting means is provided by the refractive index mismatch between the ambient medium and the surface of said recording medium opposite from the surface of incidence of the beam emitted from the source.
Claim 11
Independent Claim
173 words
A method of producing a hologram comprising the steps of positioning a mask having a plurality of respective transparent and opaque regions in the path of a direct light beam, positioning a recording medium behind the mask and closely adjacent thereto so that direct light propagated through the mask is incident on a plurality of spatially separated regions of the recording medium in accordance with the pattern of transparent regions on the mask thereby exposing said plurality of spatially separated regions, providing for a portion of said direct light which is transmitted through the recording medium to be reflected as a reference beam back onto at least those regions of the recording medium which are interspersed with said plurality of spatially separated regions, and directing another portion of the transmitted light onto an object to form an object beam which is also reflected back onto at least those regions of the recording medium which are interspersed with said plurality of spatially separated regions thereby causing interference between said reflected reference and object beams.
Claim 12
Independent Claim
122 words
A method of reconstructing an image of an object recorded as a hologram in a recording medium be interference between coherently related reflected reference and object beams derived from a direct beam after propagation thereof in succession through a mask and the recording medium disposed in closely adjacent relation with one another wherein the mask has a plurality of respective transparent and opaque regions so that only certain regions of the recording medium are exposed to the direct beam and the hologram is formed in the regions of said recording medium other than said certain regions, said method comprising the step of illuminating the recording medium with a coherent light beam thereby producing an image of the object recorded in the hologram.
Claim 13
Dependent Claim
35 words
The method of claim 13 wherein the central axis of the coherent light beam is incident on the recording medium along the same direction and at the same angle as used for recording the hologram.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |