US3752557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System of hologram reproduction
Assignee: Thales SA
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Filing: 1967-05-31
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Granted: 1973-08-14
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Expires: 1987-05-31
Abstract
Abstract An optical method for copying holograms from an original. The photographic support on which a copy is to be made, is positioned behind the original hologram and the whole is exposed to the monochromatic coherent light; the original and the copying supports need not be in contact and the copy is not a reproduction of the original hologram but has the same image forming capabilities as the latter. The exposed copy is processed according to conventional photographic technics.
Inventors
- 👤 Y Belvaux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:04
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/04; G03H1/20; G03H1/202
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
161 words
A method of copying an off-axis hologram comprising the steps of: directing an illuminating beam consisting of monchromatic spatially coherent light onto a recording surface of the offaxis hologram at an angle to produce at least one diffracted image beam at a finite angle with respect to the illuminating beam, placing a detector with respect to the hologram so that the detector receives both the illuminating beam and at least one diffracted image beam, said angle of said illuminating beam and the spacing between the recording surfaces of said hologram and said detector being so related as to produce a new interference pattern by the concurrent interaction of the illuminating beam as a reference beam and the diffracted image beam, the detector being sensitive to coherent light and capable of detecting interference fringes, and recording the new interference pattern on the detector produced by the interaction of the illuminating beam and the diffracted image beam as a copy of the hologram.
Claim 2
Independent Claim
161 words
A method of copying an off-axis hologram comprising the steps of: directing an illuminating beam consisting of monchromatic spatially coherent light onto a recording surface of the offaxis hologram at an angle to produce at least one diffracted image beam at a finite angle with respect to the illuminating beam, placing a detector with respect to the hologram so that the detector receives both the illuminating beam and at least one diffracted image beam, said angle of said illuminating beam and the spacing between the recording surfaces of said hologram and said detector being so related as to produce a new interference pattern by the concurrent interaction of the illuminating beam as a reference beam and the diffracted image beam, the detector being sensitive to coherent light and capable of detecting interference fringes, and recording the new interference pattern on the detector produced by the interaction of the illuminating beam and the diffracted image beam as a copy of the hologram.
Claim 3
Dependent Claim
30 words
A method as claimed in claim 1, wherein said spacing between the recording surfaces of said holgram and said detector is shorter than the coherence length of said illuminating beam.
Claim 4
Dependent Claim
26 words
A method as claimed in claim 1, wherein the wavelength of said illuminating beam is equal to the wavelength of light used to form said hologram.
Claim 5
Dependent Claim
37 words
A method as claimed in claim 1, wherein the angle of incidence of said illuminating beam with respect to said hologram is equal to the angle of incidence of the reference beam used to form said hologram.
Claim 6
Dependent Claim
17 words
A method as claimed in claim 1, wherein said illuminating beam is supplied from a laser source.
Claim 7
Dependent Claim
23 words
A method as claimed in claim 5, wherein said laser source is a pulsed laser whose emission determines the exposure of said detector.
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) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |