Patent US3680041A successfully refreshed from Google Patents.
US3680041A
Expired / Lapsed
US
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Filtered coherent wave holography
Assignee: Shell USA Inc
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Filing: 1969-11-28
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Granted: 1972-07-25
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Expires: 1989-11-28
Abstract
Abstract A process for producing a hologram by illuminating an object with a coherent elastic wave is improved by digitally depicting the substantially full dynamic range of the mixture of reference wave energy and diffracted wave energy that forms the holographic data, subjecting the digitally depicted data to a low-pass spatial filtration, and displaying the hologram that is provided by the filtered data.
Inventors
- 👤 Noyes D Smith Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:55
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/24; G01V1/247; G01V1/28; G03; G03H; G03H3/00; Y; Y10; Y10S; Y10S359/00; Y10S359/901
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
166 words
A process for producing a hologram comprising illuminating an object with a coherent elastic wave, receiving diffracted and reflected waves at an array of areally spaced receiving locations, and mixing the waves received at each receiving location with a correspondingly phase-adjusted reference wave to provide a mixed signal; converting each of the mixed signals to a digital signal of full dynamic range; processing the digital signals in a manner simulating spatial filtering to remove the higher spatial frequencies by transforming the mixed digitized signal into a two-dimensional Fourier transform, spatially filtering the transform using both a low-pass spatial frequency filter and a spatial frequency filter arranged to reject the spatial frequencies produced by the sampling pattern and transforming the filtered transform to produce a signal relating to a filtered hologram with limited dynamic range and with the artifacts produced by the sampling pattern removed; and visibly displaying the pattern of the intensities of said filtered signals in an array corresponding to the array of receiving locations.
Claim 2
Dependent Claim
166 words
A process for producing a hologram comprising illuminating an object with a coherent elastic wave, receiving diffracted and reflected waves at an array of areally spaced receiving locations, and mixing the waves received at each receiving location with a correspondingly phase-adjusted reference wave to provide a mixed signal; converting each of the mixed signals to a digital signal of full dynamic range; processing the digital signals in a manner simulating spatial filtering to remove the higher spatial frequencies by transforming the mixed digitized signal into a two-dimensional Fourier transform, spatially filtering the transform using both a low-pass spatial frequency filter and a spatial frequency filter arranged to reject the spatial frequencies produced by the sampling pattern and transforming the filtered transform to produce a signal relating to a filtered hologram with limited dynamic range and with the artifacts produced by the sampling pattern removed; and visibly displaying the pattern of the intensities of said filtered signals in an array corresponding to the array of receiving locations.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein the elastic wave is an acoustic seismic source and the receiving locations include seismometers.
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |