US3688101A
Expired / Lapsed
US
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Optical correlation apparatus
Assignee: Raytheon Co
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Filing: 1970-10-23
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Granted: 1972-08-29
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Expires: 1990-10-23
Abstract
Abstract An optical correlation system in which an optical modulator modulates a collimated monochromatic beam of light in accordance with an input reference signal to the modulator. An output light beam having sinusoidal light intensity variation versus phase retardation characteristics with the modulation quiescent operating point being positioned within a predetermined region of the characteristic by means of a fixed wave filter having a spatial pattern thereof applying amplitude and/or phase shift to the elements of the beam is applied to a cathode ray tube whose scanning beam is modulated in accordance with information, such as a radar signal, to be correlated with the reference signal source as modified by the modulator and wave filter to produce an output having a multiplication of the two signals.
Inventors
- 👤 Harley Barry Henning
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:00
CPC Classifications
G; G06; G06E; G06E3/00; G06E3/001; G06E3/005; G06V; G06V10/00; G06V10/88; G06V10/89; G06V10/893; G06V10/895
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
89 words
In a correlation apparatus: a source of light; a first source of signals; means for varying the spatial distribution of the frequency components of a beam of said light to produce a beam of light having spatially distributed time varying and time invariant components and including means for shifting the phase of a time invariant component by a predetermined amount and for attenuating said time varying component; a source of second signals; and multiplication means responsive to said spatial variations and to said second signals for forming product signals.
Claim 2
Dependent Claim
89 words
In a correlation apparatus: a source of light; a first source of signals; means for varying the spatial distribution of the frequency components of a beam of said light to produce a beam of light having spatially distributed time varying and time invariant components and including means for shifting the phase of a time invariant component by a predetermined amount and for attenuating said time varying component; a source of second signals; and multiplication means responsive to said spatial variations and to said second signals for forming product signals.
Claim 3
Dependent Claim
15 words
The correlation apparatus in accordance with claim 1 wherein said source supplies substantially monochromatic light.
Claim 4
Dependent Claim
103 words
In a correlation apparatus: means for producing a substantially coherent light beam having a spatial wave phase variation along a plane substantially transverse to the direction of propagation of the beam; and means for correlating said light beam phase variation comprising a structure in the path for said beam through which the transmissivity and transit time differ for different elements of said beam and the zero frequency component of said spatial wave is shifted in phase; and means for producing signals containing products of the multiplication of an additional signal with said light beam phase variations as modified by transmission through said structure.
Claim 5
Dependent Claim
103 words
In a correlation apparatus: means for producing a substantially coherent light beam having a spatial wave phase variation along a plane substantially transverse to the direction of propagation of the beam; and means for correlating said light beam phase variation comprising a structure in the path for said beam through which the transmissivity and transit time differ for different elements of said beam and the zero frequency component of said spatial wave is shifted in phase; and means for producing signals containing products of the multiplication of an additional signal with said light beam phase variations as modified by transmission through said structure.
Claim 6
Dependent Claim
36 words
The correlation apparatus in accordance with claim 3 wherein said differences in transmissivity and transit time for different elements of said beam are produced by transmission of said coherent light beam through a spatial wave filter.
Claim 7
Dependent Claim
40 words
The correlation apparatus in accordance with claim 4 wherein said spatial wave filter comprises a converging lens and means positioned substantially in the focal plane of said lens for chAnging the relative transit time of different elements of said beam.
Claim 8
Dependent Claim
29 words
The correlation apparatus in accordance with claim 4 wherein said product producing means comprises means for multiplying the intensity of said spatially distributed beam elements with an additional signal.
Claim 9
Dependent Claim
18 words
The correlation apparatus in accordance with claim 6 wherein said product producing means comprises a cathode ray tube.
Claim 10
Dependent Claim
107 words
In a correlation apparatus: a source of modulating signals; a collimated monochromatic light source; means for spatially varying the collimated monochromatic light wave in accordance with said source of modulating signals to produce a spatially distributed light wave having time varying and time invariant components thereof; means for shifting the phase of the time invariant component and for attenuating the time varying component to maintain the response of the modulating apparatus to the modulation signal within a predetermined region of the transfer characteristic of the system; and means for producing signals containing products of an additional signal and the output from said phase shifting and attenuating means.
Claim 11
Dependent Claim
107 words
In a correlation apparatus: a source of modulating signals; a collimated monochromatic light source; means for spatially varying the collimated monochromatic light wave in accordance with said source of modulating signals to produce a spatially distributed light wave having time varying and time invariant components thereof; means for shifting the phase of the time invariant component and for attenuating the time varying component to maintain the response of the modulating apparatus to the modulation signal within a predetermined region of the transfer characteristic of the system; and means for producing signals containing products of an additional signal and the output from said phase shifting and attenuating means.
Claim 12
Dependent Claim
32 words
The correlation apparatus in accordance with claim 8 wherein said time invariant component is shifted in phase by substantially one-eighth of a wavelength of the lowest frequency of said time varying components.
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) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |