US4695973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Real-time programmable optical correlator
Assignee: United States Department of the Air Force
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Filing: 1985-10-22
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Granted: 1987-09-22
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Expires: 2005-10-22
Abstract
Abstract A real-time programmable joint transform optical correlator incorporating a magneto-optic spatial light modulator and a liquid crystal light valve therein. Object functions to be correlated are input into the magneto-optic spatial light modulator by a programmable microcomputer as input signals. Real time correlation takes place at the liquid crystal light valve with a coherent read out beam. Cross correlation between the input functions (signals) are obtained through the inverse Fourier transform of the read out coherent illumination and are subsequently output from the correlator.
Inventors
- 👤 Francis T. S. Yu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:01
CPC Classifications
G; G06; G06E; G06E3/00; G06E3/001; G06E3/005
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
215 words
A real-time programmable optical correlator, comprising: means for providing a first beam of electromagnetic radiation and directing said beam of electromagnetic radiation along a preselected optical axis; means located at a first preselected location along said optical axis for receiving said first beam of electromagnetic radiation, a first input signal and a second input signal and for generating images representative of said first and said second input signals; means at a second preselected location along said optical axis for receiving said images and forming a joint Fourier transform of said images at a third preselected location along said optical axis; means for providing a second beam of electromagnetic radiation and directing said second beam of electromagnetic radiation to said third preselected location along said optical axis; means positioned at said third preselected location along said optical axis for receiving said joint Fourier transform of said images and said second beam of electromagnetic radiation and for generating a coherent power spectrum representative of said images; means positioned at a fourth preselected location along said optical axis for forming an inverse Fourier transform of said coherent power spectrum of said images at a fifth preselected location along said optical axis, said inverse Fourier transform being representative of a correlation between said first and said second input signals.
Claim 2
Dependent Claim
215 words
A real-time programmable optical correlator, comprising: means for providing a first beam of electromagnetic radiation and directing said beam of electromagnetic radiation along a preselected optical axis; means located at a first preselected location along said optical axis for receiving said first beam of electromagnetic radiation, a first input signal and a second input signal and for generating images representative of said first and said second input signals; means at a second preselected location along said optical axis for receiving said images and forming a joint Fourier transform of said images at a third preselected location along said optical axis; means for providing a second beam of electromagnetic radiation and directing said second beam of electromagnetic radiation to said third preselected location along said optical axis; means positioned at said third preselected location along said optical axis for receiving said joint Fourier transform of said images and said second beam of electromagnetic radiation and for generating a coherent power spectrum representative of said images; means positioned at a fourth preselected location along said optical axis for forming an inverse Fourier transform of said coherent power spectrum of said images at a fifth preselected location along said optical axis, said inverse Fourier transform being representative of a correlation between said first and said second input signals.
Claim 3
Dependent Claim
41 words
A real-time programmable optical correlator as defined in claim 1 further comprising means located adjacent said fifth preselected location for detecting said inverse Fourier transform and emitting an output representative of said correlation between said first and said second input signals.
Claim 4
Dependent Claim
47 words
A real-time programmable optical correlator as defined in claim 2 further comprising means operably connected to said means located at said first preselected location for receiving an image of an object and for generating said first input signal representative thereof and for generating said second input signal.
Claim 5
Dependent Claim
30 words
A real-time programmable optical correlator as defined in claim 3 further comprising means for operably interconnecting said output with said means for generating said first and said second input signals.
Claim 6
Dependent Claim
25 words
A real-time programmable optical correlator as defined in claim 3 wherein said means for generating said first and said second input signals comprises a computer.
Claim 7
Dependent Claim
29 words
A real-time programmable optical correlator as defined in claim 2 wherein said means located adjacent said fifth preselected location comprises a charge coupled array detector and a television camera.
Claim 8
Dependent Claim
24 words
A real-time programmable optical correlator as defined in claim 1 wherein said means located at said first location comprises a magneto-optic spatial light modulator.
Claim 9
Dependent Claim
25 words
A real-time programmable optical correlator as defined in claim 7 wherein said means positioned at said third preselected location comprises a liquid crystal light valve.
Claim 10
Dependent Claim
41 words
A real-time programmable optical correlator as defined in claim 8 further comprising means located adjacent said fifth preselected location for detecting said inverse Fourier transform and emitting an output representative of said correlation between said first and said second input signals.
Claim 11
Dependent Claim
47 words
A real-time programmable optical correlator as defined in claim 9 further comprising means operably connected to said means located at said first preselected location for receiving an image of an object and for generating said first input signal representative thereof and for generating said second input signal.
Claim 12
Dependent Claim
30 words
A real-time programmable optical correlator as defined in claim 10 further comprising means for operably interconnecting said output with said means for generating said first and said second input signals.
Claim 13
Dependent Claim
25 words
A real-time programmable optical correlator as defined in claim 11 wherein said means for generating said first and said second input signals comprises a computer.
Claim 14
Dependent Claim
24 words
A real-time programmable optical correlator as defined in claim 12 wherein said means for providing said first beam of electromagnetic radiation comprises a laser.
Claim 15
Dependent Claim
33 words
A real-time programmable optical correlator as defined in claim 13 wherein said means for providing said second beam of electromagnetic radiation and for directing said second beam comprises a laser and a beamsplitter.
Claim 16
Dependent Claim
28 words
A real-time programmable optical correlator as defined in claim 14 wherein said means located adjacent said fifth preselected location comprises a charge coupled array detector and television camera.
Claim 17
Dependent Claim
25 words
A real-time programmable optical correlator as defined in claim 1 wherein said means positioned at said third preselected location comprises a liquid crystal light valve.
Claim 18
Dependent Claim
24 words
A real-time programmable optical correlator as defined in claim 1 wherein said means for providing said first beam of electromagnetic radiation comprises a laser.
Claim 19
Dependent Claim
33 words
A real-time programmable optical correlator as defined in claim 1 wherein said means for providing said second beam of electromagnetic radiation and for directing said second beam comprises a laser and a beamsplitter.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-09-21 | 1991-03-23 | 1991-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-21 | 1995-03-23 | 1995-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-21 | 1999-03-23 | 1999-09-22 | $7700.00 | Window Closed / Lapsed |