US4426663A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Real-time optical filtering method with improved filtered image detection and bandwidth adjustment
Assignee: United States, UNITED STATES AIR FORCE, Secretary of
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Filing: 1982-01-06
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Granted: 1984-01-17
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Expires: 2002-01-06
Abstract
Abstract In a system for real-time coherent optical filtering of visual imagery which encompasses a laser and a set of lenses for transmitting a visual target image of an input, a Fabry-Perot interferometer for filtering the target image to produce a filtered target image at an output having a predetermined bandwidth of spatial frequency information, the improvements relate to the output being in the form of a low-light level video system capable of detecting the filtered image even when at a low level of luminance, and a laser adjustable in operating power between low and high levels and in operating wavelength within a wide range for adjusting the bandwidths of the interferometer between narrow and broad ranges.
Inventors
- 👤 David W. Evans
- 👤 Arthur P. Ginsburg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:06
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/42; G02B27/46
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
148 words
In a method of real-time coherent optical filtering of visual imagery including the steps of transmitting a visual target image of an input, filtering said transmitted target image to produce a filtered target image having a variable bandwidth of spatial frequency information, and projecting said filtered target image, the improvement which comprises the steps of: (a) receiving said projected filtered target image and detecting said image even when at a low level of luminance; and (b) coherently illuminating said visual target image of said input prior to said transmitting of the same, and adjusting said bandwidth of said filtering between narrow and broad ranges thereof, so as to vary the bandwidth of said spatial information, by varying the power at which said illuminating is carried out between low and high predetermined levels and by varying the wavelength at which said illuminating is carried out within a predetermined range.
Claim 2
Dependent Claim
148 words
In a method of real-time coherent optical filtering of visual imagery including the steps of transmitting a visual target image of an input, filtering said transmitted target image to produce a filtered target image having a variable bandwidth of spatial frequency information, and projecting said filtered target image, the improvement which comprises the steps of: (a) receiving said projected filtered target image and detecting said image even when at a low level of luminance; and (b) coherently illuminating said visual target image of said input prior to said transmitting of the same, and adjusting said bandwidth of said filtering between narrow and broad ranges thereof, so as to vary the bandwidth of said spatial information, by varying the power at which said illuminating is carried out between low and high predetermined levels and by varying the wavelength at which said illuminating is carried out within a predetermined range.
Claim 3
Dependent Claim
23 words
The real-time coherent optical filtering method of claim 1, wherein a low-light level video system is used for receiving and detecting said image.
Claim 4
Dependent Claim
46 words
The real-time coherent optical filtering method of claim 1, wherein a laser adjustable in operating power between low and high levels and in operating wavelength within a predetermined wider range is used for coherently illuminating said visual target image and adjusting said bandwidth of said filtering.
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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) | 1987-01-16 | 1987-07-18 | 1988-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-16 | 1991-07-18 | 1992-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-16 | 1995-07-18 | 1996-01-17 | $7700.00 | Window Closed / Lapsed |