US4397429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for detecting a hot point in a scene by means of infrared radiation and missile guidance system equipped with such a device
Assignee: Thomson TRT Defense
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Filing: 1980-12-29
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Granted: 1983-08-09
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Expires: 2000-12-29
Abstract
Abstract A scanning infrared beam is split into two subbeams. The first and second subbeams contain radiation of wavelengths situated in a first and second subband of the infrared wavelength band of the beam. For each subbeam there is provided a separate radiation-sensitive detector. The output signals of the detectors are applied to a subtractor circuit, whose output signal indicates the presence of a hot point.
Inventors
- 👤 Jean-Pierre Fouilloy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:30
CPC Classifications
F; F41; F41G; F41G7/00; F41G7/20; F41G7/30; F41G7/301; F41G7/303; F41G7/32; G; G01; G01S; G01S3/00; G01S3/78; G01S3/782; G01S3/789
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
191 words
A device for detecting a hot point in a scene by means of infrared radiation in an infrared wavelength band, said device comprising: a scanning system for scanning the radiation in the scene and generating a scanning beam therefrom; a radiation-sensitive detection system for converting the scanning beam into an electrical signal; and an electronic processing circuit for processing the electronic signal; characterized in that: the device further comprises a filter arranged in the path of the scanning beam, said filter splitting the scanning beam into first and second subbeams, the first subbeam containing radiation of a wavelength in a first subband of the wavelength band, the second subbeam contained radiation of a wavelength in a second subband of the wavelength band; the detection system comprises first and second radiation-sensitive detectors, the first detector converting radiation of a wavelength in the first subband into an electrical signal, the second detector converting radiation of a wavelength in the second subband into an electrical signal; and the electronic processing circuit comprises a subtractor circuit whose inputs are the outputs of the detectors, and whose output signal indicates the occurrence of a hot point.
Claim 2
Independent Claim
191 words
A device for detecting a hot point in a scene by means of infrared radiation in an infrared wavelength band, said device comprising: a scanning system for scanning the radiation in the scene and generating a scanning beam therefrom; a radiation-sensitive detection system for converting the scanning beam into an electrical signal; and an electronic processing circuit for processing the electronic signal; characterized in that: the device further comprises a filter arranged in the path of the scanning beam, said filter splitting the scanning beam into first and second subbeams, the first subbeam containing radiation of a wavelength in a first subband of the wavelength band, the second subbeam contained radiation of a wavelength in a second subband of the wavelength band; the detection system comprises first and second radiation-sensitive detectors, the first detector converting radiation of a wavelength in the first subband into an electrical signal, the second detector converting radiation of a wavelength in the second subband into an electrical signal; and the electronic processing circuit comprises a subtractor circuit whose inputs are the outputs of the detectors, and whose output signal indicates the occurrence of a hot point.
Claim 3
Dependent Claim
34 words
A device as claimed in claim 1, characterized in that the electronic processing circuit includes an adder circuit whose inputs are the outputs of the detectors, and whose output signal indicates the scene luminance.
Claim 4
Dependent Claim
32 words
A device as claimed in claim 2, characterized in that the electronic processing circuit further includes electronic elements for varying the levels of the detector output signals applied to the subtractor circuit.
Claim 5
Dependent Claim
46 words
A device as claimed in claim 3, characterized in that one of the level-varying electronic elements is controlled by the output signal of the subtractor circuit, the output signal of the subtractor circuit being set to zero when an object is observed at a chosen temperature.
Claim 6
Dependent Claim
18 words
A device as claimed in claim 4, characterized in that each detector comprises an array of radiation-sensitive elements.
Claim 7
Dependent Claim
21 words
A device as claimed in claim 5, characterized in that the wavelength band is approximately from 8 microns to 13 microns.
Claim 8
Dependent Claim
83 words
A system for guiding a missile to a target comprising: a device for detecting a hot point as claimed in claim 1; an infrared-emitting point source on the missile; an observation device for observing the missile and the target, said device having a graticule with coordinates whose center is, in operation, aimed at a target; and an electronic guidance circuit for calculating deviations between the coordinates of the infrared-emitting point source and the target, said guidance circuit supplying control signals to the missile.
Claim 9
Dependent Claim
30 words
A system as claimed in claim 7, characterized in that the output signal of the subtractor circuit is set to zero upon detection of the hottest point of the scene.
References Cited (Backward Citations)
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Cited
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Cited
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Cited
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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) | 1986-08-08 | 1987-02-07 | 1987-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-08 | 1991-02-07 | 1991-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-08 | 1995-02-07 | 1995-08-09 | $7700.00 | Window Closed / Lapsed |