US4949174A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zoom lens thermal imager incorporating a non-pixellated detector
Assignee: The General Electric Company PLC
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Filing: 1988-06-03
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Granted: 1990-08-14
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Expires: 2008-06-03
Abstract
Abstract A thermal imaging device comprises a non-pixellated detector (3) which includes a component (12), such as a liquid crystal element, having optical properties which vary with temperature. An infra-red lens (1) forms a focused image of a thermal scene on the non-pixellated detector. A visible light source (17) is arranged to illuminate the non-pixelled detector such that visible light from the source is modulated by the image formed on the non-pixellated detector. A second detector (7), such as a television camera chip, detects the modulated visible light to give an output which is representative of the image of the thermal scene. A visible light zoom lens (5) is interposed in the optical path between the non-pixellated detector and the second detector so that variation of the focal length of the zoom lens varies the field of view of the thermal imaging device.
Inventors
- 👤 Michael C. Wiltshire
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:02
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/20; H04N23/23
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
126 words
A thermal imaging device, comprising a non-pixellated detector (3) including a component (12) the optical properties of which vary with temperature; means (1) for forming a focused image of a thermal scene on said non-pixellated detector; a visible-light source (17) arranged to illuminate the non-pixellated detector such that visible light from the source is modulated by the image formed on the non-pixellated detector; a further detector (7) effective to detect said modulated visible light to give an output representative of the image of the thermal scene; and a visible light zoom lens (5) interposed in the optical path between the non-pixellated detector and the further detector such that variation of the focal length of the lens varies the field of view of the thermal imaging device.
Claim 2
Dependent Claim
126 words
A thermal imaging device, comprising a non-pixellated detector (3) including a component (12) the optical properties of which vary with temperature; means (1) for forming a focused image of a thermal scene on said non-pixellated detector; a visible-light source (17) arranged to illuminate the non-pixellated detector such that visible light from the source is modulated by the image formed on the non-pixellated detector; a further detector (7) effective to detect said modulated visible light to give an output representative of the image of the thermal scene; and a visible light zoom lens (5) interposed in the optical path between the non-pixellated detector and the further detector such that variation of the focal length of the lens varies the field of view of the thermal imaging device.
Claim 3
Dependent Claim
21 words
A thermal imaging device as claimed in claim 1, in which the component (12) of the non-pixellated detector (3) exhibits birefringence.
Claim 4
Dependent Claim
51 words
A thermal imaging device as claimed in claim 2, wherein the light source (17) is arranged off-axis and an inclined dichroic mirror (15) is arranged to deflect light from the source (17) onto the non-pixellated detector (3), the miror being arranged in the path of radiation incident on said non-pixellated detector.
Claim 5
Dependent Claim
22 words
A thermal imaging device as claimed in claim 1, in which the component (12) of the non-pixellated detector (3) exhibits optical rotation.
Claim 6
Dependent Claim
51 words
A thermal imaging device as claimed in claim 4, wherein the light source (17) is arranged off-axis and an inclined dichroic mirror (15) is arranged to deflect light from the source (17) onto the non-pixellated detector (3), the mirror being arranged in the path of radiation incident on said non-pixellated detector.
Claim 7
Dependent Claim
22 words
A thermal imaging device as claimed in claim 1, in which component (12) of the non-pixellated detector (3) is a liquid crystal.
Claim 8
Dependent Claim
19 words
A thermal imaging device as claimed in claim 1, in which the further detector (7) is a pixellated detector.
Claim 9
Dependent Claim
19 words
A thermal imaging device as claimed in claim 7, in which the pixellated detector (7) is a charge-coupled device.
Claim 10
Dependent Claim
20 words
A thermal imaging device as claimed in claim 8, in which the pixellated detector (7) is a television camera chip.
Claim 11
Dependent Claim
20 words
A thermal imaging device as claimed in claim 7, in which the pixellated detector (7) is a television camera chip.
Claim 12
Dependent Claim
51 words
A thermal imaging device as claimed in claim 7, wherein the light source (17) is arranged off-axis and an inclined dichroic mirror (15) is arranged to deflect light from the source (17) onto the non-pixellated detector (3), the mirror being arranged in the path of radiation incident on said non-pixellated detector.
Claim 13
Dependent Claim
18 words
A thermal device as claimed in claim 1, in which the further detector (7) is a television vidicon.
Claim 14
Dependent Claim
52 words
A thermal imaging device as claimed in claim 1, wherein the light source (17) is arranged off-axis and an inclined dichroic mirror (15) is arranged to deflect light from the souce (17) on to the non-pixellated detector (3), the mirror being arranged in the path of radiation incident on said non-pixellated detector.
Claim 15
Dependent Claim
18 words
A thermal imaging device as claimed in claim 1, wherein said non-pixellated detector (3) includes an analyser (23).
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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) | 1993-08-13 | 1994-02-12 | 1994-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-13 | 1998-02-12 | 1998-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-13 | 2002-02-12 | 2002-08-14 | $7700.00 | Window Closed / Lapsed |