Patent US4704534A successfully refreshed from Google Patents.
US4704534A
Expired / Lapsed
US
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Thermal radiation detector
Assignee: Leonardo UK Ltd
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Filing: 1986-03-03
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Granted: 1987-11-03
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Expires: 2006-03-03
Abstract
Abstract A thermal radiation detector comprises detecting means supported by a flexible film. To improve the absorption of incident radiation by the thermal radiation detector, the detector comprises an electrically resistive layer which is immediately adjacent the flexible film, and to which the detecting means are thermally coupled. The optical thickness of transparent dielectric material preceding the detecting means (suitably consisting only of the flexible film) is one fourth of a selected wavelength in a given wavelength range to be detected. The wavelength is selected so that the absorption of incident radiation by the resistive layer is substantially a maximum at the selected wavelength. The resistive layer may be between the flexible film and the detecting means, or it may precede the flexible film. In the latter case, an electrically conductive, reflecting layer is disposed between the flexible film and the detecting means.
Inventors
- 👤 Andrew A. Turnbull
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:29
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/10; G01J5/34; H; H10; H10N; H10N15/00; H10N15/10
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
110 words
A thermal radiation detector for detecting radiation in a selected wavelength range, said detector comprising: a flexible film which is substantially transparent to radiation in the selected wavelength range, said film having an optical thickness equal to one-quarter of a wavelength in the selected wavelength range; detection means for detecting thermal energy, said detection means being mounted on the flexible film; and an electrically resistive layer arranged adjacent to the flexible film, said resistive layer having a net effective resistance per square such that the resistive layer absorbs a substantial portion of incident radiation in the selected wavelength range, said resistive layer being highly thermally coupled to the detection means.
Claim 2
Dependent Claim
110 words
A thermal radiation detector for detecting radiation in a selected wavelength range, said detector comprising: a flexible film which is substantially transparent to radiation in the selected wavelength range, said film having an optical thickness equal to one-quarter of a wavelength in the selected wavelength range; detection means for detecting thermal energy, said detection means being mounted on the flexible film; and an electrically resistive layer arranged adjacent to the flexible film, said resistive layer having a net effective resistance per square such that the resistive layer absorbs a substantial portion of incident radiation in the selected wavelength range, said resistive layer being highly thermally coupled to the detection means.
Claim 3
Dependent Claim
23 words
A detector as claimed in claim 1, characterized in that the resistive layer is arranged between the flexible film and the detection means.
Claim 4
Dependent Claim
37 words
A detector as claimed in claim 2, characterized in that: the flexible film has a refractive index of in; and the resistive layer has a resistance per square substantially equal to 377/(1+n 2 ) ohms per square.
Claim 5
Dependent Claim
29 words
A detector as claimed in claim 3, characterized in that the detector further comprises a substantially reflecting, electrically conductive layer arranged between the resistive layer and the detection means.
Claim 6
Dependent Claim
23 words
A detector as claimed in claim 1, characterized in that the flexible film is arranged between the resistive layer and the detection means.
Claim 7
Dependent Claim
42 words
A detector as claimed in claim 1, characterized in that: the detection means has a thermal capacitance; and the resistive layer and the flexible film have a combined thermal capacitance which is much less than the thermal capacitance of the detection means.
Claim 8
Dependent Claim
21 words
A detector as claimed in claim 1, characterized in that the resistive layer extends beyond the periphery of the detection means.
Claim 9
Dependent Claim
17 words
A detector as claimed in claim 1, characterized in that the detection means is a pyroelectric element.
Claim 10
Dependent Claim
37 words
A detector as claimed in claim 1, characterized in that the flexible film has an optical thickness equal to one-quarter of a wavelength chosen to maximize absorption of radiation by the detector in the selected wavelength range.
Claim 11
Independent Claim
128 words
A method of detecting thermal radiation in a selected wavelength range, said method comprising the steps of: passing the thermal radiation to be detected through a flexible film which is substantially transparent to radiation in the selected wavelength range, said film having an optical thickness equal to one-quarter of a wavelength in the selected wavelength range so that the film absorbs thermal radiation; conducting thermal energy from the flexible film to detection means for detecting thermal energy; passing the thermal radiation to be detected through an electrically resistive layer, said resistive layer having a net effective resistance per square such that the resistive layer absorbs a substantial portion of incident radiation in the selected wavelength range; and conducting thermal energy from the resistive layer to the detection means.
Claim 12
Independent Claim
128 words
A method of detecting thermal radiation in a selected wavelength range, said method comprising the steps of: passing the thermal radiation to be detected through a flexible film which is substantially transparent to radiation in the selected wavelength range, said film having an optical thickness equal to one-quarter of a wavelength in the selected wavelength range so that the film absorbs thermal radiation; conducting thermal energy from the flexible film to detection means for detecting thermal energy; passing the thermal radiation to be detected through an electrically resistive layer, said resistive layer having a net effective resistance per square such that the resistive layer absorbs a substantial portion of incident radiation in the selected wavelength range; and conducting thermal energy from the resistive layer to the detection means.
Claim 13
Dependent Claim
37 words
A method as claimed in claim 10, characterized in that the resistive layer has a wavelength of maximum absorption chosen to substantially maximize the absorption of incident radiation by the detection means in the selected wavelength range.
Claim 14
Dependent Claim
120 words
A thermal radiation detector for detecting radiation in a selected wavelength range of 8-14 microns, said detector comprising: a flexible film which is substantially transparent to radiation in the selected wavelength range, said film having an optical thickness equal to one-quarter of a wavelength in the selected wavelength range, said film having a refractive index of n; detection means for detecting thermal energy in the wavelength range of 8-14 microns, said detection means being mounted on the flexible film; and an electrically resistive layer arranged adjacent to the flexible film, said resistive layer having a net effective resistance per square substantially equal to 377/(1+n 2 ) ohms per square, said resistive layer being highly thermally coupled to the detection means.
Claim 15
Dependent Claim
120 words
A thermal radiation detector for detecting radiation in a selected wavelength range of 8-14 microns, said detector comprising: a flexible film which is substantially transparent to radiation in the selected wavelength range, said film having an optical thickness equal to one-quarter of a wavelength in the selected wavelength range, said film having a refractive index of n; detection means for detecting thermal energy in the wavelength range of 8-14 microns, said detection means being mounted on the flexible film; and an electrically resistive layer arranged adjacent to the flexible film, said resistive layer having a net effective resistance per square substantially equal to 377/(1+n 2 ) ohms per square, said resistive layer being highly thermally coupled to the detection means.
Claim 16
Independent Claim
149 words
A method of detecting thermal radiation in a selected wavelength range of 8-14 microns, said method comprising the steps of: passing the thermal radiation to be detected through a flexible film which is substantially transparent to radiation in the selectd wavelength range, said film having an optical thickness equal to one-quarter of a wavelength in the selected wavelength range so that the film absorbs thermal radiation, said flexible film having a refractive index of n; conducting thermal energy from the flexible film to detection means for detecting thermal energy; passing the thermal radiation to be detected through an electrically resistive layer, said resistive layer having a net effective resistance per square substantially equal to 377/(1+n 2 ) ohms per square such that the resistive layer absorbs a substantial portion of incident radiation in the selected wavelength range; and conducting thermal energy from the resistive layer to the detection means.
Claim 17
Independent Claim
149 words
A method of detecting thermal radiation in a selected wavelength range of 8-14 microns, said method comprising the steps of: passing the thermal radiation to be detected through a flexible film which is substantially transparent to radiation in the selectd wavelength range, said film having an optical thickness equal to one-quarter of a wavelength in the selected wavelength range so that the film absorbs thermal radiation, said flexible film having a refractive index of n; conducting thermal energy from the flexible film to detection means for detecting thermal energy; passing the thermal radiation to be detected through an electrically resistive layer, said resistive layer having a net effective resistance per square substantially equal to 377/(1+n 2 ) ohms per square such that the resistive layer absorbs a substantial portion of incident radiation in the selected wavelength range; and conducting thermal energy from the resistive layer to the detection means.
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) | 1990-11-02 | 1991-05-04 | 1991-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-02 | 1995-05-04 | 1995-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-02 | 1999-05-04 | 1999-11-03 | $7700.00 | Window Closed / Lapsed |