US5220173A
Expired / Lapsed
US
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Pulsating infrared radiation source
Assignee: Kanstad Teknologi as
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Filing: 1990-05-22
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Granted: 1993-06-15
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Expires: 2010-05-22
Abstract
Abstract Pulsating infrared radiation source 50, which is so thin as to make its thermally stored energy less than the energy radiated during each pulse. This makes the source cooled by its own heat emission. Such sources have thicknesses commensurate with the wavelengths of infrared radiation. To avoid interference effects, the source's optical thickness may be made to equal a multiple of half wavelengths of the desired radiation. With the source mounted in a housing 53, efficient radiative cooling is obtained using windows 54 and 55 to each side. This makes it possible to extract infrared radiation from either face of the source.
Inventors
- 👤 Svein O. Kanstad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:03
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/02; G01J3/10; G01J3/108; B; B41; B41J; B41J2/00; B41J2/315; B41J2/32; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N21/3504; G01N2201/00; G01N2201/06; G01N2201/061; G01N2201/06186
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
88 words
Infrared radiation source comprising a thin, plate shaped and at least partly electrically conductive element, and energizing means for energizing the electrically conductive part of the element with pulsating electric current, whereby to vary the temperature of the element between a highest and lowest value, a physical thickness of the element being so small that thermal energy stored in the element during one pulse of the electric current is less than thermal energy radiated from the element in the course of the same pulse of the electric current.
Claim 2
Dependent Claim
88 words
Infrared radiation source comprising a thin, plate shaped and at least partly electrically conductive element, and energizing means for energizing the electrically conductive part of the element with pulsating electric current, whereby to vary the temperature of the element between a highest and lowest value, a physical thickness of the element being so small that thermal energy stored in the element during one pulse of the electric current is less than thermal energy radiated from the element in the course of the same pulse of the electric current.
Claim 3
Dependent Claim
90 words
Infrared radiation source according to claim 1, wherein the element's physical thickness t satisfies the relation t<8εσT.sup.3 /Cρf, (5) where the sign "<", means "less than", C [J/g·K] is the specific thermal capacity, ρ [g/cm 3 ] the effective density and ε<1 the emissivity of the material/combination of materials in the element, σ=5.67.10 -12 [W/cm 2 K 4 ] is the Stefan-Boltzmann constant, T [K] is the temperature to which the element becomes heated during each pulse of electric current and f [Hz] is the frequency of the current pulses.
Claim 4
Dependent Claim
52 words
Infrared radiation source according to claim 2, wherein the optical thickness of the element, l=n·t, where n is the index of refraction of the element material and t its physical thickness, as far as possible corresponds to a multiple of half the center wavelength of the desired thermal radiation from the element.
Claim 5
Dependent Claim
17 words
Infrared radiation source according to claim 1, wherein the element has been made from a semiconductor material.
Claim 6
Dependent Claim
13 words
Infrared radiation source according to claim 4, wherein the semiconductor material is doped.
Claim 7
Dependent Claim
87 words
Infrared radiation source according to claim 4, wherein the element is hermetically encapsulated in a housing devoid of reactive gases and with at least one infrared-transmitting window on at least one of opposite sides of the housing, external walls of the housing having cooling means for maintaining the temperature of the housing below the lowest value of the temperature of the element, a range of spectral transmission of the window being so wide that it encompasses a major part of the thermal energy radiated from the element.
Claim 8
Dependent Claim
29 words
Infrared radiation source according to claim 1, wherein the element has been made from a basically non-conductive material into which has been mixed at least one electrically conductive substance.
Claim 9
Dependent Claim
87 words
Infrared radiation source according to claim 7, wherein the element is hermetically encapsulated in a housing devoid of reactive gases and with at least one infrared-transmitting window on at least one of opposite sides of the housing, external walls of the housing having cooling means for maintaining the temperature of the housing below the lowest value of the temperature of the element, a range of spectral transmission of the window being so wide that it encompasses a major part of the thermal energy radiated from the element.
Claim 10
Dependent Claim
27 words
Infrared radiation source according to claim 1, wherein the element has been made from a basically non-conductive material onto which has been deposited an electrically conductive film.
Claim 11
Dependent Claim
87 words
Infrared radiation source according to claim 9, wherein the element is hermetically encapsulated in a housing devoid of reactive gases and with at least one infrared-transmitting window on at least one of opposite sides of the housing, external walls of the housing having cooling means for maintaining the temperature of the housing below the lowest value of the temperature of the element, a range of spectral transmission of the window being so wide that it encompasses a major part of the thermal energy radiated from the element.
Claim 12
Dependent Claim
87 words
Infrared radiation source according to claim 3, wherein the element is hermetically encapsulated in a housing devoid of reactive gases and with at least one infrared-transmitting window on at least one of opposite sides of the housing, external walls of the housing having cooling means for maintaining the temperature of the housing below the lowest value of the temperature of the element, a range of spectral transmission of the window being so wide that it encompasses a major part of the thermal energy radiated from the element.
Claim 13
Dependent Claim
87 words
Infrared radiation source according to claim 2, wherein the element is hermetically encapsulated in a housing devoid of reactive gases and with at least one infrared-transmitting window on at least one of opposite sides of the housing, external walls of the housing having cooling means for maintaining the temperature of the housing below the lowest value of the temperature of the element, a range of spectral transmission of the window being so wide that it encompasses a major part of the thermal energy radiated from the element.
Claim 14
Dependent Claim
26 words
Infrared radiation source according to claim 2, wherein the element material consists of a metal or a metal alloy comprising Ni, Cr, Fe and/or metallic glasses.
Claim 15
Dependent Claim
15 words
Infrared radiation source according to claim 13, wherein surfaces of the element have been oxidized.
Claim 16
Dependent Claim
87 words
Infrared radiation source according to claim 14, wherein the element is hermetically encapsulated in a housing devoid of reactive gases and with at least one infrared-transmitting window on at least one of opposite sides of the housing, external walls of the housing having cooling means for maintaining the temperature of the housing below the lowest value of the temperature of the element, a range of spectral transmission of the window being so wide that it encompasses a major part of the thermal energy radiated from the element.
Claim 17
Dependent Claim
87 words
Infrared radiation source according to claim 13, wherein the element is hermetically encapsulated in a housing devoid of reactive gases and with at least one infrared-transmitting window on at least one of opposite sides of the housing, external walls of the housing having cooling means for maintaining the temperature of the housing below the lowest value of the temperature of the element, a range of spectral transmission of the window being so wide that it encompasses a major part of the thermal energy radiated from the element.
Claim 18
Dependent Claim
81 words
Infrared radiation source according to claim 1, wherein the element is hermetically encapsulated in a housing devoid of reactive gases and with an infrared-transmitting window on one side of the housing, external walls of the housing having cooling means for maintaining the temperature of the housing below the lowest value of the temperature of the element, a range of spectral transmission of the window being so wide that it encompasses a major part of the thermal energy radiated from the element.
Claim 19
Dependent Claim
28 words
Infrared radiation source according to claim 17, characterized in that a similar infrared-transmitting window is on the other side (the rear side) of the element respectively the elements.
Claim 20
Dependent Claim
21 words
Infrared radiation source according to claim 17, wherein the major part of the total thermal radiation is more than 90% thereof.
Claim 21
Dependent Claim
52 words
Infrared radiation source according to claim 1, wherein the optical thickness of the element, l=n·t, where n is the index of refraction of the element material and t its physical thickness, as far as possible corresponds to a multiple of half the center wavelength of the desired thermal radiation from the element.
Claim 22
Dependent Claim
25 words
Infrared radiation source according to claim 1, wherein the element material consists of metal or a metal alloy comprising Ni, Cr, Fe and/or metallic glasses.
Claim 23
Dependent Claim
15 words
Infrared radiation source according to claim 21, wherein surfaces of the element have been oxidized.
Claim 24
Dependent Claim
17 words
Infrared radiation source according to claim 20, wherein the element has been made from a semiconductor material.
Claim 25
Dependent Claim
29 words
Infrared radiation source according to claim 20, wherein the element has been made from a basically non-conductive material into which has been mixed at least one electrically conductive substance.
Claim 26
Dependent Claim
27 words
Infrared radiation source according to claim 20, wherein the element has been made from a basically non-conductive material onto which has been deposited an electrically conductive film.
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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) | 1996-06-14 | 1996-12-14 | 1997-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-14 | 2000-12-14 | 2001-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-14 | 2004-12-14 | 2005-06-15 | $7700.00 | Window Closed / Lapsed |