Patent US4384207A successfully refreshed from Google Patents.
US4384207A
Expired / Lapsed
US
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Differential pyroelectric detector
Assignee: ELTEC INSTRUMENTS Inc
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Filing: 1981-01-23
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Granted: 1983-05-17
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Expires: 2001-01-23
Abstract
Abstract A pyroelectric detector comprising a body of pyroelectric material having a front surface for receiving radiation, a rear surface, a relatively thin coating of radiation absorbing and transmitting and electrically conducting material applied to the entire front surface, and a pair of relatively thicker areas of radiation reflecting and electrically conducting material applied to the rear surface in spaced-apart relation. Two heat sensitive charge generators are defined in the two regions of the pyroelectric body between the coating on the front surface and the two areas on the rear surface, and output electrical leads are attached to the two areas on the rear surface. When radiation is absorbed by either of the heat sensitive charge generators, an electrical current flows in a circuit connected to the output leads thereby providing an indication of the radiation.
Inventors
- 👤 Alan P. Doctor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:10
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/18; G08B13/189; G08B13/19; G08B13/191; G01; G01J; G01J5/00; G01J5/10; G01J5/34
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
180 words
A pyroelectric detector comprising: (a) a body of pyroelectric material having a first surface for receiving radiation and a second surface; (b) a relatively thin coating on said first surface of material which is radiation absorbing and transmitting and which is electrically conducting; (c) a pair of areas in spaced-apart relation on said second surface, each of said areas being of radiation reflecting and electrically conducting material, each being relatively thicker than said coating on said first surface; (d) a first heat sensitive charge generator defined by one of said areas, the portion of said coating in registry with said one area and the region of said body of pyroelectric material therebetween; and (e) a second heat sensitive charge generator defined by the other of said areas, the portion of said coating in registry with said other area and the region of said body of pyroelectric material therebetween; (f) whereby when radiation is absorbed by either of said heat sensitive charge generators an electric current flows in a circuit connected to said areas thereby providing an indication of said radiation.
Claim 2
Dependent Claim
180 words
A pyroelectric detector comprising: (a) a body of pyroelectric material having a first surface for receiving radiation and a second surface; (b) a relatively thin coating on said first surface of material which is radiation absorbing and transmitting and which is electrically conducting; (c) a pair of areas in spaced-apart relation on said second surface, each of said areas being of radiation reflecting and electrically conducting material, each being relatively thicker than said coating on said first surface; (d) a first heat sensitive charge generator defined by one of said areas, the portion of said coating in registry with said one area and the region of said body of pyroelectric material therebetween; and (e) a second heat sensitive charge generator defined by the other of said areas, the portion of said coating in registry with said other area and the region of said body of pyroelectric material therebetween; (f) whereby when radiation is absorbed by either of said heat sensitive charge generators an electric current flows in a circuit connected to said areas thereby providing an indication of said radiation.
Claim 3
Dependent Claim
34 words
Apparatus according to claim 1, wherein said body of pyroelectric material is in the form of a slab and said first and second surfaces are substantially oppositely directed and disposed in substantially parallel planes.
Claim 4
Dependent Claim
12 words
Apparatus according to claim 1, wherein said pyroelectric material is lithium tantalate.
Claim 5
Dependent Claim
18 words
Apparatus according to claim 1, wherein said coating has a sheet resistance of about 200 ohms per square.
Claim 6
Dependent Claim
32 words
Apparatus according to claim 1, wherein said coating comprises a first layer applied to said first surface of said body of pyroelectric material and a second layer applied to said first layer.
Claim 7
Dependent Claim
20 words
Apparatus according to claim 5, wherein said second layer has a thickness greater than the thickness of said first layer.
Claim 8
Dependent Claim
19 words
Apparatus according to claim 5, wherein said first layer is of chrome and said second layer is of nichrome.
Claim 9
Dependent Claim
41 words
Apparatus according to claim 1, further including a pair of supporting elements, each secured to a corresponding one of said areas on said second surface of said pyroelectric body, each of said supporting elements also being secured to a mounting surface.
Claim 10
Dependent Claim
17 words
Apparatus according to claim 1, further including a high megohm resistor connected electrically across said two areas.
Claim 11
Dependent Claim
17 words
Apparatus according to claim 9, further including a transistor amplifier having an input connected to said resistor.
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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) | 1986-05-16 | 1986-11-15 | 1987-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-16 | 1990-11-15 | 1991-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-16 | 1994-11-15 | 1995-05-17 | $7700.00 | Window Closed / Lapsed |