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US4825079A
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Pyroelectric infrared detector
Assignee: Sumitomo Metal Mining Co Ltd
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Filing: 1987-05-28
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Granted: 1989-04-25
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Expires: 2007-05-28
Abstract
Abstract A pyroelectric infrared detector for use in, for example, an intrusion alarming system has a pyroelectric element, a FET for picking up the output of the pyroelectric element, a capacitor connected in parallel to the pyroelectric element, and other circuit parts. These constituent parts are integrally packed in a package.
Inventors
- 👤 Keiji Takamatsu
- 👤 Hideki Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:29
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/10; G01J5/34; G01J5/35
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
45 words
A pyroelectric infrared detector, comprising a pyroelectric element and a FET for picking up the output of said pyroelectric element, a capacitor connected in parallel to said pyroelectric element, and a package in which at least said pyroelectric element and said capacitor are accommodated integrally.
Claim 2
Dependent Claim
45 words
A pyroelectric infrared detector, comprising a pyroelectric element and a FET for picking up the output of said pyroelectric element, a capacitor connected in parallel to said pyroelectric element, and a package in which at least said pyroelectric element and said capacitor are accommodated integrally.
Claim 3
Dependent Claim
16 words
A pyroelectric infrared detector according to claim 1, wherein said package is a TO-5 metal package.
Claim 4
Dependent Claim
15 words
A pyroelectric infrared detector according to claim 1, wherein said package is a plastic package.
Claim 5
Dependent Claim
13 words
A pyroelectric infrared detector according to claim 1, further comprising a leak resistor.
Claim 6
Dependent Claim
28 words
A pyroelectric infrared detector according to claim 1, wherein said capacitor has a dielectric loss not greater than 0.01 as measured at 100 Hz and at room temperature.
Claim 7
Dependent Claim
15 words
A pyroelectric infrared detector according to claim 1, wherein said capacitor is a chip-type capacitor.
Claim 8
Dependent Claim
23 words
A pyroelectric infrared detector according to claim 1, wherein the dielectric material of said capacitor is at least one of mica and ceramics.
Claim 9
Dependent Claim
44 words
A pyroelectric infrared detector according to claim 1, wherein the capacitance C 2 of said capacitor is determined by the following formula: C.sub.2 =C-C.sub.1 where C represents the equivalent input capacitance of the detector, while C 1 represents the capacitance of said pyroelectric element.
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) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |