US4755674A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Infrared detector
Assignee: Heimann GmbH
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Filing: 1986-09-26
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Granted: 1988-07-05
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Expires: 2006-09-26
Abstract
Abstract An infrared detector has at least one infrared-sensitive detector element and at least one infrared source disposed in a common housing with the detector, with the infrared radiation from the source being directed onto the detector element. A pulse generator is connected to the infrared source for pulsing the infrared radiation therefrom. A recognition circuit is connected to the detector element for identifying the pulse sequence of the detector output so as to continuously check the functioning of the detector. A number of such detector elements can be arranged in the housing, with each detector element having a respective infrared source associated therewith. The infrared source may be a heated wire, a chip resistor, or a light emitting diode.
Inventors
- 👤 Norbert Schaaf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:18
CPC Classifications
G; G08; G08B; G08B29/00; G08B29/02; G08B29/04; H; H10; H10W; H10W90/00; H10W90/701; H10W90/751; H10W90/759
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
113 words
An infrared sensor unit for use with a pulse generator and a recognition circuit, comprising: first and second separate infrared sources driven by said pulse generator to emit pulsed infrared radiation; first and second separate infrared detectors disposed for respectively receiving said pulsed infrared radiation emitted by said first and second infrared sources; and means connected to said first and second infrared detectors and to said recognition circuit for generating an electrical signal from said first and second infrared detectors and supplying said signal to said recognition circuit, said electrical signal corresponding to the signal from said pulse generator driving said infrared sources when said first and second infrared detectors are functioning properly.
Claim 2
Dependent Claim
113 words
An infrared sensor unit for use with a pulse generator and a recognition circuit, comprising: first and second separate infrared sources driven by said pulse generator to emit pulsed infrared radiation; first and second separate infrared detectors disposed for respectively receiving said pulsed infrared radiation emitted by said first and second infrared sources; and means connected to said first and second infrared detectors and to said recognition circuit for generating an electrical signal from said first and second infrared detectors and supplying said signal to said recognition circuit, said electrical signal corresponding to the signal from said pulse generator driving said infrared sources when said first and second infrared detectors are functioning properly.
Claim 3
Dependent Claim
19 words
An infrared sensor unit as claimed in claim 1, wherein said first and second infrared sources are resistance wires.
Claim 4
Dependent Claim
19 words
An infrared sensor unit as claimed in claim 1, wherein said first and second infrared sources are resistor chips.
Claim 5
Dependent Claim
20 words
An infrared sensor unit as claimed in claim 1, wherein said first and second infrared sources are light emitting diodes.
Claim 6
Dependent Claim
58 words
An infrared sensor unit as claimed in claim 1, whrein said means for generating an electrical signal comprises: first and second conductor tracks respectively connected to said first and second infrared detectors; a high impedance resistor connected between said first and second conductor tracks; and a transistor connected between one of said conductor tracks and said recognition circuit.
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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) | 1991-07-05 | 1992-01-04 | 1992-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-05 | 1996-01-04 | 1996-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-05 | 2000-01-04 | 2000-07-05 | $7700.00 | Window Closed / Lapsed |