US4016524A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sensor for a gas detector, in particular for smoke detection
Assignee: US Philips Corp
•
Filing: 1975-05-14
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Granted: 1977-04-05
•
Expires: 1995-05-14
Abstract
Abstract Sensor for selectively detecting at least one constituent of a gaseous mixture in contact with the sensor. The sensor comprises a thin layer of a semiconductor material covered with a dielectric film formed with a large number of microscopic openings.
Inventors
- 👤 Jean Pompei
- 👤 Bernard Lacroix
- 👤 Francis Pierrot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 01:17
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; G01N27/128
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
87 words
Sensor for selectively detecting at least one constituent of a gaseous mixture in contact with the sensor, the operation of this sensor being based on the variation of its electrical resistance by a reaction at the surface of the sensor, characterized in that the sensor comprises a substrate on which a layer of a semiconductor is provided to which are connected at least two electrodes and which is at least partly covered with a film of a dielectric material formed with a large number of microscopic openings.
Claim 2
Dependent Claim
87 words
Sensor for selectively detecting at least one constituent of a gaseous mixture in contact with the sensor, the operation of this sensor being based on the variation of its electrical resistance by a reaction at the surface of the sensor, characterized in that the sensor comprises a substrate on which a layer of a semiconductor is provided to which are connected at least two electrodes and which is at least partly covered with a film of a dielectric material formed with a large number of microscopic openings.
Claim 3
Dependent Claim
54 words
Sensor as claimed in claim 1, characterized in that the semiconductor layer is a metal oxide which is superficially sensitized by two metallic activating substances, the valency of one of these metals being lower than that of the metal of the semiconductor whilst the valency of the other metal is at least equal thereto.
Claim 4
Dependent Claim
21 words
Sensor as claimed in claim 2, characterized in that the dielectric film formed with microscopic openings consists of a hydrophobic substance.
References Cited (Backward Citations)
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US3748625A
Cited
US3798079A
Cited
US3872419A
Cited
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Cited
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Cited
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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) | 1980-04-04 | 1980-10-04 | 1981-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-04 | 1984-10-04 | 1985-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-04 | 1988-10-04 | 1989-04-05 | $7700.00 | Window Closed / Lapsed |