US4393434A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitance humidity sensor
Assignee: Individual
•
Filing: 1981-11-20
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Granted: 1983-07-12
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Expires: 2001-11-20
Abstract
Abstract A capacitance humidity sensor according to the disclosure a non-conductive base plate, electrodes oppositely arranged on the base plate, a metal compound membrane formed by ion-plating independently on the electrodes, the metal compound membrane being roughened on its surface by plasma etching and being active to the humidity, and a moisture permeable metal skin formed on the metal compound membrane. The metal compound is preferably an oxide or nitride of aluminum or magnesium.
Inventors
- 👤 Yoshio Imai
- 👤 Yoichi Nabeta
- 👤 Tadao Inuzuka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:11
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/22; G01N27/223; G01N27/225; G01R; G01R27/00; G01R27/02; G01R27/26; G01R27/2605
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
62 words
A capacitance humidity sensor which comprises a non-conductive base plate, electrodes oppositely arranged on the base plate, a metal compound membrane formed by ion-plating independently on the electrodes, said metal compound membrane being roughened at its surface by plasma etching and being active to the humidity, and a moisture permeable metal skin formed on the roughened surface of the metal compound membrane.
Claim 2
Dependent Claim
62 words
A capacitance humidity sensor which comprises a non-conductive base plate, electrodes oppositely arranged on the base plate, a metal compound membrane formed by ion-plating independently on the electrodes, said metal compound membrane being roughened at its surface by plasma etching and being active to the humidity, and a moisture permeable metal skin formed on the roughened surface of the metal compound membrane.
Claim 3
Dependent Claim
17 words
The capacitance humidity sensor according to claim 1, wherein the non-conductive base plate is a glass plate.
Claim 4
Dependent Claim
19 words
The capacitance humidity sensor according to claim 1 wherein the metal compound membrane consists of metal oxide or nitride.
Claim 5
Dependent Claim
32 words
The capacitance humidity sensor according to claim 1, wherein the electrodes are formed in a comb shape and are arranged oppositely so as to mesh with but not contact with each other.
Claim 6
Dependent Claim
20 words
The capacitance humidity sensor according to claim 3, wherein the metal of the oxide or nitride is aluminum or magnesium.
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) | 1986-07-11 | 1987-01-10 | 1987-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-11 | 1991-01-10 | 1991-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-11 | 1995-01-10 | 1995-07-12 | $7700.00 | Window Closed / Lapsed |