Patent US4943889A successfully refreshed from Google Patents.
US4943889A
Expired / Lapsed
US
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Electrostatic capacitor type sensing device
Assignee: Individual
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Filing: 1989-08-18
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Granted: 1990-07-24
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Expires: 2009-08-18
Abstract
Abstract An electrostatic capacitance type detecting device which includes a first electrode placed in the proximity of an object to be measured, a second electrode placed in the proximity of the first electrode, a film like dielectric member interposed between the first and the second electrodes, a first resistor one end of which is connected to one end of the first electrode, a second resistor one end of which is connected to one end of the second electrode, an a. c. signal generator connected to the other ends of the first and the second resistors and to the ground and a phase difference detecting means connected to the first and the second electrodes.
Inventors
- 👤 Naoyuki Ohmatoi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:30
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/26; G01F23/263; G01F23/268; G01B; G01B7/00; G01B7/02; G01B7/023; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/24; G01D5/2405
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
113 words
An electrostatic capacitance type sensing device comprising: a first electrode to be placed in the proximity of an object to be measured; a second electrode placed in the proximity of said first electrode; a film like dielectric spacer means interposed between said first and said second electrodes; a first resistor, one end of which is connected to one end of said first electrode; a second resistor, one end of which is connected to one end of said second electrode; an a.c. signal generator connected to the other ends of said first and the second resistors and to the ground; and a phase difference detecting means connected to said first and the second electrodes.
Claim 2
Dependent Claim
113 words
An electrostatic capacitance type sensing device comprising: a first electrode to be placed in the proximity of an object to be measured; a second electrode placed in the proximity of said first electrode; a film like dielectric spacer means interposed between said first and said second electrodes; a first resistor, one end of which is connected to one end of said first electrode; a second resistor, one end of which is connected to one end of said second electrode; an a.c. signal generator connected to the other ends of said first and the second resistors and to the ground; and a phase difference detecting means connected to said first and the second electrodes.
Claim 3
Dependent Claim
34 words
An electrostatic capacitance type sensing device as claimed in claim 1, wherein said film like dielectric means interposed between said first and second electrodes is made of glass cloth, epoxy substrate, Teflon or polyimide.
Claim 4
Dependent Claim
28 words
An electrostatic capacitance type sensing device as claimed in claim 1, wherein the thickness of said film like dielectric means is equal to or less than 2 mm.
Claim 5
Dependent Claim
28 words
An electrostatic capacitance type sensing device as claimed in claim 1, wherein the thickness of said film like dielectric means is in the order of 50μ to 100μ.
Claim 6
Dependent Claim
31 words
An electrostatic capacitance type sensing device as claimed in claim 1, wherein each of said first and said second electrodes is copper foil adhered closely to said film like dielectric means.
Claim 7
Dependent Claim
58 words
An electrostatic capacitance type sensing device as claimed in claim 1, wherein each of said first and said second electrodes and said film like dielectric means are fixed by a supporting means at the peripheral portions thereof to a hollow cylindrical casing and further said first electrode is arranged in the proximity of one end of said casing.
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) | 1993-07-23 | 1994-01-22 | 1994-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-23 | 1998-01-22 | 1998-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-23 | 2002-01-22 | 2002-07-24 | $7700.00 | Window Closed / Lapsed |