US4318042A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrometer probe
Assignee: Ricoh Co Ltd
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Filing: 1980-02-11
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Granted: 1982-03-02
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Expires: 2000-02-11
Abstract
Abstract A detecting electrode (22) is formed on a substrate (28), an amount of potential from a charged surface (23) induced in the detecting electrode (22) corresponding to a potential on the surface (23). A guard electrode (26) formed on the same surface of the substrate (28) as the detecting electrode (22) surrounds the detecting electrode (22). Part of the guard electrode (26b) is formed on the back surface of the substrate (28). The detecting electrode (22) is connected to a non-inverting input of an operational amplifier (24). The output of the operational amplifier (24) is connected to the inverting input thereof and also to the guard electrode (26) to produce unity gain and place the guard electrode (26) at the same potential as the detecting electrode (22). The substrate (28) is formed of a material such that the electrical resistance between the detecting electrode (22) and the guard electrode (26) is at least 10 9 ohms to reduce zero drift to a negligible value.
Inventors
- 👤 Tadahiro Eda
- 👤 Susumu Tatsumi
- 👤 Chikara Imai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:42
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/12
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
63 words
An electrometer probe comprising a substrate, a detecting electrode provided on the substrate and a guard electrode provided on the substrate, the substrate being formed of a material such that an electrical resistance between the detecting electrode and the guard electrode is at least 10 9 ohms; said material comprising resin; the resin comprising a reactive high molecular substance and a cyanate radical.
Claim 2
Dependent Claim
63 words
An electrometer probe comprising a substrate, a detecting electrode provided on the substrate and a guard electrode provided on the substrate, the substrate being formed of a material such that an electrical resistance between the detecting electrode and the guard electrode is at least 10 9 ohms; said material comprising resin; the resin comprising a reactive high molecular substance and a cyanate radical.
Claim 3
Dependent Claim
23 words
A probe as in claim 1, in which said material is selected such that said electrical resistance is at least 10 11 ohms.
Claim 4
Dependent Claim
31 words
A probe as in claim 1, in which the guard electrode comprises a section provided on a same surface of the substrate as the detecting electrode which surrounds the detecting electrode.
Claim 5
Dependent Claim
26 words
A probe as in claim 1, in which the guard electrode comprises a section provided on an opposite surface of the substrate from the detecting electrode.
Claim 6
Dependent Claim
50 words
A probe as in claim 1, in which the detecting electrode is provided on a front surface of the substrate, the guard electrode comprising a section provided on the front surface of the substrate which surrounds the detecting electrode and a section provided on a rear surface of the substrate.
Claim 7
Dependent Claim
69 words
An electrometer probe comprising a substrate, a detecting electrode provided on the substrate and a guard electrode provided on the substrate, the substrate being formed of a material such that an electrical resistance between the detecting electrode and the guard electrode is at least 10 9 ohms; said material comprising resin; the resin being selected from the group consisting of triazine, BT resin, teflon, 4-ethylene fluoride, polymido and xylok.
Claim 8
Dependent Claim
69 words
An electrometer probe comprising a substrate, a detecting electrode provided on the substrate and a guard electrode provided on the substrate, the substrate being formed of a material such that an electrical resistance between the detecting electrode and the guard electrode is at least 10 9 ohms; said material comprising resin; the resin being selected from the group consisting of triazine, BT resin, teflon, 4-ethylene fluoride, polymido and xylok.
Claim 9
Dependent Claim
19 words
A probe as in claim 1, further comprising gold plating formed on the detecting electrode and the guard electrode.
Claim 10
Dependent Claim
17 words
A probe as in claim 1, further comprising an electrically insulating layer formed on the detecting electrode.
Claim 11
Dependent Claim
64 words
An electrometer probe comprising a substrate, a detecting electrode provided on the substrate and a guard electrode provided on the substrate, the substrate being formed of a material such that an electrical resistance between the detecting electrode and the guard electrode is at least 10 9 ohms; and an electrically insulating layer formed on the detecting electrode; the insulating layer comprising a silicic material.
Claim 12
Dependent Claim
64 words
An electrometer probe comprising a substrate, a detecting electrode provided on the substrate and a guard electrode provided on the substrate, the substrate being formed of a material such that an electrical resistance between the detecting electrode and the guard electrode is at least 10 9 ohms; and an electrically insulating layer formed on the detecting electrode; the insulating layer comprising a silicic material.
Claim 13
Dependent Claim
56 words
An electrometer probe comprising a substrate, a detecting electrode provided on the substrate and a guard electrode provided on the substrate, the substrate being formed of a material such that an electrical resistance between the detecting electrode and the guard electrode is at least 10 9 ohms. said material comprising resin; said material further comprising fabric.
Claim 14
Dependent Claim
56 words
An electrometer probe comprising a substrate, a detecting electrode provided on the substrate and a guard electrode provided on the substrate, the substrate being formed of a material such that an electrical resistance between the detecting electrode and the guard electrode is at least 10 9 ohms. said material comprising resin; said material further comprising fabric.
Claim 15
Dependent Claim
12 words
A probe as in claim 10, in which the fabric comprises glass.
Claim 16
Dependent Claim
12 words
A probe as in claim 10, in which the resin comprises epoxy.
Claim 17
Dependent Claim
12 words
A probe as in claim 12, in which the fabric comprises glass.
Claim 18
Dependent Claim
20 words
A probe as in claim 10, in which the resin comprises a reactive high polymer substance and a cyanate radical.
Claim 19
Dependent Claim
12 words
A probe as in claim 14, in which the fabric comprises glass.
Claim 20
Dependent Claim
26 words
A probe as in claim 10, in which the resin is selected from the group consisting of triazine, BT resin, teflon, 4-ethylene fluoride, polyimido and xylok.
Claim 21
Dependent Claim
12 words
A probe as in claim 16, in which the fabric comprises glass.
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) | 1985-03-01 | 1985-08-31 | 1986-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-03-01 | 1989-08-31 | 1990-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-03-01 | 1993-08-31 | 1994-03-02 | $7700.00 | Window Closed / Lapsed |