US5465619A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitive sensor
Assignee: Xerox Corp
•
Filing: 1994-08-12
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Granted: 1995-11-14
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Expires: 2014-08-12
Abstract
Abstract An apparatus for detecting the level of material in a container. The apparatus comprises a power source and a first electrode, positioned adjacent the container, electrically connected to the power source. The apparatus further comprises a second electrode. The second electrode is spaced from the first electrode and positioned adjacent the container. The apparatus further comprises an electrical amplifier which is electrically connected to the second electrode. The amplifier amplifies a current induced in the second electrode and generates a voltage signal. The amplifier is adapted to maintain the second electrode at a virtual ground to minimize environmental impedance effects. The apparatus further comprises a rectifier, electrically connected to the amplifier, for rectifying the voltage signal and a comparator, electrically connected to the rectifier, for comparing the voltage signal to a predetermined voltage signal corresponding to the container being full with material.
Inventors
- 👤 John D. Sotack
- 👤 William L. Dezen
- 👤 Lawrence R. Benedict
- 👤 Gaith O. Zayed
- 👤 Alan J. Werner, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:08
CPC Classifications
G; G03; G03G; G03G21/00; G03G21/10; G03G21/12; G01; G01F; G01F23/00; G01F23/22; G01F23/26; G01F23/263; G01F23/265; G01F23/266; G01F23/268; G03G15/00; G03G15/06; G03G15/08; G03G15/0822; G03G15/0848; G03G15/0856; G03G15/086
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
161 words
An apparatus for detecting the level of material in a container, comprising: a power source; a first electrode, positioned adjacent the container, electrically connected to said power source; a second electrode, spaced from said first electrode, positioned adjacent the container; an electrical amplifier, electrically connected to the second electrode, for amplifying a current induced in said second electrode and for generating a voltage signal, said electrical amplifier maintaining said second electrode at a virtual ground to minimize environmental impedance effects; a rectifier, electrically connected to said amplifier, for rectifying the voltage signal; and a comparator, electrically connected to said rectifier for comparing the voltage signal to a predetermined voltage signal corresponding to the container being full with material, said comparator including a fail safe circuit that, in response to the voltage signal from said rectifier being of a voltage less than a first preselected reference voltage and less than a second predetermined voltage, generates a signal that the container is full.
Claim 2
Independent Claim
161 words
An apparatus for detecting the level of material in a container, comprising: a power source; a first electrode, positioned adjacent the container, electrically connected to said power source; a second electrode, spaced from said first electrode, positioned adjacent the container; an electrical amplifier, electrically connected to the second electrode, for amplifying a current induced in said second electrode and for generating a voltage signal, said electrical amplifier maintaining said second electrode at a virtual ground to minimize environmental impedance effects; a rectifier, electrically connected to said amplifier, for rectifying the voltage signal; and a comparator, electrically connected to said rectifier for comparing the voltage signal to a predetermined voltage signal corresponding to the container being full with material, said comparator including a fail safe circuit that, in response to the voltage signal from said rectifier being of a voltage less than a first preselected reference voltage and less than a second predetermined voltage, generates a signal that the container is full.
Claim 3
Dependent Claim
32 words
An apparatus according to claim 1, further comprising a protection circuit electrically connected between said power source and said first electrode, said protection circuit isolating said power source from electrostatic voltage discharges.
Claim 4
Dependent Claim
30 words
An apparatus according to claim 1, further comprising a protection circuit electrically connected between said second electrode and said amplifier, said protection circuit isolating said amplifier from electrostatic voltage discharges.
Claim 5
Dependent Claim
20 words
An apparatus according to claim 1, wherein said first electrode and said second electrode are positioned exterior to said container.
Claim 6
Dependent Claim
19 words
An apparatus according to claim 4, wherein said first electrode and said second electrode are opposed from one another.
Claim 7
Dependent Claim
15 words
An apparatus according to claim 1, wherein said second predetermined voltage is approximately 2.7 volts.
Claim 8
Dependent Claim
15 words
An apparatus according to claim 1, wherein said first predetermined voltage is approximately 1.5 volts.
Claim 9
Dependent Claim
171 words
An electrographic printing machine of the type having an apparatus for detecting the level of material in a container, said apparatus comprising: a power source; a first electrode, positioned adjacent the container, electrically connected to said power source; a second electrode, spaced from said first electrode, positioned adjacent the container; an electrical amplifier, electrically connected to the second electrode, for amplifying a current induced in said second electrode and for generating a voltage signal, said electrical amplifier maintaining said second electrode at a virtual ground to minimize environmental impedance effects; a rectifier, electrically connected to said amplifier, for rectifying the voltage signal; and a comparator, electrically connected to said rectifier for comparing the voltage signal to a predetermined voltage signal corresponding to the container being full with material, said comparator including a fail safe circuit that, in response to the voltage signal from said rectifier being of a voltage less than a first preselected reference voltage and less than a second predetermined voltage, generates a signal that the container is full.
Claim 10
Dependent Claim
171 words
An electrographic printing machine of the type having an apparatus for detecting the level of material in a container, said apparatus comprising: a power source; a first electrode, positioned adjacent the container, electrically connected to said power source; a second electrode, spaced from said first electrode, positioned adjacent the container; an electrical amplifier, electrically connected to the second electrode, for amplifying a current induced in said second electrode and for generating a voltage signal, said electrical amplifier maintaining said second electrode at a virtual ground to minimize environmental impedance effects; a rectifier, electrically connected to said amplifier, for rectifying the voltage signal; and a comparator, electrically connected to said rectifier for comparing the voltage signal to a predetermined voltage signal corresponding to the container being full with material, said comparator including a fail safe circuit that, in response to the voltage signal from said rectifier being of a voltage less than a first preselected reference voltage and less than a second predetermined voltage, generates a signal that the container is full.
Claim 11
Dependent Claim
33 words
A printing machine according to claim 8, further comprising a protection circuit electrically connected between said power source and said first electrode, said protection circuit isolating said power source from electrostatic voltage discharges.
Claim 12
Dependent Claim
31 words
A printing machine according to claim 8, further comprising a protection circuit electrically connected between said second electrode and said amplifier, said protection circuit isolating said amplifier from electrostatic voltage discharges.
Claim 13
Dependent Claim
21 words
A printing machine according to claim 8, wherein said first electrode and said second electrode are positioned exterior to said container.
Claim 14
Dependent Claim
20 words
A printing machine according to claim 11, wherein said first electrode and said second electrode are opposed from one another.
Claim 15
Dependent Claim
176 words
A container of the type having an apparatus for detecting the level of material in the container, said apparatus adapted to be connected to a power source, said apparatus comprising: a first electrode, positioned adjacent the container, electrically connected to said power source; a second electrode, spaced from said first electrode, positioned adjacent the container; an electrical amplifier, electrically connected to the second electrode, for amplifying a current induced in said second electrode and for generating a voltage signal, said electrical amplifier maintaining said second electrode at a virtual ground to minimize environmental impedance effects; a rectifier, electrically connected to said amplifier, for rectifying the voltage signal; and a comparator, electrically connected to said rectifier for comparing the voltage signal to a predetermined voltage signal corresponding to the container being full with material, said comparator including a fail safe circuit that, in response to the voltage signal from said rectifier being of a voltage less than a first preselected reference voltage and less than a second predetermined voltage, generates a signal that the container is full.
Claim 16
Dependent Claim
176 words
A container of the type having an apparatus for detecting the level of material in the container, said apparatus adapted to be connected to a power source, said apparatus comprising: a first electrode, positioned adjacent the container, electrically connected to said power source; a second electrode, spaced from said first electrode, positioned adjacent the container; an electrical amplifier, electrically connected to the second electrode, for amplifying a current induced in said second electrode and for generating a voltage signal, said electrical amplifier maintaining said second electrode at a virtual ground to minimize environmental impedance effects; a rectifier, electrically connected to said amplifier, for rectifying the voltage signal; and a comparator, electrically connected to said rectifier for comparing the voltage signal to a predetermined voltage signal corresponding to the container being full with material, said comparator including a fail safe circuit that, in response to the voltage signal from said rectifier being of a voltage less than a first preselected reference voltage and less than a second predetermined voltage, generates a signal that the container is full.
Claim 17
Dependent Claim
32 words
A container according to claim 13, further comprising a protection circuit electrically connected between said power source and said first electrode, said protection circuit isolating said power source from electrostatic voltage discharges.
Claim 18
Dependent Claim
30 words
A container according to claim 13, further comprising a protection circuit electrically connected between said second electrode and said amplifier, said protection circuit isolating said amplifier from electrostatic voltage discharges.
Claim 19
Dependent Claim
20 words
A container according to claim 13, wherein said first electrode and said second electrode are positioned exterior to said container.
Claim 20
Dependent Claim
19 words
A container according to claim 16, wherein said first electrode and said second electrode are opposed from one another.
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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) | 1998-11-13 | 1999-05-15 | 1999-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-13 | 2003-05-15 | 2003-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-13 | 2007-05-15 | 2007-11-14 | $7700.00 | Window Closed / Lapsed |