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US4223271A
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Integrating circuit
Assignee: Ricoh Co Ltd
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Filing: 1978-05-24
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Granted: 1980-09-16
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Expires: 1998-05-24
Abstract
Abstract An integrating capacitor is connected between the inverting input and the output of an operational amplifier. A plurality of resistors are connected in series to the inverting input. A plurality of capacitors are connected between the inverting input and junctions of the resistors respectively. The time required for the output voltage of the operational amplifier to reach a predetermined level is an exponential function of a voltage applied to the inverting input through the resistors.
Inventors
- 👤 Masamichi Furukawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:04
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/42; G01J1/4209; G01J1/4214; G01D; G01D1/00; G01D1/04; G06; G06G; G06G7/00; G06G7/12; G06G7/18; G06G7/184; G06G7/186; G06G7/24
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
52 words
An integrating circuit comprising: an operational amplifier having a first input and an output; an integrating capacitor connected between the first input and the output; a plurality of resistors connected in series to the first input; and a plurality of capacitors connected between the first input and junctions of the resistors respectively.
Claim 2
Dependent Claim
52 words
An integrating circuit comprising: an operational amplifier having a first input and an output; an integrating capacitor connected between the first input and the output; a plurality of resistors connected in series to the first input; and a plurality of capacitors connected between the first input and junctions of the resistors respectively.
Claim 3
Dependent Claim
20 words
A circuit as in claim 1, in which the operational amplifier has a second input which is connected to ground.
Claim 4
Dependent Claim
15 words
A circuit as in claim 1, in which the first input is an inverting input.
Claim 5
Dependent Claim
23 words
A circuit as in claim 2, in which the first input is an inverting input and the second input is a non-inverting input.
Claim 6
Dependent Claim
17 words
A circuit as in claim 2, further comprising a resistor connected between the second input and ground.
Claim 7
Dependent Claim
53 words
A circuit as in claim 1, in which the values of the resistors and capacitors are selected in such a manner that a time required for a voltage at the output to reach a predetermined level is an exponential function of a voltage applied to the first input through the plurality of resistors.
Claim 8
Dependent Claim
34 words
A circuit as in claim 1, further comprising a voltage comparator having a first input connected to the output of the operational amplifier and a second input to which is applied a reference voltage.
References Cited (Backward Citations)
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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) | 1983-09-16 | 1984-03-17 | 1984-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-16 | 1988-03-17 | 1988-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-16 | 1992-03-17 | 1992-09-16 | $7700.00 | Window Closed / Lapsed |