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Patent US3816756A successfully refreshed from Google Patents.
US3816756A
Expired / Lapsed
US
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Automatic bias control
Assignee: Xerox Corp
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Filing: 1972-11-20
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Granted: 1974-06-11
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Expires: 1992-11-20
Abstract
Abstract In an electrostatographic process recorder utilizing coated paper whose resistivity changes as a function of relative humidity, control apparatus for varying the process bias voltage in accordance with the resistivity of the paper in order to maintain a constant image quality.
Inventors
- 👤 H Bresnick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:55
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/065
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
94 words
In an electrostatographic process recorder, apparatus for controlling development process bias voltage in order to achieve the effect of constant paper resistivity, said apparatus comprising means for sensing the resistivity of the paper, means connected to said sensing means for supplying a voltage signal as a monotonic function of said resistivity, output means including a control element for providing said bias voltage, and control means responsive to said voltage signal and said bias voltage for controlling said control element to vary said bias voltage so as to achieve the effect of constant paper resistivity.
Claim 2
Dependent Claim
94 words
In an electrostatographic process recorder, apparatus for controlling development process bias voltage in order to achieve the effect of constant paper resistivity, said apparatus comprising means for sensing the resistivity of the paper, means connected to said sensing means for supplying a voltage signal as a monotonic function of said resistivity, output means including a control element for providing said bias voltage, and control means responsive to said voltage signal and said bias voltage for controlling said control element to vary said bias voltage so as to achieve the effect of constant paper resistivity.
Claim 3
Dependent Claim
31 words
The apparatus of claim 1 wherein said supplying means includes a plurality of resistors connected in a Wheatstone bridge configuration, one arm of said bridge being connected to saiD sensing means.
Claim 4
Dependent Claim
42 words
The apparatus of claim 1 wherein said output means comprises a voltage source, a first resistor connected to said voltage source, a second resistor connected to a reference level, and an output terminal connected between said first resistor and said second resistor.
Claim 5
Dependent Claim
32 words
The apparatus of claim 3 wherein said control element comprises a transistor having its collector connected to said output terminal and said first resistor and its emitter connected to said second resistor.
Claim 6
Dependent Claim
40 words
The apparatus of claim 4 wherein said control means includes an operational amplifier having a first input connected to said supplying means, a second input connected to said output means, and an output connected to the base of said transistor.
Claim 7
Dependent Claim
26 words
The apparatus of claim 5 wherein said control means further includes feedback means connected between said output terminal and said second input of said operational amplifier.
Claim 8
Dependent Claim
20 words
The apparatus of claim 6 wherein said feedback means comprises a plurality of resistors connected in a voltage divider configuration.
References Cited (Backward Citations)
US3463934A
Cited
US3586908A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |