Patent US5325932A successfully refreshed from Google Patents.
Patent US4074134A successfully refreshed from Google Patents.
US4074134A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Operating point regulation for a corona discharge device
Assignee: International Business Machines Corp
•
Filing: 1976-04-13
•
Granted: 1978-02-14
•
Expires: 1996-04-13
Abstract
Abstract A control circuit for a corona discharge device in which the high voltage to the corona wire is electronically controlled in response to an error voltage generated by summing a reference and a sense current. In one embodiment the sense current is proportional to the screen voltage and in another embodiment the sense current is the current to the photoconductor. In each case the sense current is isolated in a single resistor. The high voltage is adjusted by utilizing the error voltage to adjust the control voltage to the high voltage power supply.
Inventors
- 👤 Howard J. Roalson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:25
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0266; G03G15/0291; H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/338; H02M3/3385; H02M3/3387; H02M3/3388
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
194 words
A control circuit for a corona discharge device utilized to produce a uniform charge on an electrophotographic imaging member comprising: a direct current power source having a high voltage terminal and a common terminal; a corona generating device having a plurality of corona emission wires and a screen member between said corona wires and said imaging member; means for connecting said high voltage terminal to said corona wire to produce corona emission; means for connecting a first resisitor between said screen electrode and said common terminal of said power source to produce a predetermined screen current; means for connecting said screen electrode to a summing point over a circuit path including a sense resistor to produce a sense current; a direct current power source for producing a reference current and circuit means to couple this reference current to said summing point; circuit means for connecting a summing resisitor from said summing point to a reference potential tp produce an error voltage proportional to the difference between said sense current and said reference current; and means responsive to said error voltage to adjust the high voltage output inversely with the variation of the sense current.
Claim 2
Dependent Claim
194 words
A control circuit for a corona discharge device utilized to produce a uniform charge on an electrophotographic imaging member comprising: a direct current power source having a high voltage terminal and a common terminal; a corona generating device having a plurality of corona emission wires and a screen member between said corona wires and said imaging member; means for connecting said high voltage terminal to said corona wire to produce corona emission; means for connecting a first resisitor between said screen electrode and said common terminal of said power source to produce a predetermined screen current; means for connecting said screen electrode to a summing point over a circuit path including a sense resistor to produce a sense current; a direct current power source for producing a reference current and circuit means to couple this reference current to said summing point; circuit means for connecting a summing resisitor from said summing point to a reference potential tp produce an error voltage proportional to the difference between said sense current and said reference current; and means responsive to said error voltage to adjust the high voltage output inversely with the variation of the sense current.
Claim 3
Dependent Claim
21 words
The control circuit according to claim 1 additionally comprising means to vary said reference current in response to a remote signal.
Claim 4
Dependent Claim
66 words
The control circuit according to claim 2 wherein said means to vary said reference current in response to a remote signal comprises: means for supplying a remote digital signal corresponding to the desired reference; means for converting the digital signal to a current level proportional to said remote signal; and means for coupling the current level signal to produce the reference current in said control circuit.
Claim 5
Dependent Claim
85 words
The control circuit according to claim 1 wherein said direct current power source comprises control means, a converter section and a high voltage Section; said control means being operable in response to said error voltage to produce a set of drive pulses, the width of which is proportional to the error voltage, and means to couple the drive pulses to the converter section to control the output of said high voltage section in a direction so that increasing pulse width produces increasing high voltage output.
References Cited (Backward Citations)
US3496351A
Cited
US3819942A
Cited
US3934141A
Cited
US3950680A
Cited
US3961193A
Cited
US3976881A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-13 | 1981-08-15 | 1982-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-13 | 1985-08-15 | 1986-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-13 | 1989-08-15 | 1990-02-14 | $7700.00 | Window Closed / Lapsed |