Patent DE1097C successfully refreshed from Google Patents.
Patent US3909614A successfully refreshed from Google Patents.
US3909614A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scorotron power supply circuit
Assignee: Xerox Corp
•
Filing: 1974-09-30
•
Granted: 1975-09-30
•
Expires: 1994-09-30
Abstract
Abstract A scorotron for uniformly charging an electrostatographic copying photoconductive surface has a coronode wire, a conductive metal shield and a screen grid. The coronode wire is supplied through a stabilizing resistor from an electrical inverter. The screen and the shield are connected together and commonly connected to ground through two series connected resistors. From a connection point between the two resistors a feed-back loop is provided to supply feed-back signals to a regulator connected at the input of the inverter, which feed-back signals are indicative of the sum of the screen and shield currents from the coronode wire corona emission, but insensitive to proportional changes between the screen current and the shield current.
Inventors
- 👤 Richard C Marshall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:53
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0266; G03G15/0291
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
197 words
In electrostatographic copying apparatus including scorotron corona charging apparatus for charging a surface, wherein said scorotron includes a conductive shield a conductive control grid and at least one corona emitting electrode, the improvement in said scorotron charging apparatus comprising: adjustable electrical power supply means connected to said corona emitting electrode to provide a current supply thereto; sensing circuit means, including resistor means, for sensing a voltage produced on said grid by said corona emitting electrode, said sensing circuit means being connected to said power supply means to supply a control signal to said power supply means proportional to said voltage produced on said grid from said corona emitting electrode, said control signal from said sensing circuit means controlling said current supply from said power supply to said corona emitting electrode to maintain said voltage at said grid substantially constant, wherein said conductive control grid and said conductive shield are directly electrically connected together and to said resistor means of said sensing current means, said resistor means conducting the combined total current from said control grid and said conductive shield therethrough, said combined total current through said resistive means providing said control signal to said power supply means.
Claim 2
Dependent Claim
197 words
In electrostatographic copying apparatus including scorotron corona charging apparatus for charging a surface, wherein said scorotron includes a conductive shield a conductive control grid and at least one corona emitting electrode, the improvement in said scorotron charging apparatus comprising: adjustable electrical power supply means connected to said corona emitting electrode to provide a current supply thereto; sensing circuit means, including resistor means, for sensing a voltage produced on said grid by said corona emitting electrode, said sensing circuit means being connected to said power supply means to supply a control signal to said power supply means proportional to said voltage produced on said grid from said corona emitting electrode, said control signal from said sensing circuit means controlling said current supply from said power supply to said corona emitting electrode to maintain said voltage at said grid substantially constant, wherein said conductive control grid and said conductive shield are directly electrically connected together and to said resistor means of said sensing current means, said resistor means conducting the combined total current from said control grid and said conductive shield therethrough, said combined total current through said resistive means providing said control signal to said power supply means.
Claim 3
Dependent Claim
28 words
The copying apparatus of claim 1 further including regulator means connected to said resistor means, and inverter means connected between said regulator means and said corona emitting electrode.
Claim 4
Dependent Claim
115 words
In a scorotron for uniformly charging an electrostatographic copying photoconductive surface comprising a corona emitting coronode wire, a conductive metal shield and a conductive screen grid, wherein the coronode wire is electrically supplied from a regulator, the improvement wherein the screen grid and the shield are connected together and commonly connected to ground through at least two series connected resistors having a connection point therebetween and a feed-back loop is provided connecting feed-back signals from this connection point to the regulator, which feed-back signals correspond to the sum of the screen and shield currents from the coRonode wire corona emission and are insensitive to proportional changes between the screen grid current and the shield current.
Claim 5
Dependent Claim
115 words
In a scorotron for uniformly charging an electrostatographic copying photoconductive surface comprising a corona emitting coronode wire, a conductive metal shield and a conductive screen grid, wherein the coronode wire is electrically supplied from a regulator, the improvement wherein the screen grid and the shield are connected together and commonly connected to ground through at least two series connected resistors having a connection point therebetween and a feed-back loop is provided connecting feed-back signals from this connection point to the regulator, which feed-back signals correspond to the sum of the screen and shield currents from the coRonode wire corona emission and are insensitive to proportional changes between the screen grid current and the shield current.
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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |