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US4618249A
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Corona-charging apparatus
Assignee: Eastman Kodak Co
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Filing: 1985-06-10
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Granted: 1986-10-21
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Expires: 2005-06-10
Abstract
Abstract A corona-charging apparatus includes a conductive control grid, at least one corona-emitting electrode, and means for providing a current supply to the electrode. Current is sinked from the grid through a variable resistance, and means are provided for sensing the voltage produced on the insulating surface to be charged. The electrode power supply is AC, and the grid current sink includes a rectifier circuit. Means, responsive to the sensed voltage adjust the conductivity of the variable resistance in accordance with a predetermined program to thereby maintain the charge on the surface substantially constant.
Inventors
- 👤 James C. Minor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:04
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0266; G03G15/0291
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
88 words
In a corona-charging apparatus for charging an insulating layer wherein the apparatus includes a conductive control grid, at least one corona-emitting electrode, and a power supply to the electrode, the improvement comprising: a variable impedance; circuit means, without an active power supply to the grid, for sinking current from the grid through said variable impedance; means for sensing the charge in the insulating layer; and control means responsive to said sensing means for adjusting the value of said variable impedance to maintain said charge at a predetermined level.
Claim 2
Dependent Claim
88 words
In a corona-charging apparatus for charging an insulating layer wherein the apparatus includes a conductive control grid, at least one corona-emitting electrode, and a power supply to the electrode, the improvement comprising: a variable impedance; circuit means, without an active power supply to the grid, for sinking current from the grid through said variable impedance; means for sensing the charge in the insulating layer; and control means responsive to said sensing means for adjusting the value of said variable impedance to maintain said charge at a predetermined level.
Claim 3
Dependent Claim
19 words
In the corona-charging apparatus defined in claim 1, the improvement wherein said variable impedance consists of a variable resistance.
Claim 4
Dependent Claim
28 words
In the corona-charging apparatus defined in claim 1, the improvement further comprising a rectifying circuit within said sinking circuit means, and wherein said electrode power supply is AC.
Claim 5
Dependent Claim
30 words
in the corona-charging apparatus defined in claim 1, the improvement further comprising adjustment means in said control means for varying the response of said control means to said sensing means.
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) | 1989-10-20 | 1990-04-21 | 1990-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-20 | 1994-04-21 | 1994-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-20 | 1998-04-21 | 1998-10-21 | $7700.00 | Window Closed / Lapsed |