US4086650A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Corona charging device
Assignee: Xerox Corp
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Filing: 1976-12-08
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Granted: 1978-04-25
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Expires: 1996-12-08
Abstract
Abstract A corona discharge device including a corona discharge electrode and a conductive shield located adjacent the electrode, the electrode being coated with relatively thick dielectric material so as to substantially prevent the flow of conduction current therethrough. The delivery of charge to the photoconductive surface is accomplished by means of a displacement current or capacitative coupling through the dielectric material. The flow of charge to the surface to be charged is regulated by means of a d.c. bias applied to the corona shield.
Inventors
- 👤 Thomas G. Davis
- 👤 George J. Safford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:03
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0291
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
99 words
In combination, a charge collecting surface, said surface carried on with a conductive substrate held at a reference potential, a corona discharge member positioned above said surface, said member comprising a thin wire, coated at least in the discharge area with a dielectric material, means for coupling a corona generating a.c. voltage intermediate said substrate and said wire, a conductive shield adjacent said wire and first biasing means for holding said shield at a potential different than said reference potential, said dielectric material having a thickness sufficient to prevent the flow of a net d.c. current though said wire.
Claim 2
Dependent Claim
99 words
In combination, a charge collecting surface, said surface carried on with a conductive substrate held at a reference potential, a corona discharge member positioned above said surface, said member comprising a thin wire, coated at least in the discharge area with a dielectric material, means for coupling a corona generating a.c. voltage intermediate said substrate and said wire, a conductive shield adjacent said wire and first biasing means for holding said shield at a potential different than said reference potential, said dielectric material having a thickness sufficient to prevent the flow of a net d.c. current though said wire.
Claim 3
Dependent Claim
12 words
The combination recited in claim 1 wherein said reference potential is ground.
Claim 4
Dependent Claim
28 words
The combination recited in claim 1 further including second biasing means for biasing said shield to a positive or negative d.c. potential with respect to said reference potential.
Claim 5
Dependent Claim
11 words
The combination recited in claim 1 wherein said material is glass.
Claim 6
Independent Claim
81 words
A method for depositing a charge on an adjacent surface comprising the steps of locating a corona discharge electrode adjacent said surface, the electrode including a coating of dielectric material to prevent the passage of a d.c. current therethrough, coupling an a.c. corona generating potential to said electrode, positioning a conductive shield adjacent said electrode, positioning a field defining member on the side of said surface opposite said electrode, and establishing a d.c. electric field between said shield and said member.
Claim 7
Independent Claim
81 words
A method for depositing a charge on an adjacent surface comprising the steps of locating a corona discharge electrode adjacent said surface, the electrode including a coating of dielectric material to prevent the passage of a d.c. current therethrough, coupling an a.c. corona generating potential to said electrode, positioning a conductive shield adjacent said electrode, positioning a field defining member on the side of said surface opposite said electrode, and establishing a d.c. electric field between said shield and said member.
Claim 8
Dependent Claim
56 words
The method of claim 5 further including the steps of constructing said electrode in the form of an elongated wire, constructing said shield in the shape of an elongated U-shaped member, constructing said surface of a photosenstive material, mounting said surface on a conductive base, and applying a d.c. potential between said shield and said base.
Claim 9
Dependent Claim
28 words
The method of claim 5 wherein the step of establishing said d.c. field is accomplished by biasing said shield to a negative potential with respect to said member.
Claim 10
Dependent Claim
39 words
The method recited in claim 7 wherein said surface comprises a photoconductive material carried on a conductive substrate and wherein said shield and said substrate are coupled to different reference potentials in order to establish said d.c. electric field.
Claim 11
Dependent Claim
90 words
A corona generating device for depositing a negative charge on an imaging surface carried on a conductive substrate held at a reference potential comprising: a corona discharge electrode including an elongated conductive member coated with a thick dielectric coating, the thickness of the coating adapted to prevent a net d.c. current from said source through said electrode, conductive shield located adjacent said electrode, and power supply means for applying an a.c. corona generating potential to said member and a negative d.c. potential to said shield relative to said reference potential.
Claim 12
Dependent Claim
90 words
A corona generating device for depositing a negative charge on an imaging surface carried on a conductive substrate held at a reference potential comprising: a corona discharge electrode including an elongated conductive member coated with a thick dielectric coating, the thickness of the coating adapted to prevent a net d.c. current from said source through said electrode, conductive shield located adjacent said electrode, and power supply means for applying an a.c. corona generating potential to said member and a negative d.c. potential to said shield relative to said reference potential.
Claim 13
Dependent Claim
11 words
The combination recited in claim 9 wherein said coating is glass.
Claim 14
Dependent Claim
13 words
The combination recited in claim 9 wherein the coating is a ceramic material.
Claim 15
Dependent Claim
24 words
The combination recited in claim 9 wherein said power supply means is variable to effect a change in the characteristic output of said device.
Claim 16
Dependent Claim
26 words
The combination recited in claim 9 wherein said substrate is held at ground potential and said shield is held at a potential negative with respect thereto.
Claim 17
Dependent Claim
110 words
A corona generating discharge device for altering the charge on an imaging surface carried on a conductive substrate comprising a corona discharge member including an inner conductive electrode with an outer dielectric coating, the thickness of said coating being selected to prevent a net d.c. current from being drawn from said source through said electrode, a conductive shield located adjacent said member, power supply means for applying an a.c. corona generating voltage to said electrode and providing a d.c. potential between said substrate and said shield, and means for varying said power supply means to change the charge delivered by said device to an imaging surface at a given potential.
Claim 18
Dependent Claim
110 words
A corona generating discharge device for altering the charge on an imaging surface carried on a conductive substrate comprising a corona discharge member including an inner conductive electrode with an outer dielectric coating, the thickness of said coating being selected to prevent a net d.c. current from being drawn from said source through said electrode, a conductive shield located adjacent said member, power supply means for applying an a.c. corona generating voltage to said electrode and providing a d.c. potential between said substrate and said shield, and means for varying said power supply means to change the charge delivered by said device to an imaging surface at a given potential.
Claim 19
Dependent Claim
11 words
The combination recited in claim 14 wherein said coating is glass.
Claim 20
Dependent Claim
13 words
The combination recited in claim 14 wherein said coating is a ceramic material.
Claim 21
Dependent Claim
24 words
The combination as recited in claim 14 wherein said power supply means maintains said shield at a negative potential with respect to said substrate.
Claim 22
Dependent Claim
27 words
The combination recited in claim 17 wherein said power supply means holds said substrate at ground potential and said a.c. corona generating potential varies about ground potential.
Claim 23
Dependent Claim
92 words
An improved method for changing the characteristic output of a corona generating device in an electrostatographic reproduction machine including an imaging surface carried on a conductive substrate comprising the steps of: locating a corona generating member adjacent an imaging surface, said member including a conductive electrode coated with a dielectric material, positioning a conductive shield adjacent said member connecting an a.c. corona generating potential to said electrode, applying an electrical potential between said substrate and shield, and varying either of said potentials to change the characteristic charge output of said corona device.
Claim 24
Dependent Claim
92 words
An improved method for changing the characteristic output of a corona generating device in an electrostatographic reproduction machine including an imaging surface carried on a conductive substrate comprising the steps of: locating a corona generating member adjacent an imaging surface, said member including a conductive electrode coated with a dielectric material, positioning a conductive shield adjacent said member connecting an a.c. corona generating potential to said electrode, applying an electrical potential between said substrate and shield, and varying either of said potentials to change the characteristic charge output of said corona device.
Claim 25
Dependent Claim
88 words
In combination, a corona discharge member, a charge collecting surface, a conductor positioned on the side of said surface remote from said member and held a reference potential, said corona discharge member comprising a wire coated at least in the discharge area with a dielectric material, means for generating an a.c. corona discharge adjacent said member, a conductive shield adjacent said wire and biasing means for holding said shield at a potential different than said reference potential, said dielectric material preventing a net d.c. current through said wire.
Claim 26
Dependent Claim
88 words
In combination, a corona discharge member, a charge collecting surface, a conductor positioned on the side of said surface remote from said member and held a reference potential, said corona discharge member comprising a wire coated at least in the discharge area with a dielectric material, means for generating an a.c. corona discharge adjacent said member, a conductive shield adjacent said wire and biasing means for holding said shield at a potential different than said reference potential, said dielectric material preventing a net d.c. current through said wire.
Claim 27
Dependent Claim
11 words
The combination recited in claim 20 wherein said material is glass.
Claim 28
Dependent Claim
21 words
The combination recited in claim 20 wherein said shield is held at a negative potential with respect to said reference potential.
Claim 29
Dependent Claim
27 words
The combination recited in claim 20 wherein said surface to be charged is a photoconductor and said conductor is a substrate on which said photoconductor is carried.
Claim 30
Dependent Claim
78 words
In combination, a corona discharge member including an electrode having a dielectric coating to substantially prevent the flow of conduction current therethrough, a surface to be charged, first and second conductors, said surface to be charged positioned intermediate said first conductor and said member, biasing means for holding said second conductor at a constant potential relative to said first conductor in order to define a field therebetween, and means for creating an a.c. corona discharge adjacent said member.
Claim 31
Dependent Claim
78 words
In combination, a corona discharge member including an electrode having a dielectric coating to substantially prevent the flow of conduction current therethrough, a surface to be charged, first and second conductors, said surface to be charged positioned intermediate said first conductor and said member, biasing means for holding said second conductor at a constant potential relative to said first conductor in order to define a field therebetween, and means for creating an a.c. corona discharge adjacent said member.
Claim 32
Dependent Claim
11 words
The combination recited in claim 24 wherein said dielectric is glass.
Claim 33
Dependent Claim
25 words
The combination recited in claim 24 wherein said second conductor is positioned on the side of said member remote from said surface to be charged.
Claim 34
Dependent Claim
22 words
The combination recited in claim 24 wherein said second conductor is held at a negative potential with respect to said first conductor.
Claim 35
Dependent Claim
28 words
The combination recited in claim 24 wherein said surface to be charged is a photoconductor and said first conductor comprises a substrate on which said photoconductor is carried.
References Cited (Backward Citations)
US3634726A
Cited
US3775104A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-24 | 1981-10-24 | 1982-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-24 | 1985-10-24 | 1986-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-24 | 1989-10-24 | 1990-04-25 | $7700.00 | Window Closed / Lapsed |