US4400079A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Injection roller developer for electrophotographic copier and biasing system therefor
Assignee: HP Indigo BV
•
Filing: 1980-09-24
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Granted: 1983-08-23
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Expires: 2000-09-24
Abstract
Abstract A developing system for an electrophotographic copier in which a roller having a conductive outer surface is disposed adjacent to the imaging surface to form a gap. The roller is driven at a peripheral linear velocity substantially greater than the velocity of movement of the imaging surface and is supplied with liquid developer at a location spaced from the gap to cause the roller to inject the developer into the gap. The roller is coupled to a source of potential through a gas discharge tube to maintain the potential of the electrode within predetermined limits.
Inventors
- 👤 Benzion Landa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:30
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/10; G03G15/101
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
87 words
In an electrophotographic copier, a photoconductor adapted to bear an electrostatic image on its surface, a roller, means for resiliently urging said roller toward said surface, means for supplying liquid developer to said roller, means for moving said photoconductor past said roller, and means for rotating said roller at such a velocity that the hydrodynamic pressure of said liquid developer on said roller forces said roller away from said photoconductor against the action of said urging means to form a gap for the injection of said developer.
Claim 2
Dependent Claim
87 words
In an electrophotographic copier, a photoconductor adapted to bear an electrostatic image on its surface, a roller, means for resiliently urging said roller toward said surface, means for supplying liquid developer to said roller, means for moving said photoconductor past said roller, and means for rotating said roller at such a velocity that the hydrodynamic pressure of said liquid developer on said roller forces said roller away from said photoconductor against the action of said urging means to form a gap for the injection of said developer.
Claim 3
Dependent Claim
11 words
Apparatus as in claim 1 comprising means for cleaning said roller.
Claim 4
Dependent Claim
22 words
Apparatus as in claim 1 in which said supplying means comprises means for immersing a portion of said roller in liquid developer.
Claim 5
Dependent Claim
20 words
Apparatus as in claim 1 in which the surface velocity of said roller is at least forty inches per second.
Claim 6
Dependent Claim
22 words
Apparatus as in claim 1 in which the surface velocity of said roller is between forty and two hundred inches per second.
Claim 7
Dependent Claim
88 words
In an electrophotographic copier, a photoconductor adapted to bear an electrostatic image on its surface, a conductive roller, means for resiliently urging said roller toward said surface, means for supplying liquid developer to said roller, means for moving said photoconductor past said roller, and means for rotating said roller at such a velocity that the hydrodynamic pressure of said liquid developer on said roller forces said roller away from said photoconductor against the action of said urging means to form a gap for the injection of said developer.
Claim 8
Dependent Claim
88 words
In an electrophotographic copier, a photoconductor adapted to bear an electrostatic image on its surface, a conductive roller, means for resiliently urging said roller toward said surface, means for supplying liquid developer to said roller, means for moving said photoconductor past said roller, and means for rotating said roller at such a velocity that the hydrodynamic pressure of said liquid developer on said roller forces said roller away from said photoconductor against the action of said urging means to form a gap for the injection of said developer.
Claim 9
Dependent Claim
15 words
Apparatus as in claim 6 comprising means for impressing a biasing potential on said roller.
Claim 10
Dependent Claim
14 words
Apparatus as in claim 6 in which said roller has a conductive outer surface.
Claim 11
Dependent Claim
24 words
Apparatus as in claim 6 in which said roller comprises a conductor adjacent to its outer surface and an insulating layer overlying said conductor.
Claim 12
Dependent Claim
127 words
In an electrophotographic copier, a photoconductor adapted to carry an electrostatic image on its surface, a conductive roller, means for disposing said roller adjacent said surface to form a gap therebetween, means for supplying liquid developer to said roller, means for moving said photoconductor past said roller, means for driving said roller at a peripheral velocity substantially greater than the velocity of said photoconductor to inject said developer into said gap, means for providing a biasing potential, and means for coupling said roller to said biasing potential means, said coupling means including a gas discharge tube connected between said roller and said biasing potential means, whereby the difference between the potential of said roller and said biasing potential is limited to the breakdown potential of said tube.
Claim 13
Dependent Claim
127 words
In an electrophotographic copier, a photoconductor adapted to carry an electrostatic image on its surface, a conductive roller, means for disposing said roller adjacent said surface to form a gap therebetween, means for supplying liquid developer to said roller, means for moving said photoconductor past said roller, means for driving said roller at a peripheral velocity substantially greater than the velocity of said photoconductor to inject said developer into said gap, means for providing a biasing potential, and means for coupling said roller to said biasing potential means, said coupling means including a gas discharge tube connected between said roller and said biasing potential means, whereby the difference between the potential of said roller and said biasing potential is limited to the breakdown potential of said tube.
Claim 14
Dependent Claim
14 words
Apparatus as in claim 10 in which said roller comprises a conductive outer surface.
Claim 15
Dependent Claim
24 words
Apparatus as in claim 10 in which said roller comprises a conductor adjacent to its outer surface and an insulating layer overlying said conductor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-22 | 1987-02-21 | 1987-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-22 | 1991-02-21 | 1991-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-22 | 1995-02-21 | 1995-08-23 | $7700.00 | Window Closed / Lapsed |