Patent US4603961A successfully refreshed from Google Patents.
US4603961A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Development system
Assignee: Xerox Corp
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Filing: 1985-06-13
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Granted: 1986-08-05
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Expires: 2005-06-13
Abstract
Abstract An electrophotographic printing machine of the type having a photoconductive member wherein at least one electrostatic latent image is recorded thereon. A developer roller transports a developer material closely adjacent to the photoconductive member. A controller, coupled to the developer roller, generates a control signal as a function of the measured electrical potential on the photoconductive member. A second developer roller, spaced from the first developer roller, is electrically biased to a fixed potential to deposit developer material on the latent image. A third developer roller, spaced from the second developer roller, also develops the latent image with developer material. The second developer roller is interposed between the first developer roller and the third developer roller. The electrical bias on the third developer roller is controlled by the control signal from the controller.
Inventors
- 👤 Jeffrey J. Folkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:21
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/065; G03G15/08; G03G15/09; G03G15/0907
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
123 words
An electrophotographic printing machine of the type having a photoconductive member with at least one electrostatic latent image recorded thereon, wherein the improvement includes: means for supporting a developer material closely adjacent to the photoconductive member; means, coupled to said supporting means, for generating a control signal as a function of the electrical potential on the photoconductive member; first means for developing the electrostatic latent image; first means for electrically biasing said first developing means to a substantially fixed electrical bias; second means for developing the electrostatic latent image, said first developing means being interposed between said second developing means and said supporting means; and second means, responsive to the control signal from said generating means, for electrically biasing said second developing means.
Claim 2
Dependent Claim
123 words
An electrophotographic printing machine of the type having a photoconductive member with at least one electrostatic latent image recorded thereon, wherein the improvement includes: means for supporting a developer material closely adjacent to the photoconductive member; means, coupled to said supporting means, for generating a control signal as a function of the electrical potential on the photoconductive member; first means for developing the electrostatic latent image; first means for electrically biasing said first developing means to a substantially fixed electrical bias; second means for developing the electrostatic latent image, said first developing means being interposed between said second developing means and said supporting means; and second means, responsive to the control signal from said generating means, for electrically biasing said second developing means.
Claim 3
Dependent Claim
21 words
A printing machine according to claim 1, wherein said supporting means develops the electrostatic latent image recorded on the photoconductive member.
Claim 4
Dependent Claim
39 words
A printing machine according to claim 2, wherein said generating means generates the control signal as a function of the electrical potential on the photoconductive member in the region between successive electrostatic latent images recorded on the photoconductive member.
Claim 5
Dependent Claim
44 words
A printing machine according to claim 3, wherein said generating means further generates the control signal as a function of the electrical potential on the photoconductive member in the regions of the trail edge and lead edge of the electrostatic latent image recorded thereon.
Claim 6
Dependent Claim
49 words
A printing machine according to claim 2, wherein said supporting means includes: a first tubular member mounted rotatably for transporting developer material closely adjacent to the photoconductive member; and a first magnetic member disposed interiorly of and spaced from said first tubular member to attract the developer material thereto.
Claim 7
Dependent Claim
54 words
A printing machine according to claim 5, wherein said first developing means includes: a second tubular member, spaced from said first tubular member, for transporting developer material closely adjacent to the photoconductive member; and a second magnetic member disposed interiorly of and spaced from said second tubular member to attract the developer material thereto.
Claim 8
Dependent Claim
54 words
A printing machine according to claim 6, wherein said second developing means includes: a third tubular member, spaced from said second tubular member, for transporting developer material closely adjacent to the photoconductive member; and a third magnetic member disposed interiorly of and spaced from said third tubular member to attract the developer material thereto.
Claim 9
Dependent Claim
26 words
A printing machine according to claim 7, wherein said second developer electrical biasing means includes a variable voltage source electrically connected to said third tubular member.
Claim 10
Dependent Claim
34 words
A printing machine according to claim 8, wherein the generating means includes: an amplifier electrically connected to said first tubular member; and a controller electrically connected to said amplifier and said variable voltage source.
Claim 11
Dependent Claim
26 words
A printing machine according to claim 9, wherein said first developer electrical biasing means includes a fixed voltage source electrically connected to said second tubular member.
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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) | 1989-08-04 | 1990-02-03 | 1990-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-04 | 1994-02-03 | 1994-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-04 | 1998-02-03 | 1998-08-05 | $7700.00 | Window Closed / Lapsed |