Patent US4641946A successfully refreshed from Google Patents.
US4641946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Development system
Assignee: Xerox Corp
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Filing: 1985-07-29
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Granted: 1987-02-10
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Expires: 2005-07-29
Abstract
Abstract An apparatus which develops a latent image recorded on a flexible member with developer material comprising at least magnetic granules and toner particles. Developer material is transported closely adjacent to a flexible member having the latent image recorded thereon. A radial magnetic field is generated in the development zone to optimize the attraction of the toner particles from the carrier granules to the latent image. A tangential magnetic field is generated at the exit of the development zone to prevent carrier granules from adhering to the flexible member. The magnitude of the tangential magnetic field at the exit of the development zone is greater than the magnitude of the radial magnetic field at the center of the development zone.
Inventors
- 👤 II Richard L. Forbes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:56
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0921
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
193 words
An apparatus for developing a latent image recorded on a flexible member, including: magnetic means, positioned closely adjacent the flexible member to define a development zone therebetween, for transporting a developer material comprising at least magnetic carrier granules having toner particles adhering thereto into contact with the flexible member in the development zone, said magnetic member generating at least a radial magnetic field in the development zone of a magnitude to optimize the attraction of the toner particles from the carrier granules to the latent image and at least a tangential magnetic field at the exit of the development zone of a magnitude to optimize the adherence of carrier granules thereto so as to prevent carrier granules from adhering to the flexible member with the magnitude of the tangential magnetic field at the exit of the development zone being greater than the magnitude of the radial magnetic field in the center of the development zone; and means for maintaining the flexible member at a preselected tension of sufficient magnitude so that the developer material being transported into contact therewith deflects the flexible member about said magnetic means to form an extended development zone.
Claim 2
Independent Claim
193 words
An apparatus for developing a latent image recorded on a flexible member, including: magnetic means, positioned closely adjacent the flexible member to define a development zone therebetween, for transporting a developer material comprising at least magnetic carrier granules having toner particles adhering thereto into contact with the flexible member in the development zone, said magnetic member generating at least a radial magnetic field in the development zone of a magnitude to optimize the attraction of the toner particles from the carrier granules to the latent image and at least a tangential magnetic field at the exit of the development zone of a magnitude to optimize the adherence of carrier granules thereto so as to prevent carrier granules from adhering to the flexible member with the magnitude of the tangential magnetic field at the exit of the development zone being greater than the magnitude of the radial magnetic field in the center of the development zone; and means for maintaining the flexible member at a preselected tension of sufficient magnitude so that the developer material being transported into contact therewith deflects the flexible member about said magnetic means to form an extended development zone.
Claim 3
Dependent Claim
13 words
An apparatus according to claim 1, wherein the flexible member is a belt.
Claim 4
Dependent Claim
31 words
An apparatus according to claim 2, wherein said magnetic means includes: a tubular member journaled for rotary movement; and a magnetic member disposed interiorly of and spaced from said tubular member.
Claim 5
Dependent Claim
36 words
An apparatus according to claim 3, wherein said magnetic member generates at least a radial magnetic field in the center of the development zone having a magnitude ranging from about 0 gauss to about 400 gauss.
Claim 6
Dependent Claim
35 words
An apparatus according to claim 4, wherein said magnetic member generates at least a tangential magnetic field at the exit of the development zone having a magnitude ranging from about 300 to about 550 gauss.
Claim 7
Dependent Claim
207 words
An electrophotographic printing machine of the type having an electrostatic latent image recorded on a flexible photoconductive member, wherein the improvement includes: magnetic means, positioned closely adjacent the flexible photoconductive member to define a development zone therebetween, for transporting a developer material comprising at least magnetic carrier granules having toner particles adhering thereto into contact with the flexible photoconductive member in the development zone, said magnetic member generating at least a radial magnetic field in the development zone of a magnitude to optimize the attraction of the toner particles from the carrier granules to the latent image and at least a tangential magnetic field at the exit of the development zone of a magnitude to optimize the adherence of carrier granules thereto so as to prevent carrier granules from adhering to the flexible photoconductive member with the magnitude of the tangential magnetic field at the exit of the development zone being greater than the magnitude of the radial magnetic field in the center of the development zone; and means for maintaining the flexible photoconductive member at a preselected tension of sufficient magnitude so that the developer material being transported into contact therewith deflects the flexible photoconductive member about said magnetic means to form an extended development zone.
Claim 8
Dependent Claim
207 words
An electrophotographic printing machine of the type having an electrostatic latent image recorded on a flexible photoconductive member, wherein the improvement includes: magnetic means, positioned closely adjacent the flexible photoconductive member to define a development zone therebetween, for transporting a developer material comprising at least magnetic carrier granules having toner particles adhering thereto into contact with the flexible photoconductive member in the development zone, said magnetic member generating at least a radial magnetic field in the development zone of a magnitude to optimize the attraction of the toner particles from the carrier granules to the latent image and at least a tangential magnetic field at the exit of the development zone of a magnitude to optimize the adherence of carrier granules thereto so as to prevent carrier granules from adhering to the flexible photoconductive member with the magnitude of the tangential magnetic field at the exit of the development zone being greater than the magnitude of the radial magnetic field in the center of the development zone; and means for maintaining the flexible photoconductive member at a preselected tension of sufficient magnitude so that the developer material being transported into contact therewith deflects the flexible photoconductive member about said magnetic means to form an extended development zone.
Claim 9
Dependent Claim
15 words
A printing machine according to claim 6, wherein the flexible photoconductive member is a belt.
Claim 10
Dependent Claim
32 words
A printing machine according to claim 7, wherein said magnetic means includes: a tubular member journaled for rotary movement; and a magnetic member disposed interiorly of and spaced from said tubular member.
Claim 11
Dependent Claim
37 words
A printing machine according to claim 8, wherein said magnetic member generates at least a radial magnetic field in the center of the development zone having a magnitude ranging from about 0 gauss to about 400 gauss.
Claim 12
Dependent Claim
36 words
A printing machine according to claim 9, wherein said magnetic member generates at least a tangential magnetic field at the exit of the development zone having a magnitude ranging from about 300 to about 550 gauss.
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) | 1990-02-09 | 1990-08-11 | 1991-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-09 | 1994-08-11 | 1995-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-09 | 1998-08-11 | 1999-02-10 | $7700.00 | Window Closed / Lapsed |