Patent US3754526A successfully refreshed from Google Patents.
US3754526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic development apparatus
Assignee: International Business Machines Corp
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Filing: 1971-12-17
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Granted: 1973-08-28
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Expires: 1991-12-17
Abstract
Abstract A developing apparatus for an electrostatic reproduction machine includes a nonmagnetic cylinder rotatably mounted relative to a fixed magnetic field generating means. A multicomponent magnetic developer material is fed to the cylinder forming magnetic bristles of developer material thereon for brushing contact with a photosensitive electrostatic plate bearing an electrostatic latent image thereon. A portion of the developer material transfers to the plate developing the image, and the remainder is slung from the rotating cylinder onto a guide member thereby providing marked agitation and recombination of the developer material resulting in an increased triboelectric charge level of the developer material. The magnetic field is oriented to facilitate the slinging of the developer material against the guide. It further provides a directional field following the delivery point of the developer material to the cylinder which prevents developer material from flowing over the outer edges of the magnetic field existing at the development zone and post development zone. The developer material is thus prevented from being attracted to the cylinder at the development zone and thereafter prematurely slung from the rotating cylinder thereby keeping unwanted developer material from being carried away from the developer unit by the plate.
Inventors
- 👤 Caudill A Holland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:41
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0921
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
372 words
A developer apparatus for applying multicomponent developer material including magnetically attractable carrier and electrostatically charged toner to an electrostatic plate having a latent electrostatic image thereon for developing said image with toner comprising: delivery means for delivering said developer material to a delivery station; a movable applicator member having a developer material receiving surface; drive means for moving said surface of the applicator member along a path in a first direction past said delivery station through a development zone adjacent said electrostatic plate and past said development zone, said surface receiving developer material as it moves past said delivery station; first magnetic field generating means for generating a first magnetic field oriented to intersect a portion of the surface of the applicator member located at the development zone substantially normal thereto for forming developer material located on said portion of the surface into a brush-like array for brushing contact with the electrostatic plate, said first magnetic field extending across said portion of said surface in a direction perpendicular to said first direction from a first field edge to a second field edge; second magnetic field generating means for generating a second magnetic field oriented to intersect a further portion of the surface of the applicator member located beyond the development zone for retaining carrier and toner adhering thereto on said surface as it moves past said development zone, said second magnetic field extending across said further portion of the surface in a direction perpendicular to said first direction from a first field edge to a second field edge; third magnetic field generating means for generating a third magnetic field orientated to intersect a part of said surface of the applicator member located between said delivery station and said development zone for moving developer material on said part of said surface toward the center portion thereof from portions of said part of the surface which travel along said path to locations adjacent to said field edges and for retaining developer material located on said part of said surface thereon whereby developer material does not move through the edge portions of the first and the second magnetic fields as said part of said surface moves through the development zone and past the development zone.
Claim 2
Dependent Claim
372 words
A developer apparatus for applying multicomponent developer material including magnetically attractable carrier and electrostatically charged toner to an electrostatic plate having a latent electrostatic image thereon for developing said image with toner comprising: delivery means for delivering said developer material to a delivery station; a movable applicator member having a developer material receiving surface; drive means for moving said surface of the applicator member along a path in a first direction past said delivery station through a development zone adjacent said electrostatic plate and past said development zone, said surface receiving developer material as it moves past said delivery station; first magnetic field generating means for generating a first magnetic field oriented to intersect a portion of the surface of the applicator member located at the development zone substantially normal thereto for forming developer material located on said portion of the surface into a brush-like array for brushing contact with the electrostatic plate, said first magnetic field extending across said portion of said surface in a direction perpendicular to said first direction from a first field edge to a second field edge; second magnetic field generating means for generating a second magnetic field oriented to intersect a further portion of the surface of the applicator member located beyond the development zone for retaining carrier and toner adhering thereto on said surface as it moves past said development zone, said second magnetic field extending across said further portion of the surface in a direction perpendicular to said first direction from a first field edge to a second field edge; third magnetic field generating means for generating a third magnetic field orientated to intersect a part of said surface of the applicator member located between said delivery station and said development zone for moving developer material on said part of said surface toward the center portion thereof from portions of said part of the surface which travel along said path to locations adjacent to said field edges and for retaining developer material located on said part of said surface thereon whereby developer material does not move through the edge portions of the first and the second magnetic fields as said part of said surface moves through the development zone and past the development zone.
Claim 3
Dependent Claim
80 words
The developer apparatus set forth in claim 1 wherein said drive means moves said surface past a discharge zone following said development zone, said drive means further moving said surface in a closed loop past said delivery station, said development zone and said discharge zone and wherein said surface moves away from the influence of said magnetic fields at said discharge zone whereby developer material located on said surface being discharged therefrom as said surface moves past said discharge zone.
Claim 4
Dependent Claim
22 words
The developer apparatus set forth in claim 2 further comprising: a guide member positioned to receive developer material discharged from said surface.
Claim 5
Dependent Claim
30 words
The developer apparatus set forth in claim 1 wherein said surface is cylindrically shaped and wherein said drive means imparts rotary movenent of said cylindrically shaped surface about its axis.
Claim 6
Dependent Claim
27 words
The developer apparatus set forth in claim 4 wherein said first, said second and said third magnetic field generating means being located within said cylindrically shaped surface.
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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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |