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US5081503A Expired / Lapsed US ⏱️ 0.0 years remaining

Compact magnetic bead pick-off device

Assignee: Xerox Corp
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Filing: 1991-02-04
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Granted: 1992-01-14
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Expires: 2011-02-04
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Abstract

Abstract Carrier bead pick-off device including a magnet assembly and an enclosure in which the magnet assembly is reciprocated between a first position where carrier beads are picked off the photoreceptor and a second position where the carrier beads are caused to be returned to a developer housing structure. The enclosure in one embodiment of the invention forms part of the developer housing structure. The magnet is retracted such that it follows the contour of the enclosure so that the carrier beads are swept into the developer housing structure.

Inventors

  • 👤 Delmer G. Parker
  • 👤 William M. Allen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 22:30
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/095

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 189 words
Reproduction apparatus including a charge retentive surface; an image forming station for forming a latent image on the charge retentive surface; at least one developer housing structure supporting developing means for developing the latent image with toner and carrier bead; a transfer station; and a carrier bead pick-off device for removing carrier beads adhering to the charge retentive surface after development, said carrier bead pick-off device comprising: an enclosure supported such that a first portion thereof is disposed closely adjacent to said charge retentive surface; a magnet assembly supported for reciprocating movement within said enclosure between a carrier bead pick-off position adjacent said first portion and a position adjacent a second portion of said enclosure whereby carrier beads are moved from said first to said second portion for effecting return of carrier beads to said developer housing structure, said magnet assembly having a strong carrier bead attraction field concentrated at an end thereof which is closest to said first portion and a relatively uniform and weak field in a part thereof closely disposed adjacent said developer housing structure; and means for effecting periodic reciprocating movement of said magnet assembly.
Claim 2
Dependent Claim 189 words
Reproduction apparatus including a charge retentive surface; an image forming station for forming a latent image on the charge retentive surface; at least one developer housing structure supporting developing means for developing the latent image with toner and carrier bead; a transfer station; and a carrier bead pick-off device for removing carrier beads adhering to the charge retentive surface after development, said carrier bead pick-off device comprising: an enclosure supported such that a first portion thereof is disposed closely adjacent to said charge retentive surface; a magnet assembly supported for reciprocating movement within said enclosure between a carrier bead pick-off position adjacent said first portion and a position adjacent a second portion of said enclosure whereby carrier beads are moved from said first to said second portion for effecting return of carrier beads to said developer housing structure, said magnet assembly having a strong carrier bead attraction field concentrated at an end thereof which is closest to said first portion and a relatively uniform and weak field in a part thereof closely disposed adjacent said developer housing structure; and means for effecting periodic reciprocating movement of said magnet assembly.
Claim 3
Dependent Claim 14 words
Apparatus according to claim 1, wherein said enclosure is fabricated from electrically conductive material.
Claim 4
Dependent Claim 15 words
Apparatus according to claim 2 wherein said enclosure comprises part of said developer housing structure.
Claim 5
Dependent Claim 31 words
Apparatus according to claim 3 wherein said one end comprises a pole piece and said part of said magnet assembly having a relatively uniform and weak field comprises a bar magnet.
Claim 6
Dependent Claim 21 words
Apparatus according to claim 4 wherein said means for effecting movement of said magnet assembly comprises a solenoid and spring arrangement.
Claim 7
Dependent Claim 43 words
Apparatus according to claim 5 wherein said magnet assembly is supported for movement such that said pole piece follows the contour of said enclosure whereby carrier beads are swept along the surface of said enclosure from said first portion to said second portion.
Claim 8
Dependent Claim 27 words
Apparatus according to claim 6, wherein said reproduction apparatus comprises a plurality of developer housing structures and a carrier bead pick-off device for each of said structures.
Claim 9
Independent Claim 138 words
The method of removing carrier beads from a charge retentive surface, said method including the steps of: supporting an enclosure such that a first portion thereof is disposed closely adjacent to a charge retentive surface; supporting a magnet assembly for reciprocating movement within said enclosure between a carrier bead pick-off position adjacent said first portion and a position adjacent a second portion of said enclosure whereby carrier beads are moved from said said first to said second portion for effecting return of carrier beads to said developer housing structure, said magnet assembly having a strong carrier bead attraction field concentrated at an end thereof which is closest to said first portion and a relatively uniform and weak field in a part thereof closely disposed adjacent said developer housing structure; and effecting periodic reciprocating movement of said magnet assembly.
Claim 10
Independent Claim 138 words
The method of removing carrier beads from a charge retentive surface, said method including the steps of: supporting an enclosure such that a first portion thereof is disposed closely adjacent to a charge retentive surface; supporting a magnet assembly for reciprocating movement within said enclosure between a carrier bead pick-off position adjacent said first portion and a position adjacent a second portion of said enclosure whereby carrier beads are moved from said said first to said second portion for effecting return of carrier beads to said developer housing structure, said magnet assembly having a strong carrier bead attraction field concentrated at an end thereof which is closest to said first portion and a relatively uniform and weak field in a part thereof closely disposed adjacent said developer housing structure; and effecting periodic reciprocating movement of said magnet assembly.
Claim 11
Dependent Claim 15 words
The method according to claim 8 wherein said enclosure is fabricated from electrically conductive material.
Claim 12
Dependent Claim 16 words
The method according to claim 9 wherein said enclosure comprises part of said developer housing structure.
Claim 13
Dependent Claim 32 words
The method according to claim 10 wherein said one end comprises a pole piece and said part of said magnet assembly having a relatively uniform and weak field comprises a bar magnet.
Claim 14
Dependent Claim 22 words
The method according to claim 11 wherein said means for effecting movement of said magnet assembly comprises a solenoid and spring arrangement.
Claim 15
Dependent Claim 44 words
The method according to claim 12 wherein said magnet assembly is supported for movement such that said pole piece follows the contour of said enclosure whereby carrier beads are swept along the surface of said enclosure from said first portion to said second portion.
Claim 16
Dependent Claim 25 words
The method according to claim 13 including the step of providing a plurality of enclosures and magnet assemblies, one for each developer housing structure utilized.

References Cited (Backward Citations)

US4647186A Cited
US4829338A Cited
US4969015A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-01-13 1995-07-15 1996-01-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-01-13 1999-07-15 2000-01-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-01-13 2003-07-15 2004-01-14 $7700.00 Window Closed / Lapsed

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