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US4592987A Expired / Lapsed US ⏱️ 0.0 years remaining

Toner application method and developer composition

Assignee: Canon Inc
•
Filing: 1984-10-09
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Granted: 1986-06-03
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Expires: 2004-10-09
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Abstract

Abstract A method for applying a toner comprising: forming, in a container containing a toner and magnetic particles for application of the toner, a magnetic brush of the magnetic particles; circulating the magnetic particles in the container; and forming a thin layer of the toner electrically charged on the toner carrying member; wherein the magnetic particles have a particle size distribution of 30 wt. % or more in the range of 150 to 200 mesh and 5 wt. % or less of under 250 mesh, and the weight ratio of the toner to the magnetic particles is from 5:95 to 50:50 in the region where the magnetic brush is formed.

Inventors

  • 👤 Yasuo Mitsuhashi
  • 👤 Masanori Takenouchi
  • 👤 Kenji Okado
  • 👤 Eiichi Imai
  • 👤 Koshi Suematsu

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 23:20
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/06; G03G13/08; G03G13/09; Y; Y10; Y10S; Y10S222/00; Y10S222/01

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 136 words
A method for developing a latent electrostatic image comprising: forming, in a container containing a non-magnetic toner and magnetic particles for application of the toner, a magnetic brush of the magnetic particles; circulating the magnetic particles in the container; and forming a thin layer of the toner triboelectrically charged on a toner carrying member inside of which a magnet for forming said magnetic brush is disposed; wherein the magnetic particles have a particle size distreibution of 30 wt. % or more in the range of 150 to 200 mesh and 5 wt. % or less of under 250 mesh, and the weight ratio of the toner to the magnetic particles is from 5:95 to 50:50 in the region where said magnetic brush is formed, and applying said thin layer of toner to develop said electrostatic image.
Claim 2
Independent Claim 136 words
A method for developing a latent electrostatic image comprising: forming, in a container containing a non-magnetic toner and magnetic particles for application of the toner, a magnetic brush of the magnetic particles; circulating the magnetic particles in the container; and forming a thin layer of the toner triboelectrically charged on a toner carrying member inside of which a magnet for forming said magnetic brush is disposed; wherein the magnetic particles have a particle size distreibution of 30 wt. % or more in the range of 150 to 200 mesh and 5 wt. % or less of under 250 mesh, and the weight ratio of the toner to the magnetic particles is from 5:95 to 50:50 in the region where said magnetic brush is formed, and applying said thin layer of toner to develop said electrostatic image.
Claim 3
Dependent Claim 45 words
The method according to claim 1, wherein the magnetic particles have a particle size distribution of 30 wt. % or less of over 100 mesh, 60 wt. % or more of 150 to 200 mesh, and 3 wt. % or less of under 250 mesh.
Claim 4
Dependent Claim 45 words
the method according to claim 2, wherein the magnetic particles have a particle size distribution of 10 wt. % or less of over 100 mesh, 60 wt. % or more of 150 to 200 mesh, and 3 wt. % or less of under 250 mesh.
Claim 5
Dependent Claim 28 words
The method according to claim 1, wherein the weight ratio of the toner to the magnetic particles is from 6:94 to 20:80 in the magnetic brush forming region.
Claim 6
Dependent Claim 28 words
The method according to claim 4, wherein the weight ratio of the toner to the magnetic particles is from 7:93 to 15:85 in the magnetic brush forming region.
Claim 7
Dependent Claim 47 words
The method according to claim 1, wherein the magnetic particles are surface-oxidized or non-oxidized particles of a metal selected from the group consisting of iron, nickel, cobalt, manganese, chromium and rare earth metals, or an alloy of these metals, or particles of an oxide of these metals.
Claim 8
Dependent Claim 19 words
The method according to claim 1, wherein the toner is chromatically colored and substantially free of a magnetic material.

References Cited (Backward Citations)

US4337724A Cited
US4365586A Cited
JPS5669669A Cited
US4385829A Cited
JPS5799670A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-06-02 1989-12-02 1990-06-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-06-02 1993-12-02 1994-06-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-06-02 1997-12-02 1998-06-03 $7700.00 Window Closed / Lapsed

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