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US5574545A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for transferring toner from developer carrying member to image bearing member using chains of magnetic particles formed on developer carrying member and contacting image bearing member, and alternating electric field

Assignee: Canon Inc
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Filing: 1995-05-22
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Granted: 1996-11-12
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Expires: 2015-05-22
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Abstract

Abstract In a developing method, a layer of electrically charged toner particles is formed on a surface of a developer carrying member, and magnetic particles which retain on their surfaces electrically charged toner particles are dispersed on the surface of the developing carrying member. The toner particles and magnetic particles are carried on the developing carrying member to a developing position where a surface of an electrostatic latent image bearing member for bearing an electrostatic latent image is opposed with a clearance to the surface of the developer carrying member. An alternating electric field is formed at the developing position against the electrostatic image and chains of magnetic particles are formed by stationary magnetic field generating apparatus disposed behind the developer carrying member. The latent electrostatic latent image is developed by the charge toner particles on the surface of the developer carrying member and on the surface of the magnetic particles in the clearance under the alternating electric field and the stationary magnetic field.

Inventors

  • 👤 Atsushi Hosoi
  • 👤 Hatsuo Tajima
  • 👤 Takashi Saito
  • 👤 Norihisa Hoshika
  • 👤 Hiroshi Tajika
  • 👤 Masaaki Yamaji

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 10:25
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/06; G03G13/08; G03G13/09; G03G15/00; G03G15/06; G03G15/08; G03G15/09

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 99 words
A developing method comprising the steps of: disposing a developer carrying member having a surface carrying a developer containing toner particles and magnetic particles opposite an image bearing member bearing an electrostatic image, whereby the magnetic particles are formed into chains, and toner particles are carried on both the chains and the surface of the developer carrying member; contacting the chains to the image bearing member; and generating an alternating electric field between the image bearing member and the developer carrying member, for moving toner particles from the surface of the developer carrying member to the image bearing member.
Claim 2
Dependent Claim 99 words
A developing method comprising the steps of: disposing a developer carrying member having a surface carrying a developer containing toner particles and magnetic particles opposite an image bearing member bearing an electrostatic image, whereby the magnetic particles are formed into chains, and toner particles are carried on both the chains and the surface of the developer carrying member; contacting the chains to the image bearing member; and generating an alternating electric field between the image bearing member and the developer carrying member, for moving toner particles from the surface of the developer carrying member to the image bearing member.
Claim 3
Dependent Claim 36 words
A method according to claim 1, including the step of developing the electrostatic image by both toner particles on the surface of the developer carrying member and toner particles carried by the chains of magnetic particles.
Claim 4
Dependent Claim 12 words
A method according to claim 1, wherein the toner particles are non-magnetic.
Claim 5
Dependent Claim 36 words
A method according to claim 1, wherein toner particles carried on said developer carrying member are present in an amount not less than 0.05×10 -3 g/cm 2 and not more than 1.0×10 -3 g/cm 2 .
Claim 6
Dependent Claim 41 words
A method according to claim 1, including the step of forming toner particles on said developer carrying member into a layer having a thickness which is 1/50-1/5 of a gap formed between said developer carrying member and said image bearing member.
Claim 7
Dependent Claim 33 words
A method according to claim 1, wherein a weight ratio between the toner particles retained on the chains of magnetic particles and the toner particles retained on the developer carrying member is 1:2-10:1.
Claim 8
Dependent Claim 12 words
A method according to claim 6, wherein the weight ratio is 1:1-5:1.
Claim 9
Dependent Claim 22 words
A method according to claim 1, wherein trace formation on a developed image due to brushing contact by the chains is prevented.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-11-12 2000-05-13 2000-11-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-11-12 2004-05-13 2004-11-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-11-12 2008-05-13 2008-11-12 $7700.00 Window Closed / Lapsed

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