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US4606990A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for forming a thin layer of developer

Assignee: Canon Inc
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Filing: 1985-01-30
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Granted: 1986-08-19
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Expires: 2005-01-30
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Abstract

Abstract A method for forming a thin layer of one-component non-magnetic developer on the surface of a developer carrying member in a dry type developing device using one-component non-magnetic developer. The non-magnetic developer is supplied to the surface of the developer carrying member, a magnetic blade is disposed with a clearance to the surface of the developer carrying member, and a stationary magnet is disposed across the developer carrying member from the magnetic blade and upstream of the magnetic blade with respect to the direction of movement of the developer carrying member to confine the magnetic particles if formed between the magnet and the magnetic blade. The developer carrying member with the developer is moved past the confined magnetic particles to form a thin layer of dry one-component non-magnetic developer on the surface of the developer carrying member.

Inventors

  • 👤 Masao Yoshikawa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 16:11
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0914; Y; Y10; Y10S; Y10S222/00; Y10S222/01

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 107 words
A method of forming a layer of non-magnetic developer particles on a surface of a developer carrying member comprising the steps of: providing magnetic particles and non-magnetic developer particles onto a developer carrying member; forming a stationary magnetic field between a magnetic blade disposed with a clearance to the developer carrying member and a magnet stationarily disposed across the developer carrying member from the magnetic blade to confine the magnetic particles; and moving the developer carrying member to carry the non-magnetic developer particles thereon and pass them by the confined magnetic particles to form a thin layer of the non-magnetic developer particles on the developer carrying member.
Claim 2
Independent Claim 107 words
A method of forming a layer of non-magnetic developer particles on a surface of a developer carrying member comprising the steps of: providing magnetic particles and non-magnetic developer particles onto a developer carrying member; forming a stationary magnetic field between a magnetic blade disposed with a clearance to the developer carrying member and a magnet stationarily disposed across the developer carrying member from the magnetic blade to confine the magnetic particles; and moving the developer carrying member to carry the non-magnetic developer particles thereon and pass them by the confined magnetic particles to form a thin layer of the non-magnetic developer particles on the developer carrying member.
Claim 3
Dependent Claim 33 words
A method according to claim 1, wherein the thin layer of non-magnetic developer is formed on said developer carrying member by the electrostatic force between the non-magnetic developer and the developer carrying member.
Claim 4
Dependent Claim 40 words
A method according to claim 1, wherein the thin layer of the non-magnetic developer develops a latent image carried on the latent image bearing member at a developing zone where the thin layer is close to the image bearing member.
Claim 5
Dependent Claim 20 words
A method according to claim 3, wherein an electric field is applied in the developing zone without a magnetic field.
Claim 6
Dependent Claim 14 words
A method according to claim 4, wherein said electric field includes an alternating field.
Claim 7
Dependent Claim 19 words
A method according to claim 5, wherein said electric field includes an alternating field superimposed by a DC component.
Claim 8
Dependent Claim 160 words
A developing method, comprising: providing magnetic particles and non-magnetic developer particles onto a developer carrying member; forming a stationary magnetic field between a magnetic blade disposed with a clearance to the developer carrying member and a magnet stationarily disposed across the developer carrying member from the magnetic blade to confine the magnetic particles; moving the developer carrying member to carry the non-magnetic developer particles therein and pass them by the confined magnetic particles to form a thin layer of the non-magnetic developer particles on the developer carrying member, wherein the thin layer of non-magnetic developer is formed on said developer carrying member by an electrostatic force between the non-magnetic developer particles and the developer carrying member; and developing a latent image on a latent image bearing member in a developing zone where the developer carrying member is close to the latent image bearing member, under influence of an alternating electric field formed in the developing zone without a magnetic field.
Claim 9
Dependent Claim 160 words
A developing method, comprising: providing magnetic particles and non-magnetic developer particles onto a developer carrying member; forming a stationary magnetic field between a magnetic blade disposed with a clearance to the developer carrying member and a magnet stationarily disposed across the developer carrying member from the magnetic blade to confine the magnetic particles; moving the developer carrying member to carry the non-magnetic developer particles therein and pass them by the confined magnetic particles to form a thin layer of the non-magnetic developer particles on the developer carrying member, wherein the thin layer of non-magnetic developer is formed on said developer carrying member by an electrostatic force between the non-magnetic developer particles and the developer carrying member; and developing a latent image on a latent image bearing member in a developing zone where the developer carrying member is close to the latent image bearing member, under influence of an alternating electric field formed in the developing zone without a magnetic field.
Claim 10
Dependent Claim 22 words
A method according to claim 7, wherein said alternating electric field is a sum of an AC field and a DC field.

References Cited (Backward Citations)

US4331757A Cited
US4244322A Cited
US4386577A Cited
US4292387A Cited
US4391512A Cited
US4511239A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-08-18 1990-02-17 1990-08-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-08-18 1994-02-17 1994-08-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-08-18 1998-02-17 1998-08-19 $7700.00 Window Closed / Lapsed

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