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US4637706A Expired / Lapsed US ⏱️ 0.0 years remaining

Developer thin layer forming apparatus

Assignee: Canon Inc
•
Filing: 1984-06-08
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Granted: 1987-01-20
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Expires: 2004-06-08
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Abstract

Abstract A developing apparatus, including, a developer supply container, having an opening, for containing a non-magnetic developer and magnetic particles, an endlessly movable developer carrying member of a non-magnetic material for carrying a developer, which is movable between an inside of the developer supply container and an outside of the developer supply container through the opening, a magnetic particle confining member, spaced from outer surface of the developer carrying member with a gap, a magnet for generating a fixed magnetic field, having a magnetic pole disposed inside of the carrying member and upstream of the confining member with respect to movement of the developer carrying member, and a magnet, disposed outside of the carrying member in proximity with the confining member at an upstream side thereof with respect to movement of the developer carrying member.

Inventors

  • 👤 Atsushi Hosoi
  • 👤 Fumitaka Kan
  • 👤 Hidemi Egami
  • 👤 Hatsuo Tajima
  • 👤 Shunji Nakamura
  • 👤 Kimio Nakahata

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 10:16
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0914

Claims Analysis

Total Claims: 33
Claim 1
Independent Claim 138 words
A developable apparatus, comprising: a developer supply container, having an opening, for containing a non-magnetic developer and magnetic particles; an endlessly movable developer carrying member of a non-magnetic material for carrying a developer, which is movable between an inside of said developer supply container and an outside of said developer supply container through the opening; a magnetic particle confining member, spaced from an outer surface of said developer carrying member with a gap; means for generating a fixed magnetic field, having magnetic pole means disposed inside of said carrying member and upstream of said confining member with respect to the movement direction of said developer carrying member; and a magnet, disposed outside of said carrying member in proximity with said confining member at an upstream side thereof with respect to the movement direction of said developer carrying member.
Claim 2
Dependent Claim 138 words
A developable apparatus, comprising: a developer supply container, having an opening, for containing a non-magnetic developer and magnetic particles; an endlessly movable developer carrying member of a non-magnetic material for carrying a developer, which is movable between an inside of said developer supply container and an outside of said developer supply container through the opening; a magnetic particle confining member, spaced from an outer surface of said developer carrying member with a gap; means for generating a fixed magnetic field, having magnetic pole means disposed inside of said carrying member and upstream of said confining member with respect to the movement direction of said developer carrying member; and a magnet, disposed outside of said carrying member in proximity with said confining member at an upstream side thereof with respect to the movement direction of said developer carrying member.
Claim 3
Dependent Claim 39 words
An apparatus according to claim 1, wherein said magnet has a magnetic pole, opposed to said developer carrying member, of a polarity, the same as the polarity of the magnetic pole means of said fixed magnetic field generating means.
Claim 4
Dependent Claim 38 words
An apparatus according to claim 1, wherein said magnet has a magnetic pole, opposed to said developer carrying means, of a polaritiy, opposite to the polarity of the magnetic pole means of said fixed magnetic field generating means.
Claim 5
Dependent Claim 23 words
An apparatus according to claim 1 or 3, wherein said magnet provides a surface magnetic flux density of not more than 300 gauss.
Claim 6
Dependent Claim 48 words
An apparatus according to claim 1, wherein said magnet has magnetic poles disposed in a direction perpendicular to the movement direction of said developer carrying member and which poles are opposed to said carrying member, wherein adjacent ones of said magnetic poles are opposite in their magnetic polarities.
Claim 7
Dependent Claim 24 words
An apparatus according to claim 1, 2, 3 or 5, wherein said magnetic particle confining member includes a magnetic blade of a magnetic material.
Claim 8
Dependent Claim 16 words
An apparatus according to claim 6, wherein said magnet is fixedly secured to the magnetic blade.
Claim 9
Dependent Claim 186 words
A developing apparatus, comprising: a developer supply container, having an opening, for containing a non-magnetic developer and magnetic particles; an endlessly movable developer carrying member of a non-magnetic material for carrying a developer which is movable between an inside of said developer supply container and an outside of said developer supply container through the opening; a magnetic particle confining member, spaced from an outer surface of said developer carrying member with a gap; means for generating a fixed magnetic field, having magnetic pole means disposed inside of said carrying member and upstream of said confining member with respect to the movement direction of said developer carrying member; and a magnetic pole of the same polarity as that of the magnetic pole means of said fixed magnetic field generating means and disposed in close proximity with, downstream of said magnetic particle confining member with respect to the movement direction of said developer carrying member to steeply decrease, downstream thereof, a magnetic flux density, on a surface of the carrying member, of the magnetic field formed by the magnetic pole means of said fixed magnetic field generating means.
Claim 10
Dependent Claim 186 words
A developing apparatus, comprising: a developer supply container, having an opening, for containing a non-magnetic developer and magnetic particles; an endlessly movable developer carrying member of a non-magnetic material for carrying a developer which is movable between an inside of said developer supply container and an outside of said developer supply container through the opening; a magnetic particle confining member, spaced from an outer surface of said developer carrying member with a gap; means for generating a fixed magnetic field, having magnetic pole means disposed inside of said carrying member and upstream of said confining member with respect to the movement direction of said developer carrying member; and a magnetic pole of the same polarity as that of the magnetic pole means of said fixed magnetic field generating means and disposed in close proximity with, downstream of said magnetic particle confining member with respect to the movement direction of said developer carrying member to steeply decrease, downstream thereof, a magnetic flux density, on a surface of the carrying member, of the magnetic field formed by the magnetic pole means of said fixed magnetic field generating means.
Claim 11
Dependent Claim 28 words
An apparatus according to claim 8, wherein the magnetic pole of the same polarity as that of the magnetic pole means is disposed outside of said carrying member.
Claim 12
Dependent Claim 18 words
An apparatus according to claim 9, wherein said confining member includes a magnetic blade of a magnetic material.
Claim 13
Dependent Claim 34 words
An apparatus according to claim 10, wherein said magnetic pole of the same polarity as that of the magnetic pole means is a magnetic pole of a magnet fixedly mounted on said magnetic blade.
Claim 14
Dependent Claim 26 words
An apparatus according to claim 10, wherein said magnetic pole of the same polarity as that of said magnetic means is formed in said magnetic blade.
Claim 15
Dependent Claim 28 words
An apparatus according to claim 8, wherein said magnetic pole of the same polarity as that of the magnetic pole means is provided inside of said carrying member.
Claim 16
Dependent Claim 44 words
An apparatus according to claim 1, wherein a surface magnetic flux density of a pole of said magnet is smaller than a surface magnetic flux density of said magnetic pole means of said magnetic field generating means which is closest to said confining member.
Claim 17
Dependent Claim 22 words
An apparatus according to claim 2, wherein said magnetic pole provides a surface magnetic flux density of not more than 150 gauss.
Claim 18
Dependent Claim 22 words
An apparatus according to claim 3, wherein said magnetic pole provides a surface magnetic flux density of not more than 200 gauss.
Claim 19
Dependent Claim 45 words
An apparatus according to claim 1, wherein said confining member is provided with a magnetic property cooperative with said magnetic pole means to form magnetic lines of force for confining the magnetic particles, and said magnet is fixed on a surface of said confining member.
Claim 20
Dependent Claim 51 words
An apparatus according to claim 1, wherein said developer carrying member is opposed to an image bearing member bearing an electrostatic latent image thereon to establish a developing portion, where the developer in the form of a thin layer on the developer carrying member is applied to the electrostatic latent image.
Claim 21
Dependent Claim 51 words
An apparatus according to claim 8, wherein said developer carrying member is opposed to an image bearing member bearing an electrostatic latent image thereon to establish a developing portion, where the developer in the form of a thin layer on the developer carrying member is applied to the electrostatic latent image.
Claim 22
Dependent Claim 42 words
An apparatus according to claim 8, wherein a surface magnetic flux denxity of said magnetic pole is larger than a surface magnetic flux density of said magnetic pole means of said magnetic field generating means which is closest to said confining member.
Claim 23
Dependent Claim 46 words
An apparatus according to claim 8, wherein said confining member is provided with a magnetic property cooperative with said magnetic pole means to form magnetic lines of force for confining the magnetic particles, and said magnetic pole is fixed on a surface of said confining member.
Claim 24
Dependent Claim 26 words
An apparatus according to claim 11, wherein said magnet is fixed on said confining member by way of a non-magnetic member joined to said confining member.
Claim 25
Independent Claim 216 words
An apparatus for forming a thin developer layer, comprising: a developer container, having an opening, for containing a non-magnetic developer and magnetic particles; an endlessly movable developer carrying member of a non-magnetic material for carrying a developer, which is movable between an inside of said developer container and an outside of said developer container through the opening; a magnetic regulating member spaced from said developer carrying member at a position where the developer is discharged out of said developer container; means for generating a fixed magnetic field, having a magnetic pole disposed inside said carrying member and upstream of said regulating member with respect to the movement direction of said developer carrying member; and a magnet disposed outside said carrying member and adjacent to said regulating member and having a magnetic pole, the polarity of which is the same as that of said magnetic pole of said fixed magnetic field generating means; wherein by a magnetic field formed between said fixed magnetic field generating means and said magnetic regulating member and by a repelling magnetic field formed between said magnet and said magnetic pole of said fixed magnetic field generating means, the magnetic particles are confined in said developer container, and a thin layer of only the non-magnetic developer is formed on the developer carrying member.
Claim 26
Independent Claim 216 words
An apparatus for forming a thin developer layer, comprising: a developer container, having an opening, for containing a non-magnetic developer and magnetic particles; an endlessly movable developer carrying member of a non-magnetic material for carrying a developer, which is movable between an inside of said developer container and an outside of said developer container through the opening; a magnetic regulating member spaced from said developer carrying member at a position where the developer is discharged out of said developer container; means for generating a fixed magnetic field, having a magnetic pole disposed inside said carrying member and upstream of said regulating member with respect to the movement direction of said developer carrying member; and a magnet disposed outside said carrying member and adjacent to said regulating member and having a magnetic pole, the polarity of which is the same as that of said magnetic pole of said fixed magnetic field generating means; wherein by a magnetic field formed between said fixed magnetic field generating means and said magnetic regulating member and by a repelling magnetic field formed between said magnet and said magnetic pole of said fixed magnetic field generating means, the magnetic particles are confined in said developer container, and a thin layer of only the non-magnetic developer is formed on the developer carrying member.
Claim 27
Dependent Claim 47 words
An apparatus according to claim 23, wherein said developer carrying member is opposed to an image bearing member bearing an electrostatic latent image thereon to establish a developing portion where the thin layer of developer on the developer carrying member is applied to the electrostatic latent image.
Claim 28
Dependent Claim 171 words
A developing apparatus comprising a container for containing a developer including magnetic particles and electrically chargeable non-magnetic particles, said container defining an opening; a rotatable developer carrying member disposed in the opening of said developer container, said member being a non-magnetic cylinder; stationary magnetic field generating means, disposed in said developer carrying member, for generating a stationary magnetic field; a non-magnetic blade disposed adjacent a position where said rotatable developer carrying member carries the developer out of said developer container, said non-magnetic blade being spaced from said developer carrying member with a first clearance; and a magnetic member disposed on an upstream side of said non-magnetic blade with respect to the rotation direction of said developer carrying member, said magnetic member being spaced from said developer carrying member with a second clearance larger than the first clearance; wherein said stationary magnetic field generating means has a magnetic pole at a position upstream of said non-magnetic blade and said magnetic member with respect to the rotation direction of said developer carrying member.
Claim 29
Dependent Claim 171 words
A developing apparatus comprising a container for containing a developer including magnetic particles and electrically chargeable non-magnetic particles, said container defining an opening; a rotatable developer carrying member disposed in the opening of said developer container, said member being a non-magnetic cylinder; stationary magnetic field generating means, disposed in said developer carrying member, for generating a stationary magnetic field; a non-magnetic blade disposed adjacent a position where said rotatable developer carrying member carries the developer out of said developer container, said non-magnetic blade being spaced from said developer carrying member with a first clearance; and a magnetic member disposed on an upstream side of said non-magnetic blade with respect to the rotation direction of said developer carrying member, said magnetic member being spaced from said developer carrying member with a second clearance larger than the first clearance; wherein said stationary magnetic field generating means has a magnetic pole at a position upstream of said non-magnetic blade and said magnetic member with respect to the rotation direction of said developer carrying member.
Claim 30
Dependent Claim 41 words
An apparatus according to claim 25, wherein an angle formed between said non-magnetic blade and said magnetic pole with respect to a center of said cylindrical developer carrying member is not less than 5 degrees and not more than 50 degrees.
Claim 31
Dependent Claim 21 words
An apparatus according to claim 25, wherein said magnetic member provides a surface magnetic flux density not more than 300 Gauss.
Claim 32
Dependent Claim 21 words
An apparatus according to claim 27, wherein said magnetic member provides a surface magnetic flux density not more than 200 Gauss.
Claim 33
Dependent Claim 21 words
An apparatus according to claim 28, wherein said magnetic member provides a surface magnetic flux density not more than 100 Gauss.

References Cited (Backward Citations)

US4244322A Cited
US4386577A Cited
US4387664A Cited
US4391512A Cited
US4406535A Cited
US4548489A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-01-19 1990-07-21 1991-01-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-01-19 1994-07-21 1995-01-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-01-19 1998-07-21 1999-01-20 $7700.00 Window Closed / Lapsed

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