US4579082A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developing apparatus
Assignee: Canon Inc
•
Filing: 1983-08-29
•
Granted: 1986-04-01
•
Expires: 2003-08-29
Abstract
Abstract A developing apparatus wherein a thin layer of a non-magnetic developer is formed on a developer carrying member includes a developer container for containing a mixture of non-magnetic developer and magnetic particles; a device disposed adjacent to a non-magnetic developer outlet of developer container with a clearance with respect to a surface of developer carrying member, for regulating supply of the non-magnetic developer to developer carrying member surface; magnetic field generating device, disposed across developer carrying member with respect to regulating device, for forming a magnetic brush of the magnetic particles at the upstream side of regulating device with respect to movement of developer carrying member to confine the magnetic particles within developer container.
Inventors
- 👤 Yoshihiro Murasawa
- 👤 Kimio Nakahata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:43
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
162 words
An apparatus for forming a layer of non-magnetic developer particles on a surface of a developer carrying member comprising: a developer container for containing magnetic particles and non-magnetic developer particles; regulating means disposed with a clearance with respect to a surface of the developer carrying member; first magnetic field generating means stationarily disposed across the developer carrying member from said regulating means to form a magnetic field between said regulating means and first magnetic field generating means to confine the magnetic particles within said developer container; second magnetic field generating means across the developer carrying member from said regulating means to move a mixture of the magnetic particles and the non-magnetic developer particles; and means for moving the developer carrying member to carry only the non-magnetic developer particles thereon and pass them by a region of the confined magnetic particles, to form a thin layer of the non-magnetic developer particles on the developer carrying member which layer is withdrawn from said container.
Claim 2
Independent Claim
162 words
An apparatus for forming a layer of non-magnetic developer particles on a surface of a developer carrying member comprising: a developer container for containing magnetic particles and non-magnetic developer particles; regulating means disposed with a clearance with respect to a surface of the developer carrying member; first magnetic field generating means stationarily disposed across the developer carrying member from said regulating means to form a magnetic field between said regulating means and first magnetic field generating means to confine the magnetic particles within said developer container; second magnetic field generating means across the developer carrying member from said regulating means to move a mixture of the magnetic particles and the non-magnetic developer particles; and means for moving the developer carrying member to carry only the non-magnetic developer particles thereon and pass them by a region of the confined magnetic particles, to form a thin layer of the non-magnetic developer particles on the developer carrying member which layer is withdrawn from said container.
Claim 3
Dependent Claim
42 words
An apparatus according to claim 1, wherein said first magnetic field generating means includes a magnetic pole for forming a magnetic brush, disposed upstream of said regulating means by at least 5 degree with respect to movement of the developer carrying member.
Claim 4
Dependent Claim
20 words
An apparatus according to claim 1 or 2, wherein said regulating means includes a magnetic blade of a magnetic material.
Claim 5
Dependent Claim
52 words
An apparatus according to claim 1, wherein the thin layer of the non-magnetic developer is brought on the developer carrying member into facing relation with an image bearing member having an image to be developed, with a clearance between the image bearing member and the thin layer of the non-magnetic developer particles.
Claim 6
Dependent Claim
23 words
An apparatus according to claim 4, wherein an alternating bias voltage is applied between the image bearing member and the developer carrying member.
Claim 7
Dependent Claim
30 words
An apparatus according to claim 1, wherein the magnetic particle has a diameter of 30-50μ, and the content of the non-magnetic developer particles within the mixture is 25-70 wt. %.
Claim 8
Dependent Claim
15 words
An apparatus according to claim 1, wherein the developer carrying member has a rough surface.
Claim 9
Dependent Claim
31 words
An apparatus according to claim 7, wherein the developer carrying member has a surface treated by sandblasting with irregular particles, and has the pitch of roughness P=5-50μ and the roughness Rz=1-5μ.
Claim 10
Dependent Claim
31 words
An apparatus according to claim 7, wherein the developer carrying member has a surface treated by sandblasting with regular particles, and has the pitch of roughness P=10-70μ and the roughness Rz=2-10μ.
References Cited (Backward Citations)
US4386577A
Cited
US4387664A
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US4292387A
Cited
US4391512A
Cited
US4350440A
Cited
US4368971A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-03-31 | 1989-09-30 | 1990-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-31 | 1993-09-30 | 1994-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-31 | 1997-09-30 | 1998-04-01 | $7700.00 | Window Closed / Lapsed |