Patent US5070812A successfully refreshed from Google Patents.
US5070812A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic latent image developing apparatus
Assignee: Canon Inc
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Filing: 1990-05-29
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Granted: 1991-12-10
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Expires: 2010-05-29
Abstract
Abstract A developing apparatus for developing an electrostatic latent image formed on an image bearing member includes a developer chamber containing a developer comprising non-magnetic toner particles and magnetic carrier particles; a rotatable cylindrical developer carrying member, faced to the image bearing member, for carrying the developer supplied thereto in the developer chamber to supply it to the image bearing member; a magnet stationarily disposed in the developer carrying member to form a magnetic brush of the developer contactable to the image bearing member, wherein a position of maximum magnetic flux density in a direction normal to a surface of the developer carrying member provided by a developing magnetic pole of the magnet is not less than 3 degrees away from a position where the developer carrying member is closest to the image bearing member, and wherein a position of a peak of magnetic force in a direction normal to the surface of the developer carrying member provided by the developing magnetic pole is within 8 degrees from the closest position.
Inventors
- 👤 Masaaki Yamaji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:24
CPC Classifications
B; B82; B82Y; B82Y15/00; G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
170 words
A developing apparatus for developing an electrostatic latent image formed on an image bearing member; comprising: a developer chamber containing a developer comprising non-magnetic toner particles and magnetic carrier particles; a rotatable cylindrical developer carrying member, faced to the image bearing member, for carrying the developer supplied thereto in the developer chamber to supply it to the image bearing member; a magnet stationarily disposed in said developer carrying member to form a magnetic brush of the developer contactable to said image bearing member, wherein a position of maximum magnetic flux density in a direction normal to a surface of the developer carrying member provided by a developing magnetic pole of said magnet is not less than 3 degrees away from a position where said developer carrying member is closest to the image bearing member, and wherein a position of a peak of magnetic force in a direction normal to the surface of said developer carrying member provided by the developing magnetic pole is within 8 degrees from the closest position.
Claim 2
Dependent Claim
170 words
A developing apparatus for developing an electrostatic latent image formed on an image bearing member; comprising: a developer chamber containing a developer comprising non-magnetic toner particles and magnetic carrier particles; a rotatable cylindrical developer carrying member, faced to the image bearing member, for carrying the developer supplied thereto in the developer chamber to supply it to the image bearing member; a magnet stationarily disposed in said developer carrying member to form a magnetic brush of the developer contactable to said image bearing member, wherein a position of maximum magnetic flux density in a direction normal to a surface of the developer carrying member provided by a developing magnetic pole of said magnet is not less than 3 degrees away from a position where said developer carrying member is closest to the image bearing member, and wherein a position of a peak of magnetic force in a direction normal to the surface of said developer carrying member provided by the developing magnetic pole is within 8 degrees from the closest position.
Claim 3
Dependent Claim
46 words
An apparatus according to claim 1, wherein said developer carrying member carries a developer comprising non-magnetic toner particles having a volume average particle size of not more than 10 microns, and magnetic carrier particles having a weight average particle size of not more than 80 microns.
Claim 4
Dependent Claim
22 words
An apparatus according to claim 2, wherein the peak position of the magnetic force is within 5 degrees from the closest position.
Claim 5
Dependent Claim
31 words
An apparatus according to claim 2, wherein the maximum magnetic flux density position is not less than 3 degrees away and not more than 15 degrees away from the closest position.
Claim 6
Dependent Claim
31 words
An apparatus according to claim 3, wherein the maximum magnetic flux density position is not less than 3 degrees away and not more than 15 degrees away from the closest position.
Claim 7
Independent Claim
25 words
An apparatus according to any one of claims 1-5, further comprising a voltage source for applying an alternating bias voltage to said developer carrying member.
Claim 8
Dependent Claim
53 words
An apparatus according to claim 6, further comprising a regulating member for regulating a layer of the developer carried on said developer carrying member to a position where the developer is supplied to the image bearing member, the regulating member being away from said developer carrying member with a clearance of 50-900 microns.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-09 | 1995-06-10 | 1995-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-09 | 1999-06-10 | 1999-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-09 | 2003-06-10 | 2003-12-10 | $7700.00 | Window Closed / Lapsed |