Patent US5052336A successfully refreshed from Google Patents.
US5052336A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developing roller for a developing unit with transport, develop and collect magnets
Assignee: Ricoh Co Ltd
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Filing: 1990-08-21
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Granted: 1991-10-01
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Expires: 2010-08-21
Abstract
Abstract A developing roller for a developing unit of an image forming apparatus has at least a magnet with a transport pole, a magnet with a develop pole, and a magnet with a collect pole. These magnets are accommodated in a rotary sleeve and affixed to a support member. The magnet with the develop pole is dimensioned longer than the other magnets as measured in the axial direction of the roller. The developing roller surely collects a developer of a magnet brush remaining on the roller after development, and thereby frees the interior of the apparatus from contamination ascribable to the developer.
Inventors
- 👤 Yutaka Fukuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:46
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0921
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
211 words
A developing roller for a developing unit which develops a latent image electrostatically formed on an image carrier of an image forming apparatus by using a magnet brush constituted by a developer, said developing roller comprising: a rotary sleeve for forming the magnet brush on a surface thereof and transporting said magnet brush to the image carrier carrying the latent image; a transport magnet accommodated in said sleeve and comprising a transport pole; a develop magnet accommodated in said sleeve and located downstream of said transport magnet with respect to an intended direction of rotation of said sleeve in such a manner as to face the latent image carried on the image carrier, and comprising a develop pole; a collect magnet accommodated in said sleeve and located in a position downstream of said develop magnet with respect to said intended direction of rotation of said sleeve, and comprising a collect pole for collecting the developer of the magnet brush remaining on said sleeve into the developing unit; and a support member accommodated in said sleeve for securely supporting said transport magnet, said develop magnet, and said collect magnet; said collect magnet being dimensioned longer than said transport magnet and said develop magnet as measured in an axial direction of said sleeve.
Claim 2
Dependent Claim
211 words
A developing roller for a developing unit which develops a latent image electrostatically formed on an image carrier of an image forming apparatus by using a magnet brush constituted by a developer, said developing roller comprising: a rotary sleeve for forming the magnet brush on a surface thereof and transporting said magnet brush to the image carrier carrying the latent image; a transport magnet accommodated in said sleeve and comprising a transport pole; a develop magnet accommodated in said sleeve and located downstream of said transport magnet with respect to an intended direction of rotation of said sleeve in such a manner as to face the latent image carried on the image carrier, and comprising a develop pole; a collect magnet accommodated in said sleeve and located in a position downstream of said develop magnet with respect to said intended direction of rotation of said sleeve, and comprising a collect pole for collecting the developer of the magnet brush remaining on said sleeve into the developing unit; and a support member accommodated in said sleeve for securely supporting said transport magnet, said develop magnet, and said collect magnet; said collect magnet being dimensioned longer than said transport magnet and said develop magnet as measured in an axial direction of said sleeve.
Claim 3
Dependent Claim
37 words
A developing roller as claimed in claim 1, further comprising a transport restrict magnet interposed between said transport magnet and said develop magnet and comprising a transport restrict pole for retaining the magnet brush on said sleeve.
Claim 4
Dependent Claim
32 words
A developing roller as claimed in claim 1, further comprising a shield plate located in close proximity to said collect magnet for weakening a magnetic field being developed by said collect magnet.
Claim 5
Dependent Claim
22 words
A developing roller as claimed in claim 1, wherein said sleeve and said support member each is made of a non-magnetic material.
Claim 6
Dependent Claim
29 words
A developing roller as claimed in claim 1, wherein said sleeve and said support member each are made of a non-magnetic material and a magnetically highly conductive material, respectively.
Claim 7
Dependent Claim
213 words
A developing roller for a developing unit which develops a latent image electrostatically formed on an image carrier of an image forming apparatus by using a magnet brush constituted by a developer, said developing roller comprising: a rotary sleeve for forming the magnet brush on a surface thereof and transporting said magnet brush to the image carrier carrying the latent image; a transport magnet accommodated in said sleeve and comprising a transport pole; a develop magnet accommodated in said sleeve and located downstream of said transport magnet with respect to an intended director of rotation of said sleeve in such a manner as to face the latent image carried on the image carrier, and comprising a develop pole; a collect magnet accommodated in said sleeve and located in a position downstream of said develop magnet with respect to said intended direction of rotation of said sleeve, and comprising a collect pole for collecting the developer of the magnet brush remaining on said sleeve into the developing unit; and a support member accommodated in said sleeve forming said transport magnet and said collect magnet and for securely supporting said develop magnet; said collect magnet being dimensioned longer than said transport magnet and said develop magnet as measured in an axial direction of said sleeve.
Claim 8
Dependent Claim
213 words
A developing roller for a developing unit which develops a latent image electrostatically formed on an image carrier of an image forming apparatus by using a magnet brush constituted by a developer, said developing roller comprising: a rotary sleeve for forming the magnet brush on a surface thereof and transporting said magnet brush to the image carrier carrying the latent image; a transport magnet accommodated in said sleeve and comprising a transport pole; a develop magnet accommodated in said sleeve and located downstream of said transport magnet with respect to an intended director of rotation of said sleeve in such a manner as to face the latent image carried on the image carrier, and comprising a develop pole; a collect magnet accommodated in said sleeve and located in a position downstream of said develop magnet with respect to said intended direction of rotation of said sleeve, and comprising a collect pole for collecting the developer of the magnet brush remaining on said sleeve into the developing unit; and a support member accommodated in said sleeve forming said transport magnet and said collect magnet and for securely supporting said develop magnet; said collect magnet being dimensioned longer than said transport magnet and said develop magnet as measured in an axial direction of said sleeve.
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) | 1994-09-30 | 1995-04-01 | 1995-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-30 | 1999-04-01 | 1999-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-30 | 2003-04-01 | 2003-10-01 | $7700.00 | Window Closed / Lapsed |