Patent US5625441A successfully refreshed from Google Patents.
US5625441A
Expired / Lapsed
US
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Developing device for an image forming apparatus
Assignee: Ricoh Co Ltd
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Filing: 1996-04-17
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Granted: 1997-04-29
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Expires: 2016-04-17
Abstract
Abstract In an image forming apparatus, a developing device operable with toner or single component type developer has a hard first developing roller and a soft second developing roller. Fine magnetic N-S poles are formed on the periphery of the first roller. The second roller conveys the toner, electrostatically transferred thereto from the first roller, to an image carrier. The device frees a toner image from deterioration due to toner particles charged to a polarity opposite to an expected polarity. The toner forms a uniform thin layer on the first roller and is uniformly charged. Toner for use with this type of developing device is also disclosed.
Inventors
- 👤 Toshihiro Sugiyama
- 👤 Kazuhiro Yuasa
- 👤 Shuichi Endoh
- 👤 Iwao Matsumae
- 👤 Yoshiaki Tanaka
- 👤 Hiroshi Hosokawa
- 👤 Mugijiroh Uno
- 👤 Hiroshi Saitoh
- 👤 Eiji Takenaka
- 👤 Tetsuo Yamanaka
- 👤 Eisaku Murakami
- 👤 Satoru Komatsubara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:44
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/06; G03G13/08; G03G15/00; G03G15/06; G03G15/08; G03G15/0806; G03G15/0808; G03G15/09; G03G9/00; G03G9/08; G03G9/0819; G03G9/0821; G03G9/0823; G03G9/083; G03G9/0838; G03G2215/00; G03G2215/08; G03G2215/0855; G03G2215/0869
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
103 words
A developing device for an image forming apparatus and for developing a latent image electrostatically formed on an image carrier by toner, said device comprising: first conveying means for conveying the toner deposited thereon; regulating means for regulating an amount of the toner to be conveyed by said first toner conveying means while charging said toner by friction; and second conveying means contacting said first conveying means, and for receiving the charged toner from said first conveying means; wherein said first toner conveying means comprises a magnetic field generating layer which is magnetized at a pitch ranging from 1 mm to 5 mm.
Claim 2
Dependent Claim
103 words
A developing device for an image forming apparatus and for developing a latent image electrostatically formed on an image carrier by toner, said device comprising: first conveying means for conveying the toner deposited thereon; regulating means for regulating an amount of the toner to be conveyed by said first toner conveying means while charging said toner by friction; and second conveying means contacting said first conveying means, and for receiving the charged toner from said first conveying means; wherein said first toner conveying means comprises a magnetic field generating layer which is magnetized at a pitch ranging from 1 mm to 5 mm.
Claim 3
Dependent Claim
24 words
A device as claimed in claim 1, wherein said magnetic field generating layer has a flux density ranging from 10 tesla to 50 tesla.
Claim 4
Dependent Claim
15 words
A device as claimed in claim 1, wherein said regulating means comprises a magnetic member.
Claim 5
Dependent Claim
25 words
A device as claimed in claim 1, wherein said toner comprises one of single component type magnetic toner and single component type high resistance toner.
Claim 6
Dependent Claim
16 words
A device as claimed in claim 1, wherein said second conveying means comprises a dielectric layer.
Claim 7
Dependent Claim
39 words
A device as claimed in claim 1, further comprising bias applying means for applying a bias between said first and second conveying means whereby the charged toner is transferred from said first conveying means to said second conveying means.
Claim 8
Dependent Claim
125 words
A developing device for an image forming apparatus and for developing a latent image electrostatically formed on an image carrier by toner, said device comprising: first conveying means for conveying the toner deposited thereon; regulating means for regulating an amount of the toner to be conveyed by said first conveying means while charging said toner by friction; second conveying means for receiving the charged toner from said first conveying means; and bias applying means for applying a bias between said first and second conveying means whereby the charged toner is transferred from said first conveying means to said second conveying means; wherein said first conveying means comprises a magnetic field generating layer which is magnetized at a pitch ranging from 1 mm to 5 mm.
Claim 9
Dependent Claim
125 words
A developing device for an image forming apparatus and for developing a latent image electrostatically formed on an image carrier by toner, said device comprising: first conveying means for conveying the toner deposited thereon; regulating means for regulating an amount of the toner to be conveyed by said first conveying means while charging said toner by friction; second conveying means for receiving the charged toner from said first conveying means; and bias applying means for applying a bias between said first and second conveying means whereby the charged toner is transferred from said first conveying means to said second conveying means; wherein said first conveying means comprises a magnetic field generating layer which is magnetized at a pitch ranging from 1 mm to 5 mm.
Claim 10
Dependent Claim
97 words
A developing device for an image forming apparatus and for developing a latent image electrostatically formed on an image carrier by toner, said device comprising: a first roller for conveying the toner deposited thereon; a member for regulating an amount of the toner to be conveyed by said first roller while charging said toner by friction; and a second roller contacting said first roller, and for receiving the charged toner from said first roller; wherein said first roller comprises a magnetic field generating layer which is magnetized at a pitch ranging from 1 mm to 5 mm.
Claim 11
Dependent Claim
97 words
A developing device for an image forming apparatus and for developing a latent image electrostatically formed on an image carrier by toner, said device comprising: a first roller for conveying the toner deposited thereon; a member for regulating an amount of the toner to be conveyed by said first roller while charging said toner by friction; and a second roller contacting said first roller, and for receiving the charged toner from said first roller; wherein said first roller comprises a magnetic field generating layer which is magnetized at a pitch ranging from 1 mm to 5 mm.
Claim 12
Dependent Claim
119 words
A developing device for an image forming apparatus and for developing a latent image electrostatically formed on an image carrier by toner, said device comprising: a first roller for conveying the toner deposited thereon; a member for regulating an amount of the toner to be conveyed by said first roller while charging said toner by friction; a second roller for receiving the charged toner from said first roller; and a bias device for applying a bias between said first and second rollers whereby the charged toner is transferred from said first roller to said second roller; wherein said first roller comprises a magnetic field generating layer which is magnetized at a pitch ranging from 1 mm to 5 mm.
Claim 13
Dependent Claim
119 words
A developing device for an image forming apparatus and for developing a latent image electrostatically formed on an image carrier by toner, said device comprising: a first roller for conveying the toner deposited thereon; a member for regulating an amount of the toner to be conveyed by said first roller while charging said toner by friction; a second roller for receiving the charged toner from said first roller; and a bias device for applying a bias between said first and second rollers whereby the charged toner is transferred from said first roller to said second roller; wherein said first roller comprises a magnetic field generating layer which is magnetized at a pitch ranging from 1 mm to 5 mm.
References Cited (Backward Citations)
US5532804A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-04-28 | 2000-10-28 | 2001-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-04-28 | 2004-10-28 | 2005-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-04-28 | 2008-10-28 | 2009-04-29 | $7700.00 | Window Closed / Lapsed |