Patent US2776502A successfully refreshed from Google Patents.
US4368971A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developing device
Assignee: Canon Inc
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Filing: 1981-10-02
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Granted: 1983-01-18
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Expires: 2001-10-02
Abstract
Abstract In a dry type developing device having a magnetic field producing means, nonmagnetic developer supporting means, means for moving said magnetic field producing means and said nonmagnetic developer supporting means relative to each other, and means for supplying developer to that side of the nonmagnetic developer supporting means which is opposite to the magnetic field producing means, the surface of the nonmagnetic developer supporting means which is adjacent to the developer supply means is provided with plating containing grains therein.
Inventors
- 👤 Tsuyoshi Watanabe
- 👤 Kimio Nakahata
- 👤 Fumitaka Kan
- 👤 Masaaki Sakurai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:04
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0921; G03G15/0928; G03G2215/00; G03G2215/06; G03G2215/0634; G03G2215/0636
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
81 words
A developing device for forming a developed image on an image bearing member, said device comprising: developer supporting means formed of a nonmagnetic material and having a surface for receipt and conveyance of developer thereon; magnetic field producing means surrounded by said developer supporting means; and means for supplying developer to said developer supporting means, wherein the developer conveying surface of said developer supporting means is positioned adjacent to said developer supply means and is provided with plating containing grains therein.
Claim 2
Dependent Claim
81 words
A developing device for forming a developed image on an image bearing member, said device comprising: developer supporting means formed of a nonmagnetic material and having a surface for receipt and conveyance of developer thereon; magnetic field producing means surrounded by said developer supporting means; and means for supplying developer to said developer supporting means, wherein the developer conveying surface of said developer supporting means is positioned adjacent to said developer supply means and is provided with plating containing grains therein.
Claim 3
Dependent Claim
42 words
A developing device according to claim 1, wherein surface roughness of the surface of said developer supporting means after said plating treatment is such that its pitch is 5μ-100μ, its depth of valleys is 0.05μ-8μ, and its width of valleys is 0.05μ-24μ.
Claim 4
Dependent Claim
22 words
A developing device according to claim 1, wherein said developer supporting means after the plating treatment is subjected to a heat treatment.
Claim 5
Dependent Claim
25 words
A developing device according to any of claims 1 to 3, wherein the Vickers' hardness of the surface of said developer supporting means is Hv=500-1500.
Claim 6
Dependent Claim
16 words
A developing device according to claim 1, wherein the particle diameter of said grains is D=0.1-350μ.
Claim 7
Dependent Claim
31 words
A developing device according to claim 1 or 5, wherein said grains are Al 2 O 3 , Fe 2 O 3 , TiO 3 or TiC or a mixture thereof.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-01-17 | 1986-07-19 | 1987-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-17 | 1990-07-19 | 1991-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-17 | 1994-07-19 | 1995-01-18 | $7700.00 | Window Closed / Lapsed |