EP0805378A2
Expired / Lapsed
EP
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Charging apparatus and electrophotographic apparatus
Assignee: Canon Inc
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Filing: 1997-04-30
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Granted: —
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Expires: 2017-04-30
Abstract
Abstract A charging apparatus is disclosed which has an object member and a charging member. The charging member is comprised of magnetic particles, provided in contact with the object member and capable of electrostatically charging the object member upon application of a voltage. The surfaces of the magnetic particles are formed of a composite comprising conductive particles and a binder resin, and the conductive particles are in a proportion of from 80% by weight to 99% by weight in total weight based on the weight of the composite. Also, an electrophotographic apparatus having the charging member is disclosed. <IMAGE>
Inventors
- 👤 Harumi Ishiyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 15:39
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0208; G03G15/0241; G03G2215/00; G03G2215/02; G03G2215/021; G03G2215/022
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
80 words
A charging apparatus comprising an object member and a charging member comprised of magnetic particles, provided in contact with the object member and capable of electrostatically charging the object member upon application of a voltage; the surfaces of said magnetic particles being formed of a composite comprising conductive particles and a binder resin, and the conductive particles being in a proportion of from 80% by weight to 99% by weight in total weight based on the weight of the composite.
Claim 2
Dependent Claim
28 words
The charging apparatus according to claim 1, wherein said magnetic particles have a resistance value of from 1 x 10 5 Ω·cm to 1 x 10 8 Ω·cm.
Claim 3
Dependent Claim
18 words
The charging apparatus according to claim 1, wherein said magnetic particles have a sphericity of 2 or less.
Claim 4
Dependent Claim
22 words
The charging apparatus according to claim 1, wherein said conductive particles have particle size distribution having at least two peaks or shoulders.
Claim 5
Dependent Claim
46 words
The charging apparatus according to claim 4, wherein particle diameter r1 at the peak or shoulder on the smaller particle diameter side and particle diameter r2 at the peak or shoulder on the larger particle diameter side satisfy the following expression. 1.2 ≤ (r2/r1) ≤ 5.0
Claim 6
Dependent Claim
28 words
The charging apparatus according to claim 1, wherein said conductive particles have a resistance value of from 1 x 10 -2 Ω·cm to 1 x 10 8 Ω·cm.
Claim 7
Dependent Claim
15 words
The charging apparatus according to claim 1, wherein said magnetic particles are formed by polymerization.
Claim 8
Dependent Claim
16 words
The charging apparatus according to claim 1, wherein said object member is an electrophotographic photosensitive member.
Claim 9
Dependent Claim
21 words
The charging apparatus according to claim 8, wherein said electrophotographic photosensitive member has a charge injection layer as a surface layer.
Claim 10
Dependent Claim
29 words
The charging apparatus according to claim 9, wherein said charge injection layer has a resistance value of from 1 x 10 9 Ω·cm to 1 x 10 14 Ω·cm.
Claim 11
Dependent Claim
24 words
The charging apparatus according to claim 1, wherein said conductive particles are formed from a metal, an alloy or a metal oxide, having magnetism.
Claim 12
Dependent Claim
22 words
The charging apparatus according to claim 11, wherein said conductive particles have particle size distribution having at least two peaks, or shoulders.
Claim 13
Dependent Claim
15 words
The charging apparatus according to claim 12, wherein said binder resin is a thermosetting resin.
Claim 14
Dependent Claim
92 words
An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging member comprised of magnetic particles, provided in contact with the electrophotographic photosensitive member and capable of electrostatically charging the electrophotographic photosensitive member upon application of a voltage, an exposure means, a developing means, and a transfer means; the surfaces of said magnetic particles being formed of a composite comprising conductive particles and a binder resin, and the conductive particles being in a proportion of from 80% by weight to 99% by weight in total weight based on the weight of the composite.
Claim 15
Dependent Claim
28 words
The electrophotographic apparatus according to claim 14, wherein said magnetic particles have a resistance value of from 1 x 10 5 Ω·cm to 1 x 10 8 Ω·cm.
Claim 16
Dependent Claim
18 words
The electrophotographic apparatus according to claim 14, wherein said magnetic particles have a sphericity of 2 or less.
Claim 17
Dependent Claim
22 words
The electrophotographic apparatus according to claim 14, wherein said conductive particles have particle size distribution having at least two peaks or shoulders.
Claim 18
Dependent Claim
46 words
The electrophotographic apparatus according to claim 17, wherein particle diameter r1 at the peak or shoulder on the smaller particle diameter side and particle diameter r2 at the peak or shoulder on the larger particle diameter side satisfy the following expression. 1.2 ≤ (r2/r1) ≤ 5.0
Claim 19
Dependent Claim
28 words
The electrophotographic apparatus according to claim 14, wherein said conductive particles have a resistance value of from 1 x 10 -2 Ω·cm to 1 x 10 8 Ω·cm.
Claim 20
Dependent Claim
15 words
The electrophotographic apparatus according to claim 14, wherein said magnetic particles are formed by polymerization.
Claim 21
Dependent Claim
21 words
The electrophotographic apparatus according to claim 14, wherein said electrophotographic photosensitive member has a charge injection layer as a surface layer.
Claim 22
Dependent Claim
29 words
The electrophotographic apparatus according to claim 21, wherein said charge injection layer has a resistance value of from 1 x 10 9 Ω·cm to 1 x 10 14 Ω·cm.
Claim 23
Dependent Claim
24 words
The electrophotographic apparatus according to claim 14, wherein said conductive particles are formed from a metal, an alloy or a metal oxide, having magnetism.
Claim 24
Dependent Claim
22 words
The electrophotographic apparatus according to claim 23, wherein said conductive particles have particle size distribution having at least two peaks or shoulders.
Claim 25
Dependent Claim
15 words
The electrophotographic apparatus according to claim 24, wherein said binder resin is a thermosetting resin.
Claim 26
Dependent Claim
16 words
The electrophotographic apparatus according to claim 14, wherein said developing means is substantially a cleaning means.
References Cited (Backward Citations)
No citation records indexed.
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