US5701568A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image forming apparatus having dielectric constant relationship between image bearing member, intermediate transfer member and contact transfer device
Assignee: Canon Inc
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Filing: 1996-08-30
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Granted: 1997-12-23
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Expires: 2016-08-30
Abstract
Abstract An image forming apparatus includes a first image-bearing member such as an electrophotographic photosensitive member, an intermediate transfer member for receiving a transferable image formed on the first image-bearing member, and contact transfer device for transferring the transferable image from the intermediate transfer member to a transfer material. The first image-bearing member has a surface layer having a dielectric constant ε d , the intermediate transfer member has a surface layer having a dielectric constant ε ITD and the contact transfer device has a surface layer having a dielectric constant ε tr satisfying a relationship of; ε d ≦ε ITD ≦ε tr . The intermediate transfer member exhibits a volume resistivity of 10 6 -10 10 ohm.cm (at an applied voltage of 1 kV), and the contact transfer device exhibits a volume resistivity of 10 8 -10 15 ohm.cm (at an applied voltage of 1 kV). As a result, it is possible to obtain high transfer efficiencies in both primary and secondary transfer over a wide transfer bias application range.
Inventors
- 👤 Koichi Hiroshima
- 👤 Katsuhiko Nishimura
- 👤 Toru Kosaka
- 👤 Yasuo Yoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:05
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/14; G03G15/01; G03G15/0105; G03G15/0131; G03G15/16; G03G15/1605; G03G15/162; G03G2215/00; G03G2215/01; G03G2215/0167; G03G2215/0174; G03G2215/0177
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
141 words
An image forming apparatus, comprising a first image-bearing member, an intermediate transfer member for receiving a transferable image formed on the first image-bearing member, and contact transfer means for transferring the transferable image from the intermediate transfer member to a transfer material; wherein the first image-bearing member has a surface layer having a dielectric constant ε d , the intermediate transfer member has a surface layer having a dielectric constant ε ITD and the contact transfer means has a surface layer having a dielectric constant ε tr satisfying a relationship of; ε d ≦ε ITD ≦ε tr , the intermediate transfer member exhibits a volume resistivity of 10 6 -10 10 ohm.cm (at an applied voltage of 1 kV), and the contact transfer means exhibits a volume resistivity of 10 8 -10 15 ohm.cm (at an applied voltage of 1 kV).
Claim 2
Dependent Claim
141 words
An image forming apparatus, comprising a first image-bearing member, an intermediate transfer member for receiving a transferable image formed on the first image-bearing member, and contact transfer means for transferring the transferable image from the intermediate transfer member to a transfer material; wherein the first image-bearing member has a surface layer having a dielectric constant ε d , the intermediate transfer member has a surface layer having a dielectric constant ε ITD and the contact transfer means has a surface layer having a dielectric constant ε tr satisfying a relationship of; ε d ≦ε ITD ≦ε tr , the intermediate transfer member exhibits a volume resistivity of 10 6 -10 10 ohm.cm (at an applied voltage of 1 kV), and the contact transfer means exhibits a volume resistivity of 10 8 -10 15 ohm.cm (at an applied voltage of 1 kV).
Claim 3
Dependent Claim
56 words
An apparatus according to claim 1, wherein the first image-bearing member and the intermediate transfer member are adapted for successive transfer of plural colors of transferable images from the first image-bearing member to the intermediate transfer member, and simultaneous transfer of the plural colors of transferable images from the intermediate transfer member to the transfer material.
Claim 4
Dependent Claim
18 words
An apparatus according to claim 1, wherein the intermediate transfer member is in the form of a roller.
Claim 5
Dependent Claim
25 words
An apparatus according to claim 1, wherein the surface layer of the intermediate transfer member is a release layer and disposed on an elastic layer.
Claim 6
Dependent Claim
24 words
An apparatus according to claim 1, adapted for using a substantially spherical non-magnetic developer having shape factors SF1 of 100-120 and SF2 of 100-120.
Claim 7
Dependent Claim
22 words
An apparatus according to claim 1, adapted for using a magnetic developer having shape factors SF1 of 140-150 and SF2 of 120-130.
Claim 8
Dependent Claim
22 words
An apparatus according to claim 1, wherein the first image-bearing member is coated with an overcoating layer having a low dielectric constant.
Claim 9
Dependent Claim
18 words
An apparatus according to claim 7, wherein the overcoating layer has a dielectric constant of at most 3.
Claim 10
Dependent Claim
26 words
An apparatus according to claim 1, wherein ε d , ε ITD and ε tr satisfying a relationship of ε d <ε ITD ≦ε Tr .
Claim 11
Dependent Claim
30 words
An apparatus according to claim 9, wherein ε d , ε ITD and ε tr satisfying relationships of ε d +1 ≦ε ITD and ε ITD +1 ≦ε tr .
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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) | 2000-12-22 | 2001-06-23 | 2001-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-22 | 2005-06-23 | 2005-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-12-22 | 2009-06-23 | 2009-12-23 | $7700.00 | Window Closed / Lapsed |