US5081501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image forming apparatus having transfer electrode
Assignee: Canon Inc
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Filing: 1991-05-29
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Granted: 1992-01-14
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Expires: 2011-05-29
Abstract
Abstract The present invention provides an image forming apparatus having a shiftable image bearing member; an image forming device for forming an image on the image bearing member; and a transfer device for transferring the image formed on the image bearing member onto a transfer sheet at a transfer station, the transfer device urging the transfer sheet against the image bearing member and having a transfer electrode to which a voltage is applied; and wherein a resistance value between a surface of the transfer electrode facing the image bearing member and a portion of the transfer electrode at which the voltage is applied is greater at an upstream side of a shifting direction of the image bearing member than at a downstream side thereof, on the surface of the transfer electrode, whereby an image can be obtained without any transfer void.
Inventors
- 👤 Kenichiro Waki
- 👤 Takeo Tsunemi
- 👤 Akira Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:32
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/14; G03G15/16; G03G15/1665; G03G15/167; G03G15/1685; G03G2215/00; G03G2215/01; G03G2215/16; G03G2215/1604; G03G2215/1628
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
126 words
An image forming apparatus comprising: a shiftable image bearing member; an image forming means for forming an image on said image bearing member; and a transfer means for transferring the image formed on said image bearing member onto a transfer sheet at a transfer station, said transfer means urging the transfer sheet against said image bearing member and having a transfer electrode to which a voltage is applied; and wherein a resistance value between a surface of said transfer electrode facing said image bearing member and a portion of said transfer electrode at which the voltage is applied is greater at an upstream side of a shift direction of said image bearing member than at a downstream side thereof, on the surface of said transfer electrode.
Claim 2
Dependent Claim
126 words
An image forming apparatus comprising: a shiftable image bearing member; an image forming means for forming an image on said image bearing member; and a transfer means for transferring the image formed on said image bearing member onto a transfer sheet at a transfer station, said transfer means urging the transfer sheet against said image bearing member and having a transfer electrode to which a voltage is applied; and wherein a resistance value between a surface of said transfer electrode facing said image bearing member and a portion of said transfer electrode at which the voltage is applied is greater at an upstream side of a shift direction of said image bearing member than at a downstream side thereof, on the surface of said transfer electrode.
Claim 3
Dependent Claim
30 words
An image forming apparatus according to claim 1, further including a shiftable transfer sheet bearing means for holding the transfer sheet at said transfer station to perform the transferring operation.
Claim 4
Dependent Claim
18 words
An image forming apparatus according to claim 2, wherein said transfer sheet bearing means comprises a dielectric sheet.
Claim 5
Dependent Claim
53 words
An image forming apparatus according to claim 2, wherein the transfer sheet held by said transfer sheet bearing means is conveyed to said transfer station several times by said transfer sheet bearing means, whereby a plurality of images on the image bearing member are successively transferred onto the transfer sheet in superimposed fashion.
Claim 6
Dependent Claim
23 words
An image forming apparatus according to claim 4, wherein a full-color image can be formed after the successive transferring operations in superimposed fashion.
Claim 7
Dependent Claim
35 words
An image forming apparatus according to claim 2, wherein said transfer electrode can be contacted with a surface of said transfer sheet bearing means opposite to a surface thereof facing to said image bearing member.
Claim 8
Dependent Claim
59 words
An image forming apparatus according to claim 6, wherein a length of contact between said transfer electrode and said transfer sheet bearing means in the shifting direction of said image bearing member is greater than a length of contact between said image bearing member and said transfer sheet bearing means in the shifting direction of said image bearing member.
Claim 9
Dependent Claim
37 words
An image forming apparatus according to claim 1, wherein said transfer electrode has volume resistivity which is greater at the upstream side of the shifting direction of said image bearing member than at the downstream side thereof.
Claim 10
Dependent Claim
16 words
An image forming apparatus according to claim 1, wherein said transfer electrode has a sheetshaped configuration.
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) | 1995-01-13 | 1995-07-15 | 1996-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-13 | 1999-07-15 | 2000-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-13 | 2003-07-15 | 2004-01-14 | $7700.00 | Window Closed / Lapsed |