US4737816A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image transfer device
Assignee: Canon Inc
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Filing: 1985-12-03
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Granted: 1988-04-12
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Expires: 2005-12-03
Abstract
Abstract An image transfer device includes a member for carrying a transfer material thereon and an image bearing member having an image thereon, the transfer material carrying member being subjected to a transfer corona therethrough to transfer the image from the image bearing member onto the transfer material. When the transfer material is separated from the transfer material carrying member by a separation pawl, that portion of the transfer material carrying member from a position in which the transfer material is in close contact with the carrying member to another position in which the transfer material is separated from the carrying member by the separation pawl is charged by a pair of corona chargers with the transfer material carrying member being located therebetween, so that the transfer material can more readily be separated from the carrying member.
Inventors
- 👤 Takahiro Inoue
- 👤 Takao Aoki
- 👤 Yuusaku Takada
- 👤 Masahiro Gotou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:47
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/65; G03G15/6532; G03G15/14; G03G15/16; G03G15/163; G03G15/1635; G03G15/165; G03G15/1655
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
229 words
An image transfer device comprising: an image bearing member; transfer means for transferring an unfixed toner image from said image bearing member onto transfer material and including a transfer charger for applying a charge to the toner image; a transfer material carrying member for carrying said transfer material to said transfer means; separation means for separating said transfer material bearing an unfixed toner image from said transfer material carrying member; a first corona discharger for applying corona charge having a component of polarity opposite to that of the toner image to the unfixed toner image throughout a range between a position at which the transfer material is in contact with said transfer material carrying member and a position at which said transfer material is separated from said transfer material carrying member by the action of said separation means; and a second corona discharger for applying charge having a component of polarity opposite to the polarity applied by said first corona discharger to that side of said transfer material carrying member opposite to the side thereof carrying the transfer material and throughout said range; wherein said first and second corona dischargers are variable in output independently of each other, and whereby the separation of the transfer material from said transfer material carrying member takes place while the unfixed toner image is acted upon by said first and second corona dischargers.
Claim 2
Dependent Claim
229 words
An image transfer device comprising: an image bearing member; transfer means for transferring an unfixed toner image from said image bearing member onto transfer material and including a transfer charger for applying a charge to the toner image; a transfer material carrying member for carrying said transfer material to said transfer means; separation means for separating said transfer material bearing an unfixed toner image from said transfer material carrying member; a first corona discharger for applying corona charge having a component of polarity opposite to that of the toner image to the unfixed toner image throughout a range between a position at which the transfer material is in contact with said transfer material carrying member and a position at which said transfer material is separated from said transfer material carrying member by the action of said separation means; and a second corona discharger for applying charge having a component of polarity opposite to the polarity applied by said first corona discharger to that side of said transfer material carrying member opposite to the side thereof carrying the transfer material and throughout said range; wherein said first and second corona dischargers are variable in output independently of each other, and whereby the separation of the transfer material from said transfer material carrying member takes place while the unfixed toner image is acted upon by said first and second corona dischargers.
Claim 3
Dependent Claim
23 words
An image transfer device as defined in claim 1 wherein said transfer material carrying member is in the form of a perforated screen.
Claim 4
Dependent Claim
211 words
An image transfer device comprising: an image bearing member; transfer means for transferring an unfixed toner image from said image bearing member onto transfer material and including a transfer charger for applying a charge to the toner image; a transfer material carrying member for carrying said transfer material to said transfer means; separation means for separating said transfer material bearing an unfixed toner image from said transfer material carrying member; a first corona discharger for applying corona charge having a component of polarity opposite to that of the toner image to the unfixed toner image throughout a range between a position at which the transfer material is in contact with said carrying member and a position at which said transfer material is separated from said transfer material carrying member by the action of said separation means; and a second corona discharger for applying charge having a component of polarity opposite to the polarity applied by said first corona discharger to that side of said transfer material carrying member opposite to the side thereof carrying the transfer material and throughout said range; whereby the separation of the transfer material from said transfer material carrying member takes place while the unfixed toner image is acted upon by said first and second corona dischargers.
Claim 5
Dependent Claim
211 words
An image transfer device comprising: an image bearing member; transfer means for transferring an unfixed toner image from said image bearing member onto transfer material and including a transfer charger for applying a charge to the toner image; a transfer material carrying member for carrying said transfer material to said transfer means; separation means for separating said transfer material bearing an unfixed toner image from said transfer material carrying member; a first corona discharger for applying corona charge having a component of polarity opposite to that of the toner image to the unfixed toner image throughout a range between a position at which the transfer material is in contact with said carrying member and a position at which said transfer material is separated from said transfer material carrying member by the action of said separation means; and a second corona discharger for applying charge having a component of polarity opposite to the polarity applied by said first corona discharger to that side of said transfer material carrying member opposite to the side thereof carrying the transfer material and throughout said range; whereby the separation of the transfer material from said transfer material carrying member takes place while the unfixed toner image is acted upon by said first and second corona dischargers.
Claim 6
Dependent Claim
21 words
An image transfer device as defined in claim 3 wherein said separation means is in the form of a separation pawl.
Claim 7
Dependent Claim
24 words
An image transfer device as defined in claim 3 wherein each of said corona dischargers is in the form of an AC corona discharger.
Claim 8
Dependent Claim
26 words
An image transfer device as defined in claim 5 wherein the respective alternating currents used in said AC corona dischargers are out of phase by 180°.
Claim 9
Dependent Claim
50 words
An image transfer device as defined in claim 3 wherein one of said corona dischargers is energized by a direct current having the same polarity as said transfer means while the other corona discharger is energized by another direct current having a polarity opposite to that of said transfer means.
Claim 10
Dependent Claim
70 words
An image transfer device as defined in claim 3 wherein one of said corona dischargers is energized by a direct current having the same polarity as said transfer means and an alternating current superposed with said direct current while the other corona discharger is energized by a second direct current having a polarity opposite to that of said transfer means and an alternaitng current superposed with the second direct current.
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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) | 1991-04-12 | 1991-10-12 | 1992-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-12 | 1995-10-12 | 1996-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-12 | 1999-10-12 | 2000-04-12 | $7700.00 | Window Closed / Lapsed |