Patent US4674860A successfully refreshed from Google Patents.
US4674860A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image transfer device
Assignee: Konica Minolta Inc
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Filing: 1985-08-16
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Granted: 1987-06-23
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Expires: 2005-08-16
Abstract
Abstract An image transfer device which transfers a charged toner carried on an image carrier onto a copying material comprises a transfer drum having a conductive base and an insulating surface, the transfer drum being arranged opposite to the image carrier. An electrical charge is applied to the copying material in advance of the copying material arriving at the insulating surface of the transfer drum. An electrical charge is also provided on the surface of the transfer drum in advance of the copying material arriving at the insulating surface of the transfer drum for attracting the copying material to the surface of the transfer drum and to maintain the attraction by the charges during a copying operation. In place of providing a specified charge on the surface of the transfer drum, a bias voltage can be applied to the conductive base of the transfer drum to provide the attraction force for improving attraction of the copying material to the surface of the transfer drum and to maintain the attraction during a copying operation.
Inventors
- 👤 Hiroshi Tokunaga
- 👤 Shinobu Soma
- 👤 Naoki Aoki
- 👤 Tatsufumi Kusuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:26
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/14; G03G15/16; G03G15/1665; G03G15/167; G03G15/1695; G03G2215/00; G03G2215/01; G03G2215/0167; G03G2215/0174; G03G2215/16; G03G2215/1604; G03G2215/1619; G03G2215/1647; G03G2215/1657
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
129 words
An image transfer device which transfers a charged toner carried on an image carrier onto a copying material, said image transfer device comprising: a transfer drum which comprises a conductive base and an insulating surface, said transfer drum being arranged opposite to said image carrier; a first charge-providing means for providing an electric charge to said copying material in advance of said copying material arriving at said insulating surface of said transfer drum; and a second charge-providing means for providing a specified charge on the surface of said transfer drum in advance of said copying material arriving at said insulating surface of said transfer drum for attracting said copying material to said surface of said transfer drum and to maintain said attraction by said charges during a copying operation.
Claim 2
Dependent Claim
129 words
An image transfer device which transfers a charged toner carried on an image carrier onto a copying material, said image transfer device comprising: a transfer drum which comprises a conductive base and an insulating surface, said transfer drum being arranged opposite to said image carrier; a first charge-providing means for providing an electric charge to said copying material in advance of said copying material arriving at said insulating surface of said transfer drum; and a second charge-providing means for providing a specified charge on the surface of said transfer drum in advance of said copying material arriving at said insulating surface of said transfer drum for attracting said copying material to said surface of said transfer drum and to maintain said attraction by said charges during a copying operation.
Claim 3
Dependent Claim
48 words
The image transfer device of claim 1, wherein said transfer drum comprises a conductive elastic layer provided on said conductive base, and an insulating layer provided on the surface of said conductive elastic layer, the outer surface of said insulating layer comprising said insulating surface of said drum.
Claim 4
Dependent Claim
49 words
The image transfer device of claim 1, wherein: said first charge-providing means comprises means for providing a charge of the opposite polarity to that of said charged toner; and said second charge-providing means comprises means for providing a charge of the same polarity as that of said charged toner.
Claim 5
Dependent Claim
39 words
The image transfer device of claim 3, wherein said first charge-providing means includes means for providing said charge of said opposite polarity to said copying material from the reverse side of said copying material which faces said transfer drum.
Claim 6
Dependent Claim
49 words
The image transfer device of claim 1, wherein: said first charge-providing means comprises means for providing a charge of the same polarity as that of said charged toner; and said second charge-providing means comprises means for providing a charge of the opposite polarity to that of said charged toner.
Claim 7
Dependent Claim
39 words
The image transfer device of claim 5, wherein said first charge-providing means includes means for providing said charge of said same polarity to said copying material from the reverse side of said copying material which faces said transfer drum.
Claim 8
Dependent Claim
48 words
The image transfer device of claim 1, wherein: said conductive base of said transfer drum is grounded; and said second charge-providing means comprises means for providing a charge of an opposite polarity to that of the charge of said charged toner to the surface of said transfer drum.
Claim 9
Dependent Claim
48 words
The image transfer device of claim 1, wherein: said conductive base of said transfer drum is grounded; and said second charge-providing means comprises means for providing a charge of the same polarity as that of the charge of said charged toner to the surface of said transfer drum.
Claim 10
Dependent Claim
25 words
The image transfer device of claim 1, wherein said electric charge is provided to said copying material from a side thereof facing said transfer drum.
Claim 11
Dependent Claim
123 words
An image transfer device which transfers a charged toner carried on an image carrier onto a copying material, said image transfer device comprising: a transfer drum which comprises a conductive base and an insulating surface, said transfer drum being arranged opposite to said image carrier; a first charge-providing means for providing an electric charge to said copying material in advance of said copying material arriving at said insulating surface of said transfer drum; and a bias voltage applying-means for applying a bias voltage to said conductive base of said transfer drum for attracting said copying material to said surface of said transfer drum and to maintain said attraction of said copying material to said surface of said transfer drum during a copying operation.
Claim 12
Dependent Claim
123 words
An image transfer device which transfers a charged toner carried on an image carrier onto a copying material, said image transfer device comprising: a transfer drum which comprises a conductive base and an insulating surface, said transfer drum being arranged opposite to said image carrier; a first charge-providing means for providing an electric charge to said copying material in advance of said copying material arriving at said insulating surface of said transfer drum; and a bias voltage applying-means for applying a bias voltage to said conductive base of said transfer drum for attracting said copying material to said surface of said transfer drum and to maintain said attraction of said copying material to said surface of said transfer drum during a copying operation.
Claim 13
Dependent Claim
48 words
The image transfer device of claim 10, wherein said transfer drum comprises a conductive elastic layer provided on said conductive base, and an insulating layer provided on the surface of said conductive elastic layer, the outer surface of said insulating layer comprising said insulating surface of said drum.
Claim 14
Dependent Claim
50 words
The image transfer device of claim 10, wherein: said first charge-providing means comprises means for providing a charge of the opposite polarity to that of said charged toner; and said bias voltage-applying means comprises means for applying a bias voltage of the same polarity as that of said charged toner.
Claim 15
Dependent Claim
39 words
The image transfer device of claim 12, wherein said first charge-providing means includes means for providing said charge of said opposite polarity to said copying material from the reverse side of said copying material which faces said transfer drum.
Claim 16
Dependent Claim
49 words
The image transfer device of claim 10, wherein: said first charge-providing means comprises means for providing a charge of the same polarity as that of said charged toner; and said bias voltage-applying means comprises means applying a bias voltage of the opposite polarity to that of said charged toner.
Claim 17
Dependent Claim
39 words
The image transfer device of claim 14, wherein said first charge-providing means includes means for providing said charge of said same polarity to said copying material from the reverse side of said copying material which faces said transfer drum.
Claim 18
Dependent Claim
40 words
The image transfer device of claim 10, wherein said bias voltage-applying mean comprises means for applying said bias voltage of an opposite polarity to that of the charge of said charged toner to said conductive base of said transfer drum.
Claim 19
Dependent Claim
40 words
The image transfer device of claim 10, wherein said bias voltage-applying means comprises means for applying said bias voltage of the same polarity as that of the charge of said charged toner to said conductive base of said transfer drum.
Claim 20
Dependent Claim
47 words
The image transfer device of claim 10, wherein said bias voltage-applying means comprises means for changeably applying said bias voltage, of either the same polarity as or an opposite polarity to that of the charge of said charged toner, to said conductive base of said transfer drum.
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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) | 1990-06-22 | 1990-12-22 | 1991-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-22 | 1994-12-22 | 1995-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-22 | 1998-12-22 | 1999-06-23 | $7700.00 | Window Closed / Lapsed |