Patent US5559593A successfully refreshed from Google Patents.
US5559593A
Expired / Lapsed
US
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Cleaning device for an image forming apparatus
Assignee: Ricoh Co Ltd
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Filing: 1995-05-15
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Granted: 1996-09-24
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Expires: 2015-05-15
Abstract
Abstract In an image forming apparatus of the type using spherical toner or toner whose mean volume grain size is 7 mu m or less, a cleaning device has at least one cleaning roller facing, but not contacting, a photoconductive element. An electric field for causing the toner to fly from the photoconductive element to the roller is formed between the element and the roller. An alternating field, DC or AC-biased DC bias voltage is applied to the roller. Particularly, a voltage having a rectangular waveform is applied to the roller.
Inventors
- 👤 Hiroshi Yoshinaga
- 👤 Akira Sawada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:03
CPC Classifications
G; G03; G03G; G03G21/00; G03G21/0005; G03G21/0058; G03G21/0047
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
73 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: a plurality of cleaning members spaced apart from a surface of the image carrier by a predetermined gap; and bias applying means for applying a bias voltage of particular polarity to each of said plurality of cleaning members.
Claim 2
Dependent Claim
73 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: a plurality of cleaning members spaced apart from a surface of the image carrier by a predetermined gap; and bias applying means for applying a bias voltage of particular polarity to each of said plurality of cleaning members.
Claim 3
Dependent Claim
19 words
A device as claimed in claim 1, further comprising a screen member intervening between said plurality of cleaning members.
Claim 4
Dependent Claim
27 words
A device as claimed in claim 2, wherein said screen member is made of a dielectric material having a volume resistivity of 10 7 Ωcm or above.
Claim 5
Dependent Claim
38 words
A device as claimed in claim 2, wherein said screen member is made of a dielectric material and spaced apart from the surface of the image carrier by a distance which does not cause dielectric breakdown to occur.
Claim 6
Dependent Claim
87 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: cleaning means spaced apart from a surface of the image carrier by a predetermined gap; electric field forming means for forming between said cleaning means and the image carrier an electric field for causing the toner to fly from said image carrier toward said cleaning means; and said toner comprising spherical toner.
Claim 7
Dependent Claim
87 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: cleaning means spaced apart from a surface of the image carrier by a predetermined gap; electric field forming means for forming between said cleaning means and the image carrier an electric field for causing the toner to fly from said image carrier toward said cleaning means; and said toner comprising spherical toner.
Claim 8
Dependent Claim
95 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: cleaning means spaced apart from a surface of the image carrier by a predetermined gap; electric field forming means for forming between said cleaning means and the image carrier an electric field for causing the toner to fly from said image carrier toward said cleaning means; and said toner having a mean volume grain size of 7 μm or less.
Claim 9
Dependent Claim
95 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: cleaning means spaced apart from a surface of the image carrier by a predetermined gap; electric field forming means for forming between said cleaning means and the image carrier an electric field for causing the toner to fly from said image carrier toward said cleaning means; and said toner having a mean volume grain size of 7 μm or less.
Claim 10
Dependent Claim
101 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: cleaning means spaced apart from a surface of the image carrier by a predetermined gap; electric field forming means for forming between said cleaning means and the image carrier an electric field for causing the toner to fly from said image carrier toward said cleaning means; and said cleaning means having a rotatable roller, said roller having a volume resistivity of 1×10 3 Ωcm or less.
Claim 11
Dependent Claim
101 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: cleaning means spaced apart from a surface of the image carrier by a predetermined gap; electric field forming means for forming between said cleaning means and the image carrier an electric field for causing the toner to fly from said image carrier toward said cleaning means; and said cleaning means having a rotatable roller, said roller having a volume resistivity of 1×10 3 Ωcm or less.
Claim 12
Dependent Claim
134 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: cleaning means spaced apart from a surface of the image carrier by a predetermined gap; electric field forming means for forming between said cleaning means and the image carrier an electric field for causing the toner to fly from said image carrier toward said cleaning means; and the electric field formed by said electric field forming means being an alternating field, said alternating field having a DC offset having a peak-to-peak voltage in a direction for causing the toner to fly from the image carrier and lying in a range of from 2×10 6 V/m to 8×10 6 V/m.
Claim 13
Dependent Claim
134 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: cleaning means spaced apart from a surface of the image carrier by a predetermined gap; electric field forming means for forming between said cleaning means and the image carrier an electric field for causing the toner to fly from said image carrier toward said cleaning means; and the electric field formed by said electric field forming means being an alternating field, said alternating field having a DC offset having a peak-to-peak voltage in a direction for causing the toner to fly from the image carrier and lying in a range of from 2×10 6 V/m to 8×10 6 V/m.
Claim 14
Dependent Claim
108 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: cleaning means spaced apart from a surface of the image carrier by a predetermined gap; electric field forming means for forming between said cleaning means and the image carrier an electric field for causing the toner to fly from said image carrier toward said cleaning means; and the electric field formed by said electric field forming means being an alternating field having an amplitude ranging from 2×10 6 V/m to 2×10 7 V/m.
Claim 15
Dependent Claim
108 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: cleaning means spaced apart from a surface of the image carrier by a predetermined gap; electric field forming means for forming between said cleaning means and the image carrier an electric field for causing the toner to fly from said image carrier toward said cleaning means; and the electric field formed by said electric field forming means being an alternating field having an amplitude ranging from 2×10 6 V/m to 2×10 7 V/m.
Claim 16
Dependent Claim
100 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: cleaning means spaced apart from a surface of the image carrier by a predetermined gap; electric field forming means for forming between said cleaning means and the image carrier an electric field for causing the toner to fly from said image carrier toward said cleaning means; and the electric field formed by said electric field forming means being an alternating field having a rectangular waveform.
Claim 17
Dependent Claim
100 words
A cleaning device for an image forming apparatus and for removing toner left on an image carrier after a toner image has been transferred from said image carrier to a transfer medium, said device comprising: cleaning means spaced apart from a surface of the image carrier by a predetermined gap; electric field forming means for forming between said cleaning means and the image carrier an electric field for causing the toner to fly from said image carrier toward said cleaning means; and the electric field formed by said electric field forming means being an alternating field having a rectangular waveform.
Claim 18
Dependent Claim
20 words
A device as claimed in claim 10, wherein the alternating field has a duty ratio ranging from 1 to 5.
References Cited (Backward Citations)
JPS5540405A
Cited
JPS5555376A
Cited
JPS56126880A
Cited
JPS6267577A
Cited
JPS62203183A
Cited
US4769676A
Cited
JPS6348587A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-09-24 | 2000-03-25 | 2000-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-24 | 2004-03-25 | 2004-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-24 | 2008-03-25 | 2008-09-24 | $7700.00 | Window Closed / Lapsed |