US4701042A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Duplicating apparatus
Assignee: Olympus Corp
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Filing: 1985-12-02
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Granted: 1987-10-20
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Expires: 2005-12-02
Abstract
Abstract A duplicating apparatus including a charge retentive drum arranged rotatably, an electrostatic latent image forming device, a non-contact type developing device, a transferring device for transferring a toner image onto a record paper and a fixing device for fixing the toner image onto the record paper. A correction electrode is provided between the developing device and transferring device and an AC bias voltage is applied to the correction electrode to generate a vibrating electric field. Image quality of the duplicated copies can be improved by passing the toner image through the vibrating electric field.
Inventors
- 👤 Yoshiyuki Mimura
- 👤 Yasuo Isono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:51
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/065; G03G15/08; G03G15/095
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
144 words
A duplicating apparatus comprising: a rotatably mounted charge retentive member; forming means for forming an electrostatic latent image on the charge retentive member; developing means for developing the electrostatic latent image with toner particles of a dry developer to form a toner image; correction means comprising a correction electrode arranged opposite to the charge retentive member with a predetermined gap therebetween and an AC bias voltage source connected to the correction electrode to form a vibrating electric field in the gap between the charge retentive member and the correction electrode, for redistributing the toner particles within the image by alternate attraction and repulsion of the toner particles by the correction electrode responsive to said toner image being passed through said vibrating electric field; and means for transferring onto a image receiving member the toner image that has been passed through the vibrating electric field.
Claim 2
Dependent Claim
144 words
A duplicating apparatus comprising: a rotatably mounted charge retentive member; forming means for forming an electrostatic latent image on the charge retentive member; developing means for developing the electrostatic latent image with toner particles of a dry developer to form a toner image; correction means comprising a correction electrode arranged opposite to the charge retentive member with a predetermined gap therebetween and an AC bias voltage source connected to the correction electrode to form a vibrating electric field in the gap between the charge retentive member and the correction electrode, for redistributing the toner particles within the image by alternate attraction and repulsion of the toner particles by the correction electrode responsive to said toner image being passed through said vibrating electric field; and means for transferring onto a image receiving member the toner image that has been passed through the vibrating electric field.
Claim 3
Dependent Claim
42 words
An apparatus according to claim 1, wherein said developing means comprises a non-contact type developing device including a developing roller on which a toner layer is applied, the toner layer being separated from the charge retentive member by a small air gap.
Claim 4
Dependent Claim
21 words
An apparatus according to claim 2, wherein said developing means further comprises a bias voltage source connected to the developing roller.
Claim 5
Dependent Claim
34 words
An apparatus according to claim 2, wherein a plurality of copies are formed from one and the same electrostatic latent image once formed on the charge retentive member by repeating development and transfer successively.
Claim 6
Dependent Claim
15 words
An apparatus according to claim 1, wherein said correction electrode comprises a rotatable conductive roller.
Claim 7
Dependent Claim
20 words
An apparatus according to claim 5, wherein said correction electrode further comprises an insulating film applied on the conductive roller.
Claim 8
Dependent Claim
19 words
An apparatus according to claim 5, further comprising a scraper having one edge in contact with the conductive roller.
Claim 9
Dependent Claim
17 words
An apparatus according to claim 1, wherein said charge retentive member is formed as a rotatable drum.
Claim 10
Dependent Claim
29 words
An apparatus according to claim 1, wherein said bias voltage source for the correction electrode comprises a voltage source for generating an AC voltage having a sinusoidal wave form.
Claim 11
Dependent Claim
33 words
An apparatus according to claim 1, wherein said means for applying the bias voltage to the correction electrode comprises an AC voltage source for generating an AC voltage having a rectangular wave form.
Claim 12
Dependent Claim
37 words
An apparatus according to claim 1, wherein said bias voltage source for the correction electrode comprises a generator for generating an AC voltage superimposed with a DC voltage having a polarity opposite to that of the toners.
Claim 13
Dependent Claim
28 words
An apparatus according to claim 1, wherein said correction electrode is spaced from the charge retentive member by a distance of from about 0.5 to about 3 mm.
Claim 14
Dependent Claim
25 words
An apparatus according to claim 1, wherein said correction electrode comprises a conductive plate positioned in fixed relationship with respect to the charge retentive member.
Claim 15
Dependent Claim
79 words
An apparatus according to claim 1 wherein the developing means includes a rotatably mounted developing roller, coating means for coating a dry developer including toner particles on the surface of the developing roller and bias means for establishing a bias on the developing roller with respect to said charge retentive member such that the toner particles transfer to develop the electrostatic latent image, said developing roller being positioned relative to the charge retentive member with a predetermined gap therebetween.
Claim 16
Dependent Claim
64 words
An apparatus according to claim 1 wherein the vibrating electric field has a peak-to-peak value of from about 1000 to about 5000 volts and a frequency of from about 500 to about 2000 Hz superimposed on a D.C. voltage up to about -2000 volts for a latent image of negative polarity and up to about +2000 volts for a latent image of positive polarity.
Claim 17
Dependent Claim
22 words
An apparatus according to claim 1 wherein the redistributing of toner particles includes removing toner particles from non-pictorial areas of the image.
Claim 18
Dependent Claim
25 words
An apparatus according to claim 1 wherein the redistributing of toner particles includes moving toner particles within the image from non-pictorial areas to pictorial areas.
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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) | 1990-10-19 | 1991-04-20 | 1991-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-19 | 1995-04-20 | 1995-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-19 | 1999-04-20 | 1999-10-20 | $7700.00 | Window Closed / Lapsed |