Patent US4139299A successfully refreshed from Google Patents.
US4139299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Auto-bias developing apparatus
Assignee: Ricoh Co Ltd
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Filing: 1976-03-30
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Granted: 1979-02-13
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Expires: 1996-03-30
Abstract
Abstract The process and device are for use in an electrophotographic copying machine using a developing agent of liquid type. A counter-electrode is maintained closely spaced from the peripheral surface of a photosensitive drum bearing an electrostatic latent image thereon and itself electrically floating. The developing solution, which inherently has a substantial conductivity is supplied into the space between the drum surface and the counter-electrode so as to develop the latent image. During the development of latent image, a weak d.c. current flow, is passed between the counter-electrode and the drum through the segment of the developing solution filling the space so that a good relation between potentials on the drum surface and the counter-electrode is obtained to eliminate background smearing. The d.c. current may be controlled to decrease in value as the induced potential on the counter-electrode increases.
Inventors
- 👤 Seiichi Miyakawa
- 👤 Susumu Tatsumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:18
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/065
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
174 words
An auto-bias developing device for use in an electrophotographic apparatus having means including a photosensitive layer for forming an electrostatic latent image, and a d.c. discharger having an electrode spaced from said layer, said device comprising: a developing electrode closely spaced from the outer surface of said layer and adapted so there can be induced thereon, by the counter-electrode effect, a potential proportional to the average surface potential on said layer; means for supplying a developing solution into the space between said layer and said developing electrode so as to develop a latent image on said layer; and means for supplying current to said developing electrode, said current supplying means including a conductive plate member disposed opposite the electrode of said d.c. discharger, a voltage regulating element connecting said plate member to ground, means connecting a junction, between said plate member and said voltage regulating element, to said developing electrode, a grid interposed between said electrode of said d.c. discharger and said plate member, and means for supplying a control voltage to said grid.
Claim 2
Dependent Claim
174 words
An auto-bias developing device for use in an electrophotographic apparatus having means including a photosensitive layer for forming an electrostatic latent image, and a d.c. discharger having an electrode spaced from said layer, said device comprising: a developing electrode closely spaced from the outer surface of said layer and adapted so there can be induced thereon, by the counter-electrode effect, a potential proportional to the average surface potential on said layer; means for supplying a developing solution into the space between said layer and said developing electrode so as to develop a latent image on said layer; and means for supplying current to said developing electrode, said current supplying means including a conductive plate member disposed opposite the electrode of said d.c. discharger, a voltage regulating element connecting said plate member to ground, means connecting a junction, between said plate member and said voltage regulating element, to said developing electrode, a grid interposed between said electrode of said d.c. discharger and said plate member, and means for supplying a control voltage to said grid.
Claim 3
Dependent Claim
56 words
A device according to claim 1, for use in an electrophotographic apparatus which further includes an a.c. discharger having an electrode, said control voltage supplying means including a conductive second plate member disposed opposite the electrode of said a.c. discharger, and circuit means including a voltage rectifying element connecting said second plate member and said grid.
Claim 4
Dependent Claim
21 words
A device according to claim 1, further including circuit means connected across said grid for regulating the control voltage supplied thereto.
References Cited (Backward Citations)
US3576623A
Cited
US3782818A
Cited
US3892481A
Cited
US3944356A
Cited
US3980049A
Cited
US3981267A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-12 | 1982-08-14 | 1983-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-12 | 1986-08-14 | 1987-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-12 | 1990-08-14 | 1991-02-13 | $7700.00 | Window Closed / Lapsed |