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 04:14
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)
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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) | 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 |