US4335420A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Corona discharge device
Assignee: Ricoh Co Ltd
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Filing: 1979-07-10
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Granted: 1982-06-15
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Expires: 1999-07-10
Abstract
Abstract The invention relates to a corona discharge device of the scorotron system which is used for electrophotographic copying machines. According to the device the invention, an impedance element 11 is connected between grid wires 6 and the ground, and generates a voltage depending upon a corona current which flows from a corona discharge wire 8 to the grid wires 6. Here, one end of the impedance element is connected to an electrically conductive shielding plate 3. The impedance element is formed in the discharger as a unitary structure, and only one connector is required for the corona discharge wire. Hence, the positioning operation is facilitated and poor electrical connection is avoided.
Inventors
- 👤 Tanaka Mitsuo
- 👤 Tagawa Kazuaki
- 👤 Yano Takashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:17
CPC Classifications
H; H01; H01T; H01T19/00; G; G03; G03G; G03G15/00; G03G15/02; G03G15/0291
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
78 words
A corona discharge device comprising a discharger having a wire for corona discharging, an electrically conductive shielding plate and grid wires; and an impedance element which is connected in series between said grid wires and the ground and which generates a voltage responsive to a corona current flowing into said grid wires; wherein said impedance element is connected between said grid wires and said electrically conductive shielding plate and is formed as a unitary structure with said discharger.
Claim 2
Dependent Claim
78 words
A corona discharge device comprising a discharger having a wire for corona discharging, an electrically conductive shielding plate and grid wires; and an impedance element which is connected in series between said grid wires and the ground and which generates a voltage responsive to a corona current flowing into said grid wires; wherein said impedance element is connected between said grid wires and said electrically conductive shielding plate and is formed as a unitary structure with said discharger.
Claim 3
Dependent Claim
15 words
A corona discharge device according to claim 1, wherein said impedance element is made variable.
Claim 4
Dependent Claim
22 words
A corona discharge device according to claim 1, wherein a plurality of impedance elements are provided and are selected by a switch.
Claim 5
Dependent Claim
18 words
A corona discharge device according to claim 1, wherein a constant-voltage element is used as said impedance element.
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) | 1985-06-14 | 1985-12-14 | 1986-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-14 | 1989-12-14 | 1990-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-14 | 1993-12-14 | 1994-06-15 | $7700.00 | Window Closed / Lapsed |