Patent US3603851A successfully refreshed from Google Patents.
US3603851A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of contour charging
Assignee: Australian Government
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Filing: 1969-10-31
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Granted: 1971-09-07
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Expires: 1989-10-31
Abstract
Abstract The invention relates to a method of charging electrophotographic coatings wherein successive areas of coating are progressively presented to a charging electrode, the characterizing feature being the interposing of masking means between the charging electrode and the surface to be charged to extend generally transversely to the direction of motion and fixed generally in relation to the charging electrode so that the charging duration of different parts of the area being charged is varied in proportion to the charge intensity at that area. Thus charging intensity is balanced in relation to the distance from the charging electrode. The invention also relates to control of the part of the corona used.
Inventors
- 👤 Kenneth A Metcalfe
- 👤 Ian E Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:58
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0291; H; H05; H05F; H05F3/00; H05F3/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
83 words
A method of charging an electrophotographic coating, comprising advancing a coating relative to a charging electrode to expose the coating progressively to the charging electrode, interposing a fixed masking device between the charging electrode and the surface to be charged to extend generally transversely to the relative direction of advancement, and forming a window in the masking device widening laterally outwards to vary the charging duration of different parts of the area being charged in proportion to the charge intensity at that area.
Claim 2
Independent Claim
83 words
A method of charging an electrophotographic coating, comprising advancing a coating relative to a charging electrode to expose the coating progressively to the charging electrode, interposing a fixed masking device between the charging electrode and the surface to be charged to extend generally transversely to the relative direction of advancement, and forming a window in the masking device widening laterally outwards to vary the charging duration of different parts of the area being charged in proportion to the charge intensity at that area.
Claim 3
Dependent Claim
48 words
The method of charging according to claim 1, comprising forming the charging electrode as a point and forming the window as a slit increasing in width as the distance from the point increases, whereby areas more remote from the point receive similar incremental charge value as nearer areas.
Claim 4
Dependent Claim
32 words
The method according to claim 1, comprising forming the charging electrode as a point and positioning the charging electrode offset from said window and above a solid portion of the masking device.
Claim 5
Dependent Claim
31 words
The method according to claim 1, comprising forming the charging electrode as a wire extending generally in the direction of relative advancement between the charging electrode and the surface being charged.
Claim 6
Dependent Claim
123 words
Apparatus for charging an electrophotographic coating, said apparatus comprising, a base electrode, a charging electrode remote from the base electrode to form a charging zone therebetween, means to apply a charging potential between the charging electrode and the base electrode, means to provide relative movement of the coating through said charging zone, and masking means between the said charging electrode and the path of relative movement of the coating, said masking means being arranged generally transversely to the direction of relative movement of the said coating and having a shaped slit widening laterally outwards to increase the charging duration outwardly from said charging electrode during such traverse in proportion to the decrease of the intensity of the charge with distance from said electrode.
Claim 7
Dependent Claim
123 words
Apparatus for charging an electrophotographic coating, said apparatus comprising, a base electrode, a charging electrode remote from the base electrode to form a charging zone therebetween, means to apply a charging potential between the charging electrode and the base electrode, means to provide relative movement of the coating through said charging zone, and masking means between the said charging electrode and the path of relative movement of the coating, said masking means being arranged generally transversely to the direction of relative movement of the said coating and having a shaped slit widening laterally outwards to increase the charging duration outwardly from said charging electrode during such traverse in proportion to the decrease of the intensity of the charge with distance from said electrode.
Claim 8
Dependent Claim
26 words
Apparatus according to claim 5, wherein said charging electrode is a point offset from said slit and located above a solid portion of said masking means.
Claim 9
Dependent Claim
27 words
Apparatus according to claim 5, wherein said charging electrode is a wire extending generally in the direction of relative motion of said surface and across said slit.
References Cited (Backward Citations)
US2925496A
Cited
US3146687A
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US3146385A
Cited
US3160746A
Cited
US3476935A
Cited
US3335322A
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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) | 1974-09-06 | 1975-03-08 | 1975-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-06 | 1979-03-08 | 1979-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-06 | 1983-03-08 | 1983-09-07 | $7700.00 | Window Closed / Lapsed |