US3978492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the electrographic recording of charge images in a low electron affinity case
Assignee: Agfa Gevaert AG
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Filing: 1975-02-13
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Granted: 1976-08-31
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Expires: 1995-02-13
Abstract
Abstract Process for the electrophotographic recording of charge images on insulating recording material, wherein a gas discharge and the imagewise control of the discharge current which is used for charging the recording material take place in the presence of one or more gases which have an electron affinity of less than 1 eV.
Inventors
- 👤 Walter Simm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:08
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/05; G03G15/22; G03G15/32; G03G15/321; G03G15/323
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
151 words
The electrographic recording process of producing charge images on a recording material capable of being electrically charged by establishing a gas discharge current stream applying a voltage between a corona discharge electrode and a counter electrode, and controlling the density of the charge of the recording material by selectively applying a control potential to control electrodes interposed between said corona discharge electrode and said counter electrode, whereby part of the discharge current stream is changed in its intensity by means of said control electrodes, moving the recording material past the control electrodes and over the counter electrode, wherein the improvement comprises carrying on the gas discharge and control of the discharge partial current while positioning the corona discharge electrode, counter electrode and control electrode in a gas stream consisting of a gas having an electron affinity of less than 1 eV whereby this gas is ionized to selectively charge the record.
Claim 2
Dependent Claim
151 words
The electrographic recording process of producing charge images on a recording material capable of being electrically charged by establishing a gas discharge current stream applying a voltage between a corona discharge electrode and a counter electrode, and controlling the density of the charge of the recording material by selectively applying a control potential to control electrodes interposed between said corona discharge electrode and said counter electrode, whereby part of the discharge current stream is changed in its intensity by means of said control electrodes, moving the recording material past the control electrodes and over the counter electrode, wherein the improvement comprises carrying on the gas discharge and control of the discharge partial current while positioning the corona discharge electrode, counter electrode and control electrode in a gas stream consisting of a gas having an electron affinity of less than 1 eV whereby this gas is ionized to selectively charge the record.
Claim 3
Dependent Claim
66 words
A process as claimed in claim 1, in which the gas discharge current stream is produced on a needle electrode which is arranged free standing in a housing of insulating material which separates the volume between the needle electrode and the control electrodes from the external atmosphere and through which the gas stream of gas with an electron affinity of less than 1 eV is passed.
Claim 4
Dependent Claim
22 words
A process as claimed in claim 2 in which the distance between the needle electrode and the control electrode is 10 cm.
Claim 5
Dependent Claim
44 words
A process as claimed in claim 2 in which the discharge partial current is controlled by a strip of photoconductive material which is arranged along the lip of the gap of one of the two control electrodes, on the side facing the needle electrode.
Claim 6
Dependent Claim
41 words
A process as claimed in claim 2 in which the gas is admitted into the housing through an opening near the needle electrode and escapes through a gap between the control electrodes provided for the passage of the discharge partial current.
Claim 7
Dependent Claim
24 words
A process as claimed in claim 5 in which the gap between the control electrodes has a width of between 0.1 and 0.5 mm.
Claim 8
Dependent Claim
17 words
A process as claimed in claim 6 in which the gap has a width of 0.2 mm.
Claim 9
Dependent Claim
42 words
A process as claimed in claim 5, in which the recording material is passed over the counter electrode during the charging process in such a way that it forms a fold parallel to the centre of the gap between the counter electrode.
Claim 10
Dependent Claim
33 words
A process as claimed in claim 8 in which the fold in the recording material is situated at a distance of between 0.5 and 2.0 mm from the gap between the control electrodes.
Claim 11
Dependent Claim
20 words
A process as claimed in claim 9 in which the distance between the fold and the gap is 0.5 mm.
Claim 12
Dependent Claim
96 words
A process as claimed in claim 1 in which the electrodes used for controlling the discharge partial current consist of foils of insulating material covered with conductive coatings on both sides and defining gap therebetween, the conductive coating of one of the two control electrodes which form the gap being subdivided on the side facing the needle electrode into strips extending substantially perpendicularly to the gap which are insulated from each other and which end at the lip of the gap between the control electrodes and along which the electric signals are coveyed to the gap.
Claim 13
Dependent Claim
37 words
A process as claimed in claim 11 in which the discharge partial current is controlled by means of a control voltage applied to the conductive strips on the side of the control electrode facing the needle electrode.
Claim 14
Dependent Claim
23 words
A process as claimed in claim 11 in which the control electrode has a total thickness of between 0.05 mm and 1 mm.
Claim 15
Dependent Claim
19 words
A process as claimed in claim 13 in which the total thickness of the control electrode is 0.2 mm.
References Cited (Backward Citations)
US3141170A
Cited
US3161544A
Cited
US3370546A
Cited
US3495269A
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US3623123A
Cited
US3750190A
Cited
US3735416A
Cited
US3742516A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-31 | 1980-03-01 | 1980-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-31 | 1984-03-01 | 1984-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-31 | 1988-03-01 | 1988-08-31 | $7700.00 | Window Closed / Lapsed |