US3920992A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming developable electrostatic charge patterns and devices therefor
Assignee: Agfa Gevaert NV
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Filing: 1973-11-30
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Granted: 1975-11-18
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Expires: 1993-11-30
Abstract
Abstract A method of recording information as a pattern of electrostatic charges carried by an insulating charge receiving medium which comprises: EXPOSING TO A PATTERN OF X- or gamma -rays an imaging chamber containing an ionizable gas having an atomic number of at least 36 and adapted to produce therein upon such exposure electrostatic charges in a corresponding pattern, while maintaining said gas during said exposure under superatmospheric pressure; ELECTRICALLY BIASING THE CHARGES IN SAID PATTERN TOWARD AN ARRAY OF DISCRETE CLOSELY SPACED PHOTOCONDUCTORS DISPOSED ALONG ONE SIDE OF SAID CHAMBER GENERALLY NORMAL TO THE EXPOSURE DIRECTION WITHIN A FRANGIBLE INSULATING MATRIX; SAID CONDUCTORS EXTENDING FROM THE INTERIOR TO ONE EXTERIOR OF SAID CHAMBER WALL AND THUS AT THEIR EXTERNAL ENDS DURING SUCH EXPOSURE ACQUIRING A DIFFERENTIALLY CHARGED CONDITION ACCORDING TO SAID PATTERN; ARRANGING IN AT LEAST CLOSE PROXIMITY TO THE EXTERIOR ENDS OF SAID ARRAY AN INSULATING CHARGE RECEIVING MATERIAL, SAID MATERIAL DEVELOPING A DIFFERENTIALLY CHARGED CONDITION ACCORDING TO SAID PATTERN UNDER THE INFLUENCE OF THE DIFFERENTIALLY CHARGED CONDITION OF THE EXTERIOR CONDUCTOR ENDS; AND WHILE SAID CHAMBER IS MAINTAINED UNDER SAID SUPER-ATMOSPHERIC CONDITION, MECHANICALLY BIASING SAID CHARGE-RECEIVING MATERIAL OVER AN AREA AT LEAST COEXTENSIVE WITH SAID MATRIX AGAINST THE EXTERIOR SIDE OF SAID MATRIX WITH A FORCE OPPOSING THE GAS PRESSURE EXERTED AGAINST THE INNER SIDE OF SAID MATRIX.
Inventors
- 👤 Den Bogaert Jan Van
- 👤 Willy Joseph Palmans
- 👤 Den Eynde Karel Alfons Van
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:27
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/054; G03G15/0545
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
224 words
A method of recording information as a pattern of electrostatic charges carried by an insulating charge receiving medium which comprises: a. exposing to a pattern of X- or gamma -rays an imaging chamber containing an ionizable gas having an atomic number of at least 36 and adapted to produce therein upon such exposure electrostatic charges in a corresponding pattern, while maintaining said gas during said exposure under superatmospheric pressure; b. electrically biasing the charges in said pattern toward an array of discrete closely spaced photoconductors disposed along one side of said chamber generally normal to the exposure direction within a frangible insulating matrix, said conductors extending from the interior to the exterior of said chamber wall and thus acquiring at their external ends during such exposure a differentially charged condition according to said pattern; c. arranging in at least close proximity to the exterior ends of said array an insulating charge receiving material, said material developing a differentially charged condition according to said pattern under the influence of the differentially charged condition of the exterior conductor ends; and d. while said chamber is maintained under said superatmospheric condition, mechanically biasing said charge-receiving material over an area at least coextensive with said matrix against the exterior side of said matrix with a force opposing the gas pressure exerted against the inner side of said matrix.
Claim 2
Independent Claim
224 words
A method of recording information as a pattern of electrostatic charges carried by an insulating charge receiving medium which comprises: a. exposing to a pattern of X- or gamma -rays an imaging chamber containing an ionizable gas having an atomic number of at least 36 and adapted to produce therein upon such exposure electrostatic charges in a corresponding pattern, while maintaining said gas during said exposure under superatmospheric pressure; b. electrically biasing the charges in said pattern toward an array of discrete closely spaced photoconductors disposed along one side of said chamber generally normal to the exposure direction within a frangible insulating matrix, said conductors extending from the interior to the exterior of said chamber wall and thus acquiring at their external ends during such exposure a differentially charged condition according to said pattern; c. arranging in at least close proximity to the exterior ends of said array an insulating charge receiving material, said material developing a differentially charged condition according to said pattern under the influence of the differentially charged condition of the exterior conductor ends; and d. while said chamber is maintained under said superatmospheric condition, mechanically biasing said charge-receiving material over an area at least coextensive with said matrix against the exterior side of said matrix with a force opposing the gas pressure exerted against the inner side of said matrix.
Claim 3
Dependent Claim
36 words
The method of claim 1 including the steps of removing said mechanical bias from said receiving material after completion of said exposure to permit removal of said material and concurrently reducing the pressure in said chamber.
Claim 4
Dependent Claim
18 words
means for intermittently pressurizing said enclosed space with a gaseous medium at superatmospheric pressure and releasing said pressure,
Claim 5
Dependent Claim
18 words
means for intermittently pressurizing said enclosed space with a gaseous medium at superatmospheric pressure and releasing said pressure,
Claim 6
Dependent Claim
11 words
electrode means in said enclosed space spaced from said conductor array,
Claim 7
Dependent Claim
11 words
electrode means in said enclosed space spaced from said conductor array,
Claim 8
Dependent Claim
26 words
The method of claim 2 wherein the pressure in said chamber is increased and decreased and said mechanical biasing force applied and removed in substantial synchronism.
Claim 9
Dependent Claim
32 words
The method of claim 2 including the step of advancing said receiving material to bring a fresh area thereof into proximity to said conductor array while said mechanican bias is removed therefrom.
Claim 10
Dependent Claim
15 words
means in said enclosed space for emitting electrical charges upon exposure thereof to ionizing radiation,
Claim 11
Dependent Claim
15 words
means in said enclosed space for emitting electrical charges upon exposure thereof to ionizing radiation,
Claim 12
Dependent Claim
21 words
means for exposing said imaging chamber to a pattern of ionizing radiation whereby a pattern of electrical charges is produced therein,
Claim 13
Dependent Claim
21 words
means for exposing said imaging chamber to a pattern of ionizing radiation whereby a pattern of electrical charges is produced therein,
Claim 14
Dependent Claim
30 words
The method of claim 2 wherein said chamber is sealed generally pressure-tight and said pressure therein is reduced without disturbing said seal wherein loss of said ionizing gas is minimized.
Claim 15
Dependent Claim
46 words
A method according to claim 1, wherein the chamber contains said gas in contact with an electrode and said electrode through a DC-potential source is connected to another electrode that makes contact during exposure with the charge receiving material at the side opposite to said conductors.
Claim 16
Dependent Claim
23 words
electrode means arranged exteriorly of said one wall in closely spaced parallel relation to said conductor array and generally coextensive with said array,
Claim 17
Dependent Claim
23 words
electrode means arranged exteriorly of said one wall in closely spaced parallel relation to said conductor array and generally coextensive with said array,
Claim 18
Dependent Claim
32 words
an insulating charge receiving material disposed between the exterior side of said conductor array and said exterior electrode means in intimate contact with the exterior ends of the conductors in said array,
Claim 19
Dependent Claim
32 words
an insulating charge receiving material disposed between the exterior side of said conductor array and said exterior electrode means in intimate contact with the exterior ends of the conductors in said array,
Claim 20
Dependent Claim
48 words
A method according to claim 6, wherein the chamber contains xenon gas and the arithmetic product of pressure and thickness of the interspace between the electrode in the chamber and the interior ends of the conductors is in the range of 10 mm atmospheres and 200 mm atmospheres.
Claim 21
Dependent Claim
33 words
A method according to claim 1, wherein the pattern of charges is generated by imagewise irradiating the ionizable gas in the chamber from the side opposite to the exterior ends of said conductors.
Claim 22
Dependent Claim
54 words
means for applying an electrical potential between said electrode means to attract the charges of said pattern to the interior ends of said conductors thereby producing a differentially charged condition in accordance with said exposure pattern at the exterior ends of said conductors and upon the insulating charge receiving material in contact therewith, and
Claim 23
Dependent Claim
54 words
means for applying an electrical potential between said electrode means to attract the charges of said pattern to the interior ends of said conductors thereby producing a differentially charged condition in accordance with said exposure pattern at the exterior ends of said conductors and upon the insulating charge receiving material in contact therewith, and
Claim 24
Dependent Claim
44 words
means for mechanically supporting said exterior electrode means and for applying between said exterior electrode means and said conductor array with said insulating receiving means pressed therebetween a mechanical force opposite to the action of the pressure in said enclosed space on said array.
Claim 25
Dependent Claim
44 words
means for mechanically supporting said exterior electrode means and for applying between said exterior electrode means and said conductor array with said insulating receiving means pressed therebetween a mechanical force opposite to the action of the pressure in said enclosed space on said array.
Claim 26
Dependent Claim
28 words
A method according to claim 1, wherein the pattern of charges is generated by imagewise irradiating the ionizable gas in the chamber with radiation penetrating through said conductors.
Claim 27
Dependent Claim
38 words
A method according to claim 6, wherein the interior ends of said conductors are coated with a photocathode material and prior to the generation of the charges the insulating surface of the receiving material is uniformly negatively charged.
Claim 28
Dependent Claim
39 words
A method according to claim 1, wherein the charge pattern on the receiving material is produced by means of a line-wise arranged single row of conductors and the image-wise exposure of the ionizable gas in the chamber proceeds line-wise.
Claim 29
Dependent Claim
15 words
A method according to claim 1, wherein the receiving material is a transparent film material.
Claim 30
Dependent Claim
22 words
A method according to claim 1, wherein the electrostatic charge pattern obtained on the receiving material is developed with electrostatically attractable material.
Claim 31
Dependent Claim
18 words
An ionographic imaging system for producing an electrostatic charge pattern on an insulating charge receiving material which comprises:
Claim 32
Dependent Claim
18 words
An ionographic imaging system for producing an electrostatic charge pattern on an insulating charge receiving material which comprises:
Claim 33
Dependent Claim
23 words
The system of claim 14, wherein said mechanical force is applied intermittently in substantial synchronism with the intermittent pressurization of said enclosed space.
Claim 34
Dependent Claim
24 words
The system of claim 15 including means for increasing the pressure in said space and the mechanical opposing force at substantially the same rate.
Claim 35
Dependent Claim
48 words
The system of claim 14 wherein said exterior electrode means and said imaging chamber are mounted for relative bodily movement towards and away from one another and including means for biasing the same together to apply said mechanical force between said exterior electrode means and said conductor array.
Claim 36
Dependent Claim
15 words
An imaging system according to claim 14, wherein the internal electrode means is a photocathode.
Claim 37
Dependent Claim
15 words
An imaging system according to claim 18, wherein the photocathode is directly sensitive to X-rays.
Claim 38
Dependent Claim
22 words
An imaging system according to claim 14, wherein the enclosed space contains a gas having an atomic number of at least 36.
Claim 39
Dependent Claim
48 words
An imaging system according to claim 20, wherein the enclosed space contains xenon gas and the product of pressure and thickness of the interspace between the internal electrode means and the input ends of the conductors is in the range of 10 mm atmospheres and 200 mm atmospheres.
Claim 40
Dependent Claim
27 words
An imaging system according to claim 21, wherein the pressure inside the enclosed space is in the range of about 5 to about 10 kg per sq.cm.
Claim 41
Dependent Claim
25 words
An imaging system according to claim 14, wherein the input ends of the conductors are covered with photocathode material that is directly sensitive to X-rays.
Claim 42
Dependent Claim
44 words
An imaging system according to claim 14, wherein the imaging chamber is mounted on a piston that can be moved to and fro and is provided with means that can keep the pressure at both sides of the wall containing said conductors substantially equal.
Claim 43
Dependent Claim
45 words
An imaging system according to claim 24, including at the side opposite to the piston a cover with sealing ring which cover can be filled with gas or liquid building up a counterpressure against said electrode means with respect to the pressure inside the chamber.
Claim 44
Dependent Claim
52 words
An imaging system according to claim 14, wherein the chamber is mounted in a supporting frame and said electrode is backed with a pressure cushion comprising (1) a flexible membrane and (2) a rigid plate opposite to that membrane, and means for introducing a liquid or gas under pressure in said cushion.
Claim 45
Dependent Claim
21 words
An imaging system according to claim 14, wherein the conductors are made of a low atomic number metal or metal alloy.
Claim 46
Dependent Claim
16 words
An imaging system according to claim 27, wherein the conductors are made of aluminium or beryllium.
Claim 47
Dependent Claim
18 words
An imaging system according to claim 14, wherein the conductors are made of a high atomic number metal.
Claim 48
Dependent Claim
14 words
An imaging system according to claim 14, wherein the conductors form a single row.
Claim 49
Dependent Claim
31 words
An imaging system according to claim 14, wherein the solid conductors are disposed in glass as insulating material and form a pin matrix element that forms part of the chamber wall.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |