US3920992A - Process for forming developable electrostatic charge patterns and devices therefor - Google Patents

Process for forming developable electrostatic charge patterns and devices therefor Download PDF

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US3920992A
US3920992A US420560A US42056073A US3920992A US 3920992 A US3920992 A US 3920992A US 420560 A US420560 A US 420560A US 42056073 A US42056073 A US 42056073A US 3920992 A US3920992 A US 3920992A
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chamber
pattern
conductors
pressure
exterior
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Den Bogaert Jan Van
Willy Joseph Palmans
Den Eynde Karel Alfons Van
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Agfa Gevaert NV
Agfa Gevaert AG
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Agfa Gevaert AG
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/054—Apparatus for electrographic processes using a charge pattern using X-rays, e.g. electroradiography
    • G03G15/0545—Ionography, i.e. X-rays induced liquid or gas discharge

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  • 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 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;
  • a polyester foil is used as a charge receiving insulating sheet. At the sides the polyester sheet is pressed on sealing strips in order to keep the interspace filled with the ionizable gas. Each electrostatic image is obtained on a separate insulating sheet and is toner-developed on that sheet. Such procedure requires for each print the refilling of the interspace with ionizable gas before the production of a new print canstart.
  • a further object of the present invention is toprovide devices for achieving the above object.
  • information is recorded in terms of an electrostatic charge pattern formed of emitted charged particles generated in the interior of an airtight envelope, containing an ionizable gas, by a method characterized in that an electron or positive ion emission pattern created by an image-wise electrical discharge in thegas is projected in the same pattern onto an area of the inner side of the envelope which contains an array of closely spaced solid conductors separated by a solid electrically insulating material and extending from the interior to the exterior of the envelope such conductors receiving the pattern of electrons or positive ions thus formed and consequently undergoing a change in the charge condition at their exterior ends, and during or after the creation of the electrical discharge in said gas the exterior side of the envelope which contains the exterior ends of these conductors is held in contact or in close proximity with an insulating surface of a charge receiving material backed in its rearside with an electrode to which is applied a voltage such that an electrostatic charge pattern is formed on the insulating surface.
  • the charged particles produced by the electrical discharge in the ionizable gas are electron
  • the part of the emission pattern consisting of electrons is called the electron image.
  • the part of the emission pattern consisting of positive ions is called the ion image.
  • the transfer of electrons from the conductors to the receiving material or vice versa can be improved by applying an electron accelerating DC potential difference across or between the means generating the charged particles image and the rear side of the charge receiving material.
  • FIG. 1 is a cross-sectional representation of a recording system structure of the present invention
  • FIGS. 2 to 6 are cross-sectional representations of alternative imaging systems.
  • the reproducing system according to the invention in the form illustrated schematically in FIG. 1 is suitable for X-ray recording and operates with an ionizable gas under atmospheric pressure or slight overor underpressure e.g. of 1 to 10 Torr.
  • the envelope 1 is filled with an ionizable gas or gas mixture in admixture with a discharge quenching substance e.g. ethanol as described e.g. in the German Patent Specification l,497,093.
  • the filling gas is advantageously kept under an overpressure above atmospheric pressure of a few Torr, e.g. 10 Torr.
  • a useful gas mixture consists e.g. of argon and monobromotrifluoromethane (CF Br) in the volume ratio 1:5.
  • CF Br monobromotrifluoromethane
  • the applied D.C. voltage is preferably not more than 5% above the breakdown voltage of the gas.
  • the photocathode 2 is of the type described in the German Patent Specification 1,497,093 e.g. is a 1.5 micron layer of lead or a 1.0 micron layer of uranium applied on an aluminium sheet 8. During the informationwise X-ray exposure of the photocathode 2 a DC- potential difference is applied by means of the potential source between the photocathode and backing electrode 6.
  • the distance between the photocathode 2 and the input-ends of an array of conductive pins 3 embedded in an insulating matrix is preferably in the range of 0.3 to 5 mm.
  • the potential difference between the photocathode 2 and the electrode 6 contacting the conductive rear side 4 of the insulating web material 5 defines an accelerating field acting upon the electrons and determines together with the separation the kind of ionizable gas and its pressure the degree of the electron multiplication (if any) that is possible by secondary emission (i.e. an avalanching effect).
  • the photocathode 2 is provided with a screen 7 having minute holes for preventing the divergence of the electrons and improving image sharpness.
  • the height of the screen 7 and the cross-section of each individual microchannel of the screen determine the image sharpness.
  • the ratio of cross-section diameter to the height of the individual microchannels is preferably at least 1:4.
  • the clearance between the output openings of the screen and of the input ends of the conductive wires 3 is preferably not larger than 1.5 mm.
  • the minute holes of the screen 7 may have a diameter of e.g. 0.2 mm and a depth of e.g. 0.8 mm.
  • the screen can be made of a plastic material or metal.
  • the screen plate 7 is an assembly of electrically insulating resin or glass sheets or semi-conductive or conductive sheets e.g. metal sheets preferably of a metal with high atomic number e.g. higher than 50. Such metal sheets may be coated with an insulating material e.g. an insulating resin. These sheets are corrugated in a direction parallel to the desired path of electron flow, so that the corrugations cooperate to provide parallel channels or conduits for the electrons.
  • the manufacture of such channel plates but having secondary-emissive characteristics has been described in the United Kingdom Patent 954,248.
  • Other techniques for producing microchannel plates are described in the United Kingdom Patent Specifications 1,064,072 and 1,064,075. For the purpose of the embodiment discussed in connection with FIG.
  • Ionic feedback is a phenomenon which arises when ions produced at the output 4 end of the channels are accelera ed back down the channels and set free secondary electrons by striking the secondary emissive inner walls at the input ends of the channels.
  • the electron density may be increased in this way to such a degree that a self-sustaining discharge occurs, which has to be avoided.
  • a conductive internal collimator e.g. element 7 in P16. 1
  • no direct electrically conductive contact with the wires of the pin matrix 11 may exist. Therefore the bottom end of the collimator is either supported by insulating material or is spaced from the pin matrix at a distance sufficient to avoid electrical breakdown toward the pin matrix when operating the apparatus under the imaging voltage conditions.
  • the electrons. multiplied by secondary emission in the gas medium. are projected onto the inner ends of the conductive wires 3 of the pin matrix plate 11 forming part of the vacuum envelope wall.
  • the conductive wires 3 are held in substantially parallel separated relation by a matrix of solid electrically insulating material 12, e.g. glass, and extend at their outer ends at the outer side of the envelope 1 towards the electrically insulating surface of the charge receiving web 5, e.g. a polyester resin film web or dielectric paper web having an electrically conductive coating or support 4 in electrically conductive contact with the conductive backing plate 6.
  • the charge receiving web 5 is supplied by a supply reel (not shown) and moved over a guiding roller (not shown) into a toner applicator and fuser station known from electrophotography. From that station, the web moves into a cutting device comprising e.g. a movable knife and a stationary knife, and after leaving the cutting device the obtained sheets are collected in a collector tray. all as known in the art and thus not illustrated here.
  • the envelope material 1 is coated on its inside surface with electrically insulating material as at 9.
  • the envelope 1 can be evacuated and filled with ionizable gas and quenching gas at the desired pressure through a pipe fitting 13.
  • the organic quenching vapour will be decomposed after a certain number of electron avalanche dischargings so that it will be necessary to replace the ionizable gas and quenching gas by a fresh gas mixture after a given number of exposures.
  • the exposure of the photocathode e.g. with information-wise modulated X-rays may proceed from the rear side (i.e. the side of the conductive backing 8 of the photocathode or front side (i.e. the side of the charge receiving material (5,4) e.g. as described in the U.S. Pat. Nos. 2,221,776 and 3,526,767'or as in the published German Patent Application 2,231,954.
  • the photocathode may itself be in the form of a screen or an assembly of lamellae as described in our co-pending United Kingdom Patent Application filed 21st May 1973 and titled: Electrostatic Imaging Device and Process Using Same which has to be read in conjunction herewith.
  • the X-ray recording in the form of an electrostatic charge pattern is carried out with an imaging device comprising an airtight envelope with an electrode that is separated from a pin matrix wall by an interspace filled with an ionizable gas having an atomic number of at least 36.
  • the ionizable gas being preferably xenon, is kept under a pressure above atmospheric pressure.
  • the voltage applied over the electrodes is preferably such that no substantial electron multiplication, i.e. no electron avalanching, by secondary emission takes place; in other words the imaging chamber is operated in the horizontal part of the Townsend curve.
  • no substantial electron multiplication i.e. no electron avalanching
  • the imaging chamber is operated in the horizontal part of the Townsend curve.
  • the pressure under which the ionizable gas is kept may be rather high as described in the Belgian Patent 792,334.
  • the product of the pressure and the thickness of the interspace between the electrode and the input ends of the ,pin matrix may be, e.g. in the range of mm.atmospheres and 200 mm.atmospheres. A pressure of 6 atmospheres combined with an interspace of mm gives very good results.
  • the wall of the envelope directed to the X-ray exposure source preferably is not made of materials that contain or con sist of elements having a high atomic-number. So there will'be only a limited choice of X-ray penetrative wall material when the X-rary exposure dose has to be kept low which is the case e.g. formedical X-ray purposes.
  • the X-ray dose need not be kept as low as possible and the wall of the envelope directed to the X-ray source may be rather highly X-ray absorptive. In that case the X-ray exposure may be made directly through the pin matrix wall that is rather thick to sium.
  • the ends of the wires of the pin matrix inside the envelope containing ionizable gas are coated with a photocathode material e.g. as described in the U.S. Pat. No. 3,508,477.
  • the ends of the wires are preferably covered with a suitable X-ray photocathode material e.g. lead or the wires are made ofa high atomic number metal.
  • the X-ray exposure is preferably effected from the anode side and the charge image formation proceeds on an insulating surface that prior to the X-ray exposure has been charged uniformly with negative charges and is information-wise discharged through the wires of the pin matrix.
  • the apparatus illustrated in FIG. 2 relates to an embodiment in which the X-ray exposure is effected from the side of the receiving material directly through the pin matrix and in which the pin matrix has a sufficient 6 mechanical strength to withstand a gas pressure of 10 atmospheres.
  • the elements indicated in FIG. 2 by the numbers 1 and 3 to 6 and 9 to 13 have the same significance as described in FIG. 1.
  • the wires 3 are preferably made of aluminum or beryllium and the matrix material 12 incorporating the wires 3 is preferably glass that does not contain high atomic number elements e.g. is made of borosilicate glass.
  • the element 20 is an electrode (cathode) that optionally has photoelectron emitting properties when struck by X-rays e.g. is made of lead.
  • the pressure inside the imaging chamber acting upon the pin matrix wall is counteracted outside the imaging chamber by means operative to press the recording material against the outer wall of the pin matrix at a pressure that is substantially equal to the pressure inside the imaging chamber.
  • the pressure is not maintained during the transport step and therefor means are used to increase and decrease respectively the pressure inside the imaging chamber and on thepin matrix at the exterior side of the imaging chamber.
  • the imaging chamber is of the same type as described in FIG. 2.
  • the envelope wall 1 of the imaging chamber carrying the pin matrix 11 is made of steel and mounted onto a piston 21 that can be moved in upward and downward direction by the pressure applied in the cylinder 22 on a gaseous medium e.g. air or liquid medium e.g. oil supplied by the cylinder 27.
  • a web-like charge receiving material composed of a charge receiving resin film web 5 coated with a conductive backing 4 is positioned in front of the outer side of the pin matrix wall 11.
  • a conductive rigid backing plate 23 e.g. made of beryllium serves as an electrode and as a supporting wall for withstanding the pressure applied on the pin matrix 11 when the ionizable gas is introduced under pressure in the imaging chamber.
  • the pressure applied by the piston 21 and the pressure built up in the imaging chamber are kept substantially equal so that at any stage of the imaging procedure the pressure at both sides of the pin matrix wall is substantially equal.
  • the imaging chamber is likewise of the type illustrated in FIGS. 2 and 3.
  • the envelope wall of the imag- 7 ing chamber 1 opposite the pin matrix 11 is made of steel and mounted onto a piston 21 that can be moved in upward and downward direction by the pressure applied in the cylinder 22 by a gaseous medium e.g. air or liquid medium e.g. oil supplied by the cylinder 27.
  • a gaseous medium e.g. air or liquid medium e.g. oil supplied by the cylinder 27.
  • a rectangular or square cover 30 provided at its edges 31 with a pressure sealing ring 32 is pressed against a thin metal electrode 33 e.g.
  • the top wall 34 is preferably made of a metal having a low atomic number and high mechanical strength e.g. beryllium.
  • the pressure is reduced again and the web-like receiving material is moved over a distance sufficient to allow the positioning of the next image frame.
  • the film web containing the electrostatic charge pattern is before or after development cut into sheet form.
  • a modified embodiment instead of a film web separate charge receiving sheets are used that are supplied by a dispenser known to those skilled in the art of sheet feeding in copying machines.
  • the imaging chamber is likewise of the type illustrated in FIG. 2.
  • the X-ray exposure source is element 63.
  • the envelope wall 1 of the imaging chamber carrying the pin matrix 11 is made of steel and mounted in a supporting frame 40. Before the X-ray exposure a web-like charge receiving material composed of a charge recieiving resin film web 5 coated with a conductive backing 4 is positioned in front of the outer side of the pin matrix wall 11. Above the pin matrix 11 is a pressure cushion 41 having a flexible membrane 42 and rigid top plate 43 joined by a hollow rectangular or square flexible sealing ring 44 which is provided with a safety expansion valve 45. The cushion 41 receives a gaseous or liquid medium from a cylinder 46 in which the piston 47 is operated simultaneously with the piston 48 of a cylinder 49 containing an ionizable gas in order to obtain an even pressure on both sides of the pin matrix 11.
  • the ionizable gas is introduced through the pipe fitting 13 into the imaging chamber 1.
  • a DC-voltage is applied between the conductive flexible membrane 42 or conductive coating on that membrane.
  • the membrane is made e.g. of an elastomer e.g. a synthetic rubbere that is vacuum coated with aluminium in the area contacting the conductive backing 4 of the film web 5.
  • the reproducing system illustrated in FIG. 6 is a modified version of the one illustrated in FIG. 2.
  • the numeral 50 designates a steel tube of which the internal structure of the welding joint has to be inspected.
  • a dielectric web 51 covered with a conductive rear coating 52 is wrapped around the welding joint.
  • the recording head 54 containing ionizable gas contains a single row of substantially parallel conductive pins 55 embedded in the insulating wall 56 of the recording head 54.
  • the pins 55 penetrate the envelope from the outer face to the inner face and stand at the inner face of the envelope in contact with an ionizable gas that is kept under high pressure, preferably xenon, that has a high 8 absorption power for X-rays and 'y-rays.
  • the input openings of the row of pins 55 are facing an electrode strip 57.
  • the charge pattern is produced line-wise by progressively moving the tube 50 with the transport rollers 64 with respect to the recording head 54 or by progressively moving the recording head 54 along the circumference of the tube 50 while in the tube 50 at a short distance from its welding joint a radioactive source 58 e.g. a caesium 137 or cobalt 60 source emits 'y-rays.
  • a radioactive source 58 e.g. a caesium 137 or cobalt 60 source emits 'y-rays.
  • a DC potential of several kV is applied by a potential source 59 having the positive pole' connected to the grounded tube 50 and the negative pole to electrode 57.
  • the element 60 is a radiation shield containing a lead sheet 62 fixed to an electrically insulating resin layer 61.
  • electromagnetic radiation patternsof penetrating radiation e.g. X-rays, 'yrays, neutron rays, fi-rays and of ultraviolet, visible light and/or infrared may be used in the exposure step.
  • the penetrating rays e.g. X-rays, 'y-rays, B-rays and neutrons may be transformed into ultraviolet and/or visible light by fluorescent layers that are positioned in close proximity or contact with a photocathode member that is sensitive for the'fluorescent light.
  • the imaging chamber does not contain a solid state photocathode and the ionizable gas itself serves as a photo-electron emitter which is the case e.g. when using a high atomic number gas e.g. xenon in an exposure step with penetrating radiation e.g. X-rays and y-rays.
  • a high atomic number gas e.g. xenon
  • penetrating radiation e.g. X-rays and y-rays.
  • the process of the invention includes apart from the direct charging of previously uncharged insulating charge receiving surface also those embodiments in which the charge receiving material has been charged overall prior to the image-wise charge transfer from the pin matrix. So, according to one of the embodiments of the invention an insulating surface that has been overall charged with charges opposite in sign with respect to the charges conducted by the wires of the pin matrix is image-wise discharged or its charge is image-wise substantially lowered.
  • the wires of the pinmatrix are non-differentially pre-charged from outside the envelope without charging the insulating material in which the wires are embedded.
  • This may proceed in a first embodiment by using a pin-matrix having the conductive wires protruding from the external side of the imaging chamber.
  • the protruding wire ends are contacted with a charged electrode before effecting the image-wise photoexposure of the emitter of charged I 9 particles in the imaging chamber.
  • the charged wires are discharged and the charge of the
  • the external wire ends are non-differentially charged e.g.
  • the wires of the pin matrix are advantageously made of a low atomic number metal or metal alloy, preference may be given in some cases to a pin matrix with metal wires having a relatively high X-ray absorption power e.g. steel, copper, nickel and in particular cases Wolfram or platinum.
  • the heavy metal wires are directed towards the focus of the X-ray source and are interleaved with a material that is more transparent to X-rays e.g. glass or resin.
  • the primary rays (the rays coming in straight line from the X-ray source) pass through the pin matrix while the rays scattered in the object, i.e. the oblique rays, are mostly absorbed in the wires so that improved image sharpness is obtained.
  • a pin matrix element appropriate for serving as multiconductor wall of the imaging chamber is available under the trade mark Multilead from Corning Glass works, Industrial Bulb Sales Department, Corning, NY. It is available with a number of different conductor materials and sizes and a number of different spacings between the conductors.
  • the Multilead material comes in sheet or strip form and can be incorporated into the vacuum envelope wall by a suitable glass fusion technique.
  • a pin matrix can be produced with glass fibres containing a metal core as is described in the United Kingdom Patent Specification 1 ,064,072.
  • metal-cored glass fibres are drawn down till a sufficient length of 200-300 micron fibre is obtained.
  • a bundle of fibres is made by sealing the fibres together 7 and is then cut into lengths of say, cm. Each of these lengths of bundle is then drawn down in the same way as the original tube, equipped with an external cladding of thin insulating glass and drawn down till it is about 50 micron in diameter.
  • This glass fiber containing a metal wire e.g. copper is quite easy to handle.
  • 10 p. fibres can be made. Such a technique has been discussed also in Philips Technisch' Tijdschrift (1969) No. 8/9/10, page 259.
  • the wires or pins in the matrix should be preferably short and, the dielectric constant of the binder material low, to promote high charge transfer speed and maximum image resolution.
  • the transfer of the electrostatic images may proceed by conduction of electrical charges across a gas or air gap or by direct charge transfer when a gas or air gap is not present, e.g. by applying pressure or by effecting the transfer in a vacuum frame. 7
  • Image sharpness is practically not affected by charge transfer by contact. This requires, however, a close and direct contact of the ends of the conductivewires with the insulating materials. Such intimate contact is obtained in practice by operating with very smooth surfaces that are placed together under pressure.
  • the invention is not restricted to any particular type of development or transfer of the electrostatic charge undischarged wires transferred to an insulating charge receiving material.
  • the development of the electrostatic charge image proceeds preferably, with finely divided electrostatically attractable material that is preferably sufficiently nontransparent for visible light, but may proceed by surface deformation which is a technique known as Thermoplastic Recording (see e.g. Journal of the SMPTE, Vol. 74, p. 666-668.
  • the development proceeds by dusting the insulating film or film layer bearing the electrostatic image with finely divided solid particles that are image-wise electrostatically attracted or repulsed so that a powder image in conformity with the charge density is obtained:
  • the expression powder denotes here. any solid material e.g. finely divided in liquid or gaseous medium, which can form a visible image in conformity with an electrostatic charge image.
  • the present invention is not restricted to the use of dry toner. Indeed, it is likewise possible to apply a liquid development process (electrophoretic development) according to which dispersed particles are deposited by electrophoresis from a liquid medium.
  • a liquid development process electrophoresis
  • the dispersed toner particles may be any powder forming a suspension in an insulating liquid.
  • the particles acquire a negative or positive charge when in contact with the liquid due to the zeta potential built up with respect to the liquid phase.
  • the outstanding advantages of these liquid developers are almost unipolarity of the dispersed particles and their appropriateness to very high resolution work when colloidal suspensions are applied.
  • Suitable electrophoretic developers are described e.g. in the United States Patent Specification 2,907,674 and the United Kingdom Patent Specification l,l5l,l4l.
  • the electrostatic image can likewise be developed according to the principles of wetting development" e.g. as described in the United Kingdom Patent Specifications 987,766, 1,020,505 and 1,020,503.
  • the charge pattern is developed in direct relation to the quantity of charge, instead of to the gradient of charge (fringe effect development).
  • the developer material is applied while a closely spaced conductor is situated parallel to the insulating charge receiving member.
  • a transferable toner is used and the powder deposit forming the developed image is transferred from the support containing the electrostatic charge image to e.g. a flexible support e.g. transparent film or paper support.
  • a flexible support e.g. transparent film or paper support.
  • any known process for transferring powder image-wise from one support to another can be used; such powder transfer processes are well known in the art of electrophotography.
  • the powder image can be transferred by electrostatic attraction, e.g. according to the method disclosed in the United Kingdom Patent Specification 658,699. Further details are contained in the U.S. Pat. 3,384,488 and 3,565,614.
  • the powder can be transferred by magnetic attraction.
  • the transfer can likewise be carried out by adhesive pick off with an adhesive tape or sheet e.g. SCOTCH brand cellophane tape.
  • the final powder image is e.g. fixed by heat or solvent treatment.
  • the charge pattern may be formed on any type of electrographic recording material.
  • a recording web consisting of an insulating coating of plastic on a paper base having sufficient conductivity to allow electric charge to flow from the backing electrode to the paper-plastic interface is used.
  • AGC- Monthly (1972) Nr. 9, pages 4-15 For a survey of dielectric coated papers reference is made to AGC- Monthly (1972) Nr. 9, pages 4-15.
  • a special electrographic paper is described in the U.S. Pat. No. 3,620,831, and special thermoplastic recording tapes are described in the Journal of SMPTE Volume 74, p. 666-668.
  • antistatic agents preferably antistatic agents of the polyionic type, e.g. CALGON CONDUCTIVE POLYMER 261 (trade mark of Calgon Corporation, Inc. Pittsburgh. Pa., U.S.A.) for a solution containing 39.1% by weight of active conductive solids, which contain a conductive polymer having recurring units of the following type:
  • vapour deposited films of chromium or nickelchromium about 3.5 micrometer thick and that are about 65 to 70% transparent in the visible range.
  • Cuprous iodide conducting films can be made by vacuum depositing copper on a relatively thick resin base and then treated with iodine vapour under controlled conditions (see J.Electrochem.Soc., 110-119, Feb. 1963). Such films are over 90% transparent and have surface resistivities as low as 1500 ohms per square.
  • the conducting film is preferably overcoated with a relatively thin insulating layer as described e.g. in the Journal of the SMPTE, Vol. 74, p. 667.
  • a method of recording information as a pattern of electrostatic charges carried by an insulating charge receiving medium which comprises:
  • 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.
  • 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 12.
  • An ionographic imaging system for producing an electrostatic charge pattern on an insulating charge receiving material which comprises:
  • an imaging chamber including (a) one wall incorporating a frangible array of discrete closely spaced conductors arranged in an insulating matrix, said conductors extending through said wall from the interior to the exterior of said chamber and (b) an opposite wall spaced from said one wall and defining therewith an enclosed space,
  • electrode means arranged exteriorly of said one wall in closely spaced parallel relation to said conductor array and generally coextensive with said array
  • the system of claim 15 including means for increasing the pressure in said space and the mechanical opposing force at substantially the same rate.
  • An imaging system wherein the enclosed space contains xenon gas and the product of pressure and thickness of the interspace be tween the internal electrode means and the input ends of the conductors is in the range of 10 mm atmospheres and 200 mm atmospheres.
  • An imaging system 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.
  • An imaging system 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.
  • An imaging system wherein the chamber is mounted in a supporting frame and said electrode is backed with a pressure cushion comprising (l) 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.
  • conductors are made of aluminium or beryllium.

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  • Health & Medical Sciences (AREA)
  • Pathology (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Conversion Of X-Rays Into Visible Images (AREA)
  • Measurement Of Radiation (AREA)
  • Combination Of More Than One Step In Electrophotography (AREA)
  • Fax Reproducing Arrangements (AREA)
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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2363816A1 (fr) * 1976-09-02 1978-03-31 Agfa Gevaert Ag Chambre d'image pour electro-radiographie
US4424549A (en) 1981-03-16 1984-01-03 Oce-Nederland B.V. Corona device
US4521808A (en) * 1979-03-22 1985-06-04 University Of Texas System Electrostatic imaging apparatus
US4922299A (en) * 1988-04-07 1990-05-01 Unico Co., Ltd. Electrostatic charge emitting apparatus
US5194291A (en) * 1991-04-22 1993-03-16 General Atomics Corona discharge treatment
US6804013B2 (en) * 2000-01-26 2004-10-12 Krypton Electronic Engineering N.V. Optical element
US20040245925A1 (en) * 2001-07-05 2004-12-09 Kuniyoshi Yamauchi Electron tube and method of manufacturing the electron tube
US20090159995A1 (en) * 2007-12-19 2009-06-25 Shangjr Gwo Method to deposit particles on charge storage apparatus with charge patterns and forming method for charge patterns

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3965352A (en) * 1975-04-24 1976-06-22 Xonics, Inc. X-ray system with electrophoretic imaging
JPS5265442A (en) * 1975-11-27 1977-05-30 Fuji Xerox Co Ltd Method of and apparatus for picture by electrone emission photography method
US4039830A (en) * 1976-08-13 1977-08-02 General Electric Company Electrostatic x-ray image recording device with mesh-base photocathode photoelectron discriminator means
JPS6065763U (ja) * 1983-10-12 1985-05-10 桂川電機株式会社 Ｘ線電子写真撮影装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3508477A (en) * 1967-12-06 1970-04-28 Columbia Broadcasting Syst Inc Apparatus for producing electrostatic images
US3710125A (en) * 1970-04-29 1973-01-09 Univ Northwestern Secondary emission enhancer for an x-ray image intensifier
US3757351A (en) * 1971-01-04 1973-09-04 Corning Glass Works High speed electostatic printing tube using a microchannel plate
US3774029A (en) * 1972-06-12 1973-11-20 Xonics Inc Radiographic system with xerographic printing

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3508477A (en) * 1967-12-06 1970-04-28 Columbia Broadcasting Syst Inc Apparatus for producing electrostatic images
US3710125A (en) * 1970-04-29 1973-01-09 Univ Northwestern Secondary emission enhancer for an x-ray image intensifier
US3757351A (en) * 1971-01-04 1973-09-04 Corning Glass Works High speed electostatic printing tube using a microchannel plate
US3774029A (en) * 1972-06-12 1973-11-20 Xonics Inc Radiographic system with xerographic printing

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2363816A1 (fr) * 1976-09-02 1978-03-31 Agfa Gevaert Ag Chambre d'image pour electro-radiographie
US4521808A (en) * 1979-03-22 1985-06-04 University Of Texas System Electrostatic imaging apparatus
US4424549A (en) 1981-03-16 1984-01-03 Oce-Nederland B.V. Corona device
US4922299A (en) * 1988-04-07 1990-05-01 Unico Co., Ltd. Electrostatic charge emitting apparatus
US5194291A (en) * 1991-04-22 1993-03-16 General Atomics Corona discharge treatment
US6804013B2 (en) * 2000-01-26 2004-10-12 Krypton Electronic Engineering N.V. Optical element
US20040245925A1 (en) * 2001-07-05 2004-12-09 Kuniyoshi Yamauchi Electron tube and method of manufacturing the electron tube
US20090159995A1 (en) * 2007-12-19 2009-06-25 Shangjr Gwo Method to deposit particles on charge storage apparatus with charge patterns and forming method for charge patterns
US7803261B2 (en) * 2007-12-19 2010-09-28 National Tsing Hua University Method to deposit particles on charge storage apparatus with charge patterns and forming method for charge patterns

Also Published As

Publication number Publication date
GB1471858A (en) 1977-04-27
JPS5072635A (enrdf_load_stackoverflow) 1975-06-16
FR2238174B1 (enrdf_load_stackoverflow) 1976-12-24
BE817408A (nl) 1975-01-09
CA1038441A (en) 1978-09-12
DE2433766A1 (de) 1975-02-06
FR2238174A1 (enrdf_load_stackoverflow) 1975-02-14

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