Agfa-gevaert Ag

Alfred Rheude

Josef Pfeifer

Jurgen Muller

Manfred Schmidt

Rolf Eickel

Heinrich Farber

Kurt Thate

Dieter Tolksdorf

Bernhard Zrenner

Rolf Erckel

Juurgen Muller

A container for X-ray films is of the type wherein at least one side of the film is contacted by a stratum of fluorescent material. The fluorescent material is biased against the respective side or sides of the film by two layers which consist of ferromagnetic and/or magnetic material, flank the film and attract each other. Such layers can be applied to the inner or outer sides of sheet-like carriers consisting of synthetic plastic material. The aforedescribed film, stratum or strata, layers and carriers may but need not be inserted into the space between the rigid or flexible walls of an envelope. The envelope can be dispensed with if the carriers consist of opaque material. Since each of the two carriers can support the respective layer and the respective stratum of fluorescent material, the thickness of the entire package is minimal and the film can be placed into close proximity of one or more objects to be imaged so as to obtain sharp images of such object or objects. The distance between the film and the object or objects is reduced still further if the layers of ferromagnetic and/or magnetic material are applied to the inner sides of the respective carriers because the distance between the layers is then small and the thickness of such layers can be held to a minimum. The thinnest packages are obtained by mixing the ingredients of the layers with the ingredients of the fluorescent strata and applying to each carrier a single coat of the resulting suspension so that the coat is disposed between the respective carrier and the corresponding side of the film.

Containers for X-ray films or the like

Information on a patient chart is imaged onto a first portion of a dielectric receptor sheet simultaneously with, prior to or subsequent to exposure of a second portion of the receptor sheet to object-modulated X-rays in an ionography imaging chamber. The sheet has an outer layer consisting of polyvinyl chloride or polyethylene terephthalate and is brought into intimate contact with a chart at a station where the chart and the overlapping first portion of the sheet are exposed to electromagnetic radiation issuing from an electronic flash unit. This results in the formation of a latent image of the information on the first sheet portion, and such image is thereupon converted into a visible image, either on the receptor sheet or on a separate sheet, in accordance with a xerographic developing technique by resorting to toner particles. The sheet can be reused by neutralizing its charge, e.g., by heating its layer to a temperature approximately 10.degree. C. above the freezing point of the material of the layer, by moving the sheet relative to an AC corona discharge device (or vice versa), or by washing the layer with alcohol.

Electrophotographic method and apparatus

Apparatus for developing latent images of X-rayed objects on dielectric receptor sheets has a carrier which advances receptor sheets along a circular path about a horizontal axis. A tank with an open top is installed below the six o'clock position of the carrier and contains a horizontal developing electrode having narrow elongated channels extending in parallelism with the axis of the carrier. A pump draws liquid developer from a vessel in which the tank is confined and admits the developer into the bottom zone of the tank wherein the developer rises to fill and flow above the channels of the electrode and to thereby contact the latent image of a sheet on the moving carrier. The surplus of liquid developer overflows the upper edge of the tank and returns into the vessel. The electrode is movable up and down by rotary eccentrics to thereby influence the development of latent images, especially the development of outlines of dark portions of the images.

Apparatus for developing latent images of X-rayed objects

Latent images which are formed on dielectric receptor sheets during exposure to object-modulated primary and stray X-rays, while the sheets dwell in the interelectrode gap of an ionography imaging chamber, are developed in an electrophoretic unit which neutralizes the effect of stray radiation upon the receptor sheets so that the developed visible images are reproductions of those portions of latent images which are formed as a result of exposure to primary radiation. The neutralizing involves ascertaining the intensity of stray radiation behind the imaging chamber by resorting to one or more dosimeters and one or more rasters or analogous devices which absorb stray radiation, and applying to the electrodes of the developing unit a reverse potential which is proportional to the intensity of stray radiation. Alternatively, the intensity of stray radiation can be ascertained empirically and the reverse potential is selected by hand, depending on the density and thickness of the object.

Method and apparatus for making and developing ionographic images of

An ionography imaging chamber wherein the front side face of the pressure vessel is immediately adjacent to the foremost portion of the interelectrode gap and the image-receiving part of a dielectric receptor sheet in the gap extends into immediate proximity of the front side face. The front part of the margin of the sheet is bent over the front edge portion of one of the electrodes, and the gasket which seals the interelectrode gap while the latter is filled with compressed high Z gas abuts against the folded-over front part of the sheet. The sheet is attached to a drawer which carries one of the electrodes and is insertable into a compartment of the main section of the pressure vessel. One or more auxiliary electrodes are installed in the foremost portion of the gap to prevent distortion of latent images in the region which is nearest to the front side face of the pressure vessel.

Method and apparatus for making latent images of object-modulated X-rays

An ionography imaging chamber for use in X-ray systems wherein dielectric receptor sheets are introduced into an interelectrode gap of the imaging chamber and the gap is filled with compressed high Z gas during imaging of an object onto a sheet in the chamber so that the sheet is provided with a latent image of the object. The chamber has a gate defining an arcuate channel for introduction of receptor sheets into and evacuation of sheets from the interelectrode gap. In order to prevent escape of high Z gas into the atmosphere and/or penetration of air into the gap, the gate has one or more orifices for admission of a compressed buffer gas (for example, CO.sub.2 gas) which is readily separable from the high Z gas whereby the buffer gas flows toward and away from the gap and mixes with high Z gas which tends to escape from the gap by way of the channel. The gate is further formed with one or more second orifices which evacuate the mixture of buffer gas and high Z gas from the channel between the first orifice or orifices and the gap. The gap is sealed from the inlet of the channel by one or more inflatable seals before the pressure of high Z gas in the gap is raised preparatory to exposure of a receptor sheet to X-rays.

Ionography imaging chamber

Sheet-like dielectric receptors which are to be exposed to object-modulated X-rays in the interelectrode gap of an ionography imaging chamber are attached to sheet-like carriers so that the carriers extend laterally beyond the reactors. The carriers are thereupon transported through the interelectrode gap and through successive stations of a xerographic printer which renders the latent imges of objects visible and subjects the receptors to other treatment. The carriers can be attached to receptors by resorting to an adhesive, by the application of electrostatic charges and/or by causing the marginal portions of the carriers to engage the receptors by suction. The carriers are provided with semiconductive layers whose surface resistance can be varied at or prior to entry of carriers and attached receptors into the various stations; this can be achieved by utilizing semiconductive layers whose resistance can be influenced by changing the pressure of the surrounding atmosphere or by utilizing photosensitive layers whose resistance changes in response to exposure to light. The layers are regenerated upon separation of finished receptors so as to allow for renewed use of the respective carriers.

Method and apparatus for making X-ray images

An ionography imaging chamber for use in the cassette of an X-ray apparatus has a flat prismatic pressure vessel defining an interelectrode gap for compressed high Z gas and a dielectric charge-receiving sheet which is to be exposed to a pattern of X-rays. The pressure vessel fits into the compartment of a strongly deformation-resistant jacket having a centrally located sleeve consisting primarily of polyurethane foam, a thin tubular inner envelope which consists at least in part of convoluted fibrous material, and a thin tubular outer envelope which also consists at least in part of convoluted fibrous material. That envelope which takes up compressive stresses has a layer of carbon epoxy fibers. The other envelope takes up tensional stresses and contains Kevlar fibers. The pressure vessel has two flat tray-shaped main portions which consist of polyurethane foam. The main portions of the pressure vessel and/or the sleeve of the jacket may be strengthened by inserts consisting of metal or a synthetic plastic material with fibrous reinforcements embedded therein.

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Munich, Germany

Alfred Rheude