Siemens Aktiengesellschaft

Walter Greschat

Guenter Schwierz

Wolfgang Schubert

Heinz Roehrich

Silvester Schweda

Ulrich Kroener

Fritz-Wilhelm Lange

Peter Roemer

An x-ray image intensifier has a housing, an input screen, an output screen, and a number of electrodes for the electron optics, the housing including a number of joined parts and at least one of those parts consisting of electrically insulating material. The part or parts of the housing consisting of insulating material have seating surfaces to which parts, such as the electrodes, are secured by shrinking.

X-ray image intensifier with shrink-fitting parts

In an examplary embodiment wherein the x-ray image, converted into an electron image, is intensified through acceleration in the electrical field, in at least two stages which are inter-coupled via an intermediate screen, such screen contains, as significant elements, a cathodoluminescent layer and a photocathode layer which is optically in contact with the latter. Of these, the one is disposed on the one side and the other is disposed on the opposite side of a satisfactorily stable carrier plate which allows the light of the cathodoluminescent layer to pass through. In the case of this intermediate screen it is difficult to keep the surface sufficiently clean for the purpose of applying the photocathode layer. To this end, the disclosure provides that the surface of the carrier plate be coated with a coating which is resistant to the photocathode layer, which coating, for a photocathode layer of cesium antimony, can be comprised of cesium iodide and be 5 and 10 .mu.m thick. Thus a tight (or sealed) covering of the base and a clean surface are obtained. An x-ray image intensifier improved in accordance with the disclosure is particularly suited for use in medical x-ray diagnostics.

Multistage vacuum x-ray image intensifier

In the illustrated embodiments, detectors for receiving a fan-shaped beam are arranged in one row with dimensions to resolve a layer of maximum extent, while further detectors of the same dimensions are arranged in one or more adjacent rows and staggered relative to the first row so that the several rows provide comparable resolution for a layer of minimum extent. Thus in generating a computer tomograph of a layer of small extent (as in the neck region), the successive rows of detectors are rendered sequentially responsive to the fan shaped beam. If a physically continuously rotating detector assembly is used with mechanical lateral shifting of the x-ray detector rows into the beam path interpolation can correct for any change in the angles of the ray paths for the respective rows. By converting the x-ray beam into corresponding electronic radiation, electronic switching to successive electron detector rows may be used, thereby maintaining essentially the same focus location for each row, even with continuous rotation.

Tomographic x-ray apparatus for producing transverse layer images

An X-ray image amplifier or intensifier and, more particularly, an input screen for electron-optical image intensifiers having a phosphorescent or luminescent layer supported on a carrier, which is followed by a photocathode layer, and wherein a dark-colored intermediate layer is located between the luminescent layer and the photocathode layer. The darkly-colored layer employed between the luminescent layer and the photocathode layer is constituted of an at least approximately uniform surface coating of carbon or graphite facilitating the partial transmission of the light from the luminescent layer.

Growing community of inventors

Dormitz, Germany

Walter Greschat