Abstract: An X-ray image intensifier tube is constructed as a modulator system using modules which are uniform for as may different types of tube as possible. Whenever feasible, the modules are detachably combined so as to form one unit.

Abstract: An image intensifier tube comprising a photocathode, and a channel plate having an entrance electrode on the surface of the channel plate and having an input electrode, integral with the entrance electrode, which extends from the surface of the channel plate toward the photocathode. Between the photocathode and the input electrode of the channel plate, there is a single intermediate electrode which has a potential applied thereto which during operation forms a complete barrier against ions leaving the channel plate. By an optimum choice of the various potentials and shape of the electrodes, the input electrode of the channel plate comprising an upright cylinder, a distortionless image of the photocathode and a more uniform landing direction for the photo electrons is ensured.

Abstract: An image intensifier comprises an image intensifier tube which is provided with a mounting ring, having a reference face which occupies a fixed position relative to an entrance window, even in the case of temperature variations. The image intensifier tube is accommodated, with intermediate resilient material, in an envelope having a mounting face for mounting an entrance optical system to be added. When the addition is mounted, the reference face bears against the entrance optical system under spring force exerted by the resilient material and the free entrance window occupies an optimally fixed position.