Semiconductor photosensitive target for image analyser tube - has optical fibres bonded to thin face surrounded by collar before activation of surface

摘要

Optical targets used in image analysers convert platens into electrical signals which are read by a scanning electron beam, in the case of a diode mosaic vidion, or by charge transfer. The target must pref. be a thin monocrystalline semiconductor which is activated on one surface. Normally the target is too thin to be activated and this operation is done first, but the order is reversible if the target area is reinforced by a sheet of optical fibres. The target (1) is prepared from a 23 mm diameter blank 150 microns thick and a central target area 19 mm diameter thinned to 12 microns the collar (11) remains to give the target rigidity and allow handling. The material is 10 ohm-cm resistivity silicon or some other semi-conductor. A sheet of optical fibres (2) is placed in the well formed between the collar and target, covering the target area, and is glued to it with a 10 micron thick layer of epoxide resin (3). In this way the target is reinforced without optical resolution being lost by diffusion.