GB1164392A - Improvements relating to X-Ray Television Cameras - Google Patents

Abstract

1,164,392. Recording images from a fluorescent screen. OPTISCHE INDUSTRIE " DE OUDE DELFT " N.V. 24 Jan., 1967 [25 Jan., 1966], No. 3485/67. Heading H5R. In an X-ray television camera comprising a T.V. pick-up tube, a fluorescent screen adapted to be positioned in the primary X-ray beam and an optical system to form on a light sensitive surface an image of said screen which is recordable by the photocathode or target of said T.V. pick-up tube, a light transparent clear plate is positioned in close parallel relation to the screen on that side of the screen which is remote from the X-ray source, said plate being of a material such that secondary X-rays back scattered from parts of the camera lying behind the plate are completely absorbed thereby. As shown in the figure the rays 13 from a source 12 pass through diaphragm 14 and body 15 to produce an image on fluorescent screen 10 which is situated immediately adjacent the transparent lead glass plate 17, the image is transmitted via mirror 11 to the photocathode of image intensifier 2, from where it passes via optical system 3, 4 and mirror 5 to a television pick-up tube 6, e.g. of the image orthicon type. The screen 10 and its associated protective cover 8 and stray radiation absorbing plate, e.g. Bucky grid 9, together with the mirror 11 may be supported by a light-tight hood 7 which is rotatable about the optic axis of the camera. If desired, the image may be recorded via an optical system directly on the photocathode or target of the pick-up tube. The plate 17 may have a thickness such that primary rays incident thereon are only partially absorbed.