GB985518A - Improvements in or relating to apparatus for intensifying the contrast of radioscopyimages - Google Patents

Abstract

985,518. Television. SIEMENS-REINIGERWERKE A.G. Aug. 16, 1961 [Aug. 19, 1960], No. 29555/61. Heading H4F. In an arrangement for intensifying areas of fine contrast of X-ray images video signals are generated corresponding to " sharp " and " unsharp " representations of such images, combined in opposition and the combined signals fed to a picture reproducing tube. Fig. 1, shows one embodiment in which the image of an object 3 produced on the fluorescent screen (not shown) of an X-ray image amplifier 1 by a source of X-rays 2 is transformed into two sets of video signals by means of television cameras 4, 5, one of which is not focused sharply (e.g. by optical and/or electrical means), and supplied via phase inverter 6 and variable-gain amplifier 7 and via variable-gain amplifier 8 to a combining unit 12 the output from which is fed to a picture reproducing tube 14. In a second embodiment, Fig. 2, a single X-ray sensitive television camera 16 is employed and its signal output, divided in 17, is fed over channel 7<SP>1</SP> and variable gain amplifier 7 to combining unit 12 and over channel 8<SP>1</SP> and variable-gain amplifier 8 to a picture reproducing storage tube 10, the picture reproduced by which is scanned by a picture signal generating tube 11 between which and tube 10 optical de-focusing and/or electro-optical defocusing occurs, the signal output of tube 11, which is phase-displaced by 180 degrees, being also fed to combining unit 12 from which the combined signals are supplied to picture reproducing tube 14. The invention operates by virtue of the fact that signals representative of areas of coarse contrasts substantially cancel out when combined in opposition whereas signals representative of fine contrasts in the " sharp " channel are not cancelled by such signals in the " unsharp " channel. By deriving one of the two signals via a pick-up tube which reproduces all instantaneous motions of the image and the other via an image storage system supplying signals corresponding to a single movement phase the contrast of moving details of the image may be relatively intensified.