| 摘要 |
1,225,033. X-ray diagnostic equipment. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 7 March, 1968 [9 March, 1967], No. 11128/68. Heading H5R. An X-ray diagnostic apparatus comprises an image intensifier BV, rigidly secured to a frame 9, having a fluorescent screen centred in the X-ray beam from source 1 also rigidly attached to the frame; a table plate 4 adapted to slide longitudinally and laterally with respect to the frame 9 and which may pivot about the horizontal axis 16, an X-ray film cassette carriage adapted to move longitudinally and transversely inside the table plate, and a control system which starts an exposure by automatically moving the cassette carriage across the fluorescent screen so that the centre line of the fluorescent screen which extends parallel to the longitudinal axis of the table plate coincides with the corresponding centre line of that area of film being exposed. Preferably, the control system is arranged to first position the carriage relative to the table plate and then drive the carriage from a rest position, e.g. the far left of the table plate as drawn in Fig. 1, to a given position relative to the frame 9 and then move the cassette carriage across the fluorescent screen to achieve the desired coincidence. Preferably the control system comprises two sets of contacts, one ST 1 -ST 3 connected to the cassette carriage which position it relative to the table top and the other set SR 1 -SR 7 connected to the frame 9 which position the cassette relative to the frame and achieve the desired coincidence of centre lines. If desired, the table top may also contain a diaphragm system (Fig. 2, not shown), comprising two leaves which always position themselves centrally on the fluorescent screen, the cassette contacts on the frame 9 being increased so that the cassette may be positioned consecutively in a number of positions laterally across the table so that a series of exposures may be made. Preferably in moving down the table from its rest position the cassette carriage is arranged to stop so that the leading edge of the cassette coincides with the furthest edge (i.e. the R.H. edge of Fig. 1) of the image intensifier. |
