GB1528909A - X-ray apparatus displays means - Google Patents

Abstract

1528909 Television EMI Ltd 17 Nov 1975 [28 Nov 1974] 51535/74 Heading H4F A televised display of an X-ray analysing apparatus's output is produced by retiring digital signals emanating from the apparatus to a standard television rate and filling in signal gaps caused thereby with additional "lines" of signal derived by interpolation between adjacent lines emanating from the apparatus. Incoming digital data is received by a code detector I, Fig. 1 where analysing units 3 and 4 perform signal format checks. In the event of no errors (i.e.: missing end of line signal; insufficient data for complete line; etc.) gate 6 applies the signal under control of a 20 KHz clock into one of a pair of whole image capacity buffer stores 7. During loading of one register under the 20 KHz clock, the other is unloaded under a 4À625 MHz clock to desired addresses of a random access memory (RAM) 10. The addressing is controlled by units 11 to 14. The stored signals are subsequently read from RAM 10 and applied to a window video processor 18, Fig. 4 which amplitude scales the signal into a desired range of X-ray absorption parameters centred on a desired mean level controlled by means 19 and 20. From here the scaled signals pass to an interpolation arithmetic unit which derives the extra lines of video signal and inserts them in the scaled signal. The output of unit 24 feeds a display 29 via mixer 26, D/A converter 27 and processor 28. At the mixer 26 additional information is added to the signals, relating to grey scale or error messages etc., these are displayed along a vertical stripe down one side of the display. Further interpolation with associated line drop out may be employed to provide a zoom effect. In this embodiment the signals are derived from a 160 x 180 element array of picture points, however, in another embodiment, Figs. 6 and 7 (not shown) a plurality of the above devices with associated multiplexing/demultiplexing arrangements may be used to obtain higher resolution, larger picture area or a three dimensional analysis. (For figures see next column)