| 摘要 |
PURPOSE:To improve the quantity of a picture image displayed on a cathode-ray tube by making bright points which are formed on the cathode-ray tube with radiation signal pulses invariably constant in width and brightness even when the horizontal scanning speed of an electron beam is varied. CONSTITUTION:When the scanning speed of a scanning signal generator 4 is set fast, a saw-tooth wave which increases the scanning speed of the electron beam is generated and inputted to a deflecting coil 7 through a scanning signal amplifier 5 and the electron beam is scanned fast on the cathode-ray tube 6. When a high-level DC signal is generated by the signal generator 4, on the other hand, an X-ray signal pulse width variation controller 2 converts input X-ray pulses into a pulse signal which has a large amplitude and narrow pulse width and a brightness modulating amplifier 3 performs high-gain amplification and brightness modulation. When the scanning speed of the signal generator 4 is set slow, the electron beam is scanned slowly on the cathode-ray tube 6. Further, input X-ray pulses are converted into a pulse signal which has a small amplitude and wide pulse width and low-gain amplification and brightness modulation are carried out. Thus, bright points are displayed with invariably uniform brightness.
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