| 摘要 |
PURPOSE:To enable appropriate automatic exposure by sending an X-ray stop signal to an X-ray generator/controller, when an integrator output signal reaches a predetermined value, so as to stop X-ray generation. CONSTITUTION:Out of video signals from an image pickup tube 7, only those parts corresponding to a required range of fluoroscopic images are picked out to be provided to an integrator 13. The integrator 13 integrates the signals provided and when the output reaches the value predetermined by a density regulator 15, a comparator 14 outputs an X-ray stop signal. The X-ray stop signal is provided to an X-ray generator/controller 1 to stop X-ray generation. In this way, automatic exposure is actuated, and a required fixed film density can be obtained.
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