| 摘要 |
PURPOSE:To enable monitoring and correction of x-ray photographing conditions by displaying a signal which is proportional to the x-ray tube voltage while x- rays are being photographed. CONSTITUTION:The x-ray tube voltage controlled depending upon the brightness of an x-ray image is detected by a voltage divider 106 on the output side of tetrodes 103 and 103' and sent to a sampling hold circuit 15 through an adder 14 as a camera tube voltage signal. The output of the circuit 15 is sent as that of the adder 14 while x-rays are being radiated as it is and held as the tube voltage signal of the adder 14 immediately before the x-rays are stopped when they are stopped as it is. The output of the circuit 15 is sent to an A/C.BCD converter 32 through an analog switch 31 and drives an indicator 33 by the BCD-converted output. The control contacts 1a and 2a of the switch 31 are selectively operated at the times when the x-rays are photographed and not. They indicate the tube voltage during photographing start before the x-rays are photographed and the actual tube voltage while they are being photographed. |
