| 摘要 |
PURPOSE:To execute exactly a measurement by binary-coding a tube image signal by a camera being on a prescribed line of a direction orthogonal to a tube, by a high level comparator, counting a clock by its low level part, clearing it by a high level part, and specifying its clear stop. CONSTITUTION:Threshold values VS1, VS2 are inputted from setting devices 5, 12 to high and low level comparators 6, 13 for inputting a signal of an image sensor camera 4, the value VS1 is made larger than the value VS2, and a clock is counted by a counter 7 in a low level part of the comparator 6, so that it is cleared by its high level part. When it enters a gap to be measured, counting is started by the counter 7, the counting is continued by stopping the clearing by the high level part of the comparator 6, by an output S6 of the comparator 13, and the counting is stopped at the time of the end of the gap. |
