| 摘要 |
PURPOSE:To detect a mark with high accuracy by analyzing peak values included in detection signals from detecting means for a desired range set in advance and judging the conditions of the marks. CONSTITUTION:When a container 1 passes a photoelectric sensor 10, detection signal from the sensor 10 is outputted by an automatic following-up and comparing circuit 12 to a processing circuit 17 as mark signal. The detection signal from the sensor 10 is outputted to the circuit 17 via an amplifier circuit 13, an inverting circuit 14, a sample hold circuit 15 and an A/D converting circuit 16. When the circuit 17 reads the mark signal and judges the presence of a mark by the rising of the mark signal, the circuit 17 actuates an oscillator circuit 19 and starts to count clock pulses by first and second length measuring counters 20 and 21, respectively. When the counted value of the counter 20 falls on a detection starting position set in advance on the basis of the container 1, the circuit 17 starts peak detecting processing. When the counted value of the counter 21 reaches a detection terminating position set in advance, the peak detecting processing is stopped. |
