| 摘要 |
PURPOSE:To enable automatic setting of a reference value and stable and highly accurate detection of a mark, by arranging a photoelectric sensor, a peak holding circuit, a comparator circuit and the like. CONSTITUTION:A stepping motor 11, a photoelectric sensor 31, an inversion circuit 33, a peak holding circuit 34, a comparator circuit 35, a peak counter 37 and the like are arranged. When a sensor 31 detects a matching mark 3 of a container body 1, the detection signal from the sensor 31 is inputted into a circuit 33, with which only falling part caused by transition phenomenon is inverted in the detection signal. Then, a signal from the circuit 33 is inputted into the circuit 35 to be compared with a reference value memorized into the circuit 34 and when it is above the reference value, a pulse signal is outputted to the subsequent counter 37. Here, a mark 3 when the motor 11 runs in the rated state is detected to elevated the detection accuracy. In the first rotation of the motor 11, the detection signal is compared with the reference value to identify the mark 3. With such an arrangement, when the same signal is obtained in the second rotation, it is judged to indicate the position of the mark 3 thereby preventing misdetection.
|
