| 摘要 |
PURPOSE:To decide on the size of a conveyed article accurately and continuously by providing the 1st detecting means which detects the interval from the conveyed article, a means which holds its detected value, and a means which compares the held detected value with a specific reference value and decides which is larger. CONSTITUTION:When a ring 16 held by a holding member 8 moves as shown by an arrow 7 unit it faces the 1st detecting means 18, the detecting means 18 outputs a signal corresponding to the interval between the both and the output is put together with the output since wave of an oscillation circuit 28. A detecting circuit 30 outputs a DC voltage corresponding to the interval and the voltage is passed through an amplifier 32 and held by a measured value holding circuit 34. Further, when the ring 16 faces the 2nd detecting means 20, its detection signal is converted into a pulse signal through an oscillation circuit 4, detecting circuit 46, and amplifier circuit 48 and outputted as synchronizing pulses to the holding circuit 34. Then, a comparing circuit 36 compares the measured value with upper-limit and lower-limit reference voltages V1 and V2 and the holding by the holding circuit 34 is reset to outputs the comparison result indicating whether the value is within the upper and lower limit range or not to an output circuit 38. |
