| 摘要 |
PURPOSE:To perform highly accurate automatic inspection at a high speed, by performing the frequency conversion of the sensor output with respect to a sample, which is located in the detecting range of a sensor, memorizing the maximum and minimum values within the pulse width, and comparing the values with a reference value after the sample has passed the detecting range. CONSTITUTION:A microcomputer 31 in a controller 26 corresponds to a position sensor 25. As long as a conveyed sample is located in the detecting range of a sensor, which receives reflected light, the pulse width of a pulse corresponding to the detected output of the sensor, through a voltage-frequency converter 28A, a signal insulator 29A such as a photocoupler, and an interval timer 30A, is received by the computer 31, and the maximum and the minimum values are stored. After the sample has passed the detecting range of the sensor, the computer 31 compares the stored contents with the similar reference pulse width through the sensor, which receives the reflected light from a reference surface, and the quality of the sample is judged. Therefore, the comparison with the reference value is not performed for every pulse but only once, and highly accurate automatic inspection can be performed at a high speed. |
