How to detect transparent labels for packaging labeling machines

There are two ways. The utility model is characterized in that the utility model adopts a capacitance label sensor and an ultrasonic transparent label sensor.
Capacitive tag sensor faster than ultrasonic transparent label sensor. However, the detection range is not wide.
Furthermore, the detection accuracy.
The accuracy of capacitance is higher than that of ultrasonic. The faster the labeling speed. However, the label sensor on the label on the accuracy of the machine, with the speed of the standard (that is, servo motor). It is expected that the number of the servo motor pulse matches the response speed of the sensor.