Ultrasonic sensor for detecting e.g. label, has sound transducer alternatively operated in transmitting mode or receiving mode, where ultrasonic waves are detected in direction of transducer during receiving operation

摘要

The sensor (1) has a sound transducer (2) alternatively operated in a transmitting mode or a receiving mode in a periodic clock sequence. Ultrasonic waves (5) directly emitted by the transducer in the transmitting mode are guided to a surface of an object at a preset inclination angle such that the ultrasonic waves are back reflected and/or diffracted in a direction of the sound transducer, during impinging of the ultrasonic waves at an object edge. The ultrasonic waves are detected in a direction of the sound transducer during receiving operation following a transmitting operation.