Notches are cut out in {HEAD ~ the ultrasonic transducer material} to divide it into {TAIL ~ a plurality} of transducer elements arranged in the array direction and a direction perpendicular to the array direction 
Notches are cut out in { HEAD ~ the ultrasonic transducer material } to divide it into { TAIL ~ a plurality } of transducer elements arranged in the array direction and a direction perpendicular to the array direction
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH