Patent ID: 7855609

Claim:
An ultrasonic transducer driving circuit comprising: a positive field effect transistor which outputs a positive voltage onto an output line to an ultrasonic transducer at on state; a negative field effect transistor which outputs a negative voltage onto said output line at on state; a ground clamp circuit for causing said output line to return to a ground voltage when said positive field effect transistor and said negative field effect transistor are in off state; and a driver circuit which carries out at least one of the following: turning said positive field effect transistor on in accordance with a positive pulse signal supplied and turning said positive field effect transistor off after the elapse of a period of rise during which said output line rises from the ground voltage up to a predetermined positive voltage; and turning said negative field effect transistor on in accordance with a negative pulse signal supplied and turning said negative field effect transistor off after the elapse of a period of fall during which said output line falls from the ground voltage down to a predetermined negative voltage, wherein said driver circuit drives said positive field effect transistor and said negative field effect transistor based on said positive pulse signal, said negative pulse signal, and a return voltage returned from said output line.