Patent ID: 7372775

Claim:
An ultrasonic transmitter comprising: a plurality of vibrating elements driven by specific pulse signals, the vibrating elements being arranged on the surface of a transducer; and a transmitting beamformer for forming an ultrasonic transmitting beam by activating individual vibrating elements by feeding the pulse signals thereto, the transmitting beamformer including: a bridge circuit including at least first and second switching devices connected in series between a ground potential and a driving voltage which determines the amplitude of each pulse signal, wherein the bridge circuit generates the pulse signal based on drive signals fed into the individual switching devices; and a drive signal generator means for generating the drive signals to set the first and second switching devices of the bridge circuit ON and Off, the drive signal generator generating the drive signals to set the second switching device of the bridge circuit to an OFF state throughout a period when the first switching device of the bridge circuit is in an ON state, and forming a low impedance closed loop resonant circuit of the second switching device and the vibrating element by generating the drive signals to set the second switching device to the ON state throughout a period when the first switching device is in the OFF state.