Patent ID: 7755256

Claim:
An ultrasonic probe comprising: a piezoelectric vibrator including a piezoelectric material and configured to transmit and receive ultrasonic waves; an acoustic lens configured to focus the ultrasonic waves; and an acoustic matching layer arranged between the piezoelectric vibrator and the acoustic lens and configured to modify acoustic impedance from the piezoelectric vibrator to the acoustic lens, comprising, a first region arranged at center areas along a direction of transmitting and receiving of the ultrasonic waves, a second region arranged between the first region and the piezoelectric vibrator and having a rate of change of acoustic impedance less than a rate of change of acoustic impedance of the first region, and a third region arranged between the first region and the acoustic lens and having a rate of change of acoustic impedance less than a rate of change of acoustic impedance of the first region, the acoustic matching layer having a thickness along said direction that is larger than an average wavelength of ultrasonic waves propagating in the acoustic matching layer, and the acoustic matching layer excluding the piezoelectric material of the piezoelectric vibrator.