| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic probe which can obtain high-resolution, good-quality images enabling the use of a relatively simple circuit and cope with the requirement for a decrease in diameter. SOLUTION: This probe has a cable for transmitting driving voltage and echo signals, a piezoelectric element 5, an acoustic matching layer facing the acoustic radiating surface of the piezoelectric element 5, and a back load layer opposed to the acoustic matching layer, and is designed to transmit and receive ultrasonic waves. In this case, the piezoelectric element 5 which has a difference in the strength of spontaneous polarization depending on position within one piezoelectric element 5 is used, electrodes 2, 3 fitted on both of the principal planes of the piezoelectric element 5 are electrically connected to the cable, and the distribution of the strengths of the spontaneous polarization of the piezoelectric element 5 follows a zero-order Bessel function and is made to correspond to the direction and magnitude of sound pressure radiated from that position. |
