Patent ID: 8162832

Claim:
A minor axis motion type ultrasonic probe comprising: a piezoelectric element group in which a plurality of piezoelectric elements are arranged in a line in a major axis direction of the piezoelectric element group; an acoustic lens that is provided on an ultrasonic wave transmitting/receiving surface side of said piezoelectric element group and that has a curvature in a minor axis direction of said piezoelectric element group; and a sealed container that houses said piezoelectric element group with said acoustic lens provided thereon and that is filled with a liquid serving as an ultrasonic wave medium, and said piezoelectric element group is moved in said minor axis direction and ultrasonic waves are transmitted and received to and from a living body, wherein said acoustic lens is a concave lens formed from a material that has less propagation loss of ultrasonic waves than a silicone resin and that has a greater acoustic velocity than a living body, and a relationship between acoustic velocity c 1 of said concave lens, acoustic velocity c 2 of said liquid, and acoustic velocity c 3 of said living body is expressed as c 1 >c 3 >c 2 .