PROBLEM TO BE SOLVED: To provide a transducer or the like that can be made more compact.SOLUTION: A transducer 100 has an electromechanical conversion element 110 for performing conversion of an acoustic wave and an electric signal, and a backing member 120 arranged on the opposite side to the principal surface of the element 110. The backing member includes a plurality of backing layers 123, 124 substantially parallel with the principal surface, and each backing layer includes a plurality of first members 121 arranged at intervals, and a second member 122 arranged at intervals, and having an acoustic characteristic impedance different from that of the first member. In the plurality of backing layers, there are a plurality of backing layers where the distance in a direction perpendicular to the principal surface between layers is substantially odd multiple of a quarter of a predetermined wavelength of the acoustic wave in the second member, and the position of the first member in the layer is deviated each other in a direction parallel with the principal surface.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】より小型にすることができるトランスデューサ等を提供する。【解決手段】トランスデューサ100は、音響波と電気信号との変換を行う電気機械変換素子110と、素子110の主面と反対側の面に配置されたバッキング部材120を有する。バッキング部材は、前記主面に略平行な複数のバッキング層123、124を含み、各バッキング層は、間隙をおいて配置された複数の第一の部材121と、間隙に配置され、第一の部材と異なる音響特性インピーダンスを有する第二の部材122を含む。複数のバッキング層のなかに、層間の前記主面に鉛直な方向の距離が第二の部材における音響波の所定の波長の4分の1の略奇数倍であり、層中の第一の部材の位置が前記主面に平行な方向に互いにずれている複数のバッキング層がある。【選択図】図1
