| 摘要 |
PURPOSE:To prevent short-circuit between a lambda/4 plate and a driving electrode or the disconnection of the driving electrode due to mechanical contact with the lambda/4 plate by extending a part of a macromolecule piezoelectric body from the end part of a rectangular electrode in the longitudinal direction of the rectangular electrode. CONSTITUTION:Macromolecule piezoelectric bodies 11 and 11' are extended along with the longitudinal direction of driving electrodes 3 and 3' against a common electrode 2, a lambda/4 plate 6 which serves as the common electrode and the acoustic operation areas 3a and 3a' of the rectangular driving electrodes 3 and 3'. The length A of extended portion of the macromolecule piezoelectric bodies 11 and 11' can be appropriately decided according to the shape, the size and the thickness of each layer of a whole ultrasonic probe, but it is preferable to be nearly 3-10mm. As the macromolecule piezoelectric body, fluorine- containing macromolecule, such as PVF2, PVF2.TrFE or polyvinylidene fluoride.ethylene fluoride copolymer, or polyacrylonitrile copolymer of ferroelectrics ceramic are recommended.
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