ULTRASONIC HOLOGRAPHY IMAGING DEVICE HAVING A MACROMOLECULAR PIEZOELECTRIC ELEMENT AS A TRANSDUCER

摘要

An ultrasonic image device such as may be used in a holography system or scanning system and having a piezoelectric transducer in which the conversion efficiency and phase are substantially constant over a wide frequency range. A piezoelectric sheet 5 .mu.m to 1000 .mu.m thick is used for a piezoelectric element. The piezoelectric sheet is constructed of a macromolecular material including polymers and copolymers of polar monomers. A high frequency signal input device applies to the electrodes coupled to the piezoelectric sheet high frequency signals of different frequencies in a frequency range around a fundamental resonance frequency of the piezoelectric sheet of ?10 to ?70% of the fundamental resonance frequency.