| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a piezoelectric sensor and an ultrasonic diagnostic apparatus with an improved S/N ratio in an electric signal in which the strength generated according to the stress of a piezoelectric material is weak. <P>SOLUTION: A piezoelectric plate 201 vibrates when a drive signal is applied to primary electrodes 204 and 205, and a transducer 2a outputs transmission ultrasonic waves toward a subject. The transducer 2a outputs a reception signal from a secondary electrode 206 when a stress is applied to the piezoelectric plate 201 with reflected ultrasonic waves from the subject. A noise output part 19 is connected to the primary electrodes 204 and 205, applies a weak voltage V<SB POS="POST">N</SB>including noise to the primary electrodes 204 and 205 when the stress is applied to the piezoelectric plate 201 with the reflected ultrasonic waves, and amplifies the reception signal by a stochastic resonance phenomenon. <P>COPYRIGHT: (C)2013,JPO&INPIT |
