| 摘要 |
PROBLEM TO BE SOLVED: To provide an electrostatic ultrasonic transducer; capable of attaining improvement in the output sound pressure, by increasing the valid film displacement amount of a vibrating membrane, and increasing an aperture of radiating holes (through-holes) radiating ultrasonic waves. SOLUTION: The electrostatic ultrasonic transducer includes a first electrode that has through-holes, a second electrode that has through-holes, and a vibrating membrane, that is disposed such that the through-holes of the first electrode and the through-holes of the second electrode form a pair, interposed between a pair of electrodes comprising the first electrode and the second electrode, and has a conductive layer applied with a direct current bias voltage. The first electrode and the second electrode each have counter electrode portions, formed in the through-holes that faces the vibrating membrane, and a modulated wave, which is obtained by modulating a carrier wave, in an ultrasonic frequency band with a signal wave in the audible frequency band, is applied between the pair of electrodes. COPYRIGHT: (C)2008,JPO&INPIT |
