ELECTROSTATIC TYPE ULTRASONIC TRANSDUCER, ULTRASONIC LOUDSPEAKER, METHOD FOR REPRODUCING SOUND SIGNAL OF ELECTROSTATIC TYPE ULTRASONIC TRANSDUCER, DISPLAY DEVICE AND DIRECTIONAL ACOUSTIC SYSTEM

摘要

PROBLEM TO BE SOLVED: To increase the vibration area and aperture rate of a diaphragm, and to obtain a large amplitude at a low voltage in an electrostatic type ultrasonic transducer.;SOLUTION: The electrostatic type ultrasonic transducer contains a first electrode with a slitlike through-hole and a second electrode with the slitlike through-hole. The transducer further contains the diaphragm being arranged so that the slitlike through-hole of the first electrode and the slitlike through-hole of the second electrode are paired, being held by a pair of the electrodes consisting of the first electrode and the second electrode while having a conductive layer and applying a DC bias voltage to the conductive layer. The transducer has electrode layers arranged in parallel in the longitudinal direction of the slitlike through-holes at a specified space to a surface in the case of the unvibrating of the diaphragm in the depth direction in the first and second slitlike through-holes, and modulating waves modulating carrier waves in an ultrasonic frequency band by signal waves in an audio frequency band are applied between the electrode layers in a pair of the electrodes.;COPYRIGHT: (C)2008,JPO&INPIT