Electroacoustic transducer, manufacturing method thereof, and electronic device utilizing same
View Patent ↗An electroacoustic transducer comprises a piezoelectric vibrator; a casing being provided with a predetermined space from the piezoelectric vibrator and including a frustum shape cutout in an inner wall thereof; and an acoustic absorption material being fitted in the cutout wherein a sound hole is formed in the casing in front of the piezoelectric vibrator in an oscillating direction of the piezoelectric vibrator; and the casing is formed in the casing such that a hole diameter of a sound path decreases toward a front end in the oscillating direction of the piezoelectric vibrator.
1. An electroacoustic transducer, comprising:
a piezoelectric vibrator;
a casing being provided with a predetermined space from the piezoelectric vibrator and including a frustum shape cutout in an inner wall thereof; and
an acoustic absorption material being fitted in the cutout;
wherein a sound hole is formed in the casing in front of the piezoelectric vibrator in an oscillating direction of the piezoelectric vibrator; and
the casing is formed in the casing such that a hole diameter of a sound path decreases toward a front end in the oscillating direction of the piezoelectric vibrator.
2. The electroacoustic transducer according to claim 1 , wherein the casing has the cutout including a truncated polygonal shape or truncated cone shape.
3. The electroacoustic transducer according to claim 1 , wherein the acoustic absorption material includes a porous material(s).
4. The electroacoustic transducer according to claim 1 , wherein the sound hole is formed at a distance between ¼ and ½ of a wave length of an oscillating wave(s) from a vibrating surface of the piezoelectric vibrator.
5. The electroacoustic transducer according to claim 1 , wherein the piezoelectric vibrator transmits an ultrasonic wave(s) having more than 20 kHz frequency.
6. An electroacoustic transducer comprising a plurality of the electroacoustic transducer according to claim 1 arranged in parallel on a plane.
7. An electronic device, comprising the electroacoustic transducer according to claim 1 , wherein the electronic device being configured to oscillate the piezoelectric vibrator such that an ultrasonic wave(s) having more than 20 kHz frequency is emitted.
8. A manufacturing method of an electroacoustic transducer comprising a piezoelectric vibrator and a casing, the manufacturing method comprising:
providing with a predetermined space from a piezoelectric vibrator;
forming a frustum shape cutout in an inner wall of the casing;
disposing a acoustic absorption fitted in the cutout; and
forming a sound hole in the casing in front of the piezoelectric vibrator in an oscillating direction of the piezoelectric vibrator;
wherein, the cutout is formed in the casing such that a hole diameter of a sound path decreases toward a front end in the oscillating direction of the piezoelectric vibrator.
9. The manufacturing method of the electroacoustic transducer according to claim 8 , wherein the cutout including a truncated polygonal shape or cone truncated cone shape is formed.
10. The manufacturing method of the electroacoustic transducer according to claim 8 , wherein the sound hole is formed at a distance between ¼ and ½ of a wave length of an oscillating wave(s) from a vibrating surface of the piezoelectric vibrator.