US 12,384,671 B2
MEMS microphone
Kazuki Itoyama, Tokyo (JP); Hajime Kano, Tokyo (JP); Yuki Uchida, Tokyo (JP); Takuma Yoshida, Tokyo (JP); Mitsuaki Daio, Tokyo (JP); and Yasuhiro Horimoto, Tokyo (JP)
Assigned to MMI SEMICONDUCTOR CO., LTD., Tokyo (JP)
Filed by Kazuki Itoyama, Tokyo (JP); Hajime Kano, Tokyo (JP); Yuki Uchida, Tokyo (JP); Takuma Yoshida, Tokyo (JP); Mitsuaki Daio, Tokyo (JP); and Yasuhiro Horimoto, Tokyo (JP)
Filed on Mar. 22, 2023, as Appl. No. 18/187,820.
Claims priority of application No. 2022-049224 (JP), filed on Mar. 25, 2022.
Prior Publication US 2023/0303388 A1, Sep. 28, 2023
Int. Cl. B81B 3/00 (2006.01)
CPC B81B 3/0021 (2013.01) [B81B 2201/0257 (2013.01); B81B 2203/0127 (2013.01); B81B 2203/0315 (2013.01); B81B 2203/0353 (2013.01); B81B 2203/04 (2013.01); B81B 2207/015 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A micro electro mechanical systems (MEMS) microphone comprising:
a diaphragm having conductivity;
a first variable capacitor including a first fixed electrode facing the diaphragm, a capacitance of the first variable capacitor being changed in accordance with a vibration of the diaphragm;
a second variable capacitor including a second fixed electrode facing the diaphragm, a capacitance of the second variable capacitor being changed in accordance with the vibration of the diaphragm;
a first voltage output section configured to output a first voltage that is changed in accordance with a change in the capacitance of the first variable capacitor; and
a second voltage output section configured to output a second voltage that is changed in accordance with a change in the capacitance of the second variable capacitor,
wherein a first bias voltage is applied to the first fixed electrode,
wherein a reference voltage is applied to the second fixed electrode, and
wherein a second bias voltage is applied to the diaphragm, a difference between the second bias voltage and the reference voltage being half of a difference between the first bias voltage and the reference voltage.