US 12,123,798 B2
Pressure sensor
Hisayuki Yazawa, Niigata-ken (JP); Hisanobu Okawa, Niigata-ken (JP); Masahiko Ishizone, Niigata-ken (JP); Toru Takahashi, Niigata-ken (JP); and Ayako Otsuka, Niigata-ken (JP)
Assigned to ALPS ALPINE CO., LTD., Tokyo (JP)
Filed by Alps Alpine Co., Ltd., Tokyo (JP)
Filed on Aug. 25, 2021, as Appl. No. 17/411,406.
Application 17/411,406 is a continuation of application No. PCT/JP2020/007236, filed on Feb. 21, 2020.
Claims priority of application No. 2019-036554 (JP), filed on Feb. 28, 2019.
Prior Publication US 2021/0381918 A1, Dec. 9, 2021
Int. Cl. G01L 9/08 (2006.01); H10N 30/30 (2023.01); H10N 30/80 (2023.01)
CPC G01L 9/08 (2013.01) [H10N 30/302 (2023.02); H10N 30/802 (2023.02)] 10 Claims
OG exemplary drawing
 
1. A pressure sensor comprising:
a diaphragm on a substrate; and
a plurality of piezoelectric element areas that change in resistance according to distortion of the diaphragm,
wherein the plurality of piezoelectric element areas include a first piezoelectric element area, a second piezoelectric element area, a third piezoelectric element area, and a fourth piezoelectric element area,
wherein the first piezoelectric element area and the second piezoelectric element area are connected in series via a first output terminal, the third piezoelectric element area and the fourth piezoelectric element area are connected in series via a second output terminal, the first piezoelectric element area and the third piezoelectric element area are connected via an input terminal, the second piezoelectric element area and the fourth piezoelectric element area are connected via a grounding terminal, and the first piezoelectric element area to the fourth piezoelectric element area constitute a full bridge circuit, wherein, when the diaphragm is distorted, the resistance of the second piezoelectric element area and the third piezoelectric element area increases, and the resistance of the first piezoelectric element area and the fourth piezoelectric element area decreases,
wherein the diaphragm has a maximum deflection area whose stress becomes 80% or more of a maximum stress when distorted by a predetermined pressure, and
wherein the first piezoelectric element area, the second piezoelectric element area, the third piezoelectric element area, and the fourth piezoelectric element area are disposed in the maximum deflection area.