Displacement sensor, displacement detecting device, and operation device
AssigneeMurata Manufacturing Co., Ltd.
InventorsMasamichi Ando, Hideki Kawamura
Life of this patent
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Abstract
A displacement sensor having a rectangular shaped elastic member. A piezoelectric element is attached to a first main face of the elastic member. The piezoelectric element has a rectangular-shaped piezoelectric sheet and electrodes on both main faces of the piezoelectric sheet. The piezoelectric sheet is made of poly-L-lactic acid and is at least uniaxially-stretched. The piezoelectric element is attached so that the uniaxial-stretching direction of the piezoelectric sheet is 45° relative to a long-side direction of the elastic member. When the elastic member is bent along the long-side direction, the piezoelectric sheet is stretched along the long-side direction, and the piezoelectric element generates voltage of predetermined level.
Claims17
An operation device comprising:
- a casing constructed to be deformed when subject to an external force;
- a displacement sensor which detects a displacement amount in a desired direction when the casing is deformed by the external force and outputs a detection voltage based thereon;
- and
- an application executing unit which executes a predetermined application in response to the detection voltage of the displacement sensor,
- wherein the displacement sensor has a flat-film-shaped piezoelectric element, the piezoelectric element including a pair of opposed electrodes and a piezoelectric sheet therebetween, and is configured to output the detection voltage generated based on a displacement of the flat-film-shaped piezoelectric element, and
- wherein the flat-film-shaped piezoelectric element is a first flat-film-shaped piezoelectric element, the displacement sensor further comprising:
- a second flat-film-shaped piezoelectric element, the second flat-film-shaped piezoelectric element including a pair of opposed electrodes and a piezoelectric sheet therebetween, and configured to output a second detection voltage of the second flat-film-shaped piezoelectric element according to a displacement thereof;
- and
- an elastic structure between the first and second flat-film-shaped piezoelectric elements, the elastic structure comprising:
- a first flat-plate-shaped elastic member;
- a second flat-plate-shaped elastic member;
- and
- a photovoltaic element having a flat plate shape disposed between the first and second flat-plate-shaped elastic members, wherein
- the first flat-plate-shaped elastic member and the first flat-film-shaped piezoelectric element are disposed on a wave-receiving-face side of the photovoltaic element, and the first flat-plate-shaped elastic member and the first flat-film-shaped piezoelectric element have translucency.
An operation device, comprising:
- a casing constructed to be deformed when subject to an external force;
- a displacement sensor which detects a displacement amount in a desired direction when the casing is deformed by the external force and outputs a detection voltage based thereon;
- and
- an application executing unit which executes a predetermined application in response to the detection voltage of the displacement sensor,
- wherein the displacement sensor comprises:
- an elastic member;
- a flat-film-shaped piezoelectric element, the piezoelectric element including a pair of opposed electrodes and a piezoelectric sheet therebetween;
- a first insulating element arranged between a first main surface side of the piezoelectric element and the elastic member;
- and
- a second insulating element arranged on a second main surface side of the piezoelectric element opposite to the first main surface side,
- wherein the piezoelectric sheet contains polylactic acid and was stretched at least in a uniaxial direction thereof, and
- wherein a Young's modulus of the second insulating element is higher than at least that of the piezoelectric sheet.
Dependencies are inferred from the claim text.