Bending sensor and electronic apparatus
AssigneeMurata Manufacturing Co., Ltd.
InventorsYuuki Tachibana, Shiori Nagamori
Life of this patent
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Abstract
A bending sensor is provided that includes a piezoelectric element disposed on a bendable substrate; a voltage detection circuit that detects a voltage generated in the piezoelectric element; and an arithmetic unit that calculates an integrated value by integrating the voltage detected by the voltage detection circuit and associates the integrated value with a bent state of the substrate. Moreover, the arithmetic unit calculates in advance a corrected integrated value obtained by correcting a maximum value of the integrated value with a decrease value resulting from a stress relieving effect, associates the corrected integrated value with a first bent state of the substrate, and normalizes a calculated integrated value based on the corrected integrated value.
Claims18
A bending sensor comprising:
- a piezoelectric element disposed on a bendable substrate;
- a voltage detection circuit configured to detect a voltage generated in the piezoelectric element;
- and
- an arithmetic unit configured to calculate an integrated value by integrating the voltage detected by the voltage detection circuit and to associate the integrated value with a bending angle of the substrate, wherein the arithmetic unit is further configured to:
- calculate, in advance, a corrected integrated value obtained by correcting a maximum value of the integrated value with a decrease value resulting from a stress relieving effect of the bending sensor,
- associate the corrected integrated value with a first bending angle of the substrate, and
- normalize the calculated integrated value based on the corrected integrated value,
- wherein the bendable substrate is configured to be bent at a first folding position along an X axis or configured to be bent at a second folding position along a Y axis, wherein the X axis extends in a width direction of the bending sensor and the Y axis extends in a length direction of the bending sensor, and
- wherein, when the integrated value exceeds the corrected integrated value, the arithmetic unit is configured to change the integrated value based on a difference between the integrated value and the corrected integrated value.
A bending sensor comprising:
- a piezoelectric element disposed on a bendable substrate;
- a voltage detection circuit configured to detect a voltage generated in the piezoelectric element;
- and
- an arithmetic unit configured to calculate an integrated value by integrating the voltage detected by the voltage detection circuit and to associate the integrated value with a bending angle of the substrate, wherein the arithmetic unit is further configured to:
- calculate, in advance, a corrected integrated value obtained by correcting a maximum value of the integrated value with a decrease value resulting from a stress relieving effect of the bending sensor,
- associate the corrected integrated value with a first bending angle of the substrate, and
- normalize the calculated integrated value based on the corrected integrated value,
- wherein the bendable substrate is configured to be bent at a first folding position along an X axis or configured to be bent at a second folding position along a Y axis, wherein the X axis extends in a width direction of the bending sensor and the Y axis extends in a length direction of the bending sensor, and
- wherein the arithmetic unit is further configured to:
- obtain a rolling average of voltage values detected by the voltage detection circuit, and
- set a reference voltage based on the rolling average when there is no voltage fluctuation in the voltage values detected by the voltage detection circuit for a first predetermined time.
A method for detecting a bending state of an electronic apparatus, the method comprising:
- detecting, by a voltage detection circuit of a bending sensor, a voltage generated in a piezoelectric element disposed on a bendable substrate;
- calculating an integrated value by integrating the voltage detected by the voltage detection circuit;
- associating the integrated value with a bending angle of the substrate;
- calculating a corrected integrated value obtained by correcting a maximum value of the integrated value with a decrease value resulting from a stress relieving effect of the bending sensor;
- associating the corrected integrated value with a first bending angle of the substrate;
- and
- normalizing the calculated integrated value based on the corrected integrated value;
- the bendable substrate is configured to be bent with a first folding position along an X axis or configured to be bent with a second folding position along a Y axis, wherein the X axis extends in a width direction and the Y axis extends in a length direction;
- further comprising changing the integrated value based on a difference between the integrated value and the corrected integrated value when the integrated value exceeds the corrected integrated value.
Dependencies are inferred from the claim text.