Sensing device, power reception device, power transmission device, non-contact power transmission system, and sensing method
First Claim
Patent Images
1. A sensing device comprising:
- a circuit including a coil that can be electromagnetically coupled to another coil outside of the circuit and a capacitor coupled in series with the coil;
a temperature measuring unit that measures a temperature of the coil;
a sensing unit that measures a measured Q value of the circuit across the capacitor;
a correction unit that generates a temperature-corrected measured Q value using the temperature measured by the temperature measuring unit; and
a determination unit that compares the temperature-corrected measured Q value with a threshold Q value and determines the presence or absence of a metallic foreign material sufficiently proximate the sensing unit,wherein,the threshold Q value is either (a) a predetermined Q value corresponding to a Q value for the circuit when the metallic foreign material is not sufficiently proximate the sensing unit to affect the measured Q value or (b) a temperature-corrected predetermined Q value corresponding to the Q value for the circuit when the metallic foreign material is not sufficiently proximate the sensing unit to affect the measured Q value as corrected for coil temperature.
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Abstract
There is provided a sensing device including a circuit including at least a coil electromagnetically coupled to an outside; a temperature detection unit for detecting a temperature of the coil; a sensing unit for measuring a Q value of the circuit; and a correction unit for correcting the Q value measured by the sensing unit based on temperature information detected by the temperature detection unit.
23 Citations
15 Claims
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1. A sensing device comprising:
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a circuit including a coil that can be electromagnetically coupled to another coil outside of the circuit and a capacitor coupled in series with the coil; a temperature measuring unit that measures a temperature of the coil; a sensing unit that measures a measured Q value of the circuit across the capacitor; a correction unit that generates a temperature-corrected measured Q value using the temperature measured by the temperature measuring unit; and a determination unit that compares the temperature-corrected measured Q value with a threshold Q value and determines the presence or absence of a metallic foreign material sufficiently proximate the sensing unit, wherein, the threshold Q value is either (a) a predetermined Q value corresponding to a Q value for the circuit when the metallic foreign material is not sufficiently proximate the sensing unit to affect the measured Q value or (b) a temperature-corrected predetermined Q value corresponding to the Q value for the circuit when the metallic foreign material is not sufficiently proximate the sensing unit to affect the measured Q value as corrected for coil temperature. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A power reception device comprising:
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a circuit including a coil that electromagnetically receives power from outside the circuit and a capacitor coupled in series with the coil; a temperature measuring unit that measures a temperature of the coil; a sensing unit that measures a measured Q value of the circuit; a correction unit that generates a temperature-corrected measured Q value using the temperature measured by the temperature measuring unit; and a determination unit that compares the temperature-corrected measured Q value with a threshold Q value and determines the presence or absence of a metallic foreign material sufficiently proximate the sensing unit, wherein, the threshold Q value is either (a) a predetermined Q value corresponding to a Q value for the circuit when the metallic foreign material is not sufficiently proximate the sensing unit to affect the measured Q value or (b) a temperature-corrected predetermined Q value corresponding to the Q value for the circuit when the metallic foreign material is not sufficiently proximate the sensing unit to affect the measured Q value as corrected for coil temperature.
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12. A power transmission device comprising:
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a circuit including a coil that electromagnetically transmits power to an outside of the circuit and a capacitor coupled in series with the coil; a temperature measuring unit that measures a temperature of the coil; a sensing unit that measures a measured Q value of the circuit across the capacitor; a correction unit that generates a temperature-corrected measured Q value using the temperature measured by the temperature measuring unit; and a determination unit that compares the temperature-corrected measured Q value with a threshold Q value and determines the presence or absence of a metallic foreign material sufficiently proximate the unit, wherein, the threshold Q value is either (a) a predetermined Q value corresponding to a Q value for the circuit when the metallic foreign material is not sufficiently proximate the unit to affect the measured Q value or (b) a temperature-corrected predetermined Q value corresponding to the Q value for the circuit when the metallic foreign material is not sufficiently proximate the sensing unit to affect the measured Q value as corrected for coil temperature.
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13. A non-contact power transmission system comprising (a) a power transmission device for wirelessly transmitting power;
- and (b) a power reception device for receiving the power from the power transmission device, one of the power transmission device or the power reception device including;
a circuit with a coil electromagnetically coupled to another coil in the other of the power reception device or the power transmission device and a capacitor coupled in series with the coil; a temperature measuring unit that measures a temperature of the coil; a sensing unit that measures a measured Q value of the circuit across the capacitor; a correction unit that generates a temperature-corrected measured Q value using the temperature measured by the temperature measuring unit; and a determination unit that compares the temperature-corrected measured Q value with a threshold Q value and determines the presence or absence of a metallic foreign material sufficiently proximate the sensing unit, wherein, the threshold Q value is either (a) a predetermined Q value corresponding to a Q value for the circuit when the metallic foreign material is not sufficiently proximate the sensing unit to affect the measured Q value or (b) a temperature-corrected predetermined Q value corresponding to the Q value for the circuit when the metallic foreign material is not sufficiently proximate the sensing unit to affect the measured Q value as corrected for coil temperature.
- and (b) a power reception device for receiving the power from the power transmission device, one of the power transmission device or the power reception device including;
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14. A sensing method comprising:
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providing a circuit including (a) a coil that can be electromagnetically coupled to an outside of the circuit and a capacitor coupled in series with the coil, (b) a temperature measuring unit that can measure a temperature of the coil, (c) a sensing unit that can measure a measured Q value of the circuit across the capacitor, (d) a correction unit that can generate a temperature-corrected measured Q value using the temperature measured by the temperature measuring unit, and (e) a determination unit that can compare the temperature-corrected measured Q value with a threshold Q value and determine the presence of a metallic foreign material sufficiently proximate the sensing unit, the method comprising the steps of; measuring the temperature of the coil with the temperature measuring unit; measuring the measured Q value of the circuit with the sensing unit; generating the temperature-corrected Q value for the circuit with the correction unit; comparing the temperature-corrected Q value and the threshold Q value with the determination unit; and determining with the determination unit the presence of the metallic foreign material when it is sufficiently proximate the sensing unit when the temperature-corrected Q value exceeds the threshold Q value, wherein, the threshold Q value is either (a) a predetermined Q value corresponding to a Q value for the circuit when the metallic foreign material is not sufficiently proximate the sensing unit to affect the measured Q value or (b) a temperature-corrected predetermined Q value corresponding to the Q value for the circuit when the metallic foreign material is not sufficiently proximate the sensing unit to affect the measured Q value as corrected for coil temperature. - View Dependent Claims (15)
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Specification