FOREIGN OBJECT DETECTING DEVICE, WIRELESS POWER TRANSMITTING APPARATUS, AND WIRELESS POWER TRANSFER SYSTEM
First Claim
1. A foreign object detecting device comprising:
- a first coil that includes a first wound wire having first and second terminals;
a second coil that includes a second wound wire having third and fourth terminals and is disposed adjacent to the first coil, a winding direction of the second wound wire from the third terminal to the fourth terminal being the same as a winding direction of the first wound wire from the first terminal to the second terminal; and
one foreign object detecting circuit operative to;
output first detecting signal having a first predetermined waveform to the first terminal of the first coil and output a second detecting signal having a second predetermined waveform to the third terminal of the second coil to cause a first magnetic field generated from the first coil and a second magnetic field generated from the second coil to repel each other, a polarity of the second predetermined waveform being the same as a polarity of the first predetermined waveform, the repelled first and the second magnetic field being disposed between the first and second coils;
measure an amount of change of an impedance value with respect to one of the first and second coils which is caused by the presence of a foreign object; and
determine that a foreign object above the first coil or the second coil is present if the amount of change exceeds a predetermined value,wherein potential of each of the second and fourth terminals is at the same potential as reference potential of the foreign object detecting circuit,
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Accused Products
Abstract
A foreign object detecting device includes first and second coils, the winding directions of which are the same, and a foreign object detecting circuit. The foreign object detecting circuit outputs a first detecting signal having a first predetermined waveform to a first terminal of the first coil and outputs a second detecting signal having a second predetermined waveform, which has the same polarity as the first predetermined waveform, to a third terminal of the second coil to cause magnetic fields generated from the first and second coils to repel each other. The foreign object detecting circuit measures an amount of change of the impedance value of the first or second coil which is caused by the presence of a foreign object. When the amount of change exceeds a predetermined value, the foreign object detecting circuit determines that there is a foreign object above the first or second coil.
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Citations
20 Claims
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1. A foreign object detecting device comprising:
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a first coil that includes a first wound wire having first and second terminals; a second coil that includes a second wound wire having third and fourth terminals and is disposed adjacent to the first coil, a winding direction of the second wound wire from the third terminal to the fourth terminal being the same as a winding direction of the first wound wire from the first terminal to the second terminal; and one foreign object detecting circuit operative to; output first detecting signal having a first predetermined waveform to the first terminal of the first coil and output a second detecting signal having a second predetermined waveform to the third terminal of the second coil to cause a first magnetic field generated from the first coil and a second magnetic field generated from the second coil to repel each other, a polarity of the second predetermined waveform being the same as a polarity of the first predetermined waveform, the repelled first and the second magnetic field being disposed between the first and second coils; measure an amount of change of an impedance value with respect to one of the first and second coils which is caused by the presence of a foreign object; and determine that a foreign object above the first coil or the second coil is present if the amount of change exceeds a predetermined value, wherein potential of each of the second and fourth terminals is at the same potential as reference potential of the foreign object detecting circuit, - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A foreign object detecting device comprising:
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a coil group including three or more coils that includes a wound wire having first and second terminals, the three or more coils including first and second coils which are adjacent to each other, a winding direction of the first coil from the first terminal to the second terminal being the same as a winding direction of the second coil from the first terminal to the second terminal; a foreign object detecting circuit operative to; select the first and second coils which are adjacent to each other from the coil group; output a first detecting signal having a first predetermined waveform to the first terminal of the first coil and a second detecting signal having a second predetermined waveform to the first terminal of the second coil to cause a first magnetic field generated from the first coil and a second magnetic field generated from the second coil to repel each other between the first and second coils, a polarity of the second predetermined waveform being the same as a polarity of the first predetermined waveform; measure an amount of an impedance value with respect to one of the first and second coils which is caused by the presence of a foreign object; and determine that a foreign object above the first coil or the second coil is present if the amount of change exceeds a predetermined value, wherein potential of each of the second terminals of the first and second coils is at the same potential as reference potential of the foreign object detecting circuit. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. A foreign object detecting device comprising:
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a first coil on which a wire is wound; a second coil on which a wire is wound and that is disposed adjacent to the first coil; and a foreign object detecting circuit operative to; output a first detecting signal having a first predetermined waveform to the first coil and a second detecting signal having a second predetermined waveform to the second coil to cause both of a current based on the first detecting signal flowing through the first coil and a current based on the second detecting signal flowing through the second coil to flow clockwise or counterclockwise so that a first magnetic field generated from the first coil and a second magnetic field generated from the second coil repel each other, the repelled first and the second magnetic field being disposed between the first and second coils; measure an amount of an impedance value with respect to one of the first and second coils which is caused by the presence of a foreign object; and determine that a foreign object above the first coil or the second coil is present if the amount of change exceeds a predetermined value.
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Specification