Electrode unit, power transmitting device, power receiving device, electronic device, vehicle, and wireless power transmission system

Abstract

An electrode unit for use in a power transmitting device to transfer electric power to an object that is configured to be provided at a first position and at a second position of the power transmitting device and includes a power receiving device to receive electric power from the power transmitting device at the first position and at the second position. The electrode unit includes a first group of electrodes to which a first voltage is applied when power is transmitted and second group of electrodes to which a second voltage is applied when power is transmitted, wherein the second voltage has a phase that is different from a phase of the first voltage by a value greater than 90 degrees and less than 270 degrees.

What is claimed is: 
     
         1 . An electrode unit for use in a power transmitting device to transfer electric power to an object that is configured to be provided at a first position and at a second position of the power transmitting device and includes a power receiving device to receive electric power from the power transmitting device at the first position and at the second position, the electrode unit comprising:
 a first group of electrodes including a plurality of first electrodes which is configured to be provided through the first position and the second position and to which a first voltage is applied when power is transmitted; and   a second group of electrodes including a plurality of second electrodes which is configured to be provided through the first position and the second position and to which a second voltage is applied when power is transmitted, wherein the second voltage has a phase that is different from a phase of the first voltage by a value greater than 90 degrees and less than 270 degrees, wherein:   the plurality of first electrodes and the plurality of second electrodes are arranged in a first direction along an electrode installation surface;   at least two of the plurality of first electrodes and at least two of the plurality of second electrodes are arranged alternating with each other in the first direction;   each of the plurality of first electrodes and the plurality of second electrodes extends in a second direction along the electrode installation surface, the second direction intersecting the first direction; and   the second direction is the direction along a line connecting the first position and the second position.   
     
     
         2 . The electrode unit according to  claim 1 , wherein:
 the plurality of first electrodes are electrically connected to each other on a first side thereof in the second direction; and   the plurality of second electrodes are electrically connected to each other on a second side thereof, opposite to the first side, in the second direction.   
     
     
         3 . The electrode unit according to  claim 1 , further comprising at least one third electrode arranged with a gap from the first and second groups of electrodes, the at least one third electrode having a third voltage whose amplitude is less than amplitudes of the first and second voltages when power is transmitted,
 wherein at least a portion of the at least one third electrode is located outside an area that is defined by the first and second groups of electrodes as seen from a direction perpendicular to the electrode installation surface.   
     
     
         4 . The electrode unit according to  claim 1 , wherein at least one of two electrodes of the first group of electrodes and the second group of electrodes that are located at opposite sides has a width that is smaller than a width of another electrode that is adjacent to the at least one of the two electrodes. 
     
     
         5 . The electrode unit according to  claim 1 , wherein two electrodes of the first group of electrodes and the second group of electrodes that are located at opposite sides have a width that is smaller than a width of any other electrode. 
     
     
         6 . The electrode unit according to  claim 5 , wherein 0.1≤ws/wc≤0.6 is satisfied, where ws is a width of two electrodes of the first group of electrodes and the second group of electrodes that are located at opposite sides, and wc is a width of the other electrodes. 
     
     
         7 . A power transmitting device comprising:
 the electrode unit according to  claim 1 ; and   a power transmitting circuit supplying AC power to the first group of electrodes and the second group of electrodes of the electrode unit.   
     
     
         8 . A wireless power transmission system based on an electric field coupling method, comprising:
 a power transmitting device; and   an object that is configured to be provided at a first position of the power transmitting device and at a second position of the power transmitting device and to receive electric power from the power transmitting device; wherein   the power transmitting device comprising:
 an electrode unit including:
 a first group of electrodes including a plurality of first electrodes which is configured to be provided through the first position and the second position and to which a first voltage is applied when power is transmitted; and 
 a second group of electrodes including a plurality of second electrodes which is configured to be provided through the first position and the second position and to which a second voltage is applied when power is transmitted, wherein the second voltage has a phase that is different from a phase of the first voltage by a value greater than 90 degrees and less than 270 degrees, wherein: 
 the plurality of first electrodes and the plurality of second electrodes are arranged in a first direction along an electrode installation surface; 
 at least two of the plurality of first electrodes and at least two of the plurality of second electrodes are arranged alternating with each other in the first direction; 
 each of the plurality of first electrodes and the plurality of second electrodes extends in a second direction along the electrode installation surface, the second direction intersecting the first direction; and 
 the second direction is the direction along a line connecting the first position and the second position; and 
 
 a power transmitting circuit supplying AC power to the first group of electrodes and the second group of electrodes of the electrode unit, wherein 
   the object comprising:
 another electrode unit which is configured to receive electric power from the electrode unit of the power transmitting device; 
 a power receiving circuit for converting the AC power received by the other electrode unit to DC power or another form of AC power; and 
 a load that is driven by the electric power converted by the power receiving circuit.