Feed unit, feed system, and electronic device for increasing power supplied to a battery based on a device state and/or a control of a charging current

Abstract

A feed unit includes: a power transmission section configured to perform power transmission using a magnetic field or an electric field, to a device to be fed including a secondary battery; and a power-transmission control section configured to control power transmission operation in the power transmission section. In a charging period in which charging to the secondary battery is performed based on transmitted power in the power transmission, when the device to be fed including the secondary battery is activated, the power-transmission control section controls the power transmission operation, to increase the transmitted power.

1 . An electronic device, comprising:
 a power receiving coil configured to receive wireless power transmitted from a feed device;   a voltage converting circuit configured to generate a predetermined voltage based on the transmitted power;   a battery configured to receive the power from the voltage converting circuit; and   a control circuit configured to transmit a request to the feed device to:
 (i) decrease the transmitted power by one step in response to the transmitted power being larger than a minimum power value, and 
 (ii) increase the transmitted power by one step in response to the transmitted power being smaller than the minimum power value. 
   
     
     
         2 . The electronic device according to  claim 1 , wherein the request transmitted by the control circuit indicates to increase the transmitted power in response to changing from a first state to a second state of the electronic device by pushing a button of the electronic device, and
 wherein during the first state, the power receiving coil is configured to:
 receive a first power, which indicates a first power level, in response to storage of a first charge of the battery, 
 receive a second power, which indicates a second power level that is less than the first power level, in response to storage of a second charge of battery that is greater than the first change, and 
 receive a third power, which indicates a third power level that is less than the second power level, in response to a completion of a charging of the battery. 
   
     
     
         3 . The electronic device according to  claim 2 , wherein in response to the first charge being greater than a predetermined threshold, the request transmitted by the control circuit indicates to decrease the transmitted power. 
     
     
         4 . The electronic device according to  claim 3 , in response to the first charge being greater than the predetermined threshold, the feed device is configured to stepwise reduce the power wirelessly transmitted to the power receiving coil from the first power level to the second power level and then to the third power level. 
     
     
         5 . The electronic device according to  claim 2 , wherein the first state has a first load state and the second state has a second load state which is larger than the first load state. 
     
     
         6 . The electronic device according to  claim 2 , wherein the control circuit is configured to control the electronic device to enter the second state in a period before the power received by the power receiving coil is increased in response to the request transmitted to the feed device. 
     
     
         7 . The electronic device according to  claim 2 , wherein the second state includes a power-on state in which the electronic device is activated in response to a power button of the electronic device being activated, and the first state includes a power-off state in which the electronic device is not activated by the power button. 
     
     
         8 . A feed device, comprising:
 a power transmission coil configured to wirelessly supply power to an electronic device including a battery; and   a control circuit configured to:
 receive a request transmitted from the electronic device, and 
 determine whether to control the power transmission coil to increase or decrease the power wirelessly supplied to the electric device based on the request, 
   wherein in response to receiving the request from the electronic device, the control circuit is configured to:
 (i) decrease the power wirelessly supplied to the electric device by one step in response to the power wirelessly supplied to the electric device being larger than a minimum power value, and 
 (ii) increase the power wirelessly supplied to the electric device by one step in response to the power wirelessly supplied to the electric device being smaller than the minimum power value. 
   
     
     
         9 . The feed device according to  claim 8 , wherein
 the control circuit controls the power transmission coil to increase the power in response to changing a first state of the electronic device into a second state of the electronic device, and   during the first state of the electronic device, the control circuit controls the power transmission coil to:
 transmit a first power, which indicates a first power level, in response to storage of a first charge of the battery, 
 transmit a second power, which indicates a second power level that is less than the first power level, in response to storage of a second charge of battery that is greater than the first change, and 
 transmit a third power, which indicates a third power level that is less than the second power level, in response to a completion of a charging of the battery. 
   
     
     
         10 . The feed device according to  claim 9 , wherein in response to the first charge being greater than a predetermined threshold, the request transmitted by the electronic device indicates to decrease the transmitted power. 
     
     
         11 . The feed device according to  claim 10 , wherein in response to the first charge being greater than the predetermined threshold, the control circuit is configured to stepwise reduce the power wirelessly supplied to the electronic device from the first power level to the second power level and then to the third power level. 
     
     
         12 . The feed device according to  claim 9 , wherein the first state has a first load state and the second state has a second load state which is larger than the first load state. 
     
     
         13 . The feed device according to  claim 9 , wherein the electronic device is configured to enter the second state in a period before the power received by the power wirelessly supplied to the electronic device is increased in response to the request transmitted to the feed device. 
     
     
         14 . An electronic device, comprising:
 a power receiving coil configured to receive wireless power transmitted from a feed device;   a voltage converting circuit configured to generate a predetermined voltage based on the transmitted power;   a battery configured to receive the power from the voltage converting circuit; and   a control circuit configured to transmit a request to the feed device to:
 (i) decrease the transmitted power by one step in response to the transmitted power being larger than the minimum power value, and 
 (ii) increase the transmitted power by one step in response to the transmitted power being smaller than the minimum power value. 
   
     
     
         15 . The electronic device according to  claim 14 , wherein
 the request transmitted by the control circuit indicates to increase the transmitted power in response to changing a first state, in which a display of the electronic device is blank during the first state, into a second state in which information is shown on the display of the electronic device, and   during the first state, the power receiving coil is configured to:
 receive a first power, which indicates a first power level, in response to storage of a first charge of the battery, 
 receive a second power, which indicates a second power level that is less than the first power level, in response to storage of a second charge of battery that is greater than the first change, and 
 receive a third power, which indicates a third power level that is less than the second power level, in response to a completion of a charging of the battery. 
   
     
     
         16 . The electronic device according to  claim 15 , wherein in response to the first charge being greater than a predetermined threshold, the request transmitted by the control circuit indicates to decrease the transmitted power. 
     
     
         17 . The electronic device according to  claim 16 , in response to the first charge being greater than the predetermined threshold, the feed device is configured to stepwise reduce the power wirelessly transmitted to the power receiving coil from the first power level to the second power level and then to the third power level. 
     
     
         18 . The electronic device according to  claim 15 , wherein the first state has a first load state and the second state has a second load state which is larger than the first load state. 
     
     
         19 . The electronic device according to  claim 15 , wherein the control circuit is configured to control the electronic device to enter the second state in a period before the power received by the power receiving coil is increased in response to the request transmitted to the feed device. 
     
     
         20 . The electronic device according to  claim 15 , wherein the second state includes a power-on state in which the electronic device is activated in response to a power button of the electronic device being activated, and the first state includes a power-off state in which the electronic device is not activated by the power button.