Method for controlling power transmission in wireless power transmission apparatus and wireless power transmission apparatus thereof

1. A method for controlling a power transmission in a wireless power transmission apparatus, the method comprising:

detecting whether a wireless power receiving apparatus is placed on or near the charging position by measuring a phase change or a current value change for a pulse signal transmitted via a primary core of the wireless power transmission apparatus;

starting a wireless charging by transmitting a wireless power signal to the wireless power receiving apparatus;

detecting via an object detecting sensor whether a foreign object is placed on or near a charging position of the wireless power transmission apparatus during the wireless charging;

calculating a power loss of the wireless charging by a controller of the wireless power transmission apparatus if the foreign object is detected by the object detecting sensor; and

stopping the wireless charging if the power loss is over a reference value,

wherein the detecting of whether the wireless power receiving apparatus is placed on or near the charging position by measuring the phase change or the current value change for the pulse signal transmitted via the primary core of the wireless power transmission apparatus, comprises:

transmitting the pulse signal to a first transmission coil and a second transmission coil of the primary core in turns;

measuring the phase change or the current value change of the pulse signal which is generated in one of the first transmission coil and the second transmission coil; and

detecting whether the wireless power receiving apparatus is placed on one of the first transmission coil and the second transmission coil, based on the phase change or the current value change.

2. The method of claim 1 , wherein the object detecting sensor is an infrared ray sensor.

3. The method of claim 2 , wherein the infrared ray sensor has a sensing angle over 120 degrees, and a sensing distance over 20 cm.

4. The method of claim 1 , further comprising:

measuring a heating temperature of the wireless power transmission apparatus if the power loss is less than or equal to the reference value; and

stopping the wireless charging if the heating temperature is over a reference temperature.

5. The method of claim 1 , wherein the calculating of the power loss of the wireless charging by the controller of the wireless power transmission apparatus if the foreign object is detected by the object detecting sensor, comprises:

calculating the power loss using a charging state information transmitted from the wireless power receiving apparatus.

6. A wireless power transmission apparatus, comprising:

a primary core to transmit a wireless power signal;

a transmission controller detects whether a wireless power receiving apparatus is placed on the charging position by measuring a phase change or a current value change for a pulse signal transmitted via the primary core of the wireless power transmission apparatus, and to start a wireless charging by transmitting a wireless power signal if the wireless power receiving apparatus is placed on or near the charging position; and

an object detecting sensor to detect a foreign object during the wireless charging; and

wherein the transmission controller to calculate a power loss of the wireless charging if the foreign object is detected by the object detecting sensor during the wireless charging, and to stop the wireless charging if the power loss is over a reference value,

wherein:

the primary core comprises a first transmission coil and a second transmission coil; and

the transmission controller transmits the pulse signal to the first transmission coil and the second transmission coil of the primary core in turns, to measure the phase change or the current value change of the pulse signal which is generated in one of the first transmission coil and the second transmission coil, and detect that the wireless power receiving apparatus is placed on one of the first transmission coil and the second transmission coil, based on the phase change or the current value change.

7. The apparatus of claim 6 , wherein the object detecting sensor is an infrared ray sensor.

8. The apparatus of claim 7 , wherein the infrared ray sensor has a sensing angle over 120 degrees, and a sensing distance over 20 cm.

9. The apparatus of claim 7 , wherein the object detecting sensor is installed on a protrusion portion formed at one side of the wireless power transmission apparatus.

10. The apparatus of claim 9 , further comprising: an indicator installed on the protrusion portion to show that the wireless charging works normally.

11. The apparatus of claim 6 , further comprising:

a temperature measuring unit to measure a heating temperature in the wireless power transmission apparatus if the power loss is less than or equal to the reference value;

wherein the transmission controller stops the wireless charging if the heating temperature is over the reference temperature.

12. A wireless power transmission system comprising:

a wireless power transmission apparatus comprising:

a primary core to transmit a wireless power during wireless charging,

a transmission controller detects whether a wireless power receiving apparatus is placed on the charging position by measuring a phase change or a current value change for a pulse signal transmitted via the primary core of the wireless power transmission apparatus, and to start a wireless charging by transmitting a wireless power signal if the wireless power receiving apparatus is placed on or near the charging position,

an object detecting sensor to detect a foreign object during the wireless charging,

wherein the transmission controller to calculate a power loss of the wireless charging if the foreign object is detected during the wireless charging, and to alter the wireless charging if the power loss is over a reference value,

wherein the primary core comprises a first transmission coil and a second transmission coil, and

wherein the transmission controller transmits the pulse signal to the first transmission coil and the second transmission coil of the primary core in turns, to measure the phase change or the current value change of the pulse signal which is generated in one of the first transmission coil and the second transmission coil, and detect that the wireless power receiving apparatus is placed on one of the first transmission coil and the second transmission coil, based on the phase change or the current value change; and

the wireless power receiving apparatus which receives the wireless power from the primary core.

13. The wireless power transmission system of claim 12 , wherein the object detecting sensor detects whether the foreign object is on or near a charging position of the wireless power transmission apparatus and the wireless power receiving apparatus receives the wireless power from the primary core when the wireless power receiving apparatus is on or near the charging position of the wireless power transmission apparatus.