POWER TRANSMISSION CONTROL DEVICE, POWER TRANSMISSION DEVICE, NON-CONTACT POWER TRANSMISSION SYSTEM, AND ELECTRONIC INSTRUMENT

• US 20090001932A1
• Filed: 06/27/2008
• Published: 01/01/2009
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Onishi, Kota, Hasegawa, Minoru, Kamiyama, Masayuki, Shiozaki, Nobutaka, Sogabe, Haruhiko, Kamijo, Takahiro
• Granted Patent: US 8,026,694 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: G01V 3/10 using induction coils
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00045 Authentication, i.e. circuits for checking compatibility between one component, e.g. a battery or a battery charger, and another component, e.g. a power source
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A power-transmission-side control circuit causes a power transmission device to perform temporary power transmission when a switch provided in a power-transmission-side instrument has been turned ON, and performs ID authentication based on ID authentication information. The power-transmission-side control circuit detects the presence or absence of a foreign object during normal power transmission by monitoring a change in induced voltage in a primary coil, causes the power transmission device to stop temporary power transmission when the ID authentication information from the power reception device has not been received within a given period of time, causes the power transmission device to stop temporary power transmission when the ID authentication has failed, and causes the power transmission device to stop normal power transmission when removal, a metal foreign object, a takeover state, or a full-charge state has been detected after normal power transmission has started.

Claims

1. A power transmission control device provided in a power transmission device, the power transmission device being included in a non-contact power transmission system that performs non-contact power transmission from the power transmission device to a power reception device through a primary coil and a secondary coil that are electromagnetically coupled, the power transmission control device comprising,

a power-transmission-side control circuit that controls power transmission to the power reception device,

the power-transmission-side control circuit causing the power transmission device to perform temporary power transmission to the power reception device to enable ID authentication on the power reception device when a switch provided in a power-transmission-side instrument has been turned ON, performing ID authentication based on ID authentication information transmitted from the power reception device that has received the temporary power transmission, causing the power transmission device to perform normal power transmission to the power reception device after the conformity of the power reception device has been authenticated by the ID authentication, and causing the power transmission device to stop the temporary power transmission and return to an initial state that waits for the switch to be turned ON when the ID authentication information from the power reception device has not been received within a given period of time after the temporary power transmission has started, or the ID authentication has failed.

2. The power transmission control device as defined in claim 1,

the power-transmission-side control circuit causing the power transmission device to stop the temporary power transmission and return to the initial state when the ID authentication has successively failed a plurality of times.

3. The power transmission control device as defined in claim 1,

the power-transmission-side control circuit causing the power transmission device to stop the normal power transmission and return to the initial state when a power transmission stop request from the power reception device has been received after the normal power transmission has started.

4. The power transmission control device as defined in claim 3,

the power transmission stop request being a full-charge notification from the power reception device.

5. The power transmission control device as defined in claim 1

the power-transmission-side control circuit causing the power reception device to perform the normal power transmission to the power reception device after the conformity of the power reception device has been authenticated by the ID authentication, determining the presence or absence of a foreign object during the normal power transmission based on a change in waveform of an induced voltage signal of the primary coil, and causing the power transmission device to stop the normal power transmission and return to the initial state when a foreign object has been detected.

6. The power transmission control device as defined in claim 1,

the power-transmission-side control circuit detecting whether or not a power-reception-side instrument has been removed based on a change in waveform of an induced voltage signal of the primary coil, and causing the power transmission device to stop the normal power transmission when the power-transmission-side control circuit has detected that the power-reception-side instrument has been removed during the normal power transmission.

7. The power transmission control device as defined in claim 1,

the power-transmission-side control circuit detecting whether or not a takeover state has occurred, the normal power transmission being continuously performed in the takeover state while erroneously regarding a foreign object placed between the primary coil and the secondary coil as a power-reception-side instrument, and causing the power transmission device to stop the normal power transmission and return to the initial state when the power-transmission-side control circuit has detected that the takeover state has occurred.

8. The power transmission control device as defined in claim 7,

the power-transmission-side control circuit detecting whether or not the takeover state has occurred by utilizing a phenomenon that a signal transmitted from the power reception device is blocked by the foreign object and does not reach the power transmission device.

9. The power transmission control device as defined in claim 7,

the power-transmission-side control circuit detecting an intermittent change in load of the power reception device, and causing the power transmission device to stop the normal power transmission when the power-transmission-side control circuit cannot detect an intermittent change in the load during the normal power transmission.

10. The power transmission control device as defined in claim 9,

the load of the power reception device being changed cyclically during the normal power transmission;

and

the power-transmission-side control circuit causing the power transmission device to stop the normal power transmission when the power-transmission-side control circuit cannot detect a change in the load over a given number of cycles.

11. A power transmission device comprising:

the power transmission control device as defined in claim 1; and

a power transmission section that generates an alternating-current voltage and supplies the alternating-current voltage to the primary coil.

17. An electronic instrument comprising:

a switch that causes power transmission to start or stop; and

the power transmission device as defined in claim 1.

12. A non-contact power transmission system comprising a power transmission device and a power reception device, when a switch provided in a power-transmission-side instrument has been turned ON, the non-contact power transmission system performing non-contact power transmission from the power transmission device to the power reception device through a primary coil and a secondary coil that are electromagnetically coupled,

the power transmission device including a power-transmission-side control circuit that controls power transmission to the power reception device based on an induced voltage in the primary coil;

the power reception device including;

a power supply control section that controls power supply to a power-supply-target load; and

a power reception control device that includes a power-reception-side control circuit that controls the power reception device; and

the power-transmission-side control circuit of the power transmission device causing the power transmission device to perform temporary power transmission to the power reception device to enable ID authentication on the power reception device when the switch provided in the power-transmission-side instrument has been turned ON, performing ID authentication based on ID authentication information transmitted from the power reception device that has received the temporary power transmission, causing the power transmission device to perform normal power transmission to the power reception device after the conformity of the power reception device has been authenticated by the ID authentication, and causing the power transmission device to stop the temporary power transmission and return to an initial state that waits for the switch to be turned ON when the ID authentication information from the power reception device has not been received within a given period of time after the temporary power transmission has started, or the ID authentication has failed.

13. The non-contact power transmission system as defined in claim 12,

the power-transmission-side control circuit causing the power reception device to perform the normal power transmission to the power reception device after the conformity of the power reception device has been authenticated by the ID authentication, determining the presence or absence of a foreign object during the normal power transmission based on a change in waveform of an induced voltage signal of the primary coil, causing the power transmission device to stop the normal power transmission and return to the initial state when a foreign object has been detected, and causing the power transmission device to stop the normal power transmission and return to the initial state when a power transmission stop request from the power reception device has been received after the normal power transmission has started.

14. The non-contact power transmission system as defined in claim 13,

the power reception device further including a load modulation section;

the power-reception-side control circuit causing the load modulation section to regularly operate to perform regular load authentication after the normal power transmission has started; and

the power-transmission-side control circuit of the power transmission device detecting a regular change in load of the power reception device, and causing the power transmission device to stop the normal power transmission when the power-transmission-side control circuit cannot detect a regular change in the load during the normal power transmission.

15. A non-contact power transmission system comprising a power transmission device and a power reception device, when a switch provided in a power-transmission-side instrument has been turned ON, the non-contact power transmission system performing non-contact power transmission from the power transmission device to the power reception device through a primary coil and a secondary coil that are electromagnetically coupled,

the power transmission device including a power-transmission-side control circuit that controls power transmission to the power reception device based on an induced voltage in the primary coil;

the power reception device including,

a load modulation section that modulates a load of the power reception device;

a power supply control section that controls power supply to a power-supply-target load; and

a power reception control device that includes a full-charge detection section that detects whether or not the power-supply-target load has been fully charged, and a power-reception-side control circuit that controls the power reception device;

the power-reception-side control circuit causing the power reception device to transmit ID authentication information to the power transmission device due to load modulation by the load modulation section when the power reception device has received the temporary power transmission from the power transmission device, causing the power supply control section to supply power to the power-supply-target load when the power reception device has received the normal power transmission from the power transmission device, causing the load modulation section to operate to intermittently change the load of the power reception device in order to detect a takeover state when power is supplied to the power-supply-target load, and transmitting a full-charge notification to the power transmission device due to load modulation by the load modulation section when the full-charge detection section has detected that the power-supply-target load has been fully charged; and

the power-transmission-side control circuit causing the power transmission device to perform the temporary power transmission to the power reception device to enable ID authentication on the power reception device when the switch has been turned ON, performing ID authentication based on the ID authentication information transmitted from the power reception device that has received the temporary power transmission, causing the power transmission device to stop the temporary power transmission and return to an initial state that waits for the switch to be turned ON when the ID authentication information from the power reception device has not been received within a given period of time after the temporary power transmission has started, causing the power transmission device to stop the temporary power transmission and return to the initial state when the ID authentication has failed, causing the power transmission device to perform the normal power transmission to the power reception device after the conformity of the power reception device has been authenticated by the ID authentication, detecting the presence or absence of a foreign object during the normal power transmission based on a change in waveform of an induced voltage signal of the primary coil, detecting whether or not the takeover state has occurred by determining whether or not a signal based on the intermittent load modulation by the power reception device can be detected, and causing the power transmission device to stop the normal power transmission and return to the initial state when a foreign object or the takeover state has been detected or it has been detected that the power-supply-target load of the power reception device has been fully charged.

16. The non-contact power transmission system as defined in claim 15,

when the power-reception-side control circuit causes the load of the power reception device to be intermittently changed during the normal power transmission, the power-reception-side control circuit performing a load reduction process that reduces a load state of the power-supply-target load by causing the power supply control section to reduce power supplied to the power-supply-target load.