Power transmitter and wireless power transmission system

• US 9,001,922 B2
• Filed: 09/08/2011
• Issued: 04/07/2015
• Est. Priority Date: 09/10/2010
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Okamura, Shutai, Kinoshita, Keisuke, Kawamura, Junichi
• Primary Examiner(s): Bocure, Tesfaldet
• Application Number:
  US13/227,663
• Publication Number:
  US 20120063505A1
• Time in Patent Office: 1,307 Days
• US Class Current: 375/295
• CPC Class Codes: H02J 50/12 of the resonant type
• 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: H04B 5/00 Near-field transmission systems, e.g. inductive or capacitive transmission systems
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H04R 2201/028 Structural combinations of loudspeakers with built-in power amplifiers, e.g. in the same acoustic enclosure H04R2499/10 takes precedence; Single (sub)woofer with two or more satellite loudspeakers for mid- and high-frequency band reproduction driven via the (sub)woofer H04R2205/026
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones

Abstract

A power transmitter 50 is usable in a wireless power transmission system for transmitting power wirelessly. The power transmitter 50 includes a power transmitting section 51 for transmitting power; a communication section 52 for communicating information, for controlling the transmission of the power, with the power receiver 60; and a control section 53 for controlling the power transmitting section 51 such that the power to be sent out by the power transmitting section 51 is higher while the communication section 52 is performing the communication.

Claims

1. A power transmitter usable in a wireless power transmission system for transmitting power from the power transmitter to a power receiver wirelessly, the power transmitter comprising:

a power transmitting section for transmitting power;

a communication section for communicating information, for controlling the transmission of the power, with the power receiver; and

a control section for controlling the power transmitting section such that the power to be sent out is higher while the communication section is performing the communication than while the communication section is not performing the communication, wherein;

the power transmitting section transmits the power to be transmitted after converting the power into a pulse train; and

the control section controls the power transmitting section such that at least one of a pulse width and a pulse amplitude of the pulse train is larger while the communication section is performing the communication than while the communication section is not performing the communication.

2. The power transmitter of claim 1, wherein the control section controls the power transmitting section such that the pulse amplitude of the pulse train is larger while the communication section is performing the communication than while the communication section is not performing the communication.

3. The power transmitter of claim 1, wherein the control section controls the power transmitting section such that the pulse width of the pulse train is wider while the communication section is performing the communication than while the communication section is not performing the communication.

4. The power transmitter of claim 3, wherein:

the communication section starts communicating with the power receiver by transmitting a request signal to the power receiver; and

when the communication section transmits the request signal, the control section transmits a signal instructing to increase the pulse width of the pulse train to the power transmitting section.

5. The power transmitter of claim 3, wherein the power transmitting section generates the pulse train by pulse width modulation.

6. The power transmitter of claim 5, wherein:

the power transmitting section generates the pulse-width-modulated pulse train by comparing a waveform of the power to be transmitted against a triangular wave; and

the control section controls the power transmitting section so as to change an amplitude or a cycle of the triangular wave in accordance with whether the communication section is performing the communication or not.

7. The power transmitter of claim 5, wherein the control section instructs the power transmitting section to make the amplitude of the triangular wave relatively small while the communication section is performing the communication and to make the amplitude of the triangular wave relatively large while the communication section is not performing the communication.

8. The power transmitter of claim 5, wherein the control section instructs the power transmitting section to make the cycle of the triangular wave relatively long while the communication section is performing the communication and to make the cycle of the triangular wave relatively short while the communication section is not performing the communication.

9. The power transmitter of claim 1, further comprising a signal source for outputting a signal;

wherein the power transmitting section generates the pulse train by performing pulse width modulation on the signal output from the signal source.

10. The power transmitter of claim 9, wherein the signal is an audio signal.

11. The power transmitter of claim 1, wherein the power transmitting section includes:

a pulse width modulation section for outputting the pulse train by pulse width modulation;

an oscillation section for generating radio frequency power based on the pulse train output from the pulse width modulation section; and

a power transmission resonator for transmitting the radio frequency power generated by the oscillation section;

wherein the control section controls the power transmitting section by sending a control signal to the pulse width modulation section.

12. A wireless power transmission system comprising a power transmitter and a power receiver, wherein:

the power transmitter includes;

a power transmitting section for transmitting power;

a power transmitting-side communication section for communicating information, for controlling the transmission of the power, with the power receiver; and

a control section for controlling the power transmitting section such that the power to be sent out is higher while the power transmitting-side communication section is performing the communication than while the power transmitting-side communication section is not performing the communication; and

the power receiver includes;

a power receiving section for receiving the power sent out from the power transmitting section; and

a power receiving-side communication section for communicating with the power transmitting-side communication section,

wherein;

the power transmitting section transmits the power to be transmitted after converting the power into a pulse train; and

the control section controls the power transmitting section such that at least one of a pulse width and a pulse amplitude of the pulse train is larger while the communication section is performing the communication than while the communication section is not performing the communication.

13. The wireless power transmission system of claim 12, wherein:

the power transmitter further comprises a signal source for outputting a signal;

the power transmitting section generates the pulse train by performing pulse width modulation on the signal output from the signal source; and

the power receiver reproduces the signal from the power received by the power receiving section.