U.S. patent application number 15/816908 was filed with the patent office on 2018-03-15 for power supply device, electronic device, control method, and recording medium.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Yudai Fukaya.
Application Number | 20180076632 15/816908 |
Document ID | / |
Family ID | 48869601 |
Filed Date | 2018-03-15 |
United States Patent
Application |
20180076632 |
Kind Code |
A1 |
Fukaya; Yudai |
March 15, 2018 |
POWER SUPPLY DEVICE, ELECTRONIC DEVICE, CONTROL METHOD, AND
RECORDING MEDIUM
Abstract
A power supply device includes a power supply unit that
wirelessly supplies power, a communication unit that communicates
with an electronic device, and a control unit that controls the
communication unit to transmit a predetermined data to the
electronic device based on whether or not the electronic device is
connected to an external device supplying power to the electronic
device.
Inventors: |
Fukaya; Yudai;
(Kawasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
48869601 |
Appl. No.: |
15/816908 |
Filed: |
November 17, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13753345 |
Jan 29, 2013 |
9825466 |
|
|
15816908 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02J 7/00034 20200101;
H02J 50/20 20160201; H02J 7/0036 20130101; Y10T 307/696 20150401;
Y10T 307/391 20150401; H02J 7/025 20130101; H02J 7/00 20130101;
H02J 7/00716 20200101; H02J 50/12 20160201 |
International
Class: |
H02J 4/00 20060101
H02J004/00; H02J 7/00 20060101 H02J007/00; H02J 50/20 20060101
H02J050/20; H02J 7/02 20060101 H02J007/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 1, 2012 |
JP |
2012-020012 |
Claims
1. A wireless power system including a power supply device and a
power receiving device, the power supply system comprising: a power
receiving unit that receives power wirelessly from the power supply
device; a connection unit that connects between the power receiving
device and an external device, the external device being different
from the power supply device; a control unit that controls the
power receiving device to receive power from the external device in
a case where the power receiving device is in a state that enables
the power receiving device to receive power from the external
device through a connection between the power receiving device and
the external device, the external device being different from the
power supply device, and to receive power from the power supply
device in a case where the power receiving device is not in the
state that enables the power receiving device to receive power from
the external device.
2. The wireless power system according to claim 1, wherein the
control unit that transmits via the communication unit first data
to the power receiving device if the power receiving device and the
external device are connected.
3. The wireless power system according to claim 2, wherein the
control unit continues to communicate with the power receiving
device after the first data is transmitted to the power receiving
device.
4. The wireless power system according to claim 1, wherein the
control unit controls the communication unit to transmit second
data to the power receiving device if the power receiving device
and the external device are not connected.
5. The wireless power system according to claim 1, wherein the
control unit controls the power supply unit to limit power for
supplying to the power receiving device if the power receiving
device and the external device are connected.
6. The wireless power system according to claim 1, wherein the
control unit controls the communication unit to transmit
predetermined data to the power receiving device based on a first
level and a second level if the power receiving device and the
external device are connected, and wherein the first level
indicates a level of power supplied from the power supply device to
the power receiving device, and the second level indicates a level
of power supplied from the external device to the power receiving
device.
7. The wireless power system according to claim 6, wherein the
control unit controls the communication unit to transmit second
data to the power receiving device if the first level is higher
than the second level.
8. The wireless power system according to claim 6, wherein the
control unit controls the communication unit to transmit first data
to the power receiving device if the first level is not higher than
the second level.
9. The wireless power system according to claim 1, wherein the
control unit controls the power supply unit to supply predetermined
power to the power receiving device if the power receiving device
and the external device are not connected, and the predetermined
power is used for charging a battery.
10. The wireless power system according to claim 1, further
comprising a detection unit that detects one or more power
receiving devices, wherein, if the detection unit detects a
plurality of power receiving devices, the control unit controls the
communication unit to transmit command to the plurality of power
receiving devices, and wherein the command is used for controlling
not to receive power from the power supply device.
11. The wireless power system according to claim 1, further
comprising a detection unit that detects one or more power
receiving devices, and wherein the control unit performs a process
for controlling the communication unit to transmit predetermined
data if a number of power receiving devices detected by the
detection unit is changed.
12. The wireless power system according to claim 1, wherein the
external device is different from a battery.
13. The wireless power system according to claim 1, wherein the
external device includes an AC adapter.
14. The wireless power system according to claim 1, wherein the
external device includes a device that can supply power to the
power receiving device based on Universal Serial Bus (USB).
15. The wireless power system according to claim 1, wherein the
control unit that compares a level of power received from the power
supply device to a level of power supplied by the external
apparatus, wherein in response to the power receiving device being
in a state that enables the power receiving device to receive power
from the external device and the level of power received from the
power supply device being less than the level of power supplied by
the external apparatus, the control unit selects the external
apparatus to supply power to the power receiving device, and
wherein in response to either the power receiving device not being
in a state that enables the power receiving device to receive power
from the external device or the level of power received from the
power supply device being greater than the level of power supplied
by the external apparatus, the control unit selects the external
apparatus to supply power to the power receiving device.
16. A method for controlling a wireless power system including a
power supply device and a power receiving device, the method
comprising: wirelessly supplying power; communicating with the
power receiving device different from the power supply device; and
transmitting predetermined data to the power receiving device based
on whether or not the power receiving device is in a state that
enables the power receiving device to receive power from an
external device through a connection between the power receiving
device and the external device, the external device being different
from the power supply device, wherein the predetermined data
includes one of first data and second data, the first data is used
for causing the power receiving device to receive power from the
external device, and the second data is used for causing the power
receiving device to receive power from the power supply device, and
wherein the external device includes a device for supplying power
to the power receiving device.
17. A recording medium recording a program for causing a computer
to execute a method for controlling a wireless power system
including a power supply device and a power receiving device, the
method comprising: wirelessly supplying power; communicating with a
power receiving device different from the power supply device; and
transmitting predetermined data to the power receiving device based
on whether or not the power receiving device is in a state that
enables the power receiving device to receive power from an
external device through a connection between the power receiving
device and the external device, the external device being different
from the power supply device, wherein the predetermined data
includes one of first data and second data, the first data is used
for causing the power receiving device to receive power from the
external device, and the second data is used for causing the power
receiving device to receive power from the power supply device, and
wherein the external device includes a device for supplying power
to the power receiving device.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation, and claims the benefit,
of U.S. patent application Ser. No. 13/753,345 filed Jan. 29, 2013,
which claims the benefit of Japanese Patent Application No.
2012-020012 filed Feb. 1, 2012. Each of U.S. patent application
Ser. No. 13/753,345 and Japanese Patent Application No. 2012-020012
is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a power supply device for
wirelessly supplying the power, a control method, an electronic
device, and a recording medium
Description of the Related Art
[0003] In recent years, there has been a power supply system which
is known to include a battery charger having a primary coil for
wirelessly outputting the power without connector connection, and a
mobile phone having a secondary coil for wirelessly receiving the
power supplied from the battery charger.
[0004] Japanese Patent Application Laid-Open No. 2008-67532
discusses a mobile phone with which the power is supplied from an
alternating current (AC) adapter when it is connected with the AC
adapter or from a battery charger when it is inserted into the
battery charger.
[0005] Conventionally, which of the AC adapter and the battery
charger the mobile phone should receive the power from has not been
taken into consideration in a case where the mobile phone is
connected with the AC adapter and inserted into the battery
charger.
[0006] There has been a case where excessive power is supplied to
the mobile phone if the mobile phone receives the power from the AC
adapter and the battery charger. To prevent such a situation, it
has been necessary to select an apparatus capable of supplying
suitable power to a mobile phone and then supply the power to the
mobile phone with the selected apparatus.
[0007] The present invention relates to a technique for selecting
an apparatus capable of supplying suitable power to an electronic
device.
SUMMARY OF THE INVENTION
[0008] According to an aspect of the present invention, there is
provided a power supply device including a power supply unit that
wirelessly supplies power, a communication unit that communicates
with an electronic device, and a control unit that controls the
communication unit to transmit predetermined data to the electronic
device based on whether or not the electronic device and an
external device are connected, wherein the predetermined data
includes one of first data and a second data, the first data is
used for causing the electronic device to receive power from the
external device, and the second data is used for causing the
electronic device to receive power from the power supply device,
and wherein the external device includes a device for supplying
power to the electronic device.
[0009] According to another aspect of the present invention, there
is provided an electronic device including a connection unit that
connects to an external device, a power receiving unit that
wirelessly receives power from a power supply device, a
communication unit that communicates with the power supply device,
and a control unit that controls the communication unit so as to
transmit predetermined information to the power supply device,
wherein the predetermined information indicates whether or not the
connection unit and the external device are connected, and wherein
the external device includes a device for supplying power to the
electronic device via the connection unit.
[0010] According to yet another aspect of the present invention,
there is provided a method for controlling a power supply device
including wirelessly supplying power, communicating with an
electronic device, and transmitting predetermined data to the
electronic device based on whether or not the electronic device and
an external device are connected, wherein the predetermined data
includes one of first data and a second data, the first data is
used for causing the electronic device to receive power from the
external device, and the second data is used for causing the
electronic device to receive power from the power supply device,
and wherein the external device includes a device for supplying
power to the electronic device.
[0011] According to yet another aspect of the present invention,
there is provided a method for controlling an electronic device
including a connection unit that connects to an external device.
The method including wirelessly receiving power, communicating with
a power supply device, and transmitting predetermined information
to the power supply device, wherein the predetermined information
indicates whether or not a connection unit and an external device
are connected, and wherein the external device includes an device
for supplying power to the electronic device via the connection
unit.
[0012] According to yet another aspect of the present invention,
there is provided a recording medium recording a program for
causing a computer to execute a method for controlling a power
supply device. The method includes wirelessly supplying power,
communicating with an electronic device; and transmitting
predetermined data to the electronic device based on whether or not
the electronic device and an external device are connected, wherein
the predetermined data includes one of first data and a second
data, the first data is used for causing the electronic device to
receive power from the external device, and the second data is used
for causing the electronic device to receive power from the power
supply device, and wherein the external device includes a device
for supplying power to the electronic device.
According to yet another aspect of the present invention, there is
provided a recording medium recording a program for causing a
computer to execute a method for controlling an electronic device
including a connection unit that connects to an external device.
The method includes wirelessly receiving power, communicating with
a power supply device, and transmitting predetermined information
to the power supply device, wherein the predetermined information
indicates whether or not the connection unit and an external device
are connected, and wherein the external device includes a device
for supplying power to the electronic device via the connection
unit.
[0013] Further features and aspects of the present invention will
become apparent from the following detailed description of
exemplary embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate exemplary
embodiments, features, and aspects of the invention and, together
with the description, serve to explain the principles of the
invention.
[0015] FIG. 1 illustrates an example of a power supply system
according to a first exemplary embodiment.
[0016] FIG. 2 (including FIGS. 2A and 2B) is an example of a block
diagram illustrating the power supply system according to the first
exemplary embodiment.
[0017] FIG. 3 illustrates an example of a configuration of a first
switching unit of an electronic device according to the first
exemplary embodiment.
[0018] FIG. 4 is a flowchart illustrating an example of a selection
process performed by a power supply apparatus according to the
first exemplary embodiment.
[0019] FIG. 5 is a flowchart illustrating an example of a selection
process performed by a power supply apparatus according to a second
exemplary embodiment.
[0020] FIG. 6 is a flowchart illustrating an example of an
exception process performed by the power supply apparatus according
to the second exemplary embodiment.
[0021] FIG. 7 illustrates an example of a power supply system
according to the second exemplary embodiment.
[0022] FIG. 8 illustrates an example of a configuration of a first
switching unit of an electronic device according to a third
exemplary embodiment.
DESCRIPTION OF THE EMBODIMENTS
[0023] Various exemplary embodiments, features, and aspects of the
invention will be described in detail below with reference to the
drawings.
[0024] A first exemplary embodiment of the present invention will
be described in detail below with reference to the accompanying
drawings. A power supply system according to the first exemplary
embodiment includes a power supply apparatus 100 and an electronic
device 200, as illustrated in FIG. 1.
[0025] With the power supply system according to the first
exemplary embodiment, when the power supply apparatus 100 and the
electronic device 200 exist within a predetermined range, the power
supply apparatus 100 wirelessly supplies the power to the
electronic device 200. When the power supply apparatus 100 and the
electronic device 200 exist within the predetermined range, the
electronic device 200 wirelessly receives the power output from the
power supply apparatus 100. When the power supply apparatus 100 and
the electronic device 200 do not exist within the predetermined
range, the electronic device 200 cannot receive the power from the
power supply apparatus 100. The predetermined range is also a range
within which the power supply apparatus 100 and the electronic
device 200 can communicate with each other. The power supply
apparatus 100 can also wirelessly supply the power in parallel to a
plurality of electronic devices.
[0026] The electronic device 200 illustrated in FIG. 1 is supplied
from an external apparatus 400 via a cable 300. In this case, the
electronic device 200 is supplied power by wireless from the power
supply apparatus 100. The first exemplary embodiment will be
described below on the premise that the cable 300 is a
predetermined interface conforming to the Universal Serial Bus
(USB) standard.
[0027] The electronic devices 200 may be an imaging apparatus such
as a camera, or a reproducing apparatus for reproducing audio and
video data. The electronic device 200 may be a mobile device such
as a mobile phone or smart phone. The electronic device 200 may
also be a battery pack including a battery 211.
[0028] The electronic device 200 may also be a car-like apparatus
which is driven by the power supplied from the power supply
apparatus 100. The electronic device 200 may also be an apparatus
for receiving television broadcasting, a display for displaying
video data, or a personal computer. The electronic device 200 may
bean apparatus which operates on the power supplied from the power
supply apparatus 100 even if the battery 211 is not attached to the
electronic device 200.
[0029] The external apparatus 400 is to be, for example, a personal
computer or a television.
[0030] FIG. 2 (including FIGS. 2A and 2B) is a block diagram
illustrating the power supply system according to the first
exemplary embodiment. The power supply apparatus 100 includes a
conversion unit 101, an oscillator 102, a power generation unit
103, a matching circuit 104, a modulation and demodulation circuit
105, a power transmitting antenna 106, a central processing unit
(CPU) 107, a read-only memory (ROM) 108, a random access memory
(RAM) 109, a display unit 110, an operation unit 111, and a
reflected power detection circuit 112, as illustrated in FIG.
2.
[0031] When an AC power source (not illustrated) and the power
supply apparatus 100 are connected, the conversion unit 101
converts the AC power supplied from the AC power source (not
illustrated) into the direct current (DC) power and then supplies
the converted DC power to the power supply apparatus 100.
[0032] The oscillator 102 oscillates a frequency to be used to
control the power generation unit 103 to convert the power supplied
from the conversion unit 101 into the power corresponding to a
target value set by the CPU 107. The oscillator 102 may be, for
example, a crystal resonator.
[0033] Based on the power supplied from the conversion unit 101 and
the frequency oscillated by the oscillator 102, the power
generation unit 103 generates the power to be output to the outside
via the power transmitting antenna 106. The power generation unit
103 includes a field effect transistor (FET) and controls a current
flowing between source and drain terminals of the FET according to
the frequency oscillated by the oscillator 102 to generate the
power to be output to the outside. The power generated by the power
generation unit 103 is supplied to the matching circuit 104 via the
reflected power detection circuit 112. The power generated by the
power generation unit 103 includes first power and second
power.
[0034] The first power is supplied to the electronic device 200 to
enable the power supply apparatus 100 to perform wireless
communication with the electronic device 200. The second power is
supplied to the electronic device 200 when the power supply
apparatus 100 supplies the power to the electronic device 200. For
example, the first power is 1 W or less and the second power is 2 W
to 10 W. The second power may be 10 W or higher. The first power is
to be lower than the second power. The first power is not limited
to the power equal to or less than 1 W as long as it is used by the
power supply apparatus 100 to perform wireless communication.
[0035] When the power supply apparatus 100 is supplying the first
power to the electronic device 200, the power supply apparatus 100
can perform wireless communication conforming to the Near Field
Communication (NFC) standard with the electronic device 200 via the
power transmitting antenna 106. However, when the power supply
apparatus 100 is supplying the second power to the electronic
device 200, the power supply apparatus 100 cannot perform wireless
communication conforming to the NFC standard with the electronic
device 200 via the power transmitting antenna 106.
[0036] The matching circuit 104 is a resonance circuit for causing
a resonance between the power transmitting antenna 106 and a power
receiving antenna included in an apparatus corresponding to the
power supply apparatus 100, according to the frequency oscillated
by the oscillator 102. The matching circuit 104 is also a circuit
for performing impedance matching between the power generation unit
103 and the power transmitting antenna 106. The matching circuit
104 includes a capacitor, a coil, a resistor, and so on. The CPU
107 can control a resonant frequency f of the power supply
apparatus 100 by controlling the capacitor and coil included in the
matching circuit 104. The resonant frequency f is used to cause a
resonance between the power supply apparatus 100 and an apparatus
subjected to power supply from the power supply apparatus 100.
[0037] The resonant frequency f is represented by the following
formula (1), where L indicates the inductance of the matching
circuit 104, and C indicates the capacitance of the matching
circuit 104.
[ Formula 1 ] f = 1 2 .pi. LC ( 1 ) ##EQU00001##
[0038] The resonant frequency f may be a commercial frequency
(50/60 Hz), 10 to several tens MHz, or 13.56 MHz. The resonant
frequency f may also be 6.78 MHz.
[0039] The matching circuit 104 can also detect a change of the
current flowing to the power transmitting antenna 106. The matching
circuit 104 can also detect a change of the voltage supplied to the
power transmitting antenna 106.
[0040] In a state where the frequency oscillated by the oscillator
102 is set to the resonant frequency f, the power generated by the
power generation unit 103 is supplied to the power transmitting
antenna 106 via the matching circuit 104.
[0041] The modulation and demodulation circuit 105 is used for
performing wireless communication conforming to the NFC standard
between the power supply apparatus 100 and the electronic device
200. When the power supply apparatus 100 transmits to the
electronic device 200 control data (hereinafter referred to as a
command) for controlling the electronic device 200, the modulation
and demodulation circuit 105 modulates the power generated by the
power generation unit 103 based on a protocol conforming to the NFC
standard.
[0042] The modulation and demodulation circuit 105 converts the
power generated by the power generation unit 103 into a pulse
signal through the amplitude shift keying (ASK) modulation
utilizing the amplitude displacement. The pulse signal converted as
a command is transmitted to the electronic device 200 via the power
transmitting antenna 106. When the pulse signal is transmitted to
the electronic device 200, the electronic device 200 analyzes the
pulse signal to detect bit data containing information "1" and "0".
The ASK modulation is a modulation method utilizing the amplitude
displacement, and is used for communication between an integrated
circuit (IC) card and a card reader.
[0043] The modulation and demodulation circuit 105 further includes
a coding circuit conforming to a predetermined coding method.
[0044] According to a change of the current flowing to the power
transmitting antenna 106 detected by the matching circuit 104, the
modulation and demodulation circuit 105 can demodulate, through the
coding circuit, response data from the electronic device 200
corresponding to a command transmitted to the electronic device 200
and control data from the electronic device 200. Thus, based on a
load modulation method, the modulation and demodulation circuit 105
can receive from the electronic device 200 the response data
corresponding to a command transmitted to the electronic device 200
and the control data transmitted from the electronic device
200.
[0045] The modulation and demodulation circuit 105 transmits a
command to the electronic device 200 in response to an instruction
from the CPU 107. Upon reception of the response data and the
control data from the electronic device 200, the modulation and
demodulation circuit 105 demodulates the received response data and
the control data and then supplies the data to the CPU 107.
[0046] The power transmitting antenna 106 is used for outputting to
the outside the power generated by the power generation unit 103.
The power supply apparatus 100 supplies the power to the electronic
device 200 via the power transmitting antenna 106. The power supply
apparatus 100 transmits a command to the electronic device 200 via
the power transmitting antenna 106. In addition, the power supply
apparatus 100 receives from the electronic device 200 via the power
transmitting antenna 106 the control data and the response data
corresponding to a command transmitted to the electronic device
200.
[0047] The CPU (Central Processing Unit) 107 executes a computer
program stored in the ROM 108 to control the power supply apparatus
100. The CPU 107 controls the power generation unit 103 to control
the power for supplying wirelessly to the electronic device
200.
[0048] The ROM 108 stores a computer program for controlling the
power supply apparatus 100 and information such as parameters
related to the power supply apparatus 100. The RAM 109 which is a
rewritable memory records a computer program for controlling the
power supply apparatus 100, information such as parameters related
to the power supply apparatus 100, and data received from the
electronic device 200 by the modulation and demodulation circuit
105.
[0049] The display unit 110 displays either video data supplied
from the RAM 109 or video data supplied from the ROM 108.
[0050] The operation unit 111 provides a user interface for
operating the power supply apparatus 100. The operation unit 111
includes a power button of the power supply apparatus 100 and a
mode switching button of the power supply apparatus 100. Each
button is formed of a switch, a touch panel, or the like. The CPU
107 controls the power supply apparatus 100 according to a user
instruction input via the operation unit 111.
[0051] The reflected power detection circuit 112 detects
information indicating an amplitude voltage V1 of a traveling wave
of the power output by the power transmitting antenna 106. The
reflected power detection circuit 112 detects information
indicating an amplitude voltage V2 of a reflected wave of the power
output by the power transmitting antenna 106. The information
indicating the amplitude voltage V1 and the information indicating
the amplitude voltage V2 detected by the reflected power detection
circuit 112 are supplied to the CPU 107. The CPU 107 records in the
RAM 109 the information indicating the amplitude voltage V1 and the
information indicating the amplitude voltage V2 supplied from the
reflected power detection circuit 112.
[0052] The CPU 107 obtains a voltage reflection coefficient .rho.
based on the amplitude voltage V1 of the traveling wave and the
amplitude voltage V2 of the reflected wave. In addition, the CPU
107 calculates a voltage standing wave ratio (VSWR) based on the
voltage reflection coefficient .rho..
[0053] The voltage standing wave ratio (VSWR) indicates a relation
between the traveling wave of the power output from the power
transmitting antenna 106 and the reflected wave of the power output
from the power transmitting antenna 106. A value of the voltage
standing wave ratio (VSWR) closer to 1 indicates lower reflected
power, a smaller loss of the power supplied from the power supply
apparatus 100 to an external electronic device, and higher power
transmission efficiency.
[0054] The following formula (2) represents the voltage reflection
coefficient .rho..
[ Formula 2 ] .rho. = V 2 V 1 ( 2 ) ##EQU00002##
[0055] The following formula (3) represents the voltage standing
wave ratio VSWR.
[ Formula 3 ] VSWR = 1 + .rho. 1 - .rho. ( 3 ) ##EQU00003##
Hereinbelow, the voltage standing wave ratio VSWR is referred to as
"VSWR".
[0056] Based on the calculated VSWR, the CPU 107 determines whether
the electronic device 200 is placed in the vicinity of the power
supply apparatus 100.
[0057] An example of a configuration of the electronic device 200
will be described below with reference to FIG. 2. The electronic
device 200 includes a power receiving antenna 201, a matching
circuit 202, a rectifying and smoothing circuit 203, a modulation
and demodulation circuit 204, a CPU 205, a ROM 206, a RAM 207, a
current and voltage detection unit 208, a regulator 209, a charging
control unit 210, and a battery 211. The electronic device 200
further includes a first switching unit 212, a connector 213, a
detection unit 214, a current limiting unit 215, a second switching
unit 216, and a communication unit 217.
[0058] The power receiving antenna 201 is used for receiving the
power supplied from the power supply apparatus 100. The electronic
device 200 receives the power from the power supply apparatus 100
via the power receiving antenna 201. The electronic device 200
performs communication conforming to the NFC standard with the
power supply apparatus 100 via the power receiving antenna 201.
Upon reception of a command from the power supply apparatus 100 via
the power receiving antenna 201, the electronic device 200
transmits to the power supply apparatus 100 via the power receiving
antenna 201 response data corresponding to the command received
from the power supply apparatus 100.
[0059] The matching circuit 202 is a resonance circuit for
performing impedance matching so that the power receiving antenna
201 resonates with the same frequency as the resonant frequency f
of the power supply apparatus 100. Similar to the matching circuit
104, the matching circuit 202 includes a capacitor, a coil, a
resistor, and so on. The matching circuit 202 controls the matching
circuit 202 so that the power receiving antenna 201 resonates with
the same frequency as the resonant frequency f of the power supply
apparatus 100. The matching circuit 202 supplies the power received
by the power receiving antenna 201 to the rectifying and smoothing
circuit 203.
[0060] The rectifying and smoothing circuit 203 removes a command
and noise from the power received by the power receiving antenna
201 to generate DC power. The rectifying and smoothing circuit 203
further supplies the generated DC power to the regulator 209 via
the current and voltage detection unit 208 and the first switching
unit 212. The rectifying and smoothing circuit 203 supplies to the
modulation and demodulation circuit 204 the command removed from
the power received by the power receiving antenna 201.
[0061] The modulation and demodulation circuit 204 analyzes the
command supplied from the rectifying and smoothing circuit 203
according to a communication protocol corresponding to the power
supply apparatus 100 and then supplies a result of the command
analysis to the CPU 205. When the power supply apparatus 100 is
supplying the first power to the electronic device 200, the CPU 205
controls the modulation and demodulation circuit 204 so that the
load included in the modulation and demodulation circuit 204 is
fluctuated to transmit to the power supply apparatus 100 the
response data corresponding to the command. Variation in the load
included in the modulation and demodulation circuit 204 causes a
change of the current flowing to the power transmitting antenna
106. Thus, the power supply apparatus 100 detects a change of the
current flowing to the power transmitting antenna 106 so as to
receive the response data corresponding to the command transmitted
from the electronic device 200.
[0062] The CPU 205 determines what type of command that the command
received by the modulation and demodulation circuit 204 is based on
the result of the analysis supplied from the modulation and
demodulation circuit 204. The CPU 205 then controls the electronic
device 200 to perform a process and an operation specified by a
command code corresponding to the received command. The CPU 205
executes a computer program stored in the ROM 206 to control the
electronic device 200.
[0063] The ROM 206 stores a computer program for controlling the
electronic device 200. Information about the electronic device 200
is recorded in the ROM 206. The RAM 207 which is a rewritable
memory records the computer program for controlling the electronic
device 200 and data transmitted from the power supply apparatus
100.
[0064] The current and voltage detection unit 208 detects the
voltage of the power supplied from the rectifying and smoothing
circuit 203. Further, the current and voltage detection unit 208
detects the current of the power supplied from the rectifying and
smoothing circuit 203. The current and voltage detection unit 208
supplies current information indicating the detected current and
voltage information indicating the detected voltage to the CPU
205.
[0065] In response to an instruction from the CPU 205, the
regulator 209 performs control to supply to the electronic device
200 any one of the power supplied from the rectifying and smoothing
circuit 203, the power supplied from the battery 211, and the power
supplied from the external apparatus 400 via the cable 300. When
the battery 211 is being charged in the electronic device 200, the
regulator 209 supplies to the electronic device 200 either the
power supplied from the rectifying and smoothing circuit 203 or the
power supplied from the external apparatus 400 via the cable
300.
[0066] When the power is supplied from the regulator 209, the
charging control unit 210 controls charging of the battery 211. The
battery 211 is detachably attached to the electronic device 200.
The battery 211 is a rechargeable secondary battery, for example, a
lithium ion battery. The battery 211 may be a battery other than a
lithium ion battery.
[0067] The first switching unit 212 is used for supplying to the
regulator 209 either the power supplied from the rectifying and
smoothing circuit 203 or the power supplied from the external
apparatus 400 via the cable 300. When the CPU 205 controls the
first switching unit 212 so that the power supplied from the
rectifying and smoothing circuit 203 is supplied to the regulator
209, the power supplied from the external apparatus 400 via the
cable 300 is not supplied to the regulator 209. When the CPU 205
controls the first switching unit 212 so that the power supplied
from the external apparatus 400 via the cable 300 is supplied to
the regulator 209, the power supplied from the rectifying and
smoothing circuit 203 is not supplied to the regulator 209. The CPU
205 can also control the first switching unit 212 not to supply to
the regulator 209 the power supplied from the rectifying and
smoothing circuit 203 and the power supplied from the external
apparatus 400 via the cable 300.
[0068] The connector 213 is a connection terminal for connecting
the cable 300. The connector 213 is provided with a virtual bus
(VBUS) terminal, a ground (GND) terminal, a D+ terminal, and a D-
terminal.
[0069] The detection unit 214 detects the potential of the D+
terminal and the potential of the D-terminal so as to detect the
type of the power source of the external apparatus 400.
[0070] Types of power source specified in the Battery Charging
Specification in the USB standard include a standard downstream
port, a charging downstream port, and a dedicated charging port.
The detection unit 214 detects whether the external apparatus 400
conforms to any one of the standard downstream port, the charging
downstream port, and the dedicated charging port.
[0071] The standard downstream port can supply maximum 500 mA
current to the electronic device 200. Hereinbelow, the standard
downstream port is referred to as "SDP". The charging downstream
port can supply maximum 1500 mA current to the electronic device
200. The charging downstream port is referred to as "CDP". The
dedicated charging port can supply maximum 1500 mA current to the
electronic device 200. The dedicated charging port is referred to
as "DCP".
[0072] When the type of the power source of the external apparatus
400 is detected, the detection unit 214 notifies the CPU 205 of the
type of the power source corresponding to the external apparatus
400. According to the USB standard applicable to the external
apparatus 400, the detection unit 214 may detect the type of the
power source corresponding to the external apparatus 400 by
detecting how much current the external apparatus 400 can supply to
the electronic device 200.
[0073] In a case where the connector 213 and the external apparatus
400 are connected via the cable 300, when the type of the power
source corresponding to the external apparatus 400 is detected, the
CPU 205 sets a flag f to ON. The flag f is data which indicates
that the electronic device 200 can receive the power from the
external apparatus 400. The flag f is recorded in the RAM 207. In a
case where the connector 213 and the external apparatus 400 are not
connected via the cable 300, the CPU 205 sets the flag f to OFF. In
a case where the connector 213 and the external apparatus 400 are
connected via the cable 300, when the type of the power source
corresponding to the external apparatus 400 is not detected, the
CPU 205 sets the flag f to OFF.
[0074] For example, when the external apparatus 400 is detected not
to conform to the SDP, the CDP, and the DCP, even if the connector
213 and the external apparatus 400 are connected via the cable 300,
the CPU 205 sets the flag f to OFF.
[0075] In a case where the external apparatus 400 and the connector
213 are connected via the cable 300, the current limiting unit 215
limits the current supplied from the VBUS terminal according to the
type of the power source detected by the detection unit 214. For
example, when the external apparatus 400 conforms to the SDP, the
current limiting unit 215 performs control so that the current
supplied from the VBUS terminal becomes 500 mA or less. For
example, when the external apparatus 400 conforms to the CDP, the
current limiting unit 215 performs control so that the current
supplied from the VBUS terminal becomes 1500 mA or less. According
to the type of the power source of the external apparatus 400, the
current limiting unit 215 may perform control so that the current
supplied from the VBUS terminal becomes 100 mA or less. The current
controlled by the current limiting unit 215 is supplied to the
regulator 209 via the first switching unit 212.
[0076] The second switching unit 216 is used for connecting the D+
and D-terminals of the connector 213 with either the communication
unit 217 or the detection unit 214. If the mode of the electronic
device 200 is either a mass storage device mode or an imaging
device mode, the CPU 205 can control the second switching unit 216
to connect the D+ and D- terminals of the connector 213 with the
communication unit 217. When the D+ and D- terminals of the
connector 213 and the communication unit 217 are connected, the
communication unit 217 can transmit data to the external apparatus
400 and receive data from the external apparatus 400 via the cable
300. When the D+ and D- terminals of the connector 213 and the
communication unit 217 are connected, the D+ and D- terminals of
the connector 213 and the detection unit 214 are assumed to be
unconnected.
[0077] When the mode of the electronic device 200 is a human
interface device (HID) mode, the CPU 205 can control the second
switching unit 216 so as not to connect the D+ and D- terminals of
the connector 213 and the communication unit 217. When the D+ and
D- terminals of the connector 213 and the communication unit 217
are not connected, the communication unit 217 cannot transmit data
to the external apparatus 400 or receive data from the external
apparatus 400 via the cable 300. When the D+ and D- terminals of
the connector 213 and the communication unit 217 are not connected,
the D+ and D- terminals of the connector 213 and the detection unit
214 are assumed to be connected.
[0078] The communication unit 217 transmits data to the external
apparatus 400 via the cable 300 and receives data supplied from the
external apparatus 400 via the cable 300.
[0079] FIG. 3 illustrates an example of a configuration of the
first switching unit 212. The first switching unit 212 includes a
switch 501, a switch 502, a diode 503, a diode 504, and a resistor
505.
[0080] Referring to FIG. 3, the rectifying and smoothing circuit
203 and the regulator 209 are connected via the diode 503 and the
switch 501. The current limiting unit 215 and the regulator 209 are
connected via the diode 504 and the switch 502.
[0081] The resistor 505 is connected between the diode 504 and the
CPU 205. When the power is supplied from the external apparatus 400
to the electronic device 200 via the connector 213, a voltage is
generated at the resistor 505. The CPU 205 can detect whether the
power is supplied from the external apparatus 400 by detecting the
voltage of the resistor 505.
[0082] The CPU 205 can select either the power supply apparatus 100
or the external apparatus 400 as an apparatus which supplies the
power to the electronic device 200 by controlling the switches 501
and 502. When the switch 501 is turned ON and the switch 502 is
turned OFF by the CPU 205, the power supply apparatus 100 is
selected as an apparatus which supplies the power to the electronic
device 200. When the switch 501 is turned OFF and the switch 502 is
turned ON by the CPU 205, the external apparatus 400 is selected as
an apparatus which supplies the power to the electronic device
200.
[0083] The power transmitting antenna 106 and the power receiving
antenna 201 may be a helical antenna, a loop antenna, or a planar
antenna such as a meander line antenna.
[0084] In the first exemplary embodiment, the process performed by
the power supply apparatus 100 is also applicable to a system in
which the power supply apparatus 100 wirelessly supplies the power
to the electronic device 200 through electromagnetic field
coupling. Further, in the first exemplary embodiment, the process
performed by the power supply apparatus 100 is also applicable to a
system in which, when an electrode is provided on the power supply
apparatus 100 and an electrode is provided on the electronic device
200, the power supply apparatus 100 wirelessly supplies the power
to the electronic device 200 through electric field coupling.
Further, in the first exemplary embodiment, the process performed
by the power supply apparatus 100 is also applicable to a system in
which the power supply apparatus 100 wirelessly supplies the power
to the electronic device 200 through electromagnetic induction.
[0085] Further, in the first exemplary embodiment, the power supply
apparatus 100 wirelessly outputs the power to the electronic device
200, and the electronic device 200 wirelessly receives the power
from the power supply apparatus 100. However, the term "wireless"
may be replaced by "non-contact" or "contactless".
[0086] The electronic device 200 illustrated in FIG. 1 is supplies
power wirelessly from the power supply apparatus 100 and supplied
from the external apparatus 400 via the cable 300. In such a case,
the power supply apparatus 100 needs to select either the power
supply apparatus 100 or the external apparatus 400 as an apparatus
which supplies the power to the electronic device 200. Therefore,
the power supply apparatus 100 performs a selection process for
selecting an apparatus which supplies the power to the electronic
device 200.
(Selection Process)
[0087] The selection process performed by the power supply
apparatus 100 according to the first exemplary embodiment will be
described below with reference to the flowchart in FIG. 4. The
selection process can be implemented when the CPU 107 executes a
computer program stored in the ROM 108.
[0088] The CPU 107 controls the oscillator 102, the power
generation unit 103, and the matching circuit 104 to output the
first power via the power transmitting antenna 106 so as to detect
whether the electronic device 200 exists within the predetermined
range of distance. In this case, the CPU 107 monitors a change of
the VSWR and, based on a change of the VSWR, detects whether the
electronic device 200 exists within the predetermined range.
[0089] In step S401, the CPU 107 detects whether the electronic
device 200 exists within the predetermined range. When a change of
the VSWR is equal to or larger than a predetermined value A, the
CPU 107 determines that the electronic device 200 is exists within
the predetermined range. When a change of the VSWR is less than the
predetermined value A, the CPU 107 determines that the electronic
device 200 does not exist within the predetermined range. When the
CPU 107 determines that the electronic device 200 exists within the
predetermined range (YES in step S401), the process proceeds from
step S401 to step S402. When the CPU 107 determines that the
electronic device 200 does not exist within the predetermined range
(NO in step S401), the process proceeds from step S401 to step
S405. The predetermined value A may be set so that the CPU 107 can
detect that at least one electronic device is placed in the
vicinity of the power supply apparatus 100.
[0090] In step S402, the CPU 107 determines whether a plurality of
electronic devices exist within the predetermined range. For
example, in a case where the electronic device 200 and an
electronic device other than the electronic device 200 exist within
the predetermined range, the CPU 107 determines that a plurality of
electronic devices exist within the predetermined range. When the
CPU 107 determines that a plurality of electronic devices exists
within the predetermined range of distance (YES in step S402), the
process proceeds from step S402 to step S404. When the CPU 107
determines that a plurality of electronic devices does not exist
within the predetermined range (NO in step S402), the CPU 107
determines that one unit of the electronic device 200 exists within
the predetermined range. In this case (NO in step S402), the
process proceeds from step S402 to step S403.
[0091] In step S403, the CPU 107 determines whether the electronic
device 200 is in a state enabling to receive the power from the
external apparatus 400.
[0092] The CPU 107 performs wireless communication conforming to
the NFC standard to transmit to the electronic device 200 a first
command for determining whether the electronic device 200 can
receives the power from the external apparatus 400. Upon reception
of the first command from the power supply apparatus 100, the
electronic device 200 detects whether the flag f recorded in the
RAM 207 is set to ON.
[0093] If the flag f recorded in the RAM 207 is set to ON, the
electronic device 200 transmits to the power supply apparatus 100
response data indicating that the electric device 200 is in a state
enabling to receive the power from the external apparatus 400. If
the flag f recorded in the RAM 207 is set to OFF, the electronic
device 200 transmits to the power supply apparatus 100 response
data indicating that the electric device 200 is not in a state
enabling to receive the power from the external apparatus 400.
According to the response data corresponding to the first command,
the CPU 107 determines whether the electronic device 200 is in a
state enabling to receive the power from the external apparatus
400. The electronic device 200 can receive the power from the
external apparatus 400 if the electronic device 200 is in a state
enabling to receive the power from the external apparatus 400. The
electronic device 200 cannot receive the power from the external
apparatus 400 if the electronic device 200 is not in a state
enabling to receive the power from the external apparatus 400.
[0094] When the CPU 107 determines that the electronic device 200
is in a state enabling to receive the power from the external
apparatus 400 (YES in step S403), the process proceeds from step
S403 to step S404. When the CPU 107 determines that the electronic
device 200 is not in a state enabling to receive the power from the
external apparatus 400 (NO in step S403), the process proceeds from
step S403 to step S406.
[0095] In step S404, the CPU 107 performs wireless communication
conforming to the NFC standard to transmit a second command to the
electronic device 200. The second command is used for instructing
the electronic device 200 so as to select the external apparatus
400 as an apparatus which supplies the power to the electronic
device 200.
[0096] Upon reception of the second command from the power supply
apparatus 100, the CPU 205 controls the first switching unit 212 so
that the power is supplied to the regulator 209 from the external
apparatus 400. In this case, the CPU 205 performs control so that
the switch 501 is set to OFF and the switch 502 is set to ON. In
this case, the external apparatus 400 supplies the power to the
regulator 209, and the regulator 209 supplies to the electronic
device 200 the power supplied from the external apparatus 400. When
the battery 211 is not fully charged, the charging control unit 210
charges the battery 211 with the power supplied from the external
apparatus 400 via the regulator 209.
[0097] When the first switching unit 212 is controlled so that the
power supplied from the external apparatus 400 is supplied to the
regulator 209, the electronic device 200 transmits response data
corresponding to the second command to the power supply apparatus
100. When the second command is transmitted to the electronic
device 200, the process proceeds from step S404 to step S405.
[0098] In step S405, the CPU 107 controls the oscillator 102, the
power generation unit 103, and the matching circuit 104 not to
output the power via the power transmitting antenna 106. In this
case, the process in the flowchart in FIG. 4 is ended.
[0099] In step S406, the CPU 107 performs wireless communication
conforming to the NFC standard to transmit a third command to the
electronic device 200. The third command is used for instructing
the electronic device 200 so as to select the power supply
apparatus 100 as an apparatus which supplies the power to the
electronic device 200.
[0100] Upon reception of the third command from the power supply
apparatus 100, the CPU 205 controls the first switching unit 212 so
that the power received from the power supply apparatus 100 via the
power receiving antenna 201 is supplied to the regulator 209. In
this case, the CPU 205 performs control to turn ON the switch 501
and turn OFF the switch 502. In this case, the power received by
the electronic device 200 from the power supply apparatus 100 is
supplied to the regulator 209. The regulator 209 supplies power to
the electronic device 200 from the power supply apparatus 100. If
the battery 211 is not fully charged, the charging control unit 210
charges the battery 211 with the power supplied from the power
supply apparatus 100 via the regulator 209.
[0101] When the first switching unit 212 is controlled so that the
power is supplied to the regulator 209 from the power supply
apparatus 100, the electronic device 200 transmits response data
corresponding to the third command to the power supply apparatus
100. When the third command is transmitted to the electronic device
200, the process proceeds from step S406 to step S407.
[0102] In step S407, the CPU 107 controls the oscillator 102, the
power generation unit 103, and the matching circuit 104 to output
the second power via the power transmitting antenna 106. Then, the
process proceeds from step S407 to step S408.
[0103] In step S408, the CPU 107 detects whether a change of the
VSWR is equal to or larger than the predetermined value A. When the
CPU 107 determines that a change of the VSWR is equal to or larger
than the predetermined value A (YES in step S408), the process
proceeds from step S408 to step S409. When the CPU 107 determines
that a change of the VSWR is less than the predetermined value A
(NO in step S408), the process proceeds from step S408 to step
S411.
[0104] In step S409, the CPU 107 detects whether one or more
electronic devices exist within the predetermined range. When one
or more electronic devices exist within the predetermined range
(YES in step S409), the process proceeds from step S409 to step
S410. When one or more electronic devices are not exist within the
predetermined range (NO in step S409), the CPU 107 determines that
no electronic device exists within the predetermined range of
distance. In this case (NO in step S409), the process proceeds from
step S409 to step S405.
[0105] In step S410, similar to the process in step S405, the CPU
107 controls the oscillator 102, the power generation unit 103, and
the matching circuit 104 not to output the power via the power
transmitting antenna 106. Then, the process returns from step S410
to step S402.
[0106] In step S411, the CPU 107 determines whether power supply is
to be ended. For example, in step S406, if the CPU 107 detects that
no electronic device which the third command was transmitted from
the power supply apparatus 100 exists within the predetermined
range to, the CPU 107 determines that power supply is to be
ended.
[0107] For example, in step S406, if the CPU 107 detects that
charging performed by the electronic device to which the third
command was transmitted from the power supply apparatus 100 is
stopped, the CPU 107 determines that power supply is to be ended.
When the CPU 107 determines that power supply is to be ended (YES
in step S411), the process proceeds from step S411 to step S405.
When the CPU 107 determines that power supply is not to be ended
(NO in step S411), the process returns from step S411 to step S408.
When the CPU 107 determines that power supply is not to be ended
(NO in step S411), the power supply apparatus 100 continuously
supplies the power.
[0108] When the CPU 107 determines that a plurality of electronic
devices exist within the predetermined range (YES in step S402),
then in step S404, the CPU 107 transmits the second command to the
plurality of electronic devices existing within the predetermined
range.
[0109] Thus, the power supply apparatus 100 according to the first
exemplary embodiment selects an apparatus capable of suitably
supplying the power to the electronic device 200.
[0110] When a plurality of electronic devices exists within the
predetermined range (YES in step S402), the power supply apparatus
100 selects the external apparatus 400. When a plurality of
electronic devices exists within the predetermined range, the power
supply apparatus 100 supplies the power in parallel to the
plurality of electronic devices. In this case, the power supplied
from the power supply apparatus 100 to each electronic device is
lower than that in a case where the power supply apparatus 100
supplies the power to one electronic device. This means that the
electronic device 200 cannot efficiently receive the power from the
power supply apparatus 100. Therefore, in a case where a plurality
of electronic devices exists within the predetermined range, the
power supply apparatus 100 enables the plurality of electronic
devices to receive the power from the external apparatus 400.
[0111] When the electronic device 200 can receive the power from
the external apparatus 400 (YES in step S403), the power supply
apparatus 100 selects the external apparatus 400. When the power
supply apparatus 100 supplies the power to the electronic device
200, the power received by the electronic device 200 from the power
supply apparatus 100 is affected by a state of the electronic
device 200 and an operating state of the power supply apparatus
100. Thus, the external apparatus 400 is sometimes able to supply
to the electronic device 200 more stable power than the power
supply apparatus 100. Therefore, when the electronic device 200 can
receive the power from the external apparatus 400 (YES in step
S403), the power supply apparatus 100 enables the electronic device
200 to receive the power from the external apparatus 400.
[0112] When the electronic device 200 cannot receive the power from
the external apparatus 400 (NO in step S403), the power supply
apparatus 100 selects the power supply apparatus 100. In this case,
the power supply apparatus 100 enables the electronic device 200 to
receive the power from the power supply apparatus 100.
[0113] When a change of the VSWR is equal to or larger than the
predetermined value A (YES in step S408), the power supply
apparatus 100 detects whether one or more electronic devices exists
within the predetermined range. When a change of the VSWR is equal
to or larger than the predetermined value A (YES in step S408), the
number of the electronic devices existing within the predetermined
range may have changed. In this case, when one or more electronic
devices exists within the predetermined range (YES in step S409),
the CPU 107 once stops output of the power and then reselects
either the power supply apparatus 100 or the external apparatus
400. Therefore, according to a change of the number of electronic
devices existing within the predetermined range, the power supply
apparatus 100 can reselect an apparatus capable of suitably
supplying the power to the electronic device 200.
[0114] Therefore, the power supply apparatus 100 can select an
apparatus capable of supplying suitable power to the electronic
device 200.
[0115] A second exemplary embodiment according to the present
invention will be described below. In the second exemplary
embodiment, for similar configurations, processes, and operations
to the first exemplary embodiment, redundant description will be
omitted.
(Selection Process)
[0116] A selection process performed by the power supply apparatus
100 according to the second exemplary embodiment will be described
below with reference to the flowchart in FIG. 5. The selection
process in FIG. 5 can be implemented when the CPU 107 executes a
computer program stored in the ROM 108.
[0117] For the process similar to the selection process described
in the first exemplary embodiment, redundant description will be
omitted. Only different processes will be described below.
[0118] In step S501 and steps S505 to S512, the processes common to
step S401 and steps S404 to S411 are performed, thus redundant
description will be omitted.
[0119] In step S502, the CPU 107 determines whether a plurality of
electronic devices exist within the predetermined range. When the
CPU 107 determines that a plurality of electronic devices exists
within the predetermined range (YES in step S502), the process
proceeds from step S502 to step S513. When the CPU 107 determines
that a plurality of electronic devices does not exist within the
predetermined range (NO in step S502), the process proceeds from
step S502 to step S503.
[0120] In step S503, the CPU 107 determines whether the electronic
device 200 is in a state enabling to for receive the power from the
external apparatus 400. When the CPU 107 determines that the
electronic device 200 is in a state enabling to for receive the
power from the external apparatus 400 (YES in step S503), the
process proceeds from step S503 to step S504. When the CPU 107
determines that the electronic device 200 is not in a state
enabling to receive the power from the external apparatus 400 (NO
in step S503), the process proceeds from step S503 to step
S507.
[0121] In step S504, the CPU 107 determines which of the power
supply apparatus 100 and the external apparatus 400 can supply
larger power to the electronic device 200.
[0122] In this case, the CPU 107 performs wireless communication
conforming to the NFC standard to transmit a fourth command to the
electronic device 200. The fourth command is used for requesting
information indicating the power received by the electronic device
200 from the power supply apparatus 100. Upon reception of the
fourth command from the power supply apparatus 100, the electronic
device 200 detects first power information indicating the power
received by the electronic device 200 from the power supply
apparatus 100, using the current information and the voltage
information supplied from the current and voltage detection unit
208. In this case, the electronic device 200 transmits response
data including the first power information to the power supply
apparatus 100.
[0123] The CPU 107 performs wireless communication conforming to
the NFC standard to transmit a fifth command to the electronic
device 200. The fifth command is used for requesting information
indicating the power supplied from the external apparatus 400 to
the electronic device 200. Upon reception of the fifth command from
the power supply apparatus 100, the electronic device 200 detects
second power information indicating the power supplied from the
external apparatus 400 to the electronic device 200, using the
information indicating the current supplied from the current
limiting unit 215. In this case, the electronic device 200
transmits response data including the second power information to
the power supply apparatus 100.
[0124] When the first power information and the second power
information are obtained from the electronic device 200, the CPU
107 compares the power received by the electronic device 200 from
the power supply apparatus 100 with the power supplied from the
external apparatus 400 to the electronic device 200, using the
first power information and the second power information.
[0125] When the CPU 107 determines that the power received by the
electronic device 200 from the power supply apparatus 100 is larger
than the power supplied from the external apparatus 400 to the
electronic device 200 (YES in step S504), the process proceeds from
step S504 to step S507. When the CPU 107 determines that the power
received by the electronic device 200 from the power supply
apparatus 100 is not larger than the power supplied from the
external apparatus 400 to the electronic device 200 (NO in step
S504), the process proceeds from step S504 to step S505.
[0126] In step S513, the CPU 107 performs an exception process
described below. After completion of the exception process, the
process in the flowchart in FIG. 5 is ended.
[0127] Although, in step S504, the CPU 107 compares the power
received by the electronic device 200 from the power supply
apparatus 100 with the power supplied from the external apparatus
400 to the electronic device 200, the process is not limited
thereto. For example, in step S504, the CPU 107 may compare the
power output from the power transmitting antenna 106, instead of
the power received by the electronic device 200 from the power
supply apparatus 100, with the power supplied from the external
apparatus 400 to the electronic device 200.
[0128] The exception process in step S513 performed in the
selection process in FIG. 5 according to the second exemplary
embodiment will be described below with reference to a flowchart in
FIG. 6. The exception process illustrated in FIG. 6 can be
implemented when the CPU 107 executes a computer program stored in
the ROM 108.
[0129] The CPU 107 performs the exception process in step S513 when
it is determined that a plurality of electronic devices exists
within the predetermined range (YES in step S502). The exception
process in step S513 is performed in a case where the electronic
device 200 and an electronic device 500 exist within the
predetermined range, as illustrated in FIG. 7.
[0130] The exception process in a power supply system as
illustrated in FIG. 7 will be described below as an example. In
this case, it is assumed that the electronic device 500 has a
similar configuration to the electronic device 200. Further, the
electronic device 500 may be connected to the external apparatus
400 via a cable 600, as illustrated in FIG. 7. The cable 600 also
has a similar configuration to the cable 300. Further, the
electronic device 500 is supplied power from the external apparatus
400 via the cable 600. If the CPU 107 determines that the
electronic device 200 and the electronic device 500 exist within
the predetermined range, the CPU 107 performs a process of step
S601.
[0131] In step S601, the CPU 107 determines whether the electronic
device 200 and the electronic device 500 are in a state enabling to
receive the power from the external apparatus 400.
[0132] When the CPU 107 determines that the electronic device 200
and the electronic device 500 are in a state enabling to receive
the power from the external apparatus 400 (YES in step S601), the
process proceeds from step S601 to step S602. When the CPU 107
determines that the electronic device 200 and the electronic device
500 are not in a state enabling to receive the power from the
external apparatus 400 (NO in step S601), the CPU 107 determines
that at least one of the electronic device 200 and the electronic
devices 500 cannot receive power from the external apparatus 400.
In this case, (NO in step S601), the process proceeds from step
S601 to step S603.
[0133] In step S602, the CPU 107 performs wireless communication
conforming to the NFC standard to transmit the second command to
the electronic device 200 and the electronic device 500. When the
electronic device 200 receives the second command from the power
supply apparatus 100, the electronic device 200 supplies power to
the electronic device 200 from the external apparatus 400. Further,
the electronic device 200 prevents power from supplying from the
power supply apparatus 100 to the electronic device 200. When the
electronic device 500 receives the second command from the power
supply apparatus 100, the electronic device 500 supplies to the
electronic device 500 from the external apparatus 400. Further, the
electronic device 500 and prevents power from supplying from the
power supply apparatus 100 to the electronic device 500. In this
case, the process proceeds from step S602 to step S506.
[0134] In step S603, the CPU 107 determines whether an apparatus
which cannot receive the power from the external apparatus 400 is
either the electronic device 200 or the electronic devices 500.
When the CPU 107 determines that the apparatus which cannot receive
the power from the external apparatus 400 is either the electronic
device 200 or the electronic devices 500 (YES in step S603), the
process proceeds from step S603 to step S604. When the CPU 107
determines that the apparatus which cannot receive the power from
the external apparatus 400 is not either the electronic device 200
or the electronic devices 500 (NO in step S603), the electronic
device 200 and the electronic device 500 cannot receive the power
from the external apparatus 400. In this case, (NO in step S603),
the process proceeds from step S603 to step S606.
[0135] In step S604, the CPU 107 performs wireless communication
conforming to the NFC standard to transmit the third command to an
electronic device determined to be unable to receive the power from
the external apparatus 400.
[0136] For example, when the electronic device 200 receives the
third command from the power supply apparatus 100, the electronic
device 200 prevents power from supplying from the external
apparatus 400 to the electronic device 200. Further, the electronic
device 200 supplies power to the electronic device 200 from the
power supply apparatus 100. Further, for example, when the
electronic device 500 receives the third command from the power
supply apparatus 100, the electronic device 500 prevents power from
supplying from the external apparatus 400 to the electronic device
500. Further, the electronic device 500 supplies power to the
electronic device 500 from the power supply apparatus 100. In this
case, the process proceeds from step S604 to step S605.
[0137] In step S605, the CPU 107 performs wireless communication
conforming to the NFC standard to transmit the second command to an
electronic device other than the electronic device to which the
third command was transmitted in step S604. In this case, the
process proceeds from step S605 to step S508.
[0138] In step S606, the CPU 107 compares an efficiency of power
transmission from the power supply apparatus 100 to the electronic
device 200 with an efficiency of power transmission from the power
supply apparatus 100 to the electronic device 500.
[0139] The CPU 107 detects first efficiency information indicating
the efficiency of power transmission from the power supply
apparatus 100 to the electronic device 200 and second efficiency
information indicating the efficiency of power transmission from
the power supply apparatus 100 to the electronic device 500. The
CPU 107 compares the first efficiency information with the second
efficiency information to determine which of the electronic device
200 and the electronic device 500 can efficiently receive the power
from the power supply apparatus 100. In this case, the process
proceeds from step S606 to step S607.
[0140] In step S607, the CPU 107 performs wireless communication
conforming to the NFC standard to transmit the third command to an
electronic device determined to be able to efficiently receive the
power from the power supply apparatus 100.
[0141] When the efficiency of power transmission from the power
supply apparatus 100 to the electronic device 200 is higher than
the efficiency of power transmission from the power supply
apparatus 100 to the electronic device 500, the CPU 107 transmits
the third command to the electronic device 200. Otherwise, when the
efficiency of power transmission from the power supply apparatus
100 to the electronic device 200 is lower than the efficiency of
power transmission from the power supply apparatus 100 to the
electronic device 500, the CPU 107 transmits the third command to
the electronic device 500.
[0142] When the efficiency of power transmission from the power
supply apparatus 100 to the electronic device 200 is equal to the
efficiency of power transmission from the power supply apparatus
100 to the electronic device 500, the CPU 107 may transmit the
third command to an apparatus first determined to exist within the
predetermined range. Further, when the efficiency of power
transmission from the power supply apparatus 100 to the electronic
device 200 is equal to the efficiency of power transmission from
the power supply apparatus 100 to the electronic device 500, the
CPU 107 may transmit the third command to an apparatus having large
power consumption. Further, when the efficiency of power
transmission from the power supply apparatus 100 to the electronic
device 200 is equal to the efficiency of power transmission from
the power supply apparatus 100 to the electronic device 500, the
CPU 107 may transmit the third command to an apparatus having
smaller remaining capacity of the battery. In this case, the
process proceeds from step S607 to step S608.
[0143] In step S608, the CPU 107 performs wireless communication
conforming to the NFC standard to transmit the second command to an
electronic device other than the electronic device to which the
third command was transmitted in step S607. In this case, the
process proceeds from step S608 to step S508.
[0144] Thus, based on the result of the comparison between the
power received by the electronic device 200 from the power supply
apparatus 100 and the power supplied from the external apparatus
400 to the electronic device 200, the power supply apparatus 100
according to the second exemplary embodiment selects an apparatus
capable of suitably supplying the power to the electronic device
200.
[0145] When the power received by the electronic device 200 from
the power supply apparatus 100 is larger than the power supplied
from the external apparatus 400 to the electronic device 200 (YES
in step S504), the CPU 107 selects the power supply apparatus 100.
In this case, the power supply apparatus 100 can efficiently supply
the power to the electronic device 200.
[0146] When the power received by the electronic device 200 from
the power supply apparatus 100 is not larger than the power
supplied from the external apparatus 400 to the electronic device
200 (NO in step S504), the CPU 107 selects the external apparatus
400. In this case, the power supply apparatus 100 enables efficient
a supply of power from the external apparatus 400 to the electronic
device 200. Further, in this case, if the power received by the
electronic device 200 from the power supply apparatus 100 is equal
to the power supplied from the external apparatus 400 to the
electronic device 200, the CPU 107 selects the external apparatus
400. This is because it is likely that the external apparatus 400
can supply more stable power to the electronic device 200 than the
power supply apparatus 100.
[0147] According to the second exemplary embodiment, when a
plurality of electronic devices exists within the predetermined
range (YES in step S502), the CPU 107 determines whether each
electronic device is in a state enabling to receive the power from
the external apparatus 400. Further, based on the result of the
determination, the CPU 107 selects an apparatus capable of suitably
supplying the power to each electronic device.
[0148] Therefore, if a plurality of electronic devices exists
within the predetermined range of distance, the power supply
apparatus 100 can select an apparatus capable of suitably supplying
the power for each electronic device.
[0149] With the power supply apparatus 100 according to the second
exemplary embodiment, portions common to the processes and
configurations described in the first exemplary embodiment have
similar effects to the first exemplary embodiment.
[0150] Although the power supplied from the external apparatus 400
via the cable 600 is supplied to the electronic device 500, the
electronic device 500 may be supplied power from an apparatus other
than the external apparatus 400 via the cable 600.
[0151] A third exemplary embodiment according to the present
invention will be described below. In the third exemplary
embodiment, for similar configurations, processes, and operations
to the first and second exemplary embodiments, redundant
description will be omitted.
[0152] The electronic device 200 according to the third exemplary
embodiment includes a first switching unit 212 as illustrated in
FIG. 8. The first switching unit 212 according to the third
exemplary embodiment includes a diode 801, a diode 802, and a
resistor 803.
[0153] Referring to FIG. 8, the rectifying and smoothing circuit
203 and the regulator 209 are connected via the diode 801, and the
current limiting unit 215 and the regulator 209 are connected via
the diode 802.
[0154] The resistor 803 is connected between the diode 802 and the
CPU 205. When the power is supplied from the external apparatus 400
to the electronic device 200 via the connector 213, a voltage is
generated at the resistor 803.
[0155] The CPU 205 can detect whether the power is supplied from
the external apparatus 400 by detecting the voltage of the resistor
803. Whichever larger the power supplied from the power supply
apparatus 100 to the electronic device 200 or the power supplied
from the external apparatus 400 to the electronic device 200 is
supplied to the regulator 209.
[0156] The CPU 205 detects a voltage level supplied from the power
supply apparatus 100 using the voltage information supplied from
the current and voltage detection unit 208. The CPU 205 detects a
voltage level supplied from the external apparatus 400 using the
voltage information obtained by detecting the voltage of the
resistor 803. The voltage level supplied from the power supply
apparatus 100 is referred to as a first voltage level, and the
voltage level supplied from the external apparatus 400 is referred
to as a second voltage level.
[0157] According to the third exemplary embodiment, the CPU 107
performs the selection process in FIG. 5. When performing the
process in step S504, the CPU 107 may, by comparing the first
voltage level with the second voltage level, determine which of the
power supply apparatus 100 and the external apparatus 400 can
supply larger power to the electronic device 200.
[0158] In this case, the CPU 107 performs wireless communication
conforming to the NFC standard to transmit to the electronic device
200 a sixth command for requesting the first voltage level. Upon
reception of the sixth command from the power supply apparatus 100,
the electronic device 200 detects the first voltage level. The
electronic device 200 transmits response data including the first
voltage level to the power supply apparatus 100.
[0159] The CPU 107 performs wireless communication conforming to
the NFC standard to transmit to the electronic device 200 for
requesting the second voltage level. Upon reception of the seventh
command from the power supply apparatus 100, the electronic device
200 detects the second voltage level. The electronic device 200
transmits response data including the second voltage level to the
power supply apparatus 100.
[0160] When the first voltage level and the second voltage level
are obtained from the electronic device 200, the CPU 107 compares
the first voltage level with the second voltage level. When the CPU
107 determines that the first voltage level is larger than the
second voltage level (YES in step S504), the process proceeds from
step S504 to step S507. When the CPU 107 determines that the first
voltage level is not larger than the second voltage level (NO in
step S504), the process proceeds from step S504 to step S505.
[0161] With the power supply apparatus 100 according to the third
exemplary embodiment, portions common to the processes and
configurations described in the first and second exemplary
embodiments have similar effects to the first and second exemplary
embodiments.
[0162] Although, according to the first, second, and third
exemplary embodiments, the power supply apparatus 100 performs
wireless communication conforming to the NFC standard, the process
is not limited thereto. For example, the power supply apparatus 100
may perform wireless communication conforming to the International
Organization for Standardization/International Electrotechnical
Commission (ISO/IEC) 18092 standard, such as the Radio Frequency
Identification (RFID) standard or the Transfer Jet (registered
trademark) standard. Further, for example, the power supply
apparatus 100 may perform wireless communication conforming to the
Mikron Fare-collection System (MIFARE) (registered trademark)
standard or the FeliCa (registered trademark) standard.
[0163] Although, according to the first, second, and third
exemplary embodiments, the electronic device 200 can receive the
power from the external apparatus 400 via the cable 300, the
process is not limited thereto. For example, instead of the
external apparatus 400 being connected to the electronic device 200
via the cable 300, a device which outputs the DC power from a
commercial power supply may be connected to the electronic device
200. The device which outputs the DC power from a commercial power
supply is, for example, an AC adapter. The cable 300 may conform to
a standard other than the USB standard. Even in a case where an AC
adapter is connected to the electronic device 200, the power supply
apparatus 100 may perform the selection process in FIG. 4 and the
selection process in FIG. 5 similar to a case where the external
apparatus 400 is connected to the electronic device 200 via the
cable 300.
[0164] According to the first, second, and third exemplary
embodiments, the power supply apparatus 100 selects either the
power supply apparatus 100 or the external apparatus 400 as an
apparatus capable of suitably supplying the power to the electronic
device 200.
[0165] Subsequently, when the CPU 107 detects that the state of
connection between the electronic device 200 and the external
apparatus 400 has changed, the power supply apparatus 100 may
select again an apparatus capable of suitably supplying the power
to the electronic device 200. In this case, for example, when the
external apparatus 400 is selected by the power supply apparatus
100 as an apparatus which supplies the power to the electronic
device 200 and then the electronic device 200 and the external
apparatus 400 are disconnected, the power supply apparatus 100 may
select again an apparatus capable of suitably supplying the power
to the electronic device 200, by performing again the selection
process in FIG. 4 or the selection process in FIG. 5.
[0166] Further, for example, when the power supply apparatus 100 is
selected by the power supply apparatus 100 as an apparatus which
supplies the power to the electronic device 200 and then the
electronic device 200 and the external apparatus 400 are connected,
the power supply apparatus 100 may select again an apparatus
capable of suitably supplying the power to the electronic device
200, by performing again the selection process in FIG. 4 or the
selection process in FIG. 5.
[0167] Further, when the power supply apparatus 100 detects that
the power supplied from the external apparatus 400 to the
electronic device 200 has changed, the power supply apparatus 100
may select again an apparatus capable of suitably supplying the
power to the electronic device 200. In this case, for example, when
the external apparatus 400 is selected by the power supply
apparatus 100 as an apparatus which supplies the power to the
electronic device 200 and then the power supplied from the external
apparatus 400 to the electronic device 200 decreases, the power
supply apparatus 100 may select again an apparatus capable of
suitably supplying the power to the electronic device 200, by
performing again the selection process in FIG. 4 or the selection
process in FIG. 5.
[0168] Further, for example, when the power supply apparatus 100 is
selected by the power supply apparatus 100 as an apparatus which
supplies the power to the electronic device 200 and then the power
supplied from the external apparatus 400 to the electronic device
200 increases, the power supply apparatus 100 may select again an
apparatus capable of suitably supplying the power to the electronic
device 200, by performing again the selection process in FIG. 4 or
the selection process in FIG. 5.
[0169] If the power supply apparatus 100 stops power output in the
process in step S405 or S506, the power supply apparatus 100 may
continue wireless communication conforming to the NFC standard with
the electronic device 200.
[0170] Aspects of the present invention can also be realized by a
computer of a system or apparatus (or devices such as a CPU or an
MPU) that reads out and executes a program recorded on a memory
device to perform the functions of the above-described embodiments,
and by a method, the steps of which are performed by a computer of
a system or apparatus by, for example, reading out and executing a
program recorded on a memory device to perform the functions of the
above-described embodiments. For this purpose, the program is
provided to the computer for example via a network or from a
recording medium of various types serving as the memory device
(e.g., computer-readable medium).
[0171] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all modifications, equivalent
structures, and functions.
* * * * *