US20170093221A1 - Power transmission device and wireless power transmission system including the same - Google Patents

Power transmission device and wireless power transmission system including the same Download PDF

Info

Publication number
US20170093221A1
US20170093221A1 US15/281,745 US201615281745A US2017093221A1 US 20170093221 A1 US20170093221 A1 US 20170093221A1 US 201615281745 A US201615281745 A US 201615281745A US 2017093221 A1 US2017093221 A1 US 2017093221A1
Authority
US
United States
Prior art keywords
frequency
coil
resonance
power transmission
variable capacitor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
US15/281,745
Inventor
Koichiro Kamata
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Semiconductor Energy Laboratory Co Ltd
Original Assignee
Semiconductor Energy Laboratory Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to JP2010263048 priority Critical
Priority to JP2010-263048 priority
Priority to US13/300,049 priority patent/US9461476B2/en
Application filed by Semiconductor Energy Laboratory Co Ltd filed Critical Semiconductor Energy Laboratory Co Ltd
Priority to US15/281,745 priority patent/US20170093221A1/en
Publication of US20170093221A1 publication Critical patent/US20170093221A1/en
Application status is Pending legal-status Critical

Links

Images

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/10Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling
    • H02J50/12Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling of the resonant type
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F38/00Adaptations of transformers or inductances for specific applications or functions
    • H01F38/14Inductive couplings
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J5/00Circuit arrangements for transfer of electric power between ac networks and dc networks
    • H02J5/005Circuit arrangements for transfer of electric power between ac networks and dc networks with inductive power transfer
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/20Circuit arrangements or systems for wireless supply or distribution of electric power using microwaves or radio frequency waves
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/02Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from ac mains by converters
    • H02J7/04Regulation of charging current or voltage
    • H02J7/042Regulation of charging current or voltage the charge cycle being controlled in response to a measured parameter
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/02Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from ac mains by converters
    • H02J7/022Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from ac mains by converters characterised by the type of converter
    • H02J7/025Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from ac mains by converters characterised by the type of converter using non-contact coupling, e.g. inductive, capacitive

Abstract

Not a structure in which a resonance frequency of a power transmission device is set after a resonance frequency of a power receiving device is directly measured but a structure in which the resonance frequencies of the power receiving device and the power transmission device are estimated after reflection of an electromagnetic field for transmitting electric power to the power receiving device is monitored by the power transmission device is employed. After a capacitance value of a variable capacitor in a resonance coil of the power receiving device is once set to 0, an S11 parameter is detected while a frequency of an electromagnetic wave is changed, and the resonance frequency of the power transmission device is estimated on the basis of the S11 parameter.

Description

    TECHNICAL FIELD
  • The present invention relates to power transmission devices and wireless power transmission systems including the power transmission devices.
  • BACKGROUND ART
  • Various kinds of electronic devices have spread, and a wide variety of products have been shipped to the market. In recent years, portable electronic devices such as cellular phones and digital video cameras have widely spread. Further, electric propulsion moving vehicles that are powered by electric power, such as electric cars, appear on the market as products.
  • Cellular phones, digital video cameras, and electric propulsion moving vehicles include batteries that are energy storage means. The batteries are charged while being in direct contact with home AC sources that are power transmission means in many cases. In a structure without a battery or a structure where electric power stored in a battery is not used, electric power is directly transmitted to an electronic device from a home AC source through a wiring or the like so that the electronic device operates.
  • On the other hand, methods by which batteries are charged wirelessly or electric power is transmitted to loads wirelessly have been researched and developed. Typical methods are an electromagnetic coupling method (also referred to as an electromagnetic induction method), a radio wave method (also referred to as a microwave method), and a resonance method. As electronic devices such as small household electrical appliances, devices utilizing the electromagnetic coupling method have spread.
  • Resonant wireless power transmission systems have been developed in order to increase the efficiency of electric power transmission as disclosed in References 1 to 3.
  • REFERENCE
  • Reference 1: Japanese Published Patent Application No. 2010-193598
  • Reference 2: Japanese Published Patent Application No. 2010-239690
  • Reference 3: Japanese Published Patent Application No. 2010-252468
  • DISCLOSURE OF INVENTION
  • In a resonant wireless power transmission system, as disclosed in Reference 1, it is important that the resonance frequency of a device that receives electric power (hereinafter such a device is referred to as a power receiving device) be consistent with the resonance frequency of a device that transmits electric power (hereinafter such a device is referred to as a power transmission device) in increasing the efficiency of electric power transmission.
  • In particular, the resonance frequency of the power receiving device is changed depending on arrangement or the like of the power receiving device. Thus, it is important to monitor a change in resonance frequency of the power receiving device by the power transmission device.
  • However, in the case where the resonance frequency of the power receiving device is measured, the measured value of the resonance frequency is fed back to the power transmission device, and the resonance frequency of the power transmission device is changed, a structure is complex. Reference 3 discloses a specific example in which a structure is complex. In Reference 3, a structure is disclosed in which a circuit for monitoring a change in resonance frequency is provided in each power receiving device. The structure is unfavorable because additional provision of a circuit in each power receiving device leads to an increase in cost. In particular, in transmission using four elements in which electric power is transmitted wirelessly between a first coil (also referred to as a power transmission coil) of a power transmission device and a second coil (also referred to as a power receiving coil) of a power receiving device through a first resonance coil and a second resonance coil by a resonance method, it is unfavorable to provide a means for measuring a resonance frequency in the power receiving device because the size of the power receiving device is further increased.
  • Thus, it is an object of one embodiment of the present invention to provide a resonant power transmission device with which resonance frequency matching can be performed between resonance coils of the power transmission device and a power receiving device only by a change in design of the structure of the power transmission device and the efficiency of electric power transmission can be increased and a wireless power transmission system including the power transmission device.
  • One embodiment of the present invention is not a structure in which the resonance frequency of a power transmission device is set after the resonance frequency of a power receiving device is directly measured but a structure in which the resonance frequencies of a power receiving device and a power transmission device are estimated after reflection of an electromagnetic field for transmitting electric power to the power receiving device is monitored by the power transmission device. In particular, in one embodiment of the present invention, the resonance frequency of a power transmission device is estimated under the condition that a capacitance component in a resonance coil of the power transmission device is controlled so as not to influence monitoring of reflection of an electromagnetic wave when the reflection of the electromagnetic wave is monitored. Specifically, after the capacitance value of a variable capacitor in a resonance coil of the power receiving device is once set to 0, an S11 parameter that gives an indication in a scattering matrix (hereinafter referred to as an S parameter) at the time when reflection of an electromagnetic wave for transmitting electric power is monitored is detected while the frequency of the electromagnetic wave is changed, and the resonance frequency of the power transmission device is estimated on the basis of the S11 parameter.
  • One embodiment of the present invention is a power transmission device that includes a first coil, a first resonance coil, a detector, and a control device. The first coil is connected to a high-frequency power source through a coupler. The first resonance coil is connected to a variable capacitor and is electromagnetically coupled with the first coil, and electromagnetic resonance occurs between the first resonance coil and a second resonance coil that is electromagnetically coupled with a second coil in a power receiving device. The detector detects the intensity of an S11 parameter output from the coupler. The control device has a function of changing the capacitance value of the variable capacitor and the oscillation frequency of a signal output from the high-frequency power source, sets the capacitance value of the variable capacitor to 0, sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under the condition that the capacitance value of the variable capacitor is 0, as the resonance frequency of the second resonance coil, sets the resonance frequency of the first resonance coil after the capacitance value of the variable capacitor is set in accordance with the resonance frequency of the second resonance coil, and sets the oscillation frequency of the signal output from the high-frequency power source as the resonance frequencies of the first resonance coil and the second resonance coil.
  • One embodiment of the present invention is a power transmission device that includes a first coil, a first resonance coil, a detector, and a control device. The first coil is connected to a high-frequency power source through a coupler. The first resonance coil is connected to a variable capacitor and is electromagnetically coupled with the first coil, and electromagnetic resonance occurs between the first resonance coil and a second resonance coil that is electromagnetically coupled with a second coil in a power receiving device. The detector detects the intensity of an S11 parameter output from the coupler. The control device has a function of changing the capacitance value of the variable capacitor and the oscillation frequency of a signal output from the high-frequency power source, sets the capacitance value of the variable capacitor to 0, sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under the condition that the capacitance value of the variable capacitor is 0, as the resonance frequency of the second resonance coil, sets the resonance frequency of the first resonance coil after the capacitance value of the variable capacitor is set in accordance with the resonance frequency of the second resonance coil, and sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under the condition that the capacitance value of the variable capacitor is set to a capacitance value based on the resonant frequency of the second resonance coil, as the oscillation frequency of the signal output from the high-frequency power source.
  • In one embodiment of the present invention, the power transmission device may include a memory circuit in which the capacitance value of the variable capacitor for setting the resonance frequency of the first resonance coil on the basis of the resonance frequency of the second resonance coil is stored, and the memory circuit may be connected to the control device.
  • One embodiment of the present invention is a wireless power transmission system that includes a power transmission device and a power receiving device. The power transmission device includes a first coil, a first resonance coil, a detector, and a control device. The first coil is connected to a high-frequency power source through a coupler. The first resonance coil is electromagnetically coupled with the first coil and is connected to a variable capacitor. The detector detects the intensity of an S11 parameter output from the coupler. The control device has a function of changing the capacitance value of the variable capacitor and the oscillation frequency of a signal output from the high-frequency power source, sets the capacitance value of the variable capacitor to 0, sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under the condition that the capacitance value of the variable capacitor is 0, as the resonance frequency of the second resonance coil, sets the resonance frequency of the first resonance coil after the capacitance value of the variable capacitor is set in accordance with the resonance frequency of the second resonance coil, and sets the oscillation frequency of the signal output from the high-frequency power source as the resonance frequencies of the first resonance coil and the second resonance coil. The power receiving device includes the second resonance coil which causes electromagnetic resonance with the first resonance coil and is connected to a capacitor and a second coil which is electromagnetically coupled with the second resonance coil and is connected to a load.
  • One embodiment of the present invention is a wireless power transmission system that includes a power transmission device and a power receiving device. The power transmission device includes a first coil, a first resonance coil, a detector, and a control device. The first coil is connected to a high-frequency power source through a coupler. The first resonance coil is electromagnetically coupled with the first coil and is connected to a variable capacitor. The detector detects the intensity of an S11 parameter output from the coupler. The control device has a function of changing the capacitance value of the variable capacitor and the oscillation frequency of a signal output from the high-frequency power source, sets the capacitance value of the variable capacitor to 0, sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under the condition that the capacitance value of the variable capacitor is 0, as the resonance frequency of the second resonance coil, sets the resonance frequency of the first resonance coil after the capacitance value of the variable capacitor is set in accordance with the resonance frequency of the second resonance coil, and sets a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under the condition that the capacitance value of the variable capacitor is set to a capacitance value based on the resonant frequency of the second resonance coil, as the oscillation frequency of the signal output from the high-frequency power source. The power receiving device includes the second resonance coil which causes electromagnetic resonance with the first resonance coil and is connected to a capacitor and a second coil which is electromagnetically coupled with the second resonance coil and is connected to a load.
  • In one embodiment of the present invention, in the wireless power transmission system, the power transmission device may include a memory circuit in which the capacitance value of the variable capacitor for setting the resonance frequency of the first resonance coil on the basis of the resonance frequency of the second resonance coil is stored, and the memory circuit may be connected to the control device.
  • According to one embodiment of the present invention, it is possible to provide a resonant power transmission device with which resonance frequency matching can be performed between resonance coils of the power transmission device and a power receiving device only by a change in design of the structure of the power transmission device and the efficiency of electric power transmission can be increased and a wireless power transmission system including the power transmission device.
  • BRIEF DESCRIPTION OF DRAWINGS
  • In the accompanying drawings:
  • FIG. 1 illustrates a structure in Embodiment 1;
  • FIG. 2 shows a structure in Embodiment 1;
  • FIG. 3 shows a structure in Embodiment 1;
  • FIG. 4 illustrates a structure in Embodiment 1;
  • FIGS. 5A to 5C illustrate structures in Embodiment 1;
  • FIG. 6 illustrates a structure in Embodiment 2; and
  • FIGS. 7A and 7B illustrate structures in Embodiment 3.
  • BEST MODE FOR CARRYING OUT THE INVENTION
  • Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention can be implemented in various different ways, and it will be readily appreciated by those skilled in the art that modes and details of the present invention can be modified in various ways without departing from the spirit and scope of the present invention. The present invention therefore should not be construed as being limited to the description of the embodiments. Note that in structures of the invention described below, reference numerals denoting the same portions are used in common in different drawings.
  • Note that the size, the layer thickness, or the signal waveform of each component illustrated in drawings and the like in embodiments is exaggerated for clarity in some cases. Thus, embodiments of the present invention are not limited to such scales.
  • Note that in this specification, terms such as “first”, “second”, “third”, and “n-th” (n is a natural number) are used in order to avoid confusion among components and do not limit the number of components.
  • Embodiment 1
  • In this embodiment, a resonant wireless power transmission device and a resonant wireless power transmission system in one embodiment of the present invention are described.
  • FIG. 1 is a block diagram of a power transmission device and a power receiving device. FIG. 1 illustrates electric power transmission with an electromagnetic wave by resonance of a first resonance coil in the power transmission device and a second resonance coil in the power receiving device.
  • FIG. 1 illustrates a power transmission device 101 and a power receiving device 102. The power transmission device 101 includes a first coil 103 (also referred to as a power transmission coil), a high-frequency power source 104, a coupler 105 (also referred to as a directional coupler), a first resonance coil 107, a variable capacitor 106, a detector 108, a control device 109, and a memory circuit 110.
  • The power receiving device 102 includes a second resonance coil 111, a capacitor 112, a second coil 113 (also referred to as a power receiving coil), and a load 114.
  • In FIG. 1, the first coil 103 is connected to the high-frequency power source 104 through the coupler 105. A coil formed by winding of a wire may be used as the first coil 103. The first coil 103 in the power transmission device 101 has higher design flexibility than the second coil 113 in the power receiving device 102 because the position of the power transmission device 101 is not particularly limited in comparison with the position of the power receiving device 102.
  • Note that when it is explicitly described that “A is connected to B”, the case where A is electrically connected to B, the case where A is functionally connected to B, and the case where A is directly connected to B are included.
  • In FIG. 1, the high-frequency power source 104 is a power supply circuit for outputting a signal whose frequency is successively changed in accordance with control by the control device 109.
  • Note that the high-frequency power source 104 may include a voltage controlled oscillator (VCO) or the like so that the frequency of an output signal is changed in accordance with voltage input from the control device 109.
  • There is no particular limitation on a frequency which is oscillated with an AC signal output from the high-frequency power source 104 in the power transmission device 101 in this embodiment (such a frequency is referred to as an oscillation frequency), and an oscillation frequency at which electric power can be transmitted by a resonance method may be used. The oscillation frequency of a power transmission electromagnetic wave can be used, for example, in the frequency range of several kilohertz to several gigahertz. In particular, in this embodiment, in terms of transmission efficiency, the frequency range of several megahertz is preferable because resonance (magnetic resonance) can be caused.
  • In FIG. 1, the coupler 105 (the directional coupler) is a circuit for detecting an S parameter in the circuit including the high-frequency power source. In this embodiment, the coupler 105 detects an S11 parameter that gives an indication of loss due to reflection between a two-terminal port of the first coil 103 and a two-terminal port of the second resonance coil 111.
  • In FIG. 1, the first resonance coil 107 is connected to the variable capacitor 106. A coil formed by winding of a wire may be used as the first resonance coil 107. There is no particular limitation on the shape of the first resonance coil 107; however, the first resonance coil 107 in the power transmission device 101 has higher design flexibility than the second resonance coil 111 in the power receiving device 102 because the position of the power transmission device 101 is not particularly limited in comparison with the position of the power receiving device 102. Note that signals for supplying electric power wirelessly are transmitted and received between the first coil 103 and the first resonance coil 107 by electromagnetic coupling. In addition, signals for supplying electric power wirelessly are transmitted and received between the first resonance coil 107 and the second resonance coil 111 by electromagnetic resonance. Electromagnetic resonance is used in resonant wireless power transmission. By electromagnetic resonance, electric power which is higher than electric power generated by electromagnetic coupling can be transmitted within a distance of 1 m or less from an electric field or a magnetic field.
  • In FIG. 1, the variable capacitor 106 may be, for example, a variable capacitance diode utilizing the spread of a depletion layer due to a semiconductor material so that capacitance is changed by voltage applied from the outside. Alternatively, the variable capacitor 106 may be micro electro mechanical systems (MEMS) so that capacitance is changed by voltage applied from the outside.
  • In FIG. 1, the detector 108 detects the intensity of the S11 parameter obtained in the coupler 105. Specifically, the detector 108 is a circuit which converts the intensity of the S11 parameter that is an analog value into a digital value and transmits the intensity of the S11 parameter that is the digital value to the control device 109.
  • In FIG. 1, the control device 109 has a function of changing the capacitance value of the variable capacitor 106 and the oscillation frequency of a signal output from the high-frequency power source 104. The control device 109 performs a plurality of different operations.
  • Specifically, the control device 109 has a function of adjusting the capacitance value of the variable capacitor 106 to 0. Further, the control device 109 has a function of adjusting voltage to be applied to the high-frequency power source 104 so that the oscillation frequency of the high-frequency power source 104 is successively changed under the condition that the capacitance value of the variable capacitor 106 is 0.
  • Note that in this specification, the expression “the capacitance value of the variable capacitor 106 is set to 0” means that the capacitance value of the variable capacitor 106 is set such that the first resonance coil 107 does not influence signals transmitted and received between the first coil 103 and the second resonance coil 111.
  • Note that when the oscillation frequency of the high-frequency power source 104 is successively changed under the condition that the capacitance value of the variable capacitor 106 is 0, the S11 parameter obtained in the coupler 105 is changed in accordance with a change in oscillation frequency of the high-frequency power source 104. In the following description, a peak frequency at which the S11 parameter obtained by a successive change in oscillation frequency of the high-frequency power source 104 under the condition that the capacitance value of the variable capacitor 106 is 0 is changed is referred to as f0. Note that the frequency f0 detected by the control device 109 can be estimated as the resonance frequency of the second resonance coil 111.
  • FIG. 2 is a graph in which the horizontal axis represents the oscillation frequency of the high-frequency power source 104 and the vertical axis represents the intensity of the S11 parameter that is obtained in the detector 108. Specifically, a frequency f represents the intensity (dB) of a magnetic field that indicates the intensity of the S11 parameter while the frequency f is changed from 2.0 to 4.0 MHz.
  • In FIG. 2, the peak frequency f0 at the time when the intensity of the S11 parameter that is obtained in the detector 108 is changed is estimated at 3 MHz. In other words, when the oscillation frequency is 3 MHz, the intensity of the S11 parameter is low and power loss due to reflection between the first coil 103 and the second resonance coil 111 is low.
  • Note that in this specification, “the peak frequency at the time when the intensity of the S11 parameter is changed” is a frequency at the time when the intensity of the S11 parameter is markedly decreased in successively changing the oscillation frequency and then is rapidly returned to the original intensity, as illustrated in FIG. 2. Note that the peak frequency at the time when the intensity of the S11 parameter is changed might be referred to as “a frequency at which the intensity of the S11 parameter is changed”.
  • Note that FIG. 3 is a graph in which the horizontal axis represents the oscillation frequency of the high-frequency power source 104 and the vertical axis represents the intensity of magnetic fields of the S11 parameter and an S21 parameter that are obtained in the coupler 105 in the case where electromagnetic resonance occurs between the first resonance coil 107 and the second resonance coil 111. The S21 parameter gives an indication of the efficiency of electric power transmission in the S parameter.
  • As is clear from FIG. 3, the frequencies f0 at which the S11 parameter obtained in the detector 108 is changed are estimated at around 2.6 MHz and 3.6 MHz. In other words, power loss due to reflection is low when the oscillation frequencies are 2.6 MHz and 3.6 MHz. Similarly, the frequencies f0 at which the S21 parameter is changed are estimated at around 2.6 MHz and 3.6 MHz. FIG. 3 shows that the peak of the S11 parameter is consistent with the peak of the S21 parameter. That is, the efficiency of electric power transmission is high when the oscillation frequencies are 2.6 MHz and 3.6 MHz. In other words, when the frequency f0 is obtained by monitoring of a change in oscillation frequency of the S11 parameter, a frequency with high efficiency of electric power transmission, i.e., the resonance frequency of the second resonance coil 111 can be estimated.
  • Further, the control device 109 has a function of changing the capacitance value of the variable capacitor 106 into a value based on the frequency f0 after the frequency f0 is detected. Furthermore, the control device 109 has a function of fixing the oscillation frequency of the high-frequency power source 104 to the frequency f0 while the capacitance value of the variable capacitor 106 is set to the value based on the frequency f0.
  • In FIG. 1, the memory circuit 110 stores a look-up table in which voltage for adjusting the capacitance of the variable capacitor 106 by the control device 109 is estimated in advance in order that the control device 109 adjust the resonance frequency of the first resonance coil 107 in accordance with the frequency f0 that is the resonance frequency of the second resonance coil 111.
  • In FIG. 1, a coil formed by winding of a wire may be used as the second resonance coil 111. There is no particular limitation on the shape of the second resonance coil 111; however, the second resonance coil 111 in the power receiving device 102 is preferably designed such that it is smaller than the first resonance coil 107 in the power transmission device 101 because the power receiving device 102 needs to be smaller than the power transmission device 101. In particular, the Q-value of the second resonance coil 111 is preferably high. Specifically, the Q-value of the second resonance coil 111 is preferably 1000 or more. Note that signals for supplying electric power wirelessly are transmitted and received between the second resonance coil 111 and the first resonance coil 107 by electromagnetic resonance.
  • Although FIG. 1 illustrates the capacitor 112, the capacitor 112 may be parasitic capacitance generated at the time of formation of the second resonance coil 111. Alternatively, the capacitor 112 may be a capacitor provided in advance independently of the second resonance coil 111.
  • In FIG. 1, a coil formed by winding of a wire may be used as the second coil 113. There is no particular limitation on the shape of the second coil 113; however, the second coil 113 in the power receiving device 102 is preferably designed such that it is smaller than the first coil 103 in the power transmission device 101 because the power receiving device 102 needs to be smaller than the power transmission device 101. Note that signals for supplying electric power wirelessly are transmitted and received between the second coil 113 and the second resonance coil 111 by electromagnetic coupling.
  • In FIG. 1, the load 114 needs to operate by wireless power transmission. For example, a battery, an electric motor, or the like can be used. Specifically, an electronic device which operates by a battery, such as a cellular phone, or an electric propulsion moving vehicle can be used. Note that in the power receiving device 102, a circuit such as a DCDC converter or a rectifier circuit for converting AC voltage transmitted to the second coil 113 into DC voltage used in the load 114 may be provided between the load 114 and the second coil 113.
  • FIG. 4 is a flow chart of a wireless power transmission system in the present invention. FIGS. 5A to 5C are schematic diagrams in the flow chart in FIG. 4.
  • In Step 201 in FIG. 4, in the power transmission device 101, the capacitance value of the variable capacitor 106 is adjusted to 0 by control with the control device 109. In other words, in Step 201 in FIG. 4, as illustrated in the schematic diagram in FIG. 5A, the variable capacitor 106 and the first resonance coil 107 (dotted lines in the diagram) are not to be influenced by a signal output from the first coil 103.
  • In Step 202 in FIG. 4, in the power transmission device 101, the oscillation frequency of the high-frequency power source 104 is scanned by control with the control device 109 so that the oscillation frequency of the high-frequency power source 104 is changed successively.
  • In Step 203 in FIG. 4, in the power transmission device 101, whether the frequency f0 at which the intensity of the S11 parameter is changed is detected in the control device 109 when the oscillation frequency of the high-frequency power source 104 is changed successively is determined. In Step 203, if the frequency f0 is not detected, rearrangement of a power receiving device or the like by a user is required, and the steps are performed again from Step 201. In other words, in Steps 202 and 203 in FIG. 4, as illustrated in the schematic diagram in FIG. 5B, a frequency at which power loss due to reflection between the first coil 103 and the second resonance coil 111 is decreased is determined while the variable capacitor 106 and the first resonance coil 107 (dotted lines in the diagram) are not influenced by a signal output from the first coil 103. Through the series of steps, the frequency f0 is detected.
  • In Step 204 in FIG. 4, if the frequency f0 is detected in Step 203, the capacitance value of the variable capacitor is adjusted in accordance with the frequency M. The capacitance value of the variable capacitor 106 may be adjusted referring to the look-up table stored in the memory circuit 110. The look-up table stores application voltage based on the capacitance value of the variable capacitor 106 adjusted in accordance with the frequency f0 that is a resonance frequency estimated in advance.
  • In Step 205 in FIG. 4, in the power transmission device 101, voltage to be applied to the high-frequency power source 104 is adjusted by control with the control device 109 so that the frequency f0 is set as the oscillation frequency of the high-frequency power source 104. In other words, in Steps 204 and 205 in FIG. 4, as illustrated in the schematic diagram in FIG. 5C, resonance frequency matching is performed so that resonance occurs between the first resonance coil 107 and the second resonance coil 111 by application of voltage to the variable capacitor 106, and output from the high-frequency power source 104 whose oscillation frequency is the frequency f0 is obtained.
  • According to one embodiment of the present invention, it is possible to provide a resonant power transmission device with which resonance frequency matching can be performed between resonance coils of the power transmission device and a power receiving device only by a change in design of the structure of the power transmission device and the efficiency of electric power transmission can be increased and a resonant wireless power transmission system.
  • This embodiment can be combined with any of the structures described in the other embodiments as appropriate.
  • Embodiment 2
  • In this embodiment, the case where different steps are added to the flow chart in FIG. 4 in Embodiment 1 is described.
  • Note that the control device 109 in FIG. 1 in Embodiment 1 that is described in this embodiment has a function of changing the capacitance value of a variable capacitor and the oscillation frequency of a signal output from a high-frequency power source. Specifically, the control device 109 has a function of adjusting the capacitance value of the variable capacitor 106 to 0. Further, the control device 109 has a function of adjusting voltage to be applied to the high-frequency power source 104 so that the oscillation frequency of the high-frequency power source 104 is successively changed under the condition that the capacitance value of the variable capacitor 106 is 0. Further, the control device 109 has a function of changing the capacitance value of the variable capacitor 106 into a value based on the frequency f0 in accordance with the frequency f0 after the frequency f0 is detected. Furthermore, the control device 109 has a function of setting a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed while the capacitance value of the variable capacitor 106 is set to the value based on the frequency f0, as the oscillation frequency of the signal output from the high-frequency power source.
  • Note that Steps 201 to 204 in FIG. 6 are similar to those of the flow chart in FIG. 4 in Embodiment 1.
  • In Step 301 in FIG. 6, in the power transmission device 101, while the capacitance value of the variable capacitor 106 is fixed to the value adjusted in accordance with the frequency f0 that is the resonance frequency, the oscillation frequency of the high-frequency power source 104 is scanned by control with the control device 109 so that the oscillation frequency of the high-frequency power source 104 is changed successively.
  • In Step 302 in FIG. 6, in the power transmission device 101, whether the peak of a frequency at which the intensity of the S11 parameter is changed is detected in the control device 109 when the oscillation frequency of the high-frequency power source 104 is changed successively is determined. In Step 302, if the peak of the frequency is not detected, rearrangement of a power receiving device or the like by a user is required, and the steps are performed again from Step 201.
  • In Step 303 in FIG. 6, whether the peak of the frequency in Step 302 corresponds to two peaks of (f0+Δf) and (f0−Δf) that are separated from the frequency f0 detected in Step 203 is determined.
  • In Step 304 in FIG. 6, in the case where the number of peaks of the frequency is determined to be two in Step 303, in the power transmission device 101, voltage to be applied to the high-frequency power source 104 is adjusted by control with the control device 109 so that the frequency (f0+Δf) or the frequency (f0−Δf) is set as the oscillation frequency of the high-frequency power source 104. Note that one of the frequency (f0+Δf) and the frequency (f0−Δf) at which the intensity of the S11 parameter detected by a detector is lower is preferably used as the oscillation frequency.
  • In Step 305 in FIG. 6, in the case where the peak of the frequency is determined to be f0 in Step 303, in the power transmission device 101, voltage to be applied to the high-frequency power source 104 is adjusted by control with the control device 109 so that the frequency f0 is set as the oscillation frequency of the high-frequency power source 104.
  • According to one embodiment of the present invention, it is possible to provide a resonant wireless power transmission device in which resonance frequency matching can be performed between resonance coils of the power transmission device and a power receiving device only by a change in design of the structure of the power transmission device and the efficiency of electric power transmission can be increased and a resonant wireless power transmission system. In particular, in the structure of this embodiment, a decrease in efficiency of electric power transmission that is caused by separation of the peaks of frequency due to reduction in distance between a receiving device and a power transmission device can be suppressed while the resonance frequencies of resonance coils match each other.
  • This embodiment can be combined with any of the structures described in the other embodiments as appropriate.
  • Embodiment 3
  • In this embodiment, applications of the wireless power transmission system in the above embodiment are described. Note that as applications of a wireless power transmission system in the present invention, for example, portable electronic devices such as a cellular phone, a digital video camera, a computer, a portable information terminal (e.g., a mobile computer, a portable game machine, or an e-book reader), and an image reproducing device including a recording medium (specifically a digital versatile disc (DVD)) can be given. In addition, an electric propulsion moving vehicle that is powered by electric power, such as an electric car, can be given. Examples of such electronic devices are described below with reference to drawings.
  • FIG. 7A illustrates an application of a wireless power transmission system to a cellular phone and a portable information terminal, and a power transmission device 701, a cellular phone 702A including a power receiving device 703A, and a cellular phone 702B including a power receiving device 703B are included. The wireless power transmission system in the above embodiment can be provided between the power transmission device 701 and the power receiving device 703A and between the power transmission device 701 and the power receiving device 703B. Thus, it is possible to provide a resonant wireless power transmission device in which resonance frequency matching can be performed between resonance coils of the power transmission device and a power receiving device only by a change in design of the structure of the power transmission device and the efficiency of electric power transmission can be increased and a resonant wireless power transmission system.
  • FIG. 7B illustrates an application of a wireless power transmission system to an electric car that is an electric propulsion moving vehicle, and a power transmission device 711 and an electric car 712 including a power receiving device 713 are included. The wireless power transmission system in the above embodiment can be provided between the power transmission device 711 and the power receiving device 713. Thus, it is possible to provide a resonant wireless power transmission device in which resonance frequency matching can be performed between resonance coils of the power transmission device and a power receiving device only by a change in design of the structure of the power transmission device and the efficiency of electric power transmission can be increased and a resonant wireless power transmission system.
  • As described above, the wireless power transmission system in the above embodiment can be used in any object that is driven with power.
  • This embodiment can be combined with any of the structures described in the other embodiments as appropriate.
  • REFERENCE NUMERALS
  • 101: power transmission device, 102: power receiving device, 103: first coil, 104: high-frequency power source, 105: coupler, 106: variable capacitor, 107: first resonance coil, 108: detector, 109: control device, 110: memory circuit, 111: second resonance coil, 112: capacitor, 113: second coil, 114: load, 201: step, 202: step, 203: step, 204: step, 205: step, 301: step, 302: step, 303: step, 304: step, 305: step, 701: power transmission device, 702A: cellular phone, 702B: cellular phone, 703A: power receiving device, 703B: power receiving device, 711: power transmission device, 712: electric car, and 713: power receiving device.
  • This application is based on Japanese Patent Application serial No. 2010-263048 filed with Japan Patent Office on Nov. 26, 2010, the entire contents of which are hereby incorporated by reference.

Claims (9)

1. (canceled)
2. A power transmission device comprising:
a first coil;
a first resonance coil;
a high-frequency power source;
a coupler;
a variable capacitor;
a detector; and
a control device,
wherein the first coil is connected to the high-frequency power source through the coupler,
wherein the first coil is configured to be electromagnetically coupled with the first resonance coil,
wherein the variable capacitor is connected to the first resonance coil and the control device,
wherein the detector is connected to the coupler and the control device, and
wherein the first coil is configured to transmit a signal to a power receiving device under a condition that a capacitance value of the variable capacitor is set to 0.
3. The power transmission device according to claim 2, further comprising a memory circuit in which the capacitance value of the variable capacitor for setting a resonance frequency of the first resonance coil on the basis of a resonance frequency of a second resonance coil is stored, wherein the memory circuit is connected to the control device.
4. A power transmission device comprising:
a first coil;
a first resonance coil;
a high-frequency power source;
a coupler;
a variable capacitor;
a detector; and
a control device,
wherein the first coil is connected to the high-frequency power source through the coupler,
wherein the first resonance coil is connected to the variable capacitor and is configured to be electromagnetically coupled with the first coil, and electromagnetic resonance occurs between the first resonance coil and a second resonance coil electromagnetically coupled with a second coil in a power receiving device,
wherein the detector is configured to detect intensity of an S11 parameter output from the coupler, and
wherein the control device is configured to change a capacitance value of the variable capacitor and an oscillation frequency of a signal output from the high-frequency power source,
wherein the control device is configured to set the capacitance value of the variable capacitor to 0,
wherein the control device is configured to set a frequency at which the intensity of the S11 parameter which is an indication of loss due to reflection of electromagnetic wave between the first coil and the second resonance coil is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under a condition that the capacitance value of the variable capacitor is 0, as a resonance frequency of the second resonance coil,
wherein the control device is configured to set a resonance frequency of the first resonance coil after the capacitance value of the variable capacitor is set in accordance with the resonance frequency of the second resonance coil, and
wherein the control device is configured to set the oscillation frequency of the signal output from the high-frequency power source as the resonance frequencies of the first resonance coil and the second resonance coil.
5. The power transmission device according to claim 4, further comprising a memory circuit in which the capacitance value of the variable capacitor for setting the resonance frequency of the first resonance coil on the basis of the resonance frequency of the second resonance coil is stored, wherein the memory circuit is connected to the control device.
6. A wireless power transmission system comprising a power transmission device and a power receiving device,
wherein the power transmission device comprising:
a first coil;
a first resonance coil;
a high-frequency power source;
a coupler;
a variable capacitor;
a detector; and
a control device,
wherein the first coil is connected to the high-frequency power source through the coupler,
wherein the first resonance coil is configured to be electromagnetically coupled with the first coil and is connected to the variable capacitor,
wherein the detector configured to detect intensity of an S11 parameter output from the coupler,
wherein the control device is configured to change a capacitance value of the variable capacitor and an oscillation frequency of a signal output from the high-frequency power source,
wherein the control device is configured to set the capacitance value of the variable capacitor to 0,
wherein the control device sets a frequency at which the intensity of the S11 parameter which is an indication of loss due to reflection of electromagnetic wave between the first coil and a second resonance coil in the power receiving device is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under a condition that the capacitance value of the variable capacitor is 0, as a resonance frequency of the second resonance coil,
wherein the control device is configured to set a resonance frequency of the first resonance coil after the capacitance value of the variable capacitor is set in accordance with the resonance frequency of the second resonance coil, and
wherein the control device is configured to set a frequency at which the intensity of the S11 parameter is changed at the time when the oscillation frequency of the signal output from the high-frequency power source is changed under a condition that the capacitance value of the variable capacitor is set to a capacitance value based on the resonance frequency of the second resonance coil, as the oscillation frequency of the signal output from the high-frequency power source, and
wherein the power receiving device includes the second resonance coil which is configured to cause electromagnetic resonance with the first resonance coil and is connected to a capacitor and a second coil which is configured to be electromagnetically coupled with the second resonance coil and is connected to a load.
7. The wireless power transmission system according to claim 6,
wherein the power transmission device includes a memory circuit in which the capacitance value of the variable capacitor for setting the resonance frequency of the first resonance coil on the basis of the resonance frequency of the second resonance coil is stored, and
wherein the memory circuit is connected to the control device.
8. A wireless power transmission system comprising a power transmission device and a power receiving device,
wherein the power transmission device comprising:
a first coil;
a first resonance coil;
a high-frequency power source;
a coupler;
a variable capacitor;
a detector; and
a control device,
wherein the first coil is connected to the high-frequency power source through the coupler,
wherein the first coil is electromagnetically coupled with the first resonance coil,
wherein the variable capacitor is connected to the first resonance coil and the control device, and
wherein the detector is connected to the coupler and the control device,
wherein the power receiving device includes a second resonance coil which is configured to cause electromagnetic resonance with the first resonance coil and is connected to a capacitor and a second coil which is configured to be electromagnetically coupled with the second resonance coil and is connected to a load, and
wherein the first coil transmits a signal to the power receiving device under a condition that the capacitance value of the variable capacitor is set to 0.
9. The wireless power transmission system according to claim 8,
wherein the power transmission device includes a memory circuit in which a capacitance value of the variable capacitor for setting a resonance frequency of the first resonance coil on the basis of a resonance frequency of the second resonance coil is stored, and
wherein the memory circuit is connected to the control device.
US15/281,745 2010-11-26 2016-09-30 Power transmission device and wireless power transmission system including the same Pending US20170093221A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2010263048 2010-11-26
JP2010-263048 2010-11-26
US13/300,049 US9461476B2 (en) 2010-11-26 2011-11-18 Power transmission device and wireless power transmission system including the same
US15/281,745 US20170093221A1 (en) 2010-11-26 2016-09-30 Power transmission device and wireless power transmission system including the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US15/281,745 US20170093221A1 (en) 2010-11-26 2016-09-30 Power transmission device and wireless power transmission system including the same

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US13/300,049 Continuation US9461476B2 (en) 2010-11-26 2011-11-18 Power transmission device and wireless power transmission system including the same

Publications (1)

Publication Number Publication Date
US20170093221A1 true US20170093221A1 (en) 2017-03-30

Family

ID=46126124

Family Applications (2)

Application Number Title Priority Date Filing Date
US13/300,049 Active 2033-12-25 US9461476B2 (en) 2010-11-26 2011-11-18 Power transmission device and wireless power transmission system including the same
US15/281,745 Pending US20170093221A1 (en) 2010-11-26 2016-09-30 Power transmission device and wireless power transmission system including the same

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US13/300,049 Active 2033-12-25 US9461476B2 (en) 2010-11-26 2011-11-18 Power transmission device and wireless power transmission system including the same

Country Status (5)

Country Link
US (2) US9461476B2 (en)
JP (1) JP5798455B2 (en)
KR (1) KR101854420B1 (en)
DE (1) DE112011103929T5 (en)
WO (1) WO2012070634A1 (en)

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20120084659A (en) 2011-01-20 2012-07-30 가부시키가이샤 한도오따이 에네루기 켄큐쇼 Power feeding device and wireless power feeding system
JP5780894B2 (en) 2011-09-16 2015-09-16 株式会社半導体エネルギー研究所 Contactless power supply system
JP2013078171A (en) 2011-09-29 2013-04-25 Semiconductor Energy Lab Co Ltd Power receiving device and non-contact power supply system
US9502920B2 (en) 2011-11-16 2016-11-22 Semiconductor Energy Laboratory Co., Ltd. Power receiving device, power transmission device, and power feeding system
JP6016596B2 (en) 2011-12-07 2016-10-26 株式会社半導体エネルギー研究所 Contactless power supply system
TWI613882B (en) 2011-12-16 2018-02-01 半導體能源研究所股份有限公司 Dc-dc converter, power receiving device, and power feeding system
US9847675B2 (en) * 2011-12-16 2017-12-19 Semiconductor Energy Laboratory Co., Ltd. Power receiving device and power feeding system
JP6088234B2 (en) 2011-12-23 2017-03-01 株式会社半導体エネルギー研究所 Power receiving device, wireless power feeding system
US10122402B2 (en) * 2012-12-31 2018-11-06 Futurewei Technologies, Inc. Method and apparatus for a tunable antenna
JP2014204469A (en) * 2013-04-01 2014-10-27 日東電工株式会社 Wireless power transmitter, supply power control method of wireless power transmitter, and method of manufacturing wireless power transmitter
JP6144176B2 (en) * 2013-10-15 2017-06-07 日東電工株式会社 Wireless power transmission device capable of forming magnetic field space and method for forming the same
DE102014200935A1 (en) * 2014-01-20 2015-07-23 Leoni Bordnetz-Systeme Gmbh Energy supply clutch
US9806658B2 (en) * 2014-03-06 2017-10-31 The Boeing Company Wirelessly powered electric motor
JP6334316B2 (en) * 2014-08-20 2018-05-30 株式会社東芝 Filter device, receiving device, transmitting device, antenna device, and switching device
US10128789B2 (en) * 2014-10-10 2018-11-13 The Boeing Company Phantom electric motor system with parallel coils
US10320229B2 (en) 2016-05-12 2019-06-11 Honeywell International Inc. Auto-tunable wireless charger

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8143746B2 (en) * 2009-12-21 2012-03-27 Alcatel Lucent Automatic tuning for wireless power transfer
US8217535B2 (en) * 2009-03-31 2012-07-10 Fujitsu Limited Wireless power supply apparatus
US8378524B2 (en) * 2008-09-02 2013-02-19 Sony Corporation Non-contact power transmission device

Family Cites Families (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL8901659A (en) 1989-06-30 1991-01-16 Nedap Nv Multipassysteem.
JP2803943B2 (en) 1992-10-21 1998-09-24 アルプス電気株式会社 A contactless power supply device
US5790946A (en) 1993-07-15 1998-08-04 Rotzoll; Robert R. Wake up device for a communications system
US6837438B1 (en) 1998-10-30 2005-01-04 Hitachi Maxell, Ltd. Non-contact information medium and communication system utilizing the same
US6509217B1 (en) 1999-10-22 2003-01-21 Damoder Reddy Inexpensive, reliable, planar RFID tag structure and method for making same
US20020049714A1 (en) 2000-05-11 2002-04-25 Shunpei Yamazaki Communication system
US7209771B2 (en) 2000-12-22 2007-04-24 Terahop Networks, Inc. Battery powered wireless transceiver having LPRF component and second wake up receiver
US6944424B2 (en) 2001-07-23 2005-09-13 Intermec Ip Corp. RFID tag having combined battery and passive power source
US6737302B2 (en) 2001-10-31 2004-05-18 Semiconductor Energy Laboratory Co., Ltd. Manufacturing method for field-effect transistor
US7215976B2 (en) 2001-11-30 2007-05-08 Symbol Technologies, Inc. RFID device, system and method of operation including a hybrid backscatter-based RFID tag protocol compatible with RFID, bluetooth and/or IEEE 802.11x infrastructure
JP3866594B2 (en) 2002-03-15 2007-01-10 Necエレクトロニクス株式会社 The method of the delay circuit and the semiconductor memory device and semiconductor memory device
EP1559278B1 (en) 2002-10-18 2013-05-15 Symbol Technologies, Inc. System and method for minimizing unwanted re-negotiation of a passive rfid tag
US7072697B2 (en) 2002-10-22 2006-07-04 Nokia Corporation Method and device for transponder aided wake-up of a low power radio device by a wake-up event
US7652359B2 (en) 2002-12-27 2010-01-26 Semiconductor Energy Laboratory Co., Ltd. Article having display device
US7603144B2 (en) 2003-01-02 2009-10-13 Cymbet Corporation Active wireless tagging system on peel and stick substrate
JP2005235615A (en) 2004-02-20 2005-09-02 Hitachi Maxell Ltd Adapter panel, electronic equipment and cable connector recognition system
JP4611093B2 (en) 2004-05-12 2011-01-12 セイコーインスツル株式会社 Radio power generation circuit
US7394382B2 (en) 2004-07-01 2008-07-01 Power Id Battery-assisted backscatter RFID transponder
JP2006024087A (en) 2004-07-09 2006-01-26 Nec Corp Radio device, its manufacturing method, its inspecting method and inspecting device, radio apparatus, and its manufacturing method
US20060103533A1 (en) 2004-11-15 2006-05-18 Kourosh Pahlavan Radio frequency tag and reader with asymmetric communication bandwidth
CN102360442B (en) 2006-03-10 2015-01-07 株式会社半导体能源研究所 Semiconductor device and operating method thereof
CN101401112B (en) 2006-03-10 2013-01-02 株式会社半导体能源研究所 Semiconductor device
KR101433306B1 (en) 2006-03-15 2014-08-22 가부시키가이샤 한도오따이 에네루기 켄큐쇼 Electric power supply system and electric power supply system for motor vehicle
WO2007105606A1 (en) 2006-03-15 2007-09-20 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
WO2007108371A1 (en) 2006-03-15 2007-09-27 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device
WO2007139205A1 (en) 2006-05-31 2007-12-06 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device and ic label, ic tag, and ic card having the same
US8132026B2 (en) 2006-06-02 2012-03-06 Semiconductor Energy Laboratory Co., Ltd. Power storage device and mobile electronic device having the same
US20090160261A1 (en) 2007-12-19 2009-06-25 Nokia Corporation Wireless energy transfer
JP5258521B2 (en) 2008-11-14 2013-08-07 トヨタ自動車株式会社 Power supply system
JP4759610B2 (en) 2008-12-01 2011-08-31 トヨタ自動車株式会社 Non-contact power transmission device
JP2010193598A (en) 2009-02-17 2010-09-02 Nippon Soken Inc Noncontact power supply facility and noncontact power supply system
JP5621203B2 (en) 2009-03-30 2014-11-12 富士通株式会社 Wireless power supply system and wireless power supply method
JP4865001B2 (en) 2009-04-13 2012-02-01 トヨタ自動車株式会社 Non-contact power supply equipment, non-contact power receiving device and non-contact power supply system
JP2010252468A (en) 2009-04-14 2010-11-04 Sony Corp Power transmission device and method, power receiving device and method, and power transmission system
JP5303350B2 (en) 2009-05-01 2013-10-02 株式会社アルバック Dry etching equipment
JP5499955B2 (en) 2009-10-05 2014-05-21 Tdk株式会社 Wireless power supply apparatus and wireless power transmission system
JP5664019B2 (en) 2009-10-28 2015-02-04 Tdk株式会社 Wireless power feeder, wireless power transmission system, and table and table lamp using the same
JP5664018B2 (en) 2009-10-30 2015-02-04 Tdk株式会社 Wireless power feeder, wireless power transmission system, and table and table lamp using the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8378524B2 (en) * 2008-09-02 2013-02-19 Sony Corporation Non-contact power transmission device
US8217535B2 (en) * 2009-03-31 2012-07-10 Fujitsu Limited Wireless power supply apparatus
US8143746B2 (en) * 2009-12-21 2012-03-27 Alcatel Lucent Automatic tuning for wireless power transfer

Also Published As

Publication number Publication date
JP2012130237A (en) 2012-07-05
WO2012070634A1 (en) 2012-05-31
US20120133212A1 (en) 2012-05-31
JP5798455B2 (en) 2015-10-21
US9461476B2 (en) 2016-10-04
DE112011103929T5 (en) 2013-08-22
KR101854420B1 (en) 2018-05-03
KR20140002674A (en) 2014-01-08

Similar Documents

Publication Publication Date Title
KR101247419B1 (en) Repeaters for enhancement of wireless power transfer
US9583951B2 (en) Wireless power system with capacitive proximity sensing
US9431844B2 (en) System and method for wireless power control communication using bluetooth low energy
US9667085B2 (en) Wireless charger for electronic device
KR101397243B1 (en) Wireless power transmission for electronic devices including parasitic resonant tank
RU2491697C2 (en) Device and method for contact-free power supply
US9583963B2 (en) Apparatus and method of matching in a source-target structure
KR101959099B1 (en) Wireless power receiver with multiple receiver coils
US8519569B2 (en) Wireless power supply system and wireless power supply method
KR20150046114A (en) Power supply control in wireless power transfer systems
US20100190435A1 (en) Passive receivers for wireless power transmission
US8395352B2 (en) Power transmission control device, power transmission device, electronic apparatus, and load state detection circuit
US20140062395A1 (en) Wireless power transmitter for excluding cross-connected wireless power receiver and method for controlling the same
EP3179600A1 (en) Wireless power transmission system
US10396599B2 (en) Wireless power transmission apparatus and wireless power transmission method
KR101343706B1 (en) transmitters for wireless power transmission
US20130026981A1 (en) Dual mode wireless power
US20120104997A1 (en) Wireless charging device
EP2546956A2 (en) Method for wireless charging of a mobile terminal and mobile terminal for same
US9125160B2 (en) Wireless power receiver and method for setting sleep mode in wireless power receiver
US9148201B2 (en) Systems and methods for calibration of a wireless power transmitter
EP3396807A1 (en) Energy receiver, detection method, power transmission system, detection device, and energy transmitter
KR20120103501A (en) Power-receiving device, wireless power-feeding system including power-receiving device, and wireless communication system including power-receiving device
Kim et al. Optimal design of a wireless power transfer system with multiple self-resonators for an LED TV
KR101855432B1 (en) Wireless electric field power transmission system and method

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: FINAL REJECTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED