JP2015226399A - Mobile terminal, contactless battery charger, and contactless charging system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further reduce an adverse effect on the receipt of radio signals from the outside owing to mixing electromagnetic waves radiated by a built-in coil of a charging side when a mobile terminal sends radio signals to the outside on condition that a contactless battery charger changes a magnetic flux around the charging-side built-in coil in order to charge a secondary battery of the mobile terminal in comparison to as compared with prior art.SOLUTION: A mobile terminal comprises: a transmitter part which transmits a communication-state signal concerning a wireless communication state to an outside contactless battery charger; a coil which produces an electromotive force owing to a change in magnetic flux caused by a contactless battery charger which has received the communication-state signal transmitted from the transmitter part according to the communication-state signal; and a secondary battery to be charged by utilizing the electromotive force produced by the coil.

Description

  The present invention relates to a portable terminal that charges a built-in secondary battery using an electromotive force generated in a built-in coil.

2. Description of the Related Art A portable terminal that incorporates a coil and a secondary battery and charges the secondary battery using an electromotive force generated in the coil due to a change in magnetic flux is known (see, for example, Patent Document 1).
This portable terminal is mounted on a position within a predetermined range on a contactless charger having a built-in coil (hereinafter, a coil built in the contactless charger is referred to as a “charging-side coil”). An electromotive force is generated in a built-in coil (hereinafter referred to as a “portable terminal side coil”) by a change in magnetic flux generated by the charging side coil.

  In general, the contactless charger realizes a change in magnetic flux around the charging side coil by flowing a current of a predetermined frequency f through the charging side coil.

Japanese Patent Laid-Open No. 2005-6440

  When a current having a frequency f flows through the charging side coil, a portable terminal placed on the charger is used to perform a radio communication with an external device (for example, a base station). When the terminal-side radio signal is transmitted, the terminal-side radio signal is applied to the charging-side coil. Then, an electromagnetic wave (hereinafter referred to as “mixing electromagnetic wave”) having a frequency of F + n × f (n is an integer other than 0 including a negative number) is emitted from the charging side coil.

When the frequency of a signal transmitted from an external device that is a wireless communication partner of the portable terminal (hereinafter referred to as “external device-side wireless signal”) overlaps with the frequency of this mixing electromagnetic wave, the mixing electromagnetic wave is transmitted to the external device-side wireless signal. Acts as a disturbing wave. This adversely affects the reception of the external device-side radio signal by the mobile terminal.
The present invention has been made in view of the problem, and in the case where the contactless charger changes the magnetic flux around the built-in charging side coil in order to charge the secondary battery of the mobile terminal, the mobile phone It is an object of the present invention to provide a portable terminal capable of reducing the adverse effect on reception of an external device-side wireless signal due to mixing electromagnetic waves radiated from a charging-side coil when the terminal performs wireless communication. To do.

  In order to solve the above-described problem, a mobile terminal according to an aspect of the present invention is a mobile terminal having a wireless communication function, and transmits a communication state signal related to a wireless communication state to an external contactless charger. And a coil that generates an electromotive force due to a change in magnetic flux in response to the communication state signal by the contactless charger that has received the communication state signal transmitted from the transmission unit, and an electromotive force generated in the coil And a secondary battery that is charged using the battery.

  According to the mobile terminal according to one aspect of the present invention, the contactless charger that changes the surrounding magnetic flux to charge the secondary battery of the mobile terminal is related to the state of wireless communication transmitted from the mobile terminal. A communication status signal is received. For this reason, the non-contact charger can control the change of the magnetic flux so that the adverse effect on the reception of the external device-side radio signal is reduced according to the wireless communication state of the mobile terminal.

  Therefore, according to this portable terminal, when the contactless charger changes the magnetic flux around the built-in charging coil in order to charge the secondary battery of the portable terminal, the portable terminal performs wireless communication. Sometimes, the adverse effect on the reception of the external device side radio signal due to the mixing electromagnetic wave radiated from the charging side coil can be reduced as compared with the conventional case.

(A) The perspective view of the portable terminal 100 seen from the front side, (b) The perspective view of the portable terminal 100 seen from the back side Perspective view of electromotive coil 160 Perspective view of contactless charger 300 A perspective view of the radiation coil 310 The block diagram which shows the circuit structure of the portable terminal 100 The block diagram which shows the function structure of the terminal information transmission part 600 State transition diagram of states held by state holding unit 660 The block diagram which shows the circuit structure of the non-contact charger 300 The figure which shows the voltage waveform of a 1st voltage The figure which shows the voltage waveform of a 2nd voltage The figure which shows the frequency spectrum of the 1st electromagnetic wave The figure which shows the frequency spectrum of the 2nd electromagnetic wave The figure which shows the frequency spectrum of the electromagnetic waves radiated | emitted from the radiation coil 310, when a 1st voltage is supplied. The figure which shows the frequency spectrum of the electromagnetic waves radiated | emitted from the radiation coil 310 in case the 2nd voltage is supplied. The block diagram which shows the function structure of the non-contact charger 300 State transition diagram of states held by state holding unit 1560 Flow chart of terminal information transmission process Supply voltage selection process flowchart (A) The figure which shows the voltage waveform of a sawtooth waveform, (b) The figure which shows the voltage waveform of a half wave rectification sine waveform

<Embodiment>
<Overview>
Here, as an embodiment of the portable terminal according to the present invention, a portable terminal incorporating an electromotive coil that generates an electromotive force for charging a built-in secondary battery, and a radiation coil for changing the surrounding magnetic flux are provided. A non-contact charging system including a built-in non-contact charger will be described.

In this contactless charging system, a current that fluctuates in the radiating coil is placed in a state where the portable terminal is placed at a predetermined position on the contactless charger so that the electromotive coil and the radiating coil face each other. By flowing, an electromotive force is generated in the electromotive coil.
In this contactless charging system, the mobile terminal performs data communication during a period in which data communication is performed with an external base station in a state where the mobile terminal is placed at a predetermined position on the contactless charger. A communication state signal indicating that is transmitted to the contactless charger. Further, regardless of whether or not data communication is performed with an external base station, a storage information signal indicating the storage amount of the built-in battery is transmitted to the contactless charger.

On the other hand, the non-contact charger is a voltage generation circuit for causing a periodically varying current to flow through the radiating coil, and generates both a voltage that periodically varies at 400 KHz and a second voltage waveform generating circuit. A waveform generation circuit.
Here, the first voltage waveform generation circuit generates a voltage whose voltage waveform is a rectangular waveform, whereas the second voltage waveform generation circuit has a rectangular waveform generated by the first voltage waveform generation circuit. A voltage having a dull waveform that is duller than that (that is, energy of a high-frequency component in the case of Fourier transform is small) is generated.

  And this non-contact charger is based on the communication status signal and the storage information signal transmitted from the portable terminal, (1) when the portable terminal is not performing data communication, and (2) the portable terminal Is a period during which data communication is performed, and when the amount of charge of the secondary battery is less than a predetermined amount, the voltage generated by the first voltage waveform generation circuit is supplied to the radiation coil, and the radiation coil fluctuates. (3) Supply the voltage generated by the second voltage waveform generation circuit to the radiating coil when the mobile terminal is performing data communication and the amount of charge of the secondary battery is greater than the predetermined amount. And the electric current which fluctuates is sent to a radiation coil.

Hereinafter, details of the contactless charging system will be described with reference to the drawings.
<Configuration>
1A is a perspective view of the mobile terminal 100 viewed from the front side, and FIG. 1B is a perspective view of the mobile terminal 100 viewed from the back side.
As shown in FIGS. 1A and 1B, the mobile terminal 100 is a so-called smartphone having a substantially rectangular parallelepiped shape, and the operation surface of the touch panel 110 is arranged on the front main surface, and the receiver hole 120. And a microphone hole 130 are opened. An electromotive coil 160 is built inside the back main surface, and a mark 170 indicating the position of the built electromotive coil 160 is printed on the back main surface.

FIG. 2 is a perspective view of the electromotive coil 160.
As shown in the figure, the electromotive coil 160 has a configuration in which a spiral copper foil wiring 220 that electrically connects the first terminal 230 and the second terminal 240 is formed on the surface of the substrate 210. Is a planar coil.
The electromotive coil 160 generates an electromotive force between the first terminal 230 and the second terminal 240 when a change in magnetic flux occurs inside the spiral formed by the copper foil wiring 220.

The electromotive coil 160 is also used as an antenna for short-range wireless communication performed between the mobile terminal 100 and the contactless charger 300 (described later).
FIG. 3 is a perspective view of the contactless charger 300.
As shown in the figure, the contactless charger 300 includes a substantially rectangular parallelepiped casing 320, a cable 330, and a plug 340. A radiation coil 310 is built inside the main surface, and a mark 350 indicating the position of the built-in radiation coil 310 is printed on the main surface.

FIG. 4 is a perspective view of the radiation coil 310.
As shown in the figure, the radiating coil 310 is a copper foil wiring 420 that electrically connects the first terminal 430 and the second terminal 440 in a spiral shape to the surface of the substrate 410, similarly to the electromotive coil 160. It is a planar coil comprised by forming.
The radiation coil 310 changes the surrounding magnetic flux by flowing a fluctuating current between the first terminal 430 and the second terminal 440.

Similarly to the electromotive coil 160, the radiating coil 310 is also used as an antenna for short-range wireless communication performed between the mobile terminal 100 and the contactless charger 300.
Returning to FIG. 3 again, the description of the contactless charger 300 will be continued.
When the portable terminal 100 is placed on the main surface of the contactless charger 300 so that the mark 170 and the mark 350 face each other, the electromotive coil 160 and the radiation coil 310 face each other.

When a current that fluctuates is passed through the radiating coil 310 while the electromotive coil 160 and the radiating coil 310 face each other within a certain range, the magnetic flux in the electromotive coil 160 changes, and the electromotive coil An electromotive force is generated at 160.
In addition, with the electromotive coil 160 and the radiation coil 310 facing each other, the mobile terminal 100 and the non-contact charger 300 use the electromotive coil 160 and the radiation coil 310 as antennas, respectively. Performs range wireless communication.

  In this short-range wireless communication, the transmission output is limited so that communication is possible only when the electromotive coil 160 and the radiation coil 310 are facing each other within a certain range. For this reason, this short-range wireless communication is limited to a state where the portable terminal 100 is placed on the main surface of the contactless charger 300 so that the mark 170 and the mark 350 face each other within a certain range. Communication is established.

FIG. 5 is a block diagram illustrating a circuit configuration of the mobile terminal 100.
As shown in the figure, the mobile terminal 100 includes a CPU (Central Processing Unit) 500, an antenna 505, a base station communication LSI (Large Scale Integration) 510, a receiver 515, a microphone 520, and a touch panel controller 525. , Touch panel 110, memory 530, timer 535, storage amount measurement circuit 540, secondary battery 545, charging circuit 550, electromotive coil 160, filter 555, and short-range communication LSI 560. Is done.

The antenna 505 is a monopole antenna made of, for example, metal foil that is connected to the base station communication LSI 510 and used for wireless communication with the base station performed by the base station communication LSI 510.
Base station communication LSI 510 is connected to antenna 505 and CPU 500, and is controlled by CPU 500. And it has the function to perform radio | wireless communication with an external base station using the antenna 505. FIG.

There are two types of wireless communication performed between the mobile terminal 100 and the base station: control signal communication for transmitting and receiving control signals and data communication for transmitting and receiving data. Here, control signal communication is communication using a communication method that is relatively resistant to noise, and data communication is communication using a communication method that is relatively resistant to noise.
Here, it is assumed that the frequency band used for data communication to the base station is a transmission signal to the base station in the 836 MHz band and a reception signal from the base station is the 881 MHz band.

The receiver 515 is connected to the CPU 500 and controlled by the CPU 500. And it has the function to convert the electric signal sent from CPU500 into a sound, and to output the converted sound to the exterior of the portable terminal 100 through the receiver hole 120 (refer Fig.1 (a)).
The microphone 520 is connected to the CPU 500 and controlled by the CPU 500. And it has the function which converts the audio | voice input from the portable terminal 100 exterior through the microphone hole 130 (refer Fig.1 (a)) into an electrical signal, and sends the converted electrical signal to CPU500.

The touch panel 110 is configured by overlaying a transparent touch pad on the display surface of the liquid crystal display, is connected to the touch panel controller 525, and is controlled by the touch panel controller 525. And it has the operation reception function which receives the contact operation of the user who uses the portable terminal 100, and the display function which displays an image.
Touch panel controller 525 is connected to touch panel 110 and CPU 500 and is controlled by CPU 500. Then, a display control function for displaying an image based on an image signal sent from the CPU 500 on the touch panel 110 and a contact operation performed by the user using the portable terminal 100 using the touch panel 110 are converted into an electrical signal by the CPU 500. Contact operation conversion function to be sent to

The memory 530 is connected to the CPU 500 and stores a program that defines the operation of the CPU 500 and data used by the CPU 500. For example, the memory 530 is realized by a RAM (Random Access Memory), a ROM (Read Only Memory), and a flash memory.
The timer 535 is connected to the CPU 500 and has a function of measuring the passage of time.

The secondary battery 545 is connected to the storage amount measurement circuit 540 and the charging circuit 550, is charged by the charging circuit 550, and supplies power to the electronic components that constitute the mobile terminal 100.
The storage amount measuring circuit 540 is connected to the secondary battery 545 and the CPU 500 and is controlled by the CPU 500. Then, it has a function of measuring the amount of power stored in the secondary battery 545. As an example, the storage amount measurement circuit 540 outputs the voltage of the secondary battery 545 as a result of measuring the storage amount of the secondary battery 545.

Charging circuit 550 is connected to CPU 500, secondary battery 545, and electromotive coil 160, and is controlled by CPU 500. And it has the function to charge the secondary battery 545 using the electromotive force which arises in the electromotive coil 160. FIG.
The electromotive coil 160 is connected to the charging circuit 550 and the filter 555, and generates an electromotive force when the magnetic flux in the electromotive coil 160 changes.

The electromotive coil 160 is used as an antenna for short-range wireless communication by the short-range communication LSI 560 connected through the filter 555.
The filter 555 is connected to the electromotive coil 160 and the short-range communication LSI 560, and is a filter that cuts a signal in a frequency band other than the frequency band that the short-range communication LSI 560 uses for short-range wireless communication.

The near field communication LSI 560 is connected to the CPU 500 and the filter 555 and is controlled by the CPU 500. And it has the function to perform short-distance wireless communication with the non-contact charger 300 using the electromotive coil 160 connected through the filter 555.
The CPU 500 includes a base station communication LSI 510, a receiver 515, a microphone 520, a touch panel controller 525, a memory 530, a timer 535, a storage amount measuring circuit 540, a charging circuit 550, and a near field communication LSI 560. Connected. And the following smart phone control functions and a terminal information transmission function are implement | achieved by running the program memorize | stored in the memory 530. FIG.

The smartphone control function is a function in which the CPU 500 that executes the program controls a circuit connected to the CPU 500 so that the mobile terminal 100 has a function equivalent to a general function of a conventional smartphone, such as a call function, an Internet site, etc. This function realizes a browsing function, a mail transmission / reception function, a standby function, and the like.
The terminal information transmission function means that the CPU 500 that executes a program controls a circuit connected to the CPU 500 to cause the mobile terminal 100 to execute terminal information transmission processing that is a characteristic operation of the portable terminal 100, thereby Data communication in which data communication is performed with a base station in response to a predetermined signal (hereinafter referred to as “confirmation signal”) that is repeatedly transmitted from device 300 every predetermined time T1 (for example, 100 ms) This is a function for causing the non-contact charger 300 to transmit a communication state signal indicating whether or not the battery is in storage and a storage information signal indicating the storage amount of the secondary battery 545.

The terminal information transmission process will be described in detail later with reference to a flowchart in the item <terminal information transmission process>.
The configuration of the mobile terminal 100 having the above circuit configuration will be described below from the functional aspect. Here, among the functional blocks that constitute mobile terminal 100, terminal information transmission unit 600 that is a functional block that performs terminal information transmission processing, which is a characteristic operation performed by mobile terminal 100, will be mainly described.

FIG. 6 is a block diagram showing a functional configuration of terminal information transmission unit 600.
As shown in the figure, the terminal information transmission unit 600 includes a storage amount measurement unit 610, a base station communication state monitoring unit 620, a charging unit 630, an electromotive unit 640, a short-range communication unit 650, A state holding unit 660 and a control unit 670 are included.
The storage amount measuring unit 610 is connected to the control unit 670 and is realized by the CPU 500 and the storage amount measuring circuit 540. Then, it has a function of measuring the amount of electricity stored in the secondary battery 545.

The inter-base station communication state monitoring unit 620 is connected to the control unit 670 and is realized by the CPU 500 and the base station communication LSI 510. And it has the function to monitor the communication which the portable terminal 100 and a base station perform.
The electromotive unit 640 is connected to the charging unit 630 and realized by the electromotive coil 160. And when the magnetic flux in the electromotive coil 160 changes, it has the function to produce the electromotive force according to the change of magnetic flux.

Charging unit 630 is connected to control unit 670 and electromotive unit 640, and is realized by CPU 500 and charging circuit 550. And it has the function to charge the secondary battery 545 using the electromotive force which arose in the electromotive part 640. FIG.
The near field communication unit 650 is connected to the control unit 680, and is realized by the CPU 500, the near field communication LSI 560, the filter 555, and the electromotive coil 160. And it has a function which performs near field communication with non-contact charger 300.

  The state holding unit 660 is connected to the control unit 670 and is realized by the CPU 500 and the memory 530. And the state of the portable terminal 100 is a short-distance communicable state indicating that short-distance wireless communication is possible with the non-contact charger 300, or the state of the portable terminal 100 is non-contact charging. It has a function of holding a state indicating which state is in a near field communication impossible state indicating that near field wireless communication with the device 300 is impossible.

FIG. 7 is a state transition diagram of states held by the state holding unit 660.
As shown in the figure, in the case where the state is in a state in which short-distance communication is possible, (1) a confirmation signal repeatedly transmitted from the non-contact charger 300 every predetermined time T1 is transmitted within the predetermined time T1 When received by the unit 650, the state maintains the near field communication enabled state. (2) When the confirmation signal repeatedly transmitted from the contactless charger 300 every predetermined time T1 is not received by the short-range communication unit 650 within the predetermined time T1, the state becomes a short-distance communication impossible state. Transition.

  When the state is a state in which short-distance communication is impossible, (3) a confirmation signal repeatedly transmitted from the contactless charger 300 every predetermined time T1 is received by the short-range communication unit 650 within the predetermined time T1. If not, the state maintains a state where short-range wireless communication is not possible. Then, (4) when a confirmation signal repeatedly transmitted from the contactless charger 300 every predetermined time T1 is received by the short-range communication unit 650 within the predetermined time T1, the state transitions to a short-distance communicable state. .

  As described above, the portable terminal 100 can be placed on the main surface of the contactless charger 300 so that the mark 170 and the mark 350 face each other within a certain range. Wireless communication with the device 300 becomes possible. Therefore, when the portable terminal 100 is placed on the main surface of the contactless charger 300 so that the mark 170 and the mark 350 face each other within a certain range, the state is short-range communication. In the other state, the state becomes a short-distance communication impossible state.

Returning to FIG. 6 again, the description of the terminal information transmission unit 600 will be continued.
Control unit 670 is connected to power storage amount measurement unit 610, inter-base station communication state monitoring unit 620, charging unit 630, near field communication unit 650, and state holding unit 660, and is realized by CPU 500. And it has a function which controls these functional blocks connected and makes the portable terminal 100 perform the below-mentioned terminal information processing.

FIG. 8 is a block diagram illustrating a circuit configuration of the contactless charger 300.
As shown in the figure, the contactless charger 300 includes a CPU 800, a near field communication LSI 810, a filter 820, a first voltage waveform generation circuit 830, a second voltage waveform generation circuit 840, and a selector 850. , A radiation coil 310, a memory 860, and a timer 870.

The filter 820 is a filter that is connected to the short-range communication LSI 810 and the radiation coil 310 and cuts signals in a frequency band other than the frequency band that the short-range communication LSI 810 uses for short-range wireless communication.
The near field communication LSI 810 is connected to the CPU 800 and the filter 820 and is controlled by the CPU 800. And it has a function which performs short-distance wireless communication between the portable terminals 100 using the radiation coil 310 connected via the filter 820.

The first voltage waveform generation circuit 830 is connected to the CPU 800 and the selector 850 and is controlled by the CPU 800. And it has the function to generate the voltage (henceforth "the 1st voltage") which changes periodically at 400 KHz for flowing the current which changes periodically to a radiation coil.
FIG. 9 is a diagram illustrating a voltage waveform of the first voltage generated by the first voltage waveform generation circuit 830.

As shown in the figure, the voltage waveform of the first voltage is a rectangular waveform with a period of 400 KHz.
Returning to FIG. 8 again, the description of the contactless charger 300 will be continued.
Second voltage waveform generation circuit 840 is connected to CPU 800 and selector 850, and is controlled by CPU 800. And it has the function to generate the voltage (henceforth "the 2nd voltage") which changes periodically at 400 KHz for flowing the current which changes periodically to a radiation coil.

FIG. 10 is a diagram illustrating a voltage waveform of the second voltage generated by the second voltage waveform generation circuit 840.
As shown in the figure, the voltage waveform of the second voltage is duller than the rectangular waveform generated by the first voltage waveform generation circuit 830 (that is, the energy of the high frequency component in the case of Fourier transform is less), 400 MHz. This is a dull waveform.

Returning to FIG. 8 again, the description of the contactless charger 300 will be continued.
The selector 850 is connected to the first voltage waveform generation circuit 830, the second voltage waveform generation circuit 840, the CPU 800, and the radiation coil 310, and is controlled by the CPU 800. Then, one of the first voltage generated by the first voltage waveform generation circuit 830 and the second voltage generated by the second voltage waveform generation circuit 840 is selected and supplied to the radiation coil 310. It has a function.

The radiating coil 310 is connected to the selector 850 and the filter 820, and changes the surrounding magnetic flux when a fluctuating current flows.
The radiating coil 310 is used as an antenna for near field communication by the near field communication LSI 810 connected via the filter 820.
FIG. 11 is a schematic diagram showing a frequency spectrum of an electromagnetic wave radiated from the radiation coil 310 (hereinafter referred to as “first electromagnetic wave”) when the first voltage is supplied to the radiation coil 310.

In the figure, the horizontal axis is frequency and the vertical axis is energy.
As shown in the figure, the frequency component of the first electromagnetic wave is derived from a fundamental wave 1100 of 400 KHz and its n-order harmonic (first harmonic 1101, second harmonic 1102, k-order harmonic 1104, etc.). Composed. Here, the frequency components of these harmonics exist up to a band of several GHz.

FIG. 12 is a schematic diagram showing a frequency spectrum of an electromagnetic wave radiated from the radiation coil 310 (hereinafter referred to as “second electromagnetic wave”) when the second voltage is supplied to the radiation coil 310.
In the figure, the horizontal axis is frequency and the vertical axis is energy.
As shown in the figure, the frequency component of the second electromagnetic wave is derived from a fundamental wave 1200 of 400 KHz and its n-order harmonic (first harmonic 1201, second harmonic 1202, k-order harmonic 1204, etc.). Composed. Here, the frequency components of these harmonics exist up to a band of several GHz.

The energy of the fundamental wave 1200 in the second electromagnetic wave is substantially equal to the energy of the fundamental wave 1100 in the first electromagnetic wave. In contrast, the energy of each nth harmonic in the second electromagnetic wave is less than the energy of each nth harmonic in the corresponding first electromagnetic wave.
This is because the energy of the high frequency component of the second voltage is less than the energy of the high frequency component of the first voltage.

  Therefore, in the case where the relative positional relationship between the radiating coil 310 and the electromotive coil 160 is constant, the electromotive force generated in the electromotive coil 160 when the first voltage is supplied to the radiating coil 310 (hereinafter referred to as “first” Compared with the electromotive force generated in the electromotive coil 160 when the second voltage is supplied to the radiation coil 310 (hereinafter referred to as “second electromotive force”), the first electromotive force is referred to as “electromotive force”. The electromotive force is larger.

Therefore, in the case where the relative positional relationship between the radiating coil 310 and the electromotive coil 160 is the same, when the secondary battery 545 is charged with a predetermined amount of power, it is more effective to supply the radiating coil 310 with the first voltage. The coil can be charged in a shorter time than supplying the second voltage to the coil.
By the way, in general, when a current that fluctuates at a frequency f flows in a coil, when the electromagnetic wave of the frequency F is irradiated to the coil, the frequency is F + n × f (n is a value other than 0 including a negative number). There is known a phenomenon in which a mixing electromagnetic wave (an integer) is emitted.

  For this reason, when the mobile terminal 100 is mounted on the contactless charger 300, when the first voltage or the second voltage is supplied to the radiating coil 310, the mobile terminal 100 communicates with the base station wirelessly. When a signal of 836 MHz (hereinafter referred to as “terminal transmission signal”) is transmitted for communication, the frequency is 836 + n × 0.4 [MHz] (n is an integer other than 0 including a negative number) from the radiation coil 310. The mixing electromagnetic wave will be emitted.

FIG. 13 is a schematic diagram showing a frequency spectrum of electromagnetic waves radiated from the radiation coil 310 when the terminal transmission signal 1300 of 836 MHz is irradiated from the portable terminal 100 when the first voltage is supplied to the radiation coil 310. It is.
In the figure, the horizontal axis is frequency and the vertical axis is energy.
As shown in the figure, from the radiation coil 310, in addition to the fundamental wave 1100 and its n-order harmonic (see FIG. 11), the frequency is 836 + n × 0.4 [MHz] (n is a value other than 0 including a negative number). (Mixing electromagnetic wave 1301, mixing electromagnetic wave 1302, mixing electromagnetic wave 1303, etc.).

Here, a mixing electromagnetic wave (mixing electromagnetic wave 1306 in the figure) overlapping with a band of 881 MHz (terminal reception signal band 1310 in the figure) which is a frequency of a signal transmitted from the base station (hereinafter referred to as “terminal reception signal”). ) Acts as a disturbing wave that adversely affects the reception of the terminal reception signal.
In FIG. 13, the frequency of the terminal transmission signal 1300 and the frequency of the k-th harmonic 1104 are illustrated as if they are the same, but this is for convenience in order to make the drawing easier to see. However, the present invention is not necessarily limited to the case where they are matched. Even if they do not coincide with each other, the phenomenon described above, that is, a phenomenon in which mixing electromagnetic waves having a frequency of 836 + n × 0.4 [MHz] (n is an integer other than 0 including a negative number) is emitted.

FIG. 14 is a schematic diagram showing a frequency spectrum of electromagnetic waves radiated from the radiation coil 310 when the terminal transmission signal 1300 of 836 MHz is irradiated from the portable terminal 100 when the second voltage is supplied to the radiation coil 310. It is.
In the figure, the horizontal axis is frequency and the vertical axis is energy.
As shown in the figure, in the same manner as when the first voltage is supplied to the radiating coil (see FIG. 13), the radiating coil 310 adds the fundamental wave 1200 and its nth harmonic (see FIG. 12). Thus, a mixing electromagnetic wave (mixing electromagnetic wave 1401, mixing electromagnetic wave 1402, mixing electromagnetic wave 1403, etc.) having a frequency of 836 + n × 0.4 [MHz] (n is an integer other than 0 including a negative number) is emitted.

On the other hand, the energy of each mixing electromagnetic wave when the second voltage is supplied to the radiation coil is less than the energy of each mixing electromagnetic wave when the first voltage is supplied to the radiation coil.
This is because the energy of each nth harmonic in the second electromagnetic wave is less than the energy of each nth harmonic in the corresponding first electromagnetic wave.

  For this reason, when the second voltage is supplied to the radiation coil 310, the adverse effect on the reception of the terminal reception signal due to the mixing electromagnetic wave (mixing electromagnetic wave 1406 in FIG. 14) acting as an interference wave of the terminal reception signal is When the first voltage is supplied to 310, the adverse effect on the reception of the terminal reception signal due to the mixing electromagnetic wave (mixing electromagnetic wave 1306 in FIG. 13) acting as an interference wave of the terminal reception signal is reduced.

Returning to FIG. 8 again, the description of the contactless charger 300 will be continued.
The memory 860 is connected to the CPU 800 and stores a program that defines the operation of the CPU 800 and data used by the CPU 800. For example, the memory 860 is realized by a RAM, a ROM, and a flash memory.
The timer 870 is connected to the CPU 800 and has a function of measuring the passage of time.

The CPU 800 is connected to the near field communication LSI 810, the first voltage waveform generation circuit 830, the second voltage waveform generation circuit 840, the selector 850, the memory 860, and the timer 870. Then, by executing the program stored in the memory 860, the following confirmation signal transmission function and supply voltage selection function are realized.
With the confirmation signal transmission function, the CPU 800 that executes a program controls a circuit connected to the CPU 800 and sends a confirmation signal to the non-contact charger 300 every predetermined time T1 using the radiation coil 310 as an antenna. This is a function to output to the outside.

  The supply voltage selection function means that a CPU 800 that executes a program controls a circuit connected to the CPU 800 to cause the contactless charger 300 to execute a supply voltage selection process that is a characteristic operation thereof. In the case where the state of the contact charger 300 is a short-distance communicable state (described later), (1) when the portable terminal 100 is not performing data communication, and (2) the portable terminal 100 performs data communication. When the amount of power stored in the secondary battery 545 is less than a predetermined amount, the first voltage is selected as the voltage supplied to the radiation coil 310, and (3) the mobile terminal 100 performs data communication. This is a function of selecting the second voltage as the voltage to be supplied to the radiation coil 310 when the charged amount of the secondary battery 545 is greater than a predetermined period.

The supply voltage selection process will be described in detail later with reference to a flowchart in the item <Supply voltage selection process>.
The contactless charger 300 having the above circuit configuration will be described below in terms of its function.
FIG. 15 is a block diagram illustrating a functional configuration of the contactless charger 300.

As shown in the figure, the contactless charger 300 includes a first voltage waveform generation unit 1510, a second voltage waveform generation unit 1520, a supply voltage selection unit 1530, a magnetic flux fluctuation unit 1540, and a short-range communication unit. 1550, state holding unit 1560, control unit 1570, communication state determination unit 1580, and storage amount determination unit 1590.
The first voltage waveform generation unit 1510 is connected to the control unit 1570 and the supply voltage selection unit 1530 and is realized by the CPU 800 and the first voltage waveform generation circuit 830. And it has the function to produce | generate the 1st voltage which is a rectangular waveform.

The second voltage waveform generation unit 1520 is connected to the control unit 1570 and the supply voltage selection unit 1530 and is realized by the CPU 800 and the second voltage waveform generation circuit 840. And it has the function to produce | generate the 2nd voltage which is a dull waveform.
The supply voltage selection unit 1530 is connected to the control unit 1570, the first voltage waveform generation unit 1510, the second voltage waveform generation unit 1520, and the magnetic flux variation unit 1540, and is realized by the CPU 800 and the selector 850. Then, one of the first voltage generated by the first voltage waveform generation unit 1510 and the second voltage generated by the second voltage waveform generation unit 1520 is selected and supplied to the magnetic flux fluctuation unit 1540. It has the function to do.

The magnetic flux fluctuation unit 1540 is connected to the supply voltage selection unit 1530 and is realized by the radiation coil 310. And it has the function to change the surrounding magnetic flux according to the voltage supplied from the supply voltage selection part 1530. FIG.
The near field communication unit 1550 is connected to the control unit 1570, and is realized by the CPU 800, the near field communication LSI 810, the filter 820, and the radiation coil 310. And it has a function which performs short-distance wireless communication with the portable terminal 100.

  The state holding unit 1560 is connected to the control unit 1570 and is realized by the CPU 800 and the memory 860. And the state of the near-field communication which shows that the state of the non-contact charger 300 is a state in which near field communication is possible between the portable terminals 100, and the state of the non-contact charger 300 are portable terminals 100 has a function of holding a state indicating which state is in a near field communication impossible state indicating that near field communication is impossible with 100.

FIG. 16 is a state transition diagram of states held by the state holding unit 1560.
As shown in the figure, in the case where the state is a state in which near field communication is possible, (1) transmitted from the portable terminal 100 in response to a confirmation signal repeatedly transmitted from the contactless charger 300 every predetermined time T1. When the communication state signal to be received is received by the short-range communication unit 1550 within the predetermined time T1, the state maintains the short-range communication enabled state. (2) In response to the confirmation signal repeatedly transmitted from the contactless charger 300 every predetermined time T1, the communication state signal transmitted from the portable terminal 100 is transmitted by the short-range communication unit 1550 within the predetermined time T1. When it is not received, the state transits to a short range communication impossible state.

  When the state is a state in which short-distance communication is not possible, (3) a communication state signal transmitted from the mobile terminal 100 in response to a confirmation signal repeatedly transmitted from the contactless charger 300 every predetermined time T1. However, when the short-range communication unit 1550 does not receive it within the predetermined time T1, the state maintains a short-range communication impossible state. (4) In response to the confirmation signal repeatedly transmitted from the contactless charger 300 every predetermined time T1, the communication state signal transmitted from the portable terminal 100 is transmitted by the short-range communication unit 1550 within the predetermined time T1. When received, the state transitions to a near field communication enabled state.

  As described above, the portable terminal 100 can be placed on the main surface of the contactless charger 300 so that the mark 170 and the mark 350 face each other within a certain range. Wireless communication with the device 300 becomes possible. Therefore, when the portable terminal 100 is placed on the main surface of the contactless charger 300 so that the mark 170 and the mark 350 face each other within a certain range, the state is short-range communication. In the other state, the state becomes a short-distance communication impossible state.

Returning to FIG. 15 again, the description of the contactless charger 300 will be continued.
Communication state determination unit 1580 is connected to control unit 1570 and realized by CPU 800. And based on the communication status signal transmitted from the mobile terminal 100 received by the short-range communication unit 1550, the mobile terminal 100 has a function of determining whether data communication is in progress.

  The storage amount determination unit 1590 is connected to the control unit 1570 and realized by the CPU 800. Then, based on the storage information signal transmitted from the mobile terminal 100 received by the short-range communication unit 1550, the storage amount of the secondary battery 545 is a predetermined amount (for example, as a result of measuring the storage amount, It has a function of determining whether or not the voltage of the secondary battery output from the measurement circuit 540 is less than 3.5V.

The control unit 1570 is connected to the first voltage waveform generation unit 1510, the second voltage waveform generation unit 1520, the supply voltage selection unit 1530, the short-range communication unit 1550, and the state holding unit 1560, and is realized by the CPU 800. The And it has a function which controls these function blocks connected and makes the non-contact charger 300 perform the below-mentioned supply voltage selection process.
Operations performed by the portable terminal 100 and the contactless charger 300 having the above-described configuration will be described below with reference to the drawings.

<Operation>
Here, among the operations performed by the mobile terminal 100 and the contactless charger 300, terminal information transmission processing that is a characteristic operation performed by the mobile terminal 100 and supply that is a characteristic operation performed by the contactless charger 300 The voltage selection process will be described.
<Terminal information transmission process>
The terminal information transmission process is a process performed by the mobile terminal 100, and is repeatedly transmitted from the contactless charger 300 every predetermined time T1 during a period in which the state held in the state holding unit 660 is in a short-distance communication enabled state. In response to the confirmation signal, a communication state signal indicating whether or not data communication is being performed with the base station and a storage information signal indicating the storage amount of the secondary battery 545 are transmitted to the contactless charger 300. It is processing to do.

FIG. 17 is a flowchart of terminal information transmission processing.
The terminal information transmission process is started when the state held in the state holding unit 660 transitions from the near field communication disabled state to the near field communication enabled state.
When the terminal information transmission process is started, the inter-base station communication state monitoring unit 620 checks whether or not data communication is being performed between the mobile terminal 100 and the base station (step S1700).

  Here, the period in which data communication is performed between the mobile terminal 100 and the base station refers to a point in time when transmission / reception of a meaningful group of data between the mobile terminal 100 and the base station is started. Until the point at which the transmission / reception of the data is terminated, and even if the communication between the mobile terminal 100 and the base station is interrupted intermittently, This period is also included in the period during which data communication is performed.

In the process of step S1700, when the data communication is being performed between the mobile terminal 100 and the base station (step S1700: Yes), the short-range communication unit 1550 indicates that data communication is being performed. A communication state signal is transmitted to the non-contact charger 300 (step S1710).
In the process of step S1700, when the data communication is not being performed between the mobile terminal 100 and the base station (step S1700: No), the short-range communication unit 1710 indicates a communication state indicating that data communication is not being performed. A signal is transmitted to the non-contact charger 300 (step S1720).

When the process of step S1710 is completed, or when the process of step S1720 is completed, the charged amount measuring unit 610 measures the charged amount stored in the secondary battery 545 (step S1730). Then, the short-range communication unit 1710 transmits a power storage information signal indicating the measured power storage amount to the mobile terminal 100 (step S1740).
Thereafter, after the terminal information transmission process is started or when the state holding unit 660 checks whether or not the state to be held is a short-distance communication enabled state (see step S1760 described later) Wait until time T1 has passed (step S1750). Then, the state holding unit 660 checks whether or not the state to be held is a short-distance communication enabled state (step S1760).

In the process of step S1760, when the state is a short-distance communication enabled state (step S1760: Yes), the mobile terminal 100 returns to the process of step S1700 again, and performs the processes of step S1700 and subsequent steps.
If it is determined in step S1760 that the state is not in a state where short-distance communication is possible (step S1760: No), the mobile terminal 100 ends the terminal information transmission process.

<Supply voltage selection process>
The supply voltage selection process is a process performed by the contactless charger 300, and when the state held in the state holding unit 1560 is a state where short-distance communication is possible, (1) the mobile terminal 100 is performing data communication. When there is no period, and (2) when the portable terminal 100 is performing data communication and the amount of power stored in the secondary battery 545 is less than a predetermined amount, the voltage supplied to the radiation coil 310 is the first voltage. 1 voltage is selected, and (3) when the mobile terminal is performing data communication and the amount of charge of the secondary battery 545 is greater than a predetermined value, the first voltage is selected as the voltage to be supplied to the radiation coil 310. It is processing to do.

FIG. 18 is a flowchart of the supply voltage selection process.
The supply voltage selection process is started when the state held in the state holding unit 1560 transitions from the near field communication disabled state to the near field communication enabled state.
When the supply voltage selection process is started, the communication state determination unit 1580 indicates that the communication state signal received by the short-range communication unit 1550 within the predetermined time T1 indicates that data communication is being performed, It is checked whether or not the mobile terminal 100 is performing data communication by checking whether or not the communication is in progress (step S1800).

  In the process of step S1800, when the portable terminal 100 is performing data communication (step S1800: Yes), the storage amount determination unit 1590 is indicated by the storage information signal received within the predetermined time T1 by the short-range communication unit 1550. Whether or not the storage amount of the secondary battery 545 is less than a predetermined amount (for example, the amount of the secondary battery voltage output from the storage amount measurement circuit 540 as a result of measuring the storage amount is 3.5 V). This is checked (step S1810).

  In the process of step S1810, when the charged amount of the secondary battery 545 is not less than the predetermined amount (step S1810: No), the charged amount determination unit 1590 further determines that the charged amount of the secondary battery 545 is the maximum amount that can be charged. It is checked whether or not (for example, the amount of the secondary battery voltage output from the storage amount measurement circuit 540 is 4.3 V as a result of measuring the storage amount) (step S1820).

In the process of step S1820, when the charged amount of the secondary battery 545 is not the maximum chargeable amount (step S1820: No), the supply voltage selection unit 1530 uses the second voltage as the voltage supplied to the magnetic flux fluctuation unit 1540. The second voltage generated by the voltage waveform generation unit 1520 is selected (step S1830).
When the mobile terminal 100 is not in data communication in the process of step S1800 (step S1800: No), or when the charged amount of the secondary battery 545 is less than the predetermined amount in the process of step S1810 (step S1810: Yes). The supply voltage selection unit 1530 selects the first voltage generated by the first voltage waveform generation unit 1510 as the voltage to be supplied to the magnetic flux fluctuation unit 1540 (Step S1840).

  When the process of step S1830 is completed, or when the process of step S1840 is completed, since the supply voltage selection process is started, or the state held by the state holding unit 1560 last time is a state in which short-distance communication is possible (See step S1860, which will be described later) from the time when it is determined whether or not, the system waits for a predetermined time T1 (step S1850). Then, the state holding unit 1560 checks whether or not the state to be held is a short-range communication enabled state (step S1860).

In the process of step S1860, when the state is a state in which short-distance communication is possible (step S1860: Yes), the non-contact charger 300 returns to the process of step S1800 again and performs the processes of step S1800 and subsequent steps.
In the process of step S1820, when the amount of power stored in the secondary battery 545 is the maximum amount that can be stored (step S1820: Yes), or in the process of step S1760, the state is not in a short-distance communication enabled state (step (S1860: No), the supply voltage selection unit 1530 stops the voltage supply to the magnetic flux fluctuation unit 1540 (step S1870). Then, the contactless charger 300 ends the terminal information transmission process.

<Discussion>
According to the mobile terminal 100 and the non-contact charger 300 described above, in a state where the mobile terminal 100 is placed on the main surface of the non-contact charger 300 so that the mark 170 and the mark 350 face each other. When the amount of power stored in the secondary battery 545 is not the maximum amount that can be stored, the contactless charger 300 supplies the first voltage to the radiation coil 310 in order to charge the secondary battery 545 of the mobile terminal 100. Alternatively, the second voltage is supplied to change the surrounding magnetic flux.

  At this time, the non-contact charger 300 includes (1) a period during which the mobile terminal 100 is not performing data communication and (2) a period during which the mobile terminal 100 is performing data communication. Is less than the predetermined amount, the first voltage is selected as the voltage to be supplied to the radiation coil 310, and (3) the period during which the mobile terminal 100 is performing data communication and the secondary battery 545 Is greater than a predetermined amount, the second voltage is selected as the voltage supplied to the radiation coil 310.

  Further, as described above, when the mobile terminal 100 is wirelessly communicating with the base station, the case where the second voltage is supplied is more than the case where the first voltage is supplied to the radiation coil 310. The adverse effect on the reception of the terminal reception signal by the mixing electromagnetic wave emitted from the radiation coil 310 is small. On the contrary, the secondary battery 545 is charged in a shorter time when the first voltage is supplied than when the second voltage is supplied to the radiation coil 310. .

From these, the following can be said. That is, the non-contact charger 300 (1) shortens the charging time of the secondary battery 545 because it is not necessary to consider the adverse effect on the reception of the terminal reception signal during the period when the mobile terminal 100 is not performing data communication. In order to do this, the first voltage is selected as the voltage supplied to the radiation coil 310. In addition, (2) when the mobile terminal 100 is performing data communication and the amount of power stored in the secondary battery 545 is less than a predetermined amount, the secondary battery 545 is more effective than reducing the adverse effect on the reception of the terminal reception signal. The first voltage is selected as a voltage to be supplied to the radiation coil 310 in preference to shortening the charging time. (3) When the mobile terminal 100 is performing data communication and the amount of power stored in the secondary battery 545 is greater than a predetermined value, the terminal reception signal is transmitted more than the reduction in the charging time of the secondary battery 545. The second voltage is selected as the voltage to be supplied to the radiation coil 310 with priority given to the reduction of adverse effects on reception.
<Supplement>
The embodiment of the mobile terminal according to the present invention has been described by exemplifying the mobile terminal 100 in the embodiment. However, the mobile terminal according to the present invention can be modified as follows. Of course, it is not limited to the portable terminal 100 illustrated in the embodiment. Further, although the embodiment of the contactless charger according to the present invention has been described by exemplifying the contactless charger 300 in the embodiment, it can be modified as follows, and the contactless charger 300 according to the present invention can be modified. Of course, the contact charger is not limited to the contactless charger 300 illustrated in the embodiment.

  (1) In the embodiment, in the contactless charger 300, the first voltage waveform generation circuit 830 generates the first voltage having the voltage waveform shown in FIG. This is an example of a configuration for generating the second voltage having the voltage waveform shown in FIG. However, when the first voltage is supplied to the radiation coil 310, the relationship between the first voltage and the second voltage is greater than the energy of each nth harmonic in the first electromagnetic wave radiated from the radiation coil 310. When the second voltage is supplied to the coil 310, the first voltage is not necessarily shown in FIG. 9 as long as the energy of each nth-order harmonic in the second electromagnetic wave radiated from the radiation coil 310 is reduced. It is a voltage waveform as shown, Comprising: The 2nd voltage does not need to be a voltage waveform as shown in FIG. As an example, within a range in which the first voltage and the second voltage satisfy the above relationship, the first voltage is a voltage whose waveform is a sawtooth waveform (see FIG. 19A), and the second voltage is An example of a configuration in which the waveform is a voltage (see FIG. 19B) that becomes a half-wave rectified sine waveform is conceivable.

  (2) In the embodiment, the contactless charger 300 is an example of a configuration in which the first voltage and the second voltage are voltages that periodically fluctuate at 400 KHz. However, the first voltage and the second voltage are not necessarily voltages that periodically change at 400 KHz as long as they change. As an example, a configuration example in which the first voltage and the second voltage fluctuate at 500 KHz can be considered.

  (3) In the embodiment, the mobile terminal 100 is an example of a configuration in which the frequency of the terminal transmission signal in wireless communication with the base station is 836 MHz and the terminal reception signal in wireless communication with the base station is 881 MHz. . However, the frequency of the terminal transmission signal and the frequency of the terminal reception signal are necessarily 836 MHz and 881 MHz, respectively, as long as the frequencies are defined based on communication standards determined in advance with the base station. There is no. As an example, the example of the structure which is respectively 1200 MHz and 1250 MHz can be considered.

  (4) In the embodiment, the mobile terminal 100 has been described as a so-called smartphone. However, the mobile terminal 100 is not necessarily a so-called smartphone as long as the mobile terminal 100 has a function of performing wireless communication with an external device. For example, it may be a tablet personal computer having a function of performing wireless communication with an access point, a foldable mobile phone having a function of performing wireless communication with a base station, or the like.

  (5) In the embodiment, the mobile terminal 100 transmits a communication state signal indicating that data communication is being performed to the contactless charger 300 during a period of data communication with the base station. It was an example of configuration. On the other hand, as another example, during the period in which data communication or control signal communication is performed with the base station, a communication state signal indicating that data communication is being performed is sent to the contactless charger 300. An example of transmission is also conceivable. In the case of this example, the non-contact charger 300 includes (1) a period when the mobile terminal 100 is not performing data communication or control signal communication, and (2) the mobile terminal 100 performs data communication or control signal communication. When the amount of power stored in the secondary battery 545 is less than a predetermined amount, the first voltage is selected as the voltage supplied to the radiation coil 310, and (3) the mobile terminal 100 performs data communication or control. When the signal communication is performed and the amount of power stored in the secondary battery 545 is greater than a predetermined value, the second voltage is selected as the voltage supplied to the radiation coil 310.

  (6) In the embodiment, the period in which data communication is performed between the mobile terminal 100 and the base station refers to a transmission / reception of a meaningful piece of data performed between the mobile terminal 100 and the base station. Is a period from the start of the transmission to the end of the transmission / reception of the data, during which the communication between the mobile terminal 100 and the base station may be interrupted intermittently. In the above description, the suspended period is included in the period in which data communication is performed. On the other hand, as another example, the period in which data communication is performed between the mobile terminal 100 and the base station is that data transmission or data reception is continuously performed without interruption. There may be an example in which it is in a certain period. In the case of this example, every time data transmission or data reception is interrupted, the period during which data communication is performed between the mobile terminal 100 and the base station ends.

  (7) The above embodiments and the above modifications may be combined as appropriate.

  The portable terminal, the contactless charger, and the contactless charging system according to the present invention can be widely used in a contactless charging system that charges a secondary battery of a portable terminal using mutual induction between coils.

DESCRIPTION OF SYMBOLS 100 Mobile terminal 160 Electromotive coil 300 Non-contact charger 310 Radiation coil 610 Storage amount measurement part 620 Inter-base station communication state monitoring part 630 Charging part 640 Electromotive part 650 Short-range communication part 660 State holding part 670 Control part 1510 1st Voltage waveform generation unit 1520 Second voltage waveform generation unit 1530 Supply voltage selection unit 1540 Magnetic flux variation unit 1550 Short range communication unit 1560 State holding unit 1570 Control unit 1580 Communication state determination unit 1590 Power storage amount determination unit

Claims (11)

A portable terminal having a wireless communication function,
A transmission unit that transmits a communication state signal related to the state of wireless communication to an external contactless charger;
A coil that generates an electromotive force by a change in magnetic flux that is made according to the communication state signal by the contactless charger that has received the communication state signal transmitted from the transmission unit;
A mobile terminal, comprising: a secondary battery that is charged using an electromotive force generated in the coil. A storage amount measuring unit for measuring a storage amount of the secondary battery;
The transmission unit also transmits a power storage information signal related to a power storage amount of the secondary battery measured by the power storage amount measurement unit to the contactless charger,
The mobile terminal according to claim 1, wherein the change of the magnetic flux is made according to the storage information signal by the contactless charger that has received the storage information signal transmitted from the transmission unit. The transmission unit performs the transmission,
During the period when the mobile terminal is performing wireless communication with an external base station, a call state signal indicating that the wireless communication is being performed is periodically transmitted to the contactless charger,
The portable terminal according to claim 2, wherein a storage information signal indicating a storage amount measured by the storage amount measurement unit is periodically transmitted to the contactless charger. The wireless communication function includes a data communication function for performing data communication with the base station, and a control signal communication function for performing control signal communication with the base station,
The transmitter is
The call state signal indicating that the wireless communication is being performed is transmitted only when the wireless communication performed by the mobile terminal is data communication with the base station. Item 4. A portable terminal according to Item 3. To charge a secondary battery that has a wireless communication function and includes a first coil, a secondary battery, and a transmitter, and the portable terminal is located at a relative position within a predetermined range. A non-contact charger that changes the magnetic flux in the first coil in order to generate the electromotive force of the first coil,
A second coil that changes the surrounding magnetic flux by flowing a fluctuating current;
A first voltage generation circuit that generates a voltage for flowing a first current that fluctuates at a predetermined frequency through the second coil;
The current that fluctuates at the predetermined frequency, and the energy of the harmonic component corresponding to the predetermined frequency among the frequency components of the electromagnetic wave radiated from the second coil with the change of the magnetic flux is the first. A second voltage generation circuit for generating a voltage for causing a second current smaller than the current to flow through the second coil;
A receiving unit for receiving a communication state signal transmitted from the transmitting unit and relating to a state of wireless communication in the mobile terminal;
Based on a communication state signal received by the receiving unit, a voltage generated by the first voltage generation circuit and a voltage generated by the second voltage generation circuit are supplied to the second coil. A contactless charger, comprising: a selection unit that selectively selects a voltage. The waveform of the voltage generated by the first voltage generation circuit is a rectangular waveform,
The contactless charging circuit according to claim 5, wherein the waveform of the voltage generated by the second voltage generation circuit is a blunt waveform that is duller than the rectangular waveform. A communication state determination unit that determines whether or not the mobile terminal is performing wireless communication based on a communication state signal received by the reception unit;
The selection unit performs the selection so as to select a voltage generated by the second voltage generation circuit during a period in which the mobile terminal is determined to be in wireless communication by the communication state determination unit. The contactless charger according to claim 5. The reception unit also receives a storage information signal related to a storage amount of the secondary battery, transmitted from the transmission unit,
The contactless charger according to claim 7, wherein the selection unit performs the selection based on a storage information signal received by the reception unit. A storage amount determination unit that determines whether the storage amount of the secondary battery is less than a predetermined amount based on the storage information signal received by the reception unit;
In the selection unit, even if the portable state is determined by the communication state determination unit to be in wireless communication, the storage amount determination unit determines that the storage amount of the secondary battery is less than a predetermined amount. In the period determined to be, the selection is performed such that selection of the voltage generated by the second voltage generation circuit is suppressed and the voltage generated by the first voltage generation circuit is selected. The contactless charger according to claim 8. The communication state determination unit is configured to perform wireless communication with the mobile terminal during a period in which the reception unit periodically receives a call state signal indicating that the mobile terminal is performing wireless communication with a base station. The contactless charger according to claim 9, wherein the determination is performed so as to determine that the battery is in the middle. A contactless charging system having a mobile terminal having a wireless communication function and a contactless charger,
The portable terminal is
A transmission unit that transmits a communication state signal related to a state of wireless communication to the contactless charger;
In the case where the contactless charger is present at a relative position within a predetermined range, a change in magnetic flux made according to the communication state signal by the contactless charger that has received the communication state signal transmitted from the transmission unit. A first coil for generating an electromotive force by:
A secondary battery charged using an electromotive force generated in the first coil, the contactless charger,
A second coil that changes the surrounding magnetic flux by flowing a fluctuating current;
A first voltage generation circuit that generates a voltage for flowing a first current that fluctuates at a predetermined frequency through the second coil;
A current that fluctuates at the predetermined frequency, and of the frequency component of the electromagnetic wave radiated from the second coil as the magnetic flux changes, the energy of the harmonic component with respect to the predetermined frequency is greater than the first current. A second voltage generation circuit for generating a voltage for causing a small second current to flow through the second coil;
A receiving unit for receiving a communication status signal transmitted from the transmitting unit;
Based on a communication state signal received by the receiving unit, a voltage generated by the first voltage generation circuit and a voltage generated by the second voltage generation circuit are supplied to the second coil. A contactless charging system comprising: a selection unit that selectively selects a voltage.

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