JP2001218391A - Equipment to be charged, battery charger, and noncontact charge system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm whether equipment to be charged is regular, without using any communication means such as light. SOLUTION: When equipment 11 to be charged is placed in a charger 1, charging is started automatically. In the equipment 11, a charge control part 15 turns off a charge off switch 16 by a fixed period according to a signal from a timer 14. When charge is turned off in this manner, temporary increase in the voltage of a transmission coil 4 is repeated with a fixed period. In the charger 1, a confirmation detecting part 5 detects the change in the voltage of the transmission coil caused 4 by the on/off of the charge. A control part 2 determines whether the equipment 11 is regular, according to a signal that is outputted from the confirmation detecting part 5. When it is determined that equipment is not the equipment 11, a power transmission part 3 is controlled, and the charge to the equipment 11 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device to be charged, a charger, and a non-contact charging system for performing non-contact charging using, for example, electromagnetic induction.

[0002]

2. Description of the Related Art In recent years, non-contact charging systems using electromagnetic induction have become widespread in devices to be charged such as electric toothbrushes, PHSs, and cordless telephones. However, in the non-contact charging system using electromagnetic induction, even if metal such as coins other than the legitimate device to be charged is placed on the charger, if current flows due to electromagnetic induction, the power transmission coil of the charger There is a danger that excessive current will flow through the coin and that the coin will heat up.

[0003] Therefore, in order to prevent such a state, a non-contact charging system has been proposed in which foreign objects such as coins are eliminated by judging whether or not the device is a legitimately charged device. For example, a signal indicating that the device to be charged is a legitimate device to be charged is transmitted to the charger by light or the like, and it is determined that the device set based on the signal received by the charger is a legitimate device to be charged. In addition, a non-contact charging system for charging has been proposed.

[0004] A non-contact charging system has been proposed in which a foreign object such as a coin is eliminated by determining whether the device is a legitimate device to be charged based on the shape of the device to be charged. For example, in non-contact charging systems such as electric toothbrushes and cordless phones, the shape of the electromagnetic induction part of the charger is made into a hole through which metallic foreign objects such as coins cannot easily enter, and the shape of the electromagnetic induction part of the device to be charged is The shape that can be set in the hole clears the safety requirements. Also,
By forming the electromagnetic induction portion in such a shape, the power transmission coil of the charger and the power reception coil of the device to be charged easily face each other.

[0005]

However, in the non-contact charging system for electrically confirming whether or not the device is a legitimate device to be charged, both the charger and the device to be charged are legitimate devices to be charged. It is necessary to add a device for transmitting and receiving a signal indicating the fact by light or the like, which hinders the cost and the size and weight of the wireless charging system.

[0006] On the other hand, in a non-contact charging system that removes foreign matter and the like depending on the shape of the device to be charged, the device to be charged is inserted into a hole provided in the charger and charging is performed. Is constrained.

In this non-contact charging system, since the device to be charged must be correctly set in the charger, the operability regarding charging is not different from that of a contact type charging system, and lacks convenience. .

Accordingly, an object of the present invention is to provide a device to be charged which can determine whether or not the device to be charged set in the charger is a proper one without using communication means such as light.
A battery charger and a contactless charging system are provided.

Another object of the present invention is to provide a device to be charged, a charger and a non-contact charging system which can be charged by casual operation.

A further object of the present invention is to provide a device to be charged, a charger and a non-contact charging system in which the designs of the charger and the device to be charged are not restricted.

[0011]

According to a first aspect of the present invention, there is provided a power transmission coil for supplying power to a device to be charged by electromagnetic induction, and a power transmission unit for supplying power to the power transmission coil. A detection unit that detects whether or not the device to be charged is normal based on a voltage or current change generated in the power transmission coil due to ON / OFF of charging, and that the output signal of the detection unit determines that the device to be charged is normal. If the signal indicates that the power is not supplied, the power supply is stopped.

According to a second aspect of the present invention, a power transmission coil for supplying power to a device to be charged by electromagnetic induction, a power transmission unit for supplying power to the power transmission coil, and a signal received from the device to be charged via the power transmission coil. A detection unit that detects whether the device to be charged is legitimate, and an output signal of the detection unit
If the signal indicates that the device to be charged is not proper, the power supply is stopped.

According to a fifth aspect of the present invention, a power receiving coil to which power is supplied from a charger by electromagnetic induction, a secondary battery for storing power supplied to the power receiving coil, and power supply to the secondary battery in a predetermined pattern. And a control unit for turning on / off.

According to a sixth aspect of the present invention, there is provided a power receiving coil to which power is supplied from a charger by electromagnetic induction, a signal generating unit for generating a signal indicating that the battery is a legitimate object to be charged, and an electric power supplied to the power receiving coil. And a signal generated by the signal generation unit is transmitted to the charger via the power receiving coil.

According to a ninth aspect of the present invention, there is provided a non-contact charging system in which a device to be charged is charged from a charger by electromagnetic induction, wherein the device to be charged includes a power receiving coil supplied with power from the charger by electromagnetic induction; A secondary battery that stores power supplied from the charger to the power receiving coil, and a control unit that turns on / off power supply to the secondary battery,
A power transmission coil that supplies power to the device to be charged by electromagnetic induction, a power transmission unit that supplies power to the power transmission coil, and a device to be charged based on a voltage or current change generated in the power transmission coil when the device to be charged is turned on / off. And a detection unit for detecting whether or not the power supply is normal. If the output signal of the detection unit is a signal indicating that the device is not a device to be charged, the power supply is stopped. System.

According to a tenth aspect of the present invention, in the non-contact charging system for charging a device to be charged from a charger by electromagnetic induction, the device to be charged includes a power receiving coil supplied with power from the charger by electromagnetic induction, A signal generation unit that generates a signal indicating that the battery is a legitimate charging target, and a secondary battery that stores power supplied to the power receiving coil, the charger includes:
A power transmission coil that supplies power to the device to be charged by electromagnetic induction, a power transmission unit that supplies power to the power transmission coil, and detection that detects whether the device to be charged is legitimate based on a signal received from the device to be charged. When the output signal of the detection unit is a signal indicating that the device is not a device to be charged,
A contactless charging system characterized by stopping power supply.

According to a fifteenth aspect of the present invention, in a non-contact charging system in which a device to be charged is charged from a charger by electromagnetic induction, the device to be charged is provided with a power receiving coil supplied with power from the charger by electromagnetic induction, A secondary battery that stores the power supplied to the coil, a charger that transmits power to the device to be charged by electromagnetic induction, a power transmitting unit that supplies power to the power transmitting coil, and a shape of the device to be charged. A detection unit that detects whether or not the device is a device to be charged, and if the signal output from the detection unit is a signal indicating that the device is a device to be charged, charging is performed on the device to be charged. Is a contactless charging system.

According to the first, fifth and ninth aspects of the present invention, when the charging from the charger is started, the device to be charged turns on / off the charging at a predetermined cycle. The charger detects whether or not the device to be charged turns charging on / off at a predetermined cycle based on a change in the voltage or current of the power transmission coil. If it is detected that charging is not turned on / off at a predetermined cycle, charging is stopped. As a result, it is possible to prevent an induced current from flowing through a foreign substance such as a coin and heating the foreign substance.

In the invention according to claims 2, 6 and 10,
The charger turns on / off charging of the device to be charged at a predetermined cycle. The device to be charged sends a partner confirmation signal indicating that the device is a legitimate device to be charged to the charger via the electromagnetic induction unit during the charging off. The charger detects whether or not a partner confirmation signal has been sent from the device to be charged during the charging off. If it is detected that the device to be charged has not sent a partner confirmation signal during charging off,
Stop charging. As a result, it is possible to prevent an induced current from flowing through a foreign substance such as a coin and heating the foreign substance.

In the invention according to claim 15, the device to be charged is provided with a magnet at a position representative of the shape. On the other hand, the charger is provided with a magnet switch so that when the device to be charged is placed at a correct position, the magnet switch comes to a position opposing a magnet provided on the device to be charged. Therefore, if the set device is a legitimate device to be charged, all the magnet switches are turned on. The charger starts charging only when all magnet switches are turned on. This allows
It is possible to prevent an induced current from flowing through a foreign substance such as a coin and heating.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A non-contact charging system according to the present invention uses an interaction between a charger and a device to be charged via an electromagnetic induction unit to charge a signal indicating that the device is a legitimate device to be charged. It is a non-contact charging system that transmits to a device.

In the conventional contactless charging system, since this signal is transmitted by communication means using light or the like, a device for this must be added to both the charger and the device to be charged. This hinders the cost and the size and weight of the wireless charging system.

In the contactless charging system to which the present invention is applied, since this signal is transmitted via the electromagnetic induction unit,
Since the configuration is simple, it is possible to solve the above-mentioned problems of cost and reduction of size and weight. Furthermore, it is more reliable than conventional contactless charging systems.

Hereinafter, a non-contact charging system according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a non-contact charging system according to a first embodiment to which the present invention is applied. Charger 1
Are a control unit 2, a power transmission unit 3, a power transmission coil 4, a confirmation detection unit 5,
Consists of On the other hand, the device to be charged 11 includes a power receiving coil 12, a rectifier 13, a timer 14, a charge controller 15, a charge off switch 16, and a secondary battery 17.

The control section 2 supplies a signal to the power transmission section 3 based on the signal supplied from the confirmation detection section 5. Power transmission unit 3
Supplies power to the power transmission coil 4 based on a signal from the control unit 2. The power transmission coil 4 supplies power to the power transmission coil 12 by electromagnetic induction. The confirmation detection unit 5 detects the power transmission coil voltage or the power transmission coil current.

The power receiving coil 12 is supplied with power from the power transmitting coil 4 by electromagnetic induction. The rectifying unit 13 rectifies the power supplied to the power receiving coil 12 by electromagnetic induction, converts the power into a DC component, and supplies the DC component to the charging control unit 15. Timer 14
Supplies a signal for turning off the charge off switch 16 to the charge control unit 15 at a predetermined cycle. The charging control unit 15 detects the state of the secondary battery 17 based on the voltage, charging time, and the like of the secondary battery 17 and controls the supply of power to the secondary battery 17. Further, based on a signal from the timer 14, the charge off switch 16 is controlled. The charge off switch 16 turns on / off charging of the secondary battery 17. The secondary battery 17 is a secondary battery such as a lithium ion battery or a lithium hydrogen battery that stores power supplied from the charge control unit 15.

A method for electrically determining a legitimate device to be charged 11 in the contactless charging system having the above configuration will be described below. The charger 1 is a device to be charged 1
When 1 is set, charging starts. As will be described later, when a foreign object such as a coin to be charged is placed on the device to be charged 11 or other devices, the charger 1 automatically starts charging the device.

In the device to be charged 11, when charging is started, the charge control unit 15 turns off the charge off switch 16 at a predetermined cycle based on a signal from the timer 14. Immediately after the charging is turned off, the voltage in the power transmission coil 4 temporarily increases due to electromagnetic induction. Therefore, when charging is periodically turned off in this manner, the power transmission coil voltage repeats a temporary increase at a predetermined cycle.

On the other hand, in the charger 1, the confirmation detecting unit 5 detects the voltage of the power transmission coil in the power transmission coil 4 and supplies the voltage to the control unit 2. The control unit 2 determines whether or not the device is a legitimate device to be charged 11 based on the signal supplied from the confirmation detection unit 5, and supplies a signal corresponding to the determination to the power transmission unit 3.

That is, if the voltage of the power transmission coil repeats a temporary increase at a predetermined cycle, it is determined that the device 11 is a regular device to be charged, and the power supply to the power transmission coil 4 is continued. On the other hand, if the voltage in the power transmission coil does not repeat the temporary increase in a certain cycle,
It determines that the device is not a legitimate device to be charged 11, and supplies a signal to the power transmission unit 3 to stop supplying power. The power transmission unit 3 stops supplying power to the power transmission coil 4 based on the signal supplied from the control unit 2.

In the above example, the voltage of the power transmission coil
Although the method of electrically determining the legitimate device to be charged 11 has been described, the determination may be made based on the power transmission coil current.

FIG. 2 shows ON / OFF waveforms of the power transmitting coil voltage and the power transmitting coil current during charging of the non-contact charging system shown in FIG. In the case where the power supply partner is the legitimate device to be charged 11, as shown in FIG. 2, a change in which the device to be charged 11 is turned off at a predetermined cycle is caused by the change in the power transmission coil voltage and the power transmission coil. Occurs in the coil current. Note that FIG. 2 shows an example in which a constant voltage is applied to the power transmission coil for ease of explanation. However, actually, a pulsating component of a commercial power supply (50 Hz, 60 Hz) is generated by the power transmission coil. Of the applied voltage.

It is preferable that the power consumption of the charger 1 be small when the device to be charged 11 is not in the standby state. Therefore, the charger 1 turns off the power supply to the power transmission coil 4 during standby for charging, and when the device to be charged 11 is set, the charger 1 detects this and starts supplying power to the power transmission coil 4.

It is easy to determine whether there is a device to be charged or not in a charger that determines whether the device set according to the shape of the device to be charged is a legitimate device to be charged as described later. Therefore, here, a method of detecting the presence or absence of a device to be charged will be described with respect to the charger for determining whether or not the device is an electrically legitimate device to be charged.

In the charger 1, during normal charging standby, the power transmission unit 3
Supplies power intermittently to the power transmission coil 4 based on a signal supplied from the control unit 2. When the device to be charged 11 or the like is set, the voltage intermittently applied to the power transmission coil 4 decreases. The confirmation detection unit 5 detects the voltage of the power transmission coil 4 and supplies the voltage to the control unit 2. The control unit 2 determines whether or not the device to be charged 11 or the like has been set based on the signal supplied from the confirmation detection unit 5, and supplies a signal according to this determination to the power transmission unit 3.

That is, when it is determined that the voltage intermittently applied to the power transmission coil 4 is decreasing,
A signal for starting power supply is transmitted to the power transmission unit 3. The power transmission unit 3 supplies power to the power transmission coil 4 based on the supplied signal. When it is determined that there is no change in the voltage intermittently applied to the power transmission coil 4, the power transmission unit 3
The power supply to the power transmission coil 4 is intermittently continued based on the signal supplied from the control unit 2.

In the above-described example, a method has been described in which it is electrically determined that a proper device to be charged 11 or the like has been set based on the voltage of the power transmission coil. However, this determination can also be made based on the current of the power transmission coil. . However, when the device to be charged 11 or the like is set, the power transmission coil current decreases.

After the charging is started, the authorized device 1 to be charged
If it is 1, it indicates the predetermined behavior as described above, and it can be determined from this behavior whether or not the device is the legitimate device 11 to be charged. If the device is a legitimate device to be charged 11, the charging is continued, and if it is any other foreign material, the charging is stopped. However, while determining whether or not the device 11 is a legitimate device to be charged, a charging current is supplied to the other party set in the charger 1. The charger 1 can determine whether or not the device to be charged 11 is. Hereinafter, the operation of the above-described wireless charging system will be described with reference to a timing chart.

FIG. 3 is a timing chart for explaining the operation of the contactless charging system shown in FIG.
5A shows the time when the device to be charged 11 or the foreign matter is set, FIG. 5B shows the time when the presence of the device to be charged 11 or the presence of the foreign material is confirmed, and FIG.
1 is removed, (d) is when charging is turned off,
(E) shows the time when the intermittent first pulse is started, (f) shows the time when the charge is turned off after confirming the foreign matter, and (g) shows the time when the intermittent first pulse is started.

The period (1) is a period during which charging is awaited. In this period, the charger 1 intermittently supplies power to the power transmission coil 4, and thus the voltage of the power transmission coil and the waveform of the current are pulse waves. When the device to be charged 11 or a foreign object is set, the amplitude of the pulse wave of the voltage of the power transmission coil decreases. On the other hand, the amplitude of the pulse wave of the power transmission coil current increases.

(2) is a period for confirming whether or not the device 11 is a legitimate device to be charged. See Figure 2 for this period.
Has already been described, and the description is omitted here.

The period (3) is a period in which the device to be charged 11 is confirmed to be off. During this period, when the device to be charged 11 is removed, the power transmission coil current decreases or the phase coil voltage increases, so that the time required to determine whether or not the device to be charged 11 has been removed is determined. is there. However, even if the device to be charged 11 has not been removed, the charging current may not flow due to the activation of the charge control or the like. Therefore, to determine whether the device to be charged 11 has been removed, Relatively long judgment time is required.

The period (4) is a foreign matter confirmation decision period. This period is a time required to determine that there is no predetermined behavior indicated by a broken line that should be indicated by the normally charged device 11. During this period, the charging current flows to a foreign object or the like. Therefore, it is necessary to determine that the foreign substance is a foreign substance or the like within a time when the foreign substance is heated or the like and becomes in an abnormal state. Note that this time greatly differs depending on the magnitude of the charging current.

The period (5) is a halt period after foreign matter detection. This period is a period during which the foreign matter determination is finalized and charging is turned off. After this period, waiting for charging again (intermittent charging)
Becomes If the foreign matter has not been removed, a current is applied to the foreign matter again during the foreign matter confirmation determination period. Therefore, the pause period after the foreign matter detection is set to be relatively long. This time also differs greatly depending on the magnitude of the charging current, as in the foreign matter confirmation determination period. Further, the method of electrically determining a legitimate device to be charged via the electromagnetic induction unit is not limited to the above-described embodiment. For example, the charger turns off power transmission at a predetermined cycle, and transmits a partner confirmation signal indicating that the device to be charged is a legitimate device to be charged to the charger via the electromagnetic induction unit during the off period. The charger can check whether the set device is a legitimate device to be charged by checking whether a partner confirmation signal is sent from the device to be charged while the power transmission is off. .

FIG. 4 is a block diagram of a contactless charging system according to a second embodiment for determining whether or not the device is a legitimate device to be charged by the above-described method. The charger 21 includes a control unit 22, a power transmission unit 23, a charge off switch 24, a power transmission coil 25, and a confirmation detection unit 26. On the other hand, the device to be charged 31 includes a power receiving coil 32, a rectifier 33, a charge controller 34, a secondary battery 35, a signal generating power source 36, a signal generating circuit 37, and a trap 38.

The control section 22 supplies a signal to the power transmission section 23 based on the signal supplied from the confirmation detection section 26. Although not shown, the control unit 22 has a timer, and turns off the charge off switch 24 at a predetermined cycle. The power transmission unit 23 supplies power to the power transmission coil 25 based on a signal from the control unit 22. Power transmission coil 2
5 supplies power to the power receiving coil 32 by electromagnetic induction. The confirmation detection unit 26 detects a signal transmitted from the device to be charged 31 via the power transmission coil 25.

The power receiving coil 32 is supplied with power from the power transmitting coil 25 by electromagnetic induction. The rectifying unit 33 rectifies the power supplied to the power receiving coil 32 by electromagnetic induction, converts the power into a DC component, and supplies the DC component to the charging control unit 34 and the signal generating power source 36. The charging control unit 34 detects the state of the secondary battery 35 based on the voltage, charging time, and the like of the secondary battery 35, and controls the supply of power to the secondary battery 35. The secondary battery 35
It is a secondary battery such as a lithium ion battery or a lithium hydrogen battery that stores the electric power supplied from the charge control unit 34.

The signal generating power supply 36 supplies the electric power supplied from the rectifier 33 to the signal generating circuit 37. The signal generation circuit 37 generates a partner confirmation signal that is a predetermined high-frequency signal. For example, an LC oscillator or the like is used as the signal generation circuit 37. As described above, the power source of the signal generation circuit 37 is generated from the rectification unit 33 instead of the secondary battery 35, so that the partner confirmation signal is generated only during charging. Therefore, the secondary battery 35 is not charged by the signal generation circuit 37 except during charging.
Is not consumed. The trap 38 prevents the partner confirmation signal generated by the generation signal circuit 37 from returning to the direction of the secondary battery 35.

A method of electrically determining a legitimate device to be charged 31 in the contactless charging system having the above configuration will be described below. As in the non-contact charging system of the first embodiment, the charger 21 automatically starts charging the device to be charged 31 or other foreign substances when it is placed thereon.

In the charger 21, the control unit 22 turns off the charge off switch 24 at a predetermined cycle. On the other hand, in the device to be charged 31, while the charging from the charger 21 is off, the signal generation circuit 37 generates a partner confirmation signal,
The power is supplied to the power receiving coil 32.

In the charger 21, the confirmation detection unit 26 detects the partner confirmation signal received by the power transmission coil 25 and supplies the signal to the control unit 22. The control unit 22 determines whether the set device is the device to be charged 31 based on the supplied signal, and supplies a signal corresponding to the determination to the power transmission unit 23.

That is, when the other party confirmation signal is supplied while the charging is turned off, it is determined that the device 31 is a legitimate device to be charged 31, and the charging is continued. On the other hand, if the partner confirmation signal is not supplied while the charging is turned off, it is determined that the device is not a legitimate device to be charged 31, and a signal to stop supplying power is supplied to the power transmission unit 23. The power transmission unit 23 includes the control unit 22
The supply of power to the power transmission coil 25 is stopped based on the supplied signal.

The partner confirmation signal is, for example, a high-frequency (high-frequency signal such as several hundred kHz or several hundred MHz) signal having a predetermined frequency. If the frequency of the partner confirmation signal is selected to be relatively close to the frequency used for charging (inductive coupling frequency), the detection of the partner confirmation signal sent from the device to be charged 31 is stopped when charging is stopped. It will be easier.

On the other hand, if the frequency of the other party confirmation signal is selected to be considerably different from the frequency used for charging (inductive coupling frequency), for example, a further resonance circuit is provided in the charger 21 so that the other party confirmation signal is provided. Can be separated. Therefore, it is possible to determine whether or not the device 31 is a legitimate device to be charged 31 while charging is continuously performed without stopping charging. However, the power used for charging is high power,
In some cases, the battery has a wide range of frequency components. Therefore, it is better to stop charging and detect the partner confirmation signal.

FIG. 5 shows waveforms of the power transmission coil voltage and the partner confirmation signal during charging of the non-contact charging system shown in FIG. When the power supply partner is the legitimate device to be charged 31, as shown in FIG. 5, when the power transmission coil voltage is off, the partner confirmation signal is detected.

FIG. 6 is a timing chart for explaining the operation of the contactless charging system shown in FIG.
The waveforms of the transmitting coil voltage and the transmitting coil current shown in FIG. 6 are different from those shown in FIG. This is because in the contactless charging system shown in FIG.
This is because the charging of the device to be charged 31 is turned off when the device 1 is checked.

(A) shown in FIG.
1 or a time when a foreign object is set; (b) a time when the presence of the device to be charged 31 or a foreign object is confirmed; (c) a time when the device to be charged 31 is removed; and (d) the charging is turned off. Time, (e) is the time at which the intermittent first pulse is started,
(F) shows the point in time when the charge is turned off after confirming the foreign substance, and (g) shows the point in time when the intermittent first pulse is started.

The period (1) is a period during which charging is awaited. In this period, the charger 21 includes the power transmission coil 25
The power supply coil voltage and the power transmission coil current have pulse waveforms. Charged device 3
When 1 or a foreign substance is set, the amplitude of the pulse wave of the power transmission coil voltage decreases. On the other hand, the amplitude of the pulse wave of the power transmission coil current increases.

(2) is a period for confirming whether or not the device to be charged 31 is legitimate. For this period, see FIG.
, And the description is omitted here.

The period (3) is a period in which the device to be charged 31 has been removed. In this period, when the device to be charged 31 is removed, the power transmission coil current decreases or the phase coil voltage increases, so that the time required to determine whether or not the device to be charged 31 has been removed is determined. is there. However, even if the device to be charged 31 has not been removed, the charging current may not flow due to the operation of the charge control or the like. Therefore, to determine whether the device to be charged 31 has been removed, Relatively long judgment time is required. Note that the confirmation off signal shown by the broken line may not be provided.

The period (4) is a foreign matter confirmation decision period. This period is a time required to determine that there is no predetermined behavior indicated by a broken line that should be indicated by the normally charged device 31. During this period, the charging current flows to a foreign object or the like.
Therefore, it is necessary to determine that the foreign substance is a foreign substance or the like within a time when the foreign substance is heated or the like and becomes in an abnormal state. Note that this time greatly differs depending on the magnitude of the charging current.

The period (5) is a halt period after foreign matter detection. This period is a period during which the foreign matter determination is finalized and charging is turned off. After this period, waiting for charging again (intermittent charging)
Becomes If the foreign matter has not been removed, a current is again applied to the foreign matter during the foreign matter confirmation determination period. Therefore, the pause period after the foreign matter detection is set to be relatively long. This time also differs greatly depending on the magnitude of the charging current, as in the foreign matter confirmation determination period.

In the non-contact charging system according to the second embodiment, the charging device 31 is set to be in the off-confirmation period (3) in the first embodiment.
It can be set shorter than the non-contact charging system of the embodiment. This is because the charger 21 determines the timing for determining the proper device to be charged 31. Further, in this contactless charging system, the foreign matter confirmation decision period (4) can be set short. this is,
This is because if it is confirmed that there is no signal from the power supply partner, it is possible to determine that the device is not the proper device to be charged 31 by itself.

In the contactless charging system described above, the shape of the charger is made to match the shape of the device to be charged,
Furthermore, by loosening the regulation of the position where the device to be charged is placed on the charger, charging can be performed with a casual operation.

For example, when the device to be charged has a shape like headphones, the shape of the charger is such that charging is performed by putting headphones on or putting on headphones. Hereinafter, a non-contact charging system in which charging is performed by placing headphones on a charger will be described as an example.

FIG. 7 is a schematic diagram of the above-described non-contact charging system during charging. Charger 41 for electromagnetic induction
And where the headphone 51 is in contact. Power is supplied from the charger 41 to the headphones 51 by electromagnetic induction via the electromagnetic induction section. Here, the electromagnetic induction section can be provided at any one or all places indicated by 42, 43, and 44 in FIG. However,
Usually, an electromagnetic induction part is provided at one place.

FIG. 8 shows the principle of the contactless charging system. In the charger 61, the oscillator 62 converts the power into AC and supplies the power to the power transmission coil 63. In the device to be charged 71, the rectifying unit 73 rectifies the power transmitted to the power receiving coil 72 by electromagnetic induction, converts the power into a DC component, and supplies the DC component to the charging control unit 74. The charging control unit 74 detects the state of the secondary battery 75, and supplies the power supplied from the rectifying unit 73 to the secondary battery 75 based on the detected state of the secondary battery 75.

Therefore, in order to efficiently transmit power from the charger 61 to the device to be charged 71 by electromagnetic induction, it is necessary that the power transmitting coil 63 and the power receiving coil 72 are close to each other and face each other correctly. Therefore, in the non-contact charging system shown in FIG. 7, in order to efficiently transmit electric power by electromagnetic induction, the headphone is set so that the power receiving coil of the headphone 51 and the power transmitting coil of the charger 41 are close to each other and face each other. It is necessary to accurately place 51 on the charger 41.

For example, the headphone 51 is located at such a position.
A mark indicating the position to be placed on the surface of the charger 41 or a protrusion or dent is formed on the surface of the charger 41 so that the headphone 51 can be easily placed in the correct position.

However, in order to place the headphones 51 on the charger 41 casually, it is better that the position where the headphones 51 are placed on the charger 41 is not so strongly regulated. Therefore, even if the power transmission coil and the power reception coil are slightly displaced, power transmission is enabled. For example, the allowable deviation between the power transmitting coil and the power receiving coil can be increased by the following method.

FIG. 9 shows a graph that depends on the size of the coil diameter.
It is a schematic diagram which shows the intensity of electromagnetic induction with respect to the displacement of a coil. By increasing the diameter of one or both of the power transmitting coil 81 and the power receiving coil 82, electromagnetic induction is ensured even if the power transmitting coil 81 and the power receiving coil 82 are slightly displaced. As shown in FIG. 9, when the diameter of the coil is small, the tolerance of the displacement is small, but when the diameter of the coil is large, the tolerance of the displacement is large. Therefore, if the diameter of the coil is small, if the power transmission coil 81 and the power reception coil 82 are slightly displaced, the strength of electromagnetic induction is reduced, but if the diameter of the coil is large, the deviation between the power transmission coil 83 and the power reception coil 84 is small. Even if is large, the strength of electromagnetic induction does not become very small.

FIG. 10 is a schematic diagram showing the strength of electromagnetic induction with respect to coil displacement when a plurality of coils are provided. By providing a plurality of one or both of the power transmission coil 91 and the power reception coil 92, the possible range of electromagnetic induction is increased. Here, an example in which a plurality of power transmission coils 91 are provided is shown. As shown in FIG.
Providing a plurality of power transmission coils 91 increases the tolerance for displacement. Therefore, similarly to the case where the diameter of the coil is increased, by providing the plurality of power transmission coils 91, the strength of the electromagnetic induction does not become very small even if the displacement between the power transmission coil 91 and the power reception coil 92 is large.

By doing so, the regulation of the position where the headphones 51 are placed on the charger 41 is relaxed, and in extreme cases, the headphones 51 may be placed on the charger 41 in any case. However, since wastefulness increases, charging efficiency deteriorates, and other adverse effects occur, the placement of the headphones 51 is restricted to some extent so that a minimum gap between the power transmission coil and the power reception coil is allowed. I do.

In the non-contact charging system, when a metal such as a coin is placed on the charger, an excessive current flows through the power transmission coil or the coin is heated. This is because when a metal such as a coin is put on the power transmission coil of the charger, an induced current flows through these. Hereinafter, a method for preventing an excessive current from flowing through the power transmission coil and heating a metal such as a coin will be described.

When an excessive current flows through the power transmission coil,
By providing a detection unit or the like for detecting an excessive current in the non-contact charging system, the power transmission coil can be protected. On the other hand, in the case where the current is not excessive but the coin is heated, the heating of the coin is detected by the following method.

For example, by detecting the temperature of the charger, it is possible to prevent coins from being heated. Specifically, by directly monitoring the temperature in the vicinity of the power transmission coil using a temperature-sensitive element such as a thermistor, it is possible to prevent a coin or the like from being heated.

Further, the charger checks the device to be charged and proceeds with charging, thereby preventing foreign matter such as coins from being heated. In other words, the non-contact charging system has a method of confirming whether or not what is put on the charger is a legitimate device to be charged.

For example, as a method of confirming whether or not a device placed on the charger is a legitimate device to be charged, a method of electrically confirming whether or not the device placed on the charger is a legitimate device to be charged is described. There is a method of confirming whether the device is a legitimate device to be charged based on the shape of the device placed on the charger.

The method of electrically confirming whether or not the device is a legitimate device to be charged has already been described with reference to the first and second embodiments. Therefore, hereinafter, a non-contact charging system according to a third embodiment for checking whether or not the device is a legitimate device to be charged based on the shape will be described with reference to the drawings.

FIG. 11A is an explanatory diagram of a non-contact charging system for performing charging by judging that the charger has the shape of a legitimate device to be charged by magnets arranged in headphones. As shown in FIG. 11A, a magnet 105 is disposed on the right side of the headphone 101, a magnet 106 is disposed at the center of the headphone band 103, and further, an electromagnetic induction section 104 is provided.
Is arranged on the left headphone 102. Although not shown, the charger is provided with a magnet switch. These magnet switches activate the magnet 105 and magnet 1 when the headphones are in the correct position on the charger.
06.

Therefore, when the headphones are placed at the correct position of the charger, all the magnet switches of the charger are turned on, and charging is started by electromagnetic induction via the electromagnetic induction unit 104 disposed on the left headphone 102. .
As described above, by disposing the magnet switch in the main part of the shape of the headphones, those having a shape different from the headphones are excluded.

FIG. 11B is an explanatory diagram of a non-contact charging system that determines whether or not the charger has the proper shape of the device to be charged based on the weight of the headphones and performs charging. As shown in FIG. 11B, in the headphones, an electromagnetic induction unit 104 is arranged on the left side of the headphones 102. Also, the charger is provided with a micro switch 107 and a micro switch 108 so that when the headphones are placed at the correct position of the charger, they are located at positions opposite to the headphone right 101 and the headphone left 102.

Therefore, when the headphones are placed at the correct position on the charger, all the microswitches of the charger are turned on, and charging is started by electromagnetic induction via the electromagnetic induction unit 104. As described above, by providing the microswitch in the charger, a battery having a shape different from that of the headphones is excluded. Even if the micro switch is provided only at the position opposing the headphone right 101 (on the opposite side of the electromagnetic induction section), there is an effect of excluding a micro switch having a shape different from that of the headphone.

FIG. 11C shows whether the charger is a legitimate device to be charged by the spring force of the headphone band,
It is explanatory drawing of the non-contact charging system which performs charging. FIG.
As shown in FIG.
A pressing portion 109 and a pressing portion 110 for holding the headphones from the outside by the headphone left 102 are provided. The holding unit 109 is provided with a micro switch 111, and the holding unit 110 is provided with a micro switch 112.

Therefore, the headphone holding section 109
When the battery is put on the charger so as to fit into the holding unit 110, the microswitches are all turned on by the force of the spring of the headphone band 103, and charging is started by electromagnetic induction via the electromagnetic induction unit 104. In this manner, a shape different from the predetermined spring shape is excluded.

Even if the microswitch is arranged only on one end of the holding portion 109 or the holding portion 110, there is an effect of eliminating a switch having a shape different from that of the headphone. Also, here, a case has been described in which the pressing portion 109 and the pressing portion 110 are provided so as to press the headphone from the outside, but a pressing portion that presses the headphone from the inside may be provided.

Further, in these non-contact charging systems, the effect of eliminating foreign substances can be further increased by providing irregularities on the charger so as to regulate the position of the headphones to some extent. An example in which such irregularities are provided in the charger will be described below for the non-contact power receiving system shown in FIG. 11A.

FIG. 12 is a schematic diagram showing an example of the shape of a charger 121 provided with irregularities and a headphone 131 whose position is fixed by these irregularities. As shown in FIG. 12, a headphone right 132, a headphone left 133, and a headphone band 134 are used to form a regulating convex right 122, a regulating convex left 123, and a regulating convex band 124 for regulating the headphones 131 from the outside. To be provided. Further, as shown in a sectional view later, a concave portion is provided inside the regulating protrusion 122 and the regulating protrusion 123. This allows
The headphone 131 can be fixed to some extent by the headphone right 132, the headphone left 133, and the headphone band 134.

FIG. 13 is a sectional view of a schematic diagram of the contactless charging system shown in FIG. Referring to FIG.
The arrangement of the concave portion, the magnet switch, and the power transmission coil will be described, and further, the foreign matter removing function of the concave portion will be described. As shown in FIG. 13, the concave right 1
25 are provided, and the concave left 126 is arranged inside the regulating convex left 123. A magnet switch 127 is arranged in the middle of the steep slope of the concave right 125, and a power transmission coil 128 is arranged in the middle of the steep slope of the concave left 126. Here, headphone band 1
Although no magnet is arranged at 34 and a magnet switch is not arranged at the regulating protrusion 124, if necessary, magnets and magnet switches may be arranged similarly to the case shown in FIG. 13A.

These recesses are larger than foreign matters such as coins, and the right headphones 132 (and the left headphones 13).
It is a foreign matter sliding down hole having a smaller shape than 3).
Therefore, foreign matter such as coins smaller than the headphone right 132 (and the headphone left 133) is
Headphones right 1 while sliding down from recess 126
32 (and headphone left 133) settles in the position as shown in the cross-sectional view of FIG. Such recess 12
Since the magnet switch 127 and the power transmission coil 128 are arranged in the middle of the steep slope between the groove 5 and the recess 126,
It is possible to prevent a foreign substance such as a coin from staying at this position and heating.

Since the magnet switch 127 and the power transmission coil 128 are arranged at such positions, the headphone right 132 (and the headphone left 133) can be used.
Heating of a larger foreign substance can also be prevented.

In the above-described non-contact charging system, a higher foreign matter elimination function can be obtained than in a conventional non-contact charging system in which a device to be charged is inserted into a hole provided in a charger to perform charging. However, even in a conventional type of non-contact charging system, if the shape of the power transmission coil is changed to a shape in which a foreign substance or the like passes through the hole, the same effect as the above-described foreign substance removing function can be obtained. For example, the above-described foreign matter elimination function can be applied to a conventional non-contact charging system in which one side of a headphone is placed on a charger to perform charging.

FIG. 14 is a schematic diagram and a cross-sectional view for explaining an example in which the above-described foreign matter removing function is applied to a conventional type of non-contact charging system. Charger 14
1 is a holding section 14 for fixing the headphones 151.
2. It has a coin sliding hole 143 for removing foreign matter such as coins, and a power transmission coil 144 for charging the headphones 151 by electromagnetic induction. Meanwhile, the headphones 151
Although not shown, the receiving coil is connected to the headphone left 152.
The sliding down hole 143 is larger than a foreign object such as a coin and has a shape smaller than the headphone left 152. Therefore, a foreign substance such as a coin may be removed from the sliding hole 143.
More slip down. As a result, it is possible to prevent an induced current from flowing through a foreign substance such as a coin and heating the foreign substance.
Further, since the power transmission coil 144 is located in the middle of the slope of the slide-down hole 143, it is possible to prevent an induced current from flowing through a foreign substance having a shape larger than that of the headphones.

The present invention is a charging system that is comfortable even when applied to a non-contact charging system other than the headphones described above. Hereinafter, an example in which the present invention is applied to a non-contact charging system other than headphones will be described.

FIG. 15 shows a case where the present invention is applied to a jacket 161.
This is an example in which the present invention is applied to a non-contact charging system composed of a hanger-shaped charger 171 to which it is applied. Here, the jacket 161 has a thin and flexible sheet-shaped battery 162 mounted thereon as a wearable battery. In order to casually charge clothes on which such a sheet-shaped battery 162 is mounted, a non-contact power receiving system as shown in FIG. 1 which is charged when clothes are hung on a clothes hanger is natural.

This non-contact charging system has the same circuit as the non-contact charging system shown in the block diagram of FIG. 1 or FIG. For example, the jacket 161 has
A sheet-shaped battery 162 in the pocket and a control unit 16 in the chest.
3. An electromagnetic induction portion 164 is provided on the shoulder and the back. On the other hand, the hanger-shaped charger 171 is provided with an electromagnetic induction portion 164 at a portion where the shoulder and the back of the jacket 161 are in contact when the jacket 161 is hung.
Although not shown, a confirmation detection unit, a rectification unit, and the like other than these are also provided in the jacket 161 and the hanger-shaped charger 171.

Therefore, just by hanging the jacket 161 on the hanger-shaped charger 171, the sheet-shaped battery 162 mounted on the jacket 161 via the electromagnetic induction portion 164.
It is charged casually. Further, in the above-described example, the case where the hanger-shaped charger 171 is of a wall-mounted type has been described, but may be a form of a stand-type type 172.

In addition to the above, a non-contact charging system comprising a cap having a sheet-shaped battery 162 mounted thereon and a cap-shaped charger, and a non-contact charging system comprising a belt having a sheet-shaped battery 162 mounted thereon and a belt-mounted charger. For contact charging systems, etc.
The present invention may be applied.

FIG. 16 shows an example in which the present invention is applied to a non-contact charging system including a charging desk 181 and a notebook computer 191. This non-contact charging system has the same circuit as the non-contact charging system shown in the block diagram of FIG. 1 or FIG. The power transmission coil 182 is connected to the charging machine 1
It is provided on the 81 desk. On the other hand, a power receiving coil 192 is provided on the bottom surface of the notebook computer 191. This power transmission coil 18
2 is provided on a fairly wide area on the desk. Therefore, there is not much restriction on the position on the desk where the notebook computer 191 is placed. However, by restricting the placement position to some extent, favorable effects can be obtained in terms of charging efficiency, cost, and the like. Therefore, the range in which the notebook computer 191 is placed by marking the desk or providing unevenness on the desk is provided. Clarify.

Therefore, when the notebook personal computer 191 is used at home, if it is used casually on the charging desk 181, the notebook personal computer 191 is automatically charged. Therefore, even if the notebook personal computer 191 is not charged using a dedicated AC adapter or the like, the notebook personal computer 191 can be taken out and used as it is outside.

Further, if the charging desk 181 is installed at a specific place, it is possible to charge the notebook computer 191 at a place where the user does not care about the charger. Further, if an infrastructure is provided such that the charging desks 181 are arranged in many places on the go, the non-contact charging system becomes a more convenient system.

[0102]

As described above, according to the present invention, it is possible to confirm whether the device to be charged is legitimate by detecting the change in the voltage or current of the electromagnetic induction unit by the charger. In addition, the charger receives a signal from the device to be charged via the electromagnetic induction unit, so that it is possible to confirm whether the device to be charged is legitimate. Therefore, it is not necessary to add a device that receives and transmits a signal by light or the like to the non-contact charging system, so that it is possible to solve the problems of cost and miniaturization of the conventional non-contact charging system.

Further, according to the present invention, electromagnetic induction is ensured even if there is a slight shift between the power transmission coil and the power reception coil. Therefore, since the regulation of the position where the device to be charged is placed on the charger is relaxed, the device to be charged can be charged by casual operation. .

Further, according to the present invention, it is not necessary to make the shape of the electromagnetic induction portion a special shape, so that the design is not restricted as in the conventional contactless charging system.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating waveforms when a proper device to be charged is charged.

FIG. 3 is a timing chart for explaining the operation of the contactless charging system.

FIG. 4 is a block diagram showing a configuration of a second embodiment of the present invention.

FIG. 5 is a schematic diagram illustrating waveforms when a proper device to be charged is charged.

FIG. 6 is a timing chart for explaining the operation of the contactless charging system.

FIG. 7 is a perspective view showing a charging mode of the non-contact charging system according to the first and second embodiments of the present invention.

8 is a block diagram for explaining the non-contact charging system shown in FIG.

FIG. 9 is a schematic diagram used for describing a possible range of electromagnetic induction.

FIG. 10 is a schematic diagram used for describing a possible range of electromagnetic induction.

FIG. 11 is a schematic diagram used for describing a non-contact charging system according to a third embodiment of the present invention.

FIG. 12 is a schematic diagram illustrating a configuration for judging a legitimate device to be charged based on a shape according to a third embodiment of the present invention.

FIG. 13 is a schematic diagram illustrating a configuration for judging a legitimate device to be charged based on a shape in a third embodiment of the present invention.

FIG. 14 is a schematic diagram illustrating a modification of the third embodiment of the present invention.

FIG. 15 is a schematic diagram illustrating an application example of the first and second embodiments of the present invention.

FIG. 16 is a schematic diagram illustrating an application example of the first and second embodiments of the present invention.

[Explanation of symbols]

4, 25, 63, 81, 83, 91, 128, 144,
182: power transmission coil, 12, 32, 72, 82, 8
4, 92, 136, 192 ... receiving coil, 16, 2
4 ... Charge off switch, 17, 35, 75 ... Secondary battery, 38 ... Trap, 41, 121, 141
..Chargers, 101, 132 ... headphone right, 10
2, 133, 152 ... headphone left, 103, 13
4 ... headphone band, 105, 106, 135
..Magnet 127 ... Magnet switch 107,
108, 111, 112... Microswitch, 10
9, 110, 142 ... holding part, 42, 43, 4
4, 104, 164: electromagnetic induction part, 122: regulating convex right, 123: regulating convex left, 124: regulating convex band, 125: concave right, 126: concave left, 5
1, 131, 151 ... headphone, 143 ... coin sliding down hole, 162 ... sheet rechargeable battery, 163
... Charge control unit, 172 ... Stand type

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02J 7/10 H02J 7/10 FHJ (72) Inventor Mitsunori Fujikawa 6-7 Kita Shinagawa, Shinagawa-ku, Tokyo No. 35 Inside Sony Corporation (72) Inventor Kumi Yashiro 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo F-term inside Sony Corporation (reference) 3B011 AA01 AC06 AC07 5G003 AA01 BA01 CA01 CA11 FA03 FA04 GB08 5H030 AA09 AS18 BB01

Claims (17)

[Claims] 1. A power transmission coil for supplying power to a device to be charged by electromagnetic induction, a power transmission unit for supplying power to the power transmission coil, and a voltage or current change generated in the power transmission coil due to ON / OFF of charging. A detection unit that detects whether the device to be charged is legitimate. If the output signal of the detection unit is a signal indicating that the device to be charged is not legitimate, the power supply is stopped. A charger characterized in that: 2. A power transmission coil for supplying power to a device to be charged by electromagnetic induction, a power transmission unit for supplying power to the power transmission coil, and a signal received from the device to be charged via the power transmission coil. A detection unit that detects whether the device to be charged is normal or not, and when the output signal of the detection unit is a signal indicating that the device to be charged is not proper, the power supply is stopped. A charger. 3. The power transmission unit according to claim 1, wherein the power transmission unit intermittently supplies power to the power transmission coil during standby for charging, and the detection unit detects a voltage change or a current change in the power transmission coil. Detecting whether or not the device to be charged has been set, and if the output signal of the detection unit is a signal indicating that the device to be charged has been set, charging of the device to be charged is started. Charger characterized by doing. 4. The power transmission unit according to claim 2, wherein the power transmission unit turns on / off power supply to the power transmission coil.
A charger for detecting whether or not the device to be charged is legitimate based on a signal received from the device to be charged while the power supply to the power transmission coil is off, . 5. A power receiving coil to which power is supplied from a charger by electromagnetic induction, a secondary battery for storing power supplied to the power receiving coil, and turning on / off a power supply to the secondary battery in a predetermined pattern. A device to be charged, comprising: 6. A power receiving coil to which power is supplied from a charger by electromagnetic induction, a signal generating unit for generating a signal indicating that the power is to be properly charged, and a secondary for storing power supplied to the power receiving coil. A device to be charged, comprising: a battery; and a signal generated by the signal generation unit is sent to the charger via the power receiving coil. 7. The device according to claim 6, wherein the signal generated by the signal generator is a high frequency having a specific frequency. 8. The apparatus according to claim 6, wherein the signal generator generates a signal indicating that the battery is a legitimate object to be charged while the charging from the charger is turned off. machine. 9. A non-contact charging system in which a device to be charged is charged from a charger by electromagnetic induction, wherein the device to be charged includes: a receiving coil to which power is supplied from the charger by electromagnetic induction; A secondary battery that stores power supplied to the power receiving coil; and a control unit that turns on / off power supply to the secondary battery. The charger supplies power to the device to be charged by electromagnetic induction. A coil, a power transmission unit for supplying power to the power transmission coil, and whether the device to be charged is normal based on a voltage or current change generated in the power transmission coil by turning on / off the device to be charged. Non-contact power reception, wherein when the output signal of the detection unit is a signal indicating that the device is not the device to be charged, power supply is stopped. Stem. 10. A non-contact charging system in which a device to be charged is charged from a charger by electromagnetic induction, wherein the device to be charged comprises: a receiving coil to which power is supplied from the charger by electromagnetic induction; And a secondary battery that stores power supplied to the power receiving coil.A charger includes a power transmitting coil that supplies power to the device to be charged by electromagnetic induction. A power transmission unit that supplies power to the power transmission coil, and a detection unit that detects whether the device to be charged is authentic based on a signal received from the device to be charged, and an output signal of the detection unit is A non-contact charging system characterized in that when the signal indicates that the device is not the device to be charged, the power supply is stopped. 11. The power transmission unit according to claim 9 or 10, wherein the power transmission unit intermittently supplies power to the power transmission coil during standby for charging, and the detection unit detects a voltage change or a current change in the power transmission coil. Detecting whether or not the device to be charged is set, and if the output signal of the detection unit is a signal indicating that the device to be charged is set, charging of the device to be charged is started. A non-contact charging system characterized by the following. 12. The signal generation unit according to claim 10, wherein the signal generation unit generates a signal indicating that the battery is to be charged normally while the power supply from the charger is turned off. A non-contact charging system for detecting whether or not the device to be charged is legitimate based on a signal received from the device to be charged while power supply to the device to be charged is off. 13. The wireless charging system according to claim 9, wherein the power transmitting coil and the power receiving coil have different diameters. 14. The wireless charging system according to claim 9, wherein at least one of the power transmission coil and the power reception coil is provided in a plurality. 15. A non-contact charging system in which a device to be charged is charged from a charger by electromagnetic induction, wherein the device to be charged is supplied to the power receiving coil supplied from the charger by electromagnetic induction, and to the power receiving coil. A secondary battery that stores the stored power, wherein a charger supplies power to the device to be charged by electromagnetic induction, a power transmission unit that supplies power to the power transmission coil, and a shape of the device to be charged. A detection unit that detects whether or not the device is the device to be charged; and if the signal output from the detection unit is a signal indicating the device to be charged, A non-contact charging system for starting charging of a charging device. 16. The non-contact charging device according to claim 15, wherein the detection unit is a micro switch that is turned on by a representative portion of the device to be charged when the device to be charged is set. . 17. The device according to claim 15, wherein the device to be charged further has a magnet at a location representative of the shape of the device to be charged, and the detection unit is a magnet switch turned on by the magnet. Characteristic non-contact charging equipment.