JP4723424B2 - Non-contact charging device for mobile phone - Google Patents

Description

The present invention relates to a non- contact charging device, and more particularly to a portable non-contact charging device capable of charging non-contacting a portable electronic device such as a cellular phone in a place where there is no power source.

  In recent years, portable electronic devices such as mobile phones are increasingly handling video and audio signals, and even though batteries use nickel / cadmium batteries and the like, the current capacity has been increasing year by year. On the other hand, the battery has a tendency to decrease. Although the present invention can be widely applied to portable electronic devices, in the description, a case where the present invention is applied to a mobile phone will be described below as an example.

  Occasionally, you may not be able to send or receive emails or emails when you are out of the office due to the battery running out of battery. In that case, use AA or AAA batteries for the power receiving connector of the AC adapter of the mobile phone. Devices for plug-in charging are commercially available. However, since a commercially available device protrudes considerably outside the foldable mobile phone, which is currently mainstream, it is necessary to support it with the hand that does not have a mobile phone when using it while making a call. In addition, since the shape of the power receiving connector of the AC adapter differs depending on the carrier of the mobile phone, when the carrier of the mobile phone is changed, it is necessary to replace the above equipment.

In order to solve the above-mentioned problems, a portable charging device described in Patent Document 1 is a conventional example in which a charging operation is performed on a portable device such as a cellular phone even in a place where there is no commercial power source. As described above, the electric energy stored in the electric double layer capacitor from the commercial power source is used as the power source of the portable charging device, and the portable device is charged in a non-contact manner or the non-contact power transmission described in Patent Document 2 A method of charging a battery of a mobile phone in a contactless manner using a large-capacity battery of a portable computer like an apparatus is disclosed.
JP 2003-299255 A JP-A-2005-143181

  However, since the current capacity of the electric double layer capacitor is only about 1/100 of that of the primary and secondary batteries in the above-mentioned conventional patent document 1, it is usually used for temporary backup of motherboard data. Only used. For this reason, the invention described in Patent Document 1 has poor feasibility.

  In Patent Document 2, since the user of the mobile phone does not necessarily have a portable computer, there is a problem that what can be realized is limited to the user of the portable computer.

  In view of the above-described conventional example, the portable non-contact charging device of this time does not require a portable computer or the like to be charged, and a normal primary battery (or secondary battery) such as AA or AAA. ) Can be charged in a non-contact manner to a secondary battery such as a nickel-cadmium battery inside the mobile phone, and even if the battery is about to run out during a call, the portable non-contact charging device and the mobile phone By holding together with the same hand, it is possible to easily extend the talk time. As a result, if you have a spare primary battery (or secondary battery) for the portable non-contact charging device, even if the primary battery in the portable non-contact charging device runs out, By replacing the battery of the charging device, there is an advantage that electric power can be added to mobile devices such as a mobile phone one after another. Of course, by having a plurality of portable non-contact charging devices, when the battery of the first portable non-contact charging device runs out, power may be added by the next portable non-contact charging device.

  Also, by having multiple power transmission coils and mounting a magnetic sensor that detects the magnetism from the power reception coil, the position of the power reception coil can be checked even if the position of the power reception coil differs depending on the manufacturer. Charging is enabled by switching the power transmission coil.

  This eliminates the need for a power receiving connector for the current AC adapter, and thus can cope with changes in the manufacturer of the mobile phone. And since it is not necessary to expose the power receiving connector of the AC adapter that is currently exposed, it is possible to charge even when wet when it is desired to use the mobile phone when it rains on the go.

  An object of the present invention is to provide a portable non-contact charging device that enables simpler and more reliable charging when a battery of a portable device is about to run out.

In order to achieve the above object, in the non-contact charging device for a mobile phone of the present invention, the power transmitting means of the charging unit and the power receiving unit of the charged unit of the mobile phone are formed by coils, Supply is performed in a non-contact manner by electromagnetic induction of two coils of a power transmission unit and a reception unit, and the charging unit includes a power source unit that supplies a DC voltage, a conversion unit that converts the DC voltage into an AC voltage, and power. The power supply unit uses a replaceable primary or secondary battery, and the charging unit transmits power to the plurality of power transmission units and one of the plurality of power transmission units. and switching means for switching, in a non-contact charging device of a mobile phone having a detecting means for detecting a change in magnetic switches the power transmission supplying power to one of any of the plurality of power transmitting means by said switching means In this case, if the detection means does not detect a magnetic signal due to the electromagnetic induction from the power reception means that is equal to or greater than a predetermined set value, the switching means performs switching to transmit power to another power transmission means, and the setting When the magnetic signal exceeding the value is detected, the switching means does not switch, and even if power is transmitted to all the power transmission means by the switching, the detection means does not detect the magnetic signal above the predetermined set value. If this happens, the set value is lowered and the cycle of whether or not to switch is repeated. Furthermore, the non-contact charging device for a mobile phone according to the present invention is characterized in that the detecting means sets the direction of the detecting means so as to detect only the magnetism by the power receiving means.

Furthermore, the non-contact charging device for a mobile phone according to the present invention is characterized in that a magnetic shield is provided between the detection means and the power transmission means so that the detection means does not detect magnetism by the power transmission means. .

Further, the charging unit of the present invention, in the above-mentioned non-contact charging device of the mobile telephone, characterized in that it is large enough-held by one hand and the mobile terminals of both the charging unit at the same time.

  The portable non-contact charging device of the present invention has a mobile phone as long as it has a charging part in a pocket or bag even when the battery of the mobile phone is about to run out while on the go. The power can be easily supplied to the mobile phone in a non-contact manner by taking out the charging unit with the hand not holding the mobile phone and holding the mobile phone and the charging unit with the same hand.

  Furthermore, by installing a magnetic sensor that detects the magnetism from multiple power transmission coils and power reception coils, it is not necessary to strictly determine the position of the power reception coil. You can decide freely. Therefore, when actually implementing the present invention, the degree of freedom described above is often an important point.

  In addition, the output of the charged part has the same shape as the connector of the AC adapter of the mobile phone currently in use, so that the charged part as large as one AA or AAA battery can be attached to the mobile phone. To do. By adopting such a structure and introducing the charging unit and the to-be-charged unit of the present invention as a set, the present invention can be applied to an existing mobile phone that does not have a built-in power receiving coil.

  Further, a simple circuit can be configured by using a CR oscillation circuit or a DC-AC converter using a CMOS inverter as a conversion means for converting a DC voltage into an AC voltage. Furthermore, a simple circuit can be configured by using a full-wave rectifier circuit or a voltage doubler rectifier circuit as a rectifier that rectifies the AC voltage received in the charged portion into a DC voltage. Furthermore, a simple circuit can be configured by using a constant voltage circuit using a Zener diode or a constant voltage circuit using a shunt regulator as overcharge protection means for protecting overcharge in the charging unit. Furthermore, a simple circuit can be configured by using a Hall element or an MR element as detection means for detecting a change in magnetism.

  Embodiments of the portable non-contact charging device of the present invention will be described below with reference to the drawings.

FIG. 1 is a first embodiment of a portable non-contact charging apparatus according to the present invention.
In FIG. 1, a charging unit 11 is a main body part of a portable non-contact charging device according to the present invention, and a charged unit 12 has a secondary battery such as a nickel-cadmium battery in a mobile phone 13 mounted on the mobile phone body. This is a part for realizing the present invention.

  The charging unit 11 includes a charging device battery 1, a DC-AC converter 2, and a power transmission coil 3. The battery 1 for a charging device is an AA or AAA type primary or secondary charging device battery that is mounted on the charging unit 11 of the portable non-contact charging device of the present invention and can be easily replaced by opening the lid. . The DC-AC converter 2 is a DC-AC converter that converts the DC voltage into a sine wave or square wave AC voltage. The power transmission coil 3 is a power transmission coil that supplies power to the power reception coil 4 with an alternating voltage by the action of electromagnetic induction in cooperation with a power reception coil 4 described later.

  The charged portion 12 includes a power receiving coil 4, a rectifier circuit 5, an overcharge protection circuit 6, and a charged device battery 7. The power receiving coil 4 is a power receiving coil that is mounted on the mobile phone body and receives the electric power from the power transmitting coil 3 in an alternating current by the action of electromagnetic induction. The rectifier circuit 5 is a rectifier circuit that converts the sine wave or square wave AC voltage into a DC voltage. When the overcharge protection circuit 6 charges the battery 7 for a charged device such as a nickel cadmium battery in the mobile phone, the battery life of the mobile phone is remarkably shortened by overcharging, or the battery is leaked or ruptured. This is an overcharge protection circuit that prevents the internal circuit from being damaged.

  Next, the operation from the charging device battery 1 to charging the charged device battery 7 will be described. In the charging unit 11, the DC voltage generated by the battery 1 for charging device is converted into an AC voltage by the DC-AC converter 2, and the AC voltage is generated in the power transmission coil 3. At this time, electric power is supplied from the power transmission coil 3 to the power reception coil 4 by electromagnetic induction generated between the power transmission coil 3 and the power reception coil 4 of the charged portion 12. As a result, an AC voltage is generated in the power receiving coil 4, and the voltage becomes a DC voltage in the rectifier circuit 5, and is charged to the battery 7 to be charged. Here, the overcharge protection circuit 6 protects the battery 7 to be charged from being overcharged when it is charged.

  Here, in order to realize this portable non-contact charging device, the battery 1 for the charging device and the battery 7 for the charged device 7 are made of a metal outer box under the influence of magnetism from the power transmission coil 3 and the power receiving coil 4. It is possible to prevent the battery from being heated by magnetically shielding the eddy current to prevent the battery from being heated, or by attaching a heat radiating plate so as to dissipate the heat of the battery 1 for the charging device or the battery 7 for the charged device.

  In FIG. 2, an example of the external shape of a present Example is shown. When this embodiment is applied to a mobile phone, it is assumed that the battery is about to run out during a call on the mobile phone. As a method of use, the charging unit 11 of the present invention is brought into contact with the bottom surface of the mobile phone with a hand not holding the mobile phone, and the charging unit 11 of the present invention is held with one hand together with the mobile phone 13. By doing so, the battery 7 to be charged such as a nickel cadmium battery built in the mobile phone 13 is charged through the power receiving coil 4 built in the bottom of the mobile phone in advance, and during the call of the mobile phone. It is possible to avoid the case where the battery is exhausted and the call cannot be made.

  Next, operations of the DC-AC converter 2, the rectifier circuit 5, and the overcurrent protection circuit 6 will be described with reference to FIGS.

  FIG. 3 shows a circuit diagram as an example of the DC-AC converter of the charging unit of the portable non-contact charging device of the present invention.

  As a method for generating a sine wave AC voltage from a DC voltage in FIG. 3A, positive feedback and a gain of more than a loss result in three stages of 180 ° (60 °) of C (capacitor) and R (resistance). ° 3) It can be realized by a circuit composed of a transfer circuit and a transistor having a gain of 8 times or more. When the battery 1 for a charging device is two AA or AAA batteries, a sine wave of less than 3 volts (peak to peak) can be generated. The transmission frequency f can be calculated relatively easily if the values of C and R (R in the third stage is the parallel resistance of R1 and R2) are the same. For details, refer to the textbook on electronic circuits.

  In FIG. 3B, using a CMOS inverter, a square wave of 3 volts (peak to peak) can also be generated. The oscillation frequency f is f = 1 / (2.2CR).

  Next, FIG. 4 shows an embodiment of the rectifier circuit 5 of the charged portion 12 of the portable non-contact charging device of the present invention.

  In FIG. 4A, since the intermediate tap of the coil on the left side of VIN is unnecessary, a DC voltage is normally extracted from the input sine wave or square wave to VOUT by a full-wave rectifier circuit in which diodes are arranged in a bridge shape. In FIG. 4 (b), the voltage of the battery of the mobile phone is around 3.7V (the largest carrier of the current mobile phone), so if the voltage is not 3V, if VIN is 3V, 6V can be taken out to VOUT. It is sufficient to use a double voltage rectifier circuit.

  Next, FIG. 5 shows an embodiment of an overcurrent protection circuit for a charged portion of the portable non-contact charging device of the present invention. Nickel-cadmium batteries commonly used in mobile phones expand and swell when the battery is overcharged. In some cases, the battery may explode, so there is usually an overcurrent protection circuit in the charger. It is installed.

In FIG. 5A, other than D2 is a constant voltage circuit using a Zener diode D1. D2 is a reverse current prevention diode that prevents a current flowing backward from the battery when VIN suddenly disappears.
In FIG. 5B, a constant voltage circuit with a feedback circuit using a shunt regulator D3 is used except for D2, but it is a stable circuit with less variation in output voltage than the circuit of FIG.

  In the first embodiment described above, the charging unit 11 of FIG. 1 has only the battery 1 for the charging device, the DC-AC converter 2 and the coil 3 for power transmission. The size (volume) and thinness can be realized. Therefore, it is possible to place the charging unit in a notebook-like container and place it in the palm together with the mobile phone 13, and at present, the overcurrent protection circuit 6 and the battery 7 to be charged are also mounted on the current mobile phone. Therefore, the portable non-contact charging device of the present invention can be realized only by adding the power receiving coil 4 and the rectifier circuit 5 to the cellular phone.

  FIG. 6 shows a second embodiment which is another embodiment of the portable non-contact charging device of the present invention.

  In FIG. 6, the first coil 31, the second coil 32, and the third coil 33 are power transmission coils of the same material and number of turns as the power transmission coil 3 of FIG. The magnetic sensor 8 is a magnetic sensor that detects the presence / absence of magnetism from the power receiving coil 4, and the switch 9 outputs the output of the DC-AC converter 2 to the first coil 31, the second coil 32, and the third coil 33. This is a switch for switching which coil to input.

  In operation, first, the switch 9 is connected to the battery side contact 37 and the first contact 34, and a voltage is applied to the first coil 31. At this time, when the magnetism from the power receiving coil 4 is detected and the output of the magnetic sensor 8 is equal to or higher than a predetermined set value, the switch 9 connects the battery side contact 37 and the first contact 34. Leave. When the output of the magnetic sensor 8 is a voltage equal to or lower than a predetermined set value, the switch 9 switches the connection with the battery side contact 37 from the first contact 34 to the second contact 35. As a result, a current flows through the second coil 32. At this time, when the magnetism from the power receiving coil 4 is detected and a voltage higher than a preset value is generated in the output of the magnetic sensor 8, the switch 9 connects the battery side contact 37 and the second contact 35. Keep it. Further, when the output of the magnetic sensor 8 is a voltage equal to or lower than a predetermined set value, the switch 9 switches the connection with the battery side contact 37 from the second contact 35 to the third contact 36. As a result, a current flows through the third coil 33. In this way, a power transmission coil close to the power receiving coil 4 in the charged part 12 can be searched for, and power can be appropriately supplied by electromagnetic induction. Further, in the connection at all the contacts, when a voltage higher than a predetermined setting is not generated in the output, it is possible to further reduce the setting value and repeat the cycle once more.

  In the above-described embodiment, the connection of a certain contact in the switch 9 and the connection of the contact are not switched when the output of the magnetic sensor 8 is a voltage higher than a predetermined setting has been described. In this method, the switch 9 is connected to all the contacts one by one, and the output by the voltage of the magnetic sensor 8 is stored, and the switch 9 is connected to the contact when the highest voltage is output. Conceivable.

  Here, in order to realize this circuit, only the power receiving coil 4 can react so that the magnetic sensor 8 does not react due to the magnetism from the power transmitting coils (31 to 33). That is, for example, if the magnetic sensor has a reaction range for detecting magnetism in a certain direction of the magnetic sensor and is within a certain angle range with respect to that direction, the power transmission coil (31 To 33), the direction angle of the magnetic sensor is set so that only the power receiving coil 4 enters. Thereby, the magnetic sensor 8 can appropriately detect the magnetism from the power receiving coil 4 without being affected by the power transmitting coils (31 to 33). It is also possible to provide a magnetic shield between the power transmission coil 4 and the magnetic sensor 8 so as not to be affected by magnetism from the power transmission coil. Even in this case, the magnetic sensor 8 can appropriately detect the magnetism from the power receiving coil 4 without being affected by the power transmitting coils (31 to 33). According to the above control, when the present invention is applied to a mobile phone, the position of the power receiving coil 4 of the charged portion 12 does not have to be determined strictly, so that each manufacturer can freely determine the design and internal component arrangement. Can do. When such an invention is actually realized, the above-mentioned degree of freedom is often an important point.

  FIG. 7 shows the external structure of the second embodiment. In FIG. 7, the charging unit 11 switches a plurality of coils, finds the power transmission coil 31 closest to the power reception coil 4 of the mobile phone 13, and supplies power to the power reception coil using the power transmission coil 31. Is shown. In this way, power can be appropriately supplied from the charging unit 11 to the battery 7 to be charged of the mobile phone 13 regardless of the orientation of the charging unit 11 and some positional relationship. Further, since the manufacturer of the mobile phone can design freely without paying much attention to the position of the power receiving coil 4, the versatility is enhanced and the portable non-contact charging apparatus is contributed to the spread.

  6 and 7 show three coils for the sake of explanation, but the invention according to this embodiment can be realized as long as there are a plurality of coils. More desirably, the number of coils is between several and several tens.

  FIG. 8 shows a third embodiment which is another embodiment of the portable non-contact charging device of the present invention. In FIG. 8, the difference from the first embodiment shown in FIG. 1 is that the power source 7 to be charged is not provided in the charged part 12, but instead, an AC adapter connector 10 is provided. Is a point. Furthermore, when the function of the overcharge protection circuit 6 is built in the mobile phone 13, the overcharge protection circuit 6 can be omitted as shown in FIG.

  FIG. 10 shows the external structure of the third embodiment. With the charged portion 12 inserted into the power receiving connector portion 10 of the AC adapter of the mobile phone 13, the charging portion 11 is brought to the bottom of the mobile phone, whereby a chargeable structure is obtained. In this case, the battery 7 to be charged is built in the mobile phone 13 body. As described above, in the third embodiment, since the operation of the present invention can be realized only by the combination of the charging unit 11 and the charged unit 12, there is an advantage that a portable contact charging device can be retrofitted to an existing mobile phone. In addition, since it is not necessary to remove the charged part 12 in FIG. 10 once it is attached, this method is adopted because it is possible to attach a rubber packing to the connection part with the mobile phone body or waterproof with a waterproof tape. Even if compared with other Examples 1 and 2, there is no disadvantage in terms of waterproofing.

  As described above, the first to third embodiments have been described with respect to the mobile phone as an example. However, the present invention is not limited to the mobile phone, but other portable electronic devices such as a PDA, a digital video recorder, and a portable music player. In other words, the present invention can be widely applied to devices that operate on secondary batteries and are carried to places where there is no power source such as a household power source.

1 shows a portable non-contact charging apparatus according to Embodiment 1 of the present invention. The external view of the portable non-contact charging device of Example 1 of the present invention is shown. The example of the circuit diagram of the DC-AC converter of this invention is shown. (A) is a case of a sine wave (CR oscillation circuit). (B) is a case of a square wave (using a CMOS inverter). The example of the circuit diagram of the rectifier circuit of this invention is shown. (A) is a case where input voltage = output voltage (full-wave rectification circuit). (B) This is a case where the output voltage is doubled (double voltage rectifier circuit). The example of the circuit diagram of the overcurrent protection circuit of this invention is shown. (A) is a case using a constant voltage circuit (no feedback) + a reverse current prevention diode. (B) is a case of a constant voltage circuit (with feedback) + a diode for preventing reverse current. The portable non-contact charging device of Embodiment 2 of the present invention External view of portable non-contact charging device of embodiment 2 of the present invention A portable non-contact charging device according to a third embodiment of the present invention Portable non-contact charging device which is another embodiment of Embodiment 3 of the present invention External view of portable non-contact charging device of embodiment 3 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery for charger 2 DC-AC converter 3 Coil for power transmission 4 Coil for power reception 5 Rectifier circuit 6 Overcharge protection circuit 7 Battery for device to be charged 8 Magnetic sensor 9 Switch 10 Connector for AC adapter (male)
DESCRIPTION OF SYMBOLS 11 Charging part 12 Charged part 13 Mobile phone 31 1st coil 32 2nd coil 33 3rd coil 34 1st contact 35 2nd contact 36 3rd contact 37 Battery side contact

Claims (4)

The power transmission unit of the charging unit and the power reception unit of the charged unit of the mobile phone are formed by coils, and the power supply from the power transmission unit to the power reception unit is non-contact by electromagnetic induction of two coils of the power transmission unit and the reception unit The charging unit includes power supply means for supplying a DC voltage, conversion means for converting the DC voltage into AC voltage, and power transmission means for transmitting power, and the power supply means is replaceable 1 Or a secondary battery, and the charging unit includes a plurality of power transmission units, a switching unit that switches power transmission to one of the plurality of power transmission units, and a detection unit that detects a change in magnetism . In a non-contact charging device,
When switching power transmission by the switching means and supplying power to any one of the plurality of power transmission means, the detection means generates a magnetic signal by the electromagnetic induction from the power receiving means that is equal to or greater than a preset value. If not detected, the switching means performs switching to transmit power to other power transmission means, and the switching means does not perform switching when the magnetic signal greater than the set value is detected,
If the detection means does not detect the magnetic signal equal to or higher than a predetermined set value even when power is transmitted to all power transmission means by the switching, the setting value is lowered and a cycle of whether or not to switch is performed. A non-contact charging device for a mobile phone , characterized by being repeated. The contactless charging apparatus of the mobile phone according to claim 1, wherein the detecting means, non-contact charging of a mobile phone, characterized in that it has set the orientation of the detecting means so as to detect only magnetic by said receiving means apparatus. 3. The non-contact charging device for a mobile phone according to claim 1, wherein a magnetic shield is provided between the detection unit and the power transmission unit so that the detection unit does not detect magnetism generated by the power transmission unit. A non-contact charging device for a mobile phone . The non-contact charging device for a mobile phone according to any one of claims 1 to 3, wherein the charging unit is large enough to hold both the mobile terminal and the charging unit simultaneously with one hand.