JPH09190938A - Non-contact type battery charger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery charger capable of fully realizing the performance of a secondary battery and also capable of building compact, thin, lightweight, high-reliability electronic devices using chargeable secondary batteries as power sources. SOLUTION: In an electronic equipment having a charge type secondary battery 3 charging power by energy transmission from charging side to the side to be charged by means of magnetic induction, a circuit 2 at the side of power charging, and a built-in power receiving coil, a substrate 7 made of magnetic materials is arranged, which is built in the electronic equipment and formed with a power receiving coil 1 and a circuit 2 at the side to be charged, between the secondary battery side 9 and a power transmitting coil at the charging side in a state where the electronic equipment is provided at the charging side of the equipment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rechargeable battery used as a power source for a cordless telephone, a portable device, etc., which can be contactlessly supplied with electric power from a charging section to a charging section without a metal contact. The present invention relates to a charger that uses an electromagnetic induction coil for electric transmission, and relates to an electromagnetic induction device incorporated in a cordless telephone, a portable device, or the like.

[0002]

2. Description of the Related Art Electronic devices such as cordless phones, PHS, mobile phones, and transceivers that use a rechargeable secondary battery as a power source, especially portable devices, are required to be small, thin, and lightweight. On the other hand, there is a demand for improvement to make the operation time as long as possible.

In order to satisfy these contradictory requirements, a small-sized, lightweight, long-life Li-ion battery or the like is adopted as a secondary battery used in electronic equipment. However, these batteries have problems such as smoke generation due to temperature rise, etc., and in order to ensure safety, when designing a charger or power supply circuit, it is necessary to pay sufficient attention to overdischarging and overcharging. .

In particular, in order to make full use of the performance of the Li-ion battery, the voltage tolerance of the charging voltage is ± 20 mV / ce.
In addition to having to be set within l, there is a problem that metal Li is deposited when an overvoltage is applied, so that highly accurate constant current and constant voltage control is required for design. However, since the charging device that charges the secondary battery has a contact point by an electrode between the electronic device and the charging device, the charging voltage applied to the secondary battery changes due to the contact resistance, and the voltage information at both ends of the battery is the charging device. However, it is not possible to apply a sufficient charging voltage to both ends of the battery and to charge only 60 to 70% of the nominal charging capacity because it is not accurately transmitted to the battery and the variation in the voltage drop due to the contact resistance must be taken into consideration. There wasn't.

Therefore, there is no contact between the charging device and the electronic device, and the non-contact type charging device utilizing electromagnetic induction capable of supplying a stable charging voltage to the secondary battery is described in the above 2
It has come to be used to charge the next battery.

However, there is a demand for further miniaturization, thinning and weight saving of electronic equipment.

[0007]

[Problems to be solved by the invention] Cordless telephone, PH
The market demand for electronic devices such as S, mobile phones, and transceivers that use a rechargeable secondary battery as a power source, particularly portable devices, is that they are small, thin, lightweight, and have a long operating time.

In order to meet these requirements, Ni hydrogen batteries, Li ion batteries, etc., which are highly efficient secondary batteries, have been adopted, but further improvement of the charging device is desired in order to make full use of the battery performance. There is.

The present invention makes it possible to construct a small, thin and lightweight electronic device having high reliability in an electronic device using a rechargeable secondary battery as a power source, and further, to fully exhibit the performance of the secondary battery. An object of the present invention is to provide a non-contact type charging device that can be operated.

[0010]

In order to achieve the above object, the present invention provides a rechargeable battery that is charged through a non-contact type charging device that uses magnetic induction to transfer energy from a charging side to a charged side. In an electronic device including a secondary battery, the circuit to be charged, and a power receiving coil, the secondary battery and the power transmitting coil on the charging side in the state where the electronic device is installed on the charging side of the non-contact type charging device Provided is a non-contact type charging device in which a substrate made of a magnetic material, which is built in the electronic device and which constitutes a circuit to be charged and a power receiving coil, is arranged.

Further, according to the present invention, the substrate made of a magnetic material which constitutes a circuit on the side to be charged and a power receiving coil is a plate formed by mixing a thermosetting or thermoplastic resin with ferrite powder or amorphous magnetic powder. As a result, it is possible to further improve the reliability of the electronic device that incorporates the charged side of the non-contact type charging device.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A circuit to be charged, a power receiving coil and a secondary battery of a non-contact charging device incorporated in an electronic device are shown in FIG.
As shown in the block diagram as shown in FIG. 2, a configuration in which energy transmitted by electromagnetic induction from the charging side of the non-contact charging device is received by the power receiving coil 1 and the secondary battery 3 is charged via the circuit 2 on the charged side Becomes

The structure of such an electronic device is shown in FIG.
(A) is the structural drawing, (b) is the sectional view, and (c) is a conceptual drawing of the substrate.

When the electronic device 4 is charged, the electronic device 4 is mounted on the charging side 6 of the non-contact charging device as shown in (a). At that time, the charged side 5 of the contactless charging device is placed in close proximity to the charging side 6 of the contactless charging device.

In this case, as shown in the sectional view of (b), the charging side 6 of the contactless charging device is equipped with a control circuit for transmitting energy in a contactless manner by electromagnetic induction, a power transmission coil 9 and the like. The power transmission substrate 8 is arranged, and the circuit 2 on the charged side of the contactless charging device and the power receiving coil 1 are provided on the electronic device side.
The board 7 on which is mounted is disposed at a position facing the power transmission board 8 on which the control circuit for transmitting energy in a non-contact manner is mounted. Further, the secondary battery 3 is arranged on the back surface of the substrate 7 on which the circuit 2 on the charged side and the power receiving coil 1 of the contactless charging device are mounted.

The power receiving coil 1 is mounted on the substrate 7 on which the circuit 2 to be charged and the power receiving coil 1 of the contactless charging device are mounted as shown in the conceptual diagram of the substrate in (c). The power receiving coil 1 may be a thin air-core coil mounted on the substrate 7, or may be a conductor printed on the substrate 7 in a spiral shape, but the components and the power receiving coil 1 are mounted. If the power receiving coil 1 is made as thin as possible using the surface mounting technique or the like in this state, the power receiving coil 1 can be brought close to the power transmitting substrate 8 on which the control circuit or the like is mounted, and even if the secondary battery 3 is arranged on the back surface. The thinness of the electronic device 4 is not impaired.

Further, the substrate 7 on which the power receiving coil 1 is mounted
By shielding the charging side and the secondary battery by using a magnetic material, the eddy current loss generated when the energy transmitted from the charging side reaches the secondary battery 3 located on the back surface of the substrate can be eliminated. This makes it possible to prevent accidents caused by heating of the secondary battery 3 due to eddy currents more easily, leading to improved reliability.

Here, the substrate 7 on which the power receiving coil 1 is mounted
If a plate formed by mixing ferrite powder or amorphous magnetic powder with a thermosetting or thermoplastic resin is used, it can be easily molded and processed, and it has good insulating properties, so it is also reliable with good manufacturability. It is also very popular.

The higher the relative magnetic permeability of the substrate 7, the higher the power receiving coil 1
The energy received by is large, and if ferrite powder is used, the relative permeability of the substrate 7 can be increased to about 10, and if amorphous magnetic powder is used, it can be increased to about 80.

[0020]

Industrial Applicability According to the present invention, it is possible to construct a small, thin, lightweight, and highly reliable electronic device using a rechargeable secondary battery as a power source, and further improve the performance of the secondary battery. It is possible to provide a non-contact type charging device that can be sufficiently exerted.

[Brief description of the drawings]

FIG. 1 is a block diagram of a non-contact type charging device on a charged side.

FIG. 2 is a structural diagram of an electronic device in which a non-contact type charging device includes a charged side.

[Explanation of symbols]

1 Receiving coil 3 Secondary battery 7 Substrate on which circuit 2 to be charged of non-contact charging device and receiving coil and 1 are mounted

Claims (2)

[Claims] 1. A rechargeable secondary battery charged via a non-contact type charging device that transfers energy from a charging side to a charged side by using electromagnetic induction, a circuit on the charged side and a power receiving coil. In a state in which an electronic device is installed in the secondary battery and the non-contact type charging device, a substrate that is built in the electronic device and is made of a magnetic material that forms a circuit on the charged side and a power receiving coil is provided. A non-contact type charging device, which is arranged between the charging side power transmission coil and the power transmission coil. 2. The circuit board, which is made of a magnetic material and constitutes a circuit on the side to be charged and a power receiving coil, is made of a plate formed by mixing ferrite powder or amorphous magnetic powder with a thermosetting or thermoplastic resin. The non-contact type charging device according to claim 1.