JP3821023B2 - Non-contact charger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a non-contact charging device for non-contact charging of an electronic device from a power transmission device by detachably mounting an electronic device that is a charging target on the power transmission device.
[0002]
[Prior art]
A non-contact charging apparatus has a structure as shown in FIG. 9, for example. A conventional non-contact charging apparatus 1000 shown in FIG. 9 includes a charging cradle 1002 and a mobile phone 1008 which is an example of an electronic device. The cradle 1002 includes a storage recess 1001. The storage recess 1001 is formed to be inclined in one direction at the center of the upper surface of the cradle 1002.
[0003]
A printed circuit board 1004 is disposed inside the cradle 1002. This printed circuit board 1004 incorporates an electronic component 1003, and the printed circuit board 1004 constitutes a control circuit unit 1005. The code 1006 supplies AC power to the control circuit unit 1005.
[0004]
The power transmission coil 1007 is connected to the control circuit unit 1005. The power transmission coil 1007 is disposed corresponding to a part of the wall surface that forms the housing recess 1001.
[0005]
On the other hand, the cellular phone 1008 includes a circuit portion 1010 inside the housing, and the circuit portion 1010 incorporates various electronic components 1009. The lower part of the mobile phone 1008 is detachably stored in the storage recess 1001. The circuit portion 1010 includes a power receiving coil 1011, and the power receiving coil 1011 is attached to the inner surface side of the casing of the mobile phone 1008 corresponding to the power transmitting coil 1007.
[0006]
The non-contact charging referred to in this specification is a method of transmitting electric power to the power receiving coil by electromagnetic induction from the power transmitting coil and charging an electronic component such as a battery or a capacitor.
[0007]
[Problems to be solved by the invention]
However, this type of conventional non-contact charging apparatus has the following problems.
[0008]
In this type of non-contact charging device, downsizing is essential because portability is desired. However, non-contact charging devices have been commercialized in the past, such as electric toothbrushes, portable telephones, PHS (Personal Handy Phone System), PDA (Personal digital assistance), digital still cameras, mini-discs, etc. It is assumed that it is also used for charging. At the time of charging, more power than before must be transmitted, so the power transmission loss at that time becomes large and is directly exchanged for heat.
[0009]
The cause of the heat generation here may be an increase in Joule heat or eddy current loss due to an increase in current value. Due to this heat generation problem, it has not been used for PDAs or the like so far.
[0010]
Also, conventional power devices such as power transistors always have a heat sink or heat spreader directly connected to generate heat, but small devices such as PDAs and portable telephones are required to reduce the size of the housing. The space to put in such parts is disappearing.
[0011]
Until now, since the plate disposed between the power receiving coil and the power transmitting coil should not have conductivity, plastics such as ABS (acrylonitrile butadiene styrene) have been used. However, the thermal conductivity of plastics is as low as 0.2 to 0.3 W / mK, and there is a problem that heat tends to be trapped. In addition, when the heat generation amount of the power receiving coil and the power transmitting coil is large, the plastic between the coils is thermally deformed and the dimension between the coils is changed, so that the power transmission efficiency may be lowered.
[0012]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a non-contact charging device that solves the above-described problems, can prevent the temperature increase of the power transmitting coil and the power receiving coil, can be downsized, and can perform stable non-contact charging. Yes.
[0013]
[Means for Solving the Problems]
The non-contact charging device according to the present invention that achieves the above-described object charges the electronic device from the power transmission device in a non-contact manner by detachably attaching the electronic device that is a charging target to the power transmission device. since a non-contact charging apparatus, the power transmission device has a present body, a first ceramic member disposed in said body, and a power transmission coil provided in the first ceramic member, wherein the electronic The device includes a housing, a second ceramic member disposed in a portion of the housing at a position corresponding to the first ceramic member in a state where the electronic device is mounted on the power transmission device, and the second ceramic provided member, the power by electromagnetic induction from the power transmission coil possess a power receiving coil for receiving a non-contact, wherein the electronic apparatus is a portable electronic device, the body of the power transmission device, the electric A mounting holder having a concave shape for inserting and holding the insertion portion of the housing of the device, wherein the first ceramic member and the power transmission coil of the power transmission device are positioned in the mounting holder; The second ceramic member and the power receiving coil are positioned at the insertion portion of the casing of the electronic device, and the main body of the power transmission device and the casing of the electronic device are made of plastic, The first ceramic member is fitted into a first mounting recess having a first bottom portion formed from the inner surface side of the main body of the power transmission device, and the first ceramic member and the first bottom portion of the main body are connected to each other. The second ceramic member is laminated and fitted into a second mounting recess having a second bottom formed from the inner surface side of the casing of the electronic device. The second ceramic member and the second bottom portion of the electronic device are stacked, and the power transmission device is disposed in the main body and transmits the heat generated by the power transmission coil, And a heat sink that dissipates the heat that is thermally connected to the first heat conducting member and is disposed in the body, and the electronic device is disposed in the housing and generates the power receiving coil. And a heat spreader for dissipating the heat that is disposed in the housing and thermally connected to the second heat conduction member.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.
[0015]
The embodiment described below is a preferred specific example of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these forms.
[0016]
FIG. 1 shows a preferred embodiment of the contactless charging apparatus of the present invention. The non-contact charging device 200 of FIG. 1 is shown in a cross section so that the internal structure can be seen.
[0017]
FIG. 2 shows an enlarged main part of the non-contact charging apparatus 200 of FIG.
[0018]
1 and 2 schematically includes a power transmission device 50 and a mobile phone 10 as an example of an electronic device. The mobile phone (also referred to as a mobile phone) 10 is an example of a so-called portable electronic device.
[0019]
A power transmission coil 101, a first ceramic member 103, a circuit board 105, a heat conductor 99, a heat sink 97, and the like are accommodated in a main body (also referred to as a charging cradle) 90 of the power transmission device 50. A battery 100, a circuit unit 75, a second ceramic member 73, a heat conductor 66, a heat spreader 63, and the like are accommodated in the housing 12 of the mobile phone 10.
[0020]
3 and 4 show examples of the shape of the mobile phone 10.
[0021]
3 and 4 show a mobile phone as an example of an electronic device. In this example, a single battery 100 is detachably attached to the mobile phone 10.
[0022]
The mobile phone 10 includes a housing 12, a display unit 16, an antenna 14, a speaker 22, a microphone 20, an operation unit 18, and the like.
[0023]
The housing 12 has a front part 24 and a rear part 26.
[0024]
The insertion portion 25 of the housing 12 is a portion for being inserted into the power transmission device and attached during charging.
[0025]
The display part 16 is a part which displays various information, for example, can use a liquid crystal display device. The speaker 22 is for listening to voice, and the microphone 20 is a part for inputting the voice of the operator.
[0026]
The operation unit 18 includes a numeric keypad 18C, a button 18A for making a call, a button 18B for hanging up, and the like.
[0027]
The housing 12 of the mobile phone 10 is made of plastic, for example.
[0028]
The internal structure of the mobile phone 10 is shown in FIGS. The casing 12 of the mobile phone 10 includes a printed circuit board 60, a battery 100, a heat spreader 63, a heat insulating and electrically insulating member 64, a heat conductor 66, a power receiving coil 70, and a second ceramic member 73.
[0029]
The printed circuit board 60 is attached to the inside of the housing 12, and the printed circuit board 60 has a plurality of electronic components 74 mounted thereon. The electronic component 74 and the printed circuit board 60 constitute a circuit unit 75.
[0030]
As described above, the housing 12 is made of plastic. For example, at least a portion in the vicinity of the power receiving coil 70 is made of plastic, and the other portion can be made of metal such as a metal such as a magnesium alloy. .
[0031]
The lower part of the housing 12 is an insertion part 25 for being detachably fitted to the mounting holding part 80 on the power transmission device 50 side. At least the insertion part 25 is made of plastic. The other part except the insertion part 25 of the housing 12 may be a plastic, for example, or a metal such as a magnesium alloy.
[0032]
A battery 100 shown in FIGS. 1 and 2 is a secondary battery that can be repeatedly charged, for example, a lithium ion battery.
[0033]
The power receiving coil 70 is fixed to the second ceramic member 73. The power receiving coil 70 is positioned so as to protrude into the housing 12, and a heat insulating and electrically insulating member 64 is disposed between the power receiving coil 70 and the battery 100. The power receiving coil 70 is electrically connected to the printed circuit board 60 side, but the battery 100 is also electrically connected to the printed circuit board 60. In order to insulate heat and electricity from the power receiving coil 70, a heat insulating and electrically insulating member 64 is disposed between the battery 100 and the power receiving coil 70. Thereby, the battery 100 is protected from the heat generated by the power receiving coil 70, and electrical insulation can be secured.
[0034]
The second ceramic member 73 is thermally connected to the heat spreader 63 via a heat conductor 66 as a second heat conducting member. As a result, heat generated when the power receiving coil 70 is operated is transmitted to the second ceramic member 73, and this heat is transmitted from the second ceramic member 73 to the heat spreader 63 through the heat conductor 66. The heat spreader 63 can release the heat of the power receiving coil 70 to the space in the housing 12.
[0035]
Next, the structure of the power transmission device 50 shown in FIGS. 1 and 2 will be described.
[0036]
The power transmission device 50 includes a main body 90, also called a cradle, a control circuit unit 93, a heat insulating and electrically insulating member 95, a heat sink 97, a heat conductor 99 as a first heat conducting member, a power transmitting coil 101, and a first ceramic member 103. ing.
[0037]
The control circuit unit 93 includes a printed circuit board 105 and a plurality of electronic components 107, and the printed circuit board 105 is configured to be electrically connected to an AC power supply 113 through a power cord 111.
[0038]
The power transmission coil 101 is electrically connected to the circuit board 105, and the power transmission coil 101 generates electromagnetic induction and transmits power to the power reception coil 70 in a non-contact manner by supplying power from the AC power supply 113. As a result, the power receiving coil 70 supplies power to the battery 100, for example, supplies power to the liquid crystal display unit as an example of a display unit (not shown), or supplies power to the circuit unit 75. It has become.
[0039]
The heat generated when the power transmission coil 101 is operated is thermally transmitted to the heat sink 97 through the first ceramic member 103 and the heat conductor 99. The heat sink 97 releases the heat that is sent in the main body 90. Thereby, the heat of the power transmission coil 101 can be reliably released using the heat sink 97.
[0040]
The mounting holding portion 80 of the main body 90 has at least a portion to which the first ceramic member 103 is attached made of plastic, and the other portion may be made of plastic or a metal such as magnesium alloy. There may be.
[0041]
A heat insulating and electrically insulating member 95 is disposed between the power transmission coil 101 and the control circuit unit 93. By disposing the heat insulating and electrically insulating member 95, the heat generated by the power transmission coil 101 is prevented from being directly transmitted to the control circuit section 93 and the electrical insulating property is ensured.
[0042]
As the material of the heat spreader 63 and the heat sink 97, for example, a metal such as copper, aluminum alloy or magnesium alloy having excellent thermal conductivity and good heat dissipation, a graphite block, or the like can be used.
[0043]
Next, the combination of the power transmission coil 101 and the first ceramic member 103, the combination of the power receiving coil 70 and the second ceramic member 73 and the surrounding structure shown in FIGS. 2 and 3 will be described in detail.
[0044]
FIG. 5 is a cross-sectional view showing the combination of the power transmission coil 101 and the first ceramic member 103, the combination of the power receiving coil 70 and the second ceramic member 73, and the peripheral portion thereof.
[0045]
The power transmission coil 101 is fixed to the surface of the first ceramic member 103 so as to protrude into the main body 90 of the power transmission device 50. Similarly, the power receiving coil 70 is fixed on the surface of the second ceramic member 73 so as to protrude inside the insertion portion 25 of the housing.
[0046]
Both the first ceramic member 103 and the second ceramic member 73 are, for example, disk-shaped members. The first ceramic member 103 and the second ceramic member 73 can employ, for example, alumina, aluminum nitride, silicon nitride, silicon carbide or the like, but are not necessarily limited to these materials.
[0047]
The thermal conductivities of alumina, silicon nitride, aluminum nitride, and silicon carbide are 20 to 40 W / mK, 90 W / mK, 170 to 200 W / mK, and 100 to 300 W / mK, respectively, which are more than 100 times that of plastic. Has thermal conductivity.
[0048]
Although ceramics are generally said to be vulnerable to impact, silicon nitride has a large bending strength of 700 to 1100 MPa and fracture toughness of 5 to 7 MPa · m ^1/2. Since it can be made thinner and the gap between the power receiving coil and the power transmitting coil can be narrowed, the charging efficiency can be increased.
[0049]
As shown in FIG. 5, when the portion 90A of the main body 90 and the insertion portion 25 of the housing are made of plastic, a two-layer structure of the first ceramic member 103 and plastic is adopted as shown in FIG. , we adopt a two-layer structure of the second ceramic member 73 and the plastic.
[0050]
That is, in order to give the first ceramic member 103 and the second ceramic member 73 impact resistance against an external force such as dropping, a two-layer structure of a ceramic member and a plastic member is employed. .
[0051]
Specifically, as shown in FIG. 5, the first ceramic member 103 is fitted and attached to the first mounting recess 90B of the main body portion 90A. Similarly, the second ceramic member 73 is fitted and attached to the second mounting recess 25B of the insertion portion 25 of the housing. The first mounting recess 90B has a first bottom portion 90C, and the first ceramic member 103 is fitted in close contact with the first bottom portion 90C. Similarly, the first mounting recess 25B has a second bottom 25C, and the second ceramic member 73 is fitted in close contact with the second bottom 25C. An adhesive can be used when the ceramic member is attached to these bottoms.
[0052]
By doing so, the first ceramic member 103 has a two-layer structure with the plastic layer 90D, and the second ceramic member 73 has a two-layer structure with the plastic layer 25D.
[0053]
The first ceramic member 103, the power transmission coil 101, the second ceramic member 73, and the power reception coil 70 are arranged around the central axis CL. The center axis CL has a predetermined angle with respect to the vertical direction of the main body 90 of the power transmission device 50 as shown in FIG. That is, the mounting holding portion 80 has a concave shape so that the insertion portion 25 of the housing of the mobile phone 10 can be inserted and held detachably by being inclined by an angle θ formed in a direction perpendicular to the central axis CL. ing.
[0054]
Thus, since the power transmission coil 101 is fixed to the first ceramic member 103 and the power reception coil 70 is fixed to the second ceramic member 73, the heat generated by the power transmission coil 101 is a plastic part. There is no stagnation, and heat can be dispersed through the first ceramic member 103, the heat conductor 99 and the heat sink 97 as shown in FIG. Similarly, the heat generated by the power receiving coil 70 can be dispersed by the heat spreader 63 via the second ceramic member 73 and the heat conductor 66.
[0055]
The first ceramic member 103 and the second ceramic member 73 serve as partition plates for the power transmission coil 101 and the power reception coil 70, and the insertion portion of the mobile phone 10 with respect to the mounting holding portion 80 of the main body 90 of the power transmission device 50. in the portion 25 is pressed against, these first ceramic member 103 and the second ceramic member 73 are located.
[0056]
In FIG. 2, when the main body 90 of the power transmission device 50 and the casing 12 of the mobile phone 10 are made of plastic as described above, it may be difficult to disperse the heat generated by the power transmission coil 101 and the power reception coil 70. However, in this case, the heat of the power transmission coil 101 is conducted only to the heat sink 97, and the heat of the power receiving coil 70 is conducted only to the heat spreader 63. Therefore, as shown in FIG. It is effective to dispose heat by arranging 66.
[0057]
The material of the heat conductor 99 as the first heat conducting member and the heat conductor 66 as the second heat conducting member can be a metal material such as copper foil or aluminum foil, a graphite sheet, or the like.
[0058]
When a graphite sheet is used, a polymer sheet is preferably laminated on the graphite sheet. By laminating this polymer sheet, electrical insulation can be obtained even with a conductor such as a graphite sheet. In order to efficiently transfer heat from the first ceramic member and the second ceramic member to the heat conductors 99 and 66, the heat sink 97 and the heat spreader 63 are laminated with a polymer sheet on the heat conductors 99 and 66. It is better to thermally connect the parts that are not.
[0059]
The graphite sheet referred to here, which is carbon, as shown in FIG. 7 took a layered structure, the thermal conductivity in the plane of the sheet is higher than metal, such as 1000W / mK and a copper or aluminum from 400, In addition, it is a light material with a density of about 1 g / cm ³ . At the same time, it is a material with high electrical conductivity. By using this graphite sheet as a heat conductor, it is possible to efficiently transfer heat.
[0060]
As described above, the first ceramic member 103 adopts a two-layer structure with the plastic layer 90D, and the second ceramic member 73 has a two-layer structure with the plastic layer 25D. 2 can prevent the first ceramic member 103 and the second ceramic member 73 from being broken by the impact when the mobile phone 10 shown in FIG. 2 is inserted and held in the mounting holding portion 80 of the main body 90.
[0061]
Heat conductors 99 and 66 are employed to allow the first ceramic member 103 and the second ceramic member 73 to dissipate heat from the power transmission coil 101 and the power reception coil 70 satisfactorily. The heat is efficiently radiated through 97, and the heat of the power receiving coil 70 can be efficiently radiated by the heat spreader 73. This prevents the plastic main body 90 from being deformed or the housing 12 from being deformed by heat generated from the coil.
[0062]
Further, since the heat of the power receiving coil 70 is always radiated when the casing 12 of the mobile phone 10 is removed from the mounting holding unit 80, even if the hand touches the insertion portion 25 near the power receiving coil 70, low temperature burns occur. Can completely prevent such a phenomenon.
[0063]
Further, for example, the control circuit unit 93 having a low heat-resistant temperature disposed in the vicinity of the power transmission coil 101 can be insulated by the heat insulation and electrical insulation member 95, and electrical insulation can be secured. As shown in FIG. 1, even if there is a member having a low heat-resistant temperature, such as a battery 100 or a liquid crystal display unit, in the vicinity of the power receiving coil 70, the heat insulation and the electric insulation member 64 provide heat insulation and electric insulation. Sex can be secured.
[0064]
Further, a heat spreader is placed in the mobile telephone 10, since placing the heat sink in a power transmission device 50, Ru can be released heat of the power receiving coil and the transmitting coil securely respectively.
[0065]
As described above, the non-contact charging apparatus can ensure a stable charging operation.
[0066]
By the way, the present invention is not limited to the above embodiment.
[0067]
In the embodiment described above, a mobile phone which is a so-called portable electronic device is taken as an example of the electronic device of the contactless charging apparatus 200.
[0068]
In the above-described embodiment, the first ceramic member is disposed in the power transmission device and the second ceramic member is disposed in the electronic device. However, the present invention is not limited to this, and the following may be employed.
[0069]
The first glass member can be disposed instead of the first ceramic member of the power transmission device, and the second glass member can be disposed instead of the second ceramic member of the electronic device. The shapes of the first glass member and the second glass member can be the same as the shapes of the first ceramic member and the second ceramic member.
[0070]
The first glass member and the second glass member can be made of a material having electrical insulation and high thermal conductivity, like the first ceramic member and the second ceramic member. .
[0071]
However, the present invention is not limited to this, and the electronic device may naturally be a portable information terminal (PDA), other information-related device, or a portable electrical product other than the information-related device.
[0072]
【The invention's effect】
As described above, according to the present invention, it is possible to prevent the temperature increase of the power transmission coil and the power reception coil, and it is possible to achieve downsizing and stable non-contact charging. Moreover, the impact resistance of the ceramic member can be improved against an impact that occurs when an electronic device that is an object to be charged is attached to or detached from the power transmission device.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a preferred embodiment of a contactless charging apparatus of the present invention.
FIG. 2 is a cross-sectional view showing a central portion of the non-contact charging apparatus of FIG.
FIG. 3 is a front view illustrating an example of a mobile phone.
FIG. 4 is a rear view showing an example of a mobile phone.
FIG. 5 is a cross-sectional view showing the vicinity of a power transmission coil, a first ceramic member, a power receiving coil, and a second ceramic member.
FIG. 6 is a diagram showing an example of a layer structure of a graphite sheet.
FIG. 7 is a cross-sectional view showing a conventional non-contact charging device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Mobile phone (an example of electronic device), 12 ... Housing of electronic device, 50 ... Power transmission device, 70 ... Power receiving coil, 73 ... Second ceramic member, 80 ... Mounting holding part, 90 ... main body of power transmission device, 63 ... heat spreader, 64, 95 ... heat insulation and electrically insulating member, 66 ... heat conductor (second heat conducting member), 97 ... Heat sink, 99 ... heat conductor (first heat conducting member), 101 ... power transmission coil, 103 ... first ceramic member, 200 ... non-contact charging device

Claims (4)

Power transmission device by detachably mounting the electronic device is a charging object is a non-contact charging apparatus for charging in non-contact with the electronic device from the power transmitting device, the power transmitting device, the body And a first ceramic member disposed on the main body, and a power transmission coil provided on the first ceramic member, the electronic device is mounted on the housing, and the electronic device is mounted on the power transmission device In this state, the second ceramic member disposed in the housing portion at a position corresponding to the first ceramic member, and the second ceramic member are provided with electric power by electromagnetic induction from the power transmission coil. possess a power receiving coil for receiving a non-contact, and
The electronic device is a portable electronic device, and the main body of the power transmission device includes a recessed mounting holder for inserting and holding the insertion portion of the housing of the electronic device, and the power transmission device The first ceramic member and the power transmission coil are positioned on the mounting holding portion, and the second ceramic member and the power receiving coil are positioned on the insertion portion of the casing of the electronic device,
The main body of the power transmission device and the casing of the electronic device are made of plastic,
The first ceramic member is fitted and fitted into a first mounting recess having a first bottom formed from the inner surface side of the main body of the power transmission device, and the first ceramic member and the first bottom of the main body. And the second ceramic member is fitted into a second mounting recess having a second bottom formed from the inner surface side of the housing of the electronic device, and is attached to the second ceramic member. The second bottom of the electronic device is laminated,
The power transmission device is disposed in the main body and transmits heat generated by the power transmission coil, and is disposed in the main body and thermally connected to the first heat conductive member. A heat sink that dissipates the heat, and the electronic device is disposed in the housing and transmits a heat generated by the power receiving coil; and the second heat conductive member that is disposed in the housing and the second heat conduction member. A non-contact charging apparatus comprising: a heat spreader that dissipates the heat that is thermally connected to the heat conducting member . 2. The contactless charging apparatus according to claim 1, wherein the first heat conducting member and the second heat conducting member are conductive metal thick films or graphite sheets. 2. The non-contact according to claim 1, wherein a heat insulating and electrically insulating member that insulates the power transmission coil and other elements in the main body and has electrical insulation is disposed in the main body of the power transmission device. Charging device. 2. The non-contact according to claim 1, wherein a heat insulating and electrically insulating member that insulates the power receiving coil and other elements in the housing and has electrical insulation is disposed in the housing of the electronic device. Charging device.

Images