JP4412402B2 - Coil unit and electronic equipment - Google Patents

Description

  The present invention relates to a coil unit, electronic equipment, and the like related to contactless power transmission using a coil.

  Contactless power transmission is known that uses electromagnetic induction to enable power transmission even without a metal part contact. As an application example of this non-contact power transmission, charging of a mobile phone or charging of household equipment (for example, a handset of a telephone) has been proposed.

  In power transmission by electromagnetic induction, the amount of deviation of the coil on the coaxial line greatly affects the amount of transmission. Therefore, it is important that the charger is installed at an appropriate position of the charger. As techniques for achieving this, the techniques disclosed in Patent Documents 1 to 3 have been proposed.

  Patent Document 1 discloses a technique for preventing foreign matter from being inserted between a charger and a charger and ensuring charging at an appropriate position.

  Patent Document 2 discloses a technique of electromagnetic coupling by fitting an air-core solenoid coil to a convex core.

Patent Document 3 discloses a technology in which a primary side core is inserted into an air core portion of a secondary side coil to perform primary / secondary electromagnetic coupling.
Japanese Patent Laid-Open No. 6-311659 JP-A-7-322534 However, all of the techniques disclosed in Patent Documents 1 to 3 have a coil provided with a core.

  Some aspects of the present invention are to provide a thin coil unit with improved transmission efficiency, an electronic device using the coil unit, and the like.

  A coil unit according to an aspect of the present invention includes a planar air-core coil having an air-core portion, a printed wiring board disposed on a transmission surface side of the planar air-core coil, and the planar air-core coil. A magnetic sheet disposed on a non-transmission surface opposite to the transmission surface, and the planar air-core coil is provided with a lead wire for drawing an inner end wiring from the transmission surface side. The printed circuit board is provided with an accommodating portion for accommodating the lead wire.

  The lead wire at the inner end of the coil increases the thickness of the planar air-core coil. However, since this lead wire is accommodated in the housing portion of the wiring printed board, the entire thickness of the lead wire contributes to the thickness of the coil unit (planar air-core coil + magnetic sheet + wiring printed board). Can be prevented, and the thickness can be reduced.

  In one aspect of the present invention, the printed wiring board can be provided with a through-hole facing the air core portion of the planar air core coil.

  When a through hole is provided in the printed wiring board, a coil positioning protrusion is provided in a casing in which the coil unit is accommodated, so that the coil positioning protrusion is inserted into the air core of the planar air core coil through the through hole. The coil unit can be positioned with respect to the casing.

  In this case, the diameter of the through hole of the printed wiring board is smaller than the diameter of the air core portion of the planar air core coil, and the wiring printed board is a surface on which the planar air core coil is overlapped. A temperature detector can be provided around the through hole and inside the periphery of the air core.

  Instead, a temperature detector can be provided on the surface opposite to the surface on which the printed wiring board is overlapped with the planar air-core coil and at the peripheral position of the through hole.

  In either case, the temperature can be detected in the vicinity of the air-core portion of the planar air-core coil, so that the temperature of the foreign material when the foreign material is mixed between the electronic device and the charger can be accurately measured. It is possible to take measures such as turning off the power when the temperature rises above this value.

  Another aspect of the present invention defines an electronic device including a housing that houses the coil unit described above. In this case, the casing of the electronic device is formed on the inner surface thereof, and enters the air core portion of the planar air core coil through the through hole of the wiring printed board, and the planar air core. A coil positioning protrusion for positioning the coil can be provided.

  In the coil unit according to another aspect of the present invention, a planar air-core coil having an air-core portion, a magnetic sheet disposed on the non-transmission surface side opposite to the transmission surface of the planar air-core coil, A printed wiring board disposed on the magnetic sheet on a surface opposite to a surface on which the magnetic sheet is superposed on the planar air-core coil, and the planar air-core coil includes the magnetic sheet and A lead wire is provided for drawing out the wiring at the inner end of the coil from the facing side, and the wiring printed board is provided with a receiving portion for receiving the lead wire via the magnetic sheet. .

  Also in this case, it is possible to prevent the entire thickness of the lead wire from contributing to the thickness of the coil unit (planar air-core coil + magnetic sheet + wiring printed circuit board), and the thickness can be reduced.

  In the electronic device including this coil unit, the wiring printed board is not provided between the planar air-core coil and the housing of the electronic device or the like, and therefore the through hole may not be provided in the printed wiring board. The coil positioning protrusion provided on the housing of the electronic device is inserted into the air core of the planar air-core coil so that the coil unit can be positioned with respect to the housing. Further, since the planar air-core coil can be disposed in contact with the inner surface of the casing, the distance from the counterpart coil unit is shortened, and the transmission efficiency is improved.

  A coil unit according to still another aspect of the present invention can integrally have a coil housing case that is a part of the above-described charger or electronic device.

  For example, the coil unit according to still another aspect of the present invention includes a planar air-core coil having an air-core portion, a coil housing case disposed on the transmission surface side of the planar air-core coil, and the planar shape. A wiring printed circuit board disposed on the non-transmission surface side of the air-core coil, and the wiring printed circuit board is fixed to the coil housing housing so that the space between the coil housing housing and the wiring printed circuit board is The planar air-core coil is accommodated in the planar air-core coil, and the planar air-core coil is provided with a lead wire for drawing out the wiring at the inner end of the coil from the transmission surface side. An accommodation part for accommodating the wire is provided.

  This can provide a rigid structure in which a planar air-core coil is sandwiched between the coil housing case and the wiring printing machine plate before being incorporated into the casing of the electronic device or the charger, and the incorporation of the coil is improved. . In addition, it is possible to prevent the entire thickness of the lead wire from contributing to the thickness of the coil unit, and the thickness can be reduced.

  In particular, with this structure, it is possible to prevent the coil from being unwound or to be deformed during transportation or coil assembly work, and it is possible to prevent deformation of the coil that adversely affects electrical characteristics such as inductance.

  In this structure, a positioning protrusion for positioning the planar air-core coil can be provided in the coil housing case.

  Moreover, you may further have the magnetic sheet arrange | positioned at the said non-transmission surface side of the said planar air-core coil. If it carries out like this, the said planar air-core coil and the said magnetic sheet will be accommodated between the said coil accommodation housing | casing and the said wiring printed circuit board.

  In the electronic device including the coil unit, the outer surface of the coil housing can be flush with the outer surface of the housing of the electronic device. That is, the coil housing case becomes a part of the case of the electronic device, and the surface placed on the charger is flat.

  A positioned portion to be positioned by the charger can be formed in the housing of the electronic device described above. Thereby, positioning with an electronic device and a charger is attained, and transmission efficiency improves.

  Note that the structure for absorbing the thickness of the lead wire described above can also be applied to a charger.

  A coil unit according to still another aspect of the present invention includes a planar air core coil having an air core part, a printed wiring board disposed on a transmission surface side of the planar air core coil, and a non-planar coil. A magnetic sheet disposed on the transmission surface side, and the planar air-core coil is provided with a lead-out wire for drawing out wiring from the inner end of the planar air-core coil on the transmission surface side, The wiring printed board is provided with an accommodating portion for accommodating the lead wire.

A coil unit according to still another aspect of the present invention includes a planar air core coil having an air core portion, a non-transmission surface side of the planar air core coil, and a first surface being the planar air core. A magnetic sheet superposed on the coil, a wiring printed circuit board disposed on the second surface of the magnetic sheet,
The planar air-core coil is provided with a lead-out line for drawing out wiring from the inner end of the planar air-core coil on the non-transmission surface side, and the lead-out wire is provided on the wiring printed board It is characterized in that an accommodating portion for accommodating the is provided.

  Even in the coil unit according to these two aspects, the same operation and effect as the coil unit according to one aspect of the present invention can be achieved.

  A coil unit according to still another aspect of the present invention includes a planar air-core coil having an air-core portion, a coil housing case disposed on the transmission surface side of the planar air-core coil, and the planar air-core. A printed wiring board disposed on the non-transmission surface side of the coil, wherein the printed wiring board is fixed to the coil housing case, and the planar air-core coil includes the coil housing case, the printed wiring board, The planar air-core coil is provided with a lead wire for drawing out wiring from the inner end of the planar air-core coil on the transmission surface side. An accommodating portion for accommodating the lead wire is provided.

  Also in the coil unit according to this aspect, the above-described coil unit according to still another aspect of the present invention, which can achieve the same operation and effect as those in which the coil accommodating housing is provided with the accommodating portion.

  An electronic apparatus according to still another aspect of the present invention is defined to include these coil units.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are indispensable as means for solving the present invention. Not necessarily.

1. Charging System FIGS. 1 and 2 are diagrams schematically showing a charging system including a charger 10 and an electronic device charged by the charger 10 such as a mobile phone 20. FIG. 1 shows a mobile phone 20A placed horizontally on the charger 10A. Charging from the charger 10A to the mobile phone 20A is performed by non-contact power transmission using an electromagnetic induction effect generated between the coil of the coil unit 12 of the charger 10A and the coil of the coil unit 22 of the mobile phone 20A. .

Mobile phone 20A is (in a broad sense portion to be positioned) positioning recess shown in FIG. 1 is omitted, (in a broad sense positioning portion) positioning protrusion of the charger 10A is mounted is positioned by 14. Since the mobile phone 20A is mounted on the charger 10A after positioning as described above, the mobile phone 20A can be mounted on the charger 10A at an appropriate position, and transmission efficiency can be improved.

  Here, as shown in FIG. 1, the facing surface side when the coil units 12 and 22 face each other and perform contactless power transmission is referred to as a transmission surface. The coil unit 12 of FIG. 1 has a transmission surface on the upper side, and the coil unit 22 has a transmission surface on the lower side. A surface opposite to the transmission surface is referred to as a non-transmission surface.

2. Coil unit structure 2.1. Coil Unit with Leading Line at Inner End of Coil as Transmission Surface Hereinafter, the coil units 12 and 22 will be described more specifically by taking a thin coil unit 22 particularly suitable for the mobile phone 20 as an example.

  FIG. 2 is a perspective view of the coil unit 22. FIGS. 3A and 3B are cross-sectional views schematically showing cross sections of two types of coil units 22 taken along line V11-V11 in FIG. 4 and 5 are exploded perspective views of the coil unit 22 shown in FIGS. 3 (A) and 3 (B).

  The coil unit 22 has a planar air-core coil 30B, a magnetic sheet 40B, and a magnetic flux leakage prevention member 50 on a side opposite to the housing 20a side of a wiring printed board (for example, a flexible wiring board) 60 via a double-sided tape 70. Are provided sequentially.

  As shown in FIGS. 4 and 5, the planar air-core coil 30 </ b> B is provided with a lead wire 32 for leading the inner end from the transmission surface side. The lead wire 34 is drawn from the outer end of the planar air-core coil 30B. The double-sided tape 70 and the printed wiring board 60 disposed on the coil surface side from which the lead wire 32 is drawn out are provided with receiving portions 60a and 70a for receiving the lead wire 32 in a cutout manner. The accommodating parts 60a and 70a are formed with long holes, for example. As shown in FIG. 6, the lead wire 32 is accommodated so as to be accommodated in the accommodating portion 60a when viewed from the wiring printed board 60 side. By housing the lead wire 32 in the housing portions 60a and 70a in this way, it is possible to reduce the lead wire 32 from contributing to the thickness of the coil unit 22 itself or from contributing to the thickness.

  4 and 5, the printed wiring board 60 is provided with a through hole 60b at a position facing the air core portion 31B of the planar air core coil 30B. The diameter of the through hole 60b is set smaller than the diameter of the air core portion 31B of the planar air core coil 30B. The printed wiring board 60 is on the side facing the planar air-core coil 30B (the example in FIGS. 3A and 4) or the opposite side (the example in FIGS. 3B and 5), and is empty. A temperature detector 80 such as a thermistor is provided inside the core 31B. Thus, by providing the temperature detection unit 80 on the inner side of the air core 31B, the temperature of the foreign matter that has entered between the charger 10 and the mobile phone 20 can be detected. In particular, since the foreign matter that has entered the vicinity of the air core portion 31B having a high magnetic flux density generates a lot of heat due to eddy current, the temperature of the foreign matter can be accurately detected.

  The side surface of the magnetic sheet 40B can be covered with a magnetic flux leakage prevention member 50 as shown in FIGS. 3 (A) and 3 (B). As a result, it is possible to prevent the magnetic powder 40B from corroding and the magnetic powder from being broken due to chipping of the magnetic sheet.

  Further, the magnetic sheet 40 </ b> B of the mobile phone 20 can be made larger than the outer shape of the planar air-core coil 30 </ b> A of the charger 10. Thereby, it can prevent that an eddy current loss arises in the rechargeable battery and the metal of a circuit board inside the coil unit 22, and can improve the transmission efficiency of electric power.

2.2. FIG. 7 is an exploded perspective view showing a second configuration example. The coil unit has a lead wire at the inner end of the coil as a non-transmission surface side. In this configuration example, the lead wire 32 from the inner end of the planar air-core coil 30 is provided on the non-transmission surface side opposite to the transmission surface side (housing side).

  As shown in FIG. 7, a magnetic sheet 40 </ b> B is provided via a double-sided tape 72 on the non-transmission surface side (lower side in FIG. 7) opposite to the transmission surface side of the planar air-core coil 30 </ b> B. A printed wiring board 64 is provided under the magnetic sheet 40B. That is, when the surface on which the magnetic sheet 40B is overlapped with the planar air-core coil 30B is referred to as a first surface, the wiring printed board 64 is overlapped on the second surface of the magnetic sheet 40B. The printed wiring board 64 is provided with an accommodating portion (through hole or concave portion) 64 a at a position corresponding to the lead wire 32. Thus, by providing the accommodating part 64a, the thickness by the lead wire 32 can be absorbed in the accommodating part 64a through a deformation | transformation of the magnetic sheet 40B.

  Further, in the structure of FIG. 7, the transmission surface of the planar air-core coil 30 is disposed so as to face the inner surface of the casing of the mobile phone 20, so that the distance between each coil of the primary coil unit 12 and the secondary coil unit 22. Can be expected to improve transmission efficiency. Further, if the positioning protrusion protruding from the inner surface of the casing of the mobile phone 20 is inserted into the air core portion of the planar air core coil 30, the planar air core coil 30 can be positioned with respect to the housing. Therefore, in this case, the printed wiring board 64 does not require a through hole for positioning.

2.3. FIG. 8 and FIG. 9 are exploded perspective views of a coil unit including a part of the casing 20a of the mobile phone 20 shown in FIG. It is. The coil housing case is a part of the external housing of the charger 10 or the electronic device 20 described above, and the outer surface of the external housing is flush with the outer surface of the coil housing case. The configuration examples shown in FIGS. 8 and 9 are examples in which the lead wire 32 from the inner end of the planar air-core coil 30B is provided on the transmission surface side (housing side). Instead, a lead wire 32 from the inner end of the planar air-core coil 30B may be provided on the non-transmission surface side (magnetic sheet side).

  As shown in FIGS. 8 and 9, a planar air-core coil 30 </ b> B, a magnetic sheet 40 </ b> B, and a single-sided tape 74 are provided between the coil housing 20 a and the printed wiring board 66. However, the magnetic sheet 40b is not essential in this embodiment. In the coil housing case 20a, a housing portion 20b for housing the lead wire 32 from the inner end of the planar air-core coil 30B and a housing portion 20c for housing the lead wire 34 from the outer end of the planar air-core coil 30B. Is provided. The lead wire 32 at the inner end of the coil is further drawn out to the side opposite to the transmission surface and connected to the printed wiring board 66.

  10-13 is a figure which shows typically the manufacturing process of a coil unit. As shown in FIG. 10, the planar air-core coil 30B is housed and incorporated inside the ring-shaped rib 20d of the coil housing case 20a. This positioning is performed by using a positioning projection 28 provided on the coil housing case 20a. Next, as shown in FIG. 11, the magnetic sheet 40B is affixed so that it may overlap with the planar air-core coil 30B. Next, as shown in FIG. 12, the single-sided tape 74 is used to cover the soft magnetic metal powder from the outer end of the magnetic sheet 40B so that it does not drop onto the substrate provided below it. Next, as shown in FIG. 13, a substrate 66 is attached. Then, in order to prevent the material (soft magnetic metal powder) of the magnetic sheet from leaking from the accommodating portions 20b and 20c provided in the housing 20a, the accommodating portions 20b and 20c are sealed with an adhesive or a molding material.

  Especially in this structure, compared with the coil unit shown in FIGS. 2 to 7, it is possible to prevent the coil from being unwound and the coil from being deformed during transportation and coil assembly work, which has an adverse effect on electrical characteristics such as inductance. A certain coil can be prevented from being deformed.

  2 to 13 can be applied to the coil unit 12 of the charger 10 as well.

(Application example of electronic equipment)
This embodiment can be applied to all electronic devices that perform power transmission and signal transmission. For example, a wristwatch, an electric toothbrush, an electric shaving, a cordless phone, a personal handy phone, a mobile personal computer, a PDA (Personal Digital Assistants) It can be applied to a to-be-charged device and a charging device including a secondary battery such as an electric bicycle.

  Although the present embodiment has been described in detail as described above, those skilled in the art can easily understand that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention. For example, a term described at least once together with a different term having a broader meaning or the same meaning in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings.

  Although the present embodiment relates to contactless power transmission, it can be similarly applied to contactless signal transmission using the electromagnetic induction principle.

It is a figure which shows 1st Embodiment which has a charger and a mobile telephone horizontally placed on it. It is a perspective view of a coil unit. FIG. 5 is a cross-sectional view schematically showing a cross section of the coil unit along the line V11-V11 in FIG. 2. It is a disassembled perspective view of a coil unit. It is a disassembled perspective view of the other example of a coil unit. It is a figure which shows the relationship between the accommodating part of a wiring printed circuit board, and a leader line. It is a disassembled perspective view which shows the other example of a coil unit. It is a disassembled perspective view which shows the coil unit which has a coil storage housing | casing. It is the disassembled perspective view which looked at the coil unit shown in FIG. 8 from another angle. It is a figure which shows typically the 1st manufacturing process of the coil unit shown in FIG. It is a figure which shows typically the 2nd manufacturing process of the coil unit shown in FIG. It is a figure which shows typically the 3rd manufacturing process of the coil unit shown in FIG. It is a figure which shows typically the 4th manufacturing process of the coil unit shown in FIG.

Explanation of symbols

10, 10A charger, 10a housing, 12 coil unit,
14 Positioning part (positioning protrusion), 20, 20A Electronic device (mobile phone),
20a housing, 22 coil unit, 28 coil positioning projection,
30, 30A, 30B Planar air core coil, 30a air core part,
32 coil inner end lead wire, 34 coil outer end lead wire,
40A, 40B magnetic sheet, 50 magnetic flux leakage prevention member, 60 printed wiring board,
62a accommodating portion, 62b through hole, 64 wiring printed board, 64a accommodating portion, 66 substrate,
70 double-sided tape, 70a housing, 72 double-sided tape, 74 single-sided tape,
80 Temperature detector

Claims (8)

A coil having an air core;
A printed wiring board disposed on the transmission surface side of the coil;
A magnetic member disposed on a non-transmission surface opposite to the transmission surface of the coil;
Have
The coil is drawn from the inner end of the coil from the transmission surface side,
The wiring printed board is provided with a housing portion that houses the wiring,
A temperature detection unit is provided on at least a part of one side or the other side of the wiring printed board in a region where the printed wiring board overlaps with the air core when viewed from a direction perpendicular to the one side of the wiring printed board. Coil unit characterized by being. In claim 1,
The wiring printed board is provided with a through-hole facing the air core part of the coil. In claim 2,
The diameter of the through hole of the printed wiring board is smaller than the diameter of the air core part of the coil,
The coil unit is characterized in that the temperature detection unit is provided on the one surface on which the printed wiring board is overlapped with the coil, around the through hole and inside the periphery of the air core. . In claim 2,
The temperature detection unit is provided on the other surface opposite to the one surface on which the wiring printed board is superimposed on the coil, and around the through hole and inside the periphery of the air core portion. Coil unit characterized by being made. An electronic apparatus including a housing that houses the coil unit according to claim 2,
The casing of the electronic device has a coil positioning protrusion that is formed on an inner surface thereof and enters the air core portion of the coil through the through hole of the wiring printed board to position the coil. Electronic equipment characterized by In claim 5 ,
An electronic device characterized in that a positioning portion that is positioned by a charger is formed in a casing of the electronic device. A coil having an air core;
A printed wiring board disposed on the transmission surface side of the coil;
A magnetic member disposed on the non-transmission surface side of the coil;
Including
The coil is drawn from the inner end of the coil from the transmission surface side,
The wiring printed board is provided with a housing portion that houses the wiring,
A temperature detection unit is provided on at least a part of one side or the other side of the wiring printed board in a region where the printed wiring board overlaps with the air core when viewed from a direction perpendicular to the one side of the wiring printed board. Coil unit characterized by being. An electronic device comprising the coil unit according to claim 7 .

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