JP2005033278A - Antenna and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna with excellent reception sensitivity and high productivity that has an excellent flexibility without losing the shape stability of a magnetic core part against deformations and to provide a manufacturing method of the antenna. <P>SOLUTION: The magnetic core 12 is formed by wrapping a thin film magnetic member 12B with a heat shrinkable tube 12A. A coil forming process implementing winding of an insulation coating conductor 1A can easily be carried out with high accuracy without losing the shape stability of the magnetic core part 12C, resulting that the antenna with high productivity can be realized even when the antenna is miniaturized. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an antenna and a method for manufacturing the antenna, and more particularly to an antenna that has excellent reception efficiency and can be miniaturized, and a method for manufacturing the antenna.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a radio timepiece that receives a radio wave including time information such as a scheduled notification signal and corrects the time by using the radio wave is known. In order to correct the time of a radio clock, a radio wave (standard radio wave) having a frequency of 40 Hz or 60 Hz is usually used. In recent years, wristwatches having such a radio timepiece function are becoming widespread, and there is a demand for a small antenna that is excellent in standard radio wave reception and applicable to the size of a wristwatch.
[0003]
As a wristwatch having the above-described radio timepiece function, there is a wristwatch that accommodates a radio wave receiving antenna along the inside of a wristwatch case (see, for example, Patent Document 1).
[0004]
FIG. 5 is a schematic configuration diagram of a wristwatch described in Patent Document 1.
The wristwatch 20 receives a wristwatch case 21, a printed circuit board 22 accommodated in the wristwatch case 21, a stepping motor 23 for arranging the hour hand and maintaining time, and a time transmission propagated by long wave transmission. Receiving circuit 24, power storage device 25 for supplying power to the circuit, and magnetic antenna 26 formed by holding coil 26B on laminated core 26A.
[0005]
The printed circuit board 22 is formed by mounting a processor 22A for driving a timepiece and a plurality of circuit components (not shown), and includes a free space 22C for housing the coil 26B of the magnetic antenna 26, and a power storage device 25. And a concave portion 22B for accommodating the.
[0006]
The magnetic antenna 26 has a laminated core 26 </ b> A in which sheet-like soft iron is laminated to enhance reception sensitivity, and the laminated core 26 </ b> A is provided along the inner wall of the watch case 21. The laminated core 26 </ b> A and the coil 26 </ b> B are formed by soaking and curing a synthetic resin or an adhesive, and are bonded to the end portion of the printed circuit board 22.
[0007]
Further, the magnetic antenna 26 is connected to the receiving circuit 24, and when the processor 22A inputs time transmission via the receiving circuit 24, it compares the deviation with the time displayed by the hands of the clock, and calculates the deviation. In response, the time display is corrected by driving the stepping motor 23 to rotate the hands.
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-64547
[Problems to be solved by the invention]
However, the antenna disclosed in Patent Document 1 has the following problems.
(1) Since a soft iron core is used for the magnetic core, long-wave reception sensitivity is not sufficient, and as a result, it is difficult to apply to small devices because the antenna size is required to obtain sufficient sensitivity. There's a problem. In particular, when the wristwatch case is smaller like a radio timepiece for women, the above-described decrease in reception sensitivity becomes more remarkable.
(2) Since a laminated core is formed by laminating sheet-shaped soft iron and integrating with an adhesive or the like, it is difficult to form the laminated core with high density and accuracy when attempting to reduce the size of the antenna. There is a problem. Also, if the amount of bending of the laminated core becomes large, peeling will occur in the laminated part and the shape stability of the magnetic core part will be lost, so it is difficult to ensure mountability following the miniaturization of the equipment There is also a problem.
[0010]
Therefore, an object of the present invention is to provide an antenna having excellent flexibility without impairing the shape stability of the magnetic core portion due to deformation, excellent reception sensitivity, and good productivity, and a method for manufacturing the same. .
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides, as a first feature, an antenna formed by winding a conducting wire in a coil shape.
A core formed to have flexibility by a highly permeable magnetic material;
A covering portion provided so as to surround the core portion;
There is provided an antenna having a coil portion formed by winding a conductive wire with a predetermined number of turns on the covering portion.
[0012]
According to such a configuration, the coil portion and the core portion are configured to have flexibility while ensuring the reception sensitivity of the antenna.
[0013]
For the core portion, a laminated body in which thin films of magnetic material are laminated with a lamination thickness in accordance with reception characteristics required for an antenna, structural restrictions, and the like can be used.
[0014]
The covering portion can be smoothly inserted into the core portion by using a heat shrinkable tube that shrinks at a shrinkage temperature or higher. Further, after the heat shrinkage, the core portion is reinforced and the antenna portion is given flexibility.
[0015]
By using a self-bonding conductive wire having self-bonding property, the shape stability after forming the coil portion is further enhanced.
[0016]
A coil part enables the deformation | transformation according to various shapes by arrange | positioning and providing several coil parts through the non-winding part of conducting wire in the length direction of a core part.
[0017]
In order to achieve the above object, the present invention has, as a second feature, a first step of laminating a thin magnetic material having high permeability to form a core part,
A second step of inserting the core into a tube-shaped coating material;
A third step of shrinking the coating material to form a magnetic core portion integrated with the core portion;
A fourth step of forming a coil portion by winding a conductive wire on the covering material with the magnetic core portion as an axis, and a fifth step of fixing the conductive wire forming the coil portion and integrating with the magnetic core portion; The manufacturing method of the antenna characterized by including is provided.
[0018]
According to such a manufacturing method, it is possible to stably and easily manufacture a small antenna having flexibility.
[0019]
In the third step, the coating material is thermally shrunk to generate a uniform external force so as to hold the core part, and to prevent the deviation between the magnetic materials due to the deformation of the core part, thereby providing stable electrical characteristics. Can be granted.
[0020]
In the fifth step, the electrical characteristics can be stabilized by fusing the conductive wires having a self-fusing coating and integrating them in a coil shape. Moreover, the coil shape of a conducting wire is prevented from collapsing by fusing the conducting wire wound based on the energization to the conducting wire into a coil shape.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0022]
1A and 1B are partial cross-sectional views of an antenna unit according to the first embodiment. FIG. 1A is an overall view, and FIG. 1B is a partially enlarged view with a part broken away.
As shown in FIG. 1A, the antenna unit 1 has a magnetic core 12 made of a laminate of magnetic material having high permeability and a resin coating, and a frequency band of radio waves received around the magnetic core 12. And a coil 1B formed by an insulation coated conductor 1A such as an enameled wire wound with a number of turns.
[0023]
As shown in (b), the magnetic core portion 12 is integrally formed by covering a core portion 12C formed by laminating a thin film magnetic material 12B having a predetermined thickness with a heat shrinkable tube 12A. 12A adheres the thin-film magnetic material 12B to the periphery of the core portion 12C based on thermal contraction.
[0024]
Further, in the present embodiment, a constant the total amount of insulation coated conductive wire 1A by the coil 1B, the winding part length L ₁ of the coil 1B, no wound portions are formed on both sides of the coil 1B length L ₂ and L _Even when the ratio L ₁ : L ₂ : L ₃ is in the range of the size ratio of 8: 1: 1 to 2: 4: 4, it has been confirmed that good reception sensitivity can be obtained. In addition, it is good also as a structure which forms the coil 1B, without forming a non-winding part from one end of the magnetic core part 12 to the other end.
[0025]
FIG. 2 is a perspective view schematically showing a manufacturing process of the antenna portion. Hereinafter, each manufacturing process will be described.
[0026]
(A) Core part forming step [FIG. 2 (a)]
First, the core portion 12C is formed by laminating a thin film magnetic material 12B made of an amorphous metal having a thickness of 15 μm to a predetermined lamination thickness.
[0027]
(B) Resin coating insertion step [FIG. 2 (b)]
Next, the core portion 12C created in (a) is inserted into the heat shrinkable tube 12A. The heat-shrinkable tube 12A has a length that is greater than the length of the core portion 12C, and an extra length is generated at both ends of the core portion 12C when the core portion 12C is inserted therein.
[0028]
(C) Resin coating integration process [FIG. 2 (c)]
Next, the heat shrinkable tube 12A in which the core portion 12C is inserted is accommodated in a heating machine, and the heat shrinkable tube 12A is contracted by heating to a temperature equal to or higher than the heat shrinkable tube 12A to form the magnetic core portion 12.
[0029]
(D) Coil forming step Next, the insulation coated conductor 1A is densely wound at a predetermined number of turns so as not to generate a gap at a predetermined position of the magnetic core portion 12 to form a coil 1B. The winding of the coil 1B can be performed manually in addition to mechanical winding. The insulation coated conductor 1A is fixed to the coil 1B with an adhesive or the like at the winding start portion and winding end portion.
[0030]
FIG. 3 is an overall view showing a state where the antenna portion is deformed in an arc shape.
The antenna unit 1 according to the present embodiment can be deformed into a shape corresponding to a target device.
[0031]
In order to deform the antenna unit 1 in this manner, the antenna unit 1 and the magnetic core unit 12 are heated in a heater to soften the heat-shrinkable tube 12A and then deformed into a desired shape. After the deformation, the antenna unit 1 is cooled. As a result, the heat-shrinkable tube 12A is hardened again, whereby the magnetic core 12 is held in a desired shape. Further, the familiarity between the heat-shrinkable tube 12A and the insulating coated conductor 1A is improved, and the winding state is also stabilized.
[0032]
According to the first embodiment described above, the following effects are obtained.
(1) Since the core portion 12C is integrated by the heat shrinkable tube 12A covering the surface of the magnetic core portion 12, the core portion is held and shape stability can be ensured and excellent flexibility is obtained. Thus, the antenna unit 1 can be deformed into an arbitrary shape according to the target device. In addition, the coil forming process based on the winding of the insulation coated conductor 1 </ b> A can be easily performed with high accuracy on the magnetic core portion 12, and the productivity is excellent even if the size is small.
(2) Since the amorphous metal having a high initial permeability is used as the thin-film magnetic material 12B, the standard radio wave reception sensitivity is excellent. As a result, the size can be reduced as compared with the magnetic core portion 12 using a magnetic material made of other materials such as soft iron, and the mountability can be secured following the downsizing of the device.
(3) By changing the number of layers of the thin-film magnetic material 12B and the number of turns of the insulation coated conductor 1A, matching with the receiving circuit can be easily taken, and the trouble of adjusting the sensitivity in the receiving circuit is eliminated. It becomes possible to simplify the entire circuit configuration.
[0033]
In the first embodiment described above, the configuration using the insulation coated conductor 1A such as enameled wire as the winding has been described, but instead of this, the upper layer of the enameled wire is polyamide-based, butyral-based, epoxy-based or the like. A self-bonding conductive wire provided with a fusion layer composed of the main component may be used.
[0034]
In this case, after forming the coil 1B in the coil forming step described above, the antenna portion 1 and the magnetic core portion 12 are heated in a heater to heat-fuse the fusion layer, and the fusion layer is heat-shrinkable tube 12A. It is made to unite with magnetic core part 12 by making it fuse. The fusion layer can be fused by solvent treatment using a solvent such as alcohol in addition to the heat treatment described above.
[0035]
Further, the fused layer of the self-bonding lead may be fused based on a solvent treatment such as immersion in an organic solvent or spraying depending on the material. Further, a combination of heat treatment and solvent treatment, or heat treatment based on energizing the self-bonding conductor may be used in combination. Further, after the antenna portion 1 is deformed, an insulating resin may be attached to reinforce the adhering state.
[0036]
FIG. 4A is an overall view of the antenna unit according to the second embodiment.
This antenna unit 1 is provided with two coils 1B on a magnetic core part 12, and an unwrapped portion 1C of an insulation coated conductor 1A is provided between the two coils 1B. In this way, even if a plurality of coils 1B are provided via the unwinding portion 1C, good reception sensitivity can be obtained.
[0037]
FIG. 4B is a schematic configuration diagram illustrating a housing state of the antenna unit.
The antenna unit 1 according to the second embodiment has good mountability even for a shape having an acute angle portion such as the rhombus-shaped wristwatch case 21 shown in the figure, and an excellent reception sensitivity of standard radio waves is obtained. Note that the watch case 21 having a shape other than the rhombus can be mounted, and is effective for application to a small device other than the watch. The antenna unit 1 can also be deformed into an S shape or a “<” shape.
[0038]
【The invention's effect】
As described above, according to the antenna of the present invention and the manufacturing method thereof, since the magnetic core portion integrated with the core portion and the covering portion of the magnetic material having high permeability is provided, and the coil portion is provided on the outer periphery thereof, It has excellent flexibility without impairing the shape stability of the magnetic core portion due to deformation, has excellent reception sensitivity, and can improve productivity.
[Brief description of the drawings]
FIGS. 1A and 1B are partial cross-sectional views of an antenna unit according to a first embodiment of the present invention, in which FIG. 1A is an overall view and FIG.
FIG. 2 is a perspective view schematically showing a manufacturing process of the antenna portion.
FIG. 3 is an overall view showing a state where an antenna portion is deformed in an arc shape.
FIG. 4A is an overall view of an antenna unit according to a second embodiment.
(B) is a schematic block diagram which shows the accommodation state of an antenna part.
5 is a schematic configuration diagram of a wristwatch described in Patent Document 1. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, Antenna part 1A, Insulation-coated conductor 1B, Coil 1C, Unwinding part 12, Magnetic core part 12A, Heat shrinkable tube 12B, Thin film magnetic material 12C, Core part 20, Wristwatch 21, Watchcase 22, Printed circuit board 22A , Processor 22B, recess 22C, free space 23, stepping motor 24, receiving circuit 25, power storage device 26, magnetic antenna 26A, laminated core 26B, coil

Claims (9)

In an antenna formed by winding a conducting wire in a coil shape,
A core formed to have flexibility by a highly permeable magnetic material;
A covering portion provided so as to surround the core portion;
An antenna comprising: a coil portion formed by winding a conducting wire at a predetermined number of turns on the covering portion. The antenna according to claim 1, wherein the core portion is formed of a laminated body formed by laminating thin films of the magnetic material. The antenna according to claim 1, wherein the covering portion is formed of a heat shrinkable tube that shrinks at a shrinkage temperature or higher. The antenna according to claim 1, wherein the conductive wire is a self-bonding conductive wire having self-bonding properties. 2. The antenna according to claim 1, wherein the coil portion is provided by arranging a plurality of coil portions in a length direction of the core portion via a non-winding portion of the conducting wire. A first step of laminating a thin magnetic material having high permeability to form a core;
A second step of inserting the magnetic core into a tube-shaped coating material;
A third step of shrinking the coating material to form a magnetic core portion integrated with the core portion;
A fourth step of forming a coil portion by winding a conductive wire on the covering material with the core portion as an axis, and a fifth step of fixing the conductive wire forming the coil portion and integrating with the magnetic core portion; The manufacturing method of the antenna characterized by including. The antenna manufacturing method according to claim 6, wherein the third step is performed by thermally shrinking the coating material. 7. The method for manufacturing an antenna according to claim 6, wherein in the fifth step, the conductive wires having a self-bonding coating are fused to form a coil shape. 7. The method of manufacturing an antenna according to claim 6, wherein the fifth step fuses the conductive wire wound based on energization to the conductive wire in a coil shape.

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