JP2006129435A - Antenna and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily provide an antenna configured by an amorphous metal according to a purpose and electronic equipment incorporating the antenna. <P>SOLUTION: This antenna 100 is provided with a core 110 and a coil 120 wound around the core 110. The core 110 is configured of amorphous metal formed into a bulk configuration. Thus, the shape of the core is easily worked into a free shape, and the antenna with shape matched with a purpose is easily manufactured. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antenna and an electronic device that receive radio waves.

2. Description of the Related Art Conventionally, as an electronic device that receives radio waves and uses radio wave information, for example, there is an electronic watch that receives radio waves at a standard time and automatically corrects the time.
As an antenna that is provided in such an electronic wristwatch and receives radio waves, an antenna that is configured by winding a coil around a core (core material) made of a magnetic material having good reception sensitivity, such as ferrite or amorphous metal, is known. It has been.

In particular, an antenna using an amorphous metal as a core is superior in impact resistance and temperature characteristics as compared with a ferrite material, and has attracted attention in recent years.
Conventionally, an amorphous metal antenna is known in which a plurality of amorphous metal thin films are stacked (for example, Patent Document 1).
Further, an antenna is also known in which a magnetic ribbon made of amorphous metal is laminated through a deformable member to form a core, thereby improving bending resistance and impact resistance (for example, Patent Document 2). .
In addition, a raw material to be an amorphous metal (for example, Fe—Co—Ga—P—C—B system, Fe—Ga—P—C—B—Si system, etc.) is dissolved, and is 200 Mpa or more at the crystallization start temperature or lower. (For example, Patent Document 3), a raw material that becomes an amorphous metal is put in a cemented carbide mold, and heated by energization while applying a high pressure of 500 Mpa, for example. It is also known to produce a bulk amorphous metal by a method of sintering (high-pressure pulse current sintering).
JP 05-267922 A JP 2003-283231 A JP 2004-204296 A

  However, the conventional antenna using amorphous metal is formed by laminating a plurality of thin films of amorphous metal, so that the core shape can be processed into a free three-dimensional shape to produce a more suitable antenna shape. It was technically difficult and expensive.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an antenna having a shape suitable for a purpose, and an electronic device incorporating the antenna, using amorphous metal.

  In order to solve the above problem, the invention described in claim 1 includes a rod-shaped core (for example, the core 110 in FIG. 3) and a coil wound around the core (for example, the coil 120 in FIG. 3). In the antenna (for example, the antenna 100 of FIG. 3), the core is made of an amorphous metal formed in a bulk shape.

  The invention according to claim 2 is an antenna (for example, FIG. 3) including a rod-shaped core (for example, the core 110 of FIG. 3) and a coil (for example, the coil 120 of FIG. 3) wound around the core. In the antenna 100), the cross-sectional area of the end portion of the core (for example, the end portion 110C of FIG. 3) is larger than the cross-sectional area of the central portion of the core (for example, the central portion 110A of FIG. 3). Is made of an amorphous metal formed into a bulk shape.

  According to a third aspect of the present invention, in the antenna of the second aspect, the cross-sectional area of the end portion of the core decreases from the end surface portion of the core (for example, the end surface portion 110B in FIG. 3) toward the center portion. The center of the core is constant.

  According to a fourth aspect of the present invention, in the antenna according to the second aspect, the cross-sectional area of the core is changed from the end surface portion (for example, the end surface portion 210B of FIG. 5) to the center portion (for example, the center of FIG. 5). Part 210D) is characterized by being continuously reduced.

  According to a fifth aspect of the present invention, in the antenna according to the second aspect, the cross-sectional area of the core is changed from the end of the core (for example, the end 310C of FIG. 6) to the center (for example, the center of FIG. 6). It is characterized in that it decreases in steps as it goes to the section 310D).

  According to a sixth aspect of the present invention, in the antenna according to the second aspect, the number of turns of the coil is greater at the center than at the end of the core.

  According to a seventh aspect of the present invention, in the antenna according to any one of the second to sixth aspects, the end portion of the core is a recess (for example, as shown in FIG. 8) that opens toward the outside in the axial direction of the core. A concave portion 510E) is provided.

  According to an eighth aspect of the present invention, in the antenna according to the second aspect, a space (for example, in FIG. 19) in which an electronic component (for example, the electronic component 2000 in FIG. 19) can be disposed at the end of the core. A through hole X3) is formed.

  According to the ninth aspect of the present invention, in the electronic device (for example, the wristwatch 1 in FIG. 1), the antenna according to any one of the first to eighth aspects is placed in the device case (for example, the watch case 2 in FIG. 1). It is characterized by having been arranged in.

According to the first aspect of the present invention, since the core is formed by bulking amorphous metal, the shape of the core can be freely set as compared with a core formed by laminating a plurality of conventional amorphous metal thin films. Thus, an antenna having a shape suitable for the purpose can be manufactured more easily. In addition, since a thin film is not stacked unlike a conventional amorphous metal core, the number of processing steps can be reduced.
In addition, since the core made of amorphous metal formed in a bulk shape has extremely high magnetic permeability, the sensitivity of the antenna can be extremely improved. In addition, since amorphous metal has high strength, the core can be formed extremely thin and the number of turns of the coil can be increased, so that the sensitivity of the antenna can be improved. In addition, since the amorphous metal is not easily rusted and has good temperature stability, the lifetime of the antenna can be further prolonged.

According to the second aspect of the present invention, since the cross-sectional area of the end of the core is larger than the cross-sectional area of the central part of the core, more radio waves can be received and the sensitivity of the antenna is improved. be able to. In particular, since the core is made of bulk amorphous metal, it can be easily formed into such a shape as compared with a core formed by laminating a plurality of conventional amorphous metal thin films.
In addition, since the core is formed by bulking amorphous metal, it becomes easier to process the core into a free shape compared to a core formed by stacking multiple amorphous metal thin films. Thus, an antenna having a shape suitable for the purpose can be manufactured more easily. In addition, since a thin film is not stacked unlike a conventional amorphous metal core, the number of processing steps can be reduced.
In addition, since the core made of amorphous metal formed in a bulk shape has extremely high magnetic permeability, the sensitivity of the antenna can be extremely improved. In addition, since amorphous metal has high strength, the core can be formed extremely thin and the number of turns of the coil can be increased, so that the sensitivity of the antenna can be improved. In addition, since the amorphous metal is not easily rusted and has good temperature stability, the lifetime of the antenna can be further prolonged.

  According to the third aspect of the present invention, the cross-sectional area of the end portion of the core decreases from the end surface portion of the core toward the central portion, and is constant in the central portion of the core. The electrical resistance increases as it goes to, so that the induced current generated in the core can be reduced and eddy current loss can be suppressed.

  According to the invention described in claim 4, since the cross-sectional area of the core continuously decreases from the end surface portion toward the center portion, the electrical resistance increases from the end surface portion toward the center portion. Thus, the induced current generated in the core can be reduced, and eddy current loss can be suppressed.

  According to the fifth aspect of the present invention, since the cross-sectional area of the core decreases stepwise from the end of the core toward the center, the electrical resistance increases from the end toward the center. Thus, the induced current generated in the core can be reduced, and eddy current loss can be suppressed.

  According to the sixth aspect of the present invention, the number of windings of the coil is greater at the center than at the end of the core. Therefore, the magnetic flux density increases at the center, and the induced electromotive force (received voltage) generated at the center. ) Can be further increased, and the sensitivity of the antenna can be increased.

  According to the seventh aspect of the present invention, since the end of the core is provided with the recess, the cross-sectional area of the end is reduced by the amount provided with the recess without impairing the radio wave reception sensitivity of the core. can do. Thereby, the electrical resistance of the end can be increased, and eddy current loss due to the induced current generated in the core can be further suppressed.

  According to the eighth aspect of the present invention, since the space where the electronic component can be disposed is formed at the end of the core, for example, when the antenna is built in the electronic device, Electronic components such as a circuit, a capacitor, a battery, and a resistor can be disposed as appropriate, and the electronic device can be further downsized while increasing the outer shape of the core and improving the antenna sensitivity.

According to the invention described in claim 9, since the electronic device arranges the antenna according to any one of claims 1 to 8 in the device case, the antenna having a shape more suitable for the purpose is incorporated. As a result, the degree of freedom in design increases and the electronic device can be made smaller.
In addition, since the core of the built-in antenna is formed from an amorphous metal, it is possible to manufacture an electronic device that can receive radio waves with high sensitivity and that can reduce costs. In addition, since the built-in antenna has a longer lifetime, the lifetime of the electronic device can be further prolonged.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a plan view of a wristwatch 1 incorporating an antenna 100 according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view taken along the line II-II in FIG.
As shown in FIGS. 1 and 2, a wristwatch 1 as an electronic device includes a watch case 2 as a device case that houses a clock timing unit 4. The watch case 2 is attached to a wrist of a user. A band member 8 is attached.

  A watch glass 2a is fitted in the center of the upper surface of the watch case 2 via a packing 2b so that the dial 5 can be seen, and around the watch case 2 is used for instructing execution of various functions of the watch 1. A switch 3 is provided. A bezel 2f is provided on the upper outer periphery of the watch case 2, and a metal-molded back cover 2c is attached to the bottom surface of the watch case 2 via a waterproof ring 2d.

  The clock timing unit 4 includes an upper housing portion 4a, a lower housing portion 4b, an analog pointer mechanism 7 for moving the hands 7b such as an hour hand and a second hand on the dial 5, an antenna 100 for receiving a standard radio wave, an analog pointer mechanism 7 and an antenna. The circuit board 6 which connects 100 and controls these is provided. Further, the lower housing portion 4 b, the upper housing portion 4 a, and the dial plate 5 have a structure in which each peripheral portion is attached to an inner frame 2 g provided on the inner peripheral surface of the watch case 2.

  The lower housing part 4b is supported above a buffer member 2e provided on the upper part of the back cover 2c, and a circuit board 6 is disposed between the lower housing part 4b and the upper housing part 4a. In addition, a dial plate 5 is disposed on the upper surface of the upper housing portion 4a, and a frame-like member 5b is disposed on the upper peripheral portion of the dial plate 5 in contact with the lower peripheral portion of the watch glass 2a. .

  The analog pointer mechanism 7 includes a pointer shaft 7a extending upward from a shaft hole 5a formed in the dial plate 5 and pointers 7b such as an hour hand and a minute hand attached to the pointer shaft 7a. Move the hand above 5. A battery (not shown) for operating the analog pointer mechanism 7 is incorporated in the lower housing portion 4b, for example.

  The antenna 100 is disposed between the lower housing part 4b and the dial 5 while being supported by the upper housing part 4a.

  3A and 3B are diagrams for explaining the antenna 100 according to the first embodiment. FIG. 3A is a front view of the antenna 100, and FIG. 3B is a cross-sectional view taken along the line bb in FIG. FIG. 3 and FIG. 3C are side views of the antenna 100.

  As shown in FIG. 3, the antenna 100 includes a magnetic core 110 and a coil 120 wound around the core 110.

The core 110 is formed into a bulk shape using an amorphous metal as a material. Here, the bulk shape means a solid shape made using a mold and a mold. Specifically, the bulk amorphous metal is, for example, an Fe-based alloy, a Pd-based alloy, a Zr-based alloy, a Ni-based alloy, or the like, and the Fe-based alloy includes Fe-MB (M = Cr, W , Ta, Nb, Hf, Zr) type alloy, Fe—Co—RE—B (RE = Nb, Sm, Tb, Dy) type alloy and the like. More specifically, the amorphous metal has a composition such as Pd ₄₀ Cu ₃₀ Ni ₁₀ P ₂₀ or Fe ₈₁ B ₁₃ Si ₁₄ C ₂ . And when the melted alloy is processed into a bulk shape by casting, for example, the internal structure is made amorphous. More specifically, the core 110 is sintered, for example, after melting the alloy to be an amorphous metal and pouring it into a mold, and then applying a pressure of 200 Mpa or more at a temperature lower than the crystallization start temperature. Manufactured by.
The core 110 is a long rod-shaped body, and the end surface portion 110B is circular. The end portion 110C of the core 110 has a conical shape, and its cross-sectional area gradually decreases from the end face portion 110B of the end portion 110C of the core 110 toward the central portion (shaft portion) 110A. In the central portion 110A, it is substantially constant. Therefore, the area of the end surface portion 110B included in the end portion 110C of the core 110 and the cross-sectional area of the end portion 110C are larger than the cross-sectional area of the central portion 110A of the core 110.
Here, since the core 110 is made of an amorphous metal, for example, even if the central portion 110A is made thinner than the core formed of ferrite, the same or higher strength can be obtained. Specifically, for example, when the diameter of the central part (shaft part) of the core formed of ferrite is 1.5 mm, the diameter of the central part 110A of the core using amorphous metal is 0.5 to 1. 0.0 mm.

  Further, the coil 110 is wound around the core 110 in a layered manner, and the diameter obtained by adding the coil 120 laminated with the core 110 is substantially equal to the diameter of the end face portion 110 </ b> B of the core 110.

  When the antenna 100 is placed in a magnetic field (hereinafter referred to as “signal magnetic field”) using standard radio waves, the magnetic field acts on the antenna 100 as follows. Since the standard radio wave uses a long wave having a wavelength of several kilometers, the magnitude of the magnetic field component may be regarded as a parallel magnetic field that does not vary depending on the position in the antenna size range. Therefore, for the sake of simplicity, the signal magnetic field will be described below as a parallel magnetic field.

When the core 110 is placed in the signal magnetic field so that the axis of the coil 120 is parallel to the magnetic field direction, as shown in FIG. 3A, a magnetic flux (hereinafter referred to as “signal magnetic flux”) M1 due to the signal magnetic field. Concentrate on the core 110 having a relative permeability higher than that of the surrounding space. As a result, the signal magnetic flux M1 and the coil 120 are linked to each other, and the magnetic flux 120 (hereinafter referred to as “generated magnetic flux”) has a direction in which the change of the signal magnetic flux M1 inside the coil 120 is prevented according to Lenz's law. ) An induced electromotive force V that generates M2 is generated.
The signal magnetic field is an alternating magnetic field, and the magnitude and direction of the signal magnetic flux M1 change periodically. Therefore, the induced electromotive force V becomes alternating current power, and the generated magnetic flux M2 follows the temporal change of the signal magnetic flux M1. And an alternating magnetic field whose size and direction change periodically.

  The induced electromotive force V generated in the coil 120 is detected by a receiving circuit (not shown) connected to the coil 120. The receiving circuit includes a tuning capacitor and a loss resistance for tuning to a standard radio wave frequency (40 kHz or 60 kHz) desired to be received. The receiving circuit is mounted on a circuit board 6 shown in FIG. 2, for example.

Also, an induced electromotive force that generates the generated magnetic flux M2 in a direction that hinders the change of the signal magnetic flux M1 is generated inside the core 110, so that an eddy current is generated in the core 110, and the eddy current is generated in the signal magnetic flux M1. Causes eddy current loss.
Here, the electrical resistance of the core 110 is proportional to the length of the core 110 in the longitudinal direction and inversely proportional to the cross-sectional area of the core 110. For example, the core 110 formed of amorphous metal can be formed to have a thinner central portion 110A than a core formed of ferrite, and the cross-sectional area of the central portion 110A can be made smaller than the area of the end surface portion 110B. The electrical resistance of the core 110 can be increased.
Therefore, the eddy current of the signal magnetic flux M1 generated inside the core 110 is suppressed to be small, and eddy current loss due to the eddy current is suppressed.

  FIG. 4 is a block diagram showing the internal configuration of the wristwatch 1. Referring to FIG. 1, a wristwatch 1 includes a CPU (Central Processing Unit) 10, an input unit 20, a display unit 30, a ROM (Read Only Memory) 40, a RAM (Random Access Memory) 50, and a reception control unit. 60, a time code conversion unit 70, a timing circuit unit 80, and an oscillation circuit unit 82. Each part except for the oscillation circuit unit 82 is connected by a bus B, and the oscillation circuit unit 82 is connected to a time measuring circuit unit 80.

  The CPU 10 reads out a program stored in the ROM 40 in accordance with a predetermined timing or an operation signal input from the input unit 20 and develops it in the RAM 50. Based on the program, instructions and data for each unit constituting the wristwatch 1 are read. Perform forwarding, etc. Specifically, for example, the reception control unit 60 is controlled at predetermined time intervals to execute standard radio wave reception processing, and based on a standard time code (not shown) input from the time code conversion unit 70, the time measuring circuit unit 80 Correct the current time data counted in.

The input unit 20 is a switch 3 or the like for instructing execution of various functions of the wristwatch 1, and outputs a corresponding operation signal to the CPU 10 when these switches 3 are operated.
The display unit 30 includes the analog pointer mechanism 7 controlled by the dial plate 5 and the CPU 10 and displays the current time measured by the time measuring circuit unit 80.

The ROM 40 stores system programs and application programs for the wristwatch 1, programs and data for realizing the present embodiment, and the like.
The RAM 50 is used as a work area of the CPU 10 and temporarily stores a program read from the ROM 40, data processed by the CPU 10, and the like.

  The reception control unit 60 includes a radio wave receiving device 62. The radio wave receiving device 62 has an antenna 100 and a receiving circuit (not shown), cuts out unnecessary frequency components of the standard radio wave received by the antenna 100 and takes out a corresponding frequency signal, and outputs an electric signal corresponding to this frequency signal. The signal converted into the signal is output to the time code conversion unit 70.

  The time code conversion unit 70 converts the electrical signal input from the radio wave receiver 62 into a digital signal, and generates a standard time code including data necessary for a clock function such as a standard time code, an integration code, and a day code. It outputs to CPU10.

  The clock circuit unit 80 counts the signal input from the oscillation circuit unit 82 to clock the current time, and outputs the clocked current time data to the CPU 10. The oscillation circuit unit 82 is a circuit that always outputs a clock signal having a constant frequency.

As described above, according to the antenna 100 according to the first embodiment, the core 110 is manufactured by molding an amorphous metal into a bulk shape. Therefore, by processing the shape of the core 110 into a free shape, The antenna 100 having a shape suitable for the purpose can be manufactured. In addition, since a thin film is not stacked unlike a conventional amorphous metal core, the number of processing steps can be reduced, and the antenna 100 can be manufactured more easily.
Further, the core 110 is made of an amorphous metal formed in a bulk shape, and the amorphous metal has extremely high magnetic permeability, so that the sensitivity of the antenna 100 can be extremely improved. In addition, since amorphous metal has high strength, the central portion 110A of the core 110 can be formed extremely thin, and the number of turns of the coil 120 can be increased, so that the sensitivity of the antenna 100 can be improved. In addition, since amorphous metal is hard to be rusted and has good temperature stability, the lifetime of the antenna 100 can be further extended.

  Moreover, since the area of the end surface part 110B of the core 110 and the cross-sectional area of the end part 110C of the core 110 are larger than the cross-sectional area of the central part 110A of the core 110, more standard radio waves can be received. As a result, the sensitivity of the antenna 100 can be improved.

  In addition, the cross-sectional area of the central portion 110A of the core 110 is smaller than the area of the end face portion 110B of the end portion 110C of the core 110 and the cross-sectional area of the end portion 110C of the core 110. The induced current generated can be reduced, and eddy current loss can be suppressed.

  In addition, since the wristwatch 1 incorporates the antenna 100 manufactured by molding the amorphous metal into a bulk shape, the antenna 100 having a shape more suitable for the purpose can be incorporated, and the degree of design freedom increases. The wristwatch 1 can be further downsized. In addition, since the core 110 of the built-in antenna 100 is manufactured by molding amorphous metal, the wristwatch 1 that can receive radio waves with high sensitivity and suppress costs can be manufactured. Moreover, since the life of the built-in antenna 100 is further prolonged, the life of the wristwatch 1 can be further prolonged.

  The antenna 100 according to the first embodiment of the present invention may be modified as in the first to fourth modifications.

(Modification 1)
5A and 5B are diagrams for explaining an antenna 200 according to the first modification of the first embodiment, in which FIG. 5A is a front view of the antenna 200, and FIG. 5B is b- in FIG. It is b arrow sectional drawing.
As shown in FIG. 5, the antenna 200 according to the first modification of the antenna 100 according to the first embodiment includes a magnetic core 210 and a coil 220 wound around the core 210.

Like the core 110, the core 210 is formed into a bulk shape using an amorphous metal as a material. As shown in FIG. 5, the core 210 is a long rod-shaped body, and the end surface portion 210B of the end portion 210C is circular. It has become. Further, the cross-sectional area of the core 210 is continuously reduced from the end face part 210B toward the center part 210D. Specifically, it decreases continuously from the both end face portions 210B and 210B toward the center portion 210D. Therefore, the area of the end surface portion 210B of the end portion 210C of the core 210 and the cross-sectional area of the end portion 210C of the core 210 are larger than the cross-sectional area of the central portion 210A of the core 210.
Here, since the core 210 is made of an amorphous metal, for example, even if the central portion 210A is made thinner than the core formed of ferrite, the same or higher strength can be obtained.

  In addition, the number of turns of the coil 220 wound around the core 210 is greater at the center portion 210D than at both end portions 210C and 210C of the core 210.

When the antenna 200 is placed in the signal magnetic field so that the axis of the coil 220 is parallel to the magnetic field direction, the signal magnetic flux M1 has a higher relative permeability than the surrounding space, as shown in FIG. Concentrate on the core 210. As a result, the signal magnetic flux M1 and the coil 220 are linked to each other, and an induced electromotive force is generated in the coil 220 so as to generate the generated magnetic flux M2 in a direction that prevents the change of the signal magnetic flux M1 inside the coil 220 according to Lenz's law. V is generated.
The induced electromotive force V generated in the coil 220 is detected by a receiving circuit (not shown) connected to the coil 220.

Also, in the core 210, an induced electromotive force that generates the generated magnetic flux M2 in a direction that prevents the change of the signal magnetic flux M1 in the core 210 is generated, so that an eddy current is generated in the core 210, and a signal is generated. Eddy current loss due to the eddy current occurs in the magnetic flux M1.
Here, since the central portion 210A of the core 210 is formed to be thinner than the core formed of ferrite, for example, the electrical resistance of the core 210 is higher than that of the core formed of ferrite. The eddy current generated inside the core 210 is suppressed to be small, and the eddy current loss due to the eddy current of the signal magnetic flux M1 is suppressed.

According to the antenna 200 of the first modification of the first embodiment, since the cross-sectional area of the core 210 continuously decreases from the both end surface portions 210B and 210B toward the center portion 210D, the center portion extends from both end surface portions 210B and 210B. The electrical resistance increases toward 210D, the induced current generated in the core 210 can be reduced, and eddy current loss can be suppressed.
In addition, since the number of turns of the coil 220 is larger in the central portion 210A than in the end portion 210C of the core 210, the magnetic flux density is higher in the central portion 210D, and the induced electromotive force (received voltage) generated in the central portion 210D is larger. As a result, the receiving sensitivity of the antenna 200 can be increased.
Further, the core 210 has a smooth shape such that the cross-sectional area of the core 210 continuously decreases from the both end surface portions 210B and 210B toward the center portion 210D. Therefore, the core 210 can be easily molded with a mold or the like. Can do.

(Modification 2)
FIGS. 6A to 6C are perspective views for explaining an antenna 300 according to the second modification of the first embodiment.
As shown in FIG. 6, the antenna 300 according to the second modification of the antenna 100 according to the first embodiment includes a magnetic core 310 and a coil 320 wound around the core 310.

The core 310 is formed by core members 310E1 to 4 formed into a cylindrical shape with various diameters using the same amorphous metal as the core 110, and the planar portions of the core member 310E are connected and fixed to each other. .
Specifically, in the core 310, the planes of the core members 310 </ b> E <b> 1 to 4 are connected and fixed so that the diameter of the core members 310 </ b> E <b> 1 to 4 decreases stepwise toward the center portion 310 </ b> D of the core 310. Yes. As a result, the cross-sectional area of the core 310 gradually decreases from the end portion 310C of the core 310 toward the center portion 310D of the core 310. Accordingly, the area of the end surface portion 310B of the end portion 310C of the core 310 is larger than the cross-sectional area of the central portion 310A of the core 310.
Here, the adhesive for connecting and fixing the core members 310E may be any adhesive as long as it adheres amorphous metals, but non-conductive adhesive is preferred from the viewpoint of preventing eddy current generation. Is desirable.
Further, since the core 310 is made of an amorphous metal, for example, even if the central portion 310A is made thinner than the core formed of ferrite, the same or higher strength can be obtained.

  Further, the number of turns of the coil 320 wound around the core 310 is larger at the center portion 310D than at both ends 310C and 310C of the core 310.

  Moreover, since the core 310 of the second modification of the first embodiment is manufactured by connecting the core members 310E, the size and shape of the antenna 300 can be easily changed by changing the combination of the core members 310E. It can be done. For example, as shown in FIG. 6B, the length in the longitudinal direction of the center portion 310D of the core 310 is increased by making the core member 310E4 that is most thinly formed longer than that in FIG. Can do. Further, as shown in FIG. 6C, the size of the core member 310E1 used for one end portion 310C of the core 310 and the core member 310E5 used for the other end portion 310C is changed to make the antenna 300 asymmetrical. Can be molded.

According to the antenna 300 according to the second modification of the first embodiment, the cross-sectional area of the core 310 is gradually reduced from the both end portions 310C and 310C of the core 310 toward the center portion 310D. The electrical resistance of the core 310 increases as it goes from both ends 310C, 310C to the center portion 310D of the core 310, the induced current generated in the core 310 can be reduced, and eddy current loss can be suppressed. .
Further, since the number of windings of the coil 320 is larger in the central portion 310A than in the end portion 310C of the core 310, the magnetic flux density is higher in the central portion 310D, and the induced electromotive force (reception voltage) generated in the central portion 310D is larger. As a result, the reception sensitivity of the antenna 300 can be increased.
Further, since the core 310 is formed by connecting and fixing the core members 310E formed in cylindrical shapes of various sizes, the antenna 300 can be changed by changing the combination of the core members 310E constituting the core 310. Can be easily changed in size and shape.

(Modification 3)
7A and 7B are diagrams for explaining an antenna 400 according to the third modification of the first embodiment. FIGS. 7A and 7B are perspective views of the antenna 400, and FIGS. It is sectional drawing of the coil 420 wound around the core 410 of the antenna 400 of FIG. 7 (a), (b), respectively.
As shown in FIG. 7, the antenna 400 according to the third modification of the antenna 100 according to the first embodiment includes a magnetic core 410 and a coil 420 wound around the core 410.

As shown in FIG. 7, the core 410 is formed in a bulk shape using an amorphous metal similar to the core 110 as a material. The core 410 includes a long round bar-shaped central portion 410A and a columnar end portion 410C, and the plane of the end portion 410C is substantially perpendicular to the central portion 410A. Accordingly, the area of the end surface portion 410B of the core 410 is larger than the cross-sectional area of the central portion 410A of the core 410.
Further, since the core 410 is made of an amorphous metal, for example, even if the central portion 410A is made thinner than the core formed of ferrite, the same or higher strength can be obtained.

  A coil 420 is wound around the central portion 410A of the core 410 in a layered manner. First, the coil 420 is wound around the central portion 410A of the core 410 so that the diameter obtained by adding the coil 420 laminated with the central portion 410A is larger than the diameter of the end portion 410C of the core 410 (see FIG. 7 (a)), compression is performed by applying pressure to the outer peripheral surface of the antenna from a direction perpendicular to the longitudinal direction of the antenna 400. As shown in FIG. 7 (c), the cross section of the coil 420 before compression is circular, and there are slight gaps between the coils 420. The coil 420 after compression is shown in FIG. 7 (d). As shown, the coils 420 are in close contact with each other. Then, by compressing the coil 420 wound around the center portion 410A, the diameter obtained by adding the coil 420 stacked with the center portion 410A is made substantially equal to the diameter of the end portion 410C of the core 410 (FIG. 7). (B)).

  Since the core 410 is formed from an amorphous metal, for example, unlike an antenna formed from ferrite, the core 410 is not damaged even when pressure is applied after the coil 420 is wound. By applying pressure, the number of turns of the coil 420 can be increased.

(Modification 4)
FIG. 8 is a cross-sectional view for explaining an antenna 500 according to the fourth modification of the first embodiment.
As shown in FIG. 8, the antenna 500 of the fourth modification of the antenna 100 according to the first embodiment includes a magnetic core 510 and a coil 520 wound around the core 510.

The core 510 is formed in a bulk shape using an amorphous metal as a material, and as shown in FIG. 8, the core 510 is a long rod-like body, and the end surface portion 510B included in the end portion 510C of the core 510 has a circular shape. It has become. At both end portions 510C and 510C of the end portion 510C of the core 510, recesses 510E and 510E that open toward the outside in the axial direction of the core 510 are formed, and the cores are formed by the amount of the recesses 510E and 510E formed. The cross-sectional areas of the end portions 510C and 510C of 510 are small. Further, the area of the end surface portion 510B of the core 510 is larger than the cross-sectional area of the central portion 510A of the core 510.
Further, since the core 510 is made of an amorphous metal, for example, even if the central portion 510A is made thinner than the core formed of ferrite, the same or higher strength can be obtained.

  The number of turns of the coil 520 wound around the core 510 is greater at the center 510D than at both ends 510C and 510C of the core 510.

  According to the antenna 500 of the modified example 4 of the first embodiment, the both ends 510C, 510C of the core 510 are provided with the recesses 510E, 510E, so that both ends 510C, The cross-sectional area of 510C can be reduced by the amount provided with the recess 510E. Thereby, the electrical resistance of the both ends 510C and 510C can be increased, and eddy current loss caused by the induced current generated in the core 510 can be further suppressed.

(Modification 5)
FIG. 9 shows a side view of an antenna 600 according to the fifth modification of the first embodiment.
As shown in FIG. 9, an antenna 600 of Modification 5 of the antenna 100 according to the first embodiment includes a magnetic core 610 and a coil 620 wound around the core 610.

  As shown in FIG. 9, the core 610 is formed by bundling a large number of wire rods 630 formed using the same amorphous metal as the core 110. Moreover, the end side of the wire 630 is a foil-shaped portion 630A that is thinly formed in a foil shape. Then, the wire 630 is bundled so that the foil-shaped portion 630A forms the end portion 610B of the antenna 600, and the central portion 630B sandwiched between the foil-shaped portions 630A of the wire 630 forms the central portion 610A of the antenna 600. ing. A coil 620 is wound around the central portion 610 </ b> A of the antenna 600 in layers.

  Since the wire 630 is formed using an amorphous metal as a material, for example, even if the wire 630 is formed to be thinner than a wire formed from ferrite, the strength equal to or higher than that can be obtained.

  The core 610 is formed by bundling the wire 630. The central portion 630B and the foil-like portion 630A of the wire 630 are integrally formed in a bulk shape using an amorphous metal as a material, and receive a signal magnetic flux (not shown) by the plane of the foil-like portion 630A.

  According to the antenna 600 according to the fifth modification of the first embodiment, the end side of the wire 630 is a foil-shaped portion 630A that is thinly formed in a foil shape. (Not shown) can be received, and the receiving area can be made wider than the receiving area of the wire 630 as it is, and the receiving sensitivity can be increased.

(Embodiment 2)
As shown in FIGS. 10 and 11, the wristwatch 1a according to the second embodiment of the present invention is different from the antenna 100 of the first embodiment only in the structure of the antenna 700. The same reference numerals are given and the description thereof is omitted.

FIG. 10 is a plan view of a wrist watch 1 a incorporating the antenna 700 according to the second embodiment.
And the antenna 700 which concerns on Embodiment 2 is provided with the coil 720 wound around the core 710 which is a magnetic body, and the core 710, as shown in FIG.

As shown in FIG. 11, for example, the core 710 is formed by joining both end portions of a square columnar central portion 710A and a substantially central portion of a square columnar end portion 710C extending in a direction orthogonal to the central portion 710A. The shape is substantially H-shaped, and is integrally three-dimensionally formed from an amorphous metal into a bulk shape.
Accordingly, the area of the end surface portion 710 </ b> B of the core 710 is larger than the cross-sectional area of the central portion 710 </ b> A of the core 710.
Here, since the core 710 is made of an amorphous metal, for example, even if the central portion 710A of the core 710 is made thinner than the core formed of ferrite, the same or higher strength can be obtained.
Note that the end 710C and the center 710A of the core 710 have been described as a quadrangular prism, but the corners of the quadrangular prism may be smoothed or cylindrical.

When the core 710 is placed in the signal magnetic field so that the axis of the coil 720 is parallel to the magnetic field direction, the signal magnetic flux M1 is transferred to the core 710 having a relative permeability higher than that of the surrounding space as shown in FIG. concentrate. As a result, the signal magnetic flux M1 and the coil 720 are linked, and the induced electromotive force is generated in the coil 720 so as to generate the generated magnetic flux M2 in a direction that prevents the change of the signal magnetic flux M1 inside the coil 720 according to Lenz's law. V is generated.
The induced electromotive force V generated in the coil 720 is detected by a receiving circuit (not shown) connected to the coil 720.

  As shown in FIG. 10, when the antenna 700 according to the second embodiment is built in a wristwatch 1a which is a type of radio timepiece, the section X1 is partitioned into a substantially U-shape by an end portion 710C and a central portion 710A. Electronic circuits, capacitors, batteries, resistors, and the like may be provided as appropriate. At this time, by attaching a magnetic shield material to the inside of the section X1 of the end portion 710C and the central portion 710A, it is possible to reduce the influence of the generated magnetic flux M2 on the electronic circuit or the like disposed in the section X1.

  Next, a method for manufacturing the core 710 of the antenna 700 according to Embodiment 2 of the present invention will be described with reference to the flowchart shown in FIG.

  First, in step S1 of FIG. 12, an additive is added at a predetermined ratio to iron, nickel, or the like, which is an amorphous metal material constituting the core 710 according to the present invention, and is melted at a high temperature in a vacuum melting furnace (melting step). .

  Next, in step S2 of FIG. 12, as shown in FIG. 13, the mold 90 is provided with a space 90A that matches the shape of the core 710 of the antenna 700, and a funnel-shaped injection port 90B connected to the space 90A. The molten amorphous metal melt is poured quickly (injection process).

  Next, in step S3 of FIG. 12, as shown in FIG. 14, the molten metal is poured into the mold 90 and allowed to cool and solidify (cooling process). With a normal amorphous metal material composition, for example, only a thin film can be manufactured because it is necessary to supercool at a high cooling rate of 300 K / sec. However, with an amorphous metal material composition according to the present invention, for example, 10 K / sec. Since it can be amorphized by a relatively slow cooling rate of sec, a three-dimensional product can be manufactured by such mold casting.

  Next, in step S4 of FIG. 12, the cooled and solidified amorphous metal body 1000 is taken out from the mold. The extracted amorphous metal body 1000 is shown in FIG. Thereafter, the unnecessary portion 90C cooled and solidified by the injection port 90B is cut off, and then the amorphous metal body 1000 is shaped by polishing or the like (shaping process).

  Next, in step S5 of FIG. 12, the antenna 700 is manufactured by winding the coil 720 around the core 710 manufactured by shaping. The completed antenna 700 is shown in FIG.

According to the antenna 700 according to the second embodiment described above, since the area of the end surface portion 710B of the core 710 is larger than the cross-sectional area of the central portion 710A of the core 710, more standard radio waves can be received. As a result, the sensitivity of the antenna 700 can be improved.
In particular, since the core 710 is made of a bulk amorphous metal, it can be easily formed even in a complicated shape such as an H shape compared to a core formed by laminating a plurality of conventional amorphous metal thin films. it can.
In addition, since a thin film is not stacked unlike a conventional amorphous metal core, the number of processing steps can be reduced, and the antenna 700 can be easily manufactured.
In addition, an electronic circuit, a capacitor, a battery, a resistor, and the like can be appropriately disposed in a section X1 that is partitioned in a substantially U shape by the end portion 710C and the central portion 710A of the core 710, and thus the wristwatch 1a is more It can be downsized.

  The antenna 700 according to the second embodiment of the present invention can obtain the same effect even if it is modified as follows.

(Modification)
As shown in FIG. 17, an antenna 800 of a modification of the antenna 700 according to the second embodiment includes a magnetic core 810 and a coil 820 wound around the core 810.

As shown in FIG. 17, the core 810 includes, for example, both end portions of a quadrangular columnar central portion 810A and quadrangular columnar end portions 810C extending in the same direction that is orthogonal to the central portion 810A. It has a substantially U-shaped shape that is joined, and is three-dimensionally molded from an amorphous metal into a bulk shape.
Therefore, similarly to the antenna 700, the area of the end surface portion 810B of the core 810 is larger than the cross-sectional area of the central portion 810A of the core 810.
Here, since the core 810 is made of an amorphous metal, for example, even if the central portion 810A is made thinner than the ferrite core, the same or higher strength can be obtained.
Although the end portion 810C and the central portion 810A of the core 810 have been described as a quadrangular prism shape, the corner portion of the quadrangular prism may be smoothed or a cylindrical shape.

When the core 810 is placed in the signal magnetic field so that the axis of the coil 820 is parallel to the magnetic field direction, the signal magnetic flux M1 is transferred to the core 810 having a higher relative permeability than the surrounding space as shown in FIG. concentrate. As a result, the signal magnetic flux M1 and the coil 820 are linked, and an induced electromotive force is generated in the coil 820 to generate the generated magnetic flux M2 in a direction that prevents the change of the signal magnetic flux M1 inside the coil 820 in accordance with Lenz's law. V is generated.
The induced electromotive force V generated in the coil 820 is detected by a receiving circuit (not shown) connected to the coil 820.

  Further, the core 810 of the antenna 800 according to the modified example is three-dimensionally formed in the same manner as the manufacturing method of the core 710 of the antenna 700.

  When the antenna 800 according to the modification is incorporated in a wristwatch (not shown) that is a type of radio-controlled timepiece, as with the antenna 700 according to the second embodiment, the end portion 810C and the central portion 810A of the core 810 are substantially connected. An electronic circuit, a capacitor, a battery, a resistor, and the like may be appropriately disposed in the section X2 partitioned in a letter shape. At this time, by attaching a magnetic shield material to the inside of the section X2 of the end portion 810C and the central portion 810A, it is possible to reduce the influence of the generated magnetic flux M2 on the electronic circuit and the like disposed in the section X2.

(Embodiment 3)
As shown in FIGS. 18 and 19, the wristwatch 1b according to the third embodiment of the present invention is different from the antenna 100 according to the first embodiment only in the structure of the antenna 900. The same reference numerals are given and the description thereof is omitted.

FIG. 18 is a plan view of a wrist watch 1b incorporating the antenna 900 according to the third embodiment.
The antenna 900 according to the third embodiment includes a magnetic core 910 and a coil 920 wound around the core 910, as shown in FIG.

As shown in FIG. 19, the core 910 includes, for example, a quadrangular columnar central portion 910A and a first end extending in a substantially triangular shape in a plan view from one end of the central portion 910A toward the outside in the longitudinal direction. A portion 910C, and a second end portion 910D that extends from the other end of the center portion 910A toward the outside in the longitudinal direction in a substantially triangular shape in plan view, and further extends in a substantially rectangular shape in plan view. The shapes of the first end 910C and the second end 910D are asymmetric. The core 910 is integrally three-dimensionally formed from an amorphous metal into a bulk shape.
The second end portion 910D is provided with a substantially rectangular through hole portion X3 as a space portion in which the electronic component 2000 or the like can be disposed.
The area of the end surface portion 910B of the first end portion 910C and the second end portion 910D is larger than the cross-sectional area of the central portion 910A of the core 910.
Here, since the core 910 is made of an amorphous metal, for example, even if the central portion 910A is made thinner than the core formed of ferrite, the same or higher strength can be obtained.
The first end portion 910C, the second end portion 910D, and the central portion 910A of the core 910 have been described as having a substantially rectangular cross section. It may be circular.

When the core 910 is placed in the signal magnetic field so that the axis of the coil 920 is parallel to the magnetic field direction, the signal magnetic flux M1 is transferred to the core 910 having a relative permeability higher than that of the surrounding space as shown in FIG. concentrate. As a result, the signal magnetic flux M1 and the coil 920 are linked, and an induced electromotive force is generated in the coil 920 so as to generate the generated magnetic flux M2 in a direction that prevents the change of the signal magnetic flux M1 inside the coil 920 according to Lenz's law. V is generated.
The induced electromotive force V generated in the coil 920 is detected by a receiving circuit (not shown) connected to the coil 920.
Further, the through hole portion X3 provided in the second end portion 910D of the core 910 is surrounded by a magnetic body that is the core 910, and the signal magnetic flux M1 and the generated magnetic flux M2 are around the through hole portion X3. Since the magnetic material is concentrated and distributed, the magnetic flux distributed in the through hole portion X3 is extremely small.

  Then, the core 910 of the antenna 900 according to the third embodiment is three-dimensionally formed in the same manner as the manufacturing method of the core 710 of the antenna 700 according to the second embodiment.

As shown in FIG. 18, when the antenna 900 according to the third embodiment is built in a wristwatch 1 b that is a type of radio timepiece, an electron is transmitted through a through-hole portion X <b> 3 provided in the second end portion 910 </ b> D of the core 910. As the component 2000, for example, an electronic circuit, a capacitor, a battery, a resistor, and the like can be appropriately disposed. Here, the through hole portion X3 is not affected by the magnetic flux because it is away from the path of the magnetic flux generated from the coil 920, but a magnetic shield material is attached to the inner surface of the core 910 surrounding the through hole portion X3. It is better to take measures.
In the present embodiment, the through hole portion X3 has been described as being substantially rectangular, but any shape may be used.

  According to the antenna 900 according to the third embodiment described above, since the shapes of the first end 910C and the second end 910D of the core 910 are asymmetric, the antenna 900 configured to include the core 910 is configured. As a result, the degree of freedom in designing the wristwatch 1b incorporating the watch increases, and the wristwatch 1b can be further downsized. In particular, since the core 910 is made of bulk amorphous metal, it can be easily formed into such a shape as compared with a core formed by laminating a plurality of conventional amorphous metal thin films.

Since the core 910 is formed with a substantially rectangular through hole X3 as a space where the electronic component 2000 or the like can be disposed, when the antenna 900 is built in the wristwatch 1b, the through hole X3 of the core 910 is provided. Thus, electronic components 2000 such as an electronic circuit, a capacitor, a battery, and a resistor can be appropriately disposed, and the wristwatch 1b is further downsized while increasing the outer shape of the core 910 to improve the sensitivity of the antenna 900. be able to.
Further, since the magnetic flux distributed in the through hole portion X3 of the core 910 is extremely small, the influence of the magnetic flux received by the electronic component 2000 such as an electronic circuit, a capacitor, a battery, and a resistor disposed in the through hole portion X3 is extremely reduced. be able to.

  In the embodiment of the present invention, the case where the electronic device is applied to an antenna that is built in a wristwatch-type radio timepiece and receives a standard radio wave is described. However, the application of the present invention is not limited to this. For example, the present invention may be applied to an antenna for a vehicle-mounted device, a patch antenna for a portable wireless terminal, or the like.

It is a top view which shows the wristwatch which incorporated the antenna which concerns on Embodiment 1 of this invention. It is II-II sectional drawing of FIG. It is the front view (a), bb sectional view (b), and side view (c) which show the antenna concerning Embodiment 1 of the present invention. It is a block diagram which shows the internal structure of a wristwatch. It is the front view (a) which shows the antenna which concerns on the modification 1 of Embodiment 1 of this invention, bb sectional drawing (b). It is a perspective view (a)-(c) which shows an antenna concerning modification 2 of Embodiment 1 of the present invention. It is the perspective views (a) and (b) which show the antenna which concerns on the modification 3 of Embodiment 1 of this invention, and sectional drawing (c), (d) of the coil wound around an antenna. It is sectional drawing which shows the antenna which concerns on the modification 4 of Embodiment 1 of this invention. It is a side view which shows the antenna which concerns on the modification 5 of Embodiment 1 of this invention. It is a top view which shows the wristwatch which incorporated the antenna which concerns on Embodiment 2 of this invention. It is a perspective view which shows the antenna which concerns on Embodiment 2 of this invention. It is a flowchart of the manufacturing method of the antenna which concerns on this invention. It is a perspective view which shows the casting_mold | template for manufacturing the antenna which concerns on Embodiment 2 of this invention. It is a perspective view which shows a mode that the molten metal was poured into the casting_mold | template for manufacturing the antenna which concerns on Embodiment 2 of this invention. It is a perspective view which shows the core taken out from the casting_mold | template for manufacturing the antenna which concerns on Embodiment 2 of this invention. It is a perspective view which shows the antenna which concerns on Embodiment 2 of this invention completed by winding a coil around the cast core. It is a perspective view which shows the antenna which concerns on the modification of Embodiment 2 of this invention. It is a top view which shows the wristwatch which incorporated the antenna which concerns on Embodiment 3 of this invention. It is a top view which shows the antenna which concerns on Embodiment 3 of this invention.

Explanation of symbols

1,1a, 1b Wristwatch (electronic equipment)
2 Watch case (equipment case)
60 Communication controller 62 Radio wave receiver 100, 200, 300, 400, 500, 600, 700, 800, 900 Antenna 110, 210, 310, 410, 510, 610, 710, 810, 910 Core 110A, 210A, 310A, 410A, 510A, 610A, 710A, 810A, 910A Central part 110B, 210B, 310B, 410B, 510B, 710B, 810B, 910B End face part 120, 220, 320, 420, 520, 620, 720, 820, 920 Coil 110C, 210C, 310C, 410C, 510C, 610B, 710C, 810C End portions 210D, 310D, 510D Center portion 510E Recessed portion 910D Second end portion (end portion)
2000 Electronic component X3 Through hole (space)

Claims (9)

In an antenna comprising a rod-shaped core and a coil wound around the core,
The antenna is characterized in that the core is made of an amorphous metal formed in a bulk shape. In an antenna comprising a rod-shaped core and a coil wound around the core,
The antenna is characterized in that a cross-sectional area of an end portion of the core is larger than a cross-sectional area of a central portion of the core, and the core is made of an amorphous metal formed in a bulk shape.   3. The antenna according to claim 2, wherein a cross-sectional area of the end portion of the core decreases from the end surface portion toward the center portion of the core and becomes constant at the center portion of the core.   The antenna according to claim 2, wherein the cross-sectional area of the core continuously decreases from the end surface portion toward the center portion of the core.   The antenna according to claim 2, wherein the cross-sectional area of the core decreases in a stepwise manner from the end of the core toward the center.   The antenna according to claim 2, wherein the number of windings of the coil is greater at the center than at the end of the core.   The antenna according to claim 2, wherein an end portion of the core includes a concave portion that opens toward an outer side in the axial direction of the core.   The antenna according to claim 2, wherein a space in which an electronic component can be disposed is formed at an end of the core.   An electronic device comprising the antenna according to any one of claims 1 to 8 disposed in a device case.

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