HK1065652B - Antenna and method for manufadturing the same - Google Patents

Description

Antenna and method for manufacturing the same

Technical Field

The present invention relates to an antenna used for a small electronic device.

Background

Conventionally, as a small electronic device that receives radio waves and uses radio wave information, there is an electronic watch that automatically corrects time by receiving radio waves of standard time.

As an antenna for receiving radio waves provided in such an electronic watch, as disclosed in japanese unexamined patent application publication No. 2001-337181, an iron core formed of ferrite or amorphous material, which is a magnetic material having high reception sensitivity, is known, and a coil is wound around the iron core.

Further, it is known that the reception sensitivity of the antenna is also affected by the shape of the core, and the reception sensitivity can be improved by increasing the size of both ends of the core. For example, by forming a shape having a degree of freedom in shape design, a core having large ends can be easily formed, and reception sensitivity can be improved.

However, for example, in the case of forming an iron core by stacking a plurality of thin plates of a magnetic material or by bundling a plurality of magnetic material cores, the shape of the reception sensitivity cannot be optimized because the degree of freedom in designing the shape is limited and the thickness of the iron core is regulated.

Disclosure of Invention

The invention provides an antenna capable of improving receiving sensitivity by using an amorphous magnetic material core having a constant thickness.

To achieve the above object, the present invention has a core formed by stacking a plurality of thin plates of amorphous magnetic material having a certain thickness and having both end portions widened in a thickness direction, and a coil wound on the core.

According to the present invention, since the core of the antenna is formed by stacking a plurality of thin plates of amorphous magnetic material having a constant thickness such that both end portions of the core are widened in the thickness direction and both end portions of the core are thicker than the central portion in the thickness direction, the reception sensitivity can be improved.

Drawings

Fig. 1 is a front view showing an antenna of the present invention.

Fig. 2 is a rear view showing the antenna of fig. 1.

Fig. 3 is a sectional view taken along line III-III of fig. 1.

Fig. 4A is a plan view showing a thin plate constituting the antenna core of the present invention.

Fig. 4B is a side view of the sheet of fig. 4A.

Fig. 5A is a side view showing an iron core bobbin used for the antenna of the present invention.

Fig. 5B is a lateral side view as viewed from the direction of arrow B in fig. 5A.

Fig. 5C is a lateral side view as viewed from the direction of arrow C in fig. 5A.

Fig. 6A is a top view showing an upper frame of an iron core frame used for the antenna of the present invention.

Fig. 6B is a lower surface view of the upper armature of fig. 6A.

Fig. 6C is a cross-sectional view taken along line d-d of fig. 6A.

Fig. 7A is a top view showing a lower bobbin constituting an iron core bobbin used for the antenna of the present invention.

Fig. 7B is a side view of the lower armature of fig. 7A.

Fig. 7C is a lower surface view of the lower skeleton of fig. 7A.

Fig. 8 is a front view showing an antenna body in the antenna of the present invention.

Fig. 9 is a side view showing an antenna body in the antenna of the present invention.

Fig. 10 is an enlarged sectional view showing an important part of an electronic watch accommodating the antenna of the present invention.

Fig. 11 is a conceptual diagram illustrating a first modification of the antenna of the present invention.

Fig. 12 is a conceptual diagram illustrating a second modification of the antenna of the present invention.

Fig. 13 is a conceptual diagram illustrating a third modification of the antenna of the present invention.

Fig. 14 is a conceptual diagram illustrating a third modification of the antenna of the present invention.

Fig. 15 is a conceptual diagram illustrating a fourth modification of the antenna of the present invention.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 is a front view showing an antenna of the present invention. Fig. 2 is a rear view of the same antenna. Fig. 3 is a sectional view taken along line III-III of fig. 1.

As shown in fig. 1 to 3, the antenna 100 includes an antenna body 20, and a connection member 40 electrically connecting the antenna body 20 and a circuit board (not shown) of the electronic device.

The antenna body 20 is constituted by an iron core 11 formed by stacking a plurality of amorphous magnetic material sheets 1 having a constant thickness, spacers 2 sandwiched between predetermined sheets at both ends in the longitudinal direction of the iron core 11, an iron core bobbin 3 accommodating the iron core 11 therein, a coil 4 wound around the iron core bobbin 3, and the like.

As shown in fig. 4, the sheet 1 is a thin plate-like object having a core portion 1a and core end portions 1b formed at both ends of the core portion 1a in the longitudinal direction and having an approximately H-shape in plan view, and is an amorphous magnetic material. The width of the sheet 1 of the core end 1b in the width direction is wider than the width of the core 1a, and the core end 1b is formed in a shape having an inclined portion in which a substantially rectangular shape is chamfered.

Specific dimensions of the sheet are, for example, 0.016mm in thickness, 15.6mm in length in the longitudinal direction, 11.2mm in length in the longitudinal direction of the core portion 1a portion, 1.4mm in width in the width direction of the core portion 1a portion, and 4.7mm in width of the core end portion 1 b.

The thin plates 1 are stacked in multiple layers to form an iron core 11.

The spacer 2 is a wedge-shaped object which is placed between predetermined sheets when the sheets are stacked, is sandwiched between both ends of the sheet 1, and is provided with a core end portion 1b which is widened in the thickness direction of both ends thereof.

As shown in fig. 5 to 7, the core frame 3 for accommodating the core 11 therein is composed of an upper frame 3a and a lower frame 3 b.

The core bobbin 3 forms a space accommodating portion 30 between a space where the upper bobbin 3a and the lower bobbin 3b are combined, that is, a lower face of the upper bobbin 3a and an upper face of the lower bobbin 3b, and the core 11 is accommodated in the space accommodating portion 30.

The core frame 3 has a central portion 5 covering a portion corresponding to the core portion 1a of the thin plate 1 constituting the core 11, and end portions 6a, 6b provided at both ends of the central portion 5 and covering portions corresponding to the core end portions 1b of the thin plate 1 constituting the core 11. The spaces of the receiving portions 30 in the end portions 6a and 6b are gradually widened toward the tips of the end portions 6a and 6b so as to correspond to the shape of the core end portion 1b of the sheet 1 and the shape of the core 11 corresponding to the core end portion 1 b.

On the upper surface of a portion corresponding to one end 6a of the upper frame 3a, a positioning pin 7a and two positioning protrusions 7b for positioning the connecting member 40 are formed. An upper flange 8 is formed on the upper surface of a portion corresponding to the other end 6b of the upper frame 3a so as to protrude at the same height as the upper surface of the end 6 a.

Lower flanges 9 are formed on the lower surfaces of the portions corresponding to the end portions 6a and 6b of the lower frame 3b so as to protrude by the same height.

As shown in fig. 5 and 6, specific dimensions of the core metal frame 3 include, for example, a length of the core metal frame 3 in the longitudinal direction of 16.0mm, a length of the central portion 5 in the longitudinal direction of 10.4mm, a width of the central portion 5 in the width direction of 2.2mm, widths of the end portions 6a and 6b of 5.4mm, a thickness of the central portion 5 of 1.6mm, and a length from a lower surface of the lower flange 9 to an upper surface of the upper flange 8 (from a lower surface of the lower flange 9 to an upper surface of the end portion 6a) of 4.8 mm.

The coil 4 is, for example, a copper wire, and the core 11 is wound around the core bobbin 3. As shown in fig. 8 and 9, the coil 4 is wound around the central portion 5 of the core bobbin 3 with a substantially uniform thickness, and is wound on substantially the same plane as the outer surfaces of the end portions 6a and 6b of the core bobbin 3, particularly, at substantially the same height as the upper flange 8 and the lower flange 9.

The coil 4 is wound 1195 turns (14 layers) around the central portion 5 with, for example, a copper wire having a diameter of 0.1 mm.

As shown in fig. 1, the connecting member 40 is formed of a flexible bottom plate, and a positioning hole 43 for positioning the connecting member 40 at the end portion 6a is provided at one end portion 41 thereof so as to be inserted into a positioning pin 7a formed at the end portion 6a of the core frame 3 (upper frame 3 a). Further, a positioning groove 44 for defining the connecting member 40 to rotate about the positioning pin 7a is provided in the edge portion 41a of the end portion 41 so as to be engaged with the positioning projection 7b formed in the end portion 6a of the core frame 3 (upper frame 3 a). The connection member 40 is positioned at a predetermined position of the antenna body 20 (the end 6a of the core bobbin 3 (the upper bobbin 3 a)) by the positioning pin 7a and the positioning hole 43, and the positioning projection 7b and the positioning groove 44, and is mounted.

The other end 42 of the connecting member 40 is configured to be electrically connected to a circuit board (not shown) of the electronic device and assembled.

In addition, on the two wiring leads 45 provided between the one end portion 41 and the other end portion 42 of the connection member 40, lead terminal portions 45a are formed at the end portions 41, respectively. The lead terminal portions 45a are fixed to the respective ends of the coil 4 of the antenna body 20 in an electrically connected state by solder 46 by protruding from the back surface to the front surface of the connecting member 40 through holes (not shown). The wiring lead 45 of the other end 42 of the connection member 40 is electrically connected to a circuit board (not shown) of the electronic device, so that the connection member 40 can be electrically connected to the antenna body 20 and the electronic device (not shown).

The following describes an assembly manufacturing method of the antenna 100 of the present invention.

First, as a first step, the sheet 1 is formed into a planar shape, and a plurality of layers are stacked. After a predetermined number of thin plates 1 are stacked, spacers 2 are placed on core end portions 1b at both ends of the thin plates 1. At this time, the acute-angle tip sides of the wedge-shaped spacers 2 placed on both ends of the thin plate 1 are arranged facing each other from both ends toward the center.

Then, a plurality of thin plates 1 are further stacked thereon. Then, the core 1a of the sheet 1 is stacked as before, but the core end 1b is tilted near the boundary of the core 1a and the core end 1b due to the installed spacers, and the stack is widened in the thickness direction in which the sheets 1 are stacked as it is to be separated from the core end 1b stacked in front of the spacer 2.

When the core 11 is formed by stacking a predetermined number of thin plates 1 in this manner, the spacers 2 are placed between the predetermined thin plates, whereby both end portions of the core 11 can be formed into a shape having a width extending in the thickness direction.

Next, as a second process, the core 11 formed as described above is placed in the accommodating portion 30 formed between the upper bobbin 3a and the lower bobbin 3b, which is sandwiched in the thickness direction of the core 11 by the upper bobbin 3a and the lower bobbin 3 b.

Next, as a third step, the coil 4 is wound around the core 11 with a substantially uniform thickness through the central portion 5 of the core frame 3 formed by combining the upper frame 3a and the lower frame 3 b. Then, the coil 4 is wound around the core frame 3 so as to have almost the same outer shape as the end portions 6a and 6b of the core frame 3 and almost the same height as the upper flange 8 and the lower flange 9, thereby forming the antenna body 20 (see fig. 8 and 9).

Then, the positioning pin 7a and the positioning projection 7b on the antenna body 20 side and the positioning hole 43 and the positioning groove 44 on the connecting member 40 side are respectively engaged with each other, whereby the connecting member 40 is positioned and assembled at a predetermined position of the antenna body 20 (the end 6a of the core bobbin 3 (the upper bobbin 3 a)).

The antenna 100 is thus assembled and manufactured.

Next, examples and comparative examples of the above-described antenna are explained at the same time.

First, the antenna 100 of the present invention shown in fig. 1 to 3 was produced, and the Q values of the produced antenna 100 were measured for radio waves of 40kHz and 60kHz at an inductance (L) of about 20mH, and the results are shown in table 1.

In addition, as a comparative example, when the antenna of the present invention was assembled, the antenna was fabricated using the iron core in which only the thin plate 1 was laminated without using the spacer 2, and the Q values of the fabricated antenna were measured for the radio waves of 40kHz and 60kHz at an inductance (L) of about 20mH, respectively, and the results are shown in table 2.

TABLE 1

No.	40kHz		60kHz
					L(mH)	Q	L(mH)	Q
	1	19.99	98.0	20.57					95.7
2					19.89	98.0	20.50	96.4
	3	20.00	92.7	20.60					88.1
4					20.37	96.7	20.97	93.7
	5	20.12	96.7	20.22					95.5
6					20.3	98.3	20.92	95.6
	7	20.05	99.5	20.64					96.6
8					20.15	99.4	20.77	96.6
	9	20.35	91.3	20.97					86.5
10					20.25	99.6	20.87	97.3
	Average	20.15	97.02	20.70					94.20

TABLE 2

No.	40kHz		60kHz
					L(mH)	Q	L(mH)	Q
	1	20.91	86.5	21.61					86.3
2					20.55	86.4	21.22	84.0
	3	20.66	81.9	21.30					77.3
Average					20.707	84.93	21.377	81.67

As shown in fig. 1, in an antenna 100 having an iron core 11 in which the thickness direction of both end portions (core end portions 1b) of an iron core (thin plate 1) is widened by spacers 2, the average value of Q for a radio wave of 40kHz is 97.02, and the average value of Q for a radio wave of 60kHz is 94.20. On the other hand, as shown in fig. 2, in the comparative antenna in which only the thin plate 1 is stacked and which has a rod-shaped core with both ends of the core closed, the average value of Q for the radio wave of 40kHz is 84.93, and the average value of Q for the radio wave of 60kHz is 81.67.

As described above, the antenna 100 of the present invention has a Q value larger than that of the comparative antenna, and thus has better sensitivity. That is, it is understood that the reception sensitivity of the radio wave can be improved by widening both end portions of the core 11 using the spacers 2.

In this way, with respect to the core 11 provided on the antenna 100, while the thin plates 1 made of amorphous material are stacked in multiple layers, both end portions thereof are widened in the thickness direction of the core 11 on which the thin plates 1 are stacked using the spacers 2, and the reception sensitivity of radio waves can be improved.

In particular, in the sheet 1 used in the present embodiment, the core end portions 1b having a width wider than that of the core portion 1a are formed at both ends in the longitudinal direction of the core portion 1a, and have an approximately H shape in plan view, so that both ends of the core 11 have a large shape in plan view. As described above, in the present invention, by widening both end portions of the core 11 in the thickness direction, the size of both end portions can be increased, and the reception sensitivity of radio waves can be further improved.

Fig. 10 is an enlarged cross-sectional view showing an important part of an electronic watch 50 accommodating the antenna of the present invention. The electronic watch 50 has a watch case 51 made of synthetic resin. A glass 52 is disposed on the upper part of the wristwatch case 51, and a glass ring 53 made of metal is attached to the outer periphery of the upper part of the wristwatch case 51. A watch module 54 is housed in the case 51, and a metal back cover 55 is attached to a lower portion of the case 51 via a waterproof ring 56.

The meter module 54, although not shown, has at least one of an analog function or a digital function. That is, the analog function is constituted by having the analog movement mechanism accommodated in the case, the hand shaft extending above the dial plate, and hands such as hour hand and minute hand mounted on the upper portion of the extended hand shaft, which are rotated above the dial plate. In addition, the digital function is configured as a flat display panel such as a liquid crystal display panel or an EL panel (electroluminescence panel) disposed on the upper part of the case, and information such as time is displayed on the display panel by an electro-optical method. In addition, the watch module 54 is equipped as a circuit board (not shown) that drives the analog movement mechanism and the display panel.

In addition, the band attaching portion 57 is formed to protrude obliquely downward at both side portions (only the 12 th case side portion is shown in fig. 10) of the 12 th case side and the 6 th case side of the case 51, and an antenna accommodating recess 58 is provided at a side portion of the case 51 of the band attaching portion 57 located at the 12 th case side as shown in fig. 10. The antenna accommodating recess 58 accommodates the antenna 100, and opens to the outside of the case 51 while providing a communication hole 59 connecting the inside of the case 51. A protective cover 61 is mounted by welding on the outer side surface of the case 51 in the antenna accommodating recess 58 so as to cover the protective antenna 100. The protective cover 61 is formed using a synthetic resin so as not to block radio waves. The antenna body 20 of the antenna 100 is adhered to the antenna housing recess 58 and the protective cover 61 by the adhesive tapes 62 on both surfaces. In addition, the connection part 40 of the antenna 100 enters the watch module 54 in the watch case 51 through the communication hole 59, and is electrically connected to the circuit board (not shown in the figure).

As with the above-described core 11, the shape of the core 11 is not limited as long as both end portions of the core are shaped to be widened in the thickness direction.

For example, as shown in the first modification example of fig. 11, both end portions of the core 11a may be configured to be widened on both sides of the core 11a in the thickness direction by the spacers 2. With this configuration, the aperture ratio of both end portions is increased by the configuration in which the core 11 is widened on one side, thereby improving the reception sensitivity.

For example, in a second modification shown in fig. 12, a plurality of spacers 2a may be provided between the thin plates 1, each thin plate 1 may be separated, and both end portions of the core 11b may be widened in the thickness direction.

Further, for example, in a third modification shown in fig. 13, the shape of the spacer 2b may be modified to a shape suitable for separating the thin plates 1. Further, for example, in a fourth modification shown in fig. 14, a plurality of spacers 2c may be provided between the thin plates 1.

When the shape as shown in fig. 13 or 14 is adopted, the bending stress is dispersed without locally concentrating the bending stress on the thin plate 1, and the occurrence of cracks due to stress concentration, for example, can be prevented in the case of using the gasket shown in fig. 1 to 3.

For example, in a fourth modification shown in fig. 15, a plurality of wires 10 made of an amorphous material and having a constant diameter may be bundled together to form a core 11c, and the tip end portions 10a of the wires 10 may be widened outward from the center of the bundle at both ends thereof.

In this way, in the antenna core of the fourth modification example, since both end portions of the core 11c formed by bundling a plurality of wires 10 made of an amorphous material and having a constant diameter are widened from the center of the bundle, the diameter of the core 11c at both end portions is larger than that at the center portion, and the reception sensitivity of radio waves can be improved. Therefore, the same effect as that of the antenna of fig. 1 to 3 can be obtained.

In the above embodiment, the spacers are disposed and sandwiched between the thin plates to widen the core in the thickness direction, but the present invention is not limited to this, and the spacers may be omitted to form a space between the thin plates to widen the core in the thickness direction.

The spacers are not limited to being placed and held when the thin plates 1 are stacked, and may be inserted between predetermined thin plates after the core 11 is formed.

In addition, ferrite may be used as a material constituting the spacer, for example.

In addition, the thin plate and the gasket may be stacked or fixed by adhesion.

It goes without saying that other specific fine structures and the like may be appropriately changed.

Claims (11)

1. An antenna, characterized in that the antenna has:

an iron core formed by stacking a plurality of amorphous magnetic material sheets having a predetermined thickness and having both end portions widened in a thickness direction;

a coil wound on the core;

and spacers disposed between the thin plates at both end portions of the core.

2. The antenna of claim 1, wherein said antenna is an antenna for receiving long waves.

3. The antenna according to claim 1, wherein the antenna is an antenna for receiving a radio wave including time data.

4. The antenna of claim 1, wherein the antenna is housed within a case.

5. The antenna according to claim 1, further comprising a core frame accommodating the core, wherein the coil is wound around a central portion of the core frame.

6. An antenna, characterized in that the antenna has:

an iron core formed by binding a plurality of amorphous magnetic material wires having a certain diameter, both end portions of which are widened from the center of the bundle;

and a coil wound on the core.

7. The antenna of claim 6, wherein said antenna is an antenna for receiving long waves.

8. The antenna according to claim 6, wherein the antenna is an antenna for receiving radio waves including time data.

9. A method of manufacturing an antenna, the method comprising:

a first process of stacking a plurality of amorphous magnetic material thin plates having a predetermined thickness, then placing spacers at both ends thereof, and stacking a plurality of amorphous magnetic material thin plates having a predetermined thickness thereon to form an iron core,

a second step of placing the iron core in a pair of upper and lower frames,

and a third step of winding a coil around the bobbin.

10. An antenna, characterized in that the antenna has:

an iron core formed by stacking a plurality of amorphous magnetic material sheets, both end portions of which are widened in a thickness direction;

and a coil wound on the iron core,

the iron core has:

a group 1 thin plate having a constant thickness and a horizontal cross section in the longitudinal direction;

and a group 2 thin plate which is overlapped on the group 1 thin plate, has a constant thickness, is horizontal at the center of the section in the longitudinal direction, and has two end parts bent in the thickness direction.

11. The antenna according to claim 10, wherein spacers are disposed between both end portions of the group 1 thin plate and both end portions of the group 2 thin plate.