JP2001339219A - Antenna structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna structure which can stably fix an antenna pattern film to a cylindrical member (bobbin) and obtains sufficient vibration resistance and shock resistance. SOLUTION: The insulating bobbin 11 has through holes 12, penetrating the outer peripheral surface of the bobbin at right angles to the axis of the bobbin 11, at prescribed intervals along the axis and the outer peripheral surface of the bobbin is wound with the antenna pattern film 13. Rivet pins 14 made of plastic are inserted into the through holes. The rivet pins are thermally fused and fixed to the bobbin to fix the antenna pattern film to the bobbin. The antenna pattern film has a flexible insulating sheet 13a and conductor patterns 13b formed on the insulating sheet and the antenna pattern film has hole parts corresponding to the through holes.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for receiving radio waves from a satellite stationary above the earth (hereinafter also referred to as "satellite waves") or radio waves on the ground (hereinafter also referred to as "terrestrial waves"). The present invention relates to a digital radio receiver capable of listening to digital radio broadcasts, and more particularly, to an antenna used for a digital radio receiver.

2. Description of the Related Art Recently, a digital radio receiver capable of receiving a radio wave (satellite wave) or a terrestrial wave from an artificial satellite so as to listen to a digital radio broadcast has been developed and is being put to practical use in the United States. This digital radio receiver is mounted on a mobile station such as an automobile and has a frequency of about 2.3G.
It is possible to listen to a radio broadcast by receiving a radio wave of Hz. That is, the digital radio receiver is a radio receiver that can listen to mobile broadcasts. still,
The terrestrial wave is obtained by temporarily receiving a satellite wave at an earth station and then slightly shifting the frequency. About 2.3G like this
In order to receive a radio wave of a frequency of Hz, it is necessary to install an antenna outside the vehicle. As such an antenna, various antennas can be considered, but a stick type is generally used instead of a flat type (flat type). Also, as is well known, an electromagnetic wave radiated in free space is a transverse wave having an electric field and a magnetic field oscillating in a plane perpendicular to the traveling direction of the wave, and the electric field and the magnetic field change in intensity in the plane. However, this is called polarization. Satellite waves are circularly polarized waves, whereas terrestrial waves are linearly polarized waves. Therefore, in order to receive both the satellite wave and the terrestrial wave, a dedicated antenna is required for each. Hereinafter, an antenna for receiving a satellite wave will be mainly described. A helical antenna is known as one of the stick antennas. The helical antenna has a structure in which a plurality of conductors are wound in a helix (spiral) around a cylindrical or columnar member (hereinafter simply referred to as a bobbin), and can efficiently receive the above-described circularly polarized waves. it can. Therefore, the helical antenna is used exclusively for receiving satellite waves. As a material of the cylindrical member, an insulating material such as plastic is used. As the number of conductors, for example, four wires are used. On the other hand, it is actually very difficult to wind a plurality of wires in a helix on a bobbin. For this reason, it has been proposed that a flexible insulating sheet printed with a plurality of conductor patterns (hereinafter referred to as an antenna pattern film) be wound around a bobbin. After the antenna pattern film is wound around a bobbin, a tape is formed. The antenna pattern film is fixed to the bobbin using an adhesive or the like.

As described above, in the conventional helical antenna, after the antenna pattern film is wound around the bobbin, the antenna pattern film is fixed to the bobbin using a tape, an adhesive or the like. ,
The antenna pattern film may be peeled off from the bobbin due to long-term use, and it is difficult to stably fix the antenna pattern film to the bobbin. Furthermore, when a real antenna is installed in an automobile, vibration and impact are often applied. As described above, if the antenna pattern film is fixed to the bobbin using a tape, an adhesive, or the like, sufficient vibration resistance can be obtained. However, there is a problem that the resistance and impact resistance cannot be obtained. An object of the present invention is to provide an antenna structure that can stably fix an antenna pattern film to a bobbin. Another object of the present invention is to provide an antenna structure capable of obtaining sufficient vibration resistance and shock resistance.

According to the present invention, there is provided an insulating tubular member (11) and an antenna pattern film (13) wound on an outer peripheral surface of the tubular member. A plurality of through-holes (12) penetrating through the outer peripheral surface of the tubular member in a direction orthogonal to the axial direction of the tubular member are formed in the tubular member at predetermined intervals along the axial direction. A rivet pin (14) made of plastic is inserted into the through hole, and the antenna pattern film is fixed to the outer peripheral surface of the tubular member by the rivet pin. Holes are formed in the antenna pattern film corresponding to the through holes. The antenna pattern film includes a flexible insulating sheet (13a) and a plurality of conductor patterns (13b) formed on the insulating sheet. ), And the rivet pins are welded and fixed to the tubular member by heat welding, thereby fixing the antenna pattern film to the tubular member. In addition, the code | symbol in the said parenthesis is attached in order to make the understanding of this invention easy, and is only an example,
Of course, it is not limited to these.

Embodiments of the present invention will be described below with reference to the drawings. First, referring to FIG. 1A, the illustrated helical antenna includes an insulating cylindrical member (hereinafter referred to as a bobbin) 11.
1 has a plurality of through-holes 12 formed in a direction orthogonal to the center axis thereof. That is, a plurality of through holes 12 are formed in the peripheral surface of the bobbin 11. In the illustrated example, three through holes 12 are formed at predetermined intervals along the center axis direction. As shown in FIG. 1B, the above-described bobbin 1
1, an antenna pattern film 13 in which a plurality of conductor patterns 13 b are printed on a flexible insulating sheet 13 a is wound. Holes are formed in the antenna pattern film 13 corresponding to the through holes 13 described above. When the antenna pattern film 13 is wound around the bobbin 11, the through holes 12 and the holes are associated with each other to form an antenna pattern. The film 13 is wound around the bobbin 11. by this,
A plurality of conductor patterns 13b are formed on the bobbin 11 in a helical manner. Thus, the through hole 12
If the antenna pattern film 13 is wound around the bobbin 11 by associating the antenna pattern film 13 with the hole, the antenna pattern film 13 can be accurately wound around the bobbin 11. FIG.
Referring to (c), after the antenna pattern film 13 is wound around the bobbin 11 as described above, for example, a rivet pin 14 made of plastic is inserted into the through hole 12. The rivet pin 14 includes a head portion 14 a having a diameter larger than the diameter of the through hole 12 and a cylindrical body portion 14 b having a diameter slightly smaller than the diameter of the through hole 12. Until the head 14a contacts the through hole 12
Is inserted into the main body 14b. When the main body 14b is inserted into the through hole 12 in this manner, the tip of the main body 14b projects from the through hole 12 on the opposite side. Referring to FIG. 1D, after penetrating the rivet pin 14 as described above, the tip of the rivet pin 14 (that is, the tip of the main body 14a) is thermally welded. As a result, the tip of the main body 14a becomes larger than the diameter of the through hole 12, and the antenna pattern film 13 is firmly fixed to the bobbin 11 by the rivet pins 14. In this way, the antenna pattern film 13 is fixed to the bobbin 11 with the rivet pins 14, so that the antenna pattern film 13 can be stably stuck.
Not only can be fixed to the bobbin 11, but also sufficient vibration resistance and impact resistance can be obtained. As described above, the present invention has been described by the preferred embodiments, but it is needless to say that the present invention is not limited to the above embodiments.
For example, in the above embodiment, an example in which three through holes 12 are formed in the bobbin 11 has been described. However, if at least two through holes 12 are formed, the antenna pattern film 13 can be stably formed on the bobbin 11. Not only can it be fixed, but also sufficient vibration resistance and impact resistance can be obtained. Further, although a cylindrical member has been described as an example of the bobbin 11, another cylindrical member may be used as the bobbin.

As described above, according to the present invention,
After winding the antenna pattern film on the bobbin, the rivet pin is inserted into the through hole formed in the bobbin and the antenna pattern film is fixed to the bobbin with the rivet pin, so the antenna pattern film is fixed to the bobbin stably In addition to this, there is an effect that sufficient vibration resistance and impact resistance can be obtained.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing a configuration of a helical antenna according to an embodiment of the present invention, wherein FIG. 1A shows a cylindrical member (bobbin) having a through hole formed therein, and FIG. The figure which shows the state which wrapped the antenna pattern film around the bobbin shown by (c), the figure which shows the state which inserts a rivet pin in the through-hole in the state shown by (b), (d) inserts a rivet pin, It is a figure showing the state where the tip was welded.

[Explanation of symbols]

 Reference Signs List 11 Insulating cylindrical member (bobbin) 12 Through hole 13 Antenna pattern film 13a Insulating sheet 13b Conductor pattern 14 Rivet pin 14a Head 14b Main body

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masaaki Miyata 8-8-2 Kokuryo-cho, Chofu-shi, Tokyo Mitsumi Electric Co., Ltd. F-term (reference) 5J046 AA05 AA10 AA14 AB12 PA07 PA09

Claims (4)

[Claims] 1. An insulating tubular member, and an antenna pattern film wound on an outer peripheral surface of the tubular member, wherein the tubular member has a direction perpendicular to an axial direction of the tubular member. A plurality of through-holes penetrating the outer peripheral surface of the cylindrical member are formed at predetermined intervals along the axial direction, and a plastic rivet pin is inserted into the through-hole, and the rivet pin is used for the antenna. An antenna structure, wherein a pattern film is fixed to an outer peripheral surface of the tubular member. 2. The antenna structure according to claim 1, wherein holes are formed in the antenna pattern film corresponding to the through holes. 3. The antenna structure according to claim 1, wherein the antenna pattern film has a flexible insulating sheet and a plurality of conductor patterns formed on the insulating sheet. 4. The rivet pin is welded and fixed to the tubular member by heat welding to fix the antenna pattern film to the tubular member. 2. The antenna structure according to 1.