JP2529482Y2 - Retractable helical antenna - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retractable helical antenna used for mobile communication equipment.

[0002]

2. Description of the Related Art Conventionally, an antenna of a mobile communication device, particularly, a cordless telephone is provided with a helical antenna having a predetermined length so as to protrude from the device body or to be housed in the device body.

[0003]

In the above-mentioned cordless telephone, different frequencies are used for transmission and reception of the transmission / reception system, but the effective length of the antenna can be adjusted to only one of the frequencies. Therefore, in the weak electric field area, transmission or reception cannot be sufficiently performed.

[0004]

[Means for Solving the Problems] In order to solve the above-mentioned problems
In addition, the invention according to claim 1 includes a cylindrical rod, and the cylindrical rod.
The conductor inserted into the coil is wound into a coil shape and one end
The outer diameter of the coil is larger than the inner diameter of the cylindrical rod
Helical coil,
Insert the helical coil from the other end and project one end
And the helical coil in the cylindrical rod are integrated with resin
And a sliding contact terminal on the other end of the helical coil.
To form a helical rod antenna,
A cylinder with an inner diameter larger than the outer diameter of a ricard rod antenna
A helical rod antenna is formed
And the pole antenna
Numerical characteristics, and the slide inside the pole antenna
The helical rod antenna by contacting the moving contact terminals
Is movably stored. The device according to claim 2
Is a helical coil obtained by winding a conductor into a coil.
Helical coil is inserted into a cylindrical rod, and both ends of the helical coil are cylindrical.
Hold it at the position where it protrudes from the rod, and its protruding one end
And the helical coil inside the cylindrical rod is integrally molded with resin
And the other end protruding in an arc shape
Cover so that the sliding contact terminals of
The helical rod antenna is formed while the helical rod antenna is formed.
Cylindrical pole with inner diameter larger than outer diameter of pad antenna
Forming an antenna, the helical rod antenna and
Each pole antenna has different frequency characteristics.
Hold the sliding contact end inside the pole antenna.
To move the helical rod antenna.
It is stored at the moment.

[0005]

Therefore, according to the invention of claim 1, an antenna is provided.
The frequency characteristics of the antenna to two different frequencies
While the outer diameter of the coil at one end of the helical coil
By making it larger than the inner diameter of the rod,
The positioning of the cull coil can be performed accurately. Claim
According to the invention described in item 2, the frequency characteristics of the antenna are different.
Can be tuned to two frequencies
Make sure that the formed sliding contact terminals do not touch each other
Cover the other end of the helical coil in
Inward and outward elasticity at the position of the sliding contact terminal
Helical rod antenna into the cylindrical pole antenna
Easy insertion of the tena and sliding contacts
The terminal can be reliably brought into contact with the cylindrical pole antenna .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A retractable helical antenna according to the present invention will be described below with reference to the drawings.

First, as shown in FIG. 1, a wire 1 is wound into a coil shape, and a helical coil 3 is formed by slightly increasing the coil outer diameter of one end 2.

Next, as shown in FIGS. 2 and 3, the helical coil 3 is inserted and penetrated into a tubular rod 4 made of a soft resin, and the projected one end 2 and the helical coil 3 in the tubular rod 4 are formed. Are simultaneously molded integrally with a resin, the one end 2 of the helical coil 3 is bulged, and the tip 5 is formed to form a helical antenna rod.

As shown in FIG. 3, the other end 6 where the helical coil 3 protrudes out of the cylindrical rod 4 is provided with a through hole 7 at the end as shown in FIGS. 4 (a) and 4 (b). , 7 are inserted and mounted, and the arc-shaped sliding contact terminal 9 shown in FIGS. 5 (a) and 5 (b) which matches the outer diameter of the contact terminal fitting 8 is inserted. The sliding contact terminal 9 has a projection 10 formed by cutting and raising at an end thereof, and the two sliding contact terminals 9 are contact terminal fittings so that the projection 10 is fitted into the through hole 7. 8 to form a helical antenna portion.

Next, as shown in FIG. 6, a bent antenna 12 is provided at the tip of an antenna guide pipe 11 of a conductor having substantially the same length as that of the helical antenna to form a pole antenna. .

When assembling the retractable helical antenna of the present invention using the helical antenna portion, the pole antenna portion and other members, as shown in FIG. 7, a mounting hole 13 is provided at the other end of the antenna guide pipe 11. Is fitted and fixed via a ring-shaped packing 15 to the power supply terminal 14 provided with.

The return 12, 1 of the antenna guide pipe 11
The helical antenna portion is inserted from the side having 2, and the bush 16 having the edge 15 previously inserted into the cylindrical rod 4 of the helical antenna portion is inserted into the antenna guide pipe 11 and fixed by the return 12, 12. Therefore, when the helical antenna portion is pulled out, the sliding contact terminal 9 contacts the bush 16 to prevent the helical antenna portion from coming off.

In the retractable helical antenna configured as described above, the power supply terminal 14 is electrically connected to the antenna guide pipe 11 of the pole antenna, and slides the helical antenna in contact with the inner surface of the antenna guide pipe 11. The helical coil 3 is connected to the other end 6 of the helical coil 3 via the contact terminal 9 and the contact terminal fitting 8 attached to the sliding contact terminal 9.

[0014] The retractable helical antenna, when it is housed a helical antenna portion to the antenna guide pipe 11, the antenna guide pipe 11 becomes pole antenna portion, tuning characteristics in the receiving frequency 380MHz tuning example a cordless telephone to the frequency f ₁ To match.

Further, when pulling out the helical antenna portion from the antenna guide pipe 11, combined with tuning characteristic to the transmission frequency 254MHz tuning e.g. cordless telephone the helical antenna portion to the frequency f ₂ at the same time,
The pole antenna portion can be tuned to the frequency f _1.

Now, assuming that the coil outer diameter of the helical antenna portion is D mm, the coil wire diameter is d mm, the number of turns is N, and the pitch between the coils is P mm, the developed length l of the helical coil 3 is
₀ is

[0017]

(Equation 1)

## EQU1 ##

The 1 / 4λ of the transmission frequency 254 MHz is 29.5 cm, and the shortening rate α of the helical antenna portion is α.
Is

[0020]

(Equation 2)

## EQU1 ##

Α varies depending on the molding material and other factors P and d, and is determined experimentally.

The length of the antenna guide pipe 11 in the pole antenna portion corresponding to the reception frequency of 380 MHz is determined to be 1 / 4λ. However, if the length cannot be set to 1 / 4λ due to the design, a compression coil can be added to the power supply terminal 14 to increase the effective length.

[0024]

As described above, according to the invention of claim 1,
Tunes the frequency characteristics of the antenna to two different frequencies.
The helical coil at one end.
Make the outside diameter of the il larger than the inside diameter of the cylindrical rod
Of the helical rod when forming the helical rod antenna
Coil positioning can be performed accurately and easily.
The helical rod antenna to an appropriate length
A helical rod antenna can be a cylindrical pole antenna
It can be securely stored in the tena.

According to the second aspect of the present invention , the antenna
Frequency characteristics can be adjusted to two different frequencies
On the other hand, a plurality of sliding contact terminals formed in an arc shape
Cover the other end of the helical coil without touching it.
To move inward and outward at the position of this sliding contact terminal.
Inside the cylindrical pole antenna
Insertion of helical rod antenna into antenna
And a sliding contact terminal inside the cylindrical pole antenna.
The contact can be made surely.

[Brief description of the drawings]

FIG. 1 is a side view of a helical coil unit in a retractable helical antenna according to the present invention.

FIG. 2 is a side view of the helical antenna rod according to the present invention.

FIG. 3 is a sectional side view of the head of the helical antenna rod according to the present invention;

FIG. 4 is a front view and a side view of the contact terminal fitting according to the present invention.

FIG. 5 is a front view and a side view of the sliding contact terminal according to the present invention.

FIG. 6 is a sectional view of the antenna guide pipe according to the present invention;

FIG. 7 is a partially sectional side view of the retractable helical antenna according to the present invention.

[Explanation of symbols]

 Reference Signs List 3 Helical coil 4 Cylindrical rod 8 Contact terminal fitting 9 Sliding contact terminal 11 Antenna guide pipe 14 Power supply terminal 16 Bush

Claims (2)

(57) [Scope of request for utility model registration] 1. A cylindrical rod, and a cylindrical rod inserted into the cylindrical rod.
The conductor to be wound into a coil shape and the coil outer diameter at one end
Helical with a larger than the inner diameter of the cylindrical rod
And a helical coil inside the cylindrical rod.
Insert the file from the other end, and project one end and the cylindrical lock.
The helical coil inside the mold is integrally molded with resin, and
A helical coil with a sliding contact terminal at the other end of the helical coil
While forming a rod antenna, it has an inner diameter larger than the outer diameter of the helical rod antenna.
Forming a cylindrical pole antenna, and the helical rod antenna and the pole antenna
In this case, the sliding contact terminals are brought into contact with the pole antenna so that they have different frequency characteristics.
A helical antenna, wherein the helical rod antenna is movably housed . 2. A helical coil obtained by winding a conductor into a coil.
Insert the coil into the cylindrical rod, and
Hold both ends so that they protrude from the cylindrical rod.
Helical coil in one end and cylindrical rod
And the other end protruding into an arc shape
So that multiple sliding contact terminals do not touch each other
To form a helical rod antenna, while having an inner diameter larger than the outer diameter of the helical rod antenna.
Forming a cylindrical pole antenna, and the helical rod antenna and the pole antenna
In this case, the sliding contact terminals are brought into contact with the pole antenna so that they have different frequency characteristics.
A helical antenna, wherein the helical rod antenna is movably housed .