JPH0134415Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to an improvement in the structure of an FM lead wire antenna, particularly the plug portion, which is suitable for use in a small pocketable FM radio receiver.

BACKGROUND TECHNOLOGY AND PROBLEMS There are an increasing number of small, portable FM radio receivers that do not come with a rod antenna in order to make them more compact. In such cases, when using earphones, the earphone cord acts as an antenna, while when listening through speakers, an FM lead wire antenna is used. Some models that use this FM lead wire antenna have a jack dedicated to the antenna, but there are some models that use the earphone jack as an antenna jack in order to manufacture it more cheaply and to make it more compact. In the case of such an FM lead wire antenna, it is not appropriate to use the same plug type as an earphone jack because the speaker connection will be broken when the antenna plug is connected.

Therefore, conventional devices as shown in FIGS. 1 to 3 have been proposed.

FIG. 1 shows a system diagram of an FM radio receiver in which the earphone jack is also used as an antenna jack. That is, in the figure, 1 indicates an earphone jack, and 2 indicates a speaker. Also, 3 is FM tuner, and this
The output of the FM tuner 3 is detected by a detection circuit 4, and the detected output is supplied to the contacts of the earphone jack 1 via the amplifier circuit 5, or to the speaker 2 via the contacts of the earphone jack 1. It is configured so that When a plug with an earphone connected is not inserted into the earphone jack 1, the fixed contact piece terminal 102 and the chip terminal 103 of the jack 1 are connected.
The output signal via the amplifier circuit 5 is now supplied to the speaker 2.

And when using earphones, the earphone cord becomes an FM antenna. That is, when the earphone plug 10 to which an earphone (not shown) is connected via the lead wire 11 is inserted into the earphone jack 1 as shown in FIG. , chip terminal 10
3 is disconnected from the fixed contact piece terminal 102 as shown in the figure, and the signal supply to the speaker 2 is cut off. At this time, the sleeve 13 of the plug 10 is connected to the sleeve terminal 101 of the jack 1. Further, this sleeve 13 is connected to the tip portion 12 via an insulating collar 14, and the lead wire 11 of the earphone and this sleeve 13 are connected within the knob portion 15 of the plug 10.

Therefore, the earphone cord 11 serving as an antenna
is connected to the antenna input terminal 3I of the tuner 3 via the sleeve terminal 101 of the jack 1 and the high frequency capacitor 6, and the FM broadcast wave reception signal is supplied to the input terminal 3I of the tuner 3. Become. At this time, the antenna output is prevented from flowing out by the high frequency choke coils 7 and 8.

In this way, you can listen to FM broadcast waves using earphones. Note that 104 is an insulating casing for attaching the jack 1 to the case 16.

Next, when using the speaker, it is done as follows.

In this case, an FM lead wire antenna is provided. This FM lead wire antenna has a lead wire 21 connected to a plug 20 as shown in FIG. This plug 20 has a sleeve 22 made of cylindrical metal, and this sleeve 22 has a lead wire 21 inside the knob 23 of the plug
is connected to. The length of this sleeve 22 is the length of the tip terminal 103 of the earphone jack 1.
The length is so short that it does not reach that part. However, it is naturally connected to the sleeve terminal 101. Therefore, when using this FM lead wire antenna, even if the plug 20 is inserted into the earphone jack 1, it remains connected between the chip terminal 103 and the fixed contact terminal 102, and the output of the amplifier circuit 5 is supplied to the speaker 2. be done. and,
At this time, the sleeve terminal 101 and the lead wire 21 are connected, and this is used as an FM antenna, and is connected to the tuner 3 through the capacitor 6.
The received signal is input to the antenna input terminal 3I of the antenna.

In the above way, the earphone jack can be set to FM.
It can also be used as an antenna input jack for a lead wire antenna, making it very suitable as a small FM receiver.

In this case, the tip end 12 of the plug connected to the earphone fits into the chip terminal 103 of the jack 1, thereby preventing the plug 10 from falling out from the jack 1.

On the other hand, plug 2 of the FM lead wire antenna
0 is a length that does not reach the tip terminal 103, and the sleeve 22 is simply a cylindrical metal. Therefore, if left as is, the plug 20 is more likely to fall out than the jack 1, which is a problem.

Purpose of the invention As described above, this invention was designed to enable the earphone jack to also be used as an antenna input jack.
The purpose of this invention is to improve the structure of the plug part of an FM lead wire antenna used in an FM radio receiver so that the plug does not easily fall out of the jack.

Summary of the invention This invention consists of an antenna plug 30 and a lead wire 34 that is led out from this plug part 30 and becomes an antenna.
has an outer diameter that is approximately the same as the opening diameter of the earphone jack 1 when inserted into the opening of the earphone jack 1, and has a length that does not contact the signal electrode 103 of the earphone jack 1. It has a cylindrical metal body 31 and an elastic plate-like body 32 disposed inside the cylindrical metal body 31, and a pair of slits are provided at opposing positions of the cylindrical metal body 31 in the direction of insertion into the jack 1. 31A and 31B are provided,
The elastic plate-like body 32 has a pair of slits 31A,
Parts 32A and 32B protrude outward from 31B, and are biased in the radial direction of the cylindrical metal body 31, and the width of a pair of slits 31A and 31B is in the direction orthogonal to the plate surface of this plate-shaped body 32. When the plug part 30 is inserted into the earphone jack 1, the protrusions 32A and 32B of the elastic plate-like body 32 are biased toward the center of the cylindrical metal body 31, and then
This is an FM lead wire antenna in which the protrusions 32A, 32B are elastically restored so that the plug part 30 is latched to the earphone jack 1 by the protrusions 32A, 32B, and the plug part is easily removed from the jack. This is to prevent it from falling off.

Embodiment Hereinafter, an embodiment of this invention will be described with reference to FIG. 4 and subsequent figures.

FIG. 4 shows a sectional view of the plug portion of the FM lead wire antenna according to this invention.

In this example, the plug 30 consists of a sleeve 31 made of a cylindrical metal body, and a fork-shaped contact plate 32 made of an elastic metal such as stainless steel and inserted into the sleeve 31.

In this case, the length of the sleeve 31 is, of course, selected to be short enough to prevent it from being connected to the tip terminal 103 of the earphone jack 1, as shown in FIG. The sleeve 31 also has
As shown in FIG. 5, slits 31A and 31B are formed in the direction of insertion into the jack. The slits 31A and 31B are provided at positions symmetrical about the center of the sleeve 31, that is, at positions facing each other. As shown in FIG. 6, the fork-shaped contact plate 32 is made of elastic metal such as stainless steel and has a U-shape, and two tips of the U-shape protrude in the direction of the surface of the contact plate. Projections 32A and 32B are formed. As shown in FIG. 4, these protrusions 32A and 32B
The fork-like contact plate 32 is inserted into the sleeve so that the contact plate 32 projects beyond the slits 31A and 31B of the sleeve 31 to the outside of the sleeve. In other words,
The distance d ₁ from the tip of the protrusions 32A and 32B to the tip is larger than the outer diameter d ₂ of the sleeve 31. At this time, the protrusion 32A,
32B is biased in the radial direction of the sleeve 31. Further, the fork-like contact plate 32 has each protrusion 32A,
Through 32B, slits 31A and 31B restrict deflection in a direction perpendicular to the plate surface. Normally, a plate-shaped body (not limited to the fork-shaped contact plate 32 of this embodiment) is easy to bend in a direction perpendicular to a wide surface (plate surface) (on the contrary, it is difficult to bend in a direction parallel to a wide surface). properties). In this embodiment as well, the fork-shaped contact plate 32 alone is easily bent in the direction perpendicular to the plate surface, but by disposing it inside the sleeve 31, the contact plate 32 is
Since the sleeve 31 is regulated by the slits 31A and 31B through the sleeve 2A and 32B, the above-mentioned deflection does not occur. On the other hand, sleeve 31
The inner diameter of the end where the slits 31A and 31B are not formed is slightly narrowed, and a cylindrical part 33a provided at the tip of the holding member 33 as shown in FIG. 7 is attached to this narrowed part. The sleeve 3 is inserted and the cylindrical portion 33a is caulked.
1 is held by this holding member 33. The fork-shaped contact plate 32 has a protruding portion 32C that protrudes from the bottom of the U-shape.
It is adapted to protrude to the outside through the cylindrical portion 33a of No. 3. Then, the core wire 34A of the lead wire 34 is soldered 35 to this protrusion 32C.

The lead wire 34 is supported by bending pieces 33b and 33c provided on the holding member 33, as shown in FIG. 7B.

In this way, the parts consisting of the sleeve 31, the fork-shaped contact plate 32, the holding member 33, and the lead wire 34 are integrally molded with the synthetic resin material 36 so as to mainly surround the connecting part.

When the FM lead wire antenna having the plug 30 constructed in this way is connected to the earphone jack 1, it becomes as shown in FIG. This eighth
In the example shown, the earphone jack is stereo jack 1', and the chip terminals are 103A and 1'.
There are two such as 03B. Therefore, two fixed contact piece terminals, 102A and 102B, are also provided. When the plug 30 of the FM lead wire antenna is inserted, the sleeve 31 is first inserted as shown in the figure, and the protrusion 32A of the fork-shaped contact plate 32,
When reaching the part 32B, this protrusion 32A,
The fork-shaped contact plate 32 is elastically biased so that the contact plate 32B enters into the sleeve 31, and when the protrusions 32A and 32B pass the sleeve terminal 101 portion, the elasticity causes the slits 31A and 31B of the sleeve 31 to be biased. More protruding parts 32A, 32B
protrudes outward again and comes into elastic contact with the sleeve terminal 101 of the jack 1', and this serves to prevent the plug 30 from coming out.

Therefore, the protrusion 32 of the fork-like contact plate 32
As shown in FIG. 6, the shapes of A and 32B are tapered with respect to the insertion direction of the plug 30, and the side in the direction in which the plug exits from the jack 1' is arcuate, so that the plug 30 can be inserted into the jack 1. It is shaped to facilitate elastic deflection when inserted into and exited from.

In this example, the contact plate 32 is connected to the sleeve terminal 1.
01, of course, the core wire of the lead wire 34 may be connected to the sleeve 31, and the sleeve 31 may be used for connection to the sleeve terminal 101.

Effects of the invention As described above, in this invention, a slit is provided in the sleeve of the antenna plug, an elastic plate-like body is inserted into this sleeve, and the protrusion that protrudes outward from the slit is connected to the plate-like body. By providing this on the body, when the plug is inserted into the jack, the protrusion of this plate-like body prevents the plug from coming out and at the same time connects elastically to the sleeve terminal of the jack, ensuring a secure connection. This has the effect of ensuring that it is not removed.

In addition, since the outer diameter of the sleeve is approximately the same as the opening diameter of the earphone jack, a frictional force acts between the outer circumferential surface of the sleeve and the inner circumferential surface of the jack, and this surface contact friction and the above-mentioned protrusion The synergistic effect with the locking caused by the elastic return of the plug prevents the plug from coming off from the jack more reliably.

In addition, due to the nature of the plate-shaped body, each protrusion will not be deflected in the radial direction of the sleeve unless a certain amount of force is applied, so when the plug is inserted into the jack and locked by the protrusion, The connection is strong and the plug is securely prevented from coming off the jack.

Moreover, there is an advantage that the structure for this purpose is very simple.

[Brief explanation of the drawing]

Figure 1 is a block diagram of an example in which the earphone jack is also used as an antenna input jack, Figure 2 is a sectional view to explain the state in which the earphone plug is inserted into the earphone jack, and Figure 3 is a conventional Figures 4 to 7 are cross-sectional views to explain the state in which the FM lead wire antenna plug is inserted into the earphone jack, and are examples of this invention.
FIG. 8 is a diagram showing the structure of the plug portion of the FM lead wire antenna, and is a sectional view for explaining an example of the state in which the plug of the FM lead wire antenna according to this invention is inserted into an earphone jack. 31 is a sleeve made of cylindrical metal, 32 is a fork-like contact plate made of an elastic plate, 33 is a holding member, 34 is a lead wire serving as an antenna, 35 is solder, and 36 is a synthetic resin.

Claims (1)

[Scope of utility model registration request] It consists of an antenna plug part and a lead wire that leads out from this plug part and becomes an antenna. When the antenna plug part is inserted into the opening of the earphone jack, it has a diameter that is approximately the same as the opening diameter of the earphone jack. a cylindrical metal body having an outer diameter of A pair of slits are provided at opposite positions of the cylindrical metal body in the direction of insertion into the jack, and a portion of the elastic plate-like body protrudes outward from the pair of slits, and the convergence of the cylindrical metal body The plug section is elastically biased in the direction, and movement is restricted by the width of the slit in the direction perpendicular to the plate surface of the plate body, and when the plug part is inserted into the earphone jack, the plate body's movement is regulated by the width of the slit. After the protruding part is biased toward the center of the cylindrical metal body, the protruding part elastically returns, and the plug part is locked to the earphone jack by the protruding part. antenna.