JPH0338954Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to an improvement of a VTR connection adapter suitable for use in connecting a VTR set and the main body of a television receiver (TV).

Specifically, the VTR connection adapter previously proposed by the inventor of this application has a simple configuration and is easy to handle when connecting to a parallel two-wire feeder for TVs with different input impedances. By providing a connecting means with an integrated switching mechanism, you can quickly and reliably set up and connect a VCR.
We have further improved the VTR connection adapter that enables connection to the TV main unit, and have prevented unwanted contact between the terminal piece and other terminal parts that occur when the parallel two-wire feeder assembly is not in use. The present invention relates to a connection adapter that enables a good reception image of a TV to be obtained by preventing such problems.

BACKGROUND ART In general, TVs use two types of antenna terminals for input from a receiving antenna: a 300Ω parallel two-wire feeder and a 75Ω coaxial cable.

However, the output of the VTR set is a 75Ω coaxial cable.

Therefore, when connecting a VTR set and a TV, if the TV's antenna terminal is for a 300Ω parallel two-wire feeder, a connection adapter with a built-in balun transformer for impedance conversion is required. It becomes necessary.

Figures 3 1 and 2 are diagrams showing an example of the configuration of a conventional adapter for connecting a TV main body and a VTR set; 1 is a circuit diagram of the connection adapter;
2 is a plan view of a VTR connection cable and a VTR connection adapter. In the drawing, 21 is a VTR
21A is the adapter body, 21B is the parallel two-wire feeder assembly, 21C is the receptacle, 22 is the VTR connection cable, 22A is the coaxial cable, 22B
indicates a plug.

Conventional VTR sets have a 300Ω parallel two-wire feeder connection antenna terminal as shown in Figure 3, 1 and 2, so that connection is possible even when the TV body is equipped with an antenna terminal for connecting a 300Ω parallel two-wire feeder. A VTR connection cable 22 and a VTR connection adapter 21 are attached.

As shown in FIG. 3, the VTR connection cable 22 has plugs 22 at both ends of the coaxial cable 22A.
B is connected.

In addition, the adapter main body 21A has a built-in balun transformer for impedance conversion, as shown in FIG.
Receptacles 21C for 75Ω coaxial cables are connected to each.

The user must confirm that the antenna terminal of the TV they wish to connect to is
When using a 75Ω coaxial cable, the output terminal of the VTR set and the antenna terminal of the TV are connected through this VTR connection cable 22 shown in FIG. 3.

On the other hand, when the antenna terminal of the TV is for a 300Ω parallel two-wire feeder, the connection cable 22 and the VTR connection adapter 21 are used to connect the output terminal of the VTR set and the TV antenna terminal.
and use.

In other words, VTR connection cable 2 in Fig. 3 2
2 plug 22B to VTR connection adapter 21
Connect to the receptacle 21C of the parallel two-wire feeder assembly 21B of the connection adapter 21.
Match the input impedance by connecting to the TV's 300Ω antenna terminal through the connector.

In this way, users of the VTR set can
Depending on the type of antenna terminal of the TV that you wish to use in connection, you may use the VTR connection cable 22 alone or a combination of the VTR connection cable 22 and the VTR connection adapter 21.

For example, if you have two TVs, each antenna terminal has one for a 300Ω parallel two-wire feeder and one for a 75Ω
For coaxial cables, users can
Depending on the antenna terminal, the VTR connection adapter 21 may or may not be used.

Therefore, especially in such cases,
If you do not carefully store the VTR connection adapter 21, you will not be able to connect the VTR set to a TV equipped with a 300Ω parallel two-wire feeder antenna terminal.

On the other hand, from a manufacturer's standpoint, under these circumstances, I would like to use it by connecting it to a VCR set.
Whether the TV antenna terminal is a 75Ω coaxial cable or a 300Ω parallel two-wire feeder,
We had to prepare something that could adequately handle the situation, but we had the inconvenience of not being able to find something that would necessarily satisfy us.

As one method for solving such inconveniences, as already explained, the inventor of this application has previously proposed a connection adapter for VTR (Japanese Utility Model Publication No. 61-98293).

The VTR connection adapter proposed earlier solves these inconveniences associated with conventional connection adapters.

In other words, the connection adapter with a built-in balun transformer for impedance conversion is integrated with the coaxial cable and the parallel two-wire feeder, so even if the TV antenna terminal is a 75Ω coaxial cable, it will not connect to the 300Ω coaxial cable. Even in the case of a parallel two-wire feeder, it can be used immediately, and its usage is as simple as simply inserting a plug, and you can quickly set up a VTR and TV.
and can be connected.

Figure 4 shows the method proposed earlier by the inventor of this application.
FIG. 2 is a circuit diagram showing the main part configuration of a VTR connection adapter. In the drawing, 1 is a coaxial cable with a second 75Ω plug connected to the other end, 2 is a center contact, 3 is an outer contact, 4 is a tip spring, 5 is a break terminal, 6 is a balun transformer, and 7 is a parallel double The wire feeder assembly is shown.

As shown in Figure 4, the previously proposed
The VTR connection adapter includes a coaxial cable 1 whose other end is connected to the output terminal of the VTR set,
A first 75Ω plug consisting of a center contact 2, an outer contact 3, a chip spring 4 and a break terminal 5, and a balun transformer 6.
and a parallel two-wire feeder assembly 7 are provided to connect the coaxial cable 1 and the first 75Ω plug, and to connect the coaxial cable 1 to the first 75Ω plug. In this state, the coaxial cable 1 and the parallel two-wire feeder assembly 7 are connected via the tip spring 4 of the plug, the break terminal 5, and the balun transformer 6.

On the other hand, when this first 75Ω plug is attached to the receptacle, the tip spring 4 of the plug and the break terminal 5 are brought into a non-contact state by the receptacle, so that the plug is parallel to the coaxial cable 1. It operates so that the connection with the two-wire feeder assembly 7 side is cut off. the result,
The core wire of the coaxial cable 1 is connected only to the center contact 2 of the first 75Ω plug. Note that the outer contact 3 is grounded.

Figures 1 to 5 are structural diagrams showing an example of the previously proposed connection adapter for VTR; 1 is a front view;
2 is a left side view of the main part, 3 is a rear view of the main part, 4 is a partially cutaway side view of the main part, and 5 is a rear view of the main part showing a state with the cap removed. Reference numerals in the drawings are the same as in FIG. 4, and 8 is a mold case, 9 is a mold cap, 10 is a printed circuit board, and 11 is a solder terminal.

As shown in FIGS. 1 to 5, the 75Ω plug is composed of a center contact 2, an outer contact 3, a tip spring 4, and a break terminal 5.

On the printed circuit board 10, wiring constituting the necessary circuit is carried out, and in addition to these center contact 2, outer contact 3, chip spring 4, and break terminal 5, there is a balun transformer 6, and a coaxial cable 1. A solder terminal 11 for connecting and fixing the wire, a parallel two-wire feeder assembly 7, etc. are attached.

The VTR connection adapter shown in FIGS. 1 to 5 is comprised of such parts and is housed in a storage member consisting of a molded case 8 and a molded cap 9.

As already explained, the contact/non-contact operation between the tip spring 4 and break terminal 5 of the 75Ω plug is automatically performed by the receptacle attached to this plug, and when attached, the coaxial cable 1 and The connection with the parallel two-wire feeder assembly 7 side is cut off, and the operation is performed so that only the coaxial cable 1 and the plug are connected.

In this way, the VTR connection adapter previously proposed by the inventor of this application has a built-in balun transformer for impedance conversion, unlike conventional connection adapters, by integrally configuring the VTR connection adapter. The adapter body does not stand up, and when the user needs it,
Available for immediate use.

In addition, the balun transformer for impedance conversion is integrated with the adapter body, and the circuit can be switched by simply attaching the plug to the TV antenna receptacle.

However, when the 75Ω plug is attached to the receptacle, that is, when the connection between the coaxial cable 1 and the parallel two-wire feeder assembly I 7 is disconnected, the parallel two-wire feeder assembly I 7 The terminal piece is not connected to anything, and parallel two-wire feeders are relatively long, so UHF
A situation may arise in which the terminal comes into contact with the terminal.

Specifically speaking, this condition can be explained by using the VTR connection adapter shown in Figures 1 to 5 to connect the 75ΩIN.
(video output VHF) and 75ΩOUT (TV VHF)
300ΩOUT (parallel two-wire feeder) when listening to UHF channel with
There is a risk that the terminal piece may come into contact with the TV's UHF terminal.

In this case, there is an inconvenience that it adversely affects the TV and causes disturbances in the received image.

Problems to be Solved by the Invention Therefore, in the VTR connection adapter of this invention, by further improving the VTR connection adapter previously proposed by the inventor of this application, the inconveniences of the conventional connection adapter and the We solved all the inconveniences of the proposed VTR connection adapter at once, and with this VTR connection adapter,
75Ω output of VTR set and 75Ω of TV receiver
When watching a UHF channel with the TV's antenna terminal connected, the terminal piece of the unused parallel two-wire feeder may come into contact with the TV's UHF terminal, which may adversely affect the received image. The object of the present invention is to provide a connection adapter for a VTR that can provide good TV reception by removing the above.

Means for Solving the Problems This invention includes a pair of box-shaped mold cases 8 that constitute a thin box-like storage section, and a mold cap 9 that covers the storage section of the mold case 8, The storage part 8 contains the solder terminal 11, the balun transformer 6, and the first 75Ω
At one end of the joint surface between the mold case 8 and the mold cap 9,
The other end has a hole for a coaxial cable 1 to which a second 75Ω plug is connected, and the other end opposite to the one end has a hole for a parallel two-wire feeder assembly 7. The housing section of the molded case 8 has a first housing on the outer surface opposite to the mounting side of the molded cap 9, which is made up of a center contact 2, an outer contact 3, a tip spring 4, and a break terminal 5.
A plug for 75Ω is provided, the coaxial cable 1 and the first plug for 75Ω are connected, and the molded cap 9 is provided with the parallel two-wire feeder on the outer surface of the molded case 8 opposite to the installation side.・Equipped with a locking/fixing means 9A for locking/fixing the terminal piece of the assembly A 7, and when the first plug is not attached to the receptacle, the coaxial cable 1 and the parallel two-wire feeder assembly A 7 are connected to each other. are connected to the tip spring 4 of the first plug via the break terminal 5 and the balun transformer 6, and when the first plug is attached to a receptacle, the tip spring 4 is connected by the receptacle.
By bringing the break terminal 5 into a non-contact state, the connection with the parallel two-wire feeder assembly 7 is disconnected.

Embodiment Next, an embodiment of the VTR connection adapter of this invention will be described in detail with reference to the drawings.

1 to 4 are structural diagrams showing one embodiment of the VTR connection adapter of this invention; 1 is a front view;
2 is a left side view of the main part, 3 is a rear view of the main part, and 4 is a side view of the main part with a part cut away. The code in the drawing is the 4th
7A is the terminal piece of the parallel two-wire feeder assembly 7, and 9A is the same as in FIG.
1 is a locking/fixing means for a terminal piece of a parallel two-wire feeder assembly 7 provided in a mold cap 9, 12 is a center contact, and 12A is a break terminal portion thereof.

The VTR connection adapter of this invention has a molded cap 9 as shown in FIGS. 1 to 4.
A locking/fixing means 9A for the terminal piece of the parallel two-wire feeder assembly 7 is provided at . Note that the break terminal is formed between the break terminal portion 12A of the center contact 12 and the tip spring 4.

The following FIG. 2 is a side view showing the state in which the VTR connection adapter of this invention shown in FIGS. 1 to 4 is used. Reference numerals in the drawings are the same as in FIG. 1.

When 75ΩIN (video output VHF) and 75ΩOUT (TV VHF) are connected using the VTR connection adapter shown in Figure 1, 300ΩOUT
Since the terminal piece 7A of the (parallel two-wire feeder) is not particularly connected, it may come into contact with other parts.

In particular, when listening to a UHF channel, if the terminal piece 7A of the 300Ω OUT (parallel two-wire feeder) comes into contact with the TV's UHF terminal, the TV
adversely affects the received image.

Therefore, in such a connection state, the second
As shown in the figure, the terminal piece 7A of the parallel two-wire feeder assembly 7 is fixed by a terminal piece locking/fixing means 9A provided on the mold cap 9.

Effects of the invention According to the VTR connection adapter of this invention,
The impedance of the antenna terminal is 75Ω and
Two types of TV bodies with 300Ω and one with 75Ω output terminal.
When connecting to a VTR set, you can select whether to attach a 75Ω plug to the antenna terminal receptacle or connect it to the parallel two-wire feeder assembly side, depending on the type of TV antenna terminal. In particular, when the plug is attached to the receptacle, the circuit is automatically switched by the receptacle, so the attachment operation is extremely simple.

Moreover, parallel two-wire feeder assembly 7
Even if the terminal strip is disconnected, the TV's UHF
There is no risk of contact with the terminal, and there is no disturbance in the received image when viewing the UHF channel, so good reception is possible.

Furthermore, since its configuration requires the same minimum number of parts as conventional connection adapters, it has many excellent practical effects, such as being advantageous in terms of cost.

[Brief explanation of the drawing]

1 to 4 are structural diagrams showing one embodiment of the VTR connection adapter of this invention; 1 is a front view;
2 is a left side view of the main part, 3 is a rear view of the main part, 4 is a partially cutaway side view of the main part, and Fig. 2 shows how the VTR connection adapter of this invention shown in Figs. 1 to 4 is used. The side view shown in Figure 3, 1 and 2, shows the conventional TV body and
1 is a circuit diagram of the connection adapter, 2 is a plan view of the VTR connection cable and the VTR connection adapter, and FIG. A circuit diagram showing the main part configuration of the VTR connection adapter proposed by the inventor to Hikari, Figures 1 to 5 are structural diagrams showing an example of the previously proposed VTR connection adapter, 1 is a front view, 2 is a left side view of the main part, 3 is a rear view of the main part, 4 is a partially cutaway side view of the main part, and 5 is a rear view of the main part with the cap removed. In the drawing, 1 is a coaxial cable with a second 75Ω plug connected to the other end, 2 is a center contact, 3 is an outer contact, 4 is a tip spring, 5 is a break terminal, 6 is a balun transformer, 7
is a parallel two-wire feeder assembly, 7A is a terminal piece thereof, 8 is a molded case, 9 is a molded cap, 9A is a means for locking and fixing the terminal piece of the parallel two-wire feeder assembly 7; 10 is a printed circuit board, 11 is a solder terminal, 12 is a center contact, and 12A is its break terminal.

Claims (1)

[Scope of Claim for Utility Model Registration] A storage device for storing the molded case 8, comprising a pair of box-shaped molded cases 8 that constitute a thin box-like storage portion, and a molded cap 9 that covers the storage portion of the molded case 8. The part includes the solder terminal 11, the balun transformer 6, and the first 75Ω
At one end of the joint surface between the mold case 8 and the mold cap 9,
The other end has a hole for a coaxial cable 1 to which a second 75Ω plug is connected, and the other end opposite to the one end has a hole for a parallel two-wire feeder assembly 7. The housing section of the molded case 8 has a first housing on the outer surface opposite to the mounting side of the molded cap 9, which is made up of a center contact 2, an outer contact 3, a tip spring 4, and a break terminal 5.
A plug for 75Ω is provided, the coaxial cable 1 and the first plug for 75Ω are connected, and the molded cap 9 is provided with the parallel two-wire feeder on the outer surface of the molded case 8 opposite to the installation side.・Equipped with a locking/fixing means 9A for locking/fixing the terminal piece of the assembly A 7, and when the first plug is not attached to the receptacle, the coaxial cable 1 and the parallel two-wire feeder assembly A 7 are connected to each other. are connected to the tip spring 4 of the first plug via the break terminal 5 and the balun transformer 6, and when the first plug is attached to a receptacle, the tip spring 4 is connected by the receptacle.
A connection adapter for a VTR, characterized in that the connection with the parallel two-wire feeder assembly 7 is cut by bringing the break terminal 5 and the break terminal 5 into a non-contact state.