JPH0119499Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a branching device that branches signals from a main line transmitting television signals, etc., to a television receiver, etc., in a communal viewing device, for example.

For example, there is a conventional turnout 1 as shown in FIG. That is, 2 is an input terminal, 3 is an output terminal, 4 is a branch terminal, 5 and 6 are coupling amount adjusting transformers, and 7 and 8 are frequency correction resistors and capacitors. When a signal is supplied to the input terminal 2, such a branching device 1 outputs signals from 1 to 1 in the VHF band and UHF band.
An output signal is generated at output terminal 3 with an insertion loss of 1.5 dB, and a branched output signal is generated at branch terminal 4 with a coupling loss of 10 to 12 dB.
When a signal is supplied to the input terminal 2, the reverse coupling loss is large, so the signal is transmitted to the input terminal 2, but almost no signal is transmitted to the output terminal 3. Therefore, in a communal viewing system in which a large number of branchers 1 are interposed in a main line connected to a UHF antenna and a VHF antenna via a mixer, a recorded signal of a VTR, for example, is connected to a branch terminal 3 of a certain brancher 1. Even if you supply
Almost no recording signal was transmitted to the branching device 1 subsequent to this branching device 1, and a television receiver connected to the branch terminal of the subsequent branching device 1 could not obtain a good image. Therefore, as shown in Figure 2,
A two-way divider 12 is provided on the output side of the VTR 10, one of its distribution terminals is connected to a television receiver 14, the other distribution terminal is connected to one distribution terminal of another two-way divider 15, and its input terminal and the other distribution terminal are interposed in the main line 16. 1
8 and 20 are UHF and VHF antennas, and 22 is a mixer. With this configuration, as shown by the dotted line in FIG.
10 recording signals can be transmitted, but there is a problem that the recording signals are radiated into the air via UHF and VHF antennas 18 and 20, and cause interference to television receivers receiving them on other antennas. Since the two-way splitter 15 must be newly installed, modification work is troublesome, especially in the case of an existing communal viewing system.

The object of this invention is to provide a turnout that solves each of the above problems.

This invention will be explained below based on one embodiment shown in FIGS. 3 to 6. Turnout 2 of this embodiment
5 is provided with switches 1a and 1b having the same configuration as the conventional 1-brancher shown in FIG.
6 and 26 are connected to each other, the input side of one branching device 1a is set as an input terminal 28, and the input side of the other branching device 1b is set as an output terminal 30. Note that parts equivalent to those of the conventional one are given the same reference numerals and explanations will be omitted. Therefore, when a signal is supplied to the input terminal 28, the signal is transmitted to the output terminal 30 with an insertion loss twice that of a single brancher, and a coupling loss of 10 to 12 dB is transmitted to the branch terminal 4a. to transmit signals. In this case, since the coupling loss between the terminals of the branching device 1b is large, almost no signal is transmitted to the branching terminal 4b. Furthermore, when a signal is supplied to the branch terminal 4b, the reverse coupling loss of the branch 1b is large, so the signal is transmitted to the output terminal 30, but almost no signal is transmitted to the input terminal 28 side, and the branch terminal 4a, Since the coupling loss between the terminals 4b is large, almost no signal is transmitted to the branch terminal 4b.

Therefore, as shown in FIG. 4, the 2-way splitter 15 is removed from the circuit shown in FIG. 2, and one 1-way splitter 1 is replaced with a splitter 25.
is connected to the input side of the VTR 10, the output side of the VTR 10 is connected to the input side of the 2-way divider 12, and one distribution side of the 2-way divider 12 is connected to the branch terminal 4 of the splitter 25.
b and the other distribution side is connected to the television receiver 14, the television receivers 14, 2
Good images can be obtained with both UHF and VHF.
No signals are radiated from the antennas 18, 20, and other antennas do not interfere with the receiving receiver. Furthermore, unlike the one shown in Figure 2, the main line 1
There is no need to newly install a two-way distributor 15 in the
Since the single branch 25 according to this invention may be provided in place of the conventional single branch 1, installation work becomes easy.

Figure 5 shows the output of VTR 10 using converter 32.
Convert it to a UHF signal and supply it to the 2-way splitter 12,
The input to the television receiver 24 side is divided into two parts by the divider 3.
4 is used to separate the VHF signal and UHF signal, but the configuration is the same as that shown in FIG.

FIG. 6 shows a case where the VTR 10 is on the terminal side and the data is transmitted from there to the television receiver 14 side. A normal two-way branch 36 is installed in the main line 16, and one branch terminal 36a is connected to the input side of the VTR 10. death,
One distribution side of the two-way splitter 12 is connected to the other branch terminal 36b of the two-way splitter 36, and the branch terminals 4a and 4b of the splitter 25 according to this invention are connected to the television receiver 14, and the VHF antenna 20 received
The VHF signal is supplied to the television receiver 14 and VTR 10 via branch terminals 4a and 36a, and
The output of 10 is converted into a UHF signal by a UHF converter 32, and supplied to the main line 16 from a branch terminal 36b, and then to the television receiver 14 from a branch terminal 4b.

The branching device according to this invention has a configuration in which the output sides 26, 26 of the branching devices 1a, 1b, which have a large reverse coupling loss, are connected to each other, so that when a signal is supplied to the input terminal 28, it is outputted to the output terminal 30 with a predetermined insertion loss. Not only can a signal be transmitted to the terminal 30, but also a signal can be transmitted to the branch terminal 4a with a predetermined insertion loss, and when a signal is supplied to the branch terminal 4b, the reverse coupling loss is large, so almost no signal is transmitted to the input terminal 28. ,
A signal can be transmitted to the output terminal 30 side. Therefore, if the splitter according to this invention is used in a joint viewing device as shown in FIGS. 4 to 6, the antenna 1
No radio waves are emitted via 8, 20,
Other antennas do not affect the receiving receiver. Furthermore, radio wave radiation can be blocked by simply replacing the conventional single branch used in the existing community viewing equipment with the branch of this invention, making installation work easier.

Incidentally, as a device capable of obtaining the same effect as above, the devices shown in FIGS. 7 and 8 can be considered. However, the one in FIG. 7 switches between the input side and the output side using changeover switches 40 and 42, and the one in FIG.
Since the branch side is switched by switches 4 and 46, there is a problem that noise is generated when the switch is switched, and the switching is troublesome. With this invention, such a problem does not occur. Note that the same parts as shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

In the above embodiment, a 1-brancher was explained, but a configuration in which the output sides of ordinary 2-branchers, 4-branchers, etc. are connected to each other, or a 2-brancher, a 4-brancher, etc. and a 1-brancher, etc., can also be used. It is also possible to have a configuration in which the output sides of the two are connected together. In addition to the configurations shown in the above-described embodiments, various known configurations can be used for the branching devices 1a and 1b. Further, although the number of television receivers is assumed to be two, it can be increased by increasing the number of single branchers 1 interposed in the main line 16. In addition, although the signal of the VTR 10 is transmitted to the television receiver 24 side, it is also possible to transmit signals from other sources such as a video disk, a wireless microphone, a UHF, VHF, or FM antenna other than the UHF, VHF antennas 18 and 20. .

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a conventional turnout, Figure 2 is a block diagram of a communal viewing system using a conventional turnout, Figure 3 is a circuit diagram of a turnout according to this invention, and Figure 4 is a circuit diagram of this invention. Part 1 of a joint viewing and viewing device using a turnout by
Fig. 5 is a block diagram showing another example of the same device, Fig. 6 is a block diagram showing yet another example of the same device, and Fig. 7 is a switch almost similar to the turnout according to this invention. This is a block diagram showing one example of an effective turnout, and FIG. 8 is a block diagram showing another example of the same turnout. 1a, 1b...branch switch, 4a, 4b...branch terminal (branch side), 26, 26...output side, 28...
Input terminal, 30...output terminal.

Claims (1)

[Scope of utility model registration request] When a signal is supplied to the input side, most of the signal is transmitted to the output side, and part of the signal is branched to the branch side, and when a signal is supplied to the branch point, most of the signal is transmitted to the input side. A branching device in which the output sides of two branching devices each configured to transmit data are connected to each other, one input side of both branching devices is connected to an input terminal, and the other input side is connected to an output terminal. .