JPH0434568Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a television receiver in which a UV mixed signal input to a UV mixing input terminal is transmitted to a UV composite tuner via a UV signal transmission path. This relates to an antenna input circuit.

[Prior Art] The antenna input method for television receivers that is currently widely used is to connect the feeder lines that are individually connected to the VHF antenna and UHF antenna to the VHF input terminal and UHF input terminal of the television receiver. This is an individual UV input method where each is connected individually. As an alternative to this UV individual input method, there is a UV mixed input method as shown in FIG. this
The UV mixed input method combines the VHF signal and UHF signal received by VHF antenna 1 and UHF antenna 2.
Using a composite antenna 4 mixed by a UV mixer 3,
The received signal mixed by the UV mixer 3 is transmitted to one UV mixing input terminal 7 of the UV single-terminal television receiver 6 via one feeder line (for example, a coaxial cable) 5, and the internal UHF/ The signal was transmitted to a VHF composite tuner (hereinafter abbreviated as UV composite tuner) 8. The UV composite tuner 8 is
It consists of a UV demultiplexer 9, a UHF tuner section 10, and a VHF tuner section 11. In this way, the UV
According to the mixed input method, UV from the composite antenna 4
Since only one power supply line 5 is required to reach the single-terminal television receiver 6 and it is easy to handle, it is desired that UV single-terminal television receivers become popular.

[Problems to be solved by the invention] However, if a UV single-terminal television receiver is used and the power supply line is made into a single line for easier handling, the antenna must be replaced with a composite antenna at the same time. There was a problem with the increase in costs. In addition, if you try to use the VHF antenna and UHF antenna that have been installed separately in the UV single-terminal television receiver 6 as shown in FIG. A UV mixer 12 is connected before and after the UV mixing input terminal 7, and a feed line 15 from the VHF antenna 13 is connected to the UV mixer 12.
It was necessary to connect the feeder line 15b from the UHF antenna 14 to the feeder line 15b from the UHF antenna 14. In this way, since the UV mixer 12 is required as an accessory, the cost increases.Moreover, the advantage of easy handling, which is a feature of the UV single-terminal television receiver, is lost. There was a problem in that the received signal was attenuated due to the insertion loss of the duplexer, and the S/N ratio deteriorated in areas with weak electric fields compared to conventional UV individual input television receivers.

On the other hand, contrary to the above case, if you try to connect a composite antenna to a television receiver that has an individual UV input terminal, which is currently widely used, you will need to connect a splitter before the individual UV input terminal. There was a problem that it was not possible. For example, as shown in Figure 5, in the case of joint reception in buildings such as public housing, a method is used in which a composite antenna 4 is installed on the roof of the building and the output signal of the UV mixer 3 is distributed to each unit. There are many. In this case, in order to receive the television signal with the television receiver 6a equipped with the conventional UV individual input terminal,
In front of UHF input terminal 7a and VHF input terminal 7b
It was necessary to connect a UV demultiplexer 9a and connect the UV mixing input from the UV mixer 3 to the input side of the UV demultiplexer 9a. In this case, use the UV
Exactly the same drawbacks occur when a single-terminal television receiver is combined with individual UV transmission. That is,
The received signal is attenuated due to the insertion loss of the UV splitter 9a, so to compensate for this, in some cases, a booster or the like may be inserted between the UV mixer 3 and the UV splitter 9a to increase the signal level. It becomes necessary to raise the Furthermore, since the UV demultiplexer 9a is required, the cost increases.

This idea was created in view of the above-mentioned problems.
In contrast to the UV separate input method, in which the signals received by the UHF and VHF antennas are input to the antenna input terminal via separate feed lines, the UV mixed signal received by the composite antenna is input to the antenna input terminal via a single feed line. We also provide an antenna input circuit that can be adapted to the UV mixed input method that inputs to the antenna input terminal by making use of the characteristics of both.
The purpose is to promote the spread of UV single-terminal television receivers.

[Means for Solving the Problems] The present invention provides a television receiver in which a UV mixed signal input to a UV mixed input terminal is transmitted to a UV composite tuner via a UV signal transmission path. Insert the individual contacts on one side of the changeover switch and the movable side common terminal into the transmission line, connect the output side of the UV mixer to the individual contacts on the other side of the changeover switch, and connect the UHF mixer to the input side of the UV mixer.
Separate input terminals for inputting either the signal or VHF signal, and the UHF signal and VHF signal.
The UV mixed input terminal also serves as an individual input terminal for inputting the other signal, and two types of input, UV mixed input method and UV individual input method, can be achieved by switching the changeover switch. It is characterized by being adaptable to various methods.

[Operation] In the case of the UV mixed input method, connect the movable piece on the common terminal side of the changeover switch to the individual contact on one side,
Connect one feeder line that transmits the UV mixed signal to the UV mixed input terminal. Therefore, the UV mixed signal input to the UV mixed input terminal is sent to the UV composite tuner via the UV signal transmission path.

In the case of the UV individual input method, the movable piece on the common terminal side of the changeover switch is switched from the individual contact on one side to the individual contact on the other side, and the feeder lines that transmit the UHF signal and VHF signal are connected to each side. UV that doubles as an individual input terminal and another individual input terminal
Connect to mixed input terminal. For this reason, the UV
The UHF signal input to the mixed input terminal and
The VHF signal is mixed with the UV mixer and transmitted to the UV mixing tuner via the individual contacts on the other side of the changeover switch and the common terminal.

[Embodiment] Fig. 1 shows a television receiver 16 according to the present invention.
This figure shows an embodiment of the antenna input circuit 17, and the same parts as in FIGS. 3 and 4 have the same reference numerals.

In the figure, 18 is a grounded shield case. This is used to prevent foreign interference. 19 is a UHF individual input terminal as an individual input terminal for inputting the UHF signal received by the UHF antenna via a parallel two-wire feeder with a characteristic impedance of 300Ω; 75Ω
UV mixed input terminal for input via coaxial cable. This UV mixing input terminal 7
It also serves as a VHF individual input terminal for inputting VHF signals received by the VHF antenna. The UHF individual input terminal 19 is configured with a screw terminal, and the UV mixed input terminal 7 is configured with an F-type connector type.

The UV mixing input terminal 7 is connected to the UV signal transmission line 2.
0 and the individual contact 22 on one side of the changeover switch 21
It is connected to the UV composite tuner 8 via the common terminal 24 on the side of the movable piece 23 and the UV output terminal 25. The UV mixing input terminal 7 further includes UV
LPE (low pass filter) section 27 of mixer 26
It is connected to the individual contact 28 on the other side of the changeover switch 21 via.

The UHF individual input terminal 19 is connected to the H.
It is connected to the individual contact 28 on the other side of the changeover switch 21 via a PE (high pass filter) section 30.

The changeover switch 21 is integrally formed so as to be interlocked with the UHF individual input terminal 19, and when the connecting terminal of a parallel two-wire feeder is connected to the UHF individual input terminal 19, the movable piece 23 on the common terminal 24 side is connected to the individual contact 28 on the other side, and when not connected, the movable piece 23 on the common terminal 24 side is connected to the individual contact 22 on the one side.
For example, a bush type terminal already disclosed in FIG. 3 of Utility Model Application No. 56-138899 by the present applicant may be used as the UHF individual input terminal. The changeover switch 21 may be formed independently of the UHF individual input terminal 19 and configured to be electrically interlocked, or may be configured to be completely independent of the UHF individual input terminal 19 so that it can be switched manually. may be configured.

Next, the operation of the above embodiment will be explained. First, the case of the UV mixed input method in which the F-type connector of one coaxial cable from the composite antenna is connected to the UV mixed input terminal 7 will be described. At this time,
Since the parallel two-wire feeder connection terminal from the UHF antenna is not connected to the UHF individual input terminal 19, the movable piece 23 on the common terminal 24 side of the changeover switch 21 is connected to the individual contact 22 on one side.
Therefore, when a UV mixed signal is input to the UV mixed input terminal 7, this UV mixed signal passes through the UV signal transmission line 20, passes through the individual contact 22 and the common terminal 24 on one side of the changeover switch 21, and is output as a UV output. terminal 25
is sent to the UV composite tuner 8 via.

Next, connect the parallel two-wire feeder connection terminal from the UHF antenna to the UHF individual input terminal 19,
UV connecting the F type connector of the coaxial cable from the VHF antenna to the UV mixing input terminal 7 respectively.
The case of the individual input method will be explained. At this time, since the connection terminal of the parallel two-wire feeder is connected to the UHF individual input terminal 19, the movable piece 23 on the common terminal 24 side of the changeover switch 21 is connected to the individual contact 28 on the other side. Therefore,
The UHF signal input to the UHF individual input terminal 19 passes through the balloon 29, the HPF section 30 of the UV mixer 26, the individual contact 28/common terminal 24 on the other side of the changeover switch 21, and then passes through the UV output terminal 25 to the UV composite tuner. The VHF signal input to the UV mixing input terminal 7 passes through the LPF section 27 of the UV mixer 26 and is sent to the individual contact 2 on the other side of the changeover switch 21.
8. The signal is sent to the UV composite tuner 8 via the common terminal 24 and the UV output terminal 25.

In the above embodiment, the individual input terminal is a UHF individual input terminal, and the UV mixed input terminal is also used as a VHF individual input terminal to support the UV individual input method, but the present invention is not limited to this. ,
The individual input terminal can be a VHF individual input terminal, and the UV mixed input terminal can also be used as a UHF individual input terminal to make it compatible with the UV individual input method. In this case, the VHF individual input terminal can be connected directly or via an impedance converter depending on the characteristic impedance of the connected power line.
The UV mixing input terminal, which is connected to the input side of the LPF section of the UV mixer and also serves as the UHF individual input terminal, is connected to the HPF of the UV mixer directly or via an impedance converter, depending on the characteristic impedance of the connected power line. Connect to the input side of the section.

In the above embodiment, the changeover switch is a switch in which one movable piece on the common terminal side is switched and connected to two individual contacts, but the present invention is not limited to this, and for example, a switch as shown in FIG. It may also be a type changeover switch 21a. This changeover switch 21a has movable pieces 23a, 23b consisting of two sliders that slide in conjunction with each other, common terminals 24a, 24b consisting of common contacts, individual contacts 22a, 22b on one side, and Individual contacts 28a, 28
One terminal 24a of the common terminals 24a and 24b is connected to the output side of the UV mixer 26a, and the other terminal 24b is connected to the output side of the UV mixer 26a, and after passing through the UV signal transmission path 20a, a discharge gap is formed and the terminal 24b is used for cutting off the DC component. It is connected to the UV mixing input terminal 7 via a capacitor 31 consisting of a capacitor and an insulation resistor, and the individual contacts 22a and 22 on the one side
One side 22a of b is grounded, and the other side 22b is connected to UV via the UV signal transmission line 20a and coaxial cable.
One of the individual contacts 28a and 28b on the other side is connected to the UV output terminal 25 via a coaxial cable, and the other 28b is connected to the LPF section 27b of the UV mixer 26a.
connected to the input side of the 30a is the HPF section of the UV mixer 26a, and 32 and 33 are
This is a cap star inserted between the UHF individual input terminal 19 and the balloon 29. 34 is a capacitor inserted between the ground side of the UV mixing input terminal 7 and the ground.

In FIG. 2, when the movable pieces 23a and 23b of the slide type changeover switch 21a are in the illustrated state, it is the case of the UV mixed input system. That is, the common terminals 24a and 24b are connected to the movable piece 23.
Individual contacts 22 on one side by a and 23b, respectively.
a, 22b, and only the UV mixed signal input to the UV mixed input terminal 7 is sent to the capacitor 31, the UV signal transmission line 20a, and the selector switch 2.
The signal is transmitted to the UV composite tuner via the common terminal 24b of 1a, the individual contact 22b on one side, and the UV signal transmission line 20a, and then via the coaxial cable and the UV output terminal 25. On the other hand, move the movable pieces 23a and 23b of the slide type changeover switch 21a from the individual contacts 22a and 22b on one side to the individual contacts 28 on the other side.
When switching to a and 28b, the UV individual input method is used. That is, the UHF signal input to the UHF individual input terminal 19 is transmitted to the HP of the capacitors 32 and 33, the balloon 29, and the UV mixer 26.
The signal is transmitted to the UV composite tuner via the F part 30a and the common terminal 24a of the changeover switch 21a and the individual contact 28a on the other side, and then via the coaxial cable and the UV output terminal 25. In addition, the UHF signal input to the UV mixing input terminal 7 is transmitted to the capacitor 31,
UV signal transmission line 20a, common terminal 24b of changeover switch 21a, individual contact 28b on the other side, LPF section 27a of UV mixer 26, and changeover switch 21
The signal is transmitted to the UV composite tuner via the common terminal 24a on the side a and the individual contact 28a on the other side, and then via the coaxial cable and the UV output terminal 25.

[Effects of the invention] As described above, the antenna input circuit according to the invention can be used in a UV single-terminal television receiver.
For both input methods, the UV mixed input method and the UV individual input method, the configuration is such that the UV mixed signal can be sent to the UV composite tuner simply by switching the selector switch. For this reason, not only is it easier to handle the UV mixed input method by using a single power supply line, but also the UV individual input method does not require the addition of a mixer as an accessory, as in the case of the conventional method. The cost is low and handling is simple. Therefore, it is possible to promote the spread of UV single-terminal television receivers. Furthermore, when the changeover switch is configured to be changed over in conjunction with the individual input terminals, the changeover switch is automatically changed over, making handling even easier.

[Brief explanation of the drawing]

Fig. 1 is an electrical circuit diagram showing one embodiment of the antenna input circuit of a television receiver according to the present invention, Fig. 2 is an electrical circuit diagram showing another embodiment of the invention, and Fig. 3 is a standard UV Figure 4 is a conventional configuration diagram showing the reception system of a single-terminal television receiver.
A conventional configuration diagram showing a reception system in which a UV single-terminal television receiver is connected to an individual UV antenna. Figure 5 is a conventional configuration diagram showing a reception system in which a composite antenna is connected to a UV individual input television receiver. It is. 7... UV mixed input terminal (also serves as VHF individual input terminal), 8... UV composite tuner, 16... Television receiver, 17... antenna input circuit,
19...UHF individual input terminal, 20, 20a...
UV signal transmission line, 21, 21a... changeover switch, 22, 22a, 22b... individual contact on one side,
23, 23a, 23b...movable piece, 24, 24
a, 24b... common terminal, 26, 26a... UV
Mixer, 28, 28a, 28b...individual contacts on the other side.

Claims (1)

[Scope of claim for utility model registration] (1) The UV mixed signal input to the UV mixed input terminal
In a television receiver configured to transmit a UV signal to a UV composite tuner via a UV signal transmission path, an individual contact on one side of a changeover switch and a common terminal on one movable side are inserted into the UV signal transmission path, and a common terminal on one side of the changeover switch is inserted into the UV signal transmission path, Connect the output side of the UV mixer to the individual contacts on the side, and connect the output side of the UV mixer to the input side of the UV mixer.
An individual input terminal for inputting either a UHF signal or a VHF signal is combined with the UV mixing input terminal, which also serves as an individual input terminal for inputting the other of the UHF signal or VHF signal. An antenna input circuit for a television receiver, characterized in that it can adapt to two types of input methods, a UV mixed input method and a UV individual input method, by changing the changeover switch. (2) The individual input terminal for inputting one signal serves as a UHF input terminal as a screw terminal for connecting a power supply line with a characteristic impedance of 300Ω, and the UV mixed input terminal serves as a UHF input terminal for connecting a power supply line with a characteristic impedance of 75Ω. An antenna input circuit for a television receiver according to claim 1, which serves as an F-type connector seat for connecting a utility model. (3) A changeover switch is formed integrally with an individual input terminal for inputting one signal, and by connecting a power supply line to the individual input terminal, the movable piece on the common terminal side connects to one individual contact. An antenna input circuit for a television receiver according to claim 1 or 2, wherein the antenna input circuit is configured to automatically switch from one contact point to the other individual contact point.