JPH0518179U - CATV transmission system - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention is, for example, in an apartment house, to receive the CATV broadcast at a low cost by a slight modification of the existing receiving system without incurring the cost burden to the receiver of only the terrestrial broadcast. With the goal. [Structure] A CATV channel signal branched from a CATV trunk line 9 is passed through a CATV / UHF converter 15 to UH.
F It is converted to a channel corresponding to the frequency band of terrestrial broadcasting, mixed with the received signal of UHF terrestrial broadcasting obtained from the UHF antenna 1 of the existing reception system by the UHF / UHF mixer 14, and is also supplied to the TV terminal 15 for each user. UHF for decoding the derived U / V mixed signal through the demultiplexer 6 into a CATV scramble signal
It is configured by being supplied to the television receiver 7 through the home terminal 16.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a CAT V (cable television) transmission system for broadcasting a broadcast program and a self-produced program via a cable.

[0002]

[Prior Art]

 In general, CATV broadcasting has spread to single-family homes, and the number of subscribers in collective housing is very small.

That is, a terrestrial broadcasting common reception system is usually introduced in an apartment house, but it is available to users who want to receive only terrestrial broadcasting and users who subscribe to CATV and want to receive pay broadcasting. Due to the resident's demands, there has been no cheap transmission system that can receive both terrestrial broadcasting and CATV broadcasting without incurring the cost burden to the recipients of only terrestrial broadcasting.

FIG. 2 shows the configuration of a housing complex receiving system that receives only terrestrial broadcasting. In the figure, 1 is a UHF receiving antenna, 2 is a VHF receiving antenna, and 3 is a mixture of UHF signal and VHF signal. U / V mixing amplifier that compensates the distribution loss, 4 is a distributor, 5 is a TV terminal installed in each dwelling unit, 6 is a VHF and UHF terminal of the television receiver 7, and the respective signals are demultiplexed. It is a duplexer to be connected.

That is, the UHF reception signal and the VHF reception signal received by the UHF antenna 1 and the VHF antenna 2 are derived from the U / V mixing amplifier 3 via the distributor 4 to a large number of television terminals 5. The user demultiplexes the U / V mixed signal derived to the television terminal 5 into a UHF broadcast signal and a VHF broadcast signal via the demultiplexer 6 and supplies the demultiplexed signal to the television receiver 7 to request terrestrial broadcasting. You can receive the program.

FIG. 3 shows a configuration of a receiving system obtained by modifying the above-mentioned terrestrial broadcasting-compatible housing reception system for CATV broadcasting. In FIG. 3, 8 is a trunk line branch amplifier for amplifying and branching the signal of the CATV trunk line 9. 10 is tap-off for further branching the branch line to connect to the drop line, 11 is a protector, 12 is an indoor amplifier for amplifying VHF, mid band, and super high band, 13 is CATV channel can be received only by CATV subscribers. It is a home terminal with a built-in scramble decoder. 4A and 4B show frequency arrays for terrestrial broadcasting and CATV broadcasting. FIG. 4A shows a frequency array for terrestrial broadcasting, and FIG. 4B shows a frequency array for CATV broadcasting.

In the terrestrial broadcasting frequency array shown in FIG. 4A, both the VHF low channel and the VHF high channel and the VHF high channel and the UHF channel are used for wireless communication. ..

In the frequency arrangement of the CATV broadcast shown in FIG. 4B, the VHF low channel and the VHF high channel are in the mid band, and the VHF high channel and the UHF channel are in the super high frequency. Used as a CATV dedicated channel up to 450 MHz as a band.

That is, the CATV signal transmitted to the CATV trunk line 8 is derived from the trunk line branch amplifier 9 to a large number of television terminals 5 via the tap-off 10, the protector 11, the indoor amplifier 12, and the distributor 4. Then, the user can receive the desired CATV channel by decoding the CATV signal led to the TV terminal 5 at the home terminal 13 and supplying the decoded TVTV signal to the TV receiver 7. In this case, terrestrial broadcasting is also cable-transmitted from the CATV station, and UHF broadcasting is converted into an empty channel of VHF broadcasting and transmitted.

[0010]

[Problems to be solved by the device]

 However, in the conventional CATV receiving system as described above, since terrestrial broadcasting is also transmitted by cable from the CATV station, a user who wants to receive only terrestrial broadcasting must pay a corresponding reception fee to the CATV station. Compared to when it is directly received by the terrestrial broadcast collective dwelling reception system, the image quality may be slightly degraded because the broadcast signal is transmitted through many trunk line amplifiers. There is a disadvantage to the person.

On the other hand, in a newly built apartment house, a method of wiring a double cable to each house in advance at the construction stage has been adopted. However, adding cables to an existing apartment house requires a high construction cost. However, there are many cases where wiring is difficult due to the structure of the house, which is an unrealistic problem.

The present invention has been made in view of the above problems. For example, in an apartment house, a CATV broadcast can be provided inexpensively by a slight modification of an existing reception system without incurring a cost burden to a receiver of only terrestrial broadcast. The purpose is to provide a CATV transmission system that enables reception.

[0013]

[Means for Solving the Problems]

 That is, the CATV transmission system according to the present invention comprises a terrestrial broadcasting receiving system for deriving a UHF broadcasting signal from a UHF antenna and a VHF broadcasting signal from a VHF antenna from a television terminal via a UHF / VHF mixer. Then, a CATV trunk line for transmitting the CAT V broadcast signal, a trunk line branch amplifier for amplifying and branching the CATV broadcast signal transmitted to the CAT V trunk line, which is interposed in the CATV trunk line, and branched by this trunk line branch amplifier. UHF broadcasting from the UHF antenna, which is interposed between the CATV / UHF converter for converting the frequency band of the CATV broadcasting signal into the frequency band corresponding to UHF terrestrial broadcasting and the UHF antenna and the UHF / VHF mixer. The signal and the CATV broadcast signal converted into the UHF band by the CATV / UHF converter are mixed. And a UHF / UHF mixer for demultiplexing, and a UHF / VHF mixed signal derived from the above-mentioned television terminal, and a demultiplexer for demultiplexing into a UHF signal and a VHF signal and supplying them to a television receiver. ..

[0014]

[Action]

 In other words, users who receive only terrestrial broadcasting can perform good reception by directly inputting the received signals from the UHF and VHF antennas as before without requiring major changes to the existing housing complex reception system. The applicant can use the UHF selection channel to receive the CATV broadcast.

[0015]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a CATV transmission system in an apartment house. The UHF reception signal from the UHF antenna 1 and the VHF reception signal from the VHF antenna 1 are mixed and amplified by the U / V mixing amplifier 3. After that, it is led out to the television terminal 5 installed in each of a number of dwelling units through the distributor 4. Here, a UHF / UHF mixer 14 is interposed between the UHF antenna 1 and the U / V mixing amplifier 3.

On the other hand, the CATV signal transmitted to the CATV trunk line 9 is amplified and branched via the trunk line branch amplifier 8 and then further branched via the tap-off 10 to be supplied to the CATV / UHF converter 15.

The CATV / UHF converter 15 is composed of an inexpensive heterodyne frequency converter, and converts the CATV channel frequency transmitted in the mid band and the super high band into the channel frequency of the UHF broadcasting band. The CATV signal converted into the UHF band channel by the CATV / UHF converter 15 is supplied to the UHF / UHF mixer 14 via the protector 11. Here, the power supply voltage for the CATV / UHF converter 15 is supplied from the trunk line branch amplifier 8 via a tap-off 10 of a current passing type.

The UHF / UHF mixer 14 mixes the CATV signal converted into the UHF channel and the UHF reception signal obtained from the UHF antenna 1, that is, the U / V mixing amplifier 3 and The broadcasting signals derived from the television terminals 5 mixed / distributed via the distributor 4 include the terrestrial broadcasting signals received by the UHF antenna 1 and the VHF antenna 2 and the CATV obtained from the CATV trunk line 9. The broadcast signal and the CATV broadcast signal are mixed and derived by being converted into a channel in the UHF broadcast band. Here, the CATV receiving equipment from the main branch amplifier 8 to the UHF / UHF mixer 14 is assumed to be a CATV station burden.

A demultiplexer 6 is connected to the television terminal 5 at each user's house. This demultiplexer 6 demultiplexes the U / V mixed signal derived from the television terminal 5 into a UHF band and a VHF band, and when the user wants to receive only terrestrial broadcasting, this U / V band is used. Any of the demultiplexed signals may be directly supplied to the UHF input terminal and the VHF input terminal of the television receiver 7, respectively.

In this case, since the terrestrial broadcasting can be directly received from the UHF antenna 1 and the VHF antenna 2 of the existing receiving system in the housing complex, the receiving user only for the terrestrial broadcasting needs to pay the reception fee to the CATV station. In addition, it is possible to receive with good image quality.

On the other hand, when the user wants to receive the CATV broadcast as well, the VHF reception signal demultiplexed by the demultiplexer 6 is directly supplied to the VHF input terminal of the television receiver 7, and the UHF reception signal is the UHF reception signal. It may be supplied to the UHF input terminal of the television receiver 7 through the home terminal 16.

The UHF home terminal 16 bypasses the terrestrial broadcast component of the UHF reception signal obtained through the demultiplexer 6 according to the selection of the UHF channel in the television receiver 7, and scrambles the CATV broadcast. This is a code decoding device, so that if only CATV subscribers are connected to the UHF home terminal 16, CATV broadcasting can be received together with ordinary terrestrial broadcasting obtained from the UHF antenna 1 and VHF antenna 2 of the existing reception system. be able to. That is, only the CATV subscribers can receive the CATV broadcast by paying the usage fee of the UHF home terminal 16 or the CATV reception fee, for example.

Therefore, according to the CATV transmission system having the above configuration, the CATV channel signal branched from the CATV trunk line 9 is converted into the channel corresponding to the frequency band of UHF terrestrial broadcasting through the CATV / UHF converter 15, / UHF mixer 14 mixes with the received signal of the UHF terrestrial broadcasting obtained from the UHF antenna 1 of the existing receiving system, and also passes through the demultiplexer 6 of the U / V mixed signal derived to the TV terminal 15 for each user. By supplying the generated UHF signal to the television receiver 7 through the UHF home terminal 16 which decodes the CATV scrambled signal, a terrestrial broadcasting only receiving user can receive without receiving a large change to the existing housing complex receiving system. Directly input the received signals from the UHF and VHF antennas 1 and 2 as before. In addition, the CATV subscriber can connect to the UHF home terminal 16 to receive the CATV pay broadcast.

[0025]

[Effect of the device]

 As described above, according to the present invention, the terrestrial broadcasting receiving system is provided which derives the UHF broadcasting signal from the UHF antenna and the VHF broadcasting signal from the VHF antenna from the TV terminal via the UHF / VHF mixer. , A CATV trunk line through which a CATV broadcast signal is transmitted, a trunk line branch amplifier that amplifies and branches the CATV broadcast signal that is interposed in this CATV trunk line and transmitted to the CATV trunk line, and a CATV broadcast that is branched by this trunk line branch amplifier. A CATV / UHF converter for converting a frequency band of a signal into a frequency band corresponding to UHF terrestrial broadcasting, and a UHF broadcast signal from the UHF antenna, which is interposed between the UHF antenna and the UHF / VHF mixer. UHF / UHF for mixing with the CATV broadcast signal converted into the UHF band by the CAT V / UHF converter Since it is equipped with a multiplexer and a UHF / VHF mixed signal derived from the above-mentioned TV terminal into a UHF signal and a VHF signal and supplies them to the television receiver, for example, in an apartment house. It will be possible to receive CATV broadcasts at low cost by making minor changes to the existing receiving system without incurring any cost burden to the recipients of only terrestrial broadcasts.

[Brief description of drawings]

FIG. 1 C in an apartment house according to an embodiment of the present invention
The figure which shows the structure of an ATV transmission system.

FIG. 2 is a diagram showing a configuration of a housing complex reception system that receives only terrestrial broadcasting.

[Fig. 3] The above-mentioned terrestrial broadcasting-compatible housing reception system C
The figure which shows the structure of the conventional receiving system remodeled for ATV broadcasting.

FIG. 4 is a diagram showing a frequency array of terrestrial broadcasting and CATV broadcasting.

[Explanation of symbols]

1 ... UHF antenna, 2 ... VHF antenna, 3 ... U / V
Mixing amplifier, 4 ... Distributor, 5 ... TV terminal, 6 ... Demultiplexer, 7 ... TV receiver, 8 ... Trunk amplifier, 9 ... CA
TV main line, 10 ... Tap-off, 11 ... Protector, 14 ... U
HF / UHF mixer, 15 ... CATV / UHF converter,
16 ... UHF home terminal.

Claims (3)

[Scope of utility model registration request] 1. A UHF broadcast signal from a UHF antenna and a VHF broadcast signal from a VHF antenna are UHF / VH.
In a CATV transmission system equipped with a terrestrial broadcast reception system that is derived from a TV terminal via an F mixer, a CATV trunk line for transmitting a CATV broadcast signal, and a CATV broadcast line that is interposed in the CATV trunk line and transmitted to the CATV trunk line. A trunk branch amplifier for amplifying and branching a signal, a CATV / UHF converter for converting a frequency band of a CATV broadcast signal branched by the trunk branch amplifier into a frequency band corresponding to UHF terrestrial broadcasting, the UHF antenna, and the UHF / UHF / A UHF / UHF mixer that is interposed between the VHF mixer and mixes the UHF broadcast signal from the UHF antenna with the CATV broadcast signal converted into the UHF band by the CATV / UHF converter, and from the TV terminal The derived UHF / VHF mixed signal is demultiplexed into a UHF signal and a VHF signal. CATV transmission system, characterized by comprising a supplying demultiplexer, to the television receiver. 2. A UHF broadcast signal from the UHF antenna and a VHF broadcast signal from the VHF antenna are UHF / VH.
In a CATV transmission system equipped with a terrestrial broadcast reception system that is derived from a TV terminal via an F mixer, a CATV trunk line for transmitting a CATV broadcast signal, and a CATV broadcast line that is interposed in the CATV trunk line and transmitted to the CATV trunk line. A trunk branch amplifier for amplifying and branching a signal, a CATV / UHF converter for converting a frequency band of a CATV broadcast signal branched by the trunk branch amplifier into a frequency band corresponding to UHF terrestrial broadcasting, the UHF antenna, and the UHF / UHF / A UHF / UHF mixer that is interposed between the VHF mixer and mixes the UHF broadcast signal from the UHF antenna with the CATV broadcast signal converted into the UHF band by the CATV / UHF converter, and from the TV terminal The derived UHF / VHF mixed signal is demultiplexed into a UHF signal and a VHF signal. A demultiplexer to be supplied to the television receiver, and a bypass between the terrestrial broadcast component of the UHF signal, which is interposed between the television receiver of the CATV subscriber and the demultiplexer and demultiplexed through the demultiplexer, and the CATV. A CATV transmission system, comprising: a UHF home terminal that decodes a scramble code corresponding to broadcasting. 3. The CATV transmission system according to claim 1, wherein the CATV / UHF converter is supplied with power from the trunk branch amplifier.