JPH03236635A - Modulator - Google Patents

Abstract

PURPOSE:To reduce a buildup cost of a signal supply system by receiving a video information signal for service and a broadcast signal such as a television receiver to a modulator, mixing both inputs and outputting the amplified signal. CONSTITUTION:A mixer 4 is provided in a modulator 1 and a broadcast signal for a television receiver or the like is inputted to the mixer 4 via an input terminal of the modulator 1 directly. Moreover, a video information signal for service converted into a radio frequency by a converter 3 is inputted to the mixer 4, in which the signal is mixed with the broadcast signal for the television receiver. The video information signal for service and the broadcast signal for the television receiver mixed are inputted to an RF amplifier 5 and amplified, and the result is outputted to a signal supply line for common reception via an output terminal of the modulator 1. Then a signal is fed to a receiver connecting to the signal supply line.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a modulator, and particularly to a modulator that supplies a television broadcast signal to a signal supply line for communal reception, and also mixes and supplies other video information, etc. related to a device for

In recent years, video-related media have become abundant, and there are an increasing number of cases in which services are provided by using these abundant media to supply information other than television broadcast signals to community reception equipment.

[Conventional technology]

Conventionally, in a system as shown in the block diagram of FIG. 2, a television broadcast signal was supplied to a signal supply line for communal reception, and other video information was mixed and supplied.

2 is a modulator, and the video signal and audio signal of the video information for the service manually inputted to the modulator 1 are added to the modulation circuit 2 as input signals, and the modulation circuit 2 converts the video carrier wave into the video signal for the service. The audio signal of the video information for service is modulated by the video signal of the information, and the audio signal of the video information for the service is 4.5 MHz from the video carrier wave.
FM modulates the distant carrier wave and outputs it to converter circuit 3
The converter circuit 3 converts the human power into RF, outputs it, and inputs it to the RF amplifier 5.
The amplifier 5 amplifies and outputs the power, and from the output terminal of the modulator 1, a video information signal for service converted to RF is applied to one end of the mixer 9, and the other end of the mixer 9 is supplied with a video information signal for service. Other signals, such as television UHF and VHF broadcast signals, are amplified by amplifiers 7 and 8, respectively, and then added. The mixer 9 mixes the television UHF and VHF broadcast signals and the service video information signal, outputs the mixed signal to the signal supply line for communal reception, and sends the signal to the receiver connected to the signal supply line. I was trying to supply it.

[Problem to be solved by the invention]

Therefore, when constructing a signal supply system, the number of component parts is large, and it takes time and effort to process the terminals of connection cables.
The problem was that the system construction cost was high.

An object of the present invention is to reduce the cost of constructing a system by directly inputting a broadcast signal from a television or the like to a modulator.

[Means to solve the problem]

As shown in FIG. 1, a mixer 4 is provided in the modulator 1,
A broadcast signal from a TV or the like is directly input to the mixer 4 through the input terminal of the modulator 1, and a video information signal for service, which has been converted to RF by the converter 3, is input to the mixer 4 to output the TV or the like. The video information signal for the service and the broadcast signal for the television etc. are amplified by the RF amplifier 5, and then output and modulated. The signal is outputted to a signal supply line for communal reception via the output terminal of the device 1, and the signal is supplied to a receiver connected to the signal supply line.

[Effect]

In the present invention, as shown in FIG.
The UHF broadcast signal, VHF broadcast signal, and service video information signal are input and amplified, and the frequency band of the UHF broadcast signal is 470 to 770 MHz, VHF
The frequency band of the broadcast signal is 90-222MHz,
Since the frequency of the video information signal for service can be an empty channel without television broadcasting, the frequency characteristic of the RF amplifier 5 is designed to be able to amplify up to the UHF band.

〔Example〕

FIG. 1 is a block diagram of a modulator showing one embodiment of the present invention. In the figure, 1 is a modulator, and a video signal and an audio signal of a video information signal for service are applied to a modulation circuit 2 through an input terminal of the modulator 1. The modulation circuit 2 converts a video carrier wave into a video information signal for service. The audio signal of the video information for service is modulated by the video signal of the video information, and the audio signal of the video information for service is 4.5M from the video carrier wave.
Hz+! The converted carrier wave is FM-modulated and outputted and inputted to a converter circuit 3, and the converter circuit 3 converts the carrier wave into RF of an empty channel where there is no television broadcasting, outputs it, and inputs it to a mixer 4.

Further, the mixer 4 receives a second signal and a third signal, such as a UHF broadcast signal and a VHF broadcast signal of a television, which are applied via the external input terminal of the modulator l, and mixes the signals. The mixer 4 mixes and outputs these input signals, and inputs the mixed signal to the RF amplifier 5.The RF amplifier 5 uses an amplifier that can amplify frequencies up to the UHF band, and mixes and outputs these input signals with the video carrier wave of the video information for the service. , the UHF broadcast signal of the television and the VHF- broadcast signal are amplified and outputted, outputted to the signal supply line for communal reception via the output terminal 6 of the modulator 1, and connected to the signal supply line. It is designed to supply a signal to the receiver that is being used.

The IGHz band intermediate frequency converted by the satellite broadcast receiving converter is input to the mixer 4 through the external input terminal of the modulator 1, and the mixer 4, RF amplifier 5, and connection cable are connected to the mixer 4.
If a device that can be used up to the GHz band is used, a satellite broadcast signal can be supplied as a television broadcast signal.

〔Effect of the invention〕

As explained above, according to the present invention, a signal supply system is realized by inputting a video information signal for service and a broadcasting signal such as a television to a modulator, and amplifying and outputting the signals by mixing the same with the modulator. It is possible to reduce the number of component parts when constructing a system, thereby lowering the cost of constructing the system.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a modulator showing one embodiment of the present invention;
FIG. 2 is a block diagram of a signal supply system using a conventional modulator. 1-...Modulator, 2- Modulation circuit, 3...
Converter, 4° mixer, 5°7° RF amplifier, output terminal.

Claims (1)

[Claims] A modulation circuit that modulates a carrier wave with a first input signal and outputs a modulated wave, a converter circuit that converts the modulated wave into RF and outputs a first RF signal, and the first RF signal is different from the first input signal. A mixer that mixes the second RF signal input to the device and outputs the first and second RF signals, and an RF amplifier that amplifies the first and second RF signals and outputs them to the signal supply line of the receiver. A modulator characterized by: