JP3149988B2 - Television video and audio signal transmission equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for transmitting television video and audio signals, and more particularly to a device for transmitting microwaves from a studio to a transmitting station.

[0002]

2. Description of the Related Art Conventionally, when a video signal and an audio signal are transmitted from a studio of a television station to a transmitting station, when the studio and the transmitting station are close to each other, they can be directly transmitted by a microwave transmission device owned by the television station, but far away. In this case, a signal is transmitted using a commercial microwave transmission device.

[0003] The audio signal for television audio multiplex broadcasting is
For example, in the stereo mode, the signal is composed of three signals of a main channel, a sub-channel, and a pilot, and the carrier of the pilot signal has a horizontal synchronizing signal frequency (f _H ) of 3.5.
Double frequency is used. However, the frequency band of the audio signal transmission band of the commercial microwave transmission device does not extend to 3.5 × f _H. Therefore, in the case of performing audio multiplex broadcasting by performing signal transmission using a commercial microwave transmission device, as shown in FIG. 5, in addition to the video signal, the main channel, sub-channel, and pilot audio signals are converted to baseband signals. The microwave transmitter 3 is input in the form of, and sent to the transmitting station. At the transmitting station, after each signal is output from the microwave receiver 4, the three audio signals are converted into audio multiplex broadcast audio signals by the audio multiplexing terminal 1, and transmitted to the television transmitter 6 together with the video signals. The broadcast is transmitted from the transmitter 6.

FIG. 6 is a diagram showing a conventional frequency arrangement of video signals and subcarriers.

[0005]

As described above,
In order to transmit video and audio signals using a conventional commercial microwave transmission device, a plurality of subcarriers are set up on the video signal band, and the main channel signal, the subchannel signal, and the pilot signal are transmitted to the baseband signal. Therefore, the frequency occupied band needs to be widened and the voice multiplexing terminal needs to be provided at the transmitting station side. For this reason, when measuring the multiplex characteristics of the audio signal, it is necessary to go to the transmitting station,
When the audio multiplex terminal breaks down, there is a problem that a broadcaster has to broadcast abnormally until a repair person goes to the transmitting station and repairs.

[0006]

According to the present invention, a transmitting terminal is provided on the studio side, and the transmitting terminal receives an audio signal for multiplex broadcasting and frequency-modulates a carrier, and a television. It comprises a low-pass filter for band-limiting a video signal to a band necessary for John broadcasting, and a synthesizer for synthesizing the video signal passed through the filter, the modulated subcarrier, and the signal.

The transmitting station has a receiving terminal station. The receiving terminal station separates a video signal from a frequency-modulated carrier and extracts only the video signal, and a multiplex broadcast by demodulating the frequency-modulated carrier. And an audio signal demodulator for extracting a signal for use.

In the present invention, the transmitting terminal station and the receiving terminal station are connected to the video signal input / output section of the microwave transmission device, respectively, and the studio transmits the video signal using only the video signal transmission band of the microwave transmission device. Video signals and audio signals for television multiplex broadcasting.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a system diagram showing an embodiment of the present invention.
On the studio side in the figure, the audio signals of the main channel, the subchannel, and the pilot signal are
Is converted into an audio signal for television multiplex broadcasting, and then input to the transmitting terminal station 2 together with the video signal. After the audio signal for television multiplex broadcasting is synthesized with the video signal at the transmitting terminal station 2, the signal is transmitted to the microwave transmitter 3 and then transmitted to the transmitting station side.

[0010] In the transmitting terminal station 2, as shown in FIG. 2, the audio signal for multiplex broadcasting is sent to a modulator 7, where a predetermined carrier is frequency-modulated and sent to a combiner 9. On the other hand, the video signal is band-limited by a low-pass filter 8 having a steep cutoff characteristic, and then sent to a combiner 9. The output of the transmitting terminal station 2 includes a video signal and a modulated carrier, which are input to a video signal input terminal of the microwave transmitter 3.

On the transmitting side, a carrier wave received by the microwave receiver 4 and modulated by a video signal and an audio signal is output. This output signal is input to the receiving terminal 5, where the video signal is separated and the multiplex broadcast audio signal is demodulated by the configuration shown in FIG. 3, and each signal is input to the television transmitter 6. You.

FIG. 4 is a diagram showing a frequency arrangement of a video signal and a subcarrier according to the present invention.

[0013]

As described above, according to the present invention,
By adding the transmitting terminal station and the receiving terminal station to the commercial microwave transmission device, there is an effect that the video signal and the multiplex broadcast audio signal can be transmitted from the studio using the video signal transmission circuit of the commercial microwave transmission device.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a transmitting terminal in FIG.

FIG. 3 is a block diagram showing a configuration of a receiving terminal station in FIG. 1;

FIG. 4 is a diagram showing a frequency arrangement of a video signal and a subcarrier in the present invention.

FIG. 5 is a system diagram showing a conventional technique.

FIG. 6 is a diagram showing a frequency arrangement of a video signal and a subcarrier in the related art.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 audio multiplexing terminal 2 transmitting terminal 3 microwave transmitter 4 microwave receiver 5 receiving terminal 6 television transmitter 7 audio signal modulator 8 low-pass filter 9 synthesizer 10 separator 11 audio signal demodulation vessel

Continuation of front page (56) References JP-A-59-171374 (JP, A) JP-A-54-146125 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 5 / 00 H04N 5/38-5/63 H04N 7/025-7/088

Claims (1)

(57) [Claims] An audio signal modulator for frequency-modulating a sub-carrier with an audio signal for audio multiplex broadcasting comprising a main channel signal, a sub-channel signal, and a pilot signal, and a low-pass filter for limiting a band of a video signal. A transmitting terminal provided with a combiner for combining an output of the audio signal modulator and a video signal from the low-pass filter; and a separation for extracting only a video signal from a transmission output from the transmitting terminal. And a receiving terminal provided with an audio signal demodulator for demodulating a frequency-modulated subcarrier and extracting an audio signal for audio multiplex broadcasting, wherein the transmitting terminal and the receiving terminal are microwave transmission devices. Wherein the video signal and the audio signal for audio multiplex broadcasting are transmitted using only the video signal transmission band of the microwave transmission device. Transmission device.