JPH0497689A - Signal transmission system for cable television receiver - Google Patents

Abstract

PURPOSE:To receive a broadcast for a large pattern inexpensively by using three-channels of a cable television receiver so as to send independently R,G,B signals. CONSTITUTION:A transmitter A being a broadcast side and receivers B1, B2 being user sides are connected through a cable (c) to form the cable television receiver system and the cable television receiver has channels 1-n. Then R,G,B signals are sent through a cable independently by using a different channel station. Since three channels are in use, three tuners C1-C3 are required for the receiver side and since the signal sent through the cable (c) is received, the cost is low. Thus, the broadcast for a large pattern is inexpensively received.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a signal transmission system applied to cable television.

[Summary of the Invention] The present invention independently transmits R, G, and B signals using three channels, thereby making it possible to receive signals with high color resolution at low cost, and to receive broadcasts suitable for large screens at low cost. It is possible.

[Conventional technology] In recent years, television broadcasting has been changed to a large wide screen (
For example, it is commonly viewed by displaying the screen at a width of 2.4 meters (2.4 meters wide), but the color resolution of the normal broadcasting format is approximately 50 lines, which is extremely low. Therefore, a technique has been proposed in which the color resolution is increased by independently transmitting the luminance signal and chroma signal using separate channel stations in satellite broadcasting.

[Problem to be solved by the invention] However, when multiple channels are used in satellite broadcasting as described above, not only the transmitting side but also the receiving side must prepare two expensive tuners for satellite broadcasting. The drawback was that it became a very expensive transmission method.

Therefore, an object of the present invention is to provide a transmission system that can receive broadcasts suitable for large screens at low cost.

[Means for Solving the Problems To achieve the above problems, the cable television signal transmission system according to the present invention transmits the R signal, G signal and B signal constituting the television signal independently using different channel stations. It was transmitted by cable.

[Function] Since three channels are used, it is necessary to install three tuners on the receiving side, but since the signal is transmitted by cable, it is necessary to prepare a very inexpensive tuner that uses low frequencies and is not affected by external disturbances. Bye.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit block diagram of a signal transmission system showing one embodiment of the present invention. In FIG. 1, a transmitting device A on the broadcasting side and each receiving device B on the user side are connected via a cable C to form a cable television system. Cable TV has channels from 1 channel to N channel. The transmitter A has n modulators M1 to M7 corresponding to channels 1 to n, and each modulator M1 to M has a different frequency f, ~.
modulates the television signal into a f. On the other hand, the R signal, G signal, and B signal output by camera 1 are wide image size (
This is a television signal with an aspect ratio of 916), and each of these color signals is input to three modulators M1 to M3, respectively. Each color signal is transmitted as a television signal of 1 to 3 channels. Also, the R signal of the camera 1.

The G signal and B signal are also led to the picture size converter 2, where they are converted into a composite signal with a normal picture size (an aspect ratio of 3.4). As a result of the conversion, a black video signal is inserted above and below the screen where there is no television signal, and this composite signal is guided to the modulator M4 and transmitted as a 4-channel television signal. Other modulators M5~
A television signal (not shown) is also guided to M5, and the outputs of all the modulators M1 to M are superimposed by an adder 3 and transmitted.

- the receiving device B1 has three tuners 01 to C3,
A television signal from cable C is input to each tuner C1 to C3. tuner C1 to frequency f1,
Tuner C2 is tuned to frequency f2, and tuner C8 is tuned to frequency f.
Each is tuned to 3. The output of each tuner CI"Cs is led to a projector (not shown) that projects an image on a large wide screen (width 2.4 m), for example.

The other receiving device B2 has only one tuner C4, and the television signal from the cable C is input to this tuner C4 and tuned to the frequency f4 in the same manner as described above. The output of this tuner C4 is led to, for example, a small screen monitor (not shown).

In the above configuration, when broadcasting from channel 1 to channel 4 is started, the R signal of the television signal of camera 1 is converted to G as the television signal of channel 1.
The signal is transmitted as a 2-channel television signal, the B signal is transmitted as a 3-channel television signal via cable C, and the above-mentioned normal size composite signal is also transmitted as a 4-channel television signal. Receiving device B1 receives broadcasts from channel 1 to channel 3, tuner CI receives R signal, tuner C2 receives G signal, and tuner C3 receives B signal, and these signals are transmitted to the projector (Fig. (not shown) and the image is displayed on a wide screen. This video has high color resolution because each color signal is transmitted on an independent channel. And three tuners C1
~C3 is required, but since it receives the signal transmitted by cable C, it is very inexpensive. Another receiving device B2 receives the 4-channel broadcast, and this composite television signal is displayed on a monitor (not shown). Therefore, a user who has three tuners C1 to C3 can receive broadcasts suitable for large screens, and a user who has only - tuner C4 cannot receive broadcasts for large screens, but can receive the same broadcasts. Can receive.

Incidentally, on the transmitter A side, television signals such as Y signal (4.5 MHz), RY signal (1.5 MHz),
When handling B-Y signals (1.5MHz), RGB
It is preferable to convert it into a signal and then transmit it.

[Effects of the Invention] As described above, according to the present invention, the three
Since the R signal, G signal, and B signal were transmitted independently using a channel, by using an inexpensive tuner for cable TV, signals with high color resolution can be received, and broadcasts suitable for large screens can be received at low cost. This effect is achieved.

Furthermore, when transmitting by radio using multiple channels like satellite broadcasting, problems such as time lag may occur due to disturbances, but the present invention has the advantage that such problems do not occur because the transmission is carried out by cable.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram of a signal transmission system showing one embodiment of the present invention. C...Cable.

Claims (1)

[Claims] (1) A cable television signal transmission system characterized in that the R signal, G signal, and B signal constituting the television signal are independently transmitted by cable using different channel stations.