JPH04276994A - Data communication system by ntsc signal - Google Patents

Abstract

PURPOSE:To improve the utilizing efficiency of a transmission line and to reduce the cost by multiplexing a 4-channel data to an NTSC system of the television standard system and sending/receiving the resulting data. CONSTITUTION:A PLL circuit 13 and a synchronizing signal generating circuit 14 generate a video synchronizing signal synchronously with a transmission line signal and a video signal transmission circuit 31 synthesizes a video synchronizing signal and a luminance signal Y and an RGB signal outputted from an RGB encoder 21 and sends the synthesized signal. A reception section 200 uses an RGB decoder 51 to decompose the received signal into the signal Y and the RGB signal to extract a data and a PLL circuit 62 recovers a clock, converted into a serial data and it is sent from a data transmission circuit 61 to a transmission line. Thus, the multiple address system with a high utilizing efficiency of the transmission line is realized at a low cost.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadcast data communication system using NTSC signals. Data communication methods include one-to-one communication and one-to-N communication. In the case of 1-to-N broadcast communication, a line is required to simultaneously connect a broadcast data transmitting station and a plurality of receiving stations, and a special transmitting/receiving device is also required for performing broadcast communication.

[0002] There is a need for a data communication system that allows such a broadcast type communication system to be constructed at low cost and that is easy to operate.

0003

2. Description of the Related Art FIG. 4 is a diagram illustrating a conventional example. 100A in the figure indicates a transmitter, 11 in the transmitter 100A is a clock recovery circuit, and 13 is a phase-locked oscillator (hereinafter referred to as PLL).
(referred to as a circuit), 14 is a synchronizing signal generation circuit, 21A is Y
The signal encoder 31 indicates a video signal transmission circuit.

[0004] Also, 200A indicates a receiving section, and the receiving section 2
41 in 00A is a video signal receiving circuit, 51A is a Y signal decoder, 61 is a data sending circuit, and 62 is a PLL circuit. In the conventional example shown in FIG. 4, broadcast communication is performed to a large number of receiving stations by inserting data into the luminance signal Y of the NTSC signal, which is adopted as a standard signal for television, and transmitting the signal. Since NTSC signals are used here, the transmitting section 100A and receiving section 200A are equivalent to the transmitter and receiver used in the standard television system. Therefore, technically it can be easily handled using existing technology, and the system can be constructed at low cost, making it suitable as a broadcast communication system for large amounts of data.

FIG. 5 is a diagram illustrating the signal waveform of a conventional example, in which only the luminance signal Y is extracted. “High” and “low” of the luminance signal Y are converted to “1” of digital data,
It is read as "0" and sent to the transmission path.

[0006]

[Problems to be Solved by the Invention] In the conventional example shown in FIG. 4, only one channel of data is inserted into the NTSC signal, so when transmitting multiple data, it is necessary to wait until the transmission of one data is completed. It is necessary to transmit the next data, which makes the system as a whole inefficient and requires the use of an expensive video line for a long time.

The present invention attempts to realize a broadcast data communication system in which the transmitting section and the receiving section can be configured at low cost, and the transmission path is used efficiently.

[0008]

Means for Solving the Problems FIG. 1 is a block diagram illustrating the principle of the present invention. 100 in the figure is a transmitter, 20
0 is a receiving section.

Reference numeral 10 in the transmitter 100 is a first data processing means for converting serial data input from a transmission line into four-channel parallel data, and reference numeral 20 is a first data processing means 10 that converts serial data input from a transmission line into four-channel parallel data. 30 is an RGB encoding means for inserting the data separated into the luminance signal Y and RGB signals of the NTSC signal, and 30 is an RGB encoding means which adds a video synchronization signal to the data encoded by the RGB encoding means 20 and sends it as a video signal to the antenna. This is video signal transmitting means sent from A1.

Further, 40 in the receiving section 200 is an antenna A2.
50 is an RGB decoding means for extracting data from the luminance signal Y and RGB signals extracted from the video signal receiving means 40; Yes, 60 is RG
This is a second data processing means that converts the four channels of parallel data extracted by the B decoding means 50 into serial data and sends it to the transmission line. After converting to parallel data, the RGB encoding means 20 inserts it into the luminance signal Y of the NTSC signal, which is a television standard signal, and the RGB signal, and sends it out from the antenna A1.The receiving unit 200 converts the NTSC signal received from the antenna A2 into The luminance signal of the signal and R
It is characterized in that the GB signals are separated, and the RGB decoding means 50 separates the 4-channel data inserted into the signal and sends it out to the transmission path. By adopting this configuration, an efficient broadcast data communication system can be obtained using an inexpensive transmitting/receiving device.

[0011]

[Operation] The transmitter 100 converts the serial data input from the transmission path into 4-channel parallel data, and
The B encoding means 20 adds the luminance signal Y and the RGB signals of the chrominance signal and transmits it from the antenna A1.

The receiving section 200 separates the luminance signal and RGB signal of the NTSC signal received from the antenna A2, and converts the RGB signal into
The decoding means 50 separates the four channels of data inserted into the signal and sends it out to the transmission path.

FIG. 2 is a diagram for explaining an NTSC video signal, in which (A) is an NTSC video signal, (B) and (C)
, (D) respectively show a luminance signal Y, a color signal, and a synchronization signal separated from the NTSC video signal (A). Also, (E)
indicates the color signal spectrum, (RY), (B-Y)
The signal is demodulated and the (G-Y) signal is (R-Y), (B-Y
) Indicates that the signal is reproduced by vector synthesis.

Combining and separating the luminance signal Y and RGB signals is a well-known technique and will not be explained here.

[0015]

Embodiment FIG. 3 is a diagram showing an embodiment of the present invention. Figure 3
The embodiment shown in FIG.
0, the clock regeneration circuit 11, the data processing circuit 12
, a PLL circuit 13, a synchronization signal generation circuit 14, an RGB encoder 21 as an RGB encoding means 20, a video signal transmitting circuit 31 as a video signal transmitting means 30, a video signal receiving circuit 41 as a video signal receiving means 40, and an RGB encoder 21 as an RGB encoding means 20; In this example, the decoding means 50 is an RGB decoder 51, the second data processing means 60 is a data sending circuit 61, a PLL circuit 62, and antennas A1 and A2.

In the above-described embodiment, in the transmitting section 100, the clock reproducing circuit 11 regenerates a clock signal and frame pulse from the input serial data, and the data processing circuit 12 performs data processing such as serial/parallel conversion.

PLL circuit 13 and synchronization signal generation circuit 1
4, a video synchronization signal synchronized with the transmission line signal is generated, and the video signal transmission circuit 31 combines the video synchronization signal with the luminance signal Y and the RGB signal output from the RGB encoder 21 and transmits it from the antenna A1. .

In the receiving section 200, an RGB decoder 51 decomposes the signal received by the video signal receiving circuit 41 through the antenna A2 into a luminance signal Y and an RGB signal and extracts the data, and a PLL circuit 62 reproduces the clock. , the data transmission circuit 61 converts the data into serial data and transmits it to the transmission path.

[0019] Furthermore, the received signal can be directly displayed on a cathode ray tube using a television receiver.
Another advantage is that the reception status can be checked visually. Although the above embodiment uses internal synchronization, it is also possible to use an external video synchronization signal.

Each of the circuits constituting the above-described embodiment is equivalent to the transmitting circuit and receiving circuit of the standard NTSC signal of television and the circuit used in digital communication, and can be easily realized.

[0021]

[Effects of the Invention] According to the present invention, the standard TV system N
It is now possible to multiplex 4-channel data onto a TSC signal and transmit and receive it, and the circuits used are the same as those used in conventional television signal transmission and reception circuits, as well as circuits used in digital communications, resulting in low cost. This can be achieved with Also, since it is the same as the transmission and reception method of television, it is 1:N
It is effective as a broadcast communication system for transmitting large amounts of data to many parties at the same time.

[Brief explanation of the drawing]

[Figure 1] Block diagram explaining the principle of the present invention

[Figure 2
] Diagram explaining the NTSC video signal

[Figure 3] Diagram explaining an embodiment of the present invention

[Figure 4] Diagram explaining a conventional example

[Figure 5] Diagram explaining the signal waveform of the conventional example

[Explanation of symbols]

10 First data processing means 11 Clock recovery circuit 1
2 Data processing circuit 13, 62 PLL circuit 1
4 Synchronization signal generation circuit 20 RGB encoding means 2
1 RGB encoder 21A Y signal encoder 30 Video signal transmission means 3
1 Video signal transmitting circuit 40 Video signal receiving means 4
1 Video signal receiving circuit 50 RGB decoding means 5
1 RGB decoder 51A Y signal decoder 60 Second data processing means 61
Data sending circuit 100, 100A Transmitting section 200, 200A Receiving section A1, A2 Antenna

Claims (1)

[Claims] 1. A broadcast data communication system using NTSC signals, in which a transmitter (100) has first data processing means (100) that converts serial data input from a transmission line into four-channel parallel data. ) and the first
The data processing means (10) separates the data into four channels of parallel data and converts it into a luminance signal (Y
) and an RGB encoding means (20) for inserting into the RGB signal, and a video synchronization signal is added to the data encoded by the RGB encoding means (20), and the antenna (A1
), a video signal transmitting means (30), and a receiving section (
200) includes a video signal receiving means (40) for receiving a video signal input from the antenna (A2) and extracting a luminance signal (Y) and an RGB signal; and a luminance signal extracted by the video signal receiving means (40). (Y) and RGB decoding means (50) that extracts data from the RGB signals, and a second RGB decoding means (50) that converts the four-channel parallel data extracted by the RGB decoding means (50) into serial data and sends it to the transmission line. data processing means (60);
), after converting the serial data input from the transmission line into 4-channel parallel data, the RGB encoding means (20) converts the luminance signal (Y) of the NTSC signal and the RG
After inserting it into the B signal, it is converted to a video signal and sent to the antenna (
A1), and the receiver (200) receives the luminance signal (Y) of the NTSC signal received from the antenna (A2).
) and RGB signals, and the RGB decoding means (50
) is a data communication system using NTSC signals, in which four channels of data inserted into the signal are separated and sent to a transmission path.