JPS5811795B2 - Data Seigiyohouhou Oyobi Souchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method of inserting and transmitting not only video images but also digital data output from a computer or the like into a video signal.
In still image broadcasting, cable broadcast television CATV networks, etc., for example, data addition on the still image broadcast transmitting device side, and data discrimination on the still image broadcast receiving device side that receives still images with data added as normal broadcast radio waves. The present invention relates to a data control method and device for easily and reliably carrying out.

Conventionally, for still image broadcasting, in which still images in units of one frame are time-division multiplexed and broadcast in television signal format,
There is a method in which an identification code signal for distinguishing each still image frame, a control code signal for controlling the connection between presented frames, etc. are inserted at the forefront of the still image frame.

With this method, only a simple control code signal could be inserted.

In addition, conventionally, it has been considered to make the burst signal in the back porch section of the horizontal synchronization signal also serve as digital data, but in this case, it is difficult to accurately extract the sent digital data, and The amount of data available is also very limited.

SUMMARY OF THE INVENTION An object of the present invention is to provide a data control method and apparatus that can send a large amount of digital data output from a computer or the like and can reliably discriminate this digital data.

In order to achieve such an object, the present invention inserts a terminal control command indicating the type of data to be sent during the vertical retrace period of a color video signal on the transmitting side, and During transmission, a data control command consisting of digital data is inserted into a video section in place of the video signal of the TV signal, and the receiving side detects the terminal control command from the received color video signal using a timing signal. , when the terminal control command indicates reception of a data control command, the data control command in the color video signal received in the next frame is considered valid and predetermined processing is performed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 are flowcharts showing the operation of the digital data control method according to the present invention for a transmitting device and a receiving terminal, respectively.

FIG. 3 shows the location of the terminal control command 2 inserted into the vertical blanking period immediately after the first pulse 1 of the equalization pulse.

FIG. 4 shows the location of the data control command 4 inserted into the video period between the horizontal synchronization pulses 3.

The function of the flowchart in FIG. 1 is as follows.

First, if there is a command to send a terminal control command from a computer or the like, the terminal control command is inserted at the location shown at 2 in FIG. 3, that is, immediately after the first pulse of the equalization pulse.

The terminal control command 2 specifies whether the next frame is a data control command, video, audio, etc.

Here, the terminal device that receives the terminal control command 2 is a terminal device such as a still image broadcast receiving device, and is configured to perform an operation according to the terminal control command.

That is, when indicating reception of a terminal control command, the terminal device knows that a data control command is added to the video section, incorporates the data control command, and performs operations such as character display instructed by the data control command. Do the following.

Also, when the terminal control command indicates the reception of video, the terminal device knows that the video section of the frame is video, and
One frame of video is captured into a still picture video memory, refreshed and played back, and displayed as a still picture.

When the terminal control command indicates the reception of audio, a digitized audio signal is added to the video section of the frame instead of the video, and the terminal device reproduces and outputs this audio signal.

In addition, when the terminal control command indicates reception of TV broadcasting,
The terminal control command can be provided with a type of function for controlling the terminal device, such as the terminal device playing back moving images in the same way as a normal TV receiver.

In this way, the terminal control housing is configured with a terminal address code and a control code that specify which terminal is to perform what kind of operation. instruct.

In the absence of such specific instructions, maintain the previous state;
For example, continue to display still images.

When a normal TV receiver receives the signals shown in Figures 3 and 4, terminal control commands are not displayed because they exist within the vertical retrace period, but data control commands are displayed in black and white according to their codes. It will be displayed as a dot pattern.

However, terminal devices are controlled by terminal control commands, and when there is a terminal device receiving TV broadcasting, the still image broadcasting device manages it so that it does not send data control commands. There is no problem.

When sending a data control command, the data control command is inserted at the location 4 in FIG. 4, that is, in the video period between the horizontal synchronizing pulses 3.

This data control command can be inserted continuously during one frame period.

The data control command includes code data such as the receiving terminal number, character code to be displayed (address code may also be possible), etc.
This is digital data for specifying operations such as character display.

In this manner, terminal control commands and data control commands are inserted into the video signal and sent out.

Note that, prior to the data control command inserted into the video period, the receiving terminal is controlled so that the data control command is not displayed as a video.

For example, the receiving terminal is in a still image display state and is controlled to be in a state of waiting for reception of a data control command.

On the other hand, the function of the flowchart in FIG. 2 is as follows.

First, the receiving terminal detects the leading pulse 1 of the equalization pulse, learns the location of the terminal control command 2, and receives it.

If the next frame is video or audio, the terminal number to receive it is also specified, and the designated terminal receives and receives the video and audio.

If the next frame is a data control instruction, the data control instruction is inserted in the next frame.

The terminal corresponding to the terminal number specified by the terminal control command or data control command performs the specified operation.

FIG. 5 is an example of a time chart in which the insertion locations of terminal control commands and data control commands are controlled by color subcarriers.

In the figure, the upper row shows the color subcarrier, and the middle row shows the third subcarrier.
The structure of the terminal control command in the figure is shown, and the lower part shows the structure of the data control command in FIG.

Note that each section of the terminal control command 7 and the data control command 10 represents a bit of "1" or "0".

The color subcarrier 5 is counted from the rising edge of the equalization pulse 6 or the horizontal synchronization signal 8, and when a predetermined count value is reached, digital data is inserted or detected.

In FIG. 5, after counting 32 color subcarriers 5,
This shows how digital data is inserted one bit at a time for every count of 8. 7 is a terminal control command, which is an enlarged version of 2 in Figure 3, and 10 is a data control command, which is an enlarged version of 4 in Figure 3. It corresponds to an enlarged version.

7 and 10 in FIG. 5 are code signals in which each section (32 to 40.41 to 48.49 to 56, etc.) has a logical value of "1" or "0."

A receiving terminal can discriminate the digital data inserted at a predetermined position by using the color subcarrier as a clock signal.

The color subcarriers at the receiving terminal are normally phase-aligned by a color burst 9 added to the trailing edge of the horizontal synchronization signal, but one bit of digital data consists of several cycles of color subcarriers as shown in Figure 5. When expressed by the period of the subcarrier, the phases do not necessarily need to match.

FIG. 6 shows an embodiment of the present invention for a transmitting device, and FIG. 7 shows a receiving terminal.

First, the transmitting device shown in FIG. 6 will be explained.

30 is a video signal in which no digital data is inserted.

Reference numeral 12 denotes a synchronization signal separation circuit that extracts the synchronization signal 13 from the video signal 30.

Reference numeral 14 denotes a color subcarrier generation circuit that generates a color subcarrier 15 whose phase is matched by the color burst included in the video signal 30.

16 is a synchronization signal shaping circuit that generates a shaped synchronization pulse 17 at the rising edge of the synchronization signal 13;

18 is the horizontal synchronization pulse 2 from the shaped synchronization pulse 17
This is a horizontal synchronous pulse discrimination circuit that extracts 3.

Reference numeral 19 denotes an equalization pulse discrimination circuit that extracts the equalization pulse 20 from the shaped synchronization pulse 17.

21 is the leading pulse 22 of the equalization pulse from the equalization pulse 20
33 is a terminal control command insertion circuit, which extracts the terminal control command insertion command 3 from the computer based on the leading pulse 22 and the color subcarrier 15.
1, a terminal control command 35 is generated.

34 is the data control command insertion circuit Tearly, first pulse 22
, color subcarrier 15, horizontal synchronization pulse 23,
A data control command 36 is generated in accordance with a data control command insertion command 32 from the computer.

37 is the terminal control command 35 generated in this way,
This is an addition calculation circuit for adding the data control command 36 with the video signal 30 and outputting the video signal 11 into which digital data has been inserted.

In this way, digital data output from the computer is inserted into the video signal.

Note that the data control command insertion circuit 34 and the terminal control command insertion circuit 33 can be configured using a normal video mixer for adding a synchronization signal to a video signal to which no synchronization signal is added.

The receiving terminal shown in FIG. 7 performs operations such as character display according to the video signal 11 into which digital data is inserted.

The circuits for generating horizontal synchronization pulses, equalization pulses, and color subcarriers are the same as the transmitter shown in FIG.

Reference numeral 24 denotes a terminal control command discrimination circuit, which discriminates terminal control commands inserted into the video signal 11 based on the leading pulse 22 and the color subcarrier 15.

This terminal control command generates a terminal control signal 26 indicating whether the next frame is a data control command, video, audio, etc.

25 is a data control command discrimination circuit, and the leading pulse 22
, color subcarrier 15, and horizontal synchronization pulse 23 to discriminate data control entries inserted into the video signal 11.

Character generation and various terminal operations are performed by data control signals 27 corresponding to the data control commands.

When the terminal control signal 26 indicates video or audio reception, the video signal 11 is sent to the receiver for video display or audio output.

Note that the terminal control command discrimination circuit 24 and the data control command discrimination circuit 25 can be realized using an ordinary sample and hold circuit, and sequentially detect code signals 7 and 10 in FIG. 5 bit by bit.

In the terminal control command discrimination circuit 24, the code signal of the terminal control command 7 shown in FIG. 5 is sequentially detected bit by bit.

That is, the bit string of the terminal control command shown in FIG. 5 is clocked at the 36th, 44th, and 52nd clocks from the beginning of the equalization pulse by using the color subcarrier as a clock signal. The code signal is detected by sampling at the center of each bit.

Similarly, the data control command discrimination circuit 25 detects data control commands consisting of digital data such as character codes.

For example, in a terminal where the terminal control command detected by the terminal control command discrimination circuit 24 is specified as instructing still image display, a still image is displayed by loading the video signal into the video memory and refreshing and reproducing the video signal. .

Next, if a similarly discriminated terminal control command instructs character display, the designated terminal enters a waiting state for receiving the character code in the data control command.

Here, when a data control command is detected by the data control command discrimination circuit 25, characters are displayed on the terminal according to the character code in this command.

Figure 8 shows the synchronization signal separation circuit 1 in Figures 6 and 7.
2. Synchronous signal shaping circuit 16, horizontal synchronizing pulse discrimination circuit 1
8. Equalization pulse discrimination circuit 19, leading pulse generation circuit 21
3 is a time chart for showing the operation of FIG.

The synchronization signal 13 is shaped into a shaped synchronization pulse 17 with a pulse width T1.

28 is an equalization pulse strobe signal that is set at the falling edge of the shaped synchronization pulse 17 and reset after T2.

Here, 1/2H<T2<(H-T1), and H is one period of the horizontal synchronization pulse.

The equalization pulse 20 is obtained by ANDing the synchronization pulse 17 and the strobe signal 28.

By ANDing the strobe signal 28 and the sync pass pulse 17, the horizontal sync pulse 23 is obtained.

The leading pulse 22 is reset at the falling edge of the equalizing pulse 20 and is obtained from the AND of the equalizing pulse 20 and a sustaining signal 29 that is set after T3.

Here, T3 is larger than 8H and smaller than the vertical blanking period.

As described above, in the present invention, a terminal control command is inserted into a non-video period of a TV signal, a data control command is inserted and transmitted in place of the video signal of the TV signal during a desired video period, and a specific By having a configuration that performs specific control on the receiving terminal device, it is possible to reliably and easily insert digital data into a video signal or distinguish digital data from a video signal in which digital data has been inserted. It can be implemented.

In this way, static broadcasting and cable broadcasting television (CATV)
This can greatly contribute to the practical application of video information services using circuit networks.

[Brief explanation of the drawing]

1 and 2 are flowcharts showing the operations of a transmitting device and a receiving terminal, respectively, in the data control method according to the present invention, FIG. 3 is a time chart showing the location of terminal control instructions, and FIG. 4 is a data control method. A time chart showing the location of commands; FIG. 5 is a time chart showing the relationship between color subcarriers and terminal control commands and data control commands;
FIG. 6 is a diagram showing an embodiment of a transmitting device according to the present invention, FIG. 7 is a diagram showing an embodiment of a receiving terminal according to the present invention, and FIG. 8 is a diagram showing an embodiment of a receiving terminal according to the present invention. It is a time chart for showing the means to obtain. 2.7...Terminal control command, 4,10...
・Data control command, 5...Color subcarrier.

Claims (1)

[Scope of Claims] 1. A first period defined by a count value of a color subcarrier during a vertical blanking period of a color video signal on the transmitting side, with reference to a predetermined point in time of a signal indicating the vertical blanking period. A terminal control command indicating the type of data to be sent is sequentially inserted one bit at a time from From the second period defined by the count value of the color subcarrier, a data control command consisting of digital data is sequentially inserted and transmitted one bit at a time, and on the receiving side, a timing signal indicating the first period is used.
detecting the terminal control command from the color video signal;
When the terminal control command indicates reception of the data control command, the data control command detected from the received color video signal by the timing signal indicating the second time period is enabled. data control method. 2. A first generating means for generating a horizontal synchronizing pulse from the color video signal, a second generating means for generating a color subcarrier from the color video signal, and a pulse corresponding to the leading pulse of the equalization pulse from the color video signal. a third generating means for generating a vertical retrace line of the color video signal; a means for counting the output of the second generating means; Each bit has a length corresponding to an integral multiple of the color subcarrier from the first period defined by the count value from the reference position, based on the position of the pulse corresponding to the first pulse during the period. a first insertion means for sequentially inserting terminal control commands consisting of code information having a value, bit by bit;
Based on the signals from the first to third generation means, the first to third generation means specify the count value from the reference position during the desired video period of the color video signal, with reference to the position of the horizontal synchronizing pulse. 2, data control commands consisting of digital data each bit having a length that is an integral multiple of the color subcarrier are sequentially inserted one bit at a time.
A data transmitting device characterized in that it has an inserting means. 3. first generating means for generating horizontal synchronization pulses from the received color video signal; second generating means for generating color subcarriers from the received color video signal; a third generating means for generating a pulse corresponding to the leading pulse; a means for counting the output of the second generating means; and a third generating means for counting the output of the second generating means; 1 during the vertical retrace period of the color video signal, with the position of the pulse corresponding to the above-mentioned leading pulse as a reference, and from the first period defined by the above-mentioned count value from the reference position, a terminal control command is sent 1 pit. a first discriminating means for sequentially sampling and discriminating, and a position of the horizontal synchronizing pulse in a desired video period of the received color video signal based on signals from the first to third generating means; and second discriminating means for sequentially sampling and discriminating data control commands made of digital data one bit at a time from a second period defined by the count value from the reference position. Data receiving device.