JPH0447895A - Additional signal transmitter-receiver - Google Patents

Abstract

PURPOSE:To send an additional signal without revision of the stipulation of the Radio Wave Act by transmitting the additional signal by selecting a cycle number of a color burst signal based on the additional signal. CONSTITUTION:Signals Y, I, Q are converted into signals Y, I, Q of interlaced scanning structure by switches 14, 15, 16 and time expansion circuits 17, 18, 19. The signals Y, I, Q are converted into a TV signal of the NTSC system by an NTSC encoder 20. A burst replacement circuit 21 replaces a color burst signal added by the NTSC encoder 20 into a color burst signal whose cycle number is decided. A TV signal in which the replacement is finished is fed to an output terminal 22 as a transmission signal. The replacement use color burst signal is outputted from color burst generating circuits 23-26. The four color burst signals are selected alternatively by a selector 27 based on the additional signal and the selected signal is fed to the circuit 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an additional signal transmission/reception device that multiplexes and transmits and receives additional signals on a television signal.

(Prior Art) In recent years, in television broadcasting, with the demand for higher image quality, signals for higher image quality are often transmitted as additional signals along with the original television signal.

As methods for transmitting this additional signal, there are two methods: a method for transmitting within the current transmission band of television signals, and a method for creating a new transmission band exclusively for the additional signal.

However, no matter which method is adopted, there has conventionally been a problem in that the content of the television signal stipulated by the Radio Law must be significantly changed.

(Problems to be Solved by the Invention) As mentioned above, when multiplexing and transmitting additional signals on television signals, conventionally there was a problem in that the content stipulated by radio regulations had to be significantly changed. Ta.

Therefore, it is an object of the present invention to provide an additional signal transmission/reception device that can transmit additional signals without changing the contents stipulated by radio regulations.

[Structure of the Invention] (Means for Solving the Problem) In order to solve the above object, the present invention transmits the additional signal by switching the number of cycles of the color burst signal based on the additional signal. It is something.

(Function) The cycle and number of cycles of the color burst signal are not fixed, but can be set arbitrarily within a predetermined range.

Therefore, by switching the number of cycles within this allowable range, it is possible to transmit an additional signal without changing the signal content specified by the Radio Regulations.

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

FIG. 1 is a circuit diagram showing the configuration of the transmitting side of an embodiment of the present invention, and FIG. 2 is a circuit diagram showing the configuration of the receiving side.

Before explaining the configurations of FIGS. 1 and 2, an outline of one embodiment will be explained.

In this embodiment, the additional signal is transmitted by switching the number of cycles of the color burst signal based on the additional signal to be transmitted.

That is, the number of cycles of the color burst signal of NTSC television broadcasting is not fixed, but has a predetermined allowable range. This embodiment focuses on this point, and by switching the number of cycles of the color burst signal within the allowable range based on the additional signal, the additional signal is transmitted as a change in the number of cycles of the color burst signal. It is.

Here, the allowable range of the number of cycles of a color burst signal in the NTSC system will be explained.

In the television broadcasting of the NTSC system which is currently in practical use, the standards for the horizontal synchronization signal are determined by the Radio Law, and have the specifications shown in FIG. The time axis unit in this specification is defined as H. Additionally, the following items can be mentioned as notes on the table in Figure 4 regarding the horizontal period.

(1) rHJ indicates the time from the beginning of one scanning line to the beginning of the next scanning line.

(2) The leading edge and trailing edge of the horizontal blanking signal are the minimum value (x+y) and maximum value (2) in any video signal.
(see Figure 3).

(3) The color burst signal is transmitted after the horizontal sync pulse, but must not be transmitted after the horizontal sync pulse and vertical sync pulse.

(4) The numerical values of the color burst signal shown in the table of FIG. 4 are for determining the start and end times of the color burst signal, but not for determining its phase.

(5) If there is no color signal, the color burst signal can be removed.

Based on the values shown in FIG. 3 and the above five items, the minimum number of cycles of the color burst signal is determined to be 8 cycles.

On the other hand, the maximum value is calculated from the values in Figure 3: (A-B-C)/D -3,1210,279 -11 (cycles) However, A: (Sync tip + Freeze way + Color burst ) Maximum value A-0,125H (7,96μs) B: Minimum freezeway value B-0,006H (0,38μs) C Minimum value C-0,075H-0,005H (4,76μs- 0,
82 μs).

Therefore, the allowable range of the number of cycles of the color burst signal is 8 to 11 cycles. If within this range,
Color images can be reproduced even if the number of cycles of the color burst signal is changed.

By being able to set the number of cycles to four in this manner, if the additional signal is binary digital data, it is possible to transmit two bits of digital data per one color burst signal.

Now, the configuration of the transmitting side shown in FIG. 1 will be explained.

In the figure, 11, 12, and 13 are the luminance signal Y and two color difference signals of the transmitted television signal, respectively! , Q are the input terminals to which the signals are supplied. This transmitted television signal has a 1=1 sequential scanning structure with 525 scanning lines.

Each of the signals Y, I, and Q is processed by switches 14, 15, and 16 and time expansion circuits 17, 18, and 19 to form a signal Y having a 2:1 interlaced scanning structure with 525 scanning lines.

1, converted to Q.

The interlaced scanning structure signals Y, I, and Q are converted into NTSC television signals by an NTSC encoder 20.

This NTSC television signal is supplied to a burst switching circuit 21. This burst replacement circuit 21 replaces the color burst signal Jl, Il) added to the NTSC encoder 20 with a color burst signal whose number of cycles is determined based on the added signal. The television signal after this replacement is supplied to the output terminal 22 as a transmission signal.

The color burst signal for replacement is output from the color burst generation circuits 23, 24, 25, and 26. Each color burst generation circuit 23, 24°25.26 outputs a color burst signal having a cycle number of 8.9 and 10°11, respectively.

These four color burst signals having different numbers of cycles are selectively selected by the selection 27 based on the additional signal and supplied to the burst switching circuit 27.

The additional signals are extracted by the additional signal extraction circuit 28 from the signals Y, I, and Q input to the input terminals 11, 12, and 13. In other words, the additional signal in this embodiment is a signal obtained from the transmitted television signal.

The additional signal extracted by the additional signal extraction circuit 28 is
The value is converted into a digital signal. This binary digital data is converted into 4-value digital data by a 2/4-value conversion circuit 29. That is, it is converted into 2-bit binary data.

The color burst signal selection operation is controlled based on this 2-bit data. An example of this control is shown in FIG.

In addition, in this embodiment, when the color burst signal is decoded on the receiving side to reproduce the additional signal, the reference signal having the same number of cycles as the color burst signal for transmitting the additional signal is used for reproduction. . This reference signal is transmitted together with the television signal from the transmitting side.

The reference signal is transmitted, for example, during the vertical retrace period.

That is, in the first field, the color burst generating circuits 2B, 24,
The selection circuit 27 sequentially selects the outputs of 25 and 26 as reference signals in a predetermined order. Similarly, in the second field, the line number 10 before the video signal is transmitted.
The reference signal is transmitted on four lines among the ~19 lines.

From the above, the maximum line L MAX that can transmit the additional signal in one field is L MAX = 226 9 (equalization pulse, vertical synchronization pulse) - 4 (reference signal quality) - 213 (line). As a result, the maximum number of bits b MAX of the additional signal that can be transmitted in one field is t) yAx - LMA
X X2 213X2 426 (bits)

Next, the configuration of the receiving side shown in FIG. 2 will be explained.

In the figure, 31 is an input terminal to which a received television signal is input. The television signal supplied to this input terminal 31 is supplied to an NTSC decoder 32 and an additional signal extraction circuit 33.

NTSC decoder 32 decodes the input television signal into original signals Y, I, Q. The additional signal extraction circuit 33 extracts the color burst signal from the input television signal and reproduces the additional signal using the reference signal. This reproduced additional signal is extracted in the form of Y, I, and Q. This signal Y, I
, Q are supplied to adder circuits 37, 38, and 39 via buffers 34, 35, and 36, respectively, and output to an NTSC decoder 3.
It is added to the signals Y, I, and Q output from 2.

As a result, the same signals Y, I, and Q as on the transmitting side are obtained at the output terminals 40, 41, and 42.

FIG. 6 is a circuit diagram showing an example of a specific configuration of the additional signal extraction circuit 33.

In the figure, a received television signal is supplied to a gate circuit 102 through an input terminal 101.

This gate circuit 102 passes the input signal only for the superimposed portion of the color burst signal, and deletes the video signal portion.

The output of the gate circuit 102 has a pass band of approximately 3 to 4 M.
Hz band pass filter (hereinafter referred to as BPF) 103
is supplied to As a result, the BPF 103 extracts only the color burst signal from the input signal.

The output of BPF103 is four 2-frame synchronous addition circuits 1
04, 105, 106, 107. Each of the two frame synchronous adder circuits 104, 105, 106, and 107 reproduces reference signals of 8, 9, and 10.11 cycles, respectively.

This reproduction is performed by synchronously adding the color burst signals of each cycle sent as reference signals every two frames.

For example, in the 2-frame synchronous addition circuit 104 that reproduces an 8-cycle reference signal, the output of the BPF 103 is
After being multiplied by the coefficient k in the coefficient circuit 104a, the addition circuit 1
04b is added to the output of the coefficient circuit 104d. After this addition output is delayed by 2 frames by the 2 frame memory 104C, the coefficient (1-k) is generated by the coefficient circuit 104d.
is multiplied by , and supplied to the adder circuit 104b. As a result, 2-frame synchronous addition is performed, and the 8-cycle reference signal (in the first field, any one of the lines with line numbers 10 to 20; (attached to any one of the 19 lines) is played back.

Similarly, the other two frame synchronous addition circuits 105, 106 and 107 have coefficient circuits 105a and 105d.

106a, 106d, 107a, 107d, addition circuit 1
05b, 106b, 107b, 2 frame memory 105
c, 106c, and 107c.

Each 2 frame synchronous addition circuit 104, 105゜106.1
Each reference signal output from 07 is sent to a subtraction circuit 108.
, 109, 110, 111.

The output of the BPF 103 is further connected to an inverter circuit 112.
is reversed by This inverted output and the output of BPFloB are alternately selected for each line by the switch 113. As a result, the phases of all color burst signals are brought into phase.

The additional signal color burst signal obtained in the above manner is supplied to the subtraction circuits 108, 109, 110, and 111, and subtracted from the reference signal. As a result, a difference signal indicating the difference between the reference signal and the color burst signal is obtained.

Each difference signal has an absolute value circuit 114゜115.11
The absolute value is taken by 6,117.

Each difference signal whose absolute value has been taken is sent to an adder circuit 118.
．． 119, 120, 121, latch circuit 122, 123
, 124, and 125.

The cumulative addition output of each difference signal is supplied to the minimum value determination circuit 126. The minimum value determination circuit 126 determines the one with the smallest value among the four input signals. As a result, the number of cycles of the sent color burst signal is determined. For example, if the number of cycles of the sent color burst signal is 8 cycles, the value of the difference signal from the reference signal of 8 cycles will be the minimum value. Therefore, by determining the minimum value, the number of cycles of the sent color burst signal can be determined. Minimum value judgment circuit 12
6 reproduces a 2-bit additional signal from the determined cycle number and supplies it to the output terminal 127.

As described above, according to this embodiment, the additional signal is transmitted by changing the number of cycles of the color burst signal, so the additional signal can be transmitted without changing the current radio regulations. .

Further, in this embodiment, since the reference signal for reproducing the additional signal is transmitted, the additional signal can be accurately reproduced.

FIG. 7 is a circuit diagram showing the configuration of the transmitting side of another embodiment of the present invention, and FIG. 8 is a circuit diagram showing the configuration of the receiving side.

In the previous embodiment, a case has been described in which a signal obtained from a transmitted television signal is transmitted as an additional signal. On the other hand, in this embodiment, a case will be explained in which an additional signal different from the transmitted television signal is transmitted.

First, the configuration of the transmitting side shown in FIG. 7 will be explained.

In the figure, 51, 52, 53 are luminance signals Y1, color difference signals 1, . Q is the input terminal to which it is supplied. This transmitted television signal has an interlaced scanning structure with 525 scanning lines.

Signal Y supplied to input terminals 51, 52, 53.

I and Q are subjected to encoding processing to make them NTSC television signals, and a synchronization signal and a color burst signal are added.

On the other hand, in the additional signal generation circuit 55, the input terminals 51 and 52
．． An additional signal is created which is unrelated to the television signal supplied to 53. This additional signal is output as binary digital data.

This binary digital data is converted into 4-value data by a 2/4 conversion circuit 56. Based on this four-value data, the selection circuit 57 selectively selects four color burst signals of 8 to 11 cycles for each line.

The color burst generation circuit 58 is an NTSC encoder 54
It outputs four color burst signals at a line period in synchronization with the signal given from.

The color burst signal selected by the selection circuit 57 is
NTSC encoder 54 by burst switching circuit 59
The color burst signal and color burst signal of the television signal provided by The television signal whose color burst signal has been replaced is supplied to the output terminal 60 as a transmission signal.

Next, the configuration of the receiving side shown in FIG. 8 will be explained.

In the figure, 61 is an input terminal to which a received television signal is supplied. This received television signal is NTSC
The signal is supplied to a decoder 62 and a burst extraction circuit 63.

The NTSC decoder 62 decodes the received television signal in a conventional manner that is related to the number of cycles of the color burst signal. Signals Y, I, and Q thus obtained are supplied to output terminals 64 and 65°66, respectively.

On the other hand, the burst extraction circuit 63 extracts only the color burst signal from the received television signal.

Then, the number of cycles of the extracted color burst signal is detected, and the detection result is converted into four-value data of 0 to 3. This 4-value data is converted into binary 2-bit data by a 4/2 conversion circuit 67. This data is concatenated into an appropriate number of bits by an additional signal reproducing circuit 68 and then reproduced as an additional signal.

In particular, in such an embodiment, the same effects as in the previous real example can be obtained.

In addition, in the above description, the case where the number of cycles of the color burst signal is switched in the range of 8 to 11 cycles has been described.

However, for example, black and white broadcasting does not require a color burst signal, so if this invention is applied to this case,
The number of cycles of the color burst signal can be switched within the range of 0 to 11 cycles.

It goes without saying that the present invention can be modified in various other ways without departing from the spirit thereof.

[Effects of the Invention] As described above, according to the present invention, the color burst signal is transmitted by switching the number of cycles of the color burst signal based on the additional signal.
Additional signals can be transmitted without changing the current radio regulations.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of the transmitting side of an embodiment of this invention, FIG. 2 is a circuit diagram also showing the configuration of the receiving side, and FIGS. 3 to 5 explain the operation of the embodiment. Figure for, No. 6
2 is a circuit diagram showing an example of a specific configuration of an additional signal extraction circuit, FIG. 7 is a circuit diagram showing a configuration on the transmitting side of another embodiment of the present invention, and FIG. 8 is a circuit diagram showing a configuration on the receiving side in another embodiment of the present invention. FIG. 2 is a circuit diagram showing the configuration. 11.12.13.31,51,52,53゜61...
- Input terminal, 14, 15. 16... switch, 17.
18.19...Time expansion circuit, 20.54...NT
SC encoder, 21.59... Burst switching circuit, 22, 40, 41, 42, 60, 64° 65.66.
69...Output terminal, 23, 24, 25゜26.58・
... Color burst generation circuit, 27°57... Selection circuit, 28... Additional signal extraction circuit, 29°56...2
/4 conversion circuit, 32.62...NTSC decoder, 3
3... Additional signal extraction circuit, 34, 35° 36... Buffer, 37, 38. 39... Addition circuit, 55... Additional signal creation circuit, 67... 4/2 conversion circuit, 68.・
・Additional signal regeneration circuit.

Claims (5)

[Claims] (1) An additional signal transmission device that multiplexes and transmits an additional signal on a television signal, which is configured to transmit the additional signal by switching the number of cycles of a color burst signal based on the additional signal. An additional signal transmission device characterized by: (2) In an additional signal receiving device that receives a television signal multiplexed with additional signals, a color burst signal that extracts the color burst signal from the television signal whose cycle number has been switched based on the additional signal. An additional signal receiving device comprising an extracting means and an additional signal reproducing means for reproducing the additional signal based on the number of cycles of the color burst signal extracted by the color burst signal extracting means. (3) In an additional signal transmission/receiving device that multiplexes and receives an additional signal on a television signal, by changing the number of cycles of the color burst signal based on the additional signal, the additional signal is transmitted to the television signal. additional signal transmission means for multiplexing and transmitting the signal; color burst signal extraction means for receiving the television signal sent by the additional signal transmission means and extracting the color burst signal from the received signal; An additional signal transmitting/receiving device comprising additional signal reproducing means for reproducing the additional signal based on the number of cycles of the color burst signal extracted by the burst signal extracting means. (4) In an additional signal transmission device that multiplexes and transmits an additional signal on a television signal, additional signal transmission means transmits the additional signal by switching the number of cycles of a color burst signal based on the additional signal; additional signal transmission means for transmitting a reference signal for reproducing the additional signal from the color burst signal whose cycle number has been switched by the additional signal transmission means during the vertical retrace period. Device. (5) In an additional signal receiving device that receives a television signal multiplexed with an additional signal, the number of cycles of the color burst signal is switched based on the additional signal, and the color burst signal having this number of cycles is switched to the above-mentioned additional signal. color burst signal extraction means for extracting the color burst signal from a television signal to which a reference signal for reproducing the signal is added during the vertical retrace period; and a reference signal extraction means for extracting the reference signal from the television signal. and additional signal reproducing means for reproducing the additional signal based on the reference signal extracted by the reference signal extracting means from the color burst signal extracted by the color burst signal extracting means.