JP2000261770A - Device for extracting superimposed signal of television signal, and divide for searching line of superimposed signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct malfunction in vertical synchronizing signal extraction caused by an integrating circuit in a short time by counting a horizontal synchronizing signal from the position of a vertical synchronizing signal, setting a line set value within a prescribed range, comparing a counted value with the line set value and extracting a superimposed TV signal at a position within a matching range. SOLUTION: A TV signal 2 is inputted to an input terminal 1, the signal 2 is propagated to an extracting part 3, and the part 3 extracts a vertical synchronizing signal 4 by an integrating circuit. A line counter part 5 counts a horizontal synchronizing signal 6 from the rear edge position of the signal 4 obtained by the part 3 propagates a counted line counted value to a comparing part 8. The part 8 compares the line counted value counted by the line counter part with a line set value of a line set value control part 10. The part 10 stores a line set value deciding that a closed caption signal 'exists' as the position of the current superimposed signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television signal superimposing device and a television signal line (hereinafter, "LINE") for decoding a signal superimposed on a television signal such as a closed caption signal. ").

[0002]

2. Description of the Related Art Televisions having a screen size of 13 inches or more (hereinafter abbreviated as "TV") in North America are narrations, conversations, broadcast contents, etc., for people with hearing impairments. Character information about TV
It has the function of displaying on the receiver screen. This feature
Generally, it is called a caption function. In the United States, on July 1, 1993, the incorporation of a caption decoder into a TV receiver was legislated, and there has been a strong demand for a TV receiver incorporating a closed caption decoder as described below.

Conventionally, caption decoders have been sold in the US market, but most of them are of an external type separated from a TV receiver. Hereinafter, the caption decoder built in the TV receiver is particularly called a closed caption decoder. Generally, a signal or broadcast superimposed on a TV broadcast for a closed caption decoder is called a closed caption.

[0004] The closed caption signal will be described with reference to FIGS. 10 and 11. FIG. 10A shows T
5 shows a V composite signal. The closed caption signal is superimposed on this composite signal. The first field of the TV composite signal is called field 1 and the next field is called field 2. In the current system, the closed caption signal is
Exist between the 21st horizontal synchronization signal from the beginning of the vertical blanking period. The horizontal sync signal of field 1 is shown in FIG.
It is shown in (B). Note that T in field 2 in FIG.
As shown in the V composite signal,
Another closed caption signal may exist between the fourth horizontal synchronizing signal. FIG. 10D shows the horizontal synchronization signal of the field 2.

FIG. 10E shows a waveform of a closed caption signal. Closed caption signal is Cloc
It is composed of a k Run-in signal, a Start Bits signal, and 16-bit data. After the burst signal, a Clock Run-in signal is provided for seven cycles to synchronize data. Thereafter, a Start Bits signal is given by a 2-bit blanking level and a 1-bit signal indicating the start of data, followed by a 16-bit data area. FIG. 11A shows the breakdown of 16-bit data. The 16-bit data is composed of a control code for designating the color and location of the character and a character code for indicating the type of the character, and both are transmitted in 7 bits. The remaining one bit is an acknowledge bit for error detection.

FIG. 11B shows the information amount of the closed caption signal. As the information amount, 16 bits (two characters) of data can be transmitted in both field 1 and field 2 in one frame (for one screen). Since one screen is equivalent to 30 screens, the data is 480 bits (for 60 characters) from 16 bits × 30 times (each field).

Next, an example of a generally known closed caption data extraction method will be described. The operation of the conventional circuit will be described with reference to FIGS. FIG. 7 is a diagram showing a configuration of the data extraction device, and FIG. 12 is a diagram showing signal waveforms. In FIG. 7, a TV composite signal (analog signal) 51 is applied to an input terminal 50 of the data extraction device. The TV signal 51 propagates to the extraction unit 52, and the extraction unit 52 extracts a vertical synchronization signal 53 from the TV signal 51 by an integration circuit.

The LINE counting section 54 counts the horizontal synchronization signal 55 from the position of the trailing edge of the vertical synchronization signal 53 obtained by the extraction section 52. L counted here
The INE count value is transmitted to the comparison unit 57. Comparison section 5
7 is the LIN counted by the LINE counting unit 54
A comparison is made between the E count value and the LINE set value in the initial value storage section 59, and a closed caption signal to be superimposed on the coincident position is extracted. The initial value storage section 59 stores the LINE setting value of the 21st position in the vertical blanking period.

[0009] The data extraction unit 56 performs the following operations at a slice level such that the duty of the Clock Run-in signal is 1: 1.
Data slice the closed caption signal. The data-sliced closed caption signal is digitized, transmitted to the decoder unit 58, interpreted, and output as characters on the display screen of the TV receiver.

FIG. 12A shows a TV signal 51 applied to the input terminal 50 of the data extraction device of FIG.
(B) is a vertical synchronization signal 5 extracted by the extraction unit 52.
3 is shown. FIG. 12C shows the horizontal synchronizing signal 55 input to the LINE count unit 54, and the number below the waveform is LI
The data counted by the NE counting unit 54 is shown. In the TV signal 51 of FIG. 12A, unlike the signal of FIG. 10A, the horizontal synchronization signal 55 is counted from the position of the trailing edge of the vertical synchronization signal 53 and closed at the "14" th position. Since the caption signal is superimposed, data “14” is set in the initial value storage.

However, in the method of extracting the vertical synchronizing signal 53 from the TV signal 51 by the integration circuit of the extracting section 52, the TV signal 51 shown in FIG.
The integration circuit reacts to a superimposed signal different from the closed caption signal, such as a copy guard superimposed on the signal. Therefore, the position of the vertical synchronization signal 53 is
2 (E), the position at which the closed caption signal is to be extracted is shifted, which may cause a phenomenon in which characters are not displayed on the display screen of the TV receiver.

A circuit conventionally implemented to solve this problem and its operation will be described with reference to FIGS. 8 and 9. FIG. FIG. 8 is a diagram showing the configuration of the LINE search device, and FIG. 9 is a flowchart of the LINE search method.
In FIG. 8, a TV composite signal 51 is supplied to an input terminal 50. The TV signal 51 propagates to the extraction unit 52, and the extraction unit 52 extracts the vertical synchronization signal 53 by an integration circuit. The LINE counting unit 54 counts the horizontal synchronization signal 55 from the position of the trailing edge of the vertical synchronization signal 53 obtained by the extraction unit 52. LI counted here
The NE count value is propagated to the comparison unit 57.

The comparing section 57 has a LINE count value counted by the LINE counting section 54 and a LINE count value to be described later.
A comparison is made with the LINE set value of the E set value control section 69. The data extracting unit 56 performs data slicing of the TV signal superimposed on the position matched by the comparing unit 57 at a predetermined slice level. The data sliced signal is converted into an appropriate digital signal, and thereafter, the decoder unit 58 analyzes the data and outputs it as characters on the display screen of the TV receiver.

The LINE set value control section 69 stores a LINE set value to be compared with the LINE count value counted by the LINE count section 54. Also, LIN
The E setting value control unit 69 uses the value of the initial value storage unit 59 as an initial value, and changes the LINE setting value at a predetermined ratio. That is, the initial value of the LINE setting value is set as a normal value and L
The LINE set value controller 69 gradually lowers the LINE set value at a rate of one line per one frame period.

[0015] The TV signal digitized by the data extraction unit 56 is also input to a signal discrimination unit 71. The signal determination unit 71 determines whether or not a closed caption signal is superimposed on the input TV signal, that is, determines whether or not there is a closed caption signal. An example of a determination method of the signal determination unit 71 will be described. The presence or absence of the start bit “001” in the closed caption signal of FIG. 10E is checked, and the discrimination is performed by checking the parity of the data. That is, the start bit “00”
If “1” exists and the odd parity of the 2-byte data is “OK”, it is determined that the closed caption signal is “present”. The start bit “001” does not exist or the odd parity of the 2-byte data is “N”.
If it is “G”, it is determined that the closed caption signal is “none”. In this way, it is determined whether the digitized closed caption signal from the data extraction unit 56 is correct.

The signal determining section 71 is connected to the control section 74. 73 is a counter unit. The control unit 74 sends the LINE set value of the LINE set value control unit 69 to the comparison unit 57 according to the result of the determination by the signal determination unit 71. Also,
The control unit 74 causes the LINE setting value temporary storage unit 72 to temporarily store the LINE setting value of the current position of the superimposed signal based on the determination result of the signal determination unit 71. That is, the LINE setting value temporary storage unit 72 stores the signal determination unit 71
Determines that the closed caption signal is “not present” to “present”, stores the LINE setting value output from the LINE setting value control unit 69 as the current position of the superimposed signal.

With the above configuration, a LINE search device can be realized. Next, the operation will be described with reference to FIG. In step S51 in FIG. 9, the initial value of the LINE setting value set in the initial value storage 59 is transferred to the LINE setting value controller 69. That is, the LINE setting value is initialized. As the initial value, when a signal other than the closed caption signal is not superimposed on the TV signal 51, the closed caption signal when the horizontal synchronization signal is counted from the trailing edge of the vertical synchronization signal 53 extracted by the extraction unit 52 is The LINE count value of the superimposed position is set.

Next, in step S52, the data of the signal digitized by the data extraction unit 56 is taken into the signal discrimination unit 71. In the branch S53, the signal discriminating unit 71 checks the presence or absence of the start bit and the parity using the data of the fetched signal, and determines the presence or absence of the closed caption signal. Here, when it is determined in the branch S53 that the closed caption signal is “none”,
In step S54, the LINE setting value controller 69 reduces the LINE setting value by one. If the LINE setting value by the LINE setting value control unit 69 is smaller than the settable minimum value by decrementing the LINE setting value by one in step S54, the process proceeds to step S56 by branching S55, and the LINE setting value is set. After setting the maximum value that can be set as the value, the process returns to step S52. On the other hand, if it is within the set value range, the process returns to the processing S52.

If it is determined in the branch S53 that the closed caption signal is present, the process proceeds to a branch S57. In branch S57, when it is not determined that the closed caption signal “present” eight times in a row, the process returns to step S52.
If it is determined that the closed caption signal is present eight consecutive times in the branch S57, the current LINE set value is stored in the LINE set value temporary storage unit 72, and the LINE set value of the closed caption signal is determined. This 8
The counter unit 73 is used for discrimination between consecutive times. Where 8
The reason for performing the consecutive discrimination is to avoid erroneous discrimination due to the influence of noise or the like.

The subsequent setting of the LINE setting value on which the closed caption signal is superimposed is performed based on the LINE setting value stored in the LINE setting value temporary storage section 72.

[0021]

However, the LINE search device and the LI search by the LINE search method have been described.
In the method of determining the NE set value, not only is it not possible to immediately react to the switching of the TV signal, but also because the LINE search is always performed even in a frame in which the closed caption signal is not superimposed, the signal on which the closed caption signal is superimposed is used. It takes time to search. Therefore, the position of the vertical synchronization signal 53 is
In the case of the change as shown in (E), a TV signal having a period of more than ten frames or more must be taken in before reaching the LINE position of the closed caption signal.
Then, if the display start command is transmitted about every 3 seconds like a closed caption signal, even if the data of more than ten frames is lost, only the first character will not be displayed. It may not be possible to cope with a superimposed signal in which necessary data is sent every time.

The LINE position and the set value in such a case will be described with reference to FIG. FIG. 13A shows a TV signal cycle. This TV signal cycle corresponds to the signal input shown in FIG.
From the TV signal in which only the closed caption signal shown in FIG. 12A is superimposed, a TV signal in which a superimposed signal different from the closed caption signal such as the copy guard shown in FIG. This means that it is changed in the second frame period. FIG. 13B shows in which LINE position the closed caption signal is present for each frame period. FIG. 13C shows the value of the LINE setting value by the conventional LINE search device for each frame period. FIG. 13D shows the LIN of FIG. 13C.
The signal discrimination result of the data extracted by the E setting value is shown. When the signal is changed in the second frame period, the next time that the closed caption signal is determined to be “present” is the ninth frame period, and it can be seen that seven frames are required to perform the LINE search. However, in practice, several frames are required to avoid erroneous determination due to the influence of noise or the like, so that data of more than ten frames is lost.

The present invention solves such a problem,
An object of the present invention is to enable software to correct a malfunction of vertical synchronization signal extraction by an integration circuit, which may occur when a signal different from a closed caption signal is simultaneously superimposed on a TV signal.

[0024]

A superimposed signal capturing apparatus according to the present invention sets a LINE count section for counting a horizontal synchronization signal from a position of a vertical synchronization signal extracted from a TV signal, and sets a LINE set value in a specific range. A LINE set value control unit, a comparison unit that compares the count value counted by the LINE count unit with a LINE set value in a specific range set by the LINE set value control unit, A data extraction unit for extracting a TV signal to be superimposed.

With such a configuration, the LIN of a specific range in which the closed caption signal is expected to be superimposed is
The LINE setting value control unit sets the E setting value,
The count value and LIN counted by the LINE count section
The comparison unit compares the LINE set value in a specific range set by the E set value control unit, and the data extraction unit extracts a TV signal to be superimposed at a position in the matched range in the comparison unit. The malfunction of the vertical synchronizing signal extraction by the integration circuit, which may occur when a signal different from the closed caption signal is simultaneously superimposed on the signal, is corrected in a short time.

[0026]

According to the present invention, a LINE count section for counting a horizontal synchronization signal from a position of a vertical synchronization signal extracted from a TV signal, and a LI of a specific range are provided.
A LINE setting value control unit for setting an NE setting value;
The count value counted by the INE count unit and the LI
A comparison unit for comparing the LINE setting value in a specific range set by the NE setting value control unit, and a data extraction unit for extracting a TV signal to be superimposed at a position in the matching range in the comparison unit. .

With such a configuration, the LIN of a specific range in which the closed caption signal is predicted to be superimposed is provided.
The LINE setting value control unit sets the E setting value,
The count value and LIN counted by the LINE count section
The comparison unit compares the LINE set value in a specific range set by the E set value control unit, and the data extraction unit extracts a TV signal to be superimposed at a position in the matched range in the comparison unit. The malfunction of the vertical synchronizing signal extraction by the integrating circuit, which may occur when a signal different from the closed caption signal is simultaneously superimposed on the signal, is corrected in a short time.

According to a second aspect of the present invention, there is provided a storage unit for storing, for each LINE, the data output from the data extraction unit and the LINE setting value output from the LINE setting value control unit. . With such a configuration, the data output from the data extraction unit and the LINE setting values output from the LINE setting value control unit are stored by the storage unit for each LINE, and the L
It can be used for INE search.

According to a third aspect of the present invention, there is provided a signal discriminating section for discriminating the presence or absence of a closed caption signal from data of a predetermined LINE TV signal stored in the storage section, and A control unit that controls to output predetermined LINE data and that determines a LINE setting value on which the closed caption signal is superimposed when the signal determination unit determines that there is closed caption data. .

With such a configuration, the LINE setting value on which the closed caption signal is superimposed is set to L in a specific range.
Since it is determined based on the INE setting value, T
A malfunction of the vertical synchronizing signal extraction by the integrating circuit, which may occur when a signal different from the closed caption signal is simultaneously superimposed on the V signal, is corrected in a short time. According to a fourth aspect of the present invention, there is provided a discriminating section for discriminating that there is no closed caption signal based on the discrimination result of the signal discriminating section, and counting the number of discriminating operations by the discriminating section to discriminate between the closed caption signal and no closed caption signal. And a count unit for transmitting information to the effect that there is no closed caption signal to the control unit only when the number of times performed is a plurality of times. With such a configuration, after the LINE setting value is determined by the LINE search device for the superimposed signal, while decoding is performed with the same LINE setting value,
Counting the frame period having no closed caption signal is effective when data cannot be extracted in a temporary no-signal state due to the influence of noise or the like, and the accuracy of the operation of capturing the superimposed signal can be improved.

Next, an embodiment of the present invention will be described. FIG. 1 shows the overall configuration of an apparatus according to an embodiment of the present invention. Hereinafter, description will be made with reference to FIGS. FIG. 2 is a diagram showing a configuration of a superimposed signal capturing device, and FIG.
FIG. 4 is a diagram illustrating a configuration of a search device, and FIG. 4 is a diagram illustrating a configuration of a decoding device for a superimposed signal.

The TV composite signal 2 is supplied to the input terminal 1 in the superimposed signal capturing device shown in FIG. TV
The signal 2 propagates to the extraction unit 3, and the extraction unit 3 extracts the vertical synchronization signal 4 by the integration circuit. LINE count section 5
Counts the horizontal synchronization signal 6 from the position of the trailing edge of the vertical synchronization signal 4 obtained by the extraction unit 3. The LINE count value counted here is transmitted to the comparison unit 8.
The horizontal synchronization signal 6 can be counted from the position of the leading edge of the vertical synchronization signal 4.

The comparing section 8 compares the LINE count value counted by the LINE counting section 5 with a LINE set value in a specific range of a LINE set value control section 10 described later. The data extracting unit 7 determines the LI of the range matched by the comparing unit 8.
The TV signal 2 superimposed on the NE position is sliced at a predetermined slice level to extract data. The data-extracted signal is converted into an appropriate digital signal and transmitted to the storage unit 11. The storage unit 11 stores the data output from the data extraction unit 7 and the LI output from the LINE setting value control unit 10.
The NE setting value is stored for each LINE. Reference numeral 12 denotes a control unit.

The LINE set value control section 10 stores a LINE set value in a specific range to be compared with the LINE count value counted by the LINE count section 5. The LINE setting value control unit 10 sets the value of the initial value storage unit 9 as an initial value. In the present embodiment, a method is used in which an initial value of the LINE setting value is set as a normal LINE setting position, and a LINE setting position in a specific range is output to the comparing unit 8 in an abnormal state. It should be noted that a method may be used in which the LINE setting position in a specific range is output in a normal state, with the initial value being an abnormal state.

As described above, a superimposed signal capturing device according to the present invention is realized. In the LINE search apparatus for superimposed signals shown in FIG. 3, the storage unit 11 stores the data output from the data extraction unit 7 and the LINE set values output from the LINE set value control unit 10 in each of the LI lines in the configuration shown in FIG.
It is stored over a specific range of LINE setting values for each NE. LINE of a specific range stored in the storage unit 11
Data obtained by digitizing the TV signal at the set position is output to the signal discriminating unit 13 according to an instruction from the control unit 12. The signal determination unit 13 determines whether or not a target superimposition signal (here, a closed caption signal) is superimposed on the input TV signal, that is, determines whether or not there is a closed caption signal.

The discriminating method of the signal discriminating section 13 is as described in the prior art. That is, FIG.
Is checked by checking for the presence or absence of a start bit "001" in the closed caption signal, and by performing a parity check on the data. Specifically, if the start bit “001” is present and the odd parity of the 2-byte data is “OK”, it is determined that the closed caption signal is “present”. On the other hand, if the start bit “001” does not exist or the odd parity of the 2-byte data is “NG”, it is determined that the closed caption signal is “none”. In this way, it is determined whether the digitized closed caption signal is correct.

Although the above-described determination method is a more reliable method, there is another method of checking only the start bit. In the above description, the start bit is “001” and the parity is described as an odd number, but the start bits are “010”, “100”, “0”.
11 "," 101 "," 110 ", etc., and there is no problem even if the parity is an even number.

The signal discriminating unit 13 is connected to the control unit 12, and the control unit 12 transmits a TV signal at a LINE setting position in a specific range stored in the storage unit 11 according to the discrimination result by the signal discriminating unit 13. Select the digitized data.
The signal discriminating unit 13 determines that the closed caption signal is present
If it is determined that the LINE setting value is selected, the control unit 12 selects the LINE setting value at that time.

As described above, a LINE search apparatus for a superimposed signal according to the present invention is realized. Next, the TV composite signal 2 is supplied to the input terminal 1 in the decoding device of the superimposed signal of FIG. The TV signal propagates to the extraction unit 3, and the extraction unit 3 extracts the vertical synchronization signal 4 by the integration circuit. The LINE count unit 5 calculates the horizontal synchronization signal 6 from the position of the trailing edge of the vertical synchronization signal 4 obtained by the extraction unit 3.
Count. The LINE count value counted here is transmitted to the comparison unit 8. The comparing unit 8 calculates the LINE count value counted by the LINE counting unit 5 and L
The LINE setting value is compared with the LINE setting value of the INE setting value control unit 10.

The LINE setting value control unit 10 stores the LINE setting value determined to be “closed” in FIG. 3 as the position of the current superimposed signal by the control signal from the control unit 12. The LINE set value at the position where the closed caption signal is superimposed thereafter is based on the stored LINE set value by the control signal from the control unit 12.

The data extraction unit 7 slices the TV signal superimposed on the position matched by the comparison unit 8 at a predetermined slice level. The data sliced signal is converted into an appropriate digital signal, and the signal discrimination unit 13 and the decoder unit 1
Propagate to 4. The signal discriminating unit 13 discriminates the presence or absence of the closed caption signal, and when it determines that the closed caption signal is “absent”, shifts to the operation of the superimposed signal capturing device shown in FIG. On the other hand, the signal discriminating unit 1
3 determines that the closed caption signal is “present”, the decoder unit 14 analyzes the data, and the display setting unit 1
By setting the display in step 5, the TV display unit 16 outputs the characters on the display screen of the TV receiver.

As described above, an apparatus for decoding a superimposed signal according to the present invention is realized. Further, the following components are required as the best embodiment of the present invention. That is, FIG. 5 shows the superimposed signal decoding device shown in FIG. A part 18 is provided.

The counter section 18 counts the signal discriminating operation of the signal discriminating section 13 a plurality of times by the discriminating section 17 and does not make a discrimination in one "NG". NG "is transmitted to the control unit 12. The discriminating unit 17 and the counter unit 18 do not have a closed caption signal during the decoding with the same LINE setting value after determining the LINE setting value by the LINE search device for the superimposed signal shown in FIG. Counting the frame period is effective when data cannot be extracted in a temporary no-signal state due to the influence of noise or the like, and the accuracy of the operation of capturing a superimposed signal can be improved.

Next, a specific example of the present invention will be described with reference to FIG. 1 and the conventional signal waveform diagram of FIG. First, from the signal waveforms of FIGS.
The NE count set value is “14”. When the copy guard signal is superimposed on the composite signal as shown in FIG. 12D, the integration circuit reacts as shown in FIG. 12E with the vertical synchronization signal 4 extracted from the extraction unit 3. . Therefore, the count start position of the LINE count unit 5 changes as shown in FIG. 12 (F), and the position where the closed caption signal is extracted shifts.

In such a case, first, the TV signal superimposed on the range of the LINE setting value “1” to the LINE setting value “14” is digitized by the data extraction unit 7 and is taken into the storage unit 11. Next, using the data of the signal fetched into the storage unit 11, the signal determination unit 13 checks the presence / absence of a start bit and the parity to determine the presence / absence of a closed caption signal. That is, the data from the LINE set value “1” to the LINE set value “14” is determined in order, and the LINE set value determined as the closed caption signal “present” is obtained. LIN determined to be “closed” by closed caption signal by control unit 12
The E set value is stored in the LINE set value control unit 10 and the LI
The operation of the NE search ends.

When the closed caption signal is temporarily determined to be "none" due to noise or the like, the LIN
When the E search processing is performed, the LINE search processing is repeated until the next normal signal is transmitted, and finally the original L
The operation of returning to the INE setting position is performed. In such a case, the signal discriminating operation of the signal discriminating unit 13 is continuously counted by the discriminating unit 17, and the LINE is continuously repeated two or more times until the closed caption signal is determined to be “none”.
By not performing the search processing, the control unit 12 avoids a temporary no-signal state due to noise or the like.

According to the present invention, other LINE search methods can be considered. That is, in the above method, the data of the LINE position to be taken into the storage unit 11 at one time is set to the LINE setting values “1” to “14”, but the number of data to be stored may be more or less. This change makes a difference in the time required for the LINE search processing, but in the present embodiment, the LINE setting values “1” to “14” are also taken into consideration in consideration of the time required for the processing.
And

Next, the LI corresponding to the switching of the TV signal
The change between the NE position and the set value will be described with reference to FIG.
FIG. 6A shows a TV signal cycle. In this TV signal cycle, the signal input is the second frame cycle, and FIG.
From a TV signal in which only a closed caption signal is superimposed as shown in FIG. 12A, a superimposed signal different from a closed caption signal such as a copy guard as shown in FIG. This indicates that switching is performed. FIG. 6 (B)
Indicates at which LINE position the closed caption signal is present for each frame period. FIG.
(C) shows a LINE search device according to the present invention.
The setting values are shown for each frame period. FIG. 6 (D)
6 shows the signal determination result of the data extracted with the LINE setting value in FIG. 6C. When the signal is changed in the second frame period, the next determination of the presence of the closed caption signal is the fourth frame period, and it can be seen that the LINE search is possible if there are two frames. Actually, several frames are required to avoid erroneous discrimination due to the influence of noise or the like. However, since data is stored during that time, the TV is stored without data loss.
It is possible to cope with the switching of the signal.

In the embodiment described above, a LINE search of a closed caption signal has been described as an example. However, the present invention is applicable to a case where another superimposed signal to be superimposed on a TV signal is processed. be able to.

[0050]

As described above, according to the TV signal superimposed signal capturing device and the TV signal superimposed signal LINE search device of the present invention, the LINE setting position of the signal superimposed on the TV signal, for example, the closed caption signal, can be quickly determined. Can be determined.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a TV signal superimposed signal capturing device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a superimposed signal capturing device in FIG. 1;

FIG. 3 is a configuration diagram of a LINE search device in FIG. 1;

FIG. 4 is a configuration diagram of a decoding device in FIG. 1;

5 is a configuration diagram of a device in which a discriminator and a counter are added to the device of FIG.

FIG. 6 is a diagram showing a LINE position and a set value according to the present invention.

FIG. 7 is a configuration diagram of a conventional data extraction device.

FIG. 8 is a configuration diagram of a conventional LINE search device.

FIG. 9 is a flowchart showing a conventional LINE search method.

FIG. 10 is a signal waveform diagram of a conventional TV signal applied to the present invention.

FIG. 11 is a diagram illustrating a conventional closed caption signal applied to the present invention.

FIG. 12 is a signal waveform diagram of another conventional TV signal applied to the present invention.

FIG. 13 is a diagram showing a LINE position and a set value in the related art.

[Explanation of symbols]

 2 TV signal 3 Extraction unit 4 Vertical synchronization signal 5 LINE count unit 6 Horizontal synchronization signal 7 Data extraction unit 8 Comparison unit 10 LINE set value control unit 11 Storage unit 12 Control unit 13 Signal discrimination unit 17 Discrimination unit 18 Counter unit

Claims (4)

[Claims] 1. A line count unit for counting a horizontal synchronization signal from a position of a vertical synchronization signal extracted from a television signal, a line set value control unit for setting a line set value in a specific range, and the line count unit. A comparison unit that compares the counted value with a line set value in a specific range set by the line set value control unit, and a data extraction unit that extracts a television signal to be superimposed at a position in the matched range in the comparison unit. An apparatus for capturing a superimposed signal of a television signal, comprising: 2. The television according to claim 1, further comprising a storage unit for storing, for each line, data output from the data extraction unit and line setting values output from the line setting value control unit. Signal superimposed signal capturing device. 3. A signal discriminator for discriminating presence / absence of a closed caption signal from data of a television signal of a predetermined line stored in a storage unit according to claim 2, and a predetermined signal from said storage unit to said signal discrimination unit. A control unit that controls output of line data and determines a line setting value on which a closed caption signal is superimposed when the signal determination unit determines that there is closed caption data. Line search device for superimposed signals of signals. 4. A discriminator for discriminating that there is no closed caption signal based on a discrimination result of the signal discriminator, and counting the number of discrimination operations by the discriminator,
4. The superimposition of a television signal according to claim 3, further comprising: a counting section for transmitting information indicating that there is no closed caption signal to the control section only when the number of times of discrimination from the closed caption signal is a plurality of times. Signal line search device.