JP2002314955A - Closed caption decoder device and display device and video recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a closed caption decoder device, a display device, and a video recorder capable of extracting closed caption information whose decoding precision is much higher from a video signal. SOLUTION: This device is provided with a field switching processing circuit 109 for allowing a data buffer memory 110 to store a closed caption signal corresponding to first and second fields extracted from a binarized video signal by a caption signal extracting circuit 106, based on the result of line determination and result of field information determination to a synchronizing signal separated from the binarized videos signal, for executing field determination by detecting XDS data, and for executing field switching processing corresponding to the closed caption signal based on the determined result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closed caption decoder, a display device, and a video recording device, and more particularly to a closed caption decoder such as a binary character signal superimposed on a vertical blanking period of an interlaced scanning video signal. The present invention relates to a closed caption decoder for decoding caption information, a display device, and a video recording device.

[0002]

2. Description of the Related Art In transmitting a television signal, various information signals such as a character signal and a control signal are transmitted in a vertical blanking period while being superimposed on a vertical blanking signal. A device on the transmitting side of the television signal transmits these information signals, and a device on the receiving side can transmit and receive data such as character information by detecting these information signals.

[0003] As such a broadcasting system, there is a system called a closed caption system. In this closed caption broadcasting, a closed caption signal including a character signal, a control signal, and the like is transmitted while being superimposed on a vertical blanking period of a television signal.

In order to view a program broadcast in the closed caption system while displaying character information, a closed caption decoder device is connected to a television receiver or a closed caption decoder device is incorporated. It is necessary to use an existing television receiver. In this closed caption decoder device, a video signal on which a binarized caption signal is superimposed during a vertical blanking period is input, a caption signal is extracted from the video signal, and the binarized caption signal is converted to a caption. Decrypt as information. As a result, this caption information
It can be displayed on the screen of a television receiver or stored in a recording device such as a magnetic recording device.

[0005] Although a hearing-impaired person is mainly considered as a target of a broadcast program by the closed caption system, this system can also be used for learning English. For example, while listening to the character information and the voice displayed on the screen, it is also possible to perform learning such as hearing in English.

FIG. 5 is a block diagram showing the configuration of a conventional closed caption decoder device. In FIG. 5, a binarization circuit 502 superimposes a binarized closed caption signal input from an input terminal 501. The analog television video signal thus obtained is binarized.
The synchronization signal separation circuit 503 separates a synchronization signal from an analog television video signal input from the input terminal 501. The caption line determination circuit 504 determines a line position on which a closed caption signal is to be superimposed from information of the synchronization signal separated by the synchronization signal separation circuit 503. The field information determination circuit 505 determines the first and second fields from the information of the synchronization signal separated by the synchronization signal separation circuit 503. The caption extraction circuit 506 uses the line position information obtained from the caption line judgment circuit 504 and the field information obtained from the field information judgment circuit 505 to convert the video signal binarized by the binarization circuit 502 into a closed caption. The signal is extracted, a closed caption signal for the first field is output from the output terminal 507, and a closed caption signal for the second field is output from the output terminal 508.

Next, the operation of the conventional closed caption decoder will be described. When the analog television video signal on which the binarized closed caption signal is superimposed is input from the input terminal 501 to the binarization circuit 502 and the synchronization signal separation circuit 503, the binarization circuit 5
02 binarizes the analog television video signal. The synchronization signal separation circuit 503 separates a synchronization signal. Subsequently, based on the information obtained from the synchronization signal separation circuit 503, the caption line determination circuit 504 determines the line position where the closed caption signal is to be superimposed, and the field determination circuit 505 determines the position of the first and second fields. Make a decision. A caption extracting circuit 506 extracts a closed caption signal from the video signal binarized by the binarizing circuit 502. Here, the closed caption signal corresponds to the signal corresponding to the first field and the signal corresponding to the second field.
The configuration differs from that corresponding to the field. Therefore, the caption extraction circuit 506 includes the caption line determination circuit 504 and the field determination circuit 5
Using the line position information and the field information output by the device 05, the closed caption signal corresponding to the first field and the closed caption signal corresponding to the second field of the video signal are separated and extracted, and the output terminals 507 and Output from the output terminal 508.

[0008] The extracted closed caption signal is decoded, and if it is a television receiver (not shown), the caption information is displayed on the screen while gradually synchronizing it with the video along with the sound on the screen. In the case of a recording device (not shown), caption information is stored on a magnetic recording tape or the like based on a standard for storing caption information.

[0009]

As described above, in the conventional closed caption decoder, the synchronizing signal is separated from the video signal, the first and second fields of the video signal are determined, and the result is used. Thus, it has been determined which of the first and second fields each closed caption signal corresponds to.

[0010] However, in such a conventional closed capstan decoder, when the electric field strength of the reception is low, the phenomenon of erroneous field determination may occur due to the incorporation of noise into the video signal.
In such a case, as described above, since the caption information has a different structure between the first field and the second field, there is a problem that decoding of the closed caption information is not performed normally. .

In a magnetic recording apparatus or the like equipped with a system for replacing a synchronization signal called a TBC (time base collector), the first and second fields are determined based on the video signal before the replacement of the synchronization signal. However, the detection performance may be degraded due to noise or the like, resulting in erroneous field determination. As a result, there is a problem that decoding of the caption information is not performed normally due to the inverted video signal of the first and second fields.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a closed caption decoder device, a display device, and a video recording device capable of extracting closed caption information with higher decoding accuracy from a video signal. It is intended to provide a device.

[0013]

SUMMARY OF THE INVENTION A closed caption decoder according to the present invention receives a video signal on which a binarized closed caption signal is superimposed during a vertical blanking period, and binarizes the video signal. Means for separating a synchronization signal from the video signal, line determination means for performing a line determination of a closed caption signal from the synchronization signal, field information determination means for performing field information determination from the synchronization signal, and the line A closed caption signal corresponding to the first or second field from the binarized video signal based on the line determination result output by the determination means and the field information determination result output by the field information determination means And a storage unit for storing the closed caption signal. Means for reading the closed caption signal from the storage means, and judging from the data content of the closed caption signal whether the closed caption signal originally corresponds to one of the first field and the second field. Field switching means for performing field determination and replacing a field corresponding to the closed caption signal based on the result of the field determination is provided.

Further, in the closed caption decoder device, the field replacement processing means may include a second
By detecting XDS data superimposed only on a closed caption signal corresponding to a field, the first or second field is determined.

Further, in the closed caption decoder device, the field replacement processing means may determine the first or second field by detecting data of character information superimposed on the closed caption signal. It was made.

Further, in the closed caption decoder device, the field replacement processing means detects data unique to the first field or the second field superimposed on the closed caption signal, so that the first or second data is obtained. The field determination of the field is performed.

Further, the closed caption decoder device according to the present invention comprises a means for receiving a video signal on which a binarized closed caption signal is superimposed during a vertical blanking period, and for binarizing the video signal. Means for separating a synchronization signal from the video signal, line determination means for performing a line determination of a closed caption signal from the synchronization signal, and the binarized image based on a line determination result output from the line determination means. Extraction means for extracting a closed caption signal from a signal, storage means for storing the closed caption signal, and reading the closed caption signal from the storage means, from the data content of the closed caption signal,
The closed caption signal comprises a first field;
A field determination is performed to determine whether the closed caption signal corresponds to one of the second field and the second field.
And a field replacement processing means for outputting the data corresponding to the field No.

In the closed caption decoder device, the field replacement processing means may include a second
By detecting XDS data superimposed only on a closed caption signal corresponding to a field, the first or second field is determined.

Further, in the closed caption decoder device, the field replacement processing means may determine the first or second field by detecting data of character information superimposed on the closed caption signal. It was made.

Further, in the closed caption decoder device, the field replacement processing means detects data unique to the first field or the second field superimposed on the closed caption signal, so that the first or second field is detected. The field determination of the field is performed.

Further, a display device according to the present invention includes the closed caption decoder device, and displays a closed caption signal decoded by the closed caption device on a screen.

Further, the video recording apparatus according to the present invention includes the closed caption decoder, records the video signal on a recording medium, and separates the closed caption signal decoded by the closed caption device from the video signal. Then, the data is recorded on the recording medium.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIG. 1 is a block diagram for explaining a configuration of a closed caption decoder device according to Embodiment 1 of the present invention. Converts the analog television video signal input from the input terminal 101 onto which the binarized closed caption signal is superimposed. The synchronization signal separation circuit 103 separates a synchronization signal from an analog television video signal input from the input terminal 101. The caption line determination circuit 104 determines a line position on which a closed caption signal is to be superimposed from information of the synchronization signal separated by the synchronization signal separation circuit 103. The field information determination circuit 105 determines the first and second fields of the video signal from the information of the synchronization signal separated by the synchronization signal separation circuit 103. The caption extraction circuit 106 is a caption line determination circuit 1
04 and the field information obtained from the field information determination circuit 105,
A closed caption signal is extracted from the video signal binarized by the binarization circuit 102, and a closed caption signal S107 for the first field and a closed caption signal S108 for the second field are output. The field replacement processing circuit 109 receives the first field closed caption signal S107 and the second field closed caption signal S108, and temporarily stores them in the data buffer memory 110. Then, by detecting data contents indicating the characteristics of the first field and the second field with respect to the stored closed caption signal, the correspondence between the stored closed caption information and the field is normal. After determining whether or not each field of the closed caption information stored in the data buffer memory 110 is replaced, it is determined whether or not the corresponding field is to be replaced. , The closed caption signals are read from the data buffer memory 110, and these signals are
The output terminal 111 and the output terminal 112 output the caption signal S111 corresponding to the field and the caption signal S112 corresponding to the second field, respectively.

FIG. 3 shows the structure of a signal in a vertical blanking period including a closed caption in a video signal for explaining the closed caption decoder device according to the first embodiment. FIG. 3A shows a waveform near a vertical retrace period from line 18 to line 23 in the first field of the video signal, and FIG. 3B shows a vertical waveform from line 281 to line 285 in the second field of the video signal. The waveform near the retrace period is shown. In the figure, 301,
306 is a line number, 302 is VITC, 303 is Vi
DeoIDs 304 and 307 indicate closed captions, and 305 indicates a video signal. As shown in FIGS. 3 (a) and 3 (b), the transmitting-side device uses the VITC 302 and the Video ID 3
03, information such as the closed caption signal 307 is superimposed, and the receiving device detects the information signal to transmit data such as character information.

FIG. 4A is an enlarged view of the closed caption signal 304 shown in FIG. 3A in the vertical retrace period of 21 lines. In FIG. 4A, the closed caption signal is added to the head. Clock run-in signal 402 used to synchronize when decoding data bits
, And a start bit signal 403 that follows, and a data bit signal 404 that follows. 40
1 indicates a horizontal synchronizing signal, and 405 indicates a threshold value for binarization. FIG. 4B shows an information signal obtained by binarizing the closed caption signal 304 shown in FIG. 4A with a binarization threshold value 405. By decoding the binarized signal, closed caption information can be obtained. FIG. 6 is a table showing an example of closed caption information obtained as a result of decoding the binarized closed caption signal, and is shown here as 16-bit data. The closed caption information obtained by decoding the binarized closed caption signal is composed of character information, violence information called lettering, and copyright information indicating permission / non-permission of copying. Standards for these information contents are shown in EIA608A, EIA702, EIA744, and the like. According to these standards, the character information position of the closed caption signal is 2 in the first field.
It is stipulated that only one line is superimposed on 21 lines of the first field and 284 lines of the second field. XDS (Extended Data S
An extended data service of closed caption information called "ervice" is also standardized, and the transmission of violence information called "letting" and the transmission of copyright information of CGMS and APS are specified. According to the above standard, the XDS information position is defined to be superimposed only on the 284 line of the second field.

Next, the operation of the closed caption decoder according to the first embodiment will be described. When an analog television video signal on which a binarized closed caption signal is superimposed is input from a terminal 101 to a binarization circuit 102 and a synchronization signal separation circuit 103, the binarization circuit 102 converts the analog television video signal. Binarize. Further, the synchronization signal separation circuit 103 separates the synchronization signal. Subsequently, based on the information obtained from the synchronization signal separating circuit 103, the caption line determining circuit 104 determines the line position where the caption should be superimposed.
The field information determination circuit 105 determines the first and second fields from the information obtained from the synchronization signal separation circuit 103. The caption extraction circuit 106 extracts closed caption information from the video signal binarized by the binarization circuit 102. Here, the closed caption information has a different configuration from that corresponding to the first field and that corresponding to the second field. Therefore, the caption extraction circuit 106 uses the line position information and the field information output from the caption line determination circuit 104 and the field determination circuit 105 to generate a closed caption signal S107 corresponding to the first field of the video signal, The closed caption signal S108 corresponding to the field is separated and extracted, and each is output to the field replacement processing circuit 109.

The field replacement processing circuit 109 is a closed caption signal S107 corresponding to the first field and a closed caption signal S10 corresponding to the second field, which are signals from which captions have been extracted.
8 is stored in the data buffer memory 110. Then, from these closed caption signals, data contents indicating the characteristics of the first field and the second field are detected, whereby the closed caption signal S107 and the closed caption signal S108 are detected.
Are respectively corresponding to the first field and the second field. This data content detection processing will be described later. If the content of the closed caption signal S107 indicates the feature of the first field, and if the content of the closed caption signal S108 indicates the feature of the second field, the closed caption signal S10 corresponding to the first field is provided.
7 is read from the data buffer memory 110 as it is as a closed caption signal S111 corresponding to the first field, output from the output terminal 111, and output as the closed caption signal S111 corresponding to the second field.
108 is read from the data buffer memory 110 as it is as a closed caption signal S112 corresponding to the second field, and output from the output terminal 112. If the content of the closed caption signal S107 indicates the characteristic of the second field and the content of the closed caption signal S108 indicates the characteristic of the first field as a result of detecting the data content of the closed caption signal, The caption signals are exchanged and read from the data buffer memory 110. That is, the closed caption signal S107 corresponding to the first field is read out from the data buffer memory 110 as the closed caption signal S112 corresponding to the second field, output from the output terminal 112, and the closed caption signal S108 corresponding to the second field is read. Is read from the data buffer memory 110 as a closed caption signal S112 corresponding to the first field, and is output from the output terminal 111.

Next, a description will be given of a process of detecting data contents indicating the characteristics of the first field and the second field from the closed caption signal by the field replacement processing circuit 109.

The field replacement processing circuit 109 is shown in FIG.
The closed caption signal of the 21st line of the first field as shown in (b) is decoded into a binary signal, and the resulting data of the closed caption information as shown in FIG. It is stored in the buffer memory 110. Similarly, a binary caption signal of the 284 line of the second field shown in FIG. 3B is decoded, and the resulting data of the closed caption information is stored in the data buffer memory 110. Remember. Then, using the data recorded in the data buffer memory 110, the presence / absence of the XDS data of the closed caption signal is determined.

The data of the closed caption information including the XDS data has a structure in which data spanning a plurality of frames are collectively meaningful. For example, XD
In the case of copyright information such as CGMS or APS, which is a type of S data, the value of start data called a start code is 16 bits, and is 000000 in binary notation.
10,0001000, CGMS and A in subsequent frames
16-bit data indicating the code content of copyright information such as PS, and the value of end data called an end code in a subsequent frame is 16 bits and is represented by 10 in binary notation.
The structure of 001111xxxxxxxxx (x is an undefined value of 0 or 1) has the meaning as the copyright information of the XDS data.

This XDS data is stored in the second field 28
Since only four lines are defined, in the first embodiment, this XDS information is used for data content detection processing, and the data of closed caption information stored in the data buffer memory 110 is used. ,
The data pattern of the XDS information is searched, and when the XDS data is detected, it is determined that the closed caption information in which the XDS is detected is the closed caption information corresponding to the second field. As described above, the first and second fields can be determined based on the presence or absence of the XDS information included in the closed caption signal. If the field determination result obtained from the XDS data is different from the determination result of the field information determination circuit 105, the field replacement processing circuit 109 performs a process of replacing the correspondence of each field of the closed caption signal, and then performs the first process. A field closed caption signal S111 is output from an output terminal 111.
Also, the closed caption signal S of the second field
112 is output from the output terminal 112. If the field determination result obtained from the XDS data is the same as the determination result of the field information determination circuit 105, the process of exchanging the correspondence of each field of the closed caption signal is not performed, and the closed caption of the first field is not performed. The caption signal S111 is output from the output terminal 111, and the closed caption signal S112 of the second field is output from the output terminal 112.

As described above, according to the closed caption decoder of the first embodiment, the field corresponding to the closed caption signal is determined based on the presence or absence of the XDS data in the data content of the closed caption signal. And a field exchange processing circuit 109 for exchanging the correspondence of the closed caption signal to the field when the determination result is different from the determination result of the field information determination circuit 105. Even if an error occurs in the field judgment result based on the synchronization signal due to noise in the data, the normal closed caption signal that should be handled should be output for each field. Video signal Al, the effect capable of providing a closed caption decoder apparatus which can be extracted closed caption information that can be more accurate decryption.

The XD shown in the first embodiment
The value of the S data is merely an example, and in the present invention, the same effect as in the first embodiment can be obtained even if another XDS data value is used.

(Embodiment 2) FIG. 7 is a block diagram showing a configuration of a closed caption decoder device according to Embodiment 2 of the present invention. The closed caption decoder device according to the second embodiment is similar to the closed caption decoder device according to the first embodiment.
In the closed caption decoder device of the above, instead of the field replacement processing device for performing field replacement based on the presence or absence of XDS data in the closed caption signal, field replacement for performing field replacement based on the presence or absence of character information data in the closed caption signal A processing device 709 is provided, and in the figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts.

Next, the configuration and operation of the second embodiment will be described. The description of the same parts as in the first embodiment is omitted here. The field replacement processing device 709 includes a caption signal S107 for the first field input from the caption signal extracting circuit 106.
And the caption signal S108 of the second field,
The data is stored in the data buffer memory 110. Subsequently, the presence / absence of character information data of the closed caption signal is determined using the data stored in the data buffer memory 110.

As described in the first embodiment, according to the standard, the character information position is set to 2 in the first field.
It is stipulated that only one line is superimposed on 21 fields of the first field and 284 lines of the second field. Therefore, field determination can be performed based on the presence or absence of character information, and in the second embodiment, field determination is performed using this.
For example, when the data pattern of the character information is not detected from the data content of the closed caption signal S107 corresponding to the first field, and the data pattern of the character information is detected in the closed caption signal S108 corresponding to the second field, Field determination circuit 105
Since there is a high possibility that the field information for the closed caption signal S108 from the first terminal is erroneously determined, the field exchange processing circuit 709 replaces the fields of the closed caption signal, and then outputs the caption signal S111 of the first field to the output terminal 111. From the second field caption signal S112
Is output from the output terminal 112. Further, when a data pattern of character information is detected only from the character data content of the closed caption signal S107 corresponding to the first field, it is highly likely that the field determination of the field determination circuit 105 is normal. Without the replacement, the caption signal S of the first field
111 is output from the output terminal 111, and the caption signal S112 of the second field is output from the output terminal 112.

According to the second embodiment, the corresponding field of the closed caption signal is determined based on the presence or absence of character information data in the data content of the closed caption signal. By providing the field exchange processing circuit 709 for exchanging the correspondence of each closed caption signal to the field when the result differs from that of the closed caption signal, it is possible to prevent noise from being mixed into the video signal when the electric field strength of the received broadcast is low. Even if an error occurs in the field determination result based on the synchronization signal for a reason, a normal closed caption signal that should be originally handled can be output in association with each field, and from the video signal, Closed for more accurate decoding An effect that can provide closed captioning decoder device capable of taking out Yapushon information.

In the first and second embodiments, the description has been given of the case in which the field replacement processing circuit for determining the field of the closed caption signal by detecting the presence / absence of XDS data or character information is provided.
In the present invention, the field replacement processing circuit, the other data content of the closed caption signal that can determine the correspondence with the field, for example, based on the data unique to the closed caption signal corresponding to one of the fields, The field determination of the closed caption signal may be performed, and in such a case, the same effects as those of the above embodiments can be obtained.

(Embodiment 3) FIG. 2 is a block diagram for explaining a configuration of a closed caption decoder according to Embodiment 3 of the present invention. In FIG. , And binarizes the analog television video signal on which the closed caption signal is superimposed. The synchronization signal separation circuit 203
The synchronization signal is separated from the analog television video signal input from the terminal 201. The caption line determination circuit 204 determines a line position on which a closed caption signal is to be superimposed from information of the synchronization signal separated by the synchronization signal separation circuit 203. The caption extraction circuit 205 extracts a closed caption signal from the video signal binarized by the binarization circuit 202 using the information on the line position obtained from the caption line determination circuit 204, and outputs a closed caption signal S206. The field replacement processing circuit 207 receives the closed caption signals S206 of both the first and second fields, and temporarily stores them in the data buffer memory 208. Then, for each of the stored closed caption signals of the first and second fields, data contents indicating the characteristics of the first field and the second field are detected, and based on the result, the closed caption signal is converted to the second caption signal. The data is read from the data buffer memory 208 as a signal corresponding to the first or second field, and these are output as a closed caption signal corresponding to the first field and a closed caption signal corresponding to the second field. Output from terminal 210.

Next, the operation of the closed caption decoder according to the third embodiment will be described. When an analog television video signal on which a closed caption signal is superimposed is input from a terminal 201 to a binarization circuit 202 and a synchronization signal separation circuit 203, the binarization circuit 20
2 binarizes the analog television video signal. Further, the synchronization signal separation circuit 203 separates the synchronization signal. Subsequently, based on the information obtained from the synchronization signal separation circuit 203, a caption line determination circuit 204 determines a line position where a caption should be superimposed. The caption extraction circuit 205 extracts a closed caption signal S206 from the video signal binarized by the binarization circuit 202, and outputs the signal to the field replacement processing circuit 207.

The field replacement processing circuit 207 is a closed caption signal S20 for the first field and the second field, which is a signal from which the caption has been extracted.
6 is stored in the data buffer memory 208. Then, from the stored closed caption signal, by detecting data content indicating one of the characteristics of the first field and the second field, the closed caption signal S206 corresponds to either the first field or the second field. It is determined whether or not it is. This data content detection processing will be described later. If the content of the closed caption signal indicates the characteristics of the first field, the closed caption signal is changed to the closed caption signal S corresponding to the first field.
When the content of the closed caption signal S210 indicates the characteristics of the second field, the closed caption signal is read as the closed caption signal corresponding to the second field. The data is read from the buffer memory 208 and output from the output terminal 210.

Next, a description will be given of a process performed by the field replacement processing circuit 207 for detecting data content indicating any of the characteristics of the first field and the second field from the closed caption signal.

The field replacement processing circuit 207 has a first
The closed caption signals of the second and second fields are deciphered from the binarized signal, and the data of the resulting closed caption information is stored in the data buffer memory 208. Then, the presence / absence of XDS data is determined for the data of the closed caption signal of the first and second fields recorded in the data buffer memory 208.

As described in the first embodiment, the XDS information is 284 of the second field of the video signal.
Since it is defined only for the line, the data pattern of the XDS information is searched from the data of the closed caption information stored in the data buffer memory 208. For example, the XDS data is detected from the closed caption signal of one field. If the XDS data is not detected from the closed caption signal of the other field, it is determined that the closed caption information in which the XDS data is detected is the closed caption information corresponding to the second field, and the XDS data is detected. Those that are not performed are determined to be closed caption information corresponding to the first field.
XDS included in closed caption like this
The first and second fields can be determined based on the presence or absence of information. Then, a closed caption signal is read from the data buffer memory 208, and a closed caption signal S209 corresponding to the first field is output from the output terminal 209, and a closed caption signal S210 for the second field is output from the output terminal 210.

As described above, according to the closed caption decoder according to the third embodiment, the field corresponding to the closed caption signal is determined based on the presence or absence of the XDS data in the data content of the closed caption signal. The field exchange processing circuit 207 that outputs the closed caption signal corresponding to the first and second fields based on the received signal. Even if the reliability of the field determination based on the synchronization signal is low for some reason, a normal closed caption signal that should be supported can be output for each field, and the video signal can be output. Closed key that can decode with higher accuracy An effect that can provide closed captioning decoder apparatus can retrieve description information.

Further, since the determination of the field corresponding to the closed caption signal is performed based only on the data content of the closed caption signal, it is necessary to provide a field information determination circuit for performing the field determination using information from the synchronization signal separation circuit. This has the effect of simplifying the device.

The XDS shown in the present embodiment
The value of the data is merely an example, and in the present invention, even if another XDS data value is used,
An effect similar to that of the third embodiment is provided.

(Embodiment 4) FIG. 8 is a block diagram showing a configuration of a closed caption decoder device according to Embodiment 4 of the present invention. The closed caption decoder device according to the fourth embodiment is similar to the closed caption decoder device according to the third embodiment.
In the closed caption decoder device according to
Instead of a field permutation processing device that performs a field determination based on the presence or absence of XDS data in a closed caption signal, a field permutation processing device 807 that performs a field determination based on the presence or absence of character information data in a closed caption signal is provided. Was done,
In the figure, the same reference numerals as those in FIG. 2 indicate the same or corresponding parts.

Next, the configuration and operation of the fourth embodiment will be described. The description of the same parts as in the third embodiment is omitted here. The field replacement processing device 807 causes the data buffer memory 208 to store the closed caption signals S206 of the first and second fields input from the caption signal extracting circuit 205. Subsequently, the presence / absence of character information data of the closed caption signal is determined using the data stored in the data buffer memory 208.

As described above, depending on the standard, the character information position is determined to be only the 21st line of the first field or the first line.
It is stipulated that the information is superimposed on both the field 21 lines and the second field 284 lines. Therefore, the field determination can be performed based on the presence or absence of the character information data. In the fourth embodiment, the field determination is performed using this. For example, when the data pattern of the character information is not detected from the data content of one closed caption signal and the data pattern of the character information is detected from the data content of the other closed caption signal, the closed pattern in which the character information is detected is used. The caption signal S209 is determined as a closed caption signal corresponding to the first field, and the one not detected is determined as the closed caption signal S210 corresponding to the second field. Then, based on the determination result, a closed caption signal corresponding to the first field is output from the output terminal 209, and a closed caption signal corresponding to the second field is output to the output terminal 21.
Output from 0.

According to the fourth embodiment, the corresponding field of the closed caption signal is determined based on the presence or absence of character information data in the data content of the closed caption signal, and each closed caption signal is determined based on the determination result. Providing the field exchange processing circuit 807 for outputting the data corresponding to the field allows the field determination based on the synchronization signal to be performed based on the synchronization signal due to noise mixed into the video signal when the electric field strength of the received broadcast is low. Even in the case of low reliability, it is possible to output a normal closed caption signal that should be compliant with each field, and to output the closed caption with higher accuracy from the video signal. Closed capsi that can retrieve information An effect that can provide Ndekoda device.

Also, since the determination of the field corresponding to the closed caption signal is performed based only on the data content of the closed caption signal, it is necessary to provide a field information determination circuit for performing field determination using information from the synchronization signal separation circuit. This has the effect of simplifying the device.

In the third and fourth embodiments, the description has been given of the case in which the field replacement processing circuit for performing the field determination of the closed caption signal by detecting the presence / absence of XDS data or character information is described.
In the present invention, the field replacement processing circuit, the other data content of the closed caption signal that can determine the correspondence with the field, for example, based on the data unique to the closed caption signal corresponding to one of the fields, The field determination of the closed caption signal may be performed, and in such a case, the same effects as those of the above embodiments can be obtained.

In the present invention, the closed caption decoder device according to each of the first to fourth embodiments may be incorporated in a display device such as a television receiver for displaying a closed caption signal on a screen. . With this configuration, even when the reliability of the field determination based on the synchronization signal is low due to noise in the video signal or the like when the electric field strength of the received broadcast is low or the like, the video signal can be used to improve the accuracy. A display device capable of extracting closed caption information that can be decoded at a high level and displaying normal closed caption information can be obtained.

In the present invention, the closed caption decoder according to each of the first to fourth embodiments receives a video signal on which closed caption information is superimposed, extracts a closed caption signal from the video signal, and Closed caption signal
The video signal may be incorporated into a video recording device such as a magnetic recording device, a digital video disk device, or a hard disk drive device for recording a magnetic signal on a magnetic recording medium or an optical disk recording medium in a region separated from a video signal. With this configuration, even when the reliability of the field determination based on the synchronization signal is low due to noise in the video signal or the like when the electric field strength of the received broadcast is low or the like, the video signal can be used to improve the accuracy. A video recording apparatus capable of extracting closed caption information that can be decoded at a high level and recording normal closed caption information can be obtained.

[0056]

As described above, according to the closed caption decoder of the present invention, the video signal on which the binarized closed caption signal is superimposed during the vertical blanking period is input, and this video signal is input. Means for binarizing a video signal, means for separating a synchronization signal from the video signal, line determination means for performing a line determination of a closed caption signal from the synchronization signal, and field information determination means for performing field information determination from the synchronization signal A closed caption signal from the binarized video signal based on the line determination result output by the line determination unit and the field information determination result output by the field information determination unit; In addition, the extraction means for extracting and the closed caption signal are described. Reading the closed caption signal from the storage means, and determining from the data content of the closed caption signal whether the closed caption signal originally corresponds to one of the first field and the second field. Field judgment is performed, and the closed caption signal is replaced based on a result of the field judgment. Therefore, even when the reliability of the field determination based on the synchronization signal is low due to the noise mixing or the like, it is possible to obtain the effect of extracting the closed caption information with higher decoding accuracy from the video signal.

According to the closed caption decoder of the present invention, a video signal on which a binarized closed caption signal is superimposed during a vertical blanking period is input and the video signal is binarized. Means, a means for separating a synchronization signal from the video signal, a line determination means for performing a line determination of a closed caption signal from the synchronization signal, and the binarization based on a line determination result output from the line determination means. Extraction means for extracting a closed caption signal from the video signal, storage means for storing the closed caption signal, and reading the closed caption signal from the storage means, from the data content of the closed caption signal,
The closed caption signal comprises a first field;
A field determination is performed to determine whether the closed caption signal corresponds to one of the second field and the second field.
Field exchange processing means that outputs as a corresponding to the field of the field, so that the field judgment based on the synchronization signal due to the noise mixed into the video signal in the state of low reception electric field strength etc. It is necessary to provide a means for extracting closed caption information with higher decoding accuracy from the video signal even when the reliability of the video signal is low, and to provide a means for determining field information using information from the means for separating the synchronization signal. Therefore, the effect that the configuration can be simplified can be obtained.

Further, according to the display device of the present invention, the closed caption decoder device is provided, and the closed caption signal decoded by the closed caption decoder device is displayed on a screen. Extracting closed caption information that can be decoded with higher accuracy from video signals even when the reliability of field determination based on the synchronization signal is low due to noise in the video signal due to low noise etc. And a display device capable of displaying normal closed caption information can be obtained.

Further, the video recording apparatus according to the present invention includes the closed caption decoder, records a video signal on a recording medium, and separates the closed caption signal decoded by the closed caption device from the video signal. When the reliability of the field judgment based on the synchronization signal is low due to noise mixing in the video signal in a state where the electric field strength of the received broadcast is low or the like, the recording is performed on the recording medium. However, closed caption information that can be decoded with higher accuracy can be extracted from the video signal, and a video recording device that can record normal closed caption information can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a closed caption decoder device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a closed caption decoder device according to Embodiment 3 of the present invention.

FIG. 3 is a waveform diagram in a vertical blanking period in which a video signal includes a closed caption signal for explaining the closed caption decoder device according to the first embodiment of the present invention;

FIG. 4 is a diagram illustrating a closed caption signal in 21 lines and a binarized signal waveform for explaining the closed caption decoder device according to the first embodiment of the present invention;

FIG. 5 is a configuration diagram showing a configuration of a conventional closed caption decoder device.

FIG. 6 is a diagram illustrating a result of decoding a closed caption signal for describing the closed caption decoder device according to the first embodiment of the present invention.

FIG. 7 is a configuration diagram of a closed caption decoder device according to Embodiment 2 of the present invention.

FIG. 8 is a configuration diagram of a closed caption decoder device according to a fourth embodiment of the present invention.

[Explanation of symbols]

101, 201, 501 Input terminals 102, 202, 502 Binarization circuit 103, 203, 503 Synchronization signal separation circuit 104, 204, 504 Caption line determination circuit 105, 505 Field information determination circuit 106, 205, 506 Caption signal extraction circuit 109, 207, 709, 807 Field replacement processing circuit 110, 208 Data buffer memory 111, 209 Output terminal 112, 210 Output terminal 301, 306 Line number 302 VITC signal 303 Video ID signal 304, 307 Closed caption signal 305 Video signal 401 Horizontal synchronization Signal 402 Clock run-in signal 403 Start bit signal 404 Data bit signal 405 Threshold for binarization

Claims (10)

[Claims] 1. A video signal on which a binarized closed caption signal is superimposed during a vertical blanking period is input, and means for binarizing the video signal is provided, and a synchronizing signal is separated from the video signal. Means, line determination means for performing a line determination of a closed caption signal from the synchronization signal, field information determination means for performing field information determination from the synchronization signal, line determination results output by the line determination means, and the field information determination Extracting means for extracting a closed caption signal corresponding to the first or second field from the binarized video signal based on the field information determination result output by the means, and storing the closed caption signal. Storage means for reading the closed caption signal from the storage means. From the data content of the closed caption signal to determine whether the closed caption signal originally corresponds to either the first field or the second field. A closed caption decoder for performing a field replacement process for replacing a field corresponding to the closed caption signal based on the closed caption signal. 2. The closed caption decoder device according to claim 1, wherein said field replacement processing means is configured to superimpose an XD signal only on a closed caption signal corresponding to a second field.
A closed caption decoder device for performing field determination of a first or second field by detecting S (Extended Data Service) data. 3. The closed caption decoder device according to claim 1, wherein said field replacement processing means detects data of character information superimposed on a closed caption signal, thereby forming a first or second field. A closed caption decoder device for performing field judgment. 4. The closed caption decoder device according to claim 1, wherein the field replacement processing means detects data unique to the first field or the second field superimposed on the closed caption signal, and 1,
Alternatively, a closed caption decoder device that performs a field determination of a second field. 5. A video signal on which a binarized closed caption signal is superimposed during a vertical blanking period, and a means for binarizing the video signal, and separating a synchronization signal from the video signal. Means, a line determination means for performing a line determination of a closed caption signal from the synchronization signal, and a sampling means for extracting a closed caption signal from the binarized video signal based on a line determination result output from the line determination means. A storage unit for storing the closed caption signal; reading the closed caption signal from the storage unit; and determining whether the closed caption signal is a first field or a second field from the data content of the closed caption signal. Field judgment to determine whether Based on the result of the field determination, the closed caption signal, the closed caption decoder apparatus characterized in that it comprises a field replacement processing means outputs as corresponding to the first, or the second field. 6. The closed caption decoder device according to claim 5, wherein said field replacement processing means is configured to superimpose an XD signal on only a closed caption signal corresponding to a second field.
A closed caption decoder device that performs field determination of a first or second field by detecting S data. 7. The closed caption decoder device according to claim 5, wherein the field replacement processing means detects data of character information superimposed on a closed caption signal, thereby generating a first or second field. A closed caption decoder device for performing field judgment. 8. The closed caption decoder device according to claim 6, wherein the field replacement processing unit detects data unique to the first field or the second field superimposed on the closed caption signal, and 1,
Alternatively, a closed caption decoder device that performs a field determination of a second field. 9. A display device comprising the closed caption decoder device according to claim 1, wherein a closed caption signal decoded by the closed caption device is displayed on a screen. 10. A video signal comprising a closed caption decoder device according to claim 1, wherein the video signal is recorded on a recording medium, and the closed caption signal decoded by the closed caption device is converted to the video signal. A video recording device for recording on the recording medium separately from the recording medium.