JP3321959B2 - Teletext signal recording or recording / reproducing device, or magnetic recording or recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a teletext broadcast recording and reproducing apparatus for digitizing teletext and teletext data for recording and reproducing.

[0002]

2. Description of the Related Art Teletext multiplex broadcasting utilizing a time gap between television broadcast waves has already been put to practical use. The text multiplex broadcasting includes a subtitle super program, a quiz program, and the like in addition to living information such as various news, weather forecasts, and traffic information, and a melody can be played. In our country, letters,
It has been broadcast since the end of 1985 as a hybrid system combining a code system for encoding and transmitting figures and additional sounds and a pattern system for pixel transmission.

[0003] Teletext broadcasting is performed in North America (NABTS), the United Kingdom, and France, but the system is slightly different. In particular, the difference from the Japanese method is that there is no additional sound and no kanji. These three systems are called teletext broadcasting because they basically assume that 26 letters of the alphabet are transmitted. However, since the basic system is the same for teletext broadcasting and teletext broadcasting, it will be collectively called "teletext broadcasting" in the following description.

[0004] Teletext signals are multiplexed and transmitted without interrupting the image and sound of the television broadcast itself during the vertical blanking period of the television broadcast signal. Currently in Japan, 1
4, 15, 16, 21, 277, 278, 279, 28
4 are multiplexed on a total of 8 lines, but in consideration of future expandability, the standard specifies 10, 11, 12, 13, 14, 15, 16, 21 273, 274, 275, 276, 277, 278, 2
Multiplexing is possible for a total of 16 lines of 79 and 284.

In European teletext, 7 to 22,
Although it is standardized so as to be multiplexed on a total of 32 lines from 320 to 335, it is actually different for each broadcasting station. Also, VPS signals and test signals are arbitrarily inserted and used in these lines.

FIG. 17 shows an arbitrary line of a Japanese teletext signal. As shown in the figure, 296 bits of a digital signal having a pedestal level of “0” and a white level of 70% of “1” are multiplexed as shown in the figure. One data line includes a synchronization unit and a data packet unit. The synchronization unit is configured to perform a bit synchronization code (CR: Clock Ru) for achieving bit synchronization.
n-in) and a byte synchronization code (FC: Framing Code) for achieving byte synchronization.

[0007] The data packet has a prefix (PF
X: PreFiX), information data, and check code. The prefix is a service identification code (SI / IN: S) for identifying the pattern system or the hybrid system.
Service Identifier (8 bits) and 6 bits of packet control (PC: Packet Control) for controlling transmission of data packets. After that, the information data is 176 bits (22 bytes)
Subsequently, 82 bits are secured as a check code.

[0008] The other three systems differ in the details, but there is no difference in the way of thinking.

One teletext program requires a data amount of several kilobytes, depending on the contents of the program. As described above, only 176 bits can be sent per line, and
Considering the current state of transmission on one channel, one text program is transmitted only at intervals of about 20 to 30 seconds.

At present, this teletext is decoded and viewed on a teletext compatible tuner or a teletext receiving television. It is of course possible to record the decoded data on a VTR or the like, but it is impossible to record raw data before decoding on a conventional analog VTR due to its clock rate (5.7 MHz to 6.9 MHz). It is.

[0011]

SUMMARY OF THE INVENTION As described above, a current analog VTR for consumer use remains in the form of teletext broadcast.
Etc. cannot be recorded. Decoding and recording this requires a teletext decoder IC, a large-capacity memory, a kanji ROM, a control microcomputer, and the like. Especially, in the case of a consumer VTR, the cost increase and the mounting area cannot be ignored.

[0012] Even if the cost increase is suppressed slightly by mass production or the like, the program is not established until about 20 to 30 seconds are recorded in order to record one teletext broadcast. Or keep recording the previously received program (still a still image). In this case, since about 20 to 30 seconds is just an average, in some cases, a program is established in about 2 seconds, and in another case, a response such as waiting for 30 seconds is scattered.

Further, V represented by 50 Hz and 60 Hz
Since the recording rate of the original image and sound of the TR and the recording rate of about 20 to 30 seconds of the decoded text broadcast cannot be synchronized at all, it is impossible to provide a correlation between the two.

[0014] This means that even if each data of image, sound and text broadcast is recorded in one area on one track,
If emphasis is placed on images and sounds, the teletext area may be blank. On the other hand, if text broadcasting is emphasized, the images and sound areas may be blank. Therefore, when a teletext is recorded, it is recorded as image and audio information by a conventional method. At this time, it is not possible to record the television program being broadcast at the same time.

Just as audio has changed from analog recording of cassette tapes and records to digital recording of DAT, CD, MD and DCC, video is also moving from 8 mm, VHS analog recording to digital recording. Considering that the basic sampling rate of the digital VTR is 13.5 MHz, it can be easily imagined that the digital VTR can be handled without difficulty if it is at a clock rate of teletext broadcasting. Therefore, one track can be divided into image, audio, and teletext areas, and not the decoded data but the teletext data itself can be recorded, thereby eliminating the above-described problem in the analog VTR.

Further, since the data which is not decoded is recorded, the cost and the occupied area are much cheaper and the occupied area is smaller than when the decoded data is recorded. A product configuration that allows the decoding to be performed is also possible.

The greatest advantage of the digital VTR is that the sampling frequency is common to the 60 Hz system and the 50 Hz system.
5 MHz. This makes it unnecessary to change the number of rotations of the drum and the vicinity of the head, that is, the so-called electromagnetic conversion system for each destination of the 60 Hz system and the 50 Hz system as in the conventional analog VTR. 60Hz system,
The difference in the 50 Hz system is simply a difference in tape consumption such as, for example, 10 tracks / frame for the former and 12 tracks / frame for the latter, and all other track pitches and track widths may be common.

However, in the case of a VTR deck, the television tuner must be changed for each destination, and the correspondence for teletext must be changed accordingly. However, when considering a recorded tape, the difference is that the recording is performed simply in the 60 Hz system or in the 50 Hz system. Therefore, a tape recorded in the United States can be reproduced by a VTR for Japan if it is in the same 60 Hz range as in the United States and Japan. If so, the recording format of teletext is also shown in Table 1 for Japan and for North America (NABT
S) It is not advisable to prepare four types, one for the UK and one for the France, and it is better to unify the two types into one for the 60 Hz system and one for the 50 Hz system.

[0019]

[Table 1]

Further, the format must be flexible enough to cope with future expansion of teletext broadcasting.

In the case of recording and reproducing on a tape, there is a problem of dropout peculiar to the tape. As described above, the data is protected by a check code or the like, but special attention must be paid to a burst error such as dropout. This is because the alphabet is still good, but in the case of the ideographic kanji, even if one character is missing, the meaning may not be understood.

In the case of a consumer digital VTR, it is certain that it will be a compression type VTR in view of the tape consumption. In this case, the compression technology will also advance, so that 10 tracks per frame were required at present, but 5
It is quite possible that trucks will be enough. It must be a teletext recording format that can flexibly cope with this.

Accordingly, the present invention provides a digital VTR or an analog VTR having an area in which a digital signal can be recorded.
In, 1. 1. Record teletext without decoding, 2. World teletext is simply classified into two types, one for the 60 Hz band and the other for the 50 Hz band. 3. It can flexibly cope with future expansion of teletext broadcasting and halving track consumption per tape frame. An object of the present invention is to provide a recording / reproducing apparatus for teletext which is also resistant to dropouts such as side scratches on a tape and head clog.

[0024]

According to a first aspect of the present invention, there is provided a digital image signal recording means for recording a digital image signal, and a means for extracting teletext data multiplexed in a broadcast wave. Then, without decoding the extracted teletext data , the digital image signal
To store accompanying data that can be error corrected to protect
This is a teletext recording or recording / reproducing apparatus characterized by recording in the rear .

The second means according to the present invention is characterized in that, of the extracted data, a portion excluding a bit synchronization code is recorded without decoding, and the recording of the teletext is described in the first means. Or a recording / reproducing device.

The third means according to the present invention comprises a multiplex line number of teletext data multiplexed in a broadcast wave,
A teletext recording or recording / reproducing apparatus according to the second means, wherein a field and a broadcasting system code are recorded as IDs by replacing the extracted data with a byte synchronization code.

According to a fourth aspect of the present invention, teletext data multiplexed in a broadcast wave is defined as an item code.
A teletext recording or recording / reproducing apparatus according to the first means, characterized in that recording is performed using a pack structure composed of a predetermined number of bytes constituted by a data part .

According to a fifth aspect of the present invention, an end code is recorded at the end of one frame of teletext data multiplexed in a broadcast wave. A recording or recording / reproducing apparatus for teletext described in the means.

According to a sixth aspect of the present invention, a plurality of tracks are formed on a magnetic tape, and at least a tracking data area, an audio data area, and an image data area are provided on the tracks to digitally record image information. In the magnetic recording or recording / reproducing apparatus described above, an additional data area for recording additional information relating to an image is provided in the image data area, and teletext data multiplexed in a broadcast wave is extracted and recorded in the additional data area. A recording capacity of the track in the associated data area is set to a non-integer multiple of a data amount per line of the teletext data. is there.

According to a seventh aspect of the present invention, the teletext data for one frame is recorded at a distributed position on a tape by using the associated data area of a plurality of tracks. A magnetic recording or recording / reproducing apparatus according to a sixth means.

According to an eighth aspect of the present invention, the teletext data for one frame is repeatedly recorded at dispersed positions on a tape using the accompanying data areas of a plurality of tracks. A magnetic recording or recording / reproducing apparatus according to the sixth means.

[0032]

According to this, according to the following: The tape recording format can be simplified by simply combining the world teletext into two types, one for the 60 Hz band and the other for the 50 Hz band. 2. Since teletext data is also organized in frames, it can be handled in the same way as video and audio when editing a tape. 3. Even if teletext is expanded in the future, teletext data previously recorded can be reproduced on a new VTR. 4. Since the destination of teletext broadcasting can be immediately determined, for example, when a tape recorded in the United States is reproduced in Japan, the image and sound can be reproduced because the same 60 Hz system is used, but erroneous reproduction of teletext can be prevented. 5. In principle, all teletext programs on the TV channel can be recorded, so that the user can select a program after recording on the tape. 6. Since the data is recorded as digital data, it can be connected to a personal computer via a digital interface or the like to form a database. 7. Products that allow the television to have ICs and memories that increase the cost and increase the occupied area are also possible, and are rich in variations.

[0033]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an example of a track format of a digital VTR of an image compression system which is promising for consumers in the future.

One track is moved from the entry side of the head.
ITI (In) for defining margin and post-record position
sert and Track Information
n), an audio signal, an image signal, a subcode, and a margin. Between each area, a preamble and a postamble amble and a gap for securing the area are provided.

Since the teletext is arranged at the V blanking of the video signal, the accompanying data VAUX (V
(AUXiLiary). Hereinafter, the area of the image signal will be described.

FIG. 2 shows details of an example of the sync block configuration of the image signal area of FIG. The image signal area is 1
It consists of a data part of 35 sync blocks and a vertical parity C2 of 11 sync blocks. C1 is 8 bytes of horizontal parity, and C1 and C2 constitute a product code configuration. BUF in the figure
The notation is one buffering unit of compression (Buffer
ing unit). In this example, one buffering unit is composed of five sync blocks.

In one track, compressed image signal data for 27 bufferings from 0 to 26 is stored. This corresponds to 135 sync blocks.

FIG. 3 shows the contents of one buffering unit and five syncs. One sync block is composed of, for example, 90 bytes. First, a 16-bit common SYNC pattern, followed by an ID consisting of 3 bytes
There is a department. The ID portion is 2-byte ID data (ID0,
ID1) and ID parity 1 byte (ID
P). After that is the data section.

The data section contains the accompanying data VA of the image signal.
It consists of two bytes AUX0 and AUX1 for storing UX and an area for storing image signal data. Since two bytes of the AUX data are included in the product code configuration composed of C1 and C2, they are protected with the same strong error correction capability as the image signal data.

The image compression quantization table NO. Q indicating
NO is stored in the lower 4 bits of each SYNC. QN
O takes one value in one buffering unit, but is important for restoring compressed data, so it is written five times in five sync blocks to further reinforce errors. The QNO switching point SWP is placed in the upper 4 bits of each sync block. SWP has a unique value for each sync block.

Problems that occur during VTR reproduction include head clogs in which the head is clogged and so-called "lateral scratches" in which the tape is scratched in the lateral direction. A head clog often occurs in only one head, in which case data cannot be read every other track. In “lateral damage”, data at the same position on the track is almost lost.

Therefore, in the example of the present application, the writing positions of the A head and the B head are shifted. This is shown in FIG. This is obtained by arranging two bytes of AUX0 and AUX1 in FIG. 3 in the order of the sync block.

The total of 10 bytes of AUX0 and AUX1 is divided into the first 5 bytes and the second 5 bytes. The first 5 bytes contain 50/60, STYPE, APPLI, and the teletext data of the present application. “50” indicates a 50 Hz system, and “1” indicates a 60 Hz system. STYPE
Is the type of image signal to be recorded, which is standard (for example, NTSC or PAL) or wide (the aspect ratio is 1).
6: 9, the number of scanning lines is the same as the standard), Hivi
Indicates a section or the like. APPLI is an ID that defines a data recording structure in a track.

In the latter 5 bytes, other information VAUX attached to the image having the pack structure is entered.
NO. The upper 4 bytes of 26 are used for teletext of the present application.

As shown in FIG. 5, the pack structure includes a 1-byte item code and a 4-byte data portion. The VAUX area having a pack structure includes a main area and an optional area.

The main area is a place where data and the like (for example, a compression method) required at least for reproducing the information (here, image data) are stored.
R must support it. Here, the date of recording, source information, dubbing information, and closed captions for difficult-to-view audiences that have recently been legislated in the United States are included. The optional area is for optional data.

As shown in FIG. 4, in the main area, exactly the same data is written in the A head side track and the B head side track by changing the recording position, thereby causing a head clog or "lateral damage". The data is still protected.

Next, details regarding the teletext broadcasting of the present invention will be described.

The bit synchronization code (CR: Clock Run-in) for achieving bit synchronization is 16 for each system.
Is a bit. Since this is a mere repetition signal of “1” and “0”, it is easy to reproduce later if the clock frequency is known. Therefore, data other than this part is extracted and recorded.

Then, the required number of bits per line is 280 bits (35 bytes) in Japan, 272 bits (34 bytes) in North America, 344 bits (43 bytes) in the United Kingdom, and 304 bits (38 bytes) in France.

Regarding the method of recording this on a tape,
It will be described next. Teletext data appears twice in one frame in bursts in the first and second fields. In order to write this data as VAUX data in the area of the image signal, it is necessary to match the timing with the compressed image signal data. Specifically, FIF
One frame of teletext data is stored in an O-memory or the like, and a required amount is read out according to the writing timing.

As described above, teletext data is not inserted at all insertion positions determined by the standard. Depending on the broadcasting station, it may be different. Therefore, when recording on the tape, some positional information is required.

FIG. 6 shows the character signal insertable period in the broadcasting system with 525 scanning lines and the broadcasting system with 625 scanning lines. In the broadcasting system with 525 scanning lines, respectively. ~ 21 lines, and 272 ~
284 lines, and 625 scanning lines in the broadcasting system
22 lines and 318 to 335 lines are the character signal insertable period. Therefore, a gate signal of nGATE for extracting the character signal insertable period is introduced. Using this, the line number in the period of nGATE = 0 can be indicated by 0 to 17.

The circuit on the recording side will now be described with reference to FIG. Here, the description is focused on Japanese teletext broadcasting. The other methods are exactly the same except for the frequency. The composite video signal input from one input terminal is supplied to two sync separation circuits. Here ODD / EVEN
A field discrimination signal and an HSYNC signal are generated. The rising and falling of the ODD / EVEN signal are
3 by the counter clear pulse generation circuit
At that timing, the H counter becomes 4 and the line N becomes 6
o. Clear the generation circuit.

The H counter of 4 is ODD / EVEN.
HSYNC is counted from the transition point of the signal. The count output is decoded by the decoder 5 and the above-mentioned nG is counted.
Create an ATE signal. During the period of nGATE = L, the line No. 6 When the generation circuit is activated, the line No. as shown in FIG. make. In the broadcasting system with 525 scanning lines, 12 to 3 when ODD / EVEN = 0
0, ODD / EVEN = 1, line numbers 13 to 30 Is undefined. In the broadcast system with 625 scanning lines, ODD / EVEN = 0 to 17 to 30 and ODD
Line Nos. 18 to 30 when / EVEN = 1. Is undefined.

On the other hand, the input composite video signal is added to a comparator 8 after the pedestal clamp circuit 7 stabilizes the DC component of the pedestal level.
The comparison voltage is, for example, 0.5 V and a white level of 7
Set the value between 0% and the pedestal level. The output of the comparator 8 is a so-called TTL level digital signal, which is input to an S / P conversion circuit 9. The S / P conversion circuit converts a serial signal into a parallel signal, and converts it into bytes here.

The serial clock SCK is generated as follows.

First, in order to make the amplitude of the color burst signal of the input composite video signal constant, it is added to 11 burst ACC circuits. This is used as a reference signal of the fsc (subcarrier signal frequency) PLL circuit 12. This 3.58 MHz output signal is frequency-divided by 5 by the 13 frequency divider, and the next 14/16/5 fscPL
The reference signal of the L circuit is used. The clock signal stabilized by the double PLL circuit is further converted into a signal with a duty of 50% by 15 frequency dividers. This is the basic clock SCK of 5.727272 MHz.
This signal is further divided by 8 by 16 frequency dividers and used for byte conversion.

The signal converted into bytes by the S / P conversion circuit 9 is latched by a DF / F (D-type flip-flop) 10 and applied to a CRI (clock run-in) detection circuit. The output of the mono-multi circuit 17 that has triggered HSYNC and the nGATE signal are also input to this circuit.
The mono-multi circuit 17 extracts a period of up to 16 CRI pulses determined by the specification from the HSYNC signal. When nGATE = L at this timing, DF / F1
If the output of 0 is 00h, there is no CRI, so it can be determined that there is no teletext data. AAh
If (10101010) is present, nEXIST =
L. The result, nGATE, LCK, etc. are given to the next stage timing controller 22.

Now, the line number, ODD / EVEN, and the broadcast system identification code (stored in the VTR set itself) that differs for each destination are assembled as shown in FIG. The other input is DF / F
Data is supplied from a (D-type flip-flop) 10, and the data is switched by the timing controller 22 while observing the timing. The output of switch 19 is DF / F
The time is adjusted at 20 and written into the FIFO 21 by the timing controller 22.

That is, in this line ID, the lower 5
The bit indicates the line No. It is. Europe requires 5 bits because there are 17 lines in one field. Above that is ODD / EVEN discrimination. This ODD / EVE
N and a 5-bit line No. Specifies all multiplexed scanning lines of the teletext signal.

The upper two bits contain a broadcast system identification code. Here, for example, 00 for a Japanese teletext broadcast system, 01 for a North American (NABTS) teletext broadcast system, 10 for a British teletext broadcast system, and 10 for a French teletext broadcast system In this case, 11 broadcast system identification codes are entered. this is,
A fixed two bits may be obtained from a TV tuner that changes for each destination, or a mode control microcomputer that slightly changes for each destination may have it.

This line ID is inserted instead of the byte synchronization code described above. Therefore, one line of data is recorded in the order of line ID, PFX, information data, and check code. The required number of bits does not change.

The PFX, the information data, and the check code are obtained as real data in the form of 8-bit parallel data from the output 11 of FIG. The data thus created is stored in a FIFO memory or the like as described above, and waits for recording timing.

The data to be written into the FIFO 21 is determined at the end of the V blanking of the second field. However, in the case of a compression type VTR, the image data is not determined until the end of one frame. Therefore, data reading from the FIFO 21 starts from the start of the next frame in FIG.
In this case, the FIFO output data is supplied to the framing circuit, and the reading operation is sequentially performed in cooperation with the timing controller 22 and the framing circuit. When data is packed and recorded in the pack, the pack header is packed at the beginning of every 5 bytes by the packing circuit, and then sent to the framing circuit. When recording is performed directly without using a pack, the data is sent directly to the framing circuit. The switching timing of the switch 23 is similarly performed in cooperation with the timing controller 22 and the framing circuit.

Next, an example of a circuit on the reproducing side will be described with reference to FIG.

The text multiplex broadcast data is extracted from the deframing circuit or the unpacking circuit and stored in the FIFO. The framing control clock PBCK is used as the write clock. The data embedding is completed at the end of one frame period (here, for example, 10 track scans).
Take in F. Since there is a broadcast system identification code here, it is taken into the timing controller 2 which controls the timing of FIFO and the like.

Here, by comparing with the ID stored in the set itself, it is determined whether or not the set is a character multiplexing system which cannot be reproduced. If not, the captured data is discarded as it is, and subsequent operations are stopped. If reproducible,
ODD / EVEN already loaded in DF / F3,
The line number is converted by the decoder 4 into the original H line number. The unpacking circuit performs an operation of discarding a portion corresponding to the pack header in the data from the deframing circuit by the switch 24.

In the digital VTR, HSYNC and VSYNC, which are unrelated to image information for increasing the compression efficiency, are deleted and recorded. Therefore, during reproduction, they are newly generated to create a composite video output signal.

Reference numeral 7 denotes an fsc oscillator which outputs a stable clock using a crystal. Various clocks are created using this as a master clock. First, the frequency is divided by 16/5 by a frequency divider of 8, and then further divided by a frequency divider of 9 to obtain a duty of 50%. As a result, a 5.727272 MHz SCK, which is a basic clock for teletext broadcasting, is obtained. Further, an LCK clock which handles this in a byte unit is generated by a ８ frequency divider of 10.

Further, fsc is applied to a synchronization signal generator 11 to generate an HSYNC signal. At the same time, a pulse for clearing the H counter 13 is generated by the circuit 12. H
The output of the counter 13 is provided to the comparator 5.

The comparator 5 always compares with the output of the H line number of the decoder 4 and the coincidence information is given to the timing controller 2. If they match, the next data is taken into FIFO / F6 from FIFO1. The switch 25 has already prepared a CRI and an FC determined for each method. The CRI, FC, data, data... Are switched in this order and sent to the DF / F 15. The data is further converted to serial data by the S / P converter 16 using the clock SCK.

The final output composite signal is 2V
pp analog signal. Therefore T
TL level serial data and HSYNC signal are
It is converted to a predetermined voltage level by a TTL → analog level conversion circuit of 17 or 20. 8-bit image data is
The voltage is converted into an analog voltage by the A / D converter 26 and further adjusted to a predetermined level by the level converter 18. fsc is also used as a color burst signal by the circuit 19,
Adjust the level.

Whether to output image data or text multiplex broadcast data is determined by switching the analog switch 27 according to the comparator coincidence output of 5. Which data in the HSYNC is to be inserted is generated by a 14-H timing generation circuit, and the analog switch 21 is switched accordingly. As a result, HSYNC, color burst, text multiplex broadcast data, or image data are inserted into the HSYNC in this order. The switch 21 naturally adjusts the pedestal level and performs analog mixing. This output is adjusted to 2 Vpp by the amplifier 22, and is output to an output terminal 23 as a composite video signal.

The three systems other than Japan can be realized by exactly the same method.

Next, how to record these data on a tape will be described. First, consider how to store Japanese teletext. In FIG. 4, the teletext data storage area per track is 4 × 27 + 4 and has 112 bytes. Here, a total of 35 bytes of the line ID, PFX, information data, and check code are packed.

Here, the following description is based on the assumption that a 60 Hz system, 10 tracks per frame, a 50 Hz system, 12 tracks per frame.

FIG. 10 shows a method for storing Japanese teletext. This corresponds to the teletext storage area 112 bytes in FIG.
It is a figure drawn as if it were one track. The data stored in the FIFO memory is sequentially read and written in this manner. 32 blocks of 35 bytes, that is, data of 32 lines can be stored in the entire 10 tracks.

In the standard, the maximum is 16 lines per frame and the current is 8 lines. Therefore, in the present invention, the maximum of the standard is written twice on 10 tracks per frame, and the current time is four times. If you can write multiple times like this, you will be more resistant to errors. This is because if the same data is written in other places even if it is done in one place, it can be supplemented with it.

In FIG. 10, chunks of 35 bytes are shifted leftward little by little. This is intentional, and the number of recordable bytes per track is selected so as not to be an integral multiple of 35 bytes.

This effect will be described next in connection with an increase in the number of text broadcast storage lines in the future.

FIG. 11 shows an A-head clog, FIG. 12 shows a B-head clog, and FIG. 13 shows a state when a lateral scratch image is generated. The future increase of teletext storage lines will be in units of two lines, and the current eight lines, ten lines, twelve lines, fourteen lines, and up to sixteen lines have been confirmed. With the increase in the number of lines, if storage is stopped at a well-defined location, several tens of bytes may be left.

In this case, since the recording area is useless, all the operations are performed by the same FIFO simple repetitive reading (when all the contents of the FIFO are read, a read reset is performed and the data is read again from the first data). In this case, the circuit may be simplified as compared with a method in which the recording order is changed according to the required recording amount. Note that the numbers in each figure represent line numbers, but all are described from 1.

First, the effect when the head clog of FIGS. 11 and 12 occurs will be examined. Even if one head clogs, there is no problem if the other head can pick up the same data.

A closer inspection shows that there are unreproducible lines at 12 lines and 14 lines as shown in Table 2.

[Table 2]

Next, look at FIG. This is an example in which three lateral wounds are almost impossible. In this case, a line that cannot be reproduced occurs when a maximum of 16 lines are stored.

Table 3 summarizes the above.

[Table 3]

As a practical matter, when a head clog or a lateral injury occurs, the image and the sound are also usually seriously hit, and it is inconsistent to completely protect only the text broadcast data. In addition, head clogs and side injuries are of a nature that should not be originally a commodity.

When the data after the teletext is decoded and stored as it is, the result is as shown in Table 3. In the present invention, the error correction capability of the teletext itself is retained by leaving the check code inherent in the teletext. Can be used. In fact, Japanese teletext employs a shortened difference set cyclic code (272, 190) that can be decoded by majority logic.

Further, since the teletext storage area of the present invention is protected by the same strong product code structure as the image signal data as shown in FIG.
The NG part at 13 is saved.

FIGS. 10 to 13 are diagrams for convenience and actual data storage locations are dispersed as shown in FIG. This is much more resistant to side injuries than verified in FIG.

The head clog literally causes the head to be clogged. In the case of a regular head clog, no image or sound is produced, so that head cleaning is performed. Instantaneous clogs are protected with a product code configuration. With this in mind, the serious thing would be a side injury that, once followed, will never be fixed again. It is experimentally known that the width of the lateral wound is about three sync blocks. As shown in FIG. 13, this level is almost completely restored by the product code configuration of C1 and C2. Therefore, it is concluded that the recording method of the present invention has a simple circuit configuration and is robust against errors.

The points are summarized as follows. Record teletext without decoding. This makes it possible to effectively use the error correction capability inherent in teletext. 2. By recording the teletext data in the AUX area of the video, the powerful error correction capability provided for protecting the video data can be utilized. 3. By recording teletext data in the AUX area of the video in a distributed manner, it is resistant to lateral damage and instant clogging. 4. By storing the teletext data repeatedly in the storable area, the majority effect by multiple writing can be used. 5. By not intentionally increasing the required area for storing teletext data per track to an integral multiple of the required number of bytes per line, a delicate interleaving effect is created, and a majority effect by multiple writing can be exhibited.

Next, let us consider a method of recording teletext in the UK and Germany. Germany is the same formula as Britain.

In these countries, 32 lines from 7 to 22, 320 to 335, which are determined by the standard, include V
A PS signal, a test signal, and the like are also arbitrarily inserted and used, and there is no possibility that all the lines are used completely for teletext.
Since the maximum number of lines that can be used is 28, the data storage area for teletext broadcasting may be prepared for that.

FIG. 15 shows the recording method. The idea is
It is the same as FIG. 43-byte chunks of 31 and 1
Contains one byte. There is a surplus of at least three lines with respect to the maximum number of lines of 28, which is filled by FIFO simple repeated reading. In the case of German broadcasting, 15 lines are currently available, so it is possible to write twice in this area. 11 and 1
Verifications such as 2 and 13 are omitted.

Next, the world teletext will be used for the 60 Hz band.
A method of combining the two types for the 50 Hz band will be described.

The clock frequency is the same between Japan and North America, and the total length of the data line is only one byte less in North America. The clock frequency is different in the UK and France, and the total length of the data line is 5 bytes less in France. If this is all handled as shown in FIGS. 10 and 15, it is difficult to control both hardware and software.

Since the country can be identified as described above, FIG.
All zeros will be inserted into the remaining bytes as shown in Fig. 6 with Japan and the UK as standard. By this operation, the recording format of 60 Hz is summarized in the recording format of FIG. In fact, EC in Europe
With the merger, the French proprietary method called "Antiope" is gradually being transferred to the British method.

As for the embedding of 0, since it is already known as "0" at the time of reproduction, the data is checked before solving the product code configuration of FIG. Since the place where it is not "0" is an error, it is used to correct the C1 and C2 parities. By doing so, there is a high possibility that other errors can be saved. As for teletext data, it may be simply skipped there. This advantage outweighs the advantage of having extra data in the extra area, with North America and France individually addressed.

Next, a method of restoring the data recorded in this manner will be described.

First, processing for reading one frame of teletext data into the memory is performed. At this time, the broadcast system identification code in the line ID and the 50/60 in FIG.
To see if it is reproducible, and if not, stop the process.

For example, a set for Japan (60HZ: N
Even if a 50HZ (PAL, SECAM) tape is inserted into the TSC, images and sounds cannot be reproduced, so that text broadcast data cannot be reproduced.

A tape (60 Hz system) containing American teletext data in a set for Japan (60 HZ system)
, You can naturally play back images and sounds. However, if an IC that decodes Japanese teletext is included in the set, the processing is stopped because American teletext cannot be decoded, of course. If there is no decode IC, teletext data may be simply inserted into a predetermined line of the composite video and output. The rest is left to the TV.

When the data is to be stored in the memory, the error flag from the error correction circuit for solving the product code configuration shown in FIG. Since it is multiplexed, it is possible to use a majority circuit to make sure.

After finishing the beaming, the line number of the first line ID is taken out and the process stands by. A video reproducing circuit includes a composite sync generating circuit for outputting a composite video. When the signal is input to the circuit of FIG. 7 used at the time of recording, an nGATE signal as described with reference to FIG. 6 is obtained.

During the period of nGATE = [L], the line number output 9 of FIG. 7 is compared with the first line number. When they match, the first half of the bit synchronization code of "10101010" set in the parallel / serial conversion shift register in advance is output. After the shift is completed, "10101010" is loaded again, and the latter half of the bit synchronization code is output. Then it loads the next data in memory and shifts sequentially.

The composite sync output is pedestal clamped and mixed with digital signals "1" and "0". At this time, "1" is set to the 70% level of white and "0" is set to the pedestal level as shown in FIG.

After the transfer of the specified number of bytes, the line number of the next line ID is taken out and the process stands by. Continue this.

Next, a description will be given of how to cope with future advances in image compression technology.

At present, in a consumer digital VTR,
The intra-frame method of compressing one frame of data is effective. However, if 10 tracks per frame are required at present, but only half tracks in the future can be used, the recordable time of one tape can be doubled. The compression method in this case will be an inter-frame method using two frames as a compression unit.

At this time, the image consists of 10 tracks in 2 frames, 1
Although it is a recording unit of two tracks, the data amount handled in one frame unit does not change for text broadcasting. That is, one frame must be contained in five or six tracks.

In the case of the 60 Hz band, 32 35-byte blocks are included in 10 tracks as shown in FIG. Since the standard has a maximum of 16 lines, half of five tracks can store one frame of teletext data, so there is no problem at all.

In the case of the 50 Hz band, the data amount is originally 60
Since the number of lines is 1.7 times as large as that in the Hz band (up to 28 lines in the 50 Hz band), it is impossible to pack the text broadcast data for one frame into six half tracks. In this case, the optional area shown in FIG. 4 is used. This is shown in FIG.

In FIG. 18, the recording area of the teletext broadcast is shifted between the A head side and the B head side. However, this recognition and data insertion / extraction are performed by the A head / B head and the B head.
UFNO. What is necessary is just to decode information. Other processing methods are the same as those in FIG.

Further, according to the above-described digital signal recording / reproducing method, when the application data APT is "000", an AAUX signal for assisting audio data, a VAUX signal for assisting video data, a data signal of a subcode, The memory (M
Each storage area after the address “0001” of IC = Memory In Cassette) is described in the above-described common pack structure.

A pack means a minimum unit of a data group, and each pack is formed by collecting related data. 1 byte of header (= 8 bits)
Is divided into 4 bits on the MSB side and 4 bits on the LSB side.
Has a two-layer hierarchical structure as shown in FIG. The data can be further extended to a lower layer by bit assignment.

With this layering, the contents of the pack are clearly organized and its expansion is facilitated. The space of 256 by the upper header and the lower header is shown in FIG.
As shown in Table 2 below, a single pack header table is prepared with the contents of each pack. That is, the AAUX signal, the VAUX signal, the data signal of the subcode, and the storage areas after the address “0001” of the memory (MIC) provided in the tape cassette are controlled by the pack header table.

Therefore, AAU which assists audio data
The X signal is composed of 9 packs (0 to 8) per track. For example, if only 10 track packs constituting one NTSC frame are extracted and arranged, the result is as shown in FIG. In FIG. 21, packs numbered 50 to 55 are basic packs, and these packs are provided with basic data as shown in FIG.

That is, the above-mentioned numbers 50 to 55 indicate the values (hexadecimal) of the pack header. Therefore, the pack header value 50 is a pack indicating a signal source, and the pack is provided with data such as a sampling frequency, the number of quantization bits, the number of channels, and a stereo format. The pack header value 51 is a pack indicating signal source control, and the pack is provided with data such as a recording mode. When the value of the data in the recording mode is "11", all the data in the area are regarded as invalid data.

The pack header value 52 is a pack indicating the recording date. This pack is provided with data such as year, month, week, day, and time zone of the time difference. The pack header value 53 is a pack indicating the recording time,
In this pack, data such as hours, minutes, seconds, and frames of the recording time are provided as two-digit numerical values. The pack header value 54 is a pack indicating a binary group, and this pack is provided with the first to eighth binary numerical values.
Further, the pack header value 55 is an undefined pack.

Thus, the basic pack of the AAUX signal is provided. Note that these basic packs contain essential items for audio data reproduction, such as sampling frequency and quantization bit number, and are extremely important data. Has enhanced protection. Also, by changing the position of the basic pack for each track, the basic pack data can be reliably reproduced even in the case of horizontal scratches and accidents such as one-channel clog which are common in tape transport. I have.

The remaining packs excluding the above-mentioned basic packs are extracted as a, b, c,. This additional pack is N
30 packs are provided for one frame of TSC, and 36 packs are provided for one frame of PAL, and any one is selected and provided from the above header table. That is, for example, a number that divides audio data into arbitrary chapters or parts, text data of the title, and the like are provided.

The additional pack includes a common option (for example, character data) and a maker's option which is uniquely determined by each maker. Since these are additional (optional), one or both may not be present. The common option and the maker's option, or the basic pack and the maker's option, are separated by the appearance of the maker code pack, and the rest are the maker's options.

As shown in FIG. 23, the VAUX signal for assisting video data is composed of 54 packs (0 to 53) per track. When these 54 packs are extracted and arranged, for example, only the packs of 10 tracks constituting one frame of NTSC, the result is as shown in FIG. In FIG. 24, packs numbered 60 to 65 are basic packs, and each of these packs is provided with basic data as shown in FIG.

That is, the above numbers 60 to 65 indicate the values (hexadecimal) of the pack header, respectively. Therefore, the pack header value 60 is a pack indicating a signal source, and the pack is provided with data such as a television system, a screen aspect ratio, a broadcast channel (three digits), and a field frequency. The pack header value 61 is a pack indicating signal source control, and the pack is provided with data such as a recording mode. When the value of the data in the recording mode is "11", all the data in the area are regarded as invalid data.

The pack header value 62 is a pack indicating the recording date. This pack is provided with data such as year, month, week, day, and time zone of the time difference. The pack header value 63 is a pack indicating the recording time,
In this pack, data such as hours, minutes, seconds, and frames of the recording time are provided as two-digit numerical values. The pack header value 64 is a pack indicating a binary group, and the pack is provided with the first to eighth binary numerical values.
Further, the pack header value 65 is a pack of teletext (closed caption), in which the data of the upper byte and the lower byte of the closed caption data provided on the 21st scanning line of the first and second fields are provided, respectively.

Thus, the basic pack of the VAUX signal is provided. Note that these basic packs include items essential for video data reproduction, such as the television format and screen aspect ratio, and are extremely important data. Therefore, the same pack is repeatedly provided on each track.
Increased data protection. Also, by changing the position of the basic pack for each track, the basic pack data can be reliably reproduced even in the case of horizontal scratches and accidents such as one-channel clog which are common in tape transport. I have.

Further, the remaining packs except for the above-mentioned basic packs are extracted as basic packs T0, T1, T2,. This additional pack is one frame of NTSC, 480 packs, one frame of PAL.
576 packs are provided in a frame, and any one is selected and provided from the above-mentioned header table. The handling of this additional pack is the same as the case of the AAUX signal of the audio data described above.

Further, data of the above-described character multiplex signal can be recorded in this additional pack. That is, a text header pack as shown in FIG. This pack includes a TDP (= Total) indicating the total number of text packs that follow.
number of TEXT PACK) and text type data. Note that text type data is composed of 4 bits, and 0 = name, 1 = memo, etc. are defined.
= Subtitle program, 8 = complementary program, 9 = teletext, etc. A teletext pack as shown in FIG. 26B is defined as the pack header value 67. This pack is provided with teletext data.

When recording the data of the above-described character multiplex signal, these text header packs and teletext packs start with text header pack T0 (pack header value 68) as shown in FIGS. And then the teletext packs T1 to T71
(Pack header value 67) is provided so as to be continuous for the number indicated in the TDP. At the end of the teletext pack, a termination code is provided as data of the teletext.

This termination code is, for example, 00111111 in the case of the Japanese teletext broadcasting system, and North America (NABT
01111111 in the case of the teletext system of S),
In the case of the French (ANTIOP) teletext broadcasting system, it is 10111111, and in the case of the British teletext broadcasting system, it is 111111111. This is obtained by connecting 111111 to the broadcast system identification code of each system described above. The end code indicates the end of one frame of teletext data, and indicates that the next pack may be followed by a pack in which other accompanying information is recorded. If a text header pack (text type = teletext) comes next to this pack, if VT is repeatedly recorded, VT
The R VAUX processing microcomputer (not shown) can determine.

In this manner, the data of the above-described teletext signal can be recorded in the additional area of the VAUX signal by using the pack configuration. When only the data of the teletext signal is recorded in the additional area of the VAUX signal,
For example, in the Japanese teletext broadcasting system, data for one frame is composed of 72 packs. Therefore, as shown in FIG.
At the same time, the following packs are packs of invalid data. In this case, unlike the above-described embodiment, since a teletext area is not set, recording is performed using a pack and recorded together with other VAUX information. Therefore, the termination code is recorded to indicate the boundary with other VAUX information.

The sub-code data signal is provided with 5 bytes for each synchronous block described above.
Data is configured with a byte as one pack. Therefore 1
Twelve packs (0 to 11) are formed per track. For example, if only the packs of 10 tracks constituting one frame of NTSC are extracted and arranged, the result is as shown in FIG.

In FIG. 28, packs with uppercase letters A to E are basic packs, and these packs are provided with basic data such as time code, recording date and time. These basic packs are provided repeatedly as shown to protect data, and are also read out during high-speed search, so that the above-described pack search using the basic data is performed. And a
Packs with lowercase letters ~ l are additional packs,
As shown in the figure, the additional data packs are provided with the same data packs (indicated by the same characters) repeatedly to protect the data.

[0136]

According to the present invention, in a normal video recording or timer reservation recording, regardless of whether the user is conscious of the recording, all the teletext programs of that channel can be recorded on a tape or the like at that time. it can. Therefore, it becomes possible to process the data, for example, stock prices, by connecting a personal computer.

Further, 1. The tape recording format can be simplified by simply combining the world teletext into two types, one for the 60 Hz band and the other for the 50 Hz band. 2. Since teletext data is also organized in frames, it can be handled in the same way as video and audio when editing a tape. 3. Even if teletext is expanded in the future, teletext data previously recorded can be reproduced on a new VTR. 4. Since the destination of teletext broadcasting can be immediately determined, for example, when a tape recorded in the United States is reproduced in Japan, the image and sound can be reproduced because the same 60 Hz system is used, but erroneous reproduction of teletext can be prevented. 5. Since all the teletext programs of the TV channel can be recorded, the user can select a desired program after recording on a tape. 6. Since the data is recorded as digital data, it can be connected to a personal computer via a digital interface or the like to form a database. 7. Products that allow the television to have ICs and memories that increase the cost and increase the occupied area are also possible, and are rich in variations. And the like.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a format of an example of a digital VTR to which a teletext signal recording or recording / reproducing apparatus or a magnetic recording or recording / reproducing apparatus according to the present invention is applied.

FIG. 2 is a diagram for explaining a sync block configuration of an image signal area.

FIG. 3 is a diagram for explaining the contents of one buffering unit and five syncs.

FIG. 4 is a diagram showing a state in which AUXs 0 and 1 are arranged in the order of sync blocks.

FIG. 5 is a diagram illustrating an example of a pack structure.

FIG. 6 shows a line number and a line N to be multiplexed for teletext.
o. FIG.

FIG. 7 is a configuration diagram of an example of a recording-side circuit.

FIG. 8 is a diagram for explaining a line ID.

FIG. 9 is a configuration diagram of an example of a reproduction-side circuit.

FIG. 10 is a diagram showing an example of a method of storing Japanese teletext.

FIG. 11 is a diagram showing a state of an A-head clog.

FIG. 12 is a diagram showing a state of a B head clog.

FIG. 13 is a view showing a state of a lateral injury.

FIG. 14 is a diagram showing positions of actual data storage locations.

FIG. 15 is a diagram illustrating an example of a method of storing teletext in the UK and Germany.

FIG. 16 is a diagram showing a relationship between data recorded in Japan and North America, and data recorded in the United Kingdom and France.

FIG. 17 is a diagram showing a state of an arbitrary line of a Japanese teletext signal.

FIG. 18 is a diagram showing a state in which data of 50 Hz band is packed into six tracks.

FIG. 19 is a schematic diagram for explaining a hierarchical structure of a header of a pack.

FIG. 20 is a schematic diagram for explaining a pack header table.

FIG. 21 is a schematic diagram illustrating an AAUX signal pack;

FIG. 22 is a schematic diagram illustrating an example of pack data for the explanation.

FIG. 23 is a schematic diagram illustrating a pack of one track of a VAUX signal;

FIG. 24 is a schematic diagram illustrating a pack of one frame of a VAUX signal;

FIG. 25 is a schematic diagram illustrating an example of pack data for the description;

FIG. 26 is a schematic diagram illustrating an example of pack data when a character multiplex signal is recorded in an additional area.

FIG. 27 is a schematic diagram illustrating an example of a state in which a character multiplex signal is recorded in an additional area.

FIG. 28 is a schematic diagram for explaining a pack of subcode data signals.

[Explanation of symbols]

 1 input terminal 2 sync separation circuit 3 counter clear pulse generation circuit 4 H counter 5 decoder 6 line No. Generation circuit 7 Pedestal clamp circuit 8 Comparator 9 S / P conversion circuit 10, 20 DF / F (D-type flip-flop) 11 Burst ACC circuit 12, 14 PLL circuit 13, 15, 16 Divider 17 Mono-multi circuit 18 CRI detection Circuit 19, 23 Switch 21 FIFO 22 Timing controller

Claims (8)

(57) [Claims] 1. A digital image signal recording means for recording a digital image signal, and means for extracting teletext data multiplexed in broadcast radio waves, and decoding the extracted teletext data. Without error correction to protect the digital image signal.
Recording or recording / reproducing apparatus for teletext, characterized in that the recording is performed in an area for storing associated data . 2. A teletext recording or recording / reproducing apparatus according to claim 1, wherein a portion of said extracted data excluding a bit synchronization code is recorded without decoding. 3. A method in which a multiplex line number, a field, and a broadcast system code of teletext data multiplexed in a broadcast wave are recorded as IDs by replacing them with byte synchronization codes of the extracted data. The recording or recording / reproducing apparatus for teletext broadcasting according to claim 2, wherein: 4. The teletext data multiplexed in a broadcast radio wave is recorded using a pack structure comprising a predetermined number of bytes composed of an item code and a data part. A recording or recording / reproducing apparatus for the teletext described in the above. 5. The teletext recording or teletext recording according to claim 4, wherein an end code is recorded at the end of one frame of teletext data multiplexed in the broadcast radio wave. Recording and playback device. 6. A magnetic recording or recording / reproducing method in which a plurality of tracks are formed on a magnetic tape, and at least a tracking data area, an audio data area, and an image data area are provided in the tracks to digitally record image information. The apparatus further comprises: an additional data area for recording additional information relating to an image in the image data area; and means for extracting teletext data multiplexed in broadcast radio waves and recording the extracted data in the additional data area. A magnetic recording or recording / reproducing apparatus characterized in that a recordable capacity in the associated data area of a track is a non-integer multiple of a data amount per line of the teletext data. 7. The teletext data for one frame is:
7. The magnetic recording or recording / reproducing apparatus according to claim 6, wherein recording is performed at dispersed positions on the tape by using the associated data areas of a plurality of tracks. 8. The teletext data for one frame is:
7. The magnetic recording or recording / reproducing apparatus according to claim 6, wherein recording is repeatedly performed at dispersed positions on the tape using the associated data areas of a plurality of tracks.