JPS61123374A - Magnetic record regeneration device - Google Patents

Abstract

PURPOSE:To enable the titled device to record and regenerate every information sent by multi broadcast of letters by separating and recording letter signal in the extract rewound tape part over rotary head by letter multi image signal. CONSTITUTION:The inputted letter multi image signal is provided to additive circuit through LPF11 and FM modulation 12, then provided to circuit 13 through BPF14 and frequency modulation 15. Only the letter double part is taken out from the separate synchronous signal and the letter doubled signal is written in RAM22. Preamble signal in the standard length and data post amble signal within RAM22 are outputted in turn from the record and regeneration part 21, and rotary head 28, 29 are written in the record medium. Image signal record part recorded by head 28, 29 and the record part separating letter signal from input letter multi image signal are formed within the entire width of tape.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a device for recording and reproducing text multiplex video signals sent by text multiplex broadcasting on a small consumer VTR.

BACKGROUND OF THE INVENTION Conventional devices for recording and reproducing text multiplexed video signals include:
For example, JP-A-59-101985, 69-103
This is shown in Publication No. 479 and the like.

Figure K9 is a diagram showing the principle of the invention disclosed in Japanese Patent Application Laid-Open No. 10347/1983. (A) is the teletext signal that was sent, and indicates that information was sent on the 3rd H (horizontal synchronization signal). This 3HK transmission signal format is sent at 5.7272 Mbit/sea. In other words, in order to record and reproduce this signal, a signal band of 2°a is required.
eMHz must be secured. However, in home VTRs, even when the band is widened using a comb filter, the luminance signal band is about 2.5 MHz, making it impossible to record and reproduce teletext signals.

For this purpose, as shown in FIG. 9 (0:I), only 3H is expanded, for example, twice and recorded. In this way, the band is 1
, 43 MHz, sufficient recording is possible. Even if the 4th H disappears, there is no problem since there is no information because it is within the vertical flyback section. When playing next time, compress 3H as shown in Figure 9 (c), and
Just insert . That is, since this portion is within the vertical retrace period, a dark level is sufficient, and it is sufficient to insert the horizontal synchronizing signal Φ).

FIG. 10 is a diagram showing the principle of the invention disclosed in Japanese Patent Application Laid-Open No. 59-101985. This invention is conceptually similar to the invention explained earlier, in that the information sent in the 1H section is
It was agreed that the information should be divided into two parts and recorded. However, in the previous invention, the data is simply divided into two parts and recorded, whereas the clock line-in signal (CR), seven framing codes (FC), and the data part are each recorded separately as shown in FIG. This indicates that the file will be divided into two parts and recorded. Figure 10 (a) shows the input character signal input, (b) shows the structure of the character signal, (c) shows the time-expanded signal divided into two blocks, and (b) shows the time-expanded signal. This shows the structure of a character signal.

Problems to be Solved by the Invention As mentioned earlier, the problem that the band required for character signals is narrower than the brightness signal band of home VTRs has been solved, but this time extension A new problem arises, and luminance signal recording is fundamentally not achieved. That is, the character code multiplexing position is 8H between fields, and in the conventional method it is 16H, which has the problem that all the information cannot be divided and recorded in the vertical blanking section.

In view of this, an object of the present invention is to provide a device that records and reproduces all information sent through teletext broadcasting.

Means for Solving the Problems The present invention has the advantage of increasing the angle at which the magnetic medium is wound around a cylinder containing a rotating magnetic head, by wrapping the magnetic medium at an extra angle than the angle at which it is normally wound for recording video signals. This device is designed to separate and record character data from a character multiplexed video signal.

Function The present invention has the above-mentioned configuration. Since the character data is recorded in the extra wrapped part, by setting the wrapping angle in consideration of the amount of character data and the recording band, all the characters can be recorded. It becomes possible to record information.

Embodiment FIG. 2 is an example of a tape pattern diagram of the present invention, where arrow 1 indicates the rotation direction of the rotary head and arrow 2 indicates the running direction of the tape. 6 is the full width of the tape, 4 is the portion recorded by the rotating head, 6 is the control track, and 3 is the audio trunk. 7 is a portion of the trunk recorded by the rotary head for recording the video signal, and 8 is a portion for separating and recording the input character multiplexed video signal and the character signal.

FIG. 3 is a diagram showing a signal during the vertical retrace period of the video signal, and the positions where character information can be superimposed are as shown in the diagram.
In the odd field, the scanning line number whistle 10H to the second
It is between 12H up to 1H, and in an even field,
This is from the scanning line number whistle 273H to 12H at the 284th H'i. Furthermore, according to the transmission signal standard of the code system for teletext broadcasting, character information is to be superimposed on 8H out of the above 12H. The amount of data recorded in 1H, that is, the data bucket, is 3 bytes for the synchronization part and 34 bytes for the data part. The 34 bytes of the data section also includes inspection pits, but when outputting during playback, it is necessary to add and output these inspection bits, so when recording, this is also treated as data. do.

Therefore, the total amount of data recorded in the area shown in FIG. 28 is 34×8 bytes. However, if the data is recorded as is, it is impossible to deal with errors in the process of recording and reproducing onto the recording medium. Therefore, as shown in FIG. 4, an address, error correction (harrity) 9 error detection 1, etc. are added and recorded. By setting it to 7 format as shown in FIG. 4, 34×8 bytes of data can be recorded. Only the synchronization signal will be recorded with a different modulation method to ensure detection. With this configuration, the amount of data recorded in the portion shown in FIG. 8 is (8X8+13X3+16+3)X34=ae3a bits.

Also, when recording quantized data in this way, the bandwidth is not limited to 2.5 M& as in the conventional example.
s MHz can be recorded sufficiently, so in the case of the NT30 method, winding of about 8 degrees is sufficient.

If the pre-ampule is 2° and the post-ampule is 2°, the first
The wrapping angle of the portion shown in FIG. 8 only needs to be 12° or more.

Next, one embodiment of the present invention will be explained using the electrical block diagram of FIG.

Terminal 10 is a text multiplex video input terminal, and the signal input from terminal 1o is supplied to a low-pass filter 11, where a luminance signal is extracted and supplied to an FM modulator 12.
After being FM modulated, the signal is supplied to the adder circuit 13. Similarly, the signal input through the terminal 10 is supplied to the band pass filter 14, the carrier color signal is taken out, and supplied to the frequency converter 15, where the signal is frequency converted and then supplied to the addition circuit 13, where it is FM modulated. is added to the luminance signal.

SW1 to SWe are nine changeover switches, 5R is connected during recording, and P is connected during playback. The synchronization signal separated by the synchronization signal separation circuit 16 from the terminal 1Q via the R side of SWi is supplied to the timing signal generation circuit 17, and the gate signal of the portion where the character signal is superimposed (Figure 6) is created and supplied to the gate circuit 68. The signal inputted from the terminal 10 (FIG. 5A) is supplied to a gate circuit 68, where only the portion on which the character signal is superimposed is taken out and supplied to a clip circuit 69, where the horizontal synchronizing signal is removed.
The data clock demodulation circuit 18 is supplied with the data clock demodulation circuit 18. data·
The data demodulated by the clock demodulation circuit 18 is supplied to the controller 19, and is temporarily stored in the RAM 20 except for the synchronization section.
will be written to.

When a signal from the timing generation circuit 17 that has completed the character signal superimposition section is supplied to the controller 19, the information in the RAM is sequentially read out to the controller 19 and error correction is performed. The error-corrected signal is supplied to the recording/reproducing controller 21 and once written into the RAM 22.

When the data is written into the RAM 22, it is read out by the recording/reproduction controller 21, an error detection code, an error correction code, etc. are added thereto as shown in FIG. When the signal (see FIG. 6) is supplied from the pulse generator 46 to the recording/reproducing controller 21, the recording/reproducing controller 21 outputs a preamble signal of a specified length, data written in the RAM 22, and a postampule signal in this order. and is supplied to the modulator 23.

The signal supplied to the modulator 23 is modulated and then supplied to the MIX circuits 24 and 25. The MIX circuit 24.25 temporally mixes the output from the adder circuit 13 and the output from the modulator 23, and supplies the mixed signal to the sickle amplifier 26.27 to the R side of SW2 and the R side of SW3. Rotating head 2 through
8.29 and recorded on the recording medium. 6th.
6 and 7 to supplement the explanation so far, 0) in FIG. 5 is a video signal containing character information input from terminal 1o, The gate signal supplied to the circuit 68, e, the signal gated by the gate circuit 58, is a signal in which the omitted part of the signal in (c) is extended, and character information is added to the part eH. be. (E) is the output of the clip circuit 69, which is a signal containing only data from which the horizontal synchronizing signal has been removed. FIG. 6(-r) shows the head switching signal, and FIG. 6(b) shows the vertical synchronizing signal of the signal input from the terminal 10. Normally, the leading edge of the vertical synchronization signal and the head switching signal are servoed so that they become eH as shown in the figure. (C) is a signal that extracts only the character information, which is the same as in Figure 5 (E). 2) indicates the timing at which the controller 19 corrects errors in the input signal, and (E) indicates the timing at which the recording/reproduction controller adds error correction codes, error detection codes, etc. as explained earlier. , (e) indicate the timing at which the signal processed at the timing (e) is recorded. 7(a) is the same Herad switching signal as in FIG. 6(a), (b) is the output of the recording amplifier 26, and (c) is the output of the recording amplifier 27.

) shows the complete structure of the recorded signal.

As can be seen from the explanation of FIGS. 6 and 7, during recording, character information is recorded with a delay of about one field compared to the signal input to the input terminal. Further, the signal inputted from the terminal 1o is inputted to the output amplifier 44 via the R side of the switch 4, and after being made into a specified output, is outputted to the video output terminal 60.

The head 46 is a rotational phase detector and detects the rotational phase of the rotary head. 47 is an amplifier for amplifying the output of the rotational phase detector 46, and 48 is a mono-multivibrator for correcting a mounting error of the rotational phase detector 46. The output of the mono multivibrator 48 is input to the pulse generator 46, and various timing signals are created based on the output of the mono multivibrator 48. A terminal 49 is connected from the pulse generator 46 to a servo circuit (not shown).
During recording, the head switching signal (Fig. 6 A) is supplied, and during recording, the phase is compared with the vertical synchronizing signal in the input video signal, and during playback, the signal output from the reference oscillator. Figure 6 (a), li:I)
Control is applied to always rotate at a constant speed during playback so that the phase is constant as shown in FIG.

Next, recycled yarn will be explained. The signals regenerated by the rotary heads 28 and 29 are amplified by regeneration amplifiers 30 and 31 via the P side of the switch 2.3, and then sent to the head switch circuit 32. The signal is supplied to the gate circuit 33. The two systems of signals input to the head switch circuit 32 are switched by the head switching signal output from the pulse generator 46, and are output after being made into continuous signals. The output of the head switch circuit 32 is supplied to a bypass filter 34 and a low pass filter 38. noi pass filter 34
The FM signal that has passed through is passed through the limiter 36 to the FM
The signal is supplied to a demodulator 36, demodulated, and then supplied to an adder circuit 37. Furthermore, the signal that has passed through the low-pass filter 38 is
APC/AFC
An alternating signal for frequency conversion is supplied from the circuit 41, frequency-converted to the carrier frequency before recording, time axis error is corrected, and the signal is supplied to the comb filter 40 to remove inter-track crosstalk. The signal is supplied to an adder circuit 37. As a result, the original color video signal is outputted from the adder circuit 37.

On the other hand, the regenerative amplifier 30°31 supplied to the gate circuit 33
The output of the pulse generator 46 passes only the portion where the character information is recorded, becomes a single intermittent signal, and is supplied to the demodulator 42 .

After the signal supplied to the demodulator 42 is demodulated, it is once written to the RAM 22 via the recording/reproduction controller 21, and then errors are corrected using the error detection code and error correction code recorded with the data. Thereafter, only the data portion is written to the RAM 20 via the controller 19. R
The data written in the AM 20 is read out every time the character information superimposition signal which is the output of the timing generation circuit 17 comes, and is supplied to the mixer 43 with the synchronization part signal removed at the time of recording added. Ru. Further, the output of the adder circuit 37 is supplied to the mixer 43, and is also supplied to the synchronization signal separation circuit 16 via the P side of SW1, where the synchronization signal is separated. The synchronization signal separated by the synchronization signal separation circuit 16 is supplied to the timing generation circuit 17, and the timing generation circuit 1 outputs the original timing on which the character signal before recording is superimposed according to the input synchronization signal to the controller 19. supply to. As a result, in the mixer 43, the output of the adder circuit 37 and the character signal from the controller 19 are mixed and output as a character signal superimposed signal (FIG. 5A) before recording. The output of the mixer 43 is amplified by the output amplifier 44 via the P side of SW4, and then output to the video output terminal 60.

FIG. 8 is a timing diagram for supplementary explanation of FIG. 1. Figure 8 (A) shows the same head switching signal as Figure 6 (A), and as explained earlier, the vertical synchronization signal in the input video signal (Figure 8) and the line in the figure (sH The servo is applied so that the relationship is the same. Figure 8 (c) shows the timing when character information is superimposed, and (c)
The information inputted at the timing , is recorded at the timing , as explained in FIG. The signal recorded at the timing (e) is similarly reproduced at the timing (e). That is, data is written to the RAM 22 via the recording/reproducing controller 5-21 at the timing (e). The timing (f) is the timing for correcting errors caused by recording/reproduction, as described above), and is the timing for processing by the RAM 22 and the recording/reproduction controller 21. (G) is the timing at which the data corrected by the recording/reproduction controller 21 is transferred to the RAM 20 via the controller 519, and (7) is the timing when the data in the RAM 20 is transferred to the RAM 20.
This is the timing that is sequentially generated by the output of the timing generation circuit 17. As can be seen from the explanation of Figure 8 and the wavy line arrows in the figure, by recording and reproducing, text information is reproduced with a delay of one frame compared to the original vertical synchronization signal. become. However, since the video signal and text information are independent signals, there is no particular problem.

Next, recording and reproduction of audio signals will be explained. The audio signal is recorded on the audio track portion of FIG. 2 by the usual AC bias recording method.

The signal input from the audio input terminal 5o is input to the recording equalizing amplifier 61, and after being amplified, the signal is input to the recording equalizing amplifier 61.
2, is amplified, is input to an adder circuit 64, is added to the output of the bias oscillator 63, and is sent to the upper end of the tape (the part shown in FIG. 2 and 3) via the R side of the SWs by the audio head 66. recorded. During reproduction, the signal reproduced by the head 55 passes through the P side of 5W-6, is amplified by the reproduction equalizing amplifier, and then is sent to the P side of SW-6, the output amplifier 6.
7 to the audio output terminal 61.

By configuring as described above, it becomes possible to record and reproduce signals on which character information is superimposed.

FIG. 11 is a pattern diagram showing a second embodiment of the present invention, in which arrow 85 indicates the rotation direction of the rotary head, and arrow 86 indicates the running direction of the tape. 87 is Qi Gu full width, 89
is the part recorded by the rotating head, 88 is a spare track, 9
0 is a control track. 91 is a part for recording video signals among the tracks recorded by the rotary head, 92 is a part for separating and recording character signals from input character multiplexed video signals, and 93 is a part for converting audio signals into PCM. This is the part where the time axis is compressed and recorded.

The character signal will be recorded in the format shown in FIG. 4, as in the first embodiment.

FIG. 12 is a plan view showing the main parts of the tape running system for realizing the recording pattern of the second embodiment of the present invention.
2) It is traveling in the direction of arrow 86 while being wrapped around itself. Heads 28 and 29 are also mounted approximately at 1800 and rotated in the direction of 85. The part θ2 corresponds to the part 93 in FIG. 11, and is a part where the audio signal is converted to PCM and compressed on the time axis, and the part θ1 corresponds to the part 92 in FIG. This is the part extracted from the signal and recorded, and the part (18o+α) is the part where the video signal is recorded.

FIG. 13 is an electrical block diagram of the second embodiment of the present invention, and the same numbers are given to the same elements as those in the block diagram of the first embodiment (FIG. 1).

Low pass filter 11 + FMR modulator 12, band pass filter 142 frequency modulator 15. Addition circuit 1
3 operates in the same way as in Figure 1, the luminance signal is FM modulated, the carrier color signal is frequency converted, and the added signal is M
Sent to IX circuit 65.86. Similarly, the synchronization signal separation circuit 16. Timing generation circuit 17. Gate circuit 68.
Clip circuit 59° data clock demodulation circuit 18. Controller 19° RAM 20. Recording/playback:y7)C
The I-5-21, RAM 22, and modulator 23 operate in the same manner as shown in Fig. 1, extracting character information from the input video signal, processing error correction for the input information, and then performing error correction for recording and reproduction. After being subjected to code processing, the signals are modulated and supplied to MIX circuits 65 and 66.

The R and L channel audio signals inputted from the audio input terminals 69.70 are amplified by the amplifiers 73.74 and then output to the N
It is input to the O converter 7, and the sync generator 84
2fH (/H;
The RL is alternately sampled and converted into a digital signal using sample pulses at the horizontal synchronizing signal frequency.

The output of the A/D converter 77 is written to the RAMJ 30 via the audio controller 7e. RAM
For example, aO contains information (1
(R2 channel information) is written. Information during the next half rotation is then written into the RAM 81. In parallel with being written to the RAJ 481, information such as error correction, error detection, and address is added to the information in the RAM 80 by the audio controller 79, and the information is output to the modulator 82 according to a timing command from the pulse generator 68. The information modulated by the modulator 82 is supplied to MIX circuits 65 and 66, and the output of the adder circuit 13, the output of the modulator 23, and the pulse generator 6
It is temporally MIXed by the output of 8.

The outputs of the MIX circuits 65 and 66 are supplied to recording amplifiers 26 and 27, where they are amplified and then sent to SW2. The signal is supplied to the rotary heads 28 and 29 via the R side of SW3, and recorded on the tape as shown in FIG. 11.

Next, an auxiliary explanation will be given using a diagram shown in FIG. 14 showing the timing of recording with the two heads of the second embodiment.
Figure (a) is a herad switching signal similar to Figures 7 and 8 (a), and (b) and (c) are the rotary head 2B,
29 shows the tie and mink passing the recording current (in)
indicates the structure of the recorded signal.

To explain in detail, the first step is to explain the sound data.

There is a reamble, followed by audio data, and then there is a postampule of audio data. These three pieces of information are the 11th
Figure 93. What comes next, which is recorded in the section 02 of FIG. 12, is character data tab 1 fan pull, character data, and character data postamplifier. These three pieces of information are the first
1 Figure 92. 0 recorded in the part θ in Figure 12, then
A first variation before the video signal, a 1-field recording portion, and an overlap after the video signal are recorded. The information in these three parts is a continuous signal, so even if there is a time axis fluctuation in the rad switching signal during playback, no chipping will occur when the signals played from the two heads are made into one continuous signal. It looks like this. The information on these three parts is in the 11th section.
It is recorded in FIG. 91, and the front and rear overlap portions correspond to the opening in FIG.

Next, playback will be explained. The signal reproduced by the rotary head 28°29 is sent to SW2. After being input to the regenerative amplifier 30.31 through the P side of the SW3 and amplified (amplification signal in Figure 16, C), the head switch circuit 32. Gate circuit 33. The signal is supplied to the gate circuit 67. In the head switch circuit 32, the head switch pulse from the pulse generator 68 (FIG. 15A) generates a continuous signal of only the video signal (FIG. 15B). Bypass filter 34. Limiter 35, FM demodulator 36. Kajti road 3
7. low pass filter 381 frequency converter 39,
(1, Type 7 Initar 40, APC/AFC circuit 41
operates in the same manner as in FIG. 1, and a color video signal is output as the output of the adder circuit 37.

Similarly, in the gate circuit 33, the pulse generator 68
The output of the regenerative amplifier 30 (see Fig. 16) is the output of the regenerative amplifier 30 (see Fig. 16).
6) and the pulse generator 68
(FIG. 15 E), the output of the regenerative amplifier 31 (the first
A gated signal (Figure 6 c) is combined with an intermittent single signal (
It is output as Fig. 16 (G). The output of the gate circuit 33 is sent to the demodulator 42, RAM 22 . Recording/playback controller 2
1°RAM20. Controller 19. Synchronous signal separation circuit 16. The timing generation circuit 17 reproduces character information in the same manner as in FIG. The output of the adder circuit 37,
The character output from the controller 19 is input to a mixer 43, where the character information is superimposed on the video signal like a signal before being recorded. The output of the mixer 43 is S
The signal is input to the output amplifier 44 via the P side of Wa, and after being amplified, is output to the video output terminal 60.

In the gate circuit 67, the output of the pulse generator 68 (
(Figure 16), and the output of the regenerative amplifier 3o (Figure 15)
The gated signal and the output of the pulse generator 68 (
In Fig. 16 C), the output of the regenerative amplifier 31 (Fig. 15 C)
With the gated signal? , is output as a single intermittent signal (Fig. 16). The output of the gate circuit 67 is demodulated by a demodulator 83 and written to RAMs 80 and 81 alternately via an audio controller 79. For example, R
AM80 has Figure 16 (x) no s e, 9 B (D
After error correction is performed by the f-dio controller 79, the signal is output to the D/A converter 78. D/A converter 78
Now, the original analog signal is restored, and R, L
The signal becomes a two-channel signal, and after being amplified by output amplifiers 75 and 76, it is output to output terminals 71 and 72. By the method described above, it is possible to record and reproduce a video signal on which a character signal is superimposed and a signal obtained by digitizing an audio signal.

FIG. 16 is a diagram showing the timing of recording with two heads according to the third embodiment of the present invention, in which (a) shows a helad switching signal, (b) shows a signal to be recorded with one head, e→ indicates the signal recorded by the other head, and )
FIG. 2 is a diagram showing the structure of a recording signal.

The difference from the second embodiment shown in Fig. 14 is that in Fig. 14, before recording the video signal, the audio signal was digitized and the time axis compressed signal and character information were recorded.
In Figure 6, character information is recorded after the video signal. Even in this case, it can be realized by changing the output timing of the pulse generator shown in FIG. 1368.

Further, in FIG. 14, if the condition is that all character data and audio data are recorded and reproduced simultaneously, it is of course possible to exclude the audio data postampule and the character data preamble section.

As described in detail, the present invention has the effect of realizing a compact VTR that can record and reproduce text superimposed video signals as well as all the information sent, and its industrial value is immense. There is.

[Brief Description of the Drawings] Fig. 1 is a six-dimensional block diagram of an embodiment of the present invention, Fig. 2 is a diagram showing an example of a tape pattern of the present invention, and Fig. 3 is a vertical blanking line diagram of a video signal. FIG. 4 is a diagram showing an example of the format of the signal recorded in the section 8 of FIG. 1; FIG. 5 is a diagram for explaining character information separation;
Fig. 6 is a timing diagram that provides a supplementary explanation of Fig. 1, Fig. 7 is a diagram showing the timing of recording with two heads, and Fig. 8 is a timing diagram that provides a supplementary explanation of Fig. 1. , FIG. 9 is an inventive principle diagram of the first conventional example, FIG. 10 is an inventive principle diagram of the second conventional example, FIG. 11 is a pattern diagram showing the second embodiment of the present invention, and FIG. 12 is an inventive diagram of the principle of the second conventional example. A plan view showing the main parts of the tape running system for realizing the recording pattern of the second embodiment of the present invention, FIG. 13 is an electrical block diagram of the second embodiment of the present invention, and FIG. A diagram showing the timing of recording with two heads in the second embodiment of the invention, FIG. 16 is a timing chart supplementary explaining the electrical block diagram of the second embodiment of the invention, and FIG. FIG. 7 is a diagram showing the timing of recording with two heads in a third embodiment of the invention.

Claims (6)

[Claims] (1) The angle at which a magnetic medium, on which video signals are sequentially recorded as discontinuous recording trajectories by a plurality of rotating magnetic heads, is wound around a cylinder containing the rotary magnetic heads is determined by the winding angle normally required to record and reproduce video signals. At the same time, the rotating magnetic head records a signal with character information separated from the character information multiplexed video signal on the magnetic medium corresponding to the portion of the extra winding, and when reproducing the above-mentioned information. A magnetic recording/reproducing apparatus characterized in that a rotating magnetic head reproduces a video signal and outputs a signal in which reproduced character information is added to a multiplex position of the reproduced video signal. (2) The rotary head records the time-axis compressed audio signal along with character information on the magnetic medium corresponding to the extra wrapped portion, and when playing back, the time-axis compressed audio signal is time-axis expanded and continuous. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein the magnetic recording and reproducing apparatus obtains a reproduced audio signal. (3) The magnetic recording and reproducing apparatus according to claim 2, wherein the audio signal to be recorded is of two channels. (4) A method according to claim 2 or 3, characterized in that time-axis compressed audio signal data and teletext data are combined as recorded data, and a preamble and a postampule are provided before and after the recorded data. Magnetic recording and reproducing device. (5) Claims 2 or 3 characterized in that a preamble and a postampule are provided before and after each of the time-axis compressed audio signal data and teletext data.
The magnetic recording and reproducing device described in . (6) The magnetic recording and reproducing apparatus according to claim 6, characterized in that audio signal data and teletext data compressed in the time axis are recorded before and after the video signal.