JPH0466070B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording method, and particularly to a magnetic recording method in which two tracks are recorded separately by a plurality of rotating heads, and
The present invention relates to a method for selectively performing a first recording mode in which recording is performed simultaneously and a second recording mode in which recording is performed using two rotary heads based on, for example, the current low-frequency conversion color recording system.

Conventional technology Currently, helical scan magnetic recording and reproducing devices (VTR) use 1/2 inch wide magnetic tape.
Since the band that can be recorded and reproduced for home use is relatively narrow, of the luminance signal and carrier color signal separated from the color video signal, the luminance signal is frequency-modulated to become a frequency-modulated wave, and the carrier color signal is converted into a frequency-modulated wave. A so-called low-pass conversion color recording and reproducing method is adopted in which the converted carrier color signal is frequency-division multiplexed onto the frequency-modulated luminance signal, and this frequency-division multiplexed signal is recorded on a magnetic tape and reproduced. Furthermore, in order to improve tape usage efficiency, a guard bandless recording method is adopted in which the azimuth angles of each rotating head for recording adjacent tracks are made to be different. On the other hand, commercial VTRs intended for broadcasting, especially those with built-in cameras, have the same tape width as home VTRs, with the aim of making the device smaller and lighter and improving the quality of the reproduced color video signal. on magnetic tape,
A method is adopted in which the luminance signal and the color signal are recorded on separate tracks using separate rotating heads, and a guard band is provided between adjacent tracks for recording and reproduction.

FIGS. 12 and 13 respectively show examples of track patterns recorded and formed by the above-mentioned conventional camera-integrated VTR. In FIG. 12, tracks 2 ₁ and 2 are inclined with respect to the longitudinal direction of the magnetic tape 1.
₂ and 2 ₃ are tracks on which frequency modulated luminance signals (hereinafter referred to as FM luminance signals) are recorded, respectively;
Tracks 3 ₁ , 3 ₂ , and 3 ₃ are first and second tracks obtained by frequency modulating separate carrier waves with color difference signals I and Q, respectively.
This is a track on which a second frequency-modulated color difference signal (hereinafter referred to as FM color difference signal) is frequency-division multiplexed and recorded. Tracks 2 ₁ and 3 ₁ are tracks in which the FM luminance signal and FM color difference signal of the same field are recorded simultaneously and separately, and similarly, tracks 2 ₂ and 3 ₂ and 2 ₃ and 3 ₃ are tracks in which the FM luminance signal and FM color difference signal of the same field are recorded simultaneously. This is a track in which an FM luminance signal and an FM color difference signal are recorded simultaneously and separately. Furthermore, the plurality of rotating heads that record and form tracks 2 ₁ to 2 ₃ and 3 ₁ to 3 ₃ all have the same azimuth angle, and a guard band (no signal recording zone) is formed between adjacent tracks. . In addition, in Figure 12, 4 ₁
and 4 ₂ is an audio track on which the audio signals of the first and second channels are recorded; 5 is a control track formed by the control head;
6 is a time code track formed by the time code head.

On the other hand, on the magnetic tape 7 shown in FIG. 13, there are inclined tracks 8 ₁ , 8 ₂ , 9 ₁ , 9 ₂ and audio tracks 10 ₁ , 10 ₂ of the first and second channels.
A time code track 11 and a control track 12 are recorded respectively. Recording tracks 8 ₁ and 8 ₂ are tracks on which FM luminance signals are recorded by the rotary heads 13 _a and 13 _b shown in FIG. This is a track on which an FM time-base compressed color difference signal is recorded by the rotating heads 14a and 14b shown in the figure. Here, above
FM time axis compressed color difference signal is color difference signal (R-Y)
After compressing the time axes of and (B-Y) to 1/2, they are time-division multiplexed alternately every H/2 (where H is the horizontal scanning period), and the carrier wave is frequency-modulated with this time-division multiplexed signal. This is the signal obtained by two first rotary heads 13a with the above azimuth angle of −15°;
13b and two second rotating heads 14a, 14b with an azimuth angle of +15°, the track 8 ₁
After forming records of and 9 ₁ simultaneously and separately,
In the next field, tracks 8 ₂ and 9 ₂ are recorded simultaneously and separately, and thereafter, tracks are recorded two by two in the same manner. Furthermore, a guard band is formed between two adjacent tracks among tracks 8 ₁ , 8 ₂ , 9 ₁ , and 9 ₂ to avoid mutual crosstalk.

In the color video signal recording/reproducing apparatus of the so-called Y/C separation recording/reproducing method which forms either of the track patterns shown in FIGS. 12 and 13 above,
Since the luminance signal and the color difference signal are recorded on separate tracks and played back, the FM luminance signal and the low frequency conversion carrier color signal are simultaneously transmitted using the non-linear transmission system in the VTR using the low frequency conversion color recording and reproducing method described above. Moiré, which occurs when recording and reproducing on the same track on a magnetic tape, does not occur, and the recording and reproducing bands for both the luminance signal and color difference signal can be made sufficiently wide, and the low frequency conversion carrier color signal can be converted to FM. Since bias recording is not performed using luminance signals, the S/N (signal-to-noise ratio) of reproduced color difference signals can be improved.
As described above, it is possible to obtain a reproduced color video signal of higher image quality than that of a VTR using the low frequency conversion color recording and reproduction method.

Problems to be Solved by the Invention However, the above-mentioned Y/C separation recording and reproducing method
VTR uses the above-mentioned low frequency conversion color recording and playback method.
It is desirable to be able to arbitrarily select and record and play back the low frequency conversion color recording and playback method, which is not compatible with VTRs and is widely used. In this case, if one of the plurality of sets of rotary heads with different height positions is selected incorrectly to be used when forming a track pattern using the low-frequency conversion color recording method, crosstalk between the heads may cause the recording track to become distorted. There was a problem that some parts could be erased.

Therefore, the present invention selectively performs a first recording mode in which two tracks are formed separately and simultaneously, and a second recording mode in which tracks are sequentially formed one by one. An object of the present invention is to provide a magnetic recording method that solves the above problems by using a predetermined set of rotating heads depending on the relative relationship between the tape running direction and the head scanning direction.

Means for Solving the Problems The magnetic recording method according to the present invention provides first and second magnetic recording devices attached to opposite positions on the rotating surface of a rotating body.
The rotating head is located close to the mounting position of the first and second rotating heads in the rotational direction of the rotating body, and is located at the upper height position of the rotating body in the rotational axis direction. 3rd and 4th installed
Of the rotary heads, the first and third rotary heads and the second and fourth rotary heads are alternately used for each track scanning period to separately record the first and second information signals. A first recording mode in which two parallel tracks are sequentially formed on a magnetic tape, and two rotary heads are installed at opposite positions among the first to fourth rotary heads. 1
A magnetic recording method that selectively performs a second recording mode in which tracks on which a third information signal is recorded are sequentially formed one by one on a magnetic tape by being used alternately in each track scanning period, In the second recording mode, when the running direction of the magnetic tape is approximately the same as the scanning direction of the first to fourth rotary heads, the third information signal is recorded by the lower first and second rotary heads. , when the magnetic tape running direction is approximately opposite to the head scanning direction, the upper third
and recording the third information signal by a fourth rotating head.

Effect: In the first recording mode, one track scanning period includes recording the first and third tracks at different height positions.
The recording track of the first information signal and the recording track of the second information signal are simultaneously formed in parallel by the rotating head of the recording head, and during the next one track scanning period, the recording track of the first information signal and the recording track of the second information signal are formed in parallel. The recording track of the first information signal and the recording track of the second information signal are simultaneously formed in parallel by the head, and the same operation as described above is repeated. As a result, there is no restriction on the recording band as in the case where the first and second information signals are simultaneously recorded on the same track, and there is no mutual interference between the two signals, so high quality recording can be achieved.

On the other hand, in the second recording mode, the third information signal is generated by two rotating heads mounted facing each other alternately scanning the magnetic tape, one track per track scanning period. formed and recorded. Here, the running direction of the magnetic tape and the scanning direction of the rotary head are approximately the same direction, the magnetic tape is run at a speed that provides the same track pitch of 58 μm as in the standard mode of current home VTRs, and , the track width of each of the first to fourth rotating heads is 29 μm, and the third and fourth rotating heads are installed 16 μm above the first and second rotating heads. As shown in
During one track scanning period, the first rotary head draws a scanning locus inclined to the longitudinal direction of the tape as shown by the solid line _T1 , and at the same time, the third rotary head draws a scanning locus as shown by the solid line _T3 . A trajectory is drawn. In the next one-track scanning period, the second rotary head draws a scanning locus as shown by the dashed-dotted line _T2 , and at the same time, the fourth rotary head draws a scanning locus as shown by the dashed-dotted line _T4 .

Therefore, as can be seen from FIG. 9, the portion with a width of 16 (=29-58+45) μm shown by diagonal lines on the tape upstream side of the scanning locus _T3 of the third rotating head will be scanned during the next one-track scanning period. This results in overlapping scanning by the two rotating heads. Therefore, when the upper third and fourth rotary heads are used to record the third information signal, a portion of the track recorded by the third rotary head is transferred to the second rotary head. (Similarly, the first rotary head scans a portion of the track recorded by the fourth rotary head). In this case, the recording current is not supplied to the first and second rotating heads, but if leakage magnetic flux from the fourth rotating head enters the second rotating head, this magnetic flux can be removed. The second rotating head erases a small portion of the track previously formed by the third rotating head. On the other hand, if the lower first and second rotating heads are used, even if a signal is recorded by the third and fourth rotating heads due to leakage flux, the first and second rotating heads will Since the third rotary head records the third information signal, it is possible to erase the portion scanned by the first and second rotary heads among the portions recorded by the leakage magnetic flux, and moreover, the third information signal can be erased. The information signal recording track is never erased. Therefore, in the second recording mode, the third information signal is recorded by the lower first and second rotary heads.

Moreover, when the magnetic tape running direction is approximately opposite to the head scanning direction (in the opposite direction to the magnetic tape running direction in FIG. 9), contrary to the above, there is a The upper rotating head then scans the upper third and fourth parts.
The third information signal is recorded by the rotary head of the recording head.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 1.
This will be explained with reference to the drawing in FIG.

FIG. 1 shows a block diagram of an embodiment of a recording apparatus implementing the method of the present invention. In the figure, changeover switches SW ₁ , SW ₂ and SW ₃ are connected to the contact a side when recording by the Y/C separation recording method (in the first recording mode), and on the other hand, when recording by the low frequency conversion color recording method. When recording with (second recording mode)
is switched and connected to the contact b side. Also, described later
The carrier frequency of the FM modulators 39 _L , 39 _R and the pass characteristics of the band filters 40 _L , 40 _R are determined by the changeover switch.
The configuration is such that each of the values is changed to a predetermined value in response to switching of SW ₁ to _{SW 3} . First, to explain the case of recording using the Y/C separation recording method, in FIG. 1, the composite color video signal input to the input terminal 15 is supplied to the decoder 16, where frequency selection, demodulation, etc. are performed. , the luminance signal Y
and two types of color difference signals R-Y and B-Y. The luminance signal Y has a wider band than the luminance signal recorded by the low-pass conversion color recording and reproducing method, and is passed through a low-pass filter 17, a pre-emphasis circuit 18, and a white/dark (W/D) clip circuit 19, respectively.
The signal is supplied to the FM modulator 20, where it is frequency-modulated and converted into a frequency-modulated luminance signal (FM luminance signal) with a carrier wave shift band of about 5 MHz to 6 MHz.
This FM luminance signal is supplied through the recording amplifier 21 to the contact a of the switch _SW2 and the rotary head H _M2 . Note that unlike the conventional low-pass conversion color recording and reproducing system, no high-pass filter is required on the output side of the FM modulator 20. This is because only the FM luminance signal is recorded on one track.

On the other hand, the color difference signals R-Y and B-Y are sent to the FM modulator 3 through low-pass filters 22 and 23, clamp circuits 24 and 25, pre-emphasis circuits 26 and 27, and white/dark clip circuits 28 and 29.
0,31. As a result, the first FM color difference signal is extracted from the FM modulator 30,
A second FM color difference signal is extracted from the FM modulator 31. These first and second FM color difference signals are supplied to an adder 34 through a high-pass filter 32 and a low-pass filter 33, where they are frequency-division multiplexed, and then passed through a recording amplifier 35 to contact a of switch SW ₃ and rotation. Supplied to head H _S1 .

Further, the input composite color video signal is supplied to a conventional recording circuit 36, where it undergoes recording signal processing using a conventionally well-known low-frequency conversion color recording and reproducing method to convert it into an FM luminance signal and a low-frequency conversion carrier color signal. After being converted into a third frequency division multiplexed signal, the signal is supplied to contact b of switch SW ₂ and contact b of switch SW ₃ .

Furthermore, the left channel audio signal that has entered the input terminal _37L and the right channel audio signal that has entered the input terminal _37R are sent to the pre-emphasis circuits _38L , 3.
8 _R , FM modulator 39 _L , 39 _R and band filter 4
It is supplied to the adder 41 through 0 _L and 40 _R , where it is frequency division multiplexed. A first frequency division multiplexed signal consisting of first and second frequency modulated audio signals (FM audio signals) is applied to a common contact of switch _SW1 .

Here, since the switches SW ₁ to _{SW 3} are connected to contact a as described above during Y/C separation recording, the above first frequency division multiplexed signal is
The signal is supplied to the adder 34 through SW ₁ , where it is frequency-division multiplexed onto the first and second FM color difference signals, respectively, to generate a second frequency-division multiplexed signal. This second frequency division multiplexed signal is supplied to the rotary head H _S1 through the recording amplifier 35, while
It is supplied to the rotary head H _S2 through the switch _SW3 . Further, the FM luminance signal taken out from the recording amplifier 21 is supplied to the rotary head _HM2 , and is also supplied to the rotary head _HM1 through _the switch SW2.

Next, to explain in more detail the arrangement of the rotary head in the present invention, FIG. 2 shows an embodiment of the arrangement of the rotary head in the present invention. As shown in the figure, a first rotary head H _M1 and a second rotary head H _S2 are respectively installed at positions facing each other by 180 degrees on the rotating surface of a rotating body such as a rotary drum, and a third rotary head H The rotating head H _S1 and the fourth rotating head H _M2 are installed at positions facing each other by 180° on the rotating surface,
and at a position that is behind the rotating heads H _M1 and H _S2 by a distance c in the rotational direction, and above the lower end of the rotating heads H _M1 and H _S2 in the rotational axis direction of the rotary body.
It is installed 45 μm higher. The track widths of these rotating heads H _M1 , H _S1 , H _M2 and H _S2 are each equal to 29 μm, and their azimuth angles are equal to those of the current low frequency conversion color recording and reproducing system.
The azimuth angle of the rotating heads H _M1 and H _S1 is selected to be the same as the standardized azimuth angle of the VTR, for example, +6°, and the azimuth angle of the rotating heads H _M2 and H _S2 is Each angle is set to −6°.

Also, 75° above the rotational direction with respect to the rotating head H _M1.
In the leading position and rotating heads H _M1 and H _S2
The rotary audio head H _A2 is installed at a position 27.5 μm higher than the bottom edge of the head. Also, the rotating head
At the same height as H _A2 and 180° opposite,
An audio-only rotary head H _A1 is installed. Therefore, the rotary head H _A1 is installed at a position 255° ahead of the rotary head H _M1 in the rotational direction. The audio rotary heads H _A1 and H _A2 each have a track width of 27 μm, and the azimuth angle of H _A1 is +30°.
That of H _A2 is selected to be −30°, respectively.

FIG. 3A is a more detailed view of the rotary heads H _S1 and H _M1 viewed from the sliding surface, and the distance c between them is set to a value that allows H-aligned recording, as will be described later. The rotating heads H _S1 and H _M1 are as shown in Fig. 3B.
It is glued to the tip of a single head base 44 (same for rotating heads H _S2 and H _M2 ).

As a result, a track pattern as shown in FIG. 4 is formed on the magnetic tape 43. In the same figure,
Two audio tracks 45 ₁ and 45 ₂ are formed along the tape longitudinal direction at the upper end of the magnetic tape 43, and control pulses of a fixed period (for example, one frame) are formed at the tape lower end along the tape longitudinal direction. Recorded control track 4
6 is formed. Also, T _Y1 , T _Y2 and T _Y3 are the first
The luminance signal, which is the information signal of
The tracks recorded for each field (actually, the overlap recording period is added to this), T _C1 , T _C2 and T _C3 are the second information signals.
These are tracks on which the second frequency division multiplexed signal is recorded one field at a time (actually, an overlap recording period is added to this), and each track is formed at an angle with respect to the longitudinal direction of the tape. Tracks T _Y1 and T _C1 are formed separately and simultaneously by a first rotating head H _M1 and a third rotating head H _S1 via a wide guard band G ₁ , and
During the field period, tracks T _C2 and T _Y2 are formed separately and simultaneously by the second rotary head H _S2 and the fourth rotary head H _M2 via a wide guard band _G2 . Furthermore, during the next field period, the tracks T _Y3 and T _C3 are connected to the rotating heads H _M1 and H _S1.
separately and simultaneously through a wide guard band _G3 . Also, Truck T _Y2 and
No guard band is formed between T _Y3 and between T _C1 and T _C2 (or a very small guard band is formed).

In Fig. 4, the rotary heads H _M1 and H _S1 are connected to the track T _Y1 ,
When reaching the end of T _C1 , the rotating heads H _S2 and H _M2
This shows the situation when is located at the starting end of the next track T _C2 and T _Y2 .

Considering compatible playback on a home-use VTR using the current low frequency conversion color recording and playback method, the rotary heads H _M1 , H _M2 , H _S1 and H _S2 are installed, and the magnetic tape is rotated over 180 degrees. The diameter of the rotating body that is wound obliquely over the angular range must be the same as the diameter of the rotating body of the home VTR mentioned above, and the scanning track trajectory of the rotating head when the magnetic tape stops traveling must be the same. The angle with respect to the longitudinal direction of the tape (still tilt angle) must also be the same as that of the above-mentioned home VTR. Even if these conditions are satisfied, if you try to make the tape running speed faster than the tape running speed in the standard mode of the home VTR and record in H alignment in order to form the track pattern shown in FIG. If the recording time reaches a certain specific value, and if the recording time is set to a desired time, H-line recording will not be possible. However, even when the tape running speed is increased as described above, by selecting the distance c between the upper rotary head H _S1 or H _M2 and the lower rotary head H _M1 or H _S2 , it is possible to record the tape in H alignment. It is possible to do so.

For example, rotating heads mounted 180° opposite each other
A certain one of the tracks sequentially formed for each field by H _M1 and H _S2 or H _S1 and H _M2
The start of the track recorded in one field is from the start of the track recorded in the next field.
Track pattern when the distance c is selected as +0.5H when the track is located above the track width direction at the 2H (where H is the horizontal scanning period) eye (hereinafter referred to as "2H shifted pattern"). is as shown in Fig. 5, and two adjacent tracks on which the same information signal is recorded, that is, _T
and T _C2 or T _Y2 and T _Y3 horizontal synchronizing signal recording positions (indicated by solid lines in Figure ₅ ) can be recorded in an H arrangement in which they are aligned in the track width direction _. , Y ₁ and Y ₂ ) are signals having a time interval of 1 field+1.5H from each other.

On the other hand, when the above-mentioned pattern shifted by 2H is formed and the distance c is selected to be -0.5H, that is, the upper rotating heads H _S1 , H _M2
When the lower rotating heads H _M1 and H _S2 are moved forward in the rotational direction by 0.5 H, a track pattern as shown in Fig. 6 is formed, and two adjacent identical information signals are recorded. H-aligned recording is possible on a track, but the time interval between two adjacent signals Y ₁ and Y ₂ or C ₁ and C ₂ is 1 field + 2.5H, which is 1H time longer than in the case of the track pattern shown in Figure 5. The interval becomes large. In order to perform crosstalk cancellation using field correlation during playback, it is desirable that two adjacent signals be as close to one field as possible so that their signal contents are more similar, and therefore the value of c is -0.5H.
+0.5H is more desirable. That is, the lower rotating heads H _M1 and H _S2 are connected to the upper rotating head H _S1 .
It is more advantageous in terms of H alignment recording and crosstalk cancellation to install it at a position that precedes H and H _M2 in the rotational direction.

In addition, in the case where a pattern shifted by 2H is formed, the track pattern when the distance c is selected as +5.5H is as shown in FIG.
The two adjacent signals C ₁ and C ₂ , Y ₁ and Y ₂ of adjacent tracks become signals having a time interval of 1 field+3.5H from each other.

In each track pattern shown in FIGS. 5 to 7, the width of each track is 27 μm, the track pitch is 77 μm, and a guard band as small as 3 μm is formed between the same type of information signal recording tracks. , between different information signal recording tracks (e.g.
Guard bands as wide as 16 μm are formed between T _Y1 and T _C1 , T _C2 and T _Y2 , and T _Y3 and T _C9 ).

According to this embodiment, a wide guard band is provided between adjacent different information signal recording tracks, so that the wide guard band is provided between the rotating heads H _M1 and H _S1 or H _M2 and H _S2 having the same azimuth angle gap. Therefore, even if tracks are recorded simultaneously and separately, crosstalk from adjacent tracks hardly mixes into the reproduced signal. On the other hand, between adjacent information signal recording tracks of the same type, the guard band is very small or there is no guard band, but they are rotary heads H _M1 and H _M2 or H _S1 and
It is formed by H _S2 , and almost no crosstalk occurs due to the azimuth loss effect.
Crosstalk can be reduced by side-by-side recording, and since similar signals (luminance signals, color difference signals) with field correlation are recorded between adjacent tracks, crosstalk can be canceled using field correlation. From the above, crosstalk can be prevented from becoming a problem without using AST.

Note that when recording is performed based on the above-mentioned T/C separation recording method, the audio-only rotary heads H _A1 and H _A2 shown in FIG. 2 are not used.

Next, a case will be described in which recording is performed based on the low frequency conversion color recording method. Current household use
While running the magnetic tape at the same running speed as in standard mode or long-time mode on a VTR,
For the reasons mentioned above, the lower rotating heads H _M1 and H _S2
Recording is performed by In addition, rotating heads H _A1 and H _A2 are also used at this time.

In FIG. 1, when recording is performed based on the low frequency conversion color recording method, the switches SW ₁ , SW ₂ and SW ₃ are respectively connected to contact b as described above. At the same time, the recording amplifiers 21 and 35 are rendered inactive, respectively, and the rotary heads H _S1 and
Block the signal supply to H _M2 . Further, in this case, there are a standard mode and a long-time mode for recording, and one of them is selected depending on the user's intention.
In the standard mode, the magnetic tape 43 is used for current household use.
The vehicle is made to run at a predetermined running speed, such as a track pitch of 58 μm, which is the same as in the standard mode of a VTR, and in the long time mode, the track pitch is 19.3 μm, which is the same as in the long time mode of current home VTRs. Forced to drive at high speed.
Further, the third frequency division multiplexed signal taken out from the conventional recording circuit 36 is supplied to _{the rotary head H M1 through} the switch _SW3 ,
is supplied to the rotary head H _S2 through.

On the other hand, a fourth frequency division multiplexed signal consisting of the first FM audio signal and the second FM audio signal is taken out from the adder 41, and is sent to the rotary head H _A1 through the switch _SW1 and the recording amplifier 42, respectively. and H _A2
are supplied respectively.

FIG. 8A shows a track pattern in the standard mode. In Figure A, the magnetic tape 50 is run at a predetermined speed such that the track pitch is 58 μm. One field of the third frequency division multiplexed signal consisting of the frequency modulated luminance signal and the low frequency converted carrier chrominance signal occupying the vacant frequency region on the lower frequency side is first divided into widths by the rotating head H _S2 .
Recording begins on the 29 μm track (video track) T _S1 , and from the point when the rotating head H _S2 has rotated 75°,
Immediately before that, the rotary head H _A1 scans the audio track T _A1 with a width of 27 μm, on which the frequency modulated audio signal (fourth frequency division multiplexed signal) has already been recorded, and tracks it onto the audio track T _A1 .
T _S1 is formed and recorded. Here, in the audio track T _A1 , the fourth frequency division multiplexed signal is recorded from a relatively low frequency to a deep part of the magnetic layer, whereas the frequency modulated luminance signal is recorded at a high frequency. In addition, since the low frequency conversion carrier color signal is unsaturated recorded, it is recorded only on the surface layer of the magnetic layer. Therefore, both tracks
T _S1 and T _A1 can coexist at the same location on the tape.

Recording of the audio track T _A2 by the rotary head H _A2 starts from the time when the rotary head H _S2 rotates 105 degrees, and from the time the rotary head H _S2 rotates 180 degrees, the third frequency division multiplexed signal is recorded by the rotary head H _M1 . Recording for the next field starts. The rotating head H _M1 forms a track T _S2 with a width of 29 μm on the track T _A2 . Thereafter, frequency division multiplexed signal recording tracks and audio tracks are sequentially formed at a track pitch of 58 μm using the rotating heads H _M1 , H _S2 , H _A1 and H _A2 in the same manner as described above.

Next, in the long time mode, the only difference from the above standard mode is that the magnetic tape is run at a low speed with a track pitch of, for example, 19.3 μm, and switches SW ₁ to _{SW 3} in Fig. 1 are all in the standard mode. It is connected to contact b in the same way as before. In this long-time mode, a track pattern as shown in FIG. 8B is formed. In the figure B, after the third frequency division multiplexed signal is recorded on the magnetic tape 51 by the rotary head H _S2 forming a track T L1, the next track T _L1 is recorded by the rotary head H _M1 .
T _L2 is formed and recorded. Here, the rotating head
Although the width of H _S2 is 29 μm, the track pitch is 19.3 μm, so even if a track with a width of 29 μm is formed, the width on the upstream side of the tape is 9.7 μm (=29−
The portion 19.3) is erased by the next track T _L2 , and since T _L2 remains, frequency division multiplexed signal recording tracks with a width of 19.3 μm are sequentially formed without guard bands. Note that the track T _L1 has a width already formed in the deep layer of the magnetic layer by the rotating head H _A2 .
It is formed on the surface layer of the magnetic layer on the 19.3 μm audio track T _A10 , and the track T _L2 is already attached to the rotating head.
It is formed in the surface layer of the magnetic layer on the audio track T _A11 which is formed in the deep layer of the magnetic layer by H _A1 .

Next, a system for reproducing information signals on a magnetic tape recorded according to the present invention will be explained. FIG. 10 shows a block diagram of an example of this regeneration system. In the figure, changeover switches SW ₄ , SW ₅ and SW ₆ are connected to the contact a side when reproducing the Y/C separated recording track pattern (in the first reproduction mode), and on the other hand, they are connected to the contact a side when recording in the low frequency conversion color recording method. When the track pattern is reproduced (in the second reproduction mode), the contact b side is switched and connected. First, we will explain the reproduction operation of a magnetic tape having _a Y/C separated recording track pattern as shown in _FIG . The vehicle is run at the same predetermined high speed as during recording. In Fig. 10, in one field period, the rotating head
Reproduced FM obtained by scanning track T _Y1 with H _M1
The brightness signal is supplied to the switch 56 through the preamplifier ₅₃₁ and the switch _SW5 , and in the next one field period, the reproduced FM brightness signal obtained by scanning the track _TY2 with the rotary head H _M2 is supplied to the preamplifier 53.
₂ to the switch 56. Hereafter, in the same manner as above _{, 1}
FM luminance signals are alternately reproduced for each field.

Switch 56 has 5 preamps per field.
The reproduced FM luminance signals from 3 ₁ and 53 ₂ are alternately selected and outputted to the high-pass filter 60 and the first limiter 61.
is supplied to the second limiter and FM demodulator 62 through. Note that the high-pass filter 60 may be omitted. The broadband reproduced luminance signal extracted from the second limiter and FM demodulator 62 is supplied to a matrix circuit 66, which will be described later, through a low-pass filter 63, a de-emphasis circuit 64, and a noise canceller 65, respectively.

Further, the second frequency division multiplexed signals alternately taken out for each field from the rotary heads H _S1 and H _S2 are supplied to preamplifiers 54 ₁ and 54 2 through rotary transformers (not shown), and further from there to preamplifiers 54 1 and 54 ₂ . 54 ₂ output signal is switch SW ₆
switch 57 that changes every field through
Here, the signal is alternately switched with the output signal of the preamplifier 54 ₁ every field, and then supplied to a high-pass filter 67 and a low-pass filter 68, respectively. The reproduced first FM color difference signal separated by the high-pass filter 67 is transmitted to the first limiter 69 and the second FM color difference signal.
It is demodulated into a reproduced color difference signal R-Y through a limiter and an FM demodulator 70, from which a carrier is removed by a low-pass filter 71, and a de-emphasis circuit 72 imparts high-frequency attenuation characteristics complementary to the pre-emphasis circuit 26. The signal undergoes noise reduction processing using H correlation in the post-noise canceller circuit 73 and is supplied to the matrix circuit 66 .

On the other hand, the reproduced second FM color difference signal separated by the low-pass filter 68 is sent to the carrier shifter 7 after having level fluctuations removed by the first limiter 74.
5, where it is frequency-converted (carrier shifted) to a higher frequency band so that the band does not overlap with the demodulated signal, and then supplied to the second limiter and FM demodulator 76, where it is demodulated into the original reproduced color difference signal B-Y. be done. This reproduced color difference signal is supplied to the matrix circuit 66 through a low-pass filter 77, a de-emphasis circuit 78, and a noise canceller 79, respectively. The matrix circuit 66 matrixes the reproduced luminance signal and two types of reproduced color difference signals R-Y and B-Y to produce red (R),
Output terminal 8 for each primary color signal of green (G) and blue (B)
0, 81 and 82, as well as output terminal 8.
A composite synchronization signal is output to 3. Note that the difference in recording time between the luminance signal and the color difference signal is allowed within the vertical blanking period, so by considering the switching point within this period during playback, the recording time difference between the brightness signal and the color difference signal can be adjusted. Simultaneous operation can be achieved.

Next, when _reproducing the magnetic tape 50 having the track pattern shown in _FIG . Since SW ₆ is switched and connected to contact b, the reproduced signals obtained by scanning the tracks T _S1 , T _S2, etc. with the lower rotary heads H _M1 and H _S2 are sent to the preamplifiers 53 ₁ and 5.
_The conventional reproducing _{circuit 8}
4. This conventional reproduction circuit 84 is a circuit that is supplied with a third frequency division multiplexed signal consisting of an FM luminance signal and a low frequency conversion carrier color signal, and converts this into the original reproduced color video signal by conventionally well-known means. Yes, the reproduced color video signal is output to the output terminal 85.

On the other hand, the rotating heads H _A1 and H _A2 alternately move the tracks T A1 and T _A1 shown in FIG. 8A every field.
The fourth frequency division multiplexed signal reproduced from T _A2 etc. is passed through a rotary transformer (not shown), preamplifiers 55 ₁ , 55 ₂ , switches 59 and switches SW ₄ which are switched every field, and band filters 86 _L and 86 . are supplied to _R respectively. The first FM audio signal taken out from the band filter 86 _L and the second FM audio signal taken out from the band filter 86 _R are separately supplied to FM demodulation circuits 87 _L and 87 _R , where they are FM demodulated. , through the low-pass filter de-emphasis circuits 88 _L and 88 _R to the output terminal 89 _L as a reproduced audio signal of the left channel.
Also, it is outputted to the output terminal _89R as a playback audio signal of the right channel. In this way, standard mode reproduction is performed.

Next, when reproducing the magnetic tape 51 having the track pattern shown in FIG. 8B, the magnetic tape 51 is run at the same low speed as during recording, and the switches SW ₄ , SW ₅ and
Since SW ₆ is switched to contact b, the same lower rotary heads H _M1 and
Reproduction signals obtained by alternately scanning tracks T _L1 , T _L2 , etc. with H _S2 are supplied to the conventional reproduction circuit 84 through preamplifiers 53 ₁ , 54 ₂ , switches SW ₅ , SW ₆ and switch 58, respectively. After undergoing the above-described reproduction processing, the signal is returned to a reproduced color video signal and output to the output terminal 85. In addition, rotating head H _A1 and
The fourth frequency division multiplexed signal is reproduced by H _A2 , separated and demodulated in the same manner as in standard mode reproduction, and reproduced audio signals are taken out to output terminals 89 _L and 89 _R.

Incidentally, a magnetic tape recorded in the above-mentioned standard mode or long-time mode according to the present invention or a magnetic tape recorded on a current home VTR can be recorded using the rotary head having the head configuration according to the present invention shown in FIG. In that case, during still motion playback or high-speed search, rotating heads H _S1 and H _M1 or H _M2 and H _S2 are
The scanning trajectory H ₁ , H ₂ → H ₁ ′, H ₂ ′ → H ₁ ″, H ₂ ″ is drawn in the figure, and two adjacent tracks are scanned, so the playback output level of the two rotating heads is It is possible to switch to select the reproduction signal of the rotary head with the larger value, thereby obtaining a reproduction signal with less noise. in this case,
If the distance between the two rotating heads (c) is not a multiple of H, blurring of the image during special playback can be prevented by delaying one of the playback signals.

Note that the present invention is not limited to the above-mentioned embodiments; for example, the first and second information signals recorded in the track pattern shown in FIG. 4 are one of the luminance signals and the other two types of color difference signals. However, one is a luminance signal and the other is a frequency division multiplexed signal consisting of signals obtained by separately frequency modulating two types of color difference signals and an audio signal, and one is a brightness signal and the other is two types of color difference signals. PCM or 4-phase DPSK modulation or 4-phase PSK to the signal obtained by frequency modulating the
A signal obtained by frequency division multiplexing the modulated audio signal, one is a composite color video signal, the other is an audio signal, one is a luminance signal, and the other is a frequency-modulated time-axis compressed line sequential color difference signal and an audio signal modulated. Any of various combinations such as frequency division multiplexed signals may be used. Also, the rotating heads H _M1 , H _M2 , H _S1
and H _S2 may be replaced together. Furthermore, it goes without saying that the track width of each rotary head is not limited to that of the embodiment.

Effects of the Invention As described above, according to the present invention, the first and third rotary heads and the second and fourth rotary heads are used alternately every one track scanning period.
The first step is to sequentially form two parallel tracks on a magnetic tape on which information signals are recorded separately.
The third recording mode is such that two rotary heads of the first to fourth rotary heads described above, which are attached to opposite positions on the rotating surface of the rotary body, are used alternately every track scanning period. A second recording mode in which tracks on which information signals of The first and second rotating heads on the lower side are used when the tracks are in the same direction, and the third and fourth rotating heads on the upper side are used when the tracks are in the opposite direction. Part of the track is not erased in the next one track scanning period, and unnecessary tracks formed by leakage magnetic flux from the rotating head that is not originally used before one track scanning period can be erased in the next one track scanning period. It has the advantage of being able to be erased when a track is formed during the scanning period.

[Brief explanation of the drawing]

FIG. 1 is a block system diagram showing an embodiment of a recording apparatus that implements the method of the present invention, FIG. 2 is a diagram showing an embodiment of the arrangement of rotating heads, etc. in the method of the present invention, and FIGS. 3A and B 4 to 7 are diagrams each showing an example of a track pattern recorded and formed according to the present invention. FIGS. FIG. 9 is a diagram showing an example of each head scanning trajectory in the standard mode according to the present invention, and FIG. 10 is a diagram showing the track patterns recorded by the present invention in the standard mode and the long time mode. A block system diagram showing an example of a reproducing apparatus for reproducing a magnetic tape having a track pattern, FIG. 11 is a diagram showing an example of a head scanning trajectory during special playback, and FIGS. 12 and 13 each show a track pattern using a conventional recording method. FIG. 14 is a diagram illustrating the arrangement of rotating heads forming the track pattern shown in FIG. 13. 15...Composite color video signal input terminal, 16...
...Decoder, 20, 30, 31, 39 _L , 39 _R ...
...FM modulator, 34, 41...adder, 36...
Conventional recording circuit, 37 _L , 37 _R ... Audio signal input terminal, 43, 50, 51... Magnetic tape, H _M1 ...
First rotating head, H _S2 ...Second rotating head,
H _S1 ...Third rotary head, H _M2 ...Fourth rotary head, H _A1 , H _A2 ... Audio-only rotary head,
SW ₁ to SW ₆ ...Switchover switch, T _Y1 to T _Y3 ...Luminance signal recording track, T _C1 to T _C3 ...Color difference signal recording track, T _S1 , T _S2 , T _L1 , T _L2 ... Video track, T _A1 , T _A2 , T _A10 , T _A11 ... audio track, T ₁ to _{T 4} ... scanning trajectory.

Claims (1)

[Claims] 1 first and second rotating heads having gaps of mutually different azimuth angles, which are mounted at opposing positions on the rotating surface of the rotating body; ,
The first and second rotary heads are respectively close to the mounting positions in the rotational direction of the rotary body,
and third and fourth rotating heads each having a gap with a mutually different azimuth angle, each of which is mounted at an upper height position in the direction of the rotational axis of the rotating body, and the first and third rotating heads. The second and fourth rotary heads are used alternately every track scanning period to sequentially record two parallel tracks on the magnetic tape, on which the first and second information signals are recorded separately. A first recording mode in which the information is formed in the first recording manner, and a third information is recorded by alternately using two rotary heads installed at opposite positions among the first to fourth rotary heads for each track scanning period. A magnetic recording method that selectively performs a second recording mode in which tracks on which signals are recorded are sequentially formed one by one on a magnetic tape, and in the second recording mode, the running direction of the magnetic tape is set in the second recording mode. When the direction is approximately the same as the scanning direction of the first to fourth rotary heads, the third information signal is recorded by forming a track inclined with respect to the longitudinal direction of the tape by the lower first and second rotary heads. However, when the magnetic tape running direction is approximately opposite to the head scanning direction, the upper third and fourth magnetic tapes are
A magnetic recording method characterized in that the third information signal is recorded by forming a track inclined with respect to the longitudinal direction of the tape using a rotating head.