JPS62250539A - Tracking control system for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain stable tracking control by detecting an index signal on a recording medium at the reproduction, deciding the detection timing of a pilot signal based on the point of time of detection, detecting the pilot signal in the timing so as to apply the tracking control based on the result of detection. CONSTITUTION:The titled system consists of a phase adjusting circuit 8, a pulse generating circuit 9, delay multivibrator circuits 10-12, a latch circuit 13, a disk servo circuit 14, a biphase split circuit 15, a pilot signal selection circuit 16, a pilot signal generating circuit 17, a capstan servo circuit 18, a capstan motor 19 and a recording processing circuit 20. Any of plural heads constituting a multi-head detects first the index signal on a recording medium, the detection timing of the pilot signal is decided based on the point of time of detection, the pilot signal is detected by the 1st head in the timing and the tracking control is applied by the result of detection.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a tracking control method for a magnetic recording/reproducing device, and in particular, the present invention relates to a tracking control method for a magnetic recording/reproducing device, and in particular, to track a plurality of magnetic tapes on which main signals such as digitized video signals are recorded at high density. The present invention relates to a tracking control method that can be suitably used when reproducing and scanning a plurality of tracks at the same time using a multi-head that integrally holds two magnetic heads in parallel.

[Conventional technology]

Conventionally, in magnetic recording and reproducing devices (hereinafter referred to as VTRs) for home use in particular, two rotating heads with different azimuth angles are alternately scanned obliquely to the longitudinal direction of the magnetic tape, without providing a guard band. A so-called rotating head helical scan azimuth recording method is used to record video signals. It is necessary to perform tracking control so that the rotary head correctly scans the azimuthally recorded tracks on the magnetic tape during reproduction.

As one of the tracking control methods, JP-A-53-
As described in Publication No. 116120, n pieces (n
≧4) Biloft signals of different frequencies are superimposed with the video signal and recorded cyclically for each trunk, and this pilot signal is reproduced at the time of playback, and the scanning of the rotating head is determined from the reproduced pilot signal. There is a method in which the level difference between pilot signals recorded on adjacent tracks located on both sides of the main track to be recorded is detected, and the relative position of the magnetic tape and the rotation throat is controlled so that this level difference becomes zero.

Such a tracking control method will be briefly explained with reference to FIG.

FIG. 9 is an explanatory diagram showing a track pattern formed by sequentially recording four types of pilot signals, each having a frequency of -rl-f4, on each track on the magnetic tape 1.

The frequency fl””fa of these four-frequency pilot signals is
Select so that the following formula holds.

l fl -fA, l = l ft - r, l =
fAl fi hl=l f:+ fi l
-fm ≠fA Then, during playback, using local pilot signals of the same frequency as the pilot signal recorded on the main track to be scanned by the rotary heads 2 and 3, pilots detected from both adjacent tracks of the main track are used. By converting the frequency of the signal to the difference frequency fA, f from the biloft signal of the main track, the playback level difference of the signal with the frequency components fA, f is always maintained when scanning any track. , is made to represent the difference in reproduction level of pilot signals from both adjacent troughs.

Tracking control is then performed by controlling this playback level difference to zero.

Compared to other conventional methods that use control signals recorded with a fixed head in the longitudinal direction of a magnetic tape, the conventional tracking control method using pilot signals described above achieves more automated tracking control than other conventional methods that use control signals recorded with a fixed head in the longitudinal direction of the magnetic tape. This has the advantage of eliminating the need for troublesome adjustments such as making tracking adjustments by looking at images.

By the way, in recent years, helical scan type VTRs
In , there is a method in which recording signals of multiple channels are simultaneously recorded and played back in parallel on multiple tracks on a magnetic tape by rotating and scanning a multi-head that holds multiple magnetic heads integrated in parallel. It has come to be proposed.

An example of a magnetic recording and reproducing apparatus that employs such a recording and reproducing method is a VTR for recording and reproducing high-definition video signals or digital video signals.

In this VTR, since the recorded video signal has a very wide band, it is divided into video signals of multiple channels to lower the bandwidth per channel, and these are recorded simultaneously in parallel on individual helical scan recording tracks. is being carried out.

[Problem that the invention seeks to solve]

The tracking control method according to the conventional technology described above is based on the premise that tracking control is performed by detecting the amount and direction of tracking deviation for each recording track. It is difficult to apply this method to tracking control of a VTR (hereinafter sometimes referred to as a VTR with a multi-head), which records and reproduces signals of multiple channels simultaneously on multiple tracks in parallel. Even if it could be applied,
In the conventional tracking control method described above, the biloft signal is frequency-multiplexed and recorded on the video signal to be recorded, so there is an inherent problem that the pilot signal mixes with the video signal and generates spurious. There is a problem in that it becomes difficult to perform stable tracking control.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to enable a sufficient S/N ratio of a pilot signal used for tracking control even in a multi-channel magnetic recording and reproducing apparatus that is equipped with a multi-head and performs recording and reproducing. It is an object of the present invention to provide a tracking control method that can perform stable tracking control.

[Means for solving problems]

In order to achieve the above object, the present invention records signals of multiple channels simultaneously over multiple adjacent tracks on a magnetic recording medium by integrating and holding multiple magnetic heads in parallel. Alternatively, in a tracking control method of a helical scan type magnetic recording and reproducing device equipped with a multi-head configured to perform reproduction, the main signal of a certain first trunk among the plurality of mutually adjacent tracks is controlled during recording. A certain first of the plurality of heads constituting the multi-head is placed in a non-recording area.
record an index signal having a certain frequency using the heads of the first head, and use each head located on both sides of the first head to record an index signal having a certain frequency in the trunk on both sides of the index signal, where the main signal is not recorded. A pilot signal having a frequency different from that of the index signal is recorded at a position temporally delayed from the index signal recording position.

[Effect]

During reproduction, the index signal on the recording medium is first detected by one of the plurality of heads constituting the multi-head, and the detection timing of the biloft signal is determined based on the detection time point, and at this timing, the first The pilot signal is detected by the head, and tracking control is performed based on the detection result.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In the figure, 1 is a magnetic tape, 2 and 3 are multi heads, respectively. However, multi head 2 is a head (2-1),
It consists of three heads (2-2) and (2-3), and similarly, Multi-Herad 3 has a head (3-1).
It consists of three heads: , (3-2), and (3-3).

In addition, 4 is a disk, 5 is a magnet, 6 is a tack head, 7 is a disk motor, 8 is a phase adjustment circuit, 9 is a pulse forming circuit, 10 to 12 are delay multi circuits (one shot multi), and 13 is a latch circuit. , 14 is a disk servo circuit, 15 is a two-phase splitting circuit, 16 is a biloft signal selection circuit, 17 is a pilot signal generation circuit, 1
8 is a capstan servo circuit, 19 is a capstan motor, and 20 is a recording processing circuit.

FIG. 2 is a signal waveform diagram of each part for explaining the operation of the embodiment shown in FIG. 1, and corresponding parts and signal waveforms are given the same reference numerals.

FIG. 3 is an explanatory diagram showing a pattern on a track to be recorded for tracking control on the magnetic tape 1 in the embodiment shown in FIG.

The operation will be explained below with reference to FIGS. 1 to 3. The magnetic tape 1 is driven and run by a capstan motor 19, and the rotation of the capstan motor 19 is controlled at a constant speed by a capstan servo circuit 18.

As described above, the rotating multi-head 2.3 includes three heads (2-1) each having a stack structure;
(2-2), (2-3) and (3-1).

(3-2) and (3-3), which are attached to the disk 4 at an angle of 180 degrees to each other, and are rotated together with the disk 4 by a disk motor 7. The tape 1 is wound around the disk 4 in a slightly less than 180 degree range, so that on the track there are overlapping areas Q+, Q2 at both ends of the 180 degree range V, as seen in FIG. It is formed.

A magnet 5 is attached to the disk 4, which is detected by the tack head 6 and pulse A (A in Fig. 2) synchronized with the rotation of the multi-hendos 2 and 3 is applied to the tack nozzle 6.
Get more. The pulse A from the tank head 6 is outputted after the phase adjustment circuit 8 adjusts the phase of the multihead 2.3 and the magnetic tape 1 to a predetermined relative positional relationship.
(B in FIG. 2) is supplied to the pulse forming circuit 9. From this pulse forming circuit 9, a pulse C (C in Fig. 2) with a duty ratio of 50% is synchronized with the rotation of the multi-heads 2 and 3.
is output.

As mentioned earlier, 10 is a delay multi circuit (one shot multi), which is triggered by both the rising and falling edges of the pulse C from the pulse forming circuit 9, and records and is formed by the multi head 2.3. A pulse D (D in FIG. 2) with a width of time τ corresponding to the misalignment between adjacent multi-trunks in the QI and Qz regions (NB in FIG. 3) of the multitrack (QI in FIG. 3) ) is the delay multi-circuit 1
Output from 0.

Then, in the delay multi-circuit 11, the delay multi-circuit 0
A pulse E (E in FIG. 2) having a width of time τ is triggered by the falling edge of the pulse D from the delay multicircuit 12 and is similarly triggered by the falling edge of the pulse E from the delay multicircuit 11. for a predetermined time τ. A pulse F (F in FIG. 2) having a width of is output. 13 is a latch circuit in which the pulse C from the pulse forming circuit 9 is latched at the falling edge of the pulse F from the delay multi-circuit 12, so that the pulse C from the pulse forming circuit 9 is delayed by the time (τ+τ+τ.). A pulse G (G in FIG. 2) is output from the latch circuit 13.

The pulse G from the latch circuit 13 is supplied to one side of the disk servo circuit 14, and the vertical synchronization signal of the frame period of the video signal to be recorded is supplied to the other side via the terminal 100 as a reference signal for the disk servo system during recording. will be supplied.

This disk servo circuit 14 receives the pulse G from the launch circuit 13 and the reference signal (vertical synchronization signal) from the terminal 100.
are compared in phase, and a phase error signal corresponding to the phase difference between the two is output from the disk servo circuit 14 and supplied to the disk motor 7. As a result, the pulse G is servo-controlled to be phase-synchronized with the reference signal, and the multi-head 2.3 is rotated at a rotation speed equal to the frame frequency.

15 is a two-phase dividing circuit, in which the pulse E from the delay multi-circuit 11 is divided into two phases by the pulse C from the pulse forming circuit 9.
The phase is divided, and during the period when pulse C is “Low”, pulse E
l (El in Figure 2) and pulse E2 (E2 in Figure 2) are
During the period when the pulse C is "High", the pulse E1' (second
El' in the figure) and pulse E2'(E2' in Figure 2) are alternately output.

Reference numeral 17 denotes a pilot signal generation circuit, which generates a pilot signal with a frequency of f0 (hereinafter referred to as an index signal), a first pilot signal with a frequency of f, and a second pilot signal with a frequency of f2. Ru.

16 is a pilot signal selection circuit, and a head (2-2) which constitutes the multi-head 2.3 for a period of pulse width τ by the pulse D from the delay multi-circuit 10;
(3-2) A signal with frequency r0 is selected as the index signal supplied to
The first pyroft signal f1 supplied to the head (2-1) constituting a
The second pilot signal ft supplied to the head (2-3) constituting the multi-head 3 is selected, and the pulse El' from the two-phase splitting circuit 15 causes the head (3-3) constituting the multi-head 3 to be activated for a period of pulse width τ. 3) The first pilot Hg is supplied to f.

is selected, and the second pilot signal f2, which is supplied to the head (3-1) constituting the multi-node 3, is selected by the pulse E2' from the two-phase dividing circuit 15 for a period of that pulse width.

The pilot signals f, , f and index signal f0 supplied to each of the three heads constituting the multi-head from the pilot signal selection circuit 16 are sent to the rotating multi-head together with the video signal via the recording processing circuit 20. Heads (2-1) and (2-2) constituting parts 2 and 3
), (2-3).

(3-1), (3-2), and (3-3) are recorded respectively.

That is, during the period in which the pulse C is "Low", which is the scanning period of the rotating multi-head 2, the index signal f0 is supplied to the head (2-1) following recording of the index signal f0 supplied to the head (2-2). The first pilot signal f and the second pilot signal f2 supplied to the head (2-3) are simultaneously recorded by each head, and during the period when the pulse C, which is the scanning period of the rotating multi-head 3, is "High", , following the recording of the index signal f0 supplied to the head (3-2), the second pilot signal f3 supplied to the head (3-1) and the first pilot signal supplied to the head (3-3). f, and are simultaneously recorded by each head.

As mentioned above, FIG. 3 is a diagram showing the track pattern recorded and formed on the magnetic tape as described above. In the same figure, as mentioned earlier, (L, Ch
indicates an overlap region formed by winding the tape 1 around the disk 4 in a 180 degree range, and the index signal and the pyroft signal indicate the overlap region Q.

The information is recorded in the portion indicated by P as shown in the figure.

Further, as mentioned earlier, V is the recording part of the video signal formed by 180 degree winding, and the overlap area Q other than these 7 parts, and Q! A video signal is also recorded in the area, and therefore, in this case, the pilot signal is frequency-multiplexed and recorded with the video signal in the P portion, but since the video signal in this overlap area is deleted during playback, the index signal and Even if the level of the pilot signal is increased, the reproduced video signal will not deteriorate. Therefore, it is possible to separate the recording area of the pilot signal and the recording area of a certain main signal from the video signal, etc., which is considered as one of the requirements of the present invention. This is in line with the idea of separation.

It goes without saying that in order to completely separate the two, it is sufficient to temporarily stop recording the video signal in the P and M regions.

In this Fig. 3, there are three tracks (A1°B1.A
2, etc.) at the end of the multitrack (NB in the same figure)
is determined depending on the running speed of the tape 1 and the rotational speed of the rotating multi-head 2.3, and is given by τ, which is the amount of time the rotating multi-head scans.

On the other hand, as already explained, in FIG. 3, the index signal f0 is transmitted to the track (Al-2) by the heads (2-2) and (3-2) for a time τ corresponding to the above alignment deviation amount NB. ) and (B1-2), and the first pilot signal fl and second pilot signal f2 are recorded on the head (2-1).

(2-3), (3-3), and (3-1), following the index signal f0, the misaligned fiNB
Trunk (A1-1), (
Al-3), (Bl-3), and (Bl-1).

Therefore, as shown in FIG. 3, in the case of the same multi-trunk 2, the recording end point on the track of the index signal f0 coincides with the recording start point of the first pilot signal f2 and the second pilot signal f2, and If it is the adjacent multi-track 3 that follows it, it will be the same as the recording start point of the index signal f0 within 3.

In addition, the first pilot signal f3, the second pilot signal f
The recording end point of No. 2 is the recording end point of the index signal f0 in the subsequent adjacent multi-track, the recording start point of the first pilot signal f1, the second pilot signal f2,
and the index signal f in the subsequent adjacent track. coincide with the recording start point of each.

FIG. 4 shows a circuit for detecting tracking errors from the track pattern shown in FIG. 3 (main part of an embodiment of the present invention).
FIG. In Figure 4, 21 to 25
are tank circuits, 26 to 30 are envelope detection circuits, 31 to 33 are pulse shaping circuits, 34 is a differential amplifier, 36 is an OR circuit, 37 is a delay multi-circuit,
38 is a sample and hold circuit.

FIG. 5 is a waveform diagram of signals of each part in FIG. 4, and corresponding parts and signal waveforms are given the same reference numerals.

Although the servo system required during playback is not shown in FIG. 4, most of it can be used in common with the recording servo control system shown in FIG. 1, and during playback, the circuit 15 in FIG. .16.17 is unnecessary, terminal 100
A predetermined reference signal of a frame frequency is inputted to the frame frequency instead of a vertical synchronization signal of a frame period.
The difference is that the tracking error signal from the tracking error detection circuit shown in the figure is supplied to the capstan motor 9 via the capstan servo circuit 18, but everything else is the same. Therefore, the circuit operation of FIG. 4 will be explained using FIG. 1 in part.

In FIG. 1, since a frame frequency reference signal is input to the terminal 100 during playback, the pulse G from the latch circuit 13 is servo-controlled to be phase-synchronized with the reference signal as described above, and the multi-head 2 .3 is rotated at a rotation speed equal to the same frame frequency as during recording.

After the signals alternately reproduced from the tape 1 by the multi-heads 2.3 are sufficiently amplified, the signals output from each head are sent to the terminals 50. 60. The signal is supplied to the tracking error detection circuit via 70.

That is, the output signal from the head (2-1) or (3-1) is transmitted via the terminal 50 to the resonant frequency f of the index signal.
0 to the tank circuit 21, which also has the head (
The output signal from 2-3) or (3-3) is connected to the resonant frequency f via the terminal 70.

is input to the tank circuit 23 having a head (2-
The output signal from 2) or (3-2) is input to the tank circuit 22 having the resonant frequency f0 via the terminal 60, and is also input to the tank circuit 24 having the resonant frequency f1 of the first pilot signal and the second pilot signal. is input to the tank circuit 25 having a resonant frequency f2 of .

In FIG. 3, when the head scans the same track as it recorded without any tracking deviation, for example, when the multi-head 2 scans track A1 (the signal waveform diagram of each part in FIG. 4 at this time is Figure 5 (
i)), in the pilot signal recording area P,
First, the index signal f0 is reproduced from the track (AI-2) by the head (2-2), sufficiently band-limited and amplified by the tank circuit 22, then detected by the envelope detection circuit 27, and the signal H2 (the first H2) in FIG. 5(i) is output, and the pulse is further shaped by a predetermined threshold value in the pulse shaping circuit 32.

Therefore, from the OR circuit 36, a pulse (I in FIG. 5(i)) whose width in time is determined only by the detection output H2 of the index signal is obtained. The pulse I from the OR circuit 36 is supplied to the delay multi-circuit 37, which is triggered by the falling edge of the pulse (2), and the pulse J (FIG. 5(i) J) is output.

These pulses I and J change over time by setting the above-mentioned predetermined threshold value to 1/2 of the detection output of the index signal at the time of just tracking, regardless of whether the center of gravity of scanning shifts upward or downward. Never.

In other words, when the center of gravity of the scanning of the multi-head 2 shifts upward (the waveform diagram of each part in Figure 4 at this time is shown in (ii) in Figure 5).
) is the detection output of the 4-index signal f0 by the head (2-2) or (2-3), that is, the output H1, H2 from the envelope detection circuit 27.28 (shown in FIG. 5(ii)).
either Hl or H2) becomes a level above a predetermined threshold.

Also, if the center of gravity of scanning of multi-head 2 shifts downward (
The waveform diagram of each part of FIG. 4 at this time is shown in FIG. 5 (iii)). Outputs H2, H3 from (Fig. 5 (iii)
), either H2 or H3) is at a level above a predetermined threshold.

Therefore, in any case, the pulse shaping circuit 31.3
The pulse is shaped by one of the circuits in 2.33 and is generated by the detection output of the index signal f0! (Figure 5 (i
), (ii), (iii)) and pulse J (Fig. 5(i), (ii), (iii)
) to obtain J).

On the other hand, the output signal P1 (PI in FIG. 5(i)) from the envelope detection circuit 29 is output from the trunk (A) by the head (2-2).
It is a crosstalk component of the first pyro-node signal f from I-1), and is the output signal P2 from the envelope line detection circuit 30.
(P2 in FIG. 5(i)) is the crosstalk component of the second pilot signal f from the track (Al-3) by the head (2-2), and its detection level difference corresponds to the tracking error. There is.

That is, when the center of gravity of scanning of the multi-head 2 shifts upward, the detection level P1 of the first pilot signal f increases as shown in Pl and P2 in FIG. When the detection level P2 decreases and the center of gravity of scanning similarly shifts downward (see Figure 5 (iii)
), the above relationship is completely reversed as shown in PI and P2.

Also, when the multi-head 3 scans the track B1 (
The waveform diagram of each part of FIG. 4 at this time is shown in (i)' of FIG. 5). is f2, and the frequency of the crosstalk component from the lower trunk (Bl-3), which is also detected by the head (3-2), is fl. The frequency relationship of the crosstalk components obtained from is the opposite relationship.

Therefore, if the center of gravity of the scanning of the multi-head 3 shifts upward (in this case, the waveform diagram of each part in FIG. 4 is shown in FIG.
)'), the detection level P2 of the second pilot signal f2 increases and the detection level P2 of the first pilot signal f increases.
1 decreases and the center of gravity of the scan similarly shifts downward (the waveform diagram of each part of Figure 4 at this time is shown in Figure 5 (iii)'), the above increase/decrease relationship becomes completely opposite. .

Regarding the index signal f0, FIG. 5(i)
, (ii), (iii) and (i)',
(ij'!'.

(iii)'1. Multi head 2 as shown in J
is exactly the same as when scanning the track AI, so
In either case, when the center of gravity of scanning shifts upward or downward, the pulse is shaped by one of the pulse shaping circuits 31, 32, or 33, and the index signal "." is detected at the same timing as when just tracking. Obtain pulse I and pulse J by output.

The first pyroft signal f from the envelope detection circuit 29 described above
The crosstalk component P1 of , and the crosstalk component P2 of the second pilot signal f2 from the envelope detection circuit 30 are as follows.
It is input to the differential amplifier 34, and a difference voltage signal T, lower between the two is obtained.

At this time, when the scanning track is A1 and when the scanning track is 81, the increase/decrease relationship of the crosstalk component with respect to the direction of tracking deviation is reversed as described above.

Therefore, the differential amplifier 34 generates two differential voltage signals with different polarities, K (P, -Pz) = T, K (Pt - pυ・lower (
K: constant) is outputted, and this differential output signal T is supplied to the switch circuit 35, and the pulse C from the pulse forming circuit 9 of FIG. 1 inputted via the terminal 80 (FIG. For example, during the period when the pulse C is "LOW", that is, during the scanning period of the multi-head 2, the pulse C is
The switch circuit 35 is switched so as to output the low signal during the period when the signal is "High", that is, during the scanning period of the multi-channel node 3, and the output signal is supplied to the sample and hold circuit 38.

At the same time, the pulse J from the delay multi-circuit 37 is formed so that its pulse width is τ or less, and is supplied as a sampling pulse to the sample-and-hold circuit 38, and from the sample-and-hold circuit 38, the tracking error is A tracking error signal based on this is output, and the output thereof is supplied to the capstan servo circuit 18 of FIG. 1 via the terminal 90, and the capstan motor 19 is controlled by negative feedback.

Through the above tracking control, the video signals alternately reproduced by the multi-heads 2 and 3 from the video signal recording area (■) in FIG. The signals are alternately switched, the reproduction processing is performed, and a reproduced video signal is output, and the reproduced pilot signal is not mixed into the reproduced video signal.

As is clear from the above, the pilot signal recorded in the overlap area Q1 in FIG. A reproduced pilot signal can be obtained and stable tracking control can be performed.

Furthermore, in the present invention, the main signal to be recorded is not limited to only a video signal, but any other arbitrary signal such as a PCM signal obtained by digitizing a video signal or an audio signal can be recorded as the main signal. It can also be applied when

In addition, in Figure 1, the wrapping angle of the tape 1 to the disk 4 is 1
Although the case where the angle is 80 degrees is shown, the present invention is not limited to this.
In general, it can be applied to devices configured with arbitrary wrap angles, and the recording position of the pilot signal is not limited to the overlap area; for example, in a device that does not generate an overlamp area, The present invention can also be applied to a case where a main signal recording area and a pilot signal recording area are separated along the longitudinal direction and recording is performed there in a time-division manner.

Furthermore, in the above embodiment, the index signal f0 and the first
The pilot signal f1 and the second pilot signal f2 are both recorded for a time τ corresponding to the misalignment amount NB between adjacent multi-tracks at the end of the multi-trunk, but both biloft signals f, , f! There is no need to particularly limit the recording time of the pyroft signal as long as there is a period for simultaneously detecting .
3/2) It is clear that this embodiment can be applied even in the case of .

Further, in the above embodiment, the frequency fo of the index signal
and the frequencies f, , f of both pilot signals.

Although we have shown a case in which the values are different, it is clear that the present embodiment also holds true even when the pilot signal frequency f or f2 is used as the index signal.

Further, in the above embodiment, a case has been described in which two different frequencies, f and f2, are used as the first and second pilot signals, but the present invention is not limited to this, and FIG. It is clear that the present invention can be applied even if certain first and second pilot signals f are recorded from the same frequency at positions with different detection timings, as shown in FIG. In other words, although the crosstalk components from both the upper and lower sides have the same frequency f, they can be distinguished depending on the detection timing, so the difference can be taken, and tracking errors can be detected. be.

Further, in the above embodiments, a case has been described in which a rotating multi-head consisting of three heads is used, but the present invention is not limited to this, and as shown in FIG. When a head is used and Fig. 8 (i
), (ii), and (iii), the present invention is also applicable to the case where a multihead with a two-head configuration is used, and is generally applicable to the case where a multihead with an arbitrary number of heads is used. It is possible.

In FIG. 8(i), focusing on the head (2-2), the head first detects the index signal f0 and then detects the crosstalk component of f2 from the upper track at the next timing. Then, at the next timing, the same f2 crosstalk component from the upper track and the f2 crosstalk component from the lower track can be detected, so by taking the difference between them, the tracking error signal can be obtained. can be obtained.

The same applies to FIGS. 8(ii) and (iii).

〔Effect of the invention〕

As described above, according to the present invention, in a magnetic recording/reproducing device using a multi-head, pilot signals used for tracking control can be detected without malfunction, and tracking error information can be detected with a good S/N ratio. Therefore, effects such as stable and reliable tracking can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a signal waveform diagram of each part for explaining the operation of the embodiment shown in FIG. 1, and FIG. 4 is a block diagram showing a circuit for detecting a tracking error signal from the track pattern shown in FIG. 3. FIG. 5 is an explanatory diagram showing a pattern on a track to be recorded for tracking control. FIG. 4 is an operational waveform diagram of each part signal in the circuit, FIGS. 6, 7, and 8 are trunk pattern diagrams for explaining other embodiments of the present invention, and FIG. 9 is a conventional tracking pattern diagram. FIG. 3 is a track pattern diagram for explaining a control method. Explanation of symbols 9...Pulse forming circuit, 10.11.12...Delay multi circuit, 13...Latch circuit, 15...2 phase division circuit, 16...Biloft signal selection circuit, 17.・
- Biloft signal generation circuit, 34... differential amplifier, 3
5...Switch circuit. Agent Patent Attorney Akira Namiki Husband 2! ! ! E2'°" (1) ' CI+) (m) Evening 6111I Building 7 W 18 Figure (Ill)

Claims (1)

[Claims] 1. By integrating and holding a plurality of magnetic heads in parallel, signals of a plurality of channels can be transmitted on a magnetic recording medium.
In a tracking control method of a helical scan type magnetic recording/reproducing device equipped with a multi-head capable of simultaneously recording or reproducing across a plurality of mutually adjacent tracks, the tracking control method of a helical scan type magnetic recording/reproducing device includes the following: A certain first head of the plurality of heads constituting the multi-head is placed in an area of a certain first track where the main signal is not recorded.
An index signal having a certain frequency is recorded using the heads of the first head, and each head located on both sides of the first head is used to record an index signal having a certain frequency in the areas of the tracks on both sides where the main signal is not recorded. A pilot signal having a frequency different from that of the index signal is recorded at a position temporally delayed from the index signal recording position, and when reproduced, the pilot signal is recorded in one of the plurality of heads constituting the multi-head. The index signal on the recording medium is first detected, the detection timing of the pilot signal is determined based on the detection time, the pilot signal is detected by the first head at the timing, and tracking control is performed based on the detection result. A tracking control method for a magnetic recording/reproducing device, characterized in that the method performs the following.