JPH0266763A - Tracking controller - Google Patents

Abstract

PURPOSE:To shorten pull-in time to the lock point of a reproducing head by maintaining the signal level of an error signal of a sufficiently large level when the reproducing head exceeds a lock pull-in section and enters an excessive tracking dislocation section. CONSTITUTION:Based on a tracking error detecting signal S3 and a signal S3X to delay the phase of the signal S3 only for one track, an excessive tracking dislocation detecting circuit 35 detects that a reproducing head exceeds the lock pull-in section including a lock point and enters an excessive tracking dislocation section. Next, a tracking error signal forming circuit 36 forms a tracking error signal S23 of a practically sufficiently large signal level in the excessive dislocation section based on detecting outputs S24 and S25 of the means 35. Thus, even when the reproducing head is at the rear lock point vicinity position, the reproducing head can be pulled in to the lock point during a short period.

Description

[Detailed description of the invention] The present invention will be explained in the following order.

A: Industrial field of application B: Outline of the invention C: Conventional technology (Figures 4 and 5) D: Problems to be solved by the invention (Figures 2, 5, and 6) E: Solving the problem Means for (Figures 1 and 2) F action (Figures 1 and 2) G embodiment [G1] First embodiment (Figures 1 to 3) [G2] Other embodiments (Fig. 1) H Effects of the Invention A Industrial Application Field The present invention relates to a tracking control device, and is particularly suitable for application to a tracking control device of a pilot signal recording type automatic track following method (ATF method). .

B. Summary of the Invention The present invention provides a pilot signal recording type tracking control device that maintains the signal level of a tracking error signal at a value sufficiently large for practical use when the tracking position of a reproducing head enters an excessive tracking deviation section. By doing so, it is possible to further speed up the pull-in time to the lock point.

C. Prior Art This type of tracking control device is designed to cyclically record four-frequency pilot signals f, ~f4 together with video signals onto recording tracks that are successively formed across the running direction of a magnetic tape. 4-frequency ATF
) A racking control device has been proposed (Japanese Patent Application Laid-Open No. 1983-
202185).

This four-frequency ATF tracking control device has a fourth
As shown in the figure, from a playback video signal S1 played back by a playback head (composed of a recording/playback head, but functioning as a playback head in the playback mode) consisting of two or four rotating video heads, the corresponding Playback video signal S
1 is extracted by a pilot signal detection circuit 1 having a low-pass filter configuration to obtain a reproduced pilot signal S2, which is supplied to an error signal forming circuit 3. The error signal forming circuit 3 sends out a tracking error detection signal S3 formed under the control of the reference pilot signal forming circuit 4.

As shown in FIG. 5, on the magnetic tape 5, recording tracks TAI, TBI, T are formed by recording pilot signals f, f, f, f4 of four frequencies superimposed on the video signal.
A set of A2 and TB2 (TAI and TA2, TBI and TB2 each have the same azimuth angle) is formed obliquely and closely together so as to be repeated in a cyclical manner.

Here, in principle, as shown by the solid line in FIG.
When tracking in the just tracking state, the pilot signals f+, fz, f3, fa reproduced from the recording track being tracked,
Pilot signals (ra and rz), (r+ and f3) that crosstalk from adjacent recording tracks on both sides
), (rz and f4), and (rs and fl) are detected by the pilot signal detection circuit 1 as signal components of the reproduced video signal S1.
given to.

Here, as shown by the broken line in FIG.
When recording tracks TAI, TBI, TA2, TB2 are scanned with the left (or right) shifted in the running direction, the adjacent left (or right) recording tracks TB2, TA
I, TBI, TA2 (or TBI, TA2, TB2, T
The amount of crosstalk from pilot signals r4, fl, fz, f3 (or f2, f8, f4, f,) of AG) increases in accordance with the amount of track deviation.

By the way, the frequency values of the four-frequency pilot signals f and -f4 are such that the difference frequencies ΔfA and ΔfB with the adjacent pilot signals are predetermined values, for example, ΔrA = 1 r, -rz
l=l r, -r4-16 (kHz)
...... (1) Δfl = l
ft-fsl = l f, -f.

= 46 (kHz) ・・・・・・
・So that (2), f I =102 (kHz
), f t=us (kHz), f 3=164
CkH2'l, f4=148 (kHz) is selected.

Then, the recording tracks TAI and TA2 where the odd-numbered pilot signals f+ and f3 are recorded are transferred to the playback head 6.
is scanning with a left shift (or right shift), the difference frequency in the regenerated pilot signal S2 is Δf (or Δf
The signal level of the pilot signal increases as shown in A), and the reproduction radar 6 scans with a leftward (or rightward) shift in the recording tracks TBI and Ta2 where the even-numbered pilot signals f2 and f4 are recorded. When this happens, the signal level of the pilot signal becomes large so that the difference frequency becomes ΔfA (or Δf8) in the regenerated pilot signal S2.

The error signal forming circuit 3 generates a multiplication output S12 including the difference frequency ΔfA or Δrm by multiplying the reproduced pilot signal S2 by the reference pilot signal Sll in the multiplication circuit 14, and converts the signal components of the difference frequencies ΔfA and Δfl+ into a band. It is extracted by the ΔfA difference frequency detection circuit 20 and the ΔfB difference frequency detection circuit 21 having a pass filter configuration, and is applied to the error signal forming circuit 22 as error detection signals S13 and 314.

Here, the reference pilot signal forming circuit 4 generates a four-frequency pilot signal f1 obtained from the pilot signal generating circuit 16.
, ft, f3, f4 in the switch circuit 17 by the head switching signal RF-3W, the playback head 6 switches to the recording tracks TAI, TBI, Ta2, T.
At the timing of scanning a2, the pilot signals f, , f2, f3, f4 of a predetermined signal level are used as the reference pilot signal S.
11 to the multiplication circuit 14.

The error signal forming circuit 22 obtains the subtracted output of the error detection signals S13 and S14 in the subtracting circuit 23, and tracks the subtracted output through the switching input terminal P1 of the switch circuit 24 at the timing when the reproducing head 6 scans the recording tracks TAI and Ta2. It is sent as an error detection signal S3, and in response to this, the playback head 6 detects the recording track TBI.
At the timing of scanning Ta2 and Ta2, the polarity of the subtracted output is inverted by the inverter 25 and sent through the switching input terminal P2 of the switch circuit 24 as the tracking error detection signal S3.

Here, the difference output 513 between error detection signals S13 and S14
The polarity and value of -314 (-ΔfA-ΔfIl) are as follows:
This shows the difference in the amount of crosstalk between the pilot signals from the left (or right) recording track when scanning a2, and therefore the track deviation direction and track deviation amount, and the reproducing head 6 scans the recording tracks TAI, TBI, Ta2. , T
When in a leftward (or rightward) shifted state with respect to a2, the polarity is sequentially positive, negative, positive (or positive, negative, positive, negative).

Therefore, if the switch circuit 24 is switched to the switching input terminal P2 side at the timing when the polarity of the difference signals 313-314 becomes negative in the leftward (or rightward) state, all recording tracks TAI to TB2 When the reproducing head 6 is shifted to the left (or shifted to the right), the polarity of the tracking error detection signal S3 becomes positive (or negative).

Therefore, the drive servo system of the magnetic tape 5 is controlled by the tracking error detection signal S3.
If the reproducing head 6 is controlled in the direction where 3 becomes O, the reproducing head 6 can scan all the recording tracks TAI to TB2 without maintaining the just tracking state.

D Problems to be Solved by the Invention The tracking error detection signal S3 sent out from the error signal forming circuit 3 in this way is generated when the playback head 6 is shifted one track to the right or to the left from the just tracking position fiTO. Tracking position z'r I R
, T 2 R, T 3 R... or TIL,
When a tracking error occurs in T2L, T3L, etc., as shown in FIG. 6, a tracking error characteristic that repeatedly changes in the positive or negative direction depending on the amount of tracking error is exhibited, and the tracking error detection signal S3 In addition to the track position where the playback head 6 can stably perform tracking operation when becomes 0 (this is called the lock point), there are also tracks where the tracking error detection signal S3 becomes O even though the playback head 6 is not stable. location (this is called the backdoor entry point).

In other words, in FIG. 6, the track deviation position where the tracking error detection signal S3 crosses the 0 point upward to the right is locked (T4L, To, T4R...)
In contrast, the track deviation position that crosses the 0 point in the downward right direction is the back door pick point (... song T2L, T2
R, T6R...).

Incidentally, the lock lights...T4L, To, T4R...
), if there is a slight shift to the right (or left), the tracking error detection signal S3 rises in the positive (or negative) direction, causing the servo system of the magnetic tape 5 to By controlling the pull back to the lock point, a stable state can be maintained, whereas the back door lock point (...T2L, T2R1T6R...
), if the reproduction radar 6 slightly shifts to the right (or shifts to the left), the tracking error detection signal S3 becomes negative (
(or positive), a change occurs that pulls the reproducing head 6 to the right (or left), and therefore the reproducing head 6 cannot remain in a stable state.

Therefore, if the playback head 6 is left in the vicinity of the back door pick point, it will eventually be pulled back to the lock point by the tracking error detection signal S3, but in reality, the value of the tracking error detection signal S3 near the back door pick point is close to 0. Therefore, even if an attempt is made to pull the reproducing head 6 to the lock point in the shortest possible time, there is a problem that the pull-in time cannot be shortened because the tracking error detection signal S3 is small.

One way to solve this problem is to apply the reference pilot signal Sl to the multiplication circuit 14 of the error signal forming circuit 3.
A method has been proposed in which the track deviation position, which was actually the back door lock point up to the lower gold plate, is switched to the lock point by changing the order of the pilot signals f, , f, , f3, and f4 of l. -15848).

However, when doing this, the reference pilot signal Sll
If the order of the pilot signals is changed, the same magnetic head used to form the recording tracks TAI, TBL, TA2, TB2 (FIG. 5) on the magnetic tape 5 will be used with the servo lock during playback. There is an inconvenience that cannot be avoided.

For example, recording tracks TAI, TBI, TA2, TB
When trying to record and play back by assigning four unique magnetic heads to each of the two (in other words, when trying to perform so-called self-recording and playback), a magnetic head different from the one used for recording is used for playback. Then, due to the unique characteristics of each magnetic head, for example, the recording levels of the pilot signals f, , ft1, f3, f4 may become uneven, or the recording tracks TAI, TBI, TA2, TB2 may become uneven due to uneven positioning on the rotating drum. If the widths are uneven, there is a possibility that image shaking or jitter may occur in the reproduced video signal.

The present invention has been made in consideration of the above points, and even when the amount of track deviation of the playback head deviates from the vicinity of the lock point and approaches the back door vine point, it can be pulled into a predetermined lock point at a high speed. This paper attempts to propose a tracking control device that does the following.

E Means for solving problem A tracking control device that performs tracking control on the reproducing head 6 based on a tracking error detection signal S3 corresponding to the difference between the crosstalk amounts ΔfA and ΔfB of the pilot signals f and ~f4 obtained from recording tracks adjacent on both sides during reproduction of ~TB2. , the playback head 6 is at the lock point (...T4L, TO1T4R...
) is detected by the tracking error detection signal S3 and the one-track phase-delayed tracking obtained by delaying the phase of the tracking error detection signal S3 by one track. Error detection signal S3
Excessive tracking deviation detection means 35 detects based on A tracking error signal forming means 36 for forming the tracking error signal is provided.

The fact that the F-effect tracking error detection signal s3 has entered the excessive tracking deviation section TMUNLK can be detected by the excessive tracking deviation detection means 35 by monitoring the one-track phase-delayed tracking error detection signal S3X. Here, the excessive tracking deviation detection means 35 maintains the signal level of the tracking error signal S23 at a signal level sufficiently large for practical use.

By doing this, it is possible to generate a tracking error signal S23 that is large enough for practical use even when the playback head 6 is tracking near the back door lock point, so that the playback head 6 can be moved to the lock point in a sufficiently short period of time. (...T4L, TO1T4R...).

G example An embodiment of the present invention will be described in detail below with reference to the drawings.

[G1] First Embodiment In FIG. 1, in which parts corresponding to those in FIG. 4 are given the same reference numerals, the switch circuit 17 is constructed as shown in FIG. 3(B).
Of the head switching signal RF-3W, the reference pilot signals f, ft, f, , are sequentially delayed by one track in the auxiliary period M of the head portion of the switching period of f4.

Reference pilot signal 5lIX obtained by inserting f2 and f3
is supplied to the multiplication circuit 14 of the error signal forming circuit 3.

Here, in the main period M2 of the reference pilot signal 5IIX, the pilot signal f is sent to the error signal forming circuit 3.
, →ft-f, -f4, so that
A tracking error detection signal S3 similar to that described above with respect to FIG. 6 is obtained (FIG. 2(A)).

On the other hand, in the auxiliary period M, the pilot signal to the error signal forming circuit 3 is f4-f.

→f, −f3 in the order shown in Figure 2 (
As shown in the tracking error detection signal S3X with a one-track phase delay in A), the tracking error detection signal S3 obtained when the playback head 6 is shifted to the right by one track in order to delay the phase of the tracking error detection signal S3 by one track. It is possible to obtain a detection signal that is the same.

As a result, the regenerated pilot signal S2 as shown in FIG. 3 (C
As shown in 1), the lock lights...T4L, T
o, T4R...) position (FIG. 2(A)).
f, is reproduced, this switching order matches the pilot signal of the main period M2 of the reference pilot signal 511X, so that the tracking error detection signal S3 becomes O.
It becomes a state where the value of the cross point is taken.

On the other hand, since the switching order of the pilot signals in the auxiliary period M1 has a one-track distribution shift, the one-track phase-delayed tracking error detection signal 33X has a negative maximum value (FIG. 2(A)).

Thereafter, as shown in FIG. 3 (C2), (C3), and (C4), the lock points (...T4L, TO1T
4R...) for 1 track each, 2
When the reproduced pilot signal S2 indicating that the reproduction pilot signal S2 is shifted to the right by three tracks is obtained, the main period M2
The signal levels of the tracking error detection signals S3 obtained at the positions are respectively shifted by 1.2.3 tracks (...T3L, TIR, T5R...)
, (...T2L, T2R, T6R...
), (...TIL, T3R...) have a positive maximum value, 0, and a negative maximum value, respectively (Fig. 2 (A)).

On the other hand, the signal levels of the one-track phase-delayed tracking error detection signal S3X obtained in the auxiliary period M have 0, the maximum positive value, and 0, respectively (
Figure 2 (A)).

Here, in Fig. 2 (A), the lock is turned on...
・The playback head 6 moves in the leftward and rightward directions with T4L, To, T4R, etc.) as the center = 1
7 Shifted position (...T5L, TIR, T3R
......) and (...T3L, TIR,,
The range up to T5R...) is due to the tracking error detection signal S3 changing upward to the right (or downward to the left) when the playback head 6 shifts to the right (or shifts to the left). The servo system can be pulled in in the normal mode (that is, the further the playback head 6 is from the lock point, the higher the signal level of the tracking error detection signal S3 becomes in the direction of pulling the servo system into the lock point, so the servo system can be pulled in in the normal mode. force increases), and this range is called the lock retraction section TMLO (x).

On the other hand, the back entrance point (...T2L, T2
R, T6R...), the playback head 6 is shifted by one track in the leftward and rightward directions (
......T3L, TIR,, T5R...)
and (...TIL, T3R, T7R...
・) When the playback radar 6 shifts to the right (or shifts to the left), the tracking error detection signal s3 changes downward to the right (or upward to the left), and the magnetic tape servo system is set to the normal mode. Therefore, the signal level of the tracking error detection signal S3 is in the direction of pulling the servo system away from the back door pick point, that is, in the direction of pulling the servo system toward the lock point. ) by increasing
(the servo retracting force becomes smaller), and this range is called the excessive tracking deviation section TM□.

The tracking error detection signal S3 and the one-track phase-lag tracking error detection signal S3X sent out in the periods M2 and Ml in this way are transmitted to the main tracking error detection signal sampling circuit 32 of the tracking error signal processing circuit 31 and the phase-lag tracking error detection signal S3X. Sampling pulses SP, (FIG. 3 (DI)) and 5PS (FIG. 3 (D2)) given to the signal sampling circuit 33 and given from the sampling signal generation circuit 34
) sampled by

The sampling signal generation circuit 34 generates a head switching signal RF.
-3W, sampling pulses SP and SPs are generated between the main period M2 and the sub-period M2C, respectively.

Thus, the main tracking error detection signal sampling circuit 32 and the phase-lag tracking error detection signal sampling circuit 33 receive the signal level of the tracking error detection signal S3 representing the tracking position of the reproducing head 6 and the one-track phase-lag tracking error detection signal S3.
The signal level of each of be done.

The excessive tracking deviation detection circuit 35 detects when the tracking error detection signal S3 (FIG. 2 (A)) deviates from the upper right lock pull-in section TMLOC+[ and enters the downward right excessive tracking deviation section TMIINLK. This is detected by a first comparator circuit 41 that compares the signal level of the main tracking error detection signal sampling circuit 32 with a reference potential VT, which is a ground potential, and a phase-delayed tracking error detection signal sampling circuit. Sampling output S of circuit 33
22 with a reference potential VT□2 having a predetermined positive potential.

In this embodiment, the reference potential VA of the comparison circuit 42 of the cylinder 2
2 is selected as the potential of the tracking error detection signal S3 at the point where it intersects with the one track phase delayed tracking error detection signal S3X in the region where the tracking error detection signal S3 takes a positive value, as shown in FIG. 2(A). As a result, the sampling output S22 of the phase lag tracking error detection signal sampling circuit 33 is at a signal level lower than the reference potential VrHz, and the comparison output 52
4 (FIG. 2(B)) rises to the logic rHJ level, the tracking error detection signal S3 (therefore, the tracking position of the reproducing head 6 is at the backdoor hit point (...
. . . T2L, , T2R, T6R . . .)) is detecting the state at a nearby position.

The comparison output 324 of this second comparison circuit 42 is given to the switch circuit 43 as a switching control signal, and the comparison output S2
4 is at the logic rLJ level, by switching to the switching input terminal P2 side, the sampling output S21 of the main tracking error detection signal sampling circuit 32 is sent out as the tracking error signal S23 through the switching input terminal P2. .

On the other hand, the first comparison circuit 41 outputs the sampling output S of the main tracking error detection signal sampling circuit 32.
generates a comparison output 525 (FIG. 2(C)) which becomes a logic rHJ level when 21 rises to a positive signal level;
This comparison output S25 is given to the switch circuit 44 of the tracking error signal forming circuit 36 as a switching control signal.

The switch circuit 44 switches to the switching input terminal PI side when the comparison output S25 is at the logic "H" level.
The sampling output S22 of the phase lag tracking error detection signal sampling circuit 33 is supplied to the switching input terminal PI of the switch circuit 43, and when the comparison output S25 falls to the logic rLJ level, the sampling output S22 is output through the switching input terminal P2. An inverted sampling output S26 obtained by inverting the polarity in the inverter 45 is supplied to the switching input terminal P2 of the switching circuit 43.

Thus, the tracking error signal forming circuit 36
When the comparison output 524 (FIG. 2(B)) of the comparison circuit 42 rises to the logic rHJ level, the switch circuit 4
3 is switched to the switching input terminal Pl side, when the comparison output 525 (FIG. 2(C)) reaches the logic rHJ level, the sampling output S22 is sent out as the tracking error signal S23.

Here, when the comparison outputs S24 and 325 simultaneously rise to the logic rHJ level, the sampling output S22
As represented by the tracking error detection signal S3 in Figure (A>), the excessive tracking deviation section TMUNLK
, the playback head 6 shifts to the right at the back entrance point (...
...T2L, T2R1T6R...), and at this time the sampling output S22
The signal level changes from the reference potential VT)+2 to the maximum signal level. As a result, the tracking error signal S23 has a waveform WXI in FIG. 2(D).
As shown by I, the sampling output S22 (therefore, one track phase delay tracking error detection signal 53
The reference potential V TIT! It exhibits a change in which the signal rises from to the maximum signal level.

On the other hand, the period in which the comparison output S25 falls to the logic "L" level while the comparison output 324 rises to the logic rHJ level is as shown by the tracking error detection signal S3 in FIG. 2(A). , the playback head 6 shifts to the right at the back entrance point (...T2L, T2R
, T6R...), and at this time, the sampling output 522 (therefore, the one-track phase delayed tracking error detection signal 53X) is as shown in FIG.
In D), as shown by waveform WX12, the voltage changes from the negative minimum signal level to the reference potential -vTHt.

However, at this time, the switch circuit 44 switches to the switching input terminal P2 side, and becomes in a state where the inverted sampling output S26 obtained by inverting the polarity of the sampling output 322 by the inverter 45 is supplied to the switch circuit 43, and thereby the tracking error signal S23 changes from the negative minimum value to the reference potential V in the same way as the change in the inverted one-track phase-lag tracking error detection signal S3X (FIG. 2 (A)), which is obtained by inverting the polarity of the one-track phase-lag tracking error detection signal S3X. 7M! The change occurs as if the potential rises to -■T, which is obtained by reversing the sign of .

According to the above configuration, the playback head 6 is locked in the lock retraction section T.
The tracking error obtained from the tracking error signal forming circuit 36 when the state of tracking scanning in MLocx (FIG. 2 (A)) becomes a state of excessive tracking deviation until entering the excessive tracking deviation section TM-LK. The signal level of the signal 523 (FIG. 2(D)) can be maintained at a signal level higher than the threshold level determined by the reference potential VTH□O value of the second comparison circuit 42.

Therefore, when tracking the servo system of the magnetic tape 5 using the tracking error signal s23, since the signal level of the error signal is sufficiently large for practical purposes,
Lock point (...T
The running speed of the magnetic tape 5 can be controlled in such a mode that the magnetic tape 5 can be drawn into the following modes: 4L, TO1T4R, . . . ).

[G2] Other embodiments (1) In the embodiments described above, the sampling output S22 of the phase lag tracking error detection signal sampling circuit 33 is the reference potential V TH of the second comparison circuit 42
2 is exceeded only once, it is immediately determined that the playback head 6 has entered the excessive tracking deviation section TMLINLK, and the switch circuit 43 is switched. The switch circuit 43 may be configured to switch under this condition.

In this way, it is possible to effectively avoid the risk of malfunction when switching the switch circuit 43, and the running speed of the magnetic tape 5 is not changed unnecessarily.
It is possible to reproduce video signals with extremely high image quality.

(2) In the above embodiment, when the magnetic head 6 enters the excessive tracking deviation section TMt+Ntx, a part of the signal waveform of the track phase delay tracking error detection signal S3X is used as the tracking error signal S23. Although the signal level of S23 is maintained at a level equal to or higher than the reference potential V782, the waveform of the tracking error signal S23 used in the excessive tracking deviation section TMUNLK is not limited to this, and various other waveforms may be applied.

For example, in FIG. 1, as shown by the broken line, a maximum position hold circuit 50 is inserted on the output side of the phase lag tracking error detection sampling circuit 33, and its hold output is directly applied to the switching input terminal P1 of the switch circuit 44. The reference potential V of the second comparison circuit 42 is applied to the switching input terminal P2 via the inverter 45.
If the value of T)l□ is selected to be a potential near the maximum value of the tracking error detection signal S3, the waveform of the tracking error signal S23 when the reproducing head 6 enters the excessive tracking deviation section TMUNLK can be determined as shown in FIG. ), the tracking error detection signal S3 (FIG. 2(A)) is in the lock retraction section TML, as represented by the waveform WX2 indicated by a broken line.
When the maximum signal level in OCK is exceeded, it is possible to form a tracking error signal S23 having approximately the same signal level as the maximum signal level.

Therefore, even with this method, when the track deviation of the playback head 6 enters the excessive tracking deviation section TMLINLK, it is possible to send out the tracking error signal S23 with a signal level sufficiently large for practical use, thereby locking the playback head 6 in a short period of time. It can be drawn to a point.

Excessive tracking deviation section TM. The waveform of the tracking error signal 323 when the tracking error signal 323 enters the track is not limited to this, but for example, a waveform with a slope such that the signal level of the tracking error signal 323 increases linearly as the track deviation increases is selected. It can be modified in various ways such as.

Effects of the Invention As described above, according to the present invention, when the playback head exceeds the lock pull-in section and enters the excessive tracking deviation section,
By making it possible to maintain the signal level of the tracking error signal at a sufficiently high signal level for practical purposes, even if the playback head is located near the back door pick-up point, the playback head can be turned off within a sufficiently short period of time for practical purposes. It can be pulled to the lock point.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a tracking control device according to the present invention, FIG. 2 is a signal waveform diagram showing signals of each part thereof, and FIG. 3 is a signal waveform diagram for explaining the pilot signal of FIG. 1. , FIG. 4 is a block diagram showing a conventional tracking control device, FIG. 5 is a route map showing its recording format, and FIG. 6 is a signal waveform diagram showing the tracking error detection signal of FIG. 4. ■...Pilot signal detection circuit, 3...
・Error signal forming circuit, 4...Reference pilot signal forming circuit, 31...Tracking error signal processing circuit, 32...Main tracking error detection signal sampling circuit, 33... ...Phase delay tracking error detection signal sampling circuit, 34...
...Sampling signal generation circuit, 35...
Excessive tracking deviation detection circuit, 36... Tracking error signal forming circuit.

Claims (1)

[Claims] A pilot signal whose frequency changes sequentially and cyclically is recorded on a recording track, and corresponds to the difference in the amount of crosstalk between the pilot signals obtained from adjacent recording tracks on both sides when each recording track is reproduced. In a tracking control device that performs tracking control of a playback head based on a tracking error detection signal, the tracking error detection signal indicates that the playback head has exceeded a lock pull-in section including a lock point and entered an excessive tracking deviation section; excessive tracking deviation detection means for detecting the tracking error detection signal based on a one-track phase-lag tracking error detection signal obtained by delaying the phase of the tracking error detection signal by one track; A tracking control device comprising: tracking error signal forming means for forming a tracking error signal with a signal level sufficiently large for practical use in a tracking deviation section.