JP2565228B2 - Tracking controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a tracking control device for a four-head helical scan type regenerator.

[Outline of Invention]

When the scanning positions of the four rotary heads are aligned with the track on which the recording pilot signals of four frequencies are cyclically recorded, the position error of two tracks is detected and the tracking error signal is detected.
By shifting the phase of 180 ° and shifting the scanning order of 4 heads by 2 heads, the tracking servo lock-in time is shortened, and the sameness of the head to the track is maintained during recording and reproduction. It is a control device.

[Conventional technology]

For example, when it is required to make the recording / reproducing device small, such as a camera-integrated VTR, a small-diameter drum device is used. A recording / reproducing apparatus using such a small-diameter drum device is devised so that the recording tape format is the same as the recording tape format formed by the standard drum.

That is, this type of recording / reproducing apparatus is provided with four magnetic heads for recording / reproducing as shown in FIG. When the diameter of the drum is, for example, 2/3 times the diameter of the standard drum, the rotation speed and the tape winding angle are set to 3/2 times, respectively.

Then, at the time of recording, while switching the head output from 1a → 2a → 1b → 2b, four tracks are recorded by three rotations of the drum. The azimuth angles of these heads are 1a, 1b and 2a,
2b and are set to be opposite to each other.

Therefore, for example, a track recorded by head 1a
May be played in 1b. In this case as well, the reproduced image can be seen, but if there is a mounting error in the mounting angle of the head, there is a drawback that an angle division obstacle occurs on the reproduced screen despite self-recording and reproduction using the same device.

Therefore, the applicant of the present invention uses an information recording / reproducing apparatus to match the reproducing head with the recording head by using the 4-frequency ATF (automatic track following servo) which is performed in the 2-head drum device. Was filed first (Japanese Patent Application No. 61-
No. 196735).

The 4-frequency system ATF is circulated recorded in track order pilot signal f ₁ ~f ₄ consisting of four frequency during recording. During reproduction, a tracking servo is performed so that the reproduction head is positioned on a predetermined track by detecting a crosstalk difference (error signal) of pilot signals reproduced from tracks adjacent to the left and right of the scanning track.

[Problems to be solved by the invention]

When the 4-frequency type ATF is used in the 4-head drum device, the recording head and the reproducing head can be matched with each other, so that the angle division obstacle can be eliminated. However, when tracking control is performed in this way, the lock point is 4
Since there is only one track, there is the inconvenience that the lock-in time takes a long time.

Even in the two-head drum device, there is one lock point for every four tracks. Therefore, if the lock point is detected and then locked, the lock-in time becomes long. Therefore, in the tracking control device of the two-head drum device, when the point where the phase is shifted by 180 ° from the lock point (this point is called the oscillation point) is detected, the phase of the error signal obtained from the track being scanned is 180 degrees. A method is adopted in which the oscillation point is inverted and electrically converted to a lock point to be locked (see JP-A-60-201561).

In this way, when the oscillation point is detected, the phase of the error signal being detected is changed by 180 ° so that the oscillation point becomes the lock point, which is called phase inversion lock or back lock. By adopting this method, it is possible to have one lock point for two tracks, and lock-in time is 1/2.
Can be shortened to Therefore, if the above method is applied to the 4-head drum device, the lock-in time can be reduced to half as in the 2-head drum device.

However, in the case of a 2-head drum device, the pilot signal
The tracks on which f ₁ and f ₃ are recorded and the tracks on which f ₂ and f ₄ are recorded are formed by the same head. Therefore, even if the phase of the error signal is inverted by 180 ° between f ₁ f ₃ and f ₂ f ₄ and the oscillation point is changed to the lock point, no inconvenience occurs.

However in the case of 4 head drum apparatus, four tracks pilot signal f ₁ ~f ₄ is recorded are those formed by respective separate head. Therefore, when the oscillation point is converted to the lock point by using the above-mentioned back lock method, the head at the time of recording and the head at the time of reproducing are different, so that the angle division obstacle as described above occurs.

In view of the above problems, it is an object of the present invention to enable reproduction by a recording head while shortening the lock-in time.

[Means for solving problems]

As shown in FIG. 1, a tracking control device for a 4-head helical scan type reproducing apparatus according to the present invention has four frequencies recorded cyclically by repeating four tracks by four rotary heads 1a, 1b, 2a and 2b. Of the pilot signal, and a tracking error signal based on the reproduced signal, a pilot signal detection circuit 6, a multiplier 7 for multiplying (detecting) the detected reproduced pilot signal and the reference pilot signal, and a multiplier. Error signal detection circuits 11 and 12 connected to the output of the detector, and a differential amplifier 15 that forms a tracking error signal based on the difference between the detected error signals.
A control signal is supplied to a capstan motor control circuit or the like based on this tracking error signal to control tracking.

A sample hold circuit 19, a comparator 27, and flip-flops 28, 29, which are means for detecting that the correspondence between the head and the scanning track is shifted by about 2 tracks and shifting the phase of the tracking error signal by 180 °. Further provided is a phase shift circuit for the pilot signal, which is composed of a detection system including the flip-flop 22 and the timing generation circuit 8. The phase change of the tracking error signal occurs with the phase shift of the pilot signal.

Further, as the phase of 180 ° is shifted, the scanning order of the four rotary heads is shifted by 2 heads so that the rotary heads corresponding to the respective tracks scan the tracks. Field delay circuit 31, switch 2
1, 23, 32, 33, 43 are provided so that the correspondence between the four tracks and the four heads is correct, and the head identity with respect to the tracks is maintained during recording and reproduction.

[Operation] In principle, one tracking servo lock point on four tracks is provided once for every two tracks by providing a 180 ° phase shift means for the tracking error signal, and the lock-in time can be shortened. . By shifting the tracking error signal by 180 °, the lock point is shifted by 2 tracks. Therefore, if the head scanning sequence is also shifted by 2 heads accordingly, spatially one lock point can be set for 4 tracks. The relationship will not collapse. Therefore, the identity of the recording and reproducing heads is maintained.

〔Example〕

FIG. 1 is a block diagram of a tracking control device showing an embodiment of the present invention.

This tracking control device includes four heads 1a, 1b, 2a, 2b provided in a drum device of a small diameter four head system.
To automatically follow a specified track (hereinafter ATF
System)). As shown in FIG. 2A, the heads 1a, 1b, 2a and 2b are arranged in the order of 1a → 2a → 1b → 2b at 90 ° intervals along the rotation direction of the rotary drum 3. As for the azimuth angle of each head, 1a and 1b are positive angles (+) and 2a and 2b are negative angles (-).

The diameter of the rotating drum 3 is 2/3 times the standard size, 3/2
It is rotated at a double speed. A tape 4, which is a recording medium for input signals, is wound around the peripheral surface of the rotating drum 3 by 270 ° and each track T _1a , T _1b , T _2a , T formed by each head 1a, 1b, 2a, 2b. The length of _2b is the same as the track formed by a standard size drum device.

Pilot signals P _{1 to} P ₄ are sequentially recorded on each of these tracks T _1a , T _1b , T _2a , and T _2b in the order of formation tracks. That is, pilot signal P ₁ is T _1a , P ₂ is T _2a , P ₃ is T
_1b, Yes and respectively records the P ₄ in T _2b, these pilot signals P ₁ to P ₄ are reproduced together with the video signal during reproduction.

These pilot signals P _{1 to} P ₄ are low frequencies, and the respective frequencies f _{1 to} f ₄ are f ₁ = 102 (kHz), f ₂ = 116 (kHz), f ₃
= 160 (kHz) and f ₄ = 146 (kHz) are set.

At the time of reproduction, the reproduction signal S ₁ reproduced by each of the heads 1a, 2a, 1b, 2b is derived via the changeover switches 32, 33 which are switching-controlled by the head changeover signal SWP. These changeover switches 32, 33 perform a switching operation in conjunction with each other, and as shown in FIG. 5, a head changeover signal SWP (shown in FIG. 5 as SWP).
1 and SWP2) are at a high level, these changeover switches 32 and 33 select the heads 1a and 1b, respectively. When the head changeover signal SWP is low level, the changeover switch 32
Selects the head 2a, and the changeover switch 33 selects the head 2b.

The output of the selector switch 32 is the selector terminal a of the selector switch 34.
The output of the changeover switch 33 is also given to the changeover terminal b of the changeover switch 34. It is applied to the changeover terminal b of the changeover switch 34. The changeover switch 34 divides the frequency of the head changeover signal SWP into 1/2 to change the head changeover signal 1 /.
Switching is controlled by 2SWP, and the output of the changeover switch 32 is selected when the signal 1 / 2SWP is at a high level, and the output of the changeover switch 33 is selected when the signal is at a low level.

The reproduction signal S ₁ extracted through these change-over switches 32 to 34 is amplified by the preamplifier 5 and then supplied to the pilot signal detection circuit 6 having a low-pass filter structure, and the reproduction pilot signal S ₂ is detected. The detected pilot signal S ₂ is supplied to the multiplier 7, where it is multiplied with the reference pilot signal S ₃ .

The reference pilot signal S ₃ is output from the pilot signal generator 9 and is formed as a composite signal of the tracking reference pilot signal S _3a and the lock position detecting reference pilot signal S _3b , as shown in FIG. 6C. Has been done.

Tracking reference pilot signal S _3a, together with the chosen to the same frequency so as to correspond to each frequency f ₁ ~f ₄ of the reproduced pilot signal S _2, which is configured as a signal circulating in the same order, 1 / It is output to the reproduction error signal generation section W ₁ provided within the four circulation cycles W.

The lock position detection reference pilot signal S _3b is inserted in the lock position detection section W ₂ provided in the center of the 1/4 cycle section W, and the tracking reference pilot signal S _3a is circulated in the order of one track pitch. It is a shifted one. In this example, a signal whose phase is delayed by 90 ° with respect to the tracking reference pilot signal S _3a is inserted.

In order to derive the reference pilot signals S _3a and S _3b for tracking and lock position detection to the multiplier 7 at respective timings, a switch circuit 10 whose operation is controlled by a timing generation circuit 8 is provided.

The timing generation circuit 8 time-divides the 1/4 circulation period section W into an oscillation point detection section W ₂ and a reproduction error signal generation section W ₁ ,
A select signal SEL1 and SEL2 for each frequency signals f ₁ ~f ₄ of that corresponding to the section of the to be supplied to the multiplier 7 derives the switching circuit 10.

The head switching signal SWP1 is a switch pulse shaping circuit for the rotation detection signal PG output every time the rotary drum 3 makes one rotation.
It is formed by supplying it to 20 and is formed as a signal which switches between a high level and a low level four times during a period in which three rotation detection signals PG are output as shown in FIG. The head changeover signal SWP1 is directly supplied to the timing generation circuit 8 via the changeover terminal a of the changeover switch 21 and is also supplied to the frequency divider 22. Then, in the frequency divider 22,
Head switch signal 1/2 SWP ₁ divided by _1/2 is a switch
It is given to the timing generation circuit 8 through the terminal a of 23.

When the reproducing head does not normally track when the reference pilot signal S _3a corresponding to the reproduction error signal generating section W ₁ is being supplied to the multiplier 7 from the switch circuit 10 , The reproduced pilot signal S ₂ is output in a state in which the pilot signals P ₂ , P ₃ , P ₄ and P ₁ recorded on the adjacent tracks are included (FIG. 3C).

Of the multiplication calculation force S ₄ , Δf _A = | f ₁ −f ₂ | = | f ₃ −f ₄ | = 14 (kHz) Δf _B = | f ₂ −f ₃ | = | f ₄ −f ₁ | 44 ( kHz), it is possible to know which of the adjacent tracks the reproducing head is tracing by detecting the frequency differences Δf _A and Δf _B. The multiplying force S ₄ is Δ
The frequency difference components are detected by being supplied to the detection circuits 11 and 12 for f _A and Δf _B , and the respective detection outputs are supplied to the DC conversion circuits 13 and 14.

As described above, when the reproducing head is tracing with being shifted to the right, the multiplication calculation force (frequency) between the reproducing pilot signal of the crosstalk component contained in the reproducing pilot signal S ₂ and the reference pilot signal S _3a Difference component) is Δf _A ,
Since it is Δf _B , if we focus only on the components of Δf _A and Δf _B ,
Frequency difference components Δf _A and Δf _B as shown in FIG. 3D are detected from the respective tracks T _{1a to} T _2b . Therefore, the DC output circuit 13 obtains the detection output S _{5 of} FIG. 3E, and the other DC output circuit 14 obtains the detection output S ₆ of FIG.

The detection outputs S ₅ and S ₆ are supplied to the differential amplifier 15 and shown in FIG.
A signal S ₇ shown in FIG. 3 is formed, and this signal S ₇ and a signal obtained by inverting the phase of the signal S ₇ by the inverter 16 are alternately and sequentially switched in the switching circuit 17, and the negative tracking error signal S _E shown in FIG. 3H. Is formed.

Since the DC level of the tracking error signal S _E corresponds to the amount of deviation from the regular track, if this tracking error signal S _E is supplied to the capstan servo system, the tracking error of the reproducing head can be corrected. it can.

If the playback head is tracing while shifting to the left with respect to the regular track, the playback pilot signal S ₂
Is shown in FIG. 3I, the multiplication force S ₄ is shown in FIG. J, and the tracking error signal S _E has a positive DC level (K in the same figure). Therefore, the tracking error is corrected even if the tracking error signal is shifted to the left side. can do.

By the way, when the tracking servo is not operating sufficiently like the rising of the tracking servo, the subtraction output S ₇ for forming the tracking error signal becomes as shown by l ₁ in FIG. 4B.

That is, when the reproducing head causes a track shift in the forward direction (rightward direction) with reference to the track T _1a ,
The tracking deviation increases with a negative inclination until the track deviation becomes one track pitch, that is, the adjacent track T _2a .
This is because Δf _B = 0 and Δf _A increases corresponding to the tracking shift amount while the reproducing head is between the tracks T _{1a and} T _2a . The increase amount has a negative maximum value in the track T _2a , and thereafter, the subtraction output S ₇ decreases with a positive slope in a range (T _{2a to} T _2b ) in which the tracking deviation amount increases by two track pitches. It becomes 0 at the position of the track T _1b , and then becomes a positive value. This phenomenon is track T
_At the position of _2b , the maximum value becomes positive, and when the tracking deviation amount passes the position T _2b , the subtraction output S ₇ changes again with a negative slope.

In this way, when the servo is started, the subtraction output S ₇ is repeatedly increased and decreased in a triangular wave shape at a cycle of every 4 track pitches. In response to this change in the subtraction output S ₇ , tracking servo is performed such that the capstan motor is decelerated when S ₇ <0 and accelerated when S ₇ > 0.

Therefore, if the subtraction output S ₇ increases in the negative direction at the oscillation point T ₃ shown in FIG. 4B, the capstan motor is decelerated so that the tracking deviation amount decreases. Also,
Even if the subtraction output S ₇ decreases in the positive direction, S ₇ <
During 0, the capstan motor is similarly decelerated to correct the tracking deviation amount. In this way, the reproducing head is locked at the phase point T ₁ where S ₇ = 0.

With S ₇ > 0, the capstan motor is now accelerated and locked at the next phase point T ₅ .

Although S ₇ = 0 also at the phase point T _3, if the subtraction output S ₇ deviates slightly from the phase point T _{3 in the} positive direction or the negative direction, the above-mentioned servo lube works, so that the phase point T ₃ is stable. Therefore, this phase point T ₃ becomes an oscillation point.

Since such a servo loop operates, when the tracking is shifted to the vicinity of the oscillation point, the stable lock point cannot be reached unless the reproducing head is corrected by two tracks. That is, it takes time to return to a normal track.

Therefore the reference pilot signal S ₃ to the locked position detection section W ₂ as described above is provided, wherein the reference pilot signal composite reference pilot signal S ₃ obtained by dividing the time the S _3b for locking the position detection is used.

When the composite reference pilot signal S ₃ is supplied to the multiplier 7 and the tracking servo is not taken,
The reference pilot signal S _3a for detecting the tracking error and the subtraction output S ₇ (Δf _A −Δf _B ) for the reproduced pilot signal have the characteristics shown by the curve l ₁ in FIG. 4B as described above. If the phase of this subtraction output S ₇ is changed by 180 °, the fourth
Since the curve l ₃ shown in FIG. B, the lock point of the subtraction output S ₇ shown by the curve l ₃ would correspond to the oscillation point of the subtraction output S _7.

Therefore, the amount of tracking deviation is the oscillation point T ₃ of the subtraction output S _7.
When it is near, the phase of this subtraction output S ₇ is forced.
By changing 180 °, the tracking shift amount exists near the lock point of the subtraction output S ₇ , and the pull-in to the lock point becomes very fast.

In order to perform such processing, the reference pilot signal
_S3b is used. That is, the subtraction output S ₉ (= Δf _A −Δf _B ) formed from the multiplication force of the reference pilot signal S _3b for detecting the lock position and the reproduction pilot signal S ₂ is delayed by 90 ° from the reference pilot signal S _3b. Therefore, FIG. 4B
Paying attention to the fact that the characteristic becomes as shown by the curve l ₂ in Fig. 4, the detection level V _R is set as shown in Fig. 4B, and when the subtraction output S ₉ becomes equal to or higher than this detection level V _R Phase of ₇ to 18
The subtraction output ▲ ▼ changed by 0 ° is output.

Therefore, the detection level V _R is set to a predetermined error range (outside the predetermined lock-in range) including the oscillation point T ₃ .

Therefore, the subtraction output S ₉ exceeds the detection level V _R when the tracking deviation amount is near the oscillation point T ₃ as indicated by arrows c and d in FIG. 4B. Therefore, if the subtraction output S ₉ exceeds the detection level, the subtraction output S
Inverted to ▼, the oscillation point T ₃ is converted to the lock point T ₁ .
With this polarity, as shown by the arrows a and b in FIG. 4, a tracking servo that makes S ₇ = 0 works, so that the lock point can be pulled in in a short time.

In order to achieve such a detection operation, a detection system as shown in FIG. 1 is provided.

The output signal S ₈ of the switching circuit 17 is supplied to the first and second sampling and holding circuits 18 and 19, and in the sampling and holding circuit 18 of FIG. _{1, the} period W ₁ shown in FIG.
The output signal S ₈ is sampled and held, and the held output is used as the tracking error signal S _E.
In the second sampling and holding circuit 19, the output signal S ₈ of the period W ₂ is sampled and held, and this is used as the subtraction output S ₉ for detecting the oscillation point.

In order to perform such sampling and holding, each of the sampling and holding circuits from the timing generation circuit 8
Time-division signals TS-A and TS-B in 18 and 19 (D and E in FIG. 6)
Is supplied.

The subtraction output S ₉ is supplied to the level detection circuit 26. The level detection circuit 26 has a comparator 27 which uses the detection level V _R as a reference level (threshold level), and when the subtraction output S ₉ exceeds the detection level V _R , the comparison output S ₁₁ outputs the first comparison output S ₁₁ .
Of the flip-flop 28.
The flip-flop 28 is provided to divide the frequency by 1/2, and each time the comparison output S ₁₁ is input to the clock terminal C, that is, the subtraction output S ₉ exceeds the reference level V _R. The level of the detection signal S ₁₂ output from the output terminal Q is inverted.

The detection signal S ₁₂ is given to the data terminal D of the second flop-flop 29, and at the timing when the inverted signal ▲ ▼ of the head switching signal is given to the clock terminal C of this flip-flop 29, the changeover switch is outputted from the output terminal Q. 21, 23
The switching signal S _{13 of} is output.

When the changeover signal S ₁₃ is output, the changeover switches 21 and 23 are changed over to the opposite side of the changeover terminal b. Changeover switch 21
2/3 field delay circuit 31 has a phase of 2/3
A head changeover signal SWP2 shifted by the field is provided, and this is selected and derived from the changeover switch 21. Also, the head switching signal 1 / 2SWP2 on the switching terminal b side of the selector switch 23 is 180 ° out of phase with the switching terminal a side.
Is given, and this is selected and output.

When the head switching signal is switched to SWP2, 1 / 2SWP2 in this way, the timing generation circuit 8 switches to the switching circuit 10
The phases of the select signals SEL1 and SEL2 applied to the signal are inverted by 180 °. Therefore, the reference pilot signal supplied to the multiplier 7
Since the phase of S ₃ is inverted by 180 ° (this switching timing is indicated by the arrow in FIG. 5), the phase of the subtraction output S ₇ (or tracking error signal S _E ) is inverted by 180 ° and the oscillation point becomes the lock point. Electrically converted. This makes it possible to speed up the pull-in operation to the lock point even when the reproduction track is deviated to near the oscillation point, and to shorten the servo lock time.

The head switching signal for controlling the switching operation of the changeover switches 32, 33, 33 is changed from SWP1, 1 / 2SWP1 to SWP2, 1 / 2SWP2 at the timing when the lock point is converted. The phase of the head changeover signal 1 / 2SWP2 that controls the switching operation of the changeover switch 34 is inverted by 180 ° with respect to 1 / 2SWP1. Now, assuming that all the changeover switches 32, 33, 34 are changed over to the changeover terminal a side, the changeover switch 34 is changed over to the changeover terminal b side immediately after changing the lock point to T ₃ . Therefore, the output of the head 1a is switched to the output of 1b. That is, when the oscillation point is changed to the lock point, the reproducing head is switched between the heads 1a1b and 2a2 which are in the facing positional relationship.

Since the tape 4 is wound around the rotary drum 3 by 270 °, when the reproducing head is converted to the head facing 180 ° as described above, the switching timing of each head is shifted by 2/3 field. I will end up. Therefore, in order to correct this phase shift, as described above, the phase shift caused by the switching is used by using the head switching signals SWP1 and 1 / 2SWP2 in which the phase is delayed by 2/3 field through the 2/3 field delay circuit 31. Is being adjusted.

FIG. 7 shows the relationship between each head and the track when the oscillation point is detected. In this case, the head 1a is located almost directly above the track T _1b formed by the head 1b, and the head 1a is displaced near the oscillation point. In this state, if the phase of the tracking error signal S _E is shifted by 180 ° and the back is locked, the above-mentioned inconvenience occurs because the head is different during recording and during reproduction. Therefore, if the phase of the tracking error signal S _E is shifted by 180 ° and the reproducing head is converted between 1a1b and 2a2b as in the present embodiment, the oscillation point is converted to the lock point by the 4-head drum device and the lock-in is performed. Even if the time is shortened, it can be reproduced with the same head as when recording.

As a method of changing the phase of the tracking error signal S _E by 180 °, the phase of the switching pulse ATFSW provided from the timing oscillation circuit 8 to the switching circuit 17 may be changed by 180 °.

Further, a switch circuit capable of selecting an inverted output and a non-inverted output may be provided next to the DC conversion circuits 13 and 14, and the outputs from the DC conversion circuits 13 and 14 may be inverted and taken out when the oscillation point is detected. .

The present invention can also be applied to a 4-head system including a pair of double azimuth heads.

〔The invention's effect〕

According to the present invention, as described above, in the tracking system in which four rotary heads are associated with four tracks, when a tracking servo error for two tracks occurs, the tracking error signal is phase-shifted by 180 °.
Since the servo lock point is shifted by two tracks, there is one lock point for every two tracks, and the lock-in time is greatly shortened. Further, since the servo lock point is shifted by two tracks and the scanning sequence of the four-rotation head is shifted by two heads at the same time, the correspondence between the four tracks and the four heads is not broken, and recording and reproduction are performed on the tracks. Head identity is maintained. Therefore, even if there is an error in the allocation angle of the four heads on the rotary drum, the recorded information can be reproduced with high quality without causing an angle division obstacle on the reproduction screen.

[Brief description of drawings]

FIG. 1 is a block diagram of a tracking control device showing an embodiment of the present invention, FIG. 2A is a plan view of a small diameter 4 head drum device, and FIG. 2B is a small diameter 4 head drum device. FIG. 3 is a pattern diagram of the formed track, FIG. 3 is a waveform diagram of the tracking error signal, FIG. 4A is a line diagram showing a state in which the head is scanning the track on which the pilot signal f ₁ is recorded, 4B is a waveform diagram of the tracking error signal, FIG. 5 is a time chart showing the timing of head switching, FIG. 6 is a time chart showing the timing of oscillation point detection, and FIG. It is a diagram explaining the positional relationship of each head. In the reference numerals used in the drawings, 1a, 1b, 2a, 2b ... head 3 ... rotating drum 6 ... pilot signal detection circuit 7 ... multiplier 17, ... switching circuit 18, 19 ... sampling hold circuit 26 ...... Level detection circuit 32,33,34 …… Selection switch S ₂ …… Reproduction pilot signal S ₃ …… Reference pilot signal S ₇ …… Subtraction output S _E …… Tracking error signal.

Claims (1)

(57) [Claims] 1. A rotary head for reproducing a pilot signal of four frequencies cyclically recorded by repeating four tracks, a means for generating a tracking error signal based on the reproduction signal, and a tracking error signal for the tracking error signal. A means for controlling tracking based on the above, a means for detecting that the correspondence between the head and the scanning track is shifted by about two tracks, and a means for shifting the phase of the tracking error signal by 180 °, and a means for shifting the phase by 180 °. A tracking control device comprising means for shifting the scanning order of the four rotary heads by two heads so that the rotary heads corresponding to the respective tracks scan the tracks.