JPH0782626B2 - Tracking control device for magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to recording / reproducing of information along a plurality of tracks parallel to the running direction of the magnetic tape while sequentially moving the magnetic head in the width direction of the magnetic tape. The present invention relates to a tracking control device in a magnetic recording / reproducing device for performing the above.

[Conventional technology]

Conventionally, a magnetic recording / reproducing apparatus used as an audio apparatus usually has a configuration in which the number of tracks and the number of heads are equal to each other, except for those having a rotary head. The above-mentioned number of tracks refers to the total number of data tracks formed in parallel to the tape running direction, and the number of heads is included in a combination head that integrally has a magnetic head such as a recording head, a reproducing head or a recording / reproducing head. Refers to the number of magnetic heads, and so on. The magnetic recording / reproducing apparatus as described above is provided with a tape / head relative position regulating means for regulating the relative position of the magnetic tape and the magnetic head. Most commonly, a guide post having a flange is provided in the tape running path.

However, the tape head relative position regulation means described above
Since the vertical movement of the magnetic tape is prevented by contacting the upper and lower ends of the magnetic tape with the flange, when the magnetic tape with a width wider than the distance between the upper and lower flanges runs, the upper and lower ends of the magnetic tape There is a risk that mechanical stress will be applied to and damage the upper and lower ends. Therefore, in the above-mentioned regulation means, the regulation width of several tens of μm is the limit because damage to the end of the magnetic tape must be avoided.
Therefore, in a high-density magnetic recording / reproducing apparatus having an allowable off-track amount of about several tens to several tens of μm, it is not sufficient to limit the fluctuation of the magnetic tape by the above flanges.

Further, in recent years, with the development of thin-film magnetic heads, combination heads having a large number of heads have been developed, and the multi-track magnetic recording / reproducing apparatus can have a higher density. With such a device, recording with a narrow track width can be performed, but the allowable off-track amount is accordingly reduced. Therefore, as the tape / head relative position restricting means, in addition to the restricting structure by the above-mentioned flange, a relative position detecting means between the magnetic head and the magnetic tape or track, and a head driving means for moving the magnetic head in the tape width direction. Accordingly, a configuration is adopted in which the magnetic head is controlled following the waving of the magnetic tape.

An example of such a device is a fixed head digital audio tape recorder having the same number of heads and tracks. In the same device, as disclosed in, for example, IEICE Technical Report EA83-56, IEICE Technical Report EA81-64, and Sharp Technical Report 1984-28, servo-dedicated tracks recorded on a magnetic tape are arranged in the tape width direction. The two reproducing heads arranged side by side are traced, the reproduction outputs thereof are compared, and follow-up control is performed, whereby the relative position between the magnetic head and the magnetic tape is regulated.

As another example of the tape head relative position regulation means, in a magnetic recording / reproducing apparatus in which the number of heads and the number of tracks are equal, a tracking signal is recorded at one widthwise end of the magnetic tape, and this is used as a servo reproducing head. Playback with to compare the signal level with the reference level, or record the information for tracking on both widthwise ends of the magnetic tape,
A configuration has been proposed in which these are reproduced by a pair of servo reproducing heads and the signal levels are compared to perform tracking (see Japanese Patent Publication No. 63-64811).

By the way, in the multi-track magnetic recording / reproducing apparatus such as the fixed head digital audio tape recorder,
Since the track pitch was about several hundred μm, it was possible to construct a combination head in which the recording and reproducing heads corresponding to a plurality of tracks of the magnetic tape were integrated by adopting the thin film head.

However, in the case of further increasing the recording density, it is possible to narrow the track width by narrowing the gap width of the magnetic head, but there is a limit to the integration of the thin film head. It cannot be made smaller. In addition, increasing the number of heads leads to an increase in the circuit scale, resulting in an increase in cost. Therefore, the track pitch is tens of μm and the number of tracks is tens to
Hundreds of high-density magnetic recording / reproducing devices are difficult to achieve with a configuration having the same number of heads and tracks.

Therefore, in recent years, in a multi-track magnetic recording / reproducing apparatus which is a backup storage device of an information processing system and is generally called a cassette streamer, a recording method called a serpentine method in which the number of heads is smaller than the number of recording tracks is used. Has been taken.

This serpentine system will be described with reference to FIG. 5. A magnetic tape whose running direction is X and width direction is Y.
It is assumed that 21 has a track group 22 composed of ₁₆ tracks T _{1 to} T ₁₆ formed at an equal pitch a in the Y direction, for example. In this case, a combination head 23 including, for example, four recording heads W _{1 to} W ₄ and four reproducing heads R _{1 to} R ₄ is arranged for the track group 22.

The recording heads W _{1 to} W ₄ have Y pitches of equal pitch b (b = 4a).
The reproducing heads R _{1 to} R ₄ are arranged in parallel with each other in the X direction or the −X direction in pairs with the corresponding recording heads W _{1 to} W ₄ . The pair of recording heads W _{1 to} W ₄ and the reproducing heads R _{1 to} R ₄ are alternately arranged in such a manner that they are interchanged at each arrangement position in the Y direction.

At the time of recording or reproducing operation, the combination head 23 is first driven to the position shown in FIG. That is,
The centers of the recording head W ₁ and the reproducing head R ₁ coincide with the center of the track T ₁ , and similarly, the centers of the recording head W ₂ and the reproducing head R _{2 and} the center of the track T ₅ , the recording head W ₃ and the reproducing head.
It is a position where the center of R _{3 and} the center of the track T _{9, and} the centers of the recording head W ₄ and the reproducing head R ₄ and the track T ₁₃ coincide with each other.

Next, while recording this relative position, in the case of recording,
The magnetic tape 21 is run in the X direction, and the recording heads W ₁ and W ₃
Are recorded simultaneously on tracks T ₁ and T ₉ .

After recording up to one longitudinal end of the magnetic tape 21,
Next, run the magnetic tape 21 in the -X direction, and
Recording on tracks T ₅ and T ₁₃ simultaneously by W ₂ and W ₄ . Then, after recording to the other end in the longitudinal direction of the magnetic tape 21, the combination head 23 is moved in the −Y direction by the track pitch a, and the centers of the recording head W ₁ and the reproducing head R ₁ are the centers of the tracks T ₂ . Place it to match. Thereafter, while maintaining the relative position, performs recording on the track _{T 2 · T 6 · T 10} · T 14 with one back and forth the magnetic tape 21 in the X and -X directions as above, below, in the same manner Information is recorded on all the tracks T _{1 to} T ₁₆ by a total of 4 reciprocations while moving the combination head 23 by a in the −Y direction each time the magnetic tape 21 reciprocates once.

In the above-mentioned serpentine type multi-track magnetic recording / reproducing apparatus, since a small number of magnetic heads are moved in the tape width direction to perform recording and reproduction on a large number of tracks, the track pitch becomes smaller and the number of tracks increases. However, it is possible to deal with this by moving the magnetic head many times. Therefore, there is no obstacle to the integration of the thin film head.

By the way, as a head / tape relative position regulating means when recording on a magnetic tape by the above-mentioned serpentine system, for example, as disclosed in Japanese Patent Laid-Open No. 62-183019, there is a regulation by the above-mentioned flanges. In addition, a head positioning technique by open loop control using a stepping motor is known.

However, by adopting the serpentine method, for example, when the track pitch becomes several tens of μm,
Naturally, the track width is several tens of μm, and the allowable off-track amount is ten to several μm. In this case, the tape / head relative position regulating means based on the open loop control cannot cope with the allowable off-track amount.

[Problems to be Solved by the Invention]

Therefore, when adopting the serpentine method, for example,
As in the case of the fixed head method described above, tracking control can be performed by recording a servo signal at the end of the magnetic tape in the width direction, reproducing it by the servo reproducing head, and comparing it with a reference value. Conceivable. In that case, in the serpentine system, the track is switched a plurality of times. Therefore, when adopting the system of comparing the servo signal with the reference value, it is necessary to set a plurality of reference values according to each track switching position. Just do it.

By the way, if the total stroke of track switching by the serpentine system is about 1 mm and the residual error of tracking in each track switching is about 1 μm, the servo reproducing head requires a large dynamic range of about 60 dB.

However, for such a large dynamic range, S / N (SN ratio) and linearity are not guaranteed, so that there is a problem that it is difficult to obtain sufficient tracking accuracy at each track switching position.

[Means for Solving the Problems]

In order to solve the above problems, a tracking control device for a magnetic recording / reproducing apparatus according to the present invention sequentially moves a head unit having a predetermined number (one or more) of magnetic heads in the width direction of a magnetic tape. In a tracking control device in a magnetic recording / reproducing device, wherein each magnetic head performs recording or reproduction along a plurality of tracks parallel to the running direction of the magnetic tape while switching tracks, the width direction end portion of the magnetic tape. Servo signals are recorded along the line, and servo reproducing heads for reproducing the servo signals are arranged in the width direction of the magnetic tape at an interval substantially equal to the track pitch and in the same number as the number of track switching of the head unit. The servo reproducing section is provided integrally with the head unit, and the head unit is Drive means for moving the air tape in the width direction, and control means for controlling the moving amount of the head unit by the drive means based on the detection of the servo signal by the servo reproducing head corresponding to the track switching position at each track switching position. It is characterized by having and.

The servo signal may be recorded only at one end in the width direction of the magnetic tape, or may be recorded at both ends in the width direction. When servo signals are recorded on both ends of the magnetic tape in the width direction, a pair of the servo reproducing parts are provided corresponding to both ends of the magnetic tape in the width direction.

[Work]

According to the above configuration, when the head unit is sequentially moved in the width direction of the magnetic tape to perform the track switching, the servo reproducing heads of the servo reproducing section are sequentially switched to the servo controller corresponding to each track switching position. By reproducing the servo signal at the widthwise end of the magnetic tape by the reproducing head, each magnetic head of the head unit can follow the corresponding track at each track switching position. In that case, at each track switching position, the corresponding servo reproducing head reproduces the servo signal, and each servo reproducing head is made to perform the track following operation, that is, only the tracking operation.
The dynamic range of each servo reproducing head can be made relatively small, and therefore linearity and S / N can be easily obtained within the dynamic range, so that accurate tracking becomes possible.

[Embodiment 1] The following will describe one embodiment of the present invention with reference to FIG.

The magnetic recording / reproducing apparatus of the present embodiment is used as a backup storage device such as a hard disk device, for example. The serpentine system is used for recording and reproducing on tracks.

As shown in FIG. 1 (a), the magnetic recording / reproducing apparatus includes a pair of substrates 2a and 2b that extend in the Y direction, which is the width direction of the magnetic tape 1, and are bonded to each other. The recording heads W1 to W8 and the reproducing heads R1 to R8 (only a part of which are shown) formed as thin film heads constitute a combination head 3 as a head unit.
The combination head 3 is moved in the Y or -Y direction by the driving means 14 (see FIG. 2B).

As the magnetic tape 1, for example, one having a width of 1/4 inch is used, and each of the magnetic tapes 1 extends in parallel with the running direction (X direction) and has a predetermined track pitch c (for example,
120 μm) 48 tracks T1 to T48 arranged in the Y direction
Information is recorded / reproduced along the line.

One of the above-mentioned substrates 2a has an odd number of recording heads W1 and W3.
-W5 and W7 and even-numbered reproducing heads R2, R4, R6 and R8 are arranged alternately, and the gap position of each head on the substrate 2a is set on the straight line indicated by the dotted line A.

Also, on the other substrate 2b, odd-numbered read heads R1, R3,
R5 / R7 and even-numbered recording heads W2 / W4 / W6 / R8 are arranged alternately, and the gap position of each head on the substrate 2b is the dotted line B.
It is set on the straight line indicated by.

Corresponding recording heads W1 to W8 and reproducing heads R1 to R8 are arranged side by side in the X direction, which is the running direction of the magnetic tape 1, to form magnetic head pairs H1 to H8. The position of the reproducing head in the X direction is exchanged. Note that the print head W1
.. to W8 and the reproducing heads R1 to R8 are shown to have the same size in the Y direction. Is set to be slightly larger than the reproduction width of each reproduction head R1 to R8.

The distance between the adjacent magnetic head pairs in the Y direction is set to d = 6c, and the driving means 14 moves the combination 3 6 times in the Y direction by the track pitch c to perform the track switching 6 times. Recording or reproduction is performed on the tracks T1 to T48.

A servo reproducing section 5 is provided near one end of the one substrate 2a in the Y direction. The servo reproducing section 5 includes six servo reproducing heads RS1 to RS6 arranged in the Y direction at equal intervals with the track pitch c. The size e in the width direction of each of the servo reproducing heads RS1 to RS6 is set to a value slightly smaller than the track pitch c, for example, 100 μm. The number of these servo reproducing heads RS1 to RS6 is set to the same number as the above-mentioned track switching number. In the present embodiment, since the number of track switching is 6, six servo reproducing heads RS
1 to RS6 are provided. The playback head for each servo
The gaps RS1 to RS6 are also set to be located on the straight line indicated by the dotted line A.

At each track switching position, the driving means 14 moves the combination head 3 in the Y direction on the basis of the outputs of the corresponding servo reproducing heads RS1 to RS6 so that each magnetic head pair is moved.
Control means are provided for guiding H1-H8 to the center of the corresponding track.

This control means is, for example, as shown in FIG.
An amplitude detector 11 for detecting the amplitude of the output of the servo reproducing heads RS1 to RS6 currently used, a reference amplitude voltage generator 12 for generating a reference amplitude voltage, an amplitude detector 11 and a reference amplitude voltage generator 12 Of the servo reproducing heads RS1 to RS6 and the combination head 3 in the Y or -Y direction based on the error signal from the comparator 13. To move to a predetermined track T1 to T48. In addition,
As the driving means 14, for example, a voice coil type linear motor can be preferably used.

Another substrate 7 is fixedly provided on the side of the substrate 2b. A servo signal recording head WS for recording servo signals on one end of the magnetic tape 1 in the width direction is provided near one end of the substrate 7. The dotted line C is an extension line of the gap of the servo signal recording head WS.

Further, although not shown, a flange member is provided to suppress the waving of the magnetic tape 1 in the Y direction to, for example, about ± 50 μm by regulating both widthwise end portions of the magnetic tape 1.

In the above configuration, when recording is performed on the magnetic tape 1, first, the magnetic tape 1 is run in the X direction and servo signal recording is performed on the servo area 8 (indicated by a hunting for convenience) at one widthwise end of the magnetic tape 1. While recording the servo signal by the recording head WS, or after recording, the information is recorded on the tracks T1, T13, T25, T37 every 12 tracks by the odd-numbered recording heads W1, W3, W5, W7. At this time, the odd-numbered reproducing heads R1, R3, R5, and R7 are used to immediately reproduce the recorded information to check if there is any error in recording, and if there is an error, record again. I do. or,
At this time, the servo reproducing head located at the end in the -Y direction
The servo signal in the servo area 8 is reproduced by RS1, and the combination head 3 is moved in the Y direction by the driving means 14 so that the amplitude of the reproduced servo signal becomes a predetermined level, whereby each odd-numbered recording head W1, W3 ,. Tracking is performed by following tracks T1, T13, T25, and T37 that target W5 and W7.

When recording is completed along the tracks T1, T13, T25, and T37 up to the end in the X direction, this time the magnetic tape 1 is moved in the -X direction, and the forward path is moved by the even-numbered recording heads W2, W4, W6, and W8. Tracks recorded from T1, T13, T25, T37 to 6
Twelve tracks that are offset by tracks T7, T19, T31,
Recording is performed on T43, and at this time, even-numbered playback heads R2 and R
Check immediately whether the recorded information is correct by 4 ・ R6 ・ R8. Also at this time, the servo reproducing head RS1 reproduces the servo signal in the servo area 8, and tracking is performed so that the amplitude of the reproduced servo signal becomes a predetermined reference level. Since the servo signal is recorded in the servo area 8 in the outward path, it is not necessary thereafter.

When the recording is completed up to the end portion in the −X direction, the combination head 3 is moved by the track pitch c in the −Y direction by the track pitch c as shown in FIG. 1C, and the magnetic tape 1 is run in the X direction. While recording, information is recorded on the tracks T2, T14, T26, T38 by the odd-numbered recording heads W1, W3, W5, W7. At this time, the servo playback head
Tracking is performed by reproducing the servo signal in the servo area 8 with RS2 and comparing the amplitude thereof with a predetermined reference level.

When recording is completed up to the end in the X direction, this time, the magnetic tape 1 is moved in the -X direction while the even numbered recording heads are moved.
Record on tracks T8, T20, T32, T44 by W2, W4, W6, W8.

Similarly, each time the magnetic tape 1 reciprocates, the combination head 3 is moved in the -Y direction by the track pitch c, and the recording heads W1 to W1
By combining W8 and tracks T1 to T48, information is recorded on all tracks T1 to T48 by a total of 6 track changes. It should be noted that during reproduction as well as during recording, each time the magnetic tape 1 makes one reciprocation, the combination head 3 is moved in the -Y direction by a track pitch c and the tracks T1 to
Although the information of T48 is reproduced, in this case also, tracking is performed by reproducing the servo signal of the servo area 8 by the servo reproducing heads RS1 to RS6 corresponding to each track switching position.

In the present embodiment, since the same number of servo reproducing heads RS1 to RS6 as the number of track switchings 6 are provided, tracking is performed by the corresponding servo reproducing heads RS1 to RS6 at each track switching position. The dynamic range of each of the servo reproducing heads RS1 to RS6 can be made relatively small, whereby linearity and S / N within the dynamic range can be secured and accurate tracking can be performed.

Also, the combination head 3 and the servo reproducing head
Since the thin film heads are used as RS1 to RS6, the dimensional accuracy of each head is improved, and therefore the track switching accuracy can be improved.

Although the servo signal recording head WS for recording the servo signal in the servo area 8 is provided in the above embodiment, for example, if the servo signal is recorded in advance when the magnetic tape 1 is manufactured, the servo signal may be recorded. The recording head WS is unnecessary.

Second Embodiment Next, a second embodiment will be described based on FIG.

In this second embodiment, as shown in FIG.
A pair of servo signal recording heads WSa ・ W at both widthwise ends
Servo areas 8a at both ends of the magnetic tape 1 in the width direction are provided with Sb.
・ The servo signal is recorded in 8b. Further, in the servo reproducing section 5a at the end in the Y direction of the one substrate 2a provided with the combination head 3, the six servo reproducing heads RS1a to RS6a corresponding to the track switching number 6 are equal to the track pitch c. 6 servo reproducing heads RS1b to RS6b corresponding to the track switching number are arranged in the width direction of the magnetic tape 1 at intervals and in the servo reproducing section 5b at the end of the substrate 2a in the -Y direction. They are arranged in the width direction of the magnetic tape 1 at intervals equal to c. Servo playback heads RS1a to RS6a and RS1b to RS at both ends
6b have a one-to-one correspondence such as RS1a and RS1b and RS2a and RS2b. For example, RS1a is a magnetic tape 1 as shown.
When located at one widthwise end of the magnetic tape 1, the corresponding RS1b is located at the other end of the magnetic tape 1. In addition,
The parts having the same configurations as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the second embodiment, when the report is first recorded on the magnetic tape 1, the servo signal recording heads WSa and WSb are used to move the magnetic tape 1 in the X direction while the servo areas at both widthwise ends of the magnetic tape 1 are recorded. Record servo signals on 8a and 8b,
Simultaneously with or after this recording, tracks T1, T13, T25 are recorded by odd-numbered recording heads W1, W3, W5, W7.
・ Record at T37. At this time, the servo playback head RS1a
The amplitude of the servo signal of the servo area 8a reproduced by the servo reproducing head RS1b and the amplitude of the servo signal of the servo area 8b reproduced by the servo reproducing head RS1b are respectively detected by the amplitude detecting groups 15 and 16 (second
(See FIG. 2 (b)), the comparator 13 compares them, and the driving means
At 14, tracking is performed so that both amplitudes become equal. Thereafter, recording is performed on all the tracks T1 to T48 while sequentially switching the tracks as in the first embodiment. Also, during reproduction, track switching is sequentially performed as in recording, and tracking is performed as in recording.

In the second embodiment, as shown in FIGS. 2A and 2B, two sets of servo reproducing heads RS1a to RS6a and RS1b to RS are provided.
Since the outputs of 6b are compared to perform tracking, even if the magnetic characteristics of the individual magnetic tapes 1 vary, two sets of servo reproducing heads RS1a-
Since the outputs of RS6a and RS1b to RS6b cancel each other out, there is an advantage that accurate tracking can be performed.

Third Embodiment Next, a third embodiment will be described based on FIG.

The third embodiment is a modification of the first embodiment, in which the servo reproducing heads RS1 to RS6 are divided into odd-numbered and even-numbered heads and are distributed and arranged on the substrates 2a and 2b. In this way, since the integration degree of the servo reproducing heads RS1 to RS6 can be relaxed, the servo reproducing head RS1 as a thin film head
~ RS6 is easy to manufacture.

[Embodiment 4] FIG. 4 shows a fourth embodiment.

The fourth embodiment is a modification of the second embodiment, and includes servo reproducing heads RS1a to RS in the servo reproducing units 5a and 5b.
6a and RS1b to RS6 are arranged on the substrates 2a and 2b in an even numbered and even numbered manner. Also in this case, the third
Similar to the embodiment, servo reproducing heads RS1a to RS6a and RS
The integration degree of 1b to RS6b is relaxed, and the manufacturing becomes easy.

In each of the above four Examples 1 to 4, the servo reproducing heads RS1 to RS6 (RS) are arranged so as to detect the reproducing output of the tape edge side edge portion of the servo area 8 (8a, 8b).
1a to RS6a and RS1b to RS6b) are arranged, but the servo reproducing heads RS1 to RS6 (RS1a to RS6a, RS1a to RS6a
RS1b to RS6b) may be arranged.

〔The invention's effect〕

As described above, in the tracking control device of the magnetic recording / reproducing apparatus according to the present invention, servo signals are recorded along the widthwise ends of the magnetic tape, and the servo reproducing heads for reproducing the servo signals respectively track the tracks. Servo reproducing sections, which are arranged in the width direction of the magnetic tape by the same number as the track switching number of the head unit at intervals substantially equal to the pitch, are integrally provided with the head unit, and the head units are arranged in the width of the magnetic tape. Drive means for moving the head unit in each direction and control means for controlling the movement amount of the head unit by the drive means based on the detection of the servo signal by the servo reproducing head corresponding to the track switching position at each track switching position. It has a structure.

As a result, when the head unit is sequentially moved in the width direction of the magnetic tape to perform the track switching, the servo reproducing heads of the servo reproducing section are sequentially switched so that the servo reproducing heads corresponding to the respective track switching states are magnetically controlled. By reproducing the servo signal at the widthwise end of the tape, each magnetic head of the head unit can be made to follow the corresponding track at each track switching position. In that case, at each track switching position, the corresponding servo reproducing head reproduces the servo signal, and each servo reproducing head is made to perform the track following operation, that is, only the tracking operation. The dynamic range of the servo reproducing head can be made relatively small, and therefore linearity and
Since S / N can be easily obtained, accurate tracking becomes possible.

[Brief description of drawings]

FIG. 1 shows a first embodiment of the present invention. FIG. 1 (a) is a schematic front view showing the tracking control device. FIG. 3B is a block diagram showing the control means and the driving means. FIG. 7C is a schematic front view showing the track switching operation in the tracking control device. FIG. 2 shows a second embodiment of the present invention. FIG. 2A is a schematic front view showing the tracking control device. FIG. 3B is a block diagram showing the control means and the driving means. 3 and 4 are schematic front views showing the tracking control devices of the third and fourth embodiments, respectively. FIG. 5 is a schematic front view showing a magnetic recording / reproducing apparatus adopting the serpentine system. 3 is a combination head (head unit), 5 ・
5a and 5b are servo reproducing units, 14 is driving means, RS1 to RS6, RS
1a to RS6a and RS1b to RS6b are servo reproducing heads.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-260216 (JP, A) JP-A-2-260217 (JP, A) JP-A-2-260218 (JP, A)

Claims (1)

[Claims] 1. A head unit provided with a predetermined number of magnetic heads is sequentially moved in the width direction of a magnetic tape to perform track switching, and each magnetic head runs along a plurality of tracks parallel to the running direction of the magnetic tape. In a tracking control device in a magnetic recording / reproducing device for recording or reproducing, servo signals are recorded along the widthwise end of the magnetic tape, and the servo signals are reproduced respectively. A servo reproducing unit is provided integrally with the head unit, in which the servo reproducing heads are arranged along the width direction of the magnetic tape by the same number as the track switching number of the head unit at intervals substantially equal to the track pitch. Drive means for moving the head unit in the width direction of the magnetic tape, and the respective track switching positions. In addition, the magnetic recording / reproducing apparatus is provided with a control means for controlling the moving amount of the head unit by the driving means based on the detection of the servo signal by the servo reproducing head corresponding to the track switching position. Tracking controller.