JPH04344316A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To realize high density and high speed while securing the subordinate interchangeability as the peripheral equipment of computer by adopting a serpentine recording and reproducing system and a dynamic tracking. CONSTITUTION:The movement of the head accompanied by the changeover of the track adopting the serpentine recording and reproducing system requires relatively large movement amount in a track pitch (a) unit. A head movement means 8 for coarse adjusting mechanism and a head position adjustment means 9 for fine adjustment are provided. The means 8 and 9 can be driven independently, and the means 8 is driven and controlled by open loop and the means 9 by closed loop. The driving characteristic require for the means 8 is relatively low, and the stepping motor is most suitable. On the other hand, the driving characteristic required for the means 9 is relatively high and the combination of parallel leaf spring and the voice coil motor is best suited. For the closed loop control feedback signal, the driving signal from the head position adjustment means driving circuit 10 is used.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention provides information while adjusting the head position so that a magnetic head (hereinafter simply referred to as a head) follows the meandering width direction of a magnetic tape (hereinafter simply referred to as a tape). The present invention relates to a magnetic recording and reproducing device that performs recording and reproducing.

0002

[Prior Art] In order to increase the density and speed (high transfer speed) of magnetic recording and reproducing devices, various technological developments are being carried out with the aim of increasing areal recording density as a mainstream technology. . The areal recording density is generally the linear recording density, which is the density in the direction of movement of the magnetic recording medium (in units of BPI=B
It Per Inch) and the track density (using TPI=Track Per Inch as the unit), which is the density in a direction perpendicular to the above direction.

[0003] Focusing on track density and discussing it, excluding those equipped with rotating heads such as VTRs and DATs, magnetic recording and reproducing devices equipped with fixed heads generally use tapes. The number of tracks recorded on the disk is equal to the number of heads, and in order to increase the track density, the track width is narrowed and the number of tracks per unit length is increased. There is. Here, the number of tracks refers to the total number of data tracks formed parallel to the tape running direction, and the number of heads refers to the total number of data tracks formed in parallel to the tape running direction. This refers to the number of heads included.

If the number of tracks per unit length is expressed in terms of track pitch for convenience of explanation, then according to the prior art, a magnetic material such as ferrite is processed by machining technology to form the structure of the head. For bulk type heads, the limit was about several hundred μm.

On the other hand, thin film magnetic heads (
Hereinafter, this will be simply referred to as a thin film head. ), several tens of μ
It is possible to realize a track pitch of about m to 100-odd μm, and there are various reported examples of heads having a track pitch of 100-odd μm.

As described above, by employing a thin film head, it is possible to increase the number of tracks more than before, but on the other hand, there is a problem that the scale of the parallel processing circuit increases. Furthermore, it is possible to limit the scale of the parallel processing circuit and sequentially switch the tracks, but in this case, a separate track switching circuit is required, which inevitably leads to an increase in the circuit scale.

In view of the above-mentioned problems, multi-track magnetic recording and reproducing devices, typified by backup storage devices for information processing systems, employ a system called the serpentine recording and reproducing method.

[0008] This allows the number of heads to be smaller than the number of tracks on the tape (sequential switching of tracks is required), and when processing data signals, Read is used to ensure reliability.
After writing is performed, and recording and reproducing are performed in a round trip in order to further shorten processing time.

The serpentine recording and reproducing method will now be briefly explained with reference to FIG.

First, a tape 1 whose running direction is X and whose width direction is Y is formed, for example, at equal pitches a in the Y direction.
It is assumed that there is a track group 2 consisting of six tracks T1 to T16. In this case, a combination head 3 including, for example, four recording heads W1 to W4 and four reproducing heads R1 to R4 is arranged for the track group 2. The recording heads W1 to W4 are arranged in parallel in the Y direction at equal pitches b (b=4a), and in the X direction or -X direction. These pairs of recording heads W1 to W4 and reproducing heads R1 to R4 are arranged alternately at each arrangement position in the Y direction.

During a recording or reproducing operation, the combination head 3 is first driven to the position shown in FIG. That is, the centers of the recording head W4 and the reproducing head R1 coincide with the center of the track T1, and similarly the centers of the recording head W4 and the reproduction head R1 coincide with the center of the track T1.
and the center of the reproducing head R2 and the center of the track T5, and the center of the recording head W3 and the reproducing head R3 and the track T.
9, as well as the recording head W4 and the reproducing head R.
4 and the center of track T13 coincide with each other.

Next, when recording is to be performed while maintaining this relative position, the tape 1 is run in the X direction, and the recording heads W1 and W3 simultaneously record on the tracks T1 and T9.

In this case, in order to determine whether data has been correctly recorded, in track T1, immediately after data is recorded by recording head W1, reproducing head R is
1 to play the data, and (Read After
Write) Check the quality of the recording. On track T7, similar confirmation is performed simultaneously using the recording head W3 and the reproducing head R3. If a recording defect occurs on track T1, rewind the tape 1 to the point before the defective location and record data again using the recording head W1 (
Rewrite). This Read After W
rite and rewrite operations are similar to other T2~
The same is true for all tracks spanning T16. When the recording up to one end in the longitudinal direction of the tape 1 is completed in this manner, the tape 1 is now run in the -X direction, and recording is simultaneously performed on tracks T5 and T13 by the recording heads W2 and W4. After recording to the end of the tape 1 in the longitudinal direction, the combination head 3 is moved in the -Y direction by the track pitch a, and arranged so that the centers of the recording head W1 and the reproducing head R1 coincide with the center of the track T2. Set up Thereafter, while maintaining this relative position, recording is performed on tracks T2, T6, T10, and T14 while moving the tape 1 back and forth once in the X and -X directions in the same manner as described above. While moving the combination head 3 in the -Y direction by a distance each time,
Information is recorded on all tracks T1 to T16 in a total of four round trips.

In the multi-track magnetic recording and reproducing apparatus using the serpentine recording and reproducing method, recording and reproducing are performed on multiple tracks by moving a small number of heads in the tape width direction, so the track pitch becomes small and the number of tracks decreases. Even if the number increases, it is possible to cope with the increase by moving the head many times.

[0015] These conventional techniques are disclosed, for example, in Japanese Patent Application Laid-Open No. 157305/1982, and are head positioning techniques using open loop control using a stepping motor as an actuator for the movement of the head in the tape width direction. has been reported. Also, JP-A-62-183
No. 018 and Japanese Patent Application Laid-open No. 183019/1983 disclose in more detail the open-loop control head positioning technology using a stepping motor, and specifically, determine the reference position of the head with a simple configuration. A possible method for calibrating the positioning mechanism has been reported.

On the other hand, the above-mentioned magnetic recording and reproducing apparatus is equipped with a tape position regulating means for regulating the relative position of the tape with respect to the head, and the structure includes a pair of flanges that guide both ends of the tape in the width direction. Generally, a guide post or the like is provided along the tape running path.

However, the tape position regulating means described above is
Mechanical stress is applied to the top and bottom ends of the tape, which may damage the top and bottom ends. Therefore, in the above-mentioned regulation means, the regulation width of several tens of micrometers is the limit due to the need to avoid damage to the tape end, and high-density recording and reproduction where the allowable off-track amount is about ten to several tens of micrometers is the limit. In the device, it was not sufficient to restrict the meandering of the tape using the flanges mentioned above. Furthermore, in a multi-track magnetic recording/reproducing apparatus equipped with a combination of thin-film heads with a large number of heads, recording with a narrow track width is possible, but the allowable off-track amount is also reduced accordingly.

From the above, as the tape/head relative position regulating means, in addition to the above-mentioned flange regulating structure,
A means for detecting the relative position of the head and the tape or track, and a head driving means for moving the head in the width direction of the tape. A configuration is adopted in which the head is controlled to follow the waving (hereinafter referred to as waving).

An example of such a device is a fixed head digital audio tape recorder with an equal number of heads and tracks. The device uses, for example, IEICE Technical Report EA83-56, 81-64 and Sharp Technical Report 198.
As disclosed in 4-28, a servo-dedicated track recorded on a tape is traced by two playback heads arranged in parallel in the tape width direction, and the playback outputs are compared to perform follow-up control. This structure regulates the relative position between the head and the tape.

As another example of tape head relative position regulating means, in a magnetic recording/reproducing device in which the number of heads is equal to the number of tracks, a tracking signal is recorded at one end in the width direction of the tape, and this is used for servo reproduction. Either play it back with the head and compare the signal level with the reference level, or record tracking information on both ends of the tape in the width direction.
A configuration has been proposed in which tracking is performed by reproducing these signals using a pair of servo reproducing heads and comparing the signal levels (see Japanese Patent Publication No. 63-64811).

However, in either case, if you try to increase the track density (TPI), the number of heads will increase, and the parallel processing circuit scale will increase, or a track switching circuit will be required, which will increase the circuit scale. There was a point.

[0022]

[Problems to be Solved by the Invention] As mentioned above, in order to achieve higher density and higher speed in a multi-track magnetic recording/reproducing device, it is necessary to (1) increase the number of tracks (reduce the track width) ( 2) Higher accuracy in tracking (3) Reduction in the scale of parallel processing circuits (4) Shorter information processing time (5) Miniaturization and lower cost of magnetic recording and reproducing devices had to be solved. .

[0023]

[Means for Solving the Problems] In addition to employing the above-mentioned serpentine recording and reproducing method, the present invention employs a means for detecting the relative position of the head and the tape, and a head moving means for moving the head in the width direction of the tape. The above-mentioned problem is attempted to be solved by adopting a configuration (hereinafter referred to as dynamic tracking) in which the head is controlled to follow the waving of the tape. That is, the above-mentioned problems 1 and 2 are addressed by adopting dynamic tracking, and problems 3 and 4 are addressed by adopting the serpentine recording/reproducing method.

Specifically, (A) a thin film combination head is used in which a magnetic gap for recording and reproducing data signals and a magnetic gap for recording and reproducing servo signals are formed on the same substrate, and (B) a magnetic gap for recording and reproducing data signals is used. The timing is to first record a servo signal, and then record and reproduce the data signal while reproducing the servo signal. (C) Dynamic tracking arranges two servo tracks on the tape and 2 obtained by playing
(D) Performing closed-loop control based on the difference signal between two servo signals, or based on the difference signal between one of the two servo signals and a reference signal; (D) Head movement associated with track switching in accordance with the serpentine recording/playback method and head position adjustment associated with dynamic tracking may be performed using separate actuators or a single actuator (E).
) If the head movement associated with track switching based on the serpentine recording/playback method and the head position adjustment associated with dynamic tracking are performed using separate actuators, the head movement must be performed using a single actuator. If this is done, move the head and adjust the position of the head using a stepping motor.

[0025]

[Operation] By conforming to the serpentine recording and reproducing method and adopting dynamic tracking, it is possible to achieve higher density and higher speed while ensuring backward compatibility as a computer peripheral device.

[0026]

[Embodiment] An embodiment of the present invention will be explained in detail using FIGS. 1 to 6.

[0027] This example is

This shows a magnetic recording and reproducing device based on the serpentine recording and reproducing method described in [Prior Art].The number of heads is smaller than the number of tracks on a tape, and recording and reproducing is performed by running the tape back and forth while sequentially switching tracks. It is something to do.

As shown in FIG. 1, the magnetic recording/reproducing device has the following features:
A pair of substrates 3a and 3b are provided, each extending in the Y direction, which is the width direction of the tape 1, and bonded to each other.
Data signal recording heads W1 to W4 and data signal reproducing heads R1 to R4 formed as thin film heads on a and 3b.
and servo signal recording/reproducing heads S1 to S4, S1' to
S4' constitutes a combination head 3 as a head unit. combination head 3
is moved in the Y or -Y direction by the head moving means 8 shown in FIGS. 3 to 6. As the tape 1, for example, a standard product with a width of 3.8 mm is used, and the tape 1 has 16 data tracks each extending parallel to the running direction (X direction) and arranged in the Y direction at a predetermined track pitch a. Data signals are recorded and reproduced along DT1 to DT16. Furthermore, Y
Servo signals are recorded and reproduced along two servo tracks ST1 and ST2, which are located on both sides of the data tracks DT1 to DT16 in the direction and arranged with a predetermined track pitch (here, 2a). .

Next, in the combination head 3, odd-numbered data signal recording heads W1, W3 and even-numbered data signal reproducing head R2 are mounted on one substrate 3a.
, R4 and the odd-numbered servo signal recording/reproducing head S1
, S1', S3, and S3' are arranged, and the gap position of each head on the substrate 3a is set on the straight line 3c. Further, on the other substrate 3b, even-numbered data signal recording heads W2, W4, odd-numbered data signal reproducing heads R1, R3, and even-numbered servo signal recording/reproducing heads S2, S2', S4, S4' are arranged. The gap position of each head on the substrate 3b is set on the straight line 3d. Corresponding data signal recording head W1 and data signal reproducing head R1, similarly W2 and R2, W3 and R3, W4 and R
4 are arranged side by side in the X direction, which is the running direction of the tape 1, to constitute data signal recording/reproducing head pairs H1 to H4, and a data signal recording head and a data signal reproducing head are arranged for each adjacent pair of data signal recording/reproducing heads. The positions in the X direction are swapped. Also, the track width of the data signal recording head and data signal reproducing head (width in the Y direction)
In consideration of waving of the tape 1, etc., the recording width of each data signal recording head W1 to W4 is set to be slightly larger than the reproduction width of each data signal reproducing head R1 to R4. The interval in the Y direction between adjacent data signal recording/reproducing heads is set to b=4a, and the head moving means 8 moves the combination head 3 at a track pitch a.
By moving each track four times in the Y direction and switching tracks four times, data signals are recorded or reproduced in all data tracks DT1 to DT16.

Next, odd-numbered servo signal recording/reproducing heads S1, S1', and S3 disposed on one substrate 3a
and S3' constitute a pair, and the positional relationship in the Y direction is such that the center of the data signal reproducing head R4 in the Y direction is located further downward at a distance 2a from the servo signal recording head S1.
The center of the servo signal recording/reproducing head S1' in the Y direction is further upward by a distance of 1.5a from the center of the data signal recording head W1 in the Y direction (in the +Y direction). servo signal recording/reproducing head S3'
It is set so that the center of the Y direction is located. The even-numbered servo signal recording/reproducing heads S2 and S2' and S4 and S4' disposed on the other substrate 3b also constitute pairs, and the positional relationship in the Y direction is the same as that of the data signal recording/reproducing head S4. The center of the Y-direction of the servo signal recording/reproducing head S2 is located downward at a further distance of 2a, and the center of the servo signal recording/reproducing head S2 is located upward of the data signal reproducing head R1 at a distance of 2.5a from the center of the Y-direction of the servo signal recording/reproducing head. S2'
The center of the servo signal recording/reproducing head S4' in the Y direction is located above the servo signal recording/reproducing head S4' by a further distance 2a.

That is, in the Y direction, the servo signal recording/reproducing heads S2, S2 forming the next pair are located above the pair of servo signal recording/reproducing heads S1, S1' at a distance a (=data track pitch) apart. ' is located, and servo signal recording/reproducing heads S3 and S3' forming the next pair are located above a distance a in the same way, and servo signal recording/reproducing heads S3 and S3' forming the next pair are similarly located above a distance a. Recording and reproducing heads S4 and S4' are located there.

Regarding the X direction, as mentioned above, the odd numbered servo signal recording/reproducing heads S1, S1', S3,
The center of the X direction of S3' is on the straight line 3C, and the X of even numbered servo signal recording/reproducing heads S2, S2', S4,
Since the center of the direction is located on the straight line 3d, each servo signal recording/reproducing head pair has a track pitch a as shown in FIG. 1 when viewed in both the X and Y directions, and is arranged in a staggered manner. This means that it has been set up.

The layout of this servo signal recording/reproducing head has the following advantages. First of all, in order to increase the amount of information that can be recorded in the tape width direction, the area for recording data signals must be set as wide as possible. In other words, it is desirable that the area used for purposes other than recording data signals, such as servo tracks, be narrower. In order to meet this requirement, in the present invention, only two servo tracks, which are a necessary and sufficient condition, are provided on the tape. Secondly, it is desirable that the servo track width be wide in order to obtain a wide dynamic range, but for the first reason mentioned above, in the present invention, the track width is set to be equivalent to the data track width. This value indicates that tape 1 is DC in the tape width direction.
Even if there is a large change in direction (for example, when the direction of travel is reversed), it is sufficient as long as there is enough width to enable dynamic tracking.

To explain in more detail, for example, focusing on the servo track ST2 and the servo signal recording/reproducing head S1 in FIG. 1, if the tape 1 is displaced in the positive Y direction with respect to the theoretical position shown, The distance from which the servo signal recording/reproducing head S1 separates in the Y direction is 1.5a. Conversely, when the tape 1 is displaced in the negative Y direction, the servo track ST2 and the servo signal recording/reproducing head S1 separate. The distance until separation in the Y direction is 0.5a. On the other hand, if we pay attention to the servo track ST1 and the servo signal recording/reproducing head S1', we can see that the tape 1
It can be said that there is a displacement margin of 0.5a when the displacement is in the positive Y direction, and 1.5a when the displacement is in the negative Y direction. Since the servo tracks ST1, ST2 and the servo signal recording/reproducing heads S1, S1' form a pair, when the tape 1 is displaced in the positive Y direction, the servo signal recording/reproducing head S1 is displaced in the negative Y direction. If the displacement occurs, the servo signal recording/reproducing head S1' is used to pull it into dynamic tracking.
Maximum of just under 1.5a (1.5
When displaced to a, the playback output of the servo signal recording/playback head becomes 0 and cannot be pulled into dynamic tracking.)
It is possible to secure a tape displacement margin of . Here, the amount of displacement of tape 1 includes the DC displacement when the tape is stopped.D
Then, if D<1.5a, dynamic tracking can be performed no matter where the tape 1 is located. Generally, the amount of displacement D of the tape 1 can be reduced to several tens of μ by providing a position regulating means such as a tape guide.
m, so if D = 30 μm, a
>20 μm, which is a sufficiently reasonable track width compared to the currently common track width of thin-film magnetic heads, which is about 50 to 120 μm, and at the same time allows for higher recording density in the tape width direction. It can be seen that this can be adequately addressed. Thirdly, when the track pitch on a tape is reduced as the recording density increases, the pitch of adjacent heads (in particular, we will focus on the pitch of adjacent servo signal recording/reproducing heads here) must also be reduced. However, when adjacent heads are arranged on the same gap line, there are constraints such as the space required to form a head structure such as a coil winding, and track pitch = head pitch = head pitch = track width ( Here, it is difficult to set the servo track width=servo signal recording/reproducing head pitch).

In order to solve this problem, the present invention uses four pairs of servo signal recording/reproducing heads S1 as described above.
-S1', S2-S2', S3-S3', S4-S4'
are arranged in a staggered manner, so adjacent servo signal recording/reproducing heads located substantially on the same gap line have twice the head pitch (=2a), and track pitch = head pitch = It becomes possible to realize a track pattern having the same track width. This can be said to be a great advantage in reducing the track pitch. Here, the servo track width is set to 20 μm.
Assuming this, the pitch of adjacent servo signal recording/reproducing heads located on the same gap line is 40 μm, which is within the range that can be handled with the current technological level.

Next, recording on servo tracks ST1 and ST2 will be explained. FIG. 2 shows that from the state shown in FIG.
The combination head 3 is moved to Y by the head moving means 8.
It shows a state in which it has moved downward by a distance of 1/2 a. In this state, the center of the servo track ST1 in the Y direction, the center of the servo signal recording/reproducing head S2' in the Y direction, and the center of the servo track ST2 in the Y direction and the center of the servo signal recording/reproducing head S1 in the Y direction are aligned. We are doing so. However, in this case, the servo track ST
The center in the Y direction of 1 and ST2 indicates the theoretical position where the centers of both tracks should be located, and it is assumed that no servo signal is recorded on the tape 1 in this state.

In this state, the tape 1 is run in the X direction,
Servo signals are recorded on servo tracks ST1 and ST2 using servo signal recording/reproducing heads S1 and S2'. While tape 1 is running, there may be fluctuations in tape tension, vibrations of rotating bodies such as reels, or structures such as tape guides (
Waving occurs on tape 1 due to the inclination of the member (with which the tape comes into contact), and when viewed from the edge of tape 1, the two recorded servo tracks meander up and down in the Y direction. Become.

However, a pair of servo signal recording/reproducing heads (in the case of FIG. 2,
S1, S2') are fixed integrally during servo signal recording and reproduction, so the relative positional relationship between both servo tracks is constant (center distance 19a in the case of FIGS. 1 and 2).
Furthermore, when recording and reproducing data signals, dynamic tracking is performed while reproducing the servo signals of both servo tracks ST1 and ST2 (details will be described later). will be canceled.

Furthermore, recording on servo tracks ST1 and ST2 is performed using other servo signal recording/reproducing head pairs S2-S3.
', S3-S4', and in that case, the center of the servo track ST1 in the Y direction is S3.
The combination head 3 may be moved by the head moving means 8 so that the center of S2 or S4 in the Y direction coincides with the center of servo track ST2 in the Y direction. . There are no particular restrictions on the selection of the servo signal recording/reproducing head pair, and any servo signal recording/reproducing head pair may be used.

Next, reproduction of the servo track will be explained. As mentioned above, the combination head 3 moves four times in the Y direction to switch tracks. Considering this as a static head position, the position shown in FIG. 3
The positions where are moved downward in the Y direction are respectively positions 2~
Set it to 4.

At position 1, the servo signal recording/reproducing head pair S1-S1' takes the position shown in FIG. 1 with respect to the tape 1. In other words, Y of servo track ST2
With respect to the center of the servo track ST1, the center of the servo signal recording/reproducing head S1 in the Y direction is located upwardly in the Y direction by 1/2 a distance, and the servo signal recording/reproducing head S1 is located upward in the Y direction with respect to the center of the servo track ST1. The center of the reproducing head S1' in the Y direction is located at a position spaced downward in the Y direction by 1/2 the distance a. In this state, the servo signal recording/reproducing head pair S1-S1'
When the servo tracks ST1 and ST2 are reproduced using the servo signals, reproduction output voltages of V are obtained from the servo signal recording/reproducing heads S1 and S1', respectively. This corresponds to one half of the reproduction output voltage obtained when a servo signal is reproduced with the center of an arbitrary servo signal recording/reproducing head in the Y direction coinciding with the center of an arbitrary servo track in the Y direction.

Similarly, at position 2, the reproduction output voltage V is obtained by the servo signal recording/reproducing heads S2 and S2', and at position 3, the servo signal recording/reproducing heads S4 and S4', respectively.

To summarize the above, the combination head 3 is positioned at static head positions of positions 1 to 4 for track switching, but at each position, the combination head 3 is positioned at static head positions for the two servo tracks ST1 and ST2. The corresponding pairs of servo signal recording/reproducing heads are positioned at positions separated by a half pitch (1/2 a, which corresponds to 1/2 of the width of the servo signal recording/reproducing heads).

Here, when the running direction of the tape 1 is in the X positive direction, it is called an outward path, and when it is in the negative X direction, it is called a backward path, and the tracks and heads used at each position are summarized in Table 1.

[0045]

[Table 1]

In Table 1, either one of ST1 or ST2 (this will be described later) or two servo tracks are used at any position. The above has described the arrangement of tracks and heads during track switching in accordance with the serpentine recording/reproducing method.Next, the operation of dynamic tracking will be explained.

The basic operation of dynamic tracking is that when waving occurs on the tape 1 at each position and the tape 1 moves from its theoretical position in the Y direction, the servo signals of the recording and reproducing heads corresponding to the servo tracks ST1 and ST2 are activated. Based on the change in the reproduction output voltage, the combination head 3 is moved in the Y direction by the head moving means 8 in the case of FIGS. 3 and 4, and by the head position adjustment means 9 in the cases of FIGS. 5 and 6, and each data signal is This guides the recording/reproducing head pairs H1 to H4 to the center of the corresponding data track in the Y direction. This guidance is shown in Figure 3.
- This is carried out by the control means shown in FIG. First, the control means shown in FIGS. 3 and 5 includes a switch 4 for selecting the reproduction output voltage of one of the pair of servo signal recording/reproducing heads, and a reference voltage V0. a reference voltage generator 6; a comparator 5 that compares the outputs of the servo signal recording/reproducing head selected by the switch 4 and the reference voltage generator 6 to generate an error signal;
and a head moving means driving circuit 7 or head position adjusting means driving circuit 10 that outputs a drive signal to the head moving means 8 or head position adjusting means 9 based on the error signal obtained from the comparator 5, The means 8 or the head position adjusting means 9 is a head moving means driving circuit 7.
Alternatively, the combination head 3 is moved in the Y direction based on a drive signal from the head position adjustment means drive circuit 10 to follow predetermined data tracks DT1 to DT16. Here, the reference voltage V0 is a state in which the center of the servo signal recording/reproducing head corresponding to a given servo track in the Y direction is located half a pitch (=0.5a) away from the center of the servo track in the Y direction. is equal to the reproduced signal output obtained from the servo signal recording/reproducing head. Next, the control means shown in FIGS. 4 and 6 includes a comparator 5 that generates an error signal by comparing the respective outputs obtained from the pair of servo signal recording/reproducing heads, and an error signal obtained from the comparator 5. A head moving means driving circuit 7 or head position adjusting means driving circuit 1 outputs a drive signal to the head moving means 8 or head position adjusting means 9 based on
The head moving means 8 or the head position adjusting means 9 moves the combination head 3 in the Y direction based on the drive signal from the head moving means driving circuit 7 or the head position adjusting means driving circuit 10, and moves the combination head 3 to a predetermined position. It is made to follow data tracks DT1 and DT16. In the above two types of configurations, when recording a data signal on the tape 1, the combination head 3 is first moved to position 1 by the head moving means 8. Next, the tape 1 is run in the positive X direction, and while dynamic tracking is activated using the servo signal recording/reproducing head pairs S1 to S1', data signals ( information). At this time, the data signal reproducing heads R1 and R3 immediately reproduce the recorded data signal to check whether there are any errors in the recording, and if there are any errors, recording is performed again. When the tape 1 runs to the end in the positive X direction in this state, the running direction is switched to the negative X direction, and the data signal recording heads W2, W4 and the data signal reproducing heads R2, R4 are used to record the data while leaving position 1 as it is. Data track signals are simultaneously recorded and reproduced on tracks DT5 and DT13. At this time as well, using the servo signal recording/reproducing head pair S1-S1', the servo tracks ST1, S are
T2 is reproduced and the combination head 3 is moved in the Y direction by the control means shown in FIGS. The position adjustment (tracking) of the combination head 3 is performed in a closed loop so that the recording is performed at a position where the data is not recorded. When the tape 1 travels to the end in the negative X direction (=starting end in the positive X direction), the combination head 3 is moved to position 2 by the head moving means 8. Next, the tape 1 is run in the X positive direction, and at the same time the servo signal recording/reproducing head S2,
While reproducing the servo tracks ST1 and ST2 using S2' and adjusting the position of the combination head 3 to an appropriate position in the Y direction using the control means in a closed loop, data tracks are sequentially reproduced using the track and head combinations shown in Table 1 below. The data signal is recorded in the same manner as above. The above operation relates to the case where a data signal is recorded on a tape on which no data signal has been recorded or has been erased, but when a data signal is already recorded (in this case, a servo signal is also recorded), or If only the servo signal has already been recorded, move the combination head 3 to position 1, run the tape 1 in the forward X direction, and simultaneously move the servo signal recording/reproducing head S.
1, S1' is used to reproduce the servo tracks ST1, ST2, the control means adjusts the position of the combination head 3, and in the first case, the data signal reproduction heads R1, R3 are used to reproduce the data signal. In the second case, data signal recording/reproducing head pair H1,
Data signals are recorded and reproduced using H3. Thereafter, while adjusting the position of the combination head 3 to an appropriate position in the Y direction in a closed loop by the control means, data signals are sequentially recorded on the data tracks using the combinations of tracks and heads shown in Table 1 (on data tracks that have already been recorded). (including when overwriting data signals),
Alternatively, data signals of already recorded data tracks may be reproduced. In addition, the data signal recording head W mentioned above
1 to W4, data signal reproducing heads R1 to R4, and servo signal recording and reproducing heads S1, S1' to S4, and S4' have been described as thin film heads, but the present invention can also be practiced using bulk type magnetic heads. It is clear that this can be done.

Next, a description will be given of the actuator used for head movement accompanying track switching in accordance with the serpentine recording/reproducing method and head position adjustment associated with dynamic tracking.

First, the former movement of the head is an operation that involves a relatively large amount of movement (generally about 100-odd μm) in units of track pitch a in FIG. It is about Hz. Hereinafter, for convenience, this will be referred to as coarse movement. On the other hand, for the latter head position adjustment, as mentioned in the explanation of the layout of the servo signal recording/reproducing head, the amount of movement is less than a few tens of μm, but the required response frequency is about several Hz to 100 Hz. The operation is as follows. Hereinafter, for convenience, this will be referred to as microtremor. In order to perform these two operations with different amounts of movement and response frequencies, it is necessary to use two dedicated actuators that have characteristics adapted to each operation, or to use two dedicated actuators that have characteristics that are suitable for each operation, or to use an actuator that can be adapted to each operation narrower. There are two possible configurations: using one actuator that can handle each operation.

First, FIGS. 5 and 6 show the former configuration, which is provided with head moving means 8 for coarse movement and head position adjustment means 9 for fine movement. Here, the head moving means and head position adjusting means are referred to as:
This is because the actual configuration consists of the above-mentioned actuator and a mechanism section for transmitting its driving force to the outside, but in the following, it will mainly be treated as meaning the actuator. As shown, head moving means 8
A head position adjustment means 9 is mounted on the upper part of the head position adjustment means 9, and a combination head 3 is mounted on the upper part of the head position adjustment means 9. The head moving means 8 and the head position adjusting means 9 can be driven independently, and the head moving means 8 drives the head position adjusting means 9 in a closed loop.
is controlled in a closed loop. The drive characteristics required for the head moving means 8 are relatively low as described above, and specifically a stepping motor is optimal, but if a position detection sensor is provided, a DC motor can be used. You can also do it. On the other hand, the drive characteristics required for the head position adjustment means 9 are relatively high performance as described above, and several μ
Since m-order resolution is required, the combination of a parallel leaf spring and a voice coil motor is optimal. Further, a drive signal from the head position adjustment means drive circuit 10 is used as a feedback signal for performing closed loop control. If these actuators are used, it is possible to satisfy high required characteristics, but they have the disadvantages that it is difficult to miniaturize the mechanism and the scale of the drive circuit becomes large.

Next, FIGS. 3 and 4 show the latter configuration, which is provided with only head driving means 8 for both coarse and fine movement. In this case, since there is only one actuator, the range of drive characteristics that can be achieved is narrower, but it is easier to downsize the mechanism, and the drive circuit size is also smaller.
It has the advantage of being easy to reduce costs. Basically, performing open-loop control for coarse movement leads to improved cost benefits, so a stepping motor is preferable as the actuator in this case. However, since fine movement requires a resolution on the order of several μm, it is necessary to adopt a microstep driving method. In other words, if you use the open-loop drive method with 1-2 layer excitation (or 1-layer excitation, 2-layer excitation, or double-layer excitation) for coarse motion, and use the closed-loop microstep drive method for fine motion, the above requirements can be met. The dividing ability can be satisfied. Further, in order to improve the division accuracy of the microstep driving method, it is more effective to correct the excitation layer division current. As for frequency response, by adding a phase compensation circuit, characteristics close to the required characteristics can be obtained.

[0052]

Effects of the Invention The magnetic recording/reproducing device according to the present invention has (A
) A thin film combination head is adopted in which a magnetic gap for recording and reproducing data signals and a gap for recording and reproducing servo signals are formed on the same substrate. While reproducing the servo signal, record and reproduce the data signal, (C
) Dynamic tracking involves arranging two servo tracks on a tape and performing closed-loop control based on the difference signal between the two servo signals obtained by reproducing the servo tracks, or by using two servo signals. Closed-loop control is performed based on the difference signal between one of the servo signals and the reference signal, and (D) head movement associated with track switching in accordance with the serpentine recording/reproduction method and head movement associated with dynamic tracking are performed. For position adjustment, use two dedicated actuators with characteristics adapted to each operation, or use one actuator that can adapt to each operation, and (E) track switching based on the serpentine recording and playback method. When the head movement associated with dynamic tracking and the head position adjustment associated with dynamic tracking are performed using separate actuators, the movement of the head is performed, and when a single actuator is used, the movement of the head and the head position adjustment are performed using separate actuators. Since position adjustment is performed using a stepping motor, (1) increase in the number of tracks (2) increase tracking accuracy (3) reduce parallel processing circuit size (4)
Shortening of information processing time (5) Problems such as miniaturization and cost reduction of magnetic recording/reproducing devices can be solved, and further higher density and higher speed can be realized.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of a magnetic recording and reproducing apparatus showing an embodiment of the present invention.

FIG. 2 is a schematic front view of a magnetic recording/reproducing device showing an embodiment of the present invention.

FIG. 3 is a block diagram showing a control means and a head moving means of a magnetic recording/reproducing apparatus according to an embodiment of the present invention.

FIG. 4 is a block diagram showing a control means and a head moving means of a magnetic recording and reproducing apparatus according to an embodiment of the present invention.

FIG. 5 is a block diagram showing a control means and a head moving means of a magnetic recording/reproducing apparatus according to an embodiment of the present invention.

FIG. 6 is a block diagram showing a control means and a head moving means of a magnetic recording and reproducing apparatus according to an embodiment of the present invention.

FIG. 7 is a schematic front view of a magnetic recording and reproducing apparatus employing a serpentine recording and reproducing method, which is an embodiment of the prior art.

[Explanation of symbols]

1 Tape 2 Track group 3 Combination head 4 Switch 5 Comparator 6 Reference voltage generator 7 Head moving means driving circuit 8 Head moving means 9 Head position adjusting means 10 Head position adjusting means driving circuit DT1 to DT6 Data tracks ST1, ST2 Servo track W1 to W4 Data signal recording head R1 to R4 Data signal reproducing head S1, S1' to S4, S4' Servo signal recording and reproducing head

Claims (9)

[Claims] Claim 1: In a magnetic recording and reproducing device that records and reproduces information on a tape-shaped magnetic recording medium, in accordance with the serpentine recording and reproducing method, a tape for head positioning is first applied to a tape on which no information is recorded or has been erased. 1. A magnetic recording/reproducing apparatus characterized in that when recording a servo signal and then recording information, the information is recorded while adjusting a head position based on the servo signal. 2. In a magnetic recording and reproducing device that records and reproduces information on a tape-shaped magnetic recording medium, in accordance with the serpentine recording and reproducing method, a head positioning device is first applied to a tape on which no information is recorded or has been erased. When recording information next time, record the information while adjusting the head position based on the first recorded servo signal, and then play back the information or write it to another empty track. A magnetic recording/reproducing device characterized in that when recording information, the information is recorded or reproduced while adjusting the head position based on a servo signal recorded first. 3. The magnetic gap for recording or reproducing the servo signal uses a thin film head formed on the same substrate as the magnetic gap for recording or reproducing information. A magnetic recording/reproducing device according to claim 1 or claim 2. 4. Two servo tracks are arranged on the tape, and the head position is adjusted in a closed loop based on a difference signal between the two servo signals obtained by reproducing the servo tracks. Claim 1 or 2 of the scope of claims
or the magnetic recording/reproducing device according to 3. 5. The head position with respect to the tape is adjusted in a closed loop based on a difference signal between one of the two servo signals and a reference signal. 4. The magnetic recording and reproducing apparatus according to claim 1, 2 or 3. 6. Based on the movement of the head accompanying track switching in accordance with the serpentine recording/reproducing method and the difference signal between the two servo signals, or the difference signal between one of the servo signals and the reference signal. 5. The magnetic recording and reproducing apparatus according to claim 1, wherein the head position adjustment controlled in a closed loop is performed using individual actuators. 7. Based on head movement accompanying track switching in accordance with the serpentine recording/reproducing method and a difference signal between the two servo signals, or a difference signal between one of the servo signals and a reference signal. 6. The magnetic recording and reproducing apparatus according to claim 1, wherein the head position adjustment controlled in a closed loop is performed using one actuator. 8. The magnetic recording and reproducing apparatus according to claim 6, wherein a stepping motor is used as an actuator for moving the head in accordance with the serpentine recording and reproducing method when switching tracks. 9. Based on the movement of the head accompanying track switching in accordance with the serpentine recording/reproducing method and the difference signal between the two servo signals, or the difference signal between either of the servo signals and the reference signal. 8. The magnetic recording and reproducing apparatus according to claim 7, wherein a stepping motor is used as an actuator for adjusting the position of the head controlled in a closed loop.