JPS62231479A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To eliminate off-track on a magnetic recording medium by recording data for off-track correction in advance to a data magnetic recording medium and using the said data to change the voltage of a servo head applying position control on the magnetic recording medium thereby moving the servo head. CONSTITUTION:A servo magnetic recording medium 13 and two data magnetic recording media 14 recorded with off-track correction data in advance are fitted to the rotary shaft 12 of a spindle motor, and a servo head 15 and a data head 6 contact each track of the media 13, 14. The heads 15, 16 are fitted to the tip of the arm 17 at a position overlapped longitudinally and the arm 17 is moved on the media 13 and 14 by the drive mechanism of the carriage 18. Then the voltage is changed by using the required off-track correction data to move the position of the servo head on a servo magnetic recording medium from the intrinsic position. The servo head is moved in the direction reversely by the same quantity as the moved offset, resulting in that the data head is placed on the accurately on the data magnetic recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording and reproducing apparatus that corrects the position of a magnetic head in, for example, a hard disk drive.

(Prior Art) Generally, in a magnetic recording/reproducing apparatus using a magnetic recording medium, servo control is performed in order to record data at high density.

FIG. 5 shows an example of a magnetic recording/reproducing device, in which a base 11 holds a rotating shaft 12 of a spindle morph (not shown). A servo magnetic recording medium 13 dedicated to position control and a data magnetic recording medium 14 for recording data are attached to the rotating shaft 12, respectively.

The position data of the servo magnetic recording medium 13 is read by the servo head 15, and the data of the data magnetic recording medium 14 is read or written by the data head 1G in contact with the respective medium surfaces. The servo head 15 and the data head 16 are formed at the tip of an arm 17 that moves over each medium, and the other end is attached to the drive section of the carriage 18.

Here, the servo head 15 and the data head 16 are formed in vertically overlapping positions, and have a multi-stage structure. This servo head 15 is attached to the base 11.

In a magnetic recording/reproducing device configured as described above, the arm 17 is normally operated to move the servo head 15 and the data head 16 over the servo magnetic recording medium 13 and the data magnetic recording medium 14. be. Each head 15 and 16 then contacts media 13 and 14, respectively.

Here, the servo magnetic recording medium 13 has data for specifying the position recorded on the track, and when the servo head 15 reads this data, the data on the data magnetic recording medium 14 is accurately located. Set. In this way, the data head 18 moves to the position of the track where the necessary data has been recorded and comes into contact with the data magnetic recording medium 14.

However, in a magnetic recording/reproducing device having such a structure, it is difficult to obtain accurate data due to distortion caused by differences in the coefficient of thermal expansion of the individual parts used, the tilt of the base 11 due to unspecified impacts, etc. may not be possible.

FIG. 6 shows an example in which the base 11 is tilted. In this case, the relationship between the servo head 15 and the data head 16 is
It is assumed that there is no difference from normal operation shown in the figure. That is, due to the tilt of the base 11, the servo head 15
Even if the data head 16 indicates the correct position on the servo magnetic recording medium 13, the data head 16 deviates from the original track position 114o and comes into contact with positions 141 and 142, respectively, resulting in an off-track state. Become.

In this off-track state, the data output on the data magnetic recording medium 14 is reduced, causing a data read error.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned points, and the present invention has been made in view of the above-mentioned points. An object of the present invention is to provide a magnetic recording/reproducing device that eliminates off-track on a medium and improves read errors.

[Structure of the Invention] (Means for Solving the Problem) That is, the present invention provides a servo head that records off-track correction data in advance on a data magnetic recording medium and controls the position on the magnetic recording medium using this data. The servo head is moved by changing the voltage value of , so that the data head is set at an accurate position on the data magnetic recording medium.

(Function) The magnetic recording/reproducing device of the present invention records off-track correction data in advance on a track of a data magnetic recording medium,
This data is stored in a memory circuit. Then, the position of the servo head on the servo magnetic recording medium is moved from its original position by changing the voltage value based on off-track correction data for the number of cores. The servo head is moved in the opposite direction by the same amount as the offset amount, so that the data head is set at an accurate position on the data magnetic recording medium.

(Example) An example of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram showing the basic configuration of a magnetic recording and reproducing apparatus according to an embodiment of the present invention.
2, one servo magnetic recording medium 13 and two data magnetic recording media 14 on which off-track correction data for correction are recorded in advance are attached. Then, a servo head 15 is attached to each track on these media 13 and 14.
and data head 16 contact. these heads 15
and 16 are attached to the tip of the arm 17 in a multi-stage configuration so that they overlap vertically. This arm 11 is moved over the media 13 and 14 by a drive mechanism of a carriage 18.

The carriage 18 receives read/write signals according to instructions from the driver receiver 19. At the time of writing, the write circuit 20 receives the write data signal 21 from the outside and issues an instruction to the carriage 18.

On the other hand, during reading, the signal from the driver receiver 19 is amplified by the read amplifier 22, and the read data signal @24 is outputted via the read circuit 23. Further, off-track correction data of the data magnetic recording medium 14 outputted from one driver receiver is detected by a signal detection circuit 25 and sent to a sample timing generation circuit 26. and,
This output signal is output to the peak hold circuit 27. The signal amplified by the read amplifier 22 is also input to the peak hold circuit 27 .

The signal output from the peak hold circuit 27 is A/D
The signal is converted by the converter 28 and sent to the 1III11 circuit 29. Then, the offset value is stored in the offset value storage circuit 30. Further, the control circuit 29 receives the track selection data signal 31 and outputs a signal of the corresponding track, and the D/A converter 32 converts the signal.

On the other hand, the signal from the servo head 15 is input directly to the read amplifier 33 without passing through the driver receiver 19, and the signal amplified by the read amplifier 33 is output to the peak hold circuit 34. Further, the signal from the servo head 15 is also input to the signal detection circuit 35, and the signal detected here is sent to the sample timing generation circuit 36.
6 is outputted to the peak hold circuit 34.

Then, the signal obtained by the peak hold circuit 34 is output to a position signal generation circuit 37, and further output to a voice coil motor control circuit (hereinafter referred to as VCM control circuit) 38. Here, the signal converted by the D/A converter 32 is also input to the VCM control circuit 38.

A control signal from the V CM $11 m1 circuit 38 is converted from voltage to current by a voice coil motor driver (hereinafter referred to as VCM driver) 39 to drive the voice coil motor 40 . The carriage 18 is driven by the voice coil motor 40 being driven.

In the magnetic recording/reproducing device configured as described above, during writing, a write data signal 21 is sent from the outside to the write circuit 20.
is input to. The write data signal 21 is a pulse wave, which is inverted by the write gate and flip 70 in the write circuit 20 every time the pulse is input, and is output to the driver receiver 19 as a rectangular signal. Then, this rectangular signal is converted into a current by the driver receiver 19 and data is sent to the data head 16, and the data head 1G contacts the data magnetic recording medium 14 to write data on the track.

FIG. 3 (A> and (B) respectively show the magnetic recording medium 13
or the data on 14 and the head 1 that reads this data.
5 or 16, an example of the lead voltage is shown.

Now, on the track of the data magnetic recording medium 14, as shown in the figure (
Assume that data like A) has been written. This is a state in which the data magnetic recording medium 14 is saturated magnetized and bar magnets with reversed magnetization directions are arranged.

In the reading direction, the data head 16 detects magnetic flux due to residual magnetization on the data magnetic recording medium 14, and
A voltage as shown in B) is obtained. Here, each peak value of this voltage becomes a boundary between each magnetization direction.

Here, off-track correction data is stored in the data magnetic recording medium 14 in advance on the tracks 14a, as shown in FIG.
Write in 14b and 14c. these tracks 14
The a114b and 14G are data unique to this magnetic recording/reproducing apparatus, and are different from the normally used recording data tracks. Therefore, tracks 14a, 14
An erase area is provided between data tracks b and 14c and adjacent data tracks so as not to be affected by each other.

Similarly to the data head 16, the servo head 15 is
The position data recorded on the servo magnetic recording medium 13 is read. Then, the output signal from the servo head 15 is amplified by the read amplifier 33 and output to the peak hold circuit 34. Further, the signal output from the servo head 15 is output to the sample timing generation circuit 36 after the peak value of the signal is detected by the signal detection circuit 35 at the same time.

The waveform of the output signal from the servo head 15 interferes with each other due to the width of the base of the pulse voltage waveform and the influence of adjacent pulses, causing a peak shift. In order to eliminate this peak shift, the output signal from the signal detection circuit 35 is processed at an appropriate timing in a sample timing generation circuit 36.

The signal output from the sample timing generation circuit 36 and the signal amplified by the read amplifier 33 are input to the peak hold circuit 34, and the peak value of the output from the read amplifier 33 is held by the peak hold circuit 34. Place u
It is output to the M number creation circuit 37.

This much ffi! The signal generation circuit 37 determines the position of the servo head 15 on the servo magnetic recording medium 13.

FIG. 4 shows a position signal on the servo magnetic recording medium 13, and shows a point a on the N track set to an arbitrary voltage value.
Q%N+11-point bo on the rack is the servo head 15
is the exact setting position when reading data from each track. That is, as long as the voltage values at the set point aQ and point bo do not change, the accurate track position is always specified.

A signal controlling the position of the servo head 15 in this manner is output to the VCM control circuit 38. Then, the control signal output from this VCM control circuit 38 is
The driver 39 converts the voltage into current, and drives the voice coil motor 40 to 111111. The voice coil motor 40 drives the carriage 18 and moves the arm 17.

The data head 16 is moved by the arm 17 to a position on the data magnetic recording medium 14 designated by the servo head 15 and comes into contact with the designated track.

Here, if the data head 16 deviates from the original track position designated by the servo head 15, the data output will be reduced as described above. Therefore, correction data is recorded in advance on the data magnetic recording medium 14, and the correction value is stored as an offset l to perform off-track correction.

As shown in FIG. 6, the data head 16 moves from the original setting position 14a to 141 on the data magnetic recording medium 14.
The value of this deviation, that is, the amount of offset, is assumed to be Δa. In this case, in order to correct this offset amount Δa, the data head 16 must be moved 14. Shift it in the opposite direction.

That is, since the relationship between the data head 1G and the medium 14 during normal operation and the six-position relationship between the servo head 15 and the servo magnetic recording medium 13 are the same, if the servo head 15 is moved, good.

In FIG. 4, it is assumed that a point a1 moved by offset l-11Δa from the set point 8 of the N track on the servo magnetic recording medium 13 is at the same position as the position 141 on the medium 14. Then, the voltage value becomes higher than the set point a11 by α. Therefore, in order to position the data head 16 accurately, by setting the voltage value low, that is, to -α, the servo head 15 is directed to the point -al.

In this way, the position of the data head 16 is moved from its original position to correct the offset amount.

In this way, off-track correction data is recorded on the data magnetic recording medium 14, and a correction data signal is output to the read amplifier 22 and signal detection circuit 25 via the driver receiver 19. The signal detection circuit 25, sample timing generation circuit 26, and peak hold circuit 27 process the signal detected by the signal detection circuit 25 to an appropriate timing in the sample timing generation circuit 26, similar to the servo circuit. This processed signal and the signal amplified by the read amplifier 22 are transferred to the peak hold circuit 2.
Enter 1. Then, the peak value of the output from the read amplifier 33 is held, and the signal is converted by the A/D converter 28 and output to the control circuit 29.

From this control circuit 29, the most offset correction data is stored in an offset memory circuit 30, so that, for example, when the power of this magnetic recording/reproducing device is turned on, or at every fixed time when the II source is turned on, an explosive pressure can be applied. It is something that exists.

In this magnetic recording and reproducing apparatus, since there is not one magnetic recording medium 14 for data, the magnetic recording medium 14 for data is designated by the track selection data signal 31.

Then, a signal corresponding to the instruction of the data signal 31 is output from the control circuit 29, and the signal is converted by the D/A converter 32.

In this way, the signal output from the D/A converter 32 is transmitted to the VCM 11 along with the signal from the position signal generation circuit 37.
The position of the servo head 15 is determined by the control circuit 38. Then, via the VCM driver 39, the voice coil motor 4
0 drives the carriage 18 and each arm 17
move. As a result, the servo head 15 moves from the original accurate setting position to the correction value, and the data head 1
6 is set to the correct place U.

In the above embodiment, an example was shown in which the magnetic recording medium was separated for servo and data, but any magnetic recording/reproducing device using a magnetic recording medium having a servo surface and at least one data surface may be used. be.

In this way, the magnetic recording medium 14 for data is turned off.

By recording the track correction data, the servo head 15 can be moved to point the data head 16 to an accurate position.

[Effect of the Invention 1] As described above, according to the present invention, the magnetic recording medium for data can be used regardless of the influence of temperature changes at the installation location of the device, temperature rise due to the heat generation of the IA itself, or unspecified impact. The above data can be read/written accurately, thereby improving read errors and the like.

Further, it is possible to improve off-tracking caused by distortion due to changes in atmospheric pressure that occur when the magnetic recording/reproducing device is sealed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of the data magnetic recording medium in FIG. 1, and FIG. FIG. 1 is a diagram explaining an example of data for each track of the magnetic recording medium, FIG. 4 is a diagram explaining the relationship between the voltage of the servo head and the track, and FIG. 5 is the configuration of a conventional magnetic recording/reproducing device. FIG. 6 is a diagram illustrating an off-track state of the apparatus in FIG. 5. 13... Magnetic recording medium for servo, 14... Magnetic recording medium for data, 15... Servo head, 16... Data head, 25.35... Signal detection circuit, 26.3
6...Sample timing creation circuit, 27.34...
・Peak hold circuit, 29... Control circuit, 30...
- Offset amount storage circuit, 37... Position signal creation circuit, 38... V CM III control circuit. Applicant's agent Patent attorney Takehiko Suzue Figure 2 Figure 6

Claims (1)

[Scope of Claims] A magnetic recording medium having a servo surface and a data surface; a servo head for reading data on the servo surface; and a data head for reading/writing data on the data surface; position signal generating means for generating a position signal based on the servo data; and correcting the offset amount of the data head based on off-track correction data recorded in advance on the data surface by the data head. a position correction signal generating means for generating a position correction signal; and a control means for detecting the offset amount based on the position signal and the position correction signal and moving the servo head according to the offset amount. A magnetic recording/reproducing device characterized by: