JPH05342786A - Magnetic disk apparatus - Google Patents

Abstract

PURPOSE:To read information data by a magnetic head even if the head cannot be tracked to a target track position by an NRRO due to a vibration of a rotating mechanism. CONSTITUTION:The magnetic disk apparatus comprises control means 7 for rotating a disk 3 at a constant speed, loading a magnetic head 1 to a predetermined position in the disk 3 and further controlling read/write of information data with the head 1, and compensating means 10 for compensating read of the data by the head 1 if the disk 3 is eccentrically rotated or radially vibrated asynchronously. Further, the means 10 comprises swing instructing means 10-3 for swinging a head positioning mechanism 5 radially of the disk 3 in a frequency asynchronous with a basic rotating frequency of the disk 3 or its double frequency, and information data judging.combining means 10-1 for judging information data from read information data of the head 1 to combine it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device.

[0002]

2. Description of the Related Art In a magnetic disk device, a magnetic head is positioned on an arbitrary track by an actuator, and data is written in or read from the disk by the magnetic head. FIG. 11 is an overall configuration diagram showing a configuration example of a conventional magnetic disk device. In this magnetic disk device, the controller 7 causes the rotation mechanism 6 to rotate the disk 3 at a constant speed. Further, the information data and the track position data are mixed on the same surface of the same disk 3, and the current track position data is read by the magnetic head 1 into the controller unit 7. Subsequently, the controller unit 7 controls and drives the head positioning mechanism unit 5 to position the magnetic head 1 at a target track position. Then, the magnetic head 1 reads the information data into the controller unit 7.

At this time, in the controller section 7, seek control for seeking the magnetic head 1 in the vicinity of the target track, tracking control for tracking the target track, and read / write (reading and writing of information data by the magnetic head 1 are performed. The following control is performed to make this follow the track. 12
FIG. 6 is a side view showing the configuration of another conventional magnetic disk device. In this magnetic disk device, the controller 7 causes the rotation mechanism 6 to rotate the three disks 3a, 3
Rotate b and 3c at a constant speed. The track position data exists on the upper surface of the disk 3a, and the information data exists on the other disk surfaces. The current track position data is read into the controller unit 7 by the magnetic head 1a. Then, the controller unit 7 controls and drives the head positioning mechanism unit 5, and the magnetic head 1
b, 1c, 1d, 1e, 1f are positioned at target track positions. Therefore, the information data is read into the controller unit 7 by the magnetic heads 1b to 1f.

[0004]

However, the conventional magnetic disk device as described above has the following problems. That is, in a conventional magnetic disk device, radial periodic periodic vibration (hereinafter referred to as NRR) of the disk due to eccentricity of the disk due to temperature change or vibration of the rotation mechanism portion 6 is caused.
Called O. ) In order to track the magnetic head 1 to the target track position and follow it,
The control band of the head positioning mechanism unit 5 by the controller unit 7 is set to a high band, the rigidity of the head supporting mechanism unit 4 is increased, or the eccentric amount of the disk due to temperature change is measured in advance, and the positioning by the controller unit 7 is performed. The feedforward control of the mechanical section 5 had to be performed. As described above, the conventional magnetic disk device has a problem that the magnetic head 1 cannot reliably track and follow the target track and cannot read the information data on the target track unless the above various measures are taken. I had.

In view of the above situation, the present invention is concerned with the NR caused by the eccentricity of the disk due to the temperature change and the vibration of the rotating mechanism.
An object of the present invention is to provide a magnetic disk device capable of reading information data by the magnetic head even if the magnetic head cannot track the target track position by RO.

[0006]

In order to achieve the above object, a magnetic disk device of the present invention comprises a disk for recording information data, a rotating mechanism for rotating the disk, and reading of information data from the disk. In a magnetic disk device including a magnetic head for writing and a head positioning mechanism for positioning the magnetic head on the disk, the disk is rotated at a constant speed and the magnetic head is moved to a predetermined position on the disk. Control means for controlling loading and further reading and writing of information data by the magnetic head, and reading of the information data by the magnetic head when the disk is eccentrically rotated or vibrates asynchronously in its radial direction. Compensating means for compensating for the head positioning mechanism. A swing instruction means for instructing to swing in the radial direction of the disk at a frequency that is not synchronized with the basic rotation frequency of the disk or its doubled frequency, and from the information data read by the magnetic head that is rocked. An information data judging / combining means for judging and combining the information data to be read is provided.

Further, in the magnetic disk device of the present invention, the compensating means further instructs the driving rotation speed of the rotation mechanism to be a predetermined rotation speed corresponding to the swing of the magnetic head. It is characterized in that a drive instruction means is provided. Further, in the magnetic disk device of the present invention, the compensating means includes a constant velocity drive instructing means for instructing the head positioning mechanism to be driven at a constant velocity in the radial direction of the disc in synchronization with the rotation of the disc. Is characterized by.

[0008]

According to the above construction, the control means controls the rotating mechanism to rotate the disk at a constant speed. Further, the head positioning mechanism is controlled to load the magnetic head on a predetermined position on the disk, and the information data is read by the magnetic head there. Further, when the disk is eccentrically rotated due to temperature change or the like or is vibrated in the radial direction of the disk due to vibration of the rotating mechanism or the like, the compensating means compensates the read operation of the information data of the magnetic head.

In this case, the compensating means instructs the rocking instructing means to rock the head positioning mechanism in the radial direction of the disk at a frequency which is not synchronized with the basic rotation frequency of the disk or its doubled frequency. Alternatively,
The constant velocity drive instructing means instructs the head positioning mechanism to be driven at a constant velocity in the radial direction of the disk.
As a result, the magnetic head swings or moves at a constant speed.

Then, the compensating means determines the data to be read from the information data read by the swinging or constant-velocity magnetic head by the information data judging / combining means, and combines the necessary data.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a magnetic disk device according to the present invention will be specifically described below with reference to the drawings. 1 is an overall configuration diagram showing the configuration of a first embodiment of a magnetic disk device according to the present invention. In FIG. 1, 1
Is a magnetic head, 2 is a head slider, 3 is a disk, 4
Is a head support mechanism portion, 5 is a head positioning mechanism portion, 6 is a rotation mechanism portion, 7 is a controller portion, 10 is an eccentricity compensation portion,
Reference numeral 10-1 is an information data determination / synthesis unit, and 10-3 is a positioning mechanism drive command unit.

Next, the operation of the magnetic disk device will be described with reference to FIGS. In FIG. 1, when the magnetic head 1 reads data from the disk 3, the information data and the track position data are present on the same surface of the same disk 3, so first of all, a command from the controller unit 7 is issued. Thus, the rotation mechanism unit 6 using the spindle motor rotates the disk 3 at a constant speed of 3600 rpm, for example. Then, the magnetic head 1 reads the data of the current track position into the controller unit 7, and then the controller unit 7 controls and drives the head positioning mechanism unit 5 also using the spindle motor to drive the magnetic head 1 to the target track position. Seek near. In this case, the controller unit 7 does not perform tracking control or following control.

FIG. 2 is a schematic diagram showing a track 3-1 in the disk 3 of the magnetic disk device shown in FIG. As shown in the figure, the disk 3 has a rotating mechanism 6 at the center, and the tracks 3-1 are arranged concentrically. Further, FIG. 3 shows a part 3-2 of the track 3-1 taken out, which is a schematic diagram showing an arrangement of data on the track. For example, D1 to D20 each represent a data group having four data A1 to A4 (each having information data and position data).

FIG. 4 is an explanatory diagram for explaining a method of compensating for eccentricity of the magnetic disk device shown in FIG. For example,
When the track density is 2000 TPI, the magnetic head 1 and the head slider 2 have an amplitude of 6.6 μm by the positioning mechanism drive command unit 10-3 as shown in FIG.
The SIN wave is driven at 3.3 kHz. That is,
In the drawing, the projected locus of the magnetic head 1 on the track is shown in a rectangular shape with one diagonal line.

Here, the magnetic head 1 has a track width of 1 /
Assuming that the information data from the disk 3 can be read by the controller unit 7 only when the information data from the disk 3 are located on the upper surface of the magnetic head 1, the magnetic head 1 can be driven by the SIN wave drive 1 as shown in FIG. 4A. In cycles, D1-D4
Data, D7 to D14 data, D17 to D20
Each data of will be read. That is, from the start of driving, up to the 16th piece (16 pieces as all data of D1 to D4 having 4 pieces of data of A1 to A4) and the 25th to 56th pieces (all data of D7 to D14) To 80) and the 64th to 80th (D17 to D)
Each data up to 20) (corresponding to all data up to 20) can be read.

The rotation speed of the disk 3 is set to 3600 rp.
m, bit density 37 kbpi, minimum magnetization reversal time 1
If it is set to 50 nsec, the number of information data stored in one track is 1 in the case of the MFM modulation method, for example.
The number is 11111, which is not a multiple of 80 (the total number of data of D1 to D20 is 80), so 360
Disk 3 rotating at 0 rpm and SIN at 3.3 kHz
With the wave-driven head positioning mechanism section 5, a phase of about 80 deg advances every time the disk 3 makes one revolution. Therefore, in this case, 16 pieces of information data advance,
The magnetic head 1 reads the information data from D3 as shown in FIG. Therefore, in the information data determination unit 10-1, the information data shown in FIG.
The information data shown in FIG. 4C is combined with the information data shown in FIG. That is, the data of D1 to D20 are combined as one cycle of the SIN wave drive of the magnetic head 1.

FIG. 5 is an explanatory diagram for explaining a method of eccentricity compensation when the eccentricity of the disk 3 is large. For example, when only the information data as shown in FIG. 5A can be read, the information data determination unit 10-1 is provided for each rotation of the disk 3 as shown in FIGS. 5B and 5C.
Information data is sent from the magnetic head 1 to
The data is synthesized as shown in (d). Therefore,
Even if the magnetic head 1 cannot track the target track position due to NRRO due to eccentricity of the disk 3 due to temperature change or vibration of the rotation mechanism section 6, the magnetic head 1 can read information data.

FIG. 6 is an overall configuration diagram showing the configuration of the second embodiment of the magnetic disk device according to the present invention. In this figure, in addition to the first embodiment, a rotation mechanism drive command unit 10-2 is newly provided. Then, this rotation mechanism drive command unit 10-2 further controls the drive of the rotation mechanism unit 6 when the eccentricity compensation is not sufficient only by the method shown in the first embodiment. That is, the eccentricity compensation is made more reliable by changing the rotation speed of the disk 3.

FIG. 7 is an overall configuration diagram showing the configuration of a third embodiment of the magnetic disk device according to the present invention. In FIG. 7, 1 is a magnetic head, 2 is a head slider, 3 is a disk, 4 is a head support mechanism section, 5 is a head positioning mechanism section, 6 is a rotation mechanism section, 7 is a controller section, 10 is an eccentricity compensation section, and 10 is an eccentricity compensation section. -1 is an information data judgment / synthesis unit, 10-4
Is a positioning mechanism drive command unit.

Next, the operation of this magnetic disk device will be described with reference to FIGS. In FIG. 7, when the magnetic head 1 reads data from the disk 3, the information data and the track position data are present on the same surface of the same disk 3, so that the controller unit 7 first In response to the command, the rotation mechanism unit 6 using the spindle motor moves the disk 3 to, for example, 3600
Rotate at a constant speed at rpm. Then, the data of the current track position is read by the magnetic head 1 into the controller unit 7, and then the controller unit 7 drives the head positioning mechanism unit 5 also using the spindle motor to control the magnetic head 1 at a target speed. Seek near the track position. That is, in this embodiment, the information data is read by moving the magnetic head 1 in the radial direction of the disk 3 at a constant speed.

FIG. 8 is a schematic diagram showing a track 3-1 in the disk 3 of the magnetic disk device shown in FIG. As shown in the figure, in the disc 3, tracks 3-1 are spirally arranged on the disc 3. Further, FIG. 9 shows a part 3-2 of the track taken out. That is, FIG. 9 is a schematic diagram showing the arrangement of data in the track 3-2 shown in FIG. In addition, in FIG.
D1 to D20 are 20 pieces of data A1 to A20, respectively.
Shows a data group with.

Here, the track density is 2000 TPI,
When the bit recording density is 37 kbpi, the disk diameter is 1.8 inches, and the information data area has a radius of 10 mm to 22 mm, the positioning mechanism drive command unit 10-4 synchronizes the magnetic head 1 and the head slider 2 with the disk 3. Thus, the head positioning mechanism section 5 is driven at a constant speed. Also in this case, the magnetic head 1 has a track width of 1
If it is assumed that the information data from the disk 3 can be read by the controller unit 7 only when the information data is overlapped by ½ or more, the minimum magnetization reversal time is 150 ns.
In the case of ec, the number of information data stored in the track 3-1 in one rotation cycle of the disc 3 is, for example, MF.
In the case of the M modulation method, 111111 as in the first embodiment.
It becomes an individual. Then, each time the disk 3 makes one revolution, the information data read by the magnetic head 1 is taken in by the information data judging section 10-1.

FIG. 10 is an explanatory diagram for explaining a method of compensating for eccentricity of the magnetic disk device shown in FIG. When the amount of eccentricity of the disk 3 is small, as shown in FIG. 10A, when all the data D1 to D20 are read, the positioning mechanism drive command unit 10-4 is not activated, and the head positioning mechanism unit 5 is further activated. Causes the controller unit 7 to move the magnetic head 1 to the next track.

On the other hand, the eccentricity of the disk 3 is large, and as shown in FIG. 10B, D1 and D4 to D16.
If only the information data of the disk 3 can be read, the positioning mechanism drive command unit 10-4 reads 0.
By rotating 045 deg, that is, by delaying by 2 μsec and driving the head positioning mechanism section 5 at a constant speed,
The information data as shown in FIG. 10C can be read. For the third time, conversely, 1
The disc 3 is rotated by −0.045 deg with respect to the reading start position at which the information data is captured for the second time, that is, 2
By advancing by μsec and driving the head positioning mechanism section 5 at a constant speed, the information data as shown in FIG. 10D can be read. Therefore, in the information data judgment / synthesis unit 10-1, the information data D for one cycle is read from the read information data as shown in FIG.
1 to D20 are synthesized. Therefore, even if it is considerably difficult for the magnetic head 1 to track the target track position due to the eccentricity of the disk 3 due to a temperature change or the like and the NRRO caused by the vibration of the rotation mechanism portion 6, it is possible to obtain information by the magnetic head 1. Data can be read reliably.

In the first embodiment, the disk 3
The normal rotation speed was set to 3600 rpm, and the rotation speed at the time of eccentricity compensation was also set to 3600 rpm. Regarding the normal rotation speed, if the magnetic head 1 can read / write the disk 3, As for the number of rotations at the time of compensation, if the magnetic head 1 can read the disk 3, the same effect as in the case of the embodiment can be obtained regardless of the number of rotations.

In the third embodiment, the disk 3
The same number of revolutions as in the case of the same embodiment is used as long as the magnetic head 1 can read and write to the disk 3. Is obtained. Further, in the first and second embodiments, the head positioning mechanism section 5 is driven by the SIN wave at 3.3 kHz.
As long as the magnetic head 1 can read the disk 3, the same effect as in the case of the embodiment can be obtained regardless of the frequency and the waveform.

In the first, second and third embodiments, the head positioning mechanism section 5 uses a spindle motor, but a voice coil motor or the like can be linearly driven for high precision positioning and speed control. Any other actuator can be used to obtain the same effect as that of the embodiment. The track density is 2000 TPI, the bit density is 37 kbpi, and the minimum magnetization reversal time is 150.
Although the time is set to nsec, the same effect can be obtained at any recording density as long as the magnetic head 1 can read and write. Further, the information data judgment / synthesis unit 10-1 of the eccentricity compensation unit 10 is supposed to synthesize two or three pieces of information data to form one true information data. If the storage capacity of 1 and the processing speed are within the permissible range, no matter how many pieces of information data are combined, the same effect as in the case of the embodiment can be obtained.

[0028]

According to the present invention described above, the disk is controlled to rotate at a constant speed, the positioning control of the magnetic head with respect to the disk is performed, and the recording / reproduction is performed by the magnetic head.
Even if the magnetic head cannot track the target track position due to eccentricity of the disk due to temperature change or vibration of the rotation mechanism, the magnetic head can compensate for the eccentricity and ensure the information data by the magnetic head. It is possible to lead.

Further, such eccentricity compensation can be electrically controlled without using a mechanical method, and a mechanical design change of the magnetic disk device is not required. Therefore, the information data can be accurately read even when the disk is eccentric without causing a large increase in cost, and the usability is greatly improved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a configuration of a first embodiment of a magnetic disk device according to the present invention.

FIG. 2 is a schematic diagram showing tracks on a disk of the magnetic disk device shown in FIG.

FIG. 3 is a schematic diagram showing an arrangement of data in the track shown in FIG.

FIG. 4 is an explanatory diagram for explaining a method of compensating for eccentricity of the magnetic disk device shown in FIG. 1.

FIG. 5 is an explanatory diagram for explaining a method of eccentricity compensation when the eccentricity of the disk is large.

FIG. 6 is an overall configuration diagram showing a configuration of a second embodiment of a magnetic disk device according to the present invention.

FIG. 7 is an overall configuration diagram showing a configuration of a third embodiment of a magnetic disk device according to the present invention.

8 is a schematic diagram showing tracks on the disk of the magnetic disk device shown in FIG. 7. FIG.

9 is a schematic diagram showing an arrangement of data in the tracks shown in FIG.

10 is an explanatory diagram for explaining a method of compensating eccentricity of the magnetic disk device shown in FIG. 7. FIG.

FIG. 11 is an overall configuration diagram showing a configuration example of a conventional magnetic disk device.

FIG. 12 is a side view showing a configuration example of another conventional magnetic disk device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 magnetic head 2 magnetic head slider 3 disk 5 head positioning mechanism section 6 rotation mechanism section 7 controller section 10 eccentricity compensation section 10-1 information data judgment / synthesis section 10-3 positioning mechanism drive command section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Yagi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Satoshi Tan, 1006 Kadoma, Kadoma City Osaka Prefecture

Claims (3)

[Claims] 1. A disk for recording information data, a rotating mechanism for rotating the disk, and a magnetic head for reading and writing information data on the disk.
In a magnetic disk device comprising a head positioning mechanism for positioning the magnetic head on the disk, the disk is rotated at a constant speed, the magnetic head is loaded at a predetermined position on the disk, and information is further recorded by the magnetic head. A control means for controlling reading and writing of data; and a compensating means for compensating the reading of information data by the magnetic head when the disk eccentrically rotates or vibrates asynchronously in its radial direction, Further, the compensating means is rocked with a rocking instructing means for instructing the head positioning mechanism to rock in the radial direction of the disk at a frequency not synchronized with the basic rotation frequency of the disk or its doubled frequency. The information data to be read is determined from the information data read by the magnetic head. Magnetic disk apparatus characterized by comprising an information data determination and synthesis means for then synthesized. 2. The compensating means further comprises rotation mechanism drive instructing means for instructing the drive rotation speed of the rotation mechanism to be a predetermined rotation speed corresponding to the swing of the magnetic head. The magnetic disk drive according to claim 1, wherein the magnetic disk drive is a magnetic disk drive. 3. The magnetic means according to claim 1, wherein the compensating means includes a constant velocity drive instructing means for instructing the head positioning mechanism to be driven at a constant velocity in the radial direction of the disc in synchronization with the rotation of the disc. Disk device.