JPH03181078A - Magnetic disk device control method and magnetic disk device - Google Patents

Abstract

PURPOSE:To perform the stable contact start stop operation for a long time by moving the contact start stop position of a head on a magnetic disk in accordance with the frequency in execution of contact start stop or the operation time. CONSTITUTION:The final stop position of head positioning mechanisms 8 to 10 for the stop of operation is changed in accordance with the frequency in execution of contact start stop or the operation time to move the contact start stop position of a head 2 on the magnetic disk. Consequently, contact start stop is not performed in the area, to which the contact start and stop position is moved, till then and a lubricant is not reduced there, and therefore, a coefficient of friction between the magnetic disk 1 and the magnetic head 2 is reduced and the magnetic disk 1 and the magnetic head 2 are not locally worn. Thus, the stable contact start stop operation is performed for a long time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic disk drive control technology and a magnetic disk drive using the same, and is particularly applicable to a contact start/stop type magnetic disk drive. Concerning effective techniques.

[Conventional technology]

For example, a magnetic disk device is known as a type of rotary information recording device used as an external storage device in computer systems, electronic office processing equipment, and the like.

In such a magnetic disk device, a magnetic head performs information recording and reproducing operations on a rotating magnetic disk using magnetism as a medium, so the smaller the gap between the magnetic head and the magnetic disk, the more information on the magnetic disk. Recording density can be increased.

For this reason, in recent years, the so-called floating head system, in which the magnetic disk and magnetic head are separated by an extremely thin layer of air, has become commonplace.In order to meet the demand for further increases in recording density, the surface of the magnetic disk is mirror-finished. At the same time, the biasing force from the support structure that acts in the direction of moving the magnetic head closer to the magnetic disk is set to be larger, thereby increasing the lift of the magnetic head due to the airflow formed on the surface of the rotating magnetic disk. In order to overcome this, a so-called contact start-stop method has come to be used, in which a narrow gap is created between the two, and when the magnetic disk stops, the magnetic disk and the magnetic head are in contact with each other.

In other words, in this method, when the magnetic disk starts rotating, the magnetic head slides against the surface of the magnetic disk and gradually rises due to the lift force acting from the airflow formed on the surface of the magnetic disk, and reaches stable rotation. When the magnetic disk is in a stationary state, it is in a floating state with a predetermined gap, and conversely, when the power is turned off, the magnetic head gradually descends as the rotational speed of the magnetic disk decreases, and when the magnetic disk is at rest, it is in a complete contact state. Contact start/stop is repeated.

Conventionally, in magnetic disk drives using the contact start/stop method, lubricant is applied to the surface of the magnetic disk in order to reduce wear and tear on both the magnetic disk and the magnetic head. As the surface roughness of the magnetic disk decreases, a problem arises in that the adhesive force between the magnetic disk and the magnetic head due to the lubricant increases.

For this reason, in the past, as described in Japanese Patent Laid-Open No. 61-3322, for example, the surface roughness of a specific area where contact start/stop of a magnetic disk is performed is made larger than other data recording areas. Techniques have been proposed to prevent adhesion between the magnetic disk and the magnetic head.

[Problem to be solved by the invention]

However, in the case of the above-mentioned conventional technology, since the surface roughness of the contact start/stop region is large, the time for friction between the magnetic disk and the magnetic head when starting and stopping rotation is longer, and the contact start/stop area is rougher. There is a problem in that the lubricant coating film in the area is damaged and the life of the magnetic disk or magnetic head is shortened in terms of contact start/stop operations.

This becomes particularly noticeable when attempting to narrow the gap between the magnetic head and the magnetic disk in order to further improve the recording density of the magnetic disk.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a control technique for a magnetic disk device that can perform stable contact start/stop operations over a long period of time.

Another object of the present invention is to provide a magnetic disk device that can extend its life in terms of contact start/stop operations.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

That is, the control method for a magnetic disk device according to the present invention includes a magnetic disk, a head that performs at least one of recording and reproducing information on the magnetic disk, and positioning of the head to a desired area of the magnetic disk. A contact start/stop type magnetic disk, in which the head floats above the surface of the magnetic disk when the magnetic disk is stably rotating, and the magnetic disk and head are in contact when the magnetic disk is stationary. A method for controlling an apparatus, which changes the final stop position of a head positioning mechanism when the operation is stopped according to the number of executions of contact start/stop or the elapse of operating time, and controls contact start/stop on the magnetic disk of the head. It is designed to move the position.

Further, the magnetic disk device of the present invention includes a magnetic disk, a head that performs at least one of recording and reproducing information on the magnetic disk, and a head positioning device that positions the head in a desired area of the magnetic disk. It is a contact start-stop type magnetic disk device in which the head flies above the surface of the magnetic disk when the magnetic disk is rotating stably, and the magnetic disk and head are in contact when the magnetic disk is stationary. a stop position regulating means for regulating the final stop position of the head positioning mechanism when the operation is stopped;
a counter that counts at least one of the number of times the contact start/stop is executed and the operating time; and a drive mechanism that moves the position of the stop position regulating means based on the value of at least one of the number of times the contact start/stop is executed and the operating time. It has been established that

[Effect]

Generally, as the number of executions of contact start/stop increases, the amount of lubricant in the contact start/stop area decreases monotonically, and the friction coefficient between the magnetic disk and magnetic head gradually increases accordingly. It is known that when a certain limit is exceeded, wear and tear on the magnetic disk progresses at an accelerated pace.

Therefore, in the control method of the magnetic disk device of the present invention, the amount of decrease in lubricant is limited to an experimentally determined permissible limit (for example, 10
A specified value is set for the number of times contact start/stop is executed so that the contact start/stop is The operation of moving the contact start and stop positions to any other position on the recording surface of the magnetic disk is repeated.

This ensures that the area you are moving to has no contact information.
Since no start/stop is performed and therefore no lubricant decreases, the coefficient of friction between the magnetic disk and the magnetic head returns to its initial small value.

As a result, it is possible to perform stable contact start/stop operations over a long period of time without causing local wear and tear on the magnetic disk or magnetic head, thereby extending the life of the magnetic disk device.

Furthermore, in the magnetic disk drive of the present invention, the value of the counter that counts at least one of the number of contact starts and stops and the operating time is such that the magnetic disk and magnetic head are rapidly worn out due to a decrease in lubricant. Every time a predetermined value of the limit is reached, the position of the final stop position regulating means that regulates the final stop position of the head positioning mechanism when the operation is stopped is changed, and the contact start/stop position of the magnetic disk is changed. Repeat the movement to any other position on the recording surface.

This ensures that the area you are moving to has no contact information.
Since no start/stop is performed and therefore no lubricant decreases, the coefficient of friction between the magnetic disk and magnetic head returns to its initial small value, preventing local wear and tear on the magnetic disk and magnetic head. As a result, it is possible to perform stable contact start/stop operations over a long period of time without causing damage, and as a result, the life of the magnetic disk device can be extended.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a control method for a magnetic disk device according to an embodiment of the present invention and an example of a magnetic disk device using the same will be described in detail with reference to the drawings.

FIG. 1 is a plan view schematically showing an example of the configuration of a main part of a magnetic disk device that is an embodiment of the present invention, and FIGS. 2 and 3 are diagrams showing an example of its operation. It is.

The magnetic disk device of this embodiment includes a magnetic disk 1 that is rotated by a spindle motor (not shown) or the like, and a head slider 2 that generates lift by airflow or the like formed when the magnetic disk 1 rotates.

A magnetic head (not shown) is fixed to the head slider 2 for recording and reproducing information on a plurality of tracks (not shown) arranged concentrically on the magnetic disk 1 as information recording areas.

The head slider 2 is fixed to one end of the head arm 3 via a leaf spring 3a, and the head arm 3 further includes:
It is supported by a swing shaft 4 so as to be rotatable within a plane parallel to the magnetic disk 1 .

The head slider 2 is constantly urged in a direction toward the magnetic disk 1 by a leaf spring 3a, and when the magnetic disk 1 rotates steadily, air currents formed on the surface of the magnetic disk 1 generate in the head slider 2. By balancing the lifting force with the biasing force of the leaf spring 3a, a predetermined gap is formed between the magnetic head (not shown) fixed to the head slider 2 and the surface of the magnetic disk 10, and the magnetic disk 1 is kept stationary. In this state, the magnetic disk 1 and the Herad slider 2 (magnetic head) are in contact with each other.

That is, in the magnetic disk device of this embodiment, the rotating magnetic disk 1 is operated for a certain period from immediately after the rotation of the magnetic disk 1 starts until it reaches steady rotation, and for a certain period after the power is turned off until the magnetic disk 1 comes to rest. A so-called contact start/stop (hereinafter abbreviated as C5/S) is performed in which the slider 1 and the slider 2 come into sliding contact.

In addition, a desired lubricant is applied to the surface of the magnetic disk 1 to the extent that no adhesion occurs between the head slider 2 and the magnetic disk 1, so that wear during contact between the head slider 2 and the magnetic disk 1 is prevented. It's starting to ease.

A coil spring 5 is interposed between the swing shaft 4 and the head arm 3, and both ends of the coil spring 5 are respectively locked to the swing shaft 4 and the head arm 3.
It has a structure that is biased in the clockwise direction in FIG.

The other end of the head arm 3 is provided with an actuator 6 consisting of a voice coil 6a supported by the head arm 3 and a permanent magnet (not shown) supported by a housing (not shown). By energizing, the head arm 3 resists the biasing force of the coil spring 5.
The structure is such that a torque is generated to rotate the pivot shaft 4 in a desired direction.

By appropriately controlling the magnitude and direction of the torque acting on the head arm 3 from the actuator 6, the head slider 2 (magnetic head) supported at the other end of the head arm 3 is The head slider 2 (magnetic head) is moved directly above any one of the plurality of tracks formed concentrically on the surface of the magnetic disk l by controlling the displacement direction, speed, displacement amount, etc. in the radial direction. A seek operation for positioning is performed.

In this case, the actuator 6 that drives the head arm 3
A gear 7 is provided near the rotation axis 7a and is rotatable in a plane parallel to the rotation plane of the actuator 6 (head arm 3).

A stopper 8 is fixed to this gear 7 so as to move in an area intersecting the movable range of the actuator 6 by the rotational displacement of the gear 7. Furthermore, a stopper 8 is fixed to this gear 7, for example. The gear 9a driven by the gear 9a is in mesh with the gear 9a.

By appropriately controlling the direction and amount of rotation of this step motor 9, the actuator 6 within the movable range of the actuator 6 (head arm 3) is
The abutting position of the head arm 3 with respect to the head arm 3 can be set to a desired position.

The direction and amount of rotation of the step motor 9 are controlled by a step motor drive circuit 10, and this step motor drive circuit 10 has a function that counts the number of times C3/S is executed as described above. A C5/S counter 11 is connected.

Then, the C3/S counter 11, for example, C5/,
If the number of times S is executed is a predetermined value (for example, 1000 to 500)
0 times), when executing the C3/S, a command is issued to the step motor drive circuit 10 to operate the step motor 9, as will be described later, so that the step motor 9 enters an idle state with the power cut off. The contact position between the actuator 6 (head arm 3), which is biased clockwise by the coil spring 5, and the stopper 8 is changed from the previous contact position, and the head slider 2 (supported by the head arm 3) is C3 for the magnetic disk 1 of the magnetic head)
/S is operated to change the position.

Note that the specified value for the number of times C3/S is executed (1000 to 5000 times in the case of this embodiment) is determined by the amount of frictional force caused by the decrease in lubricant when C3/S is repeated at the same position on the magnetic disk l. The limit value at which the wear of the magnetic disk 1, head slider 2, etc. rapidly progresses due to the increase is set by measuring in advance.

An example of the operation of the magnetic disk device and its control method according to this embodiment will be described below.

First, in the normal operating state of the magnetic disk device in which the magnetic disk 1 is rotating at a predetermined steady rotation speed, the stopper 8
is retracted to the position (home position) where the head slider 2 contacts the actuator 6 when it moves to the innermost circumference of the magnetic disk 1, thereby avoiding interference with the seek operation of the head slider 2 by the actuator 6. are doing.

Next, when the power to the magnetic disk device is cut off, the step motor 9 is operated by a backup power source, etc., and the gear 9a is activated.
By rotating the gear 7 via the gear 7, the stopper 8 fixed to the gear 7 is moved to a predetermined position within the movable range of the actuator 6.

On the other hand, since the power is cut off, the actuator 6 and the head arm 3 (head slider 2) are in an idle state, and the biasing force of the coil spring 5 causes the actuator 6 to rotate in the direction shown by arrow C in FIG. , stopper 8
The coil spring 5 stops at the position where it comes into contact with the coil spring 5.
The stationary state is maintained by the urging force of.

Then, at the stop position of the actuator 6 (head arm 3), the position of the Herad slider 2 with respect to the magnetic disk 1 is determined, and at that position, the magnetic disk l
As the number of revolutions decreases, the head slider 2 gradually descends, and the magnetic disk 1 comes to a standstill while the head slider 2 and the surface of the magnetic disk 1 come into sliding contact.C3/
S is performed.

Next, when power is applied to the magnetic disk drive and the magnetic disk 1 starts rotating, the head slider 2 (magnetic head) supported by the head arm 3 (actuator 6) moves in the opposite direction as when the power is turned off. , C8/S is performed in which the magnetic disk 1 floats up as the rotational speed of the magnetic disk 1 increases while slidingly contacting the magnetic disk 1.

For example, when the magnetic disk l reaches steady rotation, the step motor 9 is activated to retract the stopper 8 to the home position, and then the head slider 2 is operated by the actuator 6 via the head arm 3 to perform a seek operation. Start normal operation.

In this embodiment, the C5/S counter 11 counts the number of times C3/S is executed each time the power is turned on and off.

Then, the number of executions is a predetermined value (for example, 1000 to 5
000 times〉, C5 when power is turned off.
/S, by issuing a predetermined signal from the C3/S counter 11 to the step motor drive circuit 10, the step motor drive circuit 10 executes the previous C3/S counter 11.
When executing 3/S, the abutting position of the stopper 8 and the actuator 6 is different, that is, the magnetic disk 1 is
The command value for the step motor 9 is changed so that the execution position of C3/, S of the head slider 2 is changed.

That is, on the magnetic disk 1, C3/
Due to repeated S, the thickness (1) of the lubricant film applied to the area where CS/S is performed causes rapid wear and tear on the magnetic disk l and head slider 2 (magnetic head). C3 before decreasing to advance to
This control operation is to move the execution position of /S to another location.

As a result, using the same area of the magnetic disk 1, C
Acceleration of wear and tear on the magnetic disk 1, head slider 2 (magnetic slider), etc. due to repeated 3/S is avoided, and stable C3/S operation can be performed over a long period of time.

Here, in the conventional case where the C5/S execution position is fixed at a specific position on the magnetic disk l, and in this embodiment, when the number of C3/S reaches, for example, 5000, the head Figure 2 shows the results of the inventors' measurements of changes in the remaining lubricant ratio with respect to the number of executions of C3/S in each of the cases in which the slider 2 was moved about four degrees toward the outer circumference. Similarly, changes in the friction coefficient are shown in Figure 3.

That is, in the conventional case shown by the broken line (A) in FIGS. 2 and 3, the remaining amount of lubricant decreases as the number of executions of C3/S increases, and the coefficient of friction increases. On the other hand, in the case of this example shown by the solid line (open), even if the number of executions of C8/S increases, the amount of lubricant decreases is small, and the friction coefficient remains stable at a small value. There is.

For these reasons, in the case of this embodiment, there is no need to apply excessive lubricant due to the fear that lubricant will decrease due to repetition of C5/S at the same position, and there is no need to apply excessive lubricant to the head slider 2 (magnetic In addition to reducing the adhesive force of the magnetic disk drive (head), it also avoids the acceleration of wear and tear between the magnetic disk drive and the Herad slider 2 due to an increase in the frictional force between them. It can be seen that it has the effect of extending the lifespan.

Further, as in the conventional case, the surface of the magnetic disk 1 is
This eliminates the need for complicated considerations such as dividing the area where S is performed and other areas and setting different surface roughness for each area, and productivity in the manufacturing process of the magnetic disk device can be improved.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, in the explanation of the control method of the magnetic disk device in the above embodiment, the case where the number of executions of the contact start/stop is used as a trigger to move the execution position of the contact start/stop is explained. For example, the movement of lubricant from the inner periphery to the outer periphery due to the elapse of the rotation time (operating time) of the magnetic disk is estimated, and the positions with the appropriate amount of lubricant are sequentially selected and the contact It may also be made to start and stop.

〔Effect of the invention〕

Among the inventions disclosed in this application, the effects obtained by typical inventions are briefly described below.

That is, according to the control method for a magnetic disk device according to the present invention, a magnetic disk, a head that performs at least one of recording and reproducing information on the magnetic disk, and a head that performs at least one of recording and reproducing information on the magnetic disk, and a control system that controls a magnetic disk, and a head that performs at least one of recording and reproducing information on the magnetic disk; a head positioning mechanism that performs a positioning operation; when the magnetic disk is stably rotating, the head flies above the surface of the magnetic disk; when the magnetic disk is stationary, the magnetic disk and the head are in contact; A control method for a start-stop type magnetic disk device, the head positioning mechanism changing the final stop position of the head positioning mechanism when the operation is stopped according to the number of executions of contact start-stop or the elapse of the operation time, and Since the contact start and stop positions on the magnetic disk are moved, for example, a prescribed value for the number of times contact start and stop is performed so that the amount of lubricant decreases reaches the experimentally determined allowable limit can be set. If this specified value is exceeded, the final stop position of the head positioning mechanism is changed when the i-source is disconnected, and the contact start/stop position on the magnetic disk is changed to any other position on the recording surface of the magnetic disk. It is possible to perform control such that the movement of the object is repeated.

This ensures that the area you are moving to has no contact information.
#tl! between the magnetic disk and the magnetic head since there is no start-stop and therefore no lubricant depletion! The l coefficient returns to its initial small value.

As a result, it is possible to perform stable contact start/stop operations over a long period of time without causing local wear and tear on the magnetic disk or magnetic head, thereby extending the life of the magnetic disk device.

Further, according to the magnetic disk device of the present invention, there is provided a magnetic disk, a head that performs at least one of recording and reproducing information on the magnetic disk, and a positioning operation of the head to an arbitrary area of the magnetic disk. A contact start/stop head positioning mechanism, in which the head flies above the surface of the magnetic disk when the magnetic disk rotates stably, and the magnetic disk and the head are in contact when the magnetic disk is stationary. A magnetic disk drive of the above-mentioned type, comprising: a stop position regulating means for regulating the final stop position of the head positioning mechanism when the operation is stopped; and a counter for counting at least one of the number of executions of contact start/stop and the operating time; and a drive mechanism that moves the position of the stop position regulating means based on at least one of the number of executions of the contact start/stop and the elapse of the operating time, so that, for example, when the value of the counter is Each time a predetermined limit value at which rapid wear and tear of the magnetic disk or magnetic head occurs due to decrease is reached, the position of the final stop position regulating means for regulating the final stop position of the head positioning mechanism when the operation is stopped is changed. , the operation of moving the contact start/stop position on the magnetic disk to any other position on the recording surface of the magnetic disk can be repeated.

This ensures that the area you are moving to has no contact information.
Since no start/stop is performed and therefore no lubricant decreases, the coefficient of friction between the magnetic disk and magnetic head returns to its initial small value, preventing local wear and tear on the magnetic disk and magnetic head. As a result, it is possible to perform stable contact start/stop operations over a long period of time without causing damage, and as a result, the life of the magnetic disk device can be extended.

[Brief explanation of drawings]

FIG. 1 is a plan view schematically showing an example of the horizontal aperture of the main part of a magnetic disk device according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of its operation, and FIG. It is a line diagram showing an example of an effect. 1...Magnetic disk, 2...Head slider, 3.
... Head arm, 3a... Leaf spring, 4... Swing shaft, 5... Coil spring, 6... Actuator, 6a
...Voice coil, 7...Gear (drive mechanism), 7a
...Rotation axis, 8...Stopper (stop position regulating hand &)
, 9... Step motor (drive mechanism), 9a... Gear (WI. drive mechanism), 10... Step motor drive circuit (drive mechanism), 11... C3/S counter (counter), C
...An arrow indicating the rotational force direction of the actuator when the power is turned off.

Claims (1)

[Claims] 1. A magnetic disk, and a head that performs at least one of recording and reproducing information on the magnetic disk;
It consists of a head positioning mechanism that positions the head in a desired area of the magnetic disk, and when the magnetic disk is stably rotating, the head flies above the surface of the magnetic disk, and when the magnetic disk is stationary, the magnetic disk is A control method for a contact start/stop type magnetic disk drive in which a disk and the head are in contact with each other, wherein the head when the operation is stopped is controlled according to the number of executions of contact start/stop or the elapse of operating time. The final stop position of the positioning mechanism is changed, and the contact of the head on the magnetic disk is changed.
A method for controlling a magnetic disk device, characterized in that the start and stop positions are moved. 2. a magnetic disk; a head that performs at least one of recording and reproducing information on the magnetic disk;
It consists of a head positioning mechanism that positions the head in a desired area of the magnetic disk, and when the magnetic disk is stably rotating, the head flies above the surface of the magnetic disk, and when the magnetic disk is stationary, the magnetic disk is A contact start/stop type magnetic disk device in which a disk and the head are in contact with each other, the magnetic disk drive comprising: a stop position regulating means for regulating a final stop position of the head positioning mechanism when the head positioning mechanism is stopped; and a contact start/stop method. a counter that counts at least one of the number of executions of the contact start/stop and the elapse of the operation time, and a drive mechanism that moves the position of the stop position regulating means based on the value of at least one of the number of executions of the contact start/stop and the elapse of the operation time. A magnetic disk device comprising: