JP2000123511A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a magnetic head and a magnetic disk from being damaged by avoiding an instable operation and a sticking phenomenon at the time of start up. SOLUTION: When a driving device 2 is stopping its operation, an elevating/ lowering device 4 separates a magnetic head 31 from the surface of a magnetic disk 1 by lifting a magnetic head device 3. At a starting time when the device 2 starts its operation, the device 4 brings the magnetic head 31 into contact with the surface of the disk 1 by lowering the device 3 in the starting from a time when the device 2 starts revolution till a time when the revolving speed reaches a normal revolving speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art Conventionally, as a magnetic recording / reproducing apparatus,
2. Description of the Related Art There is used a magnetic head device that flies while maintaining a gap formed by a minute air bearing between the magnetic disk and a magnetic disk by using a dynamic pressure generated by running of the magnetic disk. When the magnetic disk rotates, a dynamic lift force is generated on the air bearing surface of the slider, and the magnetic head flies at a flying height that matches the dynamic pressure and the load applied from the head support device.

As a driving method of the above-described magnetic recording / reproducing apparatus, a contact. start. Stop (CS
S) method was used. However, the CSS method has a problem in that the ABS phenomenon of the magnetic head is easily attracted to the surface of the magnetic disk when stopped.
In particular, recently, as the capacity of the magnetic recording / reproducing apparatus has increased and the recording density has increased, the flying height has been reduced.
The surface smoothness of a magnetic disk and the surface properties of an air bearing surface (hereinafter referred to as ABS) of a slider of a magnetic head have been significantly enhanced. For this reason, the adsorption phenomenon is very likely to occur. The adsorption phenomenon causes a start failure or a head crash.

Therefore, as a means for solving the problem of the CSS system, a dynamic load system using a lift device has been proposed. The lift device keeps the magnetic head away from the surface of the magnetic disk when starting the magnetic disk, and lowers the magnetic head to the surface of the magnetic disk after the magnetic disk has started rotating at high speed. When the rotation of the magnetic disk is stopped, the magnetic head is kept away from the surface of the magnetic disk. Such a lifting device is known, for example, from U.S. Pat. No. 4,933,785. Also, JP-A-5-120822, JP-A-5-303842
Japanese Unexamined Patent Publication (Kokai) No. H11-181131 discloses a similar technique.

However, in the dynamic load method,
When starting up the magnetic disk, the magnetic head is lowered onto the surface of the magnetic disk rotating at high speed. At this time, since the lift dynamic pressure is suddenly applied to the ABS of the magnetic head, the tracking performance of the magnetic head with respect to the magnetic disk becomes unstable, and an unstable operation such as a collapsed flying posture is caused. In addition, there is a risk that the magnetic head collides with the surface of the magnetic disk and damages both the magnetic head and the magnetic disk.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to prevent an attraction phenomenon from occurring between a magnetic disk and a magnetic head, and to reliably prevent startup failure and head crash due to the attraction phenomenon. An object of the present invention is to provide a magnetic recording / reproducing apparatus.

Another object of the present invention is to provide a magnetic recording / reproducing apparatus which avoids an unstable operation at the time of starting and prevents a magnetic head and a magnetic disk from being damaged due to the unstable operation.

[0008]

In order to solve the above-mentioned problems, a magnetic recording / reproducing apparatus according to the present invention includes a magnetic disk, a driving device, a magnetic head device, and a lifting / lowering device.

The drive device drives the magnetic disk to rotate. The magnetic head device includes a magnetic head and a head support device. The magnetic head is supported by the head support device and floats on the surface of the magnetic disk.

The elevating device lifts the magnetic head device when the driving device stops operating, and moves the magnetic head away from the surface of the magnetic disk. At the time of startup when the drive device starts operating, the magnetic head device is lowered, and within the startup time from when the drive device starts rotating to when the drive device reaches a steady rotation speed, the magnetic head is moved to the magnetic disk. Touch the surface.

In the magnetic recording / reproducing apparatus according to the present invention,
When the drive device stops operating, the lifting device lifts the magnetic head device to separate the magnetic head from the surface of the magnetic disk, so that the magnetic head and the magnetic disk are moved in the same manner as in the conventional dynamic load method. Durability can be improved.

At the time of start-up when the drive starts to operate, the magnetic head device is lowered, and the magnetic head is moved to the magnetic disk within the start-up time from when the drive starts to rotate to when the drive reaches a steady rotational speed. Touch the surface. Therefore, no adsorption phenomenon occurs between the magnetic disk and the magnetic head. Even if the surface smoothness of the magnetic disk and the surface properties of the ABS of the slider constituting the magnetic head are enhanced, the adsorption phenomenon does not occur. For this reason, it is possible to avoid a start-up failure and a head crash due to the suction phenomenon.

In addition, the magnetic head smoothly transitions from the low-speed rotation region at the time of startup to the high-speed rotation region at the time of steady operation, and does not receive a sudden change in lift dynamic pressure. Therefore, unlike the dynamic load method in which the magnetic head is lowered toward the surface of the magnetic disk rotating at high speed, the operation at startup is stable, and damage to the magnetic head and the magnetic disk due to unstable operation is prevented. Is done.

After startup, the rotation speed of the magnetic disk increases,
Reach steady speed. Then, a lift dynamic pressure corresponding to the number of rotations is generated between the magnetic disk and the magnetic head, and the magnetic head flies with a floating amount that balances the dynamic pressure with the load applied from the head support device.

The present invention further discloses means for adjusting the number of revolutions of the magnetic disk when the magnetic head comes into contact with the magnetic disk, and a preferable position for lowering the magnetic head. Other objects, configurations and advantages of the present invention will be described with reference to the accompanying drawings.
This will be described in more detail.

[0016]

FIG. 1 is a plan view schematically showing a state in which a read / write operation is not performed in a magnetic recording / reproducing apparatus according to the present invention. FIG. 2 is an enlarged view showing the relationship between the magnetic disk and the magnetic head device in the state shown in FIG. FIG. 3 is a plan view schematically showing a start-up state in which a read / write operation is started in the magnetic recording / reproducing apparatus according to the present invention. FIG. 4 is an enlarged view showing the relationship between the magnetic disk and the magnetic head device at the time of startup shown in FIG. The illustrated magnetic recording / reproducing apparatus includes a magnetic disk 1, a driving device 2, a magnetic head device 3, and a lifting device 4. These components 1 to 4 are housed in a closed container 5 as is well known.

The magnetic disk 1 generally has a magnetic recording layer on both sides. In the present invention, the configuration of the disk substrate of the magnetic disk 1 and the configuration of the magnetic recording layer thereon are not particularly limited. A magnetic disk 1 using a magnetic recording layer and a disk substrate that has been proposed and may be proposed in the future can be used. The magnetic disk 1 may be used with or without a solid or liquid lubrication layer on the surface. The size of the magnetic disk 1 may be arbitrary. For example, magnetic disks 1 of various sizes such as 1.8 inches, 2.5 inches, and 3.5 inches can be used. Further, the number of magnetic disks 1 is arbitrary. Usually, about 1 to 10 magnetic disks 1 are provided.

The drive unit 2 drives the magnetic disk 1 to rotate. The driving device 2 is driven by electric power supplied from a power supply 7. The driving device 2 is generally constituted by a spindle motor. The capacity of the spindle motor constituting the drive device 2 is selected according to the size and the number of the magnetic disks 1. The rotation speed is, for example, about 7200 rpm. The time required from when the spindle motor is excited to when it reaches a steady rotational speed (referred to as a start-up time) depends on the size and the number of magnetic disks 1, and is as fast as about 1 to 2 seconds and as slow as 10 seconds. On the order of seconds.

The magnetic head device 3 includes a magnetic head 31 and
And a head support device 32. The magnetic head 31 is supported by the head support device 32 and floats on the surface of the magnetic disk 1. Referring to FIG. 2, the magnetic head device 3 is provided on both sides of the magnetic disk 1. Magnetic head 3
As 1, any type that has been proposed so far and may be proposed can be applied as long as it is a floating type. The magnetic head 31 generally has a structure in which at least one write element and at least one read element are mounted on a slider. Typically, an inductive magnetic transducer is used as the writing element.
A magnetoresistive element is used as the read element.
Examples of the magnetoresistive element include a magnetic anisotropic magnetoresistive film (AMR), a GMR having a spin valve film structure, a GMR using a ferromagnetic tunnel junction effect element, and the like.

The head support device 32 has one end supported by the positioning device 6, and a magnetic head 31 mounted on a free end on the other end side. The positioning device 6 is generally constituted by a voice coil.

When the driving device 2 is not operating, the lifting device 4 lifts the magnetic head device 3 to separate the magnetic head 31 from the surface of the magnetic disk 1 by a distance H1. Therefore, similarly to the conventional dynamic load method, the durability of the magnetic head 31 and the magnetic disk 1 can be improved. Load / lift device 4
Any device having an unloading mechanism can be widely used. In this embodiment, a type in which the drive unit 41 moves the arm 42 in the directions of arrows a1 and a2 is shown. When the arm 42 is driven in the direction of the arrow a2, the head support device 31 of the magnetic head device 3 is supported by the arm 42.

The elevating device 4 is driven by electric power supplied from a power source 7 or an electric signal. The lifting device 4
At the time of activation when the drive device 2 starts operation, the magnetic head device 3 is lowered, and the magnetic head 31 is moved from the start of rotation of the drive device 2 to the time when the drive device 2 reaches a steady rotation speed. Operate to touch a surface. This will be described with reference to FIGS.

FIG. 3 is a plan view schematically showing a start-up state in which a read / write operation is started in the magnetic recording / reproducing apparatus according to the present invention. FIG. 4 is an enlarged view showing the relationship between the magnetic disk and the magnetic head device at the time of startup shown in FIG. 3 and 4, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals.

Next, the start-up operation will be described with reference to FIGS. When starting, t
At 0, power or a signal required for driving is supplied from the power supply 7 to the driving device 2 and the lifting device 4 (see FIG. 5A). As a result, the arm 42 of the lifting device 4 moves
(FIGS. 3 and 4).
The separation distance H1 between the magnetic disk 1 and the magnetic disk 1 becomes zero (see FIGS. 2 and 5B), and the magnetic head 31 comes into contact with the surface of the magnetic disk 1. The magnetic head 31 comes into contact with the magnetic disk 1 at time t2, which is delayed by time ΔT1 after the power supply 7 is turned on.

On the other hand, when the power supply 7 is turned on to the drive unit 2, the spindle motor of the drive unit 2 is started, and the magnetic disk 1 starts rotating in the direction of the arrow b1 (see FIG. 3). As described above, the spindle motor constituting the driving device 2 is about 1 to 2 seconds at a high speed and 1 at a slow speed as described above.
It has a start time Ti of about 0 seconds, and reaches the steady rotation speed Ns at t3 when the start time Ti has elapsed. Generally, the start-up time Ti is considerably longer than the time ΔT1 required for the magnetic head 31 to contact the magnetic disk 1.

Therefore, as shown in FIG. 5 (c), at the time of start-up, after the driving device 2 starts rotating, the steady-state rotational speed Ns
The magnetic head 31 can be brought into contact with the surface of the magnetic disk 1 within the activation time Ti until the magnetic disk 1 reaches the magnetic disk 1.
In particular, in the early stage of startup, by bringing the magnetic head 31 into contact with the magnetic disk 1, the rotational speed N 1 is sufficiently smaller than the steady rotational speed Ns given to the magnetic disk 1.
The magnetic head 31 can be brought into contact with the surface of the magnetic disk 1. Therefore, even if the surface smoothness of the magnetic disk 1 and the surface properties of the ABS of the slider constituting the magnetic head 31 are enhanced, the adsorption phenomenon does not occur.
Therefore, it is possible to avoid a start-up failure and a head crash due to the suction phenomenon.

In addition, the magnetic head 31 smoothly transitions from the low-speed rotation speed N1 at the time of contact to the high-speed rotation speed Ns at the time of steady operation, and does not receive a sudden change in lift dynamic pressure. Therefore, unlike the conventional dynamic loading method in which the magnetic head 31 is lowered onto the surface of the magnetic disk 1 rotating at a high speed, the operation at the time of startup is stable, and the magnetic head 31 and the magnetic disk 1 caused by the unstable operation are unstable. Damage is prevented.

FIG. 6 is a time chart showing another example of the starting operation. The time chart of FIG. 5 is based on the premise that the driving device 2 and the elevating device 4 start operating at the same time.
The example in which the magnetic head 31 is brought into contact with the surface of the magnetic disk 1 at a rotation speed N1 sufficiently smaller than the steady rotation speed Ns given to the magnetic disk 1 has been described. FIG. 6 differs from this in that the drive 2
, The rotation speed N1 that is sufficiently smaller than the steady rotation speed Ns given to the magnetic disk 1.
Thus, the magnetic head 31 is brought into contact with the surface of the magnetic disk 1.

That is, at time t0 when the power supply 7 is turned on (FIG. 6
At time t1 after the delay time ΔT2 from (a), the driving device 2 is started (see FIG. 6 (c)). According to this configuration, the delay time ΔT2 is adjusted, and the magnetic head 31 is
The magnetic disk 1 can be brought into contact with the surface at an arbitrary rotation speed N1. Specifically, the delay time ΔT2 is reduced to increase the rotation speed N1 when the magnetic head 31 comes into contact with the surface of the magnetic disk 1, or the delay time ΔT2 is increased so that the magnetic head 31 The number of revolutions N1 at the time of contact with the surface of the magnetic disk 1 can be reduced.

According to this adjustment, for example, the delay time ΔT
2 is the time required for the magnetic head 31 to make contact {T1
(See FIG. 6 (b).) When the rotation speed N1 of the magnetic disk 1 is substantially zero,
The magnetic head 31 can be brought into contact with the surface of the magnetic disk 1. The above-described delay operation of the driving device 2 is performed by the power supply 7
A delay circuit 8 (see FIG. 1)
Can be easily realized.

After the above-described starting operation, the magnetic disk 1 rotates at a high speed at the steady rotational speed Ns. A lift dynamic pressure is generated between the magnetic disk 1 and the magnetic head 31, and the magnetic head 31 flies with a floating amount that matches the dynamic pressure and the load applied from the head support device 32. Magnetic head device 2
Is driven by the positioning mechanism 6 on the magnetic disk 1 at a certain skew angle θ1 in the direction of the arrow c1 or c2 to be positioned. Then, in a predetermined track, writing and reading of magnetic recording are performed between the magnetic head 31 and the magnetic disk 1.

The magnetic disk 1 preferably has a load zone 10 (see FIGS. 1 and 3). This load zone 10 is not used as the recording zone 11. Magnetic head 31
Is brought into contact with the surface of the magnetic disk 1 in the load zone 10. According to this configuration, damage to magnetic recording data due to contact of the magnetic head 31 can be reliably avoided. The load zone 10 is located on the outer peripheral side of the recording zone 11. According to this configuration, the movable range of the lifting / lowering device 4 may be narrow, so that the structure can be simplified.

[0033]

As described above, according to the present invention, the following effects can be obtained. (A) It is possible to provide a magnetic recording / reproducing apparatus which can prevent an attraction phenomenon from occurring between a magnetic disk and a magnetic head, and can surely avoid starting failure and head crash due to the attraction phenomenon. (B) It is possible to provide a magnetic recording / reproducing apparatus that avoids unstable operation at the time of startup and prevents damage to a magnetic head and a magnetic disk due to unstable operation.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing a state when a read / write operation is not performed in a magnetic recording / reproducing apparatus according to the present invention.

FIG. 2 is an enlarged view showing a relationship between a magnetic disk and a magnetic head device when the operation shown in FIG. 1 is stopped.

FIG. 3 is a plan view schematically showing a start-up state in which a read / write operation is started in the magnetic recording / reproducing apparatus according to the present invention.

FIG. 4 is an enlarged view showing a relationship between a magnetic disk and a magnetic head device at the time of startup shown in FIG. 3;

FIG. 5 is a time chart illustrating a start-up operation of the magnetic recording / reproducing apparatus according to the present invention.

FIG. 6 is a time chart for explaining another starting operation of the magnetic recording / reproducing apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic disk 2 Drive device 3 Magnetic head device 31 Magnetic head 32 Head support device 4 Elevating device

Claims (4)

[Claims] 1. A magnetic recording / reproducing device including at least one magnetic disk, a driving device, a magnetic head device, and a lifting / lowering device, wherein the driving device rotationally drives the magnetic disk. The magnetic head device includes a magnetic head and a head support device, the magnetic head is supported by the head support device and floats on the surface of the magnetic disk, and the lift device operates the drive device. When stopped, the magnetic head device is lifted to separate the magnetic head from the surface of the magnetic disk, and when the drive device starts operating, the magnetic head device is lowered and the drive device rotates. A magnetic recording / reproducing apparatus for bringing the magnetic head into contact with the surface of the magnetic disk within a start-up time from the start of the operation until the rotation reaches the steady rotation speed. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the rotation speed of the magnetic disk when the magnetic head contacts the surface of the magnetic disk is substantially zero. . 3. The magnetic recording / reproducing apparatus according to claim 1, wherein the magnetic disk has a load zone, and the magnetic head has a load zone in the load zone. A magnetic recording / reproducing device that comes into contact with a surface. 4. The magnetic recording / reproducing apparatus according to claim 3, wherein the load zone is located on the outer peripheral side of the recording zone.