JPH0652644A - Magnetic disk device - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve CSS characteristics and reduce costs. [Structure] A magnetic disk device includes a rotatable magnetic disk 2 having a plurality of contact start / stop zones A and B having different peripheral speeds and an information recording zone, and a magnetic disk for performing recording / reproduction on the magnetic disk 2. Head 3
And a servo CPU 5, a VCM controller 6, and a voice coil motor 7 that can move the magnetic head 3 along the zone. The magnetic head 3 moves between the contact start / stop zone A and the contact start / stop zone B at the start and end of the rotation of the magnetic disk 2.

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, and more particularly to a magnetic disk device in which a magnetic head element performs contact start / stop with respect to a magnetic disk.

[0002]

2. Description of the Related Art In a conventional magnetic disk device, a contact start stop (CSS) system is adopted. In this method, the magnetic head element is in contact with the magnetic disk when the magnetic disk is not rotating, slides when the magnetic disk rotates, and reaches a height where it completely comes into non-contact state when the predetermined number of rotations is reached. Levitate from the magnetic disk. Further, when the number of rotations of the magnetic disk decreases, the flying height of the magnetic head element decreases, and at a certain height or less, the magnetic head element contacts the magnetic disk and slides until the rotation is stopped. In this way, since the magnetic head element slides on the magnetic disk at the start and end of rotation of the magnetic disk, wear and damage are likely to occur between the two. Therefore, the life of both cannot be extended, and the CSS characteristics deteriorate.

Therefore, in the conventional apparatus, the material and hardness of the slider in which the magnetic head element is embedded are appropriately selected and the CS is adjusted.
The S characteristic is improved. Further, the shape of the slider is processed to reduce the contact area with the magnetic disk and shorten the contact time at the start and end of rotation to improve the CSS characteristics.

[0004]

In the above-mentioned conventional device, it is necessary to design various materials, hardness, shape, etc. of the slider and to carry out a confirmation test for these. This test is very time consuming. Also, if the material and hardness of the magnetic disk change, the design and confirmation test must be repeated. Therefore, the cost of the device increases.

An object of the present invention is to improve CSS characteristics at low cost.

[0006]

A magnetic disk device according to the present invention comprises a magnetic disk, a magnetic head element, and a moving means. The magnetic disk has a plurality of contact start / stop zones and information recording zones having different peripheral speeds and is rotatable. The magnetic head element is for recording / reproducing on / from a magnetic disk. The moving means can move the magnetic head element along the zone, and moves the magnetic head element between the plurality of contact start / stop zones at the start and end of the rotation of the magnetic disk.

[0007]

In the magnetic disk device according to the present invention, the moving means moves the magnetic head element between a plurality of contact start / stop zones having different peripheral speeds at the start and end of the rotation of the magnetic disk. The magnetic head element that has moved in the contact start / stop zones of different peripheral velocities changes its flying height abruptly and can reach a desired flying height in a short time.

For example, when the contact start / stop zone on the inner peripheral side is moved to the contact start / stop zone on the outer peripheral side at a high peripheral speed at the start of rotation,
The flying height of the magnetic head element can be rapidly increased. At this time, compared with the case where the magnetic head element is positioned in the contact start / stop zone on the outer peripheral side from the beginning, the time required to reach the desired flying height is the same. The sliding distance with respect to the magnetic disk is shortened by the amount of being initially located in the contact start stop zone on the inner circumference side, and friction can be reduced.

At the end of rotation, the contact start / stop from the outer circumference side to the inner circumference side is completely opposite to the start time.
By moving the magnetic head element to the zone, it is possible to position the magnetic head element on the magnetic disk in a short time while floating the magnetic head element for a long time, and the friction between them can be similarly reduced. In this case, it is not necessary to design various sliders and the like, the time for the confirmation test can be shortened, and the CSS characteristics can be improved at low cost.

[0010]

1 is a block diagram of a fixed type magnetic disk device according to an embodiment of the present invention. In this fixed magnetic disk device, the magnetic head device 1 is arranged to face the magnetic disk 2. The magnetic head device 1 includes a magnetic head 3 formed of a slider in which a magnetic core portion is embedded, and an arm portion 4 having the magnetic head 3 fixed at its tip.
It consists of and. The magnetic disk 2 has a contact start / stop zone A on the inner circumference side, a contact start / stop zone B on the outer circumference side, and an information recording zone. When the rotation of the magnetic disk 2 is stopped, the magnetic head 3 is in contact with the contact start / stop zone A.

A servo CPU 5 is provided in a circuit for controlling the magnetic head device 1 and the magnetic disk 2. A VCM controller 6 for driving and controlling a voice coil motor (VCM) 7 is connected to the servo CPU 5. The voice coil motor 7 moves the magnetic head device 1. The recording information read from the magnetic disk 2 by the magnetic head 3 is sent to the head amplifier 8. Information on the position of the magnetic head 3 on the magnetic disk 2 is sent to the demodulator 9 where it is demodulated and the servo C.
It is sent to PU5. That is, the head amplifier 8 and the demodulator 9 form a position information detection circuit. The information recording on the magnetic disk 2 sent to the head amplifier 8 is sent to the read / write circuit 10.

A spindle controller 11 for rotationally driving the magnetic disk 2 is connected to the servo CPU 5, and the spindle controller 11 controls the rotational speed of the spindle motor 12 in response to a command from the servo CPU 5. A timing generation block 13 is connected to the spindle motor 12. Timing generation block 13
Is a spindle motor rotation speed detection circuit for transmitting the rotation speed of the spindle motor 12 to the servo CPU 5.

Next, the operation will be described with reference to the control flowchart of FIG. Before starting the operation, the magnetic head 3
Is in contact with the contact start / stop zone A on the inner circumference side. When the power of the fixed magnetic disk device is turned on, the rising process is executed. In this process, in step S1, a spindle motor start signal is sent from the servo CPU 5 to the spindle controller 11. As a result, the spindle motor 12 starts rotating. In step S2, it is determined whether the spindle motor 12 is rotating based on the rotation speed information sent from the timing generation block 13. Spindle motor 12
If is not rotating, the process returns to step S1 to repeat the same processing. If the spindle motor 12 is rotating, the process proceeds to step S3. In step S3, based on the rotation speed information sent from the timing generation block 13, it is determined whether or not the spindle motor 12 has reached the set rotation speed, and waits for the spindle motor 12 to reach the set rotation speed. At this set rotational speed, the peripheral speed of the contact start / stop zone B on the outer peripheral side is such that the flying height of the magnetic head 3 reaches the glide height height C at which the magnetic head 2 does not come into contact with the magnetic disk 2 reliably. It is at the peripheral speed. If it is determined in step S3 that the spindle motor 12 has reached the set speed, step S4
Move to. In step S4, the VCM controller 6
To control the voice coil motor 7 to shift the position of the magnetic head 3 from the contact start / stop zone A on the magnetic disk 2 to the contact start / stop zone B having a high peripheral speed. As a result, the magnetic head 3 reaches the flying height at which the magnetic head 3 and the magnetic disk 2 do not contact each other.

In step S5, it is determined whether or not the magnetic head 3 has reached the contact start / stop zone B, and after waiting for the arrival, the process proceeds to the subsequent read / write processing. In this read / write process, the magnetic head 3
The information recording zone of the magnetic disk 2 is made to perform a reproducing / writing operation. When the power of the fixed magnetic disk device is turned off, the fall processing is executed. In this process, in step S10, the magnetic head 3 is moved onto the contact start / stop zone B. In step S11, it is determined whether or not the magnetic head 3 has reached the contact start / stop zone B. After waiting for the magnetic head 3 to reach the contact start / stop zone B, the process proceeds to step S12. In step S12, a rotation stop signal for the spindle motor 12 is output to the spindle controller 11. as a result,
The rotation speed of the spindle motor 12 decreases. In step S13, it is determined whether or not the rotation speed of the spindle motor 12 has reached the set rotation speed. This set rotation speed is the same as the set rotation speed at the start of rotation of the magnetic disk 2,
The peripheral speed of the zone B is such that the flying height of the magnetic head 3 reaches the glide height C. When it is determined in step S14 that the rotation speed of the spindle motor 12 has reached the set rotation speed, the process proceeds to step S14, and the magnetic head 3 is moved from the contact start / stop zone B to the contact start / stop zone A. By moving from the zone B having a high peripheral speed to the zone A having a low peripheral speed, the magnetic head 3 descends at a stroke.

FIG. 3 shows the amount of work related to wear between the magnetic head 3 and the magnetic disk 2. When the magnetic head 3 is located in the contact start / stop zone B on the outer peripheral side at the start of rotation of the magnetic disk 2, the time until the flying height of the head 3 reaches the glide height C is t ₁ ,
When the magnetic head 3 is located in the contact start / stop zone A on the inner peripheral side, the time required for the flying height of the head 3 to reach the glide height C is t ₂ . Then, in the contact start-stop zone B and A, the amount of work related to wear, each C · t _1/2 and C · t ₂
/ 2.

On the other hand, the magnetic head 3 according to the present embodiment continues to fly in the zone A until the point a where the flying height reaches D, and moves to the zone B there. At that time, since the rotation speed of the zone B has reached the peripheral speed that causes the buoyancy to levitate on the glide height C, the magnetic head 3 instantly reaches the glide height C. As a result, the amount of work on the wear of this embodiment is reduced as compared with the case of floating only by either the D · t _1/2, and the zone A or zone B.

At the end of the rotation of the magnetic disk 2, when the magnetic head 3 is in the zone A, the time from the time when the head 3 descends to the glide height C to the end of the rotation is t.
_{When the} head 3 is located in the zone B, the time from the gliding height C to the lowering of the flying height to the stop is defined as t ₄ . Then, the amount of work related to wear in the zone A work amount in the C · t _3/2, and the zone B is C
- the t _4/2. In this embodiment, the spindle motor 1
When 2 stops rotating, the magnetic head 3 moves to the contact start / stop zone B. Then, the magnetic head 3 moves from the zone B to the zone A at the point b, which is lowered to the height of the glide height C. At this time, since the buoyancy for floating the magnetic head 3 in the zone A is small, the magnetic head 3 instantaneously descends to the flying height D. After that, contact start stop
Continue descending until rotation stops in zone A. as a result,
Workload related wear in the rotation at the end of the magnetic disk 2 of this embodiment is less than in the case of continued only one of the falling of D · t _4/2, and the zone A or zone B.

As described above, the fixed magnetic disk device has improved CSS characteristics, and further, it is not necessary to design various magnetic heads 3 and to carry out a confirmation test unlike the conventional example, so that the cost is reduced. To do.

[0019]

In the magnetic disk device according to the present invention, the magnetic head element is moved between a plurality of contact stop zones having different peripheral velocities at the start and end of the rotation of the magnetic disk, so that the work related to wear is reduced. .
Therefore, it is not necessary to design various magnetic head elements and perform a confirmation test on them, and the CSS characteristics can be improved at low cost.

[Brief description of drawings]

FIG. 1 is a block diagram of a fixed magnetic disk device as an embodiment of the present invention.

FIG. 2 is a flowchart showing a control operation of the magnetic disk device.

FIG. 3 is a graph showing the amount of work of wear between a magnetic head and a magnetic disk.

[Explanation of symbols]

 2 magnetic disk 3 magnetic head 5 servo CPU 6 VCM controller 7 voice coil motor

Claims (1)

[Claims] 1. A rotatable magnetic disk having a plurality of contact start / stop zones and information recording zones having different peripheral speeds, a magnetic head element for recording / reproducing on / from the magnetic disk, and the magnetic head. A magnetic disk device comprising a moving means capable of moving an element along the zone, wherein the moving means moves the magnetic head element to the plurality of contact start / stop zones at the start and end of rotation of the magnetic disk. A magnetic disk device characterized by being moved between.