JPH04355264A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To avoid the collision between a floating head slider and a magnetic disk and to prevent the floating slider and the magnetic disk from being damaged, in a magnetic disk device setting the floating head slider provided with the magnetic head apart from the magnetic head and saving it at the time of non-operation. CONSTITUTION:This device is provided with a head retracting means 6 keeping a floating head slider 2 apart from a magnetic disk 1 and retracting them and a rotating speed switching means rotating a spindle motor at least at two different speed, and by rotating the floating head slider at higher rotating speed than normal rotating speed when the slider is loaded on the magnetic disk, floating force applied to the head at the time of loading is increased an the collision between the slider and the disk is reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive which is capable of adjusting the rotational speed of a magnetic disk when its rotation is started.

0002

2. Description of the Related Art In recent years, magnetic disk drives have become smaller, lighter, and more power efficient. In particular, miniaturized magnetic disk drives are sometimes carried around, such as being installed in notebook personal computers, and therefore need to be shock resistant. For this reason, magnetic disk drives are beginning to appear in which a flying head slider equipped with a magnetic head is moved away from the magnetic disk when information is not being recorded or reproduced.

An example of a conventional magnetic disk device will be described below with reference to the drawings. FIG. 3 shows a block diagram of a conventional magnetic disk device.

[0004] Reference numeral 1 indicates a magnetic disk. 2 is a flying head slider equipped with a magnetic head for recording and reproducing information on the magnetic disk 1; 3 is a spindle motor that rotates the magnetic disk 1; 4 is a spindle drive circuit that is a spindle drive means that drives the spindle motor 3; A leaf spring 5 supports the flying head slider 2 and pushes the flying head slider 2 toward the first surface of the magnetic disk. Reference numeral 6 denotes a head evacuation means, which includes a head loading/unloading mechanism 7 (hereinafter referred to as head evacuation means) that lowers the flying head slider 2 onto the magnetic disk 1 (hereinafter referred to as loading) and removes it from the magnetic disk 1 (hereinafter referred to as unloading). L/U mechanism) and head L
The head load/unload mechanism drive circuit 8 (hereinafter referred to as head L/U mechanism drive circuit) drives the /U mechanism 7.

The operation of the magnetic disk device configured as described above will be explained below.

When the magnetic disk drive is in a standby state, the magnetic disk 1 is stopped, and the head L/U mechanism 7 expands the leaf spring 5 supporting the flying head slider 2 in a direction away from the magnetic disk 1. This keeps the flying head slider 2 away from the magnetic disk surface. (For example, JP-A-63-234471).

When recording or reproducing information, first, the drive controller 9 sends a start signal to the spindle motor drive circuit 4. The spindle motor drive circuit 4 is
The spindle motor 3 is driven, and as a result, the magnetic disk 1 begins to rotate, and after a certain period of time, rotates at a steady rotational speed that is the rotational speed necessary for recording or reproducing information.

When the magnetic disk 1 reaches a steady rotational speed, the drive controller 9 sends a head load signal to the head L/U mechanism drive circuit 8 to load the flying head slider 2 onto the magnetic disk surface. Head L/U
The mechanism drive circuit 8 drives the head L/U mechanism 7 to narrow it, and the flying head slider 2 is brought closer to the recording surface of the magnetic disk 1 little by little by the spring force of the leaf spring 5.

The flying head slider 2 includes a magnetic disk 1
As the magnetic disk 1 approaches, the air current generated by the rotation of the magnetic disk 1 receives a levitation force in the direction away from the magnetic disk 1, and this levitation force and the spring force of the leaf spring 5 are balanced, resulting in a distance of several microns above the magnetic disk surface. At this position, the flying head slider 2 floats stably.

A plate spring 5 supporting the flying head slider 2 is supported by a carriage 10. An actuator composed of a carriage 10, a coil 11, and a magnet 12 moves in the radial direction of the magnetic disk 1.

When the flying head slider 2 stably floats above the magnetic disk surface, the drive controller 9 sends an actuator drive signal to the actuator drive circuit 13 , and the actuator drive circuit 13 causes a current to flow through the coil 11 to move the flying head slider 2 . move to the target position. The magnetic head mounted on the flying head slider 2 that has moved to the target position records or reproduces information on the recording surface of the magnetic disk 1.

If the next command is not issued for a predetermined period of time, the drive controller 9 temporarily stops the spindle motor in order to save power. At this time, the drive controller 9 sends a spindle stop signal to the spindle motor drive circuit 4 to stop the spindle motor 3, and sends an unload signal to the head L/U mechanism drive circuit 8 to push up the flying head slider 2. The head L/U mechanism drive circuit 8 drives the head L/U mechanism 7 so as to spread it apart, lifts the leaf spring 5, and lifts the flying head slider 2.
away from the magnetic disk 1.

[0013]

However, in the conventional configuration, when the flying head slider is loaded onto the magnetic disk by the head L/U mechanism, the flying head slider sometimes collides with the magnetic disk surface. However, there is a problem in that the flying head slider, the magnetic disk, or both may be damaged. especially,
In recent years, as recording density has increased, the spring force of the leaf spring has tended to gradually increase to reduce the flying height of the flying head slider, which has led to an increase in the number of collisions between the flying head slider and the magnetic disk, causing damage. There are also problems that arise.

In view of the above-mentioned problems, the present invention provides a method for loading a flying head slider onto a magnetic disk.
An object of the present invention is to provide a magnetic disk device that prevents damage to the flying head slider, the magnetic disk, or both of them due to collision of the flying head slider with the magnetic disk.

[0015]

Means for Solving the Problems In order to solve the above-mentioned problems, a magnetic disk device of the present invention includes a magnetic disk, a flying head slider comprising a magnetic head for recording or reproducing information on the magnetic disk, a spindle motor that rotates the magnetic disk; a spindle drive means that drives the spindle motor; a first rotational speed when recording and reproducing information; and a second rotational speed that is higher than the first rotational speed when starting the spindle rotation. rotational speed switching means for switching the rotational speed of the magnetic disk;
The apparatus further includes a head retracting means for keeping the flying head slider away from the magnetic disk when the spindle is stopped.

[0016]

[Operation] According to the above-described structure, when the flying head slider loads the magnetic disk, the magnetic disk is rotated at a rotation speed higher than normal, thereby increasing the speed of the airflow caused by the rotation of the magnetic disk. By increasing the flying force of the magnetic disk, collision between the flying head slider and the magnetic medium can be avoided, and damage to the flying head slider and the magnetic disk can be prevented.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic disk drive according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram of a magnetic disk device according to an embodiment of the present invention. 1 is a magnetic disk, 2 is a flying head slider equipped with a magnetic head,
3 is a spindle motor that rotates the magnetic disk 1;
is a spindle drive circuit which is a spindle motor drive means for driving the spindle motor 3. 5 is a leaf spring that supports the flying head slider 2, and 6 is a head retracting means, which is a head L/U that lowers the flying head slider 2 onto the magnetic disk 1 and lifts it up from above the magnetic disk.
mechanism 7 and a head L/U that drives the head L/U mechanism 7
It consists of a mechanism drive circuit 8. 10 is a flying head slider 2
, a carriage that moves the leaf spring 5 in the radial direction of the magnetic disk 1, and is driven by a voice coil motor composed of a coil 11 and a magnet 12. 14 is a rotation speed switching circuit which is a rotation speed switching means for switching the rotation speed of the magnetic disk.

The operation of the magnetic disk device configured as described above will be explained below with reference to FIGS. 1 and 2.

When the magnetic disk drive is in a standby state, the magnetic disk 1 is stopped, and the head L/U mechanism 7 expands the leaf spring 5 supporting the flying head slider 2 in a direction away from the magnetic disk 1. This keeps the flying head slider 2 away from the magnetic disk surface.

When recording and reproducing information, first, the drive controller 9 sends a start signal to the spindle drive circuit 4. Here, the spindle drive circuit 4 receives a predetermined clock signal from the outside and rotates the spindle motor 3 at a rotational speed proportional to this clock frequency. Further, the drive controller 9 sends a rotational speed switching signal to the rotational speed switching circuit 14 . The rotational speed switching circuit 14 generates a clock frequency that achieves a rotational speed (hereinafter referred to as load rotational speed) higher than the clock frequency that achieves a steady rotational speed, and sends it to the spindle motor drive circuit 4. Therefore, when the spindle motor 3 is started, the magnetic disk 1 rotates at the load rotation speed.

When the magnetic disk 1 reaches the load rotation speed, the drive controller 9 sends a head load signal to the head L/U mechanism drive circuit 8 to load the flying head slider 2 onto the surface of the magnetic disk 1. Head L
The /U mechanism drive circuit 8 drives the head L/U mechanism 7 to narrow it, and the flying head slider 2 is brought closer to the recording surface of the magnetic disk 1 little by little by the spring force of the leaf spring 5.

The flying head slider 2 includes a magnetic disk 1
As the magnetic disk 1 approaches , a levitation force is applied in a direction away from the magnetic disk 1 due to the air flow generated by the rotation of the magnetic disk 1 . Therefore, the flying head slider 2 floats stably at a position where the flying force and the spring force of the leaf spring 5 are balanced.

FIG. 2 shows the relationship between the rotational speed of the magnetic disk and the flying force exerted on the flying head slider due to the airflow. When the rotational speed of the magnetic disk is high, the flying force exerted on the flying head slider becomes large. Therefore, even if the flying head slider 2 is pressed against the magnetic disk side with a large force when loading the flying head slider 2, since the flying force is large, collision between the flying head slider 2 and the magnetic disk 1 is prevented. Further, although the flying head slider 2 flies at a higher position than at the steady rotation speed, the flying stability is increased.

When the flying head slider 2 stably floats above the magnetic disk surface, the drive controller 9 sends a rotational speed switching signal to the rotational speed switching circuit 14 . The rotation speed switching circuit 14 generates a clock frequency that realizes a steady rotation speed, and sends it to the spindle motor drive circuit 4. The spindle motor 3 gradually shifts from the load rotation speed to a steady rotation speed, and after a certain period of time, the magnetic disk 1 rotates at the steady rotation speed. Flying head slider 2
gradually descends to the optimal flying height for recording and playback, and then floats stably.

The leaf spring 5 supporting the flying head slider 2 is supported by a carriage 10 and can be moved in the radial direction of the magnetic disk 1 by an actuator composed of the carriage 10, a coil 11, and a magnet 12.

When the magnetic disk 1 reaches a steady rotational speed and the flying head slider 2 reaches a predetermined flying height with respect to the magnetic disk 1, the drive controller 9 sends an actuator drive signal to the actuator drive circuit 13, and the actuator drive circuit 13 By passing a current through the coil 11, the flying head slider 2 is moved to the target position. The magnetic head mounted on the flying head slider 2 that has moved to the target position records or reproduces information on the recording surface of the magnetic disk 1.

If the next command is not issued for a predetermined period of time, the drive controller 9 temporarily stops the spindle motor to save power. At this time, the drive controller 9 sends a spindle stop signal to the spindle motor drive circuit 4 to stop the spindle motor 3, and sends an unload signal to the head L/U mechanism drive circuit 8 to push up the flying head slider 2. The head L/U mechanism drive circuit 8 drives the head L/U mechanism 7 so as to spread it out, and separates the flying head slider 2 from the magnetic disk 1.

As described above, according to this embodiment, a rotational speed switching circuit is provided as a rotational speed switching means, and by rotating the spindle motor at a speed higher than the steady rotational speed when starting, the flying head slider is floated when loaded. It is possible to avoid the problem of the head slider colliding with the magnetic disk and causing damage.

[0030]

As described above, the present invention provides rotation switching means for the spindle motor, and when the spindle motor starts rotating, it rotates at a high rotation speed.
This prevents the flying head slider from colliding with the magnetic disk during loading of the flying head slider and causing damage, thereby making it possible to provide a highly reliable magnetic disk device.

[Brief explanation of drawings]

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

[Figure 2] Relationship diagram between the rotational speed of the magnetic disk and the flying force of the magnetic head

[Figure 3] Block configuration diagram of a conventional magnetic disk device

[Explanation of symbols]

1 Magnetic disk 2 Floating head slider 3 Spindle motor 4 Spindle motor drive circuit 7 Head loading/unloading mechanism

Claims (1)

[Claims] 1. A flying head slider comprising a magnetic disk, a magnetic head for recording or reproducing information on the magnetic disk, a spindle motor for rotating the magnetic disk, and a spindle drive means for driving the spindle motor. a rotational speed switching means for switching the rotational speed of the magnetic disk to a first rotational speed when recording and reproducing information and to a second rotational speed that is larger than the first rotational speed when the spindle starts rotating; and the flying head slider when the spindle is stopped. a head retracting means for keeping the head away from the magnetic disk.