JPH0410286A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To prevent the data of a magnetic disk medium from being destroyed in starting the device again by stopping a spindle motor after positioning a magnetic head to a prescribed area by a control means when it is detected that the magnetic head is set at a position out of the prescribed area. CONSTITUTION:When a spindle motor rotation stop instruction is applied from a computer 6, a control part 2 of a magnetic disk device 1 controls a disk drive 3. Before stop[ping the rotation of the spindle motor 4 by the control part 2, a magnetic head 52 is positioned to an inner-most peripheral cylinder 72 on a magnetic disk medium 7, and a current to a voice coil motor 51 is cut off so as to automatically return the magnetic head 52 to a CSS (contact start stop) zone 71. Then, the position of the magnetic head 52 on the magnetic disk medium 7 is confirmed and the magnetic head 52 is positioned in the CSS zone 71. Afterwards, the rotation of the spindle motor 4 is stopped. In this case, the CSS zone 71 is provided in an inner guard band 7a, and the iner-most peripheral cylinder 72 is provided in a data zone 7b respectively.

Description

Detailed Description of the Invention Technical Field The present invention relates to a magnetic disk device, and in particular, a magnetic head writes and reads data to and from a magnetic disk medium rotated by a spindle motor. The present invention relates to a magnetic disk device having an automatic return function to be positioned at a predetermined position.

BACKGROUND ART Conventionally, in this type of magnetic disk device, the power to the device was turned off in order to stop the rotation of a spindle motor that rotates a magnetic disk medium.

At this time, the current to the positioning drive unit that drives the positioning mechanism that performs reciprocating rotational motion to position the magnetic head at a predetermined position is also cut off, and as a result, the positioning drive unit moves the magnetic head to the CSS (Contact Start Stop) zone. The automatic return function worked and the magnetic head was positioned in the C8S zone.

In such conventional magnetic disk devices, when the spindle motor stops rotating, the power to the device is cut off, and at the same time, the current to the positioning drive section is also cut off, and the automatic return function is activated, causing the magnetic head to return to the css zone. Since positioning was being performed, depending on how the device is used, the automatic return function may not work properly, meaning that the spindle motor may stop before the magnetic head is positioned in the C8S zone.
There is a possibility that the magnetic head may stop while being positioned at the data writing/reading area on the magnetic disk medium, and a contact start/stop may be performed at that position, which may cause the data on the magnetic disk medium to be destroyed. There is a drawback.

In addition, when the magnetic head moves as the current to the positioning drive turns on and off, the acceleration increases as the distance of movement increases, so when the magnetic head is near the outer periphery of the magnetic disk medium, the current to the positioning drive turns off. When this happens, the acceleration becomes large enough to cause the magnetic head to collide with the stopper, resulting in a head crash in which both the magnetic head and the magnetic disk medium are damaged.

Purpose of the Invention The present invention has been made to eliminate the drawbacks of the conventional ones as described above, and provides a magnetic disk device that can prevent data destruction on a magnetic disk medium when the device is restarted after being stopped. The purpose is to provide.

Composition of the Invention A magnetic disk device according to the present invention includes a magnetic head that writes and reads data on a magnetic disk medium rotated by a spindle motor, and a magnetic head that is set inside a cylinder area of the magnetic disk medium when the device is stopped. and a positioning control mechanism for automatically returning the magnetic head to a predetermined position, the positioning means positioning the magnetic head at the innermost periphery of a cylinder area of the magnetic disk medium in response to a stop command from a host device. and when the positioning control mechanism automatically returns the magnetic head after the positioning means positions the magnetic head at the innermost circumference of the cylinder area of the magnetic disk medium, the magnetic head includes the predetermined position. a detection means for detecting whether or not the magnetic head is positioned in the area; and when the detection means detects that the magnetic head is positioned at a position other than the area, the positioning control mechanism moves the magnetic head within the area. The spindle motor is characterized by comprising: a control means for positioning the magnetic head in the area; and a means for stopping the spindle motor after the control means positions the magnetic head in the area.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing a part of a magnetic disk medium used in the embodiment of the invention. In these figures, when a control unit 2 of a magnetic disk device 1 receives a spindle motor rotation stop command from a computer 6, it controls a disk drive 3 based on this command.

That is, before stopping the rotation of the spindle motor 4 in the disk drive 3, the control unit 2 moves the magnetic head 52 in the seek system 5 to the innermost cylinder 7 on the magnetic disk medium 7.
2, and after cutting off the current to the voice coil motor 51 and automatically returning the magnetic head 52 to the C3S (contact start/stop) zone 71, confirming the position of the magnetic head 52 on the magnetic disk medium 7, The magnetic head 52 is positioned in the C8S zone 71.

After the positioning of the magnetic head 52 in the C8S zone 71 is completed, the rotation of the spindle motor 4 is stopped.

Here, the magnetic disk medium 7 is an inner guard blade 7a.
It consists of a data zone 7b and an outer guard band 7c, and the C5S zone 71 is located within the inner guard band 7a.
The innermost cylinders 72 are provided within the data zones 7b (see FIG. 2).

FIG. 3 is a flowchart showing the operation of one embodiment of the present invention. The operation of one embodiment of the present invention will be explained using these FIGS. 1 to 3.

When the control unit 2 receives a spindle motor rotation stop command from the computer 6, it clears the status indicating that the spindle motor 4 is rotating, prohibits writing data to the magnetic disk medium 7, and rejects the command reception. state.

Next, the control unit 2 controls the voice coil motor 51 to move the magnetic head 52 to the innermost cylinder 7 of the magnetic disk medium 7.
Step 11) in Figure 3, the current to the voice coil motor 51 is cut off, the automatic return function of the magnetic head 52 to the C8S zone 71 is activated, and the magnetic head 52 is moved to the C8S zone 71.
Position in 5S zone 71 (Step 12 in Figure 3)
.

Thereafter, the control unit 2 uses a position detection circuit (not shown) to check whether the magnetic head 52 is positioned on the inner guard band 7a during the set time (approximately 2 seconds) (third
Figure step 13).

As a result of this confirmation, if the magnetic head 52 is not positioned on the inner guard band 7a, pressing forcefully restarts the voice coil motor 51 and presses the magnetic head 52 toward the inner guard band 7a. In step 14 of FIG. 3, the magnetic head 52 is positioned on the inner guard band 7a.

The control unit 2 positions the magnetic head 52 on the inner guard band 7a, and if the set time has elapsed (Step 15 in FIG. 3), stops the rotation of the spindle motor 4 (
Figure 3 step 16).

Whether or not the rotation of the spindle motor 4 has stopped is determined by monitoring the state of a hall signal (rotational position signal) whose input continues to change in height as the spindle motor 4 rotates using a rotational position signal detection circuit (not shown). This is done by

This monitoring method involves storing the Hall signal input in a memory (not shown), comparing the value stored in the memory with the value of the Hall signal input immediately after that, and checking if there is no change for 5 seconds. In this case, the control unit 2 determines that the spindle motor 4 has completely stopped (step 17 in FIG. 3).
After that, the command reception is in the state.

In this way, after the magnetic head 52 is positioned at the innermost cylinder 72 on the magnetic disk medium 7 in response to a spindle motor rotation stop command from the computer 6, the automatic return function is activated and the voice coil motor 51 moves the magnetic head 52 to the innermost cylinder 72 on the magnetic disk medium 7. 52 to the C8S zone 71, and if the magnetic head 52 is not positioned on the inner guard band 7a including the C8S zone 71, the voice coil motor 51 is forcibly restarted to move the magnetic head 52. The pressing to the inner guard band 7a side performs a seek, thereby positioning the magnetic head 52 on the inner guard band 7a and stopping the rotation of the spindle motor 4. After the device has stopped, It is possible to prevent data destruction of the magnetic disk medium when rebooting.

Furthermore, by stopping the spindle motor 4 in response to a command to stop rotation of the spindle motor from the computer 6, there is no need to turn off the power to the device each time the spindle motor 4 is stopped. This can be done easily, and the device can be started up quickly without wasting power.

Further, in response to a spindle motor rotation stop command from the computer 6, the magnetic head 52 is moved to the magnetic disk medium 7.
Since automatic return is performed after positioning to the upper innermost cylinder 72, the moving distance of the magnetic head 52 does not become long.
Even if the magnetic head 52 is positioned near the outer periphery of the magnetic disk medium 7, for example near the outer guard band 7C, the magnetic head 52 will not collide with a stopper (not shown), and the magnetic head 52 and the magnetic disk medium will not collide. It is possible to eliminate the risk of a head crash occurring between the head and the head.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, the magnetic head is automatically returned to a predetermined position after the magnetic head is positioned at the innermost circumference of the cylinder area of the magnetic disk medium in response to a stop command from a host device. and when it is detected through this automatic return that the magnetic head is positioned at a position other than the area including the predetermined position, the spindle motor is stopped after the magnetic head is positioned within the area. - There is an effect that data destruction on the magnetic disk medium can be prevented when the device is restarted after being stopped.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a diagram showing part of a magnetic disk medium used in an embodiment of the invention, and FIG. 3 is an embodiment of the invention. 3 is a flowchart illustrating an example operation. Explanation of symbols of main parts 1...Magnetic disk drive 2...Control unit 4...Spindle motor 5...Seek system 7... Magnetic disk medium 7a...Inner guard band 7b...Data zone 51...Voice coil motor 52...Magnetic head 71...C8S zone 72...Innermost cylinder

Claims (1)

[Claims] (1) A magnetic head that writes and reads data to and from a magnetic disk medium rotated by a spindle motor, and positioning that automatically returns the magnetic head to a predetermined position set inside the cylinder area of the magnetic disk medium when the device is stopped. a control mechanism, a positioning means for positioning the magnetic head at the innermost periphery of a cylinder area of the magnetic disk medium in response to a stop command from a host device; When the magnetic head is automatically returned by the positioning control mechanism after the head is positioned at the innermost circumference of the cylinder area of the magnetic disk medium, it is determined whether or not the magnetic head is positioned in an area including the predetermined position. a detection means for detecting; a control means for positioning the magnetic head within the region by the positioning control mechanism when the detection means detects that the magnetic head is positioned at a position other than the region; A magnetic disk drive comprising means for stopping the spindle motor after the magnetic head is positioned in the area by a control means.