JPH04221478A - Magnetic disk apparatus - Google Patents

Abstract

PURPOSE:To retreat a magnetic head to a refuge region of a magnetic disk when an external impact is applied by providing a vibration sensor in a housing of a magnetic disk apparatus. CONSTITUTION:When an external impact, etc., is applied to a housing 1, a vibrating part 12B is vibrated in a direction of an arrow Z to hit a pressure receiving part 12C, and a vibration sensor 12 outputs a voltage signal generated by the hitting force to a control unit as a vibration detection signal of the housing 1. When the detection signal exceeds a reference voltage value, a present position of a magnetic head 9 on a memory zone 4A of a magnetic disk 4 is stored, a control signal is output from the unit to a voice coil motor 10, a swing arm 7 is moved to the inner peripheral side of the disk 4, and the head 9 can be rapidly retracted from the zone 4A to a shipping zone 4B. If a vibration generated in the housing 1 becomes smaller than the reference voltage value, the head 9 is sought from the zone 4B to an original position on the zone 4A to be returned.

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 suitable for use as an external storage device for computers such as office computers and personal computers.

0002

2. Description of the Related Art Generally, a computer such as an office computer is provided with an external storage device such as a magnetic disk device to assist the main storage device. A magnetic disk that is arranged and rotationally driven by a disk drive motor, a magnetic head that writes and reads data on the magnetic disk, and a head drive motor that moves the magnetic head in the radial direction of the magnetic disk. It is configured.

The above-described magnetic disk drive drives the disk drive motor in response to a control signal from the control unit to rotate the magnetic disk at high speed, and then outputs a control signal to the head drive motor to prevent the evacuation of the magnetic disk. A magnetic head waiting in a shipping zone as an area is caused to seek toward the outer circumferential side of the magnetic disk. As a result, the magnetic head writes data to the magnetic disk and reads (reproduces) data from the magnetic disk by seeking in the radial direction on the magnetic disk while floating due to the airflow caused by the high-speed rotation of the magnetic disk. It is designed to do this.

On the other hand, if strong vibrations or shocks are applied from the outside during the operation of the magnetic disk drive, causing fluctuations in the rotation of the magnetic disk, the control unit corrects the rotational fluctuations due to the timing shift of the index pulse signal, etc. The control signal to the disk drive motor is stopped to stop the rotation of the magnetic disk, and rotation abnormality processing is performed to stop the access at that time, thereby preventing damage to the magnetic film of the magnetic disk or the magnetic head. It looks like this.

[0005]

[Problems to be Solved by the Invention] By the way, in the magnetic disk drive according to the above-mentioned prior art, when a fluctuation occurs in the rotation of the magnetic disk due to external vibrations, etc., the control unit has a main routine for processing normal commands. (normal control processing) is interrupted by abnormal rotation processing,
Although this stops the rotation of the disk drive motor and prevents damage to the magnetic disk or magnetic head, the control unit determines this rotational fluctuation by calculating it from the timing deviation of the index pulse signal, etc. Because of this, it takes a considerable amount of processing time to stop the rotation of the disk drive motor, and during this time, there is a risk that the magnetic head may malfunction when writing or reading data. Since the magnetic head stops at a certain position, there is a risk that the magnetic head may come into contact with the magnetic disk that has stopped rotating and destroy data.

[0006] Furthermore, once the rotation abnormality processing described above is performed, the device will not start up unless the power is turned on again (power-on reset), which is a so-called not-ready state. In addition, if the magnetic disk drive's power supply is linked to the computer's power supply, resetting the magnetic disk drive will cause the computer to There is a problem in that a program in the middle of being created on the RAM of the computer disappears.

The present invention has been made in view of the problems of the prior art described above, and provides a magnetic disk that can detect vibrations and shocks applied to a magnetic disk from the outside at an early stage, thereby preventing damage to the magnetic head and the magnetic disk. It provides equipment.

[0008]

[Means for Solving the Problems] The features of the configuration adopted by the present invention in order to solve the above-mentioned problems include a vibration detection means for detecting vibration of the housing and outputting a detection signal, and a vibration detection means for detecting vibration of the housing and outputting a detection signal. vibration determination means for determining whether or not the detection signal exceeds a predetermined vibration; and when the vibration determination means determines that the detection signal exceeds the predetermined vibration, the magnetic head is evacuated to an evacuation area of the magnetic disk. In addition, a magnetic head retraction control means for outputting a control signal to the head drive motor is provided.

[0009]

[Operation] With the above configuration, when external vibration is applied to the housing, the vibration detection means detects this vibration and outputs a detection signal, and the vibration determination means determines that this detection signal exceeds a predetermined vibration. The magnetic head retraction control means outputs a control signal to the head drive motor based on the determination by the vibration determination means, and the head drive motor can retract the magnetic head to the evacuation area of the magnetic disk.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 6, taking as an example the case where the present invention is applied to a swing arm type magnetic disk device.

In the figure, 1 is a housing of a magnetic disk drive, and 2 is a housing body constituting the housing 1. The housing body 2 has a flat bottom 2A and is erected on the outer circumferential side of the bottom 2A. The housing body 2 is formed into a rectangular tube shape with a bottom from a side wall portion 2B having a rectangular tube shape, and the opening side of the housing body 2 is covered with a cover (not shown).

Reference numeral 3 denotes a spindle motor as a disk drive motor fixed to the bottom 2A of the housing body 2. On the rotating shaft of the spindle motor 3, a plurality of magnetic disks 4, which will be described later, are arranged at predetermined intervals in the axial direction. are arranged,
The spindle motor 3 is connected to a control unit 1 which will be described later.
4 via a lead wire (not shown). The spindle motor 3 is controlled by the control unit 1.
The magnetic disk 4 is driven by a control signal from the magnetic disk 4 to rotate at a high speed.

That is, 4 is a plurality of magnetic disks (
The magnetic disk 4 has a storage zone 4A in which a large number of concentric storage tracks are formed, and a magnetic head 9, which will be described later, is located on the inner circumferential side of the storage zone 4A when the magnetic disk 4 is stopped. It consists of a shipping zone 4B as a waiting evacuation area.

Reference numeral 6 indicates a pivot shaft installed in the bottom portion 2A of the housing body 2, and reference numeral 7 indicates a swing arm swingably supported by the pivot shaft 6. On the base end side of the swing arm 7, there is provided a pivot shaft which will be described later. A voice coil motor 10 is provided, and a plurality of leaf springs 8 for attaching a magnetic head 9 are provided on the tip side.
(only one is shown) is provided. The swing arm 7 is configured to swing in the direction of arrow S about the pivot shaft 6 by a voice coil motor 10.

Reference numeral 9 indicates a plurality of magnetic heads (only one is shown) for writing and reading data into and from the storage zone 4A of the magnetic disk 4, and each magnetic head 9 is connected to the swing arm 7.
is attached to the tip side of the magnetic disk 4 via a leaf spring 8, and seeks in the radial direction of the magnetic disk 4 by swinging the swing arm 7.

Reference numeral 10 connects each magnetic head 9 to a swing arm 7.
A voice coil motor (VCM) serves as a head drive motor for seeking in the radial direction of the magnetic disk 4 via the
), the voice coil motor 10 consists of a coil 10A fitted to the base end side of the swing arm 7, and a stator 10B fixed to the housing body 2, and the voice coil motor 10 includes a flexible cable described below. 11 to a control unit 14. The voice coil motor 10 is configured to swing the swing arm 7 by receiving power from the control unit 14 to the coil 10A.

Reference numeral 11 denotes a flexible cable that is attached to the bottom 2A of the housing body 2 and is composed of an FPC cable or the like, and the flexible cable 11 connects each magnetic head 9, the coil 10A of the voice coil motor 10, etc., and the control unit. 14 are connected.

Reference numeral 12 indicates a vibration sensor as a vibration detection means provided in the housing body 2, and the vibration sensor 12
As shown in FIG. 2, the support part 12A is attached to the side wall part 2B of the housing body 2, and the distal end side is swingably supported by the support part 12A so as to extend horizontally within the housing body 2. A vibrating part 12B formed from a material into a small diameter rod shape, and a pressure receiving part 12C formed into a plate shape from a piezoelectric material, which is attached to the bottom part 2A of the housing main body 2 so that the upper surface side contacts the tip side of the vibrating part 12B. The vibration sensor 12 is connected to a flexible cable 11 via a lead wire 13, and is connected to a control unit 14 via the flexible cable 11. and,
When the vibration sensor 12 generates vibration in the housing main body 2 due to an external impact, the vibrating part 12B vibrates in the direction of arrow Z in response to the vibration, and the pressure receiving part 12C vibrates in the direction of the arrow Z.
is struck at the tip side of the vibrating part 12B to generate a voltage signal corresponding to this striking force, which is used as a detection signal V corresponding to the vibration of the housing main body 2 in the direction indicated by the arrow Z to the control unit 1.
4 via a lead wire 13 and a flexible cable 11.

Reference numeral 14 denotes a control unit, and as shown in FIG. 3, the control unit 14 is roughly composed of an arithmetic processing circuit such as a CPU and a storage circuit such as ROM, RAM, etc. and Figure 5
The program shown in and each reference voltage value V1, V2 described later
A storage area 14A is provided in which the following information is stored. Further, a spindle motor 3, a magnetic head 9, a voice coil motor 10, a vibration sensor 12, etc. are connected to the input/output circuit of the control unit 14 via a flexible cable 11. And the control unit 1
4, the voice coil motor 1 is activated based on the detection signal V from the vibration sensor 12 through a magnetic head retraction control process to be described later.
0 is controlled via a motor drive circuit or the like.

The magnetic disk device according to this embodiment has the above-mentioned configuration, and its operation will be explained next with reference to FIG.
This will be explained with reference to FIG.

First, the program shown in FIG. 4 shows the normal control processing of the magnetic disk drive according to this embodiment. In step 1, the control unit 14 reads the detection signal V from the vibration sensor 12, and in step 2, the control unit 14 reads the detection signal V from the vibration sensor 12. Reference voltage value V1 that serves as a reference for determining the presence or absence of vibration in the signal V
Determine whether it is larger than . If the determination in step 2 is "NO", the vibration within the housing body 2 is extremely small and is in a normal state that does not affect the operation of the device, so the process moves to the next step 3.

In the next step 3, the spindle motor 3
A control signal is output to rotate each magnetic disk 4 at high speed, and a control signal is output to the voice coil motor 10 to drive it, and the swing arm 7 is swung in the direction of arrow S by driving the voice coil motor 10. magnetic head 9
is sought in the radial direction of the magnetic disk 4, thereby executing a normal command for writing and reading data in the storage zone 4A of the magnetic disk 4.

[0023] Furthermore, when the determination in step 2 is ``YES'', vibration occurs in the housing body 2 due to an external shock, etc., and the detection signal V from the vibration sensor 12 exceeds the reference voltage value V1. Therefore, the process moves to the next step 4, in which the command currently being executed is stopped and the process moves to the magnetic head evacuation control process shown in FIG. 5 via connector A.

In the magnetic head retraction control process shown in FIG. 5, in step 5, the detection signal V from the vibration sensor 12 is
The reference voltage value V2 (
V2 > V1 ). If the determination in step 5 is "NO", the vibration is within an allowable level of the magnetic disk drive, and the process returns to the normal control process shown in FIG. 4.

On the other hand, if the determination in step 5 is ``YES'', this means that the vibration within the housing body 2 exceeds the predetermined permissible vibration, so the process moves to the next step 6, and in this step 6, The current position of the magnetic head 9 on the storage zone 4A of the magnetic disk 4 is stored in the storage area 1.
4A, and in the next step 7, a control signal is output to the voice coil motor 10, the swing arm 7 is swung toward the inner circumferential side of the magnetic head 4, and the magnetic head 9 is moved to the storage zone of the magnetic disk 4. The magnetic head 9 is sought from the shipping zone 4A and retracted, and the magnetic head 9 is stopped at the shipping zone 4B.

[0026] Then, in step 8, the next step 9
The detection signal V from the vibration sensor 12 is the reference voltage value V2.
The detection signal V is read from the vibration sensor 12 until it becomes smaller than , and it is determined as "YES". When it is determined as "YES" in this step 9, the vibration in the housing body 2 has become tolerably small. Therefore, the process moves to the next step 10, in which a control signal is output to the voice coil motor 10 based on the position data of the magnetic head 9 stored in step 6, and the swing arm 7 is moved to the magnetic disk 4. After the magnetic head 9 seeks from the shipping zone 4B of the magnetic disk 4 to the storage zone 4A by swinging it toward the outer circumference of the magnetic disk 4, the magnetic head 9 is thereby returned to its original position on the storage zone 4A. Return to normal control processing shown in .

Thus, according to this embodiment, the vibration generated in the housing body 2 can be reliably detected by the vibration sensor 12, and the execution of the command by the normal control process can be immediately stopped, and the vibration can be detected at a predetermined reference voltage. It can be quickly determined in step 5 whether or not the value has exceeded the value V2, and when the determination is "YES" in step 5, a control signal is output from the control unit 14 to the voice coil motor 10, and the swing arm 7 is moved to the magnetic disk. Since the magnetic head 9 can be quickly evacuated from the storage zone 4A of the magnetic disk 4 to the shipping zone 4B by swinging the magnetic head 9 toward the inner circumference of the magnetic disk 4, command execution errors may occur.
Damage to the magnetic head 9, magnetic disk 4, etc. can be reliably prevented, and the reliability of the magnetic disk device can be greatly improved.

Furthermore, when the vibration within the housing body 2 becomes smaller than the reference voltage value V2, the magnetic head 9
can be returned by seeking from the shipping zone 4B to the original position on the storage zone 4A stored in step 6, so temporarily suspended commands can be executed quickly, and work efficiency can be greatly improved. .

In the above embodiment, step 5 in the program shown in FIG. 5 is a specific example of the vibration determining means which is a component of the present invention, and steps 6 to 10 in the program shown in FIG. The above is a specific example of the magnetic head retraction control means which is a component of the present invention.

Further, in the above embodiment, the vibration sensor 12 as the vibration detection means is mounted on the side wall portion 2B of the housing body 2.
a supporting part 12A attached to the supporting part 12A; a vibrating part 12B swingably supported by the supporting part 12A so that its distal end side extends horizontally within the housing main body 2;
Bottom part 2 of housing body 2 so as to be in contact with the tip side of B.
A and a pressure receiving part 12C attached to the bottom part 2A of the housing main body 2, and vibrations in the direction of the arrow Z are detected. However, as shown in the modified example shown in FIG. 12B, and the pressure receiving part 12C is attached to the side wall 2B of the housing main body 2 to detect vibration in the direction of the arrow X. Alternatively, the vibration sensor 12 of the modified example may be mounted in the direction of the Alternatively, the vibration in the Y direction may be detected.

On the other hand, in the above embodiment, the inner shipping zone 4B of the magnetic disk 4 is used, but the shipping zone (not shown) located on the outer side of the magnetic disk 4 may also be used as an evacuation area. good.

Further, in the above embodiment, one vibration sensor 12 is provided in the housing body 2, but
Alternatively, the vibration sensor 12 may be provided on the outside of the housing body 2 or on the cover side, or a plurality of vibration sensors 12 may be provided to detect vibrations in the X, Y, and Z directions of the arrows.

Furthermore, in the embodiment described above, a vibration sensor consisting of the support section 12A, the vibration section 12B, and the pressure receiving section 12C is used as the vibration detection means, but the present invention is not limited to this. Other vibration sensors such as a vibrator-type vibration sensor that utilizes frequency changes of a child may also be used.

Further, in the embodiment described above, the voice coil motor 10 was used as an example of the head drive motor, but instead of this, other motors such as a stepping motor may be used as the head drive motor.

Furthermore, in the above embodiments, the case where the present invention is applied to a swing arm type magnetic disk device has been described as an example, but the present invention is not limited to this, and the present invention is not limited to this, but can be applied to a magnetic disk device using a linear type reciprocating mechanism. It can also be applied to

[0036]

As described in detail above, according to the present invention, there is provided a vibration detecting means for detecting the vibration of the housing and outputting a detection signal, and a detection signal for determining whether the detection signal from the vibration detecting means exceeds a predetermined vibration. vibration determining means for determining whether the vibration is high; and when the vibration determining means determines that the detection signal exceeds a predetermined vibration, outputting a control signal to the head drive motor so as to evacuate the magnetic head to an evacuation area of the magnetic disk. Since the magnetic head evacuation control means is provided, when vibration occurs in the housing due to an external shock, etc., this vibration can be reliably detected by the vibration detection means.
When the vibration determining means determines that the detection signal from the vibration detecting means exceeds a predetermined vibration, the magnetic head retraction control means outputs a control signal to the head drive motor based on the determination of the vibration determining means. The head drive motor can quickly evacuate the magnetic head to the evacuation area of the magnetic disk, effectively preventing damage to the magnetic head, etc., and improving the reliability of the magnetic disk device.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the overall configuration of a magnetic disk device showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along arrow II-II, showing the vibration sensor in FIG. 1;

FIG. 3 is a block diagram showing the circuit configuration of a control circuit of the magnetic disk device.

FIG. 4 is a flowchart showing normal control processing of the magnetic disk device.

FIG. 5 is a flowchart showing magnetic head retraction control processing following FIG. 4;

FIG. 6 is an enlarged sectional view similar to FIG. 2 showing a vibration sensor according to a modification of the present invention.

[Explanation of symbols]

1 Housing 3 Spindle motor (disk drive motor) 4
Magnetic disk 4B Shipping zone (evacuation area) 9 Magnetic head 10 Voice coil motor (head drive motor) 12
Vibration sensor (vibration detection means)

Claims (1)

[Claims] 1. A housing, a magnetic disk disposed within the housing and rotationally driven by a disk drive motor, a magnetic head for writing and reading information on the magnetic disk, and a magnetic head that is connected to the magnetic disk. A magnetic disk drive comprising: a head drive motor that moves the housing in a radial direction; a vibration determining means for determining whether or not the vibration has exceeded a predetermined value; 1. A magnetic disk device comprising a magnetic head retraction control means that outputs a control signal.