JP2910688B2 - Magnetic disk drive - Google Patents

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 provided with a magnetic head having a structure for floating on a disk medium via an air bearing having a minute gap and writing or reading predetermined information to or from the disk medium. More particularly, the present invention relates to a magnetic disk device having a function of predicting (determining) in advance an adsorption accident (that is, non-activation of a spindle motor) caused by a frictional force at an interface between a magnetic head and a magnetic disk.

[0002]

2. Description of the Related Art Conventionally, HDI (Head Disk Center) has been used.
A magnetic disk device having a function of predicting a failure of a face (head disk interface) portion is relatively frequently used. That is, from the viewpoint of the reliability of the magnetic disk device, a failure is foreseen before a failure such that information stored in the device is destroyed, and preventive replacement of the magnetic disk device and measures for avoiding the failure are performed. It is intended.

Among known examples of this kind, for example, Japanese Patent Application Laid-Open
Japanese Patent No. 78161 discloses a technique in which a reference voltage is compared with an output voltage of a magnetic head positioned on a track to predict a risk of a head crash. Further, as a countermeasure against the head slider attraction problem which is generally known as an HDI failure in a magnetic disk device, a method of increasing a starting torque by increasing a starting current of a spindle motor of a magnetic disk device, a method of increasing a starting torque, There is a method in which the motor is alternately rotated in the forward and reverse directions to avoid suction generated between the head and the disk, and the head itself (a beam or a housing supporting the head) is moved radially or circumferentially with respect to the disk. There is a method of avoiding adsorption by vibrating in the direction.

Further, an increase in the frictional force between the head and the disk due to an increase in the number of times of CSS (contact start / stop) is detected by a frictional force detection sensor attached to the head itself (a beam and a housing for supporting the head). However, a method for preventing the occurrence of an adsorption failure is also known.

[0005]

However, in each of the above-mentioned conventional examples, for example, in the case of a method of providing a frictional force detection sensor to avoid suction, the head-disk space is increased due to an increase in the number of CSS passes. Since the method of detecting an increase in frictional force is adopted, the number of heads used increases as the number of magnetic disks mounted in the magnetic disk device increases, which complicates the mechanical configuration and its control circuit. However, there was an inconvenience of soaring costs.

In the method disclosed in Japanese Unexamined Patent Publication No. 3-78161, since the starting torque is increased or the spindle motor is rotated forward / reversely, it takes time and effort to control these devices, and the entire device is normally used. There has always been the hassle of applying operation control other than operation.

[0007]

An object of the present invention is to provide a suction failure predicting function capable of improving the disadvantages of the conventional example and efficiently predicting a suction failure of a magnetic head to a magnetic disk medium without requiring a particularly complicated structure. It is an object of the present invention to provide a magnetic disk drive provided with the same.

[0008]

According to the first aspect of the present invention, there is provided a disk medium, a spindle motor for rotating the disk medium at a constant speed, and air having a minute gap on the disk medium. The magnetic head includes a magnetic head having a structure that floats via a bearing and writes or reads predetermined information to or from the disk medium, and a motor drive control circuit that controls the rotation state of the spindle motor at a constant speed.

The motor drive control circuit has a motor start information output function for detecting and outputting each timing when power is supplied to the spindle motor and when the spindle motor is actually started. In addition, the motor drive control circuit measures the rotation start time required for the spindle motor to start rotating from power-on based on the two timing signals output by operating the motor start information output function. And a timer circuit for holding.

A time comparison / judgment circuit for outputting a predetermined signal when the rotation start time held by the timer circuit exceeds a separately set comparison rotation start time is provided. A failure prediction information display means for externally displaying a predetermined output signal to be output as soft adsorption information is provided.

[0011] Therefore, in the invention according to claim 1,
First, a rotation command is transmitted from the motor drive control circuit to the spindle motor to rotate the spindle motor. At the same time, the motor drive control circuit captures the timing of the start of rotation of the spindle motor, transmits a signal to the above-described timer circuit to notify that the spindle motor has rotated, and stops the operation of the timer circuit.

Thereafter, the time comparison determination circuit compares the rotation start time of the spindle motor measured by the timer circuit with the comparison rotation start time A specified in advance. The comparison of the rotation start time is performed every time the spindle motor is started.
Then, when the rotation start time exceeds the comparison rotation start time A in the time comparison determination circuit, this is output as soft suction information.

The failure prediction information display means, which has input the soft suction information, controls the display of the soft suction information on the prediction information display section. For this reason, the progress can be known in advance by the soft suction information before the suction failure finally occurs.

According to a second aspect of the present invention, in the magnetic disk drive according to the first aspect, the number of times of signal output from the time comparison and determination circuit is provided between the time comparison and determination circuit and the failure prediction information display means. And a transcendental number comparison judging circuit having a suction prediction information output function for outputting a predetermined signal when the transcendental number exceeds a preset comparative transcendental number. Further, the failure prediction information display means has a failure prediction display function of displaying output information from the transcendence number comparison and determination circuit as suction failure prediction information.

Therefore, in the invention according to claim 2,
In addition to functioning equivalently to the first aspect of the present invention, the transcendental comparison and determination circuit counts and stores the number of times that the time comparison and determination circuit has exceeded the number of times (the number of times of output of the soft suction information), and stores it in advance. A comparison is made with the arbitrarily set transcendental number B. In this case, the number of times of output of the soft suction information may be counted by the time comparison and determination circuit, and the time comparison and determination circuit may be sent to the transcendence comparison and determination circuit as count information of the soft suction information.

If the number of times determined by the time comparison determination circuit to be greater than the number of times of transcendence B for comparison is smaller,
Upon inputting this information, the failure prediction information display means immediately activates the failure prediction display function and outputs display information indicating that "the possibility of occurrence of the adsorption failure is low" in the adsorption failure notice information.

On the other hand, when the number of times determined by the time comparison determination circuit to be greater than the number of times of transcendence B for comparison is larger,
Upon inputting this information, the failure prediction information display means immediately activates the failure prediction display function and outputs display information indicating "the possibility of occurrence of the adsorption failure is high" in the adsorption failure notice information. For this reason, it is necessary to externally display, in real time, the fact that the possibility of occurrence of a suction failure or the likelihood of the occurrence of a suction failure is low by the function of the failure prediction information display means. Can be.

According to a third aspect of the present invention, in the magnetic disk device according to the first or second aspect, the failure prediction information display means uses the soft suction information or the suction failure prediction information as display information on a host machine. The display information output control function for outputting the information to the host device is provided.

Therefore, according to the third aspect of the present invention,
In addition to functioning equivalently to the above-described claim 1 or 2, the failure prediction information display means outputs soft suction information or suction failure prediction information to a higher-level machine,
The host machine can also recognize that the possibility of occurrence of the magnetic head attraction failure has increased.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIG.
This will be described with reference to FIG. First, the magnetic disk device shown in FIG.
A spindle motor 2 configured to rotate the spindle motor 2 at a constant speed, a magnetic head 3 having a structure that floats on the disk medium 1 via an air bearing with a minute gap and writes or reads predetermined information to or from the disk medium,
And a motor drive control circuit 4 for controlling the rotation state of the motor at a constant speed.

The motor drive control circuit 4 has a motor start information output function for detecting and outputting each timing when power is supplied to the spindle motor 2 and when the spindle motor 2 is actually started. In addition, the motor drive control circuit 4 has a rotation required from when the power is turned on to when the spindle motor 2 starts rotating based on the two timing signals output by the operation of the motor start information output function described above. A timer circuit 5 for measuring and holding the start time is provided.

A time comparison / judgment circuit 6 for outputting a predetermined signal when the rotation start time held by the timer circuit 5 exceeds a separately set comparison rotation start time is provided. A failure prediction information display means 8 which is activated when a predetermined output signal is output from the circuit 6 and is externally displayed as soft suction information is provided.

Further, the number of times of signal output from the time comparison / judgment circuit 6 is counted between the time comparison / judgment circuit 6 and the failure prediction information display means 8 to determine the number of times of transcendence, and the number of times of transcendence is set in advance. A transcendence frequency comparison / judgment circuit 7 having a suction prediction information output function for outputting a predetermined signal when the number of times of comparison has been exceeded. Further, the failure prediction information display means 8 is provided with a prediction information display section 8A as shown in FIG. 1, and outputs the output information from the above-mentioned transcendence frequency comparison determination circuit 7 to the prediction information display section 8A. A failure prediction display control function for displaying as prediction information is provided.

Further, the above-mentioned fault prediction information display means 8
Has a display information output control function of externally outputting the above-mentioned soft suction information or suction failure prediction information as display information on the host machine 100.

Next, the overall operation of the above embodiment will be described. In FIG. 1, first, a timer circuit 5 for measuring the rotation start time of the spindle motor 2 is operated, and then a rotation command is transmitted from the motor drive control circuit 4 to the spindle motor 2 to rotate the spindle motor 2. . When the spindle motor 3 starts rotating, the motor drive control circuit 4 sends a signal to the timer circuit 5 to notify that the spindle motor 2 has rotated, thereby stopping the operation of the timer circuit 5.

Thereafter, the time comparison determination circuit 6 compares the rotation start time of the spindle motor 2 measured by the timer circuit 5 with the comparison rotation start time A specified in advance. The comparison of the rotation start time is performed every time the spindle motor 2 is started. When the rotation start time exceeds the comparison rotation start time A in the time comparison judgment circuit 6, the time comparison judgment circuit 6 sends a predetermined signal (soft suction information) to the transcendental comparison judgment circuit 7.

The transcendental comparison judging circuit 7 counts and stores the number of times that the time comparison judging circuit 6 has determined that the time has exceeded (the number of outputs of the soft suction information). Compare with the number of times B.

When the number of times determined by the time comparison determination circuit 6 to be exceeded is smaller than the number of times B of comparison for transcendence, the failure prediction information display means 8 having input this information immediately activates the failure prediction display function. Then, display information indicating “the possibility of occurrence of a suction failure is low” in the suction failure notice information is output to the host device 100.

On the other hand, when the number of times determined by the time comparison determination circuit 6 to be greater than the number of times of transcendence B for comparison is greater, the failure prediction information display means 8 having input this information immediately activates the failure prediction display function. Then, display information indicating “the possibility of occurrence of an adsorption failure is high” in the adsorption failure notice information is output to the host device 100.

For this reason, in this embodiment, before the attraction failure of the magnetic head occurs, the attraction failure notice information of the magnetic head is efficiently output, and the attraction failure notice information is suddenly displayed. The progress can be externally displayed beforehand by the soft adsorption information.

[0031]

Next, a specific example of the above embodiment and its operation will be described in more detail with reference to FIGS. First, in the above embodiment, since the magnetic disk device is of the CSS system,
The magnetic disk drive uses an H
In DI, CSS is repeated each time the engine is started.
CSS in the HDI of the magnetic disk 1 and the magnetic head 3
, It is generally known that the frictional force between the magnetic disk 1 and the magnetic head 3 increases (increases) as the CSS frequency increases. This embodiment is no exception, and the frictional force increases as the number of CSS increases.

[0032] Here, as the material of the magnetic head 3 mounted on the magnetic disk device used in this example, using a commonly known AL ₂ 0 ₃ -TiC (AlTiC), also commonly magnetic disk 1 A 3.5-inch disk based on a conventionally known AL substrate was used. The roughness of the disk used is about Ra 4 to 6 [nm], and the lubricant is PF
PE (perfluoropolyester) was used, and a lubricant having a thickness of 1.5 to 3.0 [nm] was used.

Next, the initial setting value 2 in the algorithm
0 will be described. For the initial setting values, initial values of the rotation start time for comparison A, the number of times of transcendence B for comparison, and the number of times of transcendence C are required.

The rotation start time A for comparison was set as follows. Spindle motor 2 in magnetic disk drive
Is converted into a frictional force generated between the magnetic head 3 and the magnetic disk 1, and the converted frictional force is 70 to 80.
The magnetic head 3 and the magnetic disk 1 are selected so that a friction force of [%] is generated in the HDI between the magnetic disk 1 and the magnetic head 3, and a magnetic disk device is created by combining the magnetic head 3 and the magnetic disk 1. Then, a control command for rotating the spindle motor is transmitted to the spindle motor in the magnetic disk device, and a time (a rotation start time) from that time until the spindle motor 2 starts rotating is measured. The start time was set as a comparative rotation start time A.

On the other hand, there are various methods for setting the comparison rotation start time A. For example, CSS 40K times (arbitrary C
The rotation start time in the magnetic disk device that has experienced (SS times may be used) may be set as the comparison rotation start time A. Next, the setting of the number of times of transcendence B for comparison is not particularly strict, and can be arbitrarily set, and the minimum set number is “1”. The initial value of the transcendence count C was set to “C = 0” on the assumption that the magnetic disk device was not operated.

Next, the overall operation will be described with reference to FIG. First, the timer circuit 5 for measuring the rotation start time D of the spindle motor 2 of the magnetic disk drive is operated to store the operation start time Ds (step S1). The timer circuit 5 is synchronized with a system clock held by the magnetic disk device itself. Of course, there is no need to synchronize the timer circuit 5 with the system clock, and an external clock may be used.

After the operation of the timer circuit 5, a control command (command) for rotating the spindle motor 2 of the magnetic disk drive is transmitted to the spindle motor control circuit 4 of the spindle motor 2 of the magnetic disk drive (step S).
2). The motor drive control circuit 4 rotates the spindle motor 2 in response to a control command for rotating the spindle motor 2. The start of the rotation of the spindle motor 2 (step S3) is determined by the motor drive control circuit 4 of the spindle motor 2, and when the start of the rotation of the spindle motor 2 is confirmed, the operation of the timer circuit 5 is stopped (step S4). ), The stop time De is stored.

Subsequently, the difference between the operation time Ds of the timer circuit 5 and the stop time De is obtained, and the rotation start time D is calculated (step S5). Next, the time comparison determination circuit 6 compares the rotation start time D with the comparison rotation start time A (step S6). If the rotation start time D exceeds the comparison rotation start time A, the transcendence number C is calculated. Accumulated as needed as “C + 1”,
It is stored (step S7). If the rotation start time D does not exceed the comparison rotation start time A, the number of times of transcendence C is set to “C
= C ”as needed (step S8).

Next, the transcendental number C is compared with the comparative transcendental number B in the transcendental comparison judging circuit 7 for comparing the transcendental number C and the comparative transcendental number B (step S9). Then, when the number of times of transcendence C exceeds the number of times of transcendence B for comparison, the failure prediction information display means 8 for displaying suction failure notice information displays the host device 10.
Information indicating that the possibility of occurrence of the adsorption failure is high is output to 0. When the number of times of transcendence C does not exceed the number of times of transcendence B for comparison, the failure prediction information display means 8 for displaying the information of the adsorption failure prediction indicates information indicating that the possibility of occurrence of the adsorption failure in the upper apparatus 100 is low. Output (Step S1
0).

There is no special condition for the display command method from the failure prediction information display means 8 for controlling the display of the suction failure notice information to the higher-level device 100, and it is sufficient that the information is notified to the higher-level device 100 in some form.

As described above, in the above embodiments and examples, the magnetic disk drive itself can easily incorporate the adsorption failure prediction function into the magnetic disk drive itself without requiring any special hardware for implementing the magnetic disk drive adsorption fault prediction method. be able to. This is because, as described above, it is only necessary to add the time comparison determination circuit 6, the transcendence comparison determination circuit 7, and the failure prediction information display means 8 when implementing the suction failure prediction method.

Further, in the above embodiments and examples, the failure prediction information display indicates that the possibility of occurrence of the suction failure to the host device is high or the possibility of the occurrence of the suction failure is low. The notification can be made in real time by the operation of the means 8. For this reason, it is possible to take measures such as preliminary replacement before an actual suction failure occurs, and in this regard, if the present embodiment is provided, the entire magnetic disk device can be maintained in a normal state for a long time, The reliability can be improved.

[0043]

Since the present invention is constructed and functions as described above, according to the present invention, it is possible to efficiently eliminate the attraction failure of the magnetic head with respect to the magnetic disk medium with a simple configuration without requiring expensive sensors and signal processing means. It is possible to well predict and externally display the information, or it is possible to output and externally display soft suction information which is likely to cause a magnetic head suction failure. Measures such as spare replacement can be taken, and in this regard, the entire device can be maintained in a normal state for a long time, and its reliability can be improved.
And an excellent magnetic disk device that has never existed before.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart illustrating the operation of the embodiment disclosed in FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 magnetic disk 2 spindle motor 3 magnetic head 4 motor drive control circuit 5 timer circuit 6 time comparison / judgment circuit 7 transcendence frequency comparison / judgment circuit 8 failure prediction information display means 8A prediction information display unit 100 host device A comparison rotation start time B comparison Number of transcendental times C Number of transcendental times D Rotation start time Ds Timer circuit operation time De Timer circuit stop time

Claims (3)

(57) [Claims] 1. A disk medium, a spindle motor for rotating the disk medium at a constant speed, and floating on the disk medium via an air bearing having a minute gap to write or read predetermined information to or from the disk medium. A magnetic disk drive comprising: a magnetic head having a structure; and a motor drive control circuit for controlling the rotation state of the spindle motor at a constant speed. The motor drive control circuit, when power is supplied to the spindle motor and the actual operation of the spindle motor, The motor drive control circuit has a motor start information output function for detecting and outputting each timing at the time of start of the motor, and the motor drive control circuit has a spindle based on the two timing signals output by activating the motor start information output function. Start of rotation required from motor power-on to start of rotation A timer circuit that measures and holds the time interval is provided, and a time comparison determination circuit that outputs a predetermined signal when the rotation start time held by the timer circuit exceeds a separately set comparison rotation start time is provided. And a failure prediction information display means for externally displaying a predetermined output signal from the time comparison determination circuit as soft suction information. 2. The magnetic disk drive according to claim 1, wherein the number of signal outputs from the time comparison / determination circuit is counted between the time comparison / determination circuit and the failure prediction information display means to be a transcendental number. A transit frequency comparison determination circuit having a suction prediction information output function of outputting a predetermined signal when the transit frequency exceeds a preset transit frequency for comparison is provided, and the failure prediction information display means includes the transit frequency A magnetic disk drive having a failure prediction display function of displaying output information from a comparison determination circuit as suction failure prediction information. 3. The display device according to claim 1, wherein the failure prediction information display means has a display information output control function of externally outputting the soft suction information or the suction failure prediction information as display information on a host machine. Or the magnetic disk device according to 2.