JPH0283857A - magnetic disk device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device used as an external storage means of a computer, and is particularly applicable to detecting the presence or absence of abnormal rotation of a spindle motor for driving a magnetic disk. The present invention relates to a magnetic disk device suitable for use.

[Prior Art] Conventionally, there is a magnetic disk device equipped with a spindle motor as a rotational drive source for a magnetic disk. The presence or absence of abnormal rotation of the spindle motor is detected based on a preset index signal generation interval and an index signal input interval.

That is, the above-mentioned magnetic disk device performs each process shown in FIG. 4, for example. Head seek execution processing (same figure (
In a)), the control unit (path shown) inputs the current cylinder NcyQ where the head is currently located and the target cylinder θcyρ to which the head seeks (step 5AI).
), calculate the seek amount S=θcyQ-NcyQ of the head (step 5A2), determine the control amount during seek of the head (step 5A3), and then cause the head to perform a seek operation to the target cylinder θcyQ (step 5A4).

On the other hand, spindle motor rotation abnormality detection processing ((b) in the same figure)
), the index signal generation interval Δ[NX
After setting (step 5BI), the input time Tn and 2 of the index signal created from the servo data read by
After inputting the input time Tn+1 of the next index signal (Steps SB2, 5B3), and calculating the input time interval ΔT-(Tn-1-1)Tn of the index signal (Step 5
B4), the ratio RT of the ΔINX and the ΔT (=1
-(ΔINX/ΔT)) (Step 5B5)
. Then, if the ratio RT is within the range of ±0.3% of the standard value, the above process is repeated, while if the ratio RT is outside the range of 0.3% above the standard value, the process moves to an error handling routine. It has become.

[Problems to be Solved by the Invention] By the way, the above conventional magnetic disk device has the following problems.

In the case of a magnetic disk drive equipped with a low actuator in which the actuator supporting the head swings around a rotation axis, the head moves in an arc with respect to the radial direction of the magnetic disk, so the moving speed of the head is equal to the radius. It has components in two directions: direction and circumferential direction. As a result, depending on the seek direction and seek amount of the head, the index signal = 3 shifts, making it appear as if a rotational abnormality has occurred in the spindle motor. There was a problem in which it was determined that a rotational abnormality had occurred.

The present invention solves the above problem, and detects abnormal rotation of a disk drive motor by considering the amount of correction of the index signal interval according to the seek direction and seek amount of the magnetic head before performing a seek of the magnetic head. The purpose of the present invention is to provide a magnetic disk device that can perform accurate and precise operations.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a magnetic disk;
a disk drive motor that rotationally drives the magnetic disk;
The magnetic head includes a magnetic head that writes information to or reads information from the magnetic disk, a head support mechanism mounted with the magnetic head, and a head drive motor that moves the head support mechanism in the radial direction of the magnetic disk. , the index signal is set to 1 for each rotation of the disk drive motor.
In a magnetic disk drive configured to detect whether or not there is an abnormality in the rotation of the disk drive motor by determining the interval between the index signal=4 and the next index signal. , before the seek operation of the magnetic head, a correction amount for the interval between an index signal and the next index signal is determined according to the seek direction, seek amount, etc. of the magnetic head, and the determined correction amount is applied to the magnetic head by the magnetic head. Add or subtract from the interval between the index signal created from the servo information read from the magnetic disk and the next index signal, and compare the interval obtained by the addition or subtraction with the preset index signal and the next index signal. It is characterized by comprising a control means for determining whether or not the ratio to the interval is within a predetermined standard value range, and detecting whether or not there is an abnormality in the rotation of the disk drive motor based on the determination result. shall be.

[Operation] According to the present invention, before performing a seek operation of the magnetic head, an index signal is generated that matches the seek direction, seek amount, etc. when the magnetic head seeks from the cylinder in which it is currently located to the target cylinder. Determine the spacing correction amount. Then, the correction amount is added or subtracted from the index signal interval created from the servo information read by the magnetic head, and the ratio of the added or subtracted interval to the index signal interval set at the time of starting the magnetic disk device. By determining whether or not is within the standard value range, it is detected whether or not there is a rotational abnormality in the disk drive motor. As a result, it is possible to prevent the conventional problem of detecting an apparent rotational abnormality of the spindle motor as an actual rotational abnormality.

[Example] Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, reference numeral 1 denotes a base of a magnetic disk device. A spindle motor 2 is mounted on the base 1, and a magnetic disk 3 (hereinafter abbreviated as disk) is fixed to the spindle motor 2.

The disk 3 is configured to rotate in the direction of arrow Y1 with the driving force of the spindle motor 2, and servo data is written in advance on the disk 3. Said disk 3
A pivot shaft 4 is rotatably disposed on the base I near the outer circumferential side of the spindle motor 2 in parallel with the rotation axis of the spindle motor 2. A row reactuator 5 is fixed to the pivot shaft 4, and is capable of swinging in an arc shape in the direction of arrows Y2-Y3 within a horizontal plane about the pivot shaft 4.

A read/write head (hereinafter referred to as head) 6 is fixed to one end of the rotary actuator 5, and is capable of swinging in an arc in the direction of arrows Y2-Y3 on the surface of the disk 3 within a horizontal plane. has been done. To the corresponding.

When the disk 3 starts rotating, the air flow generated on the disk surface causes mud to drop by 0.3 to 0.
It is designed to cause 4μ false levitation. In this case, head 6
When data is written to/read from the disk 3 by (There is a characteristic that the flying height of the head 6 decreases. Therefore, on the inner circumferential side of the disk 3 where the airflow velocity is slow and the skew angle is large and the flying characteristics deteriorate, the skew angle is set to zero in advance. Settings are being made.

An actuator drive motor 7 is disposed at the other end of the row actuator 5, and the drive motor 7 is composed of a coil 8 and a yoke 9.

That is, a coil 8 is fixed to the other end of the low reactor actuator 5, and the coil 8 swings within a yoke 9 in the direction of arrow Y2-Y3 as the actuator drive motor 7 is driven. and actuator drive motor 7
Accordingly, the rotary actuator 5 is driven in an arc shape on the disk 3 in the direction of the arrow Y2-Y3.

One end of an elastic member IO is fixed to the row reactuator 5, and the other end of the elastic member IO is fixed to the pace 1. As a result, since a tensile force is normally applied to the row reactuator 5 in the direction of the arrow Y4, when the magnetic disk drive is not operating, the hept 6 is moved to the inner circumferential side of the disk 3. It is held on the inner circumferential side.

By the way, when the head 6 is stopped at the recording cylinder of the disk 3, the index signal is input to the control unit (control means, path shown) once or more every time the spindle motor 2 rotates once. It has become. In this case, the input interval of the index signal is 16.67 m when the rotational speed of the disk 3 is, for example, 3600 rpm.
5ec C = 1/(3600/60)) interval (see Figure 2(,a)). Further, when the head 6 which is stopped in the recording cylinder is caused to seek toward the outer circumferential side of the disk 3 (in the direction of arrow Y2), the input interval of the index signal is shorter than the normal input interval of 16, 67 m5ec (second (See figure (b)). Furthermore, when the head 6 that is stopped in the recording cylinder seeks toward the inner circumferential side of the disk 3 (in the direction of arrow Y3), the input interval of the index signal is the normal input interval of 16.67 m5e.
c (see Figure 2 (c))
.

Therefore, in this magnetic disk device, before executing the seek operation of the head 6, the correction amount of the input interval of the index signal is determined according to the seek direction/seek amount of the head 6, and the correction amount and the preset amount are determined. Index signal generation interval ΔIN
By calculating the ratio RT from It is designed to detect the presence or absence.

Next, the operation of this embodiment with the above configuration will be explained based on the flowchart of FIG. 3.

In the seek execution processing of the head 6, the control section determines the current cylinder N of the disk 3 where the head 6 is currently located.
cyQ and the target cylinder θc to which the head 6 seeks.
After inputting yQ (step 5C1), the seek amount S-θcyQ −NcyQ required for the head 6 to seek to the target cylinder θcyQ is calculated (step 5
c2). Next, when the head 6 seeks, a correction amount DT for the index signal interval is determined according to the seek direction/seek amount of the head 6 (step 5C3).

Here, from step S03 of the seek execution process,
The process moves to step SD5 of spindle motor rotation abnormality detection processing.

In this case, from step SDI to step SD4 of the spindle motor rotation abnormality processing, the following processing is performed as in the conventional case. That is, when starting up the magnetic disk device, the control section presets the index signal generation interval ΔINX (step 5DI), and then sets the index signal input time Tn created based on the servo data read from the disk 3 by the head 6. , spindle motor 2
In step SD2. Step 5D3), index signal input time interval ΔT
=(Tn+1)-Tn is calculated. That is, the rotation period of the spindle motor 2 corresponding to the input time interval ΔT is calculated (step SD4).

Next, in step SD5, the +1 seek of the head 6 determined in step S03 of the seek execution process is performed. The correction amount DT of the index signal interval according to the seek direction/seek amount of the head 6 is determined in step SD4 of the spindle motor rotation abnormality detection process.
To the input time interval of the index signal calculated in T
Ratio RT (-11ΔINX
/(ΔT×D T )l) is calculated.

Next, in step SD6, if the ratio RT is within the standard value ±0.3%, the process returns to step SD2 and repeats the processing up to step SD5. In contrast,
If the ratio RT is outside the standard value ±03%, the process moves to an error handling subroutine.

Next, the process returns to step SC4 of the seek execution process again, and when the head 6 is seeking. After determining the control amount such as the drive amount of the actuator drive motor 7, step S0
In step 5, the head 6 is caused to seek from the current cylinder NcyQ to the target cylinder θcyQ, and the seek execution process is completed.

In the above embodiment, the standard value for determining the range of the ratio RT is ±0.3%, but the standard value is not limited to this value.

According to the above embodiment, the ratio RT is calculated by taking into account the amount of correction of the index signal interval according to the seek direction/seek amount of the head 6 before executing the seek operation. It becomes possible to accurately detect the presence or absence.

[Effects of the Invention] As explained above, according to the present invention, a magnetic disk,
a disk drive motor that rotationally drives the magnetic disk;
A magnetic head that writes or reads information to or from the magnetic disk, a head support mechanism mounted with the magnetic head, and a head drive motor that moves the head support mechanism in a radial direction of the magnetic disk. The index signal is outputted once every rotation of the disk drive motor.
In the magnetic disk drive configured to detect whether or not there is an abnormality in the rotation of the disk drive motor by determining the interval between the index signal and the next index signal. Before a magnetic seek operation, a correction amount for the interval between an index signal and the next index signal is determined according to the seek direction, seek amount, etc. of the magnetic head, and the determined correction amount is applied to the magnetic head by the magnetic head. Add or subtract from the interval between the index signal created from the servo information read from the magnetic disk and the next index signal, and compare the interval obtained by the addition or subtraction with the preset index signal and the next index signal. The disc drive motor is configured to include a control means for determining whether the ratio to the distance is within a predetermined standard value range and detecting whether or not there is an abnormality in the rotation of the disk drive motor based on the determination result. Therefore, the following effects can be achieved.

■Before executing a seek of the magnetic head, the amount of correction of the index signal interval is taken into account according to the seek direction and seek amount of the magnetic head, and it is possible to detect whether or not there is a rotational abnormality in the disk drive motor. The presence or absence can be detected accurately and precisely.

(2) The above (2) prevents the conventional erroneous judgment that an apparent rotational abnormality of the disk drive motor is an actual rotational abnormality, thereby improving the reliability of the magnetic disk drive.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing the configuration of a magnetic disk device according to an embodiment of the present invention, and FIGS. 2(a), (b), (c)
) is a time chart showing the output timing of the index pulse of this embodiment, FIG. 3 is a flowchart for explaining the control system of this embodiment, and FIGS. It is a flowchart for explaining a control system. 2...Spindle motor (disk drive motor), 3...Magnetic disk, 5...Low reactuator (head support mechanism), 6...
head (magnetic head), 7...actuator drive motor (head drive motor); Figure 1

Claims (1)

[Scope of Claims] A magnetic disk, a disk drive motor that rotationally drives the magnetic disk, a magnetic head that writes information to or reads information from the magnetic disk, a head support mechanism equipped with the magnetic head, and and a head drive motor that moves the head support mechanism in the radial direction of the magnetic disk, and generates an index signal once or more per rotation of the disk drive motor, and generates an index signal and the next index signal. In a magnetic disk drive configured to detect whether or not there is an abnormality in the rotation of the disk drive motor by determining an interval between the signals, the seek direction of the magnetic head is determined before the seek operation of the magnetic head; A correction amount for the interval between an index signal and the next index signal is determined according to the seek amount, etc., and the determined correction amount is applied to the index signal and the next index created from the servo information read from the magnetic disk by the magnetic head. Whether the ratio between the interval obtained by adding or subtracting and the interval between the preset index signal and the next index signal is within a predetermined standard value. 1. A magnetic disk drive comprising: a control means for determining whether or not the rotation of the disk drive motor is abnormal based on the determination result.