JPH035959A - Rotational abnormality detecting system and rotary storage device using the same - Google Patents

Abstract

PURPOSE:To prevent malfunction caused by the rotational abnormality detection of a rotary storing medium by inspecting the regularity of a position signal corresponding to the read period of information, which are recorded to the rotary storing medium, when the abnormality of a rotating speed is detected by a rotating speed monitoring means. CONSTITUTION:When the abnormality of the rotating speed is detected in a rotating speed monitoring means 2, the regularity of the first position signal corresponding to the read period of the information, which are recorded to the rotary storing medium, is inspected. When this first position signal is regular, a rotary storage device is set in an unusable state and when the first position signal is irregular, the abnormality recovery processing of the first position signal is executed. Thus, it is possible to prevent the malfunction that a magnetic disk device is made unusable by the apparent abnormality of the rotating speed to be caused by the spring-out or fall-off of an INDEX signal 10 to be caused by a noise although there is no abnormality in a real magnetic disk 5 or a spindle motor 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotational abnormality detection technique and a rotating storage device using the same, and is particularly effective when applied to rotational abnormality detection in a magnetic disk device. Regarding technology.

[Conventional technology]

For example, in an information processing system such as a computer system, a magnetic disk device, which uses a magnetic disk, which is a type of rotating storage medium, can be used as an external storage device for storing large amounts of data. It is being said.

That is, by providing a plurality of concentric tracks, which are information recording areas, on the surface of a magnetic disk that rotates at a predetermined speed, and by combining the rotation of the magnetic disk with the displacement of the magnetic head in the radial direction of the magnetic disk. ,
The magnetic head performs information recording and reproducing operations at any position on any track.

By the way, in a rotating storage device such as a magnetic disk device, in order to record and reproduce information stably and accurately, the rotational speed of the magnetic disk, which is a storage medium, must be kept constant at a predetermined value. Control is important.

For this reason, conventionally, for example, Japanese Patent Laid-Open No. 6045971
As disclosed in the above publication, the number of revolutions of a magnetic disk obtained by reproducing a specific signal such as an index marker recorded at the beginning of a track in order to identify a recording position within a track. The cycle of the index signal that reflects This is an attempt to prevent the destruction of information caused by abnormal rotation of the magnetic disk.

[Problem to be solved by the invention]

However, in the case of the above-mentioned conventional technology, no consideration is given to verifying the validity of the index signal itself used to determine rotational abnormality of the magnetic disk.
Even if the index signal is overflowing or missing due to noise, it is uniformly assumed that a rotation abnormality has occurred, so even if the magnetic disk rotation is normal, the magnetic disk drive Also, there is a problem in that it is impossible to prevent malfunctions that would render an information processing system using the magnetic disk device as an external storage device inoperable.

In addition, when a magnetic disk rotates abnormally, simply making the magnetic disk drive inoperable takes time for an external operator to identify the cause of the failure, and there is the problem that failure recovery cannot be performed quickly. be.

Note that the technology disclosed in Japanese Patent Application Laid-Open No. 177367/1983 calculates the logical sum of a logical signal indicating the driving state of the disk by the motor and a logical signal indicating the data transfer state between the disk device and the host device. By turning on a lamp that is visible to the operator from the outside, the operator can remove the disk as a storage medium during data transfer. However, this technology is intended to prevent erroneous operations such as loading and unloading disks, and does not contribute in any way to speeding up the identification of the cause of the failure.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a rotational abnormality detection method that can reliably prevent malfunctions caused by rotational abnormality detection of a rotary storage medium.

Another object of the present invention is to provide a rotation abnormality detection method that facilitates failure cause identification and recovery processing.

Still another object of the present invention is to provide a rotary storage device that can reliably prevent malfunctions caused by rotational abnormality detection of a rotary storage medium.

Still another object of the present invention is to provide a rotating storage device that facilitates identification of the cause of failure and recovery processing.

Still another object of the present invention is to improve the operating rate of an information processing system using a rotating storage device.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

That is, the rotational abnormality detection method according to the present invention includes a rotational storage medium, a spindle motor that rotates the rotational storage medium at a desired speed, a drive control means that controls the spindle motor, and a rotational storage medium that rotates the rotational storage medium at a desired speed. a rotational speed monitoring means for measuring the rotational speed of the rotary storage medium based on a first position signal corresponding to a reading cycle of recorded information;
A rotational abnormality detection method for a rotating storage device comprising a main control means for controlling and controlling each means, wherein when an abnormality in the rotational speed is detected in the rotational speed monitoring means, the validity of the first position signal is determined. is verified, and if the first position signal is valid, the rotary storage device is rendered unusable, and if the first position signal is invalid, the first position signal is restored to an abnormal state. It is designed to perform processing.

Further, the rotary storage device according to the present invention includes a rotary storage device body, a spindle motor for rotating the rotary storage medium at a desired speed, a drive control means for controlling the spindle motor, and a rotary storage medium. a rotational speed monitoring means for measuring the rotational speed of the rotary storage medium based on a first position signal corresponding to a read cycle of information recorded in the storage medium; and a display means for notifying the outside of abnormal rotation of the rotary storage medium. and a main control means that supervises and controls each means, and the control means verifies the validity of the first position signal when an abnormality in the rotation speed is detected in the rotation speed monitoring means, and controls the first position signal. If the first position signal is valid, the rotary storage device is rendered unusable and the unusable state is notified to the outside via the display means, and if the first position signal is invalid, the rotary storage device is disabled. , the abnormality recovery process for the first position signal is performed.

[Effect]

According to the rotational abnormality detection method of the present invention described above, when a rotational abnormality of the rotary storage medium is detected based on the first position signal, the validity of the first position signal is verified. Due to leakage or omission of the first position signal due to noise, etc., the rotating state of the rotating storage medium may be mistaken as abnormal even though it is normal, and the rotating storage device may become unusable. It is possible to reliably prevent malfunctions.

Furthermore, in the event of a true rotational abnormality in a rotating storage medium, the occurrence of the rotational abnormality is clearly notified to the outside by the display means, making it easier for operators, system administrators, etc. to identify the cause of the failure and perform recovery processing. .

Further, according to the above-described rotary storage device of the present invention, the first
When an abnormal rotation of the rotary storage medium is detected based on the position signal, the validity of the first position signal is verified. As a result, it is possible to reliably prevent a malfunction in which the rotational state of the rotary storage medium is mistakenly recognized as abnormal even though the rotational state is normal, resulting in an unusable state.

In addition, in the event of a true rotational abnormality in a rotating storage medium, the occurrence of the rotational abnormality is clearly notified to the outside by the display means, making it easy for operators and system administrators to identify the cause of the failure and perform recovery processing. Become.

[Embodiment 1] Hereinafter, a rotation abnormality detection method which is an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a flowchart showing an example of the operation of a rotational abnormality detection method that is an embodiment of the present invention, and FIG. 2 is a block diagram showing an example of the configuration of a magnetic disk device in which this rotational abnormality detection method is implemented. FIG. 3 is a block diagram showing a part thereof in further detail.

First, an example of the configuration of the magnetic disk device of this embodiment will be described with reference to FIGS. 2, 3, and the like.

For example, a plurality of magnetic disks 5 are mounted on a rotating shaft 1a of a spindle motor l such as a DC brushless motor.
are fixed in a parallel posture with a predetermined spacing between them, and are rotated together with the rotating shaft 1a.

The spindle motor 1 includes, for example, a Hall element, detects the rotational position of the rotating shaft 1a, and outputs a rotational position signal 4 (
The rotational position signal 4 obtained from the rotation sensor 2 is manually inputted to a motor drive circuit 3 that controls the rotational operation of the spindle motor 1.

Then, the motor drive circuit 3 performs a control operation to rotate the rotating shaft 1a to which the plurality of magnetic disks 5 are fixed at a constant rotational speed by well-known closed loop control using the rotational position signal 4. ing.

Among the plurality of magnetic disks 5 fixed to the rotating shaft 1a of the spindle motor l, the recording surface of the magnetic disk located at the top, for example, is used as a servo data recording surface 5a different from the data recording surface of the other magnetic disks 5. Servo tracks (not shown) on which various servo information for servo control are recorded are provided concentrically.

The servo information recorded on this servo track is fixed to the same actuator (not shown) as a data head (not shown) disposed opposite to a data recording surface other than the servo data recording surface 5a, and is simultaneously recorded on the magnetic disk 5. It is adapted to be read by a radially displaced servo head 6. Then, based on the servo information obtained from the servo head 6, an actuator (not shown) controls the operation of positioning the data head (not shown) at a desired position on the magnetic disk 5, thereby recording and recording information by the data head. This is where playback operations and the like are performed.

The servo radar 6 is connected to an INDEX signal generation circuit 9 via an amplifier 8, and from the servo signal 7 read from the servo radar 6 and amplified via the amplifier 8, the servo track is An INDEX signal 1 is generated once per rotation of the magnetic disk 5 by selectively detecting an index marker recorded in a specific pattern in a part of the servo track to identify the starting end of the servo track.
0 is extracted.

That is, as shown in FIG. 3, the INDEX signal generation circuit 9 includes, for example, a servo signal pulsing circuit 9a that digitizes the servo signal 7 arriving from the amplifier 8, and a servo signal pulsing circuit 9a that digitizes the servo signal 7 arriving serially. A shift register 9b converts into bit-width parallel data and a predetermined pattern such as the index marker is identified from the servo signal 7 converted into parallel data and INDEX is performed.
The INDEX pattern detection logic that generates the signal IO has a total of 9C detection logic.

Furthermore, the INDEX signal generation circuit 9 receives the incoming servo signal 7 and the I output based on the servo signal 7.
In order to match the frequency and phase of the NDEX signal lO, a servo signal pulsing circuit 9a and a shift register 9b are used.
A gate circuit 9h which receives a pulsed servo signal as one input between the gate circuit 9h, a phase comparator 9d which receives a pulsed servo signal outputted from the servo signal pulsing circuit 9a as one input, and a low frequency A pass filter 9e and a voltage variable oscillator 9f are provided.

Then, the rotation synchronization clock signal 91 outputted from the voltage variable oscillator 9f becomes the other manual power of the phase comparator 9d, so that the well-known F21Z Drottal Lube PL
L, and a part of this rotation synchronized clock signal 91,
The timing of movement of the servo signal from the servo signal pulsing circuit 9a to the shift register 9b is controlled by inputting it to the other input of the gate circuit 9h via the rotation synchronization gate signal generating circuit 9g.

Further, the phase comparator 9d is initialized upon input of a reset signal 9j from the outside.

The INDEX signal generation circuit 9 is a microprocessor 15
The rotation speed abnormality detection logic section 11 is connected to a rotation speed abnormality detection logic section 11 that monitors the presence or absence of an abnormality in the rotation speed of the magnetic disk 50 using an algorithm as described below. microprocessor 1
5 and a motor start sequence control tlIBia. Further, the motor stop control section 12 is connected to a rotation speed abnormality display circuit 14 made of a light emitting diode or the like provided at a position visible to an external operator or the like.

The motor stop control unit 12 controls the spindle motor 1 via the motor drive circuit 3 in response to a logic signal manually input from the rotation speed abnormality detection logic 1111 when a true abnormality occurs in the rotation speed of the magnetic disk 5. In addition to performing a stop operation, a predetermined logic signal is sent to the rotation speed abnormality display circuit 14 to light up a light emitting diode, thereby notifying an external operator that an abnormality in the rotation speed has occurred in the magnetic disk 5. The device is designed to perform the following actions.

Furthermore, when an abnormality actually occurs in the rotational speed of the magnetic disk 5, the motor starting sequence control section 13 uses a logical signal manually inputted from the rotational speed abnormality detection logic a't+z to generate the INDEX signal generation circuit.

9, the reset signal 9j is sent to the INDEX signal I.
In addition to carrying out the recovery operation of O, if recovery is not possible, a predetermined logic signal is issued to the motor stop control unit 12 to stop the spindle motor l and operate the rotation speed abnormality display circuit 14. It has become.

In addition to the above-mentioned parts, a normal magnetic disk drive is equipped with a part that modulates and demodulates data exchanged with a host device, as well as interface control. Since this is not particularly relevant to the explanation of the abnormality detection method, illustration and explanation thereof will be omitted.

The operation of the rotation abnormality detection method in the magnetic disk device of this embodiment will be explained below.

First, in a normal state, the rotation speed of the spindle motor 1 is controlled to be constant at a predetermined value by closed-loop control by the motor drive circuit 3 using the rotation position signal 4 obtained from the rotation sensor 2 of the spindle motor 1. The plurality of magnetic disks 5 are constantly rotating at the specified rotation speed.

Then, by controlling an actuator (not shown) based on predetermined servo information read from the servo head 6, the positioning of a plurality of data heads (not shown) in the radial direction of the magnetic disk 5 is controlled, thereby communicating with the host device. Recording/reproducing operations are performed on the magnetic disk 5, such as data exchanged between the two.

During this time, the rotational speed abnormality detection logic unit 11 provided in the microprocessor 15 performs an IN based on the servo signal 7.
The arrival cycle of the INDEX signal 10 that reflects the rotational speed of the magnetic disk 5 generated in the DEX signal generation circuit 9 is monitored, and the frequency of the spindle motor 1 (magnetic disk 5) calculated based on the INDEX signal 10 signal 1 layer period is monitored. It is determined whether the fluctuation range of the rotation speed is within ±a% of a predetermined reference rotation speed. (Step 101) The value of a is used to determine whether or not the number of rotations of the magnetic disk 5 has suddenly changed, and is set to a relatively large value of about 10% in this embodiment.

That is, if an abnormality actually occurs in the number of revolutions of the magnetic disk 50, the magnetic disk 5 and the spindle motor 1
Due to the inertia of
If the NDEX signal 10 itself has a leak or dropout due to noise or the like, such a sudden change is easily observed, so in step 101, the INDEX signal 10 is
The appearance due to an error in the EX signal 10 is used to determine whether or not there is an abnormality in the rotation speed.

If the fluctuation range of the rotational speed of the magnetic disk 5 detected based on the INDEX signal IO is within ±a%,
Furthermore, confirm whether the observed fluctuation range is within 15%, which is smaller than a. (Step 107) This value of b is used to determine the degree to which the rotation speed gradually changes due to an actual abnormality, and in the case of this embodiment,
For example, it is set to 3%.

If the fluctuation range is within 15%, it is determined that there is no abnormality and the process returns to step 101.

That is, during normal rotation, the loop from step 107 to step 101 is repeated.

On the other hand, in step 107, the fluctuation range of the rotation speed is ±b%.
If it is determined that the above is true, that is, if it is determined that the rotation speed is actually abnormal, the ±b%
It is checked whether the above fluctuation range of the rotation speed has continued for N2 rotations consecutively (step 108), and if it is determined not to be negative, the abnormality in the rotation speed is instantaneous. It is determined that this is the case, and the process returns to the beginning of step 107.

On the other hand, if it is determined in step 108 that the rotational speed fluctuation range of ±b% or more continues for N3 rotational speeds, an abnormality in the rotational speed is actually detected in the magnetic disk 5. occurs, rotation speed abnormality detection logic unit 1
1 sends a predetermined logic signal to the motor stop control section 12, and upon receiving this, the motor stop control section 12 instructs the motor drive circuit 3 to stop the spindle motor l (step 109). A predetermined logic signal is issued to the rotation speed abnormality display circuit 14 to display the rotation speed abnormality display circuit 14.
A lamp such as a light emitting diode is turned on to clearly notify the operator that the magnetic disk 5 has been stopped due to a failure caused by an abnormal rotation speed of the magnetic disk 5.

On the other hand, in step 101, the INDEX signal 1
If it is determined that the fluctuation range of the magnetic disk 50 rotation speed detected based on First, it is determined whether the fluctuation range immediately after step 101 is within 15% (step 102).
).

If the fluctuation range is within b%, INDE
It is determined that the X signal 1O signal 1 layer is instantaneous, and the process returns to step 101.

On the other hand, if the fluctuation range is ±b% or more, the fluctuation range is ±b% for N1 consecutive times corresponding to several rotations.
Determine whether the above state exists (step 103)
.

This is because if the abnormal INDEX signal 10 continues for more than a predetermined time, normal operation of the phased-lock loop PLL in the above-mentioned INDEX signal generation circuit 9 cannot be expected, so recovery processing is necessary. The only thing to do is to judge whether or not.

If the fluctuation width continues to be ±b% or more for N1 consecutive times, it is determined that the INDEX signal generation circuit 9 cannot be expected to generate the INDEX signal 10 normally, and the rotation speed abnormality is detected. The logic unit 11 sends out a predetermined logic signal to start the motor start sequence control 13, and the motor start sequence control 13
A reset signal 9J is sent to the phase comparator 9d constituting the phased-locked loop PLL of the signal generation circuit 9 to initialize the oscillation operation of the phased-locked loop PLL (step 104).

Further, it waits for t seconds necessary for the oscillation operation in the phased lock loop PLL of the IN, DEX signal generation circuit 9 to stabilize (step 105).

Thereafter, the state in which the fluctuation range of the rotational speed of the magnetic disk 5 (spindle motor 1) with respect to the reference rotational speed observed by the INDEX signal 10 is within ±b% continues for Ns.
It is checked whether it can be observed stably more than once (step 106).

If a state in which the fluctuation width is within ±b% is observed stably N5 times or more consecutively, it is assumed that the INDEX signal 1O signal 1 ratio state has been restored, and the abnormality in the rotation speed at the beginning of step 101 is determined. Return to monitoring operation.

In addition, if a state in which the fluctuation range is within ±b% is not observed stably for N times or more consecutively, it is determined that an irrecoverable abnormality has occurred in the INDEX signal 10 due to some cause, and the motor is stopped. Activate control 111m512,
The stop control of the spindle motor l in step 109 and the lighting operation of the lamp in the rotation speed abnormality display circuit 14 in step 110 are performed.

As described above, according to the rotational abnormality detection method in the magnetic disk drive of this embodiment, when an abnormality in the rotational speed of the magnetic disk 5 (spindle motor l) is detected compared to the INDEX signal lO signal l, the INDEX An operation is performed to verify the validity of the signal 10, and only when the rotational speed of the spindle motor 1 or the magnetic disk 5 is abnormal, an abnormality processing operation such as stopping the spindle motor l is performed. There is no abnormality in the spindle motor 1, but the INDEX signal 1 is caused by noise etc.
It is possible to reliably prevent malfunctions that would render the magnetic disk drive unusable due to an apparent abnormality in the rotational speed caused by the appearance or omission of zeros.

As a result, compared to the conventional case where the magnetic disk drive is immediately disabled when an abnormality in the rotation speed is detected by the INDEX signal 10, the magnetic disk drive can be moved to the right side of the magnetic disk drive and this magnetic disk drive can be used as an external storage device. Accordingly, it is possible to improve the operating rate of information processing systems.

In addition, if an abnormality in the rotational speed actually occurs in the spindle motor l, etc., the rotational speed abnormality display circuit 14
Since the abnormality in the rotation speed is clearly displayed to an external operator, failure analysis and recovery processing can be performed easily and quickly.

[Embodiment 2] FIG. 4 is a block diagram showing an example of the configuration of a magnetic disk device in which a rotation abnormality detection method according to another embodiment of the present invention is implemented.

In the second embodiment, the rotational position signal 4a obtained from the rotation sensor 2 of the spindle motor 1 is input to the rotational speed abnormality detection logic section 11, and the rotational speed abnormality detection logic section 11 detects an abnormality in the INDEX signal lO. This embodiment differs from the first embodiment in that the validity of the INDEX signal 10 is verified by comparing it with the rotational position signal 4a.

That is, the rotational position signal 4a obtained from the rotation sensor 2
The signal level is transmitted to the magnetic disk 5 via the servo head 6.
Based on the servo signal read from (INDEX signal l
It is sufficiently large compared to the O signal l and is not easily affected by noise, and the rotational position signal 4a and INDE
Since the probability that both of the X signals 10 become abnormal at the same time is small, the validity of the INDEX signal 10 can be verified.

In the second embodiment as well, when an abnormal rotation of the spindle motor 1 is detected based on the IND'EX signal 10, the INDEX signal IO is corrected without immediately disabling the magnetic disk device as in the prior art. Since the properties are verified, the same effect as in the first embodiment can be obtained.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, the algorithm for verifying the validity of the index signal in the rotation speed abnormality detection logic section is not limited to the one exemplified in the first embodiment.

Furthermore, the rotary storage device is not limited to the above-mentioned magnetic disk device, but can be widely applied to general rotary storage devices that use a rotary storage medium.

〔Effect of the invention〕

Among the inventions disclosed in this application, the effects obtained by typical inventions are briefly described below.

That is, according to the rotational abnormality detection method of the present invention, there is provided a rotational storage medium, a spindle motor that rotates the rotational storage medium at a desired speed, a drive control means that controls the spindle motor, and a rotational storage medium that rotates the rotational storage medium at a desired speed. a rotational speed monitoring means for measuring the rotational speed of the rotary storage medium based on a first position signal corresponding to a reading cycle of information recorded on the storage medium; and a main control means for controlling the respective means. A rotational abnormality detection method for a rotating storage device comprising:
When an abnormality in the rotational speed is detected in the rotational speed monitoring means, the validity of the first position signal is verified, and if the first position signal is valid, the rotational storage device is If the 10th position signal is invalid and the 10th position signal is invalid, an abnormality recovery process is performed on the 1st position signal. As a result, it is possible to reliably prevent a malfunction in which the rotational state of the rotary storage medium is mistakenly recognized as abnormal even though it is normal, and the rotary storage device falls into an unusable state.

Furthermore, in the event of a true rotational abnormality in a rotating storage medium, the occurrence of the rotational abnormality is clearly notified to the outside by the display means, making it easier for operators, system administrators, etc. to identify the cause of the failure and perform recovery processing. .

Further, according to the rotary storage device of the present invention, a rotary storage medium, a spindle motor for rotating the rotary storage medium at a desired speed, a drive control means for controlling the spindle motor, and a a rotational speed monitoring means for measuring the rotational speed of the rotary storage medium based on a first position signal corresponding to a reading cycle of information recorded on the storage medium; and a rotational speed monitoring means for notifying the outside of rotational abnormality of the rotary storage medium. and a main control means for controlling the respective means, and the control means controls the first position signal when an abnormality in the rotation speed is detected in the rotation speed monitoring means. After verifying the validity, if the first position signal is valid, the rotary storage device is made unusable, and the unusable state is notified to the outside via the display means, and the first position signal is valid. If the position signal of 1 is invalid,
Since it has a control gjJ function that performs abnormality recovery processing of the first position signal, if the rotation state of the rotary storage medium is normal due to leakage or omission of the first position signal due to noise etc. Nevertheless, it is possible to reliably prevent malfunctions that may be mistaken for abnormalities and result in an unusable state.

Furthermore, in the event of a true rotational abnormality in a rotating storage medium, the occurrence of the rotational abnormality is clearly notified to the outside by the display means, making it easier for operators, system administrators, etc. to identify the cause of the failure and perform recovery processing. .

[Brief explanation of drawings]

FIG. 1 is a flowchart showing an example of the operation of a rotational abnormality detection method that is an embodiment of the present invention, and FIG. 2 is a configuration of a magnetic disk device in which the rotational abnormality detection method that is an embodiment of the present invention is implemented. FIG. 3 is a block diagram showing a part of the magnetic disk device in further detail; FIG. 4 is a block diagram showing a magnetic disk drive in which a rotation abnormality detection method according to another embodiment of the present invention is implemented. FIG. 2 is a block diagram showing an example of the configuration of a device. l... Spindle motor, la... Rotating shaft, 2...
・Rotation sensor, 3...Motor drive circuit, 4.4a...
- Rotational position signal (second position signal), 5... Magnetic disk, 5a... Servo data recording surface, 6... Servo head, 7... Servo signal, 8... Amplifier, 9.・
・INDEX signal generation circuit, 9a... Servo signal pulse generation circuit, 9b... Shift register, 9C...I
NDEX pattern detection logic unit, 9d...phase comparator,
9e...Low pass filter, 9f...Voltage variable oscillator, 9g...Rotation synchronization gate signal generation circuit, 9h...
・・Gate circuit, 91 ・・Rotation synchronization clock signal, 9
j... Reset signal, 10... INDEX signal (first position signal), 11... Rotation speed abnormality detection logic unit, 1
2... Motor stop control section, 13... Motor start sequence control, 14... Rotation speed abnormality display circuit (display means), 15... Microprocessor (main control section), 10
1 to 110... Processing steps showing an example of an INDEX signal verification process, a... First threshold value, b... Second threshold value, PLL... Phased lock loop.

Claims (1)

[Claims] 1. A rotary storage medium, a spindle motor for rotating the rotary storage medium at a desired speed, a drive control means for controlling the spindle motor, and a drive control means for controlling the spindle motor; A rotary storage device comprising a rotational speed monitoring means for measuring the rotational speed of the rotary storage medium based on a first position signal corresponding to an information read cycle, and a main control means for controlling and controlling each of the abovementioned means. A rotation abnormality detection method for a device, wherein when the rotation speed monitoring means detects an abnormality in the rotation speed, the validity of the first position signal is verified, and the first position signal is determined to be valid. In this case, the rotary storage device is rendered unusable, and if the first position signal is invalid, an abnormality recovery process for the first position signal is performed. . 2. The validity of the first position signal is verified by comparing the fluctuation range of the rotation speed from a normal value measured based on the first position signal with two large and small first and second threshold values. The fluctuation range immediately after the abnormality detection is within the first threshold value, and the second
If the threshold value is exceeded, it is determined that the first position signal is valid and there is a true rotation abnormality of the rotary storage medium, and the rotary storage device is rendered unusable, and the display means is activated. 2. The rotational abnormality detection method according to claim 1, wherein the occurrence of rotational abnormality is notified to the outside. 3. Verification of the validity of the first position signal is performed based on a second position signal obtained from the spindle motor and used by the drive control means to control rotation of the spindle motor. The rotation abnormality detection method according to claim 1, characterized in that: 4. A rotary storage medium, a spindle motor that rotates the rotary storage medium at a desired speed, a drive control means that controls the spindle motor, and a read cycle of information recorded on the rotary storage medium. a rotational speed monitoring means for measuring the rotational speed of the rotary storage medium based on the first position signal, a display means for notifying the outside of rotational abnormality of the rotary storage medium, and a display means for controlling the respective means. and main control means for controlling, when an abnormality in the rotation speed is detected in the rotation speed monitoring means, the control means verifies the validity of the first position signal, and controls the first position signal. If the first position signal is valid, the rotary storage device is rendered unusable and the unusable state is notified to the outside via the display means, and if the first position signal is invalid, A rotary storage device characterized by having a control function for performing abnormality recovery processing of the first position signal. 5. The validity of the first position signal is verified by comparing the variation range of the rotational speed from a normal value measured based on the first position signal with two large and small first and second threshold values. The fluctuation range immediately after the abnormality detection is within the first threshold value, and the second
If the first position signal exceeds a threshold value, it is determined that the first position signal is valid and there is a true rotation abnormality of the rotary storage medium, and the rotary storage device is rendered unusable. The rotating storage device according to claim 4. 6. Verification of the validity of the first position signal is performed based on a second position signal obtained from the spindle motor and used by the drive control means to control rotation of the spindle motor. The rotating storage device according to claim 4, characterized in that: