JPH0453061A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To prevent a serious accident such as destroying a data or the like in advance by detecting the indication of head crush by a sound. CONSTITUTION:A sound detector 11 detects sounds when a spindle 9 and a magnetic disk 2 are rotated, and a filter circuit 12 cuts noise. The signal is converted to a frequency spectrum by a frequency analysis circuit 13. When a frequency comparator circuit 14 detects an abnormal frequency component, an alarm signal is transmitted through an interface circuit 15 to a high-order controller 18. When this alarm signal is detected, the high-order controller 18 instructs operations such as backing-up the data of a magnetic disk device to the other magnetic disk device or stopping the rotation of the spindle 9 by transmitting a control signal through the interface circuit 15 to a spindle control circuit 16 and an actuator control circuit 17. Therefore, before the data is destroyed, it is possible to execute the safety operation such as saving the data or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Field of Industrial Application] The present invention relates to a technique for preventing data from being destroyed by a head crash in a magnetic disk device.

[Prior Art] FIG. 3 is a block diagram of a conventional magnetic disk device disclosed in, for example, Japanese Patent Laid-Open No. 58-1858.
(1) is a magnetic head, (2) is a magnetic disk, (3) is an arm, (4) is a servo motor, (5) is a servo amplifier, (6) is a switch, and (7) is an irregular signal generator. It is a vessel.

Next, the operation will be explained. In a magnetic disk drive employing a contact start/stop type magnetic head, the magnetic disk (2) and magnetic head (1) are attracted to each other when the magnetic disk (2) stops, and when the magnetic disk (2) starts to rotate four times, the magnetic disk ( Since there is a risk of damaging the contact surface between the magnetic disk (2) and the magnetic head (1), the magnetic head (1) is slightly vibrated at the start of one rotation to avoid damaging the contact surface between the magnetic disc (2) and the magnetic head (1).
The adsorption force of 1) is reduced. To explain with a diagram, what normally controls the servo motor (4) is a signal amplified by the servo amplifier (5), but at the start of 4 rotations, the signal is amplified by the irregular signal generator (7). Connect to the servo amplifier (5) with the signal switch (8) from
The amplified signal drives the servo motor (4) to release the magnetic disk (2) from the magnetic head (1).

[Problem to be solved by the invention 1 Since the conventional magnetic disk drive is configured as described above, the main focus is on eliminating the cause of the head crash phenomenon in advance, and reducing the probability of head crash. Although I can.

There was no countermeasure against the problem of data being destroyed if a head crash occurred.

This invention was made to solve the above-mentioned problems, and by detecting signs of a head crash and reporting this information to a higher-level control device, appropriate measures can be taken before data is destroyed. The purpose of this invention is to obtain a magnetic disk device that can perform the following steps.

[Means for Solving the Problems] A magnetic disk drive according to the present invention detects the sound generated within the enclosure while the magnetic disk is rotating, detects signs of a head crash based on changes in the sound, and transmits the information. The system is designed to report to a higher-level control device.

1-Operation] The magnetic disk device of the present invention can prevent data destruction due to head crash by detecting changes in sound during operation [Embodiments of the Invention] Hereinafter, an embodiment of the present invention will be described. Explain the diagram. 1st
In the figure, (8) is the enclosure, (9) is the spindle, (10) is the actuator, (1,1) is the sound detector, (12) is the filter circuit, (13) is the frequency analysis circuit (14) is the frequency A comparison circuit, (15) an interface circuit, (16) a spindle motor control circuit, and (1, 7) an actuator control circuit, these constitute the disk device. (18) is a higher-level device that controls the disk device.

Figure 2 (a) shows an example of the frequency spectrum of sound during normal spindle motor rotation, and Figure 2 (b) shows an abnormality that occurs when the head (1) and disk (2) come into contact. It shows the frequency spectrum of sound during spindle motor rotation.

Before explaining the operation, the relationship between the contact phenomenon between the head and the disc and the head crash will be explained. A phenomenon generally referred to as a head crash is a phenomenon in which the disk surface is damaged due to contact between the head and the disk, and data recorded on the disk is destroyed.

On the other hand, head crashes do not necessarily occur at the moment the head and disk come into contact; at first, there is intermittent contact, but as the condition continues, damage to the disk surface gradually progresses. It is known that this phenomenon eventually leads to data destruction.

This invention aims to detect signs leading to a head crash and prevent data destruction.

The operation will be explained. A sound detector (11) detects the sound produced when the spindle (9) and magnetic disk (2) rotate, and a filter circuit (12) cuts the noise. The signal is converted into a frequency spectrum by a frequency analysis circuit (13). As shown in Fig. 2(a), the result is the fundamental frequency during normal rotation + 1. f2. f3. If only f4 is present, the magnetic head (1) is normally floating above the magnetic disk (2), but if f5 frequency is also observed as shown in Figure 2(b), the magnetic head (1) is floating normally on the magnetic disk (2). It can be determined that the head (1) and the magnetic disk (2) have started to come into contact with each other during rotation. This determination is made by the frequency comparison circuit (14).

When this abnormal frequency component is detected, an alarm signal is sent to the upper control device 1 (1g) via the interface circuit (15). High-level control equipment! When (1g) detects this alarm signal, it either backs up the data of the magnetic disk drive to another magnetic disk drive, or connects the spindle control circuit (16) and actuator control circuit (17) via the interface circuit (15). ) to instruct operations such as stopping the rotation of the spindle (9). Therefore.

Safe measures such as evacuating data can be taken before data destruction.

In the above example, the frequency of f5 shown in FIG. 2(b) was determined in advance, but since there are various types of head crashes and the sounds they produce, it is difficult to determine where the abnormal frequency spectrum occurs. Good too. In addition, the magnetic disk device is operated by the upper control device (18) instructing data saving operation, but when an abnormality is detected, the magnetic disk device automatically executes abnormality avoidance measures. You can do it like this.

[Effects of the Invention] As described above, according to the present invention, since signs of head clubbing are detected by sound, there is an advantage that serious accidents such as data destruction can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a magnetic disk device according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating frequencies in normal and abnormal times in the present invention, in which diagram a shows the spectrum during normal operation, and diagram b shows the spectrum during normal operation. The figure shows the spectrum of abnormal movement poetry. FIG. 3 is a block diagram of a conventional magnetic disk device. (1) is a magnetic head, (2) is a magnetic disk, (3) is an arm, (4) is a servo motor, (5) is a servo amplifier,
(6) is a switch, (7) is an irregular signal generator, (8)
is the enclosure, (9) is the spindle, (], O
) is the actuator (11) is the sound detector, (+2) is the filter circuit, (13) is the frequency analysis circuit, (1,4
) is a frequency comparison circuit, (15) is an interface circuit, (16) is a spindle morph control circuit, (17) is an actuator control circuit, and (1, 8) is a 1L device that controls the disk device. Note that the same reference numerals in Figure 1 indicate the same or equivalent parts. 10: Actuator 11: Sound 1hi Koki

Claims (1)

[Claims] A magnetic disk drive that includes a device that detects sound during rotation, a device that analyzes the frequency of the detected sound, and a device that determines whether the sound is during normal rotation or when an abnormality occurs.