JPH02121158A - Magnetic recording device - Google Patents

Abstract

PURPOSE:To prevent the damage due to the attraction caused between a mag netic head and a magnetic disk by using a detecting means which detects an attraction phenomenon between the magnetic disk and the magnetic head when the revolution of the magnetic disk is stopped and a protection mechanism which prevents the drive of a rotary drive source of the magnetic disk when the attraction phenomenon occurs. CONSTITUTION:An attraction phenomenon detecting means consisting of a strain gauge 3 and a strain meter 4 detects the presence or absence of an attrac tion phenomenon of a magnetic head 2 based on the force applied to the mag netic head 2. A protection mechanism stops the revolution of a magnetic disk 1 at occurrence of the attraction phenomenon. In this case, a microcomputer 8 which controls a torque motor 12, for example, is used as the protection mechanism. Thus the energization of the motor 12 is discontinued to prevent the revolution of the disk 1. As a result, the damage due to the attraction caused between the head 1 and the head 2 can be avoided.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording device, and more specifically, the present invention relates to a magnetic recording device, and more specifically, to magnetic disk,
It is installed in a magnetic recording device designed to prevent damage to the magnetic head.

[Prior Art] In recent years, the importance of external storage devices such as magnetic disk drives in computer systems has increased, and as a result, there has been an increasing demand for higher recording densities in magnetic recording devices that use magnetic disks. ing. Such a magnetic disk device has a recording/reproducing magnetic head (lil!ki head).
The magnetic disk rotates at high speed, and the magnetic head is placed a minute distance from the surface of the magnetic disk. In order to improve the performance of magnetic recording devices by reducing this minute interval, the load on the magnetic head can be reduced, and contact start/stop (contact start/stop) can be achieved.
A CS S ) type head floating system is adopted. In order to increase the recording density and performance of magnetic disks, it is necessary to make the magnetic disk thinner, more uniform, improve magnetic properties, and ensure a stable flying state of the head at low flying heights. In order to prevent disk collisions (head crashes), it is necessary to improve the accuracy of the roughness of the magnetic disk surface and to improve head crush resistance. The above-mentioned conventional heads include bulk heads and thin film magnetic heads, such as those described in publications (Journal of the Japan Society of Mechanical Engineers, No.
Vol. 791, pp. 79-87, published in 1984).

[Problem to be solved by the invention] However, with the improvement in the accuracy of the roughness of the magnetic disk surface,
When a magnetic disk and a magnetic head come into contact with each other, an adhesion phenomenon tends to occur between the two, and when such head-disk adsorption occurs, it is no longer possible for the magnetic head to fly due to the rotation of the magnetic disk. On the other hand, if you try to force the rotation of the magnetic disk and try to levitate the magnetic head, there are problems such as peeling or scratches on the magnetic layer, or deformation or tearing of the magnetic head support. Ta.

This invention was made to solve the above problems, and provides a magnetic recording device that prevents the magnetic disk from rotating when magnetic head/disk adsorption occurs, thereby preventing damage caused by magnetic head/disk adsorption. The purpose is to obtain.

[Means for Solving the Problems] The magnetic recording device of the present invention has a magnetic head floating when the magnetic disk rotates, and detects an attraction phenomenon between the magnetic disk and the magnetic head when the magnetic disk stops rotating. The apparatus is provided with a detection means and a protection mechanism that prevents the rotational drive source of the magnetic disk from being driven when an attraction phenomenon occurs between the magnetic disk and the magnetic head.

[Function] In this invention, it is detected whether or not an attraction phenomenon is occurring between the magnetic head and the disk, and the magnetic disk is not driven when the attraction phenomenon occurs.
Damage caused by head/disk adsorption can be prevented.

[Example] We investigated and researched the mechanism of the adsorption phenomenon that occurs between the conventional magnetic head and the magnetic disk, and found that the mechanism of this adsorption phenomenon is the generation of meniscus due to adsorbed water condensing on the contact interface between the magnetic disk and the magnetic head. Due to
It was found that this causes the magnetic head adsorption phenomenon (the surface tension of the adsorbed water creates the adsorption force).

Therefore, we investigated why so much adsorbed water is generated that condensation occurs between the magnetic head and the magnetic disk, and found the following two reasons. One of them is that the surface roughness of the magnetic disk and magnetic head is small, so the gap between the magnetic disk and the magnetic head is small, and the adsorption of water vapor in this condition is different from normal conditions. , it begins to behave like a so-called capillary condensed liquid, and the relative humidity becomes higher than the normally indicated value,
Condensation is induced even under relative humidity conditions that would be unthinkable in an open space.

This phenomenon is described in publications (Masatoshi Chikazawa, Surface Science,
5, No. 2, published in 1984, pp. 163-164).

Another reason is that when the magnetic disk is stopped rotating at high speed and the magnetic head is brought into contact with the magnetic disk, the temperature of the space where the magnetic disk and magnetic head exist (inside the magnetic disk drive system) at that point is The temperature is about 10° C. to 30° C. lower than the temperature when the valve is stopped and a sufficient amount of time has passed.

Therefore, the relative humidity within the airspace increases as the temperature decreases, and it has been found that at this time, dew condensation may occur between the magnetic disk and the magnetic head.

Therefore, in order to remove the adsorption, it is sufficient to remove the adsorbed water that has condensed on the magnetic head and the magnetic disk. just,
Before that, it is necessary to determine whether or not the magnetic head and magnetic disk are attracted to each other. Therefore, an example for determining the adsorption phenomenon will be described below.

Adsorption Phenomenon Evaluation Test FIG. 1 is a block diagram of an adsorption phenomenon evaluation apparatus assembled to evaluate the adsorption phenomenon between a magnetic disk (1) and a magnetic head (2) according to the present invention. In the figure, (1) is a magnetic disk, and (2) is a magnetic head that presses against the magnetic disk (1) with a load of about 5 g. (3) is a strain gauge attached to a support base (13) that measures the force applied to the magnetic head (2) when the magnetic disk (1) rotates. 4). Note that the force applied to the magnetic head (2) measured here is taken in as data in the microcomputer (8) and processed as data in the floppy device (9). (10) is a printer. (6) is a temperature and humidity sensor installed in the clean, constant temperature, constant humidity tank (ll), and is connected to Ambuku 7).

(5) is a torque meter provided to control the rotational force of the disk, and is controlled by a microcomputer (8). (12)
is a torque motor, which is controlled by a microcomputer (8).

Figure 2 shows the support stand (3) for the strain gauge (3) in Figure 1.
13) is a perspective view showing an example. The strain gauge (3) is manufactured by NEC Sanei Co., Ltd. with product number N-11-F.
A-03-120-22 is used, and it is glued on the support stand (13) with cyanoacrylate adhesive, and connected to the strain gauge (4) via the Wheatstone bridge (14). Bridge (14)
For the strain meter (4), product number DB-120 manufactured by Kyowa Kata Su Co., Ltd. was used, and for the strain meter (4), product number DPM-611 manufactured by Kyowa Kata Su Co., Ltd. was used.

On the other hand, the force applied to the strain gauge (4) is the force applied to the magnetic head (2).
It is calibrated to correspond to the force applied to .

Next, the adsorption phenomenon was evaluated using such an adsorption phenomenon evaluation device and will be explained.

The temperature in the constant temperature and humidity chamber (11) was kept constant at 30°C and 40%, and the magnetic head (2) was placed on the magnetic disk (1) with a load of 5.
After pressing with a force of g, the torque motor (12) is energized and the magnetic head (2
) was calculated from a strain meter (4) connected to a strain gauge (3), and was found to be 0.8 g to 1.2 g.

Next, a similar experiment was conducted 60 minutes later, and the force applied to the magnetic head (2) was 0.8 g -1.2 g. From this experiment, it was found that when the magnetic head is not attracted, a force of 0.8 g to 1.2 g is applied to the magnetic head.

Next, while keeping the magnetic disk (1) and magnetic head (2) in contact, the humidity in the constant temperature and humidity chamber (11) was increased to 90%, and after leaving it in that state for 180 minutes, a similar experiment was carried out. When this was done, the magnetic head was attracted, and after the force applied to the magnetic head reached 50 g or more, the magnetic head (2) was torn off from the support base (13).

Next, as in the previous experiment, the magnetic disk (1) and the magnetic head (2) were left in contact with each other for 180 minutes at a constant humidity of 90% in the constant temperature and humidity chamber (11), and then the magnetic head (2) was left in contact with each other for 180 minutes. When the torque motor (12) was energized under conditions that were set to stop energizing the torque motor (12) when the force applied to the head (2) reached 25 g, the magnetic disk (1) stopped rotating. It was confirmed that magnetic head adsorption occurred. Note that there was no damage to the magnetic disk (1) and magnetic head (2).

On the other hand, in the conventional magnetic recording device, since the strain gauge (3) is not attached, that is, there is no attraction detection means, even if the force applied to the magnetic head (2) is 50 g or more, attraction occurs. Even if the torque motor (1
Since it is not possible to stop the power supply to 2), that is, the rotational drive of the magnetic disk (1) cannot be stopped, the magnetic head (2) may be torn off from the support base (13), and Peeling and scratches may occur on the magnetic head (2) itself and the magnetic layer portion of the magnetic disk (1).

Next, a method for removing the attraction phenomenon between the magnetic disk (1) and the magnetic head (2) will be described. The temperature of the constant temperature and humidity chamber (11) in the adsorption phenomenon evaluation apparatus shown in Fig. 1 was set to 60°C1 and the humidity was set to 40%, and after about 120 minutes, the adhesion between the magnetic disk (1) and the magnetic head (2) When it was investigated whether or not adsorption was occurring using the adsorption phenomenon evaluation device shown in FIG. 1, it was confirmed that adsorption had been removed.

Note that the means for detecting the adsorption phenomenon according to the present invention is not limited to this, as it can also be detected by a method of measuring the torque of a torque motor, in addition to the above-mentioned strain gauges and strain meters.

The magnetic recording device of the present invention has an adhesion phenomenon detection means consisting of, for example, a strain gauge or a strain meter, and detects whether or not adhesion has occurred based on the force applied to the magnetic head, as explained in the above-mentioned adhesion phenomenon evaluation test. , has a protection mechanism that stops the rotation of the magnetic disk when it is attracted, for example, a microcomputer that controls the above-mentioned torque motor, and stops the power supply to the torque motor to prevent the magnetic disk from rotating.
This prevents damage to magnetic disks, magnetic heads, etc. caused by disk head adsorption.

[Effects of the Invention] As described above, according to the present invention, in a device in which a magnetic head floats when a magnetic disk rotates, a detection method is provided for detecting an attraction phenomenon between the magnetic disk and the magnetic head when the magnetic disk stops rotating. By providing means and a protection mechanism that prevents the rotational drive source of the magnetic disk from being driven when an attraction phenomenon occurs between the magnetic disk and the magnetic head, the magnetic disk, the magnetic head, etc. are prevented from being damaged due to attraction. This has the effect of providing a magnetic recording device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an adsorption phenomenon evaluation apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view of the main part of FIG. 1. In the figure, (1) is a magnetic disk, 2) is a magnetic head, (3) is a strain gauge, (4) is a strain meter, (8) is
is a microcomputer, and (12) is a torque motor. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Procedural amendment (voluntary) 1. Case indication patent application No. 63-272160 3. Name of the person making the amendment (601) Mitsubishi Electric Corporation Representative Moriya Shiki 4. Amendment by agent Target F! Detailed Description of the Invention in Specification A Column 6゜Contents of Amendment +11 Correct "lower." to "higher." in the first line of page 6 of the specification. On page 10, line 6 of the same page, change ``The humidity is set to 40%,'' to ``The humidity is set to 20%.'' ” is corrected. that's all

Claims (1)

[Claims] In a device in which the magnetic head floats when the magnetic disk rotates, a detection means detects an attraction phenomenon between the magnetic disk and the magnetic head when the magnetic disk stops rotating;
and a magnetic recording device comprising a protection mechanism that prevents a rotational drive source for the magnetic disk from being driven when an attraction phenomenon occurs between the magnetic disk and the magnetic head.