JP2712705B2 - Loading / unloading method of magnetic head - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard magnetic disk device used as a storage file, and more particularly to a method for loading and unloading a magnetic head.

[Conventional technology]

2. Description of the Related Art In recent years, the size and capacity of magnetic disk devices have been rapidly increased. In a magnetic disk device, there is a method in which the magnetic disk and the magnetic head are in close contact with each other when the disk is stopped, and the magnetic disk and the magnetic head are slid during the start operation and the stop operation of the magnetic disk. On the other hand, as a magnetic disk medium, a continuous thin film medium is becoming mainstream from a conventional coated medium due to a demand for high density. The thin-film magnetic disk using this continuous thin-film medium has a random texture in the circumferential direction to prevent damage due to sliding between the magnetic head and the magnetic disk and to prevent the magnetic head from sticking to the magnetic disk when stopped. It has been subjected.

However, in order to achieve high-density recording, the substrate roughness tends to be small, so that a stick-slip or the like occurs between the magnetic head and the magnetic disk medium, and the disk may be damaged. In order to avoid this, recently, when loading or unloading the magnetic head on the magnetic disk, a method of starting and stopping without contacting the magnetic head with the magnetic disk has been adopted.

[Problems to be solved by the invention]

However, in the method in which the magnetic head is not brought into contact with the magnetic disk during loading or unloading, foreign materials and the like are deposited on the magnetic head and the sliding surface of the magnetic disk due to prolonged use, and fall off to cause a gap between the magnetic head and magnetic disk medium. And caught the head, causing a head crash.

An object of the present invention is to provide a method of loading and unloading a magnetic head that solves such a problem.

[Means for solving the problem]

The present invention relates to a magnetic head load / unload method for starting and stopping a magnetic head without bringing the magnetic head into contact with the magnetic disk when loading or unloading the magnetic head onto the magnetic disk. The magnetic head is brought into contact with the surface of the magnetic disk.

The contact area between the magnetic disk and the magnetic head is preferably the inner or outer circumference other than the data surface of the magnetic disk. Further, it is preferable that the disk rotation speed at the time of sliding contact between the magnetic disk and the magnetic head is smaller than the steady rotation speed.

[Action]

By sliding in contact with the disk surface at least once after the start-up rotation, it is possible to remove foreign substances and the like that have adhered and accumulated on the magnetic head sliding surface. As a result, it is possible to prevent the magnetic head and the magnetic disk from crashing due to foreign matter. When the magnetic head comes into contact with the magnetic disk, the rotational speed of the magnetic disk is made lower than the steady rotational speed, so that wear of the magnetic disk and impact force due to head sliding can be reduced, and reliability can be improved.

〔Example〕

 Hereinafter, examples of the present invention will be described in detail.

FIG. 1 shows a basic configuration of a magnetic head and a magnetic disk according to the present invention. FIG. 1 shows a state where the magnetic disk 1 is stopped and the magnetic head is floating. For the magnetic disk 1, a 3.5 inch diameter substrate obtained by coating an Al alloy with a NiP film and performing texturing was used. A CoNiCr film was formed after the Cr film by a sputtering method, and a carbon protective film was further formed. A fluorine-based liquid lubricant was applied on the carbon protective film. A head contact sliding area 6 is provided on the inner peripheral side of the magnetic disk 1 other than the data surface.

In the magnetic head, a seek operation and a head loading / unloading operation are performed by a slider 2 having a magnetic head element 5 formed thereon, a support gimbal 3 and a head support mechanism 4 supporting these. For the slider 2, alumina calcium titanate was used.

FIG. 2 is a diagram showing a cross-sectional structure in a state where the magnetic head is in sliding contact with the surface of the magnetic disk.

According to the present embodiment, in the magnetic head and the magnetic disk configured as described above, when loading or unloading the magnetic head onto or from the magnetic disk, the magnetic head is started and stopped without contacting the magnetic disk.

Then, after the start of the magnetic disk, the contact sliding operation of the magnetic head to the head contact sliding area 6 was performed before the magnetic disk was stopped, as shown in FIG.

FIG. 3 shows an operation cycle of the magnetic head and a rotation cycle of the magnetic disk. In other words, when the magnetic disk is started, the disk rotation speed increases during the head seek operation, the disk rotation speed reaches a certain value, and when the disk becomes a steady rotation,
Load the magnetic head. When writing of information to the magnetic disk or reading of information from the magnetic disk is completed, the magnetic head is unloaded. At this time, the disk rotation speed decreases. Before the magnetic head stops, the magnetic head is loaded into the head contact sliding area 6 of the magnetic disk 1 and slid in contact therewith, as shown in FIG. I do. Then, the magnetic disk 1 is unloaded again.

An acceleration test was performed to evaluate the reliability of the magnetic disk drive. In this accelerated test method, the flying height of the magnetic head was reduced to 0.1 μm or less by making the pressure lower than the normal atmospheric pressure (0.5 atm), so that the magnetic disk and the magnetic head were lightly touched. As a result, the number of times of contact of the magnetic head with the magnetic disk becomes larger than usual, and the probability of foreign matter accumulation increases. Also, during the test, the magnetic head was floated at a predetermined track position to make it easy for foreign matter to accumulate, and the correlation between the number of stops before the head crash and the crash frequency was examined.

As a comparative example, of the conditions of the above-described embodiment, the magnetic head was made to perform only the retracting operation and not perform the contact sliding. Other conditions are the same as those of the embodiment.

FIGS. 4 (a) and 4 (b) show the comparison between the embodiment and the comparative example with respect to the number of stop times and the crash frequency of the test sample before the head crash. From the figure, it can be seen that the number of times until the head crash occurs in the example is larger than that in the comparative example, which is effective.

In this embodiment, the rotation speed of the magnetic disk when the magnetic head slides on the magnetic disk is lower than the steady rotation speed as shown in FIG. In order to examine this effect, as a comparative example, as shown in FIG.
The figure was compared with the case where the disk was slid in contact with the disk at a higher rotational speed than that of FIG.

FIG. 6 shows the correlation between the embodiment and the comparative example, with the number of stops until the disk is damaged. As shown in the figure, when the magnetic head and the magnetic disk are slid in contact with each other, it is preferable to perform the operation in the low rotation speed region of the magnetic disk.

〔The invention's effect〕

According to the present invention, the magnetic head and the magnetic disk are kept out of contact with each other when the magnetic disk is stopped, and the magnetic head is brought into contact with the disk surface at least once after the start-up rotation, so that the magnetic head or the magnetic disk slides during use. Foreign matter and the like adhering to and accumulating on the moving surface can be removed, and head crashes due to foreign matter contamination can be reduced.

Also, when the magnetic head is brought into contact with the magnetic disk, the magnetic disk is rotated in a region where the rotational speed is smaller than the normal rotational speed, so that the magnetic disk wear and impact due to head sliding can be reduced, and the mechanical durability is greatly improved. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic configuration of a magnetic head and a magnetic disk, FIG. 2 is a diagram showing a cross-sectional structure in a state where the magnetic head is in sliding contact with a magnetic disk surface, and FIG. FIGS. 4 (a) and 4 (b) are diagrams showing the number of times until a head crash and the crash frequency of a test sample, respectively. FIGS. 4 (a) and 4 (b) are diagrams showing the magnetic cycle in a comparative example. FIG. 6 is a diagram showing the relationship between the number of rotations of the magnetic disk corresponding to the contact sliding operation of the head and the retracting operation. FIG. 6 shows the correlation between the number of times the magnetic disk is stopped until damage such as scratches occurs in the embodiment and the comparative example. FIG. DESCRIPTION OF SYMBOLS 1 ... Magnetic disk 2 ... Slider 3 ... Support gimbal 4 ... Head support mechanism 5 ... Magnetic head element 6 ... Head contact sliding area

Claims (1)

(57) [Claims] 1. A method for loading and unloading a magnetic head onto and from a magnetic disk, wherein the magnetic head is started and stopped without contacting the magnetic disk. As described above, a method for loading and unloading a magnetic head, wherein the magnetic head is brought into contact with the surface of the magnetic disk.