JPH01140422A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To prevent sticking and to prevent generation of medium damage and head crush at the time of starting by providing spiral grooves to a region of the surface of a magnetic recording medium where a magnetic head executes starting and stopping. CONSTITUTION:The magnetic recording medium 11 of a magnetic disk device with which the magnetic heads executes starting and stopping in the state of maintaining contact with the surface of the recording medium 11 is constituted by providing the spiral grooves 13 to the region of the medium 11 surface of the recording medium 11 where the magnetic heads executes starting and stopping. The direction where the medium travels and the side faces of the grooves are, therefore, inclined at a certain angle and shearing force acts on the deposits on the slider surface of the head, so that the deposits are chipped away by the side faces of the grooves. The chipped-away residues are deposited in the grooves 13. The adhesion of the residues again to the slider surface is thereby prevented and the contact area between the head and medium is decreased. The sticking between the head and the medium is thus prevented.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a magnetic recording medium for a magnetic disk device that starts and stops with a magnetic head and a recording medium surface in contact with each other. The present invention relates to a magnetic recording medium designed to prevent crashes and improve sliding resistance.

[Conventional technology]

In order to achieve higher recording density and narrower spacing of magnetic recording media used in magnetic disk drives, it is desired to improve the smoothness of the media surface. On the other hand, as the smoothness increases, there is a risk that the head and the medium will stick together due to lubricant, moisture, etc. If the head is started in a sticky state, the media surface will be damaged.

In addition, during the manufacturing process or use of magnetic disk drives, dust enters from the outside and enters between the head and the medium, and the head and medium come into contact through the dust or directly, causing a so-called head crash that destroys recorded signals. phenomenon may occur. To deal with this, conventionally, JP-A-55
As described in Japanese Patent Laid-open No. 52537, the head/medium contact area, that is, the C85 (contact start/stop) zone, is made to have a predetermined surface roughness to prevent adhesion. In this method, concentric grooves are provided in the C8S zone to prevent the head from contacting the medium surface, or as described in JP-A-56-169226, the C8S zone has a roughness greater than that of the medium surface. A method has been adopted in which the head slider surface is automatically cleaned by creating a large number of scratches.

[Problem that the invention seeks to solve]

The above conventional techniques each have the following problems.

In other words, the method of making the C8S zone a predetermined surface roughness requires precise machining accuracy to achieve the predetermined surface roughness, which is costly and difficult to put into practical use. The method of providing grooves prevents adhesion but is not effective in removing head deposits, and the method of creating scratches in the C8S zone requires creating many minute scratches in order to remove head deposits. Similar to the above-mentioned method of making the C8S zone a predetermined surface roughness, there are problems in workability and practicality.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording medium having a structure with good workability and capable of preventing head crash by preventing adhesion and removing head deposits.

[Means for solving problems]

The above purpose is to create a spiral groove in the area of the magnetic recording medium surface where the magnetic head starts and stops in a magnetic recording medium of a magnetic disk device that starts and stops while the magnetic head is in contact with the magnetic recording medium surface. This is achieved by providing a configuration.

[Effect]

By providing a spiral groove in the C8S zone,
The media running direction and the groove side surface are inclined at a certain angle.
Shearing force acts on the deposits on the slider surface of the head,
The deposits are scraped off on the side surfaces of the groove, and the scraped residue is deposited in the groove. In this way, residue is deposited in the grooves, so
This can prevent the residue from adhering to the slider surface again. Further, by providing the groove in the C8S zone, the contact area between the head and the medium is reduced, and adhesion can be prevented.

In addition, since spiral grooves can be machined by simply rotating the medium while sliding the processing device, the process is easy, which is particularly advantageous when processing a large number of grooves.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
Figure (a) is a perspective view of a part of the magnetic recording medium of the example, (
b) is an enlarged view of a part of the C8S zone [part (A) in the figure (a)]. In FIG. 1, 11 is a magnetic recording medium, 12 is a C8S zone, and 13 is a spiral groove. L is the width of the C8S zone, Q is the spiral groove 13
, and n is the number of turns of the groove 13.

If the product of the width Q of the groove and the number of turns n +2Xn is large, the number of turns n of the groove within the slider width of the head is correspondingly large. and Q
The product QXno of
However, the flying height becomes smaller. The slider width of the magnetic head is b, the pressing load is W9, the circumferential speed is U, and the viscosity coefficient of air is μ.
, if the flying height is h, then h = μU...
This is because there is the relationship (1), and increasing QXno is equivalent to decreasing b.

If the flying height of the head in the C8S zone is ha (μm) and the starting flying height is ht (μm), then the appropriate value of hc is h to < h c < 0.1+ h to (μm)
--It is known from previous experimental results that it is best to set the value in the range of (2), so QXn,
The value of , can be obtained from the following equation (3). Since U and W are constants determined by the device and magnetic head, once the values of hc and b are determined, QX
The value of no is determined as a constant value from equation (3). Therefore, when it is desired to increase the width Q of the groove, the number of turns in the spiral shape is n. If you want to reduce the width of the groove, you just need to increase the number of turns.

FIG. 2 shows an embodiment of a method for forming spiral grooves on the surface of a magnetic recording medium according to the present invention. Figure 2 (a) shows the case where an electrical discharge machining device or laser machining device is used, and (b)
is for machining using a cutting tool. In the figure, 14 is an electric discharge machining device or a laser machining device, 17 is an electron beam or a laser, 15 is a spindle, and 16 is a cutting tool. By rotating the magnetic recording medium 11 integrally with the spindle 15 and moving the processing device 14 or the cutting tool 16 linearly parallel to the surface of the medium, a spiral groove can be formed. In this way, the grooves may be formed after forming the recording medium layer on the magnetic recording medium, but since the recording medium layer is relatively thin, forming the recording medium layer after forming the grooves on the substrate surface has the same effect. is obtained.

FIG. 3 is a plan view showing a state in which the slider deposits are removed from the side surface of the groove. Because the media rotation direction and the groove sides are tilted, shearing force acts on the deposits, removing them.
The residue of the removed deposits enters the groove and is deposited.
It will not adhere to the slider surface again.

〔Effect of the invention〕

According to the present invention, (1) it is possible to reduce the contact area between the head and the medium, it is possible to prevent adhesion, and it is possible to prevent damage to the medium at the time of startup; and (2) it is possible to remove substances attached to the head. (3) It is easy to process spiral grooves in the C8S zone, and the processing time can be shortened.

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view of a part of a magnetic recording medium according to an embodiment of the present invention, FIG. 1(b) is an enlarged view of part A thereof, and FIG. 2 illustrates a method of forming a spiral groove according to the present invention. In the figure, (a) is when an electrical discharge machining device or laser machining device is used, and (b) is
) is a diagram showing the case using a cutting tool, and FIG. 3 is a diagram showing a state in which the slider deposits are removed on the side surface of the groove. Explanation of symbols 11... Magnetic recording medium 12... C8S zone 13... Spiral groove 14... Processing device 15
...Spindle 16...Bite 17...
Electron beam or laser 18...Slider surface 19...Deposit agent Junnosuke Nakamura, patent attorney Figure 1 (CI)

Claims (1)

[Claims] 1. In a magnetic recording medium of a magnetic disk device that starts and stops while the magnetic head is in contact with the surface of the magnetic recording medium, there is a spiral in the area on the surface of the magnetic recording medium where the magnetic head starts and stops. A magnetic recording medium characterized by having grooves in the shape of a shape. 2. The spiral groove is configured to activate the magnetic head;
The flying height in the stop area is h_c, and the flying height at the start of floating is h_t.
_0, the slider width of the magnetic head is b, the load is W, the circumferential speed is U, the viscosity coefficient of air is μ, the groove width l, and the number of revolutions of the groove existing within the slider width b when the magnetic head is stopped n_
The product l×n_0 with 0 is h_t_0<h_c<0.1+
h_t_0 (μm), h_c=√{μU(bl×n_
0)^3/(4W)} (μm) The magnetic recording medium according to claim 1, wherein the value is selected to satisfy the relationship: 0)^3/(4W)} (μm).