JPH0445130Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic disk used for in-plane or perpendicular magnetic recording.

[Conventional technology]

Conventionally, a rigid magnetic disk has been used as one type of magnetic disk, and the base of this magnetic disk is made of a rigid material with little flexibility.

Usually, the basis of a rigid magnetic disk is
Aluminum discs (e.g. JIS A5086) are used.

Such rigid magnetic disks are generally manufactured by turning aluminum using a lathe, reducing the spacing between the head and the disk, and polishing the disk surface to enable high-density recording. Therefore, it is made by providing a magnetic layer. In this case, for high-density recording and reproduction, the smoother the surface roughness of the disk, the better, but it is difficult to obtain a surface with a centerline average roughness Ra of 0.1 μm or less with conventional aluminum-based disks. Ta. Furthermore, since the base lacks flexibility, when a magnetic layer is provided, it is extremely difficult to handle, as it is impossible to apply the magnetic layer continuously due to constraints such as the web path. Furthermore, since the influence of dust adhering to the surface is significant for high-density recording, disks must be made to prevent dust from adhering to them, making an already time-consuming process even more troublesome and complicated, and requiring a huge investment in equipment. It was made to be.

In addition, conventional substrates, such as aluminum, are rigid and have little flexibility, so when the head traces the magnetic layer of the disk, it must be non-contact, and this spacing must remain narrow and constant. It was extremely difficult to sustain this, and signal errors often occurred, and it was extremely difficult to further reduce the space between the head and the disk surface in order to further increase the recording density. On the other hand, if the head happens to come into contact with the disk surface due to narrow spacing, the sliding friction force will concentrate on the surface where the head and the magnetic layer make contact because the base is rigid. This causes surface damage and shortens the life of the disk.

Furthermore, there is a drawback that the polished aluminum substrate itself is expensive.

In contrast, recently, as shown in FIG. 2, grooves 3 are provided on both sides of a disk base 1, and a flexible disk 2 having a magnetic layer 5 on a support 4 is installed on both sides of the base 1 with the magnetic layer 5 as the surface. A magnetic disk has been proposed in which a groove portion 3 is provided between the back surface of the flexible disk 2 and the substrate 1 by bonding them together.

This type of magnetic disk has a flexible magnetic recording surface, so even if the head accidentally comes into contact with the magnetic recording surface, the head and magnetic recording surface can be brought into contact to record at a higher density. Sometimes,
Unlike rigid disks, destruction of the magnetic layer is less likely to occur. Therefore, flexible disk technology can be applied as is, and a magnetic layer with a smooth and durable surface can be used as the magnetic layer 5 for magnetic disks.
It is attracting attention as a device that can overcome the drawbacks of conventional rigid magnetic disks.

[Problem that the invention attempts to solve]

As a result of studying this type of magnetic disk, the present inventors found that there were still major problems. In other words, there is a difference in tension per unit area between the inner and outer sides of the recording area of the flexible disk of the present invention (hereinafter referred to as flexible disk), and the elasticity per unit area is greater on the inner side than on the outer side. be. This causes a difference in elasticity in the radial direction of the flexible disk, causing a change in the thickness of the air layer flowing between the head and the flexible disk. That is, a difference occurs in the gap between the head and the flexible disk, resulting in a change in so-called spacing loss, which causes a change in recording and reproducing characteristics.

An object of the present invention is to solve the above-mentioned problems, reduce the difference in spacing loss between the inner circumferential side and the outer circumferential side of the recording/reproducing area of a flexible disk, and provide a magnetic disk having uniform recording/reproducing characteristics.

[Means for solving problems]

The present invention provides a magnetic disk consisting of a base having a groove and a flexible disk bonded to the inner and outer rib portions of the groove. A magnetic disk characterized in that a plurality of fine holes are provided that communicate with the grooves.

The fine holes may be formed as appropriate depending on the effect of wrinkles on the recording area, or may be formed uniformly over the entire peripheral area from the beginning.

[Effect]

By providing an appropriate number of fine holes in the annular portion between the recording/reproducing area and the inner and outer peripheral ribs of the flexible disk, the strain that occurs when the flexible disk is attached to the base is dispersed by the small holes. Therefore, the flatness of the recording/reproducing area is guaranteed.

〔Example〕

FIG. 1 is an exploded view for explaining one embodiment of a magnetic disk according to the present invention.

Inner and outer peripheral rib portions 6a of the base plate 1 having the groove portion 3;
The flexible disk 2 was attached to 6b with adhesive. After the adhesive dried, wrinkles appeared around the attachment area of the flexible disk. Inside the wrinkles
To eliminate the influence of wrinkles on the recording/reproducing area by opening fine holes 6 with, for example, a needle, on the annular portion 9 of the flexible disks 2a, 2b between the outer circumferential rib portions 6a, 6b and the recording area 8. was completed.

[Effect of idea]

By providing a plurality of micro holes in the annular portion between the recording/reproducing area and the inner and outer peripheral rib portions of the flexible disk, it is possible to eliminate the effects of wrinkles on the surface of the recording area of the flexible disk, and to prevent head touch caused by these wrinkles. Not only was it possible to avoid deterioration in performance and obtain uniform recording and reproducing characteristics, but also
These micropores have the effect of allowing the air within the base to circulate with the outside world and preventing the flexible disk surface from expanding or contracting due to temperature changes.

[Brief explanation of the drawing]

FIG. 1 is an exploded view of one embodiment of the magnetic disk of the present invention, and FIG. 2 is a sectional view showing the basic structure of the magnetic disk to which the present invention is applied. 1...Base, 2...Flexible disk, 3
...Groove, 4...Support, 5...Magnetic layer, 6...
Fine hole, 6a... Inner circumferential rib portion, 6b... Outer circumferential rib portion, 7... Center hole, 8... Recording area.

Claims (1)

[Scope of utility model registration request] In a magnetic disk comprising a base having a groove and a flexible disk adhered to inner and outer peripheral rib portions of the groove, the groove is formed in an annular portion of the inner and outer peripheral portions of the flexible disk other than the recording/reproducing area. A magnetic disk characterized by having a plurality of communicating fine holes.