JPS6233385A - Cartridge for magnetic disk - Google Patents

Abstract

PURPOSE:To reduce rotating torque of a disk by arranging protrusions for regulating so as to place a magnetic disk at the intermediate position of a case on both internal surfaces of the case at least along the outer peripheral part of the magnetic disk. CONSTITUTION:Plural protrusions 27a, 27b for regulating positions of a magnetic disk 1 having spherical shape end parts are concentrically opposed on an upper part case 20b and a lower part case 20a in an outer periphery edge part of a magnetic disk 10. The shape of the protrusions 27a, 27b is determined so as to have an extremely small quantity of wear and a smaller quantity of the wear as a circumferential speed of the magnetic disk 10 is increased, when a contact surface of the protrusions 27a, 27b contacting the magnetic disk 10 is a spherical surface of a radius of curvature of 5-100mmR with respect to a running direction. The space between the ends of the protrusions 27a, 27b is determined so as to have a space between the ends and the magnetic disk 10 in a range in which the magnetic disk 10 does not contact the surfaces of the upper part case 20b and the lower part case 20a except for the protrusions 27a, 27b. Thereby, the surface of the magnetic disk 10 is not broken by dust or the like and a driving torque goes to small.

Description

Detailed Description of the Invention (Field of Application) The present invention records information in a spiral or concentric solid manner on the surface of a magnetic disk such as a flexible magnetic sheet disk rotatably housed inside. Or regarding a magnetic disk cartridge consisting of a case having an opening into which a head for reproducing the magnetic disk is inserted, particularly for high-speed access of metal i-model magnetic disks made of CO-based alloy i1 film etc. with excellent magnetic recording density. This invention relates to a magnetic disk cartridge that achieves high durability and reliability.

(Prior Art) In general, in the above-mentioned magnetic disks having a high information density, adhesion of dust, fingerprints, etc., and mechanical damage are very problematic. For this reason, magnetic disks are stored and carried in flexible or rigid cartridges, and when necessary, they are taken out from inside the cartridge, or information is recorded and played back through an opening provided in the cartridge. . Furthermore, the chance of adhesion of dust, etc. should be minimized, and for this purpose, the opening is opened only when the cartridge is loaded in a drive device for rotating a magnetic disk; A proposal has been made to provide a shielding mechanism for the opening so that the opening is closed when the cartridge is outside the drive device (Japanese Patent Laid-Open No. 57-21266).
Publication No. 9, etc.). These improvements improve reliability when storing magnetic disks and inserting them into drives, and γ-Fe
It can be said that cartridges for flexible magnetic disks using coated media using a coating method such as 2O3 are at a level where there are no technical problems.

On the other hand, due to the demand for higher information densities, thin-film media using magnetic thin films, and even perpendicular magnetic recording, are technologies that are expected to provide high recording density, high-speed access, and high-precision mechanisms, which are extremely difficult to achieve with coated media. A technique has been proposed (JP-A-52-134706).

JP-A-53-3209, etc.).

However, in the thin-film type flexible magnetic disk having a ferromagnetic metal or metal-based oxide thin film on the surface as the recording layer, since the surface is a thin film, the reliability of the surface condition of the conventional coating-type media is maintained. Therefore, the liner provided in the cartridge, which is made of nonwoven fabric or the like, cannot perform its function. That is, the above-mentioned liner had the function of sliding on the coated flexible disk medium, sharing a lubricating layer with the disk surface, and adsorbing dust to the surface. On the other hand, even with thin film type flexible disks provided with a protective layer such as a metal oxide layer or a single layer of carbon, when the above-mentioned cartridge for coated type disks is applied, the surface hardness of the disk is large and the surface of the liner on which it slides. There is a problem in that the reliability of the medium is reduced because the layer is worn away, and worn minute aggregates get caught between the head and the disk, causing scratches and spacing. Furthermore, even if the contact between the disk and the liner was finely adjusted, the rotational torque varied widely from cartridge to cartridge, making it difficult to realize a highly reliable drive system.

(Object of the Invention) The object of the present invention is to provide a cartridge having excellent durability and reliability for a thin film type flexible magnetic disk having a metal magnetic thin film in the recording/reproducing layer, and a 300 rpm I000r cartridge.
It is an object of the present invention to provide a cartridge for a flexible magnetic disk that has low disk rotation torque even in a wide range of pm and rotational speed.

(Structure and operation of the invention) The above objects are achieved by the invention as follows.

That is, the present invention provides a magnetic disk cartridge consisting of a case in which a magnetic disk is rotatably housed, in which a protrusion that restricts the magnetic disk to be positioned in the middle of the case is provided at least along the outer periphery of the magnetic disk. This is a magnetic disk cartridge characterized in that the cartridge is arranged on both inner surfaces of the magnetic disk.

As mentioned above, the present invention is completely different from the conventional one-liner type in which the magnetic disk is supported almost on its entire surface, but the magnetic disk is supported at the middle position of the case by a protrusion arranged on the inner surface of the case. The magnetic disk only comes into contact with the tip of the protrusion, so there is no damage to the magnetic disk surface due to dust or the like, and the driving torque is small.

The above-mentioned present invention has been made in examining the sliding characteristics between a thin film magnetic disk and a rod-shaped body made of a magnetic head slider material such as hard ceramics, and it has been discovered that very good sliding characteristics and durability can be obtained. It is something that

In the present invention described above, the protrusion may be of any shape as long as it can hold the magnetic disk at an intermediate position of the case without contacting the inner surface of the case, and the number of protrusions is limited to one.

The location is not particularly limited.

As for the shape, a columnar body whose tip end is processed into a spherical shape is preferably used. In particular, the radius of curvature of the spherical surface is 5 to 10
0m+ later is preferable from the viewpoint of durability.

In terms of stable support, it is preferable to arrange the magnetic disk along the outer peripheral edge of the magnetic disk, and it is further preferable to arrange the magnetic disk so as to support the outside of the recording area of the magnetic disk. Further, from the viewpoint of stable support, it is preferable that the protrusions on both inner surfaces of the case be arranged facing each other so that the leading end faces face each other with the magnetic disk sandwiched therebetween. Note that it is preferable that the distance between both protrusions is such that there is a slight gap from the surface of the magnetic disk when the magnetic disk is stored.

The material of the protrusions has good sliding characteristics with the magnetic disk, similar to the characteristics required of the magnetic head, and is durable, since the sliding conditions between the protrusions of the present invention and the magnetic disk are almost the same as those between the magnetic head and the magnetic disk. Any material may be used as long as it has excellent abrasion resistance, and any material that can be used as a normal head material can be used. Thin-film magnetic disks, especially those with a Wi-retention layer made of a metal oxide thin film, have high hardness. Therefore, high-hardness ceramics or hard-coated hard ceramics using sputtering, ion plating, or CVO are preferably used. . Such high hardness ceramics include /V20s*Hz Ox -Ti C.

Al2O5-Ti Op, Al10s-T! B2
, #20x-ZrOt, Al20s-Ta
N, #20x -Fez Oa -Alumina type such as -TiC, titanium type such as TiC, TiN, TiC-TiN, SLC, SLC-Si.

5L3N4. Silicon-based products such as Sialon (product name).

Zr 02. Zircon type such as Zr 02-9i, 02,
There are Sono and others #N, WC, and glassy carbon. Also, after i
The fluorine-containing glass material used in Example L can also be advantageously applied.

By the way, the present invention is particularly advantageously applied to a cartridge, such as a 3.5-inch micro-floppy cartridge, which has a rigid and rigid case that cannot be easily bent as a whole. Note that, as is well known, such a case is usually manufactured by molding a synthetic resin or the like.

Hereinafter, the details of the present invention will be explained with reference to Examples.

(Description of Embodiment) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of the cartridge of this embodiment, and FIG. 2 is a sectional view taken along the line A--A in FIG. 1 of the assembly. In the figure, 20a and 20b are upper and lower cases made of synthetic resin, each having side walls 21a and 21b at their edges for storing cartridges, and their inner surfaces are identically formed so as to face each other. . The magnetic disk 10 is rotatably housed in a space 22 formed by an upper case 20b and a lower case 20a. The hub 11 has a spindle hole 1 into which a drive shaft of a playing card device (not shown in this figure) is inserted.
2, is attached to the center of the magnetic disk 10, and rotates integrally with the magnetic disk 10. Further, the hub 11 has a stepped portion 11a on its outer periphery, which is sandwiched between the upper case 20b and the lower case 20a, so that movement of the drive shaft in the thrust direction and the radial direction is regulated within a required range. Therefore, the magnetic disk 10 can be held and hung without applying excessive force to the magnetic disk 10. The upper case 20b and the lower case 20a have elongated hole openings for abutting a magnetic head (not shown) for recording/reproducing information on the surface of the magnetic disk 1 and for moving the magnetic head in the radial direction of the magnetic disk 10. Part 23a, 2
3b is provided. The hub 11 has hub holes 24a, 2
Bosses 25a, 25 provided in the same circular shape as 4b
b and is rotatably fitted.

Detection holes 26a and 26b for detecting the index hole 13 provided in the magnetic disk 10 are formed in the upper case 20b and the lower case 20a.

Upper case 20b along the outer peripheral edge of the magnetic disk 10
On the lower case 20a, a plurality of protrusions 27a and 27b, each having a spherical tip and for regulating the position of the magnetic disk 1, are generally cut in a concentric circle and facing each other. As a result of the study on the above configuration, we found the following. Protrusion 27
As the material of a and 27b, a material having good durability in sliding with the magnetic disk 10, such as a magnetic head slider material, can be used. Among these, materials that do not cause wear of the magnetic disk 10 and cause wear of the protrusions 27a and 27b, and also have properties that prevent agglomeration of worn particles from occurring, are preferable. For the disk 10, projections 27a, 27
Among the crystallized glasses that satisfy the above-mentioned conditions, Devitron (trade name) containing fluorine was found to be excellent as the material for b.

Further, the shape of the protrusions 27a and 27b has a strong correlation with the sliding characteristics with respect to the magnetic disk 10. When the contact surfaces of the protrusions 27a and 27b that come into contact with the magnetic disk 10 are made spherical in the running direction, especially spherical surfaces with a radius of curvature of 5 to 100 mR, wear is extremely small and the circumferential speed of the magnetic disk 10 is increased. It was found that the amount of wear decreased.

The protrusions 27a and 27b are arranged so that they face each other with the magnetic disk 10 in between, but the distance between the tips of the protrusions 27a and 27b does not require that the magnetic disk 10 be tightly sandwiched between them. 27b
It is preferable that there be a simple gap between the magnetic disk 10 and the magnetic disk 10 so that it does not come into contact with the other surfaces of the upper case 20b and lower case 20a.

By the way, in order to bring out the effects of the cartridge according to the present invention, there is a combination of the contact surface materials of the magnetic disk 10 and the magnetic head. The magnetic disk 10 is a flexible disk that has the best recording and reproducing characteristics in perpendicular magnetic recording technology, and perpendicular magnetization layers of permalloy and CoCr are formed on both sides of a polyester film by 0.2 to 0.0. 5μm, 0.1
To protect the perpendicular magnetization layer of CoCr, an oxide layer using an element with a similar lattice constant such as Go-Cr oxide or Co oxide is formed to a thickness of ~o, 2 μm.
Approximately 300 people used a perpendicular magnetic recording medium, and the magnetic head was an aluminum (Al10s/Tic)
A slider was used.

The contact surface of the magnetic head, that is, the shape of the tip, has a radius of curvature of 30
．． When the disk shape is 51/4 inches, the sliding speed between the magnetic head and the magnetic disk 10 is 2T.
Changes in the reproduced signal level and the sliding state between the magnetic disk 10 and the magnetic head were examined in the range of rL/S to 7.57711/S. In order to confirm the effects of the present invention, nonwoven fabrics used in the prior art as cartridges for storing magnetic disks 10 were used for upper case 20b and lower case 2.
The cartridge of the comparative example attached to 0a and the protrusions 27a and 27b of the embodiment of the present invention were attached to the above-mentioned Devitron (
Stone Wall Glass■Product name) Using crystallized glass, the tip contact surface is shaped into a spherical shape with a radius of 2 m, and the gap between the protrusions 27a and 27b is 0.211 mm.
As III, we studied four pairs of cartridges arranged at 90° intervals including the outer periphery of the frontage portions 23a and 23b as shown in the figure. When the change in the reproduced signal level after 2 million rotations was investigated, there was no change in both the conventional example and the example.

However, in the case of the conventional example, deposits made of the nonwoven fabric composition were scattered on both sides of the magnetic disk 10, whereas in the case of the embodiment, only a small amount was deposited on the sliding parts of the protrusions 27a and 27b. There were only traces. 100 more
When the change in the reproduced signal level after 00,000 rotations was examined, it was found that in the case of the example, 90% or more of the initial signal level was maintained. On the other hand, in the case of the conventional example, the signal level partially decreased to 50% or less of the initial value. When we examined the magnetic disk 10 and the magnetic head, we found that there was no wear on the magnetic head, but in the case of the conventional example, cobalt oxide and agglomerated powder of nonwoven fabric composition, which is the protective layer of the magnetic disk 10, adhered to the head surface. Was. Also, magnetic disk 1
When the 0 surface was examined, in the case of the conventional example, an abnormal part in the form of a scratch had occurred around the head running part, but in the case of the example, no such abnormal part had occurred.

As described above, according to the present invention, a system with excellent durability and reliability is achieved in high-density magnetic recording using a flexible thin-film magnetic disk having a metal magnetic thin film as a recording layer, including perpendicular magnetic recording. can be realized.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention, and FIG. 2 is a side sectional view taken along line Δ-A in FIG. 1 of the embodiment. 10: Magnetic disk 11: Hub 20a: Lower case 20b: Upper case 27a,
27b: Protrusion Drawing C'JJ Dispute (Contents 1 unchanged) Figure 117 Figure 1 Procedural Official Letter (Method) % Formula % 1. Indication of Case Patent Application No. 171753/1986 2. Title of Invention Magnetic Disc Cartridge 3, Relationship with the Amendment Case Patent applicant: 1-11 Minamihonmachi, Higashi-ku, Osaka City? ! (300) Teijin Ltd. Representative Okamoto Sashibe 4, Agent 2-1-1-5 Uchisaiwai-cho, ChiyoEEI-ku, Tokyo Date of amendment order October 29, 1985 6 Drawings subject to amendment

Claims (1)

[Claims] 1. In a magnetic disk cartridge consisting of a case in which a magnetic disk is rotatably housed, a protrusion that restricts the magnetic disk to be located in the middle of the case is provided at least on the outer periphery of the magnetic disk. A magnetic disk cartridge characterized by being arranged along both inner surfaces of the case. 2. The magnetic disk cartridge according to claim 1, wherein the protrusions are arranged before and after the head window of the case. 3. The magnetic disk cartridge according to claim 1 or 2, wherein the protrusion is arranged so as to face outside the information recording area of the magnetic disk. 4. The magnetic disk cartridge according to claim 1, 2, or 3, wherein the protrusion is made of a glass material containing fluorine. 5. The magnetic disk cartridge according to claim 1, 2, or 3, wherein the protrusion is made of a high-hardness ceramic material. 6. Claims 1, 2, 3, and 4, wherein the tip shape of the protrusion is a spherical surface with a radius of curvature of 5 to 100 mm.
5. The magnetic disk cartridge according to item 5. 7. Claims 1, 2, 3, 4, and 5, wherein the magnetic disk is a thin-film flexible magnetic disk.
6. The magnetic disk cartridge according to item 6.