JP2000298971A - Magnetic disk cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability by obtaining a satisfactory cleaning action while reducing the increase of the rotation torque of a magnetic disk medium as much as possible. SOLUTION: A magnetic disk mediutn 4 like a disk is housed in a case obtained by joining an upper shell 1 and a lower shell 2 so that this medium can be rotated, and liners 6 and 6 are fixed to inside surfaces of the upper shell 1 and the lower shell 2 which surfaces face the magnetic disk medium 4, and at least a pair of brush members 7 are provided in upper and lower parts in the case, which parts face the magnetic disk medium 4, at least across a recording area 4a of the magnetic disk medium 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk cartridge in which a magnetic disk medium is accommodated in a case, and the magnetic disk medium is rotated and used for magnetic recording and reproduction. It is about.

[0002]

2. Description of the Related Art A magnetic disk cartridge contains a disk-shaped magnetic disk medium rotatably housed in a case formed by joining upper and lower shells. It is expensive to perform recording and reproduction on the magnetic disk medium by a magnetic head. It is necessary to ensure reliability.

[0003] From the viewpoint of ensuring the reliability, it is important that dust that causes so-called dropout does not adhere to the magnetic disk medium or the magnetic head. The dust is generated inside the magnetic disk cartridge and enters from the outside. However, it is difficult to completely prevent the generation and entry of the dust.

In order to wipe off dust adhering to the magnetic disk medium, a liner made of nonwoven fabric or the like is provided on the inner surface of the case, and the liner is brought into contact with the surface of the magnetic disk medium by a lifter to wipe the surface of the magnetic disk medium. Has been done.

[0005]

In the magnetic disk cartridge, however, the rotation speed is increased in response to the increase in the recording capacity of the magnetic disk medium, and the stability of the driving torque and the torque capacity of the motor are ensured. From the viewpoint of suppressing the up, there is a tendency to reduce the contact with the liner. Along with this, the dust removal effect on the surface of the magnetic disk medium by the liner is reduced, and problems such as occurrence of dropout due to accumulation of dust attached to the magnetic disk medium in the head gap of the magnetic head become remarkable. Needed.

For example, in a large-capacity magnetic disk cartridge system to which the present invention is applied, a recording wavelength is short, and a magnetic disk medium is used for securing a transfer rate.
This method rotates at high speed, such as rpm, to reduce the contact load of the liner on the rotational torque and to reliably clean the surface of the magnetic disk media to prevent the dust from affecting the head gap. Need to be secured. On the other hand, in this large-capacity magnetic disk cartridge drive device, it is necessary to provide a low-speed rotation drive in order to enable recording / reproduction of a conventional magnetic disk cartridge having a lower recording capacity.
It is necessary that the drive motor supports a low-speed to a high-speed rotation and obtains a certain or more rotational torque. Further, this drive device needs to be compatible with a desktop personal computer to a light and thin notebook type personal computer, and the drive motor is required to be low power and thin, and it is difficult to obtain high rotational torque.

In consideration of the above, as described above, a large-capacity magnetic disk cartridge has a drive torque of the magnetic disk medium as small as possible, that is, an interference action with a component other than the magnetic head when the magnetic disk medium rotates at a high speed. It is required that there be as little as possible.

[0010] That is, dust removal of the magnetic disk medium by wiping by pressing the liner is effective in preventing dropout, but the conventional liner and lifter completely contact the magnetic disk medium with a loss torque. The driving torque is greatly increased and is not suitable for high-speed rotation during large-capacity recording / reproduction.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and provides a magnetic disk cartridge capable of improving reliability by obtaining a good cleaning action while minimizing an increase in drive torque of a magnetic disk medium. It is something you want to do.

[0010]

According to a magnetic disk cartridge of the present invention, which solves the above-mentioned problems, a disk-shaped magnetic disk medium is rotatably housed in a case formed by joining an upper shell and a lower shell, and the magnetic disk cartridge is provided with a magnetic disk. Liners are fixed to the inner surfaces of the upper shell and the lower shell facing the disk medium, and at least one pair of brush members is provided above and below the case facing the magnetic disk medium, at least over the recording area of the magnetic disk medium. It is characterized by the following.

It is preferable that the brush member is disposed at a position distant from the magnetic head insertion opening, for example, substantially on the opposite side of the rotation center with respect to the magnetic head insertion opening.

The above-mentioned "brush member" refers to a bristle member, a fiber member, a net member, or the like, whose tip or surface layer capable of contacting the surface of the magnetic disk medium has flexibility not to damage the surface of the magnetic disk medium. , And is not limited to a brush-like raised body or a flocked body, but generically includes a soft member that enables light contact.

For example, the brush member is formed of a brush-like body in which a root portion of a bristle member set in parallel is fixed to a rod-like holding member, and the brush member can be formed by attaching the holding member to a case. . Moreover, it is also possible to wind the outer periphery of the linear holding member (core member) with a raised fiber member. Further, it is also possible to use a material in which a fibrous material is planted on a linear holding member wound in a coil shape.
Further, it may be constituted by a fiber member wound in a coil shape.

The distance between the tips of the upper and lower brush members provided in pairs on the inner surface of the case, that is, the height of the space in which the magnetic disk medium rotates, is preferably 150 μm or more, and more preferably 200 μm or more. It is desirable that the height of the upper and lower brush members be the same.

[0015]

According to the present invention as described above, at least one pair of brush members is provided above and below the case facing the magnetic disk medium at least over the recording area of the magnetic disk medium. With the rotation of the magnetic disk medium, it comes into contact with dust adhering to its surface and gives initial movement energy, thereby making it easy to move, and thereafter, due to the centrifugal force and the outer peripheral direction accompanying the rotation of the magnetic disk medium. It can be removed from the surface of the magnetic disk medium by being moved by the heading air flow, and can provide a cleaning effect on the surface of the magnetic disk medium, such as dropout caused by dust adhering to the head gap of the magnetic head. Reliability can be improved without causing the problem. In addition, the contact of the brush member is partial and the contact resistance is small, and the increase in loss torque with respect to the rotation of the magnetic disk medium is reduced, so that high-speed rotation drive can be performed stably.

Further, when the brush member is disposed at a position distant from the magnetic head insertion slot, when the surface of the magnetic disk medium is deflected by contact with the brush member during rotation of the magnetic disk medium, the deviation is reduced by the magnetic head. This is favorable in that it is restored and flattened before rotating to the insertion opening and does not affect the positional relationship with the magnetic head.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 is an exploded perspective view of the upper and lower shells of a magnetic disk cartridge according to one embodiment.

In the magnetic disk cartridge, a flat case C (hard case) is formed by joining an upper shell 1 and a lower shell 2 formed of a synthetic resin such as acrylonitrile-butadiene-styrene copolymer. A disk-shaped magnetic disk medium 4 whose central portion is attached to and held by the center core member 3 is rotatably accommodated in C. An upper liner 5 and a lower liner 6 are provided above and below the magnetic disk medium 4.

The magnetic disk medium 4 has a disk-shaped base made of a flexible polyester sheet and the like, on both surfaces of which magnetic layers are formed, and is recorded in an annular shape excluding an outer peripheral portion and an inner peripheral portion. An area 4a is set, and the inner and outer edges of the recording area 4a are non-recording areas 4b. The rotational speed of the magnetic disk medium 4 is 3000 in the case of the 3.5-inch magnetic disk medium 4.
5000 rpm, for example, 3600 rpm.

The upper shell 1 and the lower shell 2 have a substantially rectangular flat shape, and have outer peripheral ribs 1 forming side walls on the outer periphery.
a, 2a are provided, and the inner rib 1
b, 2b, and a rectangular magnetic head insertion opening 10,
An opening 11 is formed in the center portion of the lower shell 2, and a circular spindle hole 2 c is formed in a size that the center core member 3 faces. Although not shown, a shutter member slidable in the left-right direction in the figure is assembled to open and close the magnetic head insertion openings 10 and 11 of the case C.

An annular projection 12 is provided at the center of the inner surface of the upper shell 1 at a position inward of the center core member 3. The movement of the medium 4 in the radial direction is restricted.

Further, on the inner surfaces of the upper shell 1 and the lower shell 2, an octagonal (or round) upper liner 5 and a lower liner 6 made of a nonwoven fabric sheet or the like are fixed by ultrasonic welding, bonding or the like. The inner ribs 1b and 2b are formed outside the liners 5 and 6 along the shape thereof. The upper liner 5 and the lower liner 6 have the same shape, and a portion overlapping the magnetic head insertion openings 10 and 11 is cut off. A circular hole slightly larger than the outer diameter of the annular projection 12 or the spindle hole 2c is also formed at the center. It is open.

The magnetic head insertion ports 10, 11
Away from the magnetic head insertion ports 10, 1
A brush member 7 is provided between the upper and lower liners 5, 6 and the magnetic disk medium 4 above and below the magnetic disk medium 4 at a position substantially opposite to the center of rotation with respect to the rotation center.
Are arranged in pairs at the same position on the upper and lower sides. The brush member 7 is formed substantially in the shape of a bar as a whole, and extends from at least the recording area 4a of the magnetic disk medium 4 (preferably, also over the non-recording area 4b) so as to extend in the radial direction from the center to the outer periphery. Shells 1 and 2 at both ends
Is fixed to the inner surface of the first member.

The brush member 7 is disposed at a position near the center of some of the inner ribs 1b and 2b, as shown by a chain line in the drawing, in the recording area 4a of the magnetic disk medium 4.
May be arranged in a substantially radial direction so as to cross the plane.

The liners 5 and 6 at the installation portion of the brush member 7 may be cut off, or one or more brush members 7 may be provided.

The brush member 7 is a bristle member, a fiber member or a net member whose tip or surface layer capable of contacting the surface of the magnetic disk medium 4 has flexibility not to damage the surface of the magnetic disk medium 4. And so on.

As shown in FIG. 2, a specific structure of the brush member 7 is such that a bristle member 7b is set in parallel with a slanted surface of a metal or plastic rod-like holding member 7a having a substantially triangular cross section. A root portion is fixed to the holding member 7a with an adhesive or the like and provided in a brush shape. Then, the holding member 7a is disposed at a predetermined position on the inner surface of the upper and lower shells 1 and 2, for example, both ends of the holding member 7a protruding in and out of the liners 5 and 6 are bonded to the shells 1 and 2, Attach by welding or the like.

The above-described brush member 7 is provided at the same position on the upper and lower surfaces and has the same height at the top and bottom in order to ensure stability so that surface runout and the like during rotation of the magnetic disk medium 4 do not occur. And

In particular, the height of the brush member 7 is set at one side from the rotation center in the thickness direction of the magnetic disk medium 4 so that the tip of the holding member 7a does not contact the surface of the rotating magnetic disk medium 4. It is desirable to provide a space of 75 μm or more (preferably 100 μm or more) between the tip of the shaped member 7b. Therefore, the interval between the upper and lower brush members 7 is 150 μm or more, preferably 200 μm.
m or more. If the distance is smaller than the above-mentioned distance, the holding member 7 for the magnetic disk medium 4 and the brush member 7
a may approach each other and come into direct contact with each other, which may damage the surface of the magnetic disk medium 4 during high-speed rotation. Then, the bristle member 7 of the brush member 7
The tip of b is provided to such an extent that it can lightly contact the surface of the rotating magnetic disk medium 4.

FIG. 3 shows a brush member 8 according to another embodiment. In the brush member 8, a brushed thread-like fiber member 8b is wound around the outer periphery of a linear metal or plastic rod-shaped holding member 8a (core member).

If the raised thread-like fiber member 8b has a certain degree of elasticity, the rod-like holding member 8b
The fiber member 8b may be wound directly into a coil without using a to form a brush member.

FIG. 4 shows a brush member 9 according to still another embodiment. The brush member 8 includes a metal or plastic linear holding member 9a wound in a coil shape.
A fibrous material 9b is provided on the outer periphery of the (core member) by implantation.

According to the magnetic disk cartridge as described above, when the magnetic disk medium 4 is rotationally driven by being inserted into the drive device, the upper and lower brush members 7, 8 or 9
Lightly contact the surface of the magnetic disk medium 4. The dust adhering to the surface of the magnetic disk medium 4 has a slight adhesive property, and the upper and lower brush members 7,
By contacting the dust 8 or 9 and giving the dust a moving energy exceeding its static adhesion, the dust starts to move and moves in the outer peripheral direction by the centrifugal force of the dust caused by the high-speed rotation of the magnetic disk medium 4. At the same time, the rotation of the magnetic disk medium 4 generates an air flow flowing outward on the surface thereof, the air flow also moves in the outer peripheral direction, floats, and is absorbed by the upper and lower liners 5 and 6. Or
Cleaning is performed while being removed from the outside of the recording area 4a, so that dust is prevented from entering the contact portion with the magnetic head so as not to cause dropout.

The contact between the brush member 7, 8 or 9 for the cleaning action and the surface of the magnetic disk medium 4 is not only a partial contact with the entire magnetic disk medium 4 but also a slight one. As a result, the drive loss of the rotational torque of the magnetic disk medium 4 is small, and the high-speed rotation of the magnetic disk medium 4 can be stably and reliably performed by a small drive motor. further,
By arranging the brush member 7, 8 or 9 at a position distant from the magnetic head insertion openings 10 and 11, the deviation due to the contact in the rotation of the magnetic disk medium 4 can be reduced.
It is restored and flattened before rotating to 0 and 11, and does not affect the positional relationship with the magnetic head, so that the reliability of recording and reproduction by high-density recording is improved.

The liners 5, 6 do not come into contact with the magnetic disk medium 4 in the rotating state and do not perform cleaning by wiping. It is installed to prevent direct contact with the inner surface of case C.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an upper and lower shell of a magnetic disk cartridge and a magnetic disk medium according to an embodiment of the present invention.

FIG. 2 is a perspective view showing one embodiment of a brush member.

FIG. 3 is a perspective view showing another embodiment of the brush member.

FIG. 4 is a perspective view showing still another embodiment of the brush member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper shell 2 Lower shell 2c Spindle hole C case 3 Center core member 4 Magnetic disk media 4a Recording area 4b Non-recording area 5,6 Liner 7-9 Brush member 10,11 Magnetic head insertion opening 12 Ring projection

Claims (2)

[Claims] 1. A disk-shaped magnetic disk medium is rotatably accommodated in a case formed by joining an upper shell and a lower shell, and the case has a magnetic head insertion opening, and the upper surface opposes the magnetic disk medium. In a magnetic disk cartridge having liners fixed to inner surfaces of a shell and a lower shell, at least one pair of brush members is provided above and below a case facing the magnetic disk medium, at least over a recording area of the magnetic disk medium. A magnetic disk cartridge characterized by the above-mentioned. 2. The apparatus according to claim 1, wherein the brush member is disposed at a position distant from the magnetic head insertion slot.
A magnetic disk cartridge according to claim 1.