JP2000298972A - Magnetic disk cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of the magnetic recording and reproducing performance by preventing deformation of a magnetic disk medium at the time of bringing the free end of a non-fixed part of a liner into contact with the medium to clean it. SOLUTION: A magnetic disk medium 4 like a disk is housed in a case C obtained by joining an upper shell 1 and a lower shell 2 so that this medium can be rotated; and when 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, non-fixed parts 5a and 6a as a part of these liners 5 and 6 are not fixed to inside surfaces of upper and lower shells 1 and 2, and their free ends are separated from inside surfaces of shells and are brought into contact with the surface of the magnetic disk medium, and lengths h1 and h2 on the outside peripheral side and the inner peripheral side of non-fixed parts 5a and 6a in the rotation direction of an arrow D of the magnetic disk medium 4 are made approximately equal to each other.

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.

However, in the magnetic disk cartridge, the rotation speed is increased in response to the increase in the recording capacity of the magnetic disk medium, and from the viewpoint of ensuring the stability of the driving torque and suppressing the increase in the torque capacity of the motor, It tends to reduce 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.

In view of the above, in a magnetic disk cartridge in which a magnetic disk medium is rotatably accommodated in a case, as described in Japanese Patent Application Laid-Open No. H11-45541, the magnetic disk medium is vertically opposed to the magnetic disk medium. A part of the liner that is fixed to the inner surface of the case is provided with a non-fixed region that is not fixed to the inner surface of the case, and the end of the non-fixed region is set as a free end and separated from the inner surface of the case with the rotation of the magnetic disk medium. There is known a technique in which the cleaning member is brought into contact with the cleaning member to perform cleaning.

[0007]

In the case where the free end of the non-fixed area of the liner is brought into contact with the magnetic disk medium as described above, if the contact of the liner is biased, the magnetic disk medium will not be fixed. A deviation may occur in the rotation, causing a problem in contact with the magnetic head in the magnetic recording / reproducing state.

[0008] Specifically, the contents of the prior art are shown in FIG. 4, in which the same reference numerals as those used in the embodiments of the present invention described later are used, and details of the embodiments will be described. Please refer to. In this magnetic disk cartridge, a liner 60 (same for the upper shell) disposed on the inner surface of the lower shell 2 has a fan-shaped non-fixed portion 60a on the opposite side to the magnetic head insertion opening 11 on the inner surface of the lower shell 2. The other fixed portion 60 b (cross-hatched area) is not fixed, and is fixed entirely to the inner surface of the lower shell 2. The non-fixed portion 60a is cut at the downstream side in the media rotation direction to be a free end, and the free end rises (hangs down in the upper shell liner) with the rotation of the magnetic disk medium. It is formed so that it can contact the surface.

However, since the non-fixed portion 60a is formed in a fan shape with both ends formed as line segments extending substantially in the radial direction from the rotation center, the length h1 of the outer peripheral portion with respect to the direction of media rotation has the inner peripheral portion. In the state of contact with the magnetic disk medium, the non-fixed portion 6 has a larger area on the outer peripheral side of the medium than on the inner peripheral side.
It comes into contact with 0a and hits hard. In particular, the pressing force of the upper liner is larger than that of the lower liner 60 due to its own weight, and the outer periphery of the magnetic disk medium is deviated downward, and the magnetic disk medium rotates in an umbrella-shaped state as a whole. The contact may not be balanced at the inner and outer peripheral portions, affecting the recording / reproducing characteristics in high-density recording, and possibly causing a head-media interface failure.

The non-fixed portion 60 of the liner 60
The linear velocity with respect to the rotation of the media at the free end of a is slow on the inner peripheral side and the cleaning effect is reduced, and it is desirable to improve the dust removing effect on the inner peripheral side. If you make contact in a large area,
The aforementioned head-media interface is similarly difficult to take.

The present invention has been made in view of the above points, and is intended to prevent the deformation of a magnetic disk medium and to improve the reliability of magnetic recording / reproducing performance for cleaning by contacting the free end of a non-fixed portion of a liner with the magnetic disk medium. It is intended to provide a magnetic disk cartridge with improved performance.

[0012]

A magnetic disk cartridge according to the present invention, which solves the above-mentioned problems, includes a disk-shaped magnetic disk medium rotatably housed in a case formed by joining an upper shell and a lower shell. Has a magnetic head insertion opening, the liner is fixed to the inner surface of the upper shell and the lower shell facing the magnetic disk medium except for the magnetic head insertion opening, respectively, the liner is partially upper shell and A free end is provided on the inner surface of the lower shell, and a downstream side of the non-fixed portion in the medium rotation direction is provided at a free end. The free end is provided so as to be separated from the inner surface of the shell and to be able to contact the surface of the magnetic disk medium. The length of the non-fixed portion with respect to the rotation direction of the media is provided so that the inner peripheral side and the outer peripheral side are substantially And it is characterized in Rukoto.

The non-fixed portion of the liner may be provided near the magnetic head insertion opening, or may be provided at a position substantially opposite to the opening and the center of rotation.

The liner may be separated into a portion fixed to the inner surface of the shell and a non-fixed portion, and the fixed portion and the non-fixed portion may be made of different materials.

[0015]

According to the present invention as described above, a part of the liner is not fixed to the shell, and the free end is provided so as to be separated from the inner surface of the shell and to be able to contact the magnetic disk medium. By providing the length of the non-fixed portion to be substantially equal on the inner circumference side and the outer circumference side, the inner circumference side and the outer circumference side of the magnetic disk medium come into contact with substantially equal length and area, While ensuring a good cleaning action, the deviation of the inner and outer peripheries of the magnetic disk medium caused by the contact of the non-fixed portion of the liner is reduced, and the magnetic head can be contacted with the magnetic head in a good state, and the head-media interface failure can be prevented. Occurrence can be avoided and the reliability of the magnetic recording / reproducing performance can be improved.

[0016]

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 an acrylonitrile-butadiene-styrene copolymer. A disk-shaped magnetic disk medium 4 (recording medium) 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 or the like, and magnetic layers are formed on both sides of the disk-shaped base. The recording area 4a has an annular shape excluding an outer peripheral portion and an inner peripheral portion. Is set, and the inner and outer edges of the recording area 4a are non-recording areas 4b. The number of rotations of the magnetic disk medium 4 in the rotation direction D is
In the case of 3.5 inch size, 3000-5000 rpm,
For example, 3600 rpm.

The upper shell 1 and the lower shell 2 have a substantially rectangular flat shape, and outer peripheral ribs 1a and 2a forming side walls are provided on the outer periphery, and the inner rib 1 is substantially obliquely formed at a corner portion.
b, 2b, and a rectangular magnetic head insertion opening 1
The center portion of the lower shell 2 is provided with a circular spindle hole 2 c having a size facing the center core member 3. 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 projects from the center of the inner surface of the upper shell 1 at a position inside the center core member 3. The movement of the medium 4 in the radial direction is restricted.

On the flat inner surfaces of the upper shell 1 and the lower shell 2, an upper liner 5 and a lower liner 6, which are formed by cutting a nonwoven fabric sheet into a substantially octagonal shape (or a round shape), are subjected to ultrasonic welding, bonding, etc. The inner ribs 1b, 2b are formed on the outside along the shape of the liners 5, 6. The upper liner 5 and the lower liner 6 have the same shape, and the magnetic head insertion opening openings 10, 1 are formed.
The portion overlapping 1 is cut away, and a circular hole larger than the outer diameter of the annular projection 12 or the spindle hole 2c is also opened at the center.

The liners 5 and 6 have non-fixed portions 5a and 6a in the vicinity of the magnetic head insertion openings 10 and 11 corresponding to the upstream side in the medium rotation direction D.
Non-fixed to the inner surfaces of the upper shell 1 and the lower shell 2, the entire surface of the fixed portions 5b and 6b (cross-hatched areas) except for the non-fixed portions 5a and 6a uses, for example, a welding horn (not shown). Upper and lower shells 1, 2 by ultrasonic welding
It is fixed to the inner surface of. The tip surface of the welding horn has the same shape as the fixed portions 5b and 6b of the liners 5 and 6, and a welding pattern (welding line) is formed on the entire surface of the tip surface by an uneven shape.

Examples of welding patterns include liners 5 and 6
The edge corresponding to the non-recording area 4b of the magnetic disk medium 4 along the outer shape and the removed inner shape of the magnetic disk medium 4 is fixed by a short radially-welded welding line with a dense pitch, and the inside corresponding to the recording area 4a is striped. And fixed by a parallel vertical welding line (may be a broken line). In addition, the stripe shape may be a horizontal line or an oblique line.
It may be formed in a grid shape in which a vertical line and a horizontal line formed by a continuous line or a broken line intersect, a radiation shape formed by a short radiation line, or the like, and the design may be changed as appropriate.

Non-fixed portions 5a, 6 of the liners 5, 6
a is that the length h1 on the outer circumference side and the length h2 on the inner circumference side in the rotation direction D of the magnetic disk medium 4 are substantially equal (h
1 ≒ h2). That is, the free ends and the fixed ends of the non-fixed portions 5a and 6a are formed so as to be substantially parallel. At this time, either the free end or the fixed end is a line segment passing through the center of rotation, or the magnetic head insertion opening 1
It may be parallel to the sides of 0,11.

In the state of use of the assembled magnetic disk cartridge, as shown in FIG. 2, the non-fixed portions 5a and 6a of the liners 5 and 6 are caused by the air flow generated by the high-speed rotation of the magnetic disk medium 4. The free ends near the magnetic head insertion openings 10 and 11 are separated from the inner surfaces of the upper and lower shells 1 and 2, that is, the upper liner 5 hangs down, the lower liner 6 lifts up, and the inner and outer circumferences have substantially the same length and area. Cleaning is performed by lightly contacting the surface of the magnetic disk medium 4.

In this embodiment, the non-fixed portions 5a, 6
By providing a in the vicinity of the upstream side of the magnetic head insertion openings 10 and 11 in the medium rotation direction D, dust can be removed immediately before the magnetic head, which is effective in preventing dropout.

FIG. 3 shows another embodiment, in which the lower shell 2
, But the same applies to the upper shell 1. In this example, the non-fixed portions 5 of the upper and lower liners 5, 6
a, 6a with respect to the center of rotation the magnetic head insertion opening 1
This is an example in which it is arranged in a portion substantially opposite to 0 and 11.

The liner 6 is divided into right and left portions substantially opposite to the magnetic head insertion opening 11, and the downstream end region of the divided portion of the liner 6 on the upstream side in the rotation direction D of the magnetic disk medium 4 is the lower shell. 2 is provided on a non-fixed portion 6 a that is not fixed to the inner surface of the lower shell 2, and the entire surface of the other fixed portion 6 b (cross-hatched area) is fixed to the inner surface of the lower shell 2.

The non-fixed portion 6a has a length h1 on the outer peripheral side with respect to the rotation direction D of the magnetic disk medium 4.
The free end and the fixed end of the non-fixed portion 6a are formed substantially parallel so that the inner peripheral length h2 of the non-fixed portion 6a is substantially equal (h1 ≒ h2). At this time, one of the free end and the fixed end may be a line segment passing through the center of rotation, or may be parallel to the dividing line of the liner 6.

In this embodiment, the non-fixed portions 5a, 6
a is provided at a position distant from the magnetic head insertion openings 10 and 11, even if the magnetic disk medium 4 slightly shifts due to contact with the non-fixed portions 5a and 6a, the magnetic head insertion opening is provided. Restoration and flattening during rotation to the portions 10 and 11 is advantageous in securing the positional relationship with the magnetic head.

The non-fixed portions 5a and 6a of the liners 5 and 6 in both embodiments are provided on the upper and lower surfaces in order to secure stability so that the magnetic disk medium 4 does not oscillate during rotation. It is desirable to provide the same shape at the same position. The floating or hanging height of the non-fixed portions 5a, 6a is set to such a degree as to make light contact with the surface of the rotating magnetic disk medium 4, so as to avoid dusting action by securing a contact area and avoid excessive contact. The drive resistance should be reduced.

The non-fixed portions 5 of the liners 5 and 6
At least the cutting edges on the outer periphery of the a and 6a may be subjected to a fiber fixing treatment for suppressing fluffing and falling off of the fibers.
This fiber fixing treatment is performed by applying an adhesive and drying to fix the fibers, or by heating the heat-meltable fibers to thermally fuse the fibers. Further, a chemical dust treatment may be applied to the fiber fixing portion to enhance the dust adsorbing property. Further, the fiber fixing treatment is preferably performed on at least the outer peripheral cutting edge of at least the portion of the non-fixed portions 5a and 6a that contact the magnetic disk medium 4, and the portion that does not contact the magnetic disk medium 4 is processed. It is not necessary. Further, the processing may be performed on the entire periphery of the outer peripheral cut portions of the liners 5 and 6.

On the other hand, the liners 5 and 6 are shells 1 and
2 Fixed portions 5b, 6b fixed to the inner surface and non-fixed portion 5
a, 6a may be separated from each other, and the fixed portions 5b, 6
b and the non-fixed portions 5a and 6a may be made of different materials.

According to the magnetic disk cartridge as described above, when the magnetic disk medium 4 is inserted into the drive device and driven to rotate, the upper and lower liners 5, 6 are not fixed by the airflow generated by the high-speed rotation. Parts 5a, 6
The free end of “a” is separated from the inner surfaces of the upper and lower shells 1 and 2 and lightly contacts the surface of the magnetic disk medium 4 with a substantially uniform length and area on the inner and outer circumferences. The dust adhering to the surface of the magnetic disk medium 4 has a slight adhesive property, and the upper and lower non-fixed portions 5a, 6a come into contact with each other to collect the dust on the liners 5, 6, or to collect the dust. Even if the dust is not applied, the dust is given a movement energy exceeding its static adhesive force, so that the dust moves in the outer peripheral direction due to the centrifugal force of the dust accompanying the high-speed rotation of the magnetic disk medium 4 and the rotation of the magnetic disk medium 4 As a result, an airflow flowing outward is generated on the surface of the recording medium, and the airflow also moves in the outer peripheral direction by this airflow, is removed to the outside of the recording area 4a to perform cleaning, and dust comes in contact with the magnetic head. Prevent intrusion into the area to avoid dropouts.

The contact between the non-fixed portions 5a, 6a for the cleaning action and the surface of the magnetic disk medium 4 is a partial contact with the entire magnetic disk medium 4, and the free end is lifted or hangs down. The drive torque of the magnetic disk medium 4 due to the contact is small, the driving loss of the rotational torque of the magnetic disk medium 4 is small, and the high-speed rotation of the magnetic disk medium 4 is stably and reliably performed by a small drive motor. Can be performed.

[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 sectional view of a main part of the magnetic disk cartridge of FIG. 1;

FIG. 3 is a perspective view of a lower shell of a magnetic disk cartridge according to another embodiment.

FIG. 4 is a perspective view of a lower shell of a conventional magnetic disk cartridge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper shell 2 Lower shell C case 3 Center core member 4 Magnetic disk medium 4a Recording area 5,6 Liner 5a, 6a Non-fixed part 5b, 6b Fixed part 10,11 Opening for magnetic head insertion

Claims (1)

[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 an opening for inserting a magnetic head and faces the magnetic disk medium. A magnetic disk cartridge in which a liner is fixed to an inner surface of a portion of the upper shell and the lower shell other than the opening for inserting the magnetic head, wherein the liner is partially fixed to the inner surfaces of the upper shell and the lower shell. The free end is provided at the downstream end of the portion with respect to the media rotation direction, and the free end is provided so as to be separated from the inner surface of the shell and contact the surface of the magnetic disk medium, and the length of the non-fixed portion with respect to the rotation direction of the magnetic disk medium is reduced. A magnetic disk cartridge provided to be substantially equal on an inner peripheral side and an outer peripheral side.