JPH02223081A - Shell for magnetic disk - Google Patents

Abstract

PURPOSE:To attain smooth rotation even when a magnetic sheet is charged and to eliminate static electricity by providing an area having minute projection to the surface in the shell opposite to the recording face of the magnetic disk. CONSTITUTION:An area (mat face) 104 having minute projections is formed to an inner surface 103 of an upper shell 102 opposite to a nonrecording face of a magnetic disk 13. Thus, the magnetic disk 13 is charged and even when the magnetic disk 13 is in contact with the inner surface 103 of the upper shell 102, the disk is in press contact onto the tip of the projection of the mat face 104 to form a point to point contact, the sliding resistance is reduced and the charge is discharged. Thus, the charge of the magnetic disk is considerably reduced and smooth rotation is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a magnetic disk shell for housing a flexible magnetic disk such as a small floppy disk or video floppy disk.

<Prior art> Magnetic disks used as magnetic recording media are made of synthetic m
Because it is made by coating a magnetic material on a thin disk-shaped base material made of fat, it is easily bent, and if dust adheres to the surface, it will cause dropouts and other problems that will interfere with recording and playback. It is handled in the form of a magnetic sheet pack housed within a disk shell, and is used, for example, for shooting and playing back still videos.

FIG. 7 is a partially cutaway perspective view of this magnetic rate pack. As shown in FIG. 7, the magnetic sheet pack 11 is a rectangular box-shaped magnetic disk shell (hereinafter referred to as "shell").

) 12 in which a magnetic disk 13 is rotatably housed. A center core 14 is provided at the center of the magnetic disk 13 as a member for engaging with a spindle of a recording/reproducing device, and the center core 14 is exposed to the outside through a central opening 15 of the shell 12. Also,
The shell 12 has a window 16 through which a part of the magnetic disk 13 faces.
is opened, and this window portion 16 is opened and closed by a slidable shutter 17.

Here, the shell 12 is a rectangular upper shell 12a and a lower shell 12 molded from synthetic resin such as ABS wood [%].
It is manufactured by overlapping and fixing each other.

An ultrasonic welding method is used to fix the upper and lower shells 12a, 12b.

<Problems to be Solved by the Invention> In recent years, for example, floppy disks such as video discs that are smaller, thinner, and use coated media for high-density recording have been made with magnetic materials in order to ensure high output. The mixing of non-magnetic substances (for example, binder, lubricant, carbon) in the layer is avoided as much as possible. For this reason, especially when the amount of carbon is small, the surface electrical resistance of the medium increases, and as a result, there is an rRM in which the magnetic disk 13 itself becomes electrically charged.

This charging causes the magnetic disk 13 to come into contact with the smooth inner surface of the shell, increasing the rotational load torque, causing problems such as screen tilt and jitter in the case of a video camera, for example.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a shell for a magnetic disk that can rotate smoothly even when the magnetic sheet is not charged and can eliminate static electricity.

<! Means for Solving III> The structure of the first magnetic disk shell according to the present invention for achieving the above object is a magnetic disk shell that can rotatably accommodate a magnetic disk, and at least the above-mentioned magnetic disk. The inner surface of the shell opposite to the recording surface is provided with a region having a minute convex portion, and the structure of the second magnetic disk shell is such that the magnetic disk is rotatably housed therein. The shell for a magnetic disk is characterized in that a region having minute convex portions is provided at least on the inner surface of the shell facing the non-recording surface region on the recording surface side of the magnetic disk.

Even if static electricity is generated when the magnetic disk rotates and the magnetic disk is charged, the apex portion of the convex portion in the area having minute convex portions comes into contact with the magnetic disk. ,
Since it is in a point contact state, the sliding resistance is small. Furthermore, when the minute convex portions come into contact with the magnetic disk, static electricity is removed, the amount of static electricity is reduced, and smooth rotation can be maintained.

Embodiment Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

FIGS. 1(a) and 1(b) relate to this embodiment. FIG. 1A is an exploded view of a shell for an AIX disk; FIG. 1A shows a lower shell, and FIG. 1B shows an upper shell.

As shown in these drawings, a magnetic disk shell (hereinafter referred to as "shell") 100A is a lower shell 10.
The lower shell 101 and the upper shell 102 are superposed and fixed to each other to protect the magnetic disk 13. Note that 16 indicates a window portion.

In this embodiment, a shell for a magnetic disk used for single-sided recording still and video will be explained as an example. 1st
As shown in Figure (b), on the inner surface 103 of the upper shell 102 facing the non-recorded surface Ia side of the magnetic disk 13, regions 103 having minute convex portions are arranged half the circumference of the inner surface 1030.
4 are provided. An enlarged sectional view of the region 104 having minute convex portions (hereinafter referred to as "matte surface") is shown in FIG. A plurality of protrusions 104a are provided, and the tips of the protrusions 104a are at an acute angle.In this embodiment, the height d of the protrusions 104a is
was set to 20 μm. In order to tilt the plurality of convex portions 104a, it is sufficient to process a shell molding die in advance and form them integrally when molding the upper shell 102.

On the other hand, as shown in FIG. 1(a), the magnetic disk 13
A liner 106 made of, for example, nonwoven fabric is placed on the inner surface 105 of the lower shell 101 facing the recording surface side of the inner surface 105.
They are arranged half-circumferentially. This line 1106
is provided for cleaning and protecting the recording surface of the magnetic disk 13 and reducing sliding resistance, and is pasted over half the circumference of the inner surface 105 of the lower shell 101 by, for example, a method such as heat fusion. It's attached.

As described above, in this embodiment, the liner 106 is attached to the inner surface 105 of the downward L 101 facing the recording surface of the magnetic disk 13, and the inner surface of the upper shell 102 facing the non-recording surface of the magnetic disk 13 is attached. By forming a matte surface 104 on the magnetic disk 103,
Even if the V & magnetic disk 13 comes into contact with the inner surface 103 of the upper shell 102 due to charging occurring on the inner surface 103 of the upper shell 102, the tip of the convex portion 104a of the matte surface 104 provided on the inner surface 103 of the upper shell 102 This means that there is only a point contact, so the sliding resistance is small and the increase in rotational load torque is small.

Further, when the acute-angled tips of the plurality of convex portions 104a of the matte surface 104 come into contact with the magnetic disk, static electricity is removed, the amount of charge on the magnetic disk is significantly reduced, and the normal rotational state is quickly restored. , and there is no screen distortion or jitter.

Here, the above-mentioned matte surface may be any surface having a plurality of minute protrusions with acute angles on a smooth surface (a mat having the cross-sectional shape shown in FIG. 6(a) described above). In addition to the surface 104, for example, as shown in FIG.
The matte surface 104C may be formed continuously.

The height d from the top of the convex portion 104a of the matte surface 104 to the bottom surface in FIG. 6(a) is approximately 10 μm to 500 μm.
It is good to do this.

Also, in this example, it is called a matte surface, but in addition to this,
It is sometimes referred to as a so-called "pear-skinned surface" that has a rough texture. In order to perform such processing, in addition to the above-mentioned integral molding, a sandblasting method or a knurling method can also be used. Note that ribs may be formed in a mesh shape on the surface of the shell.

Next, another embodiment is shown in FIG. 2 (al, (b)) and FIG. 3 (al, (b)).

Incidentally, the same members as those in the above-mentioned embodiment are given the same reference numerals and redundant explanations will be omitted.

First, as shown in FIG. 2(a), the shell 1 of this embodiment is
In the descending L 101 of 00B, a liner 106 is provided over almost the entire circumference of the portion facing the recording surface of the magnetic disk.

In addition, as shown in FIG.
A matte surface 104 facing the outer periphery of the magnetic disk
is formed.

Further, in the embodiment described above, only the liner 106 is provided on the inner surface of the lower shell that faces the recording surface of the magnetic disk, but in the embodiment shown in FIG.
Both a semicircular liner 106 and a fan-shaped matte surface 104 are provided on the inner surface IQ5 of the lower shell 101 of the shell 100C to clean the magnetic disk and reduce sliding resistance. As shown in FIG. 3(b), the upper shell 102 of the shell 100C according to this embodiment is provided with a matte surface 104 on the inner surface of the upper shell 102 facing the entire magnetic disk, which further reduces sliding resistance. We are trying to eliminate static electricity.

Next, a preferred embodiment of the magnetic disk shell according to the second aspect of the present invention will be described with reference to FIGS. Duplicate explanations will be omitted.

As shown in FIG. 4(a), the shell 10 according to this embodiment
On the inner back m 105 of the lower shell 101 of 0D, a liner 1 is provided in a part thereof at a position facing the recording of the magnetic disk 13.
06 is provided, and the non-recording surface area on the recording surface side of the magnetic disk 13 (for example, in the case of a video recorder, an arcuate and strip-shaped area is provided over a position facing from 21 m to 23.5 m from the center of the magnetic disk 13). A matte surface 104 is integrally formed.

Further, as shown in FIG. 4(b), three fan-shaped matte surfaces 104 are formed on the inner surface 103 of the upper shell 102 of the shell 100D according to this embodiment.

By forming such a shell 100D, even when the magnetic sheet 13 is charged and comes into contact with the inner surface on the recording surface side, smooth rotation is possible and a static elimination effect can be obtained.

Furthermore, by reducing the area of the liner 106, costs can be reduced.

Furthermore, in this embodiment, since the matte surface 104 is formed in the area facing the non-recording surface of the magnetic disk 13, there is no risk of scratching the recording surface of the magnetic disk 13.

The shell 100D shown in FIG. 4 is for a magnetic disk for single-sided recording, but the shell 100E used for a magnetic disk for double-sided recording is shown in the following FIG.
An example is shown.

In the shell 100E of this embodiment, the downward L 101
is the same as FIG. 4 [al] described above. Also, Figure 5 (
The inner surface of the upper shell 102 shown in FIG.
Similar to the lower shell 101 shown in FIG. 1, arcuate and belt-shaped matte surfaces 104 are integrally formed at positions facing the non-recording area.

In this way, the same shape Nomat surface 10 is placed on the inner surface of the shell.
4 and the liner 106, even if a magnetic disk for double-sided recording is charged during use, it can rotate smoothly without scratching the recording surface, and can be defrosted quickly.

<Effects of the Invention> As described above in detail along with the examples, the magnetic disk shell of the present invention has a so-called matte surface, which is a region having minute convex portions on the inner surface of the shell, so that the H1 disk is not charged. Even if this occurs, the sliding resistance is small and the increase in rotational torque is also small. Further, when the magnetic disk comes into contact with the matte surface, the static electricity is immediately removed, and the strip of the magnetic disk is removed!
The fish are not big.

[Brief explanation of the drawing]

1 to 5 are exploded views of a magnetic disk shell according to a preferred embodiment of the present invention, No. 6r! A(a) to (cl) are respectively enlarged sectional views of the matte surfaces, and FIG. 7 is a partially cutaway perspective view of the magnetic rate pack. In the drawings, 13 is a magnetic sheet, and 100A to 100E are for magnetic disks Shell, 1 is a lower shell, 2 is an upper shell, 3 is an inner surface of the upper shell, 4 is a region having minute convex portions, 5 is an inner surface of the lower shell, and 6 is a liner.Patent applicant Fuji Photographic Film Co., Ltd. Fuji Magnedisc Co., Ltd. Agent

Claims (1)

[Scope of Claims] 1) A magnetic disk shell in which a magnetic disk is rotatably housed, the shell having a region having minute convex portions at least on the inner surface of the shell opposite to the recording surface of the magnetic disk. A shell for magnetic disks that is characterized by the following characteristics: 2) A shell for a magnetic disk in which a magnetic disk is rotatably housed, wherein an area having minute convex portions is provided at least on the inner surface of the shell facing the non-recording surface area on the recording side of the magnetic disk. A magnetic disk shell characterized by: