JPH0326471B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic disk jacket which is free from deformation due to welding and does not damage the external appearance, and which allows the magnetic head to touch stably.

In order to protect both the front and back surfaces of the magnetic disk housed in the magnetic disk jacket, and to provide the magnetic disk with low friction characteristics and contaminant scavenging characteristics, a cleaning sheet 8 made of non-woven fabric or the like as shown in FIG. 5 is used. However, magnetic disk jacket sheet 9
These sheets 8 and 9 are arranged in a laminated manner, and both sheets 8 and 9 have a plurality of fusion lines x ₁ to 1 formed at predetermined intervals.
The cleaning sheet ₈ is locally fused to the jacket sheet 9 so as not to be displaced from the jacket sheet 9 by rotation of the magnetic disk.

By the way, since the means for fixing the cleaning sheet 8 to the jacket sheet 9 using the plurality of fusion lines _x1 to _xo has a large fusion area,
Due to the difference in shrinkage rate between the jacket sheet 9 and the cleaning sheet 8, the above-mentioned fusion lines x ₁ to x _o stand out on the surface of the jacket sheet 9, making the jacket surface uneven and spoiling its appearance. In addition, there are drawbacks such as warping and fusion deformation occurring during jacket molding, making the touch of the magnetic head unstable and resulting in a decrease in output.

The object of the present invention is to eliminate the above-mentioned drawbacks and provide a magnetic disk jacket which is free from fusion deformation, does not impair its appearance, and in which a cleaning sheet is properly fixed to a jacket sheet. shall be.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a magnetic disk jacket sheet made of thermoplastic synthetic resin, and a cleaning sheet 2 made of nonwoven fabric or the like is laminated on the inner surface of the sheet. This cleaning sheet 2 is used to protect both the front and back surfaces of a magnetic disk (not shown) and to impart low friction characteristics, contaminant collection characteristics, etc. to the magnetic disk.

The magnetic disk jacket sheet 1 and the cleaning sheet 2 are fixed by spot welding a ₁ to a _o on the entire surface of the laminated portion in a rectangular pattern such as a square.

In order to prevent fusion deformation and to properly adhere the cleaning sheet to the magnetic disk jacket sheet 1, the diameter of each of the point fusions _a1 to _ao is set in the range of 0.05mm to 1.5mm. It is desirable to do so. Furthermore, for a rectangular pattern, the pitch P between each point fusion a ₁ to a _o is 1 mm as shown in Figure 2.
~10 mm, preferably a rectangular (square in the example) pattern, and its diagonal line A is a straight line in the longitudinal direction of the magnetic disk jacket sheet 1 (for example, the center line C in the longitudinal direction). )
It is recommended that the diagonal line B be arranged parallel to the straight line in the width direction (for example, the folding line D). When the diagonal lines A of the rectangular pattern are arranged parallel to the straight line in the longitudinal direction of the magnetic disk jacket sheet 1, the bending strength when the longitudinal direction of the magnetic disk jacket sheet 1 is taken as the folding line is It is larger than other arrangement patterns, and if the diagonal line B of the directional pattern is arranged parallel to the straight line in the width direction of the magnetic disk jacket sheet, the bending strength of the magnetic disk jacket sheet is improved. can do.

Diagonal lines A and B parallel to both the longitudinal and width directions of the magnetic disk jacket sheet 1
Although a rectangular pattern with one of these diagonals A and B is recommended, a rectangular pattern with one of these diagonals A and B is also effective.

Note that 11 is a welding margin when the sheet 1 is folded back to form a jacket.

In the above configuration, the jacket sheet 1 and the cleaning sheet 2 are bonded to each other by small point welding with a diameter of 0.05 mm to 1.5 mm at a predetermined interval, that is, a pitch of 1 mm to 10 mm, over the entire surface of the laminated portion. This means that the entire surface of the laminated portion is uniformly fused, and the fused area is limited to the minimum area necessary to properly fix both sheets 1 and 2. Therefore, the above point fusion a ₁ ~ _{a o}
The jacket does not stand out on the surface of the jacket sheet 1, and therefore the jacket surface does not become uneven and spoil its appearance as in the conventional case. Also,
Since the jacket sheet 1 does not undergo warping, that is, fusion deformation, even if it is used after the jacket is formed, the touch of the magnetic head will be stable and no reduction in output will occur.

Furthermore, since the diagonals A and B of the rectangular pattern are arranged parallel to the center line C and the folding line D, the vicinity of the folding line D is point-fused in a state clearly shown in FIG. This means that each side E of the rectangular pattern is connected to the center line C and the fold line D as shown in FIG.
The distance l when the point welded portion is farthest from the bending line D is smaller in the case shown in FIG. 3 than in the case where the points are arranged parallel to each other. Therefore, when a jacket is formed by folding the jacket sheet 1 and the cleaning sheet 2 inward along the folding line D, that is, in the direction in which the cleaning sheets 2 face each other, the cleaning sheet 2 may become loose near the folding line. This has the advantage that when the magnetic disk rotates, it can be brought into proper sliding contact with the peripheral edge of the magnetic disk.

[Brief explanation of the drawing]

Fig. 1 is a developed view of a magnetic disk jacket sheet and a cleaning sheet to which the present invention is applied, Fig. 2 is an explanatory diagram showing an enlarged point welding portion, and Figs. 3 and 4 are point welding parts. A comparative explanatory diagram of patterns, FIG. 5 is a developed diagram showing a conventional fused state. 1... Sheet for magnetic disk jacket, 2...
...Cleaning sheet, a ₁ ~ _{a o} ... point fusion.

Claims (1)

[Claims] 1. Point fusion bonding of magnetic disk jacket sheet 1 and cleaning sheet 2 in a rectangular pattern a ₁
~a _o In a magnetic disk jacket,
A magnetic disk jacket characterized in that the rectangular pattern is arranged with its diagonal line A parallel to a straight line in the longitudinal direction of the magnetic disk jacket. 2. The rectangular pattern is characterized in that diagonal lines A and B that intersect with each other are arranged parallel to a straight line in the longitudinal direction of the magnetic disk jacket and a straight line in the width direction of the magnetic disk jacket. The magnetic disk jacket according to item 1. 2. The magnetic disk jacket according to claim 1, wherein the three point welds a ₁ to a _o are point welds having a diameter of 0.05 to 1.5 mm. 4. The magnetic disk jacket according to claim 1, wherein the rectangular pattern has a pitch P between point welds of 1 to 10 mm.