JPH0472314B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disk cartridge characterized by a liner that is attached to the inner surface of a disk case and comes into contact with the disk surface.

[Conventional technology]

As this type of liner, a nonwoven fabric made of entangled rayon and polypropylene (for example, NOVONETTE9302 manufactured by Kendall, USA, JB-3 manufactured by Mitsubishi Rayon, etc.) has conventionally been used.
Among them, a nonwoven fabric liner in which thin synthetic resin fibers and thick synthetic resin fibers are inseparably intertwined is known, for example, from Japanese Utility Model Application Publication No. 162583/1983.

[Problem to be solved by the invention]

However, with recent high-density recording type disk cartridges, microscopic dust adhering to the disk surface becomes a problem, but the fibers that make up the conventional liner are thin, at most, about 1.5 denier, and microscopic dust adheres to the disk surface. Dust (e.g. particle size 2μ
I couldn't finish up to m). Therefore, the cleaning performance of the disk surface was poor, which caused dropouts.

Therefore, an object of the present invention is to provide a disk cartridge equipped with a liner that can effectively remove even microscopic dust from the disk surface and has excellent cleaning performance.

Another object of the present invention is to provide a disk cartridge in which the disk case is constructed in the form of a flat hard case, in which upper and lower plastic cases are integrally joined together with lids, and a liner affixed to the inside of the disk case is provided. It is hoped that this will also improve the cleaning performance of the disk surface by bringing it into effective contact with the disk surface.

[Means to solve the problem]

The present invention provides a disk case 11 with a disk 12.
In the disk cartridge, the disk case 11 has a rotatable interior and a liner 1 that contacts the disk surface is attached to the inner surface of the disk case 11. The disk case 11 has a rib 32 protruding from the inner surface of the disk case 11 at a position facing the disk 12.
The requirements are that a liner 1 is disposed on top, and that the surface of the liner 1 is made of ultrafine synthetic resin fibers 2 of 0.05 to 0.3 denier.

Here, acrylic fiber is a typical example of the ultra-fine synthetic resin fiber 2;
If the thickness is less than 0.05 denier, it will be easily worn out due to intense sliding contact with the disk, and if the thickness exceeds 0.3 denier, it will not be sufficient to capture microscopic dust. Therefore, ultrafine synthetic resin fiber 2
The thickness shall be 0.05 to 0.3 denier.

〔Effect of the invention〕

According to the present invention, the surface of the liner 1 is 0.05
Since it is made of ultra-fine synthetic resin fibers 2 of ~0.3 denier, it can reliably remove even microscopic dust from the disk surface without being worn out, dramatically improving the cleaning performance of the disk surface over the long term. .

The disk case 11 of the present invention is a hard case type in which upper and lower plastic cases 1a and 1b are integrally joined with lids.
The liner 1 is placed on a rib 32 protruding from the inner surface of the liner 1.
are arranged, the liner surface contacts the disk surface locally and reliably through the ribs 32, and since the contact is local, the disk 12
It also does not increase the rotational torque of the motor. Therefore, even in these high-density recording disk cartridges, the occurrence of dropouts can be effectively prevented over a long period of time.

〔Example〕

Next, the specific structure of the liner used in the present invention will be explained based on the drawings. FIG. 1 is a schematic longitudinal sectional view;
FIG. 2 is a photograph of the surface of the actual product taken using an electron microscope, and FIG. 3 is a photograph showing the cut end surface in the longitudinal direction.

In FIG. 1, a liner 1 includes ultrafine acrylic short fibers 2 of 0.05 to 0.3 denier and 1 to 5 mm in length, which are intertwined with each other to form the front and back surfaces.
10 to 3 polyester long fibers of 0.5 to 5 denier
It is made up of 50 bundles of nonwoven fabric, and has a cross-sectional structure in which a bundle 4 of polyester long fibers 3 runs vertically and horizontally in the plane direction between two groups of acrylic short fibers and is intertwined with the acrylic short fibers 2 inseparably. .

According to this nonwoven fabric liner 1, since there is a sheet layer in which the polyester long fibers 3 are gathered in the middle in the thickness direction, the shrinkage force of the polyester long fibers 3 prevents the acrylic short fibers 2 from falling off during heat processing and finishing. Therefore, there is no problem even if the thickness of the liner 1 is set to 0.3 mm or more, and this gives the liner 1 rich elasticity and reduces the contact pressure against the disk surface, which is the reason why cleaning performance can be improved. ing.

On the surface of the nonwoven fabric liner 1, ultrafine short acrylic fibers 2 are densely grown like wool, and these short acrylic fibers 2 pick up microscopic dust on the disk surface. The polyester long fibers 3 prevent the acrylic short fibers 2 from falling off from the cut surface or surface of the nonwoven fabric, and provide mechanical strength to the liner 1. Therefore,
The fiber composition ratio of the nonwoven fabric liner 1 is such that both the acrylic short fibers 2 and the polyester long fibers 3 are at least
It is necessary that the ratio is 20% or more, and it is preferable that these ratios are approximately the same.

Uniformly impregnating this nonwoven fabric liner 1 with an elastic binder such as urethane resin is more effective in preventing fibers from falling off, and the abrasion resistance of the surface is also improved. However, if the amount of urethane resin mixed is too large, the fluffing of the acrylic short fibers 2 on the surface of the liner will be reduced and the cleaning performance will be adversely affected, so it is preferably in the range of 2 to 20% by weight.

Furthermore, the surface of the liner is impregnated with a lubricant in order to reduce the rotational torque of the disk and improve the durability of the disk and especially the liner 1 itself. Examples of this lubricant include silicone oil, hydrocarbons such as liquid varaffin and squalane, fatty acids such as oleic acid, fatty acid esters such as oleyl oleate and butyl stearate, and fluorine oils (KRYTOX143CZ from Dupont and Daifloil from Daikin Industries, etc.). At least one type selected from Preferably, this lubricant is used in a proportion of 0.1-10%.

Next, some specific examples of disk cartridges to which the present invention is directed will be explained based on the drawings.

The disk cartridge shown in FIGS. 4 to 8 has upper and lower plastic cases 11a and 11.
A flat rectangular hard case-type disk case 11 formed by combining the lids b into one body by ultrasonic welding at several points P, and this disk case 1.
1 and a magnetic disk 12 rotatably housed inside.

This disk case 11 has a drive shaft insertion window 13 located approximately in the center, a magnetic head insertion window 14 located in front of the drive shaft insertion window 13 and long from front to back, and a small diameter magnetic head insertion window 14 located at the rear of the drive shaft insertion window 13. The index hole 15 has an index hole 15, and these windows and holes are provided vertically through each other.

In FIG. 6, the disk 12 consists of a disk-shaped magnetic sheet 16 having a hole in the center, and a hub 17 that clamps the peripheral edge of the center hole of the sheet 16.
Double-sided recording is possible by reversing the disk case 11. This sheet 16 has a base film coated with magnetic layers on both sides, and is elastically deformed as a whole.

Upper and lower cases 11 that constitute the disk case 11
On the inner surfaces of each of the disks 12 and 11b, outer circumferential walls 18 and 18, which are concentric with the outer periphery of the drive shaft insertion window 13, protrude and abut against each other. The seat 16 rotates inside the outer peripheral wall 18, facing the drive shaft insertion window 13 inside.

In FIG. 6, the hub 17 of the disk 12 is
The upper hub structure 20 and the lower hub structure 2 are molded separately from plastic and are inseparably joined together.
1, and the peripheral edge of the central hole of the magnetic sheet 16 is held by the opposing surfaces of both hub components 20 and 21.

When the disk cartridge of the present invention is loaded into a disk drive, the bifurcated drive shaft on the drive side engages the central hole 22 of the hub 17 and the insertion hole 24 provided at one location on the outer circumference of the hub 17, thereby rotating the entire disk 12. drive

In FIGS. 5 and 8, the upper and lower cases 11
a, 11b and inside the outer peripheral wall 18,
Rear left and right center area, that is, magnetic head insertion window 1
The above-mentioned nonwoven fabric liner 1 cut into small pieces is pasted at a position facing 4, and nonwoven fabric liners 1a and 1b also cut into small pieces are pasted at substantially opposing positions on the left and right sides. However, while the left and right liners 1a and 1b are attached directly to the flat inner surface of the case, the rear liner 1 is attached to the left and right longitudinal ribs 32 and 32 that protrude from the inner surface of the case. 32, 32, the protrusion height of the rear liner 1 from the inner surface of the case is set higher than that of the left and right liners 1a, 1b.

Ribs 3 protruding from the upper and lower cases 11a and 11b
2 and 32 are arranged in such a way that they alternately mesh on a virtual circumferential line around the center of the drive shaft insertion window 13.

Now, when the disk cartridge of the present invention is loaded into the disk drive and the disk 12 is driven to rotate,
The rear liners 1 and 1 located above and below are disk 1
The left and right liners 1a, 1a and 1 are in strong local contact with both sides of the sheet 16 of No. 2 through the ribs 32.
b and 1b are either in light contact with both sides of the sheet 16, or are facing each other in a slightly floating state, and the sheet 16 held between the rear liners 1 and 1 has a wavy shape at the corresponding part as shown in FIG. As it is deformed and rotated, dust adhering to its surface is removed. The left and right liners 1a and 1b only assist in cleaning the disk surface, but mainly serve to suppress the waving that occurs in the sheet 16 and to improve the contact of the magnetic head with the sheet surface. The reason why the rear liner 1 is arranged at the farthest opposing position from the magnetic head insertion window 14 is to prevent the undulations caused in the sheet 16 due to this cleaning from reaching the position where the magnetic head insertion window 14 is arranged. This is to suppress the In this example, the left and right liners 1a, 1
b is not necessarily required.

The disk cartridge shown in FIG. 9 is basically the same as the one described above, but with
The shape and method of pasting have been changed, and in this, a piece of nonwoven fabric liner 1, which is horseshoe-shaped in plan view, is pasted to the rear half of the disk rotation area in the outer peripheral wall 18, and the magnetic head insertion window is The ribs 32, 32 are arranged in the same way at positions facing the liner 14, and the rear central portion of the liner 1 where the ribs 32, 32 are located is set higher than the other portions to locally improve the disk surface at the corresponding portion. It is being cleaned.

Next, in order to confirm the effects of the present invention, the results of experiments using Examples and Comparative Examples are shown below.

Embodiment 1 In the disk cartridge shown in FIGS. 4 to 8, a horizontal width 2 is provided on each of the upper and lower inner surfaces of the disk case 11 facing the magnetic head insertion window 14.
mm, front and rear length 15mm, height 0.1~0.6mm rib 32,
32, and on these ribs 32, 32, pieces of nonwoven fabric liner 1 having a thickness of 0.6 mm and a width of 20 x 30 mm were attached in a vertically opposed manner as described above. However, the fiber composition ratio of the liner 1 is as follows.

Fiber composition of nonwoven fabric liner Acrylic short fibers (0.1 denier, length 3 mm) 40% Polyester long fibers (2 denier, 36 filaments) 55% Urethane resin 5% Example 2 Acrylic short fibers 2 of nonwoven fabric liner 1 with the above composition
0.5% of silicone oil (hydrogen polysiloxane) was impregnated onto the surface of the sample, and the other procedures were the same as in Example 1.

Example 3 The same procedure as Example 1 was carried out except that the surface of the nonwoven fabric liner was impregnated with oleyl oleate instead of the silicone oil in Example 2.

Comparative example (conventional example) Made by Kendall, consisting of rayon fiber and polypropylene fiber in a composition ratio of 80:20
NOVONETTE9302 non-woven liner (thickness 0.2mm)
was used, and the height of the rib 32 was set to 0.1 to 1.0 mm.

The disk cartridges obtained in each of the Examples and Comparative Examples of the present invention were loaded into a disk drive, and the relationship between the disk rotation torque and the number of dropouts was investigated. Figure 10 shows the results.

As is clear from this figure, although it depends on the height of the rib 32 in the disk cartridges according to each embodiment of the present invention, the disk rotation torque is generally smaller than that of the comparative example (conventional example), and even with a small disk rotation torque. The number of dropouts has been significantly reduced. This reduction in the number of dropouts confirmed that the disk surface cleaning performance of the liner according to the example of the present invention was good. Since the disk rotation torque is small, the load on the disk drive motor is also small, and stable disk running characteristics are achieved. Furthermore, it was confirmed that the ultrafine short acrylic fibers 2 on the surface of the liner were not easily abraded due to the attachment of the lubricant and had excellent durability. Such durability is shown in Example 1.
It was found that the ultrafine fibers smoothly transfer and adhere to the lubricant exuding from the disc, and that it has almost the same effect as pre-impregnation.

[Brief explanation of the drawing]

Figures 1 to 3 show the nonwoven fabric liner used in the present invention, with Figure 1 being a schematic longitudinal cross-sectional view, Figure 2 being a microscopic photograph of the surface of the liner, and Figure 3 also showing the longitudinal direction of the liner. It is a micrograph showing a cut end surface. 4 to 8 show a specific example of the disk cartridge according to the present invention, FIG. 4 is an external perspective view, FIG. 5 is a plan view showing the internal structure,
Figure 6 is a sectional view taken along line A-A in Figure 5, Figure 7 is a sectional view taken along line B-B in Figure 5, and Figure 8 is a sectional view taken along line 5 in Figure 5.
It is a sectional view taken along the line CC in the figure. FIG. 9 is a plan view showing another specific example of the disk cartridge according to the present invention. FIG. 10 is a diagram showing the relationship between the disk rotation torque and the number of dropouts in each example of the present invention and a comparative example. 1...liner, 2...acrylic staple fiber, 3...
Polyester long fibers, 4... Bunch of polyester long fibers, 11... Disk case, 12... Disk.

Claims (1)

[Claims] 1. In a disk cartridge cartridge in which a disk 12 is rotatably housed in a disk case 11 and a liner 1 that contacts the disk surface is attached to the inner surface of the disk case 11, the disk case 11 is made of plastic. The upper and lower cases 11a and 11b of the disk case 11 are combined into a flat hard case with lids fitted together to form a flat hard case.A rib 32 is provided protruding from the inner surface of the disk case 11 at a position facing the disk 12. Rib 32
A disk cartridge characterized in that a liner 1 is disposed on top, and the surface of the liner 1 is made of ultrafine synthetic resin fibers 2 of 0.05 to 0.3 denier.