JPH0458672B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a disk cartridge having a cleaning sheet provided on the inner surface of a disk case and in contact with the surface of the disk. Conventionally, this type of disk cartridge has used a nonwoven cleaning sheet made of rayon fibers, polyester fibers having a circular or elliptical cross-sectional shape, or a mixture of both fibers. However, although the rayon fibers make it easy to clean dust on the disk surface, the frictional force with the disk is large, the load torque of the motor that drives the disk becomes large, and the lubricant on the disk surface is easily absorbed into the fibers. , which reduced the durability of the disk, especially during long-term storage at high temperatures. On the other hand, although polyester fibers do not have the drawbacks of rayon fibers, they have poor cleaning performance. One of the reasons why the cleaning performance is poor is that the cross-sectional shape of the fibers is circular. SUMMARY OF THE INVENTION An object of the present invention is to provide a disk cartridge having a cleaning sheet which eliminates the above-mentioned drawbacks of the prior art, has low friction characteristics, has good cleaning performance, and is less likely to transfer disk lubricant. In order to achieve this object, the present invention is characterized in that the cleaning sheet is formed of synthetic resin fibers having an uneven cross-sectional shape. Hereinafter, preferred embodiments of the present invention will be described. As shown in Fig. 1, the disk cartridge consists of a flat rectangular hard case type disk case 1, which is made up of upper and lower plastic cases 1a and 1b that are joined together by ultrasonic welding at several points. , and a magnetic disk 2 rotatably housed in this disk case 1. The disk case 1 has a drive shaft insertion window 3 located near the front near the center, a magnetic head insertion window 4 located in front of the drive shaft insertion window 3 and long from front to back, and this magnetic head insertion window 4. The index hole 5 is located at the rear of the index hole 5, and these windows and holes penetrate vertically. As shown in FIG. 2, the center of the disk 2 is held between hubs 6, and by reversing the disk case 1, recording on both sides of the disk 2 is possible.
Magnetic layers are coated on both sides of the disk 2, and the whole disk 2 is elastically deformed, and the outer surface of the disk 2 is coated with a lubricant such as liquid paraffin. Upper and lower cases 1a constituting the disk case 1,
A cleaning sheet 7 made of non-woven fabric or woven fabric made of synthetic resin fibers, which will be described later, is attached to each inner surface of 1b. This cleaning sheet 7 is used to clean the disk 2 by partially contacting the surface of the disk 2, and may be shaped like a small piece or approximately annular to match the shape of the disk 2. Various things are possible. In the cleaning sheet 7, the synthetic resin fibers 8 such as polyester fibers, polyamide fibers, polypropylene fibers, etc. are formed with uneven sections as shown in FIGS. Or use a woven cloth. Furthermore, it is sufficient that at least 30% of the synthetic resin fibers 8 are contained in rayon, nylon, polypropylene, or polyethylene in the nonwoven or woven fabric, and it is not necessarily necessary to use 100% of the synthetic resin fibers 8. The cross-sectional shape of the synthetic resin fiber 8 is approximately triangular with a concave portion formed in the center on each side, as shown in FIG. 3, or star-shaped with rounded corners as shown in FIG. As shown in Fig. 5, the shape is irregular but clearly formed with concave and convex parts,
Possible examples include an elliptical shape with fine irregularities formed on the long side as shown in FIG. 6, and a shape with fine irregularities continuously formed around the periphery as shown in FIG. In order to obtain these cross-sectional shapes, there is a method of changing the nozzle shape of the fiber manufacturing equipment from a normal circular tube shape, or a method of changing the nozzle shape of the fiber manufacturing equipment from a normal circular tube shape, or a method of changing the shape of the synthetic resin fiber into a triangular shape, for example, to form a substantially triangular shape as shown in Fig. 3. A possible method is to insert it into a hole and pull it out. According to the cleaning sheet 7 described above, the convex portions of the synthetic resin fibers 8 produce a cleaning action, the presence of the concave portions reduces the friction coefficient compared to conventional cleaning sheets, and the lubricant transfer from the disk 2 is reduced. I'm reducing the amount. This effect will be examined using specific examples and comparative examples using conventional fibers. Example 1: A 1.5 denier polyester fiber having the cross-sectional shape shown in FIG. 3 was spun to form a nonwoven fabric consisting of 100% of this fiber with a thickness of 0.2 mm and a mass of 35 g/m ² . Example 2; 40% of the same polyester fiber as in Example 1 above
A nonwoven fabric similar to that in Example 1 was formed from 60% of 1.7 denier rayon fiber. Example 3; Polyester fiber with the cross-sectional shape shown in Figure 4
A nonwoven fabric similar to that of Example 1 was formed from 100%. Example 4: A nonwoven fabric similar to Example 1 was formed from 40% of the same polyester fibers as Example 3 and 60% of rayon fibers. Comparative Example 1: A nonwoven fabric similar to that of Example 1 was formed using 100% polyester fibers having a circular cross-sectional shape. Comparative Example 2: A nonwoven fabric similar to Example 1 was formed from 40% polyester fibers having a circular cross-sectional shape and 60% rayon fibers. Comparative Example 3: A nonwoven fabric similar to Example 1 was formed using 100% rayon fibers having a circular cross-sectional shape. In order to evaluate the cleaning performance, the carbon transferred to general copy paper was collected by rotating each of the cleaning sheets punched out in a circular shape 10 times, and the cleaning effect was applied to the carbon paper after this cleaning. A comparison was made based on changes in black density. In other words, it can be determined that the higher the carbon collection rate η, the better the cleaning performance. The collection rate can be expressed as η (%) = (C ₀ - C ₁ )/C ₀ ×100, where C ₀ is the initial concentration of the carbon paper and C ₁ is the concentration of the carbon paper after cleaning. The amount of lubricant transfer A is determined by the change in weight of the disk after adding 20 mg of liquid paraffin to the disk, sandwiching it between cleaning sheets, applying a load of 10 g/cm ² and leaving it for 8 hours at an environmental temperature of 60°C. It was determined by measuring. Furthermore, the coefficient of dynamic friction B of the cleaning sheet against the disk was also measured. The following table summarizes the values of the carbon collection rate η, the amount of lubricant transfer A, and the coefficient of dynamic friction against the disk B for each example and comparative example.

[Table] As is clear from the above table, the disk cartridges in each example have better cleaning performance, less lubricant transfer to the disk surface, and less friction with the disk than the comparative example. It has sufficient properties required for cleaning sheets. Furthermore, substantially the same effects were obtained not only in the above embodiments but also in synthetic resin fibers having the cross-sectional shapes shown in FIGS. 5 to 7. As explained above, according to the present invention, it is possible to provide a high-performance disk cartridge by providing a cleaning sheet that has good cleaning characteristics, good low friction characteristics, and does not transfer lubricant from the disk. It is something.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a disk cartridge;
Figure 2 is a sectional view of the disk cartridge, Figure 3 is a cross-sectional view of the disk cartridge.
FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are diagrams each showing the cross-sectional shape of the synthetic resin fiber of the present invention. 1...Disk case, 2...Disk, 7...
...Cleaning sheet.

Claims (1)

[Claims] 1. In a disk cartridge cartridge in which a disk is rotatably housed in a disk case, and a cleaning sheet made of synthetic resin fibers is provided on the inner surface of the disk case and is in contact with the surface of the disk, the cleaning sheet is made of synthetic resin having an uneven cross-sectional shape. A disk cartridge characterized by being made of resin fiber.