JPH04162281A - Disk cartridge - Google Patents

Abstract

PURPOSE:To reduce error caused by a method wherein a cleaning sheet is pasted on the inner face of a case in such a way that a direction in which the tensile strength of the cleaning sheet is high is nearly perpendicular to the radial direction of a magnetic disk at a head window part. CONSTITUTION:A head window part 5 is formed in a case 1 so that a magnetic head is slid on and brought into contact with the magnetic face of a magnetic disk 3. A nonwoven cloth is used for a cleaning sheet 11; it has the difference in tensile strength between the longitudinal direction (MD) and the transverse direction(TD); the cleaning sheet 11 is pasted on the inner face of the case in such a way that the direction (MD) in which the tensile strength of the cleaning sheet 11 is nearly perpendicular to the radial direction of the magnetic disk at the head window part 5. Thereby, the cleaning sheet 11 is not worn out near the head window part 5, and an error caused by abrasion powders at the magnetic head when a recording operation and a replay operation are performed, is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disk cartridge rotatably housing a magnetic disk in a hard or soft case and further having a cleaning sheet inside.

More specifically, the present invention relates to a disk cartridge with an improved arrangement of a cleaning sheet that comes into sliding contact with the magnetic layer of the magnetic disk.

[Prior Art] A disk cartridge is a cartridge containing one magnetic disk, and is used in small magnetic disk devices. Depending on the type of magnetic disk, it is broadly divided into hard disk cartridges and flexible disk cartridges.

In the case of flexible disc cartridges - for boat fishing,
As shown in FIG. 1, a flexible magnetic disk 3 is housed inside a case l made of plastic resin (eg, vinyl chloride) called a jacket. In order to bring a magnetic head (not shown) into sliding contact with the magnetic surface of the magnetic disk 3, a head window 5 is provided in the case. In addition, a first stage of rotation drive (not shown) for rotating the magnetic disk is connected to the magnetic disk 3.
A central window 7 for engagement with the rotation reference position and an index window 9 for detecting a rotational reference position are provided.

As shown in FIG. 2, the magnetic disk 3 rotates while being cleaned by a cleaning sheet 11 made of a nonwoven fabric called a liner.

[Problems to be Solved by the Invention] Conventionally, cleaning sheets have used a nonwoven fabric made by entangling thermoplastic fibers such as polyethylene terephthalate fibers or acrylic fibers, and generally, cleaning sheets have been used in the machine direction (MD) and the transverse direction. There is a difference in tensile strength between (TD) and the cleaning sheet, and the disk and the cleaning sheet have been brought into contact so that the direction of rotation of the disk and the TD of the cleaning sheet almost match.

However, with this method, when the disk is run for a long time, the thermoplastic fibers that make up the cleaning sheet soften and wear due to frictional heat, and the generated wear particles adhere to the magnetic head via the magnetic disk. This caused errors during recording and/or playback.

5eQJ] is intended to solve the drawback of the above-mentioned disk cartridge, which is fiber abrasion of the liner, and to provide a magnetic disk cartridge with fewer errors.

[Means for Solving the Problem] In order to achieve the above object, the present invention provides at least the following:
In a disk cartridge consisting of a case with a head window, a magnetic disk rotatably housed in the case, and a cleaning sheet affixed to the inner surface of the case, the direction in which the tensile strength of the cleaning sheet is high is the magnetic field in the head window. To provide a disk cartridge and a cartridge characterized in that a cleaning sheet is attached to the inner surface of the case so as to be substantially orthogonal to the radial direction of the disk.

Preferably, the disc cartridge is a flexible disc cartridge.

[Function] As described in mj, in the present invention, the cleaning sheet is attached to the inner surface of the case so that the direction (MD) of the cleaning sheet with high tensile strength is approximately perpendicular to the radial direction of the magnetic disk in the head window section. .

If the cleaning sheet is prevented from being worn out in the vicinity of the head window, errors caused by abrasion particles during recording and reproduction of the magnetic head can be significantly reduced.

Cleaning sheets are generally made by bundling fibers, so they have directionality, and the fibers are usually oriented in the roll direction (MD), resulting in high tensile strength. The tensile strength ratio of nonwoven fabrics used as cleaning sheets for flexible disk cartridges (FD) and the like in the roll direction (MD) and in the perpendicular direction (TD) is 2 to 5.
A difference of about twice as much is observed, and the tensile strength is approximately proportional to the thickness of the nonwoven fabric. In FD, it is common to use a nonwoven fabric with a thickness of 0.15 to 0.411 mm, but the directionality of the fibers has the greatest influence on the deformation of the nonwoven fabric due to the shear force at the contact surface between the disk and the nonwoven fabric. There was found.

[Example code] Hereinafter, the present invention will be explained in more detail with reference to Examples.

As shown in FIG. 3, the cleaning 7-to 11 generally includes a disk side nonwoven fabric 27 facing the magnetic disk 3, a case side nonwoven fabric 29 facing the case 1, and the disk side nonwoven fabric 27 and the case side nonwoven fabric 29. It is preferable to have a three-layer structure consisting of an intermediate nonwoven fabric layer 31 for adhering the two layers to each other.

The nonwoven fabric itself used in the disc cartridge of the present invention does not need to be anything special. All common nonwoven fabrics conventionally used in the field of magnetic recording media can be used in the disk cartridge of the present invention.

For example, both the disc nonwoven fabric layer 27 and the case side nonwoven fabric layer 29 may be made of rayon fiber. This type of structure with no front and back sides is extremely convenient since there is no need to inspect the front and back sides of the nonwoven fabric when installing the cleaning sheet in the case. As the rayon fiber, viscose rayon, copper ammonia rayon, acetate rayon, etc. can be used. Rayon fiber (staple) has a tensile strength of approximately 2.5 to 3.1 g/D1 elongation of approximately 16 to 22%, and an elongation modulus (at 3% elongation) of approximately 55 to
80%, specific gravity is approximately 1.50-1.52.

The intermediate nonwoven fabric layer 31 can also be composed of a mixed fiber layer of rayon fibers and polyamide fibers. The mixing ratio of rayon fiber and polyamide fiber is generally about 1/9 to 9/1.
It is particularly preferably within the range of 3/7 to 7/3. The polyamide fiber has a tensile strength of about 4.5 to 7.5, an elongation of about 24 to 60%, an elongation modulus (at 3% elongation) of about 95 to 100%, and a specific gravity of about 1.14.

For the intermediate nonwoven fabric layer 31, in addition to the mixture of rayon fiber and polyamide fiber as described above, various thermoplastic resins such as polyethylene terephthalate, polyethylene, polypropylene, polystyrene, polyvinyl chloride, and acrylic resin may be used. I can do it.

The cleaning sheet 11 can be made of rayon fiber alone, but by providing an intermediate nonwoven fabric layer 31 made of a nonwoven fabric containing a thermoplastic resin between the disk side nonwoven fabric layer 27 and the case side nonwoven fabric layer 29, the cleaning sheet 11 can be made of rayon fiber alone. Thermal adhesion properties are improved.

Using cleaning sheets having the configuration and characteristics shown in Table 1 above, MD and T of each cleaning sheet were used.
Attach the cleaning sheet to the inner surface of the case of the 3.5-inch flexible disk cartridge so that D is perpendicular to the longitudinal direction of the head window. We tested the relationship with numbers. A metal FD whose magnetic layer was coated with metal powder was used as the magnetic disk. The results are summarized in Table 2 below.

As is clear from the above results, it is understood that the cleaning sheet pasted so that the MD of the cleaning sheet is perpendicular to the longitudinal direction of the head window produces very few temporary errors and produces good results.

Although the present invention has been described above in detail with respect to a flexible disk cartridge, the present invention can be implemented similarly with respect to a hard disk cartridge.

Further, the size of the cartridge does not matter when implementing the present invention. A disk of 8 inches or larger (e.g. 1
The present invention can be implemented with all hard and flexible magnetic disks that are actually used, such as disks of 2 inches or smaller (for example, 2 inches) or smaller than 3.5 inches (for example, 2 inches).

The magnetic layer of the magnetic disk may be either a coating type or a thin film type. Similarly, the material of the case does not matter.

[Brief explanation of the drawing]

Fig. 1 is a rear view of a conventional flexible 7-pull disk cartridge, Fig. 2 is a cross-sectional view taken along the line ■-■, and Fig. 3 is a portion of an example of the nonwoven fabric used in the present invention. FIG. ■... Jacket (case), 3... Magnetic disk. 5... Head window, 7... Central window, 9... Index window. DESCRIPTION OF SYMBOLS 11... Cleaning sheet, 27... Disk side nonwoven fabric layer, 29... Case side nonwoven fabric layer, 31... Intermediate nonwoven fabric layer

Claims (3)

[Claims] (1) At least a case having a head window;
a magnetic disk rotatably housed within the case;
In a disk cartridge consisting of a cleaning sheet affixed to the inner surface of the case, the cleaning sheet is affixed to the inner surface of the case so that the direction of high tensile strength of the cleaning sheet is approximately perpendicular to the radial direction of the magnetic disk in the head window. Characteristic disc cartridge. (2) The disk cartridge according to claim 1, wherein the disk cartridge is a flexible disk cartridge. (3) The disk cartridge according to claim 1, wherein the disk cartridge is a hard disk cartridge.