JPS63161580A - Disk cartridge - Google Patents

Abstract

PURPOSE:To improve the characteristic for medium and the sticking characteristic by constituting a cartridge case to be made of a thermoplastic synthetic resin and forming a cleaning sheet to be made of mixture paper at least comprising acrylic group fibers and rayon fibers. CONSTITUTION:The cartridge case 1 is made up of a rectangular case sheet made of hard polyvinylchloride and three adhered ridges 5a-5c are provided to three edges for one side end part. A rectangular cleaning sheet having nearly the same area is fixed to one side of a case sheet member by deposition. The cleaning sheet is made of mixed paper of acrylic group fibers and rayon fibers or of mixed paper of acrylic group gibers, rayon fibers and thermally molten fibers. Thus, the magnetic disk cartridge case having the cleaning sheet excellent in the characteristics such as counter medium characteristic and sticking characteristic to the cartridge case is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disk cartridge such as a disk cartridge that uses a flexible cartridge case or a cartridge case molded from a hard synthetic resin, and particularly relates to a cleaning sheet for the disk cartridge. be.

[Conventional technology]

The magnetic disk car 1-ridge includes a cartridge case having a magnetic head insertion slot and a rotation drive hole,
A flexible magnetic disk rotatably housed inside the cartridge case.

The cleaning sheet is supported on the inner surface of the cartridge case.

[Problem that the invention seeks to solve]

By the way, conventional cleaning sheets for magnetic disk cartridges are made of a nonwoven fabric such as mixed fibers of rayon and polypropylene, mixed fibers of rayon and polyethylene terephthalate, or polyethylene terephthalate fibers, and these cleaning sheets are made of, for example, ultrasonic welding. It was fixed to the inner surface of the cartridge case with adhesive.

However, the above-mentioned cleaning sheet made of fibers does not have good cleaning properties for magnetic disks, and may also cause scratches on its surface when the magnetic disk comes into sliding contact with it.

There are problems in that fibers fall off from the cleaning sheet due to the sliding contact of the magnetic disk, and the fallen fibers adhere to the magnetic disk and magnetic head, adversely affecting recording and reproducing characteristics.

The purpose of the present invention is to overcome these drawbacks of the prior art and to
It has a cleaning sheet with excellent media protection properties.
Moreover, the present invention provides a disk cartridge that has high welding strength with the cartridge garst cleaning sheet.

[Means for solving problems]

In order to achieve the above-mentioned objects, the present invention uses, for example, a flexible sheet material or a rigid synthetic material! A cartridge case made of a M resin molded body, a flexible disk rotatably housed within the cartridge case,
The present invention is directed to a disk cartridge including a cleaning sheet welded and supported on the inner surface of the cartridge case.

The present invention is characterized in that the inner sheet of the cartridge case is made of a mixed paper of at least acrylic fibers and rayon fibers.

[Embodiments of the invention]

What are the media-resistant properties of cleaning sheets?

Specifically, there are cleaning properties for disks such as magnetic disks, abrasion resistance for disks, and the degree of shedding of the cleaning sheet due to the sliding contact of the disk with the disc. As a result of various studies, it was found that a nonwoven fabric made of acrylic fiber alone is suitable.

However, this non-woven fabric made only of acrylic fibers is not without its problems. In other words, when trying to heat-weld this non-woven fabric made only of acrylic fibers to the inner surface of the cartridge case, the fibers shrink and melt due to the characteristics of the acrylic fibers. As a result, the welding strength of the core cleaning sheet to the cartridge case is insufficient.
Repeated sliding of the disk may cause the cleaning sheet to peel off from the cartridge case.

In addition, hard lumps are formed on the surface of the cleaning sheet, and the cleaning performance of the disk is deteriorated, and the disk is seriously scratched, and the above-mentioned characteristics of acrylic fibers are lost.

In consideration of this point, the present invention solves the above-mentioned problems by constructing the cleaning sheet from a mixed paper of at least acrylic fibers and rayon fibers.

As the thermoplastic synthetic resin used for the cartridge case mentioned above, for example, polyvinyl chloride, ABs@gB, polyacetal resin, polystyrene resin, etc. are used, and as described below, it can be made into a jacket shape or molded into the desired shape by injection molding. The cartridge case can be formed - 1 The above-mentioned magnetic disk is made by forming a magnetic thin film on one or both sides of a base film made of polyester, polyimide, etc. by appropriate means such as coating, vapor deposition, or sputtering. It has moderate flexibility.

The structure of the cleaning sheet fixedly supported on the inner surface of the cartridge case will be explained in detail using the first specific example.

1 to 3 are diagrams for explaining a magnetic disk cartridge according to a first embodiment of the present invention. 1st
2 is a bottom view of the magnetic disk cartridge, FIG. 2 is a developed view of the cartridge case and cleaning sheet of the magnetic disk cartridge, and FIG. 3 is a plan view of the cleaning sheet.

The magnetic disk cartridge is composed of a cartridge case 1, a sheet-like flexible magnetic disk 2 rotatably housed within the cartridge case 1, and a cleaning sheet 3 fixed to the inner surface of the cartridge case 1.

As shown in FIG. 2, the cartridge case 1 is made of a rectangular case sheet material 4 made of, for example, hard polyvinyl chloride, and has three bonding edges 5a, 5 at one end.
b, 5c are provided.

A rectangular cleaning sheet material 6 having approximately the same width is fixed to one side of the case sheet material 4 by welding, which will be described later.

The two square parts 4a, 4b and 6a, 6b of the case sheet material 4 and the cleaning sheet material 6 separated by the center folding line X (imaginary line) have the center hole 7 of the magnetic disk 2 (see FIG. 1). Center hole with a larger diameter than 7
Rotation drive hole for exposing the peripheral part of 8. Magnetic head insertion port 9. Detection hole 10 for detecting the circumferential position of the magnetic disk 2 and tracking it correctly. Cutout 1 for detecting whether side A or side 8 of a magnetic disk cartridge
1, etc. are formed at symmetrical positions.

As shown in the figure, after placing the cleaning sheet material 6 on the case sheet material 4, welding 12 in spots over almost the entire surface of the cleaning sheet material 6,
The rotational drive hole 8 and the magnetic head insertion port 9. Detection hole 10
In addition, by linearly welding 13 around the notch 11, the cleaning sheet material 6 is fixed to the case sheet material 4 without impairing its flexibility or elasticity. In this case, the cleaning sheet material 6 does not necessarily have to be spot-welded 12 over the entire surface, but it is sufficient that the cleaning sheet material 6 is fixed to the extent that it does not easily separate from the case sheet material 4.

After that, the cleaning sheet material 6 is turned inward and folded in half from the above-mentioned center folding line X, and the sheets are facing each other among the laminated edge parts 5a, 5b, and 5c provided on the square part 4b. The bonding edges 5a, 5C are folded over the outside of the other square portion 4a and are partially ultrasonically welded (14) as shown in FIG. 1 to create a bag-like body with one side open. A magnetic disk 2 punched from a sheet-like raw material is inserted into this bag-like body, and then the remaining bonding edge 5b is folded over the outside of the square portion 4a and ultrasonic welding 14 is performed. The assembly of the magnetic disk cartridge as shown in the figure is completed.

The cleaning sheet 3 is made of a mixed paper of acrylic fibers and rayon fibers, or a mixed paper of acrylic tlAR, rayon fibers, and heat-fusible fibers. Acrylic fibers are synthetic fibers containing acrylonitrile of approximately 85 or higher, and are copolymerized with acrylic acid ester, vinyl ftF acid, styrene sulfonic acid, etc. in order to improve abrasion strength and dyeability. It is most similar to wool among fibers, and has excellent flexibility with a soft touch. The tensile strength of acrylic fiber (stable) is approximately 2.5 to 5.
．． 0g/D, elongation rate is approximately 25-50%, elongation modulus (3
% elongation) is about 90-95%, and the specific gravity is about 1.14-1.
It is 17. acrylic fiber.

Those having a birch degree of about 1 to 6 denier are used.

Viscose rayon is a rayon fiber.

Copper ammonia rayon and acetate rayon can be found. The tensile strength of rayon fiber (stable) is approximately 2.5 to 3.1 g/D, the elongation rate is approximately 16 to 22%, the elongation modulus (at 3% elongation) is approximately 55 to 80%, and the specific gravity is approximately 1
．． 50 to 1.52.

Examples of the heat-meltable fibers used include polyethylene terephthalate fibers, polypropylene fibers, polyvinyl chloride fibers, vinyl chloride-vinyl acetate copolymer fibers, and polyamide fibers.

In the case of mixed paper of acrylic fibers and rayon fibers, acrylic fibers are 80 to 20% by weight and rayon fibers are 20 to 8% by weight.
0! I! It is better to regulate the amount as a percentage.

If the acrylic fiber content exceeds 80% by weight, the welding strength of the cleaning sheet to the cartridge case will decrease, and when welded, hard lumps will form on the surface of the cleaning sheet, causing scratches on the disk. On the other hand, if the content of acrylic fibers is less than 20% by weight, many fibers will fall off, resulting in poor cleaning effects and cutting properties.

In addition, when the cleaning sheet is made of mixed paper such as acrylic fiber, rayon fiber, and heat-melting fiber, acrylic fiber is 80 to 20% by weight and rayon fiber is 20 to 8% by weight.
It is better to control the proportion of heat-melting fibers to 0% by weight and 5 to 30% by weight. If the content of acrylic fiber exceeds 80% by weight, the welding strength will decrease and a hard lump will be formed during welding. On the other hand, if the amount is less than 20% by weight, the cleaning effect and cutting performance will deteriorate. On the other hand, hot-melt fibers are blended with the aim of further improving the adhesive strength between fibers, but if the content exceeds 30% by weight, the cleaning effect and cutting properties will deteriorate.

The polyvinyl chloride sheet constituting the cartridge case 1 (case sheet material 4) softens at about 65 to 85°C, becomes plasticized at about 120 to 150°C, and begins to melt at about 170°C. On the other hand, the rayon fibers in the cleaning sheet 3 (cleaning sheet material 6) have the property of not melting, but begin to decompose under heat at about 260 to 300°C. Therefore, when the cleaning sheet 3 (cleaning sheet material 6) is welded to the cartridge case 1 (case sheet material 4) in a slightly compressed state.

The rayon fibers in the cleaning sheet 3 (cleaning sheet material 6) are embedded in the inner surface of the cartridge case 1 (case sheet material 4) while retaining their fiber form. Since the cross-sectional shape of the rayon fiber is generally non-circular, when it is embedded in the cartridge case l (case sheet material 4), the cleaning sheet 3 is securely supported by the cartridge case 1.

Moreover, the buried rayon fibers 24 may become entangled with other fibers in other parts. In the end, the cleaning sheet 3 is firmly supported to the cartridge case 1.

The heat-fusible fibers in the cleaning sheet 3 serve to further strengthen the bond between the acrylic fibers and the rayon fibers, as well as the bond between the cartridge case 1 and the cleaning sheet 3.

For example, by passing the cleaning sheet material 6 between rollers whose surfaces are knurled (embossed), a large number of irregularities 23 are formed on the surface of the cleaning sheet material 6, as shown in FIG. Note that the unevenness 23 is omitted in FIG. 2 to simplify the drawing. The cleaning sheet material 6 constructed in this manner is spot-welded 12 and linearly welded 13 to the case sheet material 4 as described above.

A cleaning sheet made of mixed paper containing 50% by weight of acrylic fibers and 50% by weight of rayon fibers was used and fixed to the cartridge case by heat welding (Example 1), 60% by weight of acrylic fibers and 30% by weight of rayon fibers. weight%
, and one in which a cleaning sheet made of mixed paper containing 10% by weight of polyethylene terephthalate fibers was fixed to the cartridge case by heat welding (Example 2).

A cleaning sheet is made of a nonwoven fabric made of acrylic fibers and is fixed to a cartridge case by heat welding (comparative example).

The cleaning sheet is made of a nonwoven fabric made by mixing rayon fiber and polypropylene fiber in a weight ratio of 8:2, and this is fixed to the cartridge case by heat welding (Conventional Example 1)
Magnetic disk cartridges were prepared using the following methods: (1) and (Conventional Example 2) in which a cleaning sheet was constructed from a nonwoven fabric made solely of polyethylene terephthalate fibers and was fixed to a cartridge case by heat welding (Conventional Example 2).

This example 1. Example 2. Comparative example, conventional example 1゜conventional example 2
The cutting properties, cleaning properties, magnetic disk abrasion properties, lint properties, and welding properties of the cleaning sheets were tested using the methods described below.

A. Cutting property In each of the above samples, each cleaning sheet material was fixed to the case sheet material, and then a rotary drive hole and a magnetic head insertion hole were punched together with the case sheet material at a cutting speed of 120 times per minute. The occurrence of fluff at the cut portions of the rotation drive hole and the magnetic head insertion port was observed.

B. Cleanability The magnetic disk cartridge prepared for each of the samples described above was installed in a recording/reproducing device. Then, the magnetic disk is rotated inside the cartridge case.

A small amount of iron powder was intentionally introduced into the cartridge case through the magnetic head insertion port, and after rotating for 10 minutes, the cartridge case was opened and the state of adhesion of the iron powder to the cleaning sheet was observed.

C1 Magnetic Disk Scratch Resistance When the magnetic disks of each of the above samples were rotated continuously for one week (168 hours) at room temperature, the presence or absence of scratch marks caused by the cleaning sheet on the magnetic disks was observed.

D. Lint properties For each of the above samples, a predetermined amount of the cleaning sheet was immersed in a Freon solvent, and ultrasonic vibration was applied for 10 minutes to test whether the fibers came off from the cleaning sheet.

E. Weldability For each of the above samples, cleaning sheet material was welded in spots on the case sheet material at intervals of 7w+w (this welding was done by ultrasonic welding or heat press as described above) and then fixed once. do.

Peel off part of this cleaning sheet material in a band shape of approximately 1cm wide, leaving the other end firmly attached to the case sheet material. By doing so, the part peeled off from the case sheet material hangs down from the case sheet material, and a weight is applied to the hanging part to apply a load in the direction that the cleaning sheet material peels from the case sheet material, and the amount of the load is gradually reduced. The amount of load (g) at which the fixed portion (welded portion) of the cleaning sheet material begins to peel off from the case sheet material was measured.

The results of each of these tests are shown in the table below.

As is clear from the test results, the one according to the embodiment of the present invention has good cutting properties and cleaning properties.

The scratch resistance, lint characteristics, and weldability of magnetic disks are
It can be seen that this is superior to the comparative examples and conventional examples.

4 to 8 are for explaining a magnetic disk cartridge according to a second embodiment of the present invention. FIG. 4 is an exploded perspective view of the disk cartridge, and FIG. 5 is a cleaning sheet attached to the upper case. Figure 6 is a bottom view showing the state in which the cartridge is attached, Figure 6 is a plan view showing the state in which the cartridge sheet is attached to the lower case, and Figure 7 is the vicinity of the magnetic head insertion slot showing the state in which this magnetic disk cartridge is used. FIG. 8 is an enlarged sectional view of the vicinity of the elastic piece of this magnetic disk cartridge.

The magnetic disk cartridge is stored in the cartridge case 26.
, a magnetic disk 27 rotatably housed therein, and a shutter 28 slidably supported by a cartridge case 26 .

The cartridge case 26 includes an upper case 26a and a lower case 2.
6b, which are injection molded from hard IR resin such as ABS resin.

An opening 29 for inserting a rotary drive shaft is formed approximately in the center of the lower case 26b, and a rectangular head insertion opening 3 is formed near the opening 29.
Similarly, a head insertion port 30 is provided in the upper case 26a. As shown in FIG. 4, in the vicinity of the front surfaces of the upper case 26a and the lower case 26b, recesses 31 which are slightly lowered in order to restrict the sliding range of the shutter 28 are formed, and the intermediate positions of the recesses 31 The magnetic head insertion port 30 is opened in the.

As shown in FIG. 5, there are counterbore-shaped recesses 42 on the inner surface of the upper case 26a and on both the left and right sides of the magnetic head insertion port 30.
, 42 are formed respectively.

The vertical width W1 of the recess 42 is I! in the longitudinal direction of the magnetic head insertion port 30. (vertical width) approximately equal to W2, and the width W3 of the recess 42 is at least 0.3 times the width (width) W4 in the direction perpendicular to the longitudinal direction of the magnetic head insertion port 30, preferably 0. -5
It is regulated to a range of 1.5 times to 1.5 times. ' On the upstream side of the magnetic head insertion slot 30 of the upper case 26a in the disk rotational direction, there are provided a number of linearly extending protrusions 43, two of which are slightly higher than the inner protrusions 43. .

An arc-shaped regulating rib 44 that regulates the storage position of the magnetic disk 27 is protruded from the inner surface of the upper case 26a, a part of which passes through the ends of the four parts 42, and the regulating rib 44 extends into the recess 42.
It also serves as a reinforcement for the surrounding area.

As shown in FIG. 5, a substantially C-shaped cleaning sheet 45 having the same structure as the first embodiment is inserted inside the regulating rib 44. An opening 4 provided at a position corresponding to the magnetic head insertion opening 30 of the cleaning sheet 45
The width W5 of 6 is designed to be slightly larger than the width W4 of the magnetic head insertion port 30. Cleaning sheet 45
By placing the cleaning sheet 45 on the inner surface of the upper case 26a, the four parts 42 and the projections 43 are also covered, and the peripheral portion of the cleaning sheet 45 is ultrasonically welded to the upper case 26a. As mentioned above, since the recess 42 of the upper case 26a has a sufficient width, the cleaning sheet 1 is
The edge of the opening 46 at −45 can be ultrasonically welded 47 within the recess 42 .

As shown in FIG. 6, a protruding support portion 48 and a protruding protrusion 49 for preventing sticking are provided on the inner surface of the lower case 26b at a position substantially facing the protrusion 43 of the upper case 26a.

As shown in FIGS. 6 and 8, a base portion 51 of an elastic piece 50 formed by bending a plastic sheet is attached to the inner surface of the lower case 26b and in the vicinity of the support portion 48 by an appropriate means such as adhesive or heat melting. The free end 52 of the fixed zero elastic piece 50 is supported by the support portion 48 to maintain its inclined state.

A regulating rib 44 is also protruded from the inner surface of the lower case 26b, and a cleaning sheet 45 is disposed inside the regulating rib 44. The width W5 of the opening 46 provided in the cleaning sheet 45 at a position corresponding to the magnetic head insertion opening 30 is designed to be slightly larger than the width W5 of the magnetic head insertion opening 30. By placing the cleaning sheet 45 inside the lower case 26b as shown in FIG.
0 is covered, and the peripheral portion of the cleaning sheet 45 is welded 47 to the lower case 26b, but the welding 47 is omitted near A4 of the elastic piece 50.

- When a magnetic disk cartridge is assembled by combining the E case 26a and the lower case 26b.

As shown in FIG. 8, the lower case 26b is
The cleaning sheet 45 is partially lifted, and the lifting is pushed up slightly by the protrusion 43 provided on the upper case 26a, and the magnetic disk 2 is elastically held between the upper and lower cleaning sheets 45 and 45. Ru.

As the magnetic disk 27 rotates, the cleaning sheet 45 cleans the surface of the disk.

FIG. 7 is a diagram showing how the magnetic disk cartridge is used, and numeral 53 in FIG. 1 is a magnetic head.

In this embodiment as well, the above 11! Case sheet material made of quality vinyl chloride? Similar to when using cleaning sheets made of other materials, cutting properties, cleaning properties, scratch resistance of magnetic disks, etc.
It has been confirmed that both lint properties and weldability are excellent.

〔Effect of the invention〕

The present invention is applied to a cleaning sheet as described above.

Contains acrylic fiber. This acrylic fiber is 1
It has excellent flexibility among synthetic fibers, does not damage the surface of the disk that rotates once, and has a high cleaning effect without causing fuzz. In addition, because of its good cutting properties, when manufacturing disk cartridges by cutting, for example, there is no possibility that some of the fibers will protrude inward from around the head insertion slot or rotation drive hole, especially for the head insertion slot. If the fibers protrude, this may cause errors during recording or playback, but as mentioned above, acrylic fibers have excellent cutting properties, so errors caused by protruding Iam can be avoided. No outbreak.

Furthermore, since the rayon fibers in the cleaning sheet are firmly connected to the cartridge case, the welding strength of the cleaning sheet is high, and there is no fear that the cleaning sheet will peel off from the cartridge case.

As described above, it is possible to provide a magnetic disk cartridge having a cleaning sheet with excellent properties such as anti-media properties and adhesion properties to a cartridge case.

[Brief explanation of drawings]

1 and 3 are for explaining a magnetic disk cartridge according to a first embodiment of the present invention, FIG. 1 is a bottom view of the magnetic disk cartridge, and FIG. 2 is a car 1 of the magnetic disk cartridge. - Developed view of the ridge case and cleaning sheet 2. Figure 3 is a plan view showing the state before the ridge cleaning sheet is attached to the cartridge case. Figure 4 is an exploded perspective view of the magnetic disk cartridge according to the second embodiment of the present invention. , Fig. 5 is a bottom view of the upper case with the cleaning sheet attached to the magnetic disk cartridge, and Fig. 6 is a bottom view of the upper case of the magnetic disk cartridge with the cleaning sheet attached.
Fig. 7 is an enlarged sectional view of the vicinity of the magnetic head insertion slot showing how this magnetic disk cartridge is used, and Fig. 8 is an enlarged view of the vicinity of the elastic piece of this magnetic disk cartridge. 6 which is a cross-sectional view 1...Cartridge case, 2...Magnetic disk, 3...Cleaning, sheet, 1
2... Spora 1-shaped welding, 13... Linear welding, 26... Cartridge case, 26a
...Top case, 26b...Bottom case,
27...Magnetic disk, 45...Cleaning sheet, 47...Welding. Figure 1 Figure 6 Figure 7

Claims (4)

[Claims] (1) A disk cartridge comprising a cartridge case, a disk rotatably housed in the cartridge case, and a cleaning sheet welded and supported on the inner surface of the cartridge case, wherein the cartridge case is 1. A disk cartridge made of a thermoplastic synthetic resin, wherein the cleaning sheet is made of at least a mixed paper of acrylic fibers and rayon fibers. (2) In claim (1), the cleaning sheet contains 80 to 20% by weight of acrylic fibers.
, a disk cartridge characterized in that the proportion of rayon fiber is regulated to 20 to 80% by weight. (3) A disk cartridge according to claim (1), wherein the cleaning sheet is made of a mixed paper of acrylic fibers, rayon fibers, and heat-melting fibers. (4) In claim (3), the acrylic fiber is 80 to 20% by weight and the rayon fiber is 15% by weight.
60% by weight, and the proportion of heat-melting fibers is limited to 5 to 20% by weight.