JPS60209985A - Flexible magnetic disk - Google Patents

Abstract

PURPOSE:To set the center position of a magnetic sheet with high accuracy by combining a pair of sheet holding matters made of a material having a temperature expansion coefficient approximately equal to the magnetic sheet to hold and fix them at the fringe part of a hole formed at the center of the magnetic sheet and having a contact between a core member having the excellent wear resistance and a rotary shaft of a recording/reproducing device to obtain the revolutions synchronized with the rotary shaft of the magnetic sheet via said core member in a recording/reproduction mode. CONSTITUTION:A lower magnetic sheet holding matter 9 is first pressed and fixed into a core member 5. A magnetic sheet 3 is held between the matter 9 and an upper magnetic sheet holding matter 7. Thus the fringe part of a center attachment hole 3a of the sheet 3 is held between the stage parts of both matters 9 and 7. Then the head of a calking pin 9a is fused and deformed by heat for calking, to put firmly together the sheet 3, the matter 7 and the matter 9 welded with the member 5 in a body. Thus, the core of a floppy disk 1 is obtained.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a flexible magnetic disk on which recording and reproduction are performed by a magnetic head, and in particular, to a flexible magnetic disk in which recording and reproduction are performed by a magnetic head, and in particular, to a flexible magnetic disk provided at the center of the magnetic disk around the mounting hole for a recording and reproducing device. This invention relates to a flexible magnetic disk with an improved structure.

[Technical Background of the Invention] In recent years, floppy disk devices, which are recording and reproducing devices that use thin, flexible magnetic sheets (so-called floppy disks) as storage media, have come into widespread use due to their various features. A magnetic sheet consists of a thin disc-shaped hemolecular resin film with a magnetic layer uniformly formed on the surface by coating or other means, and a hole is formed in the center for attachment to a floppy disk device. has been done. That is, when the magnetic sheet is attached to the floppy disk device, the magnetic sheet is held between the top and bottom at the periphery of the -C mounting hole by the rotary drive shaft and the holding member provided at a predetermined position of the floppy disk device. Attached to the rotating shaft. During recording or reproduction, the magnetic sheet is rotated by the rotation of the rotating shaft by the motor.
At the same time, the magnetic head is moved to a desired position in the radial direction of the magnetic sheet by another motor or the like to record or reproduce signals.

"Problems with the Background Art" However, as mentioned above, the rS magnetic sheet is a thin flexible resin film, and there is no protection provided around the periphery of the mounting hole, so it cannot be mounted on the rotating shaft of a floppy disk drive. When doing so, it is easy for a part of the mounting hole of the magnetic sheet to curl up and become deformed, or for the periphery of the mounting hole to be damaged by the rotating shaft. If the mounting hole of the magnetic sheet is deformed or damaged in this way, the center of the magnetic sheet will shift with respect to the rotation axis, resulting in a decrease in center positioning accuracy.As a result, each time the magnetic sheet is installed, the rotation axis The reproducibility of alignment between the magnetic sheet and the center of the magnetic sheet deteriorates, and it becomes impossible to record and reproduce signals at desired positions.

This means that in the current situation where floppy disks smaller than the mini-floppy level are being put into practical use due to the recent downsizing of floppy disk devices, the aforementioned decrease in center positioning accuracy may lead to a fatal problem. .

Therefore, in order to protect the floppy disk by storing it in a hard cartridge, a reinforcing core member made of synthetic resin or metal is attached to the periphery of the mounting hole numbered on the magnetic sheet. Recently, a proposal has been used to prevent the deterioration of center positioning in G.

However, by making the reinforcing core member made of synthetic resin, the part that comes into contact with the rotating shaft will wear out due to repeated mounting on the rotating shaft, and the rated number of mounting times required for a floppy disk will not be met. It is not possible to ensure repeatability of high-precision center positioning over a range.

Furthermore, the reinforcing core member is configured as a dish-shaped metal core member, and the edge of the metal core member and the peripheral edge of the center hole of the magnetic sheet are bonded together using double-sided adhesive tape or the like. In case C, the above-mentioned problem of wear due to the fact that the member that comes into contact with the rotating shaft during installation is made of metal is solved. On the other hand, since there is a configuration C in which a metal core member with a large difference in coefficient of thermal expansion and a magnetic sheet made of synthetic resin are bonded together using double-sided adhesive tape, the amount of expansion of both members due to temperature changes is different, and the bonded part The relative position of the magnetic disk between the two parts in the radial and circumferential directions may shift due to misalignment or the melting of the adhesive at high temperatures. Therefore, it is important to ensure that the center positioning is reproducible. is difficult.

Furthermore, a pair of disk-shaped reinforcing core members made of synthetic resin are provided with a pot formed on the outer periphery that also has the function of preventing the magnetic sheet from being pulled out from the cartridge, and the pair of reinforcing core members are magnetically Depending on the method of protecting the magnetic sheet, the above-mentioned problem due to the difference in temperature expansion coefficients can be solved by holding the sheet from both sides and fixing it using an adhesive. On the other hand, the diameter of the collar that holds the magnetic sheet is usually large in order to prevent the magnetic sheet from forming. The sliding contact between the magnetic head and the magnetic sheet at the inner circumferential portion lacks stability, resulting in a problem that recording and reproduction cannot be performed stably.

As described above, conventional measures have not been sufficient to prevent deterioration in center positioning with respect to the rotation axis of a recording/reproducing device in a floppy disk.

[Object of the Invention] This invention has been made in view of the above, and its object is to improve the center position of a magnetic sheet with respect to the rotation axis of a recording/reproducing device without impairing the function of recording or reproducing appropriate signals. An object of the present invention is to provide a flexible magnetic disk which can be set with high precision regardless of changes in the usage environment or aging.

[Summary of the Invention] In order to achieve the above object, the present invention provides a flexible magnetic disk that is housed in a hard storage body and that is recorded or reproduced by a magnetic head when attached to a recording/reproducing device. a magnetic sheet, which is provided with a hole, is rotated in synchronization with the rotation of the rotating shaft of the recording/reproducing device, and on which signals are recorded or reproduced by the magnetic head; and a temperature expansion coefficient that is approximately the same as that of the magnetic sheet. A movement prevention part is formed on the outer periphery to store and fix the magnetic sheet at a predetermined position in the storage body, and an inner periphery of the movement prevention part is formed with a magnetic sheet when assembled. a sheet holder formed with a fixed holding means for clamping and fixing the sheet at the peripheral edge of the hole; and a sheet holder formed of a highly wear-resistant material and provided on at least one of the sheet holders, and connected to the recording/reproducing device. The main feature is that the magnetic sheet has a core member that comes into contact with the rotating shaft when the magnetic sheet is mounted and transmits the rotation to the magnetic sheet via the sheet holder.

[Embodiments of the invention] Hereinafter, the present invention will be explained in detail using the drawings.

1 and 2 show an embodiment of a flexible magnetic disk according to the present invention, and FIG. 1 is a partial side cross-section of a flexible magnetic disk (hereinafter referred to as "floppy disk") 1 according to the embodiment. FIG. 2 shows an exploded perspective view of the floppy disk 1. As shown in FIG.

In FIG. 1, a floppy disk 1 is a magnetic sheet 3
The magnetic sheet 3 is properly attached to a floppy disk device (not shown) which is a recording/reproducing device, and the recording/reproducing device is
In order to ensure reliable reproduction, a core member 5 is assembled at the center of the magnetic sheet 3 as described below. The configuration includes upper and lower magnetic sheet holders 7 and 9, and a hard cartridge 11 that houses and protects the magnetic sheet 3 so that the data recorded on the magnetic sheet 3 is not destroyed by careless handling. It is.

The magnetic sheet 3 is based on a thin disk-shaped polymer resin film with a thickness of, for example, about 0.075i+m, and a magnetic layer is formed on the surface by means such as coating. Recording and playback is performed by sliding the head in contact, and there are mounting holes 3 in the center.
A is provided.

The core member 5 is made of a thin metal plate with excellent wear resistance, such as stainless steel, formed into a steel shape by means such as pressing,
A center hole 5b is provided at the center of the flat surface of the pot bottom, and openings 5C and 5d are provided at predetermined distances and angles from the center hole 5b, respectively. The center hole 5b is a hollow, substantially square columnar shape that stands up inside the steel core member 5, and a rotating wheel of a recording and reproducing device, which also has a substantially square columnar shape, is inserted therein for center positioning of the magnetic sheet 3. It is something. A drive bin (not shown) that applies rotational force to the magnetic sheet 3 is inserted into the opening 50 . The opening 5d has a rotation shaft inserted into the center hole 5b.
A biasing pin (not shown) is inserted to apply force in the radial direction of the core member 5 so that liquid always flows on two predetermined sides of the core member 5.

On the other hand, three flanges 5a are formed on the peripheral edge of the core member 5, and these flanges 5a are used to prevent the magnetic sheet 3 from being removed from the cartridge 11 or coming into direct contact with the inner surface of the cartridge. This is to protect the product from being damaged. Note that the core member 5 has a collar 5a.
Although three ribs are provided, the effect is the same even if two or more ribs are provided or an integral rib is provided over the entire circumference.

The lower magnetic sheet holder 9 is made, for example, by injection molding of a synthetic resin having approximately the same coefficient of thermal expansion as the material of the magnetic sheet 3, and when assembled, the core member 5 is press-fitted and fixed at the outer edge of the lower magnetic sheet holder 9 to be integrated. , there is a part C which plays the role of holding the magnetic sheet 3 on one inner peripheral surface. Its structure corresponds to each opening of the core member 5 [opening 9b
, 9c.

9d is provided, and the magnetic sheet 3 is attached near the outer periphery (
= A stepped portion 9e that is inserted into the J hole 3a at J3 and attached is formed, and a columnar rivet pin 9a is integrally formed on the inner side of the stepped portion 9e at a position that divides the circumference approximately equally. In addition,
The shapes and dimensions of the lower magnetic sheet holder 9 and the core portion 445 are as follows:
When the two parts I are combined, the parallelism between the bottom plane of the C1 core part 5 and the bottom face of the step part 9e which holds the magnetic sheet 3 of the lower magnetic sheet holder 9 is determined with high precision.

Maintaining the parallelism with high accuracy in this manner is necessary to ensure stable recording and reproduction over the entire range of the magnetic sheet 3 when the floppy disk 1 is mounted in a recording/reproduction device and the magnetic head performs recording and reproduction. There are car accessories.

The upper magnetic sheet holder 7 is molded from the same synthetic resin as the lower magnetic sheet holder 9, and has the role of sandwiching the magnetic sheets 1-3 on the inner peripheral surface on the opposite side from the lower magnetic sheet holder 9 when combined. It is responsible for Its structure includes an opening lower b at a position corresponding to the three openings of the core member 5.
, 7c, and 7d are provided with counterbore holes 7a at positions corresponding to the caulking pins 9a of the lower magnetic sheet holder 9, respectively. Furthermore, the magnetic sheet 3 is attached to its mounting hole 3 at the bottom.
A stepped portion 7e is formed at a portion a to be held at the periphery of the mounting hole 3a, and a beam is formed on the outer periphery.

A ring-shaped top 7 is provided. This brim 7f is
It has the same function as the collar 5a of the core member 5.

Note that the three open lowers b and 7c of the upper magnetic sheet holder 7
, 7d are not necessarily required depending on the lengths of the rotating shaft, driving bin, and biasing bin.

The assembly of the floppy disk 1 using the members described above is carried out, for example, as described below.

In the work, first, the lower magnetic sheet holder 9 is press-fitted into the core member 5 and fixed. The press-fitting and fixing work involves openings 9c and 9d of the lower magnetic sheet holder 9 and opening 5c of the core member 5.
. This is done by fitting it into the

Next, with the lower magnetic sheet holder 9 and the upper magnetic sheet holder 7 press-fitted into the core U5,
The work of clamping and fixing the magnetic sheet 3 is performed. This operation involves inserting the center mounting hole 3a of the magnetic sheet 3 into the stepped portion 9e of the lower magnetic sheet holder 9, and inserting the upper magnetic sheet holder 7 from above into its respective lower openings b, 7c', 7d, and stepped portion 7e. This is done by mounting so that the counterbore holes 7a are aligned with the positions of the respective openings 9b, 9c, 91 step portion 9e, and riveting pin 9a of the lower magnetic sheet holder 9, respectively.

As a result, the peripheral edges of the center mounting holes 3a of the magnetic sheets 1 to 3 are held between the stepped portions of the upper magnetic sheet holder 7 and the lower magnetic sheet holder 9. Thereafter, the head of the crimping pin 9a is heated, melted and deformed to crimp the magnetic sheet 3, the upper magnetic sheet holder 7 and the core U.
The core of the floppy disk 1 is formed by integrally and firmly fixing the lower magnetic sheet holder 9 to which the magnetic sheet holder 5 is fixed, and when this is housed and covered in the cartridge 11, the floppy disk is completed.

As described above, the flange 7'd3 of the upper magnetic sheet holder 7 and the flange 5a of the core member 5 are used to prevent the inner surface of the cartridge 11 from coming into contact with the magnetic recording/reproducing surface of the magnetic sheet 3, or to prevent the magnetic disk from being removed from the cartridge 11. Parts are coming and going,
This is for protecting the magnetic sheet 3 from damage, and is not for holding the magnetic sheet 3. Therefore, in the floppy disk 1 formed as described above, there is a slight gap between the magnetic sheet 3 and the ribs 5a and 7, and the flexibility of the magnetic sheet in this portion is reduced. There are no restrictions on sexuality. Thereby, when recording and reproducing signals, the magnetic head and the magnetic sheet 3 are stably contacted even at the inner peripheral portion of the magnetic sheet 3, so that the recording and reproducing area on the magnetic sheet 3 can be widened. In this embodiment, the brim is formed on the core member 5, but it may be formed on the lower magnetic sheet holder 9. In addition, the method of fixing the core member 5 and the lower magnetic sheet holder 9 is not limited to the fixing method as described above, but as shown in FIG. The cut-and-raised portion 5e may be provided and used as a lever to prevent removal, and may be formed integrally with the lower magnetic sheet holder 9 by insert molding, for example.

Therefore, in the assembly work of the floppy disk 1 described above, double-sided adhesive tape or adhesive is not used to fix these components, so the floppy disk 1 is stable in fixing and easy to manufacture. This makes it possible to lower assembly costs and improve reliability.

As explained above, according to the present invention, a set of sheet holders made of a material having substantially the same coefficient of thermal expansion as the magnetic sheet is combined to hold the central portion of the magnetic sheet. The magnetic sheet is clamped and fixed at the periphery of the hole provided in the magnetic sheet, and a core member with excellent wear resistance is brought into contact with the rotating shaft of the recording/reproducing device to synchronize with the rotating shaft of the magnetic sheet during recording and reproducing. Since the rotation is obtained through the core member, there is no possibility of deformation or misalignment at the clamping and fixing part between the magnetic sheet and the sheet holder due to changes in the usage environment such as large temperature changes around the recording/reproducing device, or the magnetic disk. The center position of the magnetic sheet with respect to the rotating shaft of the recording/reproducing device does not shift due to wear of the contact portion between the core member and the rotating shaft due to aging due to repeated attachment of the magnetic sheet to the rotating shaft. ,
The center position can be set with high precision. In addition, since the clamping and fixing by the sheet holder is performed at the inner circumference of the magnetic sheet from the movement prevention part to prevent the magnetic sheet from being pulled out and damaged from the cartridge that stores and protects the magnetic sheet, the magnetic sheet Good contact can be made between the magnetic head and the magnetic sheet at the inner periphery, making it possible to increase data density even with a magnetic sheet of the same diameter as before, and to record or reproduce appropriate signals. can be done.

[Brief explanation of drawings]

FIG. 1 is a partial side cross-sectional view of a flexible magnetic disk according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the flexible magnetic disk, and FIG. 3 is a core portion constituting the flexible magnetic disk. (Figure 1 shows another configuration of A. 1... Floppy disk 3... Magnetic sheet 5... Core member 7... 1 part magnetic sheet holder 9... Lower magnetic sheet holder 11・・・Car 1~Ritsugi r Figure 1 Figure 2 Figure 3 n Continuation of page 1 @ Inventor Takao Zaima Kawasaki office @ Inventor Hyakude Karaon Kawasaki @ Inventor Yokoyama Kiyoharu Yokohama Research 1 Takesai Ward Komukai Toshiba-cho 1 Tokyo Shibaura Electric Co., Ltd. General Research Takeyuki Organic - ■ Inside the facility

Claims (1)

[Scope of Claims] (1) In a flexible magnetic disk that is stored in a hard storage body and recorded or read by a magnetic head when installed in a recording/playback device, a hole is provided in the center of the sheet C, A magnetic sheet that is rotated in synchronization with the rotation of the rotation shaft of the recording/reproducing device and on which signals are recorded or reproduced by the magnetic head, and a material having approximately the same coefficient of thermal expansion as the magnetic sheet are used. A movement prevention part is formed on the outer periphery for storing and fixing the magnetic sheet at a predetermined position in the storage body, and an inner periphery of the movement prevention part is formed to prevent the magnetic sheet from moving around the periphery of the hole when assembled. a sheet holder 5 formed with a fixed holding means for clamping and fixing; a sheet holder formed of a material with high wear resistance and provided at least to h of the sheet holder;
A flexible magnetic disk characterized by having a core member that comes into contact with the rotating shaft when installed in the recording/reproducing device and transmits the rotation to the magnetic sheet via a sheet holder. (2) In the set of seat holders, one of the seat holders has a counterbore hole, and the other seat holder has a crimping pin, and when assembled, the rivet pin penetrates the counterbore hole. The flexible magnetic disk according to claim 1, wherein the flexible magnetic disk is integrated by being melted and deformed.