WO1991016706A1

WO1991016706A1 - Method of producing magnetic disks having signals

Info

Publication number: WO1991016706A1
Application number: PCT/JP1991/000507
Authority: WO
Inventors: Shinji Kawakami; Kensyu Kusumoto; Mikio Kishimoto
Original assignee: Hitachi Maxell, Ltd.
Priority date: 1990-04-17
Filing date: 1991-04-17
Publication date: 1991-10-31

Abstract

A method of producing many duplicate magnetic disks from a master disk at high speed using a simple device while preventing the demagnetization of the master disk. The disk for duplication has a magnetic layer including magnetic powder such as hexagonal ferrite crystals, a majority of which has the easy axis substantially perpendicular to the disk surface rather than along the tracks. The disk is placed in a manner that its magnetic layer is in contact with the magnetic layer of the master disk in which signals are recorded with magnetization along the tracks. The alternating magnetic field is applied over the disks in nearly a vertical direction, so that the signals of the master disk are transferred to the disk for duplication.

Description

Details

Method of manufacturing magnetic disk with signal

Technical field

The second invention relates to a method of manufacturing a magnetic disk containing a program signal and a data signal of computer software by a magnetic transfer method.

Meeting

Conventionally, magnetic disks containing signals, which are commercially available as computer software, are generally copied by a method as shown in FIG. 1 based on a master disk on which signals are recorded in advance. That is, the replica generally has a master disk 20 in which the magnetization direction of the recorded signal 2Oa is along the track direction as shown by an arrow, and an easy axis of magnetization along the in-LU direction. The unrecorded slave disk 21 is overlapped so that the magnetic layers of both disks are in contact with each other, and an alternating magnetic field as shown by the dashed arrow in the figure (only one direction in the figure) Is applied in the track direction by a magnetic head 22 to transfer the signal recorded in the former to the latter and record it. The arrow in the slave disk 21 indicates the copied signal 21a.

As a device for performing magnetic lithography by this method, the superposed master disk and slave disk are pressed together with rollers and rotated around the center of both disks to record the magnetic head. A method has been proposed in which a transfer magnetic field is sequentially applied from the start point to the end point of the recording track of the disc by the magnetic head while moving relative to the track, thereby performing the transfer recording ( Japanese Unexamined Patent Publication No. Sho 63-244424).

However, in this conventional magnetic transfer method, since it is necessary to cultivate the magnetic disk while keeping both magnetic disks in a tightly pressed state, the disk drive becomes mechanically very complicated, and the transfer device becomes complicated. There was a problem that it was expensive. Also, the disk is rotated like this: Since it takes a long time to apply the voltage from the base point to the end point of the track, there is a problem that high-speed mass replication is difficult in this method. In addition, since the transfer magnetic field is applied in the recording track direction, the signal of the master disk is magnetically disturbed (this is because the master disk has an in-plane magnetic axis so that the axis of easy magnetization is oriented in the track direction). As a result, the recorded contents of the master disk may be adversely affected.

The present invention is based on the magnetic transfer system which is capable of performing high-speed mass copying of a magnetic disk with an extremely simple mounting structure and which does not adversely affect the recorded contents of a master disk. Disclosure of invention _c intended to provide a method of manufacturing a magnetic disk containing a signal

As a result of intensive studies to arrest the above object, the present inventors have found that when a slave disk having a specific magnetic layer is used as a slave disk for magnetically transferring a signal of a master disk. On the disc surface On the other hand, by applying a transfer magnetic field in a substantially vertical direction, signals on the entire recording surface can be transferred and recorded at the same time without rotating the magnetic disk. In particular, they have found that good transfer recording can be performed with a low probability of the master disk being magnetized, and the present invention has been accomplished.

That is, the present invention provides a master disk provided with a magnetic layer having a generally high coercive force in which a magnetic signal along a concentric or spiral spiral track is previously recorded, and, for example, hexagonal fine particles as magnetic powder. The unrecorded slave disk with a magnetic extension that has a perpendicular magnetization component that is almost perpendicular to the disk surface at a higher ratio than the in-plane magnetization component in the track direction, including the unrecorded slave disk. And an alternating magnetic field having a magnetic force stronger than the vertical coercive force of the slave disk is applied to the entire surface of the disk in a direction substantially perpendicular to the disk surface. An application step to record the signal on the slave disk and a slave disk The method according to the present invention relates to a method for manufacturing a magnetic disk with signals, comprising the step of taking out from the position where the magnetic field is applied.

As described above, the magnetic field of the slave disk used in the present invention contains hexagonal ferrite particles as a magnetic powder, and has a higher ratio of the perpendicular magnetization component than the in-plane magnetization component. Therefore, by applying a magnetic field in a direction substantially perpendicular to the disk surface, a signal corresponding to the signal of the master disk can be recorded by the action of the perpendicular magnetization component. Therefore, by applying an alternating magnetic field in a direction substantially perpendicular to the disk surface in a state where the slave disk and the master disk are superimposed, the signal of one master disk is simultaneously transferred and recorded on the entire surface of the slave disk. it can.

In this magnetic transfer, the direction of the applied magnetic field is set so as to be almost perpendicular to the disk surface, so that both superimposed disks are rotated without if, unlike the conventional method. The symbols on the entire recording surface can be transcribed at the same time while the recording is stopped. Also, the magnetization direction of the signal is When a transfer magnetic field in a direction substantially perpendicular to the disk surface is applied, demagnetization is unlikely to occur in a master disk along the disk direction. There is no bad shadow hairpin in the signal itself. The more the direction of the applied magnetic field is set so as to increase the angle difference with respect to the axis of easy magnetization of the master disk, that is, the direction of the applied magnetic field is perpendicular to the axis of easy magnetization of the master disk. The closer it is, the less the demagnetization of the master disk. However, if the angle difference is made sufficiently large, it is possible to repeat the signal transfer properly even if it is not necessarily perpendicular. Further, in this method, since the magnetic transfer can be performed while both disks are stationary as described above, a complicated operation mechanism as a tilling apparatus is not required at all.

Is a hexagonal Fuwerai bets magnetic exhibition slave Day disk contains, A 0 * n F 0 A is B a shown by _3, S r, P b, one of the original even without least selected from C a A rope is preferable, and a part of the F e component in the above formula may be replaced with another component. , As the replacement component Examples include Co, Ni, Zn, Mn, Ti, Ζr, Sη, Ge, In, and V.

In the present invention, acicular iron oxide magnetic powder is used as a magnetic recording cable of the slave disk, in addition to the hexagonal flylite particles, to provide an axis of easy magnetization in the in-plane direction. Other magnetic powders may be used in small amounts as necessary.

In this invention, the slave disk is prepared by mixing and dispersing magnetic powder mainly composed of hexagonal ferrite particles together with a mixing resin, an organic solvent and the like to prepare a magnetic coating material, and using the coating material as a base material such as a polyester film. The magnetic layer can be formed by applying the composition on the upper surface by using an arbitrary application means such as a roll coater, drying and forming a magnetic layer, and then punching it into a donut disk shape. The process of punching into a disk shape can be performed at any time, such as before contacting with the master disk, while keeping it in contact with the master disk, or after performing magnetic transfer. The magnetic paint containing hexagonal frit particles can be easily magnetized by applying a magnetic field in a direction perpendicular to the magnetically extended surface immediately after coating the magnetic paint on the substrate and before drying. It is preferable to perform such a magnetic orientation because the axis is more preferably oriented in the vertical direction and the surface smoothness of the magnetic layer is improved. In this case, by setting the orientation ratio of the easy magnetization axis in the vertical direction to be as high as possible within a range of more than 0.5 and 0.9 or less, it is possible to perform good tilling of signals. Wear.

Examples of the binder resin used for preparing the above magnetic paint include vinyl chloride-vinyl acetate copolymer, polyvinyl butyral resin, woven resin, polyurethane resin, and iso resin. Conventionally used binder resins such as cyanate compounds and radiation-curable resins are widely used. -Organic solvents such as toluene, methylethyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, and ethyl ethyl dichloride, which have been used in the past, are used alone or in combination of two or more. Used. The magnetic paint may optionally contain various additives commonly used, for example, dispersants, lubricants, abrasives, and antistatic agents.

On the other hand, in the master disk used in the present invention, the coercive force of the magnetic debris is preferably larger than the coercive force in the vertical direction of the slave disk. Further, the magnetic layer of the master disk desirably has a coercive force at room temperature of not more than 3,000 elsts in order to facilitate signal recording on the master disk itself. The coercive force of the master disk is usually set to about 2,000 eelsted, so it is about 1.5 to 3 times the coercive force of the slave disk.

In addition, the magnetic debris of the master disk is composed of a metal magnetic powder composed of Fe, Co, Ni, an alloy of these or other metals or an alloy containing a small amount of a non-metallic element, and a binder resin. It is generally composed of a coating film containing, but a magnetic metal thin film made of the same metal or alloy as described above may be used. For the magnetic layer containing these metallic magnetic powders, a magnetic paint containing a magnetic powder, a binder resin, and an organic solvent is prepared in the same manner as the slave disk, and this is coated on a polyester film, polyethylene terephthalate film, or another film. It may be formed by coating and drying on a substrate such as aluminum. In this case, the same resin as the slave disk described above can be used as the binder resin, the organic solvent, the additive and the like. Further, the magnetic layer composed of a magnetic metal thin film can be formed on a substrate such as a polyester film by a known thin film forming means such as vacuum deposition in the same manner as when forming a coating.

In order to perform magnetic transfer, a master disk in which required signals such as computer software are recorded in advance, and a signal-unrecorded slave disk having magnetic eyebrows including the hexagonal fly particles described above are overlapped with each other. It is sufficient to crimp and fix it with an appropriate crimping jig in the folded state (overlapping step) and apply an alternating magnetic field of the required strength and frequency (applying step). The intensity of the alternating magnetic field applied at this time is If the coercive force is lower than the slave disk's coercive force, accurate signal transfer cannot be obtained, so it must be higher.

After transferring the signal by applying an alternating magnetic field higher than the coercive force of the slave disk, as an extraction step, the applied magnetic field is attenuated to about half or less of the coercive force of the slave disk. The magnetic field may be taken out from the magnetic field application position. If the disk is removed when the strength of the magnetic field is more than half of the coercive force, the disk will be affected by the magnetic field that changes relative to the slave disk, and noise and erroneous signals will be recorded. Because of the possibility, the applied magnetic field should be weakened as much as possible before extraction. The most preferable way to avoid adverse effects on the disk is to remove the slave disk from its position after removing the applied magnetic field. If the slave disk has magnetic layers on both sides to which signals are to be transferred, two master disks on which signals corresponding to each side are recorded should be coaxial so that the center of each recording track is coaxial. Placed in both squares The above magnetic transfer may be performed with the slave disk sandwiched between the target disks in a San-German manner.

According to the method of the present invention, a signal previously recorded on a master disk can be very easily transferred and recorded on a slave disk by a magnetic transfer method without any need for a complicated operation mechanism.玆 No magnetism occurs. Therefore, this method is extremely useful as a means for high-speed mass copying of magnetic disks containing signals such as software for computers.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic view showing a conventional magnetic transfer method using a magnetic head, FIG. 2 is a partial cross-sectional side view showing an example of a magnetic transfer apparatus to which the manufacturing method of the present invention is applied, FIG. 4 and FIG. 4 are enlarged cross-sectional views of the main parts, respectively, and FIG. 5 is a plan view of a slave disk provided with optical detection means for detecting an address.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the composition of the slave disk used in this embodiment will be described. In the following composition, “a” means parts by weight. Magnetic composition of slave disk

Haxagonal variegated particles 100 parts

(Average diameter 0.06 z m, coercive force 520 eelsted,

(Saturation magnetization 5 9 ernu / g)

Vinyl chloride-vinyl acetate-vinyl alcohol copolymer 1

(Product name V AGH manufactured by U.C.C.C. in the United States)

Urethane elastomer 6 parts

(Product name manufactured by Dai-Shon Inki Chemical Industry Co., Ltd.

(Pandex T-522)

Trifunctional low molecular weight iso-cyanate compound 4 parts

(Product name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.)

1 1 1 Toluene 1 1 1 part After the magnetic paint of the above composition is applied to both sides of a 75-m-thick polyester film, dried and dried to form a magnetic layer with a thickness of 2.δ / im after drying. A slave disk was prepared by punching out a 3.5-inch (approx. 89 cm), 1.5-inch inner diameter (approximately 38 cm) inner diameter donut plate. This slave disk had a coercive force (vertical direction) of 61 eelstead, a squareness ratio (vertical direction) of 0.64, and a saturation magnetic flux density of 1.190 gauss.

The master has a magnetic eyebrow containing metal magnetic powder, has a coercive force of 9, 960 eSted, a squareness ratio of 0.60, and a saturation magnetic flux density of 2,800 gauss. A disc was recorded, and a program signal of a recording wavelength of 1.5 m was recorded on the disc in advance.

Between the two master disks containing the above signals, the slave disk without the grave is recorded, and these are fixed by crimping with a crimping jig as shown in Figs. 2 to 4 to fix the AC electromagnet. 12 were placed between the magnetic poles. And -1 δ-An alternating magnetic field with a frequency of 60 Hz is applied perpendicularly to the disk surface, and this alternating magnetic field is gradually increased until it reaches a maximum of 1,500 Oersted, and conversely, 0 Oersted. By gradually reducing the signal to the master disk, the signal of the master disk was transferred and recorded on the slave disk to produce a signal-input floppy disk.

The illustrated device S will be specifically described. In these figures, 1 is a slave disk, 2 is a master disk, 3 is a crimping jig composed of a pair of crimping plates 3a and 3a, and 4 is an AC power supply 5 and an alternating magnetic field between both poles 4a and 4a. Is a C-shaped AC electromagnet for generating As described above, the two poles 4a, 4 of the AC electromagnet 4 are fixed with the slave disc 1 and the two master discs 2, 2 sandwiching the slave disc 1 crimped between the two crimping plates 3a, 3a. It is located between a. The slave disk 1 is formed in a donut shape as described above, and a hub 7 formed from a metal plate is attached to the inner periphery thereof as shown in an enlarged cross section in FIG. ing. This hub 7 usually fits in a plastic case A 3.5-inch floppy disk is commonly used to drive a 3.5-inch floppy disk with a disk drive unit of a computer, and has a hole 7a for the support shaft and a hole 7b for the drive bin. Are formed. Further, a through hole 3b is formed in the crimping hole 3a in the upper part of the figure, and a shaft portion 8a of the positioning material 8 for the slave disk 1 is inserted into the through hole 3b. In this positioning member 8, the shaft 58a and the pin 8b are connected by a connecting portion 8c having elasticity. The inner dimensions of the pin 8a and the pin 8b are set slightly shorter than the shortest distance between the holes 7a and 7b. Therefore, the hub 8a is inserted into the shaft 8a by inserting the shaft 8a into the hole 7a for the support shaft of the slave disk 1 and inserting the pin 8b into the hole 7b for the drive bin. 8b is recessed and slave disk 1 is positioned. By attaching the hub 7 to the slave disk 1 in this manner, the positioning of the slave disk 1 can be performed easily and reliably. Also, as shown in FIG. 4, the inner surface of each crimping plate 3 a has concentric track crimping portions 6, 6, … Are protruded, and the recording tracks of both discs 1 and 2 are tightly and uniformly adhered by these crimping holes.

In this magnetic transfer apparatus, the signals recorded on the magnetic layers of the master disks 2 and 2 are simply generated by the electromagnet 4 to generate an alternating magnetic field. Since both sides are transcribed and recorded in the calendar at the same time, by exchanging only the slave disk i with an unrecorded one at the end of each transfer, magnetic transfer can be performed by returning from the same master disk 2, 2. .

When the slave disk was repeatedly produced as described above and the above program was run using the slave disk, it operated exactly the same as the master disk, and no bad shadow was seen in the signal of the master disk. won. As described above, according to the present invention, it is possible to easily and quickly mass-produce a magnetic disk recording a signal of a computer software or the like.

In the above embodiment, the hole for the support shaft is One 〖8—

a and the disc body with the disk hub 7 with the drive pin holes 7 b attached to it is used as a recording medium by storing the disc body in a plastic case or the like. If the diameter is relatively large (such as 5 inches or 8 inches), the magnetic signal of the master disk is transferred to an indexing hole near the inner circumference of the donut-shaped disk. May be stored in a floppy jacket and used as a recording medium.

In general, the larger the recording capacity of a floppy disk, the longer it takes to detect the address. Therefore, the magnetic signal recorded on the track of the slave disk can be read out quickly and reliably. If signals other than magnetic signals, such as optically readable signals, are arranged on concentric circles or spiral lines, the address on this disk is optically captured by the disk drive unit. May be detected. For example, as shown in FIG. 5, the concentric grooves 9,. (This groove is shown only in the vicinity of the outer periphery and inner periphery of the disk in the figure), and a large number of fine concave portions or convex portions (non-protruding portions) corresponding to the address signal are provided in this groove. (Shown). These grooves 9 and recesses can be easily formed by embossing the entire slave disk from the front and back. By doing so, it is possible to quickly detect the address of the disk.

Claims

The scope of the claims

1. A slave disk with no signal recorded on at least one side of the disk base, having at least one magnetic extension having an easy axis of magnetization substantially perpendicular to the disk surface at a higher ratio than the easy axis of magnetization in the track direction; A superposition step of superimposing a master disk on which a signal having a magnetization direction along the track direction is recorded in advance so that the magnetic fields of both disks are in contact with each other;

An application step of applying an alternating magnetic field having a magnetic force stronger than the coercive force of the slave disk in the vertical direction to the entire surface of the disk in a direction substantially perpendicular to the disk surface and recording the master disk signal on the slave disk. And

A step for taking out the slave disk from the position where the magnetic field is applied;

2.The signal input magnetic disk according to claim 1, wherein the magnetic powder constituting the magnetic S of the slave disk contains hexagonal fluoride particles. Production method.

3. The method according to claim 1, wherein the orientation ratio of the easy axis of magnetization in the magnetic field of the slave disk in the direction perpendicular to the disk surface is set to be larger than 0.5 and 0.9 or less. Manufacturing method of magnetic disk with signal.

4. The removal step is a step of removing the slave disk from the position where the magnetic field is applied after reducing the intensity of the alternating magnetic field applied to the slave disk to less than half of the coercive force of the disk. A method for producing a magnetic disk with a signal according to claim 1.

5. The method of manufacturing a magnetic disk with signals according to claim 4, wherein the removing step is a step of removing the alternating magnetic field applied to the slave disk and then removing the slave disk from a position where the magnetic field is applied.

G. The above-mentioned superposition step is performed by adding two master disks to each magnetic layer of a slave disk having magnetic disks formed on both sides of the disk substrate. -22-This is the step of sandwiching the slave disk with the master disk so that the magnetic layers are in contact with each other,

2. The method according to claim 1, wherein the magnetic signal is simultaneously transferred to both sides of the slave disk by the self-application step.

7. The method according to claim 1, wherein the master disk and the slave disk are each formed substantially in a donut shape.

8. A support hole configured to receive a support shaft of a disk drive unit of a device to which the disk is applied and a drive hole configured to receive a drive bin of the drive unit on an inner circumference of the slave disk. And a hub mounting step for mounting before applying the applying step,

8. The method of manufacturing a magnetic disk with signals according to claim 7, wherein the applying step is performed while positioning the slave disk with respect to the master disk using positioning means engaging with each of the holes.

9. The method of manufacturing a magnetic disk with signals according to claim 1, wherein the magnetic field of the slave disk includes an optical detection signal indicating an address of a recorded signal.