JP2566987B2 - Method for manufacturing recorded magnetic disk - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of use) The present invention is to magnetically transfer the recorded contents of a master magnetic disk in which information is magnetically recorded on the magnetic surface of an unrecorded slave magnetic disk. To a method of manufacturing a recorded magnetic disk.

(Prior Art) Conventionally, as a method of copying a large number of recorded media,
A magnetic tape having a high coercive force magnetic layer on which information is recorded is used as a master medium, and an unrecorded magnetic tape having a magnetic layer having a lower coercive force than the master medium is used as a slave medium. A method is used in which the information recorded in the master medium is magnetically transferred to the slave medium by superimposing them and applying a bias magnetic field from the outside while advancing these.

However, this method is a magnetic transfer technique based on a magnetic tape that reproduces a signal while linearly advancing, and cannot be directly applied to a rotating disk-shaped magnetic medium, that is, a magnetic disk. In the magnetic disk, since the medium is rotated to reproduce the signal, it is newly necessary to match the rotation centers of the master and slave magnetic disks. When the centers of rotation of the both are deviated from each other, when the recorded magnetic disk after transfer is reproduced, information read errors due to track-out frequently occur. However, it is very difficult to accurately match the rotation centers of both the master and slave magnetic disks, which poses a problem in terms of reliability and productivity.

(Problems to be Solved by the Invention) As described above, according to the conventional technique, it is difficult to accurately match the rotation center of the master magnetic disk with the rotation center of the slave medium when performing magnetic transfer on the magnetic disk, and the recording is performed. There is a problem in that the reliability of the magnetic disk is poor and the productivity is poor.

Therefore, the present invention provides a method of manufacturing a recorded magnetic disk in which the center of rotation of a master magnetic disk and the center of rotation of a slave magnetic disk can be easily and accurately matched to efficiently perform highly reliable magnetic transfer. The purpose is to provide.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, in the present invention, the magnetic surface of both disks is formed before or after the magnetic transfer step from the master magnetic disk to the slave magnetic disk. It is characterized in that the slave magnetic disk is punched out from the original material of the medium in the state of being in close contact with.

(Operation) In the method according to the present invention, the positional relationship between both disks is kept constant during the magnetic transfer from the master magnetic disk to the slave magnetic disk and when the slave magnetic disk is punched out from the medium roll. As a result, if the center of rotation of the master magnetic disk is aligned with the center of the blade of the punching device, the centers of rotation of both disks will be correctly aligned.

Therefore, as compared with the method in which the rotation centers of the slave magnetic disk and the master magnetic disk are made to coincide with each other after punching, the rotation centers of both disks can be easily and more accurately aligned.

Further, the two steps of punching and transfer can be completed almost at the same time, which contributes to the improvement of productivity.

(Example) Hereinafter, the Example of this invention is described using drawing.

1 to 3 show steps of a method for manufacturing a recorded magnetic disk according to an embodiment of the present invention, which is taken along a plane including the center of rotation of the master magnetic disk and perpendicular to the master magnetic disk. FIG. The apparatus used in this embodiment, as shown in FIG. 1, is an outer blade 4 for punching a slave magnetic disk from a medium web 1 and an inner blade 5 for punching a hole for rotating the slave magnetic disk.
And a master magnetic disk 2, 3 on which information for magnetic transfer is recorded, coils 6, 7 for generating a bias magnetic field necessary for transfer, and support materials 8, 9 for supporting these.
It consists of The outer blade 4 and the inner blade 5 are arranged above the medium raw fabric 1, and the master magnetic disks 2, 3 and the bias magnetic field generating coils 6, 7 and the supports 8, 9 sandwich the medium raw fabric 1 respectively. It is arranged vertically so as to face each other.

In order to manufacture a recorded magnetic disk using the above apparatus, first, a cylindrical support member 8 and a cylindrical outer blade 4 are also used.
And the inner blade 5 is attached so that both share a center line. Next, the bias magnetic field generating coil 6 is installed at a position where a magnetic field is applied to the entire master magnetic disk 2.
Next, the center of rotation of the master magnetic disk 2 has an outer blade 4
And, it is arranged so as to be located on the center line of the inner blade 5. Similarly to the master magnetic disk 2, the master magnetic disk 3 on the lower side of the medium roll 1 is also arranged such that the center of rotation thereof is located on the center line of the outer blade 4 and the inner blade 5 to generate a bias magnetic field. Like the coil 6, the coil 7 is also arranged at a position where a magnetic field is applied to the entire master magnetic disk 3.

After arranging the respective parts as described above, the medium original fabric 1 is placed on the support material 9 as shown in FIG. 2, and the support material 8 is placed on the original fabric 1 between the master magnetic disks 2, 3 and the original fabric 1. Lower to a position where sufficient adhesion is obtained. Master magnetic disk 2,3
Then, lower it to the position where sufficient adhesion is obtained between When sufficient adhesion is obtained between the master magnetic disks 2 and 3 and the master 1, the bias magnetic field generating coils 6 and 7
Is excited to apply a bias magnetic field to the master magnetic disks 2 and 3 to perform magnetic transfer.

In this case, the bias magnetic fields applied by the coils 6 and 7 from the upper and lower sides of the medium roll 1 are transferred to the slave magnetic disk during transfer.
It is desirable to make the phases or application timings of the two different so that they do not cancel each other out.

When the magnetic transfer is completed, the outer blade 4 and the inner blade 5 are moved up and down to punch the recorded slave magnetic disk 10 (FIG. 3) on which the information has been written by magnetic transfer from the original 1. In this slave magnetic disk 10, the magnetic patterns of the master magnetic disks 2 and 3 are transferred to both magnetic surfaces thereof, and the center of the transferred circular information track is the geometric center of the slave magnetic disk 10. Match. Therefore, in the case of a magnetic disk which is clamped and rotated without a hub attached to the central portion, the rotation center of the slave magnetic disk 10 is the master magnetic disk 2, 3 in the above steps.
It coincides with the center of rotation of.

On the other hand, in the case of a magnetic disk to which a hub is attached and rotated, the rotation center of the hub may be matched with the geometric center of the slave magnetic disk 10. At this time, the chucking accuracy of the hub is sufficiently high considering the compatibility of the disk drive, so once you know the difference between the center of rotation of the hub and the geometrical center, when attaching the hub to the slave magnetic disk 10, the magnetic It is possible to accurately and reproducibly match the geometric center of the disk with the center of rotation of the hub.

The present invention is not limited to the above embodiments. For example, in the above-described embodiment, the punching process is performed after the magnetic transfer process. However, if the slave magnetic disk does not move through both processes, the order of both processes does not matter, and the magnetic transfer process is performed after the punching process. Or both steps may be performed at the same time.

Although the outer blade 4, the inner blade 5, and the supporting member 8 have different structures in the embodiment shown in the drawings, they may be integrated into a single structure as long as sufficient adhesion can be obtained between the original medium and the master magnetic disk. It is also possible to However, in the case of the integral structure, it is necessary to pay attention to the material such as non-magnetic material in order to avoid magnetizing due to the bias magnetic field.

Furthermore, regarding the method of applying the bias magnetic field during transfer,
Besides the method of simultaneously applying to the entire surface of the master magnetic disk as shown in the embodiment, a method of applying a coil or a magnetic head smaller than the master magnetic disk by moving it on the master magnetic disk can be adopted. If the above method is used, the problem that the outer blade 4 and the inner blade 5 are magnetized is alleviated as compared with the case of the above embodiment.

In addition, the present invention can be variously modified and implemented without changing the scope of the invention.

[Effects of the Invention] As described in detail above, according to the present invention, magnetic transfer is performed with both magnetic surfaces of a master magnetic disk and a slave magnetic disk in close contact with each other, and punching of a slave magnetic disk from a medium roll. By continuously or simultaneously, the rotation centers of the master magnetic disk and the slave magnetic disk can be easily and accurately aligned.
Therefore, the reliability of the magnetic transfer is enhanced, and the productivity of the recorded magnetic disk is improved.

[Brief description of drawings]

1 to 3 are cross-sectional views for explaining steps of a method of manufacturing a recorded magnetic disk according to an embodiment of the present invention. 1 …… Media roll, 2, 3 …… Master magnetic desk, 4 ……
Outer blade, 5 ... Inner blade, 6,7 ... Bias magnetic field generating coil, 8,9 ... Support, 10 ... Slave magnetic disk (recorded magnetic disk).

Claims (3)

(57) [Claims] 1. A master magnetic disk is recorded by applying a bias magnetic field to the master magnetic disk in a state where the magnetic surface of a master magnetic disk on which information is recorded and the magnetic surface of an unrecorded slave magnetic disk are in close contact with each other. A magnetic transfer step of transferring the recorded information to the slave magnetic disk, and a state in which the magnetic surface of the master magnetic disk and the magnetic surface of the slave magnetic disk are kept in close contact with each other after, before, or simultaneously with the magnetic transfer step. And a punching step of punching a slave magnetic disk from the medium roll. 2. The magnetic transfer step and the punching step, wherein the center of rotation of the master magnetic disk and the center of the blade for punching the slave magnetic disk from the original material of the medium are made to coincide with each other. Of the recorded magnetic disk of. 3. A method of manufacturing a recorded magnetic disk according to claim 1, wherein the blade for punching out the slave magnetic disk from the original fabric is a non-magnetic material.