JPH03168917A - magnetic recording medium - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording medium, and particularly to a magnetic recording medium incorporated in a fixed magnetic disk device.

[Conventional technology]

The base material of the magnetic recording medium built into a fixed magnetic disk device is aluminum alloy, which is in practical use, but base materials such as glass, ceramics, and resin are used due to its light weight and surface smoothness. is being reviewed.

The application of glass, ceramics, and resin to the base material of magnetic recording media is described, for example, in Japanese Patent Publication Nos. 43-4621, 35807-1987, 23161-1981, and 304422-1982. Some of them have already been disclosed in publications.

Figure 2 shows a conventional magnetic recording medium. In the figure, a magnetic recording disk (1), which is a magnetic recording medium, has a glass substrate (2) made of glass, a magnetic layer (3), a protective layer (4 (6) is a magnetic head that is placed facing the magnetic recording disk (1) and forms a minute gap (9), and (7) is a magnetic head (6) that has magnetic flux. (8) gives rise to the winding, (10) shows the magnetization.

The principle of magnetic recording between the magnetic recording disk (1) and the magnetic head (6) is as shown in this figure.
A current is passed through the winding (7) and a magnetic flux (8) is applied to the magnetic head (6>).
), thereby magnetizing the magnetic layer (3〉) in any direction with the leakage magnetic flux generated from the minute gap (9) (1
0) Do.

When reading information, contrary to the above-mentioned writing, the magnetic field generated from the magnetized magnetic layer (3) causes the winding (7) to
> induces a current, and this induced current is read as an electrical signal.

Fig. 3 shows a fixed magnetic disk device incorporating the magnetic recording disk (1> and magnetic head (6) shown in Fig. 2; in the figure, (l1>) indicates the magnetic recording disk (1). A fixing spindle (12) is a data hand that performs fflL'M writing via the magnetic layer on the magnetic recording disk (1);
(13Hj Servo head that reads position information recorded on one side of a predetermined magnetic recording disk (1), (14) is a head arm that supports the data head (12) and servo head (13), (15) is the head The actuator (16) is a voice coil motor that moves the actuator (15) to the target position based on the position information obtained through the servo head (13). 17) is the data surface for reading and writing data information, and (18) is the servo surface for reading position information. Next, we will explain these operations. As shown in Figure 3, the data head (12) and the servo head (13) is supported by a head arm (l4), and all heads are inserted diametrically at the same time on each side of the magnetic recording disk (1).In this case, positioning of the data head (12) on a predetermined track is the servo head (l3)
The servo head <13> reads the position information written in advance on the servo surface (18>) facing the servo head <13>, controls the voice coil motor (6) by power amplification, and moves the actuator (15) to a predetermined position. It is done by.

In addition, reading and writing data information as shown in Figure 2,
This is performed simultaneously with the position detection of the servo head (13) described above using the data head (12) selected in advance. [Problems to be Solved by the Invention] Conventional magnetic recording media are configured as described above, and the reading of position information by the servo head (13) and the writing of position information by the opposing data head (12) are performed simultaneously. It will happen. Therefore, the electromagnetic waves generated by the writing of the data head (12) penetrate the magnetic recording medium (1) and affect the position signal reading of the servo head (13) as electromagnetic noise, resulting in positioning errors. There was a risk. The present invention was made to solve the above-mentioned problems, and an object of the present invention is to obtain a magnetic recording medium in which a servo head is shielded from electromagnetic waves so that accurate positioning signals can be read.

[Means to solve the problem]

The magnetic recording medium according to the present invention has a structure in which an electromagnetic shielding layer made of a superconductor, a magnetic layer, and a protective film are sequentially laminated on a glass substrate. [Function] In the present invention, since a superconducting film is formed on the glass substrate, the Meissner effect of this superconductor blocks electromagnetic waves generated from the data head.

[Failure to implement]

FIG. 1 shows an embodiment of the present invention, in which (2) is a substrate made of glass, (5) is a superconducting thin film deposited on the substrate, (3) is a superconducting thin film (5) The shaped magnetic layer (4) is further formed into a magnetic recording medium (21) by a protective layer formed on the magnetic layer (3). As a result, electromagnetic waves generated during writing by the data head (12>) can be blocked, and accurate positioning signals from the servo head (13) can be read.

〔Effect of the invention〕

As described above, according to the present invention, an electromagnetic shielding layer, a magnetic layer, and a protective layer made of a superconductor are sequentially laminated on a glass substrate, so that unwanted electromagnetic waves are prevented by the Meissner effect of the superconductor. It is possible to read the accurate positioning signal of the servo head by blocking it.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an embodiment of the present invention, FIG. 2 is a sectional view of a main part of a conventional magnetic recording medium, and FIG. 3 is a conventional fixed magnetic disk device incorporating a magnetic recording medium and a magnetic head. FIG. (2)...Glass base material, (3>
・・Magnetic layer, (4) Protective layer, (5) ・・Electromagnetic shielding layer made of superconducting film, (6> ・・Magnetic head, (2l
)...Magnetic recording medium. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In a magnetic recording medium that is built in a fixed magnetic disk drive and has a glass base material, an electromagnetic shielding layer made of a superconductor, a magnetic layer, and a protective film are sequentially laminated on the glass base material. Features of magnetic recording media.