JPH01205710A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To shield leakage flux from a magnetic head by a magnetic shield layer formed at the time of manufacturing a magnetic disk and to make an assembly task easy by interposing the magnetic shield layer between the servo face of the magnetic disk and its data face. CONSTITUTION:Positional data for servo are recorded on one face 1a of a magnetic disk 1, the other face 1b is the data face for recording and reproducing and a magnetic shield layer 1c made of ferrite, etc., is interposed between the two faces 1a and 1b. When the disk 1 is rotated in the condition of facing a magnetic head 4 for reading servo data to the servo face 1a and facing a magnetic head 5 for recording and reproducing to the data face 1b, leakage flux 5a from the magnetic head 5 is led into the magnetic shield 1c and does not reach the magnetic head 4. Consequently, it is unnecessary to provide a magnetic shield member separately and servo information can be reproduced correctly and accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device used in electronic computers, peripheral terminal equipment, and the like.

[Conventional technology]

Figure 4 shows a conventional magnetic disk device (Japanese Patent Laid-Open No. 58-175
15), 10 is a magnetic disk, and 4 and 5 are magnetic heads.

The magnetic disk 10 has a surface 10a on which servo position data is recorded (referred to as the servo surface), and the other surface is a surface 10b for recording and reproducing data (referred to as the data surface). A magnetic head 4 for reading servo data is opposed to the servo surface 10a, and a magnetic head 5 for recording and reproducing data is opposed to the data surface 10b. In this state, it is rotated by the motor 2.

The magnetic head 4.5 is supported by a carriage 6 connected to a drive mechanism (not shown), and when receiving commands from an electronic computer etc., the magnetic head 4.5 reads position data of the magnetic head 5 relative to the magnetic disk 1 through the magnetic head 4. The carriage 6 is moved by a drive mechanism, and the magnetic head 5 is moved and positioned at a predetermined position on the magnetic disk 10.

Reference numeral 8 denotes a magnetic shielding member, which is mounted on the base 7 so as to face the outer peripheral surface of the rotating part of the magnetic disk 1 between the magnetic heads 4.5.
is fixed on the data surface 10 of the magnetic disk 10.
Magnetism is cut off so that the influence of magnetism generated from the magnetic head 5 does not affect the magnetic head 4 when recording and reproducing data to and from the magnetic head 5.

FIG. 5 is an explanatory diagram of the magnetic shielding effect of the magnetic shield member 8, in which leakage magnetic flux 5a from the magnetic head 5 is prevented from reaching the magnetic head 4 by the magnetic shield member 8.

[Problem to be solved by the invention]

By the way, in the conventional device as described above, the gap between the magnetic shield member 8 and the magnetic disk 10 prevents leakage magnetic flux 5.
It is set to be as small as possible in order to enhance the blocking effect of a. However, the narrower the gap between the magnetic disk 1 and the shield member 8, the more difficult the assembly becomes, resulting in poor workability.Furthermore, when the magnetic disk 10 expands due to temperature rise, it comes into contact with the magnetic shield member 8, generating dust and destroying the data. There were drawbacks such as the possibility of destruction.

The present invention has been made in view of the above circumstances, and its purpose is to eliminate the troublesome assembly work without impairing the leakage magnetic flux shielding function, and to solve the problem of assembling the magnetic disk and the magnetic shielding member. It is an object of the present invention to provide a magnetic disk device that can eliminate the generation of dust due to contact.

[Means to solve the problem]

In the magnetic disk device according to the present invention, a magnetic shield layer is interposed between the servo surface and the data surface of the magnetic disk.

[Effect]

According to the present invention, the magnetic shield layer can be formed during the manufacture of the magnetic disk, and the conventional assembly work of the magnetic shield member is not required.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on drawings showing embodiments thereof. FIG. 1 is a schematic cross-sectional view of a magnetic disk device according to the present invention (hereinafter referred to as the device of the present invention), in which 1 indicates a magnetic disk, and 4 and 5 indicate magnetic heads.

The magnetic disk 1 has one side la, which records servo position data (referred to as servo side), and the other side, lb, which records and reproduces data (referred to as data side).
A magnetic shield layer 1c made of ferrite or the like is interposed between these surfaces 1a and lb. The magnetic disk 1 has a central hole 1d fitted into the shaft 3 of a motor 2 attached to a base 7, and has a magnetic head 4 for reading servo data on the servo surface 1a, and a magnetic head 4 for recording and reproducing data on the data surface 1b. The magnetic healds 5 for this purpose are rotated by a motor 2 while facing each other.

The magnetic heads 4 and 5 are supported by a carriage 6 connected to a drive mechanism (not shown), and when they receive a command from an electronic computer or the like, the servo of the magnetic heads 4 and 5 relative to the magnetic disk 1 is activated via the magnetic head 4. The carriage 6 is driven by the drive mechanism while reading the data, and the magnetic head 5
is moved and positioned at a predetermined position on the magnetic disk l.

FIG. 3 is an explanatory diagram showing the magnetic shielding effect of the magnetic shield layer, in which leakage magnetic flux 5a from the magnetic head 5 is guided into the magnetic shield layer IC and does not reach the magnetic head 4.

The material and thickness of one layer of the magnetic shield layer 8 are not particularly limited, and may be appropriately set so that the leakage magnetic flux 5a does not reach the magnetic head 4. Also, the magnetic shield layer 8
It is sufficient that the formation area is the area where the magnetic heads 4 and 5 face the magnetic disk 1.

〔Effect of the invention〕

As described above, in the device of the present invention, since the magnetic shield layer is interposed within the magnetic disk, it can be formed at the time of manufacturing the magnetic disk, and there is no need to provide a magnetic shield member as in the past, making it easy to assemble, and recording and reproducing. The present invention has excellent effects, such as being able to reliably block the leakage magnetic field of the magnetic head used for the purpose of the present invention, and making it possible to correctly and accurately reproduce servo information.

[Brief explanation of the drawing]

Fig. 1 is a schematic vertical cross-sectional view of the device of the present invention, Fig. 2 is a partially enlarged view of the magnetic disk and magnetic head, Fig. 3 is an explanatory diagram of the function of the magnetic shield layer, and Fig. 4 is a schematic longitudinal cross-sectional view of the conventional device. The top view and FIG. 5 are the same (this is an explanatory diagram of the action of the magnetic shielding member. 1...Magnetic disk 1a...Servo surface ib...
Data surface for recording and reproduction 1c...Magnetic shield layer 2.
...Motor 3...Axis 4, 5...Magnetic head 6.
...Carriage In the drawings, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. In a magnetic disk device using a magnetic disk having a servo magnetic head on one side and a reproducing magnetic head on the other side, the magnetic disk has a magnetic shield layer interposed between both surfaces thereof. A magnetic disk device characterized by: