JP2002123901A - Magnetic circuit for initialization of hard disk and hard disk device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a magnetic circuit for the initialization of a hard disk capable of obtaining the strong magnetic field with the horizontal magnetic field in the magnetic circuit for the initialization of the hard disk. SOLUTION: This magnetic circuit for the initialization of the hard disk is constituted of composite permanent magnets 1a, 1b composed by tightly adhering the different magnetic poles of unit permanent magnets for each other which are opposed each other through a gap part so as to make the magnetic poles of the surfaces face to the same pole, and a pair of single permanent magnets 1c, 1d arranged in the direction nearly perpendicular to the direction of the pair of the above composite permanent magnets 1a, 1b through the above gap part to make the same poles opposite each other, then the magnetic poles of the composite permanent magnets 1a, 1b at the side opposite to the gap part and the pair of magnetic poles of the single permanent magnets at the opposite side across the gap part are tightly adhered to a common yoke 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hard disk drive, and more particularly to a hard disk initialization magnetic circuit for initializing a hard disk and a hard disk drive using the same.

[0002]

2. Description of the Related Art FIG. 2 is an external view of a conventional magnetic circuit for initializing a hard disk. The hard disk initialization magnetic circuit shown in FIG. 2 is a composite permanent magnet 3a, 3b formed by bringing a single permanent magnet into close contact with mutually different magnetic poles, through a gap so that the magnetic poles on the surfaces thereof face the same pole. The magnetic pole opposite to the gap of the composite permanent magnet is a magnetic circuit for initializing a hard disk that is in close contact with a common yoke.

FIG. 3 is an explanatory diagram of a conventional hard disk drive having a magnetic circuit for initializing a hard disk. In FIG. 3, the magnets of the same polarity with respect to the composite permanent magnets 3a and 3b of FIG. 2 are separated by 26 mm or more so that the hard disk drive 20 is inserted, and the yoke and the magnet are fixed. Has initialized the hard disk 30.

[0004]

However, the conventional magnetic circuit for initializing a hard disk requires a high magnetic field of 3000 G or more at point A. There is a problem that the strength of the magnetic field at the point A is hard to increase even if the composite permanent magnet is made large because there is a large amount of magnetic flux leaking.

Accordingly, it is an object of the present invention to provide a hard disk initialization magnetic circuit that obtains a high magnetic field with a horizontal magnetic field in a gap of the hard disk initialization magnetic circuit, and a hard disk device using the same.

[0006]

According to the present invention, there is provided a magnetic circuit for initializing a hard disk, comprising a combination of two pairs of composite permanent magnets facing each other via a gap, and a pair of permanent magnets facing each other via the gap. This is a hard disk initialization magnetic circuit composed of a combination of magnets.

That is, according to the present invention, a composite permanent magnet constituted by a single permanent magnet having different magnetic poles adhered to each other is opposed to each other via a gap so that the magnetic poles on the surface face the same pole. The pair of composite permanent magnets are arranged in a direction substantially perpendicular to the direction of the pair of composite permanent magnets through the gap, and are formed of a single pair of permanent magnets having the same polarity. The magnetic pole on the opposite side across the portion and the magnetic pole on the opposite side to the gap between the pair of single permanent magnets are a magnetic circuit for initializing a hard disk that is in close contact with a common yoke.

The present invention also relates to a hard disk drive comprising the hard disk initialization magnetic circuit and a hard disk drive unit, wherein the hard disk held in the hard disk drive unit has a one-sided recording medium unit. The circumferential part of the hard disk device is located in the gap of the hard disk initialization magnetic circuit.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic circuit for initializing a hard disk and a hard disk device using the same according to an embodiment of the present invention will be described below.

FIG. 1 is an external view of a magnetic circuit for initializing a hard disk according to an embodiment of the present invention. The hard disk initialization magnetic circuit 10 of FIG. 1 has the following configuration.

That is, a magnetic circuit 1 for initializing a hard disk
Numeral 0 indicates that the composite permanent magnets 1a and 1b, which are formed by adhering mutually different magnetic poles to a single permanent magnet, are opposed to each other via a gap so that the magnetic poles on the surfaces face the same pole. It is composed of a pair of single permanent magnets 1c and 1d which are arranged in a direction substantially perpendicular to the direction of the pair of composite permanent magnets and have the same polarity. The magnetic pole on the opposite side of the gap in the pair of composite permanent magnets and the magnetic pole on the opposite side of the gap in the pair of single permanent magnets are in close contact with a common yoke.

With the configuration of the magnetic circuit as described above, the single permanent magnets 1c and 1d have the effect of suppressing the magnetic flux leakage to the periphery of the composite permanent magnets 1a and 1b, and the magnetic disk for initializing the hard disk according to the present invention. At point A of the circuit 10, a high magnetic field can be obtained with a horizontal magnetic field. As the magnetic field at point A, a high magnetic field of 3000 G or more can be realized.

Embodiment 2 A hard disk drive according to an embodiment of the present invention has the same shape as that of FIG. 3 described above. That is, a hard disk drive is realized by using the hard disk initialization magnetic circuit of FIG. Here, in the gap of the magnetic circuit for hard disk initialization,
Since a high magnetic field of 3000 G or more is realized by a horizontal magnetic field, even a hard disk having a high coercive force can easily initialize the magnetization state.

[0014]

As described above, according to the present invention, it is possible to provide a hard disk initialization magnetic circuit that realizes a high magnetic field with a horizontal magnetic field, and a hard disk device using the same.

[Brief description of the drawings]

FIG. 1 is an external view of a magnetic circuit for initializing a hard disk according to an embodiment of the present invention.

FIG. 2 is an external view of a conventional magnetic circuit for hard disk initialization.

FIG. 3 is an explanatory diagram of a hard disk device in which a hard disk is initialized using a hard disk initialization magnetic circuit;

[Explanation of symbols]

 1a, 1b, 3a, 3b Composite permanent magnet 1c, 1d Single permanent magnet 2, 4 Yoke 10 Hard disk initialization magnetic circuit 20 Hard disk drive 30 Hard disk

Claims (2)

[Claims] 1. A composite permanent magnet comprising a single permanent magnet in which different magnetic poles are brought into close contact with each other via a gap so that the magnetic poles on the surface thereof face the same pole. And a pair of single permanent magnets arranged in a direction substantially perpendicular to the direction of the pair of composite permanent magnets and having the same polarity opposite to each other. A magnetic circuit for initializing a hard disk, wherein a magnetic pole on the opposite side and a magnetic pole on the opposite side across the gap of the single pair of permanent magnets are in close contact with a common yoke. 2. A hard disk drive comprising: a hard disk initialization magnetic circuit according to claim 1; and a hard disk drive unit, wherein the hard disk held in the hard disk drive unit has a one-sided recording medium unit. A hard disk drive wherein a radial portion in a circumferential direction is located in a gap of the hard disk initialization magnetic circuit.