JPH01173402A - Exciting element for magneto-optical recording - Google Patents

Abstract

PURPOSE:To generate a bias magnetic field with uniform distribution by providing a main core opposing to the surface of a recording medium with the surface parallel with the recording medium surface and the surface not parallel with the same. CONSTITUTION:An exciting element 1 is constituted of the main core 2, an auxiliary core 3 and a coil 4, and the surface 201 and the surface 202 are formed so as to be respectively the surface which is parallel with the recording medium surface and the surface which is provided on the opposite side of the auxiliary core 3 and is not parallel with the same. Then, as for the bias magnetic field, magnetic field vectors 5a, 5b are generated from the surface 201 of the main core 2 to be parallel with the recording medium surface, and the magnetic field vector 5c is generated from the surface 202 to be not parallel with the same. Accordingly, the magnetic field 5b of a point distant from the auxiliary core is summed with the magnetic field 5c, and the magnetic field 5b' with the nearly same intensity as 5a can be generated. Thus, the distribution of the magnetic field on the surface 201 can be uniformized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an excitation element for magneto-optical recording.

(Conventional technology 0) Conventionally, as this type of excitation element for magneto-optical recording,
As shown in Japanese Patent No. 2-172504, an excitation element having a laterally symmetrical E-shaped core has been proposed.

In Figure 2, which shows the arrangement of the medium and optical system when an excitation element is provided in a magneto-optical recording disk device, (1
) is an excitation element consisting of a main core (2), auxiliary cores (3a) and (3b), and a coil (4). (6) is a disk medium, which is composed of a magnetic layer (7) and a substrate (8).

(9) is an objective lens for converging light, and (10) is a laser light source. (5a) and (5b) are vectors of the magnetic field generated from the main core.

Next, the operation will be explained. In magneto-optical recording, first, a laser beam is generated from a laser light source (10), passes through an objective lens (9) for converging the light, and is applied to a magnetic layer (7) of a disk medium.
), a minute spot with a diameter of 1 to 2 μm is focused, a bias magnetic field is applied at the same time as the medium temperature is raised, and a signal is recorded by leaving a magnetic domain magnetized in the direction of the bias magnetic field.

By passing current through the coil (4) of the excitation element (1), bias magnetic fields (5a) and (5b) are generated from the main core (2). In addition, in order to increase the efficiency of the core, auxiliary cores (3a) and (3b) are provided on the left and right sides of one core to shorten the length of the magnetic path in the air.

(Problems to be Solved by the Invention) The conventional excitation element with an E-shaped core has auxiliary cores on the left and right sides of the main core, which not only increases the size of the core, but also makes the structure complex and difficult to process. There were some problems, such as it disappearing.

On the other hand, INTERNATI○NAL as shown in Figure 3
SYNPO3IUM ON 0PTICAL
MEMORY 1987 Since the excitation element proposed in P2N2 has one auxiliary core, the magnetic field (5b) on the main core at a point away from the auxiliary core becomes very small, causing problems such as the uniformity of the magnetic field distribution. Ta.

This invention was made to solve the above-mentioned problems, and aims to provide an excitation element that is small, has good workability, has a uniform magnetic field distribution, and has a high core efficiency.

(Means for Solving the Problems) A magneto-optical recording excitation element according to the present invention is composed of a main core and an auxiliary core disposed on the side thereof, and the main core facing the recording medium surface is It has a surface that is parallel to the surface of the recording medium and a surface that is not parallel to the surface of the recording medium.

(Function) The excitation element for magneto-optical recording according to the present invention has a main core facing the recording medium surface, which has a surface parallel to the recording medium surface and a surface nonparallel to the recording medium surface, so that a bias magnetic field with a uniform distribution can be generated. It can be generated efficiently.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
In the figure, (1) is an excitation element, (2) is the main core, (3 is
It consists of an auxiliary core () and a coil (4). (20
1) is a surface that is parallel to the recording medium surface, and (202) is a non-parallel surface provided on the opposite side of the auxiliary core. (6
) is a disk medium, which is composed of a magnetic layer (7) and a substrate (8). (9) is the objective lens for light convergence, (
10) is a laser light source. (5a), (5b), (
5b') from the plane parallel to the recording medium surface of the main core,
(5c) is the vector of the magnetic field generated by the non-parallel surfaces.

Next, the operation will be explained. The principles of recording and erasing are the same as in the conventional example. Laser light generated from a laser light source (10) is transferred to a disk medium (6) using an objective lens (9).
A signal is recorded by narrowing the spot to a minute spot with a diameter of 1 to 2 μm on the magnetization layer (7), increasing the medium temperature and simultaneously applying a bias magnetic field to leave a magnetic domain magnetized in the direction of the bias magnetic field. Recording is performed by forming reversed magnetic domains in the magnetization layer.

Bias magnetic fields (5a) and (5b) are generated from the surface (201) of the main core (2) that is parallel to the recording medium surface, and (5c) is generated from the non-parallel surface (202). Since (5C) is added to the magnetic field (5b) at a point away from the auxiliary core, it is possible to generate a magnetic field (5b') with almost the same strength as (5a), so the magnetic field distribution on (201) can be made uniform. Can be done.

In addition, the efficiency of the core is high because the magnetic path length in the air is shortened by the auxiliary core.

In the above embodiment, the case where the coil is wound around the main core has been described, but the effect remains the same even if the coil is wound around the auxiliary core.

(Effects of the Invention) As described above, according to the present invention, the distribution can be improved efficiently by having the auxiliary core, and by having the main core have a surface that is parallel to the surface of the recording medium and a surface that is not parallel to the surface of the recording medium. This has the effect of generating a uniform bias magnetic field.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an excitation element according to an embodiment of the present invention, and FIGS. 2 and 3 are side views showing conventional excitation elements. (1) is an excitation element, (2) is a main core, (3) is an auxiliary core, and (4) is a coil. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In a bias magnetic field generation core of a magneto-optical recording disk device, which is composed of a main core and an auxiliary core placed on the side thereof, the main core facing the recording medium surface is not parallel to the surface parallel to the recording medium surface. An excitation element for magneto-optical recording, characterized by having parallel surfaces.