JPH0266701A - Exciting element for magneto-optical recording - Google Patents

Abstract

PURPOSE:To obtain an exciting element for magneto-optical recording in which a temperature rise is small and a generated magnetic field intensity is stable even at the time of supplying a large current by providing a core for generating a bias magnetic field, a coil to excite the core and a radiating part adhered and arranged at least on one surface of the core. CONSTITUTION:For the recording and erasing, a laser light to occur from a laser light source 10 is diaphragmed for example to a micro spot of 1 to 2mum diameter on a magnetizing layer 7 of a disk medium 8 with an objective lens 9, a medium temperature rises, simultaneously, a bias magnetic field is impressed, the inverting magnetic domain is formed on the magnetizing layer 7 and thus, recording executed. The heat to occur in a coil 4 at the time of generating the magnetic field is communicated to a main core 2 and an auxiliary core 3, further, communicated to a radiating member 11 with a high thermal conduction ratio, diffused to the circumference, and therefore, the temperature rise of the main core 2 and the coil 4 is reduced. An exciting element for magneto-optical recording in which even at the time of supplying a large current, the temperature rise is small and the generated magnetic field intensity is stable can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an excitation element for magneto-optical recording, and particularly to improvement of its heat dissipation properties.

[Conventional technology]

Conventionally, as an excitation element for magneto-optical recording, it has been proposed to use an electromagnet having a core made of a material with high magnetic permeability, as disclosed in, for example, Japanese Patent Laid-Open No. 172504/1983. FIG. 3 shows the arrangement of a medium and an optical system when such an excitation element is provided in a magneto-optical recording disk device. In the figure, it is the tlli excitation element, and the main core (2
), auxiliary cores (3a), (3b) and coils (4)
It consists of (6) is a disk medium, which is composed of a magnetic layer (7) and a substrate (8). (9) is an objective lens for light focusing, (101U laser light source. (5g
), (5b) U are vectors of magnetic fields generated from planes parallel to and intersecting the recording medium plane of the main core (2), respectively.

Next, the operation will be explained. Magneto-optical recording a Generally, a laser beam is generated from a laser light source (101) and passed through an objective lens (9) for focusing the light to record the magnetic layer (7) of the 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 11), magnetic fields (5a) and (5b) are generated from the main core (2). In addition, in order to increase the efficiency of the core, an auxiliary core (3m)
, (3b) are provided on the left and right sides of the main core to shorten the magnetic path length in the air.

[The problem that the invention attempts to solve]

In the conventional excitation element for magneto-optical recording constructed as described above, the main core (2) and the auxiliary cores (3a)-(3b) are generally formed of ferrite having low thermal conductivity. However, since the heat generated when a current is applied is more difficult to dissipate than the element, there is a problem in that the temperature of the element increases and the strength of the generated magnetic field may become unstable.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an excitation element for magneto-optical recording that is small and has a small temperature rise even when a large current is applied.

[Means to solve section @]

The excitation element for magneto-optical recording according to the present invention includes a core for generating a bias magnetic field, a coil for exciting the core, and a heat dissipation member disposed in close contact with at least one surface of the core.

[Function] The heat dissipation member of the present invention dissipates the heat generated in the coil when a magnetic field is generated to the surroundings, thereby reducing the temperature rise of the bias magnetic field generation core and the like.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (Illi) is a heat dissipating member, made of metal such as aluminum or copper, and is arranged in close contact with three sides of the main core (2) and the auxiliary cores (3a) and (3b).

Next, the operation will be explained. The principle of recording and erasing is the same as in the conventional example, using a laser beam generated from a laser light source [10] to create a minute spot with a diameter of 1 to 27 m on the magnetic layer (7) of the disk medium (6) using the objective lens (9). Narrow it down to
Applying a bias magnetic field at the same time as increasing the medium temperature,
Recording is performed by forming reversed magnetic domains in the magnetization layer (7).

The heat generated in the coil (4) when a magnetic field is generated is transmitted to the main core (2) and the auxiliary core (3), further transmitted to the heat dissipation member (11) with high thermal conductivity, and dissipated to the surroundings.
Temperature increases in the main core (2) and coil (4) are reduced.

In the above embodiment, the main core (2) and the auxiliary core (3)
Although the case in which the heat dissipation member (II) is closely placed on the three sides of a) and (3b) is shown, this is not limited to kneading. The same effect as in the above embodiment can be obtained.

In addition, although the above embodiment shows the case where the coil (4) is wound around the main core (2), the auxiliary core (3 m) is used.

(3b) may be wound. In addition, the auxiliary core (3
This invention can also be applied to cases where a) and (3b) are not present.

〔Effect of the invention〕

As described above, according to the present invention, the core for generating a bias magnetic field, the coil for exciting the core, and the heat dissipation member disposed in close contact with at least one surface of the core are provided.
This has the effect of providing an excitation element for magneto-optical recording in which the temperature rise is small even when a large current is applied, and the strength of the generated magnetic field is stable.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an excitation element for magneto-optical recording according to one embodiment of the present invention, FIG. 2 is a perspective view showing an excitation element for magneto-optical recording according to another embodiment of the invention, and FIG. 3 is a perspective view showing a conventional excitation element for magneto-optical recording. FIG. 2 is a perspective view showing an excitation element for magneto-optical recording. In the figure, fi+ is an exciting element, (2) main core, (3
a). (3b) H auxiliary core, [41i coil, (61fi disk medium), (9) is an objective lens, (lO) is a laser light source, and (ll) is a heat dissipation member. A considerable portion is shown.

Claims (1)

[Claims] A core for generating a bias magnetic field, a coil that excites the core,
and an excitation element for magneto-optical recording, comprising a heat dissipating member closely disposed on at least one surface of the core.