JPS63113839A - Magneto-optical information recording and reproducing device - Google Patents

Abstract

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

Description

[Detailed Description of the Invention] [Summary] A magnet for generating a magnetic field in a magneto-optical head necessary for recording magneto-optical information is attached to two disks forming a recording medium.
- To provide an economical magneto-optical information recording and reproducing device by configuring a magneto-optical head so that only one magnet is needed, thereby saving space for installing magnets and reducing the number of parts.

[Industrial application field]

The present invention relates to a magneto-optical information recording/reproducing device using a magneto-optical recording method, and particularly to a magneto-optical information recording/reproducing device which records/reproduces/erases information on a plurality of magneto-optical recording media, and which simplifies the configuration of a magneto-optical head. The present invention relates to an information recording/reproducing device.

2. Description of the Related Art In recent years, magneto-optical information recording and reproducing devices have been attracting attention as a large-capacity file disk system using a magneto-optical recording method that allows recorded information to be erased and information to be recorded again.

This magneto-optical information recording/reproducing device serves as a magneto-optical recording medium.
For example, a disk is used that includes a recording layer provided on a glass disk and a protective layer that protects the recording layer. To record information, thermal energy generated by focusing laser light onto the recording layer using a lens is used.

There are a compensation point temperature recording method and a Curie point temperature recording method as information recording methods, and each method will be briefly explained below.

The disk 1i1 is magnetized in advance in one direction by an external magnetic field having a coercive force greater than the coercive force of the recording layer, and this recording layer is irradiated with a laser beam narrowed to a minute spot.
Increase the temperature of a portion of the recording layer. The coercive force of a recording medium decreases as the temperature rises.

When performing compensated temperature recording, the compensation temperature of the recording layer is set near room temperature, the temperature of the recording medium is raised to the temperature reached by laser beam irradiation, and a magnetic field is externally applied to the locations where the coercive force has decreased. to form reversed magnetic domains.

When performing Curie point temperature recording, a part of the recording layer is heated to above the Curie point temperature by irradiation with a laser beam, and a magnetic field is applied externally, or a reversal magnetic field is applied based on the magnetic force held by the recording layer. This forms an inverted magnetic domain.

Reproduction of recorded information is performed using the magneto-optic effect, ie the Kerr effect or the Faraday effect. This is because the polarization plane of reflected light or transmitted light rotates depending on the presence or absence of reversed magnetic domains, and this can be used to read information.

When erasing recorded information, there are two methods: applying an external magnetic field in the opposite direction to the magnetic field direction during recording and uniformly irradiating the laser beam; There is a method of collapsing magnetic domains.

The optical system part of the magneto-optical head that focuses the laser beam on the recording layer, that is, the optical system head, has almost the same structure as the optical head of an optical disk device, but the difference between the magneto-optical head and the optical head is that the magnet is necessary. If this magnet is installed on the same side of the disk as the optical system head, the magnetic field will be diffused and the structure will be complicated to prevent it from affecting the coil that controls the focus of the lens. are located opposite each other with the two sides in between.

By the way, magneto-optical information recording and reproducing devices generally use one disk, but in order to increase the recording capacity, it is necessary to provide multiple disks, and as the number of disks increases, the number of magneto-optical heads increases. Since the number of magneto-optical heads increases, it is desirable to simplify the structure of the magneto-optical head.

[Conventional technology]

FIG. 3 is a diagram illustrating an example of a conventional magneto-optical head.

1 is an optical system head, 2 is a lens, 3 is a disk, 4 is a protective layer, 5 is a recording layer, 6 is glass, 7 is an electromagnet, and 8 is an arm to which the optical system head 1 and magnet 7 are attached. The optical head 1 and the electromagnet 7 follow tracks provided on the disk 3 by an access mechanism that drives an arm 8.

The disk 3 has substantially the same configuration as an optical disk, and although disks with various configurations are provided, the basic configuration will be shown here. For example, the recording layer 5 of the disc 3 is marked with an arrow 9.
It is magnetized in the direction shown in . For example, a laser beam is supplied from a light source to the lens 2 of the optical system head l, and the lens 2
The light beam is focused on the recording layer 5 of the disk 3 by this.

The thermal energy generated by this focused light beam heats one point on the recording layer 5. In order to form an inverted magnetic domain at this heated location as described above, by supplying current to the coil of the electromagnet 7 and applying a magnetic field in the opposite direction to the arrow 9,
The heated point is magnetized in the opposite direction to its surroundings, as shown by arrow 10.

In the Curie point temperature recording method, the electromagnet 7 does not necessarily have to be operated, but is used to ensure magnetization.

When reproducing information, a light beam of lower power than during recording is emitted from the optical head l, and detection is made from the rotation of the deflection plane of the reflected light as described above.

When erasing is performed, for example, a magnetic field in the same direction as the arrow 9 is generated by the electromagnet 7, and a light beam is uniformly irradiated from the optical system head 1.

[Problem that the invention seeks to solve]

As described above, the magneto-optical information recording and reproducing device has an optical system head 1.
Electromagnets 7 facing each other with the disk 3 in between are required, and if a plurality of disks 3 are provided, it is necessary to provide the same number of optical system heads l and electromagnets 7 as the number of disks 3, which complicates the configuration of the magneto-optical head. Additionally, there is a problem that a large amount of installation space is required.

[Means for solving problems]

FIG. 1 is a diagram illustrating an embodiment of the present invention.

11.12 is a disk, 13.14 is an optical system head, 1
5 is an electromagnet, and 16 is an arm.

The arm 16 connects the optical heads 13 and 14 to the disks 11 and 1.
2, and the electromagnet 15 is arranged to face the optical system head 13 with the disk 11 in between, and the optical system head 14 with the disk 12 in between.
3 and 14, and the configuration is such that a magnetic field for recording or erasing is supplied to the disks 11 and 12.

[Effect]

With the above configuration, the number of component parts of the magneto-optical head can be reduced, and the installation space for the electromagnet can be reduced. Further, when a plurality of disks 11, 12 are provided and each disk is provided with an opposing optical head, the number of electromagnets can be halved, so the size of the magneto-optical information recording/reproducing apparatus can be reduced.

〔Example〕

In FIG. 1, optical heads 13 and 14 and electromagnet 15 follow target tracks on disks 11 and 12 by an access mechanism that drives arm 16. In FIG. The electromagnets 15 generate magnetic fields in directions opposite to those held by the recording layers of the disks 11 and 12, respectively.

Therefore, the magnetic field at the heating point of the disk 11 heated by the light beam sent out by the optical head 13 and the heating point of the disk 12 heated by the light beam sent out by the optical head 14 will be in the same direction as the previously held magnetic field. are magnetized in opposite directions.

FIG. 2 is a diagram illustrating another embodiment of the present invention.

FIG. 2(a) shows a case in which three disks are provided as shown at 11, 12, and 17, and the optical system heads 13 and 14 and the electromagnet 15 are connected by an arm 16 as shown by the solid line in the same manner as in FIG. Information is recorded on the disks 11 and 12.

In addition, when recording information on the disks 12 and 17, the optical system heads 13''' and 14'' and the electromagnet 15 indicated by dotted lines are used.
Replace as shown in ゛ and record in the same manner as above.

When recording information only on the disk 11, the disk 11 is sandwiched between the diagonally shaded optical system head 14'' and the electromagnet 15'', and recording is performed in the same manner as described above.

In the case of FIG. 2(a), it goes without saying that the disks 11, 12, and 17 must be provided with recording layers on both sides.

FIG. 2 (bl shows optical system heads 13, 14, 19, 20 and electromagnet 15.
21 is provided and attached to the arm 22 to follow the tracks of each disk, and information recording is the same as described above.

Note that the reproduction and erasing of recorded information is as explained in FIG. 3. Also, although this embodiment was explained using an electromagnet,
Of course, permanent magnets may also be used.

〔Effect of the invention〕

As explained above, the present invention can reduce the number of electromagnets to half of the conventional one, save the space for placing the electromagnets,
An economical magneto-optical information recording/reproducing device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining one embodiment of the present invention, FIG. 2 is a diagram for explaining another embodiment of the present invention, and FIG. 3 is a diagram for explaining an example of a conventional magneto-optical head. In the figure, 1.13, 14, 19.20 are optical system heads, 2 is a lens, 3.11.12.17.18 is a disk, 4 is a protective layer, 5 is a recording layer, 6 is glass, 7, 15 .21 is an electromagnet, 8.16.
22 is an arm. ! ? 3rd filial piety

Claims (2)

[Claims] (1) Light from a light source is passed through a lens to a recording medium (11) (
12) By heating the recording layer in a focused manner, raising the temperature of the recording layer, and applying a magnetic field in the opposite direction to the magnetic field held by the recording layer, a reversal magnetic field is formed at the heated point. This is a magneto-optical information recording and reproducing apparatus for recording information, and includes two optical heads (13) and (14) equipped with lenses that focus light from the light source onto the recording medium. A magnet (15) is placed between the two recording media (11) (12) and facing the optical system head (13) (14). 1. A magneto-optical information recording and reproducing device comprising a magneto-optical head configured by arranging a magneto-optical head. (2) Either a plurality of the above recording media (11) and (12) are provided, one of the above magneto-optical heads is provided, and the magneto-optical head is replaced, or each of the plurality of recording media is provided with the above-mentioned magneto-optical heads, and all What is claimed is: 1. A magneto-optical information recording and reproducing device for recording and/or reproducing and/or erasing information on a recording medium.