JPH0194554A - Magneto-optical recording medium and recording and reproducing method using it - Google Patents

Abstract

PURPOSE:To obtain a recording medium doing with one head for a bias magnetic field by forming a spacer, a magneto-optical magnetic film, vertical magnetic medium and protecting film on a substrate to execute an overlight at high speed. CONSTITUTION:The recording film is that, for example, a CoCr vertical magnetic film or a barium ferrite vertical magnetic film is formed on a resin substrate 1, a magneto-optical magnetic film 3 is laminated on that and further, a protecting film 4 is laminated on that. Or, the magneto-optical magnetic film 3 is laminated on the resin substrate 1, and the CoCr vertical magnetic film 2 or the barium ferrite vertical magnetic film 4 and the protecting film are laminated on that and further, those laminated elements are pasted together with the protecting film 4 sides facing each other. Recording and reproducing are executed by using a magnet-optical magnetic body of the two-layer structure of the magneto-optical magnetic film 3 and an auxiliary magnetic film, an optical head and one magnetic head for the bias magnetic field having both the optical head and a track and being in a distant position. Thus, the recording medium to execute the overlight at high speed and to with one magnetic head can be obtained.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a magneto-optical recording medium and a recording/reproducing method using the same, and particularly relates to a magneto-optical recording medium that enables high-speed override and a recording/reproducing method using the same. .

[Conventional technology]

Conventionally, MnB1 has been used as a recording medium for magneto-optical memory.
, MnAlGe, PtCo, GdFe, GdCo
, TbFe, and GdTbFe. A magneto-optical memory is obtained by forming a magnetic thin film for magneto-optical recording as a recording layer on a substrate such as glass, a silicon wafer, or a resin using a method such as a vacuum evaporation method or a sputtering method.

Characteristics of these recording media include magnetic anisotropy perpendicular to the film surface and relatively low Keeley temperature and magnetic compensation temperature. Since these recording media have perpendicular magnetic anisotropy, information is recorded with a logical value of 1o'' or 11'' depending on whether the recording layer on the substrate is magnetized upward or downward perpendicular to the film surface. This is done by writing in binary values as digital signals.

As a method for recording information, for example, an external magnetic field is applied perpendicularly to the entire film surface of the recording layer in advance to magnetize the recording layer so that it is magnetized upward, and after writing '0#, '1# is written. A laser beam is irradiated across the area to heat it.

Since the heated minute part has a small Hc, if a weak external magnetic field is applied in the direction of downward magnetization during laser beam irradiation, the magnetization will be reversed and @1'' will be recorded. A method is used to form a magnetic recording pattern in the recording layer, with or without beam irradiation.

In addition, as a method for reading information, for example, when a magnetic recording pattern is irradiated with a linearly polarized laser beam, the effect of rotating the plane of polarization of the reflected light (called magnetic force effect and magnetic Faraday effect, respectively) is recorded. For example, when using the magnetic force effect, the reflected light enters the photodetector by utilizing the fact that the rotation angle θk of the polarization plane of the reflected light differs depending on the direction of recording magnetization. The light is then passed through an analyzer and information corresponding to the direction of magnetization is read out as changes in the amount of light.

Further, information can be erased by, for example, applying a strong external magnetic field to the entire recording layer to align the magnetization direction in one direction, or heating the entire recording layer to Curie temperature.

Data is recorded and reproduced using the methods described above, but these methods do not allow so-called overriding, in which new data is directly overlaid on previous data. Recently, a method using magnetic field modulation, a method using two light beams, and a method using a two-layer structure of the magneto-optical medium have been proposed as methods for performing this override.

As a method of making a magneto-optical medium into a two-layer structure, for example, the 1985 Spring National Conference of the Japanese Society of Applied Physics, Yokusu Collection, p.
There is a paper written in ZL-3. That is, TbFe and GdTbFe are used as the memory layer and auxiliary layer of a two-layer medium, respectively, and two bias magnetic field heads are provided, one of which magnetizes only the auxiliary layer with a magnetic field, and the other that applies a bias magnetic field for recording data. give. However, the directions of the magnetic fields for the two bias magnetic fields are opposite to each other. In this way, geo-perlite is struck by light modulation.

[Problem that the invention seeks to solve]

In the above-mentioned conventional magneto-optical recording medium and recording/reproducing method using the same, in order to perform high-speed override, the magneto-optical magnetic film has a two-layer structure and two magnetic heads are used.
Magnetize the auxiliary layer in one direction using de to create a magnetic field of 10,000 yen.
Next, a reverse magnetic field is applied using a magnetic head. In this state, the magneto-optical medium is sandwiched between the two magnets, and the light at the position opposite the do is overwritten with data. This method requires two bias magnets or electromagnets, increases the cost of the optical head, and has poor data reliability because the Curie points of the two-layer media are relatively close to each other. There is a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magneto-optical recording medium that performs override at high speed and requires only one dot for a bias magnetic field, and a recording and reproducing method using the same.

[Means for solving problems]

The magneto-optical recording medium of the first invention includes a substrate, a spacer formed on the top of the substrate, a magneto-optical magnetic film formed on the spacer, and a magneto-optical magnetic film formed on the magneto-optical magnetic film. A magneto-optical recording medium according to a second aspect of the present invention includes a perpendicular magnetic medium and a protective film formed on the perpendicular magnetic medium. two magneto-optical recording elements comprising a magneto-optical magnetic film formed on the spacer, a perpendicular magnetic medium formed on the magneto-optical magnetic film, and a protective film formed on the perpendicular magnetic medium; and an adhesive layer that adheres the magnetic recording element between the protective films.

The magneto-optical recording medium of the third invention includes a substrate, a spacer formed on the top of the substrate, a perpendicular magnetic medium formed on the spacer, and an optical recording medium formed on the perpendicular magnetic medium. It is configured to include a magneto-magnetic film and a protective film formed on the magneto-optical film.

The magneto-optical recording medium of the fourth invention comprises a substrate, a spacer formed on the upper part of the substrate, a perpendicular magnetic medium formed on the spacer, and a magneto-optical magnetic film formed on the perpendicular magnetic medium. and a protective film formed on the magneto-optical magnetic film, and an adhesive layer for adhering the magneto-optical recording elements to each other.

The recording and reproducing method using the magneto-optical recording medium according to the invention of Book 5g5 uses a magneto-optical recording medium comprising at least a perpendicular magnetic medium and a magneto-optical film and one bias head, and when recording, the magneto-optical recording medium is used. Data is recorded on the bias, and when the recorded data comes to the position of the first laser beam, it is applied to the magneto-optical magnetic film according to the magnetization state of the data recorded on the perpendicular magnetic medium. The device is configured to record data and read the data using a second laser beam that is weaker than the first laser beam during reproduction.

[Effect]

In the magneto-optical recording medium of the present invention, for example, a CoCr perpendicular magnetic film or a barium ferrite perpendicular magnetic T&F film having a large Curie point is formed on a resin substrate, a magneto-optical magnetic film is formed on top of the CoCr perpendicular magnetic film or a barium ferrite perpendicular magnetic film, and a protective film is further applied thereon. A magneto-optical magnetic film is formed on a layer or a resin substrate, and a CoCr perpendicular magnetic film or a barium ferrite perpendicular magnetic film is formed thereon,
It consists of a protective film laminated thereon, and a protective film laminated to each of the above-mentioned elements with their sides facing each other.

Further, the recording and reproducing method using the magneto-optical recording medium of the present invention includes:
Same as the magneto-optical recording medium mentioned above.

When recording data, data signals are recorded on the auxiliary layer of the ferrite perpendicular magnetic film directly above the CoCB5 direct magnetic film. Then, when the recorded data signal portion of the auxiliary layer reaches the optical position, it is recorded on the magneto-optical magnetic film by the recording beam of the optical head. At this time, the data recorded on the magneto-optical film faithfully transfers the magnetization state of the data signal of the auxiliary layer. However, the condition is that the Keeley point of the CoCr perpendicular magnetic film is larger than the Curie point of the magneto-optical magnetic film. The substrates used here include glass, PMMA, and polycarbonate (PC).
The magneto-optical magnetic film is made of TbFeCo.

GdCo, 'l'bFe, etc., and Si3 for the spacer.
A CoCr perpendicular magnetic film, a barium ferrite perpendicular magnetic film, etc. are used for the auxiliary layer, and an electromagnet with a coil wound around MnZn7 elite, sendust, permalloy, etc. is used for the magnetic head for the bias magnetic field.

As described above, a magneto-optical magnetic material with a two-layer structure of a magneto-optical magnetic film and an auxiliary magnetic film, an optical head, and a bias magnetic field that shares the dots, tails, and ri but are located at a separate location are used to connect the optical head and its light. By using a method of recording and reproducing data using a magnetic head, it is possible to unify the magnetic field and the magnetic field, and to determine the magnetic properties of the auxiliary layer almost independently, so the recording magnetic field can be reduced and override is possible. can be performed at high speed. Since the magnetic head can be integrated into one, manufacturing costs can be reduced. Furthermore, since the recording power can be kept constant, highly reliable recording is possible.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view of a first embodiment of the first invention.

As shown in FIG. 1, a spacer 5 is formed on a resin substrate 1 to a film thickness of 1100 nm by a sputtering method, and a magneto-optical magnetic film 3 of TbFeCo is formed on the spacer 5 to a film thickness of 80 nm by a sputtering method. A CoCr perpendicular magnetic film 2 is formed on the magneto-optical magnetic film 3 to a thickness of 0.2 μm by sputtering.
A protective film 4 of Si3N4 is formed on the oCr perpendicular sacrificial magnetic film 2 to a thickness of 0.2 μm by sputtering.

FIG. 2 is a sectional view of a second embodiment of the first invention.

As shown in FIG. 2, the second embodiment of the first invention is a CoCr perpendicular magnetic film 2 of the first embodiment of the first invention.
The configuration is such that a barium ferrite perpendicular magnetic film 11 is used instead.

FIG. 3 is a sectional view of an embodiment of the second invention.

As shown in FIG. 3, the two protective films 4 of the magneto-optical recording element laminated in the same manner as in the first embodiment of the first invention shown in FIG. 6 is pasted together.

Note that a barium ferrite perpendicular magnetic film may be used instead of the CoCr perpendicular magnetic film 2.

FIG. 4 is a sectional view of the first embodiment of the third invention.

As shown in FIG. 4, in the first embodiment of the third invention, spacers 5 are deposited on a resin substrate 1 to a film thickness of lQQ.
CoCr perpendicular magnetic film g2 is formed on the spacer 5 to a thickness of 0.2 μm by sputtering, and a TbFeCo magneto-optical magnetic film 3 is formed on the CoCr perpendicular magnetic film 2 to a thickness of 3Q nm by sputtering. A protective film 4 of 8i3N4 is formed on the magneto-optical magnetic film 3 to a thickness of 0.2 by sputtering.
It is formed by depositing a film in μm.

FIG. 5 is a sectional view of a second embodiment of the third invention.

As shown in FIG. 5, the second embodiment of the third invention has a structure in which the CoCr perpendicular magnetic film 2 of the first embodiment of the third invention is replaced with a barium ferrite perpendicular magnetic film 11. .

FIG. 6 is a vIfr plane view of an embodiment of the fourth invention.

As shown in FIG. 6, two magneto-optical recording elements, which have been stamped in the same manner as in the first embodiment of the third invention shown in FIG. It is constructed by laminating layers 6 together.

Note that a barium ferrite perpendicular magnetic film may be used instead of the CoCr perpendicular magnetic film 2.

FIG. 7 is a block diagram of a magneto-optical disk device using an embodiment of the fifth invention.

As shown in FIG. 7, the magneto-optical disk device has the same structure as the first embodiment of the first invention described above; The bias magnetic field electromagnet 9 and the electromagnet driving power source 10 are provided, which share the same track as the electromagnet 7.

When recording data, a data signal is input to the electromagnet drive power supply 10, a recording current is passed through the coil of the bias magnetic field electromagnet 9 by the output from the electromagnet drive power supply 10, and the 5Ii field generated from the bias magnetic field electromagnet 9 is used to Data is recorded on the CoCr perpendicular magnetic PA 2, and when the recorded data reaches the position of the optical head 7 by rotating the magneto-optical disk 120 times (arrow A indicates the direction of rotation), it is exposed to a light beam 8 with a constant intensity. Data is recorded on the magneto-optical magnetic film 3 in accordance with the waxing direction of the data signal recorded on the pcocr red orthogonal magnetic film 2.

Furthermore, when overriding new data on the data recorded on the magneto-optical magnetic film 3, the data to be overwritten is first transferred to the pcocr by the bias magnetic field electromagnet 9.
The override is completed by recording on the perpendicular magnetic film 2 and recording the data on the magneto-optical magnetic film 3 when the data reaches the position of the light beam.

〔Effect of the invention〕

As explained above, the magneto-optical recording medium of the present invention can reduce the coercive force of the perpendicular magnetic film that is the auxiliary layer, so the magnetic field of the bias magnetic head can be reduced and high-speed override can be performed. effective.

Furthermore, the recording and reproducing method using the magneto-optical recording medium has the effect of reducing the cost because only one bias magnetic head can be used.

[Brief explanation of the drawing]

1 and 2 are sectional views of the first and second embodiments of the first invention, respectively, FIG. 3 is a sectional view of one embodiment of the second invention, and FIGS. 4 and 5 The figures are cross sections of the first and second embodiments of the third invention, respectively. 1... Resin substrate, 2... CoCr perpendicular magnetic film, 3... Magneto-optical film, 4...
・Protective film, 5...Spacer, 6...Adhesive layer, 7...Original head, 8...Light beam, 9... Bias magnetic field electromagnet, 10...
. . . Electromagnet drive power source, 11 . . . Barium ferrite perpendicular magnetic film, 12 . . . Magneto-optical disk. Agent Patent Attorney Susumu Uchihara Figure 2 Figure 3 - Figure 4 Figure 5 Figure 61! L

Claims (7)

[Claims] (1) a substrate, a spacer formed on the top of the substrate,
A magneto-optical magnetic film formed on the spacer, a perpendicular magnetic medium formed on the magneto-optical magnetic film, and a protective film formed on the perpendicular magnetic medium. Magneto-optical recording medium. (2) A substrate, a spacer formed on the upper part of the substrate, a magneto-optical magnetic film formed on the spacer, a perpendicular magnetic medium formed on the magneto-optical magnetic film, and a perpendicular magnetic medium formed on the perpendicular magnetic medium. two magneto-optical recording elements each having a protective film formed thereon;
A magneto-optical recording medium comprising: an adhesive layer for adhering the magneto-optical recording element to each other between the protective films. (3) The magneto-optical recording medium according to claim (1) or (2), wherein the perpendicular magnetic medium is at least one selected from the group consisting of CoCr and barium ferrite. (4) a substrate, a spacer formed on the top of the substrate,
It is characterized by comprising a perpendicular magnetic medium formed on the spacer, a magneto-optical magnetic film formed on the perpendicular magnetic medium, and a protective film formed on the magneto-optical magnetic film. Magneto-optical recording medium. (5) A substrate, a spacer formed on the top of the substrate, a perpendicular magnetic medium formed on the spacer, a magneto-optical magnetic film formed on the perpendicular magnetic medium, and a magneto-optical magnetic film formed on the magneto-optical magnetic film. two magneto-optical recording elements each having a protective film formed thereon;
A magneto-optical recording medium comprising: an adhesive layer for adhering the magneto-optical recording element to each other between the protective films. (6) The magneto-optical recording medium according to claim (4) or (5), wherein the perpendicular magnetic medium is at least one selected from the group consisting of CoCr and barium ferrite. (7) Using a magneto-optical recording medium comprising at least a perpendicular magnetic medium and a magneto-optical magnetic film and one bias head, data is recorded on the perpendicular magnetic medium by the bias head during recording, and the recorded data is When the data reaches the position of the first laser beam, the data is recorded on the magneto-optical magnetic film according to the magnetization state of the data recorded on the perpendicular magnetic medium, and during reproduction, the first laser beam, which is weaker than the first laser beam, is used. 2
1. A recording and reproducing method using a magneto-optical recording medium, characterized in that data is read out using a laser beam.