JPH0660463A - Magneto-optical recording medium, magneto-optical recording and reproducing device and magneto-optical recording method - Google Patents

Abstract

PURPOSE:To provide a magneto-optical recording medium having a region only for reproduction and a rewritable region, ensuring a wide range of selection of a material used for the recording film and enabling a user to optionally produce ROM information and to provide a device and a method using the recording medium. CONSTITUTION:A 1st dielectric protective layer 2, a magneto-optical recording layer 3 and a 2nd dielectric protective layer 4 are successively laminated on a discoid substrate 1. A magnetic shielding layer 17 which prevents the transmission of a line of magnetic force is laminated on the inner circumferential part of the resulting disk as a region only for reproduction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical recording medium for recording, reproducing and erasing information by using a laser beam, and more specifically, a read-only area (ROM portion) and a recordable area (rewritable portion). The present invention relates to a magneto-optical recording medium having the same. The present invention also relates to a magneto-optical recording / reproducing apparatus and a magneto-optical recording method used for recording / reproducing of this magneto-optical recording medium.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
The prohibition of the change of the recorded contents on the magneto-optical disk is carried out by setting the write-inhibiting hole of the cartridge accommodating the disk to the write-inhibiting state. However, with this method, the entire recorded content on the magneto-optical disk is prohibited from being changed, the recorded content portion such as the document format portion or the dictionary portion is prohibited from being changed, and the document content or the auxiliary registration dictionary is not permitted to be changed. If you want to rewrite the recorded contents frequently, you must rewrite it with the write-protect hole of the cartridge in a writable state.Therefore, you must be careful in handling so that you do not accidentally change the recorded contents that you want to prohibit. It was

On the other hand, as means for solving the above-mentioned problems, Japanese Patent Laid-Open No. 58-114343 discloses a rewritable area (RAM portion) with a reflective film provided in a read-only area (ROM portion) having pits on a substrate. There is proposed a magneto-optical recording medium provided with a reproducing film for magneto-optical recording. However, in this case, the ROM section and the RAM section have different reflectivities, which imposes a burden on the recording / reproducing apparatus. Also, ROM and RA
Since the difference in reflectance of the M portion is limited to the range in which the recording / reproducing apparatus can operate, it is impossible to arbitrarily select the material used for the recording film. Further, in order to manufacture the ROM part, it is necessary to provide ROM information to the substrate at the stage of molding the substrate, and the user cannot arbitrarily manufacture the ROM part later.

The present invention has been made in order to solve the problems of the prior art as described above, and has a ROM portion and a RAM portion, and the material used for the recording film can be arbitrarily selected, and Provided are a magneto-optical recording medium in which a user can arbitrarily create a ROM portion, and a magneto-optical recording / reproducing apparatus and a magneto-optical recording method in which a user can record desired information in the ROM portion of the magneto-optical recording medium. The purpose is to

[0005]

To achieve the above object, according to the present invention, a magneto-optical recording layer and a second dielectric protective layer are provided on a transparent substrate via a first dielectric protective layer, and In a magneto-optical recording medium in which a reflective layer and a third dielectric protective layer are laminated in that order as needed, a read-only area and a rewritable area are provided, and the outermost dielectric protective layer corresponding to the read-only area. Provided is a magneto-optical recording medium characterized in that a magnetic shield layer for preventing transmission of magnetic force lines is laminated only on the portion.

Further, according to the present invention, there is provided a magneto-optical recording device for the above-mentioned magneto-optical recording medium, which is installed on both the substrate side and the magneto-optical recording layer side with respect to the mounted magneto-optical recording medium. Magnetic field generating means, a light beam irradiating means installed on the substrate side for irradiating the recording / reproducing light beam to the magneto-optical recording medium, and magnetic field lines from the magnetic field generating means on the magneto-optical recording layer side are detected. Thus, there is provided a magneto-optical recording / reproducing apparatus including a magnetic field detecting means installed on the substrate side for recognizing the read-only area and the rewritable area.

Further, according to the present invention, there is provided a magneto-optical recording device for the above-mentioned magneto-optical recording medium, which is installed on both the substrate side and the magneto-optical recording layer side with respect to the mounted magneto-optical recording medium. Magnetic field generating means, a light beam irradiating means installed on the substrate side for irradiating the magneto-optical recording medium with a recording / reproducing light beam, and a light beam irradiating the magneto-optical recording medium with the light beam. Section and a light-reception detector that detects the light beam from the light-beam irradiator reflected by the surface of the magneto-optical recording medium. There is provided a magneto-optical recording / reproducing apparatus comprising means arranged on the layer side.

Further, according to the present invention, when recording is performed in the rewritable area using the magneto-optical recording medium, a light beam is irradiated from the substrate side and an external magnetic field is applied from the recording layer side or the substrate side. Then, when recording is performed in the read-only area, a magneto-optical recording method is provided, in which a light beam is irradiated from the substrate side and an external magnetic field is applied from the substrate side.

[0009]

According to the first aspect of the invention, the magnetic shield layer laminated on the read-only area blocks the external magnetic field applied to the read-only area at the time of recording to prevent erroneous erasure of data in the read-only area. When the user wants to write desired data in the read-only area, it is possible by applying an external magnetic field from the substrate side. Therefore, it is possible to provide a magneto-optical recording medium having a read-only area and a rewritable area, and since the recording layers can be made of the same magneto-optical recording material, the range of material selection is expanded.

According to the second aspect of the present invention, the position of the read-only area and the rewritable area can be recognized by the presence or absence of the magnetic force line by the magnetic field detection means, and only the writing in the rewritable area is performed by the magnetic field generation means and the light beam irradiation means. Not
The user can write in the reproduction-only area.

According to the third aspect of the present invention, the position of the read-only area and the rewritable area can be recognized by means of the reflectance difference between the medium reflection film and the magnetic shield layer by means provided with the light beam irradiation section and the light reception detection section, and the magnetic field By the generation means and the light beam irradiation means, not only writing in the rewritable area but also writing by the user in the reproduction-only area becomes possible.

According to the fourth aspect of the invention, when recording is performed in the rewritable area, a light beam is irradiated from the substrate side and an external magnetic field is applied from the recording layer side or the substrate side to perform recording in the read-only area. In this case, by irradiating a light beam from the substrate side and applying an external magnetic field from the substrate side, the user can arbitrarily create data in the reproduction-only area.

[0013]

EXAMPLES The present invention will be described in detail below based on examples. First, the magneto-optical recording medium according to the present invention will be described. 1 and 2 are a cross-sectional view and a plan view showing an example of the configuration of the magneto-optical recording medium according to the present invention, in which a first dielectric protective layer 2, a magneto-optical recording layer 3 The two dielectric protective layers 4 are laminated in this order, and further, the magnetic shield layer 17 for preventing the transmission of magnetic force lines is laminated on the inner peripheral portion of the disk, which is a read-only area. In FIGS. 1 and 2, the reproduction-only area is provided on the inner peripheral portion of the disc, but the reproduction-only area can be set at an arbitrary position and can be provided on the outer peripheral portion as shown in FIG. It is also possible to provide them alternately in the radial direction or the circumferential direction as shown in FIG.

In the magneto-optical recording medium of the present invention, the material of the substrate 1 is not particularly limited, but it is necessary that the substrate 1 is a transparent substrate so that the light for recording / reproducing is transmitted, and specifically, it is an inorganic material such as glass. In addition to materials, polymethylmethacrylate,
Polycarbonate, polymer alloy of polycarbonate and polystyrene, epoxy resin, polyether sulfone, polysulfone, polyetherimide, ethylene,
An organic material such as a tetracyclododecene copolymer can be used.

First dielectric protective layer 2 provided on the substrate 1
For example, SiO, SiO ₂ , Si ₃ N ₄ or the like can be used. As the magneto-optical recording layer 3, for example, TbFeCo, G
A magneto-optical recording material such as dFeCo or Pt / Co multilayer film can be used. The film thickness of the recording layer 3 is not particularly limited as long as it does not transmit the light beam. As the second dielectric protection layer 4, for example, SiO, SiO ₂ , Si ₃ N ₄ , AlN or the like can be used. The first and second dielectric protective layers 2 and 4 need to be transparent to the recording / reproducing light, and the film layers are appropriately set so as to sufficiently exert their functions. Each layer 2
4 to 17 can be produced by a vacuum film forming method such as vapor deposition or sputtering.

The magneto-optical recording medium of the present invention is characterized in that the magnetic shield layer 17 is laminated on the read-only area (in this example, on the area corresponding to the second dielectric protection layer 4). Materials used for the layer 17 include permalloy (Ni—Fe based magnetic alloy) and sendust (Si—Al).
Examples include high permeability materials such as —Fe based magnetic alloys) and Co—Zr based magnetic alloys, superconducting materials, and the like. Superconducting materials include NbN, Nb ₃ Sn, V ₃ Ga, V ₃ Si, N
metallic superconducting materials such as b ₃ Al and Nb ₃ Ge, and Ba (P
b, Bi) an organic superconducting material such as O ₃ or La-Ba-
Cu-O system, La-Sr-Cu-O system, Y-Ba-Cu
-O system, Y-Ba-Cu-O-F system, Bi-Ca-Sr
Examples include ceramic-based superconducting materials such as -Cu-O-based and Tl-Ca-Ba-Cu-O-based, but are not limited thereto. The film thickness of the magnetic shield layer 17 is not particularly limited, but about 1000Å to 0.5 mm is suitable.

The laminated portion of the magnetic shield layer 17 on the second dielectric protection layer 4 can be set arbitrarily. For example, the magnetic shield layer 17 is laminated on the inner peripheral portion to make the inner peripheral portion a read-only area, or conversely on the outer peripheral portion. Laminate and use the outer peripheral part as a read-only area, or alternately stack in the radial direction to alternately set the read-only area and rewritable area, or stack on a specific sector on the disk and write a specific sector to the read-only area. Can be

Next, another configuration example of the magneto-optical recording medium according to the present invention will be described. FIG. 6 is a cross-sectional view thereof, showing a first dielectric protective layer 2, a magneto-optical recording layer 3, a second dielectric protective layer 4, a reflective layer 5 and a third dielectric protective layer 6 on a disk-shaped substrate 1. Are laminated in this order, and further, a magnetic shield layer 17 for preventing transmission of magnetic force lines is laminated on the inner peripheral portion of the disk, which is a read-only area. In FIG. 6, the reproduction-only area is provided on the inner peripheral portion of the disc, but as in the case of the above-described configuration example, the reproduction-only area can be set at any location,
It may be provided on the outer peripheral portion, or may be provided alternately in the radial direction or the circumferential direction.

Substrate 1, first dielectric layer 2, magneto-optical recording layer 3
The necessary characteristics of the second dielectric protection layer 4 and the like are the same as those in the above-described configuration example.

As the reflective layer 5, Al, Cr or the like can be used. As the third dielectric protection layer 6, for example, SiO, SiO
₂ , Si ₃ N ₄ or the like can be used. The protective layer 6 plays a role of preventing corrosion of the reflective layer 5 by an adhesive and preventing heat diffusion from the medium to the shield layer 17. The third dielectric protective layer 6 also needs to be transparent to the recording / reproducing light, and the film thickness is appropriately set so as to sufficiently exhibit its function, and is manufactured by a vacuum film forming method such as vapor deposition or sputtering. To be done.

The magneto-optical recording medium of this configuration example is characterized in that the magnetic shield layer 17 is provided on the read-only area (in this example, on the area corresponding to the second dielectric protection layer 4). As the shield material used for the shield layer 17, the same material as the above-described configuration example can be used. The film thickness is similarly set.

The laminated portion of the magnetic shield layer 17 on the third dielectric protection layer 6 can be set arbitrarily. For example, the magnetic shield layer 17 is laminated on the inner peripheral portion to make the inner peripheral portion a read-only area, or conversely on the outer peripheral portion. Laminate and use the outer peripheral part as a read-only area, or alternately stack in the radial direction to alternately set the read-only area and rewritable area, or stack on a specific sector on the disk and write a specific sector to the read-only area. Can be

Next, a magneto-optical recording / reproducing apparatus and a magneto-optical recording method using the same according to the present invention for recording / reproducing using the above-mentioned magneto-optical recording medium will be described. FIG. 7 is a diagram showing an example of the structure of the magneto-optical recording / reproducing apparatus according to the present invention. An objective lens for passing the emitted light 7 of a light-emitting element (not shown) to the substrate side of the magneto-optical recording medium A having the structure shown in FIG. 8 is deployed,
The magneto-optical recording medium A is irradiated with the light beam 9 condensed by the objective lens 8. Further, a magnetic field generating means 10 composed of a cylindrical coil is arranged concentrically with the objective lens 8 on the substrate side with respect to the magneto-optical recording medium A, and at the position where the light beam 9 is irradiated on the recording layer side. A magnetic field generating means 11 such as a permanent magnet or a coil is provided so as to face each other. Which magnetic field generating means is used can be selected by setting or program control of the magneto-optical reproducing device itself. Further, in order to recognize the read-only area in which the magnetic shield layer 17 is laminated and the rewritable area in which the magnetic shield layer 17 is not laminated in the magneto-optical recording medium A, magnetic field detecting means 12 such as a Hall element or a coil is provided on the substrate side. ing. The magnetic field detecting means 12 is installed so as to be movable in parallel to the surface of the substrate, and the position of the magnetic shield layer 17 on the entire surface of the substrate is determined depending on whether or not the magnetic field from the magnetic field generating means 11 is detected. It is possible to recognize and memorize. In this case, recording / reproduction may be performed after the entire recognition is performed in advance, or recognition may be performed each time recording / reproduction is performed. Further, the magnetic field detection means 12 may be provided at a position adjacent to the objective lens 8 so that the presence or absence of the magnetic shield layer 17 is always recognized before the light beam 9 is irradiated onto the magneto-optical recording medium A. By the above method, the read-only area and the rewritable area can be recognized, and recording / reproduction can be performed on the magneto-optical recording medium A. According to the magneto-optical recording / reproducing apparatus of FIG. 7, recording / reproducing can be similarly performed on the magneto-optical recording medium having a configuration other than that shown in FIG.

Next, the magneto-optical recording method using the above apparatus will be described. First, before recording, it is determined which of the read-only area and the rewritable area of the magneto-optical recording medium is to be recorded. Select the recording mode according to your decision. The determination and selection are made by appropriate input means and control means incorporated in the above device.

When recording in the read-only area is selected, the magnetic field generating means 10 is used to apply a magnetic field from the side of the substrate on which the light beam 9 is incident to perform thermomagnetic recording. When the recording in only the rewritable area is selected, the magnetic field generating means 11 is used to apply a magnetic field from the side opposite to the side on which the light beam 9 is incident to perform thermomagnetic recording. When recording in both the read-only area and the rewritable area is selected, the magnetic field generating means 10 is used in the read-only area and either the magnetic field generating means 10 or the magnetic field generating means 11 is used in the writable area. You may use.

Next, another configuration example of the magneto-optical recording / reproducing apparatus according to the present invention will be described with reference to FIG. In the device of this configuration example, when the recording layer 3 or the second dielectric protection layer 4 and the magnetic shield layer 17 have significantly different reflectances in the configuration as shown in FIG. 1, and in the configuration as shown in FIG. 5 or third dielectric protection layer 6 and magnetic shield layer 1
It is particularly effective when the reflectances of 7 are greatly different.

In this magneto-optical recording / reproducing apparatus, in order to recognize the read-only area in which the magnetic shield layer 17 is laminated in the magneto-optical recording medium A and the rewritable area in which the magnetic shield layer 17 is not laminated, a semiconductor is provided on the recording layer side. A light source 13 such as a laser and a light receiving detection means 14 such as a photodiode and a phototransistor are integrally arranged. Further, the light source 13 and the light receiving detection means 14 are installed so as to be movable in parallel to the substrate surface. The direction of the light receiving portion of the light receiving detection means 14 is the recording layer 3 of the magneto-optical recording medium A or the second dielectric protective layer 4 (the reflective layer 5 or the third dielectric protective layer 6 in the medium having the configuration of FIG. 6) or the magnetic shield. It always faces the direction in which the light from the light source 13 reflected by the layer 17 is incident.

By using such means, the intensity of the reflected light from the recording layer 3 or the second dielectric protective layer 4, or the reflective layer 5 or the third dielectric protective layer 6 and the reflected light from the magnetic shield layer 17 are used. It is possible to recognize and store the position of the magnetic shield layer on the entire surface of the substrate in the magneto-optical recording / reproducing apparatus due to the difference in the intensity of the magnetic field. Further, the above means is provided adjacent to the position where the light beam 9 is irradiated onto the magneto-optical recording medium A, and the presence or absence of the magnetic shield layer 17 is always recognized before the light beam 9 is irradiated onto the magneto-optical recording medium A. You may allow it. By the above method, the read-only area and the rewritable area can be recognized, and recording / reproduction can be performed on the magneto-optical recording medium A.

As described above, according to the present invention, the read-only area (ROM section) of the magneto-optical recording medium does not have to be manufactured from the step of molding the substrate, and the user can optionally perform RO after the medium is manufactured.
M information can be recorded.

The information recorded on the magneto-optical recording medium of the present invention is, of course, recorded by a conventional magneto-optical recording / reproducing apparatus for applying thermo-magnetic recording by applying a magnetic field from the side opposite to the side on which the light beam is incident. Can be reproduced, there is no restriction on the reading of information, and recording can be performed only in the rewritable area.

[0031]

According to the first aspect of the present invention, a magnetic shield layer is provided which has a read-only area and a rewritable area and which prevents transmission of magnetic force lines only on the dielectric protective layer portion corresponding to the read-only area. Since the layers are stacked, it is possible to prevent the data in the read-only area from being accidentally erased by the external magnetic field applied to the medium during recording. Also, the user can write arbitrary data in the reproduction-only area. Further, since the recording layers can be made of the same magneto-optical recording material, the range of material selection is expanded.

According to the second aspect of the invention, the position of the read-only area and the rewritable area can be recognized by the presence or absence of the magnetic force line by the magnetic field detecting means, and further the magnetic field generating means and the light beam irradiating means move to the rewritable area. In addition to writing, users can write to the playback-only area,
The magneto-optical recording medium of the present invention can be effectively used.

According to the third aspect of the present invention, the means provided with the light beam irradiating section and the light receiving and detecting section allows the read-only area and the rewritable area to be included in the reflectance difference between the medium reflection film and the magnetic shield layer. The position can be recognized, and not only the rewritable area can be written by the magnetic field generating means and the light beam irradiating means, but also the user can write in the read-only area, and the magneto-optical recording medium of the present invention can be effectively used. It will be possible.

According to the fourth aspect of the invention, when recording is performed in the rewritable area, a light beam is irradiated from the substrate side and an external magnetic field is applied from the recording layer side or the substrate side to record in the read-only area. In this case, since the light beam is irradiated from the substrate side and the external magnetic field is applied from the substrate side, not only the normal recording but also the ROM by the user is performed.
Data can be recorded, and the magneto-optical recording medium of the present invention can be effectively used.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration example of a magneto-optical recording medium according to the present invention.

FIG. 2 is a plan view of the magneto-optical recording medium of FIG.

FIG. 3 is a plan view showing a modification of the magneto-optical recording medium shown in FIGS. 1 and 2.

FIG. 4 is a plan view showing another modified example of the magneto-optical recording medium shown in FIGS. 1 and 2.

5 is a plan view showing still another modified example of the magneto-optical recording medium shown in FIGS. 1 and 2. FIG.

FIG. 6 is a plan view showing another configuration example of the magneto-optical recording medium according to the present invention.

FIG. 7 is a cross-sectional view showing a configuration example of a magneto-optical recording / reproducing apparatus according to the present invention. It

FIG. 8 is a sectional view showing another configuration example of the magneto-optical recording / reproducing apparatus according to the present invention.

[Explanation of symbols]

1 Substrate 2 First Dielectric Protective Layer 3 Magneto-optical Recording Layer 4 Second Dielectric Protective Layer 5 Reflective Layer 6 Third Dielectric Protective Layer 7 Emitted Light 8 Objective Lens 9 Light Beams 10 and 11 Magnetic Field Generating Means 12 Magnetic Field Detecting Means 13 light source 14 received light detecting means 17 magnetic shield layer

Claims (4)

[Claims] 1. A magneto-optical recording layer and a second dielectric protective layer are provided on a transparent substrate via a first dielectric protective layer, and a reflective layer and a third dielectric protective layer are laminated in that order if necessary. In this magneto-optical recording medium, a read-only area and a rewritable area are provided, and a magnetic shield layer for preventing transmission of magnetic force lines is laminated only on the outermost dielectric protective layer portion corresponding to the read-only area. A magneto-optical recording medium characterized by the above. 2. A magneto-optical recording device for the magneto-optical recording medium according to claim 1, wherein a magnetic field is provided both on the substrate side and on the magneto-optical recording layer side with respect to the mounted magneto-optical recording medium. Means, a light beam irradiating means installed on the substrate side for irradiating a magneto-optical recording medium with a recording / reproducing light beam, and a magnetic field line from the magnetic field generating means on the magneto-optical recording layer side to detect the magnetic field. A magneto-optical recording / reproducing apparatus comprising magnetic field detecting means installed on the substrate side for recognizing a dedicated area and a rewritable area. 3. A magneto-optical recording device for the magneto-optical recording medium according to claim 1, wherein the magnetic field generation is provided both on the substrate side and on the magneto-optical recording layer side with respect to the mounted magneto-optical recording medium. Means, a light beam irradiating means installed on the substrate side to irradiate the magneto-optical recording medium with a recording / reproducing light beam, and a light beam irradiating section and a light beam irradiating the magneto-optical recording medium with the light beam It consists of a light-reception detection unit that detects the light beam from the light beam irradiation unit reflected on the surface of the magnetic recording medium. A magneto-optical recording / reproducing apparatus comprising means installed. 4. When recording is performed in the rewritable area using the magneto-optical recording medium according to claim 1, reproduction is performed by irradiating a light beam from the substrate side and applying an external magnetic field from the recording layer side or the substrate side. When recording in a dedicated area, a magneto-optical recording method is characterized in that a light beam is applied from the substrate side and an external magnetic field is applied from the substrate side.