JP3314274B2 - Magneto-optical recording medium - Google Patents

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. More specifically, the present invention relates to a read-only area (ROM section) and a recordable area (rewritable section). The present invention relates to a magneto-optical recording medium having the same.

[0002]

2. Description of the Related Art
The change of the recorded contents on the magneto-optical disk is prohibited by setting the write-protection hole of the cartridge containing the disk to the write-protected state. However, in this method, the entire recorded contents on the magneto-optical disk are prohibited from being changed, and the recorded contents such as the document format part and the dictionary part are prohibited from being changed. If you want to rewrite the recorded content frequently, you must rewrite the cartridge with the write-protection hole in a write-enabled state, so you must take care to prevent accidentally changing the recorded content that you want to prohibit from being changed. Was.

On the other hand, as means for solving the above-mentioned problem, Japanese Patent Laid-Open Publication No. Sho 58-114343 discloses that a reflective film is provided in a read-only area (ROM section) having pits on a substrate and a rewritable area (RAM section). A magneto-optical recording medium provided with a magneto-optical recording reproducing film has been proposed. But,
In this case, the reflectance is different between the ROM section and the RAM section, which imposes a burden on the recording and reproducing apparatus. Further, since the difference in reflectance between the ROM section and the RAM section is limited to the range in which the recording / reproducing apparatus can operate, it has been impossible to arbitrarily select a material used for the recording film. Furthermore, in order to manufacture the ROM section, it is necessary to provide ROM information on the board at the stage of molding the board, and the user cannot arbitrarily create the ROM section later.

The present invention has been made to solve such problems of the prior art, has a ROM section and a RAM section, and can arbitrarily select a material used for a recording film. It is an object of the present invention to provide a magneto-optical recording medium on which a user can arbitrarily form a ROM section and a magneto-optical recording / reproducing apparatus which allows a user to record desired information also on the ROM section of the magneto-optical recording medium. .

[0005]

To achieve the above object, according to an aspect of, Oite the present invention, at least the magneto-optical recording layer on a transparent substrate, the reflective layer and the magneto-optical recording medium comprising a dielectric protective layer are laminated in this order In the magneto-optical recording, a read-only area and a rewritable area are provided, and a magnetic shield plate for preventing transmission of lines of magnetic force is adhered via an adhesive layer only on the dielectric protection layer portion corresponding to the read-only area. Medium is used
You .

According to the present invention, first, in the above structure, the adhesive layer is peelable and re- adherable.
And a magneto-optical recording medium characterized by the following.

Further, according to the present invention, in the first <br/> configuration to the second, provided with a hub for clamping the magneto-optical recording medium in the drive unit, directly or via a connector to the hub There is provided a magneto-optical recording medium to which a magnetic shield plate is connected.

[0008] Oite the present invention, a magneto-optical recording device for the first or second magneto-optical recording medium as (device I)
It is the substrate side in order to irradiate the magnetic field generating means located in both the substrate side and the optical magnetic recording layer side, the recording and reproducing light beam onto the magneto-optical recording medium with respect to the loaded magneto-optical recording medium And a magnetic field detecting means installed on the substrate side for recognizing the read-only area and the rewritable area by detecting magnetic field lines from the magnetic field generating means on the magneto-optical recording layer side. of the magneto-optical recording and reproducing apparatus for
Use is advantageous .

Further, Oite the present invention, the first or
Magneto-optical recording apparatus for the second magneto-optical recording medium (device I
I) includes a magnetic field generating means provided on both the substrate side and the magneto-optical recording layer side with respect to the mounted magneto-optical recording medium, and a method for irradiating the magneto-optical recording medium with a recording / reproducing light beam. A light beam irradiating means installed on the substrate side, a light beam irradiating unit for irradiating a light beam to the magneto-optical recording medium, and detecting and receiving a light beam from the light beam irradiating unit reflected on the surface of the magneto-optical recording medium It is advantageous to use a magneto-optical recording / reproducing apparatus which comprises a light receiving detection unit and has means provided on the magneto-optical recording layer side for recognizing the read-only area and the writable area based on the light receiving detection result.

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

[0011]

According to the first aspect of the present invention, the magnetic shield plate provided above the read-only area blocks an external magnetic field applied to the read-only area during recording, thereby preventing erroneous erasure of data in the read-only area. I do. When a user wants to write desired data in the read-only area, it becomes 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 layer can be made of the same magneto-optical recording material, the range of material selection is widened.

In particular , since the adhesive layer is peelable and re-adherable, the designation of the read-only area can be changed arbitrarily.

According to the second aspect of the present invention, since the magnetic shield plate is connected to the hub directly or via the connector, the displacement due to the high-speed rotation of the medium is prevented.

In the use of the apparatus I , the magnetic field detecting means makes it possible to recognize the positions of the read-only area and the rewritable area based on the presence or absence of the magnetic field lines. Further, the magnetic field generating means and the light beam irradiating means only allow writing to the rewritable area. Instead, the user can write in the read-only area.

In the use of the apparatus II, the position difference between the read-only area and the rewritable area is determined by the difference between the reflectivity of the medium reflection film and the magnetic shield plate by means having a light beam irradiation unit and a light reception detection unit. Thus, not only writing in the rewritable area but also writing by the user in the read-only area can be performed by the magnetic field generating means and the light beam irradiating means.

In the magneto-optical recording method , when recording is performed on a 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 on the read-only area. In this case, the user can arbitrarily create data in the read-only area by irradiating a light beam from the substrate side and applying an external magnetic field from the substrate side.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. First, the magneto-optical recording medium according to the present invention will be described. 1 and 2 are a sectional view and a plan view, respectively, showing a configuration example of a magneto-optical recording medium according to the present invention. On a disc-shaped substrate 1, a first dielectric protective layer 2, a magneto-optical recording layer 3, (2) A dielectric protection layer 4, a reflection layer 5, and a third dielectric protection layer 6 are laminated in this order, and further, an inner peripheral portion of the disk, which is a read-only area, is provided with an adhesive layer 15 made of an adhesive or an adhesive sheet. A magnetic shield plate 16 made of a magnetic shield material for preventing transmission of lines of magnetic force is attached. In FIGS. 1 and 2, the read-only area is provided on the inner peripheral portion of the disc. However, the read-only area can be set at an arbitrary position, and can be provided on the outer peripheral portion as shown in FIG. 4 and FIG. 5, it is also possible to provide them alternately in the radial or circumferential direction.

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 be a transparent substrate so that light for recording and reproduction can be transmitted. In addition to materials, polymethyl methacrylate,
Polycarbonate, polymer alloy of polycarbonate and polystyrene, epoxy resin, polyethersulfone, polysulfone, polyetherimide, ethylene,
Organic materials such as tetracyclododecene copolymer can be used.

First dielectric protection layer 2 provided on 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
Magneto-optical recording materials such as dFeCo and Pt / Co multilayer films can be used. The film thickness of the recording layer 3 is not particularly limited as long as the light beam does not pass therethrough. As the second dielectric protection layer 4, for example, SiO, SiO ₂ , Si ₃ N ₄ or the like can be used.
As the reflection layer 5, Ar, Cr, or the like can be used. As the third dielectric protection layer 6, for example, SiO, SiO ₂ , Si ₃ N ₄
Etc. can be used. This protective layer 6 is a reflective layer 5 made of an adhesive.
To prevent corrosion of the metal and to prevent heat diffusion from the medium to the shield plate 16. The first to third dielectric protection layers 2, 4, and 6 need to be transparent to light for recording and reproduction, and the film layers are appropriately set so as to sufficiently exhibit their functions. Each of the layers 2 to 6 can be manufactured by a vacuum film forming method such as evaporation or sputtering.

The magneto-optical recording medium of the present invention is characterized in that a magnetic shield plate 16 is provided on a read-only area (in this example, on an area corresponding to the third dielectric protection layer 6). Permalloy (Ni-Fe based magnetic alloy), sendust (Si
-Al-Fe magnetic alloys), high magnetic permeability materials such as Co-Zr magnetic alloys, and superconducting materials. The superconducting _{material, NbN, Nb 3 Sn, V} 3 Ga, V 3 S
i, Nb ₃ Al, Nb ₃ Ge, and other metallic superconducting materials;
organic superconducting materials such as a (Pb, Bi) O ₃ and La-
Ba-Cu-O system, La-Sr-Cu-O system, Y-Ba
-Cu-O system, Y-Ba-Cu-OF system, Bi-Ca
Examples include ceramic-based superconducting materials such as -Sr-Cu-O-based and Tl-Ca-Ba-Cu-O-based, but are not limited thereto. The thickness of the magnetic shield plate 16 has an appropriate value depending on the magnetic shield effect, specific gravity, etc. of the constituent material, and is set for each material to a thickness that can utilize the magnetic shield effect with a weight that does not burden the disk rotation motor. Is done. Usually, about 0.5 mm to 2 mm is appropriate, but is not limited thereto.

As the adhesive used for forming the adhesive layer 15, for example, a synthetic rubber adhesive can be used. Further, an adhesive sheet may be used instead of the adhesive. In this case, in the present invention, since an adhesive or a pressure-sensitive adhesive sheet that can be peeled off and re-adhered is used , the designation of the read-only area can be arbitrarily changed. In addition,
The "reproduction-only area" in the detailed text is a magnetic shield plate attached
Means an area that cannot be recorded (written).

The position where the magnetic shield plate 16 is bonded on the third dielectric protection layer 6 can be set arbitrarily. For example, the inner peripheral portion is bonded to the inner peripheral portion to be a reproduction-only area, or conversely, the outer peripheral portion is bonded. Make the outer peripheral portion of the disc a read-only area, or alternately set the read-only area and the rewritable area alternately in the radial direction, or paste the specific sector on the disc on a specific sector and read it. It can be an area.

FIG. 6 is a diagram showing another example of the configuration of the magneto-optical recording medium according to the present invention, in which a magnetic shield plate 16 is connected to a hub 17 for clamping during rotation. It is the same as that shown in FIG. Hub 17
The connection between the magnetic shield plate 16 and the magnetic shield plate 16 can be performed using, for example, an adhesive or welding (including spot welding), but other appropriate methods can be used.
With such a configuration, even when the adhesive layer 15 of FIG. 1 can be peeled and re-adhered and the adhesive strength is relatively weak, the magnetic shield plate 16 moves from a predetermined position by centrifugal force during high-speed rotation. This eliminates the problem of having

When the outer peripheral portion of the disk is magnetically shielded as shown in FIG. 7, the hub 17 and the magnetic shield plate 1 are used.
6 may be connected by a connector 18 made of a material (Ni, Fe, etc.) that can transmit the lines of magnetic force. Further, as shown in FIGS. 8 and 9, it is also possible to provide a read-only area alternately in the radial direction or the circumferential direction. The connection between the hub 17 and the magnetic shield plate 16 to the connector 18 may be performed by using an adhesive or by welding.

Next, a magneto-optical recording / reproducing apparatus for performing recording / reproduction using the magneto-optical recording medium of the present invention and a magneto-optical recording method using the same will be described. FIG. 10 is a diagram showing an example of the configuration (device I) of a magneto-optical recording / reproducing apparatus. An objective lens 8 for passing outgoing light 7 of a light-emitting element (not shown) is provided on the substrate side of the magneto-optical recording medium A of the present invention. The light beam 9 collected by the objective lens 8 is applied to the magneto-optical recording medium A. A magnetic field generating means 10 composed of a cylindrical coil is provided concentrically with the objective lens 8 on the substrate side of the magneto-optical recording medium A, and the recording layer side is positioned at a position where the light beam 9 is irradiated. A magnetic field generating means 11 such as a permanent magnet or a coil is provided so as to be opposed. Which of the magnetic field generating means is to be used can be selected by setting of the magneto-optical reproducing apparatus itself or by program control. Further, the magnetic shield plate 1 in the magneto-optical recording medium A
A magnetic field detecting means 12 such as a Hall element or a coil is provided on the substrate side so as to recognize a read-only area where the magnetic shield plate 16 is bonded and a rewritable area where the magnetic shield plate 16 is not bonded. The magnetic field detecting means 12 is provided so as to be movable parallel to the substrate surface, and determines the position of the magnetic shield plate 16 over the entire surface of the substrate by detecting whether a magnetic field from the magnetic field generating means 11 is detected. Can be recognized and stored. In this case, the recording and reproduction may be performed after the entire recognition is performed in advance, or the recognition may be performed each time the recording and reproduction are performed. Further, the magnetic field detecting means 12 is provided at a position adjacent to the objective lens 8 so that the light beam 9 is constantly emitted from the magneto-optical recording medium A.
May be made to recognize the presence or absence of the magnetic shield plate before the laser beam is irradiated. With the above-described method, the read-only area and the rewritable area can be recognized, and recording and reproduction can be performed on the magneto-optical recording medium A.

Next, a description will be given of a magneto-optical recording method using the above-mentioned apparatus. First, before recording, it is determined whether to perform recording in a read-only area or a rewritable area of a magneto-optical recording medium. Select the recording mode according to the decision. This determination and selection are made by appropriate input means and control means incorporated in the above device.

Here, when recording in the read-only area is selected, a magnetic field is applied from the substrate side where the light beam 9 is incident by using the magnetic field generating means 10 to perform thermomagnetic recording. When recording only in the rewritable area is selected, a magnetic field is applied from the side opposite to the side where the light beam 9 is incident using the magnetic field generating means 11 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. May be used.

Next, another configuration example ( device) of the magneto-optical recording / reproducing apparatus will be described.
The arrangement II) will be described with reference to FIG. The device of this configuration example is particularly effective when the reflectivity of the reflective layer 5 of the magneto-optical recording medium A and the reflectivity of the magnetic shield plate 16 are significantly different.

In this magneto-optical recording / reproducing apparatus, the recording layer side for recognizing the read-only area of the magneto-optical recording medium A where the magnetic shield plate 16 is bonded and the rewritable area where the magnetic shield plate 16 is not bonded. And a light source 13 such as a semiconductor laser and a light receiving detecting means 14 such as a photodiode and a phototransistor are integrally arranged.
The light source 13 and the light receiving detection means 14 are provided so as to be movable in parallel to the substrate surface. The direction of the light receiving portion of the light receiving detecting means 14 is always in the direction in which the light from the light source 13 reflected by the reflection layer 5 or the magnetic shield plate 16 of the magneto-optical recording medium A is incident.

By using such means, the position of the magnetic shield plate over the entire surface of the substrate can be recognized and stored by the magneto-optical recording / reproducing apparatus due to the difference in the intensity of light reflected from the reflective layer 5 or the magnetic shield plate 16. Becomes Also,
The above-mentioned means is provided adjacent to the position where the light beam 9 is irradiated on the magneto-optical recording medium A, so that the presence or absence of the magnetic shield plate 16 is always recognized before the light beam 9 is irradiated on the magneto-optical recording medium A. It may be. With the above-described method, the read-only area and the rewritable area can be recognized, and recording and reproduction can be performed on the magneto-optical recording medium A.

As described above, according to the present invention, it is not necessary to prepare the read-only area (ROM section) of the magneto-optical recording medium from the stage of molding the substrate.
M information can be recorded.

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

[0033]

According to the first aspect of the present invention, a magnetic shield plate for providing a read-only area and a rewritable area and preventing transmission of lines of magnetic force only on a dielectric protection layer portion corresponding to the read-only area. Is adhered via the adhesive layer, so that data in the read-only area is not accidentally erased by an external magnetic field applied to the medium during recording. Further, the user can write arbitrary data in the reproduction-only area. Furthermore, since the recording layer can be made of the same magneto-optical recording material, the range of material selection is expanded.

In particular , since the adhesive layer is peelable and re-adherable, the designation of the read-only area can be changed arbitrarily.

According to the second aspect of the present invention, since the magnetic shield plate is connected to the hub directly or via the connector, displacement of the magnetic shield plate due to high-speed rotation of the medium is prevented.

The optical recording medium according to the present invention is provided with the above-described magneto-optical reproducing apparatus.
Location to lever to the recording and reproducing by (device I), it is possible to position recognition of the read-only area with and without the magnetic field lines and the rewritable area by the magnetic field detection means, further rewritable by a magnetic field generating means and the light beam irradiation means In addition to writing to the area, the user can write to the read-only area, and the magneto-optical recording medium of the present invention can be effectively used.

The position of the optical recording field according to the present invention is determined by the above-described magneto-optical reproduction.
Device to lever to the recording and reproducing by (apparatus II), the light beam reflectance difference of the medium reflection film and the magnetic shield plate by means having a radiation part and the light receiving detection unit, read-only area and rewriting by reflectance difference The position of the possible area can be recognized, and the magnetic field generating means and the light beam irradiating means can not only write to the rewritable area but also allow the user to write to the read-only area. Effective use becomes possible.

The optical recording medium of the present invention can be used in the above-described magneto-optical recording method.
To lever so as to record and reproduce by law, when recording in the rewritable region, applying an external magnetic field from the recording layer side or the substrate side while a light beam from the substrate side, recording the reproduction-only area In this case, a light beam is applied from the substrate side and an external magnetic field is applied from the substrate side.
Data can also be recorded, and the magneto-optical recording medium of the present invention can be effectively used.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one 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.

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

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 plan view showing a modification of the magneto-optical recording medium shown in FIG.

FIG. 8 is a plan view showing another modified example of the magneto-optical recording medium shown in FIG.

FIG. 9 is a plan view showing still another modified example of the magneto-optical recording medium shown in FIG.

FIG. 10 is a cross-sectional view showing one configuration example of a magneto-optical recording / reproducing apparatus.

FIG. 11 is a sectional view showing another configuration example of the magneto-optical recording / reproducing apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2 1st dielectric protection layer 3 Magneto-optical recording layer 4 2nd dielectric protection layer 5 Reflective layer 6 3rd dielectric protection layer 7 Outgoing light 8 Objective lens 9 Light beam 10, 11 Magnetic field generation means 12 Magnetic field detection means DESCRIPTION OF SYMBOLS 13 Light source 14 Light-receiving detection means 15 Adhesive layer 16 Magnetic shield plate

Claims (2)

(57) [Claims] At least a magneto-optical recording layer on a transparent substrate,
In magneto-optical recording medium comprising a reflective layer and a dielectric protective layer are laminated in this order, only on derivatives the protective layer portion of the portion to be a read-only area, the magnetic shield <br/> plate for preventing the transmission of magnetic field lines A magneto-optical recording medium, wherein the read-only area is formed by sticking through a peelable and re-adhesive adhesive layer, and the other area is formed as a rewritable area. 2. The optical disk according to claim 1, further comprising a hub for clamping the magneto-optical recording medium to a drive device, and a magnetic shield plate connected to the hub directly or via a connector. Magnetic recording medium.