JP3442886B2 - Magneto-optical recording device - 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 apparatus for recording information using a magneto-optical recording medium such as a magneto-optical disk and an optical card.

[0002]

2. Description of the Related Art In a magneto-optical recording medium in which a perpendicularly magnetized film made of a magnetic material is provided as a recording layer on a substrate, information is recorded / reproduced by the following method.

In recording, first, a strong external magnetic field is applied to align and initialize the magnetization direction of the recording layer in one direction (upward or downward), and then a laser beam is applied to an area to be recorded. Irradiation is carried out, and the temperature of the irradiated portion is raised to a temperature above the Curie point of the recording layer or above the compensation point. As a result, the coercive force of that part is zero,
Alternatively, after setting the value to almost zero, an external magnetic field (bias magnetic field) in the direction opposite to that at the time of initialization is applied to reverse the magnetization direction. When the irradiation of the laser beam is stopped, the temperature of the recording layer returns to room temperature, so that the reversed magnetization is fixed. In this way, information is recorded thermomagnetically.

During reproduction, a linearly polarized laser beam is applied to the magneto-optical recording medium, and the planes of polarization of reflected light and transmitted light thereof rotate in accordance with the direction of magnetization of the recording layer (magnetic Kerr effect, The magnetic Faraday effect) is used to optically read the information.

On the other hand, the magneto-optical recording medium in which information is recorded by the above-mentioned magneto-optical recording system is attracting attention as a rewritable large-capacity storage element, but the recorded information is another information. When rewriting, the two-step operation of erasing / writing, which is to erase the recorded information by the initialization of the rewritten portion and then to write new information, is required. It had a problem that it could not. Therefore, in order to solve the above problems, a magneto-optical recording medium capable of directly writing new information without erasing recorded information, that is, a magneto-optical recording medium capable of overwriting recording has been conventionally used. Proposed.

As a magneto-optical recording medium capable of recording by performing the above-mentioned overwriting, (a) a magneto-optical recording medium which modulates an applied magnetic field and rewrites information while irradiating a laser beam of a predetermined intensity ( (A magnetic field modulation overwrite type magneto-optical recording medium) and (b) the recording layer is composed of at least an exchange coupling two-layer film, and after initialization is performed by an initialization magnetic field having a relatively small strength, a magnetic field having a predetermined strength There is known a magneto-optical recording medium (a magneto-optical recording medium of an optical modulation overwrite type) that rewrites information by modulating the intensity of a light beam to be applied while applying.

As shown in FIG. 16, the above-mentioned conventional magneto-optical recording medium has a control track 30 in its inner peripheral portion, and various conditions for recording / reproducing are recorded in advance on the control track 30. Has been done. That is, for example, a data modulation / demodulation system, a servo system, a signal modulation system, an error correction system, the number of sectors per track, the disc reflectivity, the maximum laser light intensity allowed during reproduction, the type of medium (reproduction) (Discrimination between dedicated, write-once type, optical modulation overwrite type, magnetic field modulation overwrite type, etc.), conditions relating to the laser light and magnetic field strength necessary for recording are read from the control track 30,
Recording / playback is performed based on this condition.

That is, the recording / reproducing system for each magneto-optical recording medium is preset, and the recording / reproducing conditions suitable for the set recording / reproducing system are set to the control track. It is provided in the state recorded in.

[0009]

In order to rewrite information by the above-mentioned optical modulation overwrite method, it is necessary for the magneto-optical recording medium to have an exchange coupling double layer film. Recording method, that is, recording without overwriting and magnetic field modulation overwrite method,
By properly setting the recording conditions, the recording can be performed regardless of the layer structure of the magneto-optical recording medium.

However, as described above, the control track of the conventional magneto-optical recording medium is preset with a recording / reproducing system which is suitable for the set recording / reproducing system. Only one type of recording / playback condition is recorded. So, for example,
A magneto-optical recording medium capable of overwriting recording has only a control track in which only one recording condition of the magnetic field modulation overwrite system or the optical modulation overwrite system is recorded.

Therefore, for example, it is appropriate to record information in a magneto-optical recording apparatus that performs magnetic field modulation overwrite type recording by using a magneto-optical recording medium in which the recording conditions of the optical modulation overwrite type are recorded on the control track. It was not possible to do the above because recording conditions were different. Also,
For example, using a magneto-optical recording medium capable of overwriting, it is also impossible to perform appropriate recording / reproducing with a magneto-optical recording medium capable of only recording without overwriting. there were.

As described above, the conventional magneto-optical recording medium has a problem that it cannot be shared by magneto-optical recording devices having different recording / reproducing systems.

[0013]

In order to solve the above problems, the magneto-optical recording apparatus of the present invention records a recording condition.
Control track area and data recording area
Rack area and the above control track
Information recorded in the area is rewritten.
The recording condition of the recording method that requires the
The necessary recording conditions and recording conditions are recorded, and
As a recording condition of the recording method that does not require
-Write method recording conditions and light modulation overwrite method
Use a magneto-optical recording medium in which both the recording conditions are recorded.
In order to record and reproduce the information, the recording / reproducing means for recording and reproducing the information and the recording method at the time of rewriting the information based on the recording method set in advance by the recording / reproducing means.
Recording rules for recording methods that require erasing the recorded information
Conditions and recording conditions of the recording method that does not require erasing operation.
Field modulation overwrite recording conditions and optical modulation
A condition selection means for selecting a recording condition from among the recording conditions corresponding to the recording system of the record condition of the bar light type based on the selected recording condition, the laser light intensity of the recording and reproducing means or And a control means for controlling the magnetic field strength.

Further, the magneto-optical recording apparatus of the present invention is
The recording condition of the recording medium is at least the intensity of the laser beam.
And the magnetic field strength is recorded.
It

Further, the magneto-optical recording apparatus of the present invention is
The recording conditions of the recording medium are as follows: unevenness (preparation) formed on the substrate.
It has been recorded by the.

[0016]

According to the configuration of the magneto-optical recording apparatus of the present invention, for example, whether or not the recording operation does not require the erasing operation, and when the recording operation does not require the erasing operation, the magnetic field modulation overwrite method or the optical modulation overwrite method is used. When a magneto-optical recording medium in which recording conditions corresponding to each recording method are recorded is attached to a magneto-optical recording device that is preset as a recording method, a light beam based on the above recording method is used. Recording condition such as the intensity of the magnetic field or the intensity of the external magnetic field is selected by the condition selection means and read out from the magneto-optical recording medium, and the control means controls the laser light intensity or the magnetic field intensity of the recording / reproducing means based on the selected recording condition. Information is recorded / reproduced by controlling the.

Thus, from the magneto-optical recording medium in which the recording conditions corresponding to each recording method are recorded, the laser light intensity and the magnetic field of the recording / reproducing means suitable for the recording method set in the magneto-optical recording apparatus itself. Since the recording condition relating to the intensity is read and set, it becomes possible to share the magneto-optical recording medium in the magneto-optical recording devices having different recording methods. As a result, the compatibility of the magneto-optical recording medium and the magneto-optical recording device is improved.

[0018]

Embodiment 1 Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 8 and FIG.
The following is a description based on item 5.

As shown in FIG. 2, a magneto-optical disk as a magneto-optical recording medium in the present embodiment has a transparent substrate 1, a transparent dielectric layer 2, a magnetic layer 3 and a protective layer. The layer 4 and the reflective layer 5 are sequentially formed. Further, an overcoat film may be formed on the reflective layer 5 so as not to deteriorate the recording layer.

As shown in FIG. 3, the magnetic layer 3 has a large coercive force at room temperature and exhibits perpendicular magnetization from room temperature to the Curie point.

In the above structure, when recording is performed without overwriting, the magneto-optical disk is first initialized. That is, the temperature of the magnetic layer 3 is raised to T _e or more by irradiating the laser beam with the intensity of the erasing level (P _e ) as shown in FIG. 4, and the erasing magnetic field (−H _e ) as shown in FIG. 5 is applied. .
Thereby, as shown in S14 of FIG. 8, the magnetization of the magnetic layer 3 is aligned in one direction (downward).

After initialization is performed as described above, FIG.
While applying a recording magnetic field (+ H _W ) opposite to the erasing magnetic field (−H _e ) as shown in FIG. 4, intensity modulation is performed to a recording level (P _W ) and a reproduction level (P _r ) as shown in FIG. The irradiated laser light is irradiated. As a result, the recording level (P _W )
The temperature of the portion irradiated with the laser light rises above T _W , and the magnetization direction of the magnetic layer 3 is opposite to the initialization direction (downward), as shown in S12 of FIG.

On the other hand, by using the above-mentioned magneto-optical disk and changing the recording conditions, it is possible to perform recording by the magnetic field modulation overwrite method, that is, recording in which overwriting is performed. In this case, it is not necessary to initialize the magneto-optical disk.

That is, the temperature of the magnetic layer 3 is changed to T _W by irradiating a laser beam having a recording level (P _W ) as shown in FIG.
As described above, by applying the intensity-modulated magnetic field to the recording magnetic field (+ H _W ) and the erasing magnetic field (-H _e ) as shown in FIG. 7, the magnetization direction of the portion to which the recording magnetic field (+ H _W ) is applied is changed. By setting the direction opposite to the initialization direction (upward in FIG. 8),
Information can be rewritten.

The laser light intensity and the magnetic field intensity differ depending on the speed (rotation speed) of the magneto-optical disk, the irradiation time of the laser light, the wavelength of the laser light, the recording frequency, and the like. Identical Thus, P _w in the recording is not performed overwriting, P _e, H _w, and and H _e, P _w in recording by magnetic field modulation overwrite method, P _e, H _w, and A H _e, even if different In some cases,

The control track of the magneto-optical disk of this embodiment will be described with reference to FIG.

The present magneto-optical disk is provided with a control track area and a data track area. The control track area is for recording and
Information about conditions such as reproduction is composed of control tracks recorded by unevenness (pre-pits) formed on the substrate, and data track area is recorded by unevenness (pre-pits) on which address information (address) is formed on the substrate. An area and an area where a light beam guide track for magneto-optically recording data is formed on the substrate.

As shown in the figure, a control track 8 and a control track 9 are provided on the inner peripheral portion of the transparent substrate 1 of the present magneto-optical disk. The control track 8 is recorded with the recording condition without overwriting by the concavities and convexities (prepits) formed on the substrate, and the control track 9 is recorded with the magnetic field modulation overwrite system recording condition on the substrate. It is recorded by the formed unevenness (pre-pit).

Further, as shown in FIG. 15, a magneto-optical recording apparatus for recording / reproducing information using the present magneto-optical disk is divided into a recording system which does not perform overwriting and a recording system which performs overwriting. It is possible to select which is to be used for recording, and recording / reproducing means for writing and reading information on the magneto-optical disk, and appropriate recording from the control track of the magneto-optical disk via the recording / reproducing means. A condition selecting means for selectively reading conditions such as reproduction and a control means for controlling the recording / reproducing means so as to perform recording and reproduction based on the read conditions.

In the above magneto-optical recording apparatus, when recording / reproducing is performed using the present magneto-optical disk, if the recording method is recording without overwriting, the conditions provided in the magneto-optical recording apparatus. The selecting means reads out the recording condition from the control track 8 in which overwriting is not performed, and the control means controls the recording / reproducing means according to the read condition to record / reproduce information.

On the other hand, when the recording method is the recording in which the magnetic field modulation overwrite method is overwritten, the condition selecting means reads out the magnetic field modulation overwrite method recording condition from the control track 9 and is read. Information is recorded / reproduced in the same manner as described above according to the above conditions.

When the recording method is the recording in which the optical modulation overwrite method is overwritten, recording and erasing are not performed, and only the reproduction is performed only when the data modulation / demodulation method is the same. The control means controls the recording / reproducing means.

The recording method in the above-described magneto-optical recording apparatus may be initially set in the apparatus, or may be set by the user to select and set. Further, in the case of a magneto-optical recording device capable of only one of recording with overwriting and recording without overwriting,
When the magneto-optical disk of this embodiment is set in the device,
It is sufficient to select an appropriate control track and read the recording condition.

As described above, the magneto-optical disk according to the present embodiment is provided with two control tracks in which the conditions for recording without overwriting and the recording by the magnetic field modulation overwrite method are recorded. Is. As a result, it becomes possible to record information using this magneto-optical disk in a magneto-optical recording apparatus capable of at least one of recording without overwriting and recording by the magnetic field modulation overwrite method.

Further, the magneto-optical recording apparatus for recording using this magneto-optical disk selects one of the above two control tracks according to the recording method and reads the condition, and the information is recorded according to this condition. With the configuration for recording, the compatibility between the magneto-optical recording apparatus and the magneto-optical disk is improved, and the same magneto-optical disk can be shared by magneto-optical recording apparatuses having different recording methods. Play.

Second Embodiment Another embodiment of the present invention will be described below with reference to FIGS. 1 and 9 to 13. Incidentally, for convenience of explanation, the same reference numerals are given to the portions having the same functions as those in the above-mentioned embodiment, and the detailed explanation thereof will be omitted. The same applies to other embodiments described later.

The magneto-optical disk as the magneto-optical recording medium of this embodiment has a transparent dielectric on the transparent substrate 1 as shown in FIG. 9 in order to enable the optical modulation overwrite system. The body layer 2, the magnetic layer 6 and the magnetic layer 7 as the exchange coupling two-layer film, and the protective layer 4 are sequentially formed. Further, an overcoat film may be formed on the protective layer 4 in order to protect the disc surface.

As shown in FIG. 10, the magnetic layer 6 has a lower Curie point (T _C1 ) and a higher coercive force (H _C1 ) at room temperature, as compared with the magnetic layer 7, and the magnetic layer 6 has room temperature to T _C1. A transition metal-rich characteristic in which perpendicular magnetization is obtained is shown. The magnetic layer 7 has a Curie point (T _C2 ) higher than T _C1 of the magnetic layer 6 and a coercive force (H _C2 ) lower than H _C1 of the magnetic layer 6 at room temperature, and is perpendicular from room temperature to T _C2. It shows the characteristic of rare earth metal rich in magnetization.

Now, the recording process of the optical modulation overwrite system using the magneto-optical recording medium of the present invention will be described.

When recording by the optical modulation overwrite method using such a medium, the magnetic layer 7 is first initialized. That is, it is larger than H _C2 near room temperature,
An initializing magnetic field (H _init ) smaller than H _C1 is applied to align only the total magnetization of the magnetic layer 7 in one direction.

Then, while applying a recording magnetic field (H _W ) of a small intensity in the direction opposite to H _init as shown in FIG. 12, three levels of intensity (P _h , P _l , P) are obtained as shown in FIG.
_The information is rewritten by irradiating the laser beam modulated by _r ) to locally raise the temperature of the magnetic layers 6 and 7. That is, the high process in which the temperature of the portion irradiated with the laser beam of intensity P _h rises to the vicinity of T _C2 which is the Curie point of the magnetic layer 7 and the temperature of the portion irradiated with the laser beam of intensity P _l are magnetic. The low process of raising the temperature to near the Curie point T _C1 of the layer 6 is repeated, and it becomes possible to rewrite information by overwriting.

The above high process and low process will be described in more detail below with reference to FIG.

In the figure, each rectangle shows the magnetization state of the magnetic layer 6 and the magnetic layer 7, and the horizontal axis shows the temperature. Since the magnetic layer 6 and the magnetic layer 7 are rare earth-transition metal alloys, there are total magnetization and sublattice magnetizations of the rare earth metal and the transition metal. The direction of the sublattice magnetization of the transition metal of each layer is shown in each layer in the figure. Shown by an arrow inside.

First, in the vicinity of room temperature, two states S1 and S2 exist depending on the direction of magnetization of the magnetic layer 6. As described above, since the coercive force of the magnetic layer 7 near room temperature is small, the total magnetization of the magnetic layer 7 becomes parallel to the applied initializing magnetic field H _init . Since the magnetic layer 7 is rich in rare earth metals, the total magnetization is in the opposite direction to the sublattice magnetization of the transition metal. Therefore, the sublattice magnetization is opposite to H _init .

In the high process, when the laser beam is irradiated while the recording magnetic field H _W is applied and the temperature of the part irradiated with the laser beam rises to near the Curie point T _{C2 of the} magnetic layer 7, the magnetic layer is irradiated. The sublattice magnetization of No. 7 is reversed so as to be in the opposite direction to H _W. That is, the states S1 and S2 are
The state shifts to the state S5 through the states S3 and S4.

When the magneto-optical disk rotates, the portion irradiated with the laser beam moves, and when cooled, the sub-lattice magnetization of the magnetic layer 6 becomes magnetic due to the exchange force acting on the interface between the magnetic layer 6 and the magnetic layer 7. The sublattice magnetization of the layer 7 is aligned. That is, the state S5 shifts to the state S7 via the state S6.

Further, when H _init is applied at room temperature, the magnetization direction of the magnetic layer 6 having a large coercive force does not change, but the magnetization direction of the magnetic layer 7 having a small coercive force is reversed. That is, the state S7 shifts to the state S2.

Next, in the low process, when the temperature of the portion irradiated with the laser beam rises to around T _c1 , the coercive force of the magnetic layer 7 is larger than H _W , so the direction of magnetization of the magnetic layer 7 is H. Not reversed by _W.

When the irradiation portion of the laser light is moved by the rotation of the magneto-optical disk and cooled, the sub-lattice magnetization of the magnetic layer 6 acts on the interface between the magnetic layer 6 and the magnetic layer 7 as in the above process. By the exchange force to align the sub-lattice magnetization of the magnetic layer 7. That is, the states S1 and S2 shift to the state S1 via the state S3.

As described above, in the high process, the magnetic layer 6 shifts from the states S1 and S2 to the state S2 in which the total magnetization is upward (the sublattice magnetization is upward), and in the low process, the magnetic layer 6 is formed. From states S1 and S2,
The state shifts to the state S1 in which the magnetization is downward (the sub-lattice magnetization is downward). That is, regardless of whether the initial state is S1 or S2, it is possible to determine which state of S1 or S2 the transition is made to, by only modulating the intensity of the laser light to be applied. This makes it possible to directly write new information without erasing the recorded information.

When information is reproduced, it is reproduced by irradiating a laser beam (P _r ) having an intensity considerably lower than that at the time of recording and detecting the rotation of the polarization plane in the reflected light.

The laser light intensity and the magnetic field intensity differ depending on the speed (rotation speed) of the magneto-optical disk, the irradiation time of the laser light, the wavelength of the laser light, the recording frequency, and the like. Thus, P _w, P _e in the recording is not performed overwriting, and H _w, and _{H e,} P _h, P _l in recording by the optical modulation overwrite method, the same may be different from the H _w, and H _init In some cases

A control track 8 and a control track 9 are provided on the inner peripheral portion of the transparent substrate 1 of the magneto-optical disk of this embodiment. Various recording conditions such as the intensity of the laser beam and the intensity of the external magnetic field during recording without overwriting are recorded on the control track 8 by the unevenness (prepits) formed on the substrate, and on the control track 9, The recording conditions for overwriting the light modulation overwrite method are also recorded.

In the same magneto-optical recording apparatus as that described in the first embodiment, when the magneto-optical disk of the present embodiment is used for recording / reproducing, the recording method is not overwriting. In some cases, the condition selection means provided in the magneto-optical recording device reads out the recording condition from the control track 8 for which overwriting is not performed, and the control device controls the recording / reproducing device according to the read condition. Information recording / reproduction is performed.

On the other hand, when the recording method is the recording in which the optical modulation overwrite method is overwritten, the condition selection means reads the recording conditions of the optical modulation overwrite method from the control track 9 and reads them. Information is recorded / reproduced in the same manner as described above according to the above conditions.

If the recording method is the magnetic field modulation overwrite method of overwriting, recording and erasing are not performed, and only reproduction is performed only when the data modulation / demodulation method is the same. The control means controls the recording / reproducing means.

As described above, the magneto-optical disk of this embodiment is a magneto-optical disk capable of recording by the optical modulation overwrite method and having an exchange coupling double-layer film.
Further, it has a configuration provided with two control tracks in which the recording condition without overwriting and the recording condition of the light modulation overwrite method are recorded respectively.

As a result, in the magneto-optical recording apparatus capable of performing recording without overwriting and / or recording by the optical modulation overwrite system, the magneto-optical disk is used to record information. It becomes possible to do.

Further, the magneto-optical recording apparatus for recording using this magneto-optical disk selects one of the above two control tracks in accordance with the recording method and reads the condition, and the information is recorded in accordance with this condition. With the configuration for recording, the compatibility between the magneto-optical recording apparatus and the magneto-optical disk is improved, and the same magneto-optical disk can be shared by magneto-optical recording apparatuses having different recording methods. Play.

[Embodiment 3] Another embodiment of the present invention will be described below with reference to FIGS. 9 and 14.

The magneto-optical disk as the magneto-optical recording medium of the present embodiment, as shown in FIG. 9 described in the second embodiment, has a light-transmitting dielectric layer 2 on a light-transmitting substrate 1. The magnetic layer 6 and the magnetic layer 7 as an exchange coupling two-layer film and the protective layer 4 are sequentially formed. Furthermore, an overcoat layer may be formed on the protective layer 4 in order to prevent deterioration of the recording layer.

Since this magneto-optical disk has the exchange-coupling double-layer film as described above, it is possible to perform the overwriting of the optical modulation overwrite method described in the second embodiment, and at the same time, It is possible to record information by a total of three types of recording methods, that is, the recording in which the magnetic field modulation overwrite method is overwritten as described in the first embodiment and the recording in which the overwriting is not performed.

The transparent substrate 1 of the magneto-optical disk of this embodiment.
As shown in FIG. 14, a control track 21, a control track 22, and a control track 23 are provided on the inner peripheral portion of the. Control track 2
No. 1 is a recording condition without overwriting, control track 22 is a magnetic field modulation overwrite type recording condition, and control track 23 is a light modulation overwrite type recording condition. It is recorded by each pre-pit). Note that the above-mentioned recording conditions include various conditions such as the intensity of laser light and the intensity of a magnetic field applied from the outside when performing recording of each method.

The laser beam intensity and the magnetic field intensity differ depending on the speed (rotation speed) of the magneto-optical disk, the irradiation time of the laser beam, the wavelength of the laser beam, the recording frequency, and the like. _{Thus, P w, P e, H} w in the recording is not performed overwriting, and H _e and, and _{P w, P e, H w} , and H _e in recording by magnetic field modulation overwrite method, the optical modulation overwrite method The respective values of P _h , P _l , H _w , and H _init in the recording according to may be different from each other or may be the same.

Using the present magneto-optical disk, the first embodiment described above is used.
In the magneto-optical recording apparatus as described above, when recording / reproducing information, etc., when the recording method is recording without overwriting, the condition selecting means provided in this apparatus is the control track 21. Read the recording condition that does not overwrite from, and according to the read condition,
The control unit controls the recording / reproducing unit to record / reproduce information.

On the other hand, when the recording method is the recording in which the magnetic field modulation overwrite method is overwritten, the condition selecting means reads the recording condition of the magnetic field modulation overwrite method from the control track 22 and reads it. Information is recorded / reproduced in the same manner as above according to the above conditions.

When the recording method is the recording in which the optical modulation overwrite method is overwritten, the condition selection means reads the recording condition of the optical modulation overwrite method from the control track 23 and reads it. Information is recorded / reproduced in the same manner as above according to the above conditions.

As described above, since the magneto-optical disk of this embodiment is provided with the exchange coupling two-layer film, the optical modulation overwrite type recording is possible, and the recording without overwriting, This is a configuration provided with three control tracks that respectively store conditions of three types of recording methods, that is, recording of the magnetic field modulation overwrite method and recording of the optical modulation overwrite method.

As a result, it becomes possible to record information using this magneto-optical disk in a magneto-optical recording apparatus capable of recording by at least one of the above three recording methods.

Further, the magneto-optical recording apparatus for recording using this magneto-optical disk selects one of the above three control tracks in accordance with the recording method and reads the condition, and the information is recorded according to this condition. With the configuration for recording, the compatibility between the magneto-optical recording apparatus and the magneto-optical disk is further improved, and the same magneto-optical disk can be shared by magneto-optical recording apparatuses having different recording methods. .

The above-mentioned embodiments do not limit the present invention, and various modifications can be made within the scope of the invention. For example, on the surfaces of the magnetic layer 3 and the magnetic layers 6 and 7,
A reproduction layer for improving reproduction signal characteristics or for reproducing minute pits may be formed. Further, although each control track is formed by unevenness (prepits) at different places on the substrate, it may be formed at the same place or may be formed in a trial writing area. Alternatively, it may be formed by a magneto-optical signal instead of the unevenness (pre-pit).

[0072]

As described above, the magneto-optical recording apparatus of the present invention has a control track area for recording recording conditions.
Data track area for recording information and
The control track area is used for rewriting information.
However, if the recording method requires erasing the recorded information,
The recording conditions and the recording conditions of the recording method that does not require the erasing operation are described.
Recording conditions of the recording method that is recorded and does not require erasing operation
As a recording condition and optical change of the magnetic field modulation overwrite method,
Both the key and overwriting method recording conditions are recorded.
Information is recorded and reproduced using existing magneto-optical recording media.
Therefore, based on the recording / reproducing means for recording and reproducing information and the recording method preset in advance,
When rewriting information, the operation to erase the recorded information
Recording conditions of required recording method and recording method that does not require erasing operation
The recording condition of the formula, the description of the magnetic field modulation overwrite system
Recording conditions and recording conditions of optical modulation overwrite method
Condition selection means for selecting a recording condition from among the recording conditions corresponding to each recording method, and control means for controlling the laser light intensity or the magnetic field intensity of the recording / reproducing device based on the selected recording condition. This is the configuration provided.

As a result, the recording condition relating to the laser light intensity and the magnetic field intensity of the recording / reproducing means suitable for the recording system set in the magneto-optical recording apparatus is set to record / reproduce information. The magneto-optical recording medium can be shared by different magneto-optical recording apparatuses, and the compatibility between the magneto-optical recording medium and the magneto-optical recording apparatus can be improved.

[Brief description of drawings]

FIG. 1 is a schematic top view showing the configuration of a magneto-optical disk (magneto-optical recording medium) according to an embodiment of the present invention.

FIG. 2 is a sectional view showing the structure of the magneto-optical disk.

FIG. 3 is a graph showing the temperature dependence of the coercive force of the magnetic layer in the magneto-optical disk.

FIG. 4 is an explanatory diagram showing the intensity of laser light applied to the magneto-optical disk in the case of recording without overwriting.

FIG. 5 is an explanatory diagram showing the strength of an external magnetic field applied in the case of recording without overwriting in the magneto-optical disk.

FIG. 6 is an explanatory diagram showing the intensity of laser light emitted when recording is performed in the magnetic field modulation overwrite method for performing overwriting on the magneto-optical disk.

FIG. 7 is an explanatory diagram showing the strength of an external magnetic field applied when recording by the magnetic field modulation overwrite method.

FIG. 8 is an explanatory diagram showing a recording process of the magnetic field modulation overwrite method.

FIG. 9 is a sectional view showing the structure of a magneto-optical disk according to another embodiment of the present invention.

FIG. 10 is a graph showing the temperature dependence of the coercive force of each magnetic layer in the magneto-optical disk.

FIG. 11 is an explanatory diagram showing the intensity of laser light emitted when recording is performed on the magneto-optical disk by an optical modulation overwrite method for performing overwriting.

FIG. 12 is an explanatory diagram showing the intensity of an external magnetic field applied when recording is performed by the light modulation overwrite method.

FIG. 13 is an explanatory diagram showing a recording process of the light modulation overwrite system.

FIG. 14 is a schematic top view showing the configuration of a magneto-optical disk according to another embodiment of the present invention.

FIG. 15 is a block diagram showing a configuration of a magneto-optical recording apparatus of the present invention.

FIG. 16 is a schematic top view showing the configuration of a conventional magneto-optical disk.

[Explanation of symbols]

8 control tracks 9 Control track 22 Control track 23 Control Track

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Takahashi 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (56) Reference JP-A-4-105218 (JP, A) JP-A 64-- 55741 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B 11/105

Claims (3)

(57) [Claims] 1. A control track for recording a recording condition.
Area and data track area for recording information
And, in the control track area above,
When rewriting, it is necessary to erase the recorded information.
Recording method recording conditions and recording method that does not require erasing operation
A recording method in which conditions and conditions are recorded and no erasing operation is required
As the recording condition of,
Both the conditions and the recording conditions of the optical modulation overwrite method
Information is recorded and recorded using the recorded magneto-optical recording medium.
To perform fine reproduction, and recording and reproducing means for recording and reproducing information, based on the recording method set in advance itself, magneto-optical
When rewriting the information on the recording medium,
Recording conditions for recording methods that require erasing, and erasing is unnecessary
Overwriting, which is a recording condition for various recording methods
System recording conditions and optical modulation overwrite system recording
The control conditions for the magneto-optical recording medium are as follows.
It is provided with condition selecting means for reading from the rear and selecting a corresponding recording condition, and control means for controlling the laser light intensity or the magnetic field intensity of the recording / reproducing means based on the selected recording condition. Magneto-optical recording device. 2. The recording condition of a magneto-optical recording medium is
Both the intensity of the laser beam and the magnetic field intensity are recorded.
The magneto-optical recording apparatus according to claim 1, wherein 3. A recording condition of a magneto-optical recording medium is formed on a substrate.
That it is recorded by the formed unevenness (pre-pit)
The magneto-optical recording device according to claim 1 or 2.