JPH03252937A - Magneto-optical recording medium - Google Patents

Abstract

PURPOSE:To obtain a large recording capacity by controlling a light beam which irradiates a guide layer which causes reversible thermal phase transition and variation of reflection for a light beam, provided between a substrate and a recording layer. CONSTITUTION:On the surface of a pregroove layer 5 where tracks are formed, there are successively formed a guide layer 2 comprising an In-Se film which is a medium to cause chalcogenide phase transition, a recording layer 3 comprising a Tb-Fe-Co film which is a rare earth-transition metal amorphous perpendicular medium, and a dielectric layer 4 as a protective layer comprising a SiO dielectric film. By controlling the laser beam so that the irradiation time and laser output alternately change for the land area L and groove area G, information can be recorded both in the land area L and groove area G. Thus, the recording density can be doubled and the recording capacity can be increased.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magneto-optical recording medium capable of high-density recording;
In particular, the following two bands constituting the track, that is, the first phase band with high reflectance of the light beam and the adjacent second phase band which becomes the information recording band, are reversed, and the first phase band is The present invention relates to a magneto-optical recording medium that allows information to be recorded even in the area.

[Conventional technology]

Optical discs have become popular and commercially available for consumer use, as optical-related technology using semiconductor lasers as light sources has been established for read-only CDs and LDs.

In addition, by taking advantage of the greatest feature of optical disks, which is high-density, large-capacity recording, the DRAW type (Direct Read AfterW), which can record desired information and then play it back.
rite), and erasable optical disks with an erasing function have been put into practical use for computers and for files such as images and documents.

Magneto-optical disks, a type of optical disk, can record information at a high density because, compared to ordinary magnetic disks, the density of continuous tracks formed in a spiral or concentric pattern on the disk surface is significantly higher. This is due to the fact that it has increased. This result can be said to be brought about by tracking servo technology that is performed in a non-contact manner using a laser beam with a wavelength of about 800 nm that is focused on a spot with a diameter of about 1 μm.

On the substrate of such an optical disk, there is a pre-group layer in which tracks are formed, each consisting of a groove (hereinafter referred to as a group) and a raised land formed between adjacent group parts. , are fixedly provided in advance. Techniques for forming this pre-group layer include a photopolymer one-way method (2P method), a photoengraving process method (PER method), and an active ion etching method (RIE method).

Tracking control of the optical head is performed using interference between reflected lights when a laser beam irradiated from the substrate side is reflected by the land portion and the group portion of the pre-group layer.

On the other hand, information is recorded only on either the land portion or the group portion of the recording layer which is further provided with a bottom film on the pre-group layer, and neither of the land portions or the group portion serves as an information recording area. This is because it is necessary to avoid crosstalk between adjacent information recording areas. Therefore, in conventional optical discs, only about half of the width of one track is used for recording information.

Applications of optical discs such as those mentioned above are expanding to fields such as high-quality still image files, video files, communication data, and tough aisles, and the demand for large information storage capacities on optical discs is becoming increasingly tight. . In order to increase the capacity of optical discs, methods of narrowing the trunk pinch are being considered as a means of increasing the effective recording area on the disc surface. Currently, optical discs with trunk pinch set to 1.6 μm are in widespread use, but at the laboratory level, optical discs with trunk pinch of 1.2 to 1.4 μm are being tried.

[Problem to be solved by the invention]

However, the conventional magneto-optical recording medium described above has problems in that when the track pinch is narrowed, the signal strength during recording and reproduction decreases, resulting in poor C/N ratio and increased crosstalk between adjacent trunks. have. Therefore, at the current stage, there are technical limits to increasing the capacity of magneto-optical recording media by narrowing the track pitch.

It is an object of the present invention to provide magneto-optical recording that enables information to be recorded in an area corresponding to approximately 1/2 of the track width, which is not used for information recording on the conventional track, thereby increasing the recording capacity. The goal is to provide a medium.

[Means to solve the problem]

In order to solve the above-mentioned problems, the magneto-optical recording medium according to the present invention is a magneto-optical recording medium that records information by magneto-optical recording and has a recording layer made of an amorphous perpendicular magnetization film of, for example, a rare earth-transition metal system. , consisting of a phase change medium such as chalcogenide, which causes a reversible thermal phase transformation and an accompanying change in the reflectance of the light beam, between the substrate made of chemically strengthened glass and the above-mentioned recording layer. A guide layer is provided, and by controlling the light beam irradiated to the guide layer, a first phase band area with a relatively high reflectance and an information recording area adjacent to the first phase band area with a relatively low reflectance are formed. A continuous track is provided by alternately forming second phase band regions, and the guide layer is thermally phase-transformed by controlling the light beam irradiated to the guide layer. It is characterized in that the above-mentioned first phase band area and the second phase band area which becomes the information recording band can be reversed.

[Function] According to the above configuration, the guide layer undergoes a reversible thermal phase transformation, and the first phase zone in the crystalline state and the second phase zone in the amorphous state change depending on the temperature conditions. It is formed. Table 1 summarizes the relationship between the transmittance and reflectance of laser light in the crystalline state and the amorphous state.

Table 1 As can be seen from Table 1, the first phase band region in the crystalline state has a low transmittance and a high reflectance, so the reflected light of the laser beam can be used as a tracking signal source. In addition, since the second phase band region in an amorphous state has a high transmittance and a low reflectance, information is recorded or read out in the recording layer directly below the guide layer in this amorphous state to form an information recording band. be able to.

In addition, the crystallization temperature of the guide layer is T8, and the amorphous temperature is T8.
2. If the recording temperature of the recording layer is T3, each temperature is T
It satisfies the relationship I<T2<T3.

When recording information on a land portion formed in a spiral shape, first, a laser beam is irradiated onto a rotating disk from the substrate side while performing tracking control and focusing control via an optical head. The irradiation time and laser output of the laser beam are controlled so that the temperature of the irradiation part is around T2 at the land part of the guide layer and around T at the group part. As a result, the land portion of the guide layer becomes a second phase band region in an amorphous state, and as shown in Table 1, the reflectance becomes small (transmittance becomes large), and the group portion of the guide layer becomes a second phase band region in a crystalline state. It becomes a one-phase band area,
Reflectance increases (transmittance decreases).

Next, similarly to the lands of the guide layer, the lands of the recording layer formed in a spiral shape directly below are modulated into recording signals while performing tracking control and focusing control via the optical head. irradiate with a laser beam pulse.

At this time, the recording layer is initially magnetized in advance in the same direction perpendicular to the disk surface, and the direction of application of the external magnetic field applied at the same time as the laser beam pulse irradiation is opposite to the above-mentioned initial magnetization direction. ing. By irradiating the laser beam pulse, the recording temperature T3 is heated to around the Curie temperature of the recording layer, and depending on the recording medium, the region is heated to around the compensation point temperature, and the magnetization is reversed to form a magnetic domain, and when the irradiation with the laser beam pulse ends, It cools down and becomes a recording bit.

In this way, after information is recorded over the entire land portion of the recording layer, information is further recorded on a group portion that is formed in a spiral shape and is adjacent to the land portion. in this case,
The above laser beam irradiation time and laser output are
By controlling the land portion and group portion to be interchanged, the land portion of the guide layer is reversed to the first phase band region in the crystalline state, and the group portion of the guide layer is reversed to the second phase band region in the amorphous state. let Similar to the group portion of the guide layer, the recording method for the group portion of the recording layer spirally formed directly below the group portion is performed in the same manner as for the land portion described above. As a result, information is recorded on both the land portions and the group portions, and the recording density is twice that of conventional magneto-optical recording media.

Reading of the recording signal is performed by a laser beam that is irradiated onto the recording layer from the substrate side through the amorphous second phase band region of the guide layer. The reproduction output of the laser beam is set within a range in which the temperature of the guide layer does not rise above T. When reading from the land portion, the land portion of the guide layer is placed in an amorphous state with high transmittance, and the group portion of the guide layer is placed in a crystalline state with low transmittance. When reading from the group portion, the above state is reversed, and the land portion is placed in a crystalline state and the group portion is placed in an amorphous state. In this way, the recording under the first phase band region in the crystalline state with low transmittance will not be read out, making it possible to improve the recording density without deteriorating the reproduced signal due to crosstalk.

[Example 1] An example of the present invention will be described below based on FIGS. 1 and 2.

As shown in FIG. 1, the magneto-optical recording medium according to the present invention has the following features:
Outer diameter R=130φmm, inner diameter r=15φmm, thickness w=
A pre-group layer 5 having tracks of 1.2 mm and provided with tracks by the RIE method is formed on one side of the substrate 1, which is better than chemically strengthened glass. The pre-group layer 5 has raised lands and grooves formed in a spiral shape.
The land portions (hereinafter referred to as groups) are arranged alternately, and adjacent land portions and group portions G constitute one track. The land width l and the group width g are each 0.8 μm, so that the track pitch t is 1.6 μm.

A guide layer 2 made of an In-3e film, which is a chalcogenide-based phase change medium, and a Tb-FeCo film, which is an amorphous perpendicular magnetization medium of rare earth-transition metals, are attached to the track-shaped bottom surface of the pre-group layer 5. A recording layer 3 and a dielectric layer 4 made of a SiO dielectric film as a protective layer are sequentially formed to form a laminated structure. The thickness of each layer is 600 for the guide layer 2, 1000 for the recording layer 3, and 500 for the dielectric layer 4.

These films were formed continuously in the same vacuum chamber.

To form the In-3e film, a resistance heating evaporation method was used in which In and Se elements were evaporated from separate evaporation sources to form a film on the substrate at an appropriate composition ratio. For Tb-Fe-Co film formation,
Evaporating the transition metal and rare earth metal from separate deposition sources,
An electron beam evaporation method was used to form an alloy with an appropriate composition ratio on the substrate, and an electron beam evaporation method was used to form the Si◯ film.

Here, the above In-3e film and the above Tb-Fe film
The characteristics of each single layer of the -Co film were as follows.

The refractive index and extinction coefficient of In, oo-XSex (atom%) changed significantly in the range of X=30 to 50, and showed a decreasing tendency with increasing X. Film thickness 120
In the case of 0 people's I n5ts e43, it crystallizes when heated for 0.2 μs at 135°C (=crystallization temperature T1), and is rapidly cooled (<0 .2 μs), it becomes amorphous.The transmittance and reflectance of this crystalline state and the amorphous temperature varied as shown in Table 2.The laser beam had a wavelength of 830 nm.
A nm semiconductor laser was used.

Table 2 On the other hand, as a Tb-Fe-Co film, T b v (F
e8b, zc O+ff, 7)+oo-y (ajo
m%) was used. The value of Y was selected near the compensation composition where the transition metal sublattice magnetization is larger than the rare earth metal sublattice magnetization, and was set to Y=16.0 to 18.0. The Curie temperature Tc at this time was 195°C. From the above, the recording temperature when recording information on the recording layer 3 is T, :=
If Tc, then the following relationship holds true: crystallization temperature T<amorphous temperature T2>recording temperature T3.

In the magneto-optical recording medium having the above configuration, the recording layer 3
(hereinafter referred to as land portion recording), when recording on the group portion G of the recording layer 3 (hereinafter referred to as group portion recording), and when reproducing recorded information. Each control will be explained.

The optical head (not shown) used includes two semiconductor lasers with different oscillation wavelengths. When recording and reproducing information on the recording layer 3 and making the guide layer 2 amorphous, a semiconductor laser beam with a wavelength of 830 nm was used, and the irradiation spot was narrowed down to a circular shape to a diffraction limit of about 0.8 μm in diameter. On the other hand, when crystallizing the guide layer 2, the wavelength 780
Using a semiconductor laser beam of nm, the irradiation spot is approximately 0.
．． It was shaped into an oval shape of 9×3 μm. Regarding the reflected light from the disk, only the reflected light of the laser beam having a wavelength of 830 nm is detected by a photodetector (for example, a 4-split photodiode) (not shown) via a gyrochromic mirror. Further, as evaluation conditions, the recording and reproducing area was set around 40 mm from the center of the disk, the disk rotation speed was set to 1800 rpm, and the recording frequency was set to 3 MHz. Note that the laser beam irradiation time is optimized based on the disk rotation speed and laser beam shape set as described above.

First, in order to perform land recording, a laser beam with a wavelength of 830 nm is applied to the land portion of the guide layer 2 from the substrate 1 side.
It was irradiated with a 2 mW laser beam to make it amorphous, forming a second phase band region. In addition, wavelength 7 is added to the group portion G of the guide layer 2.
It was crystallized by irradiation with a laser beam of 80 nm, laser output cuff, and 0 mW to form a first phase band region. Note that the positional relationship of the irradiation spots of each laser beam was determined as shown in FIG. The circular spot a is an irradiation spot of a laser beam with a wavelength of 830 nm, and the elliptical spot b is an irradiation spot of a laser beam with a wavelength of 780 nm.

The circular spot a does not overlap with the adjacent region S corresponding to the major axis of the elliptical spot b.

Focusing control and tracking control were performed by the astigmatism method and the push-pull method, respectively, while detecting the reflected light of the circular spot a on the land portion of the broach roof 15 using the photodetector described above.

When recording information, a wavelength of 830 nm modulated at a frequency of 3 MHz is transmitted through the land portion of the amorphous guide layer 2.
The recording layer 3, which had been perpendicularly magnetized in one direction in advance, was irradiated with a laser beam pulse having a laser beam output of 8.2 mW, and the temperature of the recording layer 3 was raised to around the Curie temperature Tc. At this time, an external magnetic field having a magnitude of 3000 e was applied in a direction opposite to the initial magnetization direction. As a result, the Curie temperature Tc of the recording layer 3
The magnetization of the area heated to a nearby point was reversed, and information was recorded. Focusing control and tracking control were carried out while detecting the reflected light of the circular spot a on the land portion of the pre-blue layer 5, as described above.

When reproducing the recording, the recording layer 3 was irradiated with a laser beam having a wavelength of 830 nm and a laser output of 1.5 mW. As a result, a C/N of 37 dB was obtained, which was found to be at a practical level. The forcing control and tracking control are the same as described above.

To switch the recording area from land area recording to group area recording, the optical head is shifted by one land in the disk radial direction, and a laser beam with a wavelength of 780 nm is irradiated onto the land area, and a laser beam with a wavelength of 830 nm is irradiated onto the group area G. so that it is irradiated. In this way, by using the same laser control method as described above, the group portion G of the guide layer 2 is now amorphous and becomes a second phase band region, and the land portion of the guide layer 2 is crystallized and the second phase is formed. It became a swath.

Information is recorded in group part G of guide N2, which has become amorphous.
A laser beam with a wavelength of 830 nm controlled in the same manner as described above is irradiated onto the group portion G of the recording layer 3 through the
This is done by applying an external magnetic field similar to that described above.

When the group portion G of the recording layer 3 is irradiated with a laser beam having a wavelength of 830 nm and a laser output of 1.5 mW to reproduce information, records in adjacent land portions are read out, and no crosstalk occurs. This is because the adjacent land portions are in a crystalline state, and as shown in Table 2, the transmittance of the laser beam is low and the reflectance is high. As a result, it became possible to perform recording and reproduction in the group portion G adjacent to the land portion of the recording area, which could not be done in the past, and it was possible to obtain a recording density approximately twice that of the conventional method.

Erasing of the recording was performed by applying the external magnetic field in the opposite direction to that during recording and irradiating the recorded region with a laser beam having an output higher than the recording laser output of 8.2 mW. Since the amorphous temperature T2 of the guide layer 2 is higher than the crystallization temperature T1, the guide layer 2 did not undergo phase transformation from an amorphous state to a crystalline state during erasing and recording.

Note that the laser beam irradiated when the guide layer 2 undergoes phase transformation from crystalline to amorphous or from amorphous to crystalline may generate minute magnetic domains in the recording layer 3 or damage the already formed recording layer. Bits may become deformed. In order to prevent these adverse effects, it is sufficient to apply an auxiliary magnetic field perpendicular to the disk surface in a direction opposite to the direction in which the external magnetic field is applied during recording. In this example, the polarity of the electromagnet (not shown) used as an external magnetic field was reversed to that during recording, and the magnetic field was approximately 800 e.
An auxiliary magnetic field of magnitude was applied.

[Embodiment 2] Another embodiment of the present invention will be described below based on FIGS. 3 to 8. In this embodiment, a recording method will be described for a magneto-optical recording medium in which the pregroup layer 5 used for focusing control and tracking control of the optical head shown in the first embodiment is not provided.

The optical disk as the magneto-optical recording medium of this example has a third
As shown in the figure, a guide layer 12, a recording layer 13, and a dielectric layer 14 are sequentially formed and laminated on a substrate 11 made of chemically strengthened glass similar to that in Example 1. Each film forming method, each film thickness, and the U acid ratio of each layer are the same as in Example 1.

As shown in FIGS. 3 and 4, the optical disc substrate 1
1, a reference group G° and a reference land L are placed in the so-called lead-out area, which is the outermost periphery of the recording area.
' is formed in a spiral shape over several turns (FIG. 4 schematically shows the reference group G'').

FIG. 5 is an enlarged view of the area surrounded by the dotted line in FIG. 4. In FIG. 5, the shaded area F represents the reference group G", and point a indicates the end position of the reference croup G°. The white area E represents the initial state of the guide layer 12 (disk (This is the one immediately after fabrication, and no heat treatment has been performed.) In each case of recording, reproducing, and erasing information, the optical head used for thermal phase transformation of the guide layer 12 was the same as in Example 1. a laser beam with a wavelength of 830 nm to amorphize the guide layer 12;
The positional relationship of each irradiation spot of the laser beam with a wavelength of 780 nm for crystallizing the guide layer 12 is also determined in substantially the same manner as shown in FIG. That is, the spot X indicated by a circle in FIG. 6 represents the irradiation spot of a laser beam with a wavelength of 830 nm, and the spot X represents the irradiation spot of a laser beam with a wavelength of 780 nm.

In place of the pre-group layer 5 that had the function of guiding the optical head, there is a first phase band area that serves as a guideline in the recording area of the optical head, and a first phase band area that is adjacent to the first phase band area and serves as an information recording band. Tracking for forming the second phase band region in a spiral shape on the guide layer 12 was performed as follows.

First, in the case of land recording in which information is recorded on the land L' of the recording layer 13, the optical head irradiates the reference group G' with a laser beam with a wavelength of 780 nm, as shown by the arrow in FIG. While irradiating a laser beam with a wavelength of 830 nm to L", tracking is started from the outermost circumference toward the inner circumference in a spiral manner. At this time, focusing control and tracking control are performed using a photodetector as in Example 1. is the wavelength 830 nm at the reference land L"
The reflected light of the laser beam was detected using the astigmatism method and the push-pull method, respectively.

Next, as shown in FIG. 6, before or at the same time that the laser beam spot Y with a wavelength of 780 nm passes point a and the spot X of a laser beam with a wavelength of 830 nm passes through point a, amorphous region,
That is, the formation of a second phase band-like region that becomes an information recording band and a first-phase band-like region that becomes a crystalline portion, that is, a guideline, is started. The laser output has a wavelength of 8 as in Example 1.
The output of the 30 nm laser beam is 7.2 mW, and the wavelength is 78.
The output of the 0 nm laser beam is 7.0 mW. The crystalline region I indicated by a square in the figure represents the first phase band region formed by the spot Y on the guide layer 12, and the amorphous region H indicated by is formed by the spot X on the guide layer 12. (arrows indicate the scanning direction of the laser beam). Thus, the seventh
As shown in the figure, a crystalline region I and an amorphous region H are formed in a spiral shape in the guide layer 12. Note that, as shown in FIG. 7, the tracking control is switched until the spot X passes the point C, that is, until the guideline is formed around one track. That is, in the readout area, the tracking signal is based on the amount of light reflected by the uneven shape of the reference group G" and the reference land L" that is generated when the laser beam with a wavelength of 830 nm deviates from the center of the width of the reference land L'. In contrast, in the recording area, the crystalline region I and the amorphous region that occur when the laser beam with a wavelength of 830 nm deviates from the center of the width of the crystalline region I, which serves as a guideline. This is done by utilizing changes in the amount of reflected light due to differences in the reflectance of H.

Information is recorded, reproduced, and erased by irradiating the recording layer 13 located immediately below the amorphous region H of the guide layer 12 with a laser beam having a wavelength of 830 nm.

The method of controlling the laser output and the external magnetic field is the same as in the first embodiment.

Corresponding to the switching from land recording to group recording in which information is recorded in the group G' of the recording layer 13, the amorphous area H is changed to the crystalline area I, and the crystalline area I is changed to the amorphous area. Switch the guideline by reversing it to H. For this purpose, spot X located on reference land L' in FIG. 6 is placed in reference group G? The spot Y, which was in the reference group G', may be shifted by one line so that it is located in the reference land L'.

As a result, as shown in FIG. 8, the spot X and the spot Y are arranged one line apart from those in FIG.

Control of laser output for guideline formation is the same as described above.

Before or at the same time as the spot Y of the laser beam having a wavelength of 780 nm passes through the point d, the formation of a guideline in the recording area is started. The tracking signal source is switched until the spot X passes the point a, that is, until the guideline is formed by approximately one track. That is, in the lead-out area, the tracking signal has a wavelength of 830n.
The reference group G" and the reference land L" are generated when the laser beam of m is shifted from the center of the width of the reference group G°.
In contrast, in the recording area, when the laser beam with a wavelength of 830 nm deviates from the center of the width of the crystalline region (■), which serves as a guideline, Crystalline region I and amorphous region H
This is done by utilizing changes in the amount of reflected light due to differences in reflectance.

As described above, information is recorded, reproduced, and erased through the amorphous region H formed in the guide layer 12 in reverse.
The recording layer 13 located directly below is irradiated with a laser beam having a wavelength of 830 nm. The method of controlling the laser output and the external magnetic field is the same as in the first embodiment. As a result of the above,
Without the need for a pre-group layer 5, it is now possible to record and reproduce information even in the group section G', which is about 1/2 of the track width, which was previously impossible. Approximately twice the recording density could be obtained.

The magneto-optical recording medium according to the present invention is not limited to the above embodiments. In addition to the In-3e type, the guide layer 2 and the guide layer 12 include 5b-se type, 5b-Te type,
5b-3e-Te system, 5n-3b-3e system, Te-3n
Chalcogenide phase change media such as -3b type and Ge-Te-3b type can be used. In addition to Tb-Fe-Co, the recording layer 3 and the recording layer 13 contain GdD.
y-Fe-Co series, Gd-Tb-Fe-Co series, Tb-
An amorphous perpendicular magnetization medium of a rare earth-transition metal alloy such as Dy-Fe-Co may be used.

Furthermore, regarding the structure of the magneto-optical recording medium, between the substrate 1 and the guide layer 2 or between the guide layer 2 and the recording layer 3,
A transparent dielectric film made of St○, A/2N, SiN, ZnS, or the like can be sandwiched therebetween. By optimizing the film thickness of the guide layer 2 and the film thickness of the above-mentioned transparent dielectric film,
Using the light interference effect in each layer, the intensity of the reproduced signal from the recording layer 3 can be amplified, and furthermore, the contrast ratio between the crystalline part and the amorphous part in the guide layer 2 can also be amplified. Substrate 11, guide layer 12, and recording layer 13
The same applies to

[Effects of the Invention] As described above, the magneto-optical recording medium according to the present invention achieves a reversible thermal phase transformation and an accompanying change in the reflectance of a light beam between the substrate and the recording layer. Equipped with a guide layer that raises the
By controlling the light beam irradiated to the guide layer, a first phase band area having a relatively high reflectance and a first phase band area adjacent to the first phase band area are formed.
By providing a continuous trunk formed by alternately forming second-phase band regions that have a relatively low reflectance and serve as information recording bands, and by controlling the light beam irradiated to the guide layer, This configuration is capable of thermally transforming the phase of the guide layer and reversing the first phase band area and the second phase band area that becomes the information recording band.

In this way, information is recorded/reproduced in the amorphous second phase band region with relatively low reflectance, and furthermore, information is recorded and reproduced in the amorphous second phase band region with a relatively low reflectance. , the first phase band in the crystalline state with relatively high reflectance is reversed to the second phase band, and information is recorded and reproduced again.
The recording density of the magneto-optical recording medium can be made approximately twice as high as that of the conventional one. Furthermore, when reproducing information, the information is not read out from the first phase band, which has a relatively high reflectance, so there is no crosstalk problem and C/N deterioration of the reproduced signal can be prevented. The effect is played together.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention. FIG. 1 is a sectional view of an optical disc. FIG. 2 is an explanatory diagram showing the relative positional relationship between two types of laser beam spots. 3 to 8 show other embodiments of the present invention. FIG. 3 is a sectional view of another optical disc. FIG. 4 is a plan view showing a reference group of optical discs. FIGS. 5 to 8 are explanatory diagrams showing the phase change state of the guide layer with respect to the scanning state of the reference group and two types of laser beam spots. 1 and 11 are substrates, 2 and 12 are guide layers, 3 and 13 are recording layers, H is an amorphous region (second phase band region), and ■ is a crystalline region (first phase band region).

Claims (1)

[Claims] 1. In a magneto-optical recording medium equipped with a recording layer for recording information by magneto-optical recording, reversible thermal phase transformation and an accompanying light beam occur between the substrate and the recording layer. A guide layer that causes a change in reflectance, and by controlling a light beam irradiated to the guide layer, a first phase band area having a relatively high reflectance, and a first phase band area adjacent to the first phase band area,
By providing a continuous track formed by alternately forming second-phase band regions that have a relatively low reflectance and serve as information recording bands, and by controlling the light beam irradiated to the guide layer, A magneto-optical recording medium characterized in that the guide layer is thermally phase-transformed to reverse the first phase band area and the second phase band area which becomes an information recording band.