JP4381539B2 - Optical information recording method, optical information recording / reproducing method, and optical information recording / reproducing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical information recording method, an optical information recording / reproducing method, and an optical information recording / reproducing apparatus using a phase change type optical recording medium.
[0002]
[Prior art]
Conventionally, in the field of optical information recording, various recording methods have been developed to increase the recording density. For example, in magneto-optical and phase-change optical modulation recording, waveform control of a recording laser pulse for recording a circular or oval mark is well known. Also, in magneto-optical magnetic field modulation recording, the magnetic field inversion is performed in accordance with information, and at the same time, an arrow feather mark capable of obtaining a high track density can be recorded by irradiating a laser pulse based on a clock. Has been done. As described above, the shape of the recording mark in the field of optical information recording is roughly classified into a circular shape and an arrow feather shape.
[0003]
On the other hand, Japanese Patent Application Laid-Open No. 6-111328 proposes a method for recording a ring-shaped mark as a recording density can be further improved. This system records a ring-shaped recording mark on an overwritable optical recording medium in phase change type optical recording. In this method, since the recording mark is wide, the S / N ratio is good.
[0004]
[Problems to be solved by the invention]
However, in the optical recording described in the above publication, the ring-shaped recording mark is recorded by forming an amorphous region and a crystallized region in the recording layer. There is a problem that it cannot be made sufficiently long.
[0005]
In view of the above problems, an object of the present invention is to provide an optical information recording method, an optical information recording / reproducing method, and an optical information recording / reproducing apparatus capable of obtaining a recording mark having a long lifetime.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, the optical information recording / reproducing method of the present invention uses an optical recording medium that generates fine crystals and coarse crystals, and the optical recording medium is provided with fine crystal regions and coarse crystal regions. A recording mark is recorded by forming the recording mark, and the recording mark is reproduced by a difference in optical characteristics between a fine crystal and a coarse crystal.
[0007]
According to the above configuration, since the recording mark is recorded by forming the fine crystal region and the coarse crystal region on the optical recording medium, all of the recording mark and other portions in the recording layer are in a crystalline state. be able to. As a result, the life of the recording mark can be extended. Further, the recording mark can be reliably reproduced by the difference in the optical characteristics between the fine crystal and the coarse crystal, for example, the difference in reflectance and transmittance according to the crystal grain size.
[0008]
Further, the optical information recording method of the present invention uses an optical recording medium provided with a recording layer that changes phase between a crystalline state and an amorphous state depending on the intensity of the recording light quantity to be irradiated, and the recording layer is finely crystallized in advance. Next, the recording layer is irradiated with recording light to form an amorphous region and a recording mark made of a ring-shaped coarse crystal around the recording layer, and then the recording mark is irradiated with light weaker than the recording light. The amorphous region is finely crystallized.
[0009]
According to the above configuration, since the recording mark and all other parts in the recording layer are in a crystalline state, the life of the recording mark can be extended. Further, since the length of the recording mark can be set according to the width of the ring-shaped crystal wall forming the recording mark, high-density recording is possible.
[0010]
Further, the optical information recording / reproducing method of the present invention comprises a recording layer that changes phase between a crystalline state and an amorphous state depending on the intensity of the irradiated recording light amount, and a reproducing layer whose transmittance changes depending on the irradiated reproducing light amount. The recording layer is pre-crystallized at the time of information recording using an optical recording medium, and then the recording layer is irradiated with recording light to form a recording mark composed of an amorphous region and a ring-shaped coarse crystal around it. Then, light that is weaker than the recording light is irradiated to finely crystallize the amorphous region in the recording mark, while reproducing information is irradiated to the reproducing layer during information reproduction. An aperture having a high transmittance is generated at the irradiation center, and the recording mark is read out through the aperture.
[0011]
According to the above configuration, since the recording mark and all other parts in the recording layer are in a crystalline state, the life of the recording mark can be extended. Further, since the length of the recording mark can be set according to the width of the ring-shaped crystal wall forming the recording mark, high-density recording is possible.
[0012]
Further, when reproducing information, the reproducing layer is irradiated with reproducing light, an aperture having a high transmittance is generated at the center of irradiation of the reproducing light, and the recording mark is read through the aperture, so that the recording mark is reproduced with high resolution. And a reproduction signal having a high S / N ratio can be obtained.
[0013]
The optical information recording / reproducing apparatus of the present invention changes the phase between a crystalline state and an amorphous state depending on the intensity of the recording light quantity to be irradiated, and the transmittance is increased by the recording layer that has been finely crystallized in advance and the intensity of the reproducing light quantity to be irradiated. A light irradiating means for irradiating light to the optical recording medium using an optical recording medium having a changing reproducing layer, and an amorphous region in which recording light is irradiated to the recording layer during information recording, and a ring around it A recording mark made of a coarse crystal is formed, and then light that is weaker than the recording light is irradiated to finely crystallize the amorphous region in the recording mark. Is read by the light irradiation means via the aperture, and a control means for controlling the light irradiation means so that an aperture having a high transmittance is generated at the irradiation center of the reproduction light. It is characterized in that it comprises a reproducing means for reproducing the issued signal.
[0014]
According to the above configuration, under the control of the control means, the light irradiating means first irradiates the recording layer with the recording light to form an amorphous region and comprises a ring-shaped coarse crystal around the information recording. A recording mark is formed. Next, the light irradiating means irradiates the recording layer with light weaker than the recording light to finely crystallize the amorphous region in the recording mark.
[0015]
Thereby, since the recording mark and all other parts in the recording layer are in a crystalline state, the life of the recording mark can be extended. Further, since the length of the recording mark can be set according to the width of the ring-shaped crystal wall forming the recording mark, high-density recording is possible.
[0016]
Further, under the control of the control means, the light irradiating means irradiates the reproduction layer with the reproduction light during information reproduction, and generates an aperture having a high transmittance at the reproduction light irradiation center. Then, the light irradiating means reads out the recording mark through this aperture.
[0017]
Thus, by reading the recording mark through the aperture having a high transmittance, it is possible to perform reproduction with a good S / N ratio.
[0018]
In the optical information recording / reproducing apparatus, the control means adjusts the shape of the recording mark so that at least one of a recording light intensity, a recording light irradiation time, and a relative speed between the light irradiation means and the optical recording medium. It is good also as a structure which controls one.
[0019]
According to said structure, a ring-shaped recording mark can be recorded stably and the high-density recording / reproducing beyond the diffraction limit of light can be achieved.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS.
An optical disk as an optical recording medium used in this embodiment is a phase change type and has a structure shown in FIG. This structure is disclosed on pages 100 to 102 of the October 1998 issue of the magazine "Electronics" (issued by Ohmsha).
[0021]
In the figure, an optical disc 1 is formed by laminating a mask layer 3, a protective layer 4, a recording layer 5 and a protective layer 6 in this order on a substrate 2. As will be described later, the recording mark 7 is recorded on the recording layer 5 by irradiating the optical disc 1 with a laser spot 9 a obtained from the laser beam 9 via the objective lens 10.
[0022]
The recording layer 5 is made of Ge ₂ Sb ₂ Te ₅ which is a phase change material. The mask layer 3 is made of an antimony film. As the material of the mask layer 3, a material in which the portion corresponding to the central portion of the irradiated laser spot 9a changes from opaque to transparent is suitable, and as a result of the experiment, it is known that the antimony film is optimal. . Accordingly, when the laser spot 9 a is irradiated on the mask layer 3, an aperture 8 having a diameter smaller than the spot diameter is generated, and the recording mark 7 recorded on the recording layer 5 can be read through the aperture 8. Become.
[0023]
The thickness of the protective layer 4 is set such that the recording mark 7 can be read by the near-field light (evanescent light) 9b generated in the aperture 8 from the laser spot 9a. As a result of experiments, it has been found that this dimension is within the reachable distance of the near-field light 9b. Thereby, since the recording mark 7 can be reproduced by near-field light, high-density recording exceeding the diffraction limit of light can be performed, and the recording mark 7 of several tens of nm or less can be reproduced.
[0024]
An optical information recording / reproducing apparatus that performs an information recording / reproducing operation on the optical disc 1 has the configuration shown in FIG. That is, the optical information recording / reproducing apparatus 11 includes an optical pickup (light irradiating means) 12, a laser driving circuit 13, a recording control circuit (control means) 14, and a reproducing circuit (reproducing means) 15.
[0025]
In the optical information recording / reproducing apparatus 11, the recording signal output from the recording control circuit 14 is sent to the semiconductor laser included in the optical pickup 12 via the laser driving circuit 13 and output as a strong laser beam 9. The optical pickup 12 includes the objective lens 10, and the objective lens 10 focuses the laser beam 9 on the optical disc 1 as a laser spot 9 a. Thereby, at the time of information recording, the recording mark 7 on the ring is recorded on the optical disc 1 previously initialized as will be described later. At this time, the recording control circuit 14 optimally controls at least one of recording power, recording pulse length, and linear velocity in order to record the ring-shaped recording mark 7.
[0026]
Next, the optical disk 1 is irradiated with a medium intensity laser beam 9 from the optical pickup 12. Thereby, the amorphous region in the recording mark 7 is finely crystallized.
[0027]
At the time of reproducing information, the optical pickup 1 is irradiated with the laser beam 9 having a weak intensity on the optical pickup 12, and the reflected light from the recording mark 7 is converted into an electric signal by the photodetector provided in the optical pickup 12. This electric signal is sent to the reproduction circuit 15 and reproduced into a predetermined signal.
[0028]
In the above configuration, a method for recording / reproducing information with respect to the optical disc 1 will be described with reference to FIGS. 1 (a) and 1 (b) and FIGS.
[0029]
In the optical information recording / reproducing method in the present embodiment, information is recorded / reproduced with respect to the optical disk 1 as a phase change optical recording medium by using a ring-like coarse crystal 21 (see FIG. 1B). It has become.
[0030]
Here, in a phase change optical recording medium, it is known that a ring-shaped coarse crystal is generated around a recording mark in a state of a circular amorphous 23 (see FIG. 1B) in conventional light modulation recording. . This phenomenon is also disclosed in, for example, JP-A-1-217735. The ring-shaped coarse crystal 21 has a large grain size, and even if erased, it does not return to the fine crystal 22 (see FIG. 1B) and causes unerased noise. In order to avoid this, recording media have been developed. However, as a result of repeated research, when the ring-shaped coarse crystal 21 is used, that is, when the ring-shaped coarse crystal 21 is recorded as the recording mark 7, the mark length can be shortened to several tens of nanometers. It was found that high-density recording was possible compared to the magnetic recording method.
[0031]
When recording information on the optical disk 1, first, since the recording layer 5 after the film formation of the optical disk 1 is in an amorphous state 23, this is initialized, and as shown in FIG. Crystal 22 is formed.
[0032]
Next, as shown in FIG. 1B, the laser is turned on when the recording data is “1” and turned off when the recording data is “0”, thereby recording a laser spot 9 a having a high intensity, that is, a large amount of light. While irradiating the layer 5, the optical pickup 12 and the optical disc 1 are moved relative to each other. As a result, the circular area corresponding to the center of the laser spot 9 a in the recording layer 5 is in an amorphous state 23, and the area around the circular amorphous area 23 becomes the ring-shaped coarse crystal 21, that is, the recording mark 7. At this time, the mark length, that is, the width of the crystal wall forming the ring can be reduced to several tens of nm. Note that the recording control circuit 14 performs on / off control of the laser. The recording marks 7 are recorded so that the recording marks 7 overlap in the track direction.
[0033]
Next, when the laser spot 9a having a medium or low intensity, that is, a medium amount of light is irradiated to the regions of the ring-shaped coarse crystal 21 and the amorphous 23 in the recording layer 5 and these regions are raised to the crystallization transition temperature or higher, As shown in FIG. 2A, only the region of the amorphous 23 inside the ring-shaped coarse crystal 21 becomes the fine crystal 22. The fine crystal 22 is more stable than the amorphous 23 and can extend the life of information recorded by the recording mark 7. As described above, when the ring-shaped coarse crystal 21, that is, the recording mark 7 is recorded in the fine crystal 22, the optical characteristics, that is, the reflectance and the transmittance change depending on the size of the crystal grain, and the mark Reading is possible.
[0034]
Further, when reproducing information recorded on the optical disk 1, the mark length, which is the width of the crystal wall of the recording mark 7, is several tens of nanometers. Therefore, it is difficult to reproduce the conventional reproduction method due to the light diffraction limit. is there. Therefore, the optical disc 1 capable of reproducing the recording mark 7 beyond the diffraction limit shown in FIG. 3 is used.
[0035]
When the recording mark 7 is reproduced, as shown in FIG. 2B, the recording layer 5 is irradiated with a laser spot 9a having a low intensity, that is, a small amount of light to generate a reading aperture 8, and this aperture 8 is generated. Through the recording mark 7. Thereby, reproduction with high resolution becomes possible. That is, the recording mark 7 having a mark length of several tens of nm or less can be read.
[0036]
Further, as shown in FIG. 2B, the recording mark 7 has a ring shape and extends in the radial direction in the aperture 8. As a result, the tracking of the laser beam 9 is deviated, and as a result, even if the aperture 8 is deviated in the radial direction, the recording mark 7 can be easily secured in the aperture 8. Can be read.
[0037]
Next, FIG. 5 is a flowchart showing the recording / reproducing operation.
First, as shown in FIG. 3, the layers are laminated on the substrate 2 to form the optical disc 1 (S1).
[0038]
Next, the recording layer 5 of the optical disc 1 is initialized to form fine crystals 22 (S2).
[0039]
Next, the strong laser beam 9 is turned on / off according to the recording data, and the recording mark 7 made of the ring-shaped coarse crystal 21 is recorded on the recording layer 5 (S3).
[0040]
Next, the recording layer 5 is irradiated with a laser beam 9 having a medium intensity at which the amorphous layer 23 of the recording layer 5 reaches the crystal transition temperature, and the region of the amorphous layer 23 inside the recording mark 7 is made into a fine crystal 22 (S4).
[0041]
Next, the laser beam 9 having a weak intensity is irradiated onto the recording layer 5 to reproduce the recording mark 7 recorded on the recording layer 5 through the aperture 8 (S5).
[0042]
Since the region inside the recording mark 7 that once became the fine crystal 22 in S4 does not change in phase thereafter, the laser beam 9 having the same intensity as that used in the process of S4, that is, a medium intensity is used here. The recording mark 7 can also be reproduced by the laser beam 9. As described above, when the laser beam 9 having the same intensity is used in the process of making the region of the amorphous 23 in the recording mark 7 into the fine crystal 22 and the reproducing operation of the recording mark 7, the above S4 and S5 Processing can be performed simultaneously.
[0043]
Next, the relationship between the temperature when the recording mark 7 is recorded on the optical disc 1 and the shape of the recording mark 7 will be described.
[0044]
When the temperature of the region irradiated with the laser beam 9 in the recording layer 5 is lower than the range in which the ring-shaped coarse crystal 21, that is, the recording mark 7, can be formed, the recording mark 7 as shown in FIG. Is formed. In this case, assuming that the peak temperature at the center of the laser spot 9a irradiated on the recording layer 5 is low and the temperature distribution is assumed to be a Gaussian function type, the recording mark 7 is formed using a region with a gentle temperature gradient. . Therefore, the width of the crystal wall in the recording mark 7 is increased. That is, the mark length becomes long.
[0045]
When the recording mark 7 is reproduced, as shown in the lower part of FIG. 6A, a pulse b is generated in the reproduced waveform h at a portion corresponding to the amorphous 23 region. Further, on both sides of the pulse b, pulses b1 and b2 corresponding to the recording mark 7 and in the opposite direction to the pulse b are generated. When the region of the amorphous 23 is changed to the fine crystal 22 by the process shown in S4, the pulse b returns to the level indicated by the broken line. Therefore, the pulse b1 or b2 is read during reproduction.
[0046]
On the other hand, for example, when the temperature of the central portion irradiated with the laser spot 9a in the recording layer 5 is increased by increasing the amount of recording light, the ring-shaped coarse crystal 21, that is, the recording mark 7 is formed using a region having a large temperature gradient. . For this reason, as shown in FIG. 6B, the width of the crystal wall in the recording mark 7 becomes narrow. That is, the mark length is shortened.
[0047]
When the recording mark 7 is reproduced, in the reproduced waveform h, pulses d1 and d2 in the opposite direction to the pulse d corresponding to the recording mark 7 are generated on both sides of the pulse d. These pulses d1 and d2 are narrower than the pulses b1 and b2 shown in FIG. Similarly, when the region of the amorphous 23 is the fine crystal 22, the pulse d has a level indicated by a broken line, and the pulse d1 or d2 is read out during reproduction.
[0048]
As described above, the mark length of the recording mark 7 changes depending on the temperature of the recording layer 5 raised in temperature by the laser spot 9a during recording. Therefore, in order to record the recording mark 7 with the optimum mark length, the temperature of the recording layer 5 at the time of recording may be controlled. In order to control this temperature, the recording control circuit 14 shown in FIG. 4 controls at least one of the laser driving circuit 13 and the driving system of the optical disc 1 to record the recording power, recording pulse length or line of the laser beam 9. What is necessary is just to moderately adjust at least one of the speeds.
[0049]
【The invention's effect】
As described above, the optical information recording method of the present invention uses an optical recording medium that generates fine crystals and coarse crystals, and records by forming fine crystal regions and coarse crystal regions on the optical recording medium. The mark is recorded, and the recorded mark is reproduced by the difference in optical characteristics between the fine crystal and the coarse crystal.
[0050]
Thereby, all of the recording marks and other portions in the recording layer can be brought into a crystalline state. As a result, the life of the recording mark can be extended. Further, the recording mark can be reliably reproduced by the difference in optical characteristics between the fine crystal and the coarse crystal, for example, the difference in reflectance and transmittance according to the crystal grain size.
[0051]
Further, the optical information recording method of the present invention uses an optical recording medium provided with a recording layer that changes phase between a crystalline state and an amorphous state depending on the intensity of the recording light quantity to be irradiated, and the recording layer is finely crystallized in advance. Next, the recording layer is irradiated with recording light to form an amorphous region and a recording mark made of a ring-shaped coarse crystal around the recording layer, and then the recording mark is irradiated with light weaker than the recording light. In this configuration, the amorphous region is finely crystallized.
[0052]
Thereby, since the recording mark and all other parts in the recording layer are in a crystalline state, the life of the recording mark can be extended. In addition, since the length of the recording mark can be set by the width of the ring-shaped crystal wall forming the recording mark, there is an effect that high-density recording is possible.
[0053]
Further, the optical information recording / reproducing method of the present invention comprises a recording layer that changes phase between a crystalline state and an amorphous state depending on the intensity of the irradiated recording light amount, and a reproducing layer whose transmittance changes depending on the irradiated reproducing light amount. The recording layer is pre-crystallized at the time of information recording using an optical recording medium, and then the recording layer is irradiated with recording light to form a recording mark composed of an amorphous region and a ring-shaped coarse crystal around it. Then, light that is weaker than the recording light is irradiated to finely crystallize the amorphous region in the recording mark, while reproducing information is irradiated to the reproducing layer during information reproduction. An aperture having a high transmittance is generated at the irradiation center, and the recording mark is read out through the aperture.
[0054]
Thereby, since the recording mark and all other parts in the recording layer are in a crystalline state, the life of the recording mark can be extended. Further, since the length of the recording mark can be set by the width of the ring-shaped crystal wall forming the recording mark, high-density recording is possible.
[0055]
In addition, the recording mark can be reproduced with high resolution, and a reproduction signal having a good S / N ratio can be obtained.
[0056]
The optical information recording / reproducing apparatus of the present invention changes the phase between a crystalline state and an amorphous state depending on the intensity of the recording light quantity to be irradiated, and the transmittance is increased by the recording layer that has been finely crystallized in advance and the intensity of the reproducing light quantity to be irradiated. A light irradiating means for irradiating light to the optical recording medium using an optical recording medium having a changing reproducing layer, and an amorphous region in which recording light is irradiated to the recording layer during information recording, and a ring around it A recording mark made of a coarse crystal is formed, and then light that is weaker than the recording light is irradiated to finely crystallize the amorphous region in the recording mark. Is read by the light irradiation means via the aperture, and a control means for controlling the light irradiation means so that an aperture having a high transmittance is generated at the irradiation center of the reproduction light. A configuration in which a reproduction means for reproducing the issued signal.
[0057]
Thereby, since the recording mark and all other parts in the recording layer are in a crystalline state, the life of the recording mark can be extended. Further, since the length of the recording mark can be set according to the width of the ring-shaped crystal wall forming the recording mark, high-density recording is possible. Further, by reading the recording mark through the aperture having a high transmittance, there is an effect that reproduction with a good S / N ratio can be performed.
[0058]
In the optical information recording / reproducing apparatus, the control means adjusts the shape of the recording mark so that at least one of a recording light intensity, a recording light irradiation time, and a relative speed between the light irradiation means and the optical recording medium. It is the structure which controls one.
[0059]
As a result, the ring-shaped recording mark can be stably recorded, and there is an effect that high-density recording / reproduction exceeding the diffraction limit of light can be achieved.
[Brief description of the drawings]
FIG. 1A shows a recording mark recording method according to an embodiment of the present invention, and is an explanatory diagram showing a state in which a recording layer of an optical disc is initialized to a fine crystal during a recording operation; FIG. 1B is an explanatory diagram showing a state in which a recording mark is formed by irradiating the recording layer in the state of FIG.
FIG. 2A is an explanatory diagram showing a state in which the recording layer in the state of FIG. 1B is irradiated with a laser beam to make the amorphous inside the recording mark into a fine crystal, FIG. 2B These are explanatory drawings which show the reproduction | regeneration state of the recording mark of the state of Fig.2 (a).
FIG. 3 is an explanatory diagram showing a configuration of an optical disc on which recording marks are recorded / reproduced by the recording / reproducing method shown in FIGS. 1 and 2;
4 is a block diagram showing a configuration of an optical information recording / reproducing apparatus that implements the recording / reproducing method shown in FIGS. 1 and 2. FIG.
5 is a flowchart showing the recording / reproducing method shown in FIGS. 1 and 2. FIG.
6A is an explanatory diagram showing a recording mark formed when the recording temperature by the laser beam is low in the optical disc shown in FIG. 3 and its reproduction signal, and FIG. 6B is the same. FIG. 4 is an explanatory diagram showing a recording mark formed when a recording temperature by a laser beam is high in an optical disc and a reproduction signal thereof.
[Explanation of symbols]
1 Optical disc (optical recording medium)
5 recording layer 7 recording mark 8 aperture 9 laser beam 9a laser spot 9b near-field light 10 objective lens 11 optical information recording / reproducing device 12 optical pickup (light irradiation means)
13 Laser drive circuit 14 Recording control circuit (control means)
15 Reproduction circuit (reproduction means)
21 Ring-shaped crystal 22 Fine crystal 23 Amorphous

Claims (3)

Using an optical recording medium comprising a recording layer that changes phase between a crystalline state and an amorphous state depending on the intensity of the irradiated recording light amount, and a reproducing layer whose transmittance changes depending on the irradiated reproducing light amount,
At the time of information recording, the recording layer is crystallized in advance, and then the recording layer is irradiated with recording light to form an amorphous region and a recording mark made of a ring-shaped coarse crystal around the recording layer. While irradiating light weaker than light and performing a fine crystallization process to finely crystallize an amorphous region in the recording mark,
In an optical information recording / reproducing method for performing reproduction processing for reproducing reproduction light by irradiating the reproduction layer with reproduction light, generating an aperture having a high transmittance at the reproduction light irradiation center, and reading the recording mark through the aperture ,
An optical information recording / reproducing method, wherein the fine crystallization process and the reproduction process are simultaneously performed using light of the same intensity . An optical recording medium comprising a recording layer that is phase-changed into a crystalline state and an amorphous state depending on the intensity of the irradiated recording light quantity, and that has been finely crystallized in advance, and a reproducing layer whose transmittance varies depending on the intensity of the irradiated reproducing light quantity. Use
A light irradiation means for irradiating the optical recording medium with light;
At the time of information recording, the recording layer is irradiated with recording light to form an amorphous region and a recording mark made of a ring-shaped coarse crystal around it, and then the recording mark is irradiated with light weaker than the recording light. while fine crystallization treatment the amorphous areas are fine crystals of the inner is made, at the time of information reproduction, the aperture generator for generating a high transmittance aperture is irradiated reproduction light to the reproduction layer in the irradiation center of the reproducing light Control means for controlling the light irradiation means so that processing is performed ;
In an optical information recording / reproducing apparatus comprising: a reproducing unit that reproduces a signal read out by the light irradiation unit through the aperture ;
The optical information recording / reproducing apparatus characterized in that the control means controls the light irradiation means so that the fine crystallization process and the aperture generation process are simultaneously performed using light of the same intensity . The control means controls at least one of a recording light intensity, a recording light irradiation time, and a relative speed between the light irradiation means and the optical recording medium in order to adjust the shape of the recording mark. The optical information recording / reproducing apparatus according to claim 2 .

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