JP2006244551A - Magneto-optical recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a nano-unit irregular structure, which is formed on a magnetic layer of a magneto-optical recording medium, from being destroyed due to the irradiation of the medium with a laser beam of excessive power, so as to sufficiently exhibit an effect in the magneto-optical recording medium. <P>SOLUTION: A test recording area as well as a data recording area is set, and irregular structures are formed at least on the magnetic layers of the data recording area and test recording area with a pitch which is shorter than the wavelength of a laser beam for recording. When recording laser power is set, test recording is made to the test recording area, and a variation in reflectance before and after the test recording is measured. At that time, when a reflectance after the test recording increases at a prescribed rate or more, the power is reduced since the laser power is excessively large. When a reflectance after the test recording does not exceed a prescribed rate, whether data subjected to test recording can adequately be reproduced is determined. If the reproduction is possible, the power at that time is set to be power in recording. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a magneto-optical recording / reproducing apparatus, and is particularly suitable for use in setting a recording laser power.

  Conventionally, MO (Magnetic Optical) and MD (Mini Disc) have been developed and commercialized as magneto-optical recording media. In these magneto-optical recording media, since the Kerr rotation angle when irradiated with the reproduction light affects the SN of the reproduction signal, various methods for increasing the Kerr rotation angle have been studied so far.

  For example, in Patent Document 1 shown below, the decrease in the Kerr rotation angle with respect to the blue laser light is suppressed by improving the composition and the layer structure of the recording layer. That is, the composition of the RE-TM alloy constituting the recording layer is TMrich, an antiferromagnetic layer is formed on the recording layer, and anti-surface roughness due to the formation of the antiferromagnetic layer is anti-reverse. A flattening layer with good surface smoothness is formed on the base of the ferromagnetic layer. In addition, a method of increasing the Kerr rotation angle by repeatedly reflecting laser light on a dielectric layer has been studied.

  For magneto-optical recording media, various methods for improving the recording sensitivity have been studied. For example, in Patent Document 2 shown below, a recording auxiliary layer and a ferromagnetic layer are arranged in addition to the recording layer, and the recording auxiliary layer records a magnetic field generated by an external magnetic field and a magnetic flux concentration due to the action of the ferromagnetic layer. The magnetic field at the layer position is enhanced to improve the recording sensitivity.

Further, various methods for improving the recording density have been studied for magneto-optical recording media. For example, in Patent Document 3 shown below, recording density is improved by forming minute recording cells separately in a non-recording area.
JP 2004-30717 A JP-A-11-353725 JP 2003-109247 A

  However, according to the method of Patent Document 1, the composition of the recording layer is set to TMrich, and an antiferromagnetic layer and a flattening layer must be separately provided. There is a possibility that disadvantages may arise in this respect. In addition, when the dielectric layer is separately provided, the cost increases correspondingly, and there is a problem that the freedom degree of the medium configuration is restricted as in the case of Patent Document 1.

  In addition, according to the method of Patent Document 2, a recording auxiliary layer and a ferromagnetic layer must be separately provided in order to improve recording sensitivity, which causes a problem that the manufacturing process becomes complicated. Further, according to the method of Patent Document 3, it is necessary to form the recording cells separately in the non-recording area in order to improve the recording density, which causes a problem that the manufacturing process is complicated and the cost is increased. Arise.

  Accordingly, the applicant previously filed Japanese Patent Application No. 2005-55383 (reference number: NQC1050014), and effectively increased and recorded the car rotation angle with a simple configuration without restricting the degree of freedom of the medium configuration. A magneto-optical recording medium capable of improving sensitivity and recording density has been proposed. In such magneto-optical recording media, for example, a concavo-convex structure in nano units is formed on the substrate surface, and this concavo-convex structure is reflected in the magnetic layer (recording layer) to increase the Kerr rotation angle, increase the density, and increase the sensitivity. Is intended. However, the inventors have confirmed that when the magneto-optical recording medium is irradiated with a laser beam having an excessive power, the concavo-convex structure is crushed. When the concavo-convex structure is crushed, it is impossible to effectively increase the Kerr rotation angle, increase the density, and increase the sensitivity, and the value of the magneto-optical recording medium decreases.

Therefore, the present invention prevents this type of magneto-optical recording medium from being irradiated with an excessively high power laser beam, thereby making it possible to sufficiently exhibit the effects of the magneto-optical recording medium. That is the issue.

  In order to achieve the above object, the present invention has the following features.

  According to the first aspect of the present invention, a test recording area is set in addition to the data recording area, and at least on the magnetic layer surface of the data recording area and the test recording area at a pitch smaller than the wavelength of the recording laser beam. In a magneto-optical recording / reproducing apparatus capable of recording information on a magneto-optical recording medium having a concavo-convex structure, a change in reflectance before and after performing test recording in the test recording area is measured, and a recording laser based on the measurement result It has a laser power setting means for setting power.

  According to a second aspect of the present invention, in the magneto-optical recording / reproducing apparatus according to the first aspect, the laser power setting means is configured such that the reflectance after the test recording is increased by a predetermined ratio or more than the reflectance before the test recording. If it is, the test recording is performed again by reducing the laser power during the test recording by a predetermined level.

  According to a third aspect of the present invention, in the magneto-optical recording / reproducing apparatus according to the first or second aspect, the laser power setting means increases the reflectance after the test recording by a predetermined rate or more than the reflectance before the test recording. If not, it is determined whether or not the information recorded in the test recording has been properly reproduced, and when the information has been reproduced properly, the laser power at the time of the test recording is set as the recording laser power.

  According to a fourth aspect of the present invention, in the magneto-optical recording / reproducing apparatus according to the third aspect, when the laser power setting means cannot properly reproduce the information recorded in the test recording, the laser during the test recording is used. The test recording is performed again by increasing the power by a predetermined level.

  According to a fifth aspect of the present invention, in the magneto-optical recording / reproducing apparatus according to the fourth aspect, the laser power setting means increases the laser power during the test recording by a predetermined level, and the laser power exceeds a limit value. At this time, it is determined that the magneto-optical recording medium is abnormal, and the laser power setting operation is terminated.

  According to a sixth aspect of the present invention, in the magneto-optical recording / reproducing apparatus according to the fifth aspect, the laser power setting means is configured such that the reflectance after the test recording is increased by a predetermined rate or more than the reflectance before the test recording. The laser power is set as the limit value.

  The invention according to claim 7 is the magneto-optical recording and reproducing apparatus according to any one of claims 1 to 6, wherein when the reflectance after the test recording is increased by a predetermined ratio or more than the reflectance before the test recording, Information indicating that the position used for the test recording cannot be used for the test recording is included in the test recording management information and recorded at the management information recording position in the data recording area.

  According to an eighth aspect of the present invention, in the magneto-optical recording / reproducing apparatus according to the seventh aspect, the test recording management information includes information for specifying a position used in the next test recording in the test recording area. Recording is performed at a management information recording position in the data recording area.

  According to the present invention, since the recording laser power is adjusted to an appropriate level by performing test recording in the test recording area, the concavo-convex structure on the substrate is not destroyed by the laser light irradiation during the recording operation, and smooth. In addition, the recording operation can be executed at an appropriate power level. Therefore, it is possible to appropriately exhibit the effects obtained by the uneven structure, that is, the increase in the Kerr rotation angle, the improvement in the recording density, and the improvement in the recording sensitivity.

  According to the second to sixth aspects of the invention, the operation at the time of setting the laser power can be facilitated. In particular, according to the fifth and sixth aspects of the invention, the abnormality of the magneto-optical recording medium is also detected. can do. Furthermore, according to the seventh and eighth aspects of the present invention, the usage status of the test recording area can be managed, and the test recording operation can be facilitated.

The features of the present invention will become more apparent from the following description of embodiments. However, the embodiment described below is merely an example of the present invention, and the meaning of the term of the present invention or each constituent element is not limited to that described in the following embodiment. Absent.

Embodiments of the present invention will be described below with reference to the drawings. The magneto-optical disk according to the present embodiment has a structure in which a transparent substrate, a dielectric layer, a recording layer, a dielectric layer, a protective layer, a printing layer, and the like are laminated, as in the existing magneto-optical disk. Note that the dielectric layer disposed between the substrate and the recording layer is formed thin enough that the uneven structure of nano units formed on the recording layer side surface of the substrate is reflected in the recording layer. 2 shows an area format of the magneto-optical disk 100 according to the embodiment.

  As shown in the figure, the magneto-optical disk 100 is divided into a clamp area 100a, a lead-in area 100b, a test zone 100c, a data area 100d, and a lead-out area 100e in this order from the inner circumference side. Among these, disc management information is recorded in the lead-in area by pit strings.

  Such disk management information includes whether the magneto-optical disk is a normal magneto-optical disk, or a magneto-optical disk (hereinafter referred to as a micro-optical disk having a fine concavo-convex structure formed at a nano-unit pitch on the substrate surface on the recording layer side. Disc type information for identifying whether the disc is a “nano disc”. Information indicating the start address of the test zone, data area, and lead-out area is also included.

  In addition to the data management information for managing the information recorded in the data area, the information for managing the usage status of the test zone (test zone information) is provided at the beginning of the data area (inner side of the disc). Are recorded in the form of magneto-optical recording. Such test zone information includes information for distinguishing between areas in which test recording is possible and areas in which test recording is impossible, and information for specifying the area used in the next test recording. Contains. That is, the test zone is divided into sectors by a predetermined unit from the top, and each sector is numbered in order from the top. The first test recording is performed using the first sector. When this sector becomes unusable, the next sector is sequentially used for test recording. The test zone information includes the availability of each sector and information for specifying the sector to be used next.

  The concavo-convex structure is formed in both the test zone and the data area. That is, the test zone and the data area have the same layer structure. Here, the test zone is an area for performing test recording when setting the recording laser power. Such a test zone is disposed only on the nano disk, and is not disposed on a normal magneto-optical disk.

  In the nanodisk having such a configuration, the concave-convex structure formed on the substrate surface is reflected in the recording layer, so that the Kerr rotation angle is increased, the recording density is improved, and the recording sensitivity is improved.

  That is, due to the concavo-convex structure reflected in the recording layer, multiple reflection occurs in the reproduction laser beam, and the Kerr rotation action is superimposed each time the reflection is repeated. Thereby, the Kerr rotation angle with respect to the laser beam is increased. Further, since the light receiving surface area of the laser beam is greatly increased as compared with the case where the surface of the recording layer is flat, the heat absorption rate with respect to the laser beam is improved, and the temperature of the recording layer is efficiently increased. In addition, since the magnetic field applied from the outside is concentrated on the tip of the concavo-convex structure, a larger magnetic field is applied to the tip than when the surface is flat, and the magnetic field application efficiency at this part is increased. It is done. As described above, the concavo-convex structure reflected on the surface of the recording layer increases the thermal efficiency and the magnetic field application efficiency of the recording layer at the same time. Therefore, the sensitivity of the recording layer with respect to both the laser beam and the magnetic field is improved, and as a result, recording can be performed smoothly even with a low laser power and a low magnetic field strength.

  Furthermore, when the magnetic field is concentrated on the tip of the concavo-convex structure as described above, magnetization in the fine region at the concavo-convex structure tip becomes possible. At this time, the heat generated in the recording layer by the laser light irradiation is difficult to escape in the in-plane direction of the recording layer because the side wall of the concavo-convex structure acts as a barrier against heat transmission. For this reason, as compared with the case where the recording layer is flat, a smaller region (center region of the laser spot) is locally heated. Due to the limitation of the temperature rise region, only the more limited uneven structure tip is magnetized. As a result, the recording marks can be miniaturized and the recording density can be improved.

  Note that the operational effect when the uneven structure is formed on the substrate surface is verified in Japanese Patent Application No. 2005-55383 (reference number: NQC1050014) filed earlier by the applicant. Such a prior application also describes a method for forming an uneven structure on a substrate surface.

  FIG. 2 shows an example of a concavo-convex structure. FIG. 4A is a secondary electrophotographic image taken from the upper surface side, and FIG. 5B is a secondary electrophotographic image taken from the oblique upper surface side. The photographic image in the same figure is an image obtained when an alloy film of Co50Al50at.% Is formed on the concavo-convex structure by sputtering to 20 nm and then imaged with 10 Pt-Pd deposited for electrophotographic imaging. is there.

  As shown in the figure, a concavo-convex structure is formed on a substrate so that cylindrical protrusions are arranged at a constant pitch in the vertical and horizontal directions. The pitch of the concavo-convex structure in this photographic image (distance between adjacent cylindrical protrusions) is 250 nm in both vertical and horizontal directions, and the height of the cylindrical protrusion is 170 nm.

  Note that a light-transmitting material such as polycarbonate or polyolefin can be used as the substrate material. In addition to this, a biodegradable material can also be used as the substrate material. If it carries out like this, the environmental load etc. at the time of disposal can be made small.

  FIG. 3 shows the measurement results of the wavelength-reflectance characteristics when a reflective layer is formed on such a concavo-convex structure. This measurement was performed by forming a Co50Al50at.% Alloy film (reflective layer) to a thickness of 20 nm on the disk substrate by sputtering. Here, polycarbonate was used as the substrate material. The reflectance was measured by irradiating the thus formed reflective layer with laser light while changing the wavelength.

  FIG. 3 shows the measurement results. In the figure, as a comparative example, the measurement results of reflectivity when an alloy film of Co50Al50at.% Is formed by sputtering on a glass substrate having a flat reflective film forming surface by sputtering are shown. From this measurement result, it can be confirmed that when the concavo-convex structure is formed on the substrate, the reflectance is reduced by about 35 to 40% as compared with a glass substrate on which a flat Al—Co film is formed.

  Next, after forming a reflective layer on the concavo-convex structure, spot irradiation with high-intensity laser power was performed to measure the shape change and reflectivity change of the concavo-convex structure. In this measurement, an Al film was formed as the reflective layer. The Al film was formed by sputtering an Al film on the substrate surface on which the concavo-convex structure was formed. The thickness of the Al film was 20 nm.

  A pulse beam having a wavelength of 635 nm and a power of 10 mW was converged and applied to the disk substrate from the reflective film side. The beam spot was converged to about 1 μm spot diameter with an objective lens with NA = 0.55. The pulse frequency of the irradiation beam was constant.

  FIG. 4A shows the scanning trajectory of the pulse beam. In the figure, the white part is the irradiation position of the pulse beam. FIG. 4B shows the shape of the substrate surface after the pulse beam irradiation. From FIG. 5B, it can be seen that the portion of the substrate surface irradiated with the pulse beam is raised as compared with other portions.

  FIG. 5 shows a measurement of the cross-sectional shape of the raised portion. From this measurement result, it can be seen that the portion of the substrate surface irradiated with the pulse beam bulges larger than the other portions, and the upper surface portion thereof is flattened.

  Further, the portion scanned with the pulse beam was scanned with a low power monotonous laser beam, and the change in reflected light intensity was measured with an oscilloscope. As a result, it was measured that the frequency component of the pulse beam was about 10 to 20% higher than the other frequency components and the reflected light intensity was high. From this, it can be confirmed from this measurement result that the reflectance of the raised portion is about 10 to 20% higher than that of the non-raised portion.

  From the above measurement, it can be seen that when the concavo-convex structure is irradiated with laser light having an excessive power, the concavo-convex structure is raised and the upper surface portion thereof is flattened. When the concavo-convex structure is thus crushed, the effects of the concavo-convex structure described above, that is, the increase in the Kerr rotation angle, the improvement in the recording density, and the improvement in the recording sensitivity are not exhibited. Therefore, at the time of recording on the data area 100d, it is necessary to set the power of the recording laser light to such a level that the concavo-convex structure is not crushed.

  In the magneto-optical disk apparatus according to the present embodiment, trial writing is performed in the test zone 100c before the recording operation, and the power of the recording laser light is set to a power that does not cause the concavo-convex structure to be crushed. At this time, whether or not the concavo-convex structure is crushed is reproduced based on whether or not the reflected light intensity at that time is higher than the reflected light intensity before the test recording. Determined.

  FIG. 6 shows the configuration of the magneto-optical disk apparatus according to the embodiment.

  As shown, the magneto-optical disk apparatus includes a controller 101, a memory 102, a modulator 103, a timing pulse generation circuit 104, a magnetic head drive circuit 105, a laser drive circuit 106, a magnetic head 107, and an optical pickup. 108, a reproduction signal amplification circuit 109, a waveform shaper 110, a decoder 111, a servo circuit 112, and a disk rotation unit 113.

  The controller 101 controls each part at the time of recording / reproduction, and stores in the memory 102 the disk management information read from the lead-in area 100b when the disk is loaded, and the data management information and data zone information read from the head part of the data area 100d. Store. Further, the recording laser power setting control is performed using the laser power setting value Pw and the laser power limit value Pg at the time of test recording stored in advance in the memory 102. The recording laser power setting operation will be described in detail later.

  The memory 102 stores information such as disk management information, data management information, and data zone information supplied from the controller 101. Further, a laser power set value Pw and a laser power limit value Pg at the time of test recording which are set in advance in the magneto-optical disk device are stored.

  The modulator 103 modulates the recording data provided from the controller 101 to generate a recording signal, and outputs the recording signal to the timing pulse generation circuit 104. The timing pulse generation circuit 104 generates a timing pulse according to the recording signal input from the modulator 103 and outputs it to the magnetic head driving circuit 105 and the laser driving circuit 106. The magnetic head drive circuit 105 generates a drive signal corresponding to the pulse signal input from the timing pulse generation circuit 104 and supplies this to the magnetic head 107. The laser drive circuit 106 generates a drive signal corresponding to the pulse signal input from the timing pulse generation circuit 104 and supplies it to the optical pickup 108.

  The magnetic head 107 generates a magnetic field corresponding to the drive signal from the magnetic head drive circuit 105 and applies it to the magneto-optical disk 100. The optical pickup 108 emits a laser beam corresponding to the activation signal from the laser drive circuit 106 and irradiates the magneto-optical disk 100, and receives the reflected light from the magneto-optical disk 100 by a photodetector and outputs a sensor signal. Output to the reproduction signal amplifier circuit 109.

  The reproduction signal amplifying circuit 109 generates various signals by calculating and amplifying the sensor signal input from the optical pickup 108, and outputs the various signals to a corresponding circuit. The waveform shaper 110 shapes the waveform of the reproduction signal input from the reproduction signal amplification circuit 109 and outputs the waveform to the decoder 111. The decoder 111 decodes the signal input from the waveform shaper 110 to generate reproduction data, and outputs this to the controller 101.

  The servo circuit 112 generates a focus servo signal and a tracking servo signal from the focus error signal and tracking error signal input from the reproduction signal amplification circuit 109 and supplies them to the objective lens driving actuator in the optical pickup 108. Further, a rotation servo signal is generated from the tracking error signal, and this is output to the disk rotation unit 113. The disk rotation unit 113 drives the disk 100 to rotate according to the servo signal input from the servo circuit 112.

  FIG. 7 shows a flowchart when the recording laser power is set. The power setting process shown in FIG. 6 is performed when it is determined that the magneto-optical disk is a nanostructure disk based on the disk management information read from the lead-in area 100b.

  When the power setting process is started, first, the laser power setting value Pw and the laser power limit value Pg preset in the magneto-optical disk device to be used at the time of test recording are read from the memory 102, and these are read as recording laser power. It is set as an initial value during the setting process (S101). Also, the test zone information of the disc stored in the memory 102 is read, and among these, the sector division number n specified to be used at the next test recording is set as the sector division number used at the test recording. (S102).

  Thereafter, the magnetic head 107 and the optical pickup 108 are accessed to the position of the sector division number n set in S102 (S103), and first, the laser beam of the reproduction power level is irradiated to the position, and the reflectance at the position is determined. R1 is measured (S104). Next, the laser power set value Pw set in S101 is set as the laser power at the time of test recording (S105), and the magnetic head 107 is driven while irradiating the laser beam of this power to the position of the sector division number n. The test data is recorded at this position (S106).

  When the recording is completed, the laser power is set to the reproduction power level, and the reproduction of the position of the sector division number n is performed (S107). First, the reflectance R2 at this position is measured, and it is determined whether the reflectance R2 has increased by a predetermined rate or more than the reflectance R1 measured in S104 (S108).

  Here, if the reflectance is not increased, it is determined whether or not the reproduction data is properly obtained without error (S109). If the reproduction data is properly obtained, the laser power used for the test recording is set to the recording laser power (S110). At this time, the test zone information is reconstructed and overwritten on the head portion of the data area 100d (S120). Such overwriting may be omitted if the test zone information is not changed when the recording laser power is set. In other words, overwriting of the test zone information may be omitted when the processing step of S111 described later is not passed during the recording laser power setting processing flow.

  In S108, when it is determined that the reflectance R2 has increased by a predetermined rate or more than the reflectance R1, the position of the sector number n is set to be untestable, and the position of the sector number n + 1 is set to a new test recording position. (S111). Then, the current laser power setting value Pw is set to the laser power limit value Pg (S112), and a value obtained by subtracting a predetermined value α from the current laser power setting value Pw is set as a new laser power setting. The value Pw is set (S113). Thereafter, the process returns to S106 and the same processing is executed.

  If it is determined in S109 that the reproduction data has not been properly obtained from the test recording position, it is determined whether the current laser power setting value Pw is larger than the laser power limit value Pg (S114). If so, the recording laser power setting process is terminated as abnormal termination. On the other hand, if Pw is equal to or less than Pg, a value obtained by adding a predetermined value α to the current laser power setting value Pw is set as a new laser power setting value Pw (S115). Further, it is determined again whether the set value Pw after resetting is larger than the limit value Pg (S114). If it is larger, the recording laser power setting process is terminated as abnormal termination. On the other hand, if it is smaller, the process returns to S106 and the same processing is executed.

  According to the present embodiment, since the actual recording is performed after the test recording is performed in the test zone and the recording laser power is adjusted to an appropriate level, the uneven structure on the substrate is not destroyed during the recording operation, and smooth In addition, the recording operation can be executed at an appropriate power level. Therefore, it is possible to appropriately exhibit the effects obtained by the uneven structure, that is, the increase in the Kerr rotation angle, the improvement in the recording density, and the improvement in the recording sensitivity.

  Although the embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various other modifications are possible. For example, the shape, dimensions, and the like of the concavo-convex structure are not limited to those shown above, and can be changed as appropriate. In addition to the position shown in FIG. 1, the test zone may be arranged at an outermost peripheral position, a position further on the inner peripheral side than the lead-in area, or the like. In the above embodiment, the trial writing is performed before the recording operation. However, the present invention is not limited to this, and the trial writing can be performed immediately after the disc is mounted or when the drive is in a pause state (a state in which an instruction for recording or the like is not given). You may make it perform. By doing this, there is an advantage that it is possible to promptly shift to the recording operation because time for trial writing is not required at the start of recording.

  The embodiments of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims.

The figure which shows the area format of the magneto-optical disk which concerns on embodiment The figure which shows the secondary electrophotographic image of the uneven structure which concerns on embodiment The figure which shows the wavelength-reflectance characteristic of the uneven structure which concerns on embodiment Electrophotographic image of substrate shape according to embodiment The figure which shows the measurement result of the board | substrate cross-sectional shape which concerns on embodiment The figure which shows the structure of the magneto-optical disk apparatus based on Embodiment The figure which shows the flowchart at the time of the recording laser power setting which concerns on embodiment

Explanation of symbols

100 magneto-optical disk 100b lead-in area 100c test zone 100d data area 101 controller 102 memory

Claims (8)

A test recording area is set in addition to the data recording area, and at least the data recording area and the magnetic layer surface of the test recording area are similarly formed with an uneven structure at a pitch smaller than the wavelength of the recording laser beam. In a magneto-optical recording / reproducing apparatus capable of recording information on a magneto-optical recording medium,
Measuring a change in reflectance before and after performing test recording in the test recording area, and having a laser power setting means for setting a recording laser power based on the measurement result;
A magneto-optical recording / reproducing apparatus. In claim 1,
When the reflectance after the test recording is increased by a predetermined ratio or more than the reflectance before the test recording, the laser power setting means decreases the laser power during the test recording by a predetermined level, and again, Do test recording,
A magneto-optical recording / reproducing apparatus. In claim 1 or 2,
The laser power setting means determines whether or not the information recorded in the test recording can be properly reproduced when the reflectance after the test recording does not increase by a predetermined ratio or more than the reflectance before the test recording. When the reproduction is properly performed, the laser power at the time of the test recording is set as the recording laser power.
A magneto-optical recording / reproducing apparatus. In claim 3,
The laser power setting means, when the information recorded in the test recording could not be properly reproduced, the laser power at the time of the test recording is increased by a predetermined level, and the test recording is performed again.
A magneto-optical recording / reproducing apparatus. In claim 4,
The laser power setting means determines that the magneto-optical recording medium is abnormal when the laser power after increasing the laser power during the test recording by a predetermined level exceeds a limit value, and sets the laser power. Exit,
A magneto-optical recording / reproducing apparatus. In claim 5,
The laser power setting means sets the laser power when the reflectance after the test recording is increased by a predetermined percentage or more as the limit value before the reflectance before the test recording,
A magneto-optical recording / reproducing apparatus. In any one of Claims 1 thru | or 6,
When the reflectance after the test recording is increased by a predetermined rate or more than the reflectance before the test recording, the test record management information includes information indicating that the position used for the test recording cannot be used for the test recording. Record at the management information recording position in the data recording area,
A magneto-optical recording / reproducing apparatus. In claim 7,
Information for specifying a position used at the time of the next test recording in the test recording area is included in the test recording management information and recorded in a management information recording position in the data recording area.
A magneto-optical recording / reproducing apparatus.

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