JP2000163823A - Optical recording method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely set the intensity of recording power by tentatively writing reference information at density lower than regular recording, reading out the reference information, setting light intensity to be emitted at a regular recording time based on the result of read-out and performing the regular recording at the set light intensity. SOLUTION: A control part 14 sets the recording/reproducing power. A reference signal is tentatively written repeatedly onto a prescribed area of an optical disk while changing ratios of respective pulse heights within the prescribed range. A duty of a regenerative signal at every recording power is obtained, and the power control part 14 obtains the recording power that the duty of the regenerative signal becomes 50%, that is, the optimum recording power while referring to a storage part 15. The trial write is performed by using a test pattern while changing the reproducing power. The control part 14 obtains the reproducing power value that the regenerative signal amplitude becomes maximum while referring to the storage part 15 to store the value in the storage part 15 as the optimum reproducing power. The control part 14 ending the setting performs the recording/reproducing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording method and an optical recording apparatus for setting the light intensity to be irradiated by performing trial writing on an optical recording medium when recording information.

[0002]

2. Description of the Related Art Optical disks capable of storing data at a high density and capable of processing information at a high speed have attracted attention as audio and image applications and as external memories of computers. A system including a magneto-optical disk capable of repeatedly rewriting information in an external memory of the computer and a drive device (recording / reproducing device) thereof has been rapidly spreading.

In recording by this recording / reproducing apparatus, a rotation-controlled magneto-optical disk is irradiated with a light beam modulated at a high frequency, and a recording mark, which is a minute magnetic domain, is formed in a region heated at the center of a light spot. By forming, high-density recording is realized. By the way, in this recording, if the intensity (recording power) of the irradiated light beam is too large, the recording mark spreads to an inappropriate size, and a reading error at the time of reproduction due to crosstalk from an adjacent recording mark occurs. . On the other hand, if the recording power is too low, the change of the magnetization direction of the magneto-optical disk is incomplete, and a recording mark cannot be formed. In other words, if recording is to be performed at a proper high density, it is necessary to set an optimum recording power so that a recording mark is formed to a predetermined length.

However, the value of the optimum recording power depends on the characteristics of each magneto-optical disk, the characteristics of the light source and optical system of the apparatus,
Since it differs depending on the temperature of the magneto-optical disk and the presence or absence of dust on the surface, it is impossible to store it in the recording / reproducing apparatus in advance. In order to cope with this, in the current recording / reproducing apparatus, the standard is set for each loaded magneto-optical disk under the same conditions as the recording (hereinafter, referred to as “normal recording”) normally performed in accordance with the instruction of the user. Is recorded and read out under the same conditions as in the normal reproduction (hereinafter, referred to as "normal reproduction") performed in accordance with the instruction of the user, and the optimum recording power is obtained from the quality of the reproduced signal. . Hereinafter, such an operation of recording information on a trial basis is referred to as “test writing”.

[0005]

However, recently developed super magnetic resolution (MSR: Mgnetically induced Super R)
For the magneto-optical recording medium to which the technology of (esolution) is applied, the accuracy required for the light beam intensity (reproduction power) for reproduction is strict in order to realize high-resolution reproduction. Is not always reliably performed.

Therefore, even if the recording / reproducing apparatus itself attempts to obtain the result of the test writing as described above, whether the deterioration of the reproduced signal is caused by the inappropriate recording power,
Since it is not possible to determine whether or not the reproduction power is inappropriate, the optimum recording power cannot be determined. Further, it is impossible to determine the optimum reproducing power before the optimum recording power. The optimum reproduction power is obtained by reproducing a pattern consisting of a recording mark and a space with variously changed reproduction powers (test reading). Even if an attempt is made to form a predetermined pattern for the test reading, the optimum reproduction power is obtained. This is because it is impossible to make this into an appropriate shape when the recording power is not known.

An object of the present invention is to provide an optical recording method and an optical recording apparatus which can reliably set the recording power intensity even when recording is performed on an optical recording medium in which the accuracy required for reproduction power is strict. With the goal.

[0008]

According to a first aspect of the present invention, there is provided a test writing procedure for trial writing reference information on an optical recording medium at a lower density than normal recording, and reading the reference information from the optical recording medium. A reading procedure, a setting procedure for setting the light intensity to be applied to the optical recording medium during normal recording based on the result of the reading procedure, and normal recording on the optical recording medium with the light intensity set by the setting procedure. Recording procedure to be performed.

According to a second aspect of the present invention, in the optical recording method according to the first aspect, in the readout procedure, the readout condition is set to a condition that results in a lower resolution as compared with the normal reproduction on the optical recording medium. Then, the reference information is read out.

According to a third aspect of the present invention, in the optical recording method according to the first or second aspect, the optical recording medium comprises:
It is a magneto-optical recording medium to which a front opening detection method is applied. According to a fourth aspect of the present invention, in the optical recording method according to the first or second aspect, the optical recording medium is a magneto-optical recording medium to which a rear aperture detection method is applied.

According to a fifth aspect of the present invention, in the optical recording method according to the third or fourth aspect, in the second procedure, the read condition is set to a condition that does not cause magnetic super-resolution. It is characterized by. According to a sixth aspect of the present invention, there is provided a test writing unit for trial writing reference information at a lower density than an ordinary recording on an optical recording medium, a reading unit for reading the reference information from the optical recording medium, and an optical disc during normal recording. Setting means for setting the light intensity to be applied to the recording medium based on the result obtained by the reading means; and recording means for performing normal recording on the optical recording medium with the light intensity set by the setting means. It is characterized by.

According to a seventh aspect of the present invention, in the optical recording apparatus according to the sixth aspect, the reading means sets a reading condition to a condition at which a resolution is lower than that of a normal reproduction performed on the optical recording medium. Then, the reference information is read out. According to an eighth aspect of the present invention, in the optical recording apparatus according to the sixth or seventh aspect, the optical recording medium is a magneto-optical recording medium to which a front aperture detection method is applied.

According to a ninth aspect of the present invention, in the optical recording apparatus according to the sixth or seventh aspect, the optical recording medium comprises:
It is a magneto-optical recording medium to which a rear opening detection method is applied. The invention according to claim 10 is the invention according to claim 8
Alternatively, in the optical recording apparatus according to the ninth aspect, the reading means sets a reading condition to a condition that does not cause magnetic super-resolution.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment according to the present invention will be described with reference to the drawings. In the first embodiment,
It corresponds to all the claims except the claims 4 and 9. FIG.
FIG. 2 is a block diagram illustrating a main configuration of the recording / reproducing apparatus according to the first embodiment. This recording / reproducing apparatus includes an optical head 1
1, laser diode drive circuit (LD drive circuit) 13,
It includes a recording waveform generation circuit 12, a reproduction circuit 16, a control unit 14, a storage unit 15, a magnetic field generation circuit (not shown), and the like.

The optical head 11 mounts a laser diode, an optical system (a lens, a diffraction grating, etc.), a photodetector, and the like.
Light emitted from the laser diode at the time of recording and reproduction is condensed, and a recording or reproduction light beam is irradiated onto a track of an optical disk whose rotation is controlled. Further, at the time of reproduction, the reflected light beam for reproduction is converted into an electric signal corresponding to the polarization angle, and then supplied to the reproduction circuit 16.

The recording waveform generation circuit 12 generates a recording waveform corresponding to the data bit string of the recording signal output by the control unit 14 during recording, and outputs the waveform to the LD drive circuit 13. This recording waveform corresponds to the data bit string "1""
The timing waveform is generated in accordance with 0 "and defines the timing at which the recording light beam is at the high power level and the low power level.

The LD drive circuit 13 drives a laser diode mounted on the optical head according to the timing and level indicated by the recording waveform. Specifically, a current value corresponding to each level of the recording waveform is given to the laser diode at the timing indicated by the recording waveform. During reproduction, the laser diode is constantly driven to emit continuous light. The reproduction circuit 16 generates reproduced data by amplifying the electric signal obtained from the optical head 11 and performing A / D conversion.

A recording / reproduction control program is stored in the storage unit 15, and a program for realizing the recording method of the first embodiment includes, for example, a procedure shown in FIG. The control unit 14 controls each unit based on a recording / reproducing program stored in the storage unit 15 according to an instruction from the host computer, and realizes various functions of the recording / reproducing apparatus.

Regarding the control mode of the control unit 14, during recording, the relative position of the optical head 11 and the optical disk is controlled.
The exit of the optical head 11 is directly opposed to the designated area. Then, the recording signal (reference signal) is supplied to the recording waveform generation circuit 12, and the current value to be supplied to the optical head 11 by the LD driving circuit 13 is set to a value for recording. At the time of this recording,
By driving a magnetic field generating circuit (not shown), a recording magnetic field is applied to the optical disk.

On the other hand, at the time of reproduction, the LD drive circuit 13 sets a current value to be supplied to the optical head 11 to a value for reproduction, thereby setting a reproduction power lower than the recording power. Then, during normal reproduction, the reproduction data obtained from the reproduction circuit 16 is corrected for errors, and the restored information is output to the host computer. When reproducing a magneto-optical disk to which the MSR technique is applied, a magnetic field generating circuit (not shown) is driven to apply a magnetic field for MSR reproduction to the magneto-optical disk.

As an optical disk loaded in this recording / reproducing apparatus, for example, a magneto-optical disk 10 to which the FAD (Front Aperture Detection) technique shown in FIG. As shown in the upper part of FIG. 2, the magneto-optical disk 10 has a lower protective film 50 and a reproducing layer 51 on a disk-shaped glass substrate 41 with a tracking groove (track pitch of 1.114 m) having a thickness of 1.2 mm and a diameter of 130 mm. , Cutting layer 55, memory layer 53,
The upper protective film 54 is formed in order. Reproduction layer 5
1. The three layers of 1, the cutting layer 55 and the memory layer 53 are magnetic films, and are protected by a lower protective film 50 and an upper protective film 54 made of a dielectric film (SiN). The characteristics of each magnetic film are
This is as described below.

The memory layer 53 is made of, for example, a TbFeCo alloy and is a perpendicular magnetization film for recording information. The coercivity of this layer is relatively high and the Curie temperature is 200 ° C. The reproduction layer 51 is made of, for example, a GdFeCo alloy,
This is a perpendicular magnetization film to which a part of information of the memory layer 53 is transferred during reproduction. This layer has a relatively low coercive force, but has a relatively high Curie temperature of 400 ° C. in order to greatly change the polarization plane of the reproducing light beam.

The cutting layer 55 is made of, for example, a TbFe alloy, and appropriately prevents information in the memory layer 53 from being transferred to the reproducing layer 51. The Curie temperature of this layer is 140 ° C., which is lower than the other layers. According to this configuration, the substrate 4
At the time of reproduction in which a light beam for reproduction is irradiated from the first side and a magnetic field for MSR reproduction is applied, a mask can be formed in the rear high-temperature region 35 in the spot 33 as shown in the lower part of FIG. It is.

That is, the portion of the magneto-optical disk 10 behind the spot 33 stores heat, and becomes relatively high in temperature. If the temperature of the high-temperature area 35 is just the temperature at which the magnetization of the cutting layer 55 of the magneto-optical disk 10 is lost, the information recorded in the memory layer 53 is transferred to the reproduction layer 51 in the high-temperature area 35. There is no. At this time, if the magnetization direction of the reproducing layer 51 in the high-temperature region 35 is aligned in one direction by applying a magnetic field, the reflected light of the reproducing light beam will respond only to the information transferred to the region other than the high-temperature region 35. Will change. That is, the reproduction based on the polarization angle of the reflected light is performed in a state where the mask is formed in the high-temperature region 35.

Therefore, if the size of the light spot and the intensity of the light beam are adjusted so that only one recording mark is always present in the opening, which is the area where information is transferred in the light spot, the light spot can be adjusted. Reproduction can be performed at a higher resolution than when information is read from all areas. Hereinafter, the reproduction adjusted in this manner is referred to as “FAD reproduction”.

Next, the operation of the recording / reproducing apparatus will be described with reference to FIG. FIG. 3 is an operation flowchart of the control unit 14. The control unit 14 controls the magneto-optical disk 1
0 is recognized (FIG. S1), setting of recording power (FIGS. 3S2 to S4) and setting of reproduction power (FIGS. 3S5 to S7) are performed prior to normal recording and reproduction (S8 to S11 in FIG. 3). )I do.

At the time of setting the recording power, first, test writing is performed on a predetermined area of the magneto-optical disk 10 (S3 in FIG. 3).
2) As shown in FIG. 4, the reference signal written at this time has a length of 1 (μm), which is about 2.5 times that of normal recording (upper part of FIG. 4), if it is properly recorded. The signal is such that a recording mark and a non-recording portion (space) are alternately formed (lower part in FIG. 4). With this setting, the optical head 1
As shown in FIG. 5, in the waveform of the outgoing light of No. 1, the train of the pulse train that defines the length of the recording mark is longer than that in normal recording (FIG. 5 (1)) (FIG. 5 (2)). ).

The test writing (S2 in FIG. 3) is performed with various recording powers. However, the ratio of each pulse height of the recording waveform shown in FIG. 5 is a predetermined ratio, for example, Pw1:
Pw2: Pa = 2.0: 2.1: 1.0 is maintained, and the reference signal is repeatedly trial-written while Pw1 is changed in the range of 4 (mW) to 7 (mW). Thus, at the time of subsequent reading, data for each of various recording powers in this range is obtained.

Next, the reference signal thus test-written is read out (S3 in FIG. 3). In the first embodiment,
At this time, predetermined reproduction conditions are set so that FAD reproduction (see the upper part of FIG. 4) does not occur. Specifically, the reproduction power is set to a value sufficiently smaller than that of the normal FAD reproduction, for example, 1.0
(MW). Under this reproducing condition, as shown in the lower part of FIG. 4, no high-temperature area stored in the light spot formed on the magneto-optical disk 10 is formed, and no mask is formed. Therefore, needless to say, it is unnecessary to apply a magnetic field for forming a mask in this region.

In this reading, a test writing (S2 in FIG. 3)
The duty of the reproduction signal is obtained for each recording power set in the step (1), and stored in the storage unit 15 for each of these recording powers. Next, the control unit 14 refers to the storage unit 15 to determine the recording power at which the duty of the reproduction signal becomes 50%, that is, the recording power at which the DC component of the reproduction signal is closest to zero. This is the optimum recording power. Control unit 14
Stores the optimum recording power in the storage unit 15 and ends the setting of the recording power to be used during normal recording (S4 in FIG. 3).

Here, the test writing described above (FIG. 3S
The reference signal used in 2) and the predetermined reproduction power set at the time of reading (S3 in FIG. 3) will be described. The reference signal can be easily set. If a recording mark and space having a length of 2.5 times as shown in FIG. 4 are formed, the frequency of the reference signal is set to 1 / 2.5 times the frequency of the recording signal used in normal recording. I just need.

On the other hand, the predetermined reproducing power is determined by the following measurement. FIG. 6 is a diagram showing the results of evaluation of a certain magneto-optical disk. First, an evaluator examines the conditions under which the reproduction of a certain magneto-optical disk becomes the FAD reproduction. For example, the disk rotation speed is 3600 (rpm), the radial position of the recording area is 30 (mm), and the wavelength of the emitted light is 680.
(Nm) and a numerical aperture (NA) of an optical system of 0.55, a recording power of 5 (mW) and a recording magnetic field of 300 (Oe) for ensuring recording are set, and comparison is made in the same manner as in normal recording. A signal of 14 (MHz), which has a very high recording density, is recorded. As a result, recording marks of 0.4 (μm) and spaces are alternately formed.

Thereafter, reading is performed while changing the reproducing power under the reproducing magnetic field 300 (Oe). As shown in FIG. 6, as the reproduction power increases from 2 mW, the amplitude of the reproduction signal increases, and the reproduction power becomes 2.3 (mW).
When it is ~ 2.8 (mW), C / N is 45 (dB).
Obtained above. This shows that the playback power is 2
(MW), no mask is formed (see FIG. 6).
(1)), when the reproducing power becomes 2 (mW) or more, a mask starts to be formed, and further rises from 2.3 (mW) to 2.3 (mW).
In the range of 8 (mW), the mask has an appropriate size (FIG. 6B). In addition, 2.8 (mW)
In the above range, the mask becomes too large (FIG. 6
(3)).

In particular, the range of 2.3 (mW) to 2.8 (m
At a location slightly smaller or slightly larger than W), the effect of FAD reproduction is not only obtained because the formation of the mask is incomplete, and a phenomenon that the noise at the time of reproduction is increased is observed. Even information recorded at a relatively low density that does not require data cannot be read correctly.

Therefore, in the reading of the magneto-optical disk, which has been evaluated, if the reproducing power is set to 2 (mW) or less, it is not necessary to consider the influence of noise. Although the reproduction does not become FAD reproduction, as in the first embodiment, FAD reproduction is performed.
Information recorded at a density low enough to not require AD reproduction can be reliably read from the entire area within the light spot.

Further, the evaluation shown in FIG. 6 is performed on a plurality of magneto-optical disks, and if the variation in the characteristics is grasped, a predetermined reproducing power, that is, FAD reproduction can be obtained even when reproducing any magneto-optical disk. Instead, it is possible to obtain a value of the reproduction power such that the information is read from the entire area in the light spot. Incidentally, in the first embodiment, the predetermined reproduction power is set to 1.0 (mW).

Returning to the explanation of the operation of the control unit 14 shown in FIG. 3, when the reproduction power is set (S5 to S7 in FIG. 3), the magneto-optical disk 10 is set by the set optimum recording power.
A test pattern is formed in a predetermined area of FIG.
5). This test pattern has the same density as that at the time of the highest density recording during normal recording, for example, 0.4%.
It is assumed that recording marks having a length of (μm) and non-recording portions (spaces) are alternately arranged (similar to the pattern shown in the upper part of FIG. 4).

At this time, since the optimum recording power has already been obtained, the formation of a test pattern of this length can be easily realized only by setting the frequency of the recording signal to be written. Next, the test pattern thus formed is read as a test while changing the reproduction power (S6 in FIG. 3).
Since the purpose of this reading is to find a reproducing power that causes FAD reproduction, a magnetic field for forming a mask is applied at 300 (Oe) in advance. At this time, the reproduction power is 0.1 in the range of 2.0 (mW) to 3.0 (mW).
(MW) are set to various values, and the duty of the reproduction signal is obtained for each of these values.
Is stored in

Next, the control unit 14 refers to the storage unit 15 to determine a value of the reproduction power at which the amplitude of the reproduction signal is the largest, stores this value as the optimum reproduction power in the storage unit 15, and sets the reproduction power. Is completed (S7 in FIG. 3). In this way, the control unit 14 that has completed the setting of the recording power and the setting of the reproducing power can perform recording and reproduction in the user area of the magneto-optical disk 10 in accordance with an instruction from the host computer (S8 in FIG. 3). To S11).

In short, in the first embodiment, it is attempted to read out the test-written reference information under a reproduction condition having a resolution lower than that of FAD reproduction (S3 in FIG. 3). However,
In this test writing (S2 in FIG. 3), recording marks and spaces are formed at a lower density than normal recording (see FIG. 4) in order to enable reading under the reproducing conditions. Unlike the case of realizing FAD reproduction, the reproduction condition of such a low resolution is determined in advance as a common condition irrespective of variations in the characteristics of the magneto-optical disk and differences in the placed environment. Can reliably read test-written information without checking the optimum reproduction conditions for each magneto-optical disk.

Incidentally, regarding the correspondence between the claims and the above-described first embodiment, the test writing means, the reading means, the setting means, and the recording means mainly correspond to the control unit 14, and the test writing procedure is performed. Corresponds to step 2 of the control unit 14, step 3 of the control unit 14 corresponds to the readout procedure, and step 4 of the control unit 14 corresponds to the setting unit.
Hereinafter, a second embodiment according to the present invention will be described with reference to the drawings. The second embodiment corresponds to all claims except for claims 3 and 8.

Here, only differences from the above-described first embodiment will be described. In the second embodiment, unlike the first embodiment described above, the magneto-optical disk loaded in the recording / reproducing apparatus shown in FIG.
This is a magneto-optical disk 20 to which the technique of AD (Rear Aperture Detec-tion) is applied. The magneto-optical disk 20 includes
As the magnetic film, the reproduction layer 51, the reproduction auxiliary layer 56, the intermediate layer 5
7, a memory layer 53, and an upper protective film 54 are sequentially formed.

In the magnetic film, the auxiliary reproduction layer 56 is made of, for example, a TbFe alloy and is a layer for appropriately transferring the information of the memory layer 53 to the reproduction layer 51. The Curie temperature of this layer is 160 ° C. The intermediate layer 57 is made of, for example, GdFe
This layer is made of a Co alloy and adjusts the exchange coupling force acting between the memory layer 53 and the auxiliary reproduction layer 56. The Curie temperature of this layer is relatively high, 400 ° C.

According to this configuration, at the time of reproduction in which a light beam for reproduction is irradiated from the substrate 41 side and a magnetic field for MSR reproduction is applied, as shown in the lower part of FIG.
It is possible to form a mask in front of 3. First, a magnetic field for a mask is applied to the magneto-optical disk 20 before the light beam irradiation to the magneto-optical disk 20 of the second embodiment. Thereby, the magnetization direction of the reproducing layer 51 is aligned in one direction, and the whole is masked (reference numeral 3 in FIG. 7).
7). Thereafter, when the light beam is applied, the portion of the magneto-optical disk 20 behind the spot 33 is stored, and the temperature thereof becomes relatively high. If the temperature of the high-temperature region 35 is just the temperature at which the coercive force of the reproduction auxiliary layer 56 of the magneto-optical disk 20 is appropriately weakened, the reproduction auxiliary layer 56 follows the magnetization direction of the memory layer 53, and The information recorded in the memory layer 53 is transferred to the reproduction layer 51.

The reflected light of the light beam for reproduction is reflected in the high temperature region 3
5, the reproduction is performed based on the polarization angle of the reflected light.
Only the information existing in the high temperature region 35 can be read. Therefore, if the size of the light spot and the intensity of the light beam are adjusted so that only one recording mark is always present in the opening, which is the area where information is transferred in the light spot, the light spot from the entire area of the light spot can be adjusted. Reproduction can be performed at a higher resolution than when information is read. Hereinafter, the reproduction adjusted in this manner is referred to as “RAD reproduction”.

Next, the operation of the recording / reproducing apparatus of the second embodiment will be described with reference to FIG. As in the first embodiment, the reference signal to be trial-written at the beginning (S2 in FIG. 3) when the recording power is set is formed by alternately forming recording marks and non-recording portions (spaces) longer than during normal recording. (See FIG. 4). Incidentally, in the second embodiment, the minimum recording mark length of the 1-7 modulation is set to 0.4.
(Μm) (corresponding to 2T), recording marks and spaces having a length of 1.6 (μm) (corresponding to 8T), which is four times as long, are formed alternately.

Next, at the time of reading the reference signal (S3 in FIG. 3), different from the first embodiment, predetermined reproduction conditions are set so that RAD reproduction does not occur. Here, in general, during recording including test writing, the magnetization direction of the memory layer 53 is changed according to the reference signal. At this time,
Due to the effect of the recording magnetic field applied to reverse the magnetization direction of the memory layer 53, the magnetization direction of the reproduction layer 51 having a relatively small coercive force follows the same direction as the memory layer 53. That is,
Immediately before RAD reproduction in which a mask magnetic field is applied,
The information is in a state of protruding to the reproduction layer 51 side.

Therefore, FIG.
The reproduction condition to be adjusted in step 3 is that the magnetic field for the mask need not be simply applied. As a result, a mask as shown by hatching in FIG. 7 is not formed, and the information floating in the reproduction layer 51 is read from the entire area of the light spot as it is. In short, in the second embodiment,
The reproduction condition set when reading the reference signal is RAD
The difference from the first embodiment is that the conditions are set so as not to cause reproduction. The characteristic of the reproduction condition set at this time may be such that the value of the reproduction power is such that the normal RAD reproduction is realized or the mask is formed in an incomplete size.

Therefore, there is no need to evaluate a plurality of magneto-optical disks in advance as in the first embodiment.
In the second embodiment, the lengths of the recording marks and spaces to be trial-written are four times those of normal recording, so that it is necessary to determine whether the recording power or the reproduction power is appropriate. The measurement (S4 or S7 in FIG. 3) may be replaced with the measurement of the byte error rate of the reproduced signal. At this time, after obtaining a range of the recording power such that the error rate becomes a value (for example, 1 × 10 ⁻³ or less) allowed for the recording / reproducing apparatus, the value of the recording power within the range is determined as the optimum recording power. It is stored in the storage unit 15.

A method for further improving the recording accuracy of each of the above embodiments will be described below. Actually, the optimum recording power is slightly different between the case where a relatively long recording mark is formed as in the test writing of each of the above embodiments and the case where a relatively short recording mark is formed as in the case of normal recording. Therefore, it is possible to correct the relationship by experimentally obtaining the relationship between the two in advance using a plurality of magneto-optical disks.

This correction is performed, for example, assuming that the range of the recording power with a good error rate is (Pa to Pb) when a recording mark corresponding to 8T is trial-written, as in normal recording. The optimum recording power at the time of recording by the recording mark is simply calculated by the central value ((Pa + Pb) /
Rather than set to 2), the power divided into 1: 2 from the lower limit to the upper limit ((2 × Pa + P
This is realized by setting a lower value such as b) / 3).

In the above embodiments, the setting of the recording power and the setting of the reproducing power are performed when the disc is loaded.
After that, if the characteristics of the magneto-optical disk greatly change due to the environmental temperature, it is not always possible to perform recording and reproduction with the initially set power. Therefore, the same setting may be performed each time the temperature of the magneto-optical disk is monitored and the temperature change is equal to or more than a predetermined value, or every elapsed time is measured and the elapsed time is measured.

In each of the above embodiments, the optical disc is
The recording on the magneto-optical disk to which the AD and FAD technologies are applied has been described. However, the present invention is not limited to this. Further, the shape of these optical recording media may be a shape other than a disk.

[0054]

As described above, according to the first aspect of the present invention, the reference information can be read even when the reproduction set at the time of executing the reading procedure is lower in resolution than the normal reproduction. It becomes possible. Therefore, setting of the recording light intensity is easily realized.

According to the second aspect of the present invention, a condition for setting a resolution lower than that of normal reproduction is set. This condition is determined in advance as a common condition for optical recording media having various characteristics. be able to. Therefore, it is possible to set the recording light intensity of the optical recording medium having various characteristics.

According to the third aspect of the invention, it is possible to set the recording light intensity of the magneto-optical recording medium to which the rear aperture detection method is applied. According to the fourth aspect of the present invention, it is possible to set the recording light intensity of the magneto-optical recording medium to which the front opening detection method is applied. According to the fifth aspect of the invention, the read condition is set to a condition that does not cause magnetic super-resolution. However, for a magneto-optical recording medium to which the rear aperture detection method or the front aperture detection method is applied, the magnetic super-resolution is used. The reproduction condition set when reading is performed under a condition that does not cause the above-mentioned condition can be set as a common condition irrespective of variations in characteristics of individual magneto-optical recording media. That is, the recording light intensity of the magneto-optical recording medium to which such a magnetic super-resolution technique is applied can be reliably set.

The inventions according to claims 6 to 10 can provide an optical recording apparatus for carrying out the inventions according to claims 1 to 5.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a main configuration of a recording / reproducing apparatus.

FIG. 2 is a diagram illustrating a front opening detection method (FAD).

FIG. 3 is an operation flowchart of a control unit 14.

FIG. 4 is a diagram comparing a recording mark during normal recording with a recording mark during test writing.

FIG. 5 is a diagram comparing a recording waveform during normal reproduction with a recording waveform during test writing.

FIG. 6 is a diagram showing the results of evaluation of a certain magneto-optical disk.

FIG. 7 is a diagram illustrating a rear opening detection method (RAD).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Optical head 12 Recording waveform generation circuit 13 Laser diode drive circuit (LD drive circuit) 14 Control part 15 Storage part 10, 20 Magneto-optical disk 31 Track 33 Light spot 35 High temperature area 38 Recording mark 37 Masked area 41 Substrate 50 Lower part Protective film 51 Reproducing layer 53 Memory layer 54 Upper protective film 55 Cutting layer 56 Reproducing auxiliary layer 57 Intermediate layer

Claims (10)

[Claims] 1. A test writing procedure for trial writing reference information on an optical recording medium at a lower density than normal recording, a reading procedure for reading the reference information from the optical recording medium, and the optical recording during normal recording. The light intensity to irradiate the medium
An optical recording method, comprising: a setting procedure for setting based on a result of the reading procedure; and a recording procedure for performing normal recording on the optical recording medium with the light intensity set by the setting procedure. 2. The optical recording method according to claim 1, wherein, in the reading step, the reading condition is set to a condition that results in a lower resolution than a normal reproduction performed on the optical recording medium.
An optical recording method, comprising reading the reference information. 3. The optical recording method according to claim 1, wherein the optical recording medium is a magneto-optical recording medium to which a front aperture detection method is applied. 4. The optical recording method according to claim 1, wherein the optical recording medium is a magneto-optical recording medium to which a rear aperture detection method is applied. 5. The optical recording method according to claim 3, wherein in the second step, the read condition is set to a condition that does not cause magnetic super-resolution. Recording method. 6. A test writing means for trial writing reference information on an optical recording medium at a lower density than normal recording; a reading means for reading the reference information from the optical recording medium; The light intensity to irradiate the medium
An optical recording apparatus, comprising: setting means for setting based on a result obtained by the reading means; and recording means for performing normal recording on the optical recording medium with the light intensity set by the setting means. . 7. The optical recording apparatus according to claim 6, wherein the read unit sets the read condition to a condition that results in a lower resolution than a normal reproduction performed on the optical recording medium,
An optical recording apparatus for reading the reference information. 8. The optical recording apparatus according to claim 6, wherein the optical recording medium is a magneto-optical recording medium to which a front aperture detection method is applied. 9. The optical recording apparatus according to claim 6, wherein the optical recording medium is a magneto-optical recording medium to which a rear aperture detection method is applied. 10. The optical recording apparatus according to claim 8, wherein the read unit sets the read condition to a condition that does not cause magnetic super-resolution. .