JP2000242986A - Magneto-optical recording power deciding method and magneto-optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain high recording quality by deciding an optimum magneto- optical recording power for every recording to a magneto-optical disk with simple constitution without detecting an ambient temp. with respect to a magneto-optical recording power deciding method and a magneto-optical disk device. SOLUTION: In this magneto-optical recording power deciding method, test recordings 1, 2 by different laser powers are repeated in the PCA area of a magneto-optical disk (S3 to S6) and when level differences of peak and bottom values of RF signals at the time respective test recording parts are read back are equal to or larger than a prescribed value each other and both level differences are equal (S7 to S9), an actual recording is performed (S10, S11) with a laser power in which a prescribed value is added to the intermediate value of these laser powers. Thus, a laser power with which the level of a write-in reaches a fixed level can be detected without detecting the temp. of ambient environments.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining a magneto-optical recording power when recording on a magneto-optical disk such as a recordable mini disk, and a magneto-optical disk device.

[0002]

2. Description of the Related Art Conventionally, in a magneto-optical disk apparatus for recording and reproducing information by irradiating a recording surface of this type of magneto-optical disk with a light beam having a predetermined intensity, the recording on the magneto-optical disk recording surface is accurately performed. Therefore, it is necessary to determine the optimum laser power according to the recording conditions. If the recording conditions such as the operating environment temperature and laser power fluctuate for each recording of the magneto-optical disk, magnetic transfer on the recording surface of the magneto-optical disk will not function completely, or the temperature of the recording film will increase and sufficient magneto-optical This is because an effect may not be obtained or a certain resolution may not be obtained.

As a method of determining the magneto-optical recording power, for example, as disclosed in Japanese Patent Application Laid-Open No. 7-29238, a change in magnetic characteristics affected by ambient temperature conditions during reproduction is canceled (temperature compensation). For this purpose, the reference signal previously input to the recording layer is reproduced, the output signal amplitude is measured and compared with the initial reference signal amplitude, and based on the signal output difference, the same as the initial reference signal amplitude. There is a type that controls a laser power that is a reproduction light so that a signal of a level or a level close to the level is reproduced.

[0004]

However, in the above-described conventional method for determining the magneto-optical recording power, it is necessary to detect the ambient temperature in order to determine the optimum laser power. Since a mechanism is required, there has been a problem that the configuration of an apparatus for determining the magneto-optical recording power is complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. When recording data on a magneto-optical disk, the present invention has a simple configuration without detecting the ambient temperature and has an optimum structure for each recording. It is an object of the present invention to provide a magneto-optical recording power determining method and a magneto-optical disk drive capable of determining magneto-optical recording power and maintaining high recording quality.

[0006]

According to a first aspect of the present invention, there is provided a laser power determining method for determining a laser power during recording on a recording surface of a magneto-optical disk. A first monitor step for performing test recording in a power calibration area with a predetermined laser power and detecting a peak value and a bottom value of a reproduced RF signal when a recorded portion is read back; and a test in the first monitor step. A second monitoring step of performing test recording with a larger laser power than at the time of recording and detecting a peak value and a bottom value of a reproduced RF signal when a recorded portion is read back; and the first monitoring step and the second monitoring step. Repeat the monitoring steps
The level difference between the peak value and the bottom value of the reproduced RF signal in the test recording in the first and second monitor steps is equal to or larger than a predetermined value, and the level difference in the first monitor step and the level in the second monitor step The method comprises the steps of detecting a laser power value having the same difference as the difference, and performing actual recording using a laser power obtained by adding a predetermined power to the laser power value detected in the detecting step.

In the above configuration, the test recording of the first and second monitor steps with different laser powers is repeated in the power calibration area of the magneto-optical disk, and the RF signal at the time of reading back the respective test recording portions is repeated. When the level difference between the peak value and the bottom value is equal to or larger than a predetermined value and the level difference between the peak value and the bottom value in both steps is equal, the actual recording is performed with the laser power value obtained by adding the predetermined value to the laser power value. Is performed, it is possible to detect the laser power value at which the writing level reaches a certain level without detecting the temperature of the surrounding environment. Also, by adding a predetermined value to the laser power value, the information recording surface of the magneto-optical disk can be set slightly higher than the temperature at which the Curie temperature is reached, and the laser power used for actual recording can be rapidly recorded. It is possible to set the laser power to improve the characteristics.

[0008] The invention described in claim 2 is the first invention.
3. The method of determining a magneto-optical recording power according to claim 2, wherein the laser power at the time of test recording in the first monitoring step is smaller than the laser power at which the magnetic layer of the magneto-optical disk approaches the Curie temperature at a low temperature. It is set to a lower power.

In the above configuration, the test recording is started from a power slightly lower than the laser power at which the magnetic layer of the magneto-optical disk approaches the Curie temperature at a low temperature. Therefore, the first and second monitoring steps are repeated. When the laser power is gradually increased, it can be quickly detected that the level difference satisfies a certain standard in the detection step.

[0010] Further, the invention according to claim 3 is based on claim 1.
Or the magneto-optical recording power determining method according to claim 2, wherein the predetermined power added to the laser power value detected in the detecting step is a power that improves recording characteristics in recording at a high ambient temperature. It is determined based on the amount of addition.

In the above configuration, since the addition to the laser power value is performed based on the addition amount of the power at which the recording characteristics are improved in the recording at a high ambient temperature, the addition amount is relatively small, and Regardless, the laser power after the addition of the predetermined value reliably falls within the laser power margin.

According to a fourth aspect of the present invention, there is provided a magneto-optical disk device for recording and reproducing information by irradiating a recording surface of a magneto-optical disk with a light beam having a predetermined intensity. First recording means for performing test recording with a predetermined laser power and detecting a peak value and a bottom value of a reproduced RF signal when a recorded portion is read back; Perform test recording with laser power and read RF when reading back recorded part
The second monitoring means for detecting the peak value and the bottom value of the signal, and the detection by the first and second monitoring means are repeated, and the peak value and the peak value of the reproduced RF signal in the test recording by the first and second monitoring means are repeated. Means for detecting a laser power value at which the level difference between the bottom values is equal to or greater than a predetermined value and the level difference detected by the first monitor means is equal to the level difference detected by the second monitor means; Means for performing actual recording using a laser power obtained by adding a predetermined power to the laser power value detected by the detection means.

In the above configuration, the test recording by the first and second monitor means with different laser powers is repeated in the power calibration area of the magneto-optical disk, and the RF signal when each test recording portion is read back is read. When the level difference between the peak value and the bottom value is equal to or larger than a predetermined value and the level difference between the peak value and the bottom value in both steps is equal, the actual recording is performed with the laser power value obtained by adding the predetermined value to the laser power value. Is performed, it is possible to detect the laser power value at which the writing level reaches a certain level without detecting the temperature of the surrounding environment. Also, by adding a predetermined value to the laser power value, the information recording surface of the magneto-optical disk can be set slightly higher than the temperature at which the Curie temperature is reached, and the laser power used for actual recording can be rapidly recorded. It is possible to set the laser power to improve the characteristics.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magneto-optical recording power determining method and a magneto-optical disk drive according to an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a schematic configuration of a magneto-optical disk drive according to an embodiment of the present invention. The magneto-optical disk drive 1 is a mini disk (Mini Dis
c), etc., for recording, reproducing and erasing the magneto-optical disk 5, irradiating the information recording layer of the mini-disk with a light beam and reading information based on the reflected light thereof and an objective lens 2 And a feed motor 4 for moving the objective lens 3 in the disk direction.
The spindle motor 6 is for rotating the disk 5 when writing or reading information.

The system controller (detection means) 8
The optical pickup unit 2, the objective lens 3, the feed motor 4 and the spindle motor 6 are controlled via a servo control circuit 7. The optical pickup unit 2 includes a light-emitting element for irradiating the disk 5 with a light beam and a light-receiving element for receiving light reflected by the disk. It is sent to the encoder / decoder section 10. Further, an address signal is output from the RF amplifier 9 to the encoder / decoder unit 10 via the address decoder 11. Magnetic head (actual recording means) 13
Is for magnetically recording information on the magneto-optical film of the disk 5, and is disposed on the opposite side of the optical pickup 2 with respect to the disk 5. The system controller 8 drives the optical pickup 2 at the time of recording information to irradiate the disk 5 with a laser beam and heats the magneto-optical film to a temperature higher than the Curie temperature to eliminate the magnetism. At this time, the encoder / decoder unit 10 By reversing the direction of the current flowing through the magnetic head 13 via the head driver 14 according to the recording information, a magnetic field of “N” or “S” is generated, and the magnetic field is overwritten on the disk 5 by the magnetic field modulation overwrite method. I do.

The optical pickup section can perform test recording as described later. The RF amplifier 9 has a peak / bottom hold circuit (first and second hold circuits) for detecting a peak value and a bottom value of an RF signal. (Monitor means) 15 is connected, and the detected peak value and bottom value are converted by the A / D converter 1
After being A / D converted by 6, it is input to the system controller 8.

Next, the relationship between laser power and temperature required for recording will be described with reference to FIGS. FIG. 2 shows the relationship between the laser power required for recording and the ambient temperature, and FIG. 3 schematically shows the recording area of the magneto-optical disk.
In general, a magneto-optical disk has a TOC area used by a maker to write necessary information such as a recommended laser power for recording in addition to a program area, and information such as a start / end position of a track and a title of a recorded music. And a UTOC area used by the user is provided. The recommended laser power written in the TOC area is generally a value when the ambient temperature is 25 ° C. However, since the ambient temperature at the time of recording on the magneto-optical disk is not always 25 ° C., recording with the recommended laser power written in the TOC area is not always of high quality. Therefore, in order to perform high-quality recording, it is desired to adjust the laser power according to the ambient temperature every time recording is performed on a disk. As shown in FIG. 2, the higher the ambient temperature, the lower the laser power suitable for recording, that is, the laser power required to bring the temperature of the disk magnetic layer to the Curie temperature.

The magneto-optical disk drive 1 takes into account the relationship between the laser power and the ambient temperature as described above, and every time data is recorded on the disk, a PCA (Power Cali- bly) in the UTOC area is used.
Test recording is performed using the bration area) and the peak / peak of the RF signal when the recorded portion is read back.
The laser power suitable for the surrounding environment at the time of recording is obtained based on the level difference of the bottom value.

In order to enable recording on the disk magnetic layer, the level difference between the peak / bottom value of the RF signal when the test recording portion is read back (indicated by an arrow in FIG. 4).
Must be a laser power that is equal to or greater than a certain value.
Although this level difference increases as the laser power increases, as shown in FIG. 5, when a certain laser power is reached, the level difference is saturated at that point and does not spread further. Therefore, the test recording is performed a plurality of times by gradually increasing the level of the laser power. If the detected level differences do not change and if the level differences are equal to or more than a certain value, the temperature at the time of the recording is determined. This means that the laser power has reached the recordable laser power under the conditions.

The relationship between the error rate and the laser power will be described with reference to FIG. As shown in FIG. 6, as the value of the laser power increases, the error rate also decreases at first, but once the laser power reaches a certain value, the error rate does not decrease any more. Then, as the value of the laser power further increases, the error rate increases. Therefore, the laser power in a region where the error rate is at the minimum level is a value suitable for recording. In the area where the error rate is at the minimum level, the area shifts to the right in FIG. 6 when the ambient temperature decreases (FIG. 6 shows the case of 0 ° C.). Normal,
Since the temperature condition at the time of recording on the disc is considered to be about 0 ° C. to 50 ° C., in order to detect the area where the error rate is the minimum level under the temperature condition at the time of recording, a laser used for test recording is used. Power, ambient temperature is 0
If the disk magnetic layer is started at a power slightly lower than the laser power expected to reach the Curie temperature at a temperature of ° C., a region where the error rate is at a minimum level can be detected in a short time.

Next, a method of determining the laser power at the time of recording by the magneto-optical disk device 1 will be described with reference to the flowchart of FIG. This processing is performed by the system controller 8. R for instructing start of recording on disc
If there is an EC start command or a REC PAUSE start command (S1: YES), first, information recorded in the PCA area in the UTOC area is erased (S1).
2) A state where writing to the area by test recording is enabled. The laser power at the time of this erasing is set to a higher power value (a laser power value at which the disk magnetic layer can always reach a temperature near the Curie temperature) which is considered to be recordable, and the magnetic head 13 is not driven. By doing so (by preventing the EFM modulation current from flowing), pseudo erasure is performed.

Then, the writable PCA
Test recording 1 is performed on the area at a low temperature, for example, at 0 ° C., with a power slightly lower than the laser power that is considered to be able to reach the vicinity of the Curie temperature (S3). After the test recording 1, the portion written by the test recording 1 is read back to calculate the level difference between the peak and bottom values of the RF signal output from the RF amplifier 9 through the peak / bottom hold 15 (S4). (Not shown) (S5).
Next, test recording 2 is performed with the laser power slightly higher than in test recording 1 (S6). As in the case of the test record 1, after the test record 2, the portion written by the test record 2 is read back and the peak / peak of the RF signal is read.
The level difference between the bottom values is calculated (S7).

Next, the level difference at the time of test recording 1 is read from the memory, and it is determined whether the level difference between the test recordings 1 and 2 is both equal to or greater than a predetermined value (S8). This determination is to detect whether or not the level difference between the peak / bottom value of the RF signal has reached a level at which recording on the disk magnetic layer is possible. Is a value indicating a level difference at which recording of the level becomes possible. In this judgment, when the level difference between the test records 1 and 2 has both reached the predetermined value (S8:
(YES), and it is further determined whether or not the level differences between the test records 1 and 2 are equivalent (S9). Here, if the two level differences have the same value (S9: YE
S), an intermediate value between the laser power in test recording 1 and the laser power in test recording 2 is calculated (S10).
A value obtained by adding a predetermined value to the calculated intermediate value is set as a laser power used for actual recording (S11). This predetermined value is determined with reference to the added amount of power at which the recording characteristics are stabilized and improved in recording when the ambient temperature is high. Here, the calculated intermediate value indicates that the disk magnetic layer has reached the Curie temperature. The laser power is set to a value slightly higher than the laser power. This is because recording characteristics are sharply improved in recording with a laser power slightly higher than the laser power at which the disk magnetic layer has reached the Curie temperature.

In S8, test records 1 and 2
If any one of the level differences does not reach the predetermined value, and if the level difference between the test records 1 and 2 is not the same value in S9, the process returns to S3 and raises the laser power slightly from the previous time. Then, test recording 1 and test recording 2 are performed (S8: NO, S9: NO). The test record 1 and the test record 2 are repeated until the level difference between the test records 1 and 2 reaches a predetermined value, and the two level differences become equivalent values. As described above, the laser power used for actual recording is obtained, and recording or REC PAUSE is started with the laser power (S12).

As described above, according to the magneto-optical disk drive 1 of this embodiment, every time recording is performed on the disk, the UTO
By repeating the test recording 1 and 2 in the PCA area in the C area, a laser power suitable for the surrounding environment at the time of recording is obtained. Therefore, even if the ambient temperature is not detected, the optimum laser power according to the ambient temperature condition is obtained. Power can be sought. This makes it possible to maintain high recording quality without requiring a mechanism such as a temperature sensor.

The present invention is not limited to the configuration of the above embodiment, and various modifications are possible. For example, in the above-described embodiment, the level of the laser power used for test recording 1 is slightly lower than the laser power at which the disk magnetic layer is likely to reach around the Curie temperature at a low temperature. It is also possible to start with a different level of laser power. Further, in the above embodiment, when the laser power used for actual recording is set, the test is performed when the level difference between the test recordings 1 and 2 both reaches a predetermined value and the two level differences become the same value. An intermediate value between the laser power in the recording 1 and the laser power in the test recording 2 is calculated, and a value obtained by adding a predetermined value to the intermediate value is used as the laser power used for actual recording. Test record 1
A value obtained by adding a predetermined value to one of the laser power in the test recording 2 and the laser power in the test recording 2 may be used as the laser power used for actual recording. Further, in the above-described embodiment, a case has been described in which a mini-disk is used as the magneto-optical disk. However, the present invention is not limited to this and can be widely applied to all magneto-optical disks.

[0027]

As described above, according to the first or fourth aspect of the present invention, the surrounding environment at the time of recording is determined based on the level difference between the peak value and the bottom value in the first and second monitoring steps. Since a laser power suitable for the laser power is obtained, recording with the optimum laser power can be performed without detecting the ambient temperature. Thus, high-quality recording can be maintained with a simple configuration without requiring a mechanism such as a temperature sensor. Since the power value obtained by adding a predetermined value to the obtained laser power value is used as the laser power used for actual recording, the laser power used for actual recording is slightly increased from the temperature at which the information recording surface of the magneto-optical disk reaches the Curie temperature. It is possible to set a higher value, and it is possible to perform actual recording with a laser power that sharply improves the recording characteristics.

According to the second aspect of the present invention, at the time of low temperature, the test recording is started from a power slightly lower than the laser power at which the magnetic layer of the magneto-optical disk approaches the Curie temperature. When the laser power is gradually increased by repeating the second monitor step, it is possible to quickly detect that the level difference has reached a certain criterion in the above-described detection step, and to reduce the time required for power calibration. Can be shortened.

According to the third aspect of the present invention, the laser power value can be changed with a relatively small power addition amount based on the addition amount of the power at which the recording characteristics are improved in the recording when the ambient temperature is high. Is added, the laser power after the addition of the predetermined value can be reliably kept within the laser power margin regardless of the ambient temperature, and stable recording can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a magneto-optical disk drive according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a relationship between a laser power used for recording and an ambient environment temperature.

FIG. 3 is a diagram schematically showing a recording area of a magneto-optical disk.

FIG. 4 is an RF when a test recording portion is read back.
It is a figure showing a signal.

FIG. 5 is a diagram showing a relationship between a level difference between a peak / bottom value of the RF signal and a laser power.

FIG. 6 is a diagram showing a relationship between an error rate and laser power.

FIG. 7 is a flowchart illustrating a flow of processing when determining laser power during recording.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Magneto-optical disk drive 5 Magneto-optical disk 8 System controller (detection means) 9 RF amplifier 10 Encoder / decoder (actual recording means) 13 Magnetic head (actual recording means) 14 Head driver 15 Peak / bottom hold section (first and second hold sections) 2 monitor means)

Claims (4)

[Claims] 1. A laser power determination method for determining a laser power at the time of recording on a recording surface of a magneto-optical disk, wherein test recording is performed with a predetermined laser power on a power calibration area of the magneto-optical disk, and a recorded portion is read back. A first monitoring step for detecting a peak value and a bottom value of the reproduced RF signal at the time of performing the test recording; and a test recording was performed with a laser power larger than that at the time of the test recording in the first monitoring step, and the recorded portion was read back. A second monitoring step of detecting a peak value and a bottom value of the reproduction RF signal at the time of the reproduction, and the first monitoring step and the second monitoring step are repeated, and reproduction in test recording of the first and second monitoring steps is performed. The level difference between the peak value and the bottom value of the RF signal is equal to or greater than a predetermined value, and Detecting a laser power value at which the level difference in the first monitor step is equal to the level difference in the second monitor step; and adding a predetermined power to the laser power value detected in the detection step. And performing actual recording using the method. 2. The method according to claim 1, wherein the laser power at the time of test recording in the first monitor step is set to a power slightly lower than the laser power at which the magnetic layer of the magneto-optical disk approaches the Curie temperature at a low temperature. 3. The method for determining a magneto-optical recording power according to claim 1 or 2. 3. The method according to claim 2, wherein the predetermined power to be added to the laser power value detected in the detection step is determined based on an added amount of power at which recording characteristics are improved in recording at a high ambient temperature. Claim 1 or Claim 2
3. The method for determining a magneto-optical recording power according to item 1. 4. A magneto-optical disk drive for recording and reproducing information by irradiating a recording surface of a magneto-optical disk with a light beam having a predetermined intensity, performing test recording with a predetermined laser power in a power calibration area of the magneto-optical disk. A first monitor for detecting a peak value and a bottom value of a reproduced RF signal when a recorded portion is read back; and performing test recording with a larger laser power than at the time of test recording by the first monitor. A second monitor for detecting a peak value and a bottom value of the reproduced RF signal when the recorded portion is read back, and the detection by the first and second monitor are repeated,
The level difference between the peak value and the bottom value of the reproduced RF signal in the test recording by the first and second monitor means is equal to or more than a predetermined value, and the level difference detected by the first monitor means and the second monitor means Means for detecting a laser power value that is equivalent to the level difference in the detection of the data, and means for performing actual recording using a laser power obtained by adding a predetermined power to the laser power value detected by the detection means. A magneto-optical disk device characterized by the above-mentioned.