JP4370986B2 - Magneto-optical disk apparatus and magneto-optical recording power determination method - Google Patents

Description

  The present invention relates to a magneto-optical disk apparatus that records information on a magneto-optical disk such as an MD (mini disk) and a magneto-optical recording power determination method used therefor.

  In a magneto-optical disk apparatus that records and reproduces information by irradiating a recording surface of a magneto-optical disk with a predetermined intensity, in order to perform recording on the recording surface of the disk accurately, it is optimal for the conditions at the time of recording. It is necessary to determine the laser power. This is because if the recording conditions such as operating environment temperature and laser power fluctuate for each recording on the disk, the magnetic transfer on the recording surface of the disk does not function completely, or the temperature of the recording film increases and sufficient magnetic This is because an optical effect may not be obtained or a certain resolution may not be obtained.

  As a method for determining the laser power, for example, a method disclosed in Patent Document 1 described below is known. This method reproduces the reference signal recorded in advance in the recording layer and cancels the amplitude of the output signal in order to cancel (temperature compensation) the change in the magnetic characteristics affected by the ambient temperature condition during reproduction. This is measured and compared with the amplitude of the original reference signal, and the laser power is controlled based on the signal output difference so that a signal having the same level as or close to the amplitude of the original reference signal is reproduced. . However, in this method, since it is necessary to detect the ambient temperature in order to determine the optimum laser power, there is a problem that a temperature detection mechanism must be provided and the configuration of the apparatus becomes complicated.

  Therefore, in order to solve the above problem, the applicant of the present invention can determine an optimum magneto-optical recording power for each recording with a simple configuration without detecting the ambient temperature (hereinafter, referred to as “optical magneto-optical disk device”). (Hereinafter referred to as “prior invention”) is proposed in Patent Document 2 described later. The contents of this prior invention will be described below.

  First, the relationship between laser power and temperature required for recording will be described. FIG. 4 is a diagram showing the relationship between the laser power required for recording and the ambient environment temperature, and FIG. 5 is a diagram schematically showing the recording area of the magneto-optical disk. In general, on the magneto-optical disk, in addition to the program area, the TOC area used by the manufacturer for writing necessary information such as the recommended laser power at the time of recording, and information such as the start / end positions of tracks and the names of recorded songs A UTOC area for use by the user is provided. The recommended laser power written in the TOC area is generally a value when the ambient environment temperature is 25 ° C. However, since the ambient temperature at the time of recording on the magneto-optical disk is not always 25 ° C., the recording with the recommended laser power written in the TOC area is not always high quality. Here, as shown in FIG. 4, the higher the ambient temperature, the smaller the laser power suitable for recording, that is, the laser power required to reach the temperature of the disk magnetic layer to the Curie temperature. In order to perform the above, it is necessary to determine the laser power corresponding to the ambient temperature for each recording on the disk.

  In the above prior invention, considering such a relationship between laser power and ambient temperature, test recording is performed using a PCA (Power Calibration Area) area in the UTOC area for each recording on the disk, and the recorded portion is recorded. Based on the level difference between the peak / bottom values of the RF signal when reading back (reading immediately after recording), the laser power suitable for the ambient environment during recording is obtained.

  In order to enable recording to the disk magnetic layer, the laser power must be such that the level difference (y in FIG. 6) of the peak / bottom value of the RF signal when the test recording portion is read back is not less than a certain value. Don't be. This level difference increases as the laser power increases. However, as shown in FIG. 7, when the laser power reaches a certain level, the level difference becomes saturated at that time and does not increase any further. Therefore, when the laser power level is gradually increased and a plurality of test recordings are performed, and each level difference detected does not change and the level difference is equal to or greater than a certain value, the temperature at the time of the recording The laser power that can be recorded under the conditions is reached.

  By the way, in determining the optimum laser power, it is necessary to consider the relationship between the error rate and the laser power. FIG. 8 is a diagram showing the relationship between the error rate and the laser power. As can be seen from FIG. 8, when the laser power value increases, the error rate also decreases at the beginning. However, when the laser power reaches a certain value, the error rate does not decrease any more. As the laser power value further increases, the error rate increases. Therefore, the laser power in a region where the error rate is at the minimum level (corresponding to a laser power margin described later) is a value suitable for recording. Further, the region where the error rate is at the minimum level shifts to the right in FIG. 8 when the ambient temperature decreases (the solid line in FIG. 8 is the error rate at 50 ° C., and the broken line is the error rate at 0 ° C. Showing). Usually, since the temperature condition at the time of disk recording is about 0 ° C. to 50 ° C., the laser power used for test recording is slightly lower than the laser power that the disk magnetic layer is expected to reach the Curie temperature when the ambient temperature is 0 ° C. If the power is started from this power, it is possible to detect a region where the error rate under the temperature condition during recording is at the minimum level in a short time.

  Therefore, in the prior invention, the PCA area of the magneto-optical disk is firstly given a power slightly lower than the laser power that is predicted to be able to reach the disk magnetic layer near the Curie temperature at a low temperature (for example, 0 ° C.). Perform test record 1. Thereafter, the recorded portion is read back to calculate the level difference between the peak value and the bottom value of the reproduction RF signal. Next, test recording 2 is performed with a slightly higher laser power than in the case of test recording 1. Thereafter, the recorded portion of the test recording 2 is read back, and the level difference between the peak value and the bottom value of the reproduction RF signal is calculated. Next, whether or not the respective level differences obtained in the test record 1 and the test record 2 are equal to or greater than a predetermined value, and the level difference in the test record 1 is equal to the level difference in the test record 2 If these two conditions are not satisfied, test record 1 and test record 2 are repeated while gradually increasing the laser power. When the two conditions are satisfied, an intermediate value between the laser power in the test recording 1 and the laser power in the test recording 2 is calculated, and a value obtained by adding a predetermined value to the calculated intermediate value is used as the laser power for actual recording. .

Thus, in the prior invention, the laser power suitable for the ambient environment at the time of recording is obtained based on the level difference between the peak value and the bottom value in the test record 1 and the test record 2, so that the ambient temperature is not detected. Recording with the optimum laser power can be performed, and a temperature detection mechanism is not required, and the configuration is simplified.
JP-A-7-29238 JP 2000-242986 A JP 2001-195793 A JP 2002-25066 A

  However, in the prior invention of Patent Document 2, if the level difference between the peak / bottom values of the reproduction RF signal when the recorded portion in the test recording is read back is equal to or greater than a predetermined value, the laser power at that time is always used. Since the laser power value for actual recording is determined using the value, in the case of a disk with a small laser power margin (laser power margin for error), the error rate during actual recording increases and the recording performance deteriorates. Can happen. Hereinafter, this will be described with reference to FIG. FIG. 9A shows the relationship between the level difference between the peak / bottom values of the RF signal (FIG. 6) and the laser power, which is basically the same as FIG. Here, a change in level difference at the recording temperature (solid line) and a change in level difference at the low temperature (0 ° C.) (broken line) are shown. FIG. 9B shows the relationship between the error rate and the laser power, which is basically the same as FIG. Again, the change in error rate at the recording temperature (solid line) and the change in error rate at the low temperature (0 ° C.) (broken line) are shown.

  In the prior invention, as a result of executing the first test record 1 and test record 2, if the condition that the level differences of the RF signals are both equal to or greater than a predetermined value is satisfied, the test record 1 is increased by increasing the laser power. Without repeating step 2, the actual recording laser power is determined immediately. In FIG. 9, if the laser power (intermediate value of each laser power in the test recordings 1 and 2) is A when the above condition is satisfied, the laser power for actual recording adds a predetermined value to A. B is determined. However, if the error rate at the recording temperature is a characteristic as indicated by a solid line, the error rate when the laser power is B is a considerably large value as indicated by C in FIG. In the case of a disk having a sufficiently large laser power margin (m in the figure), an error is unlikely to occur even if the laser power slightly varies, but the laser power margin varies from disk to disk depending on the recording layer material and the like. For this reason, in a disk with a small laser power margin, there arises a problem that recording errors frequently occur and performance is deteriorated. In Patent Documents 3 and 4, methods for determining the laser power for actual recording have been proposed, but there is no disclosure of a solution to the above problem.

  The present invention solves the above-described problems, and an object of the present invention is to provide a magneto-optical disk apparatus and a magneto-optical disk apparatus that can perform good recording while suppressing errors even on a disk having a small laser power margin. It is to provide a recording power determination method.

In the magneto-optical disk apparatus according to the present invention, the first test recording is carried out and a second test recording at different laser power value in the power calibration area of the optical disk, was read back each recorded portion of each test recording in each reproduction detects a peak value and bottom value of the RF signal, a magneto-optical disk apparatus for determining a laser power value of the reference to the actual recording of the level difference between respective peak values and bottom values of the time, the first A determining means and a second determining means are provided. First determination means, when the first and second test recording is then executed for the first time, at each level difference are both higher than a predetermined value, and the level difference is not determined to be equivalent, the determination until is, while raising the laser power repeat the first and second test recording, at each level difference are both higher than a predetermined value, and, second when the respective level difference is the determination to be equivalent to The laser power value for actual recording is determined based on the laser power values at the time of the first and second test recordings . The second determining means determines whether the first and second test recordings are executed for the first time, and when the level differences are both equal to or greater than a predetermined value and the level differences are equal. A laser power value smaller than the laser power values at the time of the first and second test recordings is set as an initial power value, and the first and second test recordings are performed at power values different from the initial power value and the initial power value, respectively . the resumed, at each level difference are both higher than a predetermined value, and, until the respective level difference is determined to be equal, while increasing the laser power repeat the first and second test recording, the level difference The laser power value for actual recording is determined based on the respective laser power values at the time of the first and second test recording when it is determined that both are equal to or greater than a predetermined value and the respective level differences are equal .

In determining the laser power value of the actual recording, for example, in each level difference are both higher than a predetermined value, and when the first and second test recording when the respective level difference is determined to be equal to A value obtained by adding a predetermined value to an intermediate power value of each laser power value or one of the laser power values may be used as the laser power value for actual recording. Further, as the initial power value when restarting the test recording, it is preferable to employ a laser power value slightly lower than the laser power value that is predicted to allow the disk magnetic layer to reach the Curie point at a high temperature.

A magneto-optical recording power determination method according to the present invention is a magneto-optical recording power determination method for determining a laser power value at the time of recording on a recording surface of a magneto-optical disk, and includes the following steps.
(A) performing a first test recording at a predetermined laser power value in the power calibration area of the magneto-optical disk;
(B) A step of detecting a peak value and a bottom value of the reproduction RF signal when the recording portion in the first test recording is read back.
(C) performing a second test recording with a different laser power value is the laser power value in the first test recording.
(D) A step of detecting a peak value and a bottom value of the reproduction RF signal when the recording portion in the second test recording is read back.
(E) with reference to each of the peak value and the bottom value of the detected respective reproduced RF signal, the first test recording and the second respective levels of the peak value and the bottom value of the reproduced RF signal based on the test recording A step of determining whether or not the differences are equal to or greater than a predetermined value and the respective level differences are equal.
(F) After the first and second test recording is executed for the first time, at each level difference are both higher than a predetermined value, and if the respective level difference is not determined to be equivalent, is the the determination until, with increasing laser power repeat the first and second test recording, first and second test when each level difference are both higher than a predetermined value, and the level difference is determined to be equal to Determining a value obtained by adding a predetermined value to an intermediate power value of each laser power value at the time of recording or a laser power value of each of the laser power values, as a laser power value for actual recording.
(G) after the first and second test recording is executed for the first time, at each level difference are both higher than a predetermined value, and when the level difference is determined to be equal, the disk magnetic layer at high temperatures Setting a laser power value slightly lower than a laser power value predicted to be able to reach the Curie point as an initial power value;
(H) the initial power value and restarts the first and second test recording respectively different power values with the initial power value, at each level difference are both higher than a predetermined value, and with the level difference is equal to The first and second test recordings are repeated while increasing the laser power value until the determination is made, and the first difference when it is determined that each level difference is equal to or greater than a predetermined value and each level difference is equal . And determining a value obtained by adding a predetermined value to an intermediate power value of each laser power value at the time of the second test recording or a laser power value of each of the laser power values, as a laser power value for actual recording.

  In the present invention, after the first execution of the first and second test recordings, if the level difference between the RF reproduction signals satisfies the two conditions, the laser for actual recording is based on the laser power at that time. Rather than determining the power value, an initial power value lower than the laser power at that time is set, and the first and second test recordings are executed again from this initial power value. For this reason, even if the laser power after the first execution of test recording is a large value, the laser power that is actually determined is a smaller value, and it can be set to a laser power corresponding to a region with a low error rate. it can.

  Thus, according to the present invention, even a disk with a small laser power margin can perform good recording with fewer errors.

  FIG. 1 is a schematic configuration diagram showing an embodiment of a magneto-optical disk apparatus according to the present invention. The magneto-optical disk device 1 records and reproduces information with respect to a magneto-optical disk (hereinafter simply referred to as “disk”) 5. Here, the disk 5 is composed of a mini-disc. In the cartridge 5a. Reference numeral 2 denotes an optical pickup that irradiates the information recording layer of the disk 5 with a light beam, and reads information based on the reflected light. Reference numeral 3 denotes an objective lens constituting an optical system. The optical pickup 2 includes a light emitting element that irradiates a light beam to the disk 5 and a light receiving element that receives reflected light from the disk 5. A feed motor 4 moves the optical pickup 2 and the objective lens 3 with respect to the disk 5. A spindle motor 6 rotates the disk 5 when writing or reading information.

  7 is a servo control circuit, and 8 is a system controller. The servo control circuit 7 controls the optical pickup 2, the feed motor 4 and the spindle motor 6 based on a command from the system controller 8. The system controller 8 includes a CPU, a memory, and the like. Reference numeral 9 denotes an RF amplifier which processes a signal output from the light receiving element of the optical pickup 2 and sends it to the encoder / decoder unit 10 and outputs an address signal to the address decoder 11. The address decoder 11 decodes the address signal and gives address information to the encoder / decoder unit 10. The encoder / decoder unit 10 performs a decoding process on a reproduction signal read from the disk 5 and an encoding process on a recording signal recorded on the disk 5.

  A recording magnetic head 13 is disposed on the opposite side of the optical pickup 2 with the disk 5 interposed therebetween, and magnetically records information on the magneto-optical film of the disk 5. Reference numeral 14 denotes a head driver for driving the magnetic head 13. At the time of information recording, the optical pickup 2 is driven by the system controller 8 and the servo control circuit 7, and the disk 5 is irradiated with a laser beam to heat the magneto-optical film to a temperature above the Curie temperature, and the magnetism disappears. / Decoder unit 10 generates a magnetic field of “N” and “S” by reversing the direction of the current flowing through magnetic head 13 via head driver 14 in accordance with the recording information, and uses a magnetic field modulation overwrite method to Record in 5.

  A peak / bottom hold circuit 15 is connected to the RF amplifier 9. As will be described later, the peak / bottom hold circuit 15 detects the peak value and the bottom value of the RF signal read back after the test recording. Reference numeral 16 denotes an A / D converter for A / D converting the detected peak value and bottom value, and its output is input to the system controller 8.

  In the magneto-optical disk apparatus 1 described above, the optical pickup 2 constitutes one embodiment of the first test means and the second test means of the present invention, and the peak / bottom hold circuit 15 is the first detection means of the present invention. The system controller 8 constitutes an embodiment of the determination means, the first determination means, and the second determination means of the present invention.

  Next, a method for determining the laser power during recording in the magneto-optical disk apparatus 1 will be described. Since a detailed power determination procedure will be described later, an outline will be first described here. The test recording 1 and the test recording 2 are executed, and the level difference between the peak value and the bottom value of the reproduction RF signal obtained by reading back the recording portion in each test recording is obtained. The process is the same as before until it is determined whether or not the two level differences are substantially equal. However, the processing in the case where each level difference is determined to be substantially equal to or greater than a predetermined value after execution of the first test records 1 and 2 differs between the conventional and the present invention.

  FIG. 2 is a diagram for explaining the principle of determining the laser power and corresponds to FIG. 9 in the case of the conventional example. In FIG. 2A, a change in level difference at high temperature (50 ° C.) (one-dot chain line) is added, and in FIG. 2B, a change in error rate at high temperature (50 ° C.) (one-dot chain line). Has been added. In FIG. 2, the laser power when each level difference between the first test records 1 and 2 is determined to be equal to or greater than a predetermined value and each level difference is substantially equal (each of the test records 1 and 2 in each of the test records 1 and 2). Assume that the intermediate value of the laser power is A. Of course, the laser power at this time is not always A, and there is a possibility of E, for example. However, as will be described later, the error rate does not matter with the value of E. Since the value of A may cause the laser power to be set in the direction in which the error rate increases, in the present invention, when it is determined as described above in the first test recording, the laser power value at that time is set to A It is decided to consider it.

  In the conventional case, since the laser power B for actual recording is determined based on the laser power A, as described above, the error rate during actual recording is C and recording errors frequently occur. On the other hand, in the case of the present invention, a laser power value D smaller than the laser power A is set as an initial power value, and the test recordings 1 and 2 are restarted from this initial power value D. The initial power value D is set to a value slightly lower than the laser power value predicted to allow the disk magnetic layer to reach the Curie point at a high temperature (for example, at 50 ° C.). The initial power value D can be obtained experimentally in advance. Then, until it is determined that each level difference is equal to or greater than a predetermined value and is the same as before, test recordings 1 and 2 are repeated while increasing the laser power. The laser power F for actual recording is determined based on the power value (intermediate value of each laser power in the test recordings 1 and 2) E. Specifically, a value obtained by adding a predetermined value to the laser power value E is set as a laser power value F for actual recording as in the conventional case. At this time, the error rate at the time of actual recording becomes G, and the error rate is greatly reduced as compared with the error rate C in the conventional case.

  By doing as described above, even if the laser power A after the first execution of the test recordings 1 and 2 is a large value, the laser power F that is actually determined becomes a smaller value, and an error occurs during actual recording. It is possible to set the laser power corresponding to a region having a small rate. Therefore, even with a disk having a small laser power margin, it is possible to perform good recording with fewer errors. Also, the laser power is lowered from A to D at once, and an initial power value slightly lower than the laser power value that is expected to allow the disk magnetic layer to reach the Curie point at high temperatures is set, and test recording is performed from this initial power value. Therefore, it is possible to detect in a short time the laser power value E at which each level difference is equal to or greater than a predetermined value.

  Next, a detailed procedure of the laser power determination method will be described with reference to the flowchart of FIG. This process is executed by a CPU provided in the system controller 8. When a REC start command or REC PAUSE command for instructing the start of recording on the disk 5 is received (step S1: YES), first, information recorded in the PCA area in the UTOC area is erased (step S2). Enable writing to the area by test recording. In this case, the laser power is set to a higher power value that is always predicted to be recordable, that is, a laser power value that is expected to allow the disk magnetic layer to always reach the Curie temperature, and the magnetic head 13 is not driven. By performing (no EFM modulation current flow), pseudo erasure is performed.

  Subsequently, the flag F is set to 0 (step S3). After that, the test recording 1 with a slightly lower power than the laser power that is expected to be able to reach the disk magnetic layer at a low temperature, for example, 0 ° C., near the Curie temperature, in the writable PCA area. (Step S4). After the test record 1, the portion written by the test record 1 is read back to calculate the level difference between the peak / bottom values of the RF signal (step S5). The RF signal is output from the RF amplifier 9 and the peak / bottom hold circuit 15 detects the peak / bottom value. The calculated level difference is stored in a predetermined area of a memory (not shown) (step S6).

  Next, test recording 2 is performed (step S7). The laser power in the test record 2 is set slightly larger than the laser power in the test record 1. After the test record 2, as in the case of the test record 1, the portion written by the test record 2 is read back to calculate the level difference between the peak / bottom values of the RF signal (step S8).

  Thereafter, the level difference obtained in the test record 1 is read from the memory, and it is determined whether or not each level difference in the test record 1 and the test record 2 is equal to or greater than a predetermined value (step S9). This determination is to check whether the level difference (FIG. 6) between the peak / bottom values of the RF signal has reached a level where recording on the disk magnetic layer is possible. Is a value indicating a level difference that allows recording on the disk magnetic layer. In this determination, if both the level differences in the test records 1 and 2 have reached the predetermined value (step S9: YES), it is further determined whether or not the two level differences are equal (step S10). ).

  In step S9, if any one of the level differences in test records 1 and 2 has not reached the predetermined value (step S9: NO), and in step S10, both level differences in test records 1 and 2 are equal values. If not (step S10: NO), after setting the flag F to 1 (step S13), the process returns to step S4, and the test recording 1 and test recording 2 are performed by slightly raising the laser power from the previous time (step S4). , S7). The test records 1 and 2 are repeated until the level difference in each test record reaches a predetermined value (step S9: YES) and the level difference becomes an equivalent value (step S10: YES). When the first test records 1 and 2 are started from a small laser power, the test records 1 and 2 are repeated many times, and the difference between both levels reaches a predetermined value and reaches an equivalent value in the vicinity of E in FIG. . Then, the determinations at steps S9 and S10 are both YES, and the subsequent determination at step S11 is NO because the flag F is 1, and the process proceeds to step S14.

  In step S14, an intermediate value between the laser power in the test record 1 and the laser power in the test record 2 is calculated. Next, a predetermined value is added to the calculated intermediate value, and this value is determined as the laser power used for actual recording (step S15). Here, the predetermined value is set to such a value that the laser power for actual recording is slightly higher than the laser power when the disk magnetic layer reaches the Curie temperature.

  The laser power used for actual recording is determined according to the above procedure, and recording (or REC PAUSE) on the disk 5 is started with this laser power (step S16). The procedure so far is basically the same as that of the prior invention.

  On the other hand, when it is determined that the level differences are both equal to or greater than a predetermined value (step S9: YES) and the level differences are equal (step S10: YES) by executing the test records 1 and 2 for the first time, Since the flag is 0, the determination in step S11 is YES, and the process proceeds to step S12. The processing after step S12 is a part that characterizes the present invention.

  In step S12, a laser power value slightly lower than the laser power value that is predicted to allow the disk magnetic layer to reach the Curie point at a high temperature is set as the initial power value (D in FIG. 2). Thereafter, the flag F is set to 1 (step S13), the process returns to step S4, and test recording 1 is performed with the initial power. Then, after performing steps S5 and S6 described above, test recording 2 is performed with the power slightly increased from the initial power (step S7). Subsequently, step S8 described above is executed. Next, the determinations in steps S9 and S10 are performed, and the laser power is increased until both the determinations are YES, that is, until the level difference between the peak / bottom values of the RF signal is equal to or greater than a predetermined value. Test records 1 and 2 are repeated (steps S4 to S8).

  If both the determinations in steps S9 and S10 are YES, the subsequent determination in step S11 is NO because the flag F is 1, the process proceeds to step S14, and the laser power value for actual recording is as described above. Is determined (steps S14 and S15). Then, recording (or REC PAUSE) on the disk 5 is started with this laser power (step S16).

  In the present invention, various modifications other than the above-described embodiment are possible. For example, in the above embodiment, the laser power level used for the test recording 1 is slightly lower than the laser power at which the disk magnetic layer is expected to reach the Curie temperature at low temperatures. May be used to start the test record 1.

  In the above embodiment, the initial power is set to a value slightly lower than the laser power value that is predicted to allow the disk magnetic layer to reach the Curie point at 50 ° C. However, the temperature of 50 ° C. is an example. The initial power may be set based on a different temperature.

  In the above embodiment, when the laser power used for actual recording is set, the test recording when the level difference in both test recordings 1 and 2 reaches a predetermined value and both level differences become equal values. An intermediate value between the laser power in 1 and the laser power in test recording 2 is calculated, and a value obtained by adding a predetermined value to this intermediate value is used as the laser power for actual recording. Without calculating such an intermediate value, A value obtained by adding a predetermined value to either one of the laser power in the test recording 1 and the laser power in the test recording 2 at that time may be used as the laser power used for actual recording.

  In the above embodiment, the mini-disk is exemplified as the magneto-optical disk, but the present invention is not limited to the mini-disk and can be widely applied to all magneto-optical disks.

1 is a block diagram showing a configuration of a magneto-optical disk device according to an embodiment of the present invention. It is a figure explaining the principle of this invention. It is the flowchart which showed the procedure of laser power determination. It is a figure which shows the relationship between the laser power used for recording, and ambient environment temperature. It is a figure which shows typically the recording area of a magneto-optical disc. It is a figure which shows RF signal when a test recording part is read back. It is a figure which shows the relationship between the level difference of the peak / bottom value of RF signal, and laser power. It is a figure which shows the relationship between an error rate and laser power. It is a figure explaining the conventional problem.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magneto-optical disk apparatus 2 Optical pick-up 5 Magneto-optical disk 8 System controller 9 RF amplifier 10 Encoder / decoder 13 Magnetic head 14 Head driver 15 Peak / bottom hold circuit y Level difference m Laser power margin

Claims (4)

A magneto-optical disk device that records and reproduces information by irradiating a recording surface of a magneto-optical disk with a light beam of a predetermined intensity,
First test means for performing first test recording at a predetermined laser power value in a power calibration area of the magneto-optical disk;
First detection means for detecting a peak value and a bottom value of a reproduction RF signal when a recorded portion recorded in the first test recording is read back;
Second test means for performing second test recording with a laser power value different from that during test recording by the first test means;
Second detection means for detecting a peak value and a bottom value of the reproduction RF signal when the recorded portion recorded by the second test means is read back;
Referring to the peak value and the bottom value of the reproduced RF signals respectively detected by said first and second detection means, a peak of the first test recording and the second respectively of the reproduced RF signal based on the test recording Determining means for determining whether or not each level difference between the value and the bottom value is equal to or greater than a predetermined value, and whether each level difference is equivalent;
In a magneto-optical disk apparatus comprising: a determination unit that determines a laser power value for actual recording based on a determination result of the determination unit;
The determining means includes
After the first and second test recording is executed for the first time, each level difference at both higher than a predetermined value by the determination unit, and, if the respective level difference is not determined to be equal, Until the determination is made, the first and second test recordings are repeated while increasing the laser power value , and it is determined that each level difference is equal to or greater than a predetermined value and each level difference is equal . When the first and second test recordings are performed, a value obtained by adding a predetermined value to an intermediate power value of each laser power value or one of the laser power values is used for actual recording. First determining means for determining
After the first and second test recording is executed for the first time, each level difference at both higher than a predetermined value by the determination unit, and, if the respective level difference is determined to be equivalent, high temperature A laser power value slightly lower than the laser power value that is predicted to sometimes reach the Curie point of the disk magnetic layer is set as the initial power value, and the initial power value and the power value different from the initial power value are The first and second test recordings are restarted , and while the laser power value is increased until the determination means determines that the level differences are both equal to or greater than a predetermined value and the level differences are equal, first and repeating the second test recording, in each level difference are both higher than a predetermined value, and said first and second when the respective level difference is determined to be equal to A second determining means for determining a laser power value for the actual recording a value obtained by adding a predetermined value on either one of the laser power value of the intermediate power values or the respective laser power value of the laser power value at the time of strike recording ,
A magneto-optical disk apparatus comprising: Performing a first test recording and the second test recording at different laser power value in the power calibration area of the optical disk, the peak value of the reproduced RF signal of the recording portion upon read back, respectively, in each test recording and In a magneto-optical disk apparatus that detects a bottom value and determines a laser power value for actual recording by referring to each level difference between each peak value and bottom value.
After the first and second test recording is executed for the first time, when said each level difference are both higher than a predetermined value, and the level difference is not determined to be equivalent, until the judgment is , while increasing the laser power repeat the first and second test recording, in each level difference are both higher than a predetermined value, and said first and when the respective level difference is the determination to be equivalent to First determination means for determining a laser power value for actual recording based on an intermediate power value of each laser power value at the time of the second test recording or a laser power value of each of the laser power values ;
After the first and second test recordings are executed for the first time, when it is determined that the level differences are both equal to or greater than a predetermined value and the level differences are equal, the first and second test recordings are performed. A laser power value smaller than the laser power value at the time of the test recording is set as an initial power value, and the first and second test recordings are restarted at a power value different from the initial power value and the initial power value, respectively . , in each level difference are both higher than a predetermined value, and, until the respective level difference is determined to be equal, while increasing the laser power repeat the first and second test recording, each level difference both the above predetermined value, and, what the intermediate value or the respective laser power value of each of the first and second laser power value for test recording when the respective level difference is determined to be equal to One second determining means for determining a laser power value of the actual recording on the basis of the laser power value or,
A magneto-optical disk apparatus comprising: The magneto-optical disk apparatus according to claim 2, wherein
2. The magneto-optical disk apparatus according to claim 1, wherein the initial power value is a laser power value slightly lower than a laser power value predicted that the disk magnetic layer can reach the Curie point at a high temperature. In a magneto-optical recording power determination method for determining a laser power value at the time of recording on a recording surface of a magneto-optical disk,
Performing a first test recording at a predetermined laser power value in a power calibration area of the magneto-optical disk;
Detecting a peak value and a bottom value of a reproduction RF signal when a recorded portion in the first test recording is read back;
Performing a second test recording with a different laser power value is the laser power value in the first test recording,
Detecting a peak value and a bottom value of a reproduction RF signal when a recorded portion in the second test recording is read back;
Refer to the respective peak values and bottom values of the detected respective reproduced RF signals, each level difference between the peak value and the bottom value of the first test recording and the second respectively of the reproduced RF signal based on the test recording is Determining whether both are equal to or greater than a predetermined value and the respective level differences are equal; and
After the first and second test recording is executed for the first time, if the each level difference are both higher than a predetermined value, and the respective level difference is not determined to be equivalent, is the the determination up, while increasing the laser power repeat the first and second test recording, in each level difference are both higher than a predetermined value, and wherein the first and second when the level difference is determined to be equal to Determining a value obtained by adding a predetermined value to an intermediate power value of each laser power value at the time of test recording or a laser power value of any one of the laser power values; and a laser power value for actual recording;
After the first and second test recording is executed for the first time, when said each level difference are both higher than a predetermined value, and the level difference is determined to be equivalent, Curie disk magnetic layer at high temperatures Setting a laser power value slightly lower than the laser power value predicted to be able to reach the point as an initial power value;
The first and second test recordings are restarted at power values different from the initial power value and the initial power value, respectively , and it is determined that the level differences are both equal to or greater than a predetermined value and the level differences are equal. The first and second test recordings are repeated while increasing the laser power value until each level difference is equal to or greater than a predetermined value and each level difference is determined to be equal until A value obtained by adding a predetermined value to an intermediate power value of each laser power value at the time of the first and second test recording or a laser power value of each of the laser power values is determined as a laser power value for actual recording. Steps,
And a magneto-optical recording power determination method.

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