JP2001338422A - Optical disk device and its recording power deciding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk device and its recording power deciding method capable of obtaining the suitable power even though a fingerprint is stuck to a track whereon the trial recording is performed, when the laser power suitable for the data recording is decided by the trial recording operation performed prior to the recording of user's data. SOLUTION: The BER(byte error rate) is detected for every recorded sector, and when the detected BER becomes the prescribed threshold or lower, this sector is defined as the OK sector, and when it becomes the threshold or higher, this sector is defined as the NG sector. The power is gradually reduced from the peak power such that not less than half of the sectors among the reproduced plural sectors become the OK sectors, and the recording power such that not less than half of the sectors become the NG sectors, is detected, then the suitable peak power is decided on the basis of the detected recorded power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device, and more particularly to a recording power setting technique suitable for data recording in an optical disk device that records information by irradiating an optical disk medium with a laser beam.

[0002]

2. Description of the Related Art In recent years, optical disk apparatuses have been actively developed as means for recording and reproducing large-capacity data, and approaches for achieving higher recording densities have been made. There is a phase-change type optical disk device using a reversible state change between a crystal and an amorphous.

In a phase-change type optical disk apparatus, a semiconductor laser is irradiated on an optical disk medium with two powers, a peak power for amorphizing a crystal part and a bias power for crystallizing an amorphous part, thereby forming a mark on the optical disk medium. (Amorphous portion) and a space (crystal portion) between the marks are formed.

[0004] Since the reflectivity differs between a mark and a space, a recorded signal is read out by utilizing the difference in reflectivity during reproduction.

FIG. 10 shows a configuration of a conventional phase change type optical disk apparatus. In FIG. 10, the optical disc device includes an optical head 1002, a reproducing unit 1003, a reproduced signal quality detecting unit 1004, and an optimum recording power determining unit 100.
5, a recording unit 1006, a laser driving circuit 1007, and a recording power setting unit 1008.

FIG. 11 shows an optical disk 100 according to a conventional example.
1 shows a track configuration diagram. The optical disc 1001 has recording areas on both groove-shaped tracks (groove tracks 1101) and tracks between grooves (land tracks 1102), and the groove tracks and land tracks alternate every other turn to be connected in a continuous spiral. Optical disk.

The optical disk device performs test recording in a predetermined area of the optical disk 1001 when the optical disk 1001 is newly mounted on the optical disk device,
The optimum value of the laser power applied to the disk 1001 for data recording is set.

For this reason, when the optical disk 1001 is mounted on the optical disk device, the optical head 1002 moves to an area for setting the optimum irradiation power after predetermined operations such as disc type identification and rotation control are completed.

In the phase change type optical disk device, the power to be determined includes a peak power and a bias power.
Here, a method of determining the peak power will be described.

First, the recording power setting means 1008
The initial values of the peak power and the bias power are set in the laser drive circuit 1007. At this time, the power for recording the land track is equal to the power for recording the groove track.

Subsequently, a signal for recording one round of the land track and one round of the groove track from a predetermined position is sent from the recording means 1006 to the laser drive circuit 1007 and recorded by the optical head 1002. At this time, the optical head 1
The output light of the semiconductor laser, which is a component of 002, is converged as a light spot on the optical disc 1001, and a recording mark corresponding to the emission waveform is formed.

When the recording of the land track and the groove track is completed, the semiconductor laser of the optical head 1002 emits light at the reproduction power, reproduces the track on which recording has been performed, and changes as a reproduction signal depending on the presence or absence of a recording mark on the optical disk 1001. Signal 1009 to be reproduced
Is input to The reproduction signal 1009 is output from the reproduction means 1003
Undergoes reproduction signal processing such as amplification, waveform equalization, and binarization,
The signal 1010 is input to the reproduction signal quality detection means 1004.

The reproduction signal quality detecting means 1004 outputs the signal 10
10 is detected, and the detection result is input to the optimum recording power determining means 1005.

Here, the reproduced signal quality detecting means 1004 detects a BER (byte error rate) when reproducing the recorded signal. The BER detected at this time is the average value of the reproduced tracks. FIG. 12 shows peak power and BER.
Shows the relationship.

In FIG. 12, the horizontal axis is the peak power and the vertical axis is the BER. If the reproduction conditions are equal, generally, the smaller the BER, the more accurate the recording. Therefore, when the BER falls below a certain threshold, the detection result indicates "OK
(Good), and when it exceeds this, the detection result is “NG”.
(Bad) ”.

The optimum recording power determining means 1005 determines the recording power (peak power) according to, for example, a flowchart shown in FIG.

When the optical head moves to the irradiation power setting area on the optical disc 1001 (S101) and the initial value of the recording power is set (S102), data is written to the irradiation power setting area on the optical disc 1001 by the recording power. The data is recorded, and the recorded data is reproduced (S103). The quality of the reproduced signal is detected by detecting the BER of the reproduced signal (S104). From the detection result at that time and the previous detection result, the reproduction signal quality is changed from “OK” to “N”.
G ”or two peak powers at the time of switching from“ NG ”to“ OK ”(S104 to S10).
8). When those two peak powers are obtained, the values of those powers are averaged (S109), and the value obtained by adding a predetermined margin is set as the optimum peak power (S110).

For example, if the first result by the reproduction signal quality detection means 1004 is "NG", a peak power larger than the initial power is set (S108). If the first result is "OK", the peak power is set higher than the initial power. Also, a small peak power is set (S106), and recording and reproduction of the land track and the groove track are performed with the set peak power in the same manner as the previous time.

If the first result of the reproduction signal quality detecting means 1004 is "NG" (S104) and the second result is "OK" (S107), the optimum recording power determining means 1005 outputs the current peak power. Then, the power obtained by adding a certain margin to the average power of the previous peak power is determined as the optimum recording power (S109, S110).

If the reproduction signal quality detection means 1004
If the first result is “OK” (S104) and the second result is “NG” (S105), the optimum recording power determining means 1005 sets a certain margin between the current peak power and the average power of the previous peak power. The added power is determined as the optimum recording power (S109, S110).

[0021]

However, in the above-mentioned prior art, the BER to be detected is the average value of the reproduced track, and therefore, for example, when a fingerprint is attached to the track for detecting the BER, a reproduction error increases. However, the detected BER becomes larger than the original value, and as a result, there is a problem that a power higher than the optimum peak power is set.

In view of the above problems, the present invention provides an optical disc capable of obtaining a recording power suitable for data recording even when a fingerprint is attached to a track on which test recording is performed in order to determine irradiation power during recording. It is an object of the present invention to provide an apparatus and a recording power determining method thereof.

[0023]

SUMMARY OF THE INVENTION A method according to the present invention comprises a plurality of spirally connected tracks.
Each track is a method of determining a recording power, which is a laser output power at the time of data recording, for an optical disk device that records data on an optical disk composed of a plurality of sectors. In the method, a plurality of recording power values are set, predetermined data is recorded in a plurality of sectors within a predetermined area with the recording power of each set value, and data is reproduced from each sector after data recording and each sector is reproduced. Then, the quality of the reproduction signal is detected, and the recording power is determined based on the detection result of the reproduction signal quality obtained for each sector for each set value of the recording power.

In the above method, based on the result of detection of the reproduction signal quality, the recording power of the recording signal when the number of sectors satisfying the predetermined condition or more can be obtained from a plurality of recording power setting values. A setting value may be determined, and the recording power may be determined based on the determined recording power setting value.

Further, a first set value which is a set value of the recording power when a predetermined number or more of the sectors satisfying the predetermined condition of the reproduction signal quality is obtained, and a predetermined number of the sectors satisfying the predetermined condition of the reproduction signal quality. A second set value which is a set value of the recording power when the above cannot be obtained may be obtained, and the recording power may be determined based on the first and second set values.

As the reproduction signal quality, an error rate or jitter of the reproduction signal can be detected.

The detection result of the sector whose reproduction quality satisfies a predetermined defect condition may be excluded from the detection result used for determining the recording power.

When predetermined data is recorded, data different from the previously recorded data may be recorded in each sector.

Further, when recording the predetermined data, the data recorded in each sector may be temporarily erased and then the predetermined data may be recorded in each sector.

An apparatus according to the present invention is an optical disk apparatus for recording data on an optical disk composed of a plurality of sectors, the optical disk apparatus having a plurality of tracks connected in a spirally extending manner. Setting means for setting a plurality of recording power values as output powers; recording means for recording predetermined data in a plurality of sectors within a predetermined area with the recording power of each set value; and reproducing data from each sector after data recording. Detecting means for detecting the quality of the reproduction signal for each sector, and determining means for determining the recording power based on the detection result of the reproduction signal quality obtained for each sector for each set value of the recording power And

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical disk device according to the present invention will be described below with reference to the drawings.

(Configuration of Optical Disk Apparatus) FIG. 1 shows a configuration of a phase change type optical disk apparatus according to an embodiment of the present invention. The optical disk device is a device for recording and reproducing data on and from the optical disk 101. As shown in FIG. 1, an optical head 102, a reproducing unit 103, a reproduced signal quality detecting unit 104, an optimum recording power determining unit 105, a recording Means 106, a laser drive circuit 107 and a recording power setting means 108.

FIG. 2 shows a track configuration diagram of the optical disk 101 on which the optical disk device records and reproduces data.
The optical disc 101 has recording areas on both groove-shaped tracks (groove tracks 201) and tracks between grooves (land tracks 202), and the groove tracks and land tracks alternate every other turn to be connected in a continuous spiral. Optical disk.

(Operation of Optical Disk Apparatus) When the optical disk 101 is newly mounted on the optical disk apparatus, the optical disk apparatus performs test recording on a predetermined area of the optical disk 101, thereby recording data on the disk 101. To set the optimum value of the laser power to be irradiated.

For this reason, after the optical disc 101 is mounted on the optical disc apparatus and predetermined operations such as disc type identification and rotation control are completed, the optical head 102 sets the optimum recording power in an area (irradiation power setting area). Go to

The above-mentioned area (irradiation power setting area)
This is a recording area provided on the innermost circumference or outermost circumference of the disc other than the user area where the user records data.

The operation for determining the power for recording will now be described. In the phase change optical disk device, the power to be determined includes at least a peak power and a bias power. In the present embodiment, a method for determining the peak power will be described first, and then a method for determining the bias power will be described.

First, the recording power setting means 108
The initial values of the peak power and the bias power are set in the laser drive circuit 107. The recording power setting means 108 can set various values of recording power. At this time, the power for recording the land track is equal to the power for recording the groove track.

Subsequently, a signal for continuously recording one round of the land track and one round of the groove track from a predetermined position is sent from the recording means 106 to the laser drive circuit 107 and recorded by the optical head 102. At this time, the output light of the semiconductor laser, which is a component of the optical head 102, is condensed as a light spot on the optical disk 101, and a recording mark corresponding to the emission waveform is formed.

When the recording is completed, the semiconductor laser of the optical head 102 emits light at the reproducing power, reproduces the track on which the recording has been performed, and a signal 109 that changes depending on the presence or absence of a recording mark on the optical disk 101 is a reproducing signal. 103 is input. The reproduction signal 109 is transmitted to the reproduction unit 103
Undergoes reproduction signal processing such as amplification, waveform equalization, and binarization,
The signal 110 is input to the reproduction signal quality detection means 104.

The reproduction signal quality detecting means 104 outputs the signal 110
Is detected, and the detection result is input to the optimum recording power determining means 105. When the number of sectors of the reproduced land track is substantially equal to the number of sectors of the groove track, the reproduction signal quality detection result at this time is an average reproduction signal quality result of both the land and groove tracks.

Here, the reproduction signal quality detecting means 104 detects a BER (byte error rate) when reproducing the recorded signal. FIG. 3 shows the relationship between peak power and BER. In FIG. 3, the horizontal axis is the peak power, and the vertical axis is the BER. If the reproduction conditions are equal, generally, the smaller the BER, the more accurate the recording. Therefore, the BER is detected for each sector, and when the detected BER is equal to or less than a predetermined threshold (hereinafter, referred to as “error number threshold”), the sector is set to “OK sector (good sector)” and the detected BE is detected.
When R is equal to or larger than the error number threshold, the sector is set to “NG”.
Sector (bad sector) ".

(Method of Determining Peak Power) The optimum recording power determining means 105 determines the optimum recording power according to, for example, a flowchart shown in FIG.

The optical head 102 moves to the irradiation power setting area on the optical disc 101 (S11), and after the initial value of the recording power is set (S12), the recording power is used in the irradiation power setting area on the optical disc 101. Data is recorded in a plurality of sectors, and subsequently, recorded data is reproduced from each sector (S13). By judging the quality of the reproduced signal obtained at that time, it is judged whether or not the recording power at that time is sufficient power for data recording. By gradually changing the recording power, searching for the boundary between sufficient recording power and insufficient recording power for data recording,
Two recording powers that cross the boundary are obtained (S14).
To S18). When the recording power at these boundaries is determined, these values are averaged (S19), and a margin is added by multiplying the average value by a fixed ratio (S2).
0), the optimum recording power.

Here, the determination as to whether or not the recording power is a sufficient value for data recording is performed as follows. That is, for one recording power, the BER of the reproduction signal is detected for each sector, the sector whose BER is equal to or more than a predetermined value (error number threshold) is determined as an NG sector, and the number of NG sectors is counted. When the number of NG sectors is equal to or more than a threshold value (hereinafter referred to as “sector threshold value”), it is determined that the recording power is insufficient for data recording, and is sufficient when the number is less than the sector threshold value. In the following description, the sector threshold is set to a half of the total number of sectors for performing test recording. That is, conventionally, whether or not the laser output power for test recording is sufficient is determined based on the BER in track units. In the present embodiment, however, the BER is detected for each of a plurality of sectors. O for each sector
It is determined whether K (good) or NG (bad). When the number of NG sectors is equal to or more than a predetermined number (sector threshold), it is determined that the recording power at that time is insufficient power, and When the number is less than the number (sector threshold), it is determined that the recording power at that time is sufficient.

For example, as a result of the first detection by the reproduction signal quality detecting means 104, if a sector that is half or more of the total number of sectors in the irradiation power setting area is an NG sector (S
(YES in 14), a peak power larger than the initial power is set (S18), and if more than half the sectors are OK sectors (NO in S14), a peak power smaller than the initial power is set (S16). The recording and reproduction of the land track and the groove track are performed in the same manner as the previous time with the set peak power (S13).

If more than half of the sectors are OK sectors in the second result of the reproduction signal quality detection means 104 (NO in S14), and if more than half sectors are NG sectors in the first result (YES in S15). ), The optimum recording power determining means 105 determines the power obtained by adding a certain margin to the average power of the first peak power and the second peak power (S19, S19).
20).

If more than half of the sectors in the second result of the reproduction signal quality detecting means 104 are NG sectors (YES in S14), and if more than half of the sectors are OK sectors in the first result (YES in S17). ), The optimum recording power determining means 105 determines that the first peak power is
The power obtained by adding a certain margin to the average power of the second peak power is determined as the optimum recording power (S19,
S20).

If more than half of the sectors are OK sectors in the second result of the reproduction signal quality detecting means 104 (NO in S14), and if more than half sectors are OK sectors in the first result (S15). NO), a power smaller than the peak power recorded for the second time is set (S16), recording and reproduction are performed with this peak power, and the reproduction signal quality is detected (S13). If the half or more sectors in the third result of the reproduction signal quality detecting means 104 are NG sectors (YES in S14), the optimum recording power determining means 105 determines the average power of the second peak power and the third peak power. Is determined as the optimum recording power by adding a certain margin to the recording power (S1).
9, S20).

With reference to FIG. 5, a description will be given of a method of obtaining the boundary recording power for setting the optimum recording power.

FIG. 5 is a diagram showing a table showing a list of results when recording is performed on eight sectors while changing the set value of the recording power and the number of errors (BER) of the reproduced signal is measured. . In FIG. 5, (a) shows the result when no fingerprint is attached on the surface of all sectors, (b) shows the result when a fingerprint is attached to sector 0, and (c) shows the result when sector 0 and sector 1 are attached. This is the result when a fingerprint is attached to the. Here, the threshold of the number of errors for the track in the conventional method is set to 80, and the threshold of the number of errors for each sector in the method of the present embodiment is the error number threshold (80) for the entire track by the number of reproduction sectors (8). It is set to the value (10) divided.

At the right end of the table, the number of errors (BER)
Value) and the number of NG sectors. The number of errors is the sum of errors at each set power. The number of NG sectors is the total of NG sectors when the error number threshold value of each sector is set to 10. In the conventional method of obtaining the BER in track units, a total error in each set power is obtained. For this reason,
The number of errors increases as the set power decreases in the order of P0, P1, P2,. For example, in the example of FIG. 5A, in the conventional method (for example, the error number threshold is set to 80), P3 and P3 are set as powers around the error number threshold (80).
4 (indicated by *) is detected, and the optimum recording power is determined based on these recording power values. On the other hand, in the method according to the present embodiment, the number of NG sectors is compared with the error number threshold (10) for each sector, and the number of NG sectors is determined as the sector threshold (4 = 8 ÷ 2).
P3 and P4 as power before and after exceeding (indicated by *)
Is detected, and the optimum recording power is determined based on these recording power values.

Here, in FIG. 5A, the recording powers set in the conventional method and the method of the present embodiment are equal. That is, a value obtained by dividing the error number threshold value (80) in the conventional example by the sector number (8) is used as the error number threshold value (10) of each sector in the present embodiment, and further, half (4) of the total number of sectors
Is detecting the power that becomes the NG sector. That is, the number of errors in each sector is near a value obtained by dividing the error number threshold of the conventional example by the number of sectors near the recording power to be detected, and it is considered that about half of all sectors exceed the error number threshold. Because.

FIG. 5 when a fingerprint is attached to sector 0
In (b), the number of errors is increased by the sector 0, so in the conventional method, the powers before and after the error number are around the threshold value (80) are P2 and P3, and when the fingerprint is not attached ((a) in FIG. ), A higher recording power is set. On the other hand, in the method of the present embodiment, the same recording power is set as when no fingerprint is attached.
In addition, in FIG. 5C in which a fingerprint is attached to sector 0 and sector 1, the number of errors is increased by sector 0 and sector 1, so that the error number is set to a threshold value (8
The powers before and after 0) are P1 and P2, and a higher recording power is set than when the fingerprint is attached to only sector 0 (case (b)). On the other hand, in the method of the present embodiment, the same recording power is set as when no fingerprint is attached (case (a)).

That is, in the conventional method, since the total number of errors per track is considered, the larger the number of errors due to the attachment of the fingerprint, the more the deviation of the set recording power from the original set value. Becomes larger. On the other hand, in this embodiment, "NG" or "OK"
5B, for example, in FIG. 5B, three of the seven sectors excluding sector 0 are set to “N” due to the recording characteristics.
G "is required.
In FIG. 5C, since two sectors out of the six sectors excluding the sector 0 and the sector 1 require the recording power of “NG” due to the recording characteristics, the fingerprint is substantially attached. This is equivalent to excluding the sector, and the influence of the fingerprint can be limited. Although the number of sectors to be reproduced has been described as eight in FIG. 5, the influence of the fingerprint and the like is small as the number of sectors is large. For example, when the number of sectors is 16 or more, the set recording power is almost influenced by the fingerprint. Absent.

As described above, when test recording is performed on a plurality of sectors before recording user data, the reproduction signal quality is detected for each recorded sector, and the number of errors (BER) indicating the reproduction signal quality is set to the threshold value. When the following,
When the number of sectors is equal to or larger than the threshold value, the sector is determined to be NG.
Sector. Then, the recording power at the boundary where the number of NG sectors changes from the predetermined number or more to less than the predetermined number, or the number of OK sectors changes from the predetermined number or more to the predetermined number or less is found. Is determined when recording is performed. As a result, even if a fingerprint or a scratch is attached to the track area where the test recording is performed, the optimum power can be obtained.

It should be noted that, based on the detection result of the number of errors (BER) for each sector, a sector that is considered to be particularly bad in a bad state as compared with other sectors is not suitable for use in determining the recording power. Therefore, it may be excluded from the NG sector in advance.

For example, when the number of errors (BER) for each sector is detected, when there is a sector having a predetermined number of errors (for example, 30) or more compared to the number of errors of the sector having the minimum number of errors. May exclude the number of sectors from the number of NG sectors. At this time, the sector number threshold value is set to a value obtained by subtracting the number of excluded sectors from the total number of reproduced sectors and dividing it by two. A sector having a relatively large number of errors is considered to have a fingerprint or the like attached thereto, and is unsuitable for use in determining the recording power. Therefore, by excluding this sector, the recording power can be obtained more accurately.

For example, in FIG. 5C, the sector 0 and the sector 1 have 30 errors more than the other sectors with respect to the power of P0. 3 obtained by dividing 6 sectors obtained by subtracting 2 by 2 is set as the sector number threshold. Even in this case, P3 and P4 are detected as boundary powers for obtaining the optimum recording power, as in FIG. 5A.

When the BER of each sector is detected while changing the recording power, if there is a sector having the maximum number of errors for a predetermined number of times (for example, two times or more), the sector is excluded from the NG sector. You may. At this time, a value obtained by subtracting the number of sectors obtained by subtracting the number of removed sectors from the number of reproduced sectors by two is set as a sector number threshold. This also makes it possible to more accurately determine the recording power.

For example, in FIG. 5B, P0 and P1
Sector 0 has more errors than other sectors with the power of
A value obtained by dividing 7 sectors by subtracting 2 by 2, that is, 3.5 is set as the sector number threshold value. Even in this case, P3 and P4 are detected as boundary powers for obtaining the optimum recording power, as in FIG. 5A.

Similarly, when the BER of each sector is detected while changing the recording power, the sectors that have a predetermined number of times (for example, two times or more) and a predetermined order or less (assuming that they are arranged in order from the sector with the smallest number of errors). May be excluded from the number of NG sectors.

For example, in FIG. 5C, P0 and P1
Since sector 0 and sector 1 are the lowest in the number of errors at power of 3, this sector is excluded from the NG sector, and a value obtained by dividing 2 sectors by 8 sectors minus 2 sectors by 2 is 3
Is the sector number threshold. Even in this case, FIG.
Similarly, P3 and P4 are detected as boundary powers for obtaining the optimum recording power.

In the present embodiment, the sector number threshold is set to half of the number of reproduced sectors. However, if the correct recording power can be obtained without the influence of fingerprints or the like, the sector number threshold is set by another method. You can decide.

In the above description, the threshold value of the number of errors for each sector is set to a value obtained by dividing the threshold value of the number of errors for the entire track by the number of reproducing sectors. However, the correct recording power can be obtained excluding the influence of fingerprints and the like. If
The error number threshold of each sector may be determined by another method.

(Method of Determining Bias Power) Next, a method of determining bias power will be described. As for the bias power, the margin of the power capable of recording user data is narrower than the peak power. For example, even if the peak power margin is about 9 mW to 15 mW and about 6 mW, the bias power margin is only about 3 mW to 6 mW and about 3 mW. .

Therefore, in the present embodiment, in order to obtain the optimum value of the bias power, the lower limit and the upper limit of the bias power in which the user data can be recorded are obtained, and then the lower limit and the upper limit are calculated by calculation. Find some optimal value.

First, the recording power setting means 108 sets initial values of the peak power and the bias power in the laser drive circuit 107, for example, to obtain the lower limit of the bias power. At this time, the power for recording the land track is equal to the power for recording the groove track.

Subsequently, the recording means 106 reads the optical disk 1
A signal for continuously recording one round of the land track and one round of the groove track from a predetermined position on the optical disc 01 is sent to the laser drive circuit 107, and data is recorded on the optical disc 101 by the optical head 102. At this time, the optical head 1
The output light of the semiconductor laser, which is a component of No. 02, is converged as a light spot on the optical disc 101, and a recording mark corresponding to the emission waveform is formed on the optical disc 101.

When the recording is completed, the semiconductor laser of the optical head 102 emits light at the reproducing power, reproduces the track on which recording has been performed, and a signal (reproduced signal) that changes depending on the presence or absence of a recording mark on the optical disc 101 as a reproduced signal. 10
9 is input to the reproducing means 103. The reproduction signal 109 is subjected to reproduction signal processing such as amplification, waveform equalization, and binarization by the reproduction means 103, and the signal 110 is converted to the reproduction signal quality detection means 104.
Is input to

Here, the reproduction signal quality detecting means 104 detects a BER (byte error rate) when reproducing the recorded signal. FIG. 6 shows a relationship between bias power and BER in a certain sector. In FIG. 6, the horizontal axis is the bias power, and the vertical axis is the BER. If the reproduction conditions are equal, generally, the smaller the BER, the more accurate the recording. Therefore, the BER is detected for each sector, and the detected BER is compared with a predetermined threshold (error number threshold). When the detected BER is equal to or smaller than the error number threshold, the sector is determined to be an OK sector and equal to or larger than the error number threshold. , The sector is regarded as an NG sector.

The optimum recording power determining means 105 determines the optimum bias power according to, for example, a flowchart shown in FIG.

In the flowchart of FIG. 7, the lower limit is obtained in steps S41 to S49, and the upper limit is obtained in steps S50 to S57. The processing for obtaining the upper limit value and the lower limit value in the above steps is basically the same as the processing in the flowchart of FIG. 4 described above.

For example, when obtaining the lower limit value of the bias power, if more than half of the sectors are NG sectors in the first result of the reproduction signal quality detecting means 104 (YES in S44), the bias larger than the initial power is used. The power is set (S48), and if more than half the sectors are OK sectors (NO in S44), a bias power smaller than the initial power is set (S46), and the land track is set to the same bias power as the previous time. Then, recording and reproduction of the groove track are performed (S43).

If more than half of the sectors are OK sectors in the second result of the reproduction signal quality detection means 104 (NO in S44), and if more than half sectors are NG sectors in the first result (YES in S45). The optimum recording power determining means 105 determines the average of the current bias power and the previous bias power as the lower limit (S4).
9).

If more than half of the sectors in the second result of the reproduction signal quality detecting means 104 are NG sectors (YES in S44), and if more than half the sectors are OK sectors in the first result (YES in S47). The optimum recording power determination means 105 determines the average power of the current bias power and the previous bias power as the lower limit (S49).

If more than half of the sectors are OK sectors in the second result of the reproduction signal quality detecting means 104 (NO in S44), and if more than half sectors are OK sectors in the first result (NO in S45). ) A power smaller than the bias power recorded for the second time is set (S46), and recording and reproduction are performed with this bias power, and the reproduction signal quality is detected (S43). If the half or more sectors are NG sectors in the third result of the reproduction signal quality detection unit 104 (YES in S44), the optimum recording power determination unit 105 sets the average power of the current power and the previous power to the lower limit value. It is determined (S49).

Similarly, the upper limit value is obtained (S50 to S50).
57), the optimum recording power determining means 105 determines, for example, the average value of the lower limit value and the upper limit value as the optimum bias power (S58).

In determining the bias power, test recording is performed on a plurality of sectors, the quality of the reproduced signal is detected for each of the recorded sectors, and when the number of errors is equal to or less than the error number threshold, the sector is determined as an OK sector. When the number of thresholds is equal to or more than the threshold value, the sector is regarded as an NG sector, and a recording power at a boundary where a predetermined number or more of the sectors change from an NG sector to an OK sector or from an OK sector to an NG sector is found. By determining the recording power at the time of actually recording data by using, the optimum power can be obtained even if a fingerprint or a scratch is attached to a track on which test recording is performed.

When obtaining the lower limit and the upper limit, the initial value of the bias power for obtaining the upper limit is made larger than the initial value of the bias power for obtaining the lower limit. By starting from a value close to each limit with a difference, the bias power can be optimized in a shorter time.

In this embodiment, the average value of the lower limit value and the upper limit value is determined as the optimum bias power. However, the optimum bias power is set at the place where the user data is actually recorded due to, for example, warpage of the disk. If the effective power may be very small with respect to the power, for example, a value that internally divides the lower limit and the upper limit into 2: 1 may be set as the optimum power. By setting a value obtained by internally dividing the lower limit and the upper limit into 2: 1 as the optimum power, the margin on the low power side is increased.

(Other Possible Modes) In the present embodiment, the reproduction signal quality detecting means 104 detects the BER (byte error rate) when reproducing the recorded signal. If the error that occurs is not counted as an error, even if there is a locally defective recording area such as a scratch, it can be removed, and the optimum power can be determined more accurately.

In the present embodiment, the reproduced signal quality detecting means 104 detects the BER when reproducing the recorded signal. However, if the reproduced signal quality can be detected other than the BER, the bit error rate and the jitter can be detected. And so on.

For example, a case where a jitter is detected as a reproduced signal quality will be described. FIG. 8 shows the relationship between peak power and jitter. In FIG. 8, the horizontal axis is the peak power, and the vertical axis is the jitter. FIG. 9 shows the relationship between the bias power and the jitter. In FIG. 9, the horizontal axis is the bias power, and the vertical axis is the jitter. Jitter is a time lag between the reproduced signal and the original signal. The jitter occurs due to a decrease in the amplitude of the reproduced signal due to insufficient laser beam irradiation power, and decreases when the amplitude of the reproduced signal increases. When saturated, the amount of jitter becomes almost constant. That is, if the reproduction conditions are equal, generally, the smaller the jitter, the more accurate the recording. Therefore, when the jitter of a certain sector is less than the threshold value, the sector is determined to be an OK sector, and when the jitter is equal to or greater than the threshold value, the sector is determined to be an NG sector.

In this embodiment, the continuous recording and the continuous reproduction are performed with one round of the land track and one round of the groove track. However, in an optical disc apparatus that performs recording in block units, recording in block units may be used. .

Similarly, in the present embodiment, one round of land track and one round of groove track are used as the section for continuous recording and continuous reproduction. However, in an optical disc apparatus that performs recording in sector units, recording in sector units may be used.

Further, in this embodiment, one land track and one groove track are used as continuous recording and continuous reproduction sections. However, recording and reproduction are performed for two or more land tracks and two or more groove tracks. It doesn't matter. By performing recording and reproduction on two or more tracks of both tracks, variations in tracks can be absorbed and the optimum power can be determined more accurately.

Similarly, even when recording is performed in block units, recording and reproduction of two or more blocks of land tracks and two or more blocks of groove tracks may be performed. By performing recording and reproduction of two or more blocks on both tracks, variations between blocks can be absorbed and the optimum power can be determined more accurately.

Further, when performing continuous recording and continuous reproduction of two or more blocks, if the value of the worst block as a result of the reproduction signal quality detection means 104 is not adopted, even if there is a block having a recording defect such as a scratch, Blocks can be eliminated, and the optimum power can be determined more accurately.

Before recording for detecting the quality of the reproduced signal, a signal having a different pattern from the recording signal used for the recording may be recorded. By recording a signal of a different pattern, the component of the previously recorded signal remaining in the recording area is reduced, for example, recording is performed at a lower power than the previous recording. Is not reproduced, and power optimization can be performed more accurately.

Before each continuous recording for detecting the quality of the reproduced signal, the recording may be performed in an area where the continuous recording is performed by using only the bias power. By performing recording using only the bias power, the component of the previously recorded signal remaining in the area is reduced (that is, erased). Thus, the previously recorded signal is not reproduced, and the power can be optimized more accurately.

Further, the reproduction signal quality detecting means 104 of the present embodiment makes the judgment for each sector without discriminating between the land track and the groove track. May be determined. By distinguishing between the land track and the groove track, when the recording characteristics of the two tracks are different, it is possible to determine the recording power suitable for each.

Further, by reproducing the land track and the groove track separately, after the recording power of one track is determined, it is not necessary to reproduce the other track.
Time for determining the recording power can be saved.

The recording power setting means 108 of this embodiment sets the recording power without distinguishing between land tracks and groove tracks.
The recording power may be set for each groove track. By distinguishing the land track and the groove track, when the recording characteristics of both tracks are different, the recording power suitable for each is set as the initial set power, thereby reducing the number of times of setting the recording power, After the recording power of one track is determined, it is not necessary to record the other track, so that time for determining the recording power can be saved and deterioration due to repeated recording can be reduced.

Further, in the present embodiment, an optical disk capable of recording on both land tracks and groove tracks has been described, but the same applies to an optical disk on which only one track is recorded.

[0096]

As described above, the optical disc apparatus of the present embodiment performs test recording on a plurality of sectors before recording user data, detects the reproduction signal quality for each recorded sector, and sets a certain threshold. On the other hand, if it is less than this, the sector is regarded as an OK sector, and if it is more than a certain threshold, the sector is regarded as an NG sector. At this time, the recording power at the boundary where the number of NG sectors changes from the predetermined number or more to less than the predetermined number, or the number of NG sectors changes from less than the predetermined number to the predetermined number or more is found, and recording of this boundary is performed. By determining the recording power at the time of actually recording data using the power, it is possible to accurately determine a recording power suitable for data recording even when a fingerprint is attached to a track on which test recording is performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of an optical disk device according to the present invention.

FIG. 2 is a diagram showing a track configuration of an optical disk used in the optical disk device according to the present invention.

FIG. 3 is a view for explaining the relationship between peak power and BER (byte error rate).

FIG. 4 is a flowchart showing a method of determining a peak power in the optical disc device according to the present invention.

FIG. 5 is a view for explaining a method of determining recording power at two boundaries used for determining an optimum recording power.

FIG. 6 is a view for explaining the relationship between bias power and BER.

FIG. 7 is a flowchart showing a method for determining a bias power in the optical disc device according to the present invention.

FIG. 8 is a view for explaining the relationship between peak power and jitter.

FIG. 9 is a view for explaining the relationship between bias power and jitter.

FIG. 10 is a block diagram of an optical disk device according to the related art.

FIG. 11 is a diagram showing a track configuration of an optical disc.

FIG. 12 is a view for explaining the relationship between peak power and BER.

FIG. 13 is a flowchart showing a method for determining the recording power of an optical disk device according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Optical disk 102 Optical head 103 Reproduction means 104 Reproduction signal quality detection means 105 Optimal recording power determination means 106 Recording means 107 Laser drive circuit 108 Recording power setting means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Ishida 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Toshiya Akagi 1006 Kadoma, Kazuma, Osaka Pref.F-term in Matsushita Electric Industrial Co., Ltd. (Reference)

Claims (14)

[Claims] 1. A recording power which is a laser output power at the time of data recording of an optical disk apparatus for recording data on an optical disk composed of a plurality of sectors. A method of setting a plurality of recording power values, recording predetermined data in a plurality of sectors in a predetermined area with the recording power of each set value, reproducing data from each sector after data recording, and An optical disc apparatus for detecting the quality of a reproduction signal for each sector and determining the recording power based on the detection result of the reproduction signal quality obtained for each sector for each set value of the recording power Recording power determination method. 2. On the basis of the result of detection of the reproduction signal quality,
From among a plurality of recording power setting values, a recording power setting value at which a predetermined number or more sectors satisfying a predetermined condition of the reproduction signal quality is obtained, and based on the obtained recording power setting value, 2. The method according to claim 1, wherein the recording power is determined. 3. A first set value which is a set value of recording power when a predetermined number or more of sectors satisfying a predetermined condition of reproduction signal quality are obtained, and a predetermined number of sectors satisfying a predetermined condition of reproduction signal quality are provided. 3. The recording power according to claim 2, wherein a second set value which is a set value of the recording power when the above is not obtained is obtained, and the recording power is determined based on the first and second set values. A recording power determination method for an optical disk device. 4. The recording power determination method for an optical disk device according to claim 1, wherein an error rate or jitter of the reproduced signal is detected as the reproduced signal quality. 5. The recording power determination of an optical disk device according to claim 1, wherein a detection result of a sector whose reproduction quality satisfies a predetermined defect condition is excluded from a detection result used for determining said recording power. Method. 6. The recording power determining method for an optical disk device according to claim 1, wherein, when said predetermined data is recorded, data different from previously recorded data is recorded in each sector. 7. The method according to claim 1, wherein when recording the predetermined data, the data recorded in each sector is temporarily erased and then the predetermined data is recorded in each sector.
The recording power determination method for an optical disk device as described in the above. 8. An optical disc apparatus for recording data on an optical disc composed of a plurality of sectors, having a plurality of tracks connected in a spiral manner, wherein each track is a laser output power at the time of data recording. Setting means for setting a plurality of power values; recording means for recording predetermined data in a plurality of sectors within a predetermined area at a recording power of each set value; Detecting means for detecting the quality of the reproduction signal, and determining means for determining the recording power based on the detection result of the reproduction signal quality obtained for each set value for each set value of the recording power. An optical disc device characterized by the above-mentioned. 9. The method according to claim 1, wherein the determining unit determines, based on the detection result of the reproduction signal quality, a setting value of a plurality of recording powers.
A method for determining a recording power set value when a predetermined number or more of sectors satisfying a predetermined condition of a reproduction signal quality is obtained, and determining the recording power based on the obtained recording power set value. Item 10. An optical disk device according to item 8. 10. The method according to claim 1, wherein the determining unit determines a first set value that is a set value of recording power when a predetermined number or more sectors satisfying a predetermined condition of the reproduction signal quality are obtained, and a predetermined condition that the reproduction signal quality is a predetermined condition. A second setting value that is a setting value of the recording power when a predetermined number of sectors to be satisfied are not obtained, and the recording power is determined based on the first and second setting values. The optical disk device according to claim 9. 11. The optical disk apparatus according to claim 8, wherein said detecting means detects an error rate or a jitter of the reproduction signal as the reproduction signal quality. 12. The optical disk according to claim 8, wherein the determination unit excludes a detection result of a sector whose reproduction quality satisfies a predetermined defect condition from a detection result used for determining the recording power. apparatus. 13. The optical disk apparatus according to claim 8, wherein said recording means records data different from previously recorded data in each sector when said predetermined data is recorded. 14. The recording device according to claim 8, wherein when recording the predetermined data, the data recorded in each sector is temporarily erased and then the predetermined data is recorded in each sector. An optical disk device as described in the above.