JP3791460B2 - Recording laser power control method and recording laser power control apparatus - Google Patents

Description

[0001]
[Industrial application fields]
The present invention is a digital versatile disc (hereinafter referred to as DVD) that can be recorded by controlling recording power and erasing power with an organic dye medium such as DVD-R, DVD-RW, DVD + RW, DVR blue, or a phase change medium. The present invention relates to a method for controlling a recording laser power value applied to an optical disc, and a recording laser power control apparatus.
[0002]
[Prior art]
Currently, there are known apparatuses that perform recording and reproduction on organic dye media and phase change media such as CD-RW, DVD-R, DVD-RW, DVD + RW, and DVR blue. In such an apparatus, the quality of recording depends on the physical characteristics, optical characteristics of the phase change medium, the pickup for recording to be used, the laser wavelength, and the like, so it is necessary to control the recording laser power value to an optimum value. . For this purpose, it is necessary to know whether the power set by the apparatus is the power actually emitted, that is, the current actual power.
[0003]
A conventional calibration method for finding an optimum power in an organic dye medium or a phase change medium is described in, for example, a patent publication (Japanese Patent No. 3159454) and a prior application (specifications and drawings of Japanese Patent Application No. 2001-250150). Has been. Here, the recording signal c shown in FIG. 4D is applied to the dedicated track 3 provided in the DVD-RW as shown in FIG. Recording is performed while changing the recording signal c every predetermined time (hereinafter referred to as STEP) based on the pre-pit) sync (synchronization signal) a as shown in FIG.
[0004]
A specific example of the recording signal c is shown in FIG. As can be seen from FIG. 1, the recording signal c1 does not use the recording signal c of 8-16 modulation, which is a normal signal recorded on a DVD, but uses only 11T and 3T, 3 times the 11T pulse section, 3T It is formed in a repeating pattern of a total of 132T periods of 10 pulse intervals, 3 again 11 pulse intervals, and 12 3T pulse intervals. as a result,
“H” section of 11T pulse → 11T × 3 = 33T
“L” section of 11T pulse → 11T × 3 = 33T
“H” section of 3T pulse → 3T × 11 = 33T
“L” section of 3T pulse → 3T × 11 = 33T
As described above, the number of times of “H” level and “L” level in each pulse section is the same, in other words, the duty ratio is 50%. T is the channel frequency.
[0005]
Thereafter, the track 2 on the DVD-RW is read and reproduced, and the signal obtained by removing the DC component of the obtained 8-16 modulated RF signal (by the AC coupling capacitor) is the AC coupled reproduction signal g of FIG. The value of the recording laser power b (B4) when the relationship of the center position of the amplitude of the 3T signal (hereinafter referred to as asymmetry) substantially coincides with the center of the amplitude of the 11T signal of the AC coupled reproduction signal g. ) For the optimum recording laser power value. FIG. 6 shows eye patterns of A, B, and C portions in FIG. As can be seen from FIG. 6, the B4 portion can be said to be the optimum power value. In practice, this point is determined based on data such as the coincidence with the minimum jitter point of the reproduction signal.
[0006]
[Problems to be solved by the invention]
  However, in such a medium used as an organic dye or a phase change recording layer, particularly in a phase change medium, the center of the 11T signal amplitude is set.do itThe rate of change of the 3T signal amplitude center position relationship (deviation amount) (hereinafter referred to as asymmetry) with respect to the recording power may depend on the linear velocity, and can be detected when the rate of change is large. There is a problem that detection is difficult depending on the linear velocity.
[0007]
Generally, when a recording device is manufactured and the factory is shipped, the recording laser power is adjusted, so the target power matches the output power, but the temperature changes, changes with time, and adheres to the optical system. Therefore, it is necessary to measure the actual power actually emitted as the first step.
[0008]
Accordingly, it is an object of the present invention to provide a recording laser power control method and a recording laser power control apparatus that obtain an optimum recording laser power value accurately and in a short time.
[0009]
[Means for Solving the Problems]
  In order to solve the above-mentioned problems, the present invention provides a recording laser power control method and a recording laser power control apparatus having the following configuration.
(1) A step of reading a plurality of pieces of linear velocity information from a recordable optical recording medium corresponding to a plurality of linear velocities, and a first linear velocity for recording information among the plurality of read linear velocity information A step of determining
Determining an optimum recording laser power at a second linear velocity with a detection accuracy determined based on a detection signal used to determine an optimum laser power at a second linear velocity higher than the first linear velocity;
A method for controlling the recording laser power, comprising: determining an optimum recording laser power at the first linear velocity based on the determined recording power at the second linear velocity.
(2) The recording laser power control method according to claim 1, wherein the second linear velocity is higher than the first linear velocity.
(3) reading a plurality of pieces of linear velocity information from a recordable optical recording medium corresponding to a plurality of linear velocities;
Determining a first linear velocity for recording information among the read linear velocity information;
Determining an optimum recording laser power at a second linear velocity with a detection accuracy determined based on a detection signal used to determine an optimum laser power at a second linear velocity higher than the first linear velocity;
And a step of determining an optimum recording laser power at the first linear velocity based on the determined recording power at the second linear velocity.
(4) The recording laser power control apparatus according to claim 3, wherein the second linear velocity is a linear velocity higher than the first linear velocity.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, preferred embodiments of the present invention will be described with reference to the drawings.
[0014]
The present invention will be described with reference to FIGS.
The main part of a recordable / reproducible DVD-RW recorder for carrying out the power control method of the present invention is shown in FIG. During test recording, the DVD-RW 1 is rotated by the spindle motor 7, and the rotation is controlled by the servo circuit 10. At this time, the pickup 6 is controlled by the servo circuit 10 at a position corresponding to the track 2. The recording signal generation circuit 17 for calibration (test recording signal) is controlled by the control signal l from the controller 16 to generate the recording signal c1 and input to the recording amplifier 4 via the changeover switch 18 controlled by the changeover signal r. To do.
[0015]
The recording signal c1 is stored in advance in the pattern data of the recording signal c1 in the ROM or the like in the controller 16 without depending on the recording signal generation circuit 17 for calibration as described above, and is read out and given to the recording amplifier 4 as appropriate. It may be.
[0016]
Then, the laser diode of the pickup 6 is driven, and the recording and erasing laser power b at this time is a recording laser power to be described later, which is given via a controller (servo, mechanism, control microcomputer) 16 and a D / A converter 14. The recording amplifier 4 is variably controlled as shown in FIG. 4C by the control signal mp and the erasing laser power control signal me.
[0017]
At the time of reproduction of the test recorded signal, the recording / reproducing switch 8 is switched to the PB side, the read signal of the pickup 6 is amplified by the reproduction amplifier 9, and then the RF signal is output to the decoder. On the other hand, the RF signal output from the reproduction amplifier 9 is generated from an address signal and a wobble signal from a decoder that does not elaborate any one of the peak detection circuit 12, the bottom detection circuit 13, and the average value detection circuit 19 including the sample hold circuit. Using the switching signal 20 which is the timing signal, the signal is sampled and held, and the signal after the sample and hold is switched by the switching circuit 21. The switched signal is input to the controller 16 via the A / D converter 15 based on the timing signal of the reproduction signal from the decoder, and is used for calculation of the optimum power value described later. The peak detection circuit 12, the bottom detection circuit 13, and the average value detection circuit 19 correspond to the signals obtained by averaging the peak and bottom signals of the 11T signal and the 3T signal of FIG. 4 and FIG. 6 through the LPF. This circuit for averaging is designed so that the frequency of 3T, 4T, or 5T can be averaged by setting the LPF.
[0018]
The recording signal c1 shown in FIG. 1 is similarly used as a recording signal for test recording. A diagram corresponding to FIG. 9 is shown in FIG. The recording position is performed in a test recording area (Power Calibration Area) on the inner periphery of the DVD-RW. FIG. 4B shows a timing chart of LPP (land pre-pit) formed as a pre-pit address in the land on the outer peripheral side of the groove, which is a data recording area in accordance with the DVD-RW standard. In this way, recording is performed by changing the recording power and erasing power ratio ε to be constant while increasing the recording power.
[0019]
As can be seen from FIG. 1, the recording signal c1 does not use the 8/16 modulation recording signal c of DVD, but uses only 11T and 3T, 11T pulse interval 3 times, 3T pulse interval 10 times, and 11 pulses again. The pattern is formed by a repeating pattern of a total of 132T periods of 3 sections and 3T pulse sections 12 times. as a result,
“H” section of 11T pulse → 11T × 3 = 33T
“L” section of 11T pulse → 11T × 3 = 33T
“H” section of 3T pulse → 3T × 11 = 33T
“L” section of 3T pulse → 3T × 11 = 33T
As described above, the number of times of “H” level and “L” level in each pulse section is set to be the same, and the duty ratio is set to 50% so as not to be affected by the DC component of the signal component.
[0020]
A control algorithm for reproducing the recording signal and calculating an optimum recording power will be described.
[0021]
It moves to the place where the test recording was performed first, detects the LPP timing signal obtained from the decoder of the target LPP address, samples the peak value of the 11T signal sampled and held by the timing signal corresponding to each recording position, and 11T The bottom value of the signal is measured, and the peak value and the center value of the bottom value of the 11T signal are calculated. Next, the average value detection output that is the center of the 3T signal is measured, and the average value detection output is compared with the center value of the peak value and the bottom value. Asymmetry is obtained by dividing the difference between the peak value and the average value detection output with respect to the center value of the bottom value by the peak value and the peak-to-peak value of the bottom value.
[0022]
The value of this asymmetry is 0% or a value close to 0% (which is determined as a standard between -5% and + 15% in a DVD-RW under a predetermined condition, but the pickup and recording conditions used in an actual apparatus) Since the target value differs depending on the recording waveform (strategy), the target value is determined individually for each disc by the experimental results, and the optimum value measured in the ROM of the recording device or in the manufacturing process is recorded in the EEPROM. Therefore, the output power when the target value matches the target value compared with the target value recorded in the apparatus becomes the optimum recording power value.
[0023]
Here, the DVD-RW medium has a unique ID of the medium, a recommended recording power to be recorded recommended by the manufacturer of the medium, a ratio ε of the recommended recording power and the erasing power for determining the erasing power, and a recording condition. Recommended if there is a recording waveform heading width of recording power, multi-pulse width in the middle region, cooling pulse width to determine the trailing edge pulse or trailing edge pulse width (strategy), and asymmetry value Asymmetry values are recorded on the medium along with linear velocity information. At present, there is only a standard for 1 × speed, but when standardization at high speed such as 2 × speed or 4 × speed is performed, recommended values corresponding to the respective double speed values are similarly recorded on the medium. Information having the same meaning in DVD-R, DVD + RW, etc. is recorded on the medium.
[0024]
Therefore, when the device is developed and manufactured, the medium is evaluated, and if it can be determined that the recommended value recorded on this medium can be used as the recommended value in the device as well, or if this value is offset, If it can be determined that it can be used, the unique ID of the medium can be used as it is. Alternatively, it is stored in the ROM or EEPROM of the apparatus together with the offset. If there is no asymmetry value, the target asymmetry value corresponding to the optimum power is measured and stored in the ROM or EEPROM of the apparatus.
[0025]
Then, when evaluating the medium and determining that the recommended value recorded on the medium is not helpful for the device, the value is not used for reference, and the unique ID of the medium and each of the recommended values described above. Is stored in the ROM or EEPROM of the apparatus.
[0026]
FIG. 3 shows the asymmetry characteristics of an actual DVD-RW for 1 × speed. Single speed (hereinafter referred to as 1X) is 3.49 m / s in linear velocity. When a 1X DVD-RW disc is recorded under 1X recording conditions, a 1X DVD-RW disc is recorded under 1.5X recording conditions, compared to a smaller slope indicating the dependence on the horizontal axis. In the case of recording, it can be seen that the slope indicating the dependence on the horizontal axis increases. The reason is related to the recording mechanism of the phase change medium. When the recording speed is high, when forming a small mark such as 3T, not only the length direction but also the width direction is applied to a long mark such as 11T. If the recording linear velocity is low, the thermal diffusion time for mark formation is sufficient even for short marks such as 3T, and the width direction is not so different from that for long marks such as 11T. It is thought that the mark of the size is formed.
[0027]
FIG. 5 shows the asymmetry characteristics of the DVD-RW for double speed under development. Double speed (hereinafter referred to as 2X) is 6.98 m / s in linear velocity. The 2X disc corresponds to 1X and 2X, and the recommended value corresponding to each speed is described on the disc. When a 2X DVD-RW disc is recorded under 1X recording conditions, a 2X DVD-RW disc is recorded under 2X recording conditions compared to a very small inclination indicating the dependence on the horizontal axis power. In the case of recording, it can be seen that the slope indicating the dependence on the horizontal axis increases. The reason for this is the same as in the previous period, and it is considered that similar results can be obtained with media of other standards without being limited to the results of this experiment.
[0028]
From 1X in FIG. 3, it can be judged from this result that when recording / reproducing is performed at 1X, the asymmetry value becomes 0% when the recording power is around 13 mW, and although not shown, the jitter becomes the minimum point, but the power is reduced. The gradient of asymmetry when changing is very small. In order to accurately detect this asymmetry value, in order to increase the cost by adding the circuit scale such as increasing the resolution of the A / D converter, and to increase the measurement accuracy Unnecessary increase of time such as increase of recording and measurement time is necessary and undesirable. On the other hand, when the power is determined with low measurement accuracy, a problem occurs in recording / reproducing compatibility when recording / reproducing is performed by another apparatus.
[0029]
On the other hand, even when recording and reproducing at 1.5X, the asymmetry value becomes 0% in the vicinity of the recording power of 13 mW, which is almost the same power, and although not shown, the jitter is also the minimum point, but when the power is changed The gradient of asymmetry is very large, and it is easy to accurately detect this asymmetry value.
[0030]
In other words, the 1X medium is exclusively for 1X, and there is no description of the recommended value such as 1.5X on the medium, but if the apparatus experimentally recognizes the performance of the 1X medium in advance, the apparatus Even if the value of the actual light emission power is not known, the target power can be clearly known from this asymmetry value.
[0031]
Similarly, in 2X of FIG. 5, when recording / reproducing is performed at 1X, the asymmetry value is 2% when the recording power is around 13 mW, and the jitter is the minimum point although not shown, but when the power is changed In order to accurately detect this asymmetry value, the asymmetry slope is very small. To increase the cost by adding a circuit scale such as increasing the resolution of the A / D converter, and to increase the measurement accuracy, the recording and measurement time Unnecessary increase of time such as increasing the time is necessary, which is not desirable. On the other hand, when the power is determined with low measurement accuracy, a problem occurs in recording / reproducing compatibility when recording / reproducing is performed by another apparatus.
[0032]
On the other hand, even when recording and reproducing at 2X, the asymmetry value becomes 2% in the vicinity of the recording power of 13 mW, which is almost the same power, and although not shown, the jitter becomes the minimum point, but the asymmetry when the power is changed. The slope is very large, and it is easy to accurately detect this asymmetry value.
[0033]
In other words, when recording on a medium that supports both 1X and 2X recording, the optimum power is obtained from the asymmetry value at 2X, and the difference between the obtained optimum power and the recommended power recorded on the medium is calculated. For example, the value of the actually emitted power can be obtained, and when recording with this medium, for example, at 1X, the target recording is based on the difference between the recommended power value of 1X recorded on the medium and the previous value. You can ask for power.
[0034]
This concept is not limited to numerical values of 1X and 2X, and an optimum asymmetry measurement result with high detection sensitivity (slope) can be obtained on a medium corresponding to a plurality of recordings having different linear velocities (double speed). This means that the power actually emitted can be obtained with high accuracy on the basis of the linear velocity, and recording at other speeds can be supported.
[0035]
The process in the actual apparatus will be described below.
[0036]
 (First embodiment)
As described above, for the medium corresponding to the DVD-RW of 1 × and 2 × speeds in this embodiment, the medium specific ID and the recommended recording power and erasing power recommended by the medium manufacturer are determined. Recommended recording power to erasing power ratio ε, recording pulse as the recording condition, the first pulse width of the recording power, the multi-pulse width in the intermediate area, the cooling pulse width to determine the trailing edge pulse or the trailing edge When there is a pulse width (strategy) and an asymmetry value, the recommended asymmetry value is recorded on the medium together with the linear velocity information. When the device is developed and manufactured, the medium is evaluated, and if it can be determined that the recommended value recorded on this medium can be used as the recommended value for the device as well, or if this value is offset, it can be used. If it can be determined, the unique ID of the medium can be used as it is. Alternatively, it is stored in the ROM or EEPROM of the apparatus together with the offset. If there is no asymmetry value, the target asymmetry value corresponding to the optimum power is measured and stored in the ROM or EEPROM of the apparatus. Then, when evaluating the medium and determining that the recommended value recorded on the medium is not helpful for the device, the value is not used for reference, and the unique ID of the medium and each of the recommended values described above. Is stored in the ROM or EEPROM of the device,
(1) At startup, disc type is discriminated. If the disc type is recognizable, the disc is moved to the disc management area, and the above-mentioned unique ID of the medium and the recommended record to be recorded recommended by the manufacturer of the medium The ratio of the recommended recording power and erasing power for determining the power and erasing power ε, the leading pulse width of the recording power that is the recording waveform that is the recording condition, the multi-pulse width of the intermediate area, the pulse for determining the trailing edge pulse When there is a cooling pulse width or a trailing end pulse width (strategy) or an asymmetry value, the recommended asymmetry value reads the linear velocity information.
[0037]
(2) If the unique ID of this medium is an ID stored in the ROM or EEPROM of the apparatus, information on the management area of the usable medium is set in the recording system circuit of the apparatus based on this ID. .
(3) Next, when reading from the management area information that the medium corresponds to a plurality of linear velocities as the linear velocity information, the optimum linear velocity information stored in the device ROM or EEPROM is selected. The selected information is set in the recording system circuit.
(4) The series of test recordings are performed based on the set linear velocity, and the current power is accurately determined from the asymmetry data having a high inclination. For example, from the information in the management area, the power is 13 mW, and the test data is recorded on a data medium that can be recognized as an ID that is valid and coincides with the experimental data at 2% asymmetry. % Result is obtained, it can be determined that the amount of light emitted from the objective lens of the optical system of the apparatus has decreased for some reason. Therefore, the subsequent power setting has an offset value of 15 mW-13 mW = 2 mW. Add and output. In this way, even when this medium is recorded at a linear velocity lower than the linear velocity recorded by the test, the offset value is added to the information in the management area at the linear velocity to obtain the asymmetry. Even when the slope of the characteristic is gradual and detection is difficult, accurate power setting can be performed.
[0038]
(Second embodiment)
Next, in the medium corresponding to only the DVD-RW 1 × speed in the present embodiment, the unique ID of the medium, the recommended recording power to be recorded recommended by the manufacturer of the medium, and the recommended recording power for determining the erasing power And erasing power ratio ε, recording pulse, which is the recording waveform as the recording condition, multi-pulse width in the intermediate area, cooling pulse width for determining the trailing pulse, or trailing pulse width (strategy) If there is an asymmetry value, the recommended asymmetry value is recorded on the medium. When the device is developed and manufactured, the medium is evaluated, and if it can be determined that the recommended value recorded on this medium can be used as the recommended value for the device as well, or if this value is offset, it can be used. If it can be determined, the unique ID of the medium can be used as it is. Alternatively, it is stored in the ROM or EEPROM of the apparatus together with the offset. If there is no asymmetry value, the target asymmetry value corresponding to the optimum power is measured and stored in the ROM or EEPROM of the apparatus. Then, when evaluating the medium and determining that the recommended value recorded on the medium is not helpful for the device, the value is not used for reference, and the unique ID of the medium and each of the recommended values described above. Is stored in the ROM or EEPROM of the device,
(1) At startup, disc type is discriminated. If the disc type is recognizable, the disc is moved to the disc management area, and the above-mentioned unique ID of the medium and the recommended record to be recorded recommended by the manufacturer of the medium The ratio of the recommended recording power and erasing power for determining the power and erasing power ε, the leading pulse width of the recording power that is the recording waveform that is the recording condition, the multi-pulse width of the intermediate area, the pulse for determining the trailing edge pulse When there is a cooling pulse width or a trailing end pulse width (strategy) or an asymmetry value, the recommended asymmetry value reads the linear velocity information.
[0039]
(2) If the unique ID of this medium is an ID stored in the ROM or EEPROM of the apparatus, information on the management area of the usable medium is set in the recording system circuit of the apparatus based on this ID. .
(3) Next, when the medium corresponding to one linear velocity is read out from the management area information as the linear velocity information, the optimum test recording to be stored in the ROM or EEPROM of the apparatus is to be performed. Linear velocity information (1.5 times speed) is read, and the linear velocity information is set in the recording system circuit.
(4) The series of test recordings are performed at the set linear velocity (1.5 × speed), and the current power is accurately determined from the asymmetry data having a high inclination. For example, from the information in the management area, the power is 13 mW, and the test data is recorded on a data medium that can be recognized as an ID that is valid and coincides with the experimental data at 0% asymmetry. % Result is obtained, it can be determined that the amount of light emitted from the objective lens of the optical system of the apparatus has decreased for some reason. Therefore, the subsequent power setting has an offset value of 15 mW-13 mW = 2 mW. Then add and output. Next, normal recording is performed by returning the linear velocity of the medium to 1 × speed.
[0040]
(Third embodiment)
FIG. 7 is a characteristic in which the asymmetry of the 3T signal and the 4T signal are superimposed on the 11T signal while the asymmetry of the 3T signal is plotted against the 11T signal in FIG. 3 or FIG. When such a reproduction signal is binarized and converted into digital data, the simple condition that minimizes the reproduction jitter is preferably that the binarization level of each T is the same. When the asymmetry level becomes the same value, it can be considered that the optimum power has the best jitter. Based on this relationship, FIG. 7 shows that the point at which 3T and 4T, which have a particularly large influence on jitter, intersect, is the optimum power. Even in this way of thinking, it is also possible to perform test recording with signals including 3T and 4T, find the intersection of 3T and 4T signals, and manage the power at this intersection almost regardless of the optimum power (regardless of the value) ). Also in this method, the optimum power recorded on the medium is compared with the value stored in the ROM or EEPROM as in the above two embodiments, and the set power at this intersection is described on the medium. The difference is used as an offset value for recording at other linear velocities. Also in the method for obtaining the intersection point, it is desirable that this asymmetry is obtained with a high inclination, and it can be realized by appropriately selecting the linear velocity for test recording as in the above embodiment.
[0041]
The asymmetry described in the text is the center position relationship of the high frequency signal component with respect to the center of the amplitude of the low frequency signal in the reproduction signal, and defines the position relationship of the amplitude between the signals generated due to this difference in frequency. As long as the signal is processed digitally in the DC state, the position of the 11T signal is defined with respect to the center of the entire signal by C-cutting using a capacitor. The same applies to β in the β method described in the DVD-R and DVD-RW standards and the name of symmetry. Here, 3T, 4T, and 11T signals are used, but the T values of the low frequency signal and the high frequency signal component are appropriately changed depending on the modulation method.
[0042]
In this embodiment, the characteristics of eutectic phase change materials using materials such as AgInAsTe such as DVD-RW are described as examples. However, compound systems using single materials such as GeAsTe (single crystal system) The characteristics of the phase change material have the same tendency, and this method can be used when the same result can be obtained using an organic dye material.
[0043]
【The invention's effect】
As described above, in the present invention, when detecting the best value of the recording and erasing power, by setting the optimum linear velocity and performing test recording, the gradient of the asymmetry value with respect to the power increases, and the optimum recording power Detection accuracy is improved, power determination using test recording with low accuracy at other linear velocities is not required, and optimal power can be obtained in a short time. It is possible to maintain compatibility between devices and manufacturers when performing, and contribute to the development of the market.
[Brief description of the drawings]
FIG. 1 is a waveform diagram of a recording signal for test recording.
FIG. 2 is a principal block diagram of a DVD-RW recorder which is an embodiment of the apparatus of the present invention.
FIG. 3 is an asymmetry characteristic diagram of a DVD-RW (1 × medium) for 1 × speed.
FIG. 4 is a time chart showing an embodiment of the method of the present invention.
FIG. 5 is an asymmetry characteristic diagram of a DVD-RW (2X medium) for double speed.
6 is an explanatory diagram of an eye pattern of a DC coupled reproduction signal in the case of FIG. 4;
FIG. 7 is an asymmetry characteristic diagram of 3T signal and 4T signal in a double-speed DVD-RW.
[Explanation of symbols]
1 ... DVD-RW
2 ... Calibration area
3 ... Track
4 ... Recording amplifier
6 ... Pickup
7 ... Spindle motor
8 ... Recording / playback selector switch
9 ... Playback amplifier
10. Servo circuit
12 ... Peak detection circuit
13 ... Bottom detection circuit
14 ... D / A converter
15 ... A / D converter
16 ... Controller
17 ... Calibration recording signal generation circuit
18 ... changeover switch
19: Average value detection circuit
20 ... switching signal
21 ... switching circuit
22 ... Switch
a ... LPP sink
b ... Recording laser power
c: Recording signal
c1 Recording signal
g ... Playback signal
l ... Control signal
me: Erase laser power control signal
mp ... Recording laser power control signal
n ... Recording / playback switching signal
o ... Recording signal switching control signal
q ... Integral output
PREC: Recording power
r ... Switching signal

Claims (4)

Reading a plurality of linear velocity information from a recordable optical recording medium corresponding to a plurality of linear velocities;
Determining a first linear velocity for recording information among the read linear velocity information;
Determining an optimum recording laser power at a second linear velocity with a detection accuracy determined based on a detection signal used to determine an optimum laser power at a second linear velocity higher than the first linear velocity ;
A method for controlling the recording laser power, comprising: determining an optimum recording laser power at the first linear velocity based on the determined recording power at the second linear velocity . 2. The recording laser power control method according to claim 1, wherein the second linear velocity is higher than the first linear velocity . Reading a plurality of linear velocity information from a recordable optical recording medium corresponding to a plurality of linear velocities;
Determining a first linear velocity for recording information among the read linear velocity information;
Determining an optimum recording laser power at a second linear velocity with a detection accuracy determined based on a detection signal used to determine an optimum laser power at a second linear velocity higher than the first linear velocity;
A recording laser power control device comprising a step of determining an optimum recording laser power at the first linear velocity based on the determined recording power at the second linear velocity . 4. The recording laser power control apparatus according to claim 3, wherein the second linear velocity is higher than the first linear velocity .

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