JP2005310256A - Information recording method and information recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that when scoop phenomenon in which outgoing light quantity is varied depending on brightness (magnitude) in reflection light quantity of a recording mark and a space part occurs and when variation of the outgoing light quantity of the laser due to scoop phenomenon differs depending on each disk and positions in the radial direction of one disk , β value is deviated from an original β value obtained from the peak value and bottom value of reflected light quantity at fixed laser outgoing light quantity, and erroneous power correction is performed. <P>SOLUTION: This apparatus is provided with a scoop correcting means in which variation quantity of the outgoing light quantity of the laser in the recording mark and the space part due to the scoop is calculated and a scoop correction coefficient correcting variation of outgoing light quantity using the variation quantity is calculated, a peak value correcting means and a bottom value correcting means correcting the peak value and the bottom value, and a β value calculating means calculating the β value using the corrected peak value and the bottom value. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention modulates laser light in accordance with predetermined information and controls the light intensity to irradiate the recording medium, thereby forming a recording mark area in which the reflectance of the recording medium changes depending on the intensity of the irradiated light. The present invention relates to an information recording method and information recording apparatus.

  In recent years, with the spread of multimedia, a write-once optical disc CD-R and a rewritable CD-RW have rapidly spread, and a large capacity write-once optical disc DVD-R and a rewritable optical disc DVD-RW. DVD-RAM has also been put into practical use and has begun to spread. In any optical disc, an information recording / reproducing apparatus including an optical pickup optical system using a semiconductor laser as a light source is used to record information. In these information recording / reproducing apparatuses, various technologies have been developed in order to improve and stabilize recording or reproducing performance. One of the technologies is a semiconductor laser power control technology, and many methods have been proposed. In particular, since data cannot be rewritten in a write-once optical disc, it is important how a stable recording state can be maintained. Performing power calibration to determine the optimum laser power before starting data recording, or correcting the recording power while checking the playback quality of the recorded area after starting data recording This is because the recording quality is kept constant over the entire disk surface. In general, asymmetry, β value, and modulation degree calculated from the amount of reflected light from the recorded area are often used in order to confirm power calibration and reproduction quality immediately after recording (see, for example, Patent Document 1). FIG. 7 is a flowchart showing an operation of performing power correction while detecting the β value during recording.

Set the power correction amount for the target β value and β value in advance, detect the peak value, bottom value, and average value of the reflected light amount amplitude of the area recorded during recording, and determine the β value from the peak value, bottom value, and average value In this method, a difference from the target β value is obtained, a power correction amount is calculated from the difference from the target β value and the power correction amount for the β value that has been set, and recording is performed by changing the recording power.
JP 2001-31822 A

  The problem to be solved is that when the β value is detected, a scoop phenomenon in which the amount of emitted light of the laser fluctuates due to the brightness (magnitude) of the reflected light amount of the recording mark and the space portion, and the laser emission due to the scoop phenomenon occurs. If the amount of light fluctuation varies from disk to disk or depending on the position in the radial direction of the same disk, it will deviate from the original β value obtained from the peak value and bottom value of the reflected light quantity when the laser light quantity is constant, and incorrect power correction will be performed. It is.

  FIG. 8 is a diagram showing that the peak value and the bottom value of the reflected light amount fluctuate due to the scoop phenomenon. In FIG. 8, when there is no scoop, there is no change in the amount of laser emitted light. When a scoop occurs that causes the output light amount to be small at the recording mark part and the output light amount to be large at the space part, the peak value of the reflected light amount becomes a large level compared to the case where the output light amount does not fluctuate, and the bottom value is Compared with the case where the amount of emitted light does not fluctuate, it becomes a small level. In addition, when a scoop occurs where the output light quantity is large at the recording mark part and the output light quantity is small at the space part, the peak value of the reflected light quantity becomes a small level compared to the case where the output light quantity does not fluctuate, and the bottom value is Compared to the case where the amount of emitted light does not fluctuate, it becomes a large level. In any case, when a scoop occurs, it deviates from the original peak value and bottom value, resulting in an error in β value calculation.

  In the present invention, when measuring the β value, the peak value of the reflected light amount amplitude in the unrecorded area near the β value measurement target position and the peak value of the reflected light amount amplitude in the recorded area of the β value measurement target position The amount of fluctuation in the amount of emitted laser light due to the scoop is calculated, and the reflected light amount amplitude peak value and bottom value in the recorded area of the β value measurement target position are corrected so that they are the peak value and bottom value when the emitted light amount is constant. Main features.

  In the information recording method and information recording apparatus of the present invention, a scoop phenomenon in which the amount of emitted laser light fluctuates depending on the brightness (large or small) of the reflected light amount of the recording mark and space portion, and the fluctuation in the amount of emitted laser light due to the scoop phenomenon Even if it differs depending on the radial position of the same disk, it can detect fluctuations in the amount of laser emitted by the scoop and always detect the same β value as when the amount of emitted laser light is constant, making accurate power correction, and making the entire disk surface There is an advantage that stable and good recording quality can be maintained.

  The purpose of detecting fluctuations in the amount of laser emission due to scoops was easily realized at low cost without the need for adding a new measurement circuit by using a conventional amplitude measurement circuit for the amount of reflected light to detect the β value.

(Embodiment 1)
FIG. 1 is a block diagram showing the configuration of the information recording apparatus according to Embodiment 1 of the present invention. FIG. 2 is a flowchart showing the operation of the information recording method according to the first embodiment of the present invention.

  Reference numeral 1 denotes an optical disc capable of recording and reproducing information. A spindle motor 2 rotates the optical disk 1. Reference numeral 3 denotes a laser diode that can emit light with a predetermined light amount during recording or reproduction on the optical disc 1. A beam splitter 4 separates the light emitted from the laser diode 3 and the return light from the optical disk 1. Reference numeral 5 denotes an objective lens that condenses the laser light in a recordable or reproducible area of the optical disc 1.

  Reference numeral 6 denotes a light amount monitoring photodetector for detecting a part of the light emitted from the laser diode 3. Reference numeral 7 denotes an I / V conversion circuit that converts the current output of the light quantity monitoring photodetector 6 into a voltage. Reference numeral 8 denotes a low-pass filter (LPF) that attenuates the frequency band of the output of the I / V conversion circuit 7. Reference numeral 9 denotes a voltage amplifier (AMP) that amplifies the current output of the light quantity monitoring photodetector 6. A sample hold circuit (S / H) 10 samples and holds the output of the LPF 108 at a predetermined timing. Reference numeral 11 denotes a sample / hold circuit (S / H) that samples and holds the output of the AMP 9 at a predetermined timing. Reference numeral 12 denotes an mp detector that detects the output of the S / H 10 as an average power of recording light emission. An sp detector 13 detects the output of the S / H 11 as a bias power for recording light emission. A peak power control circuit 14 controls the peak power of recording light emission. A bias power control circuit 15 controls the bias power for recording light emission. Reference numeral 16 denotes an LD driving circuit that causes the laser diode 3 to emit light with power controlled by the peak power control circuit 14 and the bias power control circuit 15.

  Reference numerals 6 to 13 are examples of emitted light quantity control means for detecting the emitted light quantity of the laser and controlling the emitted light quantity of the laser so as to obtain a predetermined power value.

  Reference numeral 17 denotes a plurality of return light detecting photodetectors for detecting return light from the optical disc 1. Reference numeral 18 denotes a plurality of I / V conversion circuits for converting each current output of the plurality of return light detecting photodetectors 17 into a voltage. Reference numeral 19 denotes an RF adder that adds a plurality of outputs from the I / V conversion circuit 18.

  Reference numerals 17 to 19 are examples of reflected light amount detection means for receiving reflected light from the recording mark area of the recording medium and detecting the reflected light amount.

  Reference numeral 20 denotes a peak detection circuit for detecting the peak level of the output of the RF adder 19. Reference numeral 21 denotes a peak value measurement circuit that samples and holds the output of the peak detection circuit to measure the peak value.

  Reference numerals 20 to 21 are examples of peak value detection means for detecting the peak value of the amount of reflected light.

  Reference numeral 22 denotes a bottom detection circuit that detects the bottom level of the output of the RF adder 19. Reference numeral 23 denotes a bottom value measurement circuit that samples and holds the output of the bottom detection circuit to measure the bottom value.

  22 to 23 are examples of bottom value detection means for detecting the bottom value of the amount of reflected light.

  Reference numeral 24 denotes a low-pass filter (LPF) that attenuates the frequency band of the output of the RF adder 19 to a substantially DC level with almost no AC component. An average value measurement circuit 25 samples and holds the output of the low-pass filter (LPF) 24 and measures the average value of the output of the RF adder 19.

  Reference numerals 24 to 25 are examples of average value detecting means for detecting the average value of the amount of reflected light.

  26 is a scoop from an unrecorded area peak value measured by the peak value measuring circuit 21 in a predetermined unrecorded area and a recorded area peak value detected by the peak value measuring circuit 21 in a predetermined recorded area. Is a scoop measurement circuit that calculates a fluctuation amount of the emitted light quantity of the laser at the recording mark and the space portion, and calculates a scoop correction coefficient for correcting the fluctuation of the emitted light quantity using the fluctuation amount.

  A peak value correction circuit 27 corrects the peak value measured by the peak value measurement circuit 21 in the recorded area using the scoop correction coefficient calculated by the scoop measurement circuit 26.

  A bottom value correction circuit 28 corrects the bottom value measured by the bottom value measurement circuit 23 in the recorded area using the scoop correction coefficient calculated by the scoop measurement circuit 26.

  Reference numeral 29 denotes a β value calculation circuit that calculates a β value from the output of the peak value correction circuit 27, the output of the bottom value correction circuit 28, and the output of the average value measurement circuit 25.

  Reference numeral 30 denotes a target β value comparison circuit that calculates a difference between the β value calculated by the β value calculation circuit 29 and a preset target β value.

  A correction power calculation circuit 31 generates a correction power value based on a difference from the target β value calculated by the target β value comparison circuit and outputs the correction power value to the peak power control circuit 14.

  Next, the operation of the first embodiment of the present invention will be described.

  Prior to the start of data recording, a target value of β value obtained from amplitude measurement of a recorded area in advance is set in the target β value comparison circuit 30, and a conversion coefficient of recording power with respect to the β value is set in the correction power calculation circuit 31.

  When recording data, the recording is interrupted every time a predetermined area is recorded, seek to an unrecorded area near the recording end position of the recording interruption, and the peak value of the peak value of the amplitude of the unrecorded area is measured. Measurement is performed by the circuit 21. Next, seek is performed to the recorded area near the recording end position, and the peak value, bottom value, and average value of the amplitude of the recorded area are measured by the peak value measuring circuit 21, the bottom value measuring circuit 23, and the average value measuring circuit 25. . Next, from the peak value of the amplitude of the unrecorded area and the peak value of the amplitude of the recorded area, the amount of fluctuation in the amount of light emitted from the laser in the recording space due to scoop is calculated.

  The variation calculation method of the emitted light quantity is as follows. First, in the scoop measurement circuit 26, the amplitude peak value in the recorded area corresponding to the target β value with respect to the amplitude peak value in the unrecorded area when no scoop occurs. The reflectance ratio γ, which is the ratio of. The reflectance ratio γ is stored in the firmware in the information recording apparatus as a constant for each disc type and each recording speed. Next, the ratio of the peak value of the amplitude in the recorded area to the peak value of the amplitude in the unrecorded area near the recording end position is calculated as γ ′, and the ratio of γ ′ to γ when there is no scoop is S ( = Γ ′ / γ). The S value is the emission light quantity fluctuation ratio in the recording space portion. In addition, the fluctuation of the amount of emitted light at the recording mark part is considered that the recorded data has a random pattern in which the appearance frequency of the mark and the space is substantially the same, and in a band sufficiently lower than the period of the data mark and space length. Since the reproduction power control is performed using the output of the emitted light quantity monitoring photodiode 6, it is equivalent to the amount obtained by subtracting the output light quantity fluctuation level S-1 of the recording space portion from the average emitted light quantity level 1. That is, the emission light amount fluctuation ratio of the recording mark portion is 1- (S-1), and the equation is arranged to be 2-S.

  In order to normalize the peak value and the bottom value of the reflected light amount with the same emitted light amount from these emission light quantity fluctuation ratios, the scoop measurement circuit 26 sets the scoop correction coefficient for the peak value to 1 / S and the scoop correction coefficient for the bottom value. 1 / (2-S) is calculated.

  Next, the peak value correction circuit 27 corrects the peak value by multiplying the peak value in the recorded area by the scoop correction coefficient 1 / S of the peak value. Similarly, the bottom value is corrected by multiplying the bottom value in the recorded area by the bottom value scoop correction coefficient 1 / (2-S).

  Next, the β value calculation circuit 29 calculates the β value from the average value of the recorded area, the corrected amplitude peak value of the recorded area, and the bottom value, and the target β value comparison circuit 30 calculates the β value. The difference between the target value and the calculated β value is calculated, and the correction power calculation circuit 31 calculates the correction amount of the recording power from the difference of the β value and the power conversion coefficient for the β value. Recording is resumed from the recording end position of the recording interruption with the recording power obtained by adding the correction amount of the recording power to the recording power before the recording interruption.

  By the end of recording, β value detection by scoop correction is performed for each predetermined recording unit, and power correction is performed as needed.

  As described above, according to the first embodiment of the present invention, the scoop phenomenon in which the amount of emitted light of the laser fluctuates depending on the brightness (large or small) of the amount of reflected light of the recording mark and the space portion, and the amount of emitted light of the laser due to the scoop phenomenon. Even if the fluctuation varies depending on the disk or the radial position of the same disk, it can detect the fluctuation of the amount of laser emitted by the scoop and always detect the same β value as when the amount of emitted laser light is constant. Therefore, stable and good recording quality can be maintained over the entire disk surface.

  Further, the amplitude measurement of the unrecorded area in the vicinity of the recording end position according to the first embodiment has an unrecorded area of 5 tracks or more, and the average amplitude of one track of the unrecorded area is measured for two or more tracks before and after, As for the amplitude measurement of the recorded area near the recording end position, there are five or more recorded areas recorded with the same recording power, and the average amplitude of one track of the recorded area is measured for two or more tracks before and after. Therefore, the change in amplitude due to the influence of crosstalk from the non-recorded area and the adjacent track in the recorded area can be reduced, and the recording sensitivity (power) fluctuation in the circumferential direction of the disk can be measured by measuring the average amplitude for one track. Can be averaged, and the scoop correction coefficient and β value can be calculated more accurately.

  Further, the recording power conversion coefficient for the β value set in advance in the correction power calculation circuit 31 before the start of data recording in the first embodiment is such that the recording power becomes a predetermined β value prior to the start of data recording. In the required power calibration operation, after recording while varying the recording power, the β value at each recording power is measured and calculated by the change amount of the recording power with respect to the change amount of the β value in the vicinity of the predetermined β value. An accurate power correction amount that depends on the recording pulse width and recording speed can be calculated.

(Embodiment 2)
FIG. 3 is a flowchart showing the operation of the information recording method according to the second embodiment of the present invention.

The difference from the first embodiment of the present invention is that β value detection by scoop correction is performed every predetermined temperature change in addition to every predetermined recording unit, and power correction is performed as needed.
As described above, according to the second embodiment of the present invention, the scoop phenomenon in which the amount of emitted light from the laser fluctuates due to the brightness (magnitude) of the reflected light amount of the recording mark and the space portion, and the amount of emitted laser light due to the scoop phenomenon occurs. Even if the fluctuation varies depending on the disk or the radial position of the same disk, or even if the optimum recording power changes due to changes in the ambient temperature of the laser, the fluctuation of the laser emission quantity due to the scoop is detected and the laser emission quantity is always detected. The same β value as that at a constant time can be detected, accurate power correction can be performed, and stable and good recording quality can be maintained over the entire disk surface.

(Embodiment 3)
FIG. 4 is a block diagram showing the configuration of the information recording apparatus according to the third embodiment of the present invention.

  The difference from the first embodiment of the present invention is that the target β value comparison circuit 30 calculates the difference between the target value of the β value and the calculated β value, and then passes the difference through the LPF 32 for suppressing detection variation. The correction power calculation circuit 31 calculates the correction amount of the recording power from the difference between the β values of the output of the LPF 32 and the power conversion coefficient for the β value.

  As described above, according to the third embodiment of the present invention, even when a large measurement variation occurs during the measurement of the peak value, the bottom value, and the average value, the recording power is gradually corrected while suppressing the measurement variation. Thus, abrupt recording power fluctuations due to variations in β value measurement can be suppressed over the entire disk surface, and stable and good recording quality can be maintained.

(Embodiment 4)
FIG. 5 is a block diagram showing the configuration of the information recording apparatus according to the fourth embodiment of the present invention.

  The difference from Embodiment 1 of the present invention is that the β value is replaced with the modulation degree. The degree of modulation is a parameter that changes with respect to the recording power, like the β value. The degree of modulation indicates a ratio of a value obtained by subtracting the bottom value from the peak value with respect to the peak value of the recorded reflected light amount. Depending on the recording film material of the disc, there are some in which the change amount of the modulation degree is larger than the change amount of the β value with respect to the power, and it may be more effective to perform the power correction by detecting the modulation degree from the β value. In FIG. 5, the modulation degree calculation circuit 33 calculates the modulation degree from the amplitude peak value and bottom value of the recorded area subjected to the scoop correction of the recorded area, and the target modulation degree comparison circuit 34 calculates the target value of the modulation degree. A difference from the calculated modulation degree is calculated, and a correction power calculation circuit 31 calculates a correction amount of the recording power from the difference in modulation degree and a power conversion coefficient for the modulation degree. As in the first embodiment of the present invention, recording is resumed from the recording end position of the recording interruption with the recording power obtained by adding the correction amount of the recording power to the recording power before the recording interruption, The degree of modulation is detected by scoop correction for each recording unit, and power correction is performed as needed.

  As described above, according to the fourth embodiment of the present invention, the scoop phenomenon in which the amount of emitted light from the laser fluctuates due to the brightness (large or small) of the amount of reflected light at the recording mark and the space portion, and the amount of emitted light from the laser due to the scoop phenomenon. Even if the fluctuation varies from disk to disk or depending on the radial position of the same disk, it can detect the fluctuation in the amount of laser emitted by the scoop and always detect the same degree of modulation as when the amount of emitted laser light is constant, enabling accurate power correction. Therefore, stable and good recording quality can be maintained over the entire disk surface.

(Embodiment 5)
FIG. 6 is a block diagram showing the configuration of the information recording apparatus according to the fifth embodiment of the present invention.

The difference from Embodiment 1 of the present invention is that the β value is replaced with asymmetry. Asymmetry α is defined such that the peak level of the 3T space portion is h, the bottom level of the 3T mark portion is l, the peak level of the reflected light amount amplitude is p, and the bottom level of the reflected light amount amplitude is b.
α = ((p + b) / 2− (h + 1) / 2) / (p−b)
It is expressed.

  Asymmetry is a parameter that changes with respect to the recording power as well as the β value.

  In FIG. 6, the 3T amplitude measurement circuit 35 measures the peak value of the 3T space portion and the bottom value of the 3T mark portion, and the asymmetry calculation circuit 36 calculates the amplitude peak value of the recorded region after scoop correction of the recorded region. Asymmetry is calculated from the bottom value, the 3T space portion peak value, and the 3T mark portion bottom value, and the target asymmetry comparison circuit 37 calculates the difference between the target value of the asymmetry and the calculated asymmetry, and a correction power calculation circuit 31, the correction amount of the recording power is calculated from the difference of the asymmetry and the power conversion coefficient for the asymmetry. As in the first embodiment of the present invention, recording is resumed from the recording end position of the recording interruption with the recording power obtained by adding the correction amount of the recording power to the recording power before the recording interruption, Asymmetry detection is performed by scoop correction for each recording unit, and power correction is performed as needed.

  As described above, according to the fifth embodiment of the present invention, the scoop phenomenon in which the amount of emitted light of the laser fluctuates depending on the brightness (large or small) of the amount of reflected light of the recording mark and the space portion, and the amount of emitted light of the laser due to the scoop phenomenon. Even if the fluctuation varies depending on the disk or the radial position of the same disk, it can detect the fluctuation of the laser output light amount due to the scoop, always detect the same asymmetry when the laser output light quantity is constant, and perform accurate power correction, Stable and good recording quality can be maintained over the entire surface of the disk.

  Even if the β value in the second and third embodiments is replaced with the modulation factor or asymmetry, the same effect as in the second and third embodiments can be obtained.

  An information recording method and an information recording apparatus according to the present invention calculate a laser emission light amount fluctuation amount by a scoop, and calculate a reflected light amount amplitude peak value and a bottom value of a recorded region at a β value measurement target position as a peak value when the emitted light amount is constant. By correcting to the bottom value, the same β value as when the amount of light emitted from the laser is always detected can be detected, accurate power correction can be performed, and stable and good recording quality over the entire disk surface is essential. Is also applicable.

The block diagram which shows the structure of the information recording device in Embodiment 1 of this invention. The flowchart which shows operation | movement of the information recording method in Embodiment 1 of this invention. The flowchart which shows operation | movement of the information recording method in Embodiment 2 of this invention. The block diagram which shows the structure of the information recording device in Embodiment 3 of this invention. The block diagram which shows the structure of the information recording device in Embodiment 4 of this invention. Block diagram showing the configuration of an information recording apparatus in Embodiment 5 of the present invention Flow chart showing operation of conventional information recording method A figure showing that the peak value and bottom value of the reflected light amount fluctuate due to the scoop phenomenon

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk 2 Spindle motor 3 Laser diode 4 Beam splitter 5 Objective lens 6 Photodetector for light quantity monitoring 7 I / V conversion circuit 8 LPF
9 AMP
10 S / H
11 S / H
12 mp detector 13 sp detector 14 Peak power control circuit 15 Bias power control circuit 16 LD drive circuit 17 Photodetector for return light detection 18 I / V conversion circuit 19 RF adder 20 Peak detection circuit 21 Peak value measurement circuit 22 Bottom detection Circuit 23 Bottom value measurement circuit 24 LPF
25 Average value measurement circuit 26 Scoop measurement circuit 27 Peak value correction circuit 28 Bottom value correction circuit 29 β value calculation circuit 30 Target β value comparison circuit 31 Correction power calculation circuit 32 Variation suppression LPF
33 modulation degree calculation circuit 34 target modulation degree comparison circuit 35 3T amplitude measurement circuit 36 asymmetry calculation circuit 37 target asymmetry comparison circuit

Claims (10)

The laser beam is modulated according to predetermined information and the recording power is controlled to irradiate the recording medium, and information is recorded by forming a recording mark area in which the reflectance of the recording medium changes depending on the strength of the recording power, In an information recording method in which reproduction of information is performed by controlling the laser beam to have a predetermined light amount, a target value of β value obtained from amplitude measurement of a previously recorded area and a β value before data recording starts. A recording power conversion coefficient is set, and when recording data, the recording is interrupted every time a predetermined area is recorded, and the peak value of the amplitude of the unrecorded area near the recording end position of the recording interruption The peak value, bottom value, and average value of the amplitude of the recorded area are measured, and the recording in the recording space portion by scoop is determined from the amplitude peak value of the unrecorded area and the amplitude peak value of the recorded area. The fluctuation amount of the emitted light amount of the user is calculated, the scoop correction coefficient for correcting the fluctuation of the emitted light amount of the recording space portion and the recording mark portion is calculated using the fluctuation amount, and the recorded data is calculated using the scoop correction coefficient. The amplitude peak value and bottom value of the area are corrected, the β value is calculated from the average value of the recorded area and the corrected amplitude peak value and bottom value of the recorded area, and the target value of the β value and the calculation are calculated. The recording power correction amount is calculated from the β value difference and the power conversion coefficient for the β value, and the recording power correction amount is added to the recording power before the recording interruption. And resuming the recording from the recording end position of the recording interruption at the recording power. 2. An information recording method according to claim 1, wherein recording is interrupted every time recording of a predetermined area is performed, and power correction is performed by interrupting recording even when a predetermined laser ambient temperature changes. The measurement of the amplitude of the unrecorded area near the recording end position according to claim 1 includes measurement of an average amplitude of one track of the unrecorded area in which there are five or more unrecorded areas, and two or more tracks before and after the recording end position. The amplitude measurement of the recorded area in the vicinity of the position is characterized in that there are recorded areas of five or more tracks recorded with the same recording power, and the average amplitude of one track of the recorded area is measured for two or more tracks before and after. Information recording method. The difference between the β value according to claim 1 and the difference between the β values when calculating the correction amount of the recording power from the power conversion coefficient with respect to the β value are input to a low-pass filter for suppressing measurement variation, and the filter output is the β value. An information recording method characterized by being used as a difference between the two. The conversion coefficient of the recording power with respect to the β value according to claim 1 is optimal from the relationship between the recording power and the β value after recording while varying the recording power in order to obtain the optimum recording power prior to the start of data recording. An information recording method comprising calculating together with a recording power. The information recording method according to claim 1, wherein the β value according to claim 1 is a modulation degree calculated from an amplitude measurement of a recorded area in the same manner as the β value. The information recording method according to claim 1, wherein the β value according to claim 1 is an asymmetry calculated from an amplitude measurement of a recorded area in the same manner as the β value. The laser beam is modulated according to predetermined information and the recording power is controlled to irradiate the recording medium, and information is recorded by forming a recording mark area in which the reflectance of the recording medium changes depending on the strength of the recording power, In an information recording apparatus in which information is reproduced by controlling the laser emission light to have a predetermined light quantity,
An emitted light amount control means for detecting the emitted light amount of the laser and controlling the emitted light amount of the laser so as to have a predetermined power value;
A reflected light amount detecting means for receiving reflected light from the recording medium and detecting a reflected light amount;
Peak value detecting means for detecting a peak value of the detected light quantity of the reflected light quantity detecting means;
Bottom value detection means for detecting the bottom value of the detected light quantity of the reflected light quantity detection means;
An average value detecting means for detecting an average value of the detected light quantity of the reflected light quantity detecting means;
Recording mark by scoop from unrecorded area peak value detected by the peak value detecting means in a predetermined unrecorded area and recorded area peak value detected by the peak value detecting means in a predetermined recorded area And a scoop correction means for calculating a fluctuation amount of the emitted light quantity of the laser in the space portion, and calculating a scoop correction coefficient for correcting the fluctuation of the emitted light quantity using the fluctuation amount;
Peak value correcting means for correcting the peak value using the scoop correction coefficient;
Bottom value correcting means for correcting the bottom value using the scoop correction coefficient;
Β value calculating means for calculating a β value using the peak value corrected by the peak value correcting means, the bottom value corrected by the bottom value correcting means, and the average value detected by the average value detecting means; ,
Target β value comparing means for calculating a difference between the β value calculated by the β value calculating means and a preset target β value;
And a correction power value generation unit that generates a correction power value based on a difference from the target β value calculated by the target β value comparison unit and outputs the correction power value to the emission light amount control unit. Information recording device. The laser beam is modulated according to predetermined information and the recording power is controlled to irradiate the recording medium, and information is recorded by forming a recording mark area in which the reflectance of the recording medium changes depending on the strength of the recording power, In an information recording apparatus in which information is reproduced by controlling the laser emission light to have a predetermined light quantity,
An emitted light amount control means for detecting the emitted light amount of the laser and controlling the emitted light amount of the laser so as to have a predetermined power value;
A reflected light amount detecting means for receiving reflected light from the recording medium and detecting a reflected light amount;
Peak value detecting means for detecting a peak value of the detected light quantity of the reflected light quantity detecting means;
Bottom value detection means for detecting the bottom value of the detected light quantity of the reflected light quantity detection means;
Recording mark by scoop from unrecorded area peak value detected by the peak value detecting means in a predetermined unrecorded area and recorded area peak value detected by the peak value detecting means in a predetermined recorded area And a scoop correction means for calculating a fluctuation amount of the emitted light quantity of the laser in the space portion, and calculating a scoop correction coefficient for correcting the fluctuation of the emitted light quantity using the fluctuation amount;
Peak value correcting means for correcting the peak value using the scoop correction coefficient;
Bottom value correcting means for correcting the bottom value using the scoop correction coefficient;
A modulation degree calculation means for calculating a modulation degree using the peak value corrected by the peak value correction means and the bottom value corrected by the bottom value correction means;
Target modulation degree comparison means for calculating a difference between the modulation degree calculated by the modulation degree calculation means and a preset target modulation degree;
And a correction power value generation unit that generates a correction power value based on a difference from the target modulation degree calculated by the target modulation degree comparison unit and outputs the correction power value to the emitted light amount control unit. Information recording device. The laser beam is modulated according to predetermined information and the recording power is controlled to irradiate the recording medium, and information is recorded by forming a recording mark area in which the reflectance of the recording medium changes depending on the strength of the recording power, In an information recording apparatus in which information is reproduced by controlling the laser emission light to have a predetermined light quantity,
An emitted light amount control means for detecting the emitted light amount of the laser and controlling the emitted light amount of the laser so as to have a predetermined power value;
A reflected light amount detecting means for receiving reflected light from the recording medium and detecting a reflected light amount;
Peak value detecting means for detecting a peak value of the detected light quantity of the reflected light quantity detecting means;
Bottom value detection means for detecting the bottom value of the detected light quantity of the reflected light quantity detection means;
3T amplitude value detecting means for detecting the amplitude of the 3T mark portion and 3T space portion of the detected light amount of the reflected light amount detecting means;
Recording mark by scoop from unrecorded area peak value detected by the peak value detecting means in a predetermined unrecorded area and recorded area peak value detected by the peak value detecting means in a predetermined recorded area And a scoop correction means for calculating a fluctuation amount of the emitted light quantity of the laser in the space portion, and calculating a scoop correction coefficient for correcting the fluctuation of the emitted light quantity using the fluctuation amount;
Peak value correcting means for correcting the peak value using the scoop correction coefficient;
Bottom value correcting means for correcting the bottom value using the scoop correction coefficient;
Asymmetry using the peak value corrected by the peak value correcting means, the bottom value corrected by the bottom value correcting means, and the amplitude values of the 3T mark portion and 3T space portion detected by the 3T amplitude value detecting means. An asymmetry calculating means for calculating
Target asymmetry comparison means for calculating a difference between the asymmetry calculated by the asymmetry calculation means and a preset target asymmetry;
Correction power value generation means for generating a correction power value based on a difference from the target asymmetry value calculated by the target asymmetry comparison means, and outputting the correction power value to the emitted light quantity control means. Recording device.

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