JP2009277324A - Method for recording information, information recording device, and information storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for recording information capable of performing recording with high recording signal quality regardless of existence of change of inclination of a β value. <P>SOLUTION: In the method for recording information, a plurality of test information matters are recorded by changing recording power, the recorded information matters are reproduced, β values showing asymmetry of each of a plurality of reproduced signals corresponding to the plurality of test information matters are measured, a change amount of the β values in the range of 0.20>β>0.05 and a change amount of β values in the range of -0.05>β>-0.20 are measured, the recording power corresponding to a prescribed β value included in the range where the change amount of the β values is larger is detected, the optimal recording power Pw is controlled based on the recording power and a prescribed coefficient α and actual recording information is recorded by the optimal recording power Pw. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to information recording in which information is recorded on an optical disc while the recording power is changed, the recorded information is reproduced, the asymmetry of the reproduced signal is evaluated, and the recording power is controlled to an optimum state. The present invention relates to a method and an information recording apparatus. The present invention also relates to an information storage medium for storing information recording information recorded with a recording power controlled by such optimum recording power control.

  There are roughly three types of optical disks: a read-only ROM disk, a write-once R disk, a rewritable RW or a RAM disk. As information capacity increases, optical disks are also required to have a large capacity and a high transfer rate. There are CDs and DVDs on the optical disk currently on the market. For example, in order to meet the market demand for shortening the recording time of optical disks that can be recorded, CD-R is 48 times faster and DVD-R is 16 times faster. The transfer rate has been increased.

  Here, in order to further increase the capacity of the optical disc, a type of optical disc called HD DVD has been developed. The data capacity of the HD DVD-ROM and HD DVD-R is 15 GB on one side, and the capacity is increased by more than three times compared with 4.7 GB of the conventional DVD. An organic dye material is used for such a recording layer of HD DVD-R (see, for example, Patent Document 1 and Patent Document 2).

  As a power calibration method for recording information, a β method has been proposed for a write-once optical disc (see, for example, Patent Document 3).

Further, in the above-mentioned patent document 3, the recording laser power value and Δβ, which is the amount of change of the β value, correspond to the specific change of β value due to individual differences caused by distortion of the optical disk or unevenness of the dye. A technique is disclosed in which a recording laser power value is determined in consideration of the Δβ value by obtaining a relationship with the value. In this Patent Document 3, it is assumed that the β value has a substantially linear relationship with the recording laser power value.
JP 2006-205683 A JP-A-2005-271587 JP 2002-260230 A

  However, unlike conventional CD-Rs and DVD-Rs, it has been found that some HD DVD-Rs change with a recording laser power value having a slope of β. The change in the inclination of β is considered to be caused by the dye characteristics and the disk structure. If the slope of β changes, it will be very difficult to find the optimum recording power with the conventional method, and there is a concern that the recording signal quality will be degraded. In particular, when the inclination of β is small, the optimum recording power error becomes large.

  An object of the present invention is to provide an information recording method and an information recording apparatus capable of recording with high recording signal quality regardless of whether or not the inclination of β is changed. Another object of the present invention is to provide an information storage medium applicable to such an information recording method and information recording apparatus.

  An information recording method according to an embodiment of the present invention records a plurality of test information by changing recording power, reproduces the plurality of recorded test information, and reproduces a plurality of reproductions corresponding to the plurality of test information. Measure the β value indicating the asymmetry of each signal, and measure the amount of change in β value in the first β value range greater than 0 and the amount of change in β value in the second β value range less than 0. When the β value change amount in the first β value range is larger than the β value change amount in the second β value range, the first β value included in the first β value range Is detected, and when the amount of change in β value in the second β value range is larger than the amount of change in β value in the first β value range, the second β Detecting a second recording power corresponding to a second β value included in the range of values, The optimum recording power is controlled based on the first recording power and the predetermined coefficient, or the second recording power and the predetermined coefficient, and actual recording information is recorded with the optimum recording power.

  An information recording apparatus according to an embodiment of the present invention controls a recording means for recording a plurality of test information by changing a recording power, a reproducing means for reproducing the plurality of recorded test information, and an optimum recording power. Recording control means for measuring the β value indicating the asymmetry of each of the plurality of reproduction signals corresponding to the plurality of test information, and β in the first β value range greater than 0. A change amount of the value and a change amount of the β value in the second β value range smaller than 0 are measured, and the change amount of the β value in the first β value range is in the second β value range. When the amount of change in the β value is larger, the first recording power corresponding to the first β value included in the first β value range is detected, and the change in the β value in the second β value range is detected. From the amount of change in β value in the first β value range In the case of a threshold, a second recording power corresponding to a second β value included in the second β value range is detected, and the first recording power and a predetermined coefficient, or the second recording power and the The optimum recording power is controlled based on a predetermined coefficient, and the recording means records actual recording information with the optimum recording power.

  An information storage medium according to an embodiment of the present invention stores a first area storing information about the first β value, the second β value, and the predetermined coefficient, and the plurality of test information. And a third area for storing actual recording information recorded with the optimum recording power.

  According to the present invention, it is possible to provide an information recording method and an information recording apparatus capable of recording with high recording signal quality regardless of whether or not the inclination of β is changed. In addition, an information storage medium applicable to such an information recording method and information recording apparatus can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Optical disk>
FIG. 1 is a schematic diagram of an optical disc (information storage medium). The optical disc 1 is provided with a chucking hole 2 for chucking at the center, and has one or more information recording layers (hereinafter referred to as layers). An optical disk with one layer is called a single-layer optical disk, and two optical disks are called a double-layer optical disk. When there are multiple layers, the layout of the information area is slightly different for each layer. The information recording layer of the single-layer optical disc is divided into a lead-in area 3, a data area 4, and a lead-out area 5 from the inner peripheral side. In some cases, the BCA area 6 is disposed inside the lead-in area 3.

  The lead-in area 3 is used for the optical disc apparatus to record management information and test information, and for the optical disc manufacturer to record necessary management information in advance. The management information may be recorded by a recording mark, but may be recorded by a technique such as emboss pit, wobble, land pre-pit, or the like. In the data area 4, user information and additional management information are recorded. Management information and test data are recorded in the lead-out area 5. A groove is formed in a spiral shape in part or all of the lead-in area 3, the data area 4, and the lead-out area 5, and the groove serves as a guide groove for scanning the laser beam condensed by the optical disk apparatus. Fulfill.

  In addition, there are two types of optical discs: a write-once type in which a recording mark can be written only once in one place and a rewritable type in which the recording mark can be overwritten and erased. Management information such as a physical address is stored in the groove portion by a method such as wobble or land pre-pit. Information stored as recording marks and embossed pits is obtained by modulating the original data such as ETM (Eight to Twelve modulation) or 1-7PP (Parity Preserve). It has been added. Here, ETM (Eight to Twelve Modulation) is one of modulation methods, and is a method of recording a signal by converting 8 bits of information bits into 12-bit channel bits having redundancy. Thus, by providing redundancy to the original data, the reliability of information recording / reproduction is greatly improved as compared with the case where the data is directly recorded on the optical disk.

<Lead-in area>
FIG. 2 is a diagram illustrating an example of the layout of the lead-in area. From the inner periphery side, it is divided into a test area 31, a management information storage area 32, an initial area 33, a buffer area 34, a control data area 35, and a buffer area 36. The test area 31 is an area used for optimizing a recording waveform (OPC: Optimum power control) by the optical disk apparatus. The management information storage area 32 stores information such as the current disk status (unrecorded, recording, ROM compatible status), data area usage status, and recording waveform setting values after OPC (information about β0 and coefficient α described later). This is an area for sequential recording. In the initial area 33 and the buffer areas 34 and 36, dummy data for allowing servo overrun is recorded. In the control data area 35, physical format information and copyright protection information, which will be described later, are formed by pre-pits, wobbles or recording marks.

  In the BCA area 6, a BCA mark is recorded in advance by a groove in the substrate, peeling of the reflective film, or a change in the storage medium. Here, disc identification information and copyright protection information are stored. The BCA mark is modulated in the circumferential direction of the optical disk, and is a comb-shaped mark in which the same information is arranged in the radial direction. The BCA code is modulated and recorded by the RZ modulation method. A pulse with a narrow pulse width needs to be narrower than half the channel clock width of this modulated BCA code. Further, since the BCA mark has the same shape in the radial direction, it is not necessary to perform tracking, and information can be reproduced only by focusing.

<Management information>
FIG. 3 is a diagram showing an example of physical format information recorded in the control data area. For optical discs, the physical format information includes the disc type, physical characteristics, disc recording speed, serial number, disc manufacturer ID, recommended recording waveform shape optimized for the disc, and OPC target. The OPC target value and the like are stored in advance by a disk manufacturer or the like. Furthermore, a plurality of recording waveform shapes and OPC target values are stored in accordance with the recording speed, the corresponding optical disk device, and the like. The shape of the recording waveform and the target value of OPC are determined and stored in the procedure described later. Further, a plurality of OPC target values can be stored for one recording speed. For example, the OPC target value is set according to the range of the recording waveform setting value such as the recording power such as the OPC target value for the low recording power and the OPC target value for the high recording power. The optical disc apparatus adjusts the optimization of the recording waveform with reference to the information before or during the recording of the user information on the optical disc. As a result, it becomes possible to perform recording on each optical disc under optimum conditions, and the stability of user information recording and the compatibility between apparatuses are improved.

  FIG. 4 is a diagram illustrating an example of management information stored in the management information storage area. In the optical disc, as management information, information indicating the status of the optical disc, such as whether the optical disc is unrecorded, recorded or formatted, and a data area such as the start position and end position of recorded user data Can be stored, information indicating the usage status of the optical disc, the ID of the optical disc apparatus in which the information is registered, the recommended recording waveform shape optimized for the disc, the OPC target value that is the target of OPC, and the like. The management information is automatically recorded on the optical disc by the optical disc apparatus.

<Optical disk device>
FIG. 5 is a block diagram of an optical disc apparatus (information recording apparatus) according to an embodiment of the present invention. The optical disk apparatus collects laser light emitted from a pickup head (PUH) 11 (for example, a violet wavelength band in the range of 400 nm to 410 nm) on an information recording layer of the optical disk, and records and reproduces information. The light reflected from the optical disk again passes through the optical system of the PUH 11 and is detected as an electric signal by the photodetector.

  The detected electrical signal is amplified by the preamplifier 12 and output to the signal processing circuit 13 including a servo circuit, an RF signal processing circuit, an address signal processing circuit, and the like.

  In the servo circuit, servo signals such as focus, tracking, and tilt are generated, and each signal is output to the focus, tracking, and tilt actuators of the PUH.

  The RF signal processing circuit reproduces information such as recorded user information by mainly processing the sum signal among the detected signals. As a demodulation method at this time, there are a slice method and a PRML method.

  The address signal processing circuit processes the detected signal to read physical address information indicating a recording position on the optical disc and output it to the control unit 14. Based on this address information, the control unit 14 reads information such as user information at a desired position, or records information such as user information at a desired position. At this time, the user information is modulated into data suitable for optical disc recording by a recording signal processing circuit constituting the recording waveform generating circuit 16. At this time, for example, modulation methods such as (1, 10) RLL (Run length limited) modulation and (1, 7) RLL modulation are used for data modulation. In (1, 10) RLL modulation, the shortest code used for data modulation is 2T, and the longest code is 11T. Further, the recording waveform generation circuit 16 generates a signal for controlling the laser emission waveform based on the inputted code, and the LD drive circuit 15 drives an LD (laser driver) based on the laser issue waveform control signal. Thereby, information is recorded on the optical disc.

  Further, the optical disc apparatus has a function of recording information by changing power, a function of reproducing recorded information, and a function of calculating feature quantities such as asymmetry of reproduced signals under the control of the control unit 14. Furthermore, a function for evaluating the read characteristics of information that is the quality of the reproduced signal from the reproduced signal, a function for calculating the allowable range of recording power, and a feature amount such as asymmetry by dividing the range for changing the recording power into multiple A function that evaluates the recording waveform, a function that changes the setting or setting method of the recording waveform according to the evaluation result of the asymmetry, the evaluated feature value, the reading characteristics, and the optimized recording waveform shape information in the memory 17 attached to the device or an optical disk It has a combination of functions to save.

  When the asymmetry is evaluated by dividing the range in which the recording power is changed into two, for example, the asymmetry value at the upper limit value of the allowable range of the recording power and the asymmetry value at the lower limit value of the allowable range can be calculated. . The reproduction signal read characteristics are, for example, various error rates such as byte, bit, and symbol error rates, and characteristics such as SbER, PRSNR, and jitter.

<Playback waveform>
Next, features that can be evaluated from the reproduction waveform of the recording signal will be described. The optical disc apparatus calculates the feature amount of the reproduction waveform, evaluates the feature amount, and determines the optimum shape of the recording waveform based on the evaluation result. That is, the optical disc apparatus optimizes the recording waveform according to such a procedure. Examples of the feature amount include asymmetry, modulation degree, 2T3T asymmetry, 3T8T asymmetry, asymmetry change amount, and modulation degree change amount.

  FIG. 6 is a diagram showing an example of a reproduction waveform (eye pattern) of a recording signal. The reproduction waveform on the left side of FIG. 6 shows a state where the asymmetry value is 0, and the reproduction waveform on the right side of FIG. Indicates a non-zero state.

  FIG. 7 is a diagram showing a signal obtained by coupling the reproduced waveform on the left side of FIG. 6 and the reproduced signal on the right side with an AC (Alternating Current). Further, the 0 level in FIG. 7 indicates the output level when the optical disk is not reproduced.

  For example, it is assumed that 2T to 8T data is recorded on the optical disc. Since the largest signal amplitude is 8T, the signal generated at the lowest level and the signal generated at the highest level are the reproduction signals of the 8T data. Here, the lowest signal obtained from 8T data is I8L and the higher signal is I8H. Similarly, the lowest part signal obtained from 2T data is I2L, the high part signal is I2H, the lowest part signal obtained from 3T data is I3L, and the high part signal is I3H. The amplitudes of signals obtained from 2T, 3T, and 8T data are referred to as I2, I3, and I8.

  Here, asymmetry will be described. Asymmetry is an index for evaluating whether the center levels of the signals of 2T, 3T, and 8T are at the same level. The asymmetry of the reproduction signal is expressed by the following equation.

Asymmetry = [(I8H + I8L)-(I2H + I2L)] / [2 × (I8H-I8L)] ... (1)
Based on the above equation (1), the asymmetry of the reproduced waveform in FIG. 6 can be calculated. In the reproduced waveform on the left side of FIG. 6, the center of the level of the signal obtained from 8T data and the center of the level of the signal obtained from 2T data are substantially equal. Therefore, the asymmetry of the reproduced waveform on the left side of FIG. 6 is a value close to zero.

  On the other hand, in the reproduced waveform on the right side of FIG. 6, the level of the signal obtained from 2T is relatively higher than the level of the signal obtained from 8T data. Therefore, the asymmetry of the reproduced waveform on the left side of FIG. 6 is a negative value.

  In this way, it is possible to evaluate the shape of the reproduction signal using the feature quantity called asymmetry. Other asymmetry evaluation methods include 2T3T asymmetry and 3T8T asymmetry. The former is a method of comparing the center level of the code closest to the densest code and the code closest to the densest code among the modulation codes used in the optical disc. An example is a method of comparing the center levels of 2T and 3T signals. The latter is a method of comparing the center level of the code with the shortest code next to the densest code and the sparsest code. An example is a method of comparing the center levels of a 3T signal and an 8T signal.

2T3T asymmetry = [(I3H + I3L)-(I2H + I2L)] / [2 × (I8H-I8L)] (2)
3T8T asymmetry = [(I8H + I8L)-(I3H + I3L)] / [2 × (I8H-I8L)] (3)
Furthermore, another example for evaluating asymmetry will be described.

  The waveform shown in FIG. 7 is an output waveform obtained by AC coupling of a reproduction signal when recording data is reproduced. Here, if the difference between the level of the maximum value portion and the 0 level of the signal is A and the difference between the level of the minimum value portion of the signal and the 0 level is B, the asymmetry β calculated from this signal is expressed by the following equation. The

Asymmetry β = (A + B) / (AB) (4)
Based on the above equation (4), the asymmetry of the reproduced waveform in FIG. 7 can be calculated. In the reproduced waveform on the left side of FIG. 7, the upper and lower portions of the signal are targets. Therefore, when AC coupling is performed, the width of the waveform portion positioned above the 0 level and the waveform portion positioned below is the same. Therefore, the asymmetry of the reproduced waveform on the left side of FIG.

  On the other hand, in the reproduced waveform on the right side of FIG. 7, the top and bottom of the signal are asymmetric. For this reason, when AC coupling is executed, the width of the waveform portion located on the upper side of the 0 level is different from the width of the waveform portion located on the lower side. Therefore, the asymmetry of the reproduced waveform on the right side of FIG. 7 is negative. As described above, asymmetry can be evaluated in the same manner as in equation (1) even when β is used.

  Next, the modulation degree will be described. The modulation degree is an index for evaluating the amplitude of the signal. The modulation degree m is expressed by the following equation.

Modulation m = I8 / I8H (5)
The asymmetry change amount is a value for evaluating the change amount of the asymmetry with respect to the change of the recording waveform setting. For example, when recording is performed with the recording power N [mW], the asymmetry of the signal reproduced by the laser having the first wavelength when the recording is performed with the recording power N [mW] is asymmetry (N). When the asymmetry of the reproduced signal is asymmetry (M), the asymmetry change amount is expressed by the following equation.

Asymmetry change = (Asymmetry (M) -Asymmetry (N)) / (MN) (6)
Similarly, the change amount of the modulation degree is a value for evaluating the change amount of the modulation degree with respect to the change of the recording waveform setting. Here, the modulation degree of the reproduction signal when recording is performed with the recording power N [mW] is defined as the modulation degree (N), and the modulation degree of the reproduction signal when recording is performed with the recording power M [mW]. Assuming that the degree of modulation is (M), the measured amount of change in the degree of modulation is expressed by the following equation.

Modulation degree change amount = (Modulation degree (M) −Modulation degree (N)) / (MN) (7)
Further, in order to make the value of the degree of modulation change with respect to the difference in recording power as constant as possible, it is possible to use the degree of modulation change γ expressed by the following equation.

γ = [(degree of modulation (M) −degree of modulation (N)) / (MN)] × [M / degree of modulation (M)] (8)
As described above, the optical disc apparatus has a function of extracting various feature amounts from the reproduction waveform of the recorded signal.

<Recording waveform>
FIG. 8 is a diagram for explaining an example of a recording waveform by the optical disk device. Note that the reference clock signal shown in FIG. 8 is a signal used in the optical disc apparatus. Further, the NRZI waveform shown in FIG. 8 shows recording data in a state converted into the NRZI format. The recording waveform shown in FIG. 8 shows a recording waveform for recording the recording data. The pregroove shown in FIG. 8 is a recording place of a recording mark corresponding to the recording data. The shape of the recording mark is as shown in FIG.

  The recording waveform shown in FIG. 8 is a waveform called multi-pulse in which a plurality of pulses are used to record one mark. Of the plurality of pulses, the first one is called the first pulse, the last one is called the last pulse, and the one in between is called the multi-pulse. In addition, a portion for outputting bias power 1 after the last pulse is also provided. The shape of the recording waveform is defined by four levels in the level direction: recording power, erasing power, bias power 1 and bias power 2. In the time direction, it is defined by time information such as a first pulse start time F1, a first pulse end time F3, and a first pulse interval F2, based on the rising edge of NRZI format data and the clock signal. In addition, with respect to parameters such as the first pulse start time F1 and the last pulse end time L3 that are particularly likely to affect the formation of the recording mark, the intervals are dynamically changed during recording according to the pattern of the NRZI signal. These recording waveform setting values are managed as shape information of the recording waveform in the memory 17 in the optical disc apparatus, and are also stored in the information storage medium as physical format information and management information.

  FIG. 9 is a diagram for explaining another example of a recording waveform by the optical disk device. FIG. 9 is a diagram for explaining a waveform called a block pulse. The recording waveform shown in FIG. 9 does not include a multi-pulse, but includes a first pulse, a last pulse, and a cooling pulse, and a recording mark is formed by these pulses. Even in this case, setting information such as the start position of the pulse with respect to the clock signal and the end position of the leading protrusion is defined.

  Next, the procedure for determining the physical format information of the optical disk using the optical disk apparatus, the shape information of the optimum recording waveform stored in the optical disk apparatus, and the OPC target value will be described. The determination of the optimum recording waveform shape information and the OPC target value is performed when the optical disc manufacturer executes the optical disc before shipment and determines the shipment or stores the determined result in the physical format information of the optical disc. . It is also used when an optical disk manufacturer implements and determines a result stored in the memory of the optical disk apparatus. Furthermore, it is performed in advance by the optical disc apparatus before recording user information (actual recording information), and is used when determining whether recording is possible or saving the determined result in the management information storage area.

  FIG. 19 is a flowchart showing an outline of an information recording method according to an embodiment of the present invention.

  (ST1) The optical disc apparatus reads information on the target β0 and the coefficient α (see FIG. 18) from the management area 32 on the optical disc.

  (ST2) The optical disc apparatus records a plurality of test information in the test area 31 on the optical disc while changing the recording power.

  (ST3) The optical disc apparatus reproduces a plurality of recorded test information.

  (ST4) The optical disc apparatus measures the β value indicating the asymmetry of each of the plurality of reproduction signals corresponding to the plurality of test information.

  (ST5) The optical disk apparatus has a β value change amount (slope) in a first β value range (0.20> β> 0.05) larger than 0 and a second β value range (−0.05> β smaller than 0). > 0.20) Measure the amount of change (slope) in β value. Further, when the change amount of the β value in the first β value range is larger than the change amount of the β value in the second β value range, the optical disc apparatus includes the first β value included in the first β value range. If the β value (β0) is selected and, on the contrary, the amount of change in β value in the second β value range is greater than the amount of change in β value in the first β value range, the second β value range The second β value (β0) included in is selected.

  (ST6) The optical disc apparatus detects the first recording power (Pw0) corresponding to the selected first β value. Alternatively, the optical disc apparatus detects the second recording power (Pw0) corresponding to the selected second β value.

  (ST7) The optical disc apparatus determines the optimum recording power Pw based on the first recording power (Pw0) and the coefficient α (Pw = α × Pw0). Alternatively, the optical disc apparatus determines the optimum recording power Pw based on the second recording power (Pw0) and the coefficient α.

  (ST8) The optical disc apparatus records actual recording information in the data area 4 on the optical disc with the optimum recording power Pw.

  If it is already determined in advance that the amount of change in β value in the first β value range is larger than the amount of change in β value in the second β value range, the memory 17 notifies the change. The first recording power (Pw0) corresponding to the first β value (β0) included in the range of the first β value is detected, and the first recording power (Pw0) and the coefficient α are detected. Based on this, the optimum recording power Pw may be determined. Similarly, if it is known in advance that the amount of change in β value in the range of the second β value is larger than the amount of change in β value in the range of the first β value, the fact is stored in the memory 17. , The second recording power (Pw0) corresponding to the second β value (β0) included in the second β value range is detected, and the second recording power (Pw0) and the coefficient α are detected. The optimum recording power Pw may be determined based on the above.

  Hereinafter, the above-described information recording method will be described in detail.

  FIG. 10A is a diagram showing the relationship between β of the information storage medium A and the recording power. FIG. 10B is a diagram showing the relationship between β of the information storage medium B and the recording power. The information storage medium A is characterized in that the inclination of β is linear with respect to the recording power. On the other hand, the information storage medium B is characterized in that the slope of β is nonlinear with respect to the recording power.

  Therefore, the target β0 and the coefficient α are obtained in advance and stored in the management information storage area 32 of the information storage medium. The optical disc apparatus reads the target β0 and the coefficient α from the management information storage area 32, and the memory 17 stores the target β0. And the coefficient α are stored. In this case, the target β0 is β0> 0.05 (0.20> β0> 0.05). When recording information, OPC is performed first, and at that time, a recording power Pw0 corresponding to the target β0 is obtained. The coefficient α stored in the memory 17 of the optical disc apparatus is read, the optimum recording power Pw calculated by multiplying the recording power Pw0 by the coefficient α is obtained, and the actual recording information is recorded with the optimum recording power Pw.

  In the information storage medium A, β = 0 when the optimum recording power Pw is 9.5 mW. At this time, β0 = 0.10, Pw0 = 8.1 mW, and α = 1.17.

  In the information storage medium B, β = −0.03 when the optimum recording power Pw is 8.8 mW. At this time, β0 = 0.10, Pw0 = 7.5 mW, and α = 1.17.

  On the other hand, in the conventional optimum recording power control, the following results are obtained.

  A recording power with β = 0 is found by OPC, and this recording power is set as the optimum recording power. FIG. 11A is a diagram illustrating a result of finding the recording power by performing OPC five times on the information storage medium A. FIG. In the information storage medium A, the recording power at which β = 0 is approximately 8.1 mW, and the optimum recording power can be found almost correctly.

  FIG. 11B is a diagram illustrating a result of finding the recording power by performing OPC five times on the information storage medium B. In the information storage medium B, even when trying to find a recording power with β = −0.03, the slope of β with respect to the recording power is small near the optimum recording power, and the change from 8.0 mW to 9.5 mW is difficult to understand, and the optimum recording power is found It was difficult.

  In the information recording method according to the embodiment of the present invention, the optimum recording power Pw is determined as follows.

  First, the recording power Pw0 to be β0 is obtained, the optimum recording power Pw calculated by multiplying the recording power Pw0 by the coefficient α is obtained, and the actual recording information is recorded with the optimum recording power Pw.

  FIG. 12A is a diagram illustrating a result of applying OPC to the information storage medium A five times. FIG. 12B is a diagram illustrating a result of applying OPC to the information storage medium B five times. In both the information storage media A and B, the optimum recording power could be found almost accurately.

  The information storage medium described in the present embodiment includes, for example, a 1.1 mm thick substrate, an Ag alloy reflecting film formed on the substrate, a dye applied on the Ag alloy reflecting film, and a 0.1 mm cover layer. It is the structure which laminated | stacked. Also, a dye is applied on a 0.6 mm thick substrate, an Ag alloy reflective film is laminated thereon, and a 0.6 mm thick substrate is laminated on the Ag alloy reflective film, that is, a 0.6 mm thick substrate. The same effect was obtained with the bonded structure.

  As a low to high type (L to H type) organic dye that can be used in an embodiment of the present invention, an organic dye complex composed of a dye part and a counter ion (anion) part can be used. As the dye portion, cyanine dyes, styryl dyes, porphyrin dyes, azo dyes, and the like can be used. In particular, cyanine dyes, styryl dyes, and azo dyes are preferable because they can easily control the absorptance with respect to the recording wavelength.

  Among L to H type organic dyes, a monomethine cyanine dye having a monomethine chain is a maximum absorption and absorbance in a recording wavelength region (400 nm to 405 nm) by thinning a recording film applied to a transparent resin substrate. Can be easily adjusted to around 0.3 to 0.5, preferably around 0.4. For this reason, it is possible to improve the recording / reproducing characteristics and to design both the light reflectance and the recording sensitivity well.

  As the anion portion of the organic dye, an organometallic complex is preferable from the viewpoint of light stability. An organometallic complex having cobalt or nickel as a central metal is particularly excellent in light stability.

  As the organometallic complex, for example, an azo metal complex can be used, and the solubility when 2,2,3,3-tetrafluoro-1-propanol (TFP) is used as a solvent is good, and spin coating is performed. Can be easily prepared. In addition, since recycling after spin coating is possible, the cost of manufacturing the information recording medium can be reduced.

  Note that the organometallic complex can be dissolved in a TFP solution and spin-coated. In particular, since the azo metal complex is less likely to be deformed after recording, when used for an information recording medium having two recording layers, the azo metal complex is good for the L0 recording layer having a thin Ag alloy layer. Cu, Ni, Co, Zn, Fe, Al, Ti, V, Cr, Y can be used as the central metal. Cu, Ni, and Co have particularly good reproduction light resistance, and Cu has no genotoxicity. The signal quality is excellent.

  Various ligands (ligands) surrounding the central metal can be used. For example, dyes represented by the following structural formulas (D1) to (D6) are used. You may make another structure combining the ligand which came out here.

Further, the number of central metals is not necessarily one, and a plurality of so-called binuclear complex structures may be employed. In this case, the ratio of the ligand to the central metal depends on the coordination number of the central metal and the size and structure of the ligand, but 1: 1, 1: 2, 1: 3, 1: 4, 2: 2, 2 : 3, 2: 4, 2: 5, 2: 6, 3: 3, 3: 4, 3: 5, 3: 6, 3: 7, 3: 8, 4: 4, 4: 5, 4: 6 , 4: 7, 4: 8, 4: 9, 4:10, etc. By using a binuclear complex, the quality of the recording / reproducing signal is excellent particularly at a wide recording speed. Of these, dyes having a ratio of 2: 2, 3: 3, 4: 4 are particularly excellent because they have good reproduction durability and a wide recording power margin even at high linear speeds.

  FIG. 20 shows four examples of dyes A to D as organic dye materials that can be used as the L to H type organic dye layer that can be used in the present invention. In the dye A, the dye part (cation part) is a styryl dye and the anion part is an azo metal complex 1. In the dye C, the dye part (cation part) is a styryl dye and the anion part is an azo metal complex 2. In the dye D, the dye part (cation part) is a monomethine cyanine dye and the anion part is an azo metal complex 1. In addition, the simple substance of an organometallic complex can also be used. For example, the dye B is a nickel complex dye.

Here, the following general formula (E1) shows a general formula of a styryl dye that becomes the dye part of the dyes A and C, and the following general formula (E2) shows an azo metal complex that becomes the anion part of the dyes A and C. The general formula is shown. Further, the following general formula (E3) shows a general formula of a monomethine cyanine dye that becomes the dye portion of the dye D, and the following general formula (E4) shows a general formula of the azo metal complex that becomes the anion portion of the dye D. Show.

  In the general formula of the styryl dye, Z3 represents an aromatic ring, and the aromatic ring may have a substituent. Y31 represents a carbon atom or a hetero atom. R31, R32, and R33 represent the same or different aliphatic hydrocarbon groups, and these aliphatic hydrocarbon groups may have a substituent. R34 and R35 each independently represent a hydrogen atom or an appropriate substituent. When Y31 is a heteroatom, either or both of R34 and R35 are not present.

  In the general formula of the monomethine cyanine dye, Z1 and Z2 represent the same or different aromatic rings, and these aromatic rings may have a substituent. Y11 and Y12 each independently represent a carbon atom or a heteroatom. R11 and R12 represent an aliphatic hydrocarbon group, and these aliphatic hydrocarbon groups may have a substituent. R13, R14, R15, and R16 each independently represent a hydrogen atom or an appropriate substituent. When Y11 and Y12 are heteroatoms, a part or all of R13, R14, R15, and R16 are not present.

  Examples of the monomethine cyanine dye used in this embodiment include imidazoline rings, imidazole rings, which are the same or different from each other and may have one or more substituents at both ends of the monomethine chain which may have one or more substituents. Benzimidazole ring, α-naphthimidazole ring, β-naphthimidazole ring, indole ring, isoindole ring, indolenine ring, isoindolenine ring, benzoindolenine ring, pyridino indolenine ring, oxazoline ring, oxazole ring , Isoxazole ring, benzoxazole ring, pyridinooxazole ring, α-naphthoxazole ring, β-naphthoxazole ring, selenazoline ring, selenazole ring, benzoselenazole ring, α-naphthoselenazole ring, β-naphthoselenazole ring , Thiazoline ring, thiazole ring Isothiazole ring, benzothiazole ring, α-naphthothiazole ring, β-naphthothiazole ring, tellurazoline ring, tellurazole ring, benzotelrazole ring, α-naphthotelrazole ring, β-naphthotelrazole ring, and acridine ring , Anthracene ring, isoquinoline ring, isopyrrole ring, imidazolane ring, indandione ring, indazole ring, indalin ring, oxadiazole ring, carbazole ring, xanthene ring, quinazoline ring, quinoxaline ring, quinoline ring, chroman ring, cyclohexanedione ring, Cyclopentanedione ring, cinnoline ring, thiodiazole ring, thiooxazolidone ring, thiophene ring, thionaphthene ring, thiobarbituric acid ring, thiohydantoin ring, tetrazole ring, triazine ring, naphthalene ring, naphthyridine ring , Piperazine ring, pyrazine ring, pyrazole ring, pyrazoline ring, pyrazolidine ring, pyrazolone ring, pyran ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrylium ring, pyrrolidine ring, pyrroline ring, pyrrole ring, phenazine ring, phenanthridine ring And a dye formed by bonding a cyclic nucleus such as a phenanthrene ring, a phenanthroline ring, a phthalazine ring, a pteridine ring, a furazane ring, a furan ring, a purine ring, a benzene ring, a benzoxazine ring, a benzopyran ring, a morpholine ring, or a rhodanine ring. Can do.

  In addition, through the general formulas of monomethine cyanine dye and styryl dye, Z1 to Z3 represent aromatic rings such as benzene ring, naphthalene ring, pyridine ring, quinoline ring, quinoxaline ring, and the aromatic ring has a substituent. One or more may be provided. Examples of the substituent include methyl group, trifluoromethyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, tert -Aliphatic hydrocarbon groups such as pentyl group, 1-methylpentyl group, 2-methylpentyl group, hexyl group, isohexyl group, 5-methylhexyl group, heptyl group, octyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group An alicyclic hydrocarbon group such as cyclohexyl group, phenyl group, biphenylyl group, o-tolyl group, m-tolyl group, p-tolyl group, xylyl group, mesityl group, o-cumenyl group, m-cumenyl group, p -Aromatic hydrocarbon group such as cumenyl group, methoxy group, trifluoromethoxy group, ethoxy group, propo Si group, isopropoxy group, butoxy group, sec-butoxy group, tert-butoxy group, ether group such as pentyloxy group, phenoxy group, benzoyloxy group, methoxycarbonyl group, trifluoromethoxycarbonyl group, ethoxycarbonyl group, propoxy Ester groups such as carbonyl group, acetoxy group and benzoyloxy group, halogen groups such as fluoro group, chloro group, bromo group and iodo group, thio groups such as methylthio group, ethylthio group, propylthio group, butylthio group and phenylthio group, methyl Sulfamoyl groups such as sulfamoyl group, dimethylsulfamoyl group, ethylsulfamoyl group, diethylsulfamoyl group, propylsulfamoyl group, dipropylsulfamoyl group, butylsulfamoyl group, dibutylsulfamoyl group , First grade Amino groups such as mino group, methylamino group, dimethylamino group, ethylamino group, diethylamino group, propylamino group, dipropylamino group, isopropylamino group, diisopropylamino group, butylamino group, dibutylamino group, piperidino group, Carbamoyl groups such as methylcarbamoyl group, dimethylcarbamoyl group, ethylcarbamoyl group, diethylcarbamoyl group, propylcarbamoyl group, dipropylcarbamoyl group, and further, hydroxy group, carboxy group, cyano group, nitro group, sulfino group, sulfo group, And a mesyl group. In the general formula, Z1 and Z2 may be the same as or different from each other.

  Y11, Y12, and Y31 in the general formulas of the monomethine cyanine dye and the styryl dye represent a carbon atom or a hetero atom. Examples of the hetero atom include Group 15 and Group 16 atoms in the periodic table such as a nitrogen atom, an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom. Note that the carbon atoms in Y11, Y12, and Y31 may be atomic groups mainly composed of two carbon atoms such as an ethylene group and a vinylene group. Y11 and Y12 in the general formula of the monomethine cyanine dye may be the same as or different from each other.

  R11, R12, R13, R32, and R33 in the general formulas of the monomethine cyanine dye and the styryl dye represent an aliphatic hydrocarbon group. Examples of aliphatic hydrocarbon groups include methyl, ethyl, propyl, isopropyl, isopropenyl, 1-propenyl, 2-propenyl, butyl, isobutyl, sec-butyl, tert-butyl. Group, 2-butenyl group, 1,3-butadienyl group, pentyl group, isopentyl group, neopentyl group, tert-pentyl group, 1-methylpentyl group, 2-methylpentyl group, 2-pentenyl group, hexyl group, isohexyl group , 5-methylhexyl group, heptyl group, octyl group and the like. This aliphatic hydrocarbon group may have one or more substituents similar to those in Z1 to Z3.

  Note that R11, R12 in the general formula of the monomethine cyanine dye and R13, R32, R33 in the general formula of the styryl dye may be the same as or different from each other.

  R13 to R16, R34, and R35 in the general formulas of the monomethine cyanine dye and the styryl dye each independently represent a hydrogen atom or an appropriate substituent. Examples of the substituent include methyl group, trifluoromethyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, tert -Aliphatic hydrocarbon groups such as pentyl group, 1-methylpentyl group, 2-methylpentyl group, hexyl group, isohexyl group, 5-methylhexyl group, heptyl group, octyl group, methoxy group, trifluoromethoxy group, ethoxy Group, propoxy group, butoxy group, tert-butoxy group, pentyloxy group, phenoxy group, benzoyloxy group and other ether groups, fluoro group, chloro group, bromo group, iodo group and other halogen groups, further hydroxy group, A carboxy group, a cyano group, a nitro group, etc. are mentioned. In the general formulas of monomethine cyanine dye and styryl dye, when Y11, Y12, and Y31 are heteroatoms, a part or all of R13 to R16 in Z1 and Z2 and one of R34 and R35 in Z3 Or both will not exist.

  In the general formula of the azo metal complex, A and A ′ include one or more heteroatoms selected from a nitrogen atom, an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom. It represents a 5-membered to 10-membered heterocyclic group such as a furyl group, a thienyl group, a pyrrolyl group, a pyridyl group, a piperidino group, a piperidyl group, a quinolyl group, or an isoxazolyl group. This heterocyclic group is, for example, methyl group, trifluoromethyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, tert-pentyl group, 1-methylpentyl group, 2-methylpentyl group, hexyl group, isohexyl group, aliphatic hydrocarbon group such as 5-methylhexyl group, methoxycarbonyl group, trifluoromethoxycarbonyl group, ethoxycarbonyl group, Propoxycarbonyl group, acetoxy group, trifluoroacetoxy group, benzoyloxy group and other ester groups, phenyl group, biphenylyl group, o-tolyl group, m-tolyl group, p-tolyl group, o-cumenyl group, m-cumenyl group P-cumenyl group, xylyl group, mesityl group, styryl group, N'namoiru group, an aromatic hydrocarbon group such as a naphthyl group, more, carboxy group, hydroxy group, cyano group, which may have 1 or more substituents such as nitro groups.

  A specific example of what consists of a pigment part and a counter ion (anion) part is shown.

As a pigment | dye part, it is possible to have the structure shown to the following F1-F6.

Moreover, as a counter ion (anion) part, the structure shown to the following G1-G6 can be taken. These dye parts and counter ion parts can be used in appropriate combination.

  The azo compound constituting the azo-based organometallic complex represented by the general formula includes R21, R22 corresponding to the general formula or a diazonium salt having R23, R24 corresponding to the general formula, and carbonyl in the molecule. It can be obtained by reacting a heterocyclic compound having an active methylene group adjacent to the group, such as an isoxazolone compound, an oxazolone compound, a thionaphthene compound, a pyrazolone compound, a barbituric acid compound, a hydantoin compound, or a rhodanine compound. . Y21 and Y22 represent, for example, the same or different heteroatoms selected from Group 16 elements in the periodic table, such as an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom.

  The azo metal complex represented by the general formula is usually used in the form of a metal complex in which one or more of them are coordinated to a metal (central atom). Examples of metal elements that are central atoms include, for example, scandium, yttrium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium. , Iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury and the like, and cobalt is particularly preferable.

The central atom may be one or a plurality of so-called binuclear complexes. In that case, the ratio of ligand to central atom is 1: 2, 2: 2, 2: 3, 2: 4, 3: 3, 3: 4, 3: 5, 3: 6, 4: 4, It can be 4: 5, 4: 6, 4: 7, 4: 8, etc. Below, an example (H1) of a binuclear complex is shown.

  Here, R1 to R4 each independently represent a hydrogen atom or an appropriate substituent in each general formula. For example, when R1 = isopentyl group, R2 = R3 = ethyl group, and R4 = hydrogen, n can take a value from 2 to 6.

  FIG. 21A shows the change in absorbance of the dye A with respect to the wavelength of the irradiated laser beam. FIG. 22B shows a change in absorbance of the dye B with respect to the wavelength of the irradiated laser beam. FIG. 22C shows the change in absorbance of the dye C with respect to the wavelength of the irradiated laser beam.

  FIG. 22A shows a change in absorbance of the dye D with respect to the wavelength of the irradiated laser beam. FIG. 22B shows the change in absorbance with respect to the wavelength of the irradiated laser beam in the anion portion of the dye D.

  As is clear from the characteristics shown in FIGS. 21 and 22, the maximum absorption wavelength region of each of the dyes A to D is shifted to the longer wavelength side than the recording wavelength (405 nm). The recording optical disk described in this embodiment includes an organic dye having the above characteristics in the recording film, and has a higher light reflectance after laser light irradiation than that before laser light irradiation. By configuring so as to have the so-called L to H characteristics, even when a short wavelength laser beam such as a blue laser beam is used, storage durability, reproduction signal SN ratio, bit error rate, etc. It is possible to record and reproduce information with high density and sufficient performance suitable for practical use.

  That is, in this write-once optical disc, since the maximum absorption wavelength of the recording film containing the organic dye is on the longer wavelength side than the wavelength of the recording laser beam, it is possible to suppress the absorption of light having a short wavelength such as ultraviolet rays. Excellent light stability and high reliability of information recording and reproduction.

  Further, since the light reflectance is low at the time of recording information, cross-write due to reflection / diffusion does not occur. Therefore, even when information is recorded on the adjacent track, the reproduction signal SN ratio and bit error rate are Degradation can be reduced. Furthermore, the contrast and resolution of the recording mark can be maintained with high quality against heat, and the recording sensitivity can be easily designed.

  Next, the relationship between SbER, which is a recording characteristic index up to the information storage medium A-E, and β will be described. 13 is a diagram showing the relationship between SbER, which is a recording characteristic index of information storage medium A, and β, and FIG. 14 is a diagram showing the relationship between SbER, which is a recording characteristic index of information storage medium B, and β. FIG. 15 is a diagram illustrating the relationship between SbER, which is a recording characteristic index of the information storage medium C, and β, and FIG. 16 illustrates the relationship between SbER, which is a recording characteristic index of the information storage medium D, and β. FIG. 17 is a diagram illustrating a relationship between SbER, which is a recording characteristic index of the information storage medium E, and β.

  For information storage medium A, β is linear, but for information storage medium B, the slope of β changes near zero. Specifically, with respect to the information storage medium B, the smaller the β value, the smaller the β inclination, and the larger the β value, the larger the β inclination. Regarding the information storage medium C, the slope of β becomes smaller as the value of β is smaller than the value of β as 0.01. Regarding the information storage medium D, the slope of β changes when the value of β is around 0, and the slope of β increases as the value of β decreases. Regarding the information storage medium E, the inclination of β changes when the value of β is around −0.01, and the inclination of β increases as the value of β decreases.

  FIG. 18 is a diagram showing an example of setting β0, Pw0, α, and Pw in the above-described five types of information storage media A-E. The set β0 and α are stored in the management information storage area 32 of the information storage medium as described above.

  When the β slope is small (β value range) and the β slope is large (β value range), the measurement error is large on the small β slope side. For this reason, it is preferable not to use β0 for determining the optimum power.

  The change point of the slope of β is between 0.05 and -0.05 from the experimental results. In the vicinity of the change point, an error between the original optimum recording power and the recording power calculated by the calibration tends to increase when performing power calibration.

  When the value of β is larger than 0.20, the signal characteristic is greatly deteriorated and the signal amplitude is also decreased, so that the measurement error tends to increase. Further, when the value of β is smaller than −0.20, the signal characteristic is greatly deteriorated, and the measurement becomes difficult.

  Therefore, within the range of 0.20> β> 0.05 or within the range of -0.05> β> -0.20, set β0 and α on the side where the slope (change amount) of β is large, and perform power calibration from this value. Is preferred.

  Here, α is preferably in the range of 0.5 <α <1.5. Within this range, it is expected that the recording characteristics will be relatively good and the β measurement error will be small.

  The present embodiment will be summarized below.

  The information recording method uses a semiconductor laser having a wavelength of 450 nm or less, changes the recording power, records the test information in the test area of the information storage medium, reproduces the recorded test information, and indicates the asymmetry of the reproduced signal. The value is measured, and the value obtained by satisfying the following (formula 1) within the range of β> 0.05 (more specifically, the range of 0.20> β> 0.05 or the range of −0.05> β> −0.20) The optimum recording power Pw is obtained from the target β0 and the coefficient α, and actual recording information is recorded with the optimum recording power Pw.

Pw = α x Pw0 (Formula 1)
(Pw: optimum recording power, α: recording power coefficient, Pw0: recording power when β0)
According to this information recording method, for an information storage medium having the characteristic that the slope of β decreases in response to high recording power, any target β0 within the range in which the slope of β increases in response to low recording power. Is set, and the optimum recording power Pw is obtained from the relationship between the recording power Pw0 corresponding to the target β0 and the coefficient α. This makes it possible to record information with high quality.

  Further, according to this information recording method, for an information storage medium having the characteristic that the slope of β decreases in response to a low recording power, any information within a range in which the slope of β increases in response to a high recording power A target β0 is set, and the optimum recording power Pw is obtained from the relationship between the recording power Pw0 corresponding to the target β0 and the coefficient α. This makes it possible to record information with high quality.

  The information storage medium has at least a transparent resin substrate on which concentric or spiral grooves and lands are formed, and a recording layer formed on the grooves and lands of the transparent resin substrate, and the recording layer is , Has a predetermined area (management information storage area 32) including parameters related to recording, and this predetermined area stores information on targets β0 and α.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. In addition, the embodiments may be appropriately combined as much as possible, and in that case, the combined effect can be obtained. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be obtained as an invention.

It is a schematic diagram of an optical disk. It is a figure which shows an example of the layout of a lead-in area | region. It is a figure which shows an example of the physical format information recorded on the control data area. It is a figure which shows an example of the management information preserve | saved in a management information preservation | save area | region. 1 is a block diagram of an optical disc apparatus according to an embodiment of the present invention. It is a figure which shows an example of the reproduction | regeneration waveform (eye pattern) of a recording signal. FIG. 7 is a diagram showing a signal obtained by coupling the reproduction waveform of the recording signal shown in FIG. 6 with AC (Alternating current). It is a figure for demonstrating an example of the recording waveform by an optical disk apparatus. It is a figure for demonstrating another example of the recording waveform by an optical disk apparatus. 6 is a diagram showing a relationship between β and recording power of the information storage medium A. FIG. FIG. 4 is a diagram showing the relationship between β of information storage medium B and recording power. 6 is a diagram showing a result of finding a recording power by performing OPC five times on the information storage medium A. FIG. 6 is a diagram showing a result of finding a recording power by performing OPC five times on the information storage medium A. FIG. 10 is a diagram showing a result of applying OPC five times to information storage medium A. FIG. 10 is a diagram illustrating a result of applying OPC to the information storage medium B five times. 4 is a diagram showing the relationship between SbER, which is a recording characteristic index of information storage medium A, and β. FIG. 4 is a diagram showing a relationship between SbER and β, which are recording characteristic indexes of the information storage medium B. FIG. 6 is a diagram showing the relationship between SbER, which is a recording characteristic index of information storage medium C, and β. FIG. 6 is a diagram showing a relationship between SbER and β, which are recording characteristic indexes of the information storage medium D. FIG. 4 is a diagram showing a relationship between SbER and β, which are recording characteristic indexes of the information storage medium E. FIG. It is a figure which shows the example of a setting of (beta) 0, Pw0, (alpha), and Pw in five types of information storage media A-E. It is a flowchart which shows the outline | summary of the information recording method which concerns on one Embodiment of this invention. It is a figure which shows four examples of pigment | dye AD as an organic pigment | dye material which can be used as a L to H type organic pigment | dye layer. It is a figure which shows the change of the light absorbency with respect to the wavelength of the laser beam irradiated in pigment | dye AC. It is a figure which shows the change of the light absorbency with respect to the wavelength of the laser beam irradiated in the pigment | dye D, and the change of the light absorbency with respect to the wavelength of the laser beam irradiated in the anion part of the pigment | dye D.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical disk, 2 ... Clamp hole, 3 ... Lead-in area | region, 4 ... Data area | region, 5 ... Lead-out area | region, 6 ... BCA area | region, 11 ... PUH, 12 ... Preamplifier, 13 ... Signal processing circuit, 14 ... Control part, 15 ... LD driving circuit, 16 ... recording waveform generating circuit, 17 ... memory

Claims (6)

Record multiple test information by changing the recording power,
Playing back the plurality of recorded test information,
Of the β values indicating the asymmetry of each of the plurality of reproduction signals corresponding to the plurality of test information, a change amount of the β value in the first β value range larger than 0 is a second β value smaller than 0. A first recording power corresponding to a first β value included in the first β value range is detected based on information indicating that the amount of change in the β value is greater than the range;
Based on information indicating that the amount of change in β value in the second β value range is greater than the amount of change in β value in the first β value range, the second β value range includes Detecting a second recording power corresponding to a β value of 2;
Controlling the optimum recording power based on the first recording power and the predetermined coefficient, or the second recording power and the predetermined coefficient,
Record actual recording information with the optimum recording power,
An information recording method characterized by the above. Record multiple test information by changing the recording power,
Playing back the plurality of recorded test information,
Measuring a β value indicating asymmetry of each of a plurality of reproduction signals corresponding to the plurality of test information;
Measuring the amount of change in β value in the first β value range greater than 0 and the amount of change in β value in the second β value range less than 0;
When the amount of change in β value in the first β value range is larger than the amount of change in β value in the second β value range, the first β value included in the first β value range is Detecting the corresponding first recording power,
When the amount of change in β value in the second β value range is greater than the amount of change in β value in the first β value range, the second β value included in the second β value range Detecting the corresponding second recording power,
Controlling the optimum recording power based on the first recording power and the predetermined coefficient, or the second recording power and the predetermined coefficient,
Record actual recording information with the optimum recording power,
An information recording method characterized by the above. The range of the first β value is 0.20>β> 0.05,
The range of the second β value is −0.05>β> −0.20,
The information recording method according to claim 1 or 2, characterized in that Recording means for recording a plurality of test information by changing the recording power,
Reproducing means for reproducing the recorded plurality of test information;
Recording control means for controlling the optimum recording power;
With
The recording control means includes
Measuring a β value indicating asymmetry of each of a plurality of reproduction signals corresponding to the plurality of test information;
Measuring the amount of change in β value in the first β value range greater than 0 and the amount of change in β value in the second β value range less than 0;
When the amount of change in β value in the first β value range is larger than the amount of change in β value in the second β value range, the first β value included in the first β value range is Detecting the corresponding first recording power,
When the amount of change in β value in the second β value range is greater than the amount of change in β value in the first β value range, the second β value included in the second β value range Detecting the corresponding second recording power,
Controlling the optimum recording power based on the first recording power and the predetermined coefficient, or the second recording power and the predetermined coefficient,
The recording means includes
Record actual recording information with the optimum recording power,
An information recording apparatus characterized by that. Recording a plurality of test information by changing the recording power, reproducing the plurality of recorded test information, measuring a β value indicating the asymmetry of each of a plurality of reproduction signals corresponding to the plurality of test information, The amount of change in β value in the first β value range greater than 0 and the amount of change in β value in the second β value range less than 0 are measured, and the β value in the first β value range is measured. When the amount of change is larger than the amount of change in β value in the second β value range, the first recording power corresponding to the first β value included in the first β value range is detected, and When the amount of change in β value in the second β value range is larger than the amount of change in β value in the first β value range, it corresponds to the second β value included in the second β value range The second recording power is detected, the first recording power and the predetermined coefficient, or the first recording power An information storage medium for controlling the optimum recording power based on the recording power of 2 and the predetermined coefficient, and storing the actual recording information recorded by the optimum recording power,
A first region storing information about the first β value, the second β value, and the predetermined coefficient;
A second area for storing the plurality of test information;
A third area for storing actual recording information recorded with the optimum recording power;
An information storage medium comprising: Comprising an organic dye layer containing an organometallic complex,
6. The information storage medium according to claim 5, wherein the first, second, and third regions are formed in the organic dye layer.

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