HK1115933A - Data recording evaluation method and optical disk recording and reproduction device - Google Patents

Abstract

Novel evaluation indexes are introduced to allow both of a total evaluation of data recording and an evaluation of individual detection patterns. A data recording evaluation method includes a step of reproducing a result of data recording performed on an optical disk and identifying a predetermined detection pattern in a reproduction signal, a step of detecting a signal state of the reproduction signal associated with the predetermined detection pattern, and a first calculation step for calculating a first evaluation index value based on the detected signal state and a reference state identified from the predetermined detection pattern. When there is a plurality of predetermined detection patterns as described above, a second calculation step is further provided for calculating a second recording state evaluation index value using the first evaluation index value calculated from each of the predetermined detection patterns. Data recording can be properly evaluated using the first and second recording state evaluation index values.

Description

Data recording evaluation method and optical disc recording/reproducing apparatus

Technical Field

The present invention relates to a technique for evaluating data recording on an optical disc.

Background

Optical discs (referred to as optical discs), such as recordable blu-ray discs (referred to as BD-R) and recordable HD-DVD discs (referred to as HD-DVD-R), have a structure in which a recording layer, a reflective layer, and, if necessary, a protective layer are formed on one surface of a light transmissive disc substrate. On one surface of the substrate on which the recording layer and the reflective layer are formed, spiral or concentric grooves called grooves (grooves) are formed, and projections called lands (lands) are formed between adjacent grooves. In such an optical disc, recording is performed by forming pits (pits) by tracking a recording laser beam along grooves and irradiating the recording layer on the grooves with the laser beam by an optical disc recording/reproducing apparatus. Reproduction is performed by irradiating the reproduction laser beam and converting the reflected light into a reproduction signal, using the pit length nT (T is the bit length between reference channel clocks, and nT is the length of n integral multiples), the length nT of a part (hereinafter referred to as a space) between the pits, and the arrangement thereof.

The recording/reproducing apparatus for an optical disc that performs such recording and reproduction is designed to be applicable to recording conditions that are different for each recording on an individual optical disc depending on, for example, a drive, an optical disc (also referred to as a medium), a recording speed, and the like. In order to cope with the recording conditions, the recording/reproducing apparatus adopts a method of optimally setting the laser intensity (hereinafter, referred to as recording power). As this method, a device using OPC (Optimal Power Calibration) as a selection method is used. The OPC performs test recording by changing the recording power in a test Area (power calibration Area) in the recording disc before data recording. Then, the optimum recording power is selected and set to have a good recording quality in the test recording result by comparing the initial condition with the pre-recorded initial condition. The data recording area of the optical disc is recorded using the recording laser beam of the set optimum recording power. Next, various evaluation indexes are calculated from the waveform reproduced with the recording waveform, and after the optimum recording power is determined so that the evaluation index value can reach the target value or approach the target value, optimum recording correction is performed as a parameter indicating the recording state in accordance with the change in the recording/reproduction signal after the recording power condition is changed.

There are many forms of such methods, and in a brief description, examples of using PRML (Partial response maximum Likelihood) signal processing techniques are included. The PRML signal processing method processes an incomplete frequency response having inter-code interference left in relation to a frequency response for realizing a distortion-free condition, and combines the incomplete frequency response with a maximum likelihood decoding technique to eliminate the inter-code interference and prevent the signal quality from being degraded.

For example, japanese patent laid-open No. 2004-335079 discloses a technique of setting a recording parameter most suitable for a maximum likelihood decoding method. Specifically, for each combination of a predetermined mark length and a preceding space length and for each combination of a mark length and a following space length, a reliability value | Pa-Pb | -Pstd corresponding to a maximum likelihood decoding result of a portion where the recording mark edge starts and ends and where the error occurrence probability is high in the maximum likelihood decoding method is calculated, a recording parameter for optimizing the edge shift position is obtained from the calculation result, and the content reflecting the obtained recording parameter is recorded.

Further, japanese patent laying-open No. 2003-303417 discloses a technique for optimizing a recording strategy with high accuracy without being affected by noise even in high-density recording. Specifically, the pulse response is set so as to minimize the difference between a reproduction waveform obtained by recording and reproducing a recording pulse signal in which a high-frequency pulse is superimposed on recording data on an optical recording medium and a waveform obtained by convolving the recording data with the pulse response, thereby optimizing the recording strategy. In this case, the same recording pulse waveform is recorded 3 times or more on the same track of the optical recording medium, and a value obtained by averaging sampling values of the reproduced waveform in each sampling order is used as data of the reproduced waveform. Since the averaged data is used, the influence of random noise on the reproduction waveform can be removed.

Further, Japanese patent laid-open No. 2003-151219 discloses a technique related to the quality evaluation of a reproduced signal. Specifically, a predetermined reproduction signal, a 1 st pattern corresponding to a signal waveform pattern of the reproduction signal, and an arbitrary pattern (2 nd or 3 rd pattern) other than the 1 st pattern and corresponding to a signal waveform pattern of the reproduction signal are used. First, a distance difference D between a distance Eo between a reproduction signal and the 1 st pattern and a distance Ee between the reproduction signal and an arbitrary pattern is obtained as Ee-Eo. Next, the distribution of the distance difference D is obtained for a plurality of samples of the reproduction signal. Then, a quality evaluation parameter (M/σ) of the reproduced signal is set based on a ratio between the average M of the obtained range differences D and the distribution standard deviation σ of the obtained range differences D. Then, the quality of the reproduction signal is determined based on an evaluation index value (Mgn) indicated by the quality evaluation parameter.

Further, japanese patent laid-open No. 2003-141823 discloses a technique for evaluating signal quality based on an index that can appropriately predict an error rate of a binarization result obtained by using maximum likelihood decoding. Specifically, in a maximum likelihood decoding method that has a plurality of states at time k (k is an arbitrary integer) and has state transition terms for obtaining n (n is an integer of 2 or more) state transition arrangements from a state at time k-j (j is an integer of 2 or more) to a state at time k, and estimates a most probable state transition arrangement among the n state transition arrangements, a state transition likelihood value from the state at time k-j to the state at time k in the most probable state transition arrangement among the n state transition arrangement transition arrangements is represented by PA, a state transition likelihood value from the state at time k-j to the state at time k in the second most probable state transition arrangement is represented by PB, and a reliability of a decoding result from the state at time k-j to the state at time k is represented by | PA-PB', the value of PA-PB is obtained at a predetermined time or a predetermined number of times, and the deviation is obtained, thereby obtaining an index representing the signal quality related to the error rate of the binarization result of the maximum likelihood decoding.

Further, japanese patent laying-open No. 2002-197660 discloses a recording state detection technique that can detect a recording state matching a channel when reproducing information recorded at high density using a viterbi detector. Specifically, a reproduced signal read from the optical disc device is corrected to a specific channel characteristic by a band-limiting filter and an equalizer, and then read as a Digital signal x by an a/D (Analog to Digital) converter at the timing of a synchronous clock generated by a PLL (Phase-Locked Loop) circuit_i. X is to be_iThe output signal is input to a Viterbi detector to obtain a Viterbi detected output signal. Will be provided withThe Viterbi detection output is input to the reference level determiner and the error calculating circuit. Error calculation circuit calculates digital signal x_iDifference E of the sum Viterbi detection output_iAnd then output to the recording state detection circuit. The recording state detection circuit detects the amplitude or amplitude level and asymmetry using the output of the reference level determiner, and outputs detection information.

[ patent document 1] Japanese patent laid-open No. 2004-335079

[ patent document 2] Japanese patent laid-open No. 2003-303417

[ patent document 3] Japanese patent laid-open No. 2003-151219

[ patent document 4] Japanese patent laid-open No. 2003-141823

[ patent document 5] Japanese patent application laid-open No. 2002-197660

Disclosure of Invention

As described above, although there are various techniques for evaluating data records, it is not possible to appropriately link evaluation of the entire data record with evaluation of the data record of an individual recording pattern.

Therefore, an object of the present invention is to provide a technique for comprehensively evaluating data records by introducing a new evaluation index.

Another object of the present invention is to provide a technique for introducing a new evaluation index to appropriately evaluate an individual recording pattern.

Another object of the present invention is to provide a technique for appropriately linking the overall evaluation of data records and the evaluation of individual record pattern data records.

Another object of the present invention is to provide a technique for appropriately adjusting recording conditions and recording parameters in accordance with evaluation of data recording.

The data recording and evaluating method of the present invention comprises the steps of: reproducing a specific period of a result of data recording on the optical disc, and detecting a reproduction signal based on the reproduction; specifying a predetermined detection pattern including a code based on the detected reproduction signal; detecting a signal state of the reproduction signal corresponding to the detection pattern; and a 1 st calculation step of calculating a 1 st evaluation index value based on the detected signal state and a reference state specified by the detection pattern.

By calculating the 1 st evaluation index value, it is possible to determine whether or not appropriate data recording is performed in relation to the reference state with respect to a predetermined detection pattern. That is, the evaluation of the individual recording pattern can be appropriately determined.

In addition, the data recording and evaluating method may further include a 2 nd calculation step of calculating a 2 nd evaluation index value using a 1 st evaluation index value associated with each of the predetermined detection patterns when the predetermined detection patterns are plural. By calculating the 2 nd evaluation index value in this manner, comprehensive evaluation data recording can be performed for various recording patterns.

In addition, the data record evaluation method may further include a 1 st modification step of modifying the recording condition of the data record based on the 2 nd evaluation index value. The recording conditions for data recording can be appropriately adjusted in a comprehensive form according to the 2 nd evaluation index value.

The 2 nd calculation step may include a step of cumulatively calculating a plurality of products of the appearance probability of the predetermined detection pattern and the evaluation index value of the 1 st recording condition for each detection pattern that matches the appearance probability. The reason for this is that the weight is increased for more appearing detection patterns, and the influence on the data record is comprehensively reflected in the 2 nd evaluation index value.

In addition, the data recording evaluation method of the present invention may further include the steps of: judging whether the 2 nd evaluation index value exceeds a preset threshold value; and when the 2 nd evaluation index value exceeds the predetermined threshold value, specifying the detection pattern that exerts an influence of a certain degree or more (for example, a specific value or more or a specific number of more) on the 2 nd evaluation index value according to the corresponding 1 st recording state evaluation index value. Whereby a recording pattern in which a problem occurs can be specified.

Furthermore, the data recording evaluation method of the present invention may further include a 2 nd modification step of modifying a recording parameter used in data recording based on a 1 st evaluation index value associated with the specified detection pattern. Thereby, recording parameter adjustment can be performed efficiently.

In some cases, the detection pattern includes at least one mark and one space.

Further, the frequency of occurrence of the predetermined detection pattern may be equal to or higher than a predetermined value. When the frequency of occurrence is too low, the predetermined detection pattern is removed from the processing object in order to reduce the processing load.

The 1 st modification step may include a step of specifying the recording condition when the 2 nd evaluation index value reaches an optimum value, based on data indicating a relationship between the recording condition and a 2 nd evaluation index value calculated from data obtained during a specific period of reproducing a data recording result in the recording condition. For example, the optimum recording conditions at the time of data recording may be specified before the start of data recording.

The 1 st modification step may include a step of calculating a correction amount of the current recording condition using data indicating a relationship between the recording condition and a 2 nd evaluation index value calculated from data obtained during a specific period of reproducing a data recording result in the recording condition and the current 2 nd evaluation index value. As described above, the 2 nd evaluation index value may be used when adjusting the recording conditions when recording data.

The data indicating the relationship between the recording condition and the 2 nd evaluation index value calculated from the data obtained in the specific period of the data recording result in the recording condition may be data obtained in the test recording. This is because if test recording is being performed, the recording conditions can be changed and the 2 nd evaluation index value for each recording condition can be calculated.

The 2 nd modification step may include a step of specifying the recording parameter when the 1 st evaluation index value reaches the optimum value, based on data indicating a relationship between the recording parameter and the 1 st evaluation index value calculated from data obtained during a specific period of reproducing the data recording result using the recording parameter.

The 2 nd modification step may include a step of calculating a correction amount of the current recording parameter using data indicating a relationship between the recording parameter and a 1 st evaluation index value calculated from data obtained during a specific period of reproducing a data recording result using the recording parameter, and the current 1 st evaluation index value.

The data indicating the relationship between the recording parameter and the 1 st evaluation index value calculated from the data obtained during the specific period of reproducing the data recording result using the recording parameter is the data obtained at the time of test recording.

The 1 st calculation step may include a step of calculating a magnitude of a difference between the detected signal state and a reference state specified by a predetermined detection pattern. Thus, the optical disc recording and reproducing system for high-density recording and reproducing using the PRML signal processing method (a system conforming to the Blu-ray standard or the HD-DVD standard) can be sufficiently supported.

The optical disc recording/reproducing system for high-density recording/reproducing (referred to as an optical disc recording/reproducing apparatus) of the present invention includes: means for reproducing a predetermined period of time after the data recording result on the optical disk and designating a predetermined detection pattern in the reproduced signal; means for detecting a signal state of a reproduction signal corresponding to the detection pattern; and means for calculating a 1 st evaluation index value based on the detected signal state and a reference state specified by the detection pattern.

In addition, the optical disc recording and reproducing system according to the present invention may further include 2 nd calculation means for calculating a 2 nd evaluation index value using the 1 st evaluation index value associated with each of the detection patterns when the predetermined detection pattern is a plurality of patterns.

The optical disc recording and reproducing apparatus of the present invention may further include 1 st changing means for changing the recording condition for data recording based on the 2 nd evaluation index value.

The 2 nd calculation means cumulatively calculates a plurality of products of the appearance probability of the predetermined detection pattern and the 1 st evaluation index value.

The optical disc recording and reproducing apparatus of the present invention may further include: a means for judging whether or not the 2 nd evaluation index value exceeds a predetermined threshold value; and a means for specifying a detection pattern that affects the 2 nd evaluation index value to a certain extent or more, based on the corresponding 1 st evaluation index value, when the 2 nd evaluation index value exceeds a predetermined threshold value.

The optical disc recording and reproducing apparatus of the present invention may further comprise a 2 nd modification unit configured to modify a recording parameter used for data recording based on a 1 st evaluation index value associated with the specified detection pattern.

The 1 st optical information recording medium of the present invention records a 2 nd evaluation index value threshold value, wherein the 2 nd evaluation index value threshold value is obtained by cumulatively calculating a plurality of products of the following 1 st evaluation index value and the following detection pattern appearance probability, and the 1 st evaluation index value corresponds to a deviation between a signal state of a reproduction signal corresponding to a detection pattern specified by a reproduction signal and a reference state specified by the detection pattern.

The 2 nd optical information recording medium of the present invention records data indicating a relationship between a 2 nd evaluation index value obtained by cumulatively calculating a plurality of products of a 1 st evaluation index value and an appearance probability of the detection pattern, and a recording condition of data recording as a basis for calculating the 2 nd evaluation index value, the 1 st evaluation index value corresponding to a deviation between a signal state of the reproduction signal corresponding to the detection pattern specified by the reproduction signal and a reference state specified by the detection pattern.

In the 3 rd optical information recording medium of the present invention, data indicating a relationship between a 1 st evaluation index value corresponding to a deviation between a signal state of the reproduction signal corresponding to a detection pattern specified by a reproduction signal and a reference state specified by the detection pattern and a recording parameter of data recording as a basis for calculating the 1 st evaluation index value is recorded.

A program for causing a processor to execute the data recording evaluation method of the present invention can be created, and the program is stored in a storage medium or a storage device such as an optical disk such as a floppy disk or a CD-ROM (Compact disk-Read Only Memory), a magneto-optical disk, a semiconductor Memory, or a hard disk, or a nonvolatile Memory of the processor. Also, the program may sometimes be distributed as a digital signal through a network. The data in the middle of the processing is temporarily stored in a storage device such as a memory of the processor.

[ Effect of the invention ]

According to the invention, new evaluation indexes can be imported to comprehensively evaluate data records.

Further, according to another aspect of the present invention, a new evaluation index can be introduced to appropriately evaluate the individual recording pattern.

In addition, according to another aspect of the present invention, the overall evaluation of the data record and the evaluation of the data record with respect to the individual record pattern can be appropriately linked.

In addition, according to another aspect of the present invention, the recording conditions and the recording parameters can be appropriately adjusted according to the evaluation of the data recording.

Drawings

FIG. 1 is a diagram illustrating the time transition of amplitude levels.

Fig. 2 is a diagram showing a relationship between a recording pattern and an appearance probability.

Fig. 3 is a diagram showing the relationship between the effective pattern and the PRerror _ ttl and the pattern efficiency.

Fig. 4 is a diagram showing a relationship between the recording power and DCJ and PRerror _ ttl.

Fig. 5 is a diagram showing a relationship between the recording power and SER and the PRerror _ ttl.

Fig. 6 is a diagram showing the relationship between the recording parameters dTtop2T, SER, and PRerror _ ttl.

Fig. 7 is a schematic diagram of changing the PRerror _ ptn (p) after the recording pattern is changed.

Fig. 8 is a schematic diagram of changing the PRerror _ ptn (p) after the recording pattern is changed.

Fig. 9 is a schematic diagram of changing the PRerror _ ptn (p) after the recording pattern is changed.

Fig. 10 is a schematic diagram of changing the PRerror _ ptn (p) after the recording pattern is changed.

Fig. 11 is a schematic diagram of changing the PRerror _ ptn (p) after the recording pattern is changed.

Fig. 12 is a schematic diagram of changing the PRerror _ ptn (p) after the recording pattern is changed.

Fig. 13 is a schematic diagram of changing the PRerror _ ptn (p) after the recording pattern is changed.

Fig. 14A is a schematic diagram of changing the PRerror _ ptn (p) after the recording pattern is changed.

Fig. 14B is a diagram showing the relationship between dTtop2T and PRerror _ ptn (p).

Fig. 15 is a functional block diagram of an optical recording/reproducing system according to an embodiment of the present invention.

Fig. 16 is a schematic diagram of a processing flow for optimizing recording conditions before data recording.

Fig. 17 is a schematic diagram of a process flow for optimizing recording parameters prior to data recording.

Fig. 18 is a schematic diagram of a processing flow for correcting recording conditions in data recording.

Fig. 19 is a schematic diagram of the processing flow of the recording condition correction amount determination processing.

Fig. 20 is a schematic diagram of a processing flow for correcting recording parameters in data recording.

Fig. 21 is a schematic diagram showing the flow of the recording parameter correction amount determination process.

Fig. 22 is a schematic diagram showing an example of a data structure when reference data is stored on an optical disc.

[ description of symbols ]

1 optical unit (PU)

3 Pre-equalizer (Pre-EQ)

5 ADC

7 equalizer

9 viterbi decoder

11 control part

13 recording waveform generating part

15 optical disk

111 code recognition unit

113 detection instruction unit

115 detection part

117 arithmetic unit

Detailed Description

[ principles of the invention ]

(1) PRerror of different patterns

Fig. 1 shows the amplitude level when a predetermined detection pattern is read together with a pattern including a 3T space (a 3T-length space, also referred to as a land) adjacent to both sides of a 4T mark (a 4T-length mark, also referred to as a pit), for example. In fig. 1, the vertical axis represents the amplitude level, and the horizontal axis represents the data sample of the position information in the extending direction of the 4T mark affected by the adjacent 3T interval. The influence of the adjacent interval becomes larger as it is separated from the center position of the 4T mark. In the graph described above, the ideal detection signal (ideal signal), i.e., the reference state, is a value obtained by converting the ideal signal obtained from the distribution value (1, 3, 5, 6, 5, 3, 1) into an amplitude level and plotting the amplitude level under, for example, a medium condition in which the mark length is a condition that the amount of reflected light at the mark portion is larger than the amount of reflected light at the space portion, i.e., a "Low to High" condition, when PR (1, 2, 2, 1) used in the Blu-ray specification is used. In contrast, the amplitude level at the center position of the 4T mark in the actual detection signal reaches the peak value, but the value of the amplitude level affected by the adjacent interval at a position away from this center position is converted into the same proportion as the ideal signal value, and then the actual detection signal is plotted. As shown in fig. 1, the value deviates from the reference state depending on the hard disk, medium (also referred to as optical disk), recording condition. Therefore, the deviation amount (1 st evaluation index value) between the ideal signal and the detection signal is specified by using the formula (1), and the recording state is evaluated (1 st calculation step).

[ number 1]

Here, D (x) represents the value of the detection signal, R (x) represents the value of the ideal signal, x represents the data distribution number, a represents the operation start data number, n represents the number of operation data samples [ number ], and p represents the recording pattern type (number).

In the above description, PR (1, 2, 2, 1) in the Blu-ray standard is used for description, but PR (1, 2, 2, 2, 1) in the HD-DVD standard may be used. In addition, a medium condition that the amount of reflected light of the mark portion is smaller than that of the space portion, that is, a "High to Low" condition, may be adopted, which is different from the example shown here. The graph is an example, and other graphs may be evaluated using formula (1). For example, the object of the present invention can be achieved without fail by using a 2T interval or mark, a 2T mark or space, a 2T interval or mark collection code pattern (also referred to as a collection recording pattern), a 2T interval or mark, a 3T mark or space, a 2T interval or mark collection recording pattern, a 2T interval or mark, a 4T mark or space, a 2T interval or mark collection recording pattern, a 3T interval or mark, a 2T mark or space, a 3T interval or mark collection recording pattern, a 4T interval or mark, a 2T mark or space, a 4T interval or mark collection recording pattern, a 4T interval or mark, a 3T mark or space, a 4T interval or mark collection recording pattern, or the like.

For example, the 1 st evaluation index value, namely, the PRerror _ ptn (p) is calculated using 7 points where a is 1 and n is 7 and the peak is the center, but the PRerror _ ptn (p) may be calculated using 3 points where a is 3 and n is 3 and the peak is the center. Further, p is a number assigned to specify the collection record pattern, and the number thereof is the number of the collection record patterns necessary for evaluation, and varies depending on how many code arrangements the unit structure of the collection record pattern is defined. It is noted here that in the calculation, the example of fig. 1 must simultaneously reflect the interval mark intervals and mark interval marks as 1 collective recording pattern. That is, better results can be obtained by reflecting both the mark and the space in the same set recording pattern of nT. Although the above description has been made using three nT set recording patterns, the object of the present invention can be achieved regardless of whether two nT set recording patterns, four nT set recording patterns, or five nT set recording patterns are set recording patterns whose occurrence probability affects an error.

Equation (1) represents the calculation performed when the recording pattern p is detected 1 time, and actually, it is preferable to take the average value of a plurality of (cnt (p)) values in consideration of the influence of recording or detection unevenness. cnt (p) is a detection count value of the set recording pattern p obtained from sample data of a specific length, and when deriving the final value of the prrror _ ptn (p), it is preferable to record the prrror _ ptn (p) calculated for each detection as the prrror _ ptn (p, cnt (p)) in a memory and then perform an averaging process using the following value.

(2) Comprehensive evaluation index PRerror _ ttl

Next, a method of comprehensively evaluating a reproduction signal using the aforementioned priror _ ptn (p) will be described.

Within a predetermined data range, the frequency of occurrence of the collective recording pattern p is different, and the degree of influence on the recording characteristics is also different. That is, the higher the frequency of occurrence of the recording pattern, the more easily the recording characteristic is affected. Therefore, when comprehensively evaluating the recording characteristics of the reproduction signal, it is preferable to calculate the 2 nd evaluation index value, i.e., the PRerror _ ttl (p) — that comprehensively quantifies the recording characteristics of the reproduction signal, using the characteristic value PRerror _ ptn (p) of the collective recording pattern p and the appearance probability (or appearance frequency) of the recording pattern p in a predetermined data range (also referred to as the 2 nd calculation step). Specifically, PRerror _ ttl is calculated according to the following equation.

[ number 2]

Probability of occurrence (p)

Fig. 2 shows an example of the relationship between a plurality of collection record patterns and the occurrence probability thereof. In fig. 2, the vertical axis represents the appearance probability when all the record patterns are set to 100%, and the horizontal axis represents the record pattern type when 1 set record pattern is arranged in an array of 3 set codes [ T ]. In the horizontal axis symbols, 2 represents the first (front) interval or mark code representing x, y and z represent the second (center) mark or interval code y [ T ] and the third (rear) interval or mark code z [ T ], respectively, and the values of y and z are 2 to 8[ T ] (9 [ T ] when a synchronization code is included) represented by the 1-7PP modulation method adopted in the Blu-ray standard, and the values are larger toward the right side in FIG. 2. As can be seen from fig. 2, the shorter the code is, the higher the occurrence probability is, and therefore, the higher the occurrence probability is for the set recording pattern using the short code. In contrast, a recorded pattern using a long code has a low probability of occurrence. If the mark or the interval with the short code is repeated as described above, the amplitude level of the reproduced signal is small, and thus an error is likely to occur in the display. This is the reason for adopting the probability of occurrence in the present invention.

As described above, if the probability of occurrence is high, it can be said that the recording characteristic of the recording pattern, i.e., the size of the formula value of the PRerror _ ptn (p), has a large influence on the entire recording characteristic. Conversely, for an aggregate recording pattern with a very low probability of occurrence, the size of the value of the recording characteristic (the PRerror _ pt (p)) is hardly reflected in the entire recording characteristic, and therefore, it can be disregarded.

Therefore, as shown in fig. 2, the recording characteristics of the reproduction signal can be comprehensively quantified by using a predetermined occurrence probability as a predetermined value and only recording patterns equal to or greater than the predetermined value as effective patterns. As a result, the accuracy of the characteristic value (PRerror _ ttl) to be obtained can be maintained, and the calculation load of the characteristic value can be reduced.

In fig. 3, when the appearance probability predetermined value is changed, the change in the ratio of the total number of effective patterns (pattern effective rate) among the total number of all recorded patterns in a predetermined measurement range and the change in the PRerror _ ttl at that time are plotted, and the relationship therebetween is shown. In fig. 3, the left vertical axis represents the value of PRerror _ ttl, the right vertical axis represents the graph effective rate, and the horizontal axis represents the predetermined value (threshold) of the effective graph.

From fig. 3, it can be confirmed that, even if the characteristic value PRerror _ ttl is not calculated using a recording pattern whose occurrence probability is lower than a predetermined value, a predetermined value that can ensure the accuracy of the PRerror _ ttl can be set. That is, in the verification result of fig. 3, the PRerror _ ttl hardly changes even if the predetermined value is set to 0.3%. Further, since the effective pattern rate is about 70%, the operation load can be reduced by about 30%.

As described above, the accuracy can be ensured without calculating the PRerror _ ptn (p) for all the recording patterns, by calculating the PRerror _ ptn (p) for the recording patterns having the occurrence probability of 0.3% or more, for example, and the comprehensive evaluation index PRerror _ ttl can be calculated.

Next, the change in the PRerror _ ttl after the recording power is continuously changed is compared with the DC jitter (also referred to as DCJ) and the bit error rate (also referred to as SER) which are current evaluation indexes, and is shown in fig. 4 and 5. In fig. 4, the left vertical axis represents DCJ [% ], the right vertical axis represents PRerror _ ttl, and the horizontal axis represents recording power [ mW ]. In fig. 5, the left vertical axis represents SER, the right vertical axis represents PRerror _ ttl, and the horizontal axis represents recording power [ mW ].

As is clear from fig. 4 and 5, the evaluation value PRerror _ ttl is an index that is closely related to the current evaluation index (DCJ and SER). Therefore, the recording characteristics can be improved by adjusting the recording conditions in accordance with the change in this evaluation value priror _ ttl (this adjustment will be carried out as a 1 st modification step). Specifically, when the pre _ ttl can be calculated for a plurality of recording conditions, the optimal recording characteristics can be obtained by adopting and setting the recording condition under which the pre _ ttl becomes the minimum. Also, although detailed description will be made below, even in the case where the priror _ ttl cannot be calculated for a plurality of recording conditions, the recording conditions may be adjusted using the priror _ ttl calculated from the detection result. In this modification 1, in actual operation, when the error _ ttl as the 2 nd evaluation index value is set to be smaller within a range of a fixed value or less in consideration of the data in fig. 4 and 5, the recording quality of the optical disc can be kept high. For example, in FIG. 4, if DCJ [% ] is about 7% or less, the desired result can be obtained. If the number of PRERROR _ tt is substantially 0.17 or less, the same object can be achieved. Further, for example, in FIG. 5, when the SER is about 2.0E-04 or less, a satisfactory result can be obtained. If the same as the aforementioned PRERROR _ ttl is approximately 0.17 or less, a result suitable for the purpose can be obtained.

(3) Evaluation of influence quantity of different set recording graphs on comprehensive evaluation index PRerror _ ttl

Next, a method of evaluating the recording state of each recording pattern by comparing the influence amounts (PRerror _ ptn (p)) of different sets of recording patterns constituting the PRerror _ ttl will be described.

When writing a signal to an optical disc as a code, writing is performed while controlling the laser intensity. In order to write a mark having a length of not less than 3T mark, for example, among marks having a fixed width nT code, the laser beam is divided into a plurality of short rectangular waves instead of a single rectangular wave, and heat is sometimes left at the end of writing by performing heat control. The way in which writing is done in this way using the modulation waveform is called the light trajectory. When writing is started, laser irradiation is performed while controlling the amount of shift moving forward and backward from the reference position (0) of the start position (called dTtop) of the front end pulse so that a mark of length nT can be written at a fixed width from the target position.

Fig. 6 shows changes in the PRerror _ ttl and SER after only the center y after the interval 2T is changed in the specific rule parameter dTtop 2T. In fig. 6, the left vertical axis represents prrror _ ttl, the right vertical axis represents SER, and the horizontal axis represents dTtop 2T. As described above, it can be confirmed that, with respect to the change of dTtop2T, both of the prrror _ ttl and the SER exhibit the same U-shape with the minimum change in value. It is also known that the actual PRerror _ ttl and SER minima are both around-1. The value is detected and reflected in the amount of shift from the reference position of the start position (referred to as dTtop) of the front end pulse.

Fig. 7 to 10 are general experimental data showing the influence amount (prrror _ ptn (p)) of different recording patterns of prrror _ ttl when the correction amount of dTtop2T in fig. 6 is 0. FIG. 7 shows each PRerror _ ptn (p) in the case where the main code is a flag nT [ T ] and the adjacent code is a preceding interval nT [ T ] as the Pit _ f pattern. Fig. 8 shows each of the prrror _ ptn (p) when the main code is a flag nT [ T ] and the adjacent code is a rear interval nT [ T ] as the Pit _ r pattern. FIG. 9 shows each PRerror _ ptn (p) in the case where the main code is a space nT [ T ] and the adjacent code is a forward flag nT [ T ] as a Land _ f pattern. FIG. 10 shows each PRerror _ ptn (p) in the case where the main code is interval nT [ T ] and the adjacent code is rear flag nT [ T ] as the Land _ r graph.

In fig. 7 to 10, the reason why the influence amount of the pattern including the short code such as the mark 2T or the space 2T is large is that the 2T code is difficult to form an opening and easily deviates from the ideal state, and the appearance probability of the pattern including the code is high.

As described above, each collective recording pattern can be evaluated by the PRerror _ ptn (p) constituting the integrated evaluation index value PRerror _ ttl.

In fig. 7 to 10, only the influence of the combined pattern of the main code and the one-side adjacent code (front or rear) is shown due to the problems shown in the figures, but in an actual system, it is more preferable to evaluate the collective pattern in which the main code and both-side adjacent codes (front and rear) are combined. In addition, graphics may be included that combine codes further forward or further rearward of the adjacent code as appropriate.

Next, a change in the influence amount (PRerror _ ptn (p)) of different patterns after dTtop2T is continuously changed (-2 to +1) will be described. Fig. 11 to 14A show changes in the Pit _ f pattern (the main code is a flag nT [ T ], and the adjacent code is a forward interval nT [ T ]) that significantly indicate the influence of changes in dTtop 2T.

As is clear from fig. 11 to 14A, the change in dTtop2T largely affects the PRerror _ ptn (p) corresponding to the recording pattern, such as the flag 2T after the interval 2T. In particular, when dTtop2T is-2 (fig. 11), the effect is significantly increased.

Next, fig. 14B shows a change in the PRerror _ ptn (p) of the recording pattern such as the flag 2T after the interval 2T with respect to a change in the recording parameter such as dTtop 2T. In fig. 14B, the vertical axis represents prrror _ ptn (p), and the horizontal axis represents dTtop 2T. Further, the diamond-shaped points represent actual calculated values, and the curves represent results of 2-time curve regression based on the actual calculated values. If such data is used, the recording parameter dTtop2T may be optimized or adjusted using the prrror _ ptn (p) (this adjustment will be referred to as the 2 nd modification step).

In addition, dTtop2T is described above as an example of the variation parameter, and may be applied to various recording parameters. In fig. 11 to 14A, changes in the amount of influence of the marks after the preceding interval in the combination pattern are shown, and the selection of the combination pattern is determined by the recording parameters. When the PRerror _ ptn (p) of the specific recording pattern indicates a large value and it is determined that the processing is necessary, a recording parameter that can be associated with the adjustment target may be specified.

[ embodiment ]

Fig. 15 is a functional block diagram of an optical disc recording and reproducing system according to an embodiment of the present invention. The optical recording/reproducing system of the present embodiment includes: an optical unit (PU) l for recording or reproducing the optical disc 15 by irradiating laser light; a Pre-equalizer (Pre-EQ)3 for performing waveform equalization processing to easily convert the electric signal from the photodetector included in the optical unit 1 into a digital signal of the next step; an ADC (Analog Digital Converter) 5 that converts an Analog signal into a Digital signal; an equalizer 7 for equalizing the binarized digital signal into a waveform in which the amplitude level at the center position in the nT flag length direction reaches a peak value with respect to the incomplete frequency response of the residual inter-code interference, and the value of the amplitude level affected by the adjacent nT intervals along the position apart from the center position reaches the same ratio as the ideal signal waveform; a viterbi decoder 9 for selecting and decoding a most probable standard signal series from the reproduced signal converted by the equalizer 7 and subjected to waveform equalization processing, and outputting a maximum likelihood decoded signal (a signal returned to a binarized digital signal) close to an ideal signal without being affected by noise; a control unit 11 that performs processing using outputs from the equalizer 7 and the viterbi decoder 9; and a recording waveform generating section 13 that generates a recording waveform for writing data (Write data) according to the setting output of the control section 11 and outputs the recording waveform to the optical unit 1.

The high-density optical recording/reproducing system is connected to a display device or a personal computer, not shown, and may be connected to a network to communicate with 1 or more computers, depending on the case.

The control unit 11 includes: a code identifying unit 111 for correlating the output of the equalizer 7 (the reproduced RF signal obtained by subjecting the waveform to linear equalization) with the output of the viterbi decoder 9 (maximum likelihood decoded code data); a detection instruction section 113 that specifically instructs detection of the amplitude level when the occurrence of a predetermined detection pattern, for example, a recording state of the nT flag amplitude level affected by an adjacent nT interval is detected based on the code data from the code recognition section 111; a detection unit 115 for detecting a signal state of an amplitude level of the RF signal from the code recognition unit 111 in accordance with an instruction from the detection instruction unit 113; and a calculation unit 117 having a memory (not shown) and generating a reference state based on an output from the detection unit 115, and performing the calculation described below to set the recording waveform generation unit 13. The arithmetic unit 117 may be realized by combining a program for implementing the functions described below with a processor, for example. In this case, a program may be stored in a memory in the processor.

Next, the processing contents of the optical recording and reproducing system will be described with reference to fig. 16 to 21. First, a description will be given of a recording condition optimization process that is performed before data recording and uses a test writing area provided on the innermost circumference of the optical disc 15.

First, a procedure of generating a reference signal of an amplitude level as a part of the operation of fig. 15 will be described with reference to fig. 16. For example, the calculation unit 117 of the control unit 11 sets predetermined recording conditions as parameters for the individual optical disk in the recording waveform generation unit 13 (step S1). Next, the recording waveform generating section 13 writes a predetermined recording pattern in the trial writing area of the optical disc 15 by the PU1 according to the set recording conditions (step S3). Then, the PU1, the pre-equalizer 3, the equalizer 7, and the viterbi decoder 9 read the writing result performed in step S3, and the code identification unit 111 associates the output of the equalizer 7 with the output of the viterbi decoder 9. The detection instruction unit 113 sets all detection patterns (detected codes [ T ]) according to the settings]And (4) columns. The same as the recorded pattern if correctly decoded) or a predetermined effective pattern is detected, the detection section 115 is instructed to detect the amplitude level of the RF signal. The detection unit 115 detects the amplitude level of the RF signal based on the instruction signal from the detection instruction unit 113, and outputs the detection result to the calculation unit 117. Next, the arithmetic unit 117 calculates the PRerror _ ptn (p) for each detection pattern p, and stores the calculated result in a storage device such as a memory (step S5). As described above, since the detection pattern p is detected a plurality of times, an average value is calculated for the PRerror _ ptn (p). In additionIn addition, the specific detection pattern p to be used later is stored in the arithmetic section 117_cThe relative amplitude level of (c). It is also possible to store only the peak values.

Thereafter, the arithmetic unit 117 calculates the error _ ttl for each detection pattern p calculated in step S5 using the error _ ptn (p) and the appearance probability of each detection pattern p stored in the memory in advance, and stores the calculated error _ ttl in a storage device such as a memory in accordance with the recording conditions set in step S1 (step S7). This data can also be used for adjustment of recording conditions in data recording.

Next, the arithmetic unit 117 determines whether or not all predetermined recording conditions, for example, test records, are set (step S9), and if there are any unset recording conditions, it returns to step S1. On the other hand, when the setting of all the predetermined recording conditions is completed, the recording condition in which the prrror _ ttl reaches the minimum value is designated as the optimum recording condition based on the prrror _ ttl for each recording condition (step S11). For example, as shown in fig. 4, the recording power at which the PRerror _ ttl reaches the minimum value, or the like may be specified, and therefore this recording power or the like may be employed.

Next, the computing unit 117 sets the optimum recording condition in the recording waveform generating unit 13 (step S13). Furthermore, a specific recording pattern p in the optimum recording condition is set_cThe correlation amplitude level is stored as a reference signal in a storage device such as a memory (step S15). This data can be used in adjusting the recording conditions in the data recording.

By performing this processing, the recording conditions using the trial writing area can be optimized in accordance with the PRerror _ ttl, and the recording power and the like can be set to the optimum recording conditions.

Next, as an example 2 of optimizing the recording conditions of the trial writing area, a procedure of generating a reference signal of an amplitude level when using the individual PRerror _ ptn (p) will be described with reference to fig. 17.

For example, the calculation unit 117 of the control unit 11 sets a predetermined recording parameter in the recording waveform generation unit 13 (step S21). Next, the recording waveform generating unit 13 writes a predetermined recording pattern in the test writing area of the optical disc 15 by the PU1 in accordance with the set recording parameters (step S23). Next, the PU1, the pre-equalizer 3, the equalizer 7, and the viterbi decoder 9 read the write result performed in step S23, and the code recognition unit 111 associates the output of the equalizer 7 with the output of the viterbi decoder 9. The detection instruction section 113 instructs the detection section 115 to detect the amplitude level of the RF signal with respect to a predetermined detection pattern p. The detection unit 115 detects the amplitude level of the RF signal in accordance with the detection instruction unit 113, and outputs the detection result to the calculation unit 117. Next, the arithmetic unit 117 calculates the PRerror _ ptn (p) for the detection pattern p, and stores the calculated prrror _ ptn (p) in a storage device such as a memory in association with the recording parameters set in step S21 (step S25). This data is used for the adjustment of recording parameters in the data recording. As described above, since the detection pattern p is detected a plurality of times, an average value is calculated for the PRerror _ ptn (p). The calculation unit 117 stores the correlation amplitude level of the detected pattern p. It is also possible to store only the peak values.

Next, the arithmetic unit 117 determines whether or not all the predetermined values of the recording parameters are set (step S27), and if there is any recording condition that is not set, returns to step S21. On the other hand, when the setting of all the predetermined values of the recording parameters is completed, the arithmetic unit 117 designates, as an optimum value, the recording parameter value at which the value of the prrror _ ptn (p) becomes the minimum value, based on each of the prrror _ ptn (p) corresponding to each value of the recording parameters (step S29). As described above, each detection pattern p has a recording parameter suitable for adjustment, and therefore, in step S29, this recording parameter suitable for adjustment is specified as an optimum value. For example, as shown in fig. 14B, since the value (-1) of dTtop2T at which the PRerror _ ptn (p) reaches the minimum value can be specified for the detection pattern p of the flag 2T following the interval 2T, this value of dTtop2T is adopted.

Next, the calculation unit 117 sets the specified optimum value in the recording waveform generation unit 13 (step S31). Then, the amplitude level of the detection pattern p having the optimum value is stored in a storage device such as a memory as a reference signal (step S33). This data is used for the adjustment of recording parameters in the data recording.

By performing such processing, it is possible to optimize at least a part of the recording parameters by optimizing the recording parameters using the trial writing area based on the PRerror _ ptn (p).

Next, the processing when adjusting the recording conditions after starting the data recording will be described with reference to fig. 18 and 19 as example 1.

First, description is made with reference to fig. 15 and fig. 18. The recording waveform generating section 13 writes data to be written by the PU1 according to the set recording conditions (step S41). Here, it is assumed that a certain amount of data or writing for a certain time is performed. Next, the PU1, the pre-equalizer 3, the equalizer 7, and the viterbi decoder 9 are used to read the write result performed in step S41, and the code identification unit 111 associates the output of the equalizer 7 with the output of the viterbi decoder 9. The detection instruction section 113 instructs the detection section 115 to detect the amplitude level of the RF signal for all the detection patterns or when a predetermined effective pattern is detected, according to the setting. The detection unit 115 detects the amplitude level of the RF signal in accordance with the detection instruction unit 113, and outputs the detection result to the calculation unit 117. Next, the arithmetic unit 117 calculates the PRerror _ ptn (p) for each detection pattern p, and stores the calculated result in a storage device such as a memory (step S45). As described above, since the detection pattern p is detected a plurality of times, an average value is calculated for the PRerror _ ptn (p). The arithmetic unit 117 stores the detection pattern p specified in the optimum recording condition to be used subsequently_cThe relative amplitude level value of (a). It is also possible to store only the peak value of this value.

Thereafter, the arithmetic unit 117 calculates the error _ ttl for each detection pattern p calculated in step S45 using the error _ ptn (p) and the appearance probability of each detection pattern p stored in advance in the memory, and stores the calculated error _ ttl in a storage device such as a memory (step S47).

Next, the arithmetic unit 117 determines whether or not the PRerror _ ttl exceeds a predetermined threshold (step S49). When the PRerror _ ttl does not reach the predetermined threshold, the process proceeds to step S55 since no adjustment of the recording condition is necessary this time. On the other hand, when the PRerror _ ttl exceeds the predetermined threshold, the calculation unit 117 performs a process of determining a correction amount as a basic recording condition of the PRerror _ ttl (step S51).

The process of determining the correction amount as the recording condition will be described with reference to fig. 19. First, the arithmetic unit 117 specifies the detection pattern p_cThe difference between the amplitude level of the ideal signal and the reference signal specified by step S15, for example, as illustrated in fig. 16, is calculated (step S61). As described above, the difference between the peak values may be calculated, or the differences between the peak values and the other portions may be added. In addition, since it is determined in step S49 that the error _ ttl exceeds the predetermined threshold, the difference between the amplitude level and the reference signal is not 0.

Next, the arithmetic unit 117 determines whether or not the difference is positive (step S63). If the difference is positive, the recording condition for which the difference is positive and which corresponds to the value of the prrror _ ttl calculated in step S47 is specified (step S65) from the relationship between the prrror _ ttl and the recording condition (the result of step S7 in fig. 16). In the case shown in fig. 4, the value of the prrror _ ttl is the smallest at a recording power of 3.3mW, and increases below or above 3.3 mW. Therefore, when the PRerror _ ttl value calculated in step S47 is, for example, 0.15, the corresponding recording power is about 3.1mW or about 3.7 mW. The correction direction and the correction amount differ depending on the recording power. If the amount is 3.1mW, the amount is increased by 0.2 mW. If the amount is 3.7mW, the amount is reduced by 0.4 mW. The recording power is determined by at least one of the medium characteristics, recording conditions, and detection patterns for recording data. For example, for an individual optical disc, it is determined whether the amplitude level is increased or decreased with respect to an increase in recording power, based on the type identifier recorded in advance. Then, for example, if the amplitude level is increased due to an increase in the recording power and the difference is positive, the recording power is too high. That is, it can be judged that the electric power is in the same state as about 3.7 mW. Therefore, the recording power is reduced by 0.4 mW. On the other hand, when the amplitude level is decreased due to an increase in the recording power and the difference is positive, the recording power is too low. That is, it can be judged that the concentration is about 3.1 mW. Therefore, the recording power was increased by 0.2 mW. In addition, instead of performing the determination based on the type identification code, the actual condition may be determined during the test recording, and the determination may be performed based on the determination result. After specifying such a relationship in advance, step S65 specifies which recording condition is appropriate.

Then, the calculation unit 117 calculates the difference between the specified recording condition and the optimum recording condition as a correction amount (step S69). And then returns to the original processing.

On the other hand, if the difference is negative, a recording condition in which the difference is negative and which corresponds to the value of the prrror _ ttl calculated in step S47 is specified from the relationship between the prrror _ ttl and the recording condition (step S67). For example, when the amplitude level is determined to increase with the increase of the recording power according to the type identifier of the optical disc, and the difference is negative, it is determined that the recording power is too low, i.e., in the same state as about 3.1 mW. Therefore, the recording power was increased by 0.2 mW. On the other hand, if the amplitude level is determined to decrease with increasing recording power according to the type identifier of the optical disc, and the difference is negative, it can be determined that the recording power is too high, i.e. in the same state as about 3.7 mW. Therefore, the recording power is reduced by 0.4 mW. After specifying such a relationship in advance, step S67 specifies which recording condition is appropriate. Next, the process proceeds to step S69.

Returning to the description of fig. 18, the description of the processing is continued. The computing unit 117 sets the correction amount of the recording condition determined in step S51 in the recording waveform generating unit 113 (step S53). Next, it is judged whether or not the data recording is ended (step S55), and when the data recording is not ended, the process returns to step S41. On the other hand, the process is ended when the data recording ends.

By performing the above processing, the recording conditions can be adjusted even during data recording.

Next, a process when the recording parameter is corrected based on the error _ ptn (p) will be described with reference to fig. 20 and 21.

First, description is made with reference to fig. 20. Recording waveform generationThe generating unit 13 writes data to be written by the PU1 according to the set recording conditions (step S71). Here, it is assumed that writing of a certain amount of data or a certain time is performed. Next, the PU1, the pre-equalizer 3, the equalizer 7, and the viterbi decoder 9 read the write result performed in step S71, and the code recognition unit 111 is used to correlate the output of the equalizer 7 with the output of the viterbi decoder 9. The detection instruction unit 113 instructs the detection unit 115 to detect the amplitude level of the RF signal for all the detection patterns or when a predetermined effective pattern is detected, according to the setting. The detection unit 115 detects the amplitude level of the RF signal in accordance with the detection instruction unit 113, and outputs the detection result to the calculation unit 117. Next, the arithmetic unit 117 calculates the PRerror _ ptn (p) for each detection pattern p, and stores the calculated result in a storage device such as a memory (step S73). As described above, since the detection pattern p is detected a plurality of times, an average value is calculated for the PRerror _ ptn (p). The arithmetic unit 117 stores the specific detection pattern p to be used later_cThe relative amplitude level value of (a). It is also possible to store only the peak value of this value.

Thereafter, the arithmetic unit 117 calculates the error _ ttl for each detection pattern p calculated in step S73 using the error _ ptn (p) and the appearance probability of each detection pattern p stored in advance in the memory, and stores the calculated error _ ttl in a storage device such as a memory (step S75).

Next, the arithmetic unit 117 determines whether or not the PRerror _ ttl exceeds a predetermined threshold (step S77). When the PRerror _ ttl does not reach the predetermined threshold, the flow proceeds to step S87 because no adjustment of the recording condition is necessary this time. On the other hand, when the PRerror _ ttl exceeds the predetermined threshold, the arithmetic unit 117 specifies the PRerror _ ptn (p) exceeding the predetermined threshold (step S79). The PRERROR _ ttl may also be a predetermined larger value rather than exceeding a predetermined threshold. Next, the recording parameters of the correlation detection pattern p corresponding to the designated prrror _ ptn (p) are designated (step S81). For example, in the case of a pattern having a flag 2T after an interval 2T, the pattern ID is stored in advance in, for example, a memory or the like in association with the pattern ID, as in dTtop2T2T, and the association is used.

Next, the calculation unit 117 performs a process of determining a correction amount of the PRerror _ ptn (p) basic recording parameter (step S83).

The determination process of the recording parameter correction amount will be described with reference to fig. 21. First, the arithmetic unit 117 calculates a specific detection pattern p_cThe difference between the correlated amplitude level of (b) and the reference signal specified in, for example, step S33 (step S91). As described above, only the difference between the peak values may be calculated, or the difference between the peak values may be accumulated. In addition, since it is determined in step S77 that the error _ ttl exceeds the predetermined threshold, the difference between the amplitude level and the reference signal is not 0.

Next, the arithmetic unit 117 determines whether or not the difference is positive (step S93). If the difference is positive, the value of the recording parameter whose difference is positive and which corresponds to the value of the prrror _ ptn (p) specified in step S79 is specified in accordance with the relationship between the prrror _ ptn (p) and the recording parameter (result of step S25) (step S95). When viewed as in FIG. 14B, the value of PRerror _ ptn (p) is minimized at about-0.1 at dTTop2T, and values other than this minimum increase PRerror _ ptn either by decreasing or increasing dTTop 2T. Therefore, when the value of the PRerror _ ptn (p) calculated in step S73 is, for example, 0.01, the corresponding dTtop2T is about-1 or about 0.7. The correction direction and the correction amount of the optical recording power value differ from value to value. If it is-1, it is increased by 0.9. If it is 0.7, it is decreased by 0.8. The value of dTtop2T is determined by at least one of the media characteristics, recording conditions, and detection patterns for recording data. The media characteristics are preferably determined as follows. For example, in step S25 (see fig. 17), the amplitude level of each value of the recording parameter is stored in association with the detection pattern p, and step S25 is performed a plurality of times to determine whether the amplitude level is increased or decreased when the recording parameter increases, and the determination result is used again. For example, if it is determined from the determination result that the amplitude level increases as dTtop2T increases and the difference is positive, it can be determined that dTtop2T is too high, that is, in the same state as 0.7. Thus, dTtop2T was reduced by 0.8. On the other hand, when it is determined from the determination result that the amplitude level decreases as dTtop2T increases and the difference is positive, it can be determined that dTtop2T is too low, i.e., is in the same state as about-1. Thus, dTtop2T was increased by 0.9. After specifying such a relationship in advance, step S95 specifies which recording condition is appropriate.

Then, the calculation unit 117 calculates a difference between the specified value of the recording parameter and the optimum value of the recording parameter as a correction amount (step S99). And then returns to the original processing.

On the other hand, if the difference is negative, the value of the recording parameter whose difference is negative and which corresponds to the value of the prrror _ ptn (p) is specified from the relationship between the prrror _ ptn (p) and the recording parameter (step S97). For example, if it is determined from the previous determination result that the amplitude level increases as dTtop2T increases and the difference is negative, it can be determined that dTtop2T is too low, that is, is in the same state as about-1. Thus, the value of dTtop2T was increased by 0.9. On the other hand, when it is determined from the result of the previous determination that the amplitude level decreases as the value of dTtop2T increases and the difference is negative, it can be determined that the value of dTtop2T is too high, that is, the same state as about 0.7. Therefore, the value of dTtop2T was reduced by 0.8. After specifying such a relationship in advance, step S97 specifies which recording condition is appropriate. Next, the process proceeds to step S99.

Returning to the description of fig. 20, the calculation unit 117 sets the recording parameter correction amount determined in step S83 in the recording waveform generation unit 113 (step S85). Then, it is judged whether or not the data recording is ended (step S87), and if the data recording is not ended, the process returns to step S71. On the other hand, when the data recording ends, the processing is ended.

Since the above-described processing is performed, the recording parameters can be adjusted even during data recording.

Note that, the example of obtaining the reference signal value in the processing flow of fig. 19 or 21, the relationship between the prrror _ ttl and the recording condition in fig. 4 or 14B, or the relationship between the prrror _ ptn (p) and the recording parameter in the processing flow of fig. 16 or 17 is shown, but the reference signal value may be stored in the memory in advance. When the optical disk recording/reproducing apparatus is connected to a network, data can be acquired from another computer. In the processing flow of fig. 16 or 17, data stored in advance in a memory or the like may be corrected or updated.

In addition, although fig. 19 and 21 show the case where data recording is temporarily interrupted, the recording conditions and recording parameters may be adjusted simultaneously with data recording.

In addition, fig. 16 and 17 show an example in which data is recorded under one recording condition or the like and then reproduced, and further data is recorded under another recording condition or the like and then reproduced, and data may be recorded under all recording conditions at once and then reproduced.

Other process flows may be changed as desired.

The embodiments of the present invention have been described above, but the present invention is not limited to these embodiments. For example, the functional block diagram of the optical disc recording and reproducing apparatus shown in fig. 15 is an example, and the functional block diagram is not limited to the functional block configuration of fig. 15 as long as the above-described functions can be realized.

In addition, the above shows an example of adjusting the value of dTtop2T, and when it is necessary to adjust the rear interval, an appropriate recording parameter is specified in advance from the detection pattern and adjusted, as in the case of adjusting Tlp as a recording pulse falling parameter. In the above-described embodiment, the reference data such as the threshold value for adjusting the recording conditions and the like in the data recording is stored in the memory built in the arithmetic unit 117 or the memory outside the arithmetic unit 117, but it is not necessarily held in the memory. For example, it may be held in the optical disk 15. When held in the optical disk 15, is held in a Lead-in area shown in fig. 22. The Lead-in area is roughly divided into a system Lead-in area including an initial zone (intra zone), a buffer zone (buffer zone), a control data zone (control data zone), and a buffer zone, a connection zone (connection area), and a data Lead-in area. In addition, the connection region contains a connection zone (connection zone). In addition, the data Lead-in area includes a guard track area (guard track zone), a disc test area (disc test zone), a drive test area (drive test zone), a guard track area, an RMD (recording management data) copy area (replication zone), a recording management area (recording management zone), an R-physical format information area (R-physical format information zone), and a reference code area (reference code zone).

In the present embodiment, the control data area of the system Lead-in area includes a recording condition data area (recording condition data zone) 170.

This recording condition data area 170 is caused to hold the reference data held by the memory and read out the reference data as needed. The value to be recorded may be an average value of the optical disk 15, or may be a value corresponding to a test performed before shipment of the optical disk 15.

Since the optical disk 15 holds the corresponding value corresponding to the optical disk 15 on which recording is performed, the processing load on the drive side may be reduced. In addition, the value held in the optical disk 15 may be corrected and used as needed.

Claims (24)

1. A data record evaluation method, comprising the steps of: reproducing a specific period of a result of data recording on the optical disc, and detecting a reproduced signal based on the reproduction; specifying a detection pattern including a predetermined code based on the detected reproduction signal; detecting a signal state of the reproduction signal corresponding to the detection pattern; and a 1 st calculation step of calculating a 1 st evaluation index value based on the detected signal state and a reference state specified by the detection pattern.

2. The data recording evaluation method according to claim 1, further comprising a 2 nd calculation step of calculating a 2 nd evaluation index value using the 1 st evaluation index value calculated from each of the plurality of detection patterns when the detection pattern is a plurality of patterns.

3. The data recording evaluation method according to claim 2, further comprising a 1 st modification step of modifying a recording condition of the data recording according to the 2 nd evaluation index value.

4. The data recording evaluation method according to claim 2, wherein the 2 nd calculation step further comprises a step of cumulatively calculating a plurality of products of the appearance probability of the detection pattern and the 1 st evaluation index value of each detection pattern that coincides with the appearance probability.

5. The data record evaluation method of claim 2, further comprising the steps of:

judging whether the 2 nd evaluation index value exceeds a preset threshold value; and

when the 2 nd evaluation index value exceeds the predetermined threshold value, the detection pattern that affects the 2 nd evaluation index value to some extent or more is specified according to the corresponding 1 st recording state evaluation index value.

6. The data recording evaluation method according to claim 5, further comprising a 2 nd modification step of modifying a recording parameter for data recording in accordance with the 1 st evaluation index value of the specified detection pattern.

7. The data recording evaluation method of claim 1, wherein the detection pattern is composed of at least one mark and a space.

8. The data recording evaluation method according to claim 1, wherein the detection pattern is a detection pattern having an appearance frequency of a fixed value or more.

9. The data recording evaluation method according to claim 3, wherein the 1 st modification step further comprises a step of specifying the recording condition in which the 2 nd evaluation index value is in a range of a fixed value or less, based on data indicating a relationship between a recording condition and the 2 nd evaluation index value calculated from data obtained by reproducing a data recording result under the recording condition.

10. The data record evaluation method of claim 3 wherein said 1 st modification step comprises the steps of,

the correction amount of the current recording condition is calculated by using the data representing the relationship between the recording condition and the 2 nd evaluation index value calculated from the data obtained during the specific period of reproducing the data recording result under the recording condition and the current 2 nd evaluation index value.

11. The data recording evaluation method according to claim 9, wherein the data indicating the relationship between the recording condition and the 2 nd evaluation index value calculated from the data obtained during the specific period of reproducing the data recording result under the recording condition is data obtained at the time of test recording.

12. The data recording evaluation method according to claim 6, wherein the 2 nd modification step includes a step of specifying the recording parameter when the 1 st evaluation index value is an optimum value, based on data indicating a relationship between a recording parameter and the 1 st evaluation index value calculated from data obtained during a specific period of reproducing a data recording result using the recording parameter.

13. The data recording evaluation method according to claim 6, wherein the 2 nd modification step includes a step of calculating a correction amount of the current recording parameter using data indicating a relationship between the recording parameter and the 1 st evaluation index value calculated from data obtained during a specific period of reproducing a data recording result using the recording parameter, and the current 1 st evaluation index value.

14. The data recording evaluation method according to claim 12, wherein the data indicating the relationship between the recording parameter and the 1 st evaluation index value calculated from data obtained during a specific period of reproducing a data recording result using the recording parameter is data obtained at the time of test recording.

15. The data recording evaluation method according to claim 1, wherein the 1 st calculation step includes a step of calculating a magnitude of a difference between the detected signal state and a reference state specified by the detection pattern.

16. An optical disk recording/reproducing apparatus, comprising:

means for reproducing a specific period of the data recording result on the optical disk and specifying a predetermined detection pattern in the reproduced signal;

means for detecting a signal state of the reproduction signal corresponding to the detection pattern; and

means for calculating a 1 st evaluation index value based on the detected signal state and a reference state specified by the detection pattern.

17. The optical disc recording and reproducing device according to claim 16, further comprising a 2 nd calculation means for calculating a 2 nd evaluation index value using the 1 st evaluation index value associated with each of the detection patterns when there are a plurality of detection patterns.

18. The optical disc recording/reproducing apparatus according to claim 17, further comprising 1 st modification means for modifying a recording condition for data recording based on the 2 nd evaluation index value.

19. The optical disc recording/reproducing apparatus according to claim 17, wherein said 2 nd calculating means cumulatively calculates a product of a probability of occurrence of said detection pattern and said 1 st evaluation index value for each detection pattern that matches said probability of occurrence.

20. The optical disc recording and reproducing apparatus according to claim 17, further comprising:

means for determining whether or not the 2 nd evaluation index value exceeds a predetermined threshold value; and

and a means for specifying the detection pattern that affects the 2 nd evaluation index value to a certain extent or more, based on the 1 st evaluation index value when the 2 nd evaluation index value exceeds the predetermined threshold value.

21. The optical disc recording/reproducing apparatus according to claim 20, further comprising a 2 nd modification means for modifying a recording parameter used for data recording based on the 1 st evaluation index value associated with the specified detection pattern.

22. An optical information recording medium, wherein a 2 nd evaluation index value threshold value is recorded, the 2 nd evaluation index value threshold value is obtained by adding up a plurality of products of a 1 st evaluation index value and an appearance probability of a detection pattern, and the 1 st evaluation index value corresponds to a deviation between a signal state corresponding to the detection pattern specified by a reproduction signal and a reference state specified by the detection pattern.

23. An optical recording information medium, characterized in that data representing a relationship between a 2 nd evaluation index value and a recording condition of data recording as a basis for calculating the 2 nd evaluation index value is recorded, wherein the 2 nd evaluation index value is obtained by cumulatively calculating a plurality of products of a 1 st evaluation index value and an appearance probability of a detection pattern, and the 1 st evaluation index value corresponds to a deviation between a signal state corresponding to the detection pattern specified by a reproduction signal and a reference state specified by the detection pattern.

24. An optical recording information medium, characterized in that data indicating a relationship between a 1 st evaluation index value and a recording parameter of a data record as a basis for calculating the 1 st evaluation index value is recorded, wherein the 1 st evaluation index value corresponds to a deviation between a signal state corresponding to the detection pattern specified by a reproduction signal and a reference state specified by the detection pattern.