JP4225187B2 - Recording apparatus, recording method, and recording medium manufacturing method - Google Patents

Description

  The present invention relates to a recording apparatus, a recording method, and a recording medium manufacturing method for manufacturing a recording medium such as an optical disk.

Japanese Patent Laid-Open No. 10-31825 Japanese Patent Laid-Open No. 10-162428

  Various standard optical disc recording media such as CD (Compact Disc), DVD (Digital Versatile Disc), and Blu-ray Disc (Blu-Ray Disc) have been developed. In these optical disc fields, intersymbol interference that occurs during recording and playback. Due to the influence of the above, there has been a known problem that jitter occurs in the reproduction signal and the quality of the reproduction signal deteriorates. When such signal degradation occurs, an error may occur when data is decoded, and is therefore a problem to be solved.

  For example, in the case of a CD, data (audio data, etc.) recorded at the time of mastering is subjected to predetermined processing, and then EFM (Eight-to-Fourteen Modulation) modulation, whereby a predetermined basic period T is obtained. A pulse train having a limited run length such as a period of 3T to 11T is formed. Based on the pulse train as the EFM data, recording is performed so that a pit train is formed on the disc master (glass master). A disc as a CD is manufactured in a predetermined process based on the disc master manufactured in this way.

In a reproduction apparatus for reproducing a CD, a reproduction signal whose signal level changes in accordance with the amount of the return light is obtained by irradiating the CD with a laser beam and receiving the return light, and the reproduction signal is obtained at a predetermined slice level. To generate a binary signal. Further, a PLL circuit is driven from the binarized signal to generate a reproduction clock, and the binarized signal is sequentially latched by the reproduction clock, whereby a period 3T to 11T corresponding to a pit string formed on the compact disc. Reproduction data (EFM data) is generated. Further, the EFM data is demodulated and predetermined processing such as error correction processing is performed to reproduce the audio data.
However, the reproduced signal includes jitter due to intersymbol interference from the front and rear pits, and the presence of jitter in the reproduced signal is an obstacle to accurate data decoding, depending on the degree. .

  Therefore, in the case of CD, for the purpose of eliminating intersymbol interference, a technique for correcting a signal edge in accordance with an EFM signal pattern in the manufacturing process has been developed and proposed in Patent Documents 1 and 2 above.

A CD manufacturing process in which edge correction for removing intersymbol interference is performed will be described with reference to FIGS.
FIG. 5 schematically shows a process of manufacturing a CD of a certain CD title. First, the master disc 90 is manufactured by the mastering device 100.
In the mastering apparatus 100, data for recording is output from the data source 102. The recording data includes audio data and various management information (subcode information such as TOC and address), and is data of a predetermined format that is interleaved with an error correction code added. .
This recording data is EFM-modulated by the CD encoder 103 to form a pulse train as EFM-modulated data (3T to 11T run-length limited code).

The pulse train as the EFM modulation data is input to the edge correction circuit 104.
The edge correction circuit 104 is provided with an edge correction table 104b, which stores a correction value of a pulse edge for each pattern of the pulse data string.
The pattern of the pulse data string is, for example, a continuous pulse run such as a pattern of 3T → 4T → 3T or a pattern of 4T → 6T → 7T as shown by patterns A and B in FIGS. It is a long pattern. For example, in the case of the pattern A in FIG. 6A, the correction value corresponding to the pattern instructs processing to delay the rising edge by Δt in response to the rise of the 4T rising edge timing. Value.
However, edge shifts in various patterns as shown in FIGS. 6A and 6B are observed during reproduction on a manufactured CD. That is, due to intersymbol interference due to the situation of the front and rear lands / pits in the manufactured CD 92, it is observed as an edge shift of EFM data during reproduction, that is, a jitter component.
The occurrence of various patterns and the deviation of the edge for each EFM data pattern at the time of reproduction vary depending on the contents of the recorded data, and are also caused by the manufactured pit / land shape and the like. Of course, this also affects individual differences of the mastering device 100 itself and subsequent processing steps.

This means that when a CD of a certain title is manufactured, it is not known what kind of edge shift occurs in what pattern until the CD 92 is manufactured at least once and reproduced. means.
For this reason, when the disc master 90 is first manufactured, average correction information is stored in the edge correction table 104b of the edge correction circuit 104.
In the edge correction circuit 104, the pattern detection circuit 104a detects the pulse pattern of the EFM data. Then, in accordance with the detected pulse pattern, the correction value is read from the edge correction table 104b and supplied to the edge shift circuit 104c. The edge shift circuit 104c shifts the pulse edge of the EFM data based on the correction value.

The EFM data corrected in this way is supplied to an AOM (acousto-optic modulator) 106. The recording laser beam output from the recording laser 105 is modulated by AOM based on the EFM data, and is irradiated to the disk master 90 in which a glass substrate is coated with a photoresist, so that a pit row is formed.
The master disc 90 is developed and electroformed to form a master disc as a so-called glass master, and a stamper 91 is manufactured based on the master disc 90.
Then, the CD 92 is manufactured by molding using the stamper 91.

However, the CD 92 manufactured at this time is not yet subjected to appropriate edge correction by the edge correction circuit. Therefore, the manufactured CD 92 is reproduced by the reference CD player 110, and the reproduced signal is input to the computer 120 for signal analysis. At this time, for example, an edge shift (jitter component) as shown in FIGS. 6A and 6B is observed.
The computer 120 determines what kind of edge correction should be performed for what pulse pattern based on the signal analysis result, and generates data of the edge correction table. For example, correction data such that Δt edge correction is performed for pattern A in FIG. 6A, and Δt1 and Δt2 edge correction is performed for pattern B in FIG. 6B. Will accumulate.
And the data of the edge correction table 104b in the edge correction circuit 104 of the mastering apparatus 100 is updated with the correction data.
When the data in the edge correction table 104b is updated, the master disc 100 is manufactured again by the mastering device 100.

  By repeating the above steps many times, the edge correction is gradually improved adaptively, and finally a CD 92 can be manufactured in which the jitter due to intersymbol interference is not problematic. In particular, as the number of repetitions of the above steps is increased, the accuracy of the manufactured CD 92 can be improved.

  However, repeating the manufacturing process of manufacturing the CD 92 from the disc master manufacturing 90 and updating the edge correction table 104b based on the analysis of the reproduction signal of the manufactured CD 92 many times, time, manufacturing efficiency, cost, etc. This is not preferable.

In practice, the above process cannot be repeated indefinitely, so a certain upper limit number of repetitions is determined.
Further, what kind of correction is performed for each generated pulse pattern is analyzed and used as correction data. However, there are various types of generated pulse patterns that are considered to be equivalent to infinity in practice. Of course, since the pulse pattern varies depending on data such as music, the generated pulse pattern differs for each CD title to be manufactured, which also hinders the efficiency of the process.

  Since the number of repetitions of the above process is limited and the number of pulse patterns that can be stored in the edge correction table 104b (can be corrected) is limited, for example, even if the above process is repeated up to the upper limit, sufficient However, it cannot be said that a CD 92 with reduced jitter can be manufactured.

A CD is roughly divided into a TOC area in which management information (index information about tracks such as music pieces) is recorded and a program area in which music programs are recorded in units of tracks. Since EFM data based on music data is recorded in the program area, the number of types of generated pulse patterns is enormous. Actually, it can also be said to be an area where a random pulse pattern is recorded.
On the other hand, in the TOC area, management information is recorded by the subcode, and the audio data portion is all 0 data, so that many fixed patterns are generated as generated pulse patterns.
That is, in the TOC area, the recording data string (EFM data string) frequently has a fixed pattern, and in the program area, the recording data string has a very low frequency. In other words, a huge number of types of pulse patterns are generated in the program area, but there are few types of pulse patterns generated in the TOC area.
Here, considering that a correction value can be set only for a finite pulse pattern as described above, when extracting a pulse pattern of EFM data by the computer 120 and setting a correction value for each pulse pattern, the TOC region The probability of including a pulse pattern generated in is reduced. Then, there is a high possibility that the edge correction is insufficient for the data in the TOC area.

For this reason, in practice, there is a tendency that jitter included in a reproduction signal in a region having a large number of fixed patterns such as a TOC region is not easily reduced.
Of course, the management information of the TOC area is important information at the time of reproduction, and it is very unpreferable that the reproduction performance of the TOC area deteriorates due to the influence of jitter.
In addition to the TOC area, for example, a silence portion between tracks of audio data (between songs) continues with zero data, and therefore, a frequency of a fixed pattern is high. Furthermore, there may be a region where fixed patterns occur frequently depending on the data, but correction is insufficient in regions where the frequency of these fixed patterns is high, which is a problem.

  In view of the above, the present invention has an object to make it possible to manufacture a recording medium (such as a CD) with high accuracy in consideration of a finite number of process repetitions and a limited number of pulse patterns that can be corrected. To do.

As an example, the recording apparatus of the present invention can be applied as a mastering apparatus for producing a master disk or a recording apparatus for a recordable disc such as a CD-R. In other words, a recording medium (for example, a disc master ) having an index area (for example, TOC) where the frequency of the recording data string becomes a fixed pattern and a program area where the frequency of the recording data string becomes a fixed pattern compared to the index area. As a recording device for recording data on a recording pulse generator, a recording pulse generator for encoding data to be recorded into a recording pulse train with a limited run length, and a recording pulse train output from the recording pulse generator, A discriminating means for discriminating whether the recording pulse train is to be recorded in the index area or a recording pulse train to be recorded in the program area; and when the discriminating means discriminates a recording pulse train for the index area , 1 is used to correct the edge timing of the recording pulse obtained by the recording pulse generating means, and When it is judged that the recording pulse train for serial program area, an edge correction means for using the second pattern correction information performs edge timing correction of a recording pulse obtained by the recording pulse generating means, in the edge correction unit Recording means for performing recording on the recording medium based on the corrected recording pulse that has been corrected.

Further, in this recording apparatus, the edge correction means includes a rising edge detecting means for detecting a rising edge of the pulse generated by the recording pulse generating means, and a falling edge of the pulse generated by the recording pulse generating means. The falling edge detecting means for detecting the pattern, the pattern detecting means for detecting the pulse pattern of the pulse generated by the recording pulse generating means, and the first pattern correction information are stored and detected by the pattern detecting means. A first storage means for outputting a correction value based on the first pattern correction information according to the pulse pattern and a second pattern correction information stored in accordance with the pulse pattern detected by the pattern detection means. The second storage means for outputting a correction value based on the second pattern correction information and the discrimination means When it is judged that the recording pulse train for the index region, the first to select a correction value from the storage unit, when it is judged that the recording pulse train for the program area, the correction from the second storage means Selection means for selecting a value, rising edge delay means for delaying the rising edge detected by the rising edge detection means based on the correction value selected by the selection means, and detection by the falling edge detection means The corrected recording pulse is formed from the falling edge delay means for delaying the falling edge based on the correction value selected by the selection means, and the outputs of the rising edge delay means and the falling edge delay means. Correction recording pulse output means for outputting .

According to the recording method of the present invention, data is recorded on a recording medium having an index area where the frequency of the recording data string is a fixed pattern and a program area where the frequency of the recording data string is a fixed pattern compared to the index area. This is a recording method for recording. Then, a recording pulse generation step for encoding data to be recorded into a recording pulse train with a limited run length, and whether the recording pulse train output in the recording pulse generation step is a recording pulse train for recording in the index area , or A discriminating step for discriminating whether the recording pulse train is recorded in the program area; and when the discriminating step discriminates a recording pulse train for the index area , the recording pulse generation is performed using the first pattern correction information. The edge timing of the recording pulse obtained in the step is corrected, and when it is determined that the recording pulse train is for the program area , the recording pulse obtained in the recording pulse generation step is used using the second pattern correction information. Edge correction step for edge timing correction and correction by the above edge correction step Correction on the basis of the recording pulse, and a recording step of performing recording on the recording medium.

The recording medium manufacturing method of the present invention includes a recording medium having an index area in which a recording data string has a fixed pattern frequency and a program area in which the recording data string has a low frequency pattern in comparison with the index area ( For example, a CD). Then, a correction information storing step for storing the first pattern correction information generated corresponding to the index area and the second pattern correction information generated corresponding to the program area , and data to be recorded, A recording pulse generation step for encoding into a recording pulse train with a limited run length, and a recording pulse train output in the recording pulse generation step is a recording pulse train for recording in the index area , or a recording pulse train for recording in the program area And when the discriminating step discriminates a recording pulse train for the index area , the first pattern correction information stored in the correction information storing step is used to record the recording pulse. performs edge timing correction of the resulting recording pulse in pulse generation step, also pairs in the program area An edge correction step for correcting the edge timing of the recording pulse obtained in the recording pulse generation step using the second pattern correction information stored in the correction information storage step. A master generating step for performing recording on the recording medium master based on the corrected recording pulse corrected in the edge correcting step, a recording medium manufacturing step for manufacturing a recording medium based on the recording medium master, and the recording medium An evaluation step for reproducing the recording medium manufactured in the manufacturing step to perform quality evaluation, a recording medium manufactured in the recording medium manufacturing step is reproduced, and a reproduction signal of the index area is analyzed to analyze the first pattern. It generates the correction information, to generate the second pattern correction information by analyzing the reproduction signal of the program area And a correction information generating step. A series of operations as the correction information generation step, the correction information storage step, the recording pulse generation step, the determination step, the edge correction step, the master generation step, and the recording medium manufacturing step are performed in the evaluation step. The process is repeatedly executed until a predetermined evaluation result is obtained, a predetermined mastering upper limit number is reached, or the number of the first or second pattern correction information that can be stored in the correction information storing step reaches an upper limit.

That is, in the present invention, for example, TOC area, and frequently an index region to be a recording data sequence is fixed pattern, record data string is generated in a random pattern, a low frequency which is a fixed pattern program area (audio data, etc. In the manufacturing process of the recording medium having the recording area) , the edge correction is separately performed in the index area and the program area . That is, the pulse edge correction is performed on the index area and the program area using the first pattern correction information and the second pattern correction information, respectively. The first pattern correction information is generated by analyzing the reproduction signal of the index area of the manufactured recording medium, and the second pattern correction information is generated by analyzing the reproduction signal of the program area .

According to the present invention, the first and second pattern correction information are individually set in the index area and the program area , respectively. For example, in the mastering process, the data pulse to be recorded is the recording pulse recorded in the index area. Depending on the case and the case where the recording pulse is recorded in the program area , the edge timing correction is performed by using the first and second pattern correction information separately.
In this case, the first pattern correction information is obtained by extracting a pulse pattern from a reproduction signal having a high frequency in which the recording data string becomes a fixed pattern, and setting a correction value for each pulse pattern. The correction information is obtained by extracting a pulse pattern from a reproduction signal of a random pattern with a low frequency in which the recording data string becomes a fixed pattern, and setting a correction value for each pulse pattern. Therefore, pattern correction information can be set appropriately for each region. For example, a pulse pattern appearing in the index area is not buried in a huge variety of pulse patterns appearing in the program area and not reflected as correction information.
Therefore, it is possible to carry out appropriate edge timing correction in the index area and the program area under the condition that the number of process repetitions is finite and the number of pulse patterns that can be corrected is finite. There is an effect that the quality can be improved. In particular, it is also effective in that the quality deterioration in the TOC area (index area) can be prevented.

Further, since the division for the edge timing correction processing is simple such as the index area and the program area , the reproduction signal is analyzed, the pattern correction information is generated, and the first and second pattern correction information is used. The edge correction processing is not difficult, and there is an advantage that introduction is easy.

Hereinafter, as an embodiment of the present invention, an apparatus and process for manufacturing a CD will be described as an example.
First, referring to FIG. 1, a description will be given of the configuration of the mastering apparatus 1 for producing a master disc 90 for manufacturing a CD, that is, for performing a recording process for forming pits based on audio data or the like on a glass substrate subjected to a photoresist.

As described above, the stamper 91 is formed from the disc master 90, and the CD 92 is mass-produced from the stamper 91. The disc master 90, stamper 91, and CD92 all have the same pit row. It is a medium. These recording media have a so-called CD format area structure. That is, a pit row is formed according to an EFM signal obtained by EFM modulation of recording data, and a TOC area is formed on the inner periphery side of a program area where a music track or the like is recorded. In the TOC area, information serving as an index for each track in the program area and information such as the number of tracks are recorded as subcode information for the main data.
The TOC area is an area where the EFM signal pulse train has a fixed frequency because the main data is a 0 data string. On the other hand, since the music area is recorded in the program area, the EFM signal pulse train is It can be said that the frequency of the fixed pattern is low and the pulse pattern is a random region.

In the mastering apparatus 1, the glass substrate as the disc master 90 is set to be rotated by the spindle motor 9, and the mastering is started.
The spindle motor 9 supplies the spindle servo circuit 10 with rotational speed information from, for example, an FG signal generator, for example, an FG signal whose signal level rises at every predetermined rotation angle. The spindle servo circuit 10 drives the spindle motor 9 so that the frequency of the FG signal becomes a predetermined frequency in accordance with the exposure position of the disk master 2, thereby rotating the disk master 2 under the condition that the linear velocity is constant. .

The recording laser 6 is constituted by a gas laser or the like, and emits a laser beam for disc master exposure. The AOM (optical modulator) 7 is composed of an electroacoustic optical element, and performs on / off control of the laser beam from the recording laser 6 using a modulation signal (EFM pulse) supplied from the edge correction circuit 5.
The laser beam modulated by the AOM 7 is focused on the disc master 90 by the objective lens 8. The objective lens 8 (and a predetermined portion of the optical path from the AOM 7 (not shown) to the objective lens 8) is sequentially moved in the radial direction of the disc master 90 in synchronization with the rotation of the disc master 90 by a thread mechanism (not shown). Thus, the exposure position by the laser beam is sequentially displaced in the outer peripheral direction of the disc master 90.
In the mastering apparatus 1, tracks (pit rows) are formed on the disk master 90 in a spiral shape by moving the objective lens 8 while the disk master 90 is rotationally driven in this manner.

The data source 2 outputs recording data. The data for recording includes audio data and various management information (subcode information such as TOC and address), and is data of a predetermined format that is interleaved with an error correction code added. .
This recording data is EFM-modulated by the CD encoder 3 and is used as a pulse train as EFM-modulated data (3T to 11T run-length limited code) whose run length is limited.

The pulse train as the EFM data is input to the edge correction circuit 5 and the region determination unit 4.
The area determination unit 4 determines whether the EFM data is a TOC area recording signal or a program area recording signal from the input EFM data, and outputs an area determination signal S1. The determination process by the area determination unit 4 can be performed by extracting a subcode from the EFM data and obtaining information such as an index, a track number, and an address known as subcode Q data. Alternatively, if a fixed pulse pattern is frequently observed in the EFM data, the section may be determined as a TOC area, and if it is in a random pulse pattern, it may be determined as a program area. Further, since the area determination may be performed by confirming the address and other subcode information, the subcode information is supplied from the data source 2 or the CD encoder 3 to the area determination unit 4 in synchronization with the EFM data. You may make it do.

The edge correction circuit 5 detects the pulse pattern of the EFM data, and corrects the edge timing of the EFM pulse train so as to effectively avoid intersymbol interference during reproduction according to the pulse pattern.
As will be described later, the edge correction circuit 5 includes two correction tables for edge timing correction. That is, a TOC correction table storing a pulse pattern and a correction value corresponding to the TOC area, and a normal correction table storing a pulse pattern and a correction value corresponding to the program area. Then, based on the region determination signal S1 from the region determination unit 4, which correction table is used is selected, and edge timing correction is performed.
The EFM data corrected by the edge correction circuit 5 is supplied to the AOM 7 as a modulation signal. As a result, pits corresponding to the pulse train of EFM data are formed on the master disc 90.

The configuration of the edge correction circuit 5 is shown in FIG.
The EFM data input to the edge correction circuit 5 is supplied to the pattern detection unit 20, the rising edge detection unit 25, and the falling edge detection unit 28.
The pattern detection unit 20 detects various specific patterns such as 3T → 4T → 3T pattern, 5T → 8T → 8T → 3T pattern, etc. as a pulse train of EFM data, and the detection pattern P Is output as table search information.

As shown in the figure, the edge correction circuit 5 is provided with a normal correction table 21 and a TOC correction table 22.
The normal correction table 21 includes a rising correction table 21a and a falling correction table 21b. The normal correction table 21 is a table for storing information on edge timings to be corrected in various pulse patterns observed in the program area. In the case of various pulse patterns, correction values for correcting rising edges are stored in the rising correction table 21a. The correction value for correcting the falling edge in the case of various pulse patterns is stored in the falling correction table 21b.
The TOC correction table 22 also includes a rising correction table 22a and a falling correction table 22b. The TOC correction table 22 is a table that stores information on edge timings to be corrected in various pulse patterns observed in the TOC region. In the case of various pulse patterns, correction values for correcting rising edges are stored in the rising correction table 22a. The correction value for correcting the falling edge in the case of various pulse patterns is stored in the falling correction table 22b.

Each correction table 21a, 21b, 22a, 22b searches the stored pulse pattern based on the detection pattern P from the pattern detection unit 20, and if the corresponding pulse pattern exists, it corresponds in a table format. Then, the stored correction value is output.
The correction values read from the rising correction tables 21a and 22a are supplied to the data selector 23.
The correction values read from the falling correction tables 21b and 22b are supplied to the data selector 24.
The data selectors 23 and 24 select an input based on the region determination signal S1. That is, when it is determined as the TOC area, the data selector 23 selects the correction value from the rising correction table 22a, and the data selector 24 selects the correction value from the falling correction table 22b. That is, the TOC correction table 22 side is selected.
On the other hand, when it is determined as the program area, the data selector 23 selects the correction value from the rising correction table 21a, and the data selector 24 selects the correction value from the falling correction table 21b. That is, the normal correction table 21 side is selected.

The rising edge detector 25 detects the rising edge of the pulse train of the input EFM data, and supplies a rising edge signal (edge timing signal) to the delay unit 26. The delay unit 26 corrects the rising edge timing back and forth based on the correction value supplied from the data selector 23. Then, the rising edge signal whose timing is corrected is supplied to the EFM signal reconstruction unit 27.
The falling edge detection unit 28 detects the falling edge of the pulse train of the input EFM data, and supplies the falling edge signal (edge timing signal) to the delay unit 29. The delay unit 29 corrects the falling edge timing back and forth based on the correction value supplied from the data selector 24. Then, the timing-corrected falling edge signal is supplied to the EFM signal reconstruction unit 27.
The EFM signal reconstruction unit 27 reconstructs a pulse train as EFM data from the corrected rising edge signal and falling edge signal and outputs the pulse train to the AOM 7.

That is, according to the edge correction circuit 5, the edge timing is corrected based on the stored value of the TOC correction table 22 for the EFM pulse train that is the data train recorded in the TOC area, and is recorded in the program area. For the EFM pulse train as a data train, the edge timing is corrected based on the stored value of the normal correction table 21.
Based on the EFM data corrected in this way, pit rows are formed on the disc master 90.

A CD manufacturing process including the process of the mastering apparatus 1 as described above will be described with reference to FIG.
First, a pit row is formed on the disc master 90 by the mastering device 1 described above, and a master disc as a so-called glass master is obtained through development processing and electroforming processing. A stamper 91 is manufactured based on the disc master 90.
Then, a disk-shaped substrate is created by molding using the stamper 91, and a CD 92 is manufactured by forming a reflective film and a protective film on the disk-shaped substrate.

The manufactured CD 92 is reproduced by the reference CD player 110. The reproduced signal is input to the computer 50 for signal analysis.
Here, in the computer 50, a TOC region pattern analysis unit 51 and a normal region pattern analysis unit 52 are provided as signal analysis functions, and a reproduction signal from the TOC region of the CD92 is analyzed by the TOC region pattern analysis unit 51. . A reproduction signal from the program area of the CD 92 is analyzed by the normal area pattern analysis unit 52.
The TOC region pattern analysis unit 51 and the normal region pattern analysis unit 52 respectively extract the pulse pattern of the EFM data string as a reproduction signal and perform jitter analysis for each pulse pattern. That is, it is detected what kind of edge timing deviation occurs in what kind of pulse pattern.

The computer 50 also has functions as a TOC correction table data generation unit 53 and a normal correction table data generation unit 54.
The TOC correction table data generation unit 53 calculates a correction value for eliminating the edge shift based on the edge shift for each pulse pattern extracted by the TOC region pattern analysis unit 51. In other words, timing correction values for rising edges and falling edges are calculated for various pulse patterns, and the correction values corresponding to the pulse patterns are calculated.
The normal correction table data generation unit 54 calculates a correction value for eliminating the edge shift based on the edge shift for each pulse pattern extracted by the normal region pattern analysis unit 52. In other words, timing correction values for rising edges and falling edges are calculated for various pulse patterns, and the correction values corresponding to the pulse patterns are calculated.
Accordingly, the TOC correction table data generation unit 53 generates data that tabulates the correction values of the rising edge or the falling edge corresponding to various pulse patterns, that is, update data of the TOC correction table 22, and normal correction. The table data generation unit 54 also generates data in which correction values of rising edges or falling edges are tabulated corresponding to various pulse patterns, that is, update data of the normal correction table 21.
These update data are reflected in the TOC correction table 22 and the normal correction table 21 of the edge correction circuit 5 in the mastering device 1. That is, the contents of the TOC correction table 22 and the normal correction table 21 in the edge correction circuit 5 are updated.

When the TOC correction table 22 and the normal correction table 21 are updated, the master disc 1 is manufactured again by the mastering device 1. Then, the CD 92 is manufactured from the disc master 90 through the stamper 91. The CD 92 is reproduced by the reference CD player 110, the EFM data pulse pattern analysis is performed by the computer 50, and update data of the TOC correction table 22 and the normal correction table 21 is generated again. The contents of the TOC correction table 22 and the normal correction table 21 in the edge correction circuit 5 are also updated.
By repeating such steps, a CD 92 having a jitter component sufficiently reduced finally at a certain point in time is manufactured.

FIG. 4 shows the procedure of the manufacturing process.
Step ST1: The first master disc 90 is manufactured by the mastering apparatus 1. At this time, the contents of the normal correction table 21 and the TOC correction table 22 are average values. For example, the correction value corresponding to various pulse patterns is set to a value indicating the center tap of the delay unit 26 (delay line).
Step ST2: A stamper 91 is manufactured from the master disc 90, and a CD 92 is manufactured using the stamper 91.
Step ST3: The manufactured CD92 is reproduced, pattern analysis is performed, and jitter is evaluated.
Process ST4: If the jitter evaluation result is good, the manufacturing process is terminated. That is, the CD 92 at that time is regarded as a finally manufactured CD.
Process ST5: If the number of mastering repetitions has reached the upper limit, the manufacturing process is terminated.
Step ST6: If the number of correction patterns registered in the normal correction table 21 and the TOC correction table 22 has already reached the upper limit, the manufacturing process ends.
Step ST7: When the process is not completed under the conditions of Step 4, Step 5, and Step 6, mastering is repeated. Therefore, the computer 50 generates update data for the TOC correction table 22 and update data for the normal correction table 21 based on the analysis results of the TOC area and the program area.
Step ST8: After updating the TOC correction table 22 and the normal correction table 21, the process returns to step ST1.

The above-described process of FIG. 4 is repeated until the process is completed in processes ST4, ST5, and ST6. By repeating the processes from mastering to evaluation / analysis / correction table update in this way, the contents of the normal correction table 21 and the TOC correction table 22 are gradually optimized, and the accuracy of the manufactured CD 92 is increased. It will follow.
However, the upper limit number of repetitions is set from the upper limit of the manufacturing process time and cost, and the pulse pattern to be corrected has an upper limit.
However, in the case of this example, the correction table is provided independently for the TOC area and the program area, and the edge timing correction is performed, so that the correction accuracy for each area can be efficiently pursued even with a small number of repetitions. To be done. For example, only the pulse pattern in the program area is targeted for correction, and it does not occur that correction of the TOC area is difficult to be performed.
Therefore, by repeating the process within the upper limit number of times, both the program area and the TOC area can be steadily improved in accuracy, and a CD 92 with high reproduction quality can be manufactured.

  In the case of this example, since the division for the edge timing correction processing is a simple TOC area and program area, reproduction signal analysis, pattern correction information generation, and further use in the edge correction circuit 5 are performed. The correction table switching process is also simple and easy to introduce.

Although the embodiment has been described above, various modifications other than the above examples are also conceivable. For example, a fixed pulse pattern is frequently generated in a silent area between tracks (songs) in the program area, that is, between so-called songs. Therefore, edge correction may be performed on the EFM data corresponding to the area between music pieces by selecting the TOC correction table 22 as in the TOC area. In that case, the TOC area pattern analysis unit 51 of the computer 50 also executes the analysis of the reproduction signal in the inter-song area.
Further, the recording medium is not limited to a CD and a recording medium in a CD manufacturing process, but the present invention can be applied to other types of optical disks. For example, various discs such as DVD and Blu-ray DISC can be applied to a reproduction-only type manufacturing process.
Further, as a recording device for a recordable disk medium such as a CD-R, an apparatus including a correction table for each area can be configured as in the mastering apparatus 1. In particular, in a disk drive or the like built in a personal computer or the like, signal analysis and correction table updating can be performed after recording. For example, the same data recording is repeated using a large number of media such as CD-Rs. Thus, high-precision recording is possible. Further, in the case of a rewritable disc such as a CD-RW, it is conceivable that recording is repeatedly performed on a single disc and driven with high accuracy.

It is a block diagram of the mastering apparatus of an embodiment of the invention. It is a block diagram of the edge correction circuit of the mastering apparatus of an embodiment. It is explanatory drawing of CD manufacturing process of embodiment. It is a flowchart of CD manufacturing process of embodiment. It is explanatory drawing of the conventional CD manufacturing process. It is explanatory drawing of edge correction.

Explanation of symbols

  1 mastering device, 2 data source, 3 CD encoder, 4 area determination unit, 5 edge correction circuit, 6 recording laser, 7 AOM, 8 objective lens, 9 spindle motor, 10 spindle servo circuit, 20 pattern detection unit, 21 normal correction Table, 22 TOC correction table, 23, 24 data selector, 25 rising edge detection unit, 26, 29 delay unit, 27 EFM signal reconstruction unit, 28 falling edge detection unit, 50 computer, 51 TOC region pattern analysis unit, 52 Normal area pattern analysis unit, 53 TOC correction table data generation unit, 54 normal correction table data generation unit, 90 disc master, 91 stamper, 92 CD

Claims (4)

And frequently index area recording data sequence becomes a fixed pattern, as a recording apparatus recording data sequence as compared to said index area for recording data in a recording medium having a fixed pattern become infrequent program area,
Recording pulse generation means for encoding data to be recorded into a recording pulse train with a limited run length;
Discriminating means for discriminating whether the recording pulse train output from the recording pulse generating means is a recording pulse train to be recorded in the index area or a recording pulse train to be recorded in the program area ;
When the discriminating means discriminates the recording pulse train for the index area , the edge timing correction of the recording pulse obtained by the recording pulse generating means is performed using the first pattern correction information, and the program An edge correction unit that corrects an edge timing of the recording pulse obtained by the recording pulse generation unit using the second pattern correction information when it is determined as a recording pulse train for the region ;
Recording means for recording on a recording medium based on the corrected recording pulse corrected by the edge correction means;
A recording apparatus comprising: The edge correction means is
Rising edge detecting means for detecting the rising edge of the pulse generated by the recording pulse generating means;
A falling edge detecting means for detecting a falling edge of the pulse generated by the recording pulse generating means;
Pattern detecting means for detecting a pulse pattern of the pulses generated by the recording pulse generating means;
First storage means for storing the first pattern correction information and outputting a correction value based on the first pattern correction information in accordance with the pulse pattern detected by the pattern detection means;
Second storage means for storing the second pattern correction information and outputting a correction value based on the second pattern correction information in accordance with the pulse pattern detected by the pattern detection means;
When the discriminating means discriminates the recording pulse train for the index area, the correction value from the first storage means is selected, and when the discriminating means discriminates the recording pulse train for the program area , the second Selecting means for selecting a correction value from the storage means;
Rising edge delay means for delaying the rising edge detected by the rising edge detection means based on the correction value selected by the selection means;
Falling edge delay means for delaying the falling edge detected by the falling edge detection means based on the correction value selected by the selection means;
Correction recording pulse output means for forming and outputting the correction recording pulse from the outputs of the rising edge delay means and the falling edge delay means;
The recording apparatus according to claim 1, further comprising: And frequently index area recording data sequence becomes a fixed pattern, as a recording method for recording data sequence as compared to said index area for recording data on a recording medium having a fixed pattern become infrequent program area,
A recording pulse generating step for encoding data to be recorded into a recording pulse train with a limited run length;
A determination step of determining whether the recording pulse train output in the recording pulse generation step is a recording pulse train to be recorded in the index area or a recording pulse train to be recorded in the program area ;
When it is determined in the determination step that the recording pulse train is for the index area , the edge timing correction of the recording pulse obtained in the recording pulse generation step is performed using the first pattern correction information, and the program An edge correction step for correcting the edge timing of the recording pulse obtained in the recording pulse generation step using the second pattern correction information when determined as a recording pulse train for the region ;
A recording step for recording on a recording medium based on the corrected recording pulse corrected in the edge correction step;
A recording method comprising: And frequently index area comprising a recording data sequence is fixed pattern, as a manufacturing method for a recording medium having a said index region as compared to the recording data string is fixed pattern become infrequent program area,
A correction information storage step for storing first pattern correction information generated corresponding to the index area and second pattern correction information generated corresponding to the program area ;
A recording pulse generating step for encoding data to be recorded into a recording pulse train with a limited run length;
A determination step of determining whether the recording pulse train output in the recording pulse generation step is a recording pulse train to be recorded in the index area or a recording pulse train to be recorded in the program area ;
When it is determined in the determination step that the recording pulse train is for the index area , the first pattern correction information stored in the correction information storage step is used to record the recording pulse obtained in the recording pulse generation step. When the edge timing correction is performed and the recording pulse train for the program area is determined, the recording obtained in the recording pulse generation step is performed using the second pattern correction information stored in the correction information storage step. An edge correction step for correcting the edge timing of the pulse;
Based on the corrected recording pulse corrected in the edge correction step, a master generating step for performing recording on the recording medium master,
A recording medium manufacturing step for manufacturing a recording medium based on the recording medium master,
An evaluation step of performing quality evaluation by reproducing the recording medium manufactured in the recording medium manufacturing step;
The recording medium manufactured in the recording medium manufacturing step is reproduced, the reproduction signal in the index area is analyzed to generate the first pattern correction information, and the reproduction signal in the program area is analyzed to analyze the second signal. A correction information generation step for generating the pattern correction information of
With
A series of operations as the correction information generation step, the correction information storage step, the recording pulse generation step, the determination step, the edge correction step, the master generation step, and the recording medium manufacturing step are predetermined in the evaluation step. Recording medium manufacturing repeatedly executed until an evaluation result is obtained, a predetermined mastering upper limit number is reached, or the number of the first or second pattern correction information that can be stored in the correction information storing step reaches an upper limit Method.

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