JP2800695B2 - Optical recording / reproducing method, recording / reproducing apparatus, and optical recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of recording a mark length on a sequential channel word formed by channel bits obtained by converting a first data word to be recorded and reproduced according to a predetermined modulation method. The same recording information as the recording information to be reproduced from the conventional optical recording medium which has been recorded by applying the above, can be completely reproduced by the conventional optical reproducing device, and in the conventional optical recording medium. A conventional optical recording / reproducing method and a recording / reproducing apparatus, a recording / reproducing apparatus, and an optical recording / reproducing method compatible with an optical recording medium capable of recording / reproducing recording information having a larger information amount than the recording information amount. The present invention relates to a recording / reproducing device and an optical recording medium.

[0002]

2. Description of the Related Art With the increasing demand for recording various information signals at a high recording density, in recent years, high-density recording of information signals has been achieved by using information recording media made based on various constitutional principles and operating principles. Reproduction is performed. For example, magnetic recording according to an information signal is performed on a ferromagnetic recording layer of an information recording medium, or recording and reproduction is performed by optical means using a magneto-optical recording medium. Or, for example, it is already practical to record information signals by forming irregularities corresponding to the information signals on the signal surface of the information recording medium, and to reproduce the recorded information signals by optical means. In addition, in order to meet the demands for high-density recording and reproduction in various technical fields, the recording layer of the information recording medium is irradiated with a beam intensity-modulated by an information signal. By causing a physical change or chemical change in response to the information signal in the recording layer in the information recording medium, now also commercialized information recording medium as the recording of the information signal.

[0003] As semiconductor lasers that operate stably can be easily obtained, various types of optical recording media (hereinafter, referred to as optical discs) capable of performing high-density recording and reproduction using laser light. (May be described)
However, since it is possible to perform recording and reproduction in a non-contact state, it is resistant to scratches and dust, and has the advantage that a large storage capacity can be obtained by high-density recording.
It is also well known that research and development for practical use is being carried out, and it is well known that pits formed as geometric concave or convex portions reproduce a large amount of information signals from a master on which information signals are recorded. Compacted optical discs (playback-only optical discs)
In addition to the widespread use of disks, rewritable optical disks, such as magneto-optical disks and other optical disks,
For example, it has been put to practical use in office file memories and other uses.

When recording information is recorded as digital data on an optical disc, the recording and reproducing efficiency is high and a good recording and reproducing operation can be obtained in conformity with the characteristics of the recording system and the characteristics of the reproducing system. In order to achieve this, successive channel words formed by channel bits obtained by converting a first data word to be recorded / reproduced according to a predetermined modulation method are used for a mark length recording method or an inter-mark recording method. It is well known that recording on an optical disk by applying the recording method described above has been widely performed.

By way of example, a compact disk (CD) widely known as the already-recorded optical disk (read-only optical disk) described above will be described as an example.
In D, the first data word targeted for recording and playback is
Recording information is recorded on a signal surface by applying a mark length recording method to sequential channel words formed by channel bits obtained by conversion according to a so-called EFM modulation method. When reproducing recorded information, light having a wavelength of 780 nm emitted from a semiconductor laser is focused on a signal surface by an objective lens having an NA of 0.45 as a light spot having a diameter of about 1.4 μm. The difference in the amount of light due to the diffraction phenomenon depends on whether the reflected light from the light spot generated on the signal surface, that is, whether the light spot generated on the signal surface is at the position of the mark (pit) or not. Is processed by an electric signal obtained by photoelectrically converting the reflected light having an optical signal by the photodetector, so that the original signal that has been subjected to recording and reproduction is reproduced.

As described above, by applying the mark length recording method, a mark row (pit row) based on the presence or absence of a mark (pit) is provided.
Information is recorded in the length direction of a mark (pit) in a conventional general optical disk, such as the CD in which information tracks are sequentially recorded and formed at predetermined track pitches in the radial direction of the optical disk. I am trying to be. And in the optical disk as described above,
Even when the recording density is increased and the amount of information recorded on the optical disc is increased, it is caused by various factors that deteriorate optical reading performance such as tilt of the optical disc, defocus, offset, and increase in aberration of the optical system. In order to keep the increase in the amount of jitter and error within an acceptable range for the system, the data words based on the information to be recorded / reproduced are converted into channel bits according to their respective modulation schemes. It is well known that the minimum mark length (minimum bit length) formed on the optical disk is made large.

An example of an optical disk in which a data word based on information to be recorded / reproduced is converted into channel bits in accordance with a modulation method to increase a minimum mark length (minimum bit length) formed on the optical disk. In the case of a CD, the so-called EF is used as the modulation method.
Using a well-known modulation method called M, an 8-bit data word (1) based on information to be recorded / reproduced.
Symbol) is converted into a channel word of 14 channel bits according to a predetermined conversion table, and when the channel bit interval (cycle of the channel clock) is T, the shortest inversion interval (minimum inversion interval) 3T to the maximum inversion on the optical disk. An information track is formed by pits or lands having pit lengths or land lengths in the range up to the interval 11T.

That is, the above-mentioned CD has 12 symbols.
A data word (data before modulation) to which a 1-byte subcode is added is provided for each of 32 symbols including two sets of (one symbol is 8 bits... 1 byte) data and a 4-symbol correction code. , One-symbol data word is converted into a 14-channel bit channel word according to a conversion table of EFM (a part of the conversion table is illustrated in FIG. 18),
From the 17 channel bits in which the combined 14-bit channel words are connected to the combined bits of 3 channel bits for merging and DC component suppression (or also referred to as connection bits, margin bits, etc.), respectively. A frame is composed of a total of 588 channel bits by the following EFM modulation code, a synchronizing signal of 24 channel bits and a combination bit of 3 channel bits, and an information track is formed on a signal surface by a mark length recording method. In such a case, the recording information is recorded in a state where the power spectrum control (DSV control) for suppressing the low frequency component is performed.
It is well known that the sign content of the combination bit is changed.

By the way, for example, image data is recorded even on a CD originally provided as an optical disk used for recording and reproducing acoustic information data.
In recent years, it has become desirable to increase the storage capacity of optical discs. However, as is well known, the spot diameter of light, which is closely related to the performance of reading recorded information from optical discs, And the numerical aperture NA of the reading lens (objective lens), and the spot diameter of the reading light (reproducing light) cannot be arbitrarily reduced. Since the shortest pit length dimension to be formed is also limited, it is difficult to improve the recording density of the optical disc in a direction in which the shortest pit length dimension to be formed on the signal surface of the optical disc is reduced.

As means for solving the above problems, for example, Japanese Patent Application Laid-Open No. Hei 4-74317 discloses the presence / absence of a mark for giving a phase change to irradiated light on an information track of a recording medium, An optical recording method of recording digital information on an optical disc by causing both the displacement of the mark in the horizontal direction and the displacement of the mark in a small amount sufficiently smaller than the cycle, a reproducing method, a recording / reproducing apparatus, and a recording medium. In addition to the description, Japanese Patent Application Laid-Open No. 4-89639 discloses an optical recording system in which a pit row (mark row) of a pattern based on a first information signal is recorded on an optical recording medium. Pit row (mark row) is 2nd
An optical recording system is described which vibrates in a direction intersecting with the column direction in accordance with the information signal to record the information on the optical recording medium.

[0011]

SUMMARY OF THE INVENTION
In either case, the amount of information recorded on the optical disk is increased by recording and reproducing information by the mark sequence on the optical disk and displacing the mark or the mark sequence in the horizontal direction of the mark sequence in accordance with the information to be recorded and reproduced. I'm trying to get it. However, in the technique disclosed in Japanese Patent Laid-Open No. 4-74317, the period of displacing a mark in the mark row in the horizontal direction of the mark row is irrelevant to a small data amount unit in the mark row direction. The unit of the data amount in the small direction and the cycle of displacing the mark in the mark row in the horizontal direction of the mark row are not synchronized. Therefore, as a solution to the above point, as a pit position (mark position modulation) method, a 4/1 such that the number of pits in one channel word becomes constant is considered.
1 shows an embodiment employing one modulation scheme.

On the other hand, in the pit edge method, the number of marks (pits) in one channel word is not always the same. It is proposed to insert an additional 4-byte signal so that the DSV control can perform an ideal operation with respect to the number of pits. That is, when the data is divided into sectors of a predetermined size and recorded in sector units, the number of "H" level bits of the first channel code signal C1 in the sector is not always halved. So, the first channel C
There is a possibility that the last bit of the second information cannot be recorded due to the lack of one “H” level bit. Since the first channel code signal C1 inserts a bit for adjusting the DSV every four bytes, the "H" level channel bits are not short more than half by more than four bytes. After the first channel code signal, an "H" level channel bit having a length equivalent to 4 bytes must be added so that the second information having a half information amount of the first information is recorded. .

However, the above-mentioned means is to insert useless data, which not only reduces the information efficiency but also adds the "H" level signal for four consecutive bytes as described above. Then, the DC component of the signal formed in that portion is biased, and the state of DSV control deteriorates,
Also, if the number of pits (marks) formed by the "H" level signal is large as described above, the amount of reflection of the read light is reduced, so that the detection gain of the focus servo system is reduced and the focus servo signal is adversely affected. Is caused. Japanese Patent Application Laid-Open No. Hei 4-74317 discloses that information to be recorded is divided into first and second information, and the first information is recorded based on the presence or absence of a mark, and the second information is recorded by shifting a mark. It is described that such a configuration facilitates compatibility with a conventional recording medium that records using only the presence or absence of a mark. However, each of the above-mentioned recording methods has an optimum condition, a system tolerance is different, and there is a code configuration and an error correction suitable for each transmission path. Nothing is shown.

Further, Japanese Patent Application Laid-Open No. 4-89639 discloses a recording pattern for displacing a mark row in the horizontal direction of the mark row in accordance with information to be recorded / reproduced. Judging from the description in FIG. 1, it is recognized that the displacement has been made in an analog manner in accordance with the information to be recorded / reproduced. This technique is similar to the technique in which the information track is position-modulated so as to meander with a low-frequency information signal, and is not considered suitable for recording and reproducing digital information.

[0015]

According to the present invention, a mark length is recorded on successive channel words formed by channel bits obtained by converting a first data word to be recorded and reproduced according to a predetermined modulation method. When recording by applying the law,
Among the mark portions having a mark length substantially equal to or longer than the shortest mark length defined by the modulation method, at least the same number as the predetermined number including the first appearing mark in the individual channel word. A plurality of mark patterns including a mark pattern formed by adding restrictions to the normal rule that the logical 1 corresponds to the inversion position of the mark and the non-mark so that the mark portion is provided. A desired mark pattern corresponding to a channel word is selected and used from a predetermined number of mark pattern groups, and a mark sequence consisting of the presence or absence of a mark is sequentially formed on the signal surface of the optical recording medium by the mark length recording method described above. The information track constituted by, is sequentially recorded and formed at a predetermined track pitch in the radial direction of the optical recording medium,
For the same predetermined number of mark portions including the first appearing mark in the above-mentioned individual channel word, a predetermined specific position among a plurality of positions preset in the width direction of the information track is selected. An optical recording method for an optical recording medium to be recorded as a mark displaced in accordance with a second data word to be recorded and reproduced, and a first data to be recorded and reproduced When recording by applying a mark length recording method to a sequential channel word obtained by converting a word according to a predetermined modulation method, a mark portion having a mark length substantially equal to or longer than the shortest mark length determined by the modulation method Among the marks having at least a predetermined number of the same number of marks including the first appearing mark in the individual channel word described above. A predetermined number of mark patterns consisting of a plurality of mark patterns including a mark pattern formed by adding restrictions to the normal rule of associating a logical 1 with a mark / non-mark reversal position so that recording by turns can be performed. Means for preparing a mark pattern group; and a means for separately recording a sequential channel word corresponding to a sequential first data word to be recorded and reproduced on an optical recording medium by a mark length recording method. The desired mark patterns including at least a predetermined same number of mark portions including the first appearing mark in the channel word are sequentially selected so that the mark patterns can be sequentially recorded on the optical recording medium. Means, and the presence or absence of a mark on the signal surface of the optical recording medium sequentially by a mark length recording method using the selected mark pattern. Means for sequentially recording and forming information tracks constituted by a series of marks at a predetermined track pitch in the radial direction of the optical recording medium; and a predetermined means including a mark which appears first in the individual channel word. The same number of mark portions is displaced to a selected specific position among a plurality of preset positions in the width direction of the information track in accordance with the second data word targeted for recording and reproduction. Recording means for recording an optical recording medium comprising a means for recording as a mark in a state of being changed, and a channel bit obtained by converting a first data word to be recorded and reproduced according to a predetermined modulation method When recording by applying the mark length recording method to the sequential channel words formed in the above, when the minimum mark length determined by the modulation method or more A logical one is marked such that it comprises at least a predetermined number of the same number of mark portions, including the first appearing mark in the individual channel word, among the mark portions having substantially the mark length. A channel word corresponding to a channel word from a predetermined number of mark pattern groups prepared in advance including a plurality of mark patterns including a mark pattern configured by adding restrictions to the normal rule of making the mark correspond to the inversion position of a non-mark. A desired mark pattern is selected, and a sequential information track is recorded and formed on a signal surface of the optical recording medium at a predetermined track pitch in a radial direction of the optical recording medium in accordance with a mark row including presence or absence of a mark. And a predetermined same number of mark portions including the first appearing mark in the individual channel words described above, Optical information recorded as a mark displaced in accordance with a second data word targeted for recording and reproduction at a specific position selected from a plurality of positions preset in the width direction of the information track. A light spot having a small diameter for reading information is irradiated on a signal surface of the objective recording medium, and a change in light amount due to the presence or absence of a mark by a channel bit corresponding to the first data word is detected, and recording / reproduction is performed. Regenerate the first data word targeted by
The position information of each mark displaced in the width direction of the information track according to the second data word is obtained based on the reproduction content of the first data word, and the position information of each mark is displaced in the width direction of the information track. An optical system for sampling the individual marks displaced in the width direction of the information track in accordance with the second data word using the position information of the individual marks, and reproducing the second data word. And a mark length recording method applied to sequential channel words formed by channel bits obtained by converting a first data word to be recorded and reproduced according to a predetermined modulation method. Sometimes, at least a portion of the mark portion having a mark length substantially equal to or longer than the shortest mark length defined by the modulation method, including the first mark appearing in the individual channel word described above. A plurality of marks including a mark pattern formed by adding restrictions to the normal rule of associating a logical 1 with an inverted position of a mark and a non-mark so as to have a predetermined same number of mark portions. A desired mark pattern corresponding to a channel word is selected from a predetermined number of mark pattern groups prepared in advance, and is optically recorded on a signal surface of an optical recording medium by a mark sequence sequentially including presence or absence of a mark. A sequential information track is recorded and formed at a predetermined track pitch in the radial direction of the medium, and a predetermined same number of mark portions including a mark first appearing in the individual channel word, A second selected recording / reproduction target is a specific position selected from a plurality of preset positions in the width direction of the information track. A light spot having a small diameter for reading information is imaged on a signal surface of an optical recording medium recorded as a mark displaced according to a data word, and recording information is recorded from the signal surface of the optical recording medium. An optical head that optically reads, and a change in the amount of light due to the presence or absence of a mark due to a channel bit corresponding to the first data word is detected from recording information read by the above-described optical head, and the target of recording and reproduction is detected. Means for reproducing the first data word described above, and position information of each mark displaced in the width direction of the information track in accordance with the second data word from the recorded information read by the optical head. And the position information of each mark displaced in the width direction of the information track in accordance with the second data word, using the means for obtaining the first data word based on the reproduced content of the first data word. Means for sampling the individual marks displaced in the width direction of the information track to reproduce the second data word, and the first data word to be recorded / reproduced. When recording by applying the mark length recording method to sequential channel words formed by channel bits obtained by conversion according to a predetermined modulation method, a mark length equal to or longer than the shortest mark length determined by the modulation method described above. Of the mark 1 having at least a predetermined number of the same number of mark portions, including the first appearing mark in the individual channel word, as described above. A predetermined number of mark patterns prepared in advance consisting of a plurality of mark patterns including a mark pattern formed by adding restrictions to the normal rule of corresponding to the inversion position of the mark. From the group, a desired mark pattern corresponding to the channel word is selected, and is sequentially arranged on the signal surface of the optical recording medium at a predetermined track pitch in the radial direction of the optical recording medium by a mark row including presence or absence of a mark. A sequential information track is recorded and formed, and a predetermined same number of mark portions including the first appearing mark in the individual channel word described above,
It is recorded as a mark displaced in accordance with a second data word targeted for recording / reproduction at a specific position selected from among a plurality of positions preset in the width direction of the information track. An optical recording medium is provided.

[0016]

The mark length recording method is applied to successive channel words formed by channel bits obtained by converting a first data word to be recorded / reproduced in accordance with a predetermined modulation method, to thereby obtain light intensity. From an information track optically recorded on the optical recording medium (optical disk) according to the present invention as a mark row by the presence or absence of a mark by modulation, an information signal that is optically read as a change in intensity of a read light amount according to the presence or absence of the mark is converted. A reproduction signal based on a first data word obtained based on the first data word is a sequential channel formed by channel bits obtained by converting the first data word targeted for recording and reproduction on a conventional optical disc according to a predetermined modulation method. A mark length recording method is applied to a word to read from an information track optically recorded as a mark row consisting of the presence or absence of a mark according to the presence or absence of a mark. Can be the first data word obtained based on the optically read is an information signal as an intensity change in the amount obtained in the same manner as the reproduction signal.

Therefore, even if the recorded information is reproduced from the optical disk of the present invention by using the conventional optical disk reproducing apparatus, the information optically recorded as a mark sequence including the presence or absence of the mark on the optical disk of the present invention is obtained. The information signal can be read optically as a change in the intensity of the read light amount according to the presence or absence of the mark from the track. Conversely, using the reproducing apparatus of the present invention, the mark of the conventional optical disc can be read. An information signal can be optically read from an information track optically recorded as a mark row consisting of the presence or absence as a change in the intensity of the read light amount according to the presence or absence of a mark.

The mark length recording method is applied to sequential channel words formed by channel bits obtained by converting the first data word to be recorded / reproduced as described above according to a predetermined modulation method. When configuring an optically recorded information track as a mark train consisting of the presence or absence of a mark, a mark having a mark length equal to or longer than the shortest mark length determined by the modulation method, and determined by the modulation method A mark having a mark length that is at least twice the shortest mark length, such as a mark portion used so that it can function as two mark portions, such as a mark portion having a length equal to or longer than the shortest mark length determined by the modulation method. At least a predetermined number of the mark portions including the first appearing mark in the individual channel word among the mark portions substantially having the mark length of In accordance with the second data word to be recorded / reproduced to a specific position selected from a plurality of positions preset in the width direction of the information track by the second data word. Recording is performed in a position-modulated state as a mark in a state where the mark is displaced, and the second data word is recorded and reproduced according to the state of displacement of the mark, thereby increasing the data recording capacity as compared with the conventional optical disk. Can be done.

By the way, as described above, the mark length recording method is applied to successive channel words formed by channel bits obtained by converting the first data word according to a predetermined modulation method, and the intensity of light is modulated. In the sequential channel words constituting the information track optically recorded as a mark row including the presence or absence of a mark, a mark length substantially equal to or longer than the shortest mark length defined by the above-mentioned predetermined modulation method is substantially used. Of the mark portion of the
The mark portion to be position-modulated to a selected specific position among a plurality of preset positions in the width direction of the information track by the data word of the information track, that is, the mark which appears first in each individual channel word is included. In the case where a sequential channel word in which at least a predetermined number of the same mark portions are set is recorded as an information track based on the presence or absence of a mark by the mark length recording method, the predetermined modulation An information track must be formed by a mark pattern including a mark portion having a mark length from the shortest mark length to the longest mark length defined by the method and a non-mark portion.

That is, in each individual channel word, at least a predetermined portion including a first appearing mark among mark portions having a mark length substantially equal to or longer than the shortest mark length determined by the above-mentioned modulation method. The sequential channel words in the state where the same number of mark portions are set as position modulation marks by the second data word,
In the state recorded as an information track including the presence or absence of a mark by a mark length recording method, a mark portion and a non-mark portion having a mark length from the shortest mark length to the longest mark length determined by the predetermined modulation method described above. The information track is constituted by a mark pattern consisting of: and the optical disk of the present invention provided with the information track having the above-described structure is optically formed as a mark row including the presence or absence of a mark even when reproduced by a conventional optical disk reproducing apparatus. The first data word is converted into a channel word according to a predetermined modulation method so that the recorded information track can be read optically as a change in the intensity of the read light amount according to the presence or absence of a mark. The conversion table used when obtaining the channel words to be recorded on the conventional optical disc In addition to having the same conversion contents as the conversion table used when converting the first data word into the channel word according to the predetermined modulation scheme, the second data word described above is provided for each individual channel word. In the state in which the mark portion for position modulation is set, the mark portion includes a mark portion having a mark length from the shortest mark length to the longest mark length determined by the above-described predetermined modulation method, and a non-mark portion. There is a need for a mark pattern for selecting a mark pattern for forming an information track by the mark pattern.

The conversion table used when converting the first data word into a channel word according to a predetermined modulation method includes a channel obtained by converting the first data word according to a predetermined modulation method. When a mark length recording method is applied to sequential channel words formed of bits to form an information track optically recorded as a mark sequence including the presence or absence of a mark, a mark portion by the sequential channel word and a non- A mark that can be formed by a mark pattern composed of a mark portion having a mark length from the shortest mark length to the longest mark length defined by a predetermined modulation method, and a non-mark portion, the arrangement state of the mark portion. So that you can choose a pattern,
Use a mark pattern group having a predetermined number of mark patterns including a plurality of mark patterns including a mark pattern formed by adding a restriction to a normal rule that a logical 1 corresponds to an inverted position of a mark and a non-mark. I do.

When recording is performed by applying a mark length recording method to sequential channel words formed by channel bits obtained by converting a first data word to be recorded and reproduced according to a predetermined modulation method. Of the mark portions having a mark length substantially equal to or longer than the shortest mark length determined by the modulation method, at least the same predetermined mark including the first mark appearing in the individual channel word described above. A pre-preparation consisting of a plurality of mark patterns including a mark pattern formed by adding restrictions to the normal rule of making logical 1 correspond to the inversion position of a mark and a non-mark so as to have a number of mark portions A desired mark pattern corresponding to the channel word is selected from the predetermined number of mark pattern groups thus determined, and the signal surface of the optical disc is sequentially checked for the presence or absence of the mark. A series of information tracks are recorded and formed at a predetermined track pitch in the radial direction of the optical disk by the mark train, and a predetermined same number including the first appearing mark in the individual channel word. Mark in a state where the mark portion is modulated at a specific position selected from a plurality of positions preset in the width direction of the information track by the second data word targeted for recording and reproduction. Is rotated at a predetermined number of revolutions, and the signal surface of the optical disk is irradiated with a light spot having a small diameter for reading information, and a mark is formed by a channel bit corresponding to the first data word. A change in the amount of light due to the presence or absence of is detected, and the first data word targeted for recording and reproduction is reproduced. Based on the reproduced content of the first data word, information on the position of each mark that is position-modulated in the width direction of the information track in accordance with the second data word is obtained, and the position-modulated individual is obtained. The sampling of the mark is performed to reproduce the second data word.

[0023]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an optical recording / reproducing method according to the present invention; FIG. 1 is a block diagram of a schematic configuration of an optical recording device of the present invention used when recording information (recording data) to be recorded / reproduced on an optical recording medium according to the optical recording method of the present invention. (A) of FIG. 1 and an optical recording medium on which information (recording data) to be recorded / reproduced by the optical recording apparatus of the present invention shown in (a) of FIG. 1 is recorded. FIG. 1 is a block diagram (FIG. 1B) showing a schematic configuration of an optical reproducing apparatus of the present invention for reproducing information targeted for recording / reproducing according to the optical reproducing method of the present invention.

In the optical recording apparatus of the present invention shown in FIG. 1A, 1 is an input terminal of a first data word to be recorded and reproduced, and 11 is a first data word to be recorded and reproduced. 2 data word input terminals, and 2, 4, 12
Is an encoder, 3 and 13 are interleave processing units, 5 is an EFM modulation unit, 6 is an optical modulator drive circuit, 7 is a light source, 8 is an optical modulator, 9 is an optical deflector, 10 is an objective lens, and Dr is a master disk. , 14 are mark position modulation units (wobble modulation units), and 15 is an optical deflector drive circuit. In the optical reproducing apparatus of the present invention shown in FIG. 1B, D is a recorded optical recording medium (optical disk), 16 is an optical head, 17 is an EFM demodulator, and 22 is a mark position demodulator (wobble). Demodulation unit), 18, 20, 24 are decoders, 19,
Reference numeral 23 denotes a deinterleave demodulation unit, reference numeral 21 denotes an output terminal of a first data word to be recorded and reproduced, and reference numeral 25 denotes an output terminal of a second data word to be recorded and reproduced.

The optical recording medium (recorded optical recording medium, optical disk) D of the present invention is recorded and reproduced by an optical recording apparatus as exemplified in FIG. A mark length recording method is applied to sequential channel words formed by channel bits obtained by converting the first data word according to a predetermined modulation method, and the intensity of the light is modulated in accordance with the presence or absence of a mark. A mark having a mark length equal to or longer than the shortest mark length determined by the modulation method, and a mark having a mark length twice or more the shortest mark length determined by the modulation method, to two mark portions. Among the mark portions having a mark length substantially equal to or longer than the shortest mark length defined by the modulation method, such as the mark portion used so as to function as At least a predetermined number of mark portions including the first appearing mark in the channel word is selected by a second data word in a selected one of a plurality of positions preset in the width direction of the information track. After exposing the photoresist layer of the master disc Dr to a light-deflected state at an appropriate position, the master disc Dr is developed and then produced by a well-known optical disc manufacturing process. 1
Is 8 bits (1 byte), and a well-known EFM method is used as a modulation method for converting the data word into a channel word.

In a well-known modulation method referred to as EFM, an 8-bit data word (one symbol) based on information to be recorded / reproduced is partially shown in FIG. According to such a conversion table, the channel word is converted into a channel word of 14 channel bits. And the C
In D, a data word (data before modulation) in which a 1-byte subcode is added to each of 32 symbols composed of two sets of 12 symbol data and 4 symbol correction codes.
Is converted from a one-symbol data word to a 14-channel bit channel word in accordance with the above-mentioned EFM conversion table, and the 14-bit channel words are sequentially combined into three combined channel bits for merging and DC component suppression ( Alternatively, it is also referred to as a connection bit, a margin bit, or the like.) A total of 588 channel bits including an EFM modulation code composed of 17 channel bits connected with each other, a synchronization signal of 24 channel bits and a combination bit of 3 channel bits And that a power spectrum control (DSV control) for suppressing low frequency components is performed when an information track is formed on a signal surface by a mark length recording method. The code content of the connection bit is As is well known, when the channel bit interval (cycle of the channel clock) is T, the shortest inversion interval (minimum inversion interval) is 3T on the optical disk and the maximum inversion interval is 11T. The information track is formed by pits or lands having the pit length or land length of the optical disk, but the following description describes a case where the optical disk of the present invention is implemented as an optical disk compatible with a CD. .

First, a well-known C in which the same data word is recorded.
The fact that D and the optical disc D of the present invention are compatible will be described with reference to FIGS. FIG. 18 shows a part of the contents of a conversion table used when converting an 8-bit data word into a 14-bit channel word by using a well-known modulation method called EFM, as described above. A sequence of 14 numbers “01001100000000” described on the right side of # 0 shown in FIG.
Is the data word "00000" indicated by # 0 in FIG.
000 "indicates a channel word of 14 channel bits converted by the conversion table, and the above-mentioned sequence of 14 numbers" 01001100000000 "
The waveform diagram shown below the channel word indicated by is a waveform diagram when the above-mentioned channel word is subjected to NRZI modulation. Further, FIG. 19B shows the NRZI modulation This shows a state in which marks (pits) and non-marks (lands) have been recorded on the optical disc by the waveforms obtained.

FIG. 19C shows reflected light generated by irradiating a mark on an optical disc with a spot of light having a small diameter larger than the width of the mark, and forming a far-field image via an optical system. Two output signals from two photodetectors in the given two-segment photodetector (the center of a light spot having a small diameter larger than the width of the mark is located at the center line of the mark on the optical disc). State: an added output of an output signal when there is no tracking error). The above-mentioned two-segment photodetector is arranged such that the boundary between the two photodetectors coincides with the extension direction of the mark row {the extension direction of the dotted line in FIG. 19B}. ing. (D) and (e) of FIG.
When the center of the spot of light having a small diameter larger than the width of the mark is positioned on the center line of the mark on the optical disk as described above, the two-divided photodetector is configured. FIG. 19F shows the output signals output from the two photodetectors, and FIG. 19F shows the output signals of FIG. 19 output from the two photodetectors constituting the above-described two-segment photodetector. 19 shows the difference signal between the output signals shown in (d) and (e). The output signals shown in (d) and (e) of FIG. 19 have the same polarity and magnitude. Because
The difference signal shown in FIG. 19 (f) becomes zero.

As a photodetector to which the reflected light from the optical disc is given as a far-field image, instead of using the two-segment photodetector as described above, a well-known four-part photodetector is used.
A split photodetector may be used, and if a 4-split photodetector is used instead of a 2-split photodetector,
The arrangement is such that the boundary line between the two pairs of photodetectors in the four photodetectors coincides with the extension direction of the mark row {the extension direction of the dotted line in FIG. 19 (b)}. 19 (d) and (e) of FIG. 19, as described above, the center of the light spot having a small diameter larger than the width of the mark is located at the center line of the mark on the optical disk as described above. In the state, the four photodetectors constituting the above-mentioned quadrant photodetector
FIG. 19 (f) shows output signals output from two sets of photodetectors forming a pair in each of the four photodetectors, and FIG. 19 (f) shows four lights constituting the four-divided photodetector. 19 shows the difference signal between the output signals shown in (d) and (e) of FIG. 19, which are output from the two pairs of photodetectors forming a pair in the detector. As a photodetector to which the reflected light from the optical disc is given as a far-field image, a two-divided photodetector and a well-known
The fact that either of the split photodetectors can be selectively used also applies to the optical reproducing apparatus of the present invention described later.

As described above, the mark array P formed on the signal surface of the optical disk illustrated in FIG.
1, P2... Are data words "0000" indicated by # 0 in FIG.
0000 "is a data word to be recorded / reproduced, and the data word is described by a conversion table shown in FIG. 18 as a channel word of 14 channel bits, that is, at the right side of # 0 in FIG. Is converted into a channel word represented by a sequence of fourteen numbers "0100100010000000", and then the information track is formed on the optical disk by NRZI modulation by a sequence of marks (pits) and non-marks (lands). The position of each mark is determined such that the center line in the extension direction of each mark always coincides with the center line of the information track. And compact disc CD (and CD-
The information track in the ROM is constituted by the above-described mark train. Therefore, in a CD (and CD-ROM) in which an information track is constituted by mark rows P1, P2,... As exemplified in FIG.
The recorded data is reproduced by using the fact that the amount of reflected light generated by the spot of the read light emitted from the optical head to the information track on the signal surface changes according to the presence or absence of a mark, that is, pits and lands. I have.

On the other hand, in the optical disk of the present invention, in order to obtain compatibility with the conventional optical disk, a mark is added to sequential channel words formed by channel bits obtained by conversion according to a predetermined modulation method (for example, EFM). An information signal that is optically read as an intensity change of the amount of light read out from an optically recorded information track as a mark train by the presence or absence of a mark by light intensity modulation by applying the long recording method. Is converted into a sequential channel word formed by channel bits obtained by converting a data word targeted for recording and reproduction on a conventional optical disc according to a predetermined modulation method. By applying the mark length recording method, it is possible to respond to the presence / absence of a mark from an information track optically recorded as a mark train consisting of the presence / absence of a mark. In the same manner as the reproduction signal based on the first data word obtained based on the information signal optically read as the intensity change of the read light amount, the above point is, for example, compatible with the optical disk of the present invention. The case where the optical disk is a CD (and a CD-ROM) will be described as an example.

When the optical disk of the present invention is configured as an optical disk compatible with a CD (and a CD-ROM), a data word to be recorded and reproduced is indicated by, for example, # 0 in FIG. Data word "000000"
In the case of "00", the data word is converted into a channel word of 14 channel bits by the conversion table shown in FIG. 18, that is, 14 data words described on the right side of # 0 in FIG. The sequence of numbers "0100100010
0000 "and then convert it to a mark (pit) on the optical disc by NRZI modulation.
An information track is constituted by a row of a mark (pit) and a non-mark (land), and the sequential information track by the row of the mark (pit) and the non-mark (land) is formed at a predetermined track pitch in a radial direction of the optical disk. Is done. Thus, from the information track optically recorded as the mark sequence including the presence or absence of the mark on the optical disc of the present invention, the mark of the mark is reproduced in the same manner as when reproducing the recorded information from the conventional CD (and CD-ROM). A reproduction signal based on the first data word can be obtained based on an information signal optically read as a change in the intensity of the read light amount depending on the presence or absence.

Therefore, the conventional CD (and CD-ROM)
Even when the recorded information is reproduced from the optical disk of the present invention by the reproducing apparatus of the present invention, the amount of light read out from the information track optically recorded as a mark train consisting of the presence or absence of the mark on the optical disk of the present invention in accordance with the presence or absence of the mark. An information signal can be read optically as a change in intensity, and, conversely, using the reproducing apparatus of the present invention,
It is possible to optically read an information signal as a change in the intensity of a read light amount from an information track recorded on a conventional CD (and CD-ROM) according to the presence or absence of a mark.

Further, in the optical disk of the present invention, as described above, the first data word is marked on a sequential channel word formed by channel bits obtained by converting the first data word according to a predetermined modulation method (EFM in the description example). When an information track that is optically recorded as a mark row composed of the presence or absence of a mark is formed by applying the long recording method, the information track having the shortest mark length (3T) or more defined by the modulation method (EFM) is used. A mark having a mark length, and the modulation method (EF
M), as in the case of a mark portion used so that a mark having a mark length twice or more the shortest mark length (3T) defined in M) can function as two mark portions, the modulation method (EFM) )), At least a predetermined number of the mark portions including the first appearing mark in the individual channel word among the mark portions substantially having the mark length longer than the shortest mark length (3T) defined in Is moved to a specific position selected from a plurality of positions preset in the width direction of the information track by the second data word in accordance with the second data word targeted for recording and reproduction. A conventional light beam is recorded by recording a position-modulated state as a mark in a state where the mark is displaced, and recording and reproducing the second data word according to the state of displacement of the mark. So that it is possible to increase the recording capacity of data than disk.

In FIGS. 19 (g) and (h), P1, P2
.. Apply the mark length recording method to sequential channel words formed by channel bits obtained by converting the first data word according to a predetermined modulation method (EFM in the description example) as described above. Marks (pits) P1, P2,... Shown in (g) and (h) of FIG. 19 are data strings "# 0" shown in FIG. 00000000 "is a data word to be recorded / reproduced. The data word is converted to a channel word of 14 channel bits by the conversion table shown in FIG. 18, that is, to the right of # 0 in FIG. 19A. A sequence of 14 numbers “01001001” described
0000 "
When the information track is composed of a row of marks (pits) and non-marks (lands) on the optical disc by NRZI modulation, the information track is recorded on the optical disc corresponding to the channel word of 14 channel bits.
Among the marks (pits) P1 and P2, the recording position of the mark P1 that first appeared for the channel word is
The state where the second data word is displaced to a specific position selected from two preset positions in the width direction of the information track is illustrated.

That is, the mark P1 shown in (g) of FIG. 19 is located below the center line of the information track shown by the dotted line in the figure (the arrow mark indicating the moving direction of the optical disk). On the left side of the center line of the information track (see FIG. 3), displaced by a second data word "0" and recorded.
The mark P1 shown in (h) of FIG. 19 is located above (in the direction of the arrow showing the moving direction of the optical disk) the center line of the information track shown by the dotted line in the figure. It is shown on the right side of the center line of the information track) by the second data word “1” that the data track is displaced and recorded. FIGS. 19 (g) and 19 (h) show the marks which are displaced to a specific position selected from a plurality of preset positions in the width direction of the information track by the second data word. An example of the case where the first appearing mark P1 is set for the channel word No. is shown. Although the one mark P1 is displaced to a selected one of two preset positions in the width direction of the information track, an increase in the recording capacity of one bit can be obtained. This increase in the recording capacity of one bit is caused by the first bit of the eight bits.
The data capacity of the optical disk is increased by 12.5% as compared with the case where only the data word is recorded on the optical disk.

On a signal surface of an optical disk having an information track composed of a mark row of a mark pattern as exemplified in FIG. 19 (g) or FIG. Reflected light generated by irradiating a spot of light with a diameter is given as a far-field image via an optical system. Two output signals (optical discs) from the two photodetectors in the above-described two-segment photodetector. In the state where the center of the light spot having a small diameter larger than the width of the mark is located on the center line of the mark in the above-mentioned condition (the output signal when there is no tracking error), the added output of FIG. It will be as shown by (c).

19 (i) {or (j)} of FIG. 19 corresponds to (g) of FIG. 19 or (h) of FIG.
The center of a light spot having a small diameter larger than the width of the mark is located at the center line of the mark on the signal surface of the optical disk having the information track including the mark row of the mark pattern as exemplified in FIG. In this state, the difference signal between the output signals output from the respective photodetectors of the two photodetectors constituting the two-segment photodetector is illustrated. FIG. 19 (i), FIG.
(J) indicates that the mark P1 in the mark patterns illustrated in (g) of FIG. 19 and (h) of FIG. 19 is displaced more to either side from the center line of the information track. Signals having different polarities and magnitudes depending on whether the output signals are output from the respective photodetectors of the two photodetectors constituting the above-described two-segment photodetector. Based on the polarity and magnitude of the difference signal, it is possible to detect on which side and how much the mark in the information track formed on the signal surface of the optical disc is displaced from the center line of the information track.

The pulse Ps shown in FIG.
Is a sampling pulse generated at a time position near the center of the difference signal shown in FIG. 19 (i) and FIG. 19 (j). This sampling pulse Ps is Since the position of the mark position-modulated by the second data word is known in advance, signal processing is performed on the sum signal of the output signals from the two photodetectors in the above-mentioned two-segment photodetector. The information on the position of each mark that has been position-modulated in the width direction of the information track by the second data word based on the reproduced content of the first data word generated based on the EFM demodulated signal obtained in the above manner. , And is generated at a time position where sampling can be performed for each of the position-modulated marks. The signal shown in (l) of FIG. 19 is generated by the above-described sampling pulse Ps.
9 illustrates a signal in the case where the positive difference signal shown in FIG. 9 (j) is sampled. It is needless to say that when the negative difference signal shown in FIG. 19 (i) is sampled by the sampling pulse Ps, a negative polarity signal is obtained.

In the optical disk of the present invention described above with reference to FIG. 19, recording / reproduction is performed at a specific position selected from two predetermined positions in the width direction of the information track. Although the mark displaced according to the second data word is recorded by position modulation, the optical disc of the present invention constitutes an optically recorded information track as a mark train including the presence or absence of the mark. Sometimes, a mark having a mark length equal to or longer than the shortest mark length (3T) defined by the modulation method (EFM) and a mark having a mark length twice or more the shortest mark length (3T) specified by the modulation method (EFM) Like the mark part used so that a mark having a length can function as two mark parts, the minimum mark length (3T) or more defined by the modulation method (EFM) Of the mark portions having substantially the mark length, as described later, two mark portions including the first appearing mark in the individual channel word are set in advance in the width direction of the information track. The second data word may be displaced to a selected one of the four positions by a second data word, in which case a 2-bit increase in storage capacity is obtained for each individual channel word. Thus, an increase in the storage capacity of two bits for each individual channel word can increase the storage capacity of the optical disk by 25% compared to a case where only the first 8-bit data word is recorded on the optical disk. .

As described above, two mark portions including the first appearing mark in the individual channel word are selected from among four positions preset in the width direction of the information track by the second data word. In the case of displacing the mark to one of the above-described positions, each of the difference signals generated corresponding to the mark displaced to the specific position in the width direction of the information track by the second data word as described above. A sampling pulse is generated near the center, and the information of the second data word is sampled from the mark position-modulated by the second data word using the sampling pulse. The sampling pulse used in this case also has the position of the mark position-modulated by the second data word, which is known in advance. Based on the reproduction content of the first data word generated based on the EFM demodulated signal obtained by performing signal processing on the sum signal of the two output signals, a position in the width direction of the information track is determined by the second data word. Information on the position of each modulated mark is obtained, and is generated at a time position at which sampling can be performed on each position-modulated mark.

FIG. 4 shows a case where a mark length recording method is applied to successive channel words formed by channel bits obtained by converting the first data word in accordance with the EFM to form an optical mark array having marks. When configuring an information track recorded on a disc, a mark having a mark length equal to or longer than the shortest mark length (3T) defined by EFM, and the shortest mark length (3T) defined by the above-described modulation method (EFM). )
The shortest mark length (3T) or more that is determined by the above-mentioned modulation method (EFM), such as a mark portion used so that a mark having a mark length twice or more of the above can function as two mark portions. Among the mark portions having a mark length of substantially the same, the mark which appears first in the individual channel word is replaced by a second data word in a plurality of positions preset in the width direction of the information track. Used for recording data when obtaining an optical disk recorded in a position-modulated state as a mark displaced in accordance with a second data word targeted for recording and reproduction at a selected specific position. FIG. 3 is a diagram for explaining a configuration of a recording signal.

In FIG. 4, (a) of FIG. 4 shows a first data word (EFM modulation in FIG. 1) supplied to the input terminal 1 of the first data word shown in (a) of FIG. In part 5,
(It may be the first data word supplied from the encoder 4), and in the example shown in FIG.
The first data word is sequentially displayed on the time axis in the order of # 0, # 0 in FIG.
It is assumed to be an 8-bit data word shown in # 1. FIG. 4B shows a second data word (the mark position modulation unit 14 in FIG. 1) supplied to the input terminal 11 of the second data word shown in FIG. In the example shown in FIG. 4A, the second data word is "1" sequentially on the time axis. ",
It is described as a 1-bit data word that is "0" (however, a logical value 1 is represented as "1" and a logical value 0 is represented as "0" in this specification). FIG. 4C shows the input terminal 1 of the first data word shown in FIG.
Is the data before modulation supplied to the EFM modulator 5 in a state where the encoder 2, the interleave processor 3, and the encoder 4 have respectively received known signal processing. The pre-modulation data is composed of an 8-bit subcode, and 32 symbols including two sets of data of 12 symbols (1 symbol is 8 bits... 1 byte) and a correction code of 4 symbols. .

FIG. 4D shows that the second data word supplied to the input terminal 11 of the second data word shown in FIG. Reference numeral 13 denotes 1-bit data supplied to the mark position modulation unit (wobble modulation unit) 14 in a state in which the signal processing has been performed. (E) of FIG.
By the EFM modulation performed in the EFM modulation unit 5 shown in FIG. 1A, the first 8-bit data words are sequentially converted according to the conversion specified in the EFM conversion table shown in FIG. FIG. 18 shows a state in which the channel words are sequentially converted into 14 channel bit channel words as shown in FIG. 4F based on the mode {# 0, # 1 in FIG.
Should be compared with the contents described in (a) and (f) of FIG. Further, in the EFM modulating unit 5, three channel bit combination bits in which each channel bit is set to a specific logical value are provided between successive 14 channel bit channel words. This is given to the optical modulator drive circuit 6 shown in FIG.

The E consisting of the 17 channel bits described above
The FM modulation code is recorded as an NRZI modulation code on the optical disk by a mark length recording method. In the optical disk of the present invention in which information is recorded by a recording signal having a configuration as shown in FIG. The mark to be recorded first as a mark (pit) on the optical disc for each EFM modulation code composed of bits is shown in FIG.
(H) mark position modulation data (second
Is obtained on the optical disk in a position-modulated state according to the
The mark position modulator 14 shown in FIG. 1A is supplied with information on a mark to be subjected to position modulation from the EFM modulator 5. And the EF mentioned above
The M modulating unit 5 includes, for example, the following constituent parts, that is, a converting unit using a ROM table used for converting an 8-bit first data word into 14 channel bits, and data conversion in units of subcodes. A frame synchronization signal addition unit for adding a frame synchronization signal, and a margin bit generation unit for determining a logical value array of connection bits according to the DSV; And a parallel / serial conversion unit for converting parallel data into serial data, and modulating the serial data into a mark / non-mark arrangement pattern, and controlling a modulation pattern so that position modulation is performed on a mark having a mark length as long as possible. An NRZI conversion unit;
A DSV integrator provided for detecting the DC component of the EFM signal for controlling the DSV of the EFM signal, and a mark position data output for generating bit position information (pulse) of the mark position-modulated by the second data word One having each component such as a unit can be used. (I) of FIG.
Is a mark position modulation drive signal generated by the mark position modulation section 14 shown in FIG. 1A corresponding to the mark position modulation data exemplified in FIG. 4H. (Wobble modulation drive signal) is transmitted to the optical deflector drive circuit 1
5 is supplied.

The recording light (laser light) emitted from the light source (laser light source) 7 is intensity-modulated by the optical modulator 8 to which the output signal of the optical modulator drive circuit 6 is supplied. The light enters the optical deflector 9 to which the optical deflection signal is supplied from the optical deflector driving circuit 15 and
In the state where only the position of the specific mark is position-modulated as a mark displaced to a specific position selected from a plurality of positions preset in the width direction of the information track by the second data word. Marks other than the above-mentioned specific mark are recorded in a state where the center line of the information track coincides with the center line in the direction in which the mark extends. That is, the optical modulator 8 and the optical deflector 9
The photoresist layer is exposed to light corresponding to the mark pattern by the light focused on the photoresist layer of the master disk Dr by the objective lens 10 after the above. After developing the master disk Dr, a recorded optical disk (optical disk) D is produced by a known optical disk process. FIG. 4 (j) is a diagram illustrating a state in which sequential marks are recorded on the signal surface of the optical disk as described above,
FIG. 4K is a diagram showing the configuration of the recording signal of the optical disk. The recording signal of one frame of 588 channel bits is composed of a combination of 24 channel bits and 3 channel bits and a plurality of 17 channel bits. (Record data) is formed.

The operation of reproducing the recorded data from the optical disk D on which the recorded data is recorded as described above with reference to FIG. 4 has the structure shown in FIG. 1B. This can be performed by the playback device of the embodiment. That is, an optical head 16 that reads recorded information while tracking an information track based on a mark train formed on a signal surface of an optical disc D that is rotated at a predetermined rotation speed by a rotation driving device (not shown). An intensity-modulated signal output corresponding to a mark (pit) and a non-mark (land) on the optical disk, that is, an optical head output from the optical head (detailed structure will be described later with reference to FIG. 2). The reflected light from the light spot irradiated on the signal surface of the optical disk D from 16 is the added signal of the output signal from the two-segment photodetector given as a far-field image by the optical system in the optical head {FIG. (B) The reference｝ is supplied to the EFM demodulation unit 17, and the position modulation signal obtained corresponding to the position modulation of the mark, that is, the above-mentioned two division The difference signal of the two output signals from the two light detector in the detector {shown in FIG. 5 (c) see} is given to the mark position demodulator 22.

A mark pattern of a part of an information track constituted by an array of marks (pits) and non-marks (lands) on an optical disc D on which a recording signal is recorded as described above with reference to FIG. In FIG. 5A showing an example, a dotted straight line extending in the horizontal direction indicates the center line of the information track. Among the sequential marks forming the information track, the mark recorded with the center line of the mark coinciding with the center line of the information track is not position-modulated by the second data word. A mark which is a mark and is position-modulated by the second data word has a predetermined minute distance (for example, 10 distances between the center lines of the sequential information tracks) with respect to the center line of the information track.
%, I.e., a distance of about 10% of the track pitch). The difference signal between the two output signals from the two photodetectors in the two-segment photodetector is shown in FIG. 5 corresponding to the displacement state of the mark position-modulated by the second data word. (C).

Next, the optical disk D by the optical head 16
The operation of reading the recording data from the memory will be described more specifically with reference to FIG. 2 and the like.
In the optical head 16 surrounded by a frame indicated by a dashed line in FIG. 2A, 26 is a semiconductor laser, 27 is a beam splitter, 28 is a lens, 29 is a half mirror, 3
0 is an objective lens, 31 is a cylindrical lens, 32 is a photodetector, 33 is a servo actuator, 34 is a condensing lens, 35 is a 2 split photodetector (or 4 split photodetector), and 36 and 37 are amplifiers. , 38 are adders, 39 is a subtractor, and 51 is a servo system.

Semiconductor laser 26 in optical head 16
The light emitted from the lens is transmitted through the beam splitter, converted into parallel light by the lens, and then transmitted through the half mirror 29 to enter the objective lens 30. The objective lens 3
0 is attached to the actuator 33 of the servo system, and according to a focus control signal and a tracking control signal supplied to the actuator 33 from the servo system 51,
The actuator 33 controls the objective lens 30 for focus control and tracking control. Servo system 51
Then, the optical disk D is transmitted through the optical path of the objective lens 30 → the transmission through the half mirror 29 → the lens 28 → the beam splitter 27 → the cylindrical lens 31 → the photodetector 32.
The focus control signal and the tracking control signal described above are generated based on an output signal from a photodetector 32 (for example, a four-divided photodetector) to which the reflected light from the light is supplied, and the generated signals are supplied to an actuator 33.

Now, of the reflected light from the optical disk D, the two-divided photodetector 35 passes through the optical path of the objective lens 30 → the reflection by the half mirror 29 → the condensing lens 34 → the two-divided photodetector 35. Its two photodetectors 35a, 35b
Are supplied to an adder 38 and a subtractor 39 after being amplified by amplifiers 36 and 37, respectively. The two-divided photodetector 35 is provided so that the boundary between the two photodetectors 35a and 35b coincides with the extension direction of the information track on the optical disc D. The output signal from the adder 38 is a signal as shown in FIG. 5B, that is, an intensity signal of reflected light whose light intensity is changed in accordance with the presence or absence of a mark on an information track on the optical disc D. This is the same type of signal as a reproduction signal reproduced from a conventional optical disk.

The output signal from the subtractor 39 is position-modulated by a second data word in a signal as shown in FIG. 5C, that is, in a mark in an information track on the optical disk D. This is a signal in a state where the polarity and the magnitude of the mark in the changed state are changed corresponding to the state of the displacement of the mark. An output signal from the adder 38, that is, an intensity modulation signal of light indicating a change in the amount of reflected light generated in correspondence with the presence or absence of a mark due to the spot of the reading light emitted from the optical head to the information track on the signal surface. Is shaped by the binarization circuit 40,
This is a binary signal based on a light intensity modulation signal composed of a pulse train having a pulse length in the range of 3T to 11T according to the arrangement of marks and non-marks on the information track of the optical disc.
The binarized signal output from the binarization circuit 40 is supplied to the phase locked loop 42, the EFM demodulation unit 17, and the gate circuit 41. The phase locked loop 42 generates a bit clock signal from the binarized signal supplied from the binarization circuit 40 and supplies the bit clock signal to the EFM demodulation unit 17.

FIG. 5D is a diagram showing the frame structure of the intensity-modulated signal output from the adder 38, and FIG. 5E is a diagram showing two channel words each consisting of 14 channel bits. FIG. 5F shows a pattern of a logical value with a combination bit consisting of three channel bits interposed between two channel words. FIG. 5F shows an output signal from the binarization circuit shown in FIG. 5 corresponds to the data shown in FIG. 5E, where the high-level portion corresponds to the land portion of the optical disk, and the low-level portion corresponds to the pit portion of the optical disk. FIG. 5G shows output data from the EFM demodulator 17 described above, and shows data words obtained by demodulating the two channel words shown in FIG. 5E with an EFM conversion table. .
FIG. 5H shows a sampling pulse generated by the sampling pulse generator 45 shown in FIG.
FIG. 5 (i) shows the output signal of the sampling circuit 44 in a state where the signal shown in FIG. 5 (c) is sampled and held by the sampling pulse. FIG.
(J) indicates the position modulation information demodulation unit 46 shown in FIG.
Is a position modulation information signal obtained by binarization using a predetermined comparison level. FIG. 5 (k) shows the frame configuration by the first data word (32 bytes / 1 frame) at the top, and the frame configuration by the second data word (24 bytes).
(Bit / 1 frame) is shown below.

The EFM demodulation unit 17 converts the binarized signal supplied from the binarizing circuit 40 by a light intensity modulation signal composed of a pulse train having a pulse length in the range of 3T to 11T into data by an EFM code. The data is demodulated into intensity modulated signal data using the conversion table and output. Further, in the gate circuit 41 in which the signal output from the binarization circuit 40 is supplied as a pit signal pulse, the signal output from the subtractor 39 is used as the pit signal pulse as a gate signal. The signal is gated to extract only the signal corresponding to the mark (pit) in the output signal of the subtractor 39, and the extracted signal is sent to the mark position demodulation unit (mark position information demodulation unit) 22. give. The mark position demodulation unit 22 is also supplied with the data of the intensity modulation signal output from the EFM demodulation unit 17. Then, the mark position demodulation unit 2 shown in FIG.
2 is the shortest mark length defined by the EFM method (3
T) Among the mark portions having a mark length substantially equal to or longer than one mark, the first mark appearing in the individual channel word is replaced by a plurality of marks preset in the width direction of the information track by the second data word. Configuration used when demodulating the second data word from the optical disc of the present invention when recorded in a position-modulated state as a mark displaced to a specific position selected from among the positions A signal delay unit 43 and a sampling circuit 44
, A sampling pulse generating section 45 and a position modulation information demodulation circuit 46.

The mark position demodulation section 22 shown in FIG. 2B is a part of the mark portion having a mark length substantially equal to or longer than the shortest mark length (3T) defined by the EFM method. The two marks, including the first one appearing in the individual channel word, are identified by a second data word in a selected specific one of a plurality of positions preset in the width direction of the information track. In a configuration used when demodulating a second data word from the optical disc of the present invention having a configuration as described later, which is recorded in a position-modulated state as a mark displaced to a position And an analog-to-digital converter 47 and a memory 48
, A sampling pulse generator 45 and a position modulation information demodulation circuit 50.

In the mark position demodulation unit 22, as described above, a specific mark portion including the first appearing mark in the individual channel word is set in advance in the width direction of the information track by the second data word. When performing a demodulation operation by extracting a second data word from a reproduction signal from an optical disc recorded so as to be displaced to a selected one of a plurality of positions, the EFM demodulation is performed. Part 1
Based on the data of the intensity modulated signal demodulated in step 7,
Of the mark generated in correspondence with the mark whose position is modulated by the data word {see FIG. 5 (c)}
At a time position near the center of the sampling pulse from the sampling pulse generator 45 {see FIG.
Is generated, and the second sampling is performed using the sampling pulse.
Sampling from the displacement signal of the mark corresponding to the mark whose position has been modulated by the data word of FIG.
Perform reference｝.

The signal delay unit 43 in the mark position demodulation unit 22 shown in FIG. 2A and the memory 48 in the mark position demodulation unit 22 shown in FIG. And whether the data starts at a mark (pit) or a non-mark (land) at the time of NRZI modulation. On the basis of the information and the ROM table data, the sampling pulse generator 45 generates a sampling pulse at a time position near the center of the signal generated in correspondence with the mark position-modulated by the second data word. Considering the time delay until the mark is generated, the displacement amount of the mark generated corresponding to the mark whose position is modulated in the width direction of the information track by the second data word. It is for providing a predetermined amount of time delay No..

By the way, as described above with reference to FIG. 19, the mark which is position-modulated by the second data word and generates the output signal of the subtractor 39 in the state including the mark displacement signal is generated. Since the recording position is known in advance at the time of reproduction, the time position of the displacement signal of the mark generated corresponding to the mark is determined by the reproduction of the first data word output from the EFM demodulation unit 17. Since it can be known based on the contents, the sampling pulse generators 45 and 49 provided in the mark position demodulator 22 described above are based on the reproduction contents of the first data word output from the EFM demodulator 17. For example, by using a reference table or the like, information on the position of each mark that is position-modulated in the width direction of the information track of the optical disc is obtained, and the position-modulated individual mark is obtained. For it is possible to generate the time position capable of performing sampling.

In the mark position demodulation unit 22 shown in FIG. 2A, a mark displacement signal in a state where a predetermined amount of time delay is given by the signal delay unit 43 is supplied. In the sampling circuit 44, sampling is performed from the displacement amount signal of the mark corresponding to the mark position-modulated by the second data word and supplied to the position modulation information demodulation unit 46, The second data word information is output from the position modulation information demodulation section 46, and the mark position demodulation section 22 shown in FIG. 2 (b) outputs the second data word information as shown in FIG. 2 (a). The analog displacement signal of the mark generated corresponding to the mark whose position is modulated in the width direction of the information track by the second data word supplied from the gate circuit 41 to the analog-to-digital converter 47 is converted into an analog data signal. And Tal converted and stored in the memory 48. The analog-to-digital converter 47 is supplied with a clock signal CLK having a predetermined cycle from a signal source (not shown).

The analog-to-digital converter 47 provided in the mark position demodulator 22 shown in FIG.
And the memory 48 as delay means for giving a predetermined time delay to a displacement signal of a mark generated corresponding to a mark position-modulated in the width direction of the information track by the second data word. Functioning, the data of the mark displacement signal read from the memory 48 is supplied to the position modulation information demodulation unit 50 at a predetermined timing. The position modulation information demodulation unit 50 includes a sampling pulse generation unit 4
The sampling pulse generated at 9 is supplied, and the position modulation information demodulation section 46 outputs the second data word information.

As described above, the data of the intensity-modulated signal output from the EFM demodulator 17 in FIG. 2 is supplied to the decoder 18 shown in FIG.
The second data word information output from the mark position demodulation unit 22 in FIG. 2 is supplied to the deinterleave processing unit 23 illustrated in FIG. The above-mentioned decoder 1
7 is supplied to the decoder 20 after being deinterleaved in the deinterleave processing unit 19, so that the first data word is output from the decoder 20 to the output terminal 21. Is output. The second data word information is supplied to the decoder 24 after being deinterleaved in the deinterleave processing unit 23,
A second data word is output from the decoder 24 to an output terminal 25. The first data word and the second data word to be recorded / reproduced by the optical disk as described above may have completely independent information contents or may have mutually related information contents. You may.

Next, when configuring an information track optically recorded as a mark train including the presence or absence of a mark, a mark length equal to or longer than the shortest mark length (3T) defined by a specific modulation method (for example, EFM). And a mark having a mark length that is at least twice the shortest mark length (3T) defined by the specific modulation method (for example, EFM) can be used as two mark portions. In a mark portion having a mark length substantially equal to or longer than the shortest mark length (3T) defined by a specific modulation method (for example, EFM), a separate channel word is provided for each individual channel word. Two mark portions, including the first appearing mark in the channel word, are divided into four positions preset in the width direction of the information track by the second data word. So as to displace the-option has been one position, the case where an increase in the recording capacity of 2 bits to configure the optical disk of the present invention so as to obtain.

As described above, for each individual channel word, two marks including the first mark appearing in the individual channel word are included.
As a specific example of the case where the position of each of the mark portions is modulated by the second data word, the above-described specific modulation method will be described using the EFM method. As already mentioned, E
In the FM system, when converting from a data word to a channel word, an 8-bit sequential data word is converted to 14 using a conversion table that exemplifies a part of the conversion content in FIG.
Since the channel words are successively converted to channel words, two marks (pits) are necessarily position-modulated by the second data word in each channel word in the present invention as described above. For example, in the case where successive channel words have consecutive marks having a long mark length, two marks (pits) are formed for each channel word by the second data word. The position cannot be modulated.

That is, the information track of the optical disk is
The mark part and the non-mark part are arranged in such a way that the mark part and the non-mark part are sequentially and alternately arranged, and the mark part and the non-mark part are in a range between the shortest mark length and the longest mark length. It is supposed that only a mark having a mark length within the range can be used. However, even under the above-described conditions, a channel word in which two mark portions exist in one channel word is referred to as a “mark portion”. It must be a structure that can be recorded on the optical disc in a state such as "→ non-marked part → marked part" or "non-marked part → marked part → non-marked part → marked part". now,
A channel word is composed of 14 channel bits, and the shortest mark length (or the shortest non-mark length) is 3T.
And the longest mark length (or the longest non-mark length is 11T)
, A channel word in which two mark portions exist in one channel word is defined as a mark (or non-mark) having a mark length close to the defined minimum mark length. However, this is limited to the case where non-marks (or marks) having a mark length close to the shortest mark length are sequentially and alternately arranged. In this case, the position of each channel word is determined by the second data word. It would not be possible to have two marks to be modulated.

On the other hand, according to the present invention, as described above, an optical disk compatible with the conventional optical disk and a reproducing apparatus are configured. Therefore, the mark train constituting the information track of the conventional optical disk is formed. Is converted to an 8-bit data word by using an EFM conversion table whose conversion contents are partially illustrated in FIG. 18, for example.
After the channel words are converted into 4-channel bits, the channel words are recorded by a mark length recording method in a state where the respective channel words are connected by a 3-bit connection bit. When the EFM method is used, the mark sequence forming the information track of the optical disc of the present invention is also
The present invention employs the modulation method EFM employed by the conventional method of the other party for which compatibility is to be maintained.
When converting to a channel word of 4 channel bits,
As in the case of the conventional method, after converting an 8-bit data word into a 14-channel bit channel word using an EFM conversion table whose conversion contents are partially illustrated in FIG. In this case, the data must be connected by three connection bits and recorded by the mark length recording method.

Therefore, in the present invention, a predetermined number of bits is used by using a conversion table of the same modulation scheme as that used in the modulation scheme employed in the conventional scheme to which the present invention is to maintain compatibility. Is converted into a sequential channel word having a predetermined number of channel bits to ensure compatibility with the other party's conventional method, and to form a channel word. Adjacent logical value 1 in an array pattern of logical values of channel bits
(Logical value 1 is displayed as "1" and logical value as "0")
If a portion where "0" is present in a specific number or more (5 or more in the case of the EFM method) is recorded as a mark (pit) in the information track of the optical disc, The above portion is used as substantially two mark portions (substantially two pit portions) [In the case of the EFM system, a mark having a mark length twice or more the shortest mark length (3T)] Are used so that they can function as two mark portions]. Further, the array pattern of the logical values of a plurality of channel bits constituting the preceding and following channel words is marked (pit) at the time of NRZI modulation. In accordance with the distinction of whether to start with a non-mark (pit) or a non-mark (pit), the logical value array pattern of a predetermined number of combined bits provided between successive channel words is reserved. By so chosen defined pattern, the first data word of the reproducing operation,
This is performed in a state where compatibility with the conventional optical disk is guaranteed, and for each successive channel word,
The position modulation by the second data is enabled for every two marks.

FIGS. 12 to 16 show that the modulation method employed in the conventional method of the other party to which the present invention is to be compatible is EFM.
In the case of the system, each mark portion defined as two marks to be subjected to position modulation by the second data is satisfied for each channel word while satisfying the above conditions, It is a diagram indicated by an underline in the drawing, and in each item described in the uppermost column in FIGS. 12 to 16, # 0, # 1, # 2... # 255 described in a column below “intensity modulation data” Is the instruction number # in FIG.
Corresponding to 0, # 1, # 2, etc., the data words are shown as an array of eight numbers in the data word column in FIG. That is, for example, # 0 described in the column below [Intensity Modulation Data] in FIG. 12 corresponds to the data described in the data word column in FIG. 18 corresponding to the instruction number # 0 in FIG. The intensity modulation data indicated by the word “00000000” means, for example, # 3 described in the column below [intensity modulation data] in FIG. 12 corresponds to the instruction number # 3 in FIG. This means intensity-modulated data indicated by the data word “00000011” described in the data word column in FIG. 18, and this point is shown in FIGS.
About.

The case where the array pattern of the logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation is described in the uppermost column in FIGS.
And [When the array pattern of logical values of 14 channel bits starts at a non-mark (land) at the time of NRZI modulation]
Are arranged in the lower column of the above-mentioned [intensity modulation data].
The 8-bit intensity modulation data (data word) indicated by 255 indicates a 14-channel bit channel word converted by an EFM conversion table as shown in FIG. For example, # 0 in the column below [Intensity Modulation Data] means 8
Bit modulation data “00000000” is a channel word “01001000100” of 14 channel bits.
000 "and, for example, 8-bit modulated data" 00000011 "represented by # 3 described in the column below [Intensity Modulated Data] (see FIG. 18).
Is a 14-bit channel word "10001"
000100000 ".

As described above, the numbers or characters described below the [combination bit pattern] described in the uppermost column in FIGS. 12 to 16 correspond to the predetermined number of bits provided between successive channel words. 7 shows an array pattern of logical values of connection bits. Also, in the portion corresponding to the case where the [intensity modulation data] is # 0 in FIG. 12, and below the item of [position modulation data] in the uppermost column in FIG. 01, "10" and "11" are described, but the two-digit numbers "00", "01", "10" and "1"
The "1" is a 2-bit second bit for displacing two mark portions including the first appearing mark in an individual channel word into four displacement states for each individual channel word in the present invention as described above. 2 shows the contents of the data word.

The [Intensity Modulation Data] in FIG. 12 corresponds to the case where the intensity modulation data is # 0, and the [14 channel bit logical value array pattern in the uppermost column in FIG. (Begins at (pit)) and under [if array pattern of logical values of 14 channel bits starts at non-mark (land) during NRZI modulation].
[Intensity Modulation Data] corresponds to # 0 corresponding to each of the two-digit numbers “00”, “01”, “10”, and “11” indicating the position modulation data by the data word of “14”.
The channel word of the channel bit “01010001
00000 "is described, but this is how the two mark portions provided for each channel word are displaced in the width direction of the information track by the 2-bit second data word. FIG. 2 for explaining the possibility
This is for correspondence with the illustrated contents of FIG.

FIG. 23 (a) shows a channel word composed of 14 channel bits corresponding to the 8-bit data word "00000000" indicated by the instruction number # 0 in the EFM conversion table shown in FIG. The mark (pit) starts at the logical value array "0100100010000000" and the first logical value 1 in the above-mentioned channel word, and changes to a non-mark (land) at the next logical value 1 appearing after the lapse of three channel bit periods. After that, a signal having a waveform such that a mark (pit) is started again after a lapse of four channel bit periods, and an arrangement mode of a mark (pit) and a non-mark (land) in an information track are shown. The pit shown in FIG. 23A is not displaced by position modulation.

FIGS. 23 (b) to 23 (e) show, in a mark portion having a mark length substantially equal to or longer than the shortest mark length (3T) defined by the EFM method, in each individual channel word. Two marks including the first appearing mark are logical values "00" and "0" of the 2-bit second data word.
1) Any one of four types of displacement modes preset in the width direction of the information track according to “10” and “11”.
23, and (f) and (g) of FIG. 23 show the 8-bit data word “0” indicated by the instruction number # 1 in the EFM conversion table shown in FIG.
0000001 ”and an array of logical values“ 1000 ”representing a channel word composed of 14 channel bits corresponding to“ 10000001 ”.
0110000000 "and the E shown in FIG.
A combination of three channel bits between the 8-bit data word “00000111” indicated by the instruction number # 7 in the FM conversion table and the logical value array “0010010000000” representing the corresponding channel word composed of 14 channel bits "001" {case (f) of FIG. 23} or a combination of three channel bits "10
0 "(case (g) of FIG. 23) is provided.

In FIG. 23 (f), the instruction number #
An array of logical values “10000100000000000” representing a channel word composed of 14 channel bits corresponding to the 8-bit data word “00000001” indicated by 1
The logical value 10000000 in "0" is represented by M
Divided into two parts indicated by SB and LSB, two marks (pits) to be subjected to position modulation are set in one channel word. An array of logical values “00110010000000” representing a channel word composed of 14 channel bits corresponding to the data word “00000111”
By forming one mark by the logical value 1001 part in "0" and forming another mark by the following three channel bits 100, the MS in the figure is obtained.
As shown by B and LSB, two marks (pits) to be subjected to position modulation are set in one channel word.

In FIG. 23 (g), the instruction number #
An array of logical values “10000100000000000” representing a channel word composed of 14 channel bits corresponding to the 8-bit data word “00000001” indicated by 1
By forming one mark by a logical value 100001 part in "0" and forming one other mark by the following three channel bits 100 and a part of the following channel word, in the figure, As shown by MSB and LSB, two marks (pits) to be subjected to position modulation are set in one channel word,
Further, the 8-bit data word “00” indicated by the instruction number # 7
An array of logical values “00100” representing a channel word composed of 14 channel bits corresponding to “000111”
10000000 ”, the part of the logical value 10000000 is indicated by MSB and LSB in the figure.
In two parts, two marks (pits) to be subjected to position modulation are set in one channel word.

FIGS. 23 (h) to 23 (k) show the marks having a mark length twice or more the shortest mark length (3T) defined by the EFM method, the shortest mark length being 3T or more. And the two marks to be provided for each individual channel word by the two parts, that is, the logical values “00” and “01” of the second data word
In order to explain that two marks to be placed in any one of four types of displacement modes preset in the width direction of the information track according to “10” and “11” are configured. In the illustrated example, marks having a mark length of 6 channel bit intervals (6T) are respectively assigned to E.
An example is shown in which the mark is divided into two mark portions having the shortest mark length (3T) defined by the FM method.

FIG. 20 shows that the pit (mark) width is 0.279 μm.
m, the pit depth is 0.175λ (however, the light wavelength λ
Is 0.68 μm), and the pit (mark) length is nT (where T is 0.155 μm and n is any value of 2, 3, 4, 5).
When lands are sequentially arranged with lands (non-mark portions) having the same length as above, the sequentially arranged pits are positioned at the center line of the information track as shown in FIG. An optical disk having an information track in which the pits are displaced by the pit width alternately on both sides in a sequential manner is used for an optical disk having an NA of 0.6 and a wavelength of 0.68.
The light of μm is condensed, and the reflected light from the condensing point is divided into two light detectors as described above (for example, 35 in FIG. 2).
FIG. 20 (a) shows a waveform diagram of a sum signal of two output signals output from the two photodetectors in the above-described two-segment photodetector when the light is received and photoelectrically converted in the above-described manner. FIG. 20B is a waveform diagram of a difference signal between two output signals output from the two photodetectors in the two-segment photodetector.
The vertical axis in the figure is the relative magnitude of the signal, and the horizontal axis is the axis of the moving distance or moving time of the spot in the pit row direction with 1T being 5 divisions.

Parameters 8T, 12T, 16T, 20T attached to each signal waveform in FIGS. 20 (a) and (b)
Is n at 4 nT shown in FIG.
Are 2, 3, 4, and 5, respectively. FIG. 20A showing an intensity modulation signal of light generated corresponding to a pit pattern in an information track.
(B) of FIG. 20 showing a position modulation signal of a pit in an information track, and (b) of FIG. 20 showing an intensity modulation signal of light from an information track having an array of pits having a pit length of 2T. Looking at the signal waveform of the parameter 8T in a), the light intensity modulation signal in the case of the parameter 8T is a signal in a state that is not suitable for the reproducing operation at all. The position modulation signal of the pit in the information track having the arrangement of FIG.
As shown in the signal waveform of the parameter 8T in (b) of 0, it can be seen that a good reproduction operation is possible.

Next, FIG. 21 shows that the pit (mark) width is 0.2
79 μm, pit depth 0.175 λ (light wavelength λ is 0.68 μm), pit (mark) length 2 nT
(However, T is 0.155 μm, n is any value of 2, 3, 4, and 5). A pit (non-mark portion) having the same length as the pit length nT is separated from the pit formed. When sequentially arranging the pits, the pits sequentially arranged are divided into two parts, and the two parts of the pits are divided into two parts as shown in FIG.
As shown in FIG. 2, the NA of an optical disk having an information track in which pits displaced by a pit width are arranged on both sides of the center line of the information track has an NA of 0.6.
Using the objective lens described above, the light having a wavelength of 0.68 μm is condensed, and the reflected light from the condensing point is received by the above-described two-segment photodetector (for example, 35 in FIG. 2). FIG. 21A shows a waveform diagram of a sum signal of two output signals output from two photodetectors in the above-described two-segment photodetector when the photoelectric conversion is performed. FIG. 21 (b) shows a waveform diagram of a difference signal between two output signals output from two light detection units in the detector, and the vertical axis of the figure indicates the relative magnitude of the signal. The horizontal axis is time (the distance that the light spot moves on the pit row). The parameters 8T, 12T, 16T, and 20T attached to the respective signal waveforms in FIGS. 21A and 21B are shown in FIG.
The value of n at 4nT shown in (c) is 2,
The cases of 3, 4, and 5 correspond respectively.

FIG. 22 is a diagram showing the relationship between the mark length (pit length) and the signal level of the position modulation signal. The horizontal axis indicates the mark length using the bit interval T as a unit. On the vertical axis, a position modulation signal (difference signal between output signals from two photodetectors in the above-described two-segment photodetector)
Are normalized to show the relative values of the signal levels. FIG.
21 shows the signal level of the position modulation signal obtained when the position modulation is performed by the mark as shown in FIG. 20C, and the curve B in FIG. The signal level of the position modulation signal obtained when position modulation is performed by two portions of one mark as shown in (c) is shown. In consideration of S / N and other factors, the signal level of the position modulation signal for performing a good reproduction operation is desirably 60% or more of the maximum signal level. If a mark having a mark length of 6T must be divided into two parts and used as two marks, the signal level of the position modulation signal at that time is 50% or more of the maximum signal level. Will be used.

Next, FIG. 6 shows a case where a mark length recording method is applied to sequential channel words formed by channel bits obtained by converting the first data word in accordance with the EFM to form a mark string including presence or absence of a mark. When constructing an optically recorded information track, a particular modulation scheme (eg EF)
M) a mark having a mark length equal to or longer than the shortest mark length (3T) defined in M), and a mark length twice or more as long as the shortest mark length (3T) defined in the specific modulation method (for example, EFM). A mark length longer than the shortest mark length (3T) defined by a specific modulation method (for example, EFM), such as a mark portion used so that a mark having Are set in advance in the width direction of the information track by a second data word, including a mark that first appears in the individual channel word, for each individual channel word. Data when the optical disk of the present invention is configured to be displaced to a selected one of the four positions so as to obtain a 2-bit recording capacity increase. It is a diagram for explaining a configuration of a recording signal used in recording.

In FIG. 6, (a) of FIG. 6 shows a first data word (EFM modulation in FIG. 1) supplied to the input terminal 1 of the first data word shown in (a) of FIG. In part 5,
(It may be the first data word supplied from the encoder 4), and in the example shown in FIG.
The first data word is sequentially indicated on the time axis, and the instruction number # 152 in the EFM conversion table partially shown in FIG.
It is assumed to be an 8-bit data word of # 102 (not shown in FIG. 18). FIG. 6B shows an input terminal 1 of the second data word shown in FIG.
1 (which may be the second data word supplied from the interleave processing unit 13 to the mark position modulation unit 14 in FIG. 1), and In the example shown, the second data word is a 2-bit data word such as “1” · “0”, “0” · “1” sequentially on the time axis. .

FIG. 6C shows that the first data word supplied to the input terminal 1 of the first data word shown in FIG. 1A is the encoder 2, the interleave processing unit 3, The encoder 4 shows data before modulation supplied to the EFM modulator 5 in a state where the encoder 4 has undergone signal processing. The data before modulation is an 8-bit subcode and 12 symbols (1 symbol). Are composed of two sets of data of 8 bits... 1 byte) and a correction code of 4 symbols. 6D shows that the second data word supplied to the input terminal 11 of the second data word shown in FIG. 1A is output by the encoder 12 and the interleave processing unit 13. The figure shows 2-bit data supplied to the mark position modulating unit (wobble modulating unit) 14 in a state where each of them has been subjected to well-known signal processing.

FIG. 6E shows sequential 8-bit first data words shown in FIG. 18 by the EFM modulation performed in the EFM modulator 5 shown in FIG. 1A. FIG. 18 shows a state in which the channel words are sequentially converted into 14 channel bit channel words as shown in FIG. 6F based on the conversion mode defined in the EFM conversion table shown in FIG. Are the instruction numbers # 152 and #
Although there is no description corresponding to 101, # 15 in FIG.
2, # 101 in the column of intensity modulation data.
Further, in the EFM modulating unit 5, three channel bit combination bits in which each channel bit is set to a specific logical value are provided between successive 14 channel bit channel words. This is given to the optical modulator drive circuit 6 shown in FIG.

The E consisting of the 17 channel bits described above
The FM modulation code is recorded as an NRZI modulation code on the optical disk by a mark length recording method. In the optical disk of the present invention in which information is recorded by a recording signal having a configuration as shown in FIG. For each EFM modulation code composed of bits, the mark to be recorded first as a mark (pit) on the optical disc is, for example, “1”, “0”, or “0” shown in FIG.
It must be recorded on the optical disk in a state where it is position-modulated according to 2-bit mark position modulation data (obtained based on the second data word) such as "0" / "0", "0" / "1". Therefore, the EFM modulator 5 is supplied with information on a mark to be subjected to position modulation from the EFM modulator 5 to the mark position modulator 14 shown in FIG. FIG. 6 (i) corresponds to the mark position modulation data exemplified in FIG. 6 (h) and corresponds to FIG. 1 (a).
The mark position modulation drive signal (wobble modulation drive signal) generated by the mark position modulation unit 14 shown therein is supplied to the optical deflector drive circuit 15.

The recording light (laser light) emitted from the light source (laser light source) 7 is intensity-modulated by the optical modulator 8 to which the output signal of the optical modulator drive circuit 6 is supplied. The light enters the optical deflector 9 to which the optical deflection signal is supplied from the optical deflector driving circuit 15 and
In the state where only the position of the specific mark is position-modulated as a mark displaced to a specific position selected from a plurality of positions preset in the width direction of the information track by the second data word. Marks other than the above-mentioned specific mark are recorded in a state where the center line of the information track coincides with the center line in the direction in which the mark extends. That is, the optical modulator 8 and the optical deflector 9
The photoresist layer is exposed to light corresponding to the mark pattern by the light focused on the photoresist layer of the master disk Dr by the objective lens 10 after the above. After developing the master disk Dr, a recorded optical disk (optical disk) D is produced by a known optical disk process. FIG. 6 (j) is a diagram illustrating a state where sequential marks are recorded on the signal surface of the optical disk as described above,
FIG. 6 (k) is a diagram showing the configuration of a recording signal of an optical disk, wherein a combined signal of 24 channel bits and 3 channel bits and a plurality of 17 channel bits constitute a 588 channel bit recording signal of one frame. (Record data) is formed.

The reproduction operation of the recorded data from the optical disk D on which the recorded data described above with reference to FIG. 6 is recorded as a mark string as shown in FIG. This can be performed by a reproducing apparatus having a configuration as shown in FIG. That is, an optical head 16 that reads recorded information while tracking an information track by a mark train formed on a signal surface of an optical disc D rotated at a predetermined rotation speed by a rotation driving device (not shown). The intensity modulation signal output from the optical disk 16 (see FIG. 2) corresponding to the mark (pit) and the non-mark (land) on the optical disk, that is, the light emitted from the optical head 16 to the signal surface of the optical disk D. The reflected light from the spot is given as a far-field image by the optical system in the optical head, and the added signal of the output signal from the two-segment photodetector (see FIG. 7B) is supplied to the EFM demodulation unit 17. And a position modulation signal obtained corresponding to the position modulation of the mark, that is, from the two light detection units in the two-divided photodetector. {Shown in FIG. 7 (c) see} difference signal of the two output signals are applied to the mark position demodulator 22. Then, the EFM modulator 5 and the mark position modulator 14 described above are used.
The specific mode of the operation is described in detail with reference to FIGS. 17, 10, and 11. FIG. Further, the EFM modulator 5
The mark position modulating unit 14 has, for example, the following configuration, that is, the order of processing steps (i) (where
Are processing step counters indicating 1, 2, 3, 4...
The above EFM modulation code including 17 channel bits (the first data word of 8 bits is converted into 14 channel bits by using a ROM table,
A ROM table referred to when an EFM modulation code with a combined word of 3 channel bits attached at a mark (pit) at the time of NRZI modulation, and an EFM modulation code composed of the above 17 channel bits, NR
ROM table (L start EFM conversion RO) referred to when starting with a non-mark (land) during ZI modulation
M table), a P start position modulation bit ROM table used to refer to the start bit position of the mark position in the EFM modulation code belonging to the P start EFM conversion ROM table, and an EFM belonging to the L start EFM conversion ROM table. A P start position modulation bit ROM table used to refer to a start bit position of a non-mark position in a modulation code, and a pattern combination for determining a mark length 3T to 11T in an EFM modulation code and determining a conflict between combined words. An establishment judging unit, a correction processing unit for correcting a preceding channel word, a combination word belonging to the channel word and a combination process, a correction process counter for indicating a position where the correction process has been performed, and a mark. Mark pattern memory for storing pattern data and scrambled state A position modulation data memory for storing position modulation data, a bit position data memory for storing bit position data indicating a bit position to start position modulation, a mark pattern data, position modulation data, and bit position data are stored in a channel word (symbol). A) a symbol counter for taking out in units, and a light modulator driving circuit and an optical deflector for absorbing a time when a state in which the EFM modulation operation does not advance in real time but returns to the front for correction processing occurs. It has a buffer memory for enabling the drive circuit to operate in synchronization with it, a subcode sync adding section for dividing data in units of subcodes, and a counter used to compose data in units of frames. A frame synchronization signal adding unit for adding a signal;
A margin bit generator for determining the logical value array of the connection bits according to the SV, a parallel / serial converter for converting parallel data into serial data, and a mark / non-mark array pattern according to the mark data in the mark pattern memory according to the serial data. NRZI converter, a DSV integrator provided to detect the DC component of the EFM signal for controlling the DSV of the EFM signal, and bit position information (pulse) of a mark position-modulated by the second data word. )
A device having each component such as a mark position data output unit that generates an error can be used.

A mark pattern of a part of an information track formed by an arrangement of marks (pits) and non-marks (lands) on an optical disc D on which a recording signal is recorded as described above with reference to FIG. In FIG. 7A showing an example, a dotted straight line extending in the horizontal direction shows the center line of the information track. Among the sequential marks forming the information track, the mark recorded with the center line of the mark coinciding with the center line of the information track is not position-modulated by the second data word. A mark which is a mark and is position-modulated by the second data word has a predetermined minute distance (for example, 10 distances between the center lines of the sequential information tracks) with respect to the center line of the information track.
%, I.e., a distance of about 10% of the track pitch). The difference signal between the two output signals from the two photodetectors in the two-segment photodetector corresponding to the displacement state of the mark position-modulated by the two-bit second data word is shown in FIG. 7 (c).

The operation of reading recorded data from the optical disk D by the optical head 16 is performed as described above with reference to FIG. 2 and the like. → reflected by the half mirror 29 → condensing lens 34 → via the optical path of the two-segment photodetector 35, the two-segment photodetector 35
a and 35b are output from amplifiers 36 and 3 respectively.
After being amplified by 7, it is provided to an adder 38 and a subtractor 39. The aforementioned two-segment photodetector 35 is
The boundary between the light detection units 35a and 35b is
Is provided so as to coincide with the extension direction of the information track. The output signal from the adder 38 is a signal as shown in FIG. 7 (b), that is, an intensity signal of reflected light whose light intensity changes in accordance with the presence or absence of a mark on an information track on the optical disc D. This is the same type of signal as a reproduction signal reproduced from a conventional optical disk.

The output signal from the subtractor 39 is position-modulated by a second data word in a signal as shown in FIG. This is a signal in a state in which the polarity and the magnitude of the mark in the changed state are changed corresponding to the state of the displacement of the mark. An output signal from the adder 38, that is, an intensity modulation signal of light indicating a change in the amount of reflected light generated in correspondence with the presence or absence of a mark due to the spot of the reading light emitted from the optical head to the information track on the signal surface. Is shaped by the binarization circuit 40,
This is a binary signal based on a light intensity modulation signal composed of a pulse train having a pulse length in the range of 3T to 11T according to the arrangement of marks and non-marks on the information track of the optical disc.

The binarized signal output from the binarizing circuit 40 is supplied to the phase locked loop 42, the EFM demodulation unit 17, and the gate circuit 41. The phase locked loop 42 generates a bit clock signal from the binarized signal supplied from the binarization circuit 40 and supplies the bit clock signal to the EFM demodulation unit 17. The EFM demodulation unit 17 converts the binarized signal supplied from the binarizing circuit 40 by the light intensity modulation signal composed of the pulse train having the pulse length in the range of 3T to 11T into data by the EFM code. , And demodulates the data into an intensity-modulated signal and outputs the data. Further, in the gate circuit 41 in which the signal output from the binarization circuit 40 is supplied as a pit signal pulse, the signal output from the subtractor 39 is used as the pit signal pulse as a gate signal. Gate to extract only the signal corresponding to the mark (pit) in the output signal of the subtractor 39,
The extracted signal is supplied to a mark position demodulation unit (mark position information demodulation unit) 22 shown in FIG. The mark position demodulation unit 22 is also supplied with the data of the intensity modulation signal output from the EFM demodulation unit 17.

The mark position demodulation section 22 shown in FIG. 2B has a mark length substantially equal to or longer than the shortest mark length (3T) determined by the EFM method as described above. Within the portion, two marks, including the first one appearing in an individual channel word, are selected by a second data word from a plurality of positions preset in the width direction of the information track. In order to demodulate the second data word from the optical disc of the present invention having a configuration as described later, which is recorded in a position-modulated state as a mark displaced to a specific position, analog-to-digital conversion is performed. It comprises a device 47, a memory 47, a sampling pulse generator 45, and a position modulation information demodulation circuit 50.

In the mark position demodulation unit 22, a specific mark portion including a mark first appearing in an individual channel word is defined by a plurality of positions set in advance in the width direction of the information track by the second data word. When a second data word is extracted and demodulated from a reproduction signal of an optical disc on which information has been recorded while being displaced to a position selected in the above, the intensity modulation demodulated by the EFM demodulation unit 17 is performed. The signal {see FIG. 7 (a)} data and information for distinguishing whether the data starts at a mark (pit) or a non-mark (land) during NRZI modulation. Referring to the ROM table data, the displacement signal of the mark generated corresponding to the mark position-modulated by the second data word {shown in FIG. A sampling pulse is generated from the sampling pulse generator 49 at a time position near the center of the position modulation signal る, and the sampling pulse is used to correspond to a mark in a position modulated by the second data word using the sampling pulse. The sampling is performed from the displacement signal of the mark. The sampling pulse at the time position indicated by the upward arrow in FIG. 7D is generated near the center of the displacement signal of the mark generated in correspondence with the mark position-modulated by the second data word. This is a sampling pulse for performing sampling, and position modulation information in a good state can be obtained by sampling as described above.

FIG. 7E is a diagram showing the frame structure of the intensity-modulated signal output from the adder 38, and FIG. 7F is a diagram showing two channel words each consisting of 14 channel bits, FIG. 7 (g) is a diagram showing a pattern of a logical value with a combination bit consisting of three channel bits interposed between two channel words. FIG. The signal is shown in FIG.
The high level portion corresponds to the land portion of the optical disk, and the low level portion corresponds to the pit portion of the optical disk. (H) of FIG. 7 shows output data from the EFM demodulator 17 described above, and shows a 1-byte data word obtained by demodulating the two channel words shown in (f) of FIG. 7 in the EFM conversion table. Have been. FIG. 7 (i) shows a sampling pulse generated at a time position (a channel bit position shown by hatching in FIG. 12) corresponding to the center of the position-modulated mark. (J) of FIG. 7 is (c) of FIG.
Sampling circuit 4 in a state where the signal shown in FIG.
4 shows the output signal. (K) of FIG. 7 is a position modulation information signal obtained by binarization using a predetermined comparison level in the position modulation information demodulation section 46 shown in FIG. There is a bit of information. In FIG.
(l) shows the frame configuration (32 bytes / 1 frame) based on the first data word at the top, and the frame configuration (48 bits / 1 frame) based on the second data word at the bottom.

The position is modulated by the second data word as described above, and the mark displacement signal (position modulation signal)
The recording position of the mark that generates the output signal of the subtractor 39 in a state that includes is known in advance at the time of reproduction, and the time position of the displacement amount signal of the mark generated corresponding to the mark is: Since the determination can be made based on the reproduction content of the first data word output from the EFM demodulation unit 17, the sampling pulse generation unit 49 provided in the mark position demodulation unit 22 outputs the data output from the EFM demodulation unit 17. Based on the reproduced content of the first data word, information on the position of each mark that has been position-modulated in the width direction of the information track on the optical disk is obtained using, for example, a look-up table or the like, and the position modulation is performed. It can be generated at a time position where sampling can be performed for each individual mark. In the mark position demodulation unit 22 shown in FIG. 2B, the second signal supplied to the analog-to-digital converter 47 from the gate circuit 41 shown in FIG.
Is converted into an analog-to-digital signal and stored in the memory 48 in accordance with the mark whose position is modulated in the width direction of the information track by the data word.
The analog-to-digital converter 47 is supplied with a clock signal CLK having a predetermined cycle from a signal source (not shown).

The analog-to-digital converter 47 and the memory 48 provided in the mark position demodulation section 22 are generated in correspondence with the marks whose position is modulated in the width direction of the information track by the second data word. The data of the mark displacement amount signal read from the memory 48 is supplied to the position modulation information demodulation unit 50 at a predetermined timing. Is done. The position modulation information demodulation unit 50 is supplied with the sampling pulse generated by the sampling pulse generation unit 49, and the position modulation information demodulation unit 50 outputs the second data word information. As described above, the data of the intensity-modulated signal output from the EFM demodulation unit 17 in FIG. 2 is supplied to the decoder 18 shown in FIG. The second data word information output from the demodulation unit 22 is supplied to a deinterleave processing unit 23 shown in FIG. The data of the intensity-modulated signal supplied to the decoder 17 is deinterleaved by the deinterleave processing unit 19 and then supplied to the decoder 20, whereby the data of the decoder 2 is output.
From 0, the first data word is output to the output terminal 21.

Further, the second data word information is supplied to the decoder 24 after being deinterleaved in the deinterleave processing unit 23, so that the output terminal 25 outputs the second data word information from the decoder 24 to the output terminal 25. Is output. The first data word and the second data word to be recorded / reproduced by the optical disk as described above may have completely independent information contents or may have mutually related information contents. You may. As described above, the information track of an optical disk having a mark portion and a non-mark portion arranged alternately and sequentially has the length of the mark portion and the non-mark portion. Can use only the mark length within the range between the shortest mark length and the longest mark length,
Under the constraint that sequential channel words are NRZ
Although the channel words used in the conventional method are recorded on the optical disk which is recorded by the I modulation method but has the above-described recording mode, the mark word → non-mark portion → mark portion and “non-mark portion → An information track cannot be constituted by a mark row in a recording state such as “marked part → non-marked part → marked part”, that is, a state in which two marks exist for each channel word.

Therefore, in the present invention, a predetermined bit is used by using a conversion table of the same modulation scheme as that used in the modulation scheme employed in the conventional scheme of the partner to which the present invention is to maintain compatibility. A first data word consisting of numbers is converted into a sequential channel word consisting of a predetermined number of channel bits to ensure compatibility with the conventional method, and the logical value of the channel bits that make up the channel word "0" is a specific number or more between adjacent logical values 1 in the array pattern (5 or more "0" in the case of the EFM method)
When the existing portion is recorded as a mark (pit) in the information track of the optical disc, the above portion is used as substantially two mark portions (substantially two pit portions). In some cases, a logical value array pattern of a predetermined number of combined bits provided between successive channel words is marked with an array pattern of logical value of a plurality of channel bits constituting the preceding and succeeding channel words when performing NRZI modulation. The reproduction of the first data word is performed by selecting a predetermined pattern according to the distinction of whether to start with a pit) or a non-mark (pit). This is performed in a state where compatibility with the conventional optical disk is guaranteed, and the second data is used for two marks for each successive channel word. Position so that the modulation is possible.

If the modulation method employed in the conventional method to be compatible with the present invention is assumed to be the EFM method, the second condition is satisfied in the state where the above-mentioned conditions are satisfied. Each of the two mark portions for each channel word to be subjected to 2-bit position modulation by the data word is constituted by a logical value portion underlined in each of FIGS. Can be done. By the way, in FIGS. 12 to 16, # 0, # 1, # 2,.
255 are the instruction numbers # 0 and # in FIG.
1, # 2... Means that the data is intensity-modulated data by an 8-bit data word exemplified. Then, # 0,
.. # 255 are converted into 14 as shown in FIG.
The channel word of the channel bit.

In FIGS. 12 to 16, 256 channel words each composed of 14 channel bits represented by an array of 14 logical values (numbers) are underlined. The portion is formed on the information track for each channel word (a channel word itself consisting of 14 channel bits, or a component portion of 17 channel bits which is considered as a unit of the above-mentioned channel word and 3-bit combined bits). The position of the two marks for position modulation to be performed, and the position of the underline is
[Array pattern of logical values of 14 channel bits is NR
When starting at mark (pit) during ZI modulation],
[Array pattern of logical values of 14 channel bits is NR
In the case of starting with a non-mark (land) during ZI modulation].

Incidentally, the 256 channel words shown in FIGS. 12 to 16 have the following various configurations. (1) The column of [When the array pattern of the logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation] in FIG. 12 to FIG. 16 and the array pattern of the logical values of 14 channel bits are the NRZI modulation Sometimes non-mark
(In the case of starting with (land))] and two columns (hereinafter, referred to as two columns in which the same 14 numeral strings representing channel words are described). (For example, # 9, # 12, # 16, # 21, # 26, # 30, #) 3
2, # 38, many others ← first type channel words),
(2) In one of the two columns in which the same 14 numeral strings representing the channel words are described, the column of the combination bit pattern following (to the right in the figure) one of the two columns , 3
A numeric string in which only one of the logical values is designated by a specific number (for example, 0XX...
(For example, # 2 or 0 may be used) is described.
8, # 31, # 96 to # 100, # 103, # 104, #
106, # 107, many others ← second type channel words),

(3) The pattern of the combined bit pattern following (to the right in the figure) any one of the two columns in which the same 14 numeral strings representing the channel words are described. In the column, a channel word (for example, # 57, # 60, etc.) in which a numerical string (for example, 00X) in which only two of the three logical values are designated by a specific number is described.
# 128 to # 132, # 134, # 138 and many others ← third type of channel word), (4) Any one of two columns in which the same 14 numeral strings representing channel words are described In the column of the combination bit pattern following (rightward in the figure) one column, a numerical string (for example, 100,000) in which three logical values are specified by specific numbers is described. Channel words (for example, # 0 to # 8, #
10, # 11, # 14, # 15 and many others ← fourth type channel words),

(5) The pattern of the combined bit pattern preceding (to the left in the figure) any one of the two columns in which the same 14 numeral strings representing the channel words are described In the column, a channel word (# 108, # 166, #) in which a numerical string (for example, XX0) in which only one of the three logical values is designated by a specific number is described.
188, # 220, # 230, # 252 ← fifth type of channel word), (6) Any one of two columns in which the same 14 numeral strings representing channel words are described In the column of the combined bit pattern preceding (to the left in the figure), a numeral string (for example, X00) in which only two of the three logical values are designated by a specific numeral The described channel words (# 105, # 112, # 1
44, # 153, # 185, # 217, # 249 ← sixth type channel word), (7) Any one of two columns in which the same 14 numeral strings representing channel words are described In one column, a numerical string (for example, 001) in which three logical values in the preceding (left in the figure) combination bit pattern column are designated by specific numbers is described. Channel words in the state (# 101, # 109, # 133, ←
A seventh type of channel word),

(8) The pattern of the combined bit pattern preceding (left in the figure) one of the two columns in which the same 14 numeral strings representing the channel words are described Channel words (# 115, # 147, # 191, # 223, #) in a state where a number string (XXX) in a state that may be specified by an arbitrary number is described as three logical values in the column.
231, # 255 ← the eighth type of channel word),
(9) A state in which there is a description in the column of any one of the combination bit patterns before and after (both right and left in the figure) two columns in which the same 14 numeral strings representing channel words are described Channel word (# 111 ← ninth type channel word) (10) Before and after one of two columns in which the same 14 numeral strings representing channel words are described (in the figure, left and right Channel words (# 124, # 127) in the state where there is an entry in the column of the combined bit pattern of both
← Tenth type channel word) Among the above first to tenth types of channel words, the first type channel words are arranged and used via three-bit connection bits. If so, the three combined bits to be provided before and after the channel word may each be used simply as determined to be a logical value effective for DSV control, in which case the conventional method is used. There is no difference from the handling in.

Also, for each of the above-described second to tenth types of channel words, the column in which the logical value of the 3-bit combination bit following the channel word is not specified in FIGS. When the indicated 14-bit channel word is selected and used (for example, when the array pattern of the logical values of the 14 channel bits starts at a non-mark (land) at the time of NRZI modulation), it is indicated in the column. # 0, # 1, # 8, # 24, # 28, and a number of other channel words, and [When the array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation] # 2 to # 7, # 10, # 1 shown
In the case of 1, # 14, # 15, # 18, # 20, and many other channel words, the three combined bits to be provided before and after the channel word are simply DS.
It may be used so as to be determined to a logical value effective for V control, and in this case, there is no difference from the handling in the conventional method.

However, in each of the above-described second to eighth types of channel words, the column in which the logical value of the combination bit used in connection with the channel word in FIGS. In the case where the indicated 14-bit channel word is selectively used (for example, when the array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation), it is shown in the column of #
0, # 1, # 8, # 24, # 28, and many other channel words, and in the column of [When the array pattern of logical values of 14 channel bits starts at non-mark (land) at the time of NRZI modulation]. # 2 to # 7, # 10, # 1
In the case of 1, # 14, # 15, # 18, # 20, and many other channel words, the three bits shown in FIGS. 12 to 16 are connected bits to be provided in connection with the channel word. It is required to have a logical value as described. Therefore, a pattern having a logical value pattern of each of the above-mentioned channel words and a specific logical value pattern as the following three connection bits is prepared and can be selected and used. In addition,
In the case of each of the ninth and tenth types of channel words, a pattern having a logical value pattern of the channel word and a specific logical value pattern as connection bits used in connection with the channel word is prepared. That is, it is made available for selection.

By the way, in the case of the above-mentioned second to fourth types of channel words, as shown in FIGS. 12 to 16, the logical value used by connecting to each channel word is specified. The combined bits are 3 bits following each channel word.
Since these are bit combination bits, there is no problem even if a pattern having a logic value pattern of the above-described channel word and a pattern of a specific logic value as the subsequent 3-bit combination bit is selectively used. . However, in the case of the above-mentioned fifth to tenth types of channel words, as shown in FIGS. 12 to 16, the array of logical values used by being connected to each channel word is used. Since the state-specific combination bits are the three-bit combination bits in the state preceding each channel word, that is, the three-bit combination bits following the channel word preceding the channel word. When a pattern is selected for the fifth to tenth types of channel words, it may be necessary to redo the operation of selecting a pattern for the preceding channel word for which pattern selection has already been completed. In some cases, it is necessary to redo the operation of selecting a pattern for a plurality of preceding channel words.

FIG. 17 is a flow chart for explaining a procedure for selecting a predetermined pattern for a channel word in the range of # 0 to # 255 (the synchronizing signal forming unit is omitted). Is)
In FIG. 17, a pattern selecting operation starts in step (1), and an N-th first data word and an (N + 1) -th first data word are input in step (2). The N-th first data word and the (N + 1) -th first data word when the pattern selecting operation is started are as follows:
Both are new data, but in step (2) of the next process that is performed after the process has completed one cycle, the previous N
The + 1st first data word is used as the Nth first data word in the next process. Next, step (3)
Converts the data word into a channel word by a predetermined modulation method (for example, EFM).

Next, in step (4), the N-th first
An array pattern of logical values of a predetermined number of channel bits constituting a channel word (hereinafter, also referred to as an Nth channel word) based on the data word of NRZ
When the pattern selection process is performed as a pattern starting with a mark (pit) at the time of I modulation (P), the arrangement pattern of the logical value of a predetermined number of channel bits constituting the Nth channel word is different from the pattern selection process. , NRZI modulation, the pattern selection processing is performed as a pattern starting at a non-mark (land) (L). In FIG. 17, the content of step (4) is changed to "N is P
/ L? ". In the following description, P
Expressions such as a start channel word and an L start channel word may be used.

In step (4) when the pattern selecting operation is started, the N-th channel word is determined to be the P-start channel word, and the flow advances to step (5).
In step (5), when the (N + 1) th channel word is in the state of the P-start channel word with respect to the N-th channel word of the P start, the array pattern of the logical values of the channel bits of the two channel words Thus, it is determined whether or not a mark train can be formed in a state where two mark portions are provided for each of the channel words. If YES, the process proceeds to step (6). The criterion in the step (5) is (a) whether or not an arrangement of marks and non-marks according to the mark length within the range of the shortest mark length 3T to the longest mark length 11T according to the EFM coding rule is determined. Utilizing an array of logical values of channel bits of a combined word provided between two channel words,
In the case where a specific number of mark portions can be formed for each channel word, it is determined whether or not the combined word is shared as a mark portion of two channel words located before and after the combined word. ｛Steps (9), (11), (1)
The same applies to the criteria in 4), (20), (22), and (24).

In step (6), the arrangement pattern of the logical values of the combination words provided between the two channel words is determined. The array pattern of the logical values of the combination words indicates which one of the above-described first to tenth types of channel words the channel word belongs to, and the channel whose channel word is P-start. The degree of freedom in determining an array pattern of logical values is large depending on whether the state is a word state or an L-start channel word state. Good or only a specific pattern is allowed (see FIGS. 10 to 16). When the arrangement pattern of the logical value of the combination word provided between the two channel words is determined, the process proceeds to step (7). In step (7), the mark pattern determined as described above is output to the memory, which is stored in the memory, and proceeds to step (8). In step (8), the mark pattern determined as described above is determined. And outputs the position modulation data and position modulation start bit position data (data indicating at which bit position in the channel word of the first data word position modulation is to be started) determined for the mark pattern to the memory. Is stored in the memory. Then, since one round has been made, N is changed to N + 1, and the process returns to the first step (2) of the cyclic loop.

If the result of the determination in step (5) is NO, that is, for the N-th channel word at the start of P, the N + 1-th channel word is the same as the state of the P-start channel word. Then, it is determined that depending on the array pattern of the logical values of the channel bits of the two channel words, it is not possible to form a mark row in a state where two mark portions are provided for each of the channel words. If so, step (9)
In step (9), when the (N + 1) th channel word is in the state of the L-start channel word with respect to the N-th channel word of the P start, the logical values of the channel bits of the two channel words Depending on the arrangement pattern, it is possible to form a mark row in a state where two mark portions are provided for each of the channel words,
Judgment is made and if YES, step (10)
In step (10), the arrangement pattern of the logical value of the combined word provided between the two channel words is determined, and the process proceeds to step (7). Step (7)-
The operation of (8) is the same as described above, changes N to N + 1, and returns to step (2).

Here, as the N-th channel word and the (N + 1) -th channel word, the channel word of # 105 shown as the eighth channel word in FIG.
The channel word of # 106, which is the ninth channel word and which is shown as the ninth channel word in FIG. 11, is the (N + 1) th channel word. The case where the answer is NO and the process proceeds from step (5) to step (9) will be described with a specific example. # 1 as the eighth channel word
The channel word of “05” has a two-digit logical value of “1” at the end in the 14-channel bit array constituting it.
0 ", and in the channel word of # 105 at the start of P, the last two-digit logical value" 10 "ends with the mark part.

The ninth channel word of # 106 has a logical value array of "100" at the head in the 14-channel bit array constituting the ninth channel word. In the channel word No., the part of the logical value array "100" at the head is the mark part. Thus, the channel word # 105, which is the eighth channel word, is the P-start channel word, and the channel word # 106, the ninth channel word, is the P-start channel word. In some cases, the arrangement of logical values in a case where connection is made via a combination bit XXX consisting of three channel bits between the two channel words is "... mark part state 10 → combination word XXX → mark part state". Of 100
.. ", The modulation method (EFM) that the shortest mark length (shortest non-mark length) is 3T even if the logical value array of the compound word XXX is set to" 100 "or" 010 ". )), Only the state that does not satisfy the regulation is obtained, so the result of the determination in step (5) is NO, and the process proceeds from step (5) to step (9).

In step (9), the (N + 1) th channel word, that is, 9
The #th channel word of # 106 is changed from the P-start state to the L-start state, and between the eighth P-start # 105 channel word and the ninth L-start # 106 channel word, Combined bit XXX consisting of 3 channel bits
The array of logical values in the case of being connected with intervening is "... in the mark part state → the compound word XXX → 100 in the non-mark part state". When the logical value array of the combined word XXX is set to “000”, the state of connection between the two channel words is “...
→ combined word 000 → non-marked part state 100 ... ”
Since the shortest mark length (shortest non-mark length) is 3T and the longest mark length (shortest non-mark length) is 11T, the modulation method (EFM) is satisfied. YES, and proceed to step (10).

As a connecting word between the channel word of # 105 at the start of P and the channel word of # 106 at the start of L, "0"
Since "00" is not permitted, in step (10), the logical value array of the compound word is written in the "subsequent compound word" column corresponding to the eighth channel word # 105 in FIG. Is determined to be "000", and step (7)
Proceed to. In step (7), the eighth channel word is P
The starting # 105 channel word is stored in memory and the ninth channel word is L starting # 106.
Is stored in the memory as a channel word. Next, in step (8), for the above-mentioned channel word of # 105 at the start of the eighth P, the column of "bit position where position modulation is performed" corresponds to the eighth channel word # 105 in FIG. Are stored in the memory at the bit positions of "1 and 4" described in the above, and the ninth L-start # 106 channel word is referred to as the ninth channel word # 106 in FIG. Correspondingly, the data at the bit positions of "4 and 16" described in the column of "bit position where position modulation is performed" is stored in the memory.

The specific example of the step (9) described above relates to the case where the determination in the step (9) is YES. Next, as the Nth channel word and the (N + 1) th channel word, The channel word of # 100 shown as the third channel word in FIG. 11 is the Nth channel word, and the channel word of # 101 shown as the fourth channel word in FIG. 11 is , N + 1-th channel word, and the result of the determination in step (5) is NO.
And a case where the process proceeds from step (5) to step (9) will be described as a specific example. First, for the channel word of # 100, which is the third channel word, the two-digit logical value array at the end of the 14-channel bit array that constitutes it is "10", and # 1 at the start of P
In the channel word 00, the last two-digit logical value array "10" ends with a mark portion.

The channel word of # 101, which is the fourth channel word, has a logical value of "00" at the head in the 14-channel bit array constituting it.
0 ", and in the channel word of # 101 at the start of P, the logical value of the head part is" 000 ", which starts at the mark part. Therefore, both the channel word # 100, which is the third channel word, and the channel word # 101, which is the fourth channel word, are P-start channel words. In case,
The arrangement of logical values in the case where connection is made with a combination bit XXX composed of three channel bits interposed between the two channel words is "... in the state of the mark part → 000 in the state of the pit part → 000 in the state of the pit part ..." However, as the logical value of the compound word XXX, only an arrangement mode other than “000” can be used. That is, in the above case, when the arrangement mode of the logical value of the combination word is other than “000”, the inversion of the mark and the non-mark twice is based on the condition of the shortest mark length 3T specified by the modulation method (EFM). I can't do it from the point of view.

However, as described above, the connecting word is changed to "00".
When it is set to “0”, the mark part starting from the two-digit logical value array “10” at the end of the channel word of # 100 is composed of three channel bits “000” of the combined word and eight channel bits “# 100” of the channel word of # 101. 0000 000
0 "and a modulation method (EF
The condition of the longest mark length 13T defined in M) is not satisfied. Therefore, the determination in step (5) is NO, and the process proceeds from step (5) to step (9).

In step (9), the (N + 1) -th channel word, that is, 4
The #th channel word of # 101 is changed from the P start state to the L start state, and between the third P start # 100 channel word and the fourth L start # 101 channel word, Combined bit XXX consisting of 3 channel bits
The array of logical values in the case of being connected with intervening is "... in the mark part state → the compound word XXX → 100 in the non-mark part state". Then, the logical value array of the above-described combined word XXX may be either “010” or “001”. However, # in the state of L start
Since the channel word of 101 is the seventh type of channel word as described above, the logical value array is required to be “001” as the preceding combining word. In the connection between the channel word of # 100 at the start of P and the channel word of # 101 at the fourth start of L,
Since the connecting word is shared between the two, the determination in step (9) is NO, and the process proceeds to step (11).

When the result of the determination in the above step (9) is NO, that is, when the (N + 1) th channel word is in the state of the L-start channel word with respect to the N-th channel word of the P start In addition, it was determined that depending on the array pattern of the logical values of the channel bits of the two channel words, it is not possible to form a mark row with two mark portions provided for each of the channel words. In this case, the process proceeds to step (11). In step (11), the N-th channel word is set as the L-start channel word, and the (N + 1) -th channel word is set as the P-start channel word. In the state where two mark portions are provided for each of the channel words according to an array pattern of logical values of channel bits of Is determined, and in the case of YES, the process proceeds to step (13). In step (13), the array pattern of the logical value of the combination word provided between the two channel words is set. And proceeds to step (14).

When the result of the determination in step (11) is NO, that is, when the (N + 1) th channel word is in the state of the P-start channel word with respect to the N-th channel word of the L start It has been determined that, depending on the array pattern of the logical values of the channel bits of the two channel words, it is not possible to form a mark row with two mark portions for each of the channel words. In this case, the process proceeds to step (12). In step (12), the N-th channel word is set to the L-start channel word, and the (N + 1) -th channel word is set to the L-start channel word. In step (13), an array pattern of logical values of the combination words provided between the two channel words is determined, and step (1) is performed. ) Proceeds to step (14) in-fix processing steps comprising steps (16) (19).

In the step (14) in the correction processing step (19), the (N-1) th channel word and N
It is checked whether the continuation of the logical value array pattern with the channel word is proper. If the pattern is proper, the process proceeds to step (16). If not, the process proceeds to step (15). Here, the state where the continuation state of the array pattern of the logical values of the two channel words that are continuous on the time axis is inappropriate is, as described above, a state where 2
When a mark string is to be formed with a number of mark portions, an EFM comprising 17 channel bits consisting of a channel word of 14 channel bits followed by a 3-bit combined word attached thereto In some cases, the modulation mark constitutes the two mark portions. In this case, two channel words located before and after the 3-bit combination word are combined with the same 3-bit combination word. If no word is used, it means a state where a mark string having two mark portions for each channel word cannot be formed.

In the step (16), the aforementioned 2
The logical value array pattern of the combination word provided between the two channel words is determined, and the process proceeds to step (17). In step (15), the pattern of the mark non-mark of the (N-1) th channel word is inverted and the process proceeds to step (16). In step (16), the logic of the combined word provided between the two channel words is set. The value arrangement pattern is determined, and the process proceeds to step (17). Step (1) as described above
Correction processing step (1) consisting of 4) to step (16)
In 9), it is checked whether or not the pattern of the Nth channel word and the immediately preceding channel word, the (N-1) th channel word, are appropriate. The correction operation is performed by inverting the pattern of the mark non-mark of the channel word. If the correction operation is performed in the correction processing step (19), the pattern of the mark non-mark of the (N-1) th channel word is changed. Therefore, the decision result in the step (17) becomes YES, whereby N is reduced by 1 in the step (18), and the N-1-1 = N-2th channel word is changed to the step (14). A correction process is performed in a correction process step (19) consisting of steps (16) to (16).

Then, the correction processing step (1)
9) → Step (17) → Step (18) → Step
(19) → The correction processing by one loop is repeated until the determination result of step (17) becomes NO. That is, if the result of the determination in step (17) is YES, that is, the array pattern of the logical values of the Ni-th channel word and the N- (i + 1) (where i is a natural number) channel word If the condition is not appropriate, the correction processing for the channel words that are sequentially traced back is performed continuously, and if the result of the determination in step (17) is NO, the process proceeds to step (7). And
In step (7), the mark pattern determined as described above is output to a memory and stored in the memory, and the process proceeds to step (8). In step (8), the mark pattern determined as described above is determined. Is output to the memory, and is stored in the memory. Then, N is changed to N + 1, and the process returns to step (2).

Until now, in step (4), N
Although the description has been made on the assumption that the Nth channel word is the L-start channel word in step (4), the description has been made on the assumption that the Nth channel word is the P-start channel word. ), And step (20)
When the (N + 1) th channel word is in the state of the P-start channel word with respect to the N-th channel word of the L-start, depending on the array pattern of the logical values of the channel bits of the two channel words, It is determined whether or not a mark train can be formed in a state where two mark portions are provided for each channel word of YES.
In the case of, the process proceeds to step (21), and step (21)
Then, the arrangement pattern of the logical values of the combination words provided between the two channel words is determined, and the process proceeds to step (7). The operations in steps (7) to (8) are the same as described above, change N to N + 1 and return to step (2).

If the result of the determination in step (20) is NO, that is, if N at the start of L,
If the (N + 1) th channel word is a P-start channel word with respect to the channel word, depending on the array pattern of the logical values of the channel bits of the two channel words, two for each of the channel words If it is determined that the mark train cannot be formed in a state where the mark portion is provided, the process proceeds to step (22). On the other hand, the N + 1-th channel word is also in the state of the L-start channel word, and is provided with two mark portions for each of the channel words according to an array pattern of logical values of channel bits of the two channel words. It is determined whether or not the mark string can be formed in the state in which the mark is present.
Proceeding to 3), in step (23), the arrangement pattern of the logical values of the combined words provided between the two channel words is determined, and the process proceeds to step (7). Step (7)-
The operation of (8) is the same as described above, changes N to N + 1, and returns to step (2).

If the result of the determination in step (22) is NO, that is, for the N-th channel word at the start of L, the (N + 1) -th channel word is also L
In the state of the start channel word, a mark string is formed in a state where two mark portions are provided for each of the channel words depending on an array pattern of logical values of channel bits of the two channel words. If it is determined that it cannot be performed, the process proceeds to step (24),
In step (24), both the N-th channel word and the (N + 1) -th channel word are put into the state of the P-start channel word, and the respective channel words are arranged according to a logical value array pattern of the channel bits of the two channel words. It is determined whether or not a mark row can be formed in a state where two mark portions are provided every time. If YES, the process proceeds to step (26). The arrangement pattern of the logical value of the combination word provided between the two channel words is determined, and the process proceeds to the step (14) in the correction processing step (19) including the steps (14) to (16) described above.

If the result of the determination in step (24) is NO, that is, if the Nth channel word and the (N + 1) th channel word are both P-start channel words, the two channels If it is determined that depending on the array pattern of the logical values of the channel bits of the word, it is not possible to form a mark train in a state where two mark portions are provided for each channel word, step (25) ), And in step (25), the N-th channel word is set as the P-start channel word,
The (N + 1) -th channel word is also set to the state of the L-start channel word, and the process proceeds to step (26).
Then, the arrangement pattern of the logical values of the combination words provided between the two channel words is determined, and the step (14) in the correction processing step (19) consisting of the steps (14) to (16) described above. Proceed to. Correction processing step (19) → step (17) → step (1)
8) → Step (19) → The correction processing in a single loop is repeated until the determination result of Step (17) becomes NO, and the operations of Steps (7) to (8) have been described above. When step (8) is completed, N is changed to N + 1 and the process returns to step (2).

The operation of selecting a predetermined pattern for channel words in the range of # 0 to # 255 is performed according to the procedure as described with reference to FIG. FIG. 9 is a diagram showing a specific example of a pattern selecting operation when a representative type of channel word is combined from 256 channel words including the tenth type of channel word. 6 to 1
This will be described with reference to FIG. First,
In FIG. 6, two channel words shown as being continuous on the time axis are a channel word of # 152 (see FIG. 14) and a ## as shown in FIG.
101 (see FIG. 14). The channel word of # 152 belongs to the third type of channel word, and the channel word of # 101 belongs to the seventh type of channel word.

The channel word of # 152 belonging to the third type is the same as the case of FIG. 6 when the array pattern of logical values of 14 channel bits starts at a non-mark (land) at the time of NRZI modulation. ], There is no restriction on the logical value of the combination bit from the description of the combination bit column in FIG. Also, the channel word of # 101 belonging to the seventh type is used as [a case where an array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation] as shown in FIG. In this case, there is no restriction on the logical value of the combination bit from the description of the combination bit column in FIG. Thus, in the example shown in FIG.
Is divided into two marks having a mark length of "3T" or more, which is formed in correspondence with the "10000000" portion in the 14-channel bit array constituting the channel word of "1". The two mark portions are, for example, two mark portions modulated by two position modulation data "1" and "0" as shown in FIG. 6 (j). You.

Also, in the example shown in FIG.
The logical value of the combination bit between the part of “00000000” in the array of 14 channel bits constituting the channel word of 101, the channel word of # 152, and the channel word of # 101 is, for example, “001”. And the logical value “1” in the above-mentioned combined bit and # 1
01 in the array of logical values in the channel word 01
One mark formed corresponding to the part of "10000000" by the part of "00000" is divided into two mark parts having a mark length of "3T" or more, and the two mark parts are divided. Are two mark portions in a state modulated by two position modulation data “0” and “1”, for example, as shown in FIG.

The channel word of # 152 belonging to the third type of channel word illustrated in FIG.
Of a mark in a case where a mark train is formed in a state where two mark portions are provided for each of the above-mentioned channel words, by using two channel words with a channel word of # 101 belonging to the type of channel word. The configuration example is described in the above 2
One channel word happens to be used in both cases, as in the case of the first kind of channel word, with no restrictions imposed on the arrangement of logical values of the combination bits following the channel word. Next, the arrangement of the logical values of the combination bits provided between the successive channel words is described below. A description will be given with reference to FIGS.

First, FIG. 8A shows the channel word “900000” of # 9 belonging to the first type of channel word.
01000000 "and the # 9 channel word" 1000000000000 "belonging to the first type of channel word
0 ", # 127 channel word" 0010000000000010 "belonging to the tenth type, and # 105 channel word" 1000 "belonging to the sixth type of channel word.
0001000010 "shows an example of a case where a mark string is formed in a state where a coupling bit is provided between the respective channel words. The channel word # 9 belonging to the first type of channel word “100000001000000” belonging to the first type of channel word used in the specific example shown in FIG.
"0" is originally a pattern of [when an array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation] or [14].
When the array pattern of the logical values of the channel bits starts with a non-mark (land) at the time of NRZI modulation], the logical values of the combination bits before and after the channel word are channel words of a type that can be arbitrarily selected. is there.

However, the # 127 channel word "001" that follows the # 9 channel word "1000000000000000" via a connection bit is connected.
“0000000000010” is a channel word belonging to the tenth type of channel word, and is used as a pattern [when the array pattern of logical values of 14 channel bits starts with a non-mark (land) at the time of NRZI modulation]. When the channel word of # 127 is used as a pattern [when the array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation], there is no problem. this#
The combined bit to be placed before the channel word 127 is required to have at least the last bit in the mark state (see FIG. 14), and is placed after the channel word # 127. However, there is a restriction that the array of logical values of the combined bits must be set to “0XX”.

In addition, the channel word “100000000010” of # 127 described above is followed by the channel word “100” of
Since “00001000010” is a channel word belonging to the sixth type of channel word, it is used as a pattern [when an array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation]. In this case, there is no problem. However, if the channel word # 105 is used in the pattern [when the array pattern of logical values of 14 channel bits starts with a non-mark (land) at the time of NRZI modulation], There is a restriction that the logical value of the combination bit placed before the channel word must be “X00”.

Therefore, for example, when the first type of channel word, the tenth type of channel word, and the sixth type of channel word are sequentially displayed as shown in FIG. , The tenth type of channel word is required [14
When the array pattern of logical values of channel bits starts with non-marks (lands) during NRZI modulation], the combined bits preceding the tenth type of channel word are A channel word to which the combined bit is attached, so that at least the last bit is in a mark state. In the specific example illustrated in FIG. 8A, as a channel word immediately before the channel word of # 127. The # 9 channel word “10
00000000000000} is used as a pattern [when the array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation], or the array pattern of logical values of 14 channel bits. If NRZI modulation starts with non-mark (land)] pattern.

This means that, when the tenth type channel word appears as described above, the channel word preceding the tenth type channel word is also represented by [14 channel bits. When an array pattern of logical values starts with a mark (pit) at the time of NRZI modulation] or [1
The array pattern of logical values of 4 channel bits is NRZI
Starting with non-mark (land) at the time of modulation] means that it must be reconsidered. The above point is the tenth
The same applies to the fifth to ninth channel words in addition to the type of channel word.

That is, the fifth type of channel word to the first
When the channel word appears like a channel word of type 0, a channel word of 14 channel bits arranged before the channel word and a 3-bit attached after the channel word. 1 by compound word
A channel word of such a kind that a pattern of a mark sequence by an EFM modulation code composed of 7 channel bits needs to be reexamined is a special channel word. In the specific example of the arrangement of the channel words shown in FIG. 8A, the first to the tenth channel words that can be used without any restrictions are followed by the fifth to tenth channel words. If a special channel word, such as a type channel word, follows, it indicates that the special channel word that appears later may cause restrictions when using the first type channel word. ing.

That is, in the specific example of the arrangement of the channel words shown in FIG. 8A, the tenth type of the word of the tenth type is preceded by the first type of the word of the word which can be used without any restrictions. Since a special channel word such as a channel word continues, # 9 belongs to the first type channel word placed immediately before the # 127 channel word belonging to the tenth type channel word. Of a channel word of 14 channel bits of the channel word of the above, followed by a 3-bit connecting word attached thereto.
In the EFM modulation code composed of 7 channel bits, the channel word of the 14 channel bits is necessarily [the arrangement pattern of the logical values of the 14 channel bits is NR.
Starting with non-mark (land) at the time of ZI modulation], and a 3-bit code attached following the # 9 channel word belonging to the first type channel word. The constraint that the logical value of the combination word is “100” is added.

However, # 9 belonging to the first type channel word arranged immediately before the # 127 channel word belonging to the tenth type channel word.
The EFM modulation code consisting of 17 channel bits consisting of a channel word of 14 channel bits of a channel word and a 3-bit combining word attached to the channel word of the channel word of the 14th channel word is arranged further ahead of the first. The # 9 channel that constitutes an EFM modulation code composed of 17 channel bits composed of a channel word of 14 channel bits of the # 9 channel word belonging to the same type of channel word and a 3-bit combined word appended thereto. The word may be used as a pattern [when the array pattern of logical values of 14 channel bits starts with a mark (pit) during NRZI modulation] or when the array pattern of logical values of 14 channel bits is N
In the case of starting with a non-mark (land) at the time of RZI modulation], even if used under any of the above-mentioned usage modes, the above-mentioned channel word of # 9 is preceded. The logical value of the subsequent compound word attached to the # 9 channel word is "100" as shown in FIG. 8A.

In the specific example of the arrangement of the channel words shown in FIG. 8A, the special channel word # 127 which is a special channel word follows immediately after the tenth type of # 127 channel word. Although there are six types of # 105 channel words, in the specific example of the channel word array shown in FIG. 8A, the tenth type of # 127 channel words is [14 channel bits]. When the array pattern of the logical values of (1) starts at the non-mark (land) at the time of NRZI modulation], the above-mentioned # 12 is used.
The portion of the 3-bit combined word attached after the channel word of No. 7 is a non-mark portion, and the channel word of # 105 of the sixth type is [array pattern of logical values of 14 channel bits. When starting with mark (pit) at the time of NRZI modulation], no problem occurs.

Next, FIG. 8B shows the channel word “10000” of # 16 belonging to the first type of channel word.
000100000 "and # 12 belonging to the tenth type
7 channel word "0010000000000010"
An example is shown in which a mark string is composed of # 105 channel word "1000001000010" belonging to the sixth type of channel word, with connection bits provided between the respective channel words. The channel word “1” of # 16 belonging to the first type of channel word used in the specific example shown in FIG.
0000000100000 "is the first type of channel word, so even though it is originally a pattern of [when the array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation], Alternatively, even if the pattern is a pattern in which the array pattern of logical values of 14 channel bits starts at a non-mark (land) at the time of NRZI modulation, the logical values of the combined bits before and after the channel word should be arbitrarily selectable. It is a channel word.

However, as described above, the # 16 channel word “10000000” belonging to the first type channel word is used.
100000 ", the channel word" 0011000000000000 "of # 127 following via the combining bit.
Since "10" is a channel word belonging to the tenth type of channel word, it is used as a pattern [when the array pattern of logical values of 14 channel bits starts with a non-mark (land) at the time of NRZI modulation]. If the channel word of # 127 is [the array pattern of logical values of 14 channel bits is NR
In the case of starting with a mark (pit) at the time of ZI modulation], at least the last bit of the combined bit to be placed before the # 127 channel word is in the mark state. (See FIG. 14), and there is a restriction that the array of logical values of the combination bits arranged after the channel word of # 127 must be "0XX". .

Further, the channel word “100000000010” of # 127 described above is followed by the channel word “100” of
Since “00001000010” is a channel word belonging to the sixth type of channel word, it is used as a pattern [when an array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation]. In this case, there is no problem. However, if the channel word # 105 is used in the pattern [when the array pattern of logical values of 14 channel bits starts with a non-mark (land) at the time of NRZI modulation], There is a restriction that the logical value of the combination bit placed before the channel word must be “X00”.

In the specific example of the arrangement of the channel words shown in FIG. 8B, the tenth channel word of the first kind, which can be used without any restriction, is followed by the tenth word. Although a special channel word such as a channel word of the following type follows, the channel word of # 127 belonging to the channel word of the tenth type is referred to as [the array pattern of the logical value of 14 channel bits is not marked when the NRZI modulation is performed. (Starting at (land)], the 14th channel of the # 16 channel word belonging to the first type of channel word disposed immediately before the # 127 channel word to be used as the pattern EFM consisting of 17 channel bits consisting of a channel word in bits followed by a 3-bit combined word attached
The modulation code is connected to channel word # 127 belonging to the tenth type of channel word in an unmarked state.

In the specific example of the arrangement of the channel words shown in FIG. 8B, a channel word composed of 14 channel bits of the # 16 channel word belonging to the first type of channel word, and a succeeding channel word. A channel word of # 16 which constitutes an EFM modulation code composed of 17 channel bits by a 3-bit combined word attached thereto is marked as [a mark pattern (pit) when an array pattern of logical values of 14 channel bits is NRZI modulated. ) Is used as a pattern, or [1
The array pattern of logical values of 4 channel bits is NRZI
When starting at non-mark (land) at the time of modulation]. However, the channel word of # 16 is [when the array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation].
When used as a pattern, the 3-bit connecting word attached to the channel word of # 16 is a logical value array of "000", and the channel word of # 16 is [14]. When an array pattern of logical values of channel bits starts at a non-mark (land) at the time of NRZI modulation], the # 1 pattern is used.
The 3-bit combination word attached after the channel word 6 is a logical value array of "100" {(b) in FIG.
reference}.

Next, the specific example of the arrangement of the channel words shown in FIG. 8C is a channel word of "# 160000000000" which belongs to the first type of channel word which can be used without any restrictions. "And a channel word" 10000001000010 "of # 105 belonging to the sixth type of special channel word indicate a case where mark strings are arranged in a state where connection bits are provided between the respective channel words. Then, the channel word # 16 belonging to the first type of channel word “1,000,000”
0100000 ", and the channel word" 1000000100 "of # 105 following via the combination bit.
Since “0010” is a channel word belonging to the sixth type of channel word, it is used as a pattern [when an array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation]. In this case, there is no problem, but the channel word of # 105 is [the array pattern of logical values of 14 channel bits is NR.
When starting with a non-mark (land) at the time of ZI modulation], the logical value of the combination bit placed before the channel word must be “X00”. There is.

Therefore, in the specific example shown in FIG. 8C, the channel word “10500000100” of # 105, which is a channel word belonging to the sixth type of channel word.
0010 "is used as a pattern [when the array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation].
A channel word composed of 14 channel bits of the # 16 channel word belonging to the first type of channel word disposed immediately before the # 105 channel word, followed by 3 bits attached thereto An EFM modulation code consisting of 17 channel bits with the combination of
# Belonging to the sixth type of channel word in an unmarked state
It is connected to 105 channel words.

In the specific example of the arrangement of the channel words shown in FIG. 8 (c), the channel word of 14 channel bits of the # 16 channel word belonging to the first type of channel word, and the succeeding channel word. A channel word of # 16 which constitutes an EFM modulation code composed of 17 channel bits by a 3-bit combined word attached thereto is marked as [a mark pattern (pit) when an array pattern of logical values of 14 channel bits is NRZI modulated. ) Is used as a pattern, or [1
The array pattern of logical values of 4 channel bits is NRZI
In the case of starting with a non-mark (land) at the time of modulation], it may be used in any of the above-mentioned use modes and attached to the above-mentioned channel word of # 16. The logical value of the connecting word is shown in FIG.
It is set to “000” as shown in FIG.

Next, FIG. 9A shows the channel word “00100” of # 39 belonging to the fourth type of channel word.
100001000 "and the # 39 channel word" 00100100001 "belonging to the first type of channel word.
000 ", the # 8 channel word" 01010010000000 "belonging to the fourth type, and the # 105 channel word" 1000 "belonging to the sixth type channel word.
0001000010 "shows an example of a case where a mark string is formed in a state where a coupling bit is provided between the respective channel words. The channel words # 39 and # 8 belonging to the fourth type of channel word used in the specific example shown in FIG.
There is no problem if both of them are used as a pattern [when the array pattern of logical values of 14 channel bits starts at a non-mark (land) at the time of NRZI modulation], there is no problem. When an array pattern of logical values of 14 channel bits is started with a mark (pit) during NRZI modulation], the combined bits to be placed after the # 8 channel word are logical values Is required to be "100" (see FIG. 12).

The channel word "01" of # 8
In contrast to "001001000000", the channel word "1000000" of # 105 following via the combining bit
Since “01000010” is a channel word belonging to the sixth type of channel word, it is used as a pattern [when an array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation]. In this case, there is no problem, but the channel word of # 105 is [when the array pattern of logical values of 14 channel bits starts with a non-mark (land) at the time of NRZI modulation].
, The logical value of the combination bit placed before the channel word is “X0”.
There is a restriction that it must be "0". Therefore, as described above, in the case where three fourth-type channel words are successively displayed and the sixth-type channel word is sequentially displayed, as shown in FIG. All four types of channel words are used in such a manner that all the channel words are necessarily used in the pattern [when the array pattern of logical values of 14 channel bits starts with a non-mark (land) at the time of NRZI modulation]. Is done.

That is, in FIG. 9 (a), the above-mentioned state corresponds to the first # belonging to the fourth type of channel word, as shown by the mark string indicated by arrow B at the lower left end in FIG.
When the channel pattern of the 39 words is [the array pattern of logical values of 14 channel bits is non-mark (land) during NRZI modulation]
Starting with?], And through a combined bit whose logical value is set to "000",
[Array pattern of logical values of 14 channel bits is NR
Starting with non-mark (land) at the time of ZI modulation] that belongs to the fourth type of channel word used in the pattern
It is connected to the # 39th channel word and then inverted by the logical value "1" provided in the combination bit following the second # 39 channel word, as indicated by the upward arrow A in the figure. # 8 belonging to a fourth type of channel word used so as to be a pattern of [a case where the array pattern of logical values of 14 channel bits starts with a non-mark (land) during NRZI modulation] in the marked mark sequence Connected to the channel word. Then, the # 8 channel word belonging to the fourth type channel word is connected to the # 105 channel word belonging to the sixth type channel word via a combining word whose logical value array is set to "100". "10
000000100001 "is used as a pattern [when the array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation].

FIGS. 9B and 9C show the channel word “010” belonging to the third type of channel word of # 152.
01000000001 "and # 1 belonging to the seventh type
01 channel word "0000000000100010"
An example is shown in which a mark string is composed of # 105 channel word "1000001000010" belonging to the sixth type of channel word, with connection bits provided between the respective channel words. The # 152 channel word belonging to the third type of channel word and the # 101 channel belonging to the seventh type used in the specific examples shown in FIGS. 9B and 9C. Both the word and the channel word of # 105 belonging to the sixth type of channel word are [when the array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation]. There is no problem when used as a pattern.

However, the channel word of # 152 belonging to the above-described third type of channel word is referred to as [14
When an array pattern of logical values of channel bits starts at a non-mark (land) at the time of NRZI modulation], it should follow the channel word as shown in FIG. There is a restriction that a connecting word having a logical value sequence such as “00X” is required. In addition, the above-mentioned channel word of # 101 belonging to the seventh type is expressed as [logical value of 14 channel bits. When the array pattern starts with a non-mark (land) at the time of NRZI modulation], as shown in FIG. 14, the combined word preceding this channel word is “001”. Is necessary.
Further, # belonging to the sixth type of channel word described above.
The channel word of 105 is defined as [the array pattern of logical values of 14 channel bits is not marked when the NRZI modulation is performed.
(Starting at (land)]], the logical value of the combination bit disposed prior to the channel word must be “X00” as shown in FIG. Must be restricted.

Now, in the specific examples shown in FIGS. 9B and 9C, the channel words arranged sequentially on the time axis are the channel word of # 152 → the channel word of # 101 → # 105 channel words, in this example #
Special channel words, such as the channel word 101 and the channel word # 105, which may affect the arrangement state of the logical values of the combination bits preceding the channel word, are arranged in a continuous state. I have. Then, when a plurality of special channel words are continuously arranged as in the above-described example, among a plurality of special channel words that are continuously arranged, first, a position is located at the end of the arrangement. As for two channel words, that is, a special channel word and a special channel word located immediately before the special channel word, each channel word has two mark portions. The mark pattern is determined so that the continuation of the logical value array pattern of the two channel words is in an appropriate state, and thereafter, the mark pattern for the precedingly arranged channel word is determined. .

FIGS. 9B and 9C show a state where two special channel words # 101 and # 105 are continuously arranged.
In (b) of FIG. 9 of the specific example, first, regarding the last special channel word # 105 in the continuous array of two special channel words, [array of logical values of 14 channel bits] Case where Pattern Starts with Mark (Pit) at NRZI Modulation]. As shown in FIG. 9 (b), the last special channel word # 105 in the continuous sequence of two special channel words is [1
The array pattern of logical values of 4 channel bits is NRZI
In the case of starting with a mark (pit) at the time of modulation], the channel word # 1 arranged before the channel word # 105 is used.
The combination word following 01 is in a non-mark (land) state.

In FIG. 9 (b), the channel word # 105 arranged prior to the channel word # 105
101 is used as a pattern [when the array pattern of logical values of 14 channel bits starts at a non-mark (land) at the time of NRZI modulation], the channel word of # 101 belonging to the seventh type is Is used as a pattern [when the array pattern of logical values of 14 channel bits starts at a non-mark (land) at the time of NRZI modulation], as shown in FIG.
The combination word preceding this channel word has a logical value sequence such as “001”.

Therefore, the channel word of # 152, which is arranged prior to the channel word of # 101 described above, necessarily includes [the array pattern of logical values of 14 channel bits starts at a non-mark (land) at the time of NRZI modulation. If you do
9 (b), looking at the mark pattern of the sequential channel words shown in FIG. 9 (b), there is a difference between the channel word of # 101 and the channel word of # 152. If the pit composed of the combined word portion is not used in both the channel word of # 101 and the channel word of # 152, a mark pattern having two mark portions for each channel word is obtained. However, since the mark length of the above portion does not have a mark length that can be used as two mark portions of 3T or more, the mark pattern as shown in FIG. 9B cannot be adopted. Become.

FIG. 9C shows the case where two special channel words, the channel word of # 101 and the channel word of # 105, are consecutively arranged as described above.
FIG. 9C shows an arrangement of mark patterns in which a mark pattern having two mark portions is obtained for each channel word. FIG. 9C shows two special channel words. The special channel word # 105 located at the end of the continuous arrangement is used as a pattern [when the arrangement pattern of logical values of 14 channel bits starts with a non-mark (land) at the time of NRZI modulation]. As shown in FIG. 9 (c), for the last special channel word # 105 in the continuous array of two special channel words, [the array pattern of logical values of 14 channel bits is non-modulated during NRZI modulation. Mark (Land)
When the pattern is used as a pattern, the logical value of the combination word following the channel word # 101 arranged prior to the channel word # 105 is shown in FIG. "X00"
Must.

In FIG. 9 (c), the channel word # 105 arranged before the channel word # 105
No. 101 is used as a pattern [when the array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation].
The channel word of # 152, which is arranged prior to the channel word of, is also used as a pattern [when the array pattern of logical values of 14 channel bits starts with a mark (pit) at the time of NRZI modulation]. Looking at the mark patterns of the sequential channel words shown in FIG. 9C, the channel word of # 152, the channel word of # 101, and the channel word of # 105 are respectively provided for each channel word. The mark pattern has two mark portions.

In FIGS. 10 and 11, channel words # 98 → # 99 → # 100 → # 101... Are arranged in the order of the numbers described in the column of “order on the time axis” at the left end in the figures. FIG. 12 is a diagram for explaining what kind of mark pattern a sequential channel word forms when it is determined that a channel word of 14 channel bits and a channel word between each channel word in FIGS. With respect to the combined bits of the three channel bits provided, the logical value array portion at the position where the two mark portions to be formed for each of the sequential channel words is to be formed is underlined and described above. When a specific logical value array is required as an array of logical values of the combination bits to be provided between the channel words, the preceding compound word and the following compound word Indicates the logical value, The channel word array pattern of logic values of the 14-channel bit N
When starting with a mark (pit) at the time of RZI modulation], the character of P is described in the column of distinction between P and L, and the channel word is [logical value of 14 channel bits]. In the case where the arrangement pattern starts with a non-mark (land) at the time of NRZI modulation], the letter L is described in the column for distinguishing P and L.

FIG. 11 is a diagram exemplifying a part of the progress of the process until the final result as shown in FIG. 10 is obtained. An asterisk in the column of “Order” indicates “Adopt,
In the entry column of "Rejection", it is indicated that the rejected data is entered. FIG.
Numerals in the rightmost column “position of bits subjected to position modulation” are bit positions defined corresponding to the bit position numbers shown in the lowermost column of FIG.
The two bit positions shown in this column indicate the start positions of the two mark portions, respectively. In the arrangement mode of the sequential channel words illustrated in FIG. 10, since many of the special channel words described above are included in a continuous state, when determining the pattern of the mark string, the preceding channel words are already determined. Although it was accompanied by a change for the determined mark pattern, even in the case of such a complicated arrangement of channel words of processing,
The mark pattern is easily determined by the processing described above with reference to the flowchart of FIG.

Referring to the 256 channel words described in the EFM conversion tables illustrated in FIGS. 12 to 16, for example, the [14 channel bit logical value array pattern in the # 0 channel word is NRZI modulated. When starting with a mark (pit) at a time], there is only one mark, and the array pattern of logical values of 14 channel bits in the # 0 channel word is a non-mark (at the time of NRZI modulation). In case of starting with land), three marks can be formed by using the combination bits of the following three channel bits attached to the channel bit. That is, by using the mark for position modulation, an increase in the information amount of 1 bit or 3 bits can be obtained.

EFM illustrated in FIGS. 12 to 16
FIG. 24 is a diagram showing the result of viewing the state of an increase in the amount of information from the above-mentioned point of view for a part of the 256 channel words described in the conversion table. Although the number of marks that can be used for position modulation is not the same depending on the mark portion having a mark length of 3T or more, the average number of marks per channel word is approximately two. You can see that. It is needless to say that if not only the channel word but also the combination word is used for forming the mark, the number of marks per channel word can be surely set to two. By the way, in each of the above-described embodiments, in order to provide a predetermined number of marks for each channel word without fail as a mark for position modulation by the second data word, successive channel words are sequentially changed. According to the arrangement mode, an appropriate mark pattern is selected, including the arrangement of the logical values of the combination words, so that the position modulation signal based on the second data word has an intensity based on the first data word. No special synchronization signal for the position modulation signal was required because it was in synchronization with the modulation signal. However, if a longer period is set as compared to the channel word and the average number of bits is increased at an average for each of the periods, a synchronization signal for the set period is required for demodulation operation. Is done.

FIG. 3 shows a recording in which a mark sequence formed by a channel word corresponding to a first data word is position-modulated by a second data word, with a period set as a longer period than a channel word as a frame period. 1 is a block diagram showing a schematic configuration of an optical disc reproducing apparatus configured to be able to reproduce a completed optical disc D. FIG. The optical disk D is driven and rotated at a predetermined rotation speed by a disk drive motor 52 driven under the control of a rotation control system 56. The rotation control system 56 performs a rotation control operation based on the frame synchronization signal FCK supplied from the frame synchronization signal detection unit 57.

The optical head 16 surrounded by an alternate long and short dash line frame 16 in FIG. 3 has the same configuration as the optical head 16 already described with reference to FIG. However, the optical head 16 shown in FIG. 3 also includes a coarse movement motor 53 that forms a part of a moving mechanism for moving the optical head 16 in the radial direction of the optical disk D. Is shown as being composed of a focus servo system 68, a tracking servo system 54, and a coarse movement motor system 55. Since the configuration and operation of each servo system are well known, description thereof will be omitted. Optical head 1
6, a servo system 5 is provided from the photodetector 32.
It is sufficient that an output signal within the frequency range required for the operation 1 is obtained, but the two-segment photodetector (or the four-segment photodetector) 35 outputs a high-quality output signal having high resolution. What can be used is used.

The output signal from the adder 38 in the optical head 16 is an intensity signal of reflected light whose light intensity is changed corresponding to the presence or absence of a mark on an information track on the optical disk D. A signal of the same type as the reproduced signal to be reproduced, which is shaped according to the arrangement of marks and non-marks on the information track of the optical disc after being shaped by the binarization circuit 40.
It is a binarized signal by a light intensity modulation signal composed of a pulse train having a pulse length in the range of T to 11T. And said 2
The binarized signal output from the binarizing circuit 40 is supplied to the phase locked loop 42 and the frame synchronization signal detecting unit 57. In the phase locked loop 42,
A bit clock signal CLK is generated from the binarized signal supplied from the binarization circuit 40 and supplied to the frame synchronization signal detection unit 57 and the mark position demodulation unit 59.

The above-mentioned frame synchronizing signal detecting section 57 also outputs a binarized signal based on the light intensity modulation signal.
The signal is supplied to the demodulation unit 17 and the subcode demodulation unit 58.
The EFM demodulation unit 17 converts the binarized signal based on the light intensity modulation signal including the pulse train having a pulse length in the range of 3T to 11T supplied from the binarization circuit 40,
The data based on the EFM code is demodulated into the data of the intensity modulation signal using the conversion table, and supplied to the intensity modulation information signal processing unit 61 and also supplied to the mark position demodulation unit 59. The intensity modulation information signal processing section 61 performs various operations such as CIRC demodulation operation, error correction operation, deinterleave operation, and decoding operation by a decoder while exchanging data with the random access memory 60. Then, the reproduction signal is sent to the output terminal 69.

The output signal from the subtractor 39 indicates the displacement of the mark of the mark in the information track on the optical disc D, the position of which is modulated by the second data word. The signal is in a state where the polarity and the magnitude are changed correspondingly. The pit signal pulse Pp output from the binarization circuit 40 is supplied to the gate circuit 41 to which the output signal from the subtractor 39 is supplied. The signal output from the subtractor 39 is gated using the pit signal pulse Pp generated corresponding to (mark) as a gate signal, and the mark (pit) in the output signal of the subtractor 39 is gated. And extracts only the signal of the portion corresponding to the mark position demodulation unit (mark position information demodulation unit) 59
Give to.

As the mark position demodulation section 59, a mark position demodulation section having the configuration described with reference to FIG. 2B may be used, and the mark position demodulation section 59 is defined by the EFM method. Of the mark portions having a mark length substantially equal to or longer than the shortest mark length (3T),
From the reproduction signal from the optical disc recorded so as to be displaced to a selected one of a plurality of preset positions in the width direction of the information track by the data word of the second data word. When extracting and performing the demodulation operation, the displacement amount of the mark generated corresponding to the mark position-modulated by the second data word based on the data of the intensity modulation signal demodulated by the EFM demodulation unit 17 At a time position near the center of the signal, sampling is performed from the displacement signal of the mark corresponding to the mark position-modulated by the second data word. Then, the mark position demodulation section 59 outputs the second data word information.

The second output from mark position demodulating section 59
Is supplied to the position modulation information signal processing unit 62. The position modulation information modulation processing unit 62 stores the second data word information for each frame period output from the mark position demodulation unit 59 in the first-in first-out memory 63, and stores the second data word information in frame period units. To be synchronized. The synchronization in the frame period unit is performed by the first-in first-out memory 63, the frame synchronization signal output from the frame synchronization signal detection unit 57, and the synchronization information output from the synchronization information detection unit 65. 64 is performed.
When the first-in-first-out memory 63 starts inputting data with a frame synchronization signal and manages the data amount in basic units (counts and manages the input data amount), the memory 64 is unnecessary, but This is necessary when input data is handled in units of blocks (frames or sectors) in which the data amount is set in advance and separated from the first-in first-out memory 63 to perform deinterleave processing. In this case, for example, a write operation to the memory 64 is performed at a high speed at the beginning of the next block. The synchronizing information detecting section 65 extracts synchronizing information from the output signal from the first-in first-out memory Fifo and supplies it to the memory 64. The second data word information read from memory 64 is
After being deinterleaved by the deinterleave processing unit 66, it is demodulated by the decoder 67, converted into a second data word, and sent to the output terminal 70. When the synchronization period for the second data word is performed in sector units, a signal having a sector cycle is used as the synchronization information.

[0172]

As is apparent from the above description, the optical recording / reproducing method, the recording / reproducing apparatus and the optical recording medium according to the present invention are the first recording / reproducing apparatus. According to the present invention, a mark length recording method is applied to sequential channel words formed by channel bits obtained by converting a data word according to a predetermined modulation method, and a light intensity modulation is used to form a mark sequence according to the presence or absence of a mark. A reproduction signal based on a first data word obtained based on an information signal optically read as an intensity change of a reading light amount according to the presence or absence of a mark from an information track recorded on the optical recording medium of the related art is a conventional optical disc. The mark length is converted into a sequential channel word formed by channel bits obtained by converting the first data word targeted for recording and reproduction in accordance with a predetermined modulation method. The first method is based on an information signal that is optically read as a change in the intensity of a read light amount according to the presence or absence of a mark from an information track that is optically recorded as a mark train including the presence or absence of a mark by applying a recording method. Since it can be obtained in the same manner as a reproduced signal based on a data word, even if the recorded information is reproduced from the optical disk of the present invention using a conventional optical disk reproducing apparatus, the mark formed by the presence or absence of the mark on the optical disk of the present invention An information signal can be read optically as a change in the intensity of the read light amount according to the presence or absence of a mark from an information track optically recorded as a column. Conversely, the reproducing apparatus of the present invention can be used. Then, according to the presence / absence of a mark, information is read out from an information track optically recorded as a mark row including the presence / absence of a mark on a conventional optical disc. It is possible to perform the reading of optically information signals as an intensity change of light intensity, good compatibility with the conventional method can be obtained. Also,
The mark length recording method is applied to sequential channel words formed by channel bits obtained by converting the first data word to be recorded / reproduced as described above according to a predetermined modulation method, and When configuring an optically recorded information track as a mark string consisting of presence or absence, a mark having a mark length equal to or longer than the shortest mark length determined by the modulation method, and the shortest mark determined by the modulation method A mark length that is longer than the shortest mark length defined by the modulation method, such as a mark portion used so that a mark having a mark length twice or more than the mark length of the above can function as two mark portions. At least a predetermined number of mark portions including the first appearing mark in the individual channel word described above. A mark displaced to a specific position selected from a plurality of positions preset in the width direction of the information track by the second data word according to the second data word to be recorded / reproduced. By recording in a position-modulated state, and by allowing the second data word to be recorded / reproduced depending on the state of the displacement of the mark, the data recording capacity can be increased as compared with a conventional optical disc. Further, there is an advantage that no special synchronization signal is required for recording and reproducing the second data word as described above.

[Brief description of the drawings]

FIG. 1 is an optical recording apparatus and an optical recording medium of the present invention used when recording information (recording data) to be recorded / reproduced on an optical recording medium according to the optical recording method of the present invention. FIG. 2 is a block diagram of a schematic configuration of an optical reproducing apparatus used for reproducing recorded information from a computer.

FIG. 2 is a block diagram of an optical reproducing apparatus according to the present invention.

FIG. 3 is a block diagram of the optical reproducing apparatus of the present invention.

FIG. 4 is a diagram for explaining a configuration example of a recording signal.

FIG. 5 is a diagram illustrating a configuration example of a reproduction signal.

FIG. 6 is a diagram illustrating a configuration example of a recording signal.

FIG. 7 is a diagram illustrating a configuration example of a reproduction signal.

FIG. 8 is a diagram for explaining an arrangement of channel words.

FIG. 9 is a diagram for explaining an arrangement of channel words.

FIG. 10 is a diagram for explaining an arrangement of channel words and combination words.

FIG. 11 is a diagram for explaining an arrangement of channel words and combination words.

FIG. 12 is a diagram for explaining an arrangement of channel words and combination words.

FIG. 13 is a diagram for explaining the arrangement of channel words and combination words.

FIG. 14 is a diagram for explaining the arrangement of channel words and combination words.

FIG. 15 is a diagram for explaining the arrangement of channel words and combination words.

FIG. 16 is a diagram for explaining the arrangement of channel words and combination words.

FIG. 17 is a flowchart of an operation for determining the arrangement of channel words and combination words.

FIG. 18 is a diagram for explaining a part of a conversion table between data words and channel words.

FIG. 19 is a diagram illustrating channel words and mark strings.

FIG. 20 is a diagram for explaining a relationship between a mark length and a signal level.

FIG. 21 is a diagram for explaining a relationship between a mark length and a signal level.

FIG. 22 is a diagram for explaining a relationship between a mark length and a signal level.

FIG. 23 is a diagram illustrating channel words and mark strings.

FIG. 24 is a diagram for explaining a relationship between a channel word and an increased number of bits.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Input terminal of 1st data word, 2, 4, 12 ... Encoder, 3, 13 ... Interleave processing part, 5 ... EFM modulation part, 6 ... Optical modulator drive circuit, 7 ... Light source, 8 ... Optical modulator , 9 ... optical deflector, 10 ... objective lens, 11 ... input terminal of the second data word to be recorded / reproduced, 14 ...
Mark position modulator (wobble modulator), 15: optical deflector drive circuit, 16: optical head, 17: EFM demodulator, 1
8, 20, 24, 67: decoder, 19, 23: deinterleave demodulator, 21: output terminal of first data word, 22, 59: mark position demodulator (wobble demodulator), 25: target for recording and reproduction , A semiconductor laser, 27 a beam splitter, 28 a lens, 29 a half mirror, 30 an objective lens, 31 a cylindrical lens, 32 a photodetector, 33 ... Servo actuator, 34: condenser lens, 35: split photodetector (or quad split photodetector),
36, 37: amplifier, 38: adder, 39: subtractor, 4
0: binarization circuit, 41: gate circuit, 42: phase locked loop, 43: signal delay unit, 44: sampling circuit, 45, 49 ... sampling pulse generation unit, 46,
47 ... analog-digital converter, 48 ... memory, 50 ...
Position modulation information demodulation circuit, 51 servo system, 52 disk drive motor, 53 coarse movement motor, 54 tracking servo system, 55 coarse movement motor system, 56 rotation control system
57: frame synchronization signal detector, 58: subcode demodulator, 60: RAM, 61: intensity modulation information signal processor, 6
2 ... Position modulation information signal processing unit, 63 ... Fifo, 64 ...
Memory, 65: Synchronous information processing unit, 66: Deinterleave processing unit, Dr: Master disk,

Claims (7)

(57) [Claims] 1. A mark length recording method is applied to sequential channel words formed by channel bits obtained by converting a first data word to be recorded / reproduced according to a predetermined modulation method. Sometimes, among the mark portions having a mark length substantially equal to or longer than the shortest mark length determined by the modulation method, at least a predetermined mark including a mark first appearing in the individual channel word is used. Consisting of a plurality of mark patterns including a mark pattern formed by adding restrictions to the normal rule of associating a logical 1 with an inverted position of a mark and a non-mark so as to have the same number of mark portions. A desired mark pattern corresponding to a channel word is selected and used from a predetermined number of mark pattern groups prepared in advance, and the mark is formed on the signal surface of the optical recording medium. In accordance with the mark length recording method, an information track composed of a mark row consisting of the presence or absence of a mark is sequentially recorded and formed at a predetermined track pitch in the radial direction of the optical recording medium, and the individual channel described above is formed. For a predetermined same number of mark portions including a mark first appearing in a word, a recording / reproduction target is selected at a specific position selected from a plurality of positions preset in the width direction of the information track. An optical recording method for an optical recording medium which is recorded as a mark displaced in accordance with a second data word set forth above. 2. Each successive channel word formed by channel bits obtained by converting a first data word to be reproduced according to a predetermined modulation scheme, first in the individual channel words described above. In a state where the mark appears in a state where it is displaced to a selected specific position among a plurality of preset positions in the width direction of the information track in accordance with the second data word targeted for recording and reproduction. 2. An optical recording method for an optical recording medium according to claim 1, wherein recording is performed. 3. A method according to claim 1, wherein each of the sequential channel words formed by channel bits obtained by converting a first data word to be recorded / reproduced in accordance with a predetermined modulation method includes: The two mark portions including the first appearing mark are placed at a selected specific position among a plurality of positions preset in the width direction of the information track, and the second data word targeted for recording / reproduction is set. 2. The optical recording method for an optical recording medium according to claim 1, wherein the recording is performed as a mark displaced according to the following. 4. A method according to claim 1, wherein said first data word to be recorded and reproduced is recorded by applying a mark length recording method to a sequential channel word converted according to a predetermined modulation method. A mark portion having a mark length substantially equal to or longer than the shortest mark length, including at least a predetermined number of mark portions including a mark first appearing in the individual channel word. A predetermined mark pattern including a plurality of mark patterns including a mark pattern formed by adding restrictions to a normal rule that a logical 1 corresponds to a reversal position between a mark and a non-mark so that recording can be performed by a mark pattern that is not used. Means for preparing a number of mark pattern groups, and mark length recording of a sequential channel word corresponding to a sequential first data word to be recorded / reproduced. When recorded on an optical recording medium according to the method, a desired mark pattern having at least a predetermined number of the same number of mark portions including the first appearing mark in each channel word is sequentially optically recorded. Means for sequentially selecting mark patterns that can be recorded on an optical recording medium, and a mark sequence consisting of the presence or absence of a mark on the signal surface of the optical recording medium by a mark length recording method using the selected mark pattern. Means for sequentially recording information tracks to be formed at a predetermined track pitch in the radial direction of the optical recording medium, and a predetermined number of the same number of marks including a mark first appearing in the individual channel word. The mark portion is recorded at a specific position selected from a plurality of positions preset in the width direction of the information track. Optical recording apparatus for an optical recording medium comprising a means for recording a mark of a state of being displaced in accordance with a second data word being the raw subject. 5. A mark length recording method is applied to successive channel words formed by channel bits obtained by converting a first data word to be recorded and reproduced according to a predetermined modulation method. Sometimes, among the mark portions having a mark length substantially equal to or longer than the shortest mark length determined by the modulation method, at least a predetermined mark including a mark first appearing in the individual channel word is used. Consisting of a plurality of mark patterns including a mark pattern formed by adding restrictions to the normal rule of associating a logical 1 with an inverted position of a mark and a non-mark so as to have the same number of mark portions. From a predetermined number of mark pattern groups prepared in advance, a desired mark pattern corresponding to a channel word is selected, and on a signal surface of an optical recording medium,
A sequential information track is recorded and formed at a predetermined track pitch in the radial direction of the optical recording medium by a mark row consisting of the presence or absence of a mark in order, and a mark which first appears in the individual channel word is described. A predetermined number of mark portions including a second data word targeted for recording / reproduction at a specific position selected from a plurality of positions preset in the width direction of the information track. The signal surface of the optical recording medium recorded as a mark displaced according to the above is irradiated with a light spot having a small diameter for reading information, and a mark formed by a channel bit corresponding to the first data word. Detects a change in light amount due to the presence or absence of a data word, reproduces a first data word targeted for recording and reproduction, and reproduces a data word in the width direction of an information track according to a second data word. The position information of each positioned mark is obtained based on the reproduction content of the first data word, and by using the position information of each mark displaced in the width direction of the information track, An optical reproducing method for reproducing the second data word by sampling individual marks displaced in the width direction of the information track in accordance with the second data word. 6. A mark length recording method is applied to successive channel words formed by channel bits obtained by converting a first data word to be recorded / reproduced according to a predetermined modulation method. Sometimes, among the mark portions having a mark length substantially equal to or longer than the shortest mark length determined by the modulation method, at least a predetermined mark including a mark first appearing in the individual channel word is used. Consisting of a plurality of mark patterns including a mark pattern formed by adding restrictions to the normal rule of associating a logical 1 with an inverted position of a mark and a non-mark so as to have the same number of mark portions. From a predetermined number of mark pattern groups prepared in advance, a desired mark pattern corresponding to a channel word is selected, and on a signal surface of an optical recording medium,
A sequential information track is recorded and formed at a predetermined track pitch in the radial direction of the optical recording medium by a mark row consisting of the presence or absence of a mark in order, and a mark which first appears in the individual channel word is described. A predetermined number of mark portions including a second data word targeted for recording / reproduction at a specific position selected from a plurality of positions preset in the width direction of the information track. A light spot having a small diameter for reading information is imaged on a signal surface of an optical recording medium recorded as a mark displaced according to the above, and recorded information is optically read from the signal surface of the optical recording medium. The optical head that reads the data, and the change in the amount of light depending on the presence or absence of the mark by the channel bit corresponding to the first data word, from the recorded information read by the optical head. Means for detecting the first data word to be recorded and reproduced, and a displacement in the width direction of the information track from the recorded information read by the optical head according to the second data word. Means for obtaining the position information of the individual marks being performed based on the reproduction content of the first data word, and the position information of the individual marks displaced in the width direction of the information track, Means for sampling the individual marks displaced in the width direction of the information track in accordance with the second data word and reproducing the second data word. 7. A mark length recording method is applied to sequential channel words formed by channel bits obtained by converting a first data word to be recorded / reproduced according to a predetermined modulation method. Sometimes, among the mark portions having a mark length substantially equal to or longer than the shortest mark length determined by the modulation method, at least a predetermined mark including a mark first appearing in the individual channel word is used. Consisting of a plurality of mark patterns including a mark pattern formed by adding restrictions to the normal rule of associating a logical 1 with an inverted position of a mark and a non-mark so as to have the same number of mark portions. From a predetermined number of mark pattern groups prepared in advance, a desired mark pattern corresponding to a channel word is selected, and on a signal surface of an optical recording medium,
A sequential information track is recorded and formed at a predetermined track pitch in the radial direction of the optical recording medium by a mark row consisting of the presence or absence of a mark in order, and a mark which first appears in the individual channel word is described. A predetermined number of mark portions including a second data word targeted for recording / reproduction at a specific position selected from a plurality of positions preset in the width direction of the information track. An optical recording medium recorded as a mark displaced according to the following.