JP2003085774A - Optical information recording medium, information recording and reproducing method, and crosstalk removing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical information recording medium which allows normalization of a signal without being affected by a crosstalk signal from adjacent tracks in reproducing information yielding a reproduced signal whose level is multi-valued. SOLUTION: On the optical information recording medium, address information or recording data are recorded with ternary or more multi-valued information and patterns for normalizing the reproduced signal are included before an address information area or a data area D and information is recorded on tracks with the CAV (Constant Angular Velocity) system, the ZCAV (Zone Constant Angular Velocity) system, or the ZCLV (Zone Constant Linear Velocity) system. Normalizing pattern areas B consisting of pattern strings for normalizing the reproduced signal are shifted in the circumferential direction so that they may not overlap in the radial direction between adjacent tracks, and therefore, a normalized pattern signal which is not affected by the crosstalk signal from adjacent tracks can be detected at the time of reproducing multi-valued information because the normalizing pattern areas B do not overlap between adjacent tracks, and the influences of the variance in reflection factor of the optical disk, the variance caused by mechanical precision, the fluctuation of the recording and reproducing power, etc., are removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium such as an optical disc suitable for reproducing multi-value recorded data, an information recording / reproducing method and a crosstalk removing method thereof.

[0002]

2. Description of the Related Art Generally, in an optical disc, binary digital data is recorded on a spiral or concentric track.
Concavo-convex pit by embossing (ROM disc)
It is recorded by the formation of holes in the inorganic / organic recording film (write-once disc), the difference in crystal state (phase change disc), the difference in magnetization direction (magneto-optical disc), etc. When reproducing these recorded data, a laser beam is irradiated onto the track to detect the intensity difference of the reflected light, the polarization direction difference due to the magnetic Kerr effect and the like to obtain a reproduction RF signal. Then, the obtained reproduction RF signal is processed with, for example, a fixed threshold value to detect binary data.

In order to increase the recording density of information, a method of recording multi-valued data of three or more values instead of binary data has been considered, but in an optical disk, there is a difference in reflectance between the disks and one Level fluctuations and amplitude fluctuations occur in the reproduced signal due to various factors such as the difference between the reproduced frequency characteristics on the inner and outer circumference sides of the optical disk. For this reason,
If the threshold value for multi-value conversion is fixed, there is a problem that the reproduced signal may be detected with an incorrect value. In particular, when the data is ternary, quaternary, etc., there is a problem that the threshold value becomes plural and the possibility of erroneous detection of multivalued data increases.

From the above, for example, Japanese Unexamined Patent Publication No.
According to Japanese Patent No. 54391, in order to solve the above problem, a reproduction signal from a recording medium on which multivalued data is recorded is A / D-converted based on a reference clock, and a signal obtained by this A / D conversion. When detecting multi-valued data by comparing the level data with a threshold value, the reproduction signal is A / D
The signal level data obtained by the conversion is stored in the memory means for each predetermined signal unit, the distribution information of the signal level data is obtained for each predetermined signal unit stored in the memory means, and based on the distribution information Thus, the threshold value used when the signal level data in the signal unit is multivalued is set. In this case, it is premised that a format in which the ratio of the level value of recorded data is determined is adopted.

For example, signal level data obtained by A / D converting the reproduction signal in a predetermined signal unit such as a reproduction signal in sector units in a recording format on an optical disk is temporarily stored in a memory, and the frequency of occurrence is generated by using a CPU. By obtaining the distribution information, the optimal threshold is obtained as the criterion for multi-valued
The signal level data stored again by using the threshold value is converted into multilevel data to detect the data. Therefore, even when there are fluctuations in the level or amplitude of the reproduced signal,
There is an effect that the possibility of erroneous detection of multi-valued data is reduced and an accurate multi-valued detection operation is realized, and as a result, high density recording data is promoted.

Further, according to Japanese Patent Laid-Open No. 8-287609, crosstalk and intersymbol interference are solved in order to solve signal fluctuation due to crosstalk from adjacent tracks and intersymbol interference from preceding and following recording marks on the same track. It has been proposed to learn and correct the influence of the above. The structure of this learning pattern is shown in the learning track recognition area of FIG. 2 in the publication for learning the crosstalk amount, and in the equalization coefficient learning area of FIG. 2 in the publication for learning the intersymbol interference. ing. The feature of this learning pattern is that it is composed of one maximum recording mark and unrecorded marks (mirrors) among the recording marks to be multi-valued recorded. With this effect, the SN ratio of the reproduced signal can be improved, and the density of the multi-level recorded data can be increased.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the example of Japanese Patent No. 391, in order to cope with a variation in a long section such as a signal level variation on the inner and outer circumferences of the optical disc, for example, a threshold for multi-value quantization is optimized by learning a level variation distribution for each sector. This level fluctuation learning is effective for fluctuations lower than the carrier frequency, such as fluctuations in reflectance of the optical disk, mechanical accuracy (surface deviation, eccentricity), fluctuations due to recording / reproducing power, and the like. But,
Crosstalk in the same frequency band as the carrier frequency and intersymbol interference cannot be removed as fixed level fluctuations.

According to the latter Japanese Patent Laid-Open Publication No. 8-287609, the problems (crosstalk and intersymbol interference) in the Japanese Laid-Open Publication No. 5-54391 can be solved, but the Japanese Laid-Open Patent Publication No. 8-287609 discloses. In the configuration of one largest recorded mark and an unrecorded mark (mirror) as shown in FIG. 2 in the middle, an error occurs in the signal value obtained from the largest recorded mark due to the sampling time shift, and the correction is correct. There is a problem that does not work.

These points will be described with reference to a more practical multilevel recording example. FIG. 19 shows the relationship between the multilevel recording mark and the reproduction signal. An optical information recording medium having a tracking groove formed on its surface and a recording / erasable recording material applied thereto records information as marks at predetermined time intervals. The area corresponding to the predetermined time interval is a unit of multi-valued information recording / reproducing called an information cell (or simply cell). For example, when a phase change (PC) recording film is used as a recording / erasable recording material, the shape of the recording mark (size) is adjusted by irradiating the cell with laser light and adjusting the recording / erasing light amount and their timing. ) Is changed to form a recording mark having a plurality of reproduction signal levels. In FIG. 19, cells having 8 values from 0 level in which no recording mark is formed to 7 level in which the largest mark is formed are recorded. That is, each cell has 8 = 2
^{Since it is 3,} 3-bit information is recorded. If the level of each cell can be reproduced as recorded, an ordinary optical disk can record with 1 bit with or without a mark, so that a recording capacity of 3 times can be obtained. Also, to increase the storage capacity,
It is necessary to make the cell small, and if it is made small, as shown in FIG. 19, the recording marks of three consecutive cells are included in the reproduction beam diameter.

As a recording / erasable recording material, a magneto-optical (MO) recording film can be used in addition to the phase change film. In addition to the above laser light, the shape of the recording mark can be obtained by a cooperative work with a magnetic field from a magnetic head (not shown). Is changed to form recording marks of a plurality of reproduction levels. Furthermore, it is also possible to apply a recording material capable of recording once, and it is possible to use an organic dye or a metal film as the recording material, irradiate the cell with laser light, and adjust the recording light quantity and the timing thereof. By changing the shape of the recording mark, recording marks of a plurality of reproduction levels are formed. Similarly, in a read-only information medium, recording marks can also be formed on the substrate in the form of unevenness called phase pits, and the length, area, or optical depth of the phase pits can be modulated to increase the number of recording marks. Value recording is possible.

When multi-valued recording is adopted for an optical disk and the track density is reduced to increase the density, the influence of crosstalk from adjacent tracks must be taken into consideration. In particular, when a certain pattern (normalized pattern) is recorded to normalize the reproduced signal and then reproduced to normalize the reproduced signal in the data area, crosstalk from an adjacent track occurs in the normalized pattern. When included, the probability of error occurrence increases for all normalized signals. Further, if crosstalk from an adjacent track is added to the synchronization signal used to generate the timing signal for detecting the multilevel signal, a phase error occurs and the error detection probability of data detection increases. That is, the signal is detected at the center of the recording mark, but the timing is deviated.

In order to eliminate the influence of such crosstalk, crosstalk is performed using a three-beam optical pickup that irradiates an adjacent track with a light beam (irradiates a side beam) in order to detect a signal from the adjacent track. It is possible to cancel. This also reduces crosstalk from adjacent tracks.

However, when the side beam is irradiated to detect the signal on the adjacent track and the crosstalk is canceled by the calculation, an amplitude error occurs.

For example, CLV (Constant Linear Vel)
When the ocity = constant linear velocity) format is used, the status of the area in the adjacent track of the area where the normalization pattern is inserted to normalize the reproduced signal (normalization pattern area) and the area where the multi-valued data is actually written Many different cases occur. Therefore, even if the reproduction signal of the normalization pattern for normalizing the reproduction signal is corrected by the three-beam optical pickup, an error will occur.

Therefore, according to the present invention, when reproducing information in which the level of the reproduction signal is multi-valued, the signal can be normalized without being affected by the crosstalk signal from the adjacent track. The purpose is to provide.

Further, according to the present invention, when reproducing the information in which the level of the reproduced signal is multi-valued, the signal can be normalized without being affected by the crosstalk signal, and the margin for the sampling timing deviation can be obtained. It is an object of the present invention to provide a wide optical information recording medium.

Another object of the present invention is to provide an optical information recording medium having high format efficiency when recording / reproducing information in which the level of a reproduction signal is multi-valued.

It is another object of the present invention to provide an optical information recording medium capable of accurately detecting a normalized pattern when reproducing information whose reproduction signal level is multi-valued.

Another object of the present invention is to provide an optical information recording medium capable of accurately sampling multi-valued data when recording / reproducing information in which the reproduction signal level is multi-valued.

The present invention also provides an optical information recording medium and an information recording / reproducing method capable of accurately recording / reproducing multivalued data when recording / reproducing information in which the level of a reproduction signal is multivalued. The purpose is to

A further object of the present invention is to provide a crosstalk removing method capable of removing the crosstalk signal with high accuracy when recording / reproducing information in which the level of the reproduction signal is multivalued.

[0022]

The invention according to claim 1 is
Address information or recorded data is recorded as multi-valued information of three or more values, and a pattern for normalizing a reproduction signal is included in an area where the address information exists or a data area in which the recorded data is recorded. The CAV method or the ZCAV method or Z
An optical information recording medium in which information is recorded on a track by the CLV method, wherein a normalization pattern area composed of a pattern sequence for normalizing the reproduction signal is circular so that adjacent tracks do not overlap each other in the radial direction. It is shifted in the circumferential direction.

Therefore, when reproducing the information in which the level of the reproduction signal is multi-valued, the normalization pattern areas do not overlap between adjacent tracks, so that the detection of the normalization pattern which is not affected by the crosstalk signal can be performed. Therefore, it is possible to eliminate the influence of the fluctuation of the reflectance of the optical disk, the fluctuation of the mechanical accuracy, the fluctuation of the recording / reproducing power, and the like.

According to a second aspect of the present invention, in the optical information recording medium according to the first aspect, the tracks adjacent to the normalized pattern area are non-signal areas where no mark exists.

Therefore, by making the adjacent track of the normalized pattern area a non-signal area where no mark exists, the crosstalk does not affect the reproduced signal from the normalized pattern.

According to a third aspect of the present invention, in the optical information recording medium according to the first or second aspect, the normalized pattern area is composed of a combination of a plurality of mark rows of the same size and a non-signal area. , The length ML1 of the mark row, the length ML2 of the non-signal area, and the spot diameter BD of the recording / reproducing beam.
Is set to satisfy the relationship of ML1> BD and ML2> BD.

Therefore, when reproducing the information in which the level of the reproduction signal is multi-valued, the structure of the normalization pattern area for normalizing the signal without being affected by the crosstalk signal is provided.
Furthermore, since a signal having a flat portion with respect to the normalized pattern area can be generated and the normalized pattern area is configured to be resistant to the deviation of the sampling timing, fluctuations in reflectance of the optical information recording medium, fluctuations due to mechanical precision, and recording It is possible to remove the influence of the fluctuation of the reproduction power with high accuracy (specifically, a wide margin with respect to the sampling timing deviation).

According to a fourth aspect of the present invention, in the optical information recording medium according to the first, second or third aspect, the address information is formed by phase pits recorded as the same multi-valued information as the recording data. .

Therefore, by forming the address information in which the position information is more important than the signal level by the phase pits, it is possible to record and reproduce the address information with high reliability.

The invention according to claim 5 is the invention according to claims 1 to 4.
In any one of the optical information recording media described above, the pattern of the pattern sequence for normalizing the reproduction signal is a combination pattern that does not exist in the data area.

Therefore, it is possible to improve the detection accuracy of the pattern string for normalizing the reproduction signal.

The invention according to claim 6 is the invention according to claims 1 to 5.
In the optical information recording medium according to any one of 1, the synchronization signal area including a preamble signal for generating a timing signal at the time of data reproduction is provided in front of or behind the area in which the address information exists, or in front of the data area. The sync signal area is formed by phase pits recorded with binary information, arranged so as to overlap each other in the radial direction between adjacent tracks.

Therefore, when recording / reproducing information in which the level of the reproduction signal is multi-valued, regarding the sync signal area including the preamble signal, there is no deviation in the peak position of the signal between adjacent tracks. Since they are arranged so as to overlap each other, that is, they are aligned in the radial direction, they can be accurately detected using crosstalk, and the format efficiency can be increased. Further, since the multi-valued data is sampled based on the synchronization signal accurately formed by the phase pits, the multi-valued data can be sampled accurately and the demodulation error due to the timing shift can be reduced.

The invention described in claim 7 is,
Alternatively, in the optical information recording medium described in 6, the wobble basic period of the groove or land forming the track is C.
The number of wobbles in each track is the same in the AV recording area or the zone area of the ZCAV method or the ZCLV method, and the adjacent tracks in which the wobbles are not modulated meander in phase.

Therefore, when recording / reproducing information in which the level of the reproduction signal is multivalued, the wobble phases are aligned between adjacent tracks, so that phase shift due to crosstalk due to wobble can be reduced, and multivalued. Data can be sampled accurately, and demodulation errors due to timing deviation can be reduced.

According to an eighth aspect of the present invention, in the optical information recording medium according to the seventh aspect, the normalized pattern area or the sync signal area includes wobbles of a constant cycle including adjacent tracks without wobble or modulation. Is.

Therefore, in the optical information recording medium according to the seventh aspect, when recording / reproducing information in which the level of the reproduction signal is multivalued, the normalization pattern area and the synchronization signal area are not wobbled or modulated. Since there is no wobble with a constant cycle, there is no disturbance due to wobble in the detection of the normalization pattern and the synchronization signal, and it is possible to detect the normalization pattern and the synchronization signal with higher reliability. As a result, it is possible to accurately remove the influence of the fluctuation of the reflectance of the optical information recording medium, the fluctuation of the mechanical accuracy, the fluctuation of the recording / reproducing power, and the like.

The information recording / reproducing method of the invention described in claim 9 is intended for the optical information recording medium according to claim 7, and controls the rotation of a drive source for rotationally driving the optical information recording medium based on wobble information. During recording, a recording pulse for recording multi-valued information from the wobble information is generated and multi-valued data is recorded at a target address position based on the address information, and during reproduction, level fluctuations of a reproduction signal are removed based on a normalized pattern. At the same time, the sampling position is determined based on the synchronization signal to reproduce the multi-valued data.

Therefore, when recording / reproducing information in which the level of the reproduced signal is multi-valued, it is based on both the information of the wobble signal in which the crosstalk from the adjacent track is reduced and the synchronizing signal formed by the phase pits. Since the multi-valued data is sampled by using the multi-valued data, the multi-valued data can be sampled accurately and the demodulation error due to the timing deviation can be reduced.

According to a tenth aspect of the present invention, there is provided a crosstalk removing method for a reproduction track which is a target of the optical information recording medium according to the second or third aspect, and two adjacent tracks which are adjacent to the reproduction track. When reproducing the normalized pattern area of the optical information recording medium by allocating a reproducing beam to each of them, the magnitude of the crosstalk signal from the mark row of the adjacent track is detected in the non-signal area, and the crosstalk signal is detected based on this detection result. The correction coefficient for correcting the talk is learned.

Therefore, when recording / reproducing information in which the level of the reproduced signal is multivalued, the degree of influence of the crosstalk signal can be estimated by the normalized pattern, so that it is not necessary to separately provide a learning area for crosstalk ( Therefore, the format efficiency is high) and the crosstalk signal can be accurately removed.

[0042]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of the present invention.
Or, it demonstrates based on FIG.

In the present embodiment, the address information or the record data is recorded as multi-valued information of three or more values, and the area where the address information exists or the data area for recording the record data includes a pattern for normalizing the reproduction signal. A CAV (Constant Angular Veloci)
ty = constant angular velocity) method or ZCAV (zone CAV)
The present invention is intended for an optical information recording medium in which information is recorded on a track by the method or ZCLV method. CAV method or ZCAV
The method is applied because the sector head positions are aligned in the radial direction. Even with the ZCLV system, it is simply C
Unlike the LV method, the sector head positions are aligned in the radial direction when considered on a zone-by-zone basis, which is applicable.

First, FIG. 1 schematically shows a basic format example applied to the optical information recording medium of the present embodiment. Normalization of reproduction signal (normalization of amplitude of data area D)
Standardized signal (normalized pattern) with a fixed period for
This signal is inserted in the ZCAV format zone or at a constant angular position on the CAV format at regular intervals and discretely. At this time, the normalization pattern area B including the normalization pattern is formed by being shifted in the circumferential direction so that adjacent tracks do not overlap each other in the radial direction. That is, the normalization pattern does not exist in the adjacent track of the normalization pattern area B.

For example, as shown in FIG. 1, (n-1),
In an odd-numbered track (groove G) such as (n + 1), a normalized pattern area B is inserted at an odd-numbered position (m-1), (m + 1), etc. in the track, and an even-numbered track such as n A normalization pattern area B having a constant period is inserted at an even-numbered position such as 2 m in the track, and therefore m in an odd-numbered track such as (n-1) and (n + 1) is inserted. The format is such that nothing is written at even-numbered positions such as. g is a gap.
By doing so, basically, the disturbance of the normalized pattern detection signal due to crosstalk between adjacent tracks can be reduced.

The data area is "preamble".
"Address + CRC (3)""Data part (data + E
CC) ”format.

Here, the influence (level fluctuation) due to the crosstalk signal will be examined. FIG. 20B shows a case where there is an influence of crosstalk (when a recording mark exists in an adjacent track and is indicated by a broken line in the drawing) and a case where there is no influence of crosstalk (a recording mark exists in an adjacent track. In the case where there is no such a case, the change in the reproduction signal (reproduction sum signal = RF signal) level indicated by the solid line in the figure is shown.
FIG. 20A is an explanatory diagram schematically showing the scanning operation by the spot S of the recording / reproducing beam on the optical information recording medium on which the recording mark M (or the phase pit) is formed.

When there is the influence of crosstalk, the level of the reproduction signal is reduced by δ. Therefore, in order to remove the influence of the fluctuation of the reflectance of the optical information recording medium, the fluctuation due to the mechanical accuracy, the fluctuation of the recording / reproducing power, etc., the signal level detected from the normalized pattern arranged at regular intervals is used. , The fluctuation component is corrected by normalizing the level of the reproduction signal. As an example of normalization, when the maximum value of the signal level observed from the normalization pattern is max, the minimum value is min, and the observed signal value is Rf, it is calculated by (Rf-min) / (max-min) . However, if the influence of the crosstalk signal influences the signal detected from the normalization pattern, this crosstalk signal component becomes noise, which causes a problem that it is not properly normalized, resulting in an increase in errors in multilevel level judgment. Become. For this reason, it is necessary to configure the normalized pattern formed in the normalized region into a pattern that is not affected by crosstalk.

Therefore, in this embodiment, as a more realistic normalized pattern configuration, it is configured so as not to be affected by crosstalk. FIG. 2 is a conceptual diagram showing a configuration example of a normalized pattern that is not affected by crosstalk. That is, the non-signal area where the mark does not exist is A,
When the normalized pattern area is B, the synchronization signal area is C, and the data area is D, the adjacent track portion to the normalized pattern area B is set to be a no-signal area A. The sync signal area C is set so as to overlap in the track radial direction between adjacent tracks as described later.

FIG. 3 schematically shows a configuration example in which a normalized pattern that is not affected by crosstalk is formed on the groove G which is a track of the actual optical information recording medium 1 based on the principle of FIG. 2 ( The sync signal area C is omitted in FIG.

With such a configuration, the normalized pattern areas B do not overlap between adjacent tracks. Further, since the track area adjacent to the normalization pattern area B is a non-signal area (mirror area where no recording mark exists) A, the crosstalk does not affect the reproduction signal from the normalization pattern. Further, in constant linear velocity recording (CLV method), when recording is performed with a constant sector length, the head positions of the sectors do not match in the radial direction. Therefore, as described above, constant angular velocity recording (CAV system, ZCAV system, or ZCLV system) in which the head positions of the sectors are aligned in the radial direction
It is necessary to record and playback with. In this embodiment, the normalization pattern always exists in front of the data part of each sector.

Next, a pattern configuration example of the normalized pattern will be examined. First, as a comparative example, FIG. 21 shows an example of the recording mark for the normalization pattern shown in FIG. 1 and the reproduction signal waveform thereof in the above-mentioned conventional example (JP-A-8-287609). In this example, the maximum playback signal level ma
By sampling and detecting x and the minimum value min, normalization is performed as in the case described above. However, since the detection is performed at the peak (maximum) position of the minimum value min, if the sampling timing is deviated by Δt,
A detection error δ will occur.

In consideration of such a point, in the present embodiment, the normalization pattern has a mark row pattern configuration as shown in FIG. That is, a recording mark string (length ML) composed of a single recording mark of the same size.
1) and a non-signal area (length ML2) are combined, and M is larger than the spot diameter BD of the recording / reproducing beam.
The size relations of L1> BD and ML2> BD are set. As described above, if the lengths ML1 and ML2 are both large with respect to the spot diameter BD of the recording / reproducing beam, FIG.
It is possible to generate a reproduction signal having a flat portion as shown therein. Maximum value max and minimum value m in this flat area
If in is sampled, the detection error due to the timing deviation Δt can be greatly improved.

Further, in FIG. 2 described above, a synchronization signal (preamble) for generating sampling timing used for reproducing a signal in recording mark units (cell units).
The area C is arranged after the normalized pattern area B or the no-signal area A. The synchronization signal is a signal necessary for sampling the reproduction signal in recording mark units (cell units), and is preferably configured in the same unit as the cell frequency.

Such a sync signal will be described later, but the groove G forming a track as shown in FIG.
It is also possible to detect that the meandering is meandering by an optical pickup and to record at the same time in synchronization with a wobble signal output, but as another embodiment, it is possible to preliminarily record the phase at the time of manufacturing the optical information recording medium. It is also possible to form it as a pit. In this case, if a recording pulse (recording clock) is generated based on the reproduced synchronizing signal, the error due to the rotation fluctuation of the spindle motor can be corrected. As described above, regarding the mark used as the synchronization signal, the position information on the mark is more important than the signal level. Therefore, by forming this synchronizing signal by phase pits formed in advance on the substrate as a concave-convex shape, highly reliable data recording / reproducing becomes possible.

As described above, the sync signal area C is an important area for the optical disk device, and if noise is mixed in the signal reproduced from the sync signal, it becomes a fatal problem for the system. FIG. 22 shows how the waveform of the sync signal is disturbed by the crosstalk signal in the sync signal area C. In FIG. 22B, when there is an influence of crosstalk (when there are phase pits in adjacent tracks,
(Represented by a broken line in the figure) and a reproduction signal (reproduction sum signal = R) when there is no influence of crosstalk (when there is no phase pit in an adjacent track and is described by a solid line in the figure)
(F signal) level change is shown.

When the synchronizing signal in the synchronizing signal area C is binarized due to the disturbance of the waveform, the maximum value of the signal detected by the rising position (or the falling position) or the differentiation of the binary signal is deviated. Then, an error occurs in the sync signal. In order to solve this problem, as in the case of the normalized pattern area B, a method in which the adjacent track is set to the non-signal area A is also possible. It is more preferable not to increase the length required for the synchronization signal area C because the sector can be made longer.

Therefore, in the present embodiment, conversely, the method of using the crosstalk signal is used. In the configuration shown in FIG. 2, the recording marks or phase pits of the adjacent tracks in the sync signal area C are aligned in the radial direction. In this case, the level of the reproduction signal changes due to the influence of crosstalk, but the peak (maximum) position of the signal does not deviate (Δt =
0). Therefore, it can be said that the recording marks or the phase pits in the synchronization signal area C may be recorded or arranged so as to overlap between the adjacent tracks.

When the synchronizing signal area C is generated by the phase pits and the writing clock or the reproducing clock is generated on the basis of the phase pits, since the phase error due to the crosstalk is reduced in the synchronizing signal, a highly accurate recording / reproducing clock is generated. it can. However, as will be described later, since the recording mark is formed in the data actually recorded on the disc surface in a state of being delayed from the recording pulse (the phase is shifted), the reproduction clock shifts the phase by this amount.

When data is recorded with the recording clock generated from the wobble signal described above, if the sync signal is recorded in the sync signal area C so that the adjacent tracks overlap with each other as described above, the reproduction is performed. The phase error due to crosstalk is reduced in the sync signal detected from the sync signal area C when performing. Since the data recorded on the disc surface has a recording mark (a phase shift) in a state of being delayed from the recording pulse, if the reproduction clock generated from the wobble signal is reproduced, the phase is corrected by the synchronization signal. A more accurate reproduced clock can be generated.

A second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the normalized pattern area B
The normalization pattern in the inside is formed by a mark row of the recording marks M, and the sync signal in the sync signal area C is constituted by the phase pits P. This normalization pattern is also used as a mark indicating the beginning of a sector or block in order to reproduce the data area D and process the data in sector units or block units.

As an algorithm for sampling and detecting data, a desired initial value is obtained by synchronizing with a wobble signal detecting a wobble on the optical information recording medium and a reference pulse signal having a wobble signal frequency at a target speed. The spindle motor is rotated at the number of revolutions, the normalization pattern that is the start position of the sector is recognized, the synchronization signal area that follows it is detected, and the sampling timing signal or recording clock that is the reproduction clock is used based on this synchronization signal. Generate a clock for a recording pulse.

Therefore, it is important to detect the normalization pattern first, and if the same pattern as the normalization pattern exists in the data area D, the start position of the sector cannot be detected correctly.

Therefore, in the present embodiment, the modulation of the data area D is restricted so that the same pattern as the normalized pattern does not occur in the data area D. Conversely, the pattern of the normalized pattern is a combination pattern that does not exist (do not appear) in the data area D.

Further, the address information indicating the address of the sector (the address area is not shown) may be arranged after this normalization pattern area B. In the case of the format including the sync signal area C, the address area is arranged after the sync signal area C. In order to use the same demodulation circuit as the data information, it is desirable that the same multivalued data as in the data area D is recorded. In this case, the wobble-modulated address information is reproduced and positioned, and the normalization pattern area B, the synchronization signal area C, the address area, and the data area are recorded at the time of recording. Further, in order to easily format the address information, the substrate may be formed in advance as an uneven shape as a phase pit. In this case, the address information area is binarized information, the sync signal area C arranged before this is also formed by phase pits, and the normalized pattern area is naturally recorded at the time of recording. Further, when the normalization pattern area B and the synchronization signal area C and the phase pits in which the address information and the record data are recorded as multi-valued information are used, the signal normalization operation at the time of data reproduction is also performed, and only high-density reproduction is performed. Optical disc (ROM) can be realized. When the ROM having such a format is realized, it is possible to inexpensively record or reproduce the rewritable type medium, the write-once type medium, and the ROM medium with the same optical disk device at low cost.

A third embodiment of the present invention will be described with reference to FIG. At the time of recording or reproducing operation, first, after rotating the spindle motor at a desired initial value rotation speed,
In order to detect the normalization pattern area B and the synchronization signal area C, it is necessary to rotate the area to a certain extent.

Therefore, basically, as shown in FIG. 10, the groove G as used in the CD-R or the CD-RW is used.
Is wobbled, and a tracking error signal by the push-pull method that detects the state of this wobble by the difference of the two-divided photodetector of the optical pickup is passed through a bandpass filter and reproduced. Here, this reproduction signal is described as a wobble signal. The rotation of the spindle motor is controlled based on this wobble signal.

However, since the wobbled groove G also affects the reproduced signal, it is not desirable that the groove G meanders in the above-described normalized pattern area B and the sync signal area C. Thus, the crosstalk includes both the data signal of the adjacent track and the signal from the wobble due to the meandering track.

When the wobbles are out of phase between adjacent tracks, the phase of the wobble signal at a constant cycle shifts due to the crosstalk of the adjacent wobbles. This phase shift of the wobble signal also becomes a phase shift of the recording or reproduction clock generated from the wobble, and causes a reproduction data error. In order to reduce the influence of crosstalk due to this adjacent wobble, in this embodiment, the sum of crosstalk from adjacent tracks is made constant. That is, as shown in FIG. 6, the groove G (or the land L)
Wobble basic period within the CAV recording system area or ZC
In the AV (ZCLV) zone area in some cases, the number of wobbles in each track is the same, and the adjacent tracks are meandered so that the phases of the cycles are aligned. As a result, not only the problem of phase shift of the recording or reproduction clock but also the influence of the wobble on the reproduction signal at the time of data reproduction can be reduced.

A fourth embodiment of the present invention will be described with reference to FIG. According to the third embodiment described above, it is possible to reduce crosstalk from adjacent tracks by wobble including the data part. In the present embodiment, the signal quality of the normalization pattern for normalizing the reproduction signal in the data area is further improved.

Specifically, in the normalization pattern area B for recording the normalization pattern for normalizing the reproduction signal, the tracks including adjacent tracks are made straight (no wobble) as shown in FIG. That is, the straight groove areas As and the wobble groove areas Aw are formed alternately. According to this, the normalization pattern for normalization is more accurate than the method using the fact that the crosstalk due to wobbles on both sides of the track changes but the sum does not change as in the case of the third embodiment. Can detect signals. That is, in the case of the third embodiment, the influence of the meandering quality of adjacent tracks is included.

Further, like CD-R and CD-RW,
In order to insert the address information on the optical information recording medium onto the wobble of the track, it is normal to partially modulate (the information is entered by changing a certain period of the meander), but in the data area D In order to improve the signal quality of the normalization pattern for normalizing the reproduction signal, if the normalization pattern area B and the adjacent track area are wobbled but not modulated (without modulation), the The normalized pattern signal can be detected.

Further, a sync signal area C containing a sync signal (preamble signal) for generating a sampling signal which is a reproduction clock at the time of reproducing multi-valued data is provided, and the sync signal areas C are overlapped with each other in the radial direction between adjacent tracks. Even if there is crosstalk from the adjacent track, the synchronization signal (preamble) Since the phase of the signal) does not deviate, it has already been described that a recording / reproducing clock with high accuracy can be generated by generating a recording or reproducing clock with the PLL circuit based on this, but this wobble is also modulated in this synchronizing signal area. If you do not, or if you make the track straight (no wobble), a better quality sync signal (preamble signal) It is. The phase of the highly accurate sync signal from the sync signal area C is compared with that of the reproduced clock, which is the PLL output, and the PLL is controlled so as to match the reproduced clock with the phase of the synchronized signal. Data errors can be reduced by using the recovered clock of the state.

As described above, in the case of writing information such as address information in the meandering (wobble) of a track in accordance with a rule such as a phase modulation method, the wobble area modulated to write information such as address information is Only a part of the length of the sector or the block is used, and the other part has a constant period. Then, the PLL is configured so that the phase is compared by the input of the phase comparator of the PLL only when the signal of this fixed cycle is generated, and the recording or reproducing clock is generated,
Further, at the time of reproduction, a highly accurate clock can be formed by the above-described PLL circuit that can detect and correct the phase difference between the reproduction clock signal output from the PLL and the synchronization signal (preamble signal), and the disturbance such as rotation fluctuation can be prevented. It will be a strong method.

FIG. 8 and FIG. 9 show the fifth embodiment of the present invention.
It will be described based on. This embodiment uses the format as shown in FIG.
The present invention relates to a learning method for removing a crosstalk signal from an adjacent track by using an optical pickup of a 3-beam method using m and sub beams Bs1 and Bs2.

That is, by using the format and the three-beam method as shown in FIG. 3, the magnitude of the crosstalk signal from the adjacent track is detected, and the correction coefficient for correcting the crosstalk is learned based on the detection result. Yes (sub-beams Bs1, B in crosstalk correction with 3 beams
The correction amount of the signal detected by s2 can be determined).

As shown in FIG. 3, the normalized pattern area B
Since the adjacent track is a signalless area A in a signalless state, naturally there is a signalless area on the recording target track. At the time of reproduction, such a non-signal area A is used as a crosstalk measurement area to measure the crosstalk amount from an adjacent track and make a correction corresponding to the measurement amount. In the CAV recording area or the ZCAV (ZCLV in some cases) zone which is the object of the present embodiment, the sector positions, which are a group of data recording / reproducing, are aligned in the radial direction.

A measurement / learning method using this principle will be described in more detail with reference to FIGS. 8 and 9. In FIG. 8, the normalization pattern is formed by a pattern in which a crosstalk signal does not mix from adjacent tracks. Therefore, it is possible to remove the crosstalk signal by learning this pattern. Regarding the method of removing the crosstalk signal, it is assumed that three beam spots are used as described in the conventional example (Japanese Patent Laid-Open No. 8-287609). Three beams Bm, Bs1, B
The spot s2 is located at the center of three tracks adjacent to each other, as shown in FIG. Main beam B
m is projected onto the target track. In addition, the hatched area in FIG. 8 is the normalized pattern area B, and FIG.
It is composed of a recording mark row and a signalless area as shown in FIG.

Now, the track number Tr No. = 4n is set as the target reproduction track, and the (4n-1) th and (4n) th tracks are set.
The +1) th track is the track adjacent to it. With such an arrangement, the main beam Bm causes the track number Tr N
FIG. 9 shows a waveform example of a reproduction signal obtained based on the beams Bm, Bs1, and Bs2 when scanning is performed on the reproduction track of o. = 4n.

In FIG. 8, the beam Bs1 and the beam Bs2 are arranged so as to be offset from the beam Bm in the front-back direction with respect to the track direction. The signal originally detected based on the beam Bs1 and the beam Bs2 is shifted by Δt time back and forth with respect to the signal detected by the beam Bm. However, in FIG. 9, Δt = 0 is drawn for ease of explanation.

First, in FIG. 8, the magnitudes min (ms1) and min (ms2) of the crosstalk signal amount from the normalized patterns arranged on the (4n-1) th and (4n + 1) th tracks are calculated. Can be detected. In addition, the signal values of the normalized pattern detected on the own track by the spots of the sub-beams Bs1 and Bs2 at this time are mi.
Assuming that n (s1) and min (s2), from the adjacent track on the (4n-1) th side, the signal detected by the sub beam Bs1 is crossed at a ratio of (min (ms1) / min (s1)). It can be learned that the talk signal influences, and in the same manner, for the signal detected by the sub beam Bs2, (min (m
It can be learned that the crosstalk signal affects at a ratio of (s2) / min (s2)). In this way, by arranging the normalization patterns so that the normalization patterns do not overlap in adjacent tracks as in the above-described format, the correction coefficient for crosstalk signal removal can be learned. That is, the reproduction data detected in the beam Bs1 or the beam Bs2 is used to correct the reproduction data in the data section using the correction coefficient.

In the example shown in FIG. 8, the accuracy is improved by adopting a format in which the crosstalk of adjacent tracks on both sides can be separately and independently measured. However, as in the embodiment shown in FIG. In the case of a format in which there is a crosstalk of the normalization pattern from the adjacent track, the signal values of the normalization pattern detected on the own track by the sub-beams Bs1 and Bs2 are min (s1) ′ and min (s), respectively.
2) ′ and the magnitude of the amount of crosstalk signals from the normalized patterns arranged on adjacent tracks on both sides of the main beam Bm (reproduction track) is min, the signal detected by the sub beam Bs1 is (min / Min
The crosstalk signal is treated as having an influence of (s1) ′) / 2, and the signal detected by the sub-beam Bs2 is crossed at a rate of (min / min (s2) ′) / 2 in the same manner. It can be treated as if the talk signal affects it.

Even if there is data only on one side of the tracks adjacent on both sides, the correction coefficients are similarly derived in the embodiment shown in FIG. That is, since there is no crosstalk from a track having no recording data (or phase pit data), min (ms1) / min (s1) = 0 or min (ms2) / min (s2) = 0. However, in the embodiment as shown in FIG. 7, the ratio of the influence of crosstalk on the data side of the adjacent track is (mi
n / min (s1) ') or (min / min (s2)'). Therefore, when there is no data on the adjacent track on one side, it can be determined whether there is data or not by the signal detected based on the beam Bs1 or the beam Bs2, and the correction coefficient can be determined based on that. Further, in deriving the correction coefficient, reliability is further improved by taking in a plurality of data and removing abnormal data (data not considered due to noise or the like) and performing averaging processing.

Incidentally, the track in FIGS. 2, 5, 6, 8, 20, and 22 is the groove G.
Although the land L and the land L are not drawn for ease of explanation, for example, when recording is performed with the center of the groove G on the disc as a reference, the half of the line between the centers of the groove G is a track boundary.

In this embodiment, the normalization pattern is used as the signal for crosstalk correction, but another area, for example, the crosstalk correction signal area after the normalization pattern may be formed. Of course, also in this case, the relationship with the adjacent track is the same as the above-mentioned normal pattern area. In this case, the same multilevel data as in the recording unit is recorded in a constant pattern, for example, by recording all multivalued quantization levels for a certain length, and the abnormal data is removed and the quantization levels are averaged in consideration of the probability of occurrence. The reliability is further improved by processing. It is clear that the amount of crosstalk in multi-value recording changes depending on the recording mark length. That is, FIG.
As can be seen from Fig. 9, the cells are set at constant intervals, and the recording mark length is changed in the cells to realize multiple values.
The amount of crosstalk from a short mark is naturally small.

Here, a recording clock or a reproduction clock is generated based on the above-mentioned wobble signal, and at the time of recording, it has the same length and the same phase as the cell of the multi-value recording of the data portion in the synchronization signal area C (synchronization signal area C and data The cell center position of each part constitutes a continuous cell of which the cell interval is an integer multiple of the cell interval), and a synchronization signal in which a recording mark having a constant length (for example, 1/2 of the cell length) is recorded from the tip of each cell is used. A specific embodiment of a circuit system for correcting the phase of the recovered clock will be described as a sixth embodiment with reference to FIGS.
Further, as shown in FIG. 10, if a wobble having the same phase between adjacent tracks is formed, the phase of the cycle of the wobble signal is not shifted due to the crosstalk due to the wobble of the adjacent tracks. A highly accurate recording / reproducing clock can be generated based on the reference.

First, FIG. 11 shows a wobble detection signal formed in the groove G of the optical information recording medium used in the present embodiment. Here, the wobble is configured with a cycle that is 32 times (= 32T) the basic unit cycle T of the multilevel signal recording / reproducing. Further, FIG. 12 shows an example of binary recording, but basically it shows that the mark recorded on the optical information recording medium is recorded with a deviation of Td from the recording data (recording signal). . This is because, for example, in the case of a phase change medium, the recording mark is displaced from the recording clock due to the disc-to-disc variation and disc in-plane variation due to the recording layer material or disc manufacturing variation, so that the phase of the clock formed based on the wobble signal is always used. In order to bring them closer to each other, it is necessary to generate a recording clock whose timing is corrected in consideration of the phase shift amount, and referring to FIG. 12, it is necessary to generate recording data at a timing Td before recording at the time of recording. is there. Therefore, it is shown that the timing of the reproduction signal is generally deviated from that at the time of recording.

Under such a premise, a basic circuit configuration example for generating and outputting the write / reproduce clock of the present embodiment to the controller 11 based on the wobble detection signal is shown in FIG.
Shown in. Basically, it is composed of a phase comparator 12, a charge pump 13, a loop filter 14, and a voltage variable frequency oscillator (VCO) 15, and a PLL (Phase Locked Loop) which receives a wobble detection signal of 32T cycle as an input.
A circuit 16 is provided. Between the input and output of this PLL circuit 16 (between VCO 15 and phase comparator 12), 1/12
An 8 counter 17 and a 1/32 counter 18 are connected.

Thus, at the time of recording, the controller 1
1 is this PLL circuit 16 (1/128 counter 17)
The operation is controlled so that the data is recorded on the optical information recording medium in synchronization with the basic clock of the 32-times output of the wobble signal obtained by. At this time, the delay time of the wobble detection signal (binarization signal) by the phase delay correction variable bit shift register 19 is set to zero. On the other hand, at the time of reproduction, the sync signal (preamble) area on the optical information recording medium (the mark length is T / 2, so that the basic clock cycle is T).
Area where continuous marks with space length T / 2 are recorded)
Of the wobble signal of the PLL circuit 16 by reproducing the signal of
The phase difference with the doubled output is compared. That is, since a continuous mark synchronized with the basic clock of the 32 × output of the wobble signal is recorded in this preamble area during recording, this phase difference (corresponding to Td in FIG. 12) is deviated from the recorded data during reproduction. Becomes Therefore, it is necessary to generate a reproduction clock in which this deviation is corrected.

In the basic circuit shown in FIG. 13, a phase delay correction variable bit shift register 19 for correcting this phase difference is provided on the input side of the PLL circuit 16. Also, a 128-base counter 2 for detecting the phase difference
0 is provided on the output side of the PLL circuit 16. To measure this phase difference, 128 × 32 =
A control clock of 4096 multiplication is used. This one
The 28-ary counter 20 is connected to a digital differentiating circuit 21 having a rising differential structure for controlling the start (trigger) of the counting operation based on the output of the wobble signal multiplied by 32. That is, the time from the rise of the clock of the wobble signal multiplied by 32 (the output of the 1/128 counter 17) is counted by the 128-ary counter 20 with the 4096 multiplied clock. The phase difference data counted by the 128-ary counter 20 is stored in the register 37 at the rising timing of the sync signal pulse coming from the pre-angle area. The output of this register 37 is the controller 1
Sent to 1. The timing generation to be latched by the above-mentioned register is generated by such a circuit. Controller 1
Based on the designation of the preamble area from 1, the AND gate 23 for controlling the register 37 to latch the output of the 128-ary counter 20 at the rising timing of the synchronization signal pulse in the preamble area, the digital differentiating circuit 24 of the rising differentiating configuration, and An AND gate 25 is provided.

The latch signal output from the AND gate 25 is also input to the controller 11 as an interrupt signal INT. The controller 11 uses this interrupt signal I
When NT is received, the phase difference information of the register 37 is received.
Since the interrupt signal INT is input by the number of sync pulses in the preamble area, the controller 11 receives a plurality of pieces of phase difference information. The controller 11 performs arithmetic processing using the plurality of pieces of phase difference information, and sends more accurate phase difference information to the register 22. In the information processing, for example, the abnormal phase difference information is removed, and the averaging process is performed thereafter. Then, the phase delay correction variable bit shift register 11 delays the wobble signal binarized by the information set in the register 22. This input signal causes the PLL circuit 16
Is operated, the generated reproduction clock can realize highly reliable data part multi-valued data reproduction.

FIG. 14 shows an example of the configuration of the phase delay correction variable bit shift register 19. The phase delay correction variable bit shift register 19 includes a digital differentiating circuit 26 that performs a rising differentiating operation on a wobble detection signal, a flip-flop 27 that outputs an enable signal EN every time the output of the digital differentiating circuit 26 is input, When the data of the phase delay amount latched in the register 22 is preset and the output of the flip-flop 27 is enabled, the carry signal is output to the PLL circuit 16 when the phase difference is counted by the 4096 multiplication clock. It is composed of a presettable counter 28. With this configuration, a signal obtained by delaying the input signal by the delay information set by the register 22 can be obtained.

As the phase delay correction variable bit shift register 19, the wobble detection signal is input and the phase shift correction variable bit shift register 19 is latched in the register 22 and the register 22, which is shifted at the timing of the 4096 multiplication clock, as shown in FIG. Designated by a decoder 30 that converts the data of the phase delay amount, a plurality of AND gates 31 that match the output of the shift register 29 and the output of the decoder 30 for each bit, and the output of the decoder 30 of these AND gates 31. It may be configured by a combination in which the binarized wobble detection signal output from the gate that is delayed by the delay time set by the register 22 is output to the PLL circuit 16 through the OR gate 32. .

FIG. 16 shows a configuration example of the digital differentiating circuit 21, 24 or 26. Digital differentiating circuit 21,
Reference numeral 24 or 26 inputs the signal to be differentiated to two-stage connected JK type flip-flops 33 and 34, and a combination of the inputs and outputs thereof, depending on whether it is a rising differential or a falling differential by AND gates 35 and 36. Is configured to switch the output. In the present embodiment, both are AND gates 35.
It is considered to be a rising differential method using the output of.

FIG. 17 shows the relationship between the binarized wobble detection signal (32T) used in the basic circuit shown in FIG. 13, the recording clock (T) and the control clock (T / 128). Shown in. Also, a synchronization signal pulse (a signal reproduced from a recording mark written in the preamble area)
Is the basic clock of 32 times output of wobble signal (record /
FIG. 18 shows the principle of detection in the case of being behind the reproduction clock). If the recording / reproducing clock (T) is at the H level at the rising edge of the synchronizing signal pulse, there is a phase delay.
The synchronizing signal pulse is always in a phase delay state as shown in FIG. In order to measure this phase delay amount Δ (phase difference), 128 × 32 = 40 for the wobble detection signal.
The 96-times control clock is used.

Based on such a principle, the 128-ary counter 20 has the digital differentiating circuit 21 in order to start counting at the rising edge of the 32 × output of the binarized wobble signal.
Is always triggered to start counting (actually, the 128-base counter 20 is cleared),
Then, the clock of 4096 multiplication output from the PLL circuit 16 is counted. Then, based on the designation of the preamble area from the controller 11, when the above-mentioned sync signal pulse in the preamble area comes as a reproduction binarized signal from the optical pickup (rising timing of the sync signal pulse), a 128-base counter is set in the register 37. Two
Since the output of 0 is latched, the output of the 128-ary counter 20 at that time is latched in the register 37 as the phase difference. A plurality of pieces of data (phase difference = phase delay amount) latched in the register 37 are taken into the controller 11, the controller 11 performs arithmetic processing, and the delay time of the phase delay correction variable bit shift register 19 is set based on the result. To be done. The phase delay correction variable bit shift register 19 outputs the wobble detection signal to the PLL circuit 16 side at a timing delayed by the data of the register 22 (phase difference = phase delay amount) by a clock of 4096 multiplication. Since the PLL circuit 16 operates in this state, the 32 × output of the wobble signal can be used as a clock (sampling signal) that can accurately reproduce multi-valued record data.

When the above-mentioned preamble area (synchronization signal area) is formed by phase pits and is recorded / reproduced, which is an effective method when the groove of the disk is formed by a track in which wobble is not performed, it is binarized in FIG. A recording / reproducing clock is generated by a circuit system that inputs an oscillator output that generates a 32T time period instead of the wobble detection signal input. During recording and reproduction, the recording or reproduction clock is adjusted to the phase of the sync signal pulse in the preamble area in the same manner as described above. Then, since the recorded data in the data portion causes a time delay during reproduction, as described above, after the reproduction clock is generated by the circuit configuration shown in FIG. 13, the time delay is estimated in advance to delay the reproduction clock. Alternatively, a pre-angle portion is formed at the beginning of the recording data portion, and the circuit configuration shown in FIG.

In the latter method, since the pre-angle portion at the head of the recording data portion only needs to be slightly corrected since it is already synchronized once in the synchronization signal area, it may be shorter than the normal preamble. That is, the PLL circuit 16 of FIG.
Since the pull-in operation has been completed, a slight correction will be sufficient. When the reproduction clock is phase-corrected by the sync signal clock in the preamble area in a multi-valued read-only disc (ROM), an oscillator output that generates a 32T time period instead of the binary wobble detection signal input in FIG. 13 described above. Is performed by the circuit system for inputting.

[0099]

According to the first aspect of the present invention, the address information or the record data is recorded as multivalued information of three or more values, and the reproduction signal is recorded in the area where the address information exists or the data area in which the record data is recorded. Is included in the pattern, and the CAV method, the ZCAV method, or the ZCLV method is included.
An optical information recording medium in which information is recorded on a track by a method, wherein a normalization pattern area composed of a pattern sequence for normalizing the reproduction signal is circular so that adjacent tracks do not overlap each other in the radial direction. Since it is shifted in the direction, the normalization pattern area is not affected by the crosstalk signal because the normalization pattern areas do not overlap between adjacent tracks when reproducing multilevel information of the reproduction signal. Signal can be detected, and influences such as fluctuations in reflectance of the optical disk, fluctuations due to machine accuracy, fluctuations in recording / reproducing power can be eliminated.

According to the second aspect of the invention, in the optical information recording medium according to the first aspect, since the adjacent track of the normalized pattern area is a non-signal area where no mark exists, reproduction from the normalized pattern is performed. It is possible to prevent the influence of crosstalk on the signal.

According to the third aspect of the invention, in the optical information recording medium according to the first or second aspect, the normalization pattern area is a combination of a plurality of mark rows of the same size and a non-signal area. By setting the length ML1 of the mark row, the length ML2 of the non-signal area, and the spot diameter BD of the recording / reproducing beam in the relationship of ML1> BD and ML2> BD, the reproduction signal level is increased. Providing a configuration of a normalized pattern region that normalizes the signal without being affected by the crosstalk signal when reproducing the valued information, and further generates a signal having a flat portion with respect to the normalized pattern region. Since the normalized pattern area is configured to be strong against deviations in sampling timing, it is possible to reduce fluctuations in reflectance of the optical information recording medium, fluctuations due to mechanical precision, fluctuations in recording / reproducing power, etc. Hibiki to can be accurately removed.

According to the invention of claim 4, claim 1,
In the optical information recording medium described in 2 or 3, since the address information in which the position information is more important than the signal level is formed by the phase pits, it is possible to record and reproduce the address information with high reliability.

According to a fifth aspect of the present invention, in the optical information recording medium according to any one of the first to fourth aspects, the pattern of the pattern sequence for normalizing the reproduction signal is a combination that does not exist in the data area. By setting the pattern
It is possible to improve the detection accuracy of the pattern string that normalizes the reproduction signal.

According to a sixth aspect of the present invention, in the optical information recording medium according to any one of the first to fifth aspects, the front or rear of the area where the address information exists, or
A sync signal area including a preamble signal for generating a timing signal at the time of data reproduction is provided in front of the data area,
This sync signal area is formed by phase pits that are recorded as binary information in such a manner as to overlap each other in the radial direction between adjacent tracks, so that the preamble can be used when recording and reproducing the information in which the level of the reproduction signal is multivalued. With regard to the sync signal area that includes signals, the fact that there is no shift in the peak positions of the signals between adjacent tracks makes it possible to arrange them so that they overlap each other, that is, are arranged in the radial direction. , Can be accurately detected using crosstalk,
The format efficiency can be improved, and multi-valued data is sampled based on the synchronization signal formed with the phase pits with high accuracy. Therefore, the multi-valued data can be sampled with high accuracy, and the demodulation error due to the timing deviation can be reduced. You can

According to the invention of claim 7, claim 1,
In the optical information recording medium described in 2, 5, or 6, the wobble basic period of the groove or land forming the track is in the CAV recording area or in the ZCAV recording or ZC recording.
The number of wobbles in each track is the same in the zone area of the LV system, and the adjacent tracks in which the wobbles are not modulated meander in a uniform phase, so that the level of the reproduction signal is multivalued. At the time of recording / reproducing, the phase shift due to the crosstalk caused by the wobble can be reduced, the multi-valued data can be sampled accurately, and the demodulation error due to the timing shift can be reduced.

According to the eighth aspect of the present invention, when recording / reproducing information in which the level of the reproduction signal is multi-valued on the optical information recording medium according to the seventh aspect, the normalization pattern area and the synchronization signal area are wobbled. Not, or because it is a wobble of a constant cycle without modulation, there is no disturbance due to wobble in the detection of the normalization pattern or synchronization signal, it is possible to detect a more reliable normalization pattern or synchronization signal, As a result, it is possible to accurately remove the influence of the fluctuation of the reflectance of the optical information recording medium, the fluctuation of the mechanical accuracy, the fluctuation of the recording / reproducing power, and the like.

According to the information recording / reproducing method of the invention described in claim 9, the optical information recording medium according to claim 7 is targeted, and the rotation of the drive source for rotationally driving the optical information recording medium based on wobble information is performed. When controlling and recording, a recording pulse for recording multi-valued information from the wobble information is generated, and multi-valued data is recorded at a target address position based on the address information, and at the time of reproduction, level fluctuation of a reproduction signal based on a normalized pattern. Since the sampling position is determined based on the sync signal and multi-valued data is played back, crosstalk from adjacent tracks is reduced when recording and playing back multi-valued information of the playback signal level. The multi-valued data is sampled based on the information of both the wobble signal and the synchronization signal formed by the phase pits. Accurately be sampled, it is possible to reduce the demodulation error due to timing misalignment.

According to the crosstalk removing method of the tenth aspect of the present invention, there are provided a reproduction track as a target for the optical information recording medium of the second or third aspect and two adjacent tracks adjacent to the reproduction track. On the other hand, when reproducing the normalized pattern area of the optical information recording medium by allocating a reproducing beam to each of them, the magnitude of the crosstalk signal from the mark train of the adjacent track is detected in the non-signal area, and based on this detection result Since the correction coefficient for correcting the crosstalk is learned, the influence of the crosstalk signal can be estimated by the normalized pattern when recording / reproducing the information in which the level of the reproduction signal is multivalued. It is not necessary to separately provide a learning area for crosstalk, the format efficiency can be increased, and the crosstalk signal can be accurately removed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a basic format example of a first embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a configuration example of a normalized pattern that is not affected by crosstalk.

FIG. 3 is a schematic diagram showing an example of the format.

FIG. 4 is an explanatory diagram showing a mark row shape and the like.

FIG. 5 is an explanatory diagram showing a configuration example of a normalization pattern and a synchronization signal according to a second embodiment of the present invention.

FIG. 6 is a schematic diagram showing a format example of a third embodiment of the present invention.

FIG. 7 is a schematic diagram showing a format example of a fourth embodiment of the present invention.

FIG. 8 is a schematic diagram showing a three-beam measurement method according to a fifth embodiment of the present invention.

FIG. 9 is a waveform diagram showing an example of the reproduced signal.

FIG. 10 is a schematic diagram showing a wobble shape of a groove according to a sixth embodiment of the present invention.

FIG. 11 is a waveform diagram showing the wobble detection signal.

FIG. 12 is a timing chart showing a deviation between recorded data and a reproduced signal.

FIG. 13 is a circuit diagram showing a basic configuration example.

FIG. 14 is a block diagram showing a configuration example of the phase delay correction variable bit shift register.

FIG. 15 is a block diagram showing another configuration example of the phase delay correction variable bit shift register.

FIG. 16 is a block diagram showing a configuration example of a digital differentiating circuit.

FIG. 17 is a timing chart showing a relationship among a wobble detection signal, a recording clock, and a control clock.

FIG. 18 is a timing chart for explaining a principle of detecting a phase difference between a reproduction clock and a recording clock.

FIG. 19 is a schematic diagram for explaining a multilevel information recording method.

FIG. 20 is an explanatory diagram showing a level variation of a reproduction signal due to a crosstalk signal.

FIG. 21 is an explanatory diagram showing a conventional example of a minimum value detection method.

FIG. 22 is an explanatory diagram showing a problem of crosstalk in the synchronization signal area.

[Explanation of symbols]

A signalless area B Normalized pattern area C sync signal area D data area

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI theme code (reference) G11B 7/24 561 G11B 7/24 561Q 11/105 511 11/105 511F 516 516A 521 521J 586 586B (72) Inventor Hirofumi Sakagami 1-3-6 Nakamagome, Ota-ku, Tokyo (72) Inventor Yuichi Kadokawa 1-3-6 Nakamagome, Tokyo Ota-ku, Tokyo (72) Inventor, Koji Takeuchi F-terms within Ricoh Co., Ltd., 1-3-6 Nakamagome, Ota-ku, Tokyo (reference) 5D029 JB11 JB33 JB46 5D075 CC23 FF15 FG18 5D090 AA01 BB12 BB20 CC01 CC04 DD03 DD05 EE13 EE17 GG02 GG03 GG11 HH01 KK01

Claims (10)

[Claims] 1. A CAV in which address information or recorded data is recorded as multi-valued information of three or more values, and a pattern for normalizing a reproduction signal is included in an area where the address information exists or a data area where recorded data is recorded. Method or ZC
An optical information recording medium in which information is recorded on a track by an AV system or a ZCLV system, wherein normalized pattern areas formed by a pattern sequence for normalizing the reproduction signal do not overlap each other in the radial direction between adjacent tracks. The optical information recording medium is characterized by being shifted in the circumferential direction as described above. 2. The optical information recording medium according to claim 1, wherein a track adjacent to the normalized pattern area is a non-signal area where no mark exists. 3. The normalized pattern area is composed of a combination of a plurality of mark rows of the same size and a non-signal area, the length of the mark row ML1, the length of the non-signal area ML2, and recording. 3. The optical information recording medium according to claim 1, wherein the spot diameter BD of the reproducing beam is set to satisfy the relationship of ML1> BD and ML2> BD. 4. The optical information recording medium according to claim 1, wherein the address information is formed by phase pits recorded as the same multivalued information as the recording data. 5. The optical information recording according to claim 1, wherein the pattern of the pattern sequence for normalizing the reproduction signal is a combination pattern that does not exist in the data area. Medium. 6. A sync signal area including a preamble signal for generating a timing signal at the time of data reproduction is provided in front of or behind the area in which the address information exists, or in front of the data area. 6. An optical information recording medium according to claim 1, wherein the optical information recording medium is formed by phase pits recorded with binary information, which are arranged so as to overlap each other in the radial direction between adjacent tracks. 7. The wobble number is the same in each of the tracks where the wobble basic period of the groove or land forming the track is the same in the CAV recording area or the ZCAV or ZCLV zone area, and the wobble is modulated. 7. The optical information recording medium according to claim 1, 2, 5 or 6, characterized in that the phases of the periods are aligned and meander in the non-adjacent tracks. 8. The optical information recording medium according to claim 7, wherein, in the normalized pattern area or the sync signal area, tracks including adjacent tracks are wobbles having no wobble or no modulation and having a constant period. 9. The optical information recording medium according to claim 7, wherein the rotation of a drive source that rotationally drives the optical information recording medium is controlled based on wobble information, and at the time of recording, multi-valued information is obtained from the wobble information. A multi-valued data is recorded at a target address position based on the address information while generating a recording pulse for recording, and at the time of reproduction, the level fluctuation of the reproduction signal is removed based on the normalization pattern and the sampling position is determined based on the synchronization signal. An information recording / reproducing method characterized by reproducing multi-valued data. 10. The optical information recording medium according to claim 2 or 3, wherein a reproduction beam is assigned to each of a target reproduction track and two adjacent tracks adjacent to the reproduction track. When reproducing the normalized pattern area of, the magnitude of the crosstalk signal from the mark row of the adjacent track is detected in the non-signal area, and the correction coefficient for correcting the crosstalk is learned based on the detection result. Crosstalk removal method.