JP2004335066A - Optical storage medium, information-recording device, and information-reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical storage medium which can prevent effectively illegal use of the optical storage medium, accompanied by a copyright infringement free from impairing the function of reproducing physical format information and optical storage-medium manufacture information. <P>SOLUTION: This optical storage medium is provided with a main information area 41b, where enciphered data information is recorded as a pit string which can be read through light, and a control data area 41a. On the control data area 41a, key information for solving the cipher of data information, physical format information, and optical storage-medium manufacture information are recorded by wobbling grooves. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical storage medium and an information recording / reproducing apparatus for recording or reproducing information on or from the optical storage medium, and more particularly to a video or audio for protecting a copyrighted work from unauthorized duplication. And an information recording / reproducing apparatus for recording / reproducing information on / from the optical recording medium on which the recording signal is encrypted and recorded.
[0002]
[Prior art]
An optical disk represented by a DVD (Digital Versatile / Video Disc) is widely used as a medium for recording large-capacity digital data such as AV (Audio Visual) data and a computer. For example, high-quality moving images of two hours or more are recorded and sold. In order to prevent such digital works from being illegally copied to another recording medium, a method called content encryption is adopted (for example, see Non-Patent Document 1).
[0003]
In this method, a compressed digital work such as a movie is encrypted using a three-layer secret key (title key, disk key, master key) and recorded in a user area accessible to the user. . The most important master key among the secret keys is notified only to the authorized manufacturer, and the disc key and title key required for each DVD and each title are encrypted based on the master key. Are stored in a control information area that cannot be accessed by the user. As a result, the user is restricted from accessing the private key required for decryption, and cannot perform illegal copying by file copying or the like. However, such a technique cannot cope with an illegal act in which the contents of the entire area including the control information area in which the secret key is recorded are illegally copied to another optical disk as it is.
[0004]
Therefore, as shown in FIG. 53, by recording a unique pit sequence (B in FIG. 53) in which the recording marks recorded on the optical disk are displaced in the frame direction (A in FIG. 53) in the radial direction, a legitimate optical disk can be identified. There has been proposed a method of determining whether an optical disk has been copied to an optical disk (for example, Patent Document 1).
[0005]
The existence of such a unique pit row can be detected by a burst TE signal (D in FIG. 53) generated from the tracking error signal (C in FIG. 53). Therefore, it is possible to count the number of frames whose signal levels match in the internally generated reference signal and the burst TE signal, and determine whether the medium is a legitimate medium or a copied medium based on this count value. it can.
[0006]
As described above, even if the optical disc whose recording mark is displaced in the radial direction is copied by a normal method, no unique pit is generated in the copied optical disc. For this reason, it is possible to determine the optical disk that has been illegally copied.
[0007]
[Patent Document 1]
Japanese Patent No. 3061098
[0008]
[Non-patent document 1]
ITE Technical Report Vol. 21, no. 31 pp. 15-19
[0009]
[Problems to be solved by the invention]
However, by recording the pit string by wobbling, the allowable range for off-track is narrowed accordingly, and the reliability of the optical storage medium and the information reproducing apparatus is reduced. In order to ensure the reliability, the pitch of the track for recording the pit row must be increased by the amount of the wobble, and there is a problem that the recording capacity is reduced accordingly.
[0010]
Further, in the above-described conventional technology, since the disc is determined based on only the existence of the unique pit, it is necessary to generate an arbitrary unique pit string at that position as long as the position where the unique pit exists becomes clear. This allows illegal copying. As a result, there is a possibility that an unauthorized distribution of digital contents may be hindered by a large number of copied digital works created by an unauthorized disk creator who has not received a license.
[0011]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and it is possible to accurately identify an optical storage medium without lowering a recording capacity and to perform optical storage with copyright infringement. It is an object of the present invention to provide an optical storage medium capable of effectively preventing illegal use of a medium, and an information recording / reproducing apparatus for recording and reproducing information on and from the optical storage medium.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a first optical storage medium according to the present invention comprises: a main information area in which information is recorded as a row of concave or convex marks readable through light; An optical recording medium having an information recording layer having an area, wherein the control data area wobbles a concave or convex groove with respect to a side on which light enters the optical storage medium information relating to the optical storage medium. It is characterized by being recorded by doing.
[0013]
In order to achieve the above object, a second optical storage medium according to the present invention has a main information area in which information is recorded as a mark train readable via light, and a control data area. An optical storage medium having an information recording layer, characterized in that optical storage medium information relating to the optical storage medium is recorded in the control data area by wobbling a mark sequence.
[0014]
In order to achieve the above object, a third optical storage medium according to the present invention has a main information area in which information is recorded as a mark string readable via light, and a control data area. An optical storage medium provided with an information recording layer, wherein information on an optical storage medium relating to the optical storage medium is recorded in a mark sequence in the control data area, and a mark sequence recorded in the main information area is wobbled. And the track pitch is Tp₂, The maximum amplitude of the displacement amount of the wobble is Tp₂/ 30 or less.
[0015]
In order to achieve the above object, a fourth optical storage medium according to the present invention includes a main information area in which information is recorded as a mark string readable via light, and an optical storage medium related to the optical storage medium. A plurality of information recording layers having a control data area in which medium information is recorded, and optical control medium information relating to all information recording layers in a control data area of any one of the plurality of information recording layers. Is recorded.
[0016]
In order to achieve the above object, an information reproducing apparatus according to the present invention has a structure in which encrypted main data information is recorded in a main information area, and key information for decrypting the main data information, or an authorized manufacturing method. The optical storage medium information including identification information indicating that the optical storage medium has been subjected to the reproduction or that the information may be reproduced, wobble a concave or convex groove with respect to the mark row or the side on which light is incident. An optical pickup for irradiating the optical storage medium recorded in the control data area with light to read main data information and optical storage medium information recorded on the optical storage medium, and a signal read by the optical pickup. Key information detecting means for detecting the key information based on the key information, and demodulating means for decrypting the main data information based on the key information detected by the key information detecting means. The features.
[0017]
In order to achieve the above object, a fifth storage medium according to the present invention is an optical storage medium in which main information is recorded in frame units with a synchronization code by an optically readable recording mark, In at least a part of the frame, at a portion where the synchronization code is not recorded, the recording mark is displaced minutely toward the outer peripheral side of the optical storage medium with respect to a standard position or minutely displaced toward the inner peripheral side. The sub-information is recorded by forming at the position.
[0018]
In order to achieve the above object, an information recording apparatus according to the present invention is an information recording apparatus that records main information on an optical storage medium in frame units to which a synchronization code is added by optically readable recording marks. A modulation unit that modulates the main information and inserts a synchronization code at predetermined intervals; a displacement control signal generation unit that generates a displacement control signal based on a timing at which the synchronization code is inserted; A sub-information recording section for recording sub-information by displacing the recording mark by a small amount toward the outer periphery or the inner periphery by a control signal.
[0019]
In order to achieve the above object, a second information reproducing apparatus according to the present invention is an apparatus for reproducing main information from a recording mark formed on an optical disc in a frame unit accompanied by a synchronization code, A radial phase difference detection unit that detects a displacement in a radial direction, a clock extraction unit that extracts a reference clock signal synchronized with the reproduction signal from the reproduction signal of the recording mark, and detects the synchronization code from the reproduction signal; A reproduction signal processing unit that demodulates the reproduction signal, a correlation sequence generation unit that generates a correlation sequence based on the timing at which the synchronization signal is detected, and a radial phase difference signal generated by the radial phase difference detection unit. A sub-information detecting unit that detects sub-information by using the correlation sequence.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
In the first optical storage medium of the present invention, optical storage medium information relating to the optical storage medium is recorded in the control data area by wobbling a concave or convex groove with respect to the light incident side. . The optical storage medium information includes, in addition to the physical format information and the optical storage medium manufacturing information, key information for decoding data information encrypted and recorded in the main information area. In this way, by recording the optical storage medium information by wobbling the groove in the control data area, it is possible to provide an optical storage medium capable of accurately identifying each medium without reducing the recording capacity. Further, since the optical storage medium information including the key information is recorded by wobbling the groove, it is difficult to illegally copy this optical storage medium information to another optical storage medium. Thereby, illegal use of the optical storage medium with infringement of the copyright of the data information can be effectively prevented.
[0021]
In the second optical storage medium of the present invention, information of the optical storage medium relating to the optical storage medium is recorded in the control data area by wobbling the mark string. The optical storage medium information includes physical format information, optical storage medium manufacturing information, and the like. As described above, by recording the optical storage medium information by wobbling the mark string in the control data area, it is possible to provide an optical storage medium capable of accurately identifying each medium without reducing the recording capacity. . In addition, since the mark string is recorded by being wobbled, it is difficult to illegally copy this optical storage medium information to another optical storage medium.
[0022]
Further, in the third optical storage medium, since the mark row in the main information area is wobbled, illegal duplication can be prevented. Furthermore, the track pitch is set to Tp₂, The maximum amplitude of the displacement amount of the wobble is Tp₂When the ratio is / 30 or less, the influence of crosstalk can be completely ignored.
[0023]
The fourth optical storage medium records any one of the plurality of information recording layers by recording the optical storage medium information on all the information recording layers in the control data area of any one of the information recording layers. By accessing the control data area of a layer, it is possible to obtain optical storage medium information on all information recording layers. Thereby, the learning time can be reduced.
[0024]
According to the information reproducing apparatus of the present invention, by reading the optical storage medium information recorded by wobbling concave or convex grooves or mark rows with respect to the light incident side from the control data area, Can be accurately identified. In addition, by performing information reproduction using the key information detected from the optical storage medium information, illegal use of the optical storage medium with infringement of copyright can be effectively prevented. It goes without saying that the information reproducing apparatus of the present invention is not limited to a reproduction-only apparatus, but includes an apparatus having a recording function and the like.
[0025]
In the first or second optical storage medium, it is preferable that the information recorded in the main information area is recorded as a concave or convex mark row with respect to the light incident side. By recording information in both the main information area and the control data area as a mark array, the molding pressure when manufacturing the optical storage medium can be reduced, and the cost of the molding machine can be reduced. Further, it is preferable that the mark row is wobbled. Thereby, unauthorized duplication can be more reliably prevented.
[0026]
In the second optical storage medium, it is preferable that a mark row recorded in the main information area is a mark row that is concave or convex with respect to a side on which light is incident.
[0027]
In the second or third optical storage medium, the track pitch in the control data area is set to Tp.₁And the mark width is Mw₁And when
0.3 × Tp₁≦ Mw₁≦ 0.7 × Tp₁
Is preferably established. This is because, even when a manufacturing error of the mark width occurs, the influence on the recorded optical storage medium information is small.
[0028]
In the second or third optical storage medium, the width of the mark recorded in the control data area is set to Mw.₁And the width of the mark recorded in the main information area is Mw₂And when
Mw₁> Mw₂
Is preferably established. This is because good signals can be obtained for both the information recorded in the main information area and the information recorded in the control data area. In this configuration, the track pitch in the main information area is Tp₂, Mark width Mw₂And when
Mw₂<0.5 × Tp₂
Is more preferably satisfied. This is because even if a mark width production error occurs, the influence on the reproduction signal is small.
[0029]
In the second or third optical storage medium, the displacement of the wobble is preferably performed at the timing of the space in the mark row. By displacing the wobble in the space portion, the signal is hardly affected by the cutting machine, and good signal detection becomes possible. Further, it is preferable to have a plurality of conversion tables for finely adjusting the recording operation by the apparatus for recording the mark sequence so that the displacement of the wobble is set to the timing of the space in the mark sequence. This makes it possible to appropriately adjust the timing of the displacement of the wobble, thereby preventing jitter deterioration.
[0030]
In the second or third optical storage medium, it is preferable that information recorded in the control data area is represented by an edge portion of the mark. This is because the same S / N as in the case where the continuous groove is wobbled can be secured, so that the information recorded in the control data area can be detected with high reliability. In the second optical storage medium, it is also preferable that information recorded in the control data area is represented by a central portion of the mark. This is because the influence of the jitter is small and the information recorded in the control data area can be detected with high reliability.
[0031]
In the second or third optical storage medium, the mark string has a synchronization pattern used at the time of reproducing information at a specific cycle, and wobbles are performed in synchronization with the synchronization pattern. preferable. This is because a clock signal can be generated from a mark row, and a signal can be stably detected even when the wobble amount is minute.
[0032]
In the above configuration, the cycle of one synchronization pattern is Cy₁And the cycle of the wobble is Cy₂And when
Cy₂= Cy₁× M / 2 (M is a natural number)
Relationship, or
Cy₁= Cy₂× M / 2 (M is a natural number)
Is preferably established. According to this preferred configuration, it is possible to avoid the influence of bit slip. When the latter relationship is satisfied, it is possible to detect a signal at the timing of the synchronization pattern.
[0033]
In the second or third optical storage medium, the length of a mark recorded in the control data area is set to ML.₁And, when the wavelength of the light emitted when recording the mark is λ, and the numerical aperture of the optical system for irradiating the light is NA,
ML₁≧ 2 × λ / NA
Is preferably established. This is because a signal having a sufficiently large amplitude can be obtained without using an equalizer when generating a clock signal.
[0034]
In the second or third optical storage medium, the length of a mark recorded in the control data area is set to ML.₁And, when the wavelength of the light emitted when recording the mark is λ, and the numerical aperture of the optical system for irradiating the light is NA,
ML₁≧ λ / (2 × NA)
It is also preferable that the following relationship holds. This is because a clock signal can be generated using a signal obtained from repetition of a mark and a space.
[0035]
In the second or third optical storage medium, it is preferable that the length of each of the mark and the space recorded in the control data area is an integral multiple of the predetermined period T based on the predetermined period T. Further, it is preferable that each of the mark and the space has a single length or a plurality of types of lengths.
[0036]
In the first to third optical storage media, information recorded in a main information area is encrypted data information, and the optical storage medium information includes key information for decrypting the data information. Is also good. According to this configuration, it is possible to effectively prevent illegal use of the optical storage medium with copyright infringement. Further, it is preferable that the key information is recorded by wobbling a concave or convex groove or mark array. It is more preferable that the key information be represented by the center of the wobble. In addition, in the first to third optical storage media, instead of the key information, a configuration including identification information indicating that the optical storage medium is a properly manufactured optical storage medium or that information may be reproduced. It is good.
[0037]
In the first to third optical storage media, it is preferable that the wobble period is longer than the length of a pair of the mark and the space. This is because the influence of the adjacent track can be reduced. It is more preferable that the wobble cycle is at least four times the length of the pair of the mark and the space.
[0038]
In the first to third optical storage media, the wobble period is preferably an integral multiple of the predetermined period T based on the predetermined period T. This is because wobble-modulated optical storage medium information can be detected using a clock signal that can be generated from repetition of marks and spaces.
[0039]
In the first to third optical storage media, the optical depth of the mark or groove recorded in the control data area is Md.₁And, when the wavelength of light emitted when recording the mark or groove is λ,
λ / 8 ≦ Md₁≤λ / 4
Is preferably established. This is because a high-quality signal can be obtained.
[0040]
In the first to third optical storage media, it is preferable that a wobble frequency in the control data area is higher than a tracking servo band.
[0041]
In the first to third optical storage media, it is preferable that the wobble does not have a DC component in the tracking servo band. This is because stable tracking becomes possible.
[0042]
In the first to third optical storage media, the timing at which the wobble is displaced is preferably pseudo-random. This is because decryption becomes more difficult.
[0043]
In the first to third optical storage media, it is preferable that a plurality of wobbles are assigned to one bit of the key information. This is because a DC component or a low frequency component can be canceled at the time of signal detection, and the S / N is improved.
[0044]
In the first to third optical storage media, the key information is preferably recorded discretely or continuously. Discrete recording is advantageous in that the degree of difficulty of decryption is improved, and continuous recording is advantageous in that the time required for reading is reduced and the user's waiting time during reproduction is reduced. .
[0045]
In the first to third optical storage media, it is preferable that a buffer area having a groove or a mark that does not hinder reading is provided at a boundary between the control data area and the main information area. This groove or mark row may be concave or convex with respect to the side on which light is incident. This is because a good quality tracking error signal can be obtained even at the boundary between the control data area and the main information area.
[0046]
In the first or second optical storage medium, the track pitch Tp of the control data area₁Is the track pitch Tp of the main information area.₂Preferably, it is different. Also, the track pitch Tp of the control data area₁Is the track pitch Tp of the main information area.₂It is preferably larger than. This is because a reproduction signal and a tracking error signal of good quality can be obtained for both the control data area and the main information area.
[0047]
The first to third optical storage media each include a plurality of the information recording layers, and information is recorded as a concave or convex mark row in a main information area of at least one information recording layer of the plurality of information recording layers, The optical storage medium information on all the information recording layers may be recorded in the control data area of at least one of the plurality of information recording layers. Accordingly, by accessing the one information recording layer, it is possible to obtain the optical storage medium information for all the information recording layers, so that the learning time can be reduced.
[0048]
In the first to third optical storage media provided with the plurality of information recording layers or the fourth optical storage medium, an optical storage medium relating to all information recording layers is provided in each control data area of the plurality of information recording layers. Preferably, information is recorded. This is because, regardless of which information recording layer is focused, optical storage medium information on all information recording layers can be read, and the optical storage medium can be correctly identified.
[0049]
In the first to third optical storage media or the fourth optical storage medium provided with the plurality of information recording layers, an optical storage medium for all information recording layers is provided in a control data area in a reference layer of the optical storage medium. Preferably, information is recorded.
[0050]
In the first to third optical storage media provided with the plurality of information recording layers, or the fourth optical storage medium, the control data area of at least one of the plurality of information recording layers includes the plurality of information recording layers. Preferably, information on the polarity of the tracking error signal is recorded. More preferably, the information on the polarity of the tracking error signal is recorded in a control data area in a reference layer of the optical storage medium or in a control data area in all information recording layers of the optical storage medium. This is because the time for learning the polarity of the tracking error signal during reproduction of the optical storage medium can be reduced.
[0051]
In the first to third optical storage media provided with the plurality of information recording layers, or the fourth optical storage medium, the control data area in at least one of the plurality of information recording layers, It is preferable that recording layer information relating to a surface shape formed for recording information is recorded. The recording layer information is information indicating whether the recording form of information in the control data area is a concave groove, a convex groove, a concave mark, or a convex mark with respect to the light incident side. is there. More preferably, the recording layer information includes information on a depth of the surface shape.
[0052]
The first to fourth optical storage media are optical storage media having, as the information recording layer, at least two types of information recording layers of a read-only type, a write-once type, and a rewritable type. The information may be recorded at approximately the same radial position in the control data area. This configuration is preferable in that the time for learning the polarity of the tracking error signal during reproduction of the optical storage medium can be reduced.
[0053]
The information reproducing apparatus includes: a determination unit configured to determine whether the optical storage medium has been illegally copied in accordance with a detection result of the key information detection unit; and an optical storage medium to be reproduced is illegally copied. It is preferable that a reproduction prohibition unit that prohibits reproduction of information from the optical storage medium when the determination unit determines that the information is stored is further provided. Thereby, illegal duplication can be effectively eliminated.
[0054]
In the information reproducing apparatus according to the present invention, it is further preferable that the reproduction prohibiting means stops outputting a signal from the demodulating means. Alternatively, it is preferable that the reproduction prohibiting means discharges the optical storage medium to be reproduced from the information reproducing apparatus. Further, when the determination means determines that the optical storage medium to be reproduced has been illegally copied, the apparatus further comprises warning means for warning that the optical storage medium is illegally copied. Is preferred. With these configurations, illegal duplication of the optical storage medium can be more reliably eliminated.
[0055]
The information reproducing apparatus of the present invention has, as the optical storage medium, at least two types of information recording layers of a read-only type, a write-once type, and a rewritable type, and the optical storage medium information has a common control data area. It is preferable to use an optical storage medium recorded at a position using a common modulation method. Thereby, it is possible to realize an information reproducing apparatus capable of preventing unauthorized duplication on an optical storage medium having various types of information recording layers.
[0056]
The information reproducing apparatus of the present invention, if the key information detecting means does not detect the key information, if the determining means can detect a duplicatable identifier from a signal read from an optical storage medium by the optical pickup, It is preferable to determine that the optical storage medium has not been illegally copied. This is because it is possible to prevent the information that does not need to be prohibited from being excessively protected from being excessively protected, and to ensure the convenience of the user.
[0057]
In the information reproducing apparatus of the present invention, it is preferable that the wobble detection means used for detecting the wobbled signal is a differential operation means or a phase comparison means. If the differential operation means is used, the configuration of the detection system can be simplified. If the phase comparison means is used, it is not affected by the DC component, so that the reliability can be improved.
[0058]
The information reproducing apparatus of the present invention preferably demodulates key information using signals obtained from a plurality of wobbles. This is because the reliability is improved. Also, as the number of wobbles used to obtain key information is increased, the wobble amplitude can be reduced, and the influence of crosstalk is reduced.
[0059]
It is preferable that the information reproducing apparatus of the present invention demodulates key information by integrating and averaging the signals output from the wobble detecting means. Note that the S / N is improved as the number of times of integration is increased, and the reliability of the read key information can be improved.
[0060]
It is preferable that the information reproducing apparatus of the present invention generates a clock signal using a signal obtained from a mark string, and detects key information using the clock signal. This is because a signal can be stably detected.
[0061]
It is preferable that the information reproducing apparatus of the present invention generates a clock signal using a signal obtained from the mark sequence in order to demodulate a signal obtained from the mark sequence, and detects key information using the clock signal. This is because the circuit configuration can be simplified.
[0062]
In the fifth storage medium, it is preferable that there is no displacement from the outer peripheral side to the inner peripheral side or no displacement from the inner peripheral side to the outer peripheral side in the recording mark.
[0063]
In the fifth storage medium, it is preferable that a displacement amount of the recording mark in a radial direction is within a radial displacement amount allowed in an optical storage medium on which the sub-information is not recorded.
[0064]
In the fifth storage medium, it is preferable that at least one bit of the sub information is recorded by slightly displacing recording marks of the plurality of frames in a radial direction. The plurality of frames are preferably a group of frames continuously arranged on a track of the optical storage medium or a group of frames discretely arranged at predetermined intervals on the track.
[0065]
In the fifth storage medium, it is preferable that the minute displacement in the radial direction is not performed on a specific frame and / or a specific region in the frame.
[0066]
In the fifth storage medium, it is preferable that the area where the sub-information is recorded by the minute displacement of the recording mark in the radial direction is a lead-in area in the optical storage medium.
[0067]
In the fifth storage medium, a portion where the synchronization code is not recorded in the frame is divided into a plurality of blocks having non-uniform lengths, and the recording mark is displaced minutely toward the outer side and the inner side for each block. It is preferable that the periods to be performed are different, and that the length of the recording mark displaced inwardly and the length of the recording mark displaced outwardly in each block be substantially equal. Further, in all the frames, it is preferable that the sum of the lengths of the recording marks displaced inwardly and the sum of the lengths of the recording marks displaced outwardly are substantially equal.
[0068]
In the fifth storage medium, a portion in which the synchronization code is not recorded in the frame is divided into a plurality of blocks each having a predetermined length, and a period in which the recording mark is slightly displaced toward the outer peripheral side and the inner peripheral side for each of the blocks. It is preferable that the sum of the lengths of the recording marks displaced toward the inner periphery and the sum of the lengths of the recording marks displaced toward the outer periphery are substantially equal in each block.
[0069]
In the fifth storage medium, a portion where the synchronization code is not recorded in the frame is divided into n blocks (n is a natural number of 4 or more) of a predetermined length, and the blocks are m blocks (m is 1 of n). ), The period for displacing the recording mark by a small amount to the outer peripheral side and the inner peripheral side is different, and the sum of the length of the recording mark displaced to the inner peripheral side in each block and the outer peripheral side It is preferable that the total length of the displaced recording marks is substantially equal.
[0070]
In the fifth storage medium, it is preferable that information necessary for reproducing the sub-information is recorded in a frame where the sub-information is not recorded by displacing a recording mark by a very small amount to an outer peripheral side and an inner peripheral side. . The information necessary for reproducing the sub information is, for example, an error correction code of the sub information.
[0071]
In the fifth storage medium, it is preferable that the recording mark displacement amounts toward the outer peripheral side and the inner peripheral side are determined based on a signal obtained by superimposing dummy information on the sub information.
[0072]
In the information recording apparatus according to the present invention, it is preferable that at least the synchronization code inserted in the frame unit is not subjected to a minute displacement in the radial direction.
[0073]
In the information recording apparatus according to the present invention, it is preferable that the displacement control signal is a signal obtained by spectrum-spreading sub-information using a pseudo-random number sequence initialized at a timing of inserting the synchronization code.
[0074]
In the information recording apparatus according to the present invention, it is preferable that the displacement control signal is PE-modulated so that the probability of displacement of the recording mark toward the outer periphery and the probability of displacement toward the inner periphery are substantially equal.
[0075]
In the information recording apparatus according to the present invention, the displacement control signal may make the probability of displacement of the recording mark toward the outer periphery and the probability of displacement toward the inner periphery substantially equal, and in a section where the recording mark is formed, the displacement control signal. It is preferable that no change point exists.
[0076]
In the information recording apparatus according to the present invention, it is preferable that at least one bit of the sub information is recorded in units of a plurality of frames. Further, it is preferable that the plurality of frames are a group of frames continuously arranged on a track of the optical storage medium or a group of frames discretely arranged at a predetermined interval.
[0077]
In the information recording apparatus according to the present invention, a portion in which the synchronization code is not recorded in the frame is divided into a plurality of blocks having non-uniform lengths, and the recording mark is slightly displaced toward an outer peripheral side and an inner peripheral side for each block. It is preferable to change the period of the recording and make the length of the recording mark displaced inwardly and the length of the recording mark displaced outwardly substantially equal in each block.
[0078]
In the information recording apparatus according to the present invention, it is preferable that the sum of the lengths of the recording marks displaced inward and the sum of the lengths of the recording marks displaced outward be substantially equal in all frames.
[0079]
In the information recording apparatus according to the present invention, a portion in which the synchronization code is not recorded in the frame is divided into a plurality of blocks each having a predetermined length, and a recording mark is displaced by a small amount to an outer peripheral side and an inner peripheral side for each block. It is preferable to make the sum of the lengths of the recording marks displaced inwardly in each block substantially equal to the sum of the lengths of the recording marks displaced outwardly in each block.
[0080]
In the information recording apparatus according to the present invention, a portion where the synchronization code is not recorded in the frame is divided into n (n is a natural number of 4 or more) blocks of a predetermined length, and the m blocks (m is 1 of n) The cycle of displacing the recording mark by a very small amount to the outer circumference and the inner circumference is different for each of the divisors, and the sum of the length of the recording mark displaced to the inner circumference in each block and the outer circumference It is preferable that the sum of the lengths of the recording marks displaced to be substantially equal to each other.
[0081]
In the information recording apparatus according to the present invention, information necessary for reproducing the sub-information is recorded in a frame where the sub-information is not recorded by displacing a recording mark by a very small amount toward an outer peripheral side and an inner peripheral side. Is preferred.
[0082]
In the information recording apparatus according to the present invention, it is preferable to determine a recording mark displacement amount toward an outer peripheral side and an inner peripheral side based on a signal in which dummy information is superimposed on the sub information.
[0083]
In the second information reproducing apparatus according to the present invention, it is preferable that the correlation sequence is generated by performing PE modulation on a pseudo-random number sequence initialized at a timing when the synchronization code is detected.
[0084]
In the second information reproducing apparatus according to the present invention, it is preferable that the correlation sequence has no change point in a section in which the recording mark is reproduced.
[0085]
In the second information reproducing apparatus according to the present invention, it is preferable that at least one bit of the sub information is extracted by reproducing the plurality of frames.
[0086]
In the second information reproducing apparatus according to the present invention, it is preferable that the sub information is not detected from at least the synchronization code in the frame.
[0087]
Hereinafter, embodiments of an optical storage medium and an information recording / reproducing apparatus according to the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals denote the same components or those having the same action and operation.
[0088]
(Embodiment 1)
FIG. 1 is a diagram showing an example of the configuration of an optical storage medium according to the present invention. The optical storage medium 41 has a control data area 41a and a main information area 41b. In the main information area 41b, a mark string from which encrypted data information can be read out via light is recorded as pits. On the other hand, in the control data area 41a, optical storage medium information including key information for decrypting the data information recorded in the main information area 41b is recorded by wobbling the groove. The optical storage medium information includes physical format information, optical storage medium manufacturing information, and the like, in addition to the key information.
[0089]
When the linear velocity when reproducing the information recorded on the optical storage medium 41 is about 5 m / s, the wobble frequency is about 1 MHz, and the modulation is performed at a frequency sufficiently higher than the tracking servo band. Information recorded on the optical storage medium 41 is read using an optical pickup having a wavelength λ of 400 to 420 nm and a numerical aperture NA of the objective lens of 0.8 to 0.9.
[0090]
FIG. 2 is an enlarged plan view showing a state near the boundary between the main information area 41b and the control data area 41a of the optical storage medium 41. Here, the track pitch Tp of the control data area 41a is₁Is 0.35 μm, the track pitch Tp of the main information area 41b.₂Is set to 0.32 μm. That is, the track pitch Tp of the control data area 41a₁Is the track pitch Tp of the main information area 41b.₂Wider than. This includes (1) a reproduction signal for reading information recorded in the main information area 41b, (2) a tracking error signal used for reading information recorded in the main information area 41b, and (3) a control data area 41a. This is in order to obtain good quality for both the reproduction signal when reading the information recorded in the control data area 41 and the tracking error signal used when reading the information recorded in the control data area 41a.
[0091]
From the viewpoint of signal quality, the quality of the reproduced signal when reading the information recorded in the main information area 41b is determined when the pit depth is λ / 4 when the cross section of the pit can be formed into an ideal rectangle. Become the best. Further, if the tracking error signal is detected by the phase difference method, the quality of the tracking error signal used when reading the information recorded in the main information area 41b becomes the best when the pit depth is λ / 4. On the other hand, a reproduction signal for reading information recorded in the control data area 41a and a tracking error signal used for reading information recorded in the control data area 41a are both formed by a push-pull method of performing a differential operation. For detection, when the groove cross section can be formed into an ideal rectangle, the quality is best when the groove depth is λ / 8. However, when the groove depth is set to λ / 4, which is the optimum depth for reading the information recorded in the main information area 41b, the worst and good signal cannot be obtained. Further, if the depth of the pit is smaller than λ / 8, the influence of the noise of the medium itself and the noise of the light source becomes noticeable, which is not preferable. Therefore, the depths of the grooves and pits need to be shallower than λ / 4 and deeper than λ / 8, and λ / 8 to λ / 5 are preferable. The pits and grooves that are actually formed have cross sections that are not ideal rectangles but have slopes, so that the equivalent depth is smaller than the actual depth. The influence of the slope is more remarkable in the tracking error signal detected by the push-pull method than in the information signal for reading out the information recorded in the main information area 41b. By providing the pits or grooves with a predetermined slope, even if the depths of the grooves and pits are set to λ / 4, an information signal for reading information recorded in the main information area 41b and tracking detected by the push-pull method The quality of both signals of the error signal can be kept high. That is, substantially equivalent groove and pit depths Md₁But,
λ / 8 ≦ Md₁≤λ / 4
, A high-quality signal can be obtained.
[0092]
FIG. 9 schematically shows a cross section of the pit. FIG. 9A shows a case where the cross section of the pit is formed in an ideal rectangular shape, and FIG. 9B shows a cross section of the pit. Each of the cases is shown as a trapezoid. Pt width₁The pit depth d₁When the cross section of the pit is rectangular as shown in FIG. 9A, the equivalent pit depth Md₁Is d₁It is as it is. On the other hand, when the cross section of the pit is trapezoidal as shown in FIG. 9B, the width of the trapezoidal slope is Pe.₁, The width of the trapezoidal base is Pd₁And the equivalent depth Md₁Is generally
Md₁= D₁× Pe₁/ Pt₁
Becomes Note that Pt₁= Pd₁+ 2 × Pe₁It is. Therefore, for example, the width Pd of the bottom of the pit₁Is zero, the equivalent depth Md₁Is d₁/ 2, the pit depth d₁Is equivalent to λ / 4, the equivalent depth Md₁Is λ / 8, and the tracking error signal detected by the push-pull method can obtain a large amplitude. Of course, when determining the actual depth, it is needless to say that the refractive index of the material constituting the optical storage medium must be considered.
[0093]
The optical storage medium 41 is provided with a buffer area 41c formed of a groove and a buffer area 41d formed of pits at a boundary between the control data area 41a and the main information area 41b, which does not hinder the read operation. I have. The buffer area 41c and the buffer area 41d are provided so that information recorded at the boundary between the control data area 41a and the main information area 41b can be read without any trouble, that is, even at the boundary between the control data area 41a and the main information area 41b. It is provided so that a good tracking error signal can be obtained.
[0094]
In the optical storage medium 41 of the present embodiment, optical storage medium information including duplication prevention information (key information) is recorded as a wobble signal modulated at a frequency sufficiently higher than the tracking servo band. For this reason, even if an attempt is made to copy the optical storage medium 41 using a normal information recording / reproducing apparatus, the groove subjected to the wobble modulation cannot be copied. Therefore, it is not possible to copy the optical storage medium 41 having the copy protection information. Can not. In this way, unauthorized duplication is effectively eliminated.
[0095]
The optical storage medium 41 can record information that can be copied. In this case, the data recorded in the main information area 41b does not need to be encrypted, and of course, no key information for decrypting the encryption is required, so that no key information is recorded in the control data area 41a.
[0096]
In addition, by recording an identifier capable of identifying whether or not the information recorded in the main information area 41b may be duplicated in the control data area 41a or the main information area 41b, whether the information can be duplicated is recorded. Can be efficiently identified.
[0097]
The optical storage medium 41 of the present embodiment has a track pitch Tp of the control data area 41a.₁Is the track pitch Tp of the main information area 41b.₂By making it wider, the signal quality of the tracking error signal by the push-pull method is improved even when the groove depth is λ / 5. The ratio of the control data area 41a in the entire optical storage medium 41 is 5% or less, and even if the track pitch is slightly widened, the decrease in the recording capacity is 1% or less, which is almost negligible.
[0098]
Also, since the data recorded in the main information area 41b does not wobble, there is no increase in crosstalk, that is, the signal quality does not decrease, and a highly reliable optical storage medium can be provided. .
[0099]
(Embodiment 2)
FIG. 3 is a block diagram showing a configuration example of the information reproducing apparatus according to the present invention. As the optical storage medium, the optical storage medium 41 described in Embodiment 1 is used. The optical pickup 4 irradiates the optical storage medium 41 with laser light having a wavelength λ of 400 nm, and reproduces a signal recorded on the optical storage medium 41. The transfer controller 5 moves the optical pickup 4 in the radial direction of the optical storage medium 41 in order to reproduce a signal at an arbitrary position on the optical storage medium 41. The optical storage medium motor 6 rotates the optical storage medium 41. The first control means 7 controls the optical pickup 4, the transfer controller 5, and the optical storage medium motor 6. The amplifier 8 amplifies the signal read by the optical pickup 4.
[0100]
Reference numeral 9 denotes second control means. The output signal of the amplifier 8 is input to the second control means 9. The second control means 9 generates a servo signal such as a focus error signal and a tracking error signal required when the optical pickup 4 reads the signal of the optical storage medium 41 from the signal, and converts the servo signal into the first signal. Output to control means 7.
[0101]
FIG. 10 shows a photodetector 51 which is one of the components of the optical pickup 4 and differential operation units 52 and 53 which are one of the components of the control means 9. The optical pickup 4 has a different configuration depending on the focus error signal and tracking error signal detection method. Here, the optical pickup 4 imparts astigmatism to the beam reflected by the optical storage medium 41, and has four light receiving units 51a to 51d. A case of a general configuration in which light is received by a photodetector 51 is shown. The focus error signal is obtained by performing a differential operation on a signal output from the light receiving units 51a and 51c and a signal output from the light receiving units 51b and 51d by the differential operation unit 52. On the other hand, the tracking error signal is obtained by performing a differential operation on a signal output from the light receiving units 51a and 51d and a signal output from the light receiving units 51b and 51c by the differential operation unit 52. The method of detecting the focus error signal is a well-known method called the astigmatism method, and the method of detecting the tracking error signal is called the push-pull method. Wobbling a groove or a pit is similar to the fact that the beam focused from the optical pickup 4 is off-track from a desired position according to the wobble. Therefore, by using the means for detecting the tracking error signal, the signal recorded by wobbling the groove or pit can be detected. That is, the method is not limited to the push-pull method as long as it can detect the tracking error signal, and various methods such as the phase difference method and the three spot method can be used for detecting the wobble signal. When the push-pull method is used, the optical system of the optical pickup 4 and the tracking error signal detecting means constituting the second control means 9 can be configured in the simplest manner, so that an inexpensive information reproducing apparatus is provided. be able to. Of course, the method of detecting the focus error signal does not impose any restrictions on the present invention, and any method can be used.
[0102]
The signal input to the second control means 9 is an analog signal, and the second control means 9 digitizes (binarizes) the analog signal. The second control means 9 determines whether or not the optical storage medium 41 has been illegally copied. If it is determined that the optical storage medium 41 has been illegally copied, the output prohibiting means 13 stops outputting the signal. To the control signal.
[0103]
The demodulation means 10 analyzes the digitized signal read from the optical storage medium 41 and, based on the key information read from the control data area 41a of the optical storage medium 41, encrypts the video, music, etc. Decrypts the data. The decoded signal is output from the output means 14. The detecting means 11 detects an address signal or the like from the signal output from the second control means 9 and outputs it to the system control means 12.
[0104]
The system control means 12 identifies the optical storage medium based on the optical storage medium information (physical format information and optical storage medium manufacturing information) read from the control data area 41a, decodes the reproduction conditions and the like, and Take control of the whole.
[0105]
When reproducing the information recorded on the optical storage medium 41, the first control means 7 controls the drive of the transfer controller 5 according to the instruction of the system control means 12. As a result, the transfer controller 5 moves the optical pickup 4 to a position corresponding to the control data area 41a. Then, the optical pickup 4 reads the optical storage medium information recorded in the control data area 41a. Based on these information, the system control means 12 sends an instruction to the first control means 7. In accordance with an instruction from the system control means 12, the first control means 7 controls the drive of the transfer controller 5. As a result, the transfer controller 5 moves the optical pickup 4 to a desired position in the main information area 41b, and the optical pickup 4 reads a recording signal (data information) on the optical storage medium 41.
[0106]
Even though the optical storage medium 41 is originally a copy-protected optical storage medium, if there is no key information in the optical storage medium information read from the control data area 41a by the optical pickup 4, the output prohibiting means 13 outputs a signal. Stop output of Further, the optical storage medium 41 may be ejected from the information reproducing apparatus. In addition, a warning unit (not shown) for issuing a warning indicating an illegally duplicated optical storage medium may be provided. By adding the output prohibiting means 13 and the warning means, the copyright protection function can be strengthened.
[0107]
As described in the first embodiment, the optical storage medium 41 may store copyable information. In this case, it is preferable to record, in the control data area 41a or the main information area 41b, an identifier (copyable identifier) indicating that the information recorded in the main information area 41b may be copied. When such an optical storage medium 41 is used, the information reproducing apparatus can perform the signal read from the optical storage medium 41 even if there is no key information in the data read by the optical pickup 4 from the control data area 41a. If the copyable identifier is detected, it is determined that the optical storage medium 41 is not illegally copied, and the optical storage medium 41 is reproduced. According to this configuration, information that does not need to be prohibited from being copied is not excessively protected, so that convenience for the user is not impaired.
[0108]
Although the information reproducing apparatus has been described here, in the case where the optical storage medium has a plurality of information recording layers and one information recording layer is a write-once type or a rewritable type, a recordable information reproducing apparatus is used. It does not matter.
[0109]
(Embodiment 3)
FIG. 4 shows a configuration of an optical storage medium 42 as still another embodiment according to the optical storage medium of the present invention. The optical storage medium 42 has two information recording layers 42a and 42b. The information recording layer 42a is a read-only information recording layer, and the information recording layer 42b is a rewritable information recording layer. The control data area 42a is used for both the information recording layers 42a and 42b.₁, 42b₁And the main information area 42a₂, 42b₂have. Control data area 42a of information recording layers 42a and 42b₁, 42b₁In each of the examples, optical storage medium information including key information for decoding information recorded in the main information area is recorded by wobbling grooves in the same modulation method. The control data area 42a of the information recording layers 42a and 42b₁, 42b₁Both record optical storage medium information of the information recording layer 42a and optical storage medium information of the information recording layer 42b. Thus, when reproducing information or recording information recorded on the optical storage medium 42, it is possible to determine the configuration of the optical storage medium 42 regardless of which information recording layer is focused. It can be easily identified.
[0110]
On the other hand, the main information area 42a of the information recording layer 42a₂Information is recorded in a pit string in the main information area 42b of the information recording layer 42b.₂Is formed with a groove from which a tracking error signal can be obtained. Main information area 42b₂The same applies to the case where the information recording layer 42b is a write-once type. Control data area 42a₁, 42b₁The position and modulation method used when recording information to be recorded in a wobble are common to the read-only optical storage medium, the rewritable optical storage medium, and the optical storage medium that can be written only once. Thus, since the time required to determine what the optical storage medium is after inserting the optical storage medium into the information recording / reproducing apparatus is shortened, the time required for the information recording / reproducing apparatus to perform recording / reproduction is reduced. Shorter. In addition, since the process of determining the optical storage medium is the same regardless of the type of optical storage medium, the hardware and software are shared between a read-only information device and a recordable / reproducible information device. The cost of development and mass production of the device can be reduced accordingly, so that an inexpensive information device can be provided. Of course, the optical storage medium may have three or more information recording layers, and the information recording layer may be any of a read-only type, a write-once type, and a rewritable type. In the case of a recordable optical storage medium in which a groove is formed in the main information area and information is recorded in a mark row, the depth of the groove and the pit is preferably in the range of λ / 16 to λ / 8. The reason is as follows. That is, when information is recorded in the mark row, the smaller the groove depth, the smaller the diffraction loss due to the groove, and thus the signal amplitude of the information signal obtained from the mark row increases. On the other hand, the tracking error signal by the push-pull method becomes maximum when the groove depth is λ / 8, and when the groove depth is smaller than λ / 8, the amplitude of the tracking error signal decreases as the groove depth becomes smaller. I do. The tracking error signal when the groove depth is λ / 16 has half the intensity of the tracking error signal when the groove depth is λ / 8. A reduction in the signal amplitude of the tracking error signal can be sufficiently tolerated up to about 1/2. Therefore, considering both the tracking error signal and the information signal, the optimum groove depth is in the range of λ / 16 to λ / 8.
[0111]
In addition, the act of illegally duplicating the optical storage medium by peeling off the protective layer of the optical storage medium, exposing the pit formation part, plating it to make a master, and stamping as it is, has become a problem. . In contrast, duplication can be prevented by using a barcode as disclosed in JP-A-2000-76659 in combination with the optical storage medium described in the above embodiment. Further, when the optical storage medium has a plurality of information storage layers as in the present embodiment, it is extremely difficult to peel off the protective layer to expose the pit formation portion and to duplicate it.
[0112]
In the above description, the control data area 42a of the information recording layers 42a and 42b₁, 42b₁In both cases, the configuration in which both the optical storage medium information of the information recording layer 42a and the optical storage medium information of the information recording layer 42b are recorded, these optical storage medium information are stored in the information recording layer 42a. , 42b of at least one control data area 42a₁, 42b₁May be recorded. In that case, it is preferable that the reference layer of the optical storage medium 42 be an information recording layer for recording information of the optical storage medium.
[0113]
Further, in the above description, the control data area 42a of the information recording layers 42a and 42b₁, 42b₁However, in both cases, the optical storage medium information including the key information for decrypting the information recorded in the main information area is recorded by wobbling the groove with the same modulation method, but the groove is wobbled. You don't have to.
[0114]
(Embodiment 4)
FIG. 5 shows an example of the configuration of another optical storage medium according to the present invention. FIG. 5 is an enlarged view of the vicinity of the boundary between the main information area 43b and the control data area 43a of the optical storage medium according to the present embodiment. This optical storage medium has a control data area 43a, a main information area 43b, and a buffer area 43c, like the optical storage medium 41 according to the first or second embodiment. In the main information area 43b, information to be stored is recorded as a pit string that can be read out via light. In the control data area 43a, optical storage medium information (physical format information, optical storage medium manufacturing information, and the like) is recorded as a pit string that can be read through light. A pit row is also formed in the buffer area 43c. In the optical storage medium 41 of the first embodiment, the information (optical storage medium information) to be recorded in the control data area 41a is recorded by wobbling continuous grooves, but in the optical storage medium of the present embodiment, Information recorded in the control data area 43a is recorded as a wobbled pit string. Since a pit row is also formed in the control data area 43a, a tracking error signal can be generated by the phase difference method, and tracking control can be performed using the signal.
[0115]
The reproduction signal of the information recorded in the main information area 43b is obtained by receiving the beam applied to the main information area 43b with a photodetector and obtaining the total light amount (hereinafter referred to as a sum signal). On the other hand, the reproduced signal of the information recorded in the control data area 43a receives the irradiated beam by a photodetector having two light receiving portions, and performs a differential operation on signals output from the two light receiving portions. (Hereinafter referred to as a differential signal). By recording both information in the control data area 43a and the main information area 43b as a pit row, the molding pressure for producing the optical storage medium can be reduced, and the cost of the molding machine can be reduced accordingly. In addition, since the time required for molding can be shortened, an inexpensive optical storage medium can be provided.
[0116]
Here, the track pitch Tp of the main information area 43b₂Is 0.32 μm, the track pitch Tp of the control data area 43a.₁Is 0.35 μm. Further, the width of the pit formed in the control data area 43a is set to Mw.₁Then
Mw₁= 0.5 × Tp₁
It is. If the width of the pit formed in the main information area 43b is Mw2,
Mw₂= 0.3 × Tp₂
It is. That is, the width Mw of the pit formed in the control data area 43a₁Is the width Mw of the pit formed in the main information area 43b.₂Thicker than. As a result, both the information recorded in the control data area 43a and the information recorded in the main information area 43b can be reproduced with high reliability. Pit width Mw formed in control data area 43a₁And the pit width Mw formed in the main information area 43b₂The reason is that the reproduction signal of the information recorded in the control data area 43a is obtained by using the sum signal, and the reproduction signal of the information recorded in the main information area 43b is obtained by using the differential signal. This is because the optimum conditions for the pit width are different. The width Mw of the pit formed in the control data area 43a₁Is
0.3 × Tp₁≦ Mw₁≦ 0.7 × Tp₁
It is preferable that When a signal is obtained by performing a differential operation, the signal quality is
Mw₁= 0.5 × Tp₁
And the width Mw of the pit generated during the production of the optical storage medium₁This is because the fluctuation of the signal amplitude due to the variation of the signal amplitude is also minimal. Within the above range, substantially good signal quality can be ensured.
On the other hand, the width Mw of the pit formed in the main information area 43b₂Is 0.5 × Tp₂In the following cases, a good signal can be obtained.
[0117]
It is preferable that the effective lengths of the pits and spaces formed in the control data area 43a, the main information area 43b, and the buffer area 43c are all integral multiples of the predetermined period T based on the predetermined period T. The period T is, for example, 0.08 μm. The pits and spaces formed in the main information area 43b are coded using 1-7 modulation, and each have a length of 2T to 8T. On the other hand, each of the pits and spaces formed in the control data area 43a has a single length of 8T.
[0118]
By setting the pits and the space to have a single length, it is possible to prevent an erroneous output of an invalid phase comparison result in the phase comparison operation of the phase comparator forming the phase locked loop. As a result, an extremely stable clock signal can be generated. In addition, since the pit and the space have a single length, the differential signal can be input to a narrow-band bandpass filter to significantly reduce noise, thereby increasing the S / N of the differential signal. can do. Therefore, the information recorded in the control data area 43a can be reproduced with high reliability.
[0119]
The length ML of the pit and space formed in the control data area 43a₁Is given assuming that the wavelength of the light source of the optical pickup is λ (for example, 405 nm) and the numerical aperture of the objective lens is NA (for example, 0.85).
ML₁≧ 2 × λ / NA
Is preferably established. When this relationship is satisfied, the signal obtained from the pits and spaces has a sufficiently large amplitude without using an equalizer when generating a clock signal, and a good clock signal can be obtained, and the circuit scale is reduced. Accordingly, an inexpensive information reproducing device can be provided.
[0120]
The equivalent pit depth Md₁about,
λ / 8 ≦ Md₁≤λ / 4
It is preferable to satisfy the relationship described above, since a high-quality signal can be obtained.
[0121]
Further, by setting the lengths of the pits and spaces formed in the control data area 43a and the period of the wobble to be integral multiples of the period T, respectively, the wobbles are generated using a clock signal that can be generated from the repetition of the pits and spaces. The information recorded in the modulated control data area 43a can be detected. Since pits and spaces can always be formed alternately, they have a higher frequency of existence than wobbles, so that a stable clock signal can be generated and the information recorded in the control data area 43a can be detected with high reliability. Will be able to
[0122]
FIG. 6 shows an example of a wobble pit recorded in the control data area 43a and a digital signal detected using a differential signal.
[0123]
In this example, the length Wob1 of one wobble is 16T, and a pit having a length of, for example, 8T exists at the center of information corresponding to 1 or 0. That is, pulse position modulation is performed. By using pulse position modulation, jitter becomes strong, so that information recorded in the control data area 43a can be reproduced with high reliability. In addition, since the transition time required to wobble the pit exists at the timing of the space, a high-speed response is not required, and an inexpensive modulation element such as an acousto-optic element can be used. An optical storage medium can be provided.
[0124]
Also in the optical storage medium of the present embodiment, information recorded in the control data area is recorded as a wobble signal modulated at a frequency sufficiently higher than the tracking servo band. For this reason, even if an attempt is made to copy the optical storage medium using an ordinary information recording / reproducing apparatus, the pits modulated by wobble cannot be copied, so that the optical storage medium cannot be copied. In this way, unauthorized duplication is effectively eliminated.
[0125]
Here, each of the pits and spaces formed in the control data area 43a has a single length of 8T, but like the pits recorded in the main information area, a plurality of types of lengths are used according to a specific modulation rule. Pits and spaces may be formed. In that case, information can be stored in the pits and the space itself, and accordingly, a high-capacity optical storage medium can be realized. Identification information indicating that the optical storage medium is properly manufactured or that the information may be reproduced is recorded in a wobble, and key information for decoding the encrypted data information is stored in a pit and space. This is especially useful when you have the columns themselves. At this time, since high-capacity information can be given to the key information, it becomes difficult to illegally analyze and decrypt the encrypted data information. Therefore, the confidentiality of the data information recorded in the main information area can be increased. By making the modulation rule of pits and spaces recorded in the control data area 43a the same as the modulation rule of pits and spaces recorded in the main information area 43b, a circuit for demodulation can be commonly used. Thus, an inexpensive information reproducing apparatus can be provided.
[0126]
In the present embodiment, an example is shown in which the information recorded in the main information area 43b is not encrypted. However, it is also possible to record the encrypted data information in the main information area 43b. In this case, similarly to the optical storage medium according to the first embodiment, in addition to the physical format information and the optical storage medium manufacturing information, key information for decrypting the encrypted data information is controlled as optical storage medium information. What is necessary is just to record in the data area 43a. Further, an information reproducing apparatus for reproducing the optical storage medium can be configured in the same manner as the information reproducing apparatus according to the second embodiment.
[0127]
(Embodiment 5)
FIG. 7 shows a wobble pit recorded in a control data area and a digital signal detected using a differential signal as a modification of the optical storage medium according to the fourth embodiment. The optical storage medium according to the fourth embodiment is different from the optical storage medium according to the fourth embodiment in that a pit exists at the center of information corresponding to 1 or 0, whereas the optical storage medium according to the fourth embodiment is different from the optical storage medium according to the fourth embodiment. In the optical storage medium described in the embodiment, a pit is present at an end of information corresponding to 1 or 0. When the optical storage medium of the present embodiment is used, the differential signal is sampled at the timing of the end of the information corresponding to 1 or 0, and 1 or 0 is determined, so that the continuous groove is wobbled. The same S / N as in the case of the above can be secured. This makes it possible to detect information recorded in the control data area 43a with high reliability.
[0128]
(Embodiment 6)
FIG. 8 shows a wobble pit recorded in a control data area and a digital signal detected using a differential signal, as a further modification of the optical storage medium according to the fourth embodiment. The optical storage medium according to the fourth embodiment is different from the optical storage medium according to the fourth embodiment in that the pits and spaces are each substantially 8 T in length, but the optical storage medium according to the present embodiment is different from the optical storage medium according to the fourth embodiment. , Pits and spaces are each substantially 2T in length.
[0129]
Pit and space length ML₁Is ML₁≧ λ / (2 × NA). At this time, a clock signal can be generated using a signal obtained from repetition of pits and spaces.
[0130]
The length Wob1 of one wobble is set to 16T, and the cycle of the wobble when the wobble always exists is 32T. On the other hand, since the repetition period of the pit and the space is 4T, the period of the wobble is eight times the period of the repetition of the pit and the space. By setting the cycle of the wobble to be at least four times the cycle of repeating the pits and spaces, it is less likely to be affected by the formation of pits or spaces in adjacent tracks, and the wobble is recorded in the control data area 43a with high reliability. Information can be detected.
[0131]
Also, by making the repetition period of pits and spaces shorter than the period of wobble, a differential signal is input to a narrow-band bandpass filter that passes a signal having a frequency corresponding to the repetition period of pits and spaces, and noise is reduced. Can be significantly reduced, so that the S / N of the differential signal can be increased. Further, at this time, it is less likely to be affected by whether a pit or a space is formed in an adjacent track. Therefore, the information recorded in the control data area 43a can be reproduced with high reliability.
[0132]
(Embodiment 7)
FIG. 11 schematically shows a photodetector 51 which is one of the components of the optical pickup 4 and a configuration for detecting a tracking error signal and a wobbling signal as a further modified example of the information reproducing apparatus according to the present invention. The configuration for detecting the tracking error signal and the wobbling signal is a part of the components of the control unit, and the information reproducing apparatus can be configured by replacing the tracking error signal detection unit of the control unit 9 with this configuration. Here, the tracking error signal and the wobbling signal are detected by the phase difference method. The signals output from the light receiving units 51a and 51c are added by an adding unit 54, and the signals output from the light receiving units 51b and 51d are added by an adding unit 55. The signals output from the adders 54 and 55 are input to the timing comparator 56. The timing comparing section 56 outputs a signal corresponding to the timing at which the diffracted light of the beam applied to the start and end of the mark formed on the information recording layer of the optical storage medium 41 from the optical pickup 4 changes. The signal output from the timing comparison unit 56 becomes a tracking error signal after a high-frequency component unnecessary for tracking servo is reduced by the low-pass filter 57. Further, the signal output from the timing comparing section 56 is integrated and averaged by an integrating and averaging device 58, and then becomes a wobbling signal.
[0133]
The adding unit 59 adds the signals output from the light receiving units 51a to 51d, and outputs the signal to the clock signal generating unit 60. The clock signal generation unit 60 generates a clock signal, a frame synchronization signal, and a wobble polarity signal from a mark sequence formed on the information recording layer of the optical storage medium 41 and outputs the clock signal, the integration averager 58, and the like. The integrated average performed by the integrated averager 58 is controlled by a signal output from the clock signal generator 60.
[0134]
FIG. 12 shows a format of information recorded on the information recording layer of the optical storage medium 41. On the information recording layer, a frame synchronization pattern Sync and data strings Data1, Data2,... Are recorded alternately. Normally, by providing a synchronization pattern of about 1 to 10 bytes for a data string of about 10 to 1 kilobyte, a large amount of errors due to bit slip or the like when reading information is avoided. After the code conversion, data corresponding to 1 or 0 is recorded in the data string as a mark or a space, respectively. In EFM, a mark or space having a length of 3T to 8T is recorded. In EFMplus, a mark or space having a length of 3T to 14T is recorded. In 1-7pp modulation, a mark or space having a length of 2T to 8T is recorded. . EFM is a compact disc, EFMplus is a DVD, and 1-7pp is a code conversion method used for a Blu-ray disc. Here, T is the basic period, and the 3T mark is a mark having a length three times as long as T.
[0135]
In the present optical storage medium, one bit of key information is assigned to one data string. 6P1 to 6P10 are sets of wobble patterns, and as shown in the pattern table of FIG. 13, one wobble pattern is composed of 6 bits. In the case of the wobble pattern 6P1, if the bit of the key information is 1, the state is 000111. If the bit of the key information is 0, the state is 111000. That is, the complement is assigned. By allocating the complement, the configuration of hardware or software used to identify whether the bit of the key information is 1 or 0 becomes very simple, and an inexpensive information reproducing apparatus can be provided. The same applies to the wobble patterns 6P2 to 6P10, as shown in FIG.
[0136]
In addition, by making the wobble symmetrical with respect to the center of the track in accordance with 1 or 0 of the wobble pattern, a DC-free characteristic is realized in the range of each wobble pattern. Do not give. Also, by wobbling the mark sequence based on the wobble pattern shown in the pattern table of FIG. 13, the wobble is recorded as a kind of pseudo-random pattern. Become. Further, here, the ten wobble patterns 6P1 to 6P10 assigned to one data string are patterns synchronized with each of the synchronization pattern Sync and the data recorded in the data string.
[0137]
In the case of the data string Data1 in FIG. 12, the case where the bit of the key information is 1 is shown. The mark recorded on the information recording layer is wobbled according to the state of the wobble patterns 6P1 to 6P10. A signal waveform schematically representing the wobble timing is a waveform WB. One bit length of the wobble patterns 6P1 to 6P10 corresponds to one cycle of the wobble clock signal WCLK. The wobble waveform is given a change in wobble at the rising timing of the wobble clock signal WCLK. One cycle of the wobble clock signal WCLK is preferably several times to about 10000 times the basic cycle T. The shortest length is constrained by the code conversion method on the condition that the longest length does not adversely affect the servo characteristics of the tracking servo. Here, one cycle of the wobble clock signal WCLK is set to 100 times the basic cycle T. Therefore, there are a plurality of marks and spaces in the length corresponding to one bit of the wobble pattern. Therefore, a plurality of signals corresponding to the number of marks are output from the timing comparing section 56. In the integrating and averaging unit 58, based on the wobble pattern rule shown in FIG. 13 and the wobble polarity signal output from the clock signal generating unit 60, a plurality of signals output from the timing comparing unit 56 are switched while the integration polarity is switched. Are integrated and averaged. Assuming that the number of integrations performed by the integration and averaging unit 58 is N, the signal-to-noise ratio is improved by the square root of N. Therefore, the greater the number N of times of integration, the higher the reliability of the read key information. The number of wobbles to be assigned to 1-bit key information can be freely designed according to the number of bits of the key information to be recorded, the time allowed for reading, the required signal-to-noise ratio, and the like. . Assuming that the required signal-to-noise ratio is constant, the greater the number of wobbles assigned to one-bit key information, the smaller the amplitude of the wobbles may be, and the effect of crosstalk is reduced accordingly. Therefore, even if the key information is recorded not only in the control information area but also in the main information area, the key information can be recorded without impairing the signal quality of the main information area. When the wobble is set to 1/30 or less of the track pitch, the influence of the crosstalk can be completely ignored.
[0138]
Although the format of FIG. 12 shows a case where the key information is continuously input, the key information may be input discretely in the information recording layer. In that case, the degree of difficulty of decryption becomes higher, so that illegal duplication is less likely. When key information is continuously input, the time required for reading is shortened, so that the waiting time of the user of the information reproducing apparatus can be shortened.
[0139]
Also, here, the case where DC free is realized in a range where one wobble pattern is 6 bits has been described. However, there is no particular limitation, and it may be realized with 4 bits as shown in the pattern table of FIG. Alternatively, it may be realized by using more bits.
[0140]
Further, here, the wobble pattern used after the data string Data2 has not been described, but a pattern having the same rule as the pattern recorded in the data string Data1 may be recorded or may be different. Alternatively, only a specific wobble pattern may be used, such as recording only the wobble pattern 6P1 in each data string. The fewer the wobble patterns used, the simpler the configuration of the information reproducing apparatus and the lower the cost. On the other hand, the more wobble patterns used, the more difficult it is to decipher, so that unauthorized duplication is less likely to occur.
[0141]
A plurality of pattern tables may be provided so that the timing at which the polarity of the wobble changes is not a mark but a space. By setting the timing at which the polarity of the wobble changes to a space, adverse effects due to the performance of the modulator that deflects the beam when cutting the master disk of the optical storage medium are less likely to occur, so that the reliability is increased accordingly. An optical storage medium from which key information can be read can be provided.
[0142]
The clock signal generation unit 60 shown in FIG. 11 includes a data clock signal DCLK used for reading data and a wobble used for reading a frame synchronization signal and a wobble based on a signal that changes according to a mark and a space column. A clock signal WCLK and a wobble polarity signal are generated. The wobble clock signal WCLK and the wobble polarity signal can be generated because the wobble pattern is synchronized with the frame synchronization pattern and the data string. By generating the wobble clock signal WCLK based on a signal that changes according to the mark and space columns, the wobble clock signal WCLK can be generated even when the wobble amplitude is small or when the wobble clock is discretely recorded. . Further, by setting one cycle of the wobble clock signal WCLK to be an integral multiple of the data clock signal DCLK, the wobble clock signal WCLK can be generated using a counter circuit without newly having a phase lock loop. Accordingly, it is possible to provide an inexpensive information reproducing apparatus which can be realized with a simple circuit configuration. In order to synchronize the frame synchronization pattern and the wobbles, it is sufficient that there are M / 2 wobbles for one frame synchronization pattern. Further, there may be M / 2 frame synchronization patterns for one wobble. Here, M is a natural number. Therefore, the relationship between the frame synchronization pattern and the wobble can be freely set by a desired design.
[0143]
Also, the configuration of the detection unit that detects the tracking error signal by the phase difference method described here is an example, and the configuration in which a delay unit is added and the signals output from two of the four light receiving units are output. It goes without saying that any configuration for detecting the tracking error signal by the phase difference method, such as a configuration for comparing changing timings, is applicable.
[0144]
This detection method is particularly effective when the mark string is wobbled. The phase difference method is a method of detecting a timing at which light diffracted by a mark changes, and it is only necessary to input an AC-coupled signal to a phase comparator, so that the influence of an offset which may be generated electrically or optically. No signal is received, and the signal can be detected with high reliability.
[0145]
Also, the optical conditions such as the wobble period, track pitch, light source wavelength, objective lens numerical aperture, and the like shown in each of the above-described embodiments are merely examples, and may be various values without departing from the spirit of the present invention. May be.
[0146]
There is no limitation on the shape of the optical storage medium, and various shapes such as a disk shape and a card shape may be used as necessary.
[0147]
In each of the above-described embodiments, the optical storage medium in which the optical storage medium information including the key information is recorded by wobbling the grooves or pits in the control data area is exemplified. Either is fine. Also, the wobble modulation may be binary or ternary, and there are no restrictions on the modulation rule of the coding, so that various modulation rules can be applied.
[0148]
Further, in an optical storage medium having a plurality of information recording layers, recording layer information relating to how a surface shape for recording information is formed in each information recording layer, or information relating to the polarity of a tracking error signal. (Hereinafter referred to as polarity information) is preferably recorded in the control data area as optical storage medium information. The recording layer information indicates whether the information formed in the information recording layer is a concave or convex groove or a concave or convex pit with respect to the light incident side. This is the information to represent. By recording the polarity information in this manner, even when a tracking error signal is detected by the push-pull method, a tracking operation can be performed on a desired track. When the polarity information is not recorded, when the information is recorded or reproduced on the optical storage medium for the first time, the polarity of the tracking error signal is not known. Time is required to learn the polarity. When the polarity information is recorded in the control data area as the optical storage medium information, the polarity of the tracking error signal of each layer is known in advance, so that the time for learning the polarity is unnecessary, and the information is recorded or reproduced accordingly. The time required to do so can be reduced. It is desirable that the polarity information be recorded on at least a reference layer among the plurality of information recording layers. The reference layer in an optical storage medium having a plurality of information recording layers is a layer at the same position as the information recording layer in an optical storage medium having a single information recording layer. That is, in an optical storage medium having a single information recording layer, assuming that the distance from the surface on which light is incident to the information recording layer is x, in an optical storage medium having a plurality of information recording layers, The information recording layer located at the distance x becomes the above-mentioned reference layer. In an optical storage medium having a plurality of information recording layers, it is even better if polarity information is recorded on each information recording layer.
[0149]
Further, the present invention is applied to the case where the mark is formed by any of the irregularities, so that when the optical storage medium is manufactured, various methods can be freely selected. Thereby, an inexpensive optical storage medium can be provided.
[0150]
Furthermore, the present invention is not limited to a medium in which mark rows are formed as pits having irregularities, but is also applicable to an optical storage medium in which mark rows are formed by shading of a dye.
[0151]
When data is recorded in a concave or convex pit row in the main information area, it is also preferable that information is recorded in a control data area in a concave or convex pit row. By recording both the main information area and the control data area with a pit row, the molding operation when manufacturing an optical storage medium is extremely easy as compared with the case where pits and grooves are mixed, and accordingly, The yield at the time of manufacturing an optical storage medium is improved, and an inexpensive optical storage medium can be provided. At this time, information recorded on the optical storage medium recorded in the control data area is recorded as a pit string of the same modulation method as the information recorded in the main information area, thereby reproducing the information recorded in the main information area. The hardware used when performing the operation can be used as it is when reproducing the information recorded in the control data area, and an inexpensive information reproducing apparatus can be provided. Further, it is also preferable that information on the optical storage medium is recorded as a pit string, and is recorded by wobbling pits for recording key information in a control data area. When the information recorded in the control data area is read, the key information can be read at the same time, that is, the time required for reading the key information can be substantially eliminated. It is possible to provide an information reproducing apparatus in which the time required from the insertion into the apparatus to the reproduction of the information recorded on the optical storage medium is not restricted, and the additional burden of waiting time is not required. In place of the key information, a legitimate optical storage medium or an illegally duplicated optical storage medium such as identification information indicating that the optical storage medium has been properly manufactured or that the information may be reproduced. Information that can be used to identify the above may be used, and the object of the present invention is likewise achieved. Further, in the case of an optical storage medium having a format that does not hinder the reproduction of information by applying the phase difference method, it is preferable that the substantial pit depth is about λ / 4. At this time, the jitter of the signal obtained from the pit train is the best, and the S / N of the tracking error signal obtained by the phase difference method is also the highest, resulting in a highly reliable optical storage medium.
[0152]
In addition, the fact that the signal-to-noise ratio can be improved by applying the integrating averager is not limited to the detection method using the phase difference method. The signal to noise ratio can be improved by applying a filter.
[0153]
(Embodiment 8)
Hereinafter, an eighth embodiment of the present invention will be described in detail with reference to the drawings. Hereinafter, a DVD will be exemplified as an optical storage medium, but the optical storage medium of the present invention is not limited to a DVD.
[0154]
FIG. 15 is a conceptual diagram illustrating the displacement of a recording mark in the DVD of the present embodiment. The DVD according to the present embodiment is a DVD in which main information is recorded in frame units, and has a synchronization code section 101 and a data section 102. In the present DVD, in at least a part of the frames, the recording mark of the data section 102 excluding the synchronization code section 101 is displaced (wobbled) in a small amount in the radial direction (radial direction) based on the displacement control signal. The sub information is recorded.
[0155]
The displacement control signal of the DVD according to the present embodiment is a signal obtained by spectrum-spreading sub-information using a pseudo-random number sequence initialized at a position where a synchronization code is inserted. In the section in which the displacement control signal is "1", the recording mark has a small displacement amount D on the outer peripheral side of the disk.₁Is only displaced. On the other hand, in a section where the displacement control signal is “0”, the recording mark is shifted toward the inner peripheral side of the disk by a small displacement amount D.₀Is only displaced.
[0156]
The displacement of the recording mark is preferably in the range of 5 nmp-p (nanometer peak to peak) to 20 nmp-p. By setting the amount of displacement of the recording mark in the radial direction within this range, observation with a scanning electron microscope (SEM) is difficult and wobble can be read out stably.
[0157]
Further, it is preferable that a cycle (wobble cycle) for displacing the recording mark is a band equal to or longer than a band that the tracking servo follows. This is because if the tracking servo follows, the wobble cannot be detected. For example, in the case of a 16T wobble, the frequency is preferably 3.75 MHz or more.
[0158]
Further, it is preferable that an integer number of wobbles exist in each frame. This is because a pit shift in wobble detection can be corrected, and a wobble synchronized with the main information can be formed.
[0159]
On the other hand, in the area important for the reproduction of the main information such as the synchronization code unit 101, since the recording mark is not displaced in the radial direction as described above, even when the sub information is recorded, It is possible to minimize the influence on the reading accuracy.
[0160]
In a DVD, an ID important for reproducing main information is recorded in a first frame in a sector.
[0161]
The DVD according to the present embodiment does not perform displacement in the radial direction in an important frame to which an ID is assigned (for example, the frame 105 shown in FIG. 15). That is, whether or not to perform displacement in the radial direction is controlled in frame units.
[0162]
Further, in the DVD according to the present embodiment, the sub-information is recorded by slightly displacing the recording mark in the radial direction, so that the recording mark displaced in the radial direction and the recording mark on the adjacent track are mutually reciprocated during reproduction. (Crosstalk), and the reproduction quality may be degraded. Therefore, in the DVD according to the present embodiment, the track pitch Tp of the area for recording the sub-information, that is, the area for slightly displacing the recording mark in the radial direction._AIs the track pitch Tp of the area where the sub-information is not recorded, that is, the area where the recording mark is not displaced minutely in the radial direction._BWith the above, the crosstalk problem is solved. However, when the radial displacement of the recording mark is so small that the crosstalk problem does not occur, the track pitch of the area where the sub-information is recorded may be equal to the track pitch of the area where the sub-information is not recorded.
[0163]
Further, in the DVD according to the present embodiment, the amount of displacement of the recording mark in the radial direction may be equal to or less than the amount of radial displacement allowed in a normal optical disc that does not perform displacement in the radial direction. This makes it difficult to confirm the presence or absence of sub-information based on the shape of the recording mark, and makes it possible to record more confidential information as sub-information.
[0164]
Next, a format for recording sub-information on the DVD according to the present embodiment by minute displacement of a recording mark in the radial direction will be described with reference to FIG.
[0165]
The DVD has 16 sectors 202 in an ECC block 201 which is a logical read unit. In the sector 202, there are 26 frames 207 having a synchronization code section 203 and a data section 204. The first frame (# 0) in the sector 202 has an ID 205 assigned to the data section 204.
[0166]
In the eighth embodiment, an example will be described in which recording marks of three frames are slightly displaced in the radial direction to record one bit of sub-information.
[0167]
That is, in the example shown in FIG. 16, 1-bit security information (secure info [0]) is recorded as sub-information in three frames of the second to fourth frames (# 1 to # 3). Similarly, up to the 25th frame (# 22 to # 24) secure info [7], 1-bit sub information is recorded every three frames. Here, the security information is shown as an example of the sub information, but the type and use of the sub information are not limited to the security information itself.
[0168]
The synchronization code recorded in the synchronization code unit 203 detects the frame shift at the time of playback by comparing the synchronization code with the preceding and following synchronization codes to determine the number of the frame in the sector. A shift, a byte shift, and the like are provided for the purpose of simultaneously detecting and correcting the shift. Therefore, if the detection accuracy of the synchronization code is deteriorated, the above-described reproduction deviation cannot be detected, and it becomes difficult to correct abnormal reproduction to a normal state. In the optical disc according to the present embodiment, in order to record the sub-information without deteriorating the reproduction quality as described above, the synchronization code unit 203 does not perform the displacement of the recording mark in the radial direction by a small amount. In other words, the minute displacement in the radial direction of the recording mark is not performed by the synchronization code section 203 important for the reproduction of the main information, and only the recording mark of the data section 204 in the frame is slightly displaced in the radial direction. .
[0169]
In the DVD, a first frame in a sector is provided with an ID 205 as a sector identifier. The ID 205 is used as position information in the optical disc for a reproducing apparatus for reproducing the present optical disc. For this reason, if the reading accuracy of the ID 205 is deteriorated, the reading accuracy is seriously affected as in the case of the reading of the synchronization code. Accordingly, in the optical disc according to the present embodiment, the recording mark of the first frame in the sector including the ID 205 and the frame before the frame to which the ID 205 is added (the 26th frame (frame # 25) of the previous sector) is recorded in the radial direction. No displacement is performed.
[0170]
As described above, in the DVD according to the present embodiment, out of the total of 26 frames in the sector which is a unit to which an ID is assigned, 24 frames excluding the first frame and the 26th frame have a plurality of frame units (this embodiment). One bit of sub-information is recorded every three frames (in mode 8). That is, in the eighth embodiment, 8 bits are recorded in one sector and 128 bits are recorded in one ECC block.
[0171]
Next, a method of recording sub information by slightly displacing a recording mark in the radial direction in the DVD according to the present embodiment will be described with reference to FIG.
[0172]
The DVD generates a channel code (A in FIG. 17) by modulating the main information to be recorded into 16-bit information every 8 bits (8-16 modulation) and inserting a synchronization code at regular intervals. In a normal DVD, a channel signal (B in FIG. 17) is generated by performing NRZI conversion of a channel code, and a recording mark (C in FIG. 17) is formed on an optical disk by changing a recording laser power according to the channel signal. Generate
[0173]
In the DVD according to the present embodiment, a pseudo-random number sequence (E in FIG. 17) is generated during the period when the displacement permission signal (D in FIG. 17) is “H”, and the recording mark is shifted to the inner circumference side or the pseudo-random number sequence by this pseudo random number sequence. Sub-information is recorded by slightly displacing the outer side. Note that the displacement permission signal is “L” during a period during which a synchronization code is inserted in each frame and during periods of the first and 26th frames in each sector. Also, while the displacement permission signal is "L", the recording mark is not displaced in the radial direction by a very small amount.
[0174]
When “0” is recorded as the sub information bit value, the displacement control signal (FIG. 17) is obtained by performing an exclusive OR operation on the pseudo-random number sequence (E in FIG. 17) and the sub information “0”. F). Then, the recording mark is slightly displaced in the radial direction according to a PE modulation displacement control signal (G in FIG. 17) obtained by subjecting the displacement control signal to PE modulation. In the eighth embodiment, the recording mark in the section where the PE modulation displacement control signal is “H” is moved toward the outer circumference of the optical disk, and the recording mark in the section where the PE modulation displacement control signal is “L” is moved toward the inner circumference of the optical disk by a small amount. Let it. In this way, the displacement recording mark (H in FIG. 17) on which the sub information “0” is superimposed is formed on the optical disc.
[0175]
On the other hand, when “1” is recorded as the sub-information bit value, similarly, the above-mentioned pseudo-random number sequence (E in FIG. 17) and the sub-information “1” are subjected to an exclusive OR operation to perform displacement control. A signal (I in FIG. 17) is generated. Then, the recording mark is slightly displaced in the radial direction according to a PE modulation displacement control signal (J in FIG. 17) obtained by subjecting the displacement control signal to PE modulation. In the eighth embodiment, the recording mark in the section where the PE modulation displacement control signal is “H” is moved toward the outer circumference of the optical disk, and the recording mark in the section where the PE modulation displacement control signal is “L” is moved toward the inner circumference of the optical disk by a small amount. Let it. Thus, the displacement recording mark (K in FIG. 17) on which the sub information “1” is superimposed is formed on the optical disc.
[0176]
As described above, the recording mark of the DVD according to the present embodiment has the bit value “0” recorded as the sub-information, except for the recording mark that generates the synchronization code and the recording mark that configures the first and 26th frames. In the section where the synchronization code is inserted, a small amount of displacement in the radial direction is performed in accordance with a PE modulation displacement control signal obtained by performing PE modulation on a pseudo random number sequence based on the insertion position of the synchronization code. Conversely, in the section where the bit value “1” is recorded as the sub-information, the pseudo-random number sequence is inverted based on the insertion position of the synchronization code, and then finely modulated in the radial direction according to the PE modulation displacement control signal subjected to PE modulation. A small displacement is performed.
[0177]
Next, an information recording apparatus according to the present embodiment will be described. Although an example in which a DVD is used as an optical disk is shown here, the present invention is not limited to this.
[0178]
FIG. 18 shows a main block configuration of the DVD recording apparatus according to the present embodiment. The DVD recording apparatus according to the eighth embodiment records main information by forming optically readable recording marks in a spiral shape on an optical disk (DVD), and inserts a synchronization code in a frame unit of the main information. This is an apparatus for recording sub-information by displacing the recording mark by a small amount in the radial direction according to a displacement control signal generated based on timing. This DVD recording device includes a timing generator 401, a modulator 402, a random number generator 403, an XOR 404, a PE modulator 405, a recording channel 406, a radial modulator 408, and a recording head 407.
[0179]
The timing generator 401 generates a synchronization signal, a byte clock, a displacement permission signal, and a PE signal. The synchronization signal indicates a timing at which a synchronization code is added from a recording clock that is a reference clock signal for recording main information. The byte clock is a signal that is synchronized in units of bytes, and in the case of a DVD, the clock is divided by sixteen. As described above, the displacement permission signal is a signal that becomes “L” only at the timing at which the first and 26th frames and the synchronization code are added. The PE signal is a signal that repeats 8 clocks “L” after 8 clocks “H”. The timing generator 401 sends the generated synchronization signal to the modulator 402, the random number generator 403 and the XOR 404, the byte clock to the random number generator 403, the displacement permission signal to the radial modulator 408, and the PE signal to the PE modulator 405. To each output.
[0180]
The synchronization signal is a signal indicating a timing at which a synchronization code is inserted at regular intervals with respect to a result of modulation of the main information by the modulator 402, and is a signal indicating a 32 clock section from the head of a frame to be recorded in DVD.
[0181]
The byte clock is a clock signal synchronized with a byte unit (16 recording clocks) of main information to be recorded, and is generated by dividing the recording clock by 16 in DVD.
[0182]
The displacement permission signal is a signal which becomes "Low" in the section of the first and 26th frames in the sector for recording and recording the synchronization code by the modulator 402 in the DVD, and becomes "High" in the other sections.
[0183]
The PE signal is a signal in which the first 8 bits in the byte unit (16 recording clocks) of the main information to be recorded are “High” and the last 8 bits are “Low”.
[0184]
The modulator 402 converts the data into 16-bit information (8-16 modulation) in units of bytes (8 bits) of the main information to be recorded, and outputs a synchronization code in a section where the synchronization signal from the timing generator 401 is “High”. A channel code is generated by insertion. Then, a channel signal is generated by subjecting the channel code to NRZI conversion and output to the recording channel 406.
[0185]
The random number generator 403 generates a pseudo random number sequence from the synchronization signal from the timing generator 401 and the byte clock. The detailed block is shown in FIG.
[0186]
The random number generator 403 of this embodiment includes a shift register 501 and an XOR 502. The random number generator 403 presets an initial value secretly stored in the information recording device in a section in which the synchronization signal is “High”. On the other hand, in a section in which the synchronization signal is “Low”, the LSB of the shift register is output as one bit of a pseudo-random number sequence at a timing of a byte clock synchronized with a byte unit of the main information from the timing generator 401. At the same time, the shift register 501 shifts one bit from the LSB to the MSB, and the exclusive OR of the shift register [10] and the shift register [14] is fed back to the shift register [0]. In this way, the random number generator 403 generates a random number sequence that is updated one bit at a time in byte units of the main information, and outputs it to the XOR 404.
[0187]
The XOR 404 is a part that calculates the exclusive OR of the random number sequence and the sub information to be recorded. As shown in FIG. 20, the XOR 404 mainly includes the sub information storage unit 601, the sub information update unit 602, and the exclusive OR calculation. It comprises a unit 603.
[0188]
The sub information storage unit 601 is a part that stores sub information to be recorded (128 bits in the eighth embodiment of the present invention) for each ECC block that is a logical information unit of main information.
[0189]
The sub-information updating unit 602 calculates a recording sector position and a frame position from the synchronization signal from the timing generator 401. Then, for each area in which one bit of sub information is recorded (in this embodiment, one bit is recorded in three frames as shown in FIG. 16), one bit of sub information corresponding to the current sector position and frame position is set. It is extracted from the sub information storage unit 601 and output to the exclusive OR calculation unit 603.
[0190]
As described above, the sub-information updating unit 602 extracts 1-bit sub-information from the sub-information storage unit 601 for every three frames in all 24 frames except the first and 26th frames in the sector. Therefore, sub-information of 8 bits in one sector and 128 bits of 1 ECC block are sequentially extracted.
[0191]
The PE modulator 405 generates a PE modulation displacement control signal from the displacement control signal output from the XOR 404 and the PE signal output from the timing generator 401, and outputs the generated PE modulation displacement control signal to the radial modulator 408. The PE modulator 405 of this embodiment is configured by an exclusive OR gate.
[0192]
The recording channel 406 generates a control signal for turning “ON” and “OFF” the recording beam for exposing the optical disk (DVD) 410 in accordance with “1” and “0” of the channel signal from the modulator 402, and outputs the control signal to the recording head 407. I do.
[0193]
The recording head 407 records main information by irradiating a recording beam on the optical disc 410 based on “ON” and “OFF” signals from the recording channel to form recording marks.
[0194]
The radial modulator 408 refracts a recording beam emitted from the recording head 407 to the optical disk 410 by controlling a voltage applied to an electrode 409 provided near the recording head 407. As a result, recording can be performed with the recording mark slightly shifted in the radial direction. As shown in FIG. 21, the radial modulator 408 includes a digital wobble signal generator 701, a DA converter 702, and an LPF 703.
[0195]
The digital wobble signal generator 701 receives the displacement permission signal from the timing generator 401 and the PE modulation displacement control signal from the PE modulator 405. When the displacement permission signal is “Low”, the level is “0”. When the displacement permission signal is “High” and the PE modulation displacement control signal is “High”, the level is “+”, and the displacement permission signal is “High”. When “PE modulation displacement control signal is“ Low ”, a digital wobble signal indicating three levels of“ − ”level is generated and output to the DA converter 702. For example, if the digital wobble signal is 10 bits, “+” level is hexadecimal “3FF”, “0” level is hexadecimal “200”, and “−” level is hexadecimal “001”. Generate.
[0196]
The DA converter 702 performs digital-to-analog conversion (DA conversion) of the digital wobble signal output from the digital wobble signal generator 701 in three stages. The DA converter 702 generates analog wobble signals obtained by converting the input “+” level, “−” level, and “0” level digital wobble signals to + V, −V, and ground level, respectively, and outputs the analog wobble signals to the LPF 703. I do. The LPF 703 generates an analog displacement control signal by cutting a high frequency component, which is a noise component, from the analog wobble signal, and outputs the analog displacement control signal to the electrode 409.
[0197]
As described above, the recording beam is refracted in the radial direction according to the voltage level applied to the electrode 409. Therefore, for example, when the voltage of + V is applied to the electrode, the recording mark is slightly displaced in the outer peripheral direction when the voltage of + V is applied to the electrode. Thus, it is formed on the optical disk 410.
[0198]
Next, an operation in which main information and sub-information are recorded by the present information recording apparatus will be described with reference to FIGS. FIG. 22 is a timing chart showing the operation when recording the sub information bit value “0”, and FIG. 23 is the timing chart showing the operation when recording the sub information bit value “1”.
[0199]
In this information recording apparatus, the modulator 402 converts the main information to be recorded into 16-bit information in units of bytes (8-16 conversion) to generate channel codes (A in FIG. 22 and A in FIG. 23). In addition, in a section where the synchronization signal (C in FIG. 22 and C in FIG. 23) indicating the timing of inserting the synchronization code from the timing generator 401 is “High”, the synchronization code is inserted into the channel code and then NRZI converted. As a result, channel signals (B in FIG. 22 and B in FIG. 23) are generated and output to the recording channel 406.
[0200]
In addition, the timing generator 401 outputs a displacement permission signal (“D” in FIG. 22 and FIG. 23) that becomes “High” in a section of the synchronization coding unit 801 in each frame and a section excluding the first frame and the 26th frame. D) is generated and output to the radial modulator 408.
[0201]
FIG. 24 is a timing chart showing a change in the displacement permission signal within a sector. The displacement permission signal includes a synchronization code section 1001 for recording the synchronization code section 801 for each of all 26 frames in the sector, a section 1002 for recording the first frame, and a section 1003 for recording the 26th frame. The section 1004 for recording “Low” and the data area 802 is a signal that becomes “High”.
[0202]
The random number generator 403 presets the falling timing of the synchronization signal (C in FIG. 22 and C in FIG. 23) from the timing generator 401 as an initialization timing 803, and presets an initial value secretly stored therein, According to the byte clock from the timing generator 401, a random number sequence (FIGS. 22E and 23E) is generated bit by bit and output to the XOR 404. In the eighth embodiment, since an example of application to a DVD is shown, a 1-bit random number sequence is generated for each 16-bit channel signal unit corresponding to 1 byte of main information.
[0203]
The XOR 404 stores 128-bit sub information in ECC units to be recorded in advance and counts the synchronization signal from the timing generator 401 to determine the currently recorded sector number and frame number, and One bit of the existing sub information is extracted from the sub information stored in advance. By calculating the exclusive OR of the extracted 1-bit sub information (F in FIG. 22 and F in FIG. 23) and the random number sequence from the random number generator 403, the displacement control signal (G in FIG. 23 G) is generated.
[0204]
Therefore, the displacement control signal generated by the XOR 404 is the same signal (G in FIG. 22) as the random number sequence generated by the random number generator 403 when the sub information bit to be recorded is “0”. Conversely, when the sub information bit to be recorded is “1”, the signal is equivalent to a signal (G in FIG. 23) obtained by inverting the random number sequence generated by the random number generator 403.
[0205]
Next, the displacement control signal (G in FIG. 22 and G in FIG. 23) generated by the XOR 404 is a PE signal generated by the timing generator 401 and inverting “1” “0” for every 8 bits of the channel signal. (H in FIG. 22 and H in FIG. 23) perform PE modulation. As a result, a PE modulation displacement control signal (I in FIG. 22 and I in FIG. 23) is obtained and output to the radial modulator 408.
[0206]
The radial modulator 408 receives the displacement permission signal (D in FIG. 22 and D in FIG. 23) from the timing generator 401 and the PE modulation displacement control signal (I in FIG. 22 and I in FIG. 23) from the PE modulator 405. And an analog displacement control signal (J in FIG. 22 and J in FIG. 23) having three types of levels (GND level, + V level, and −V level). The analog displacement control signal is at a + V level while the PE modulation displacement control signal is “1”, and is at a −V level while the PE modulation displacement control signal is “0”. By outputting the analog displacement control signal to the electrode 409, the analog displacement control signal is + V based on the light spot position formed by the recording beam emitted from the recording head 407 when a voltage of the GND level is applied to the electrode. In the case of the level, the light beam is refracted so that a light spot is formed by Δd toward the outer periphery of the optical disk, and in the case of −V level, the light spot is formed by Δd toward the inner periphery of the optical disk. Thereby, the recording mark excluding the synchronization code and the first frame and the 26th frame is slightly shifted in the radial direction by Δd toward the outer periphery and Δd toward the inner periphery (K in FIG. 22). , FIG. 23K) can be formed on the optical disc.
[0207]
Therefore, if the channel signal for recording the sub-information “0” and the sub-information “1” is the same, the information recording apparatus according to the present embodiment can record the sub-information “0” and the recording mark for the sub-information “1”. Is formed on the optical disk in a shape inverted with respect to the center line of the recording mark.
[0208]
Next, as a specific example of an information reproducing apparatus for simultaneously reproducing main information and sub-information from an optical storage medium according to the present invention, an apparatus for reproducing a DVD in which recording marks are spirally formed on a disk will be described. However, the playback device according to the present invention is not limited to this example.
[0209]
FIG. 25 is a block diagram showing main blocks of the information reproducing apparatus of the present embodiment. The information reproducing apparatus according to the present embodiment includes a reproducing head 1101, a reproducing channel 1102, a clock extractor 1103, a reproduced signal processing circuit 1104, a random number generator 1105, a PE modulator 1106, a TE signal AD converter 1107, and a sub information detector 1108. It has.
[0210]
The reproducing head 1101 condenses and irradiates a recording beam on the recording mark on the optical disc 1109 with a light beam, and converts the reflected light into an electric signal by a photodetector, thereby obtaining an RF signal which is a reproduction signal of information recorded by the recording mark. Is generated and output to the reproduction channel 1102. At the same time, the reproducing head 1101 is provided with an analog TE indicating the phase error in the radial direction of the recording mark obtained as a result of causing the center position of the light beam to follow the center position of the recording mark spirally recorded on the optical disk 1109. A signal is generated and output to the TE signal AD converter 1107.
[0211]
FIG. 26 is a conceptual diagram showing a main configuration for generating a TE signal indicating a radial displacement of a recording mark.
[0212]
The reproducing head 1101 condenses the light emitted from the semiconductor laser 1201 by the optical system 1202 so that the light is focused on the recording mark on the optical disc 1109. In the optical system 1202, the laser beam irradiated to the optical disk 1109 is separated from the reflected light from the optical disk 1109, and the reflected light is converted into an electric signal by the photo detectors 1203 and 1204. The photodetectors 1203 and 1204 are provided symmetrically on the outer peripheral side and the inner peripheral side with respect to the center line of the recording mark. Since the photodetectors 1203 and 1204 electrically determine the brightness of the reflected light on the outer peripheral side or the inner peripheral side, by taking the difference between the signal levels of the photodetector 1203 and the photodetector 1204, the displacement of the recording mark in the radial direction is obtained. Can be extracted.
[0213]
Usually, the center of the laser beam is tracked to the center position of the recording mark by the tracking servo. For example, when the recording mark is displaced in the outer peripheral direction, the reflected light detected by the photodetector 1203 is Since it is higher than the photodetector 1204, a “+” potential is output as a TE signal. On the other hand, when the center position of the recording mark is displaced inward, the reflected light sensed by the photodetector 1203 is lower than that of the photodetector 1204, so that a "-" potential is output as a TE signal. Further, such a TE signal is output in the same band as an RF signal which is an analog read signal of a recording mark.
[0214]
The reproduction channel 1102 converts the RF signal from the reproduction head into a digital read signal by performing waveform equalization and shaping, and outputs the digital read signal to the clock extractor 1103 and the reproduction signal processing circuit 1104.
[0215]
The clock extractor 1103 incorporates a PLL (Phase Locked Loop) circuit for extracting a clock signal synchronized with the digital read signal from the digital read signal digitized by the reproduction channel 1102. In addition, the clock signal extracted from the PLL circuit is frequency-divided by 16 at the timing of the synchronization signal from the reproduction signal processing circuit 1104 to be described later, and the byte clock synchronized with the 16-bit unit of the digital read signal and the digital read signal 16 A PE signal having 8 bits before “High” and 8 bits after “Low” is generated in bit units. The clock extractor 1103 outputs the byte clock to the reproduction signal processing circuit 1104, the random number generator 1105, and the sub information detector 1108, and outputs the PE signal to the PE modulator 1106.
[0216]
The reproduction signal processing circuit 1104 generates a synchronization signal indicating that a synchronization code has been detected from the digital read signal from the reproduction channel and the clock from the clock extractor 1103, and based on the detection position of the synchronization code, The main information is reproduced by demodulating the digital read signal into 1-byte (8-bit) main information in 16-bit units. Further, a synchronization signal generated as a result of detecting a synchronization code from the digital read signal is output to the clock extractor 1103, the random number generator 1105, and the sub information detector 1108.
[0217]
The random number generator 1105 has the same function as the random number generator 403 of the information recording apparatus according to the eighth embodiment, and internally stores secretly at the “High” timing of the synchronization signal from the reproduction signal processing circuit 1104. The random number sequence (correlation sequence) is generated bit by bit at the timing of the byte clock from the clock extractor 1103 and output to the PE modulator 1106. The reproduction signal processing circuit 1104 also determines the frame number in the currently reproduced sector from the synchronization code, and determines “Low”, “Low” in the section where the first frame, the 26th frame, and the synchronization code are detected in the sector. The data section other than the above generates a correlation detection permission signal that becomes “High” and outputs the signal to the sub information detector 1108.
[0218]
The PE modulator 1106 has the same function as the PE modulator 405 in the information recording apparatus according to the eighth embodiment, is configured by an exclusive OR gate, and receives a random number sequence (correlation sequence) from the random number generator 1105 and a clock. By calculating an exclusive OR with the PE signal from the extractor 1103, a PE-modulated correlation sequence is generated and output to the sub-information detector 1108.
[0219]
The TE signal AD converter 1107 samples the TE signal from the reproduction head 1101 at the timing of the clock from the clock extractor 1103, and converts it into a digital signal. The AD converted digital TE signal is output to sub information detector 1108.
[0220]
The sub information detector 1108 receives the byte clock from the clock extractor 1103, the synchronization signal from the reproduced signal processing circuit 1104, the correlation detection enable signal, the PE modulation correlation sequence from the PE modulator 1106, and the TE signal AD converter 1107. The sub information is detected based on the digital TE signal. As shown in FIG. 27, the sub information detector 1108 includes a selector 1301, a sub information update timing generator 1302, a level integrator 1303, and a threshold value determiner 1304.
[0221]
The selector 1301 converts the level of the digital TE signal output from the TE signal AD converter 1107 according to the PE modulation correlation sequence from the PE modulator 1106, and outputs the result to the level integrator 1303. In the eighth embodiment, the digital TE signal is set to the 0 level when the recording mark is at the center position, the “+” level when the recording mark is displaced toward the outer periphery, and the recording mark toward the inner periphery. Is displaced, the level is set to the "-" level, and a two's complement expression is used. For example, when the PE modulation correlation sequence from the PE modulator 1106 is “1”, the selector 1301 sets the “+” level to “+” level and the “−” level to “−”. The signal is output to the level integrator 1303 as it is. Conversely, when the PE modulation correlation sequence is “0”, the “+” level is output to the level integrator 1303 in a state where the “+” level is inverted to the “−” level and the “−” level is inverted to the “+” level. I do.
[0222]
The sub information update timing generator 1302 calculates the frame number in the sector being reproduced by counting the clock from the clock extractor 1103 and the synchronization signal from the reproduction signal processing circuit 1104, and calculates the frame number in the sector being reproduced. A timing signal for updating sub-information in units of three frames is generated in all 24 frames excluding the 1st and 26th frames, and is output to the level integrator 1303 and the threshold value judging unit 1304.
[0223]
The level integrator 1303 calculates the integral value of the partially inverted two's complement digital TE signal output from the selector 1301 in the section where the correlation detection permission signal from the reproduction signal processing circuit 1104 is “High”. Part.
[0224]
The level integrator 1303 outputs the integration result to the threshold value determiner 1304 at the timing of the sub information update timing signal output once every three frames from the sub information update timing generator 1302, and also outputs the level integrator 1303. Clear the internal integral value (set to 0).
[0225]
Therefore, the present level integrator 1303 detects when the PE modulation correlation sequence is “1” and the digital TE signal is “+” level, or when the PE modulation correlation sequence is “0” and the digital TE signal is only the “−” level. , Continues to increase to a positive value as an integral value. Symmetrically, if the PE modulation correlation sequence is "1" and the digital TE signal is "-" level, or if the PE modulation correlation sequence is "0" and the digital TE signal is only "+" level, the integral value is obtained. Continues to decrease to negative values.
[0226]
The threshold value determiner 1304 internally stores a positive threshold value and a negative threshold value, and determines the integrated value output every three frames from the level integrator 1303 based on the positive and negative threshold values. By performing the threshold determination, if a detection flag indicating the presence or absence of sub information and sub information exist, the sub information is output.
[0227]
In the threshold value determination process of the threshold value determination unit 1304, when the integrated value output from the level integrator 1303 is equal to or more than a positive threshold value, a bit value “0” is output as sub-information. At the same time, “High” is output as a detection flag. When the integrated value is equal to or smaller than the negative threshold value, a bit value “1” is output as sub-information and “High” is output as a detection flag. On the other hand, when the integral value is less than the positive threshold value and larger than the negative threshold value (that is, the integral value is closer to 0 than the positive and negative threshold values), Is not detected, "Low" is output to the detection flag.
[0228]
Next, an operation of reproducing the main information and the sub information by the present information reproducing apparatus will be described.
[0229]
FIGS. 28 and 29 are timing charts when the main information and the sub information are reproduced by the present information reproducing apparatus. FIG. 28 shows the case where the bit value "0" of the sub information is detected. This is a case where the value “1” is detected.
[0230]
The present information reproducing apparatus irradiates a recording mark (A in FIG. 28, A in FIG. 29) formed on an optical disk with a light beam, converts reflected light into an electric signal by a photodetector, and then reproduces the reproduced channel 1102. To generate digital read signals (B in FIG. 28 and B in FIG. 29).
[0231]
Further, a clock (C in FIG. 28 and C in FIG. 29) synchronized with the digital read signal is generated by the clock extractor 1103 based on the digital read signal.
[0232]
Also, the reproduction signal processing circuit 1104 detects the synchronization code from the digital read signal to detect the synchronization code section 1401, and generates a synchronization signal (D in FIG. 28 and D in FIG. 29).
[0233]
Also, the reproduction signal processing circuit 1104 determines the position of the currently reproduced frame by counting the number of synchronization signals in the sector, and in each frame, the synchronization code section 1401, which is the area where the synchronization code is recorded, and the first and second frames. A correlation detection permission signal (E in FIG. 28 and E in FIG. 29) that becomes “High” in a section excluding the frame and the 26th frame is generated.
[0234]
Therefore, as shown in FIG. 24, as a correlation detection permission signal in a sector, as shown in FIG. 24, a section for reproducing the synchronization code section 1401 of each frame (see section 1001 in FIG. 24) and a section for reproducing the first frame and the 26th frame ( It is possible to generate a signal that becomes “High” in a section excluding sections 1002 and 1003 in FIG. 24).
[0235]
The random number generator 1105 presets an internally stored secret value in advance at the timing when the synchronization signal is detected (initialization timing 1403), and outputs the byte clock from the clock extractor 1103 (based on the synchronization signal. Correlation sequences (F in FIG. 28 and F in FIG. 29) are generated bit by bit in accordance with the clock obtained by dividing the clock by 16.
[0236]
The PE modulator 1106 uses a PE signal (G in FIG. 28 and G in FIG. 29) that repeats “High” and “Low” in units of 8 bits based on the synchronization signal output from the clock extractor 1103, and generates a random number. The correlation sequence from the generator 1105 is subjected to PE modulation. The resulting PE-modulated correlation signal (H in FIG. 28, H in FIG. 29) is output to the sub-information detector 1108.
[0237]
The sub information detector 1108 generates a PE-modulated correlation sequence (FIG. 28) from the PE modulator 1106 based on a digital TE signal obtained by digitizing the TE signal (I in FIG. 28 and I in FIG. 29) generated by the reproducing head 1101. 29, H) of FIG. 29 is "High", the level of the digital TE signal is integrated as it is. When the PE modulation correlation sequence (H in FIG. 28 and H in FIG. 29) is “Low”, the level of the digital TE signal is inverted and integrated.
[0238]
The sub information detector 1108 determines the presence or absence of sub information by comparing the integrated value (J in FIG. 28 and J in FIG. 29) of the internal level integrator 1303 with a positive or negative threshold value. Further, when the sub information exists, the sub information is detected.
[0239]
FIG. 28 shows a process in which the sub information bit value “0” is detected. The integrated value (J in FIG. 28) continues to increase in the positive direction. On the other hand, FIG. 29 shows a process in which the sub information bit value “1” is detected. The integrated value (J in FIG. 29) keeps decreasing in the negative direction.
[0240]
In the eighth embodiment, 1-bit sub-information is detected every three frames in all 24 frames except the first frame and the 26th frame in the sector. FIG. 30 shows the relationship between the generated frame and the integrated value in the eighth embodiment.
[0241]
In the sector, the main information is reproduced by reading the recording mark continuously from the first frame to the 26th frame, and the sub information is read every 3 frames in all 24 frames excluding the 1st frame and the 26th frame. An update timing signal (B in FIG. 30) is generated by the sub information update timing generator 1302.
[0242]
The level integrator 1303 calculates the integrated value (C in FIG. 30) by integrating the levels of the digital TE signal in the section until the sub information update timing is output, and outputs the sub information update timing. Then, the integrated value of the three frames is output to the threshold value determiner 1304 and the integrated value of the level integrator 1303 is cleared. When the correlation detection permission signal (A in FIG. 30) is “Low”, the integrated value of the level integrator 1303 is held.
[0243]
As described above, according to the eighth embodiment, it is possible to record the sub-information on the optical disc on which the main information is recorded by the optically readable recording marks by the displacement of the recording marks in the radial direction. Since information recorded by such displacement in the radial direction is difficult to copy to another medium, it can be used for recording an encryption key or the like of a digital work recorded on an optical disk.
[0244]
Further, according to the eighth embodiment of the present invention, a synchronization code portion necessary for correcting a bit shift, a byte shift, and a frame shift during reproduction among record marks, and a sector in which a sector ID is recorded in a DVD. No displacement in the radial direction is performed on the recording marks constituting the first frame and the like. This makes it possible to record the sub-information while minimizing the deterioration of the reliability of the main information.
[0245]
In addition, the sub-information can be recorded in accordance with the recording format of the main information by a minute displacement in the radial direction of the recording mark synchronized with the synchronization code of the main information. Can be reproduced.
[0246]
Also, as in Embodiment 8 of the present invention, by making the amount of displacement in the radial direction equal to or less than the amount permitted when no sub-information is recorded, it is easy to determine that sub-information is being recorded. This makes it possible to record highly confidential information.
[0247]
When the sub-information is used for copyright protection or the like as described above, the amount of displacement in the radial direction is desirably such that it can be detected within the noise range of the TE signal. This is because, when the displacement amount is large and is clearly output as the TE signal, it is easy to see that the recording mark is displaced in the radial direction. Therefore, the amount of displacement of the recording mark in the radial direction is desirably set to such a degree that the recording mark can be generated even in a recording mark of a normal recording method that does not perform displacement in the radial direction.
[0248]
(Embodiment 9)
Embodiment 9 of the present invention will be described in detail with reference to the drawings.
[0249]
FIG. 31 shows a DVD sector format of the present embodiment in which main information is recorded by recording marks and sub-information is recorded by displacing the recording marks by a small amount in the radial direction.
[0250]
Similarly to the optical disk described in the eighth embodiment, the optical disk according to the ninth embodiment of the present invention is configured such that 8-bit sub information is recorded in all 24 frames except the first and 26th frames in a sector. is there. However, the present embodiment is different from the eighth embodiment in that sub-information is divided and recorded in three non-consecutive frames having regularity, instead of having 1-bit sub-information in three consecutive frames.
[0251]
In the present embodiment, as shown in FIG.
(2nd frame, 10th frame, 18th frame) 1 bit of sub information
(3rd frame, 11th frame, 19th frame) 1 bit of sub information
(4th frame, 12th frame, 20th frame) Sub information 1 bit
(5th frame, 13th frame, 21st frame) Sub information 1 bit
(6th frame, 14th frame, 22nd frame) 1 bit of sub information
(7th frame, 15th frame, 23rd frame) Sub information 1 bit
(8th frame, 16th frame, 24th frame) 1 bit of sub information
(9th frame, 17th frame, 25th frame) 1 bit of sub information
, Sub-information of 8 bits is recorded in the sector.
[0252]
FIG. 32 is a conceptual diagram showing the formation of recording marks on the optical disc according to the ninth embodiment of the present invention.
[0253]
The optical disk according to the ninth embodiment of the present invention modulates the main information to be recorded and inserts a recording code based on a signal obtained by NRZI-converting a channel signal (FIG. 32A) generated by inserting a synchronization code in frame units. The main information is recorded by irradiating to form a spiral recording mark (FIG. 32B) on the optical disk.
[0254]
FIG. 32B shows a standard recording mark in which the recording mark is not displaced in the radial direction (no sub-information is recorded).
[0255]
On the other hand, when the sub information is recorded due to the minute displacement of the recording mark in the radial direction, the displacement permission signal indicating the area other than the first and 26th frames in the sector and the area where the synchronization code of each frame is inserted. According to (C in FIG. 32), a pseudo-random number sequence (D in FIG. 32) initialized at the timing of inserting the synchronization code is generated.
[0256]
The recording mark to which the sub information is added is recorded in a state where the recording mark is displaced to the inner side or the outer side by a small amount in accordance with the special PE modulation displacement control signal (G, K in FIG. 32). The special PE modulation displacement control signal is a displacement control signal (FIG. 32) calculated from an exclusive OR of a sub-information bit to be recorded and a pseudo-random number sequence (D in FIG. 32) initialized at the timing of inserting a synchronization code. E, I) are subjected to special PE modulation.
[0257]
F and J in FIG. 32 show the PE modulation displacement control signal subjected to the normal PE modulation according to the eighth embodiment for comparison with the special PE modulation displacement control signal according to the present embodiment.
[0258]
As can be seen from comparison with F and J in FIG. 32 and the displacement recording marks (H and L in FIG. 32), the special PE modulation displacement control signals (G and K in FIG. Is controlled so as not to have a change point of the minute displacement in the radial direction during the formation of.
[0259]
Next, a DVD recording device will be described as an example of the information recording device according to the present embodiment. However, the information recording device of the present invention is not limited to a DVD recording device.
[0260]
FIG. 33 is a block diagram showing a main block configuration of the information recording apparatus according to the present embodiment. The present information recording apparatus records main information by using a recording mark, and records sub-information by displacing the recording mark so as not to have a change point of the minute displacement in the radial direction. This information recording apparatus includes a timing generator 1901, a modulator 1902, a random number generator 1903, a sub information updater 1904, an XOR 1905, a special PE modulator 1906, a recording channel 1907, a recording head 1908, and a radial modulator 1909. ing.
[0261]
The timing generator 1901 outputs a synchronization signal indicating the timing of inserting a synchronization code for each frame recording timing to the modulator 1902, the random number generator 1903, and the sub information updater 1904, and synchronizes with one byte of main information. And outputs to the random number generator 1903 a PE signal in which the first 8 bits of one byte (16 channel bits) of the main information are “High” and the last 8 bits are “Low”, and the special PE is generated. Output to modulator 1906.
[0262]
The modulator 1902 modulates (8-16 modulation) into information of 16 channel bits for each byte of the main information, and inserts a synchronization code at the timing of the synchronization signal from the timing generator 1901 to thereby convert the channel signal. It is generated and output to the recording channel 1907.
[0263]
The random number generator 1903 is a block having the same function as the random number generator 403 of the information recording device according to the eighth embodiment. The random number generator 1903 initializes at the falling timing of the synchronization signal from the timing generator 1901, generates a random number sequence of one bit at a time in synchronization with the byte clock from the timing generator, and outputs it to the XOR 1905.
[0264]
The sub information updater 1904 stores all sub information bits (8 bits) to be superimposed and recorded on the main information in units of sectors in advance, and counts the synchronization signal from the timing generator 1901 to obtain the currently recorded sector. And outputs the sub information to the XOR 1905 bit by bit as described below.
[0265]
(2nd frame, 10th frame, 18th frame) 1 bit of first sub information
(3rd frame, 11th frame, 19th frame) 1 bit of second sub information
(4th frame, 12th frame, 20th frame) 3rd sub information 1 bit
(5th frame, 13th frame, 21st frame) 4th sub information 1 bit
(Sixth frame, Fourteenth frame, Twenty-second frame) Fifth sub information 1 bit
(7th frame, 15th frame, 23rd frame) 6th sub information 1 bit
(8th frame, 16th frame, 24th frame) 7th sub information 1 bit
(9th frame, 17th frame, 25th frame) 8th sub information 1 bit
XOR 1905 is configured by an exclusive OR gate, and generates a displacement control signal by calculating exclusive OR of a random number sequence from random number sequence generator 1903 and one bit of sub information from sub information updater 1904. , To the special PE modulator 1906.
[0266]
The special PE modulator 1906 is a block that performs special PE modulation on the displacement control signal from the XOR 1905 based on the PE signal from the timing generator 1901 and the channel signal from the modulator 1902. FIG. 34 shows the detailed block configuration.
[0267]
The special PE modulator 1906 includes a PE modulator 2001, an edge determiner 2002, a distance determiner 2003, a distance determiner 2004, a selector 2005, an UP / DOWN counter 2006, and a special PE modulation displacement control signal generator 2007. ing.
[0268]
The PE modulator 2001 is a block having the same function as the PE modulator 405 of the information recording device according to the eighth embodiment. The PE modulator 2001 includes an exclusive OR gate, and generates a PE modulation displacement control signal by calculating an exclusive OR of the PE signal from the timing generator 1901 and the displacement control signal from the XOR 1905. Output to the edge determiner 2002.
[0269]
From the recording channel signal from the modulator 1902 and the PE modulation displacement control signal from the PE modulator 2001, the edge determiner 2002 determines a PE modulation displacement control signal edge A in the recording mark and a PE modulation displacement control signal edge B in the recording mark. It is generated and output to the distance determiners 2003 and 2004, respectively. The edge A of the PE modulation displacement control signal in the recording mark indicates a rising edge position of the PE modulation displacement control signal in a section of the recording channel signal “High” indicating a portion for generating the recording mark on the optical disc. The PE modulation displacement control signal edge B in the recording mark indicates a falling edge position of the PE modulation displacement control signal in a section of the recording channel signal “High”.
[0270]
The distance judging unit 2003 calculates a period from the recording channel signal from the modulator 1902 and the edge A of the PE modulation displacement control signal in the recording mark from the edge judging unit 2002 to the rising edge of the recording channel signal from the edge A of the PE modulation displacement control signal in the recording mark. The distance A (plus) and the distance A (minus) from the edge A of the PE modulation displacement control signal in the recording mark to the fall of the recording channel signal are calculated and output to the selector 2005.
[0271]
The distance judging device 2004 receives a signal from the recording channel signal from the modulator 1902 and the edge B of the PE modulation displacement control signal in the recording mark from the edge judging device 2002 to the rising edge of the recording channel signal from the edge B of the PE modulation displacement control signal in the recording mark. The distance B (minus) and the distance B (plus) from the edge B of the PE modulation displacement control signal in the recording mark to the fall of the recording channel signal are calculated and output to the selector 2005.
[0272]
When the UP / DOWN counter value is “positive”, the selector 2005 determines the distance A (minus) or the distance B (minus) on the basis of the value of the UP / DOWN counter 2006, which will be described later, with the UP / DOWN counter 2006 and the special PE. When the UP / DOWN counter value is “negative”, the distance A (plus) and the distance B (plus) are sent to the modulation displacement control signal generator 2007 and the UP / DOWN counter 2006 and the special PE modulation displacement control signal generator 2007. Output to
[0273]
The UP / DOWN counter 2005 is configured with a counter that counts up the distance A (plus) and the distance B (plus) and counts down the distance A (minus) and the distance B (minus), with the initial counter value being “0”. You.
[0274]
When the distance A (plus) is selected according to the distance selected by the selector 2005, the special PE modulation displacement control signal generator 2007 advances the rising edge position of the PE modulation displacement control signal by the distance A (plus). On the other hand, when the distance A (minus) is selected, the rising edge position of the PE modulation displacement control signal is delayed by the distance A (minus). When the distance B (plus) is selected, the falling edge position of the PE modulation displacement control signal is delayed by the distance B (plus). On the other hand, when the distance B (minus) is selected, the distance B (minus) is selected. The falling edge position of the PE modulation displacement control signal is advanced by B (minus).
[0275]
Therefore, the special PE modulator 1906 performs PE modulation of the displacement control signal from the XOR 1905, and has no change point in the recording mark, and the sections of “High” and “Low” are approximately equal. A modulation displacement control signal is generated and output to the radial modulator 1907.
[0276]
FIG. 35 is a timing chart showing the operation of the special PE modulator 1906.
[0277]
The recording channel signal (A in FIG. 35) and the PE modulation control signal (B in FIG. 35) shown in FIG. 35 are delayed for a sufficient time while being stored in a shift register or the like in advance, so that the timing chart shown in FIG. Control is possible.
[0278]
The special PE modulator 1906 generates a PE-modulated displacement control signal (B in FIG. 35) obtained by subjecting the displacement control signal to PE modulation, and a recording channel indicating a section in which a recording mark is generated on the optical disc by the edge determiner 2002. In a section in which the signal (A in FIG. 35) is “High”, an edge A in the recording mark (C in FIG. 35) indicating the rising edge of the PE modulation displacement control signal (B in FIG. 35) is generated. Further, in a section in which the recording channel signal (A in FIG. 35) is “High”, an edge B in the recording mark (F in FIG. 35) indicating the falling edge of the PE modulation displacement control signal (B in FIG. 35) is generated.
[0279]
The distance determiner 2003 extracts the distance (time) from the position indicated by the recording mark edge A (C in FIG. 35) to the rise of the recording channel signal as the distance A (plus) (D in FIG. 35). The distance (time) from the position indicated by the edge A in the recording mark (C in FIG. 35) to the fall of the recording channel signal is extracted as the distance A (minus) (E in FIG. 35).
[0280]
Similarly, the distance determiner 2004 extracts the distance (time) from the position indicated by the edge B in the recording mark (F in FIG. 35) to the rise of the recording channel signal as the distance B (minus) (G in FIG. 35). The distance (time) from the position indicated by the edge B in the recording mark (F in FIG. 35) to the fall of the recording channel signal is extracted as the distance B (plus) (H in FIG. 35).
[0281]
I in FIG. 35 shows a counter value of the UP / DOWN counter 2006 of the special PE modulator 1906, and J in FIG. 35 shows a special PE modulation displacement control signal which is an output of the special PE modulator 1906.
[0282]
If the change point of the PE modulation displacement control signal exists in the “High” section of the recording channel (exists within the recording mark), the special PE modulator 1906 advances or delays the change point outside the recording mark. Thus, a special PE modulation displacement control signal having no change point in the recording mark is generated.
[0283]
As an example, a case where the edge eg1 of the PE modulation displacement control signal (B) is displaced to eg6 of the special PE modulation displacement control signal (J) in FIG. 35 will be described in detail.
[0284]
Here, in the recording channel signal (A in FIG. 35), it is assumed that the falling edge eg1 of the PE modulation displacement control signal exists in the section of the recording mark corresponding to eight recording reference clocks. Therefore, the edge B in the recording mark indicates the location of eg1.
[0285]
When the falling edge eg1 is detected in the recording mark by the edge B in the recording mark, “5” indicating five clocks from the eg1 to the rising edge eg11 of the recording channel signal is set as the distance B (minus). Also, “3” indicating three clocks from eg1 to the falling edge eg12 of the recording channel signal is generated as the distance B (plus).
[0286]
The UP / DOWN counter value (judgment counter value) (I in FIG. 35) indicates “0” at the time when eg1 is detected. That is, since the determination counter value is determined as “0”, the smaller of the distance B (minus) and the distance B (plus), that is, the distance B (plus) is adopted, and the position eg6 obtained by delaying eg1 by three clocks. And the distance B (plus) is added to the UP / DOWN counter value.
[0287]
Next, the displacement from eg2 to eg7 will be described.
[0288]
Here, it is assumed that the rising edge eg2 of the PE modulation displacement control signal (B in FIG. 35) exists in the recording mark for 6 clocks. The position is shown at the edge A in the recording mark.
[0289]
If the edge A in the recording mark indicates that the edge of the PE modulation control signal exists in the recording mark, "2" indicating two clocks of the distance from eg2 to the rising edge eg13 of the recording channel signal is the distance. As the A (plus), “4” indicating four clocks of the distance from eg2 to the falling edge eg14 of the recording channel signal is extracted as the distance A (minus).
[0290]
The UP / DOWN counter value at the timing when eg2 is detected is “3” indicating that eg1 has been delayed by three clocks, that is, since it is a “positive” value, the distance A (minus) is calculated. Adopted, displaces eg2 to position eg7 delayed by distance A (minus), and updates the UP / DOWN counter value by subtracting distance A (minus).
[0291]
Similarly, eg3 is detected as a change point in the recording mark, and the distance A (plus) from eg3 to the rising edge of the recording channel signal = “6”, and the distance A (minus) from eg3 to the falling edge of the recording channel signal. ) = "6" is detected.
[0292]
Since the judgment counter value at the timing when eg3 is detected is “−1”, the distance A (plus) is adopted, eg3 is displaced to the position eg8 advanced by 6 clocks, and the counter value becomes “6”. "Addition is performed and updated to" 5 ".
[0293]
As described above, the value of the UP / DOWN counter 2006 of the special PE modulator 1906 is controlled to ± 11 in the case of a DVD having 11T as the maximum recording mark width, and has a changing point within the recording mark. No special PE modulation displacement control signal can be generated.
[0294]
A recording channel 1907 of the present information recording apparatus adjusts the intensity of the recording beam or the recording beam interval based on the channel signal from the modulator 1902, and controls the recording beam for forming a recording mark on the optical disk. Is generated and output to the recording head 1908.
[0295]
The recording head 1908 records main information by irradiating a recording beam to the optical disc 1911 based on a recording beam control signal from the recording channel 1907 to form a recording mark.
[0296]
The radial modulator 1909 has an electrode 1910. When the displacement permission signal from the timing generator 1901 is “High”, “+” charges are applied to the electrode 1910 in accordance with the PE displacement control signal from the special PE modulator 1906. Alternatively, the recording beam emitted from the recording head 1908 is displaced toward the inner circumference or the outer circumference of the optical disk by giving “−” charges. As a result, the sub-information is recorded by recording with the recording mark on the optical disk being displaced inward or outward. Note that the basic configuration of this part is the same as that of the radial modulator 408 in the information recording apparatus of the eighth embodiment.
[0297]
Next, an information reproducing apparatus according to the ninth embodiment will be described. FIG. 36 is a main block diagram of the information reproducing apparatus according to the present embodiment. The information reproducing apparatus according to the present embodiment includes a reproducing head 2201, a reproducing channel 2202, a clock extractor 2203, a reproduced signal processing circuit 2204, a random number generator 2205, a special PE modulator 2206, a TE signal AD converter 2207, and sub information. A detector 2208 is provided.
[0298]
The reproduction head 2201 irradiates the optical disk 2209 with a light beam, generates an analog read signal from the reflected light, and outputs the analog read signal to the reproduction channel 2202. The reproducing head 2201 generates an analog TE signal indicating a phase error of the recording mark in the inner circumferential direction or the outer circumferential direction with respect to the track center position, and outputs the analog TE signal to the TE signal AD converter 2207.
[0299]
The reproduction channel 2202 generates a digital read signal by amplifying or equalizing the waveform of the analog read signal read from the reproduction head 2201, and outputs the digital read signal to the clock extractor 2203 and the reproduction signal processing circuit 2204.
[0300]
The clock extractor 2203 generates a clock synchronized with the digital read signal from the digital read signal from the playback channel 2202, outputs the clock to the playback signal processing circuit 2204, and outputs the clock synchronized with the byte unit of the digital read signal. A clock is generated and output to the reproduction signal processing circuit 2204, the random number generator 2205, and the sub information detector 2208.
[0301]
The reproduction signal processing circuit 2204 detects the synchronization code portion from the digital read signal from the reproduction head 2202, and converts 16-bit information into 8-bit information according to the clock and byte clock from the clock extractor 2203 (this embodiment). The main information is extracted by performing 8-16 modulation in the case of a DVD as described above.
[0302]
The random number generator 2205 has a function equivalent to that of the random number generator 1905 in the information recording apparatus according to the present embodiment, and is internally stored secretly at the timing of the synchronization signal from the reproduction signal processing circuit 2204. An initial value is preset, a random number sequence is generated bit by bit at the timing of the byte clock from the clock extractor 2203, and output to the special PE modulator 2206.
[0303]
The special PE modulator 2206 is a part having the same function as the special PE modulator 1906 in the information recording device according to the present embodiment. The special PE modulator 2206 converts the correlation sequence from the random number generator 2205 from “High” to a section in which the recording mark is reproduced by the PE signal from the clock extractor 2203 and the digital read signal from the reproduction channel 2202. A special PE modulation correlation sequence that does not have a transition point from “Low” or from “Low” to “High” is generated and output to the sub information detector 2208.
[0304]
The TE signal AD converter 2207 performs AD conversion of the analog TE signal from the reproducing head 2201 according to the clock from the clock extractor 2203, and outputs a digitized digital TE signal to the sub information detector 2208.
[0305]
The sub-information detector 2208 receives a synchronization signal from the reproduction signal processing circuit 2204, a special PE modulation correlation sequence from the special PE modulator 2206, and a digital TE signal from the TE signal AD converter 2207, The sub information is detected according to the byte clock. As shown in FIG. 37, the sub information detector 2208 mainly includes a selector 2301, a sub information update timing generator 2302, a level integrator 2303, and a threshold value determiner 2304.
[0306]
When the special PE modulation correlation sequence from the special PE modulator 2206 is “High”, the selector 2301 outputs the digital TE signal to the level integrator 2303 as it is, and when the special PE modulation correlation sequence is “Low”. In this case, the sign of the digital integrated value is inverted and output to the level integrator 2303.
[0307]
The sub-information update timing generator 2302 extracts the frame position information being reproduced from the synchronization signal from the reproduction signal processing circuit 2204 and the byte clock from the clock extractor 2203, and outputs the level integrator 2303 as a frame identification signal. Output to
[0308]
The level integrator 2303 has eight storage units 2303 [0] to 2303 [7] therein. Based on the frame identification signal from the sub information update timing generator 2302, the inverted or non-inverted signal output from the selector 2301 is output. The inverted digital TE signal levels are integrated in the following correspondence. The digital TE signal levels integrated in the storage units 2303 [0] to 2303 [7] are output to the threshold value determination unit 2304 as correlation values [0] to [7].
[0309]
(2nd frame, 10th frame, 18th frame) Storage section 2303 [0]
(3rd frame, 11th frame, 19th frame) Storage section 2303 [1]
(4th frame, 12th frame, 20th frame) Storage section 2303 [2]
(5th frame, 13th frame, 21st frame) Storage section 2303 [3]
(Sixth frame, Fourteenth frame, Twenty-second frame) Storage unit 2303 [4]
(7th frame, 15th frame, 23rd frame) Storage section 2303 [5]
(8th frame, 16th frame, 24th frame) Storage section 2303 [6]
(9th frame, 17th frame, 25th frame) Storage section 2303 [7]
Also, the integrator 2303 uses the sub information update timing signal output from the sub information update timing generator 2302 for each sector to generate the TE signal of each of the TE signals stored in the storage units 2303 [0] to 2303 [7]. After the level integration value (correlation value [0] to correlation value [7]) is output to the threshold value judgment unit 2304, the value is cleared (set to 0).
[0310]
The threshold value determiner 2304 compares the eight integrated values (correlation values) output from the level integrator 2303 at the sub-information update timing with a positive threshold value and a negative threshold value stored in advance therein. Thus, 8-bit sub information is extracted in one sector.
[0311]
The optical disc according to the ninth embodiment of the present invention has the format shown in FIG.
(2nd frame, 10th frame, 18th frame) Sub information [0]
(3rd frame, 11th frame, 19th frame) Sub information [1]
(4th frame, 12th frame, 20th frame) Sub information [2]
(5th frame, 13th frame, 21st frame) Sub information [3]
(6th frame, 14th frame, 22nd frame) Sub information [4]
(7th frame, 15th frame, 23rd frame) Sub information [5]
(8th frame, 16th frame, 24th frame) Sub information [6]
(9th frame, 17th frame, 25th frame) Sub information [7]
As described above, 8-bit sub-information is stored in one sector by radial displacement of a recording mark.
[0312]
FIG. 38 is a conceptual diagram showing a correlation value calculated in the sub information detector 2208.
[0313]
Normally, an optical disk reproducing apparatus continuously reproduces a sector having a plurality of frames recorded in a spiral form from the inner peripheral side to the outer peripheral side.
[0314]
This information reproducing apparatus identifies the frame numbers of all 26 frames in one sector by the synchronization code given to the frames, and extracts the correlation value in the level integrator 2303 using the storage unit corresponding to each frame number. I do.
[0315]
FIG. 38A shows the above-mentioned frame identification signal, which corresponds to 24 frames excluding the first frame and the last frame in the sector.
(2nd frame, 10th frame, 18th frame) Identifier [0]
(3rd frame, 11th frame, 19th frame) Identifier [1]
(4th frame, 12th frame, 20th frame) Identifier [2]
(5th frame, 13th frame, 21st frame) Identifier [3]
(6th frame, 14th frame, 22nd frame) Identifier [4]
(7th frame, 15th frame, 23rd frame) Identifier [5]
(8th frame, 16th frame, 24th frame) Identifier [6]
(9th frame, 17th frame, 25th frame) Identifier [7]
Is output to the level integrator 2303.
[0316]
The level integrator 2303 has eight storage units 2303 [0] to 2303 [7] therein, and stores the inverted or non-inverted digital TE signal level output from the selector 2301 by the storage unit corresponding to the identifier. Perform integration.
[0317]
FIG. 38B illustrates a case where the sub information bit “0” is recorded by displacing the recording marks of the second, tenth, and eighteenth frames in the radial direction by a small amount, and the special PE modulation correlation sequence is “ This is the case where only “High” and the digital TE signal are “positive”, the special PE modulation correlation sequence is “Low”, and only the digital TE signal is “negative”. In this case, the correlation value [0] of the storage unit 2303 [0] simply increases in the positive direction in the second, tenth, and eighteenth frame sections.
[0318]
FIG. 38C shows a case where the sub-information bit “1” is recorded by slightly displacing the recording marks of the third, eleventh, and nineteenth frames in the radial direction. Is “High” and the digital TE signal is “negative”, or the special PE modulation correlation sequence is “Low” and only the digital TE signal is “positive”. In this case, the correlation value [1] of the storage unit 2303 [1] simply decreases in the negative direction in the sections of the third, eleventh, and nineteenth frames.
[0319]
As described above, in the optical disc according to the ninth embodiment of the present invention, the main information is recorded in units of frames accompanied by a synchronization code, and the recording marks of three non-consecutive frames on the disc are arranged in units of sectors consisting of a plurality of frames. One bit of sub information is recorded by intentional displacement in the direction. As a result, even when a burst error that extends over a plurality of frames is present, it is possible to reduce the risk that three frames on which sub-information is recorded are completely erased.
[0320]
Further, the information recording apparatus according to the ninth embodiment of the present invention applies a special PE modulation to the internally generated random number sequence without having a change point in the recording mark. As a result, even in an optical disc on which sub-information is recorded by displacing a small amount in the radial direction, no displacement in the radial direction is made in the recording mark, so that it is difficult to find the displacement in the radial direction.
[0321]
Further, the information reproducing apparatus according to the ninth embodiment of the present invention can stably record the main information and the sub information from an optical disc in which one bit of sub information is recorded in three discontinuous frames and the recording mark is not displaced in the radial direction. Information can be reproduced.
[0322]
As described above, since the sub information of the optical disc according to the present embodiment is recorded by the minute displacement of the recording mark in the radial direction, it is difficult to copy the sub information to a normal rewritable optical disc. Therefore, for example, it is also possible to record a decryption key or the like for decrypting the content to be recorded on the optical disc as sub-information. Alternatively, in a DVD or the like, a disk identifier recorded by a special recording method using an expensive and high-output initializer can be recorded as the sub-information, and the manufacturing cost can be reduced.
[0323]
In the case of a read-only optical disk represented by a DVD-ROM, an identifier of a stamper for generating the disk may be recorded as sub-information.
[0324]
In the eighth and ninth embodiments, the initial value of the random number sequence of the random number sequence generator of the information recording device and the reproducing device is secretly stored internally. By setting the disk identifier recorded by the special recording method using the initializer as the initial value of the random number sequence generator, a pirated maker or the like having no initializer can be eliminated.
[0325]
In addition, it is also possible to initialize the initial value of the random number sequence generator of the information recording device and the reproducing device of the eighth and ninth embodiments using the sector address given in sector units. In this case, different initial values can be set for each sector, and the confidentiality of the sub information can be improved.
[0326]
Further, in the above-described eighth and ninth embodiments, the form in which the sub-information is recorded by three consecutive frames or three non-continuous frames has been described, but the present invention is not limited to this. For example, an optical disk that records one bit of sub-information over a plurality of frames and a recording device or a reproducing device thereof all belong to the technical scope of the present invention. For example, there is a case where sub-information is reproduced by dividing one frame into a plurality of sections (0 to N) and calculating a correlation in each of the 0 to N sections over a plurality of frames.
[0327]
Further, in the above-described eighth and ninth embodiments, the form in which the initial value of the random number sequence generator is secretly stored inside the block has been described, but the present invention is not limited to this. For example, if an identifier unique to each optical disc is used as the initial value of the random number sequence, it is possible to record a recording mark by a displacement in the radial direction unique to each optical disc medium.
[0328]
Further, for example, key information output as a result of the device invalidation process can be used as the initial value of the random number sequence. In this case, it is also possible to invalidate a device that records or reproduces the sub information.
[0329]
In addition, it is also possible to use address information recorded on an optical disc and an encrypted content key as the initial value of the random number sequence.
[0330]
In addition, since the random number initial value is the most important information for protecting the sub information from fraud, it may be possible to secretly generate the initial value inside the device.
[0331]
(Embodiment 10)
Embodiment 10 of the present invention will be described in detail with reference to the drawings.
[0332]
The optical disc according to the tenth embodiment is different from the eighth and ninth embodiments in that the main information is recorded by the recording marks and the sub information is recorded by displacing (wobbling) the recording marks by a small amount in the radial direction. Is the same as However, this embodiment differs from the eighth and ninth embodiments in that the data portion of each frame in which the recording mark is wobbled is divided into a plurality of blocks having a random length in the track direction, and the wobble cycle differs for each of these blocks.
[0333]
If the wobble cycle of the recording mark is constant, the wobble cycle may be detected relatively easily by observing the tracking error signal with a spectrum analyzer or the like. When the wobble period is detected, there is a risk that sub-information may be decoded from the tracking error signal using a band-pass filter.
[0334]
On the other hand, in the optical disc of the present embodiment, the wobble cycle differs for each block in the frame as described above, and therefore, it is difficult to detect the wobble cycle even when observing with a spectrum analyzer. Thus, it is possible to prevent the sub information from being decrypted by a person who intends to make an illegal copy.
[0335]
Note that the wobble periods of all the blocks need not be different from each other, and the wobble periods may be the same in some blocks as long as irregularities are maintained to the extent that it is difficult to detect the wobble period illegally. .
[0336]
Here, the configuration and operation of the information recording apparatus according to the present embodiment will be described with reference to FIGS. As shown in FIG. 39, the information recording apparatus according to the present embodiment has a timing generator 411 that outputs a random number generation clock instead of the timing generator 401 that generates the byte clock, and the information recording apparatus according to the eighth embodiment. Has the same configuration as the information recording device according to the above. In the present embodiment, blocks having the same functions as the blocks described in the eighth embodiment are denoted by the same reference numerals as in the eighth embodiment, and detailed descriptions of the configuration, functions, and operations are omitted. The same applies to the later-described embodiments 11 and 12.
[0337]
As shown in FIG. 40, the timing generator 411 includes a random number generator 411a, an adder 411b, and a down counter 411c. The frame number is set in the random number generator 411a as the initial value of the random number sequence. The adder 411b adds the random number (B in FIG. 40) output from the random number generator 411a and a predetermined cycle lower limit value, and outputs the result to the down counter 411c as a preset value (C in FIG. 41). In the example of FIG. 41, the cycle lower limit is set to “7”. The down counter 411c outputs a random number generation clock (D in FIG. 41) to the random number generator 403 when the counter value becomes “0”, and newly sets a preset value output from the adder 411b. The down count (E in FIG. 41) is started.
[0338]
The PE signal (F in FIG. 41) output from the timing generator 411 according to the present embodiment is “Low” in the first half of the section from when the down counter 411c is preset to when the counter value becomes “0”. The signal becomes “High” in the latter half of the same section. If the number of clocks in the interval from when the down counter 411c is preset to when the counter value becomes “0” is an odd number, one of “Low” and “High” is alternately lengthened by one clock. For example, in the example shown in FIG. 41, "Low" is 7 clocks and "High" is 8 clocks in the first 15 clock section, and "Low" is 6 clocks in the next 11 clock section. “High” is 5 clocks. Further, for example, if “Low” is one clock more in the immediately preceding odd frame, “High” is made one clock more in the current odd frame.
[0339]
As described above, in the present embodiment, the frame in which the recording mark is wobbled is divided into a plurality of blocks having random lengths, and the section between “Low” and “High” is substantially equal for each block having an uneven length. A PE signal is generated so as to be equal, and a PE modulation displacement control signal is generated based on the generated PE signal. As a result, the wobble period in the frame becomes random, and it is difficult to detect the wobble period even if it is observed by a spectrum analyzer. Therefore, it is possible to realize an optical disk in which it is difficult to decode and illegally copy sub information.
[0340]
Next, an information reproducing apparatus according to the tenth embodiment will be described. FIG. 51 is a block diagram illustrating a main configuration of the information reproducing apparatus according to the present embodiment. In FIG. 51, blocks having the same functions as those of the information reproducing apparatus according to the eighth embodiment (see FIG. 25) are assigned the same reference numerals as those of the eighth embodiment, and detailed descriptions thereof will be omitted.
[0341]
As shown in FIG. 51, the information reproducing apparatus according to the present embodiment is different from the eighth embodiment in that a timing generator 1411 is provided instead of the random number generator 1105 and the PE modulator 1106 (see FIG. 25). This is different from the information reproducing apparatus.
[0342]
The internal configuration of the timing generator 1411 is almost the same as that of the timing generator 411 shown in FIGS. 39 and 40. (1) The input clock is reproduced by the clock extractor 1103 as shown in FIG. (2) The timing generator 411 differs from the timing generator 411 in that a synchronization signal detected by the reproduction signal processing circuit 1104 is also input. The timing generator 1411 initializes a random number sequence according to these inputs, and generates and outputs a random number generation clock as described in the eighth embodiment.
[0343]
In the information reproducing apparatus according to the eighth embodiment, the input to the sub-information detector 1108 is the PE-modulated correlation sequence, but in the information reproducing apparatus according to the present embodiment, the input is to the sub-information detector 1108. Is a PE signal (F in FIG. 41). In other respects, the operation of the information reproducing apparatus according to the present embodiment is the same as that of the information reproducing apparatus according to the eighth embodiment.
[0344]
(Embodiment 11)
Embodiment 11 of the invention will be described in detail with reference to the drawings.
[0345]
The optical disc according to the present embodiment differs from Embodiments 8 and 9 in that the main information is recorded by recording marks and the sub-information is recorded by displacing (wobbling) the recording marks by a small amount in the radial direction. The same is true. However, it differs from the optical discs according to the eighth and ninth embodiments in that the frame in which the recording mark is wobbled is divided into a plurality of blocks of a predetermined length, and the period in which the recording mark is wobbled differs for each block. .
[0346]
Here, the information recording apparatus according to the present embodiment will be described with reference to FIGS. As shown in FIG. 42, the information recording apparatus according to the present embodiment differs from the information recording apparatus according to Embodiment 8 in that a timing generator 421 and an XOR 425 are provided instead of the timing generator 401 and the PE modulator 405. It has the same configuration as the recording device.
[0347]
The timing generator 421 does not generate a PE signal as in the timing generator 401 according to the eighth embodiment, but generates a reference displacement signal. The XOR 425 performs an exclusive OR operation on the displacement control signal from the XOR 404 and the reference displacement signal from the timing generator 421, and outputs the result to the radial modulator 408 as a displacement control signal.
[0348]
As shown in FIG. 43, the timing generator 421 of the present embodiment includes a frequency divider 421a, a counter 421b, and a conversion table 421c. The frequency divider 421a generates the byte clock (B in FIG. 44) by dividing the recording clock (A in FIG. 44) by 16, and outputs the byte clock (B in FIG. 44) to the random number generator 403 and the counter 421b. The counter 421b increments the value by one each time a byte clock is input from the initial value “0” and outputs the value to the conversion table 421c. This counter value indicates the block number (D in FIG. 44). The conversion table 421c determines the cycle of the reference displacement control signal (E in FIG. 44) using the block number and the random number (C in FIG. 44). The random number of C in FIG. 44 is the same as the random number sequence from the random number generator 403.
[0349]
For example, in the example of FIG. 44, the cycle of the reference displacement control signal of the first block (block number “0”) is 16T, the cycle of the reference displacement control signal of the second block (block number “1”) is 8T, The cycle of the reference displacement control signal of the third block (block number “2”) is 4T. In each block, the sum of the lengths of the sections in which the reference displacement control signal is “Low” is equal to the sum of the lengths of the sections in which the reference displacement control signal is “High”.
[0350]
As described above, in the present embodiment, the frame in which the recording mark is wobbled is divided into a plurality of blocks of a predetermined length, and the period in which the recording mark is wobbled is changed for each block, so that the frame is observed by the spectrum analyzer. However, it is difficult to detect the wobble period. Therefore, it is possible to realize an optical disk in which it is difficult to decode and illegally copy sub information.
[0351]
Next, an information reproducing apparatus according to the eleventh embodiment will be described. FIG. 52 is a block diagram showing a main configuration of the information reproducing apparatus according to the present embodiment. In FIG. 52, blocks having the same functions as those of the information reproducing apparatus according to the tenth embodiment (see FIG. 51) are assigned the same reference numerals as those of the tenth embodiment, and detailed descriptions thereof will be omitted.
[0352]
In FIG. 52, reference numeral 1421 denotes a timing generator, which has substantially the same configuration as the timing generator 421 shown in FIGS. 42 and 43. (1) A clock to be input is, as shown in FIG. The timing generator 421 differs from the timing generator 421 in that a clock reproduced by the reproducing unit 1103 and (2) a synchronization signal detected by the reproduction signal processing circuit 1104 are also input. The information reproducing apparatus according to the present embodiment further includes a random number generator 1422 and an XOR 1423.
[0353]
In the information reproducing apparatus according to the tenth embodiment, the PE signal is input to the sub-information detector 1108. However, in the information reproducing apparatus according to the present embodiment, the PE signal is initialized by a synchronization signal and updated by a byte clock. A displacement control signal obtained by calculating a random number sequence (output from the random number generator 1422) and a reference displacement signal output from the timing generator 1421 by the XOR 1423 is input to the sub information detector 1108. In other respects, the operation of the information reproducing apparatus according to the present embodiment is the same as that of the tenth embodiment.
[0354]
(Embodiment 12)
A twelfth embodiment of the present invention will be described in detail with reference to the drawings.
[0355]
The optical disc according to the present embodiment differs from Embodiments 8 and 9 in that the main information is recorded by recording marks and the sub-information is recorded by displacing (wobbling) the recording marks by a small amount in the radial direction. The same is true. However, the frame in which the recording mark is wobbled is divided into n blocks (n is a natural number of 4 or more) of a predetermined length, and the cycle of wobbling the recording mark is m (m is a divisor other than 1 of n). It differs from the optical discs according to the eighth and ninth embodiments in that each block is different.
[0356]
Here, the information recording apparatus according to the present embodiment will be described with reference to FIGS. As shown in FIG. 45, the information recording apparatus according to the present embodiment is the same as the embodiment except that a timing generator 451 and a modulation signal generator 455 are provided instead of the timing generator 401 and the PE modulator 405. 8 has the same configuration as the information recording apparatus according to the first embodiment.
[0357]
In the information recording apparatus of the present embodiment, the timing generator 451 generates a byte clock (B in FIG. 46) by dividing the recording clock (A in FIG. 46) by 16, and outputs the byte clock (B in FIG. 46) to the random number generator 403. . The random number generator 403 outputs a 1-bit random number sequence of “0” or “1” (C in FIG. 46) to the XOR 404. The XOR 404 calculates the exclusive OR of one bit of the sub information to be recorded in the frame (D in FIG. 46) and the random number sequence from the random number generator 403, thereby obtaining the displacement control signal (E in FIG. 46). Is generated and output to the modulation signal generator 455.
[0358]
Based on the displacement control signal, the modulation signal generator 455 has a different wobble cycle for each period (F in FIG. 46) composed of m blocks, and has a length of a section of the modulation signal “Low” in each period. Are generated such that the sum of the lengths of the “High” sections is equal to the sum of the lengths of the “High” sections. In the example shown in FIG. 46, m = 3, and n is a multiple of three.
[0359]
FIG. 47 shows an example of the internal configuration of the modulation signal generator 455. In FIG. 47, 455a is a serial-parallel converter, 455b is a conversion table, and 455c is a parallel-serial converter.
[0360]
As described above, in the present embodiment, the frame in which the recording mark is wobbled is divided into n (n is a natural number of 4 or more) blocks of a predetermined length, and the period in which the recording mark is wobbled is m (m is n Since it is different for each block of (divisor other than 1), it is difficult to detect the wobble period even if it is observed by a spectrum analyzer. Therefore, it is possible to realize an optical disk in which it is difficult to decode and illegally copy sub information.
[0361]
(Embodiment 13)
As shown in FIG. 48, the optical disc according to the present embodiment is configured such that the recording mark is displaced (wobbled) in the radial direction by a small amount every three frames of the second to 25th frames (# 1 to # 24). This is similar to the optical disc according to the eighth embodiment in that 1-bit sub information is recorded. However, the optical disc according to the present embodiment reproduces the sub information in the first frame (# 0) and the 26th frame (# 25) at a period different from the wobble period of the recording marks of the second to 25th frames. Embodiment 8 is different from Embodiment 8 in that information necessary for this is recorded. Information necessary for reproducing the sub information may be, for example, a CRC of the sub information, but is not limited thereto.
[0362]
As an example, when the wobble period of the recording marks of the second to 25th frames is set to 16T, the recording marks of the first frame (# 0) and the 26th frame (# 25) are wobbled at a period of 8T, whereby It is conceivable to record the CRC of the information.
[0363]
As described above, information necessary for reproducing the sub-information is recorded by wobbling the recording mark in a frame different from the wobble period of the sub-information in a frame in which the sub-information is not recorded, so that a 16T having a different frequency is recorded. Unless both wobbles and 8T wobbles are copied, the optical disk according to the present embodiment cannot be copied. This makes it possible to more reliably prevent unauthorized copying of the optical disc.
[0364]
(Embodiment 14)
The optical disc according to the present embodiment is similar to the optical disc according to the eighth embodiment in that the sub-information is recorded by displacing (wobbling) the recording mark by a small amount in the radial direction. However, as shown in FIG. 49, the recording wobble on the optical disc of the present embodiment is a wobble generated by superimposing a dummy wobble having a phase different from that of the sub-information on the wobble of the sub-information. This is different from the eighth embodiment.
[0365]
Due to the superimposition of the dummy wobbles, it is extremely difficult to extract the wobble signal of the sub information even if the tracking error signal is observed by the spectrum analyzer. Therefore, it is possible to realize an optical disk in which it is difficult to decode and illegally copy sub information.
[0366]
In order to generate such a recording wobble, the information recording apparatus according to the present embodiment uses a PE modulator 405 and a radial modulator in the information recording apparatus according to the eighth embodiment (see FIG. 18) as shown in FIG. 408 is provided with an adder 491. By adding the output of the PE modulator 405 and the dummy wobble signal from the dummy wobble generator 492 in the adder 491, a recording wobble as shown in FIG. 49 can be generated.
[0367]
By disclosing the method of generating the dummy wobble in the dummy wobble generator 492 only to the manufacturer of the regular drive, it is possible to more reliably prevent the illegal duplication of the sub information.
[0368]
In the above-described embodiments 8 to 14, the optical disc in which the main information is recorded by the recording mark is illustrated, but the “recording mark” includes both concave and convex marks.
[0369]
Further, in the information reproducing apparatus for reproducing the optical storage medium according to the eighth to fourteenth embodiments, as described in the second embodiment, it is determined that the optical storage medium is not a proper medium based on the result of the reproduction of the sub information. In such a case, it is also preferable to take measures such as output prohibition and warning.
[0370]
【The invention's effect】
As described above, according to the present invention, it is possible to accurately identify an optical storage medium without reducing the recording capacity, and to effectively prevent illegal use of the optical storage medium that infringes copyright. And an information recording / reproducing apparatus.
[Brief description of the drawings]
FIG. 1 is a diagram schematically illustrating a configuration of an optical storage medium according to a first embodiment of the present invention.
FIG. 2 is an enlarged schematic diagram showing a boundary between a control data area and a main information area of the optical storage medium shown in FIG. 1;
FIG. 3 is a diagram schematically showing a configuration of an information reproducing apparatus according to a second embodiment of the present invention.
FIG. 4 is a diagram schematically showing a configuration of an optical storage medium according to a third embodiment of the present invention.
FIG. 5 is an enlarged schematic diagram showing a boundary between a control data area and a main information area of an optical storage medium according to a fourth embodiment of the present invention.
FIG. 6 is a schematic diagram showing wobble pits and digital signals of an optical storage medium according to Embodiment 4 of the present invention.
FIG. 7 is a schematic diagram showing wobble pits and digital signals of an optical storage medium according to Embodiment 5 of the present invention.
FIG. 8 is a schematic diagram showing wobble pits and digital signals of an optical storage medium according to Embodiment 6 of the present invention.
9A and 9B schematically show a cross section of a pit in an optical storage medium. FIG. 9A shows a case where the cross section of the pit is formed in an ideal rectangular shape, and FIG. Sectional drawing which respectively shows the case where it was formed in trapezoid shape.
FIG. 10 is a schematic diagram illustrating a photodetector and a differential operation unit included in the information reproducing apparatus according to the second embodiment of the present invention.
FIG. 11 is a schematic diagram illustrating a photodetector and a wobbling signal detector that constitute an information reproducing apparatus according to a seventh embodiment of the present invention.
FIG. 12 is a schematic diagram showing a format of information recorded on an information recording layer of an optical storage medium used in an information reproducing device according to a seventh embodiment of the present invention.
FIG. 13 shows a wobble pattern recorded on an information recording layer of an optical storage medium used in the information reproducing apparatus according to the seventh embodiment of the present invention.
FIG. 14 shows another wobble pattern recorded on the information recording layer of the optical storage medium used in the information reproducing apparatus according to the seventh embodiment of the present invention.
FIG. 15 is a conceptual diagram showing the shape of a recording mark on the optical disc of the eighth embodiment.
FIG. 16 is a conceptual diagram showing a recording format of sub information according to the eighth embodiment.
FIG. 17 is a conceptual diagram showing a recording mark in which sub information bit “0” and sub information bit “1” are recorded according to the eighth embodiment.
FIG. 18 is a schematic block diagram of an information recording apparatus according to an eighth embodiment.
FIG. 19 is a diagram showing details of a random number generator of the information recording device and the information reproducing device of the present invention.
FIG. 20 is a detailed block diagram of an XOR according to the eighth embodiment.
FIG. 21 is a detailed block diagram of a radial modulator according to the eighth and ninth embodiments.
FIG. 22 is a timing chart in the case where a sub information bit “0” is recorded by the information recording apparatus of the eighth embodiment.
FIG. 23 is a timing chart when recording the sub information bit “1” by the information recording apparatus of the eighth embodiment.
FIG. 24 is a timing chart of a displacement permission signal of the information recording device and a correlation detection permission signal of the information reproducing device according to the present invention.
FIG. 25 is a schematic block diagram of an information reproducing apparatus according to the eighth embodiment.
FIG. 26 is a detailed block diagram of a reproducing head of the information reproducing apparatus according to the eighth embodiment.
FIG. 27 is a detailed block diagram of a sub information detector in the information reproducing apparatus according to the eighth embodiment.
FIG. 28 is a timing chart for detecting a sub information bit “0” in the information reproducing apparatus of the eighth embodiment.
FIG. 29 is a timing chart for detecting a sub information bit “1” in the information reproducing apparatus of the eighth embodiment.
FIG. 30 is a timing chart showing an integrated value of a level integrator in a sub information detector of the information reproducing apparatus according to the eighth embodiment.
FIG. 31 is a conceptual diagram showing a recording format of sub-information on the optical disc according to the ninth embodiment;
FIG. 32 is a conceptual diagram showing a recording mark in which sub information bit “0” and sub information bit “1” are recorded according to the ninth embodiment.
FIG. 33 is a schematic block diagram of an information recording apparatus according to a ninth embodiment;
FIG. 34 is a detailed block diagram of a special PE modulator in the information recording device and the information reproducing device according to the ninth embodiment.
FIG. 35 is a timing chart showing the operation of the special PE modulator in the information recording device and the information reproducing device according to the ninth embodiment;
FIG. 36 is a schematic block diagram of an information reproducing apparatus according to a ninth embodiment;
FIG. 37 is a detailed block diagram of a sub information detector of the information reproducing apparatus according to the ninth embodiment;
FIG. 38 is a timing chart showing the transition of the integration value of the level integrator in the sub information detector of the information reproducing apparatus according to the ninth embodiment.
FIG. 39 is a schematic block diagram of an information recording apparatus according to a tenth embodiment.
FIG. 40 is a block diagram of a timing generator according to the tenth embodiment.
FIG. 41 is a timing chart in the information recording apparatus of the tenth embodiment.
FIG. 42 is a schematic block diagram of an information recording apparatus according to an eleventh embodiment.
FIG. 43 is a block diagram of a timing generator according to the eleventh embodiment;
FIG. 44 is a timing chart in the information recording apparatus of the eleventh embodiment.
FIG. 45 is a schematic block diagram of an information recording apparatus according to a twelfth embodiment.
FIG. 46 is a timing chart in the information recording apparatus of the twelfth embodiment.
FIG. 47 is a block diagram of a modulation signal generator according to a twelfth embodiment.
FIG. 48 is a conceptual diagram showing a recording format of sub information according to the thirteenth embodiment.
FIG. 49 is an explanatory diagram showing generation of a recording wobble of sub information according to the fourteenth embodiment;
FIG. 50 is a schematic block diagram of an information recording apparatus according to a fourteenth embodiment.
FIG. 51 is a schematic block diagram of an information reproducing apparatus according to a tenth embodiment.
FIG. 52 is a schematic block diagram of an information reproducing apparatus according to an eleventh embodiment.
FIG. 53 is a conceptual diagram showing the state of recording marks on a conventional optical disc.
[Explanation of symbols]
1 Semiconductor laser light source
31 Photodetector
31a-31h light receiving section
4 Optical pickup
5 Transfer controller
6 Optical storage medium motor 6
7 First control means
8 Amplifier
9 Second control means
10 Demodulation means
11 Detecting means
12 System control means
41, 42 Optical storage medium
42a, 42b Information recording layer
41a, 43a Control data area
41b, 43b Main information recording area
41c, 41d, 43c buffer area
101, 203 synchronization code section
102,204 Data section
103,104 Recording mark displaced in radial direction
105 Standard Recording Mark
201 ECC block
202 sectors
Frame containing 205 ID
401,1901 Timing generator
402, 1902 modulator
403, 1903 random number generator
404,1905 XOR
405 PE modulator
406, 1907 Recording channel
407, 1908 Recording head
408,1909 Radial modulator
410, 1911 Optical disk
501 shift register
601 Sub-information storage unit
602 Sub-information update unit
701 Digital wobble signal generator
702 DA converter
703 LPF
1101,201 playback head
1102, 2202 playback channel
1103, 2203 Clock extractor
1104, 2204 playback signal processing circuit
1105, 2205 random number generator
1106 PE modulator
1107, 2207 TE signal AD converter
1108, 2208 Sub-information detector
1109 Optical disk
1201 Semiconductor laser
1202 Optical system
1203, 1204 Photodetector
1301 Selector
1302 Sub information update timing generator
1303 Level integrator
1304 Threshold judgment unit
1904 Sub-information updater
1906 Special PE modulator
2001 PE modulator
2002 Edge Judge
2003, 2004 Distance judgment device
2005 selector
2006 counter
2007 Special PE modulation displacement control signal generator
2206 Special PE modulator
2301 Selector
2302 Sub-information update timing generator
2303 integrator
2304 Threshold judgment unit

Claims (96)

An optical storage medium comprising an information recording layer having a main information area in which information is recorded as a concave or convex mark array readable through light, and a control data area, wherein the control data An optical storage medium characterized in that optical storage medium information relating to the optical storage medium is recorded in a region by wobbling a concave or convex groove with respect to a light incident side. An optical storage medium including an information recording layer having a main information area in which information is recorded as a mark string that can be read via light, and a control data area, wherein the control data area includes: An optical storage medium characterized in that optical storage medium information on an optical storage medium is recorded by wobbling a mark sequence. 3. The optical storage medium according to claim 2, wherein the mark row recorded in the main information area is a mark row that is concave or convex with respect to the side on which light is incident. 4. The optical storage medium according to claim 1, wherein a mark sequence recorded in the main information area is wobbled. An optical storage medium including an information recording layer having a main information area in which information is recorded as a mark string that can be read via light, and a control data area, wherein the control data area includes: When the optical storage medium information on the optical storage medium is recorded in a mark row, the mark row recorded in the main information area is wobbled, and when the track pitch is Tp ₂ , the maximum amplitude of the displacement amount of the wobble is Tp _2. / 30 or less. The optical storage medium according to claim 5, wherein the mark row recorded in the main information area is a mark row that is concave or convex with respect to a light incident side. When the track pitch in the control data area is Tp ₁ and the mark width is Mw ₁ ,
0.3 × Tp ₁ ≦ Mw ₁ ≦ 0.7 × Tp ₁
The optical storage medium according to any one of claims 2 to 6, wherein the following relationship is satisfied. When the width of the mark recorded in the control data area is Mw ₁ and the width of the mark recorded in the main information area is Mw ₂ ,
Mw ₁ > Mw ₂
The optical storage medium according to claim 2, wherein the following relationship is satisfied. When the track pitch in the main information area is Tp ₂ and the mark width is Mw ₂ ,
Mw ₂ <0.5 × Tp ₂
The optical storage medium according to claim 2, wherein the following relationship is further satisfied. The optical storage medium according to any one of claims 2 to 9, wherein the displacement of the wobble is performed at a timing of a space in the mark row. The optical storage medium according to claim 10, further comprising a plurality of conversion tables for fine-tuning a recording operation performed by a device that records the mark row so that the displacement of the wobble is set to a timing of a space in the mark row. 12. The optical storage medium according to claim 2, wherein the information recorded in the control data area is represented by a center of the mark. The optical storage medium according to claim 2, wherein the information recorded in the control data area is represented by an edge of a mark. 14. The mark sequence has a synchronization pattern used at the time of reproducing information at a specific cycle, and wobbles are performed in synchronization with the synchronization pattern. Optical storage medium. When the cycle of one synchronization pattern is Cy ₁ and the cycle of the wobble is Cy ₂ ,
Cy ₂ = Cy ₁ × M / 2 (M is a natural number)
The optical storage medium according to claim 14, wherein the following relationship is satisfied. When the cycle of one synchronization pattern is Cy ₁ and the cycle of the wobble is Cy ₂ ,
Cy ₁ = Cy ₂ × M / 2 (M is a natural number)
The optical storage medium according to claim 14, wherein the following relationship is satisfied. The length of the mark to be recorded in the control data area and ML _1, and the wavelength of light irradiated at the time of recording the mark lambda, when a numerical aperture of an optical system for irradiating light to the NA,
ML ₁ ≧ 2 × λ / NA
The optical storage medium according to any one of claims 2 to 16, wherein the following relationship is satisfied. The length of the mark to be recorded in the control data area and ML _1, and the wavelength of light irradiated at the time of recording the mark lambda, when a numerical aperture of an optical system for irradiating light to the NA,
ML ₁ ≧ λ / (2 × NA)
The optical storage medium according to any one of claims 2 to 16, wherein the following relationship is satisfied. 19. The optical storage medium according to claim 2, wherein the length of each of the mark and the space recorded in the control data area is an integral multiple of the predetermined period T based on the predetermined period T. . 20. The optical storage medium of claim 19, wherein the mark and the space are each of a single length. 20. The optical storage medium of claim 19, wherein each of the mark and the space have a plurality of lengths. 22. The information according to claim 1, wherein information recorded in the main information area is encrypted data information, and the optical storage medium information includes key information for decrypting the data information. The optical storage medium according to any one of the preceding claims. 23. The optical storage medium according to claim 22, wherein the key information is recorded by wobbling a concave or convex groove or mark array. The optical storage medium of claim 23, wherein the key information is represented by a wobble center. The optical storage medium according to any one of claims 1 to 21, wherein the optical storage medium information includes identification information indicating that the optical storage medium is a properly manufactured optical storage medium or that the information may be reproduced. Medium. 26. The optical storage medium according to claim 25, wherein the identification information is recorded by wobbling concave or convex grooves or mark rows. 27. The optical storage medium according to claim 26, wherein the identification information is represented by a center of a wobble. 28. The optical storage medium according to claim 1, wherein the wobble period is longer than the length of a pair of the mark and the space. 29. The optical storage medium according to claim 28, wherein the wobble period is at least four times the length of the pair of the mark and the space. 30. The optical storage medium according to claim 1, wherein the wobble cycle is an integral multiple of the predetermined cycle T based on the predetermined cycle T. When the optical depth of a mark or groove recorded in the control data area is Md ₁ and the wavelength of light emitted when recording the mark or groove is λ,
λ / 8 ≦ Md ₁ ≦ λ / 4
31. The optical storage medium according to claim 1, wherein the following relationship is satisfied. 32. The optical storage medium according to claim 1, wherein the wobble frequency in the control data area is higher than a tracking servo band. 33. The optical storage medium according to any one of claims 1 to 32, wherein the wobble has no DC component in the band of the tracking servo. 34. The optical storage medium according to claim 1, wherein the timing at which the wobble is displaced is pseudo-random. 35. The optical storage medium according to claim 22, wherein a plurality of wobbles are assigned to one bit of the key information. The optical storage medium according to any one of claims 22 to 35, wherein key information is discretely recorded. The optical storage medium according to any one of claims 22 to 35, wherein key information is continuously recorded. 35. The optical storage medium according to claim 25, wherein a plurality of wobbles are assigned to one bit of the identification information. 39. The optical storage medium according to claim 25, wherein the identification information is discretely recorded. The optical storage medium according to any one of claims 25 to 34, 38, wherein identification information is continuously recorded. 41. The optical storage medium according to claim 1, wherein a buffer area having a groove or a mark is provided at a boundary between the control data area and the main information area. Control track pitch Tp ₁ of the data area, the main information different from the track pitch Tp ₂ region, an optical storage medium according to any one of claims 1 to 41. Control track pitch Tp ₁ of the data area is larger than the track pitch Tp ₂ of the main information area, the optical storage medium of claim 42, wherein. A plurality of information recording layers having a main information area in which information is recorded as a mark string that can be read through light and a control data area in which optical storage medium information regarding the optical storage medium is recorded,
Information is recorded as a series of concave or convex marks in a main information area of at least one information recording layer of the plurality of information recording layers,
An optical storage medium, wherein optical storage medium information relating to all information recording layers is recorded in a control data area of at least one of the plurality of information recording layers. Comprising a plurality of the information recording layer,
Information is recorded as a series of concave or convex marks in a main information area of at least one information recording layer of the plurality of information recording layers,
The optical storage according to any one of claims 1 to 43, wherein optical storage medium information regarding all information recording layers is recorded in a control data area of at least one of the plurality of information recording layers. Medium. 46. The optical storage medium according to claim 44, wherein optical storage medium information relating to all information recording layers is recorded in each control data area of the plurality of information recording layers. The optical storage medium according to claim 44 or 45, wherein optical storage medium information on all information recording layers is recorded in a control data area in a reference layer of the optical storage medium. 48. The optical storage medium according to any one of claims 44 to 47, wherein the information recorded as the optical storage medium information includes information regarding the polarity of the tracking error signal. 49. The information according to any one of claims 44 to 48, wherein the information recorded as the optical storage medium information includes recording layer information on a surface shape formed for recording information on the plurality of information recording layers. Optical storage medium. 50. The optical storage medium according to claim 49, wherein information recorded as optical storage medium information includes information on a depth of the surface shape. An optical storage medium having at least two types of information recording layers of a read-only type, a write-once type, and a rewritable type as the information recording layer, wherein the optical storage medium information is located at substantially the same radial position in a control data area. The optical storage medium according to any one of claims 1 to 50, which is recorded. Encrypted main data information is recorded in the main information area, and key information for decrypting the main data information, or that the optical storage medium has been properly manufactured, or that the information may be reproduced. Optical storage medium information including identification information indicating, irradiating light to the optical storage medium recorded in the control data area by wobbling a concave or convex groove to the mark row or the side where light is incident, An optical pickup for reading main data information and optical storage medium information recorded on the optical storage medium,
Key information detecting means for detecting the key information based on a signal read by the optical pickup,
An information reproducing apparatus, comprising: a demodulating means for decrypting the main data information based on the key information detected by the key information detecting means. Determining means for determining whether or not the optical storage medium has been illegally copied, according to a detection result of the key information detecting means,
53. The reproduction control device according to claim 52, further comprising a reproduction prohibition unit for prohibiting reproduction of information from the optical storage medium when the determination unit determines that the optical storage medium to be reproduced is illegally copied. Information reproducing device. 54. The information reproducing apparatus according to claim 53, wherein the reproduction prohibiting unit stops outputting a signal from the demodulating unit. 55. The information reproducing apparatus according to claim 53, wherein the reproduction prohibiting unit discharges the optical storage medium to be reproduced from the information reproducing apparatus. When the determining means determines that the optical storage medium to be reproduced is illegally copied, the warning means is further provided with a warning means for warning that the optical storage medium is illegally copied. Item 55. The information reproducing apparatus according to any one of Items 52 to 55. The optical storage medium has at least two types of information recording layers of a read-only type, a write-once type, and a rewritable type, and the optical storage medium information is recorded in a common position in a control data area by a common modulation method. The information reproducing apparatus according to any one of claims 52 to 56, wherein the information reproducing apparatus uses a recorded optical storage medium. If the key information detection means does not detect the key information, and if the determination means can detect a duplicatable identifier from a signal read from the optical storage medium by the optical pickup, the optical storage medium is illegally copied. 58. The information reproducing apparatus according to any one of claims 52 to 57, wherein the information reproducing apparatus determines that the information is not a result. The information reproducing apparatus according to any one of claims 52 to 58, wherein the wobble detection means used for detecting the wobbled signal is a differential operation means. The information reproducing apparatus according to any one of claims 52 to 58, wherein the wobble detection means used for detecting the wobbled signal is a phase comparison means. The information reproducing apparatus according to any one of claims 52 to 60, wherein key information is demodulated using signals obtained from a plurality of wobbles. 62. The information reproducing apparatus according to claim 52, wherein the key information is demodulated by integrating and averaging the signals output from the wobble detecting means. 63. The information reproducing apparatus according to claim 52, wherein a clock signal is generated using a signal obtained from a mark string, and key information is detected using the clock signal. 63. A signal according to any one of claims 52 to 62, wherein a clock signal is generated using a signal obtained from the mark sequence to demodulate a signal obtained from the mark sequence, and key information is detected using the clock signal. Information reproducing device. An optical storage medium in which main information is recorded in frame units with a synchronization code by an optically readable recording mark,
In at least a part of the frame, at a portion where the synchronization code is not recorded, the recording mark is displaced minutely toward the outer peripheral side of the optical storage medium with respect to a standard position or minutely displaced toward the inner peripheral side. An optical storage medium characterized in that sub-information is recorded by being formed at a position. 66. The optical storage medium according to claim 65, wherein there is no displacement from the outer peripheral side to the inner peripheral side or no displacement from the inner peripheral side to the outer peripheral side within the recording mark. 67. The optical storage medium according to claim 65, wherein a displacement amount of the recording mark in the radial direction is within a radial displacement amount allowed in an optical storage medium that does not record the sub-information. 67. The optical storage medium according to claim 65, wherein at least one bit of the sub information is recorded by slightly displacing recording marks of the plurality of frames in a radial direction. 69. The optical storage medium according to claim 68, wherein the plurality of frames are a group of frames continuously arranged on a track of the optical storage medium or a group of frames discretely arranged at predetermined intervals on the track. 67. The optical storage medium according to claim 65 or 66, wherein the minute displacement in the radial direction is not performed on a specific frame and / or a specific region in the frame. 67. The optical storage medium according to claim 65, wherein the area in which the sub-information is recorded by the minute displacement of the recording mark in the radial direction is a lead-in area in the optical storage medium. In the frame, the portion where the synchronization code is not recorded is divided into a plurality of blocks of uneven length,
For each block, the cycle of displacing the recording mark by a very small amount to the outer peripheral side and the inner peripheral side differs, and the length of the recording mark displaced to the inner peripheral side and the recording mark displaced to the outer peripheral side in each block. 66. The optical storage medium of claim 65, wherein the length is substantially equal. 73. The optical storage medium according to claim 72, wherein in all frames, the sum of the lengths of the recording marks displaced inwardly and the sum of the lengths of the recording marks displaced outwardly are substantially equal. In the frame, the portion where the synchronization code is not recorded is divided into a plurality of blocks of a predetermined length,
For each of the blocks, the period for displacing the recording mark by a small amount to the outer peripheral side and the inner peripheral side is different,
66. The optical storage medium according to claim 65, wherein the sum of the lengths of the recording marks displaced inwardly in each block is substantially equal to the sum of the lengths of the recording marks displaced outwardly in each block. In the frame, a portion where the synchronization code is not recorded is divided into n (n is a natural number of 4 or more) blocks of a predetermined length,
For each of the m blocks (m is a divisor other than 1 of n), the cycle of displacing the recording mark by a very small amount toward the outer peripheral side and the inner peripheral side is different, and the recording mark is displaced toward the inner peripheral side in each block. 66. The optical storage medium according to claim 65, wherein the total length of the marks is substantially equal to the total length of the recording marks displaced toward the outer periphery. 67. The light according to claim 65 or 66, wherein information necessary for reproducing the sub-information is recorded in a frame in which the sub-information is not recorded by displacing a recording mark by a small amount to the outer peripheral side and the inner peripheral side. Storage medium. 77. The optical storage medium according to claim 76, wherein the information necessary for reproducing the sub information is an error correction code of the sub information. 67. The optical storage medium according to claim 65, wherein a recording mark displacement amount toward an outer peripheral side and an inner peripheral side is determined based on a signal in which dummy information is superimposed on the sub information. An information recording device that records main information on an optical storage medium in units of frames to which a synchronization code is added by an optically readable recording mark,
A modulation unit that modulates the main information and inserts a synchronization code at predetermined intervals,
A displacement control signal generation unit that generates a displacement control signal based on the timing of inserting the synchronization code,
An information recording device, comprising: a sub-information recording unit that records sub-information by displacing a small amount of the recording mark toward an outer peripheral side or an inner peripheral side by the displacement control signal. 80. The information recording apparatus according to claim 79, wherein at least the synchronization code inserted in the frame unit is not subjected to a minute displacement in the radial direction. 80. The information recording apparatus according to claim 79, wherein the displacement control signal is a signal obtained by spectrally spreading sub-information with a pseudo-random number sequence initialized at a timing of inserting the synchronization code. 80. The information recording apparatus according to claim 79, wherein the displacement control signal is PE-modulated so that a probability of displacement of the recording mark toward the outer periphery and a probability of displacement toward the inner periphery are substantially equal. The displacement control signal, while making the probability of displacement of the recording mark toward the outer periphery and the probability of displacement toward the inner periphery substantially the same, and in the section where the recording mark is formed, there is no change point of the displacement control signal. 80. The information recording device according to 79. 80. The information recording apparatus according to claim 79, wherein at least one bit of the sub information is recorded in units of a plurality of frames. 85. The information recording apparatus according to claim 84, wherein the plurality of frames are a group of frames continuously arranged on a track of an optical storage medium or a group of frames discretely arranged at a predetermined interval. In the frame, the portion where the synchronization code is not recorded is divided into a plurality of blocks of uneven length,
For each of the blocks, the period of minutely displacing the recording mark to the outer peripheral side and the inner peripheral side is made different, and the length of the recording mark displaced to the inner peripheral side and the recording mark displaced to the outer peripheral side in each block 80. The information recording apparatus according to claim 79, wherein a length of the information recording device is substantially equal to a length of the information recording device. 89. The information recording apparatus according to claim 86, wherein the total length of the recording marks displaced inward and the total length of the recording marks displaced outward are substantially equal in all frames. In the frame, the portion where the synchronization code is not recorded is divided into a plurality of blocks of a predetermined length,
For each of the blocks, the recording mark is displaced in a small amount toward the outer peripheral side and the inner peripheral side by different periods,
80. The information recording apparatus according to claim 79, wherein the sum of the lengths of the recording marks displaced inwardly in each block is substantially equal to the sum of the lengths of the recording marks displaced outwardly in each block. In the frame, a portion where the synchronization code is not recorded is divided into n blocks (n is a natural number of 4 or more) of a predetermined length,
For each of the m blocks (m is a divisor other than 1 of n), the period for displacing the recording mark by a small amount to the outer peripheral side and the inner peripheral side is changed, and the recording mark is displaced to the inner peripheral side in each block. 80. The information recording apparatus according to claim 79, wherein the total length of the recording marks is substantially equal to the total length of the recording marks displaced to the outer peripheral side. 80. The information recording apparatus according to claim 79, wherein information necessary for reproducing the sub-information is recorded in a frame where the sub-information is not recorded by slightly displacing a recording mark to an outer peripheral side and an inner peripheral side. . 80. The information recording apparatus according to claim 79, wherein a recording mark displacement amount toward an outer peripheral side and an inner peripheral side is determined based on a signal in which dummy information is superimposed on the sub information. An apparatus for reproducing main information from a recording mark formed on an optical disc in frame units accompanied by a synchronization code,
A radial phase difference detection unit for detecting a radial displacement of the recording mark,
A clock extraction unit that extracts a reference clock signal synchronized with the reproduction signal from the reproduction signal of the recording mark;
A reproduction signal processing unit that detects the synchronization code from the reproduction signal and demodulates the reproduction signal;
A correlation sequence generation unit that generates a correlation sequence based on the timing at which the synchronization signal is detected,
An information reproducing apparatus, comprising: a sub-information detecting unit that detects sub-information based on a radial phase difference signal generated by the radial phase difference detecting unit and the correlation sequence. 93. The information reproducing apparatus according to claim 92, wherein the correlation sequence is generated by performing PE modulation on a pseudo-random number sequence initialized at a timing at which the synchronization code is detected. The information reproducing apparatus according to claim 92, wherein the correlation sequence does not have a change point in a section in which the recording mark is reproduced. The information reproducing apparatus according to claim 92, wherein at least one bit of the sub information is extracted by reproducing the plurality of frames. The information reproducing apparatus according to claim 92, wherein the sub information is not detected from at least a synchronization code in the frame.

Images