JP2005078680A - Optical disk, method for reproducing optical disk and manufacturing method of optical disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medium in which its subsidiary information which is not easily copied is recorded and which has a technical content that the subsidiary information can not be recorded in a write-once medium even if the subsidiary information concerning security of a medium to be copied is acquired from a driving device. <P>SOLUTION: The optical recording medium which is provided with a user information region comprising user information and a management information region comprising management information which are recorded in the optical recording medium in regions different from each other on the optical information medium and whose subsidiary information can not be easily copied is realized by forming tracks for recording management information recorded in the management information region spirally or concentrically, forming recording tracks in the user information recording region spirally or concentrically and forming spiral or concentric tracks for recording the subsidiary information concerning an optical disk or recording information recorded in the optical disk in a third region other than the above regions so that the track pitch is made variable in the optical recording disk. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical recording medium, a manufacturing method thereof, a recording / reproducing method, and a recording / reproducing apparatus, and more specifically includes a management information area including management information necessary for driving the optical recording medium, and user information. A method for recording secondary information such as security data in a third area on an optical recording medium formed in a different area from the user information area on the optical recording medium, and the secondary information in the third area The present invention relates to an optical recording medium recorded on the recording medium, a manufacturing method thereof, a reproducing method, and a recording / reproducing apparatus.

  In the field of optical discs, the structure of the track format becomes complicated as the density of optical discs increases, and there are increasing examples of adopting different formats not only for the data recording unit but also for the management information area to be driven by the drive. .

  As shown in FIG. 1, the optical disk generally has a structure including a management information area 12 including management information on the inner periphery side of the optical disk 1 and a user information area 10 including user information outside thereof. This structure is common in an optical disc of a type that records information from the inner periphery side of the disc, such as a DVD-RAM. In the case of an optical disc that records information from the outer periphery side of the disc, a management information area is formed on the outer periphery side. Although not referred to as a management information area, there is a case where a control track area (an area where management information is recorded) is provided on both the inner circumference and the outer circumference.

  The format of information tracks formed in the management information area and user information area of the optical disk varies depending on the type of the optical disk. For example, information tracks formed on CD-R and CD-RW, which are optical disks that can be additionally written and rewritten. Has a track format with excellent productivity because it is composed only of meandering grooves, so that there is no need to form pits.

  On the other hand, write-once and rewritable DVD-R, DVD-RW, and DVD-RAM, which are optical discs with higher recording density than CD-R and CD-RW, have a variety of types and complicated track formats. Is adopted. For example, in DVD-R and DVD-RW, land pre-pits (LPP) are formed between the meandering grooves to synchronize during recording. In DVD-RAM, a physical area is provided in the mirror area on the extension line between the land and the groove. An ID pit is provided.

  In these optical discs, the track format of the user information area varies depending on the type of read-only, write once or rewritable type, but the management information recording format is shared among various optical recording media to ensure mutual compatibility. In this case, it is necessary to devise the track format of the management information area.

  For example, the track format of the management information area may be unified among DVD-ROM, DVD-RAM, DVD-R, and DVD-RW optical discs in consideration of compatibility. At this time, the recording form of the user information area of each optical disc varies depending on the type of the recording medium, and the pre-pit mark, the recording track having the groove, or the land area between the grooves meanders, and the pre-emboss mark is formed on the land. It is formed in various formats. However, the selection of the track format of the common management information area has been performed centering on the read-only DVD-ROM medium that was first commercialized. For this reason, the DVD-ROM format is to be followed with respect to the format of the management information area of DVD-RAM, DVD-R and DVD-RW. That is, the management information area of DVD-RAM, DVD-R, and DVD-RW is formed by the same pre-pit method as that of DVD-ROM.

  However, in the write-once and rewritable media (hereinafter referred to as recordable media as appropriate) such as phase change recording media such as DVD-RW and dye recording media such as DVD-R, it is necessary for the format of the management information area. The depth of the pre-pit and the groove depth required for information recording in the user information area are optically different. The phase depth required for the prepits in the management information area is λ / 4, but the depth required for the groove depth in the user information area is λ / 8 to λ / 6. It is necessary to make the groove depth shallower than the area pre-pits. In other words, it is necessary to produce uneven patterns having different depths in the user information area and the management information area when the substrate is manufactured. Therefore, when manufacturing a write-once and rewritable optical disc substrate, it is required to execute mark formation with different physical specifications in one recordable medium.

  Further, in the read-only optical disc, the management information formed by pre-pits in the management information area is reproduced by the same signal processing system as the user information in the user information area, so that the management information can be easily duplicated. On the other hand, in the management information area of a recordable medium such as CD-R, CD-RW, DVD-R or DVD-RW, the management information is formed in a meandering groove before information recording (initial state). After the information recording, the management information area is formed in such a manner that the recording marks and the meandering grooves are juxtaposed with the recording marks such as pits and domains. Therefore, in the recordable media CD-R, CD-RW, DVD-R or DVD-RW, additional write pits and pre-pits for copy prevention information are formed, but these records are recorded after user information is recorded. Since the management information in the possible medium is formed by recording marks, the management information signal can be reproduced by the same data signal processing system as the data information signal. Therefore, it is possible to reproduce and analyze management information and form it as a recording mark, and it is difficult to completely prevent duplication of information.

  In general, it is difficult to use information processed in the same data signal processing system as the data information signal in the drive device as security, and even if the security information is read out to the outside, the information cannot be reproduced as an optical disc. There was a problem that it would be possible to easily duplicate an optical disc without any ingenuity.

  Therefore, as a means for forming security information that cannot be copied, Japanese Patent Laid-Open No. 8-96492 discloses that detection is performed by varying the track pitch as an identifier for copy protection. This copy prevention identifier confirms the presence or absence of a flag and provides a fixed pattern, and does not record sub information. In general, it is not a special technique to partially provide portions having different track pitches on an optical disc, and is usually performed in a medium in which ROMs and RAMs having different formats are mixed, for example. In an optical disc defined as an international standard specification, it is required to record at different track pitches in an area called PEP describing a control track and a control track area (called SFP) in a data format area. Although this has nothing to do with security, it has been conventionally performed to partially change the track pitch.

  Japanese Patent Application Laid-Open No. 2001-67676 discloses a technique for recording with different track pitches between a lead-in area as a management information area and a user information area to differentiate from a copy product. It is detected that the track pitch is different, and those that cannot be detected are determined as copy products. In either case, the track pitch is variable, but it is only used as a flag for a fixed pattern, and no method for recording secondary information has been proposed.

JP-A-8-96492 JP 2001-67676 A

  The area to be reproduced by the normal drive device is described in detail in a physical specification that describes a format and the like created for ensuring compatibility. This technical information is the minimum necessary for recording and reproducing data, and the contents regarding security are not disclosed. Security is for protecting the information to be recorded, and does not restrict the physical medium, but can be adopted as necessary. In other words, the basic idea is that secondary information for ensuring security is not necessarily required for recording and playback of media, and therefore the presence of secondary information should not cause any trouble in the specifications. It is.

  The problem with the absence of secondary information is related to the reproduction of user information that is protected by security, and this has the property that copyright protection can be achieved.

  It is also used to identify media. Record the manufacturer's identification code as proof of the manufacturer's media reliability. There has been a case where a third party supplies media to the market by illegally using this identification code. The identification code is specific to a particular manufacturer, and its use is undesirable because it interferes with the credibility and market of the forged manufacturer. In order to avoid this, it is required to record an identification code, a trademark code, and other unique data in a form that is not easily forged.

  A first object of the present invention is to record secondary information of a medium that is not easily copied, and even if secondary information related to the security of a copy medium is obtained from a drive device, it cannot be recorded on a write-once medium. It is to provide a medium by contents.

  The second object is an area in which the secondary information recording area of the medium is sandwiched between a user information area including user information and a management information area including management information, and the track has a predetermined track pitch. The recording system is characterized in that it is formed by a groove or a pit row, and the track pitch in the secondary information recording area is varied by secondary information. Also, a reproducing method and apparatus for reproducing the subsidiary information from the track information detected by the optical head by tracing the subsidiary information recording area in the radial direction at a constant speed in order to reproduce the medium on which the subsidiary information is recorded. It is.

  A third object is an area in which a secondary information recording area of the medium is sandwiched between a user information area including user information and a management information area including management information, and the track has a predetermined track pitch. It is an object of the present invention to provide a recording apparatus which is formed by a groove or a pit row and records subsidiary information by changing the track pitch in the subsidiary information recording area according to subsidiary information.

  According to the first aspect of the present invention, an optical recording medium comprising a user information area containing user information recorded on an optical recording medium and a management information area containing management information in different areas on the optical recording medium In the optical recording disk, a track for recording management information to be recorded in the management information area is formed in a spiral or concentric circle, and a recording track in the user information recording area is formed in a spiral or concentric circle, There is provided an optical disc characterized in that secondary information relating to the optical disc or recording information recorded thereon is recorded outside the recording region in the third region by changing the track pitch of the spiral or concentric tracks.

  In the optical recording medium of the present invention, the third area for recording the subsidiary information includes a user information area including user information to be recorded on the optical recording medium and a management information area including management information on the optical recording medium. A method of reproducing secondary information which is an area sandwiched between different areas and which is read when the optical head is moved from the management information area to the user information recording area is presented.

  Further, in the optical recording medium of the present invention, the third area for recording the subsidiary information is an area formed so that the reflectance of the user information area and the management information area including the management information has the same characteristics. Thus, the recorded secondary information can be reproduced with a good reproduction signal without greatly changing the reflection signal level from the medium.

  In addition, the track pitch of the user information area and the management information area including the management information is the same, and the track pitch of the third area for recording the subsidiary information is set to the track interval of the subsidiary information centered on the track pitch interval. The optical disc is characterized in that it modulates according to the contents, and it is an optical disc that can easily detect the modulation of secondary information due to a change in track pitch.

  In addition, the change in track pitch is recorded as sub-phase information being bi-phase modulated so that it can be easily demodulated from track pitch signals detected before and after the detected track pitch width. At this time, since the track pitch fluctuation is performed in the track circumferential direction, it is sometimes difficult to detect because the track width is excessively changed and recorded. In order to perform the modulation after waiting for the round in which the track width is surely determined, a track pitch modulation method over a plurality of tracks is adopted.

  In order to manufacture the optical recording medium of the present invention, a feed rate control based on modulation according to the secondary information is performed on the feed rate of the recording optical head. Alternatively, the manufacturing method is characterized in that feed rate control is performed by modulation according to secondary information for spin degree rotation control for rotationally driving an optical recording medium.

  According to the optical recording medium reproducing method, the optical recording medium, and the optical recording medium recording / reproducing apparatus of the present invention, the management information necessary for driving the optical recording medium modulates and changes the track pitch in the management information area. Can be reproduced by sweeping the optical disk in the radial direction.

  Furthermore, according to the reproducing method, optical recording medium, and optical recording medium recording / reproducing apparatus of the present invention, a management information area including management information necessary for driving the optical recording medium is provided regardless of the type of the optical recording medium. Since it can be formed outside the range defined by the specification, the security between various optical recording media is further enhanced, and a more reliable optical recording medium system can be constructed.

  The optical recording medium recording / reproducing method, the optical recording medium, and the optical recording medium recording / reproducing apparatus of the present invention will be specifically described below using examples, but the present invention is not limited thereto.

  An embodiment of the present invention will be described with reference to FIG. The optical disk 1 includes an area 10 for recording user information and an area 12 for recording management information related to user information recording. A third region 11 that is not used for normal recording is provided between the region 10 and the region 12, and may be filled with a mirror surface, a groove, or a pit row. The area is provided as a so-called buffer area and absorbs different format configurations of the area 10 and the area 12.

  The region 11 provided as the buffer region is a region that is always provided when the region 10 and the region 12 are configured with different track pitches, and has no special meaning. Therefore, when the drive device drives the optical medium, the optical head is moved to the user recording area 10 after accessing the management area 12, but the area 11 is not accessed.

  Tracks by grooves or pit rows are formed in the buffer area 11, and secondary information recording is performed in this range by changing the track pitch. The portion 11a-11b in the region 11 will be described in detail.

FIG. 2 is a diagram showing the contents of the buffer area 11. Here, a track formed by a groove is described in the image, but even if the groove is a pit row, the effect is not affected.
Here, a diagram in which the track pitch is changed in units of two tracks is shown. However, the two tracks need not have exactly the same track pitch, and there is no problem if the differentiation from the wider track can be clarified.

  FIG. 2 shows a state in which the buffer area 11 is composed of track pitches (Tp = b) and (Tp = c) different from the track pitch (Tp = a) of the management area. The track width is b <c and is changed according to the subsidiary information. When the subsidiary information is “0”, the information is changed in the order of narrow (N), narrow (N), wide (W), wide (W) as viewed from the management information 10 side. When the subsidiary information is “1”, the change is made in the order of wide (W), wide (W), narrow (N), and narrow (N) as viewed from the management information 10 side.

  This is bi-phase modulation when the track width is regarded as a phase, and the track pitch is changed correspondingly.

  In this way, the subsidiary information can be recorded by changing the track pitch according to the subsidiary information.

  Note that making the track pitch variable in this way is impossible with a write-once optical disc in which the guide pitch is recorded with the track pitch fixed in advance. It is possible to change the track pitch only in the case of recording on a medium in which tracks are not engraved in advance, that is, only in the mastering process of recording on the optical disc master. Furthermore, it is difficult to modulate the track pitch that has been fixed in advance on a medium that records with high-density recording with a narrow track pitch, and this is only possible in the mastering process that records on the optical disc master. become.

  Also, in a mastering device for recording on an optical disc master, recording is generally performed while moving the optical head at a constant speed, and it is not easy to record by modulating the moving speed. This is because the track width must be modulated during the lap period, and a high-speed response is required, and a modulation function for the feed speed is required.

  Therefore, it is preferable to use a biphase method as a data modulation method. Bi-phase modulation is a modulation method that enables self-clock reproduction by measuring the lengths of previous and subsequent marks or the length between marks, so that data reproduction discrimination is easy even if the lengths are somewhat uneven. Data reproduction is possible while observing the width between tracks.

  FIG. 3 shows the track shape and reproduction waveform in which the subsidiary information is recorded. Although the track shape is shown as being U-shaped, it is the same whether the track shape is V-shaped or continuous pit marks.

  Reproduction is performed by moving the optical head from the 11a direction to the 11b direction in FIG. If the moving speed is as constant as possible, a reproduction signal faithful to the pattern arrangement can be obtained. Although the optical head may be moved from the direction 11b to the direction 11a, it is more convenient in terms of data recording / reproduction to determine the data reproduction direction. This is because when recording is performed with a synchronization pattern, it is necessary to record on both the 11a side and the 11b side. If the direction is determined to be swept from the inner peripheral side, for example, it may be arranged only on the 11a side. In general, since the control area recorded on the inner circumference side is reproduced before the information area is accessed, it is better to record the subsidiary information from 11a on the inner circumference side.

An example of the recording data arrangement of the subsidiary information is shown in FIG. As an array, the synchronization pattern is arranged at the head, and then the secondary information and the error detection code such as CRC are arranged in this order. An error detection code is not essential, but adding it improves system reliability if it is not controlled with incorrect sub information. When 20 μm is allocated as the secondary information recording area, (Tpw + Tpn) = 0.4 μm,
20 / (0.4 * 2) = 25 (bits)
Can be recorded.

  Here, 8 bits can be assigned as a synchronization pattern, 16 bits can be configured as subsidiary information, and 1 bit can be configured as parity data.

Since it is 12 bits at 10 μm, it is possible to record only subsidiary information without providing a synchronization pattern.
FIG. 6 shows a subsidiary information reproducing apparatus. The optical disc 1 on which the subsidiary information is recorded is driven to rotate by the spindle 5. An optical disk is reproduced by the optical head 2, and these are controlled by the controller 4. Secondary information is detected from a push-pull signal detected from a detector (not shown) divided into two in the radial direction in the reproduction signal of the optical head. The reproduction signal shown in FIG. 3 is a push-pull signal, which can be detected as a signal having an amplitude center (zero cross position) at the center of the groove or between the grooves. It is also possible to detect from the reflected light fluctuation signal of the detector. The reproduction signal is demodulated by the modulation / demodulation circuit 6 to extract secondary information, and the controller 4 determines the operation of the driving device based on the information.

  In the optical disk of the above embodiment, the secondary information recording area is provided between the inner circumferential lead-in area and the information recording area. However, the present invention is not limited to this and may be provided on the outer circumferential side. The secondary information may be recorded in the information recording area within a range in which the track pitch modulation variable is not increased and can be detected, and the recorded data reproduction is not hindered.

  Note that the ROM medium records user information at the time of mastering, and it is necessary to record secondary information related to security using a technique that is not easily forged at the time of recording. Specifically, an optical recording disk comprising a user information area containing user information to be recorded on an optical recording medium and a management information area containing management information in different areas on the optical recording medium, wherein the optical recording disk The track for recording the management information to be recorded in the management information area is formed in a spiral or concentric circle, the recording track in the user information recording area is formed in a spiral or concentric circle, and the optical disk or this is outside the recording area. In the third area for recording the secondary information related to the recording information to be recorded, the data pits of the secondary information are formed in spiral or concentric tracks and the track pitch is varied.

  FIG. 5 shows a recording apparatus for recording secondary information according to the present invention. This is a master exposure apparatus for creating a stamper to be a mold for an optical disc. The recording optical head 20 is driven by a servo system that moves in the radial direction relative to the master 10 (not shown). The recording radius position is monitored by a linear scale 19 and is controlled by a closed servo loop. The formatter 17 generates information data, management information, groove signals, and the like to drive the optical head. The entire system is managed by the controller 16, and the track pitch is also servo-controlled here. Track pitch modulation is performed in this servo control, and the secondary information controls the track pitch according to the contents supplied from the formatter 17.

  The master disk is driven to rotate by the spindle 14 and forms a unique servo loop. Track pitch modulation is possible even if the master disk rotation speed is modulated using this thermo loop. The spindle 14 is driven by a spindle driver 15.

1 is a schematic plan view of an optical disc of the present invention. It is a figure explaining the Example of the management information area | region where management information is formed by the track pitch modulation in the optical recording medium of this invention. It is explanatory drawing which detects the tracking signal for detecting the management information of the optical recording medium of this invention. It is a figure explaining an example of the arrangement | sequence for recording management information with the optical recording medium of this invention. It is a figure explaining the subsidiary information recording device of this invention. It is a figure explaining the drive device which reproduces | regenerates the optical disk in which the management information of this invention was formed by track pitch modulation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk 2 Optical head 4 Controller 5 Spindle 6 Modulation / demodulation circuit 10 User information area 11a, 11b 3rd area 12 Management information area 13 Master 14 Spindle 15 Spindle driver 16 Control roller 17 Formatter 19 Linear scale 20 Recording optical head

Claims (10)

  An optical disk comprising a user information area including user information and a management information area including management information in different areas, wherein the optical disk has a spiral or concentric track for recording management information recorded in the management information area And a recording track of the user information recording area is formed in a spiral or concentric circle, and records the secondary information on the optical disc or information recorded on the optical disc outside the management information area and the user information area. Is performed by changing the track pitch of a spiral or concentric track.   The third area for recording the subsidiary information is an area in which a user information area including user information to be recorded on an optical recording medium and a management information area including management information are sandwiched between different areas on the optical recording medium. The optical disk according to claim 1, wherein:   The third area for recording the subsidiary information is an area formed so that the reflectance of the user information area and the management information area including the management information have similar characteristics. 1. The optical disc according to 1.   The track pitch of the user information area and the management information area including the management information is the same, and the track pitch of the third area in which the sub information is recorded is based on the content of the sub information with the track interval centered on the track pitch interval. The optical disk according to claim 1, wherein the optical disk is modulated.   2. The optical disc according to claim 1, wherein the secondary information is modulated by a bi-phase modulation method.   6. The optical disk according to claim 5, wherein the bi-phase modulation is recorded in units of a plurality of circulating tracks.   An optical disc comprising a first area containing management information and a second area containing user information, wherein a third area for recording secondary information on the optical disc or user information recorded on the optical disc, A track for recording information is formed in a spiral or concentric circle in the first area, the second area, and the third area, provided between the first area and the second area. The track pitches of the tracks in the first area and the second area are constant, and the track pitches of the tracks formed in the third area are modulated by the sub information and differ. An optical disc characterized by being formed at intervals.   A user information area including user information to be recorded on the optical recording medium and a management information area including management information are recorded on the optical disk or on the optical recording disk provided in different areas on the optical recording medium. A method of reproducing an optical disc in which a third area for recording secondary information relating to recording information to be recorded is formed by varying a track pitch of a spiral or concentric track, wherein the optical head tracks the third area. A method for reproducing an optical disc, comprising: detecting a change in track pitch using reflected light obtained by tracing in a direction crossing the track.   9. The optical disk reproducing method according to claim 8, wherein in the reproducing method, self-demodulation is performed on the assumption that a change in track pitch is recorded by bi-phase modulation.   A user information area including user information to be recorded on the optical disk and a management information area including management information are provided in different areas on the optical disk, and secondary information on the optical disk or recording information to be recorded on the optical disk is recorded outside the area. A method of manufacturing an optical disk provided with a third area, wherein tracks for recording management information to be recorded in the management information area are formed in a spiral or concentric circle at a constant track pitch, and the track is formed in the third area. The optical disk manufacturing method is characterized in that the track pitch is modulated based on the secondary information and formed at different intervals, and the recording tracks in the user information recording area are formed in a spiral or concentric circle with a constant track pitch.

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