JP4148163B2 - Optical disk device - Google Patents

Description

  The present invention relates to an optical disk apparatus, and more particularly to a high-density optical disk apparatus that records / reproduces data using grooves and lands.

  In recent years, HD (High-Definition) -DVD has been proposed as a next-generation DVD. In HD-DVD, the disk structure of the current DVD is followed and compatibility with DVD is ensured while achieving higher density than DVD.

  One characteristic of the HD-DVD is that a land / groove recording system for recording information on both lands and grooves is adopted. The land track and groove track are wobbled (meandering), and address information is embedded in the wobble. Specifically, the address information is expressed by using phase modulation, with the phase at 0 degree being “0” and the phase at 180 degrees being “1”. The address information is embedded in the wobble by converting the binary data into a gray code. Here, the gray code is a code in which the inter-code distance between adjacent binary data, that is, the number of inverted bits is 1. Thus, the address “0” is “00000000”, the address 1 is “00000001”, the address “2” is “00000011”, the address “3” is “00000010”, the address “4” is “00000110”, etc. Expressed.

  FIG. 5 schematically shows the wobble of HD-DVD. A certain groove track is embedded with address information such as “0” in which both the inner and outer wobbles are 0 degrees, and “1” to “0001” in which both the inner and outer wobbles are 180 degrees, Similarly, for the next groove track, the inner wobble and the outer wobble are both “0”, and the inner wobble and the outer wobble are both 180 degrees “1” to “0011”. Embedded. On the other hand, in the land track in the meantime, the inner and outer wobbles are out of phase at the inverted bit positions of successive groove tracks (position 100 in the figure), and no wobble signal is specified.

  Therefore, in the HD-DVD, a dedicated area for embedding the track address of each land and groove is provided and is shifted along the track direction. Thereby, when reading the address information of the land track, the groove dedicated area is skipped and the track address in the next land dedicated area is read.

  FIG. 6 schematically shows the address configuration of the HD-DVD. In the drawing, the groove dedicated area is shown as “G track address system”, and the land dedicated area is shown as “L track address system”. Each of the groove track and the land track is divided into a plurality of segments in the track direction. The segment address is stipulated to be reset every time the disk goes around. That is, the segment 1 of the land N is arranged next to the segment 1 of the groove N, and the segment 1 of the groove N + 1 is arranged next to the segment N. Is done.

  An address “N” is embedded in the G track address system of the groove N with the in-phase wobble, and an address “N” is embedded in the L track address system of the adjacent land N with the in-phase wobble. Therefore, when tracing the groove track N (groove N), the wobble signal of the segment and G track address system is reproduced, and when tracing the land track N (land N), the G track address system is next to the segment. The address information is obtained by skipping and reproducing the wobble signal of the L track address system.

“Nikkei Electronics October 13 issue”, Nikkei Business Publications, October 13, 2003, p126-134

  In this way, when the land N is traced, the L track address system is read out by skipping the G track address system, so the G track address system indicated by A in FIG. 6 becomes an unnecessary or wasted area when reproducing address information. End up. Similarly, since the L track address system is not used when tracing the groove N + 1, the L track address system indicated by B in FIG. 6 becomes a useless area. Since these areas contain reversed-phase wobbles, the address information is indefinite, but a technology that makes effective use of these information is desired.

  An object of the present invention is to provide an optical disc apparatus capable of effectively utilizing L track address information even during groove track tracing.

  It is another object of the present invention to provide an optical disc apparatus capable of effectively utilizing G track address information even during land track tracing.

  In the present invention, address information is embedded by wobbling the groove and land, and the address information is converted into a gray code in which the encoding distance of two consecutive address values is 1, and embedded in the groove and land of the optical disc. The groove address information includes a groove track address system defined by an in-phase wobble in which the phase of the inner and outer wobbles forming the groove is the same. And two address systems of a land track address system defined including a reverse phase wobble in which the phases of the inner and outer wobbles forming the groove are reversed, and reproducing the groove track address system A method of demodulating the first groove address information X from the obtained wobble signal And means for demodulating second groove address information Y from a wobble signal obtained by reproducing the land track address system, and for the first groove address information X, the second groove address information Y is X = Y or Means for determining an error in the first groove address information X when X = Y + 1.

  The present invention also embeds address information by wobbling the groove and land, and the address information is converted into a gray code in which the coding distance between two consecutive address values is 1, and the groove of the optical disk embedded. And the land address information includes land tracks defined by in-phase wobbles having the same phase of the inner and outer wobbles forming the land. Reproducing the land track address system, including two address systems, an address system and a groove track address system defined including a reverse phase wobble in which the phases of the inner and outer wobbles forming the land are reversed Means for demodulating the first land address information X from the wobble signal obtained by Means for demodulating second land address information Y from a wobble signal obtained by reproducing the groove track address system, and for the first land address information X, the second land address information Y is X = Y or X = Means for determining an error in the first land address information X when none of Y−1.

  The present invention also embeds address information by wobbling the groove and land, and the address information is converted into a gray code in which the coding distance between two consecutive address values is 1, and the groove of the optical disk embedded. And an optical disk device for recording or reproducing data on a land, and the address information of the groove is a groove track defined by an in-phase wobble in which the phase of the inner and outer wobbles forming the groove is the same. The address information of the land includes two address systems, an address system and a land track address system defined by including a reverse phase wobble in which the phases of the inner and outer wobbles forming the groove are reversed. Is the same phase of the inner and outer wobbles forming the land There are two address systems: a land track address system defined by a certain in-phase wobble and a groove track address system defined by including a reverse phase wobble in which the phases of the inner and outer wobbles forming the land are reversed. Means for demodulating first address information X from a wobble signal obtained by reproducing a groove track address system during groove tracing or a wobble signal obtained by reproducing a land track address system during land tracing, Means for demodulating second address information Y from a wobble signal obtained by reproducing the land track address system at the time of tracing or a wobble signal obtained by reproducing the groove track address system at the time of the land trace; 1 address information X And, said second address information Y is, | X-Y | when a> 1, characterized by having a means for determining an error in the first address information X.

  In the present invention, when tracing a groove, the address information is demodulated from the groove track address system, and the address information is also demodulated from the land track address system which is inherently indefinite because it includes a reverse phase wobble. Compare Although the address information read from the land track address system is indefinite, the address information is encoded with a gray code having a code-to-code distance of 1, and thus is one of the adjacent track addresses. That is, the second address information Y obtained from the land track address system is equal to or smaller by 1 than the first groove address value X obtained from the groove track address system (from the inner circumference side to the outer circumference). When the groove 1, the land 1, the groove 2, the land 2 ... are formed toward the side). Therefore, it is determined whether or not the address information X and the address information Y satisfy a predetermined relationship, that is, X = Y or X = Y + 1. If the address information X and the address information Y satisfy the predetermined relationship, the address information X may be normal. It can be determined that the address information X is an error.

  Also, when tracing a land, the address information is demodulated from the land track address system, and the address information is also demodulated from the groove track address system which is inherently indefinite because it includes a reverse phase wobble, and both address information are compared. To do. Although the address information read from the groove track address system is indefinite, the address information is encoded with a gray code having a code-to-code distance of 1, and thus is one of the adjacent track addresses. That is, the second address information Y obtained from the groove track address system is equal to or larger by 1 than the first groove address value X obtained from the land track address system (from the inner circumference side to the outer circumference). When the groove 1, the land 1, the groove 2, the land 2 ... are formed toward the side). Therefore, it is determined whether or not the address information X and the address information Y satisfy a predetermined relationship, that is, X = Y or X = Y−1, and if so, the address information X may be normal and is satisfied. Otherwise, it can be determined that the address information X is an error.

  According to the present invention, the address information of the groove track can be verified by utilizing the land track address system formed on the groove track.

  Further, the address information of the land track can be verified by utilizing the groove track address system in which the land track is formed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an overall configuration diagram of an optical disc apparatus according to the present embodiment. The optical disk 10 is rotationally driven by a spindle motor (SPM) 12. The spindle motor SPM 12 is driven by a driver 14, and the driver 14 is servo-controlled by a servo processor 30 so as to have a desired rotation speed. In this embodiment, as an example, the driver 14 divides the optical disk 10 into a plurality of zones between the inner periphery and the outer periphery, and drives the zones so that the angular velocity is constant (ZCAV) in each zone.

  The optical pickup 16 includes a laser diode (LD) for irradiating the optical disk 10 with laser light and a photodetector (PD) that receives reflected light from the optical disk 10 and converts it into an electrical signal, and is disposed opposite to the optical disk 10. . The optical pickup 16 is driven in the radial direction of the optical disk 10 by a thread motor 18, and the thread motor 18 is driven by a driver 20. The driver 20 is servo-controlled by the servo processor 30 similarly to the driver 14. The LD of the optical pickup 16 is driven by a driver 22, and the driver 22 is controlled by an auto power control circuit (APC) 24 so that the drive current becomes a desired value. The APC 24 controls the drive current of the driver 22 so that the optimum recording power selected by OPC (Optimum Power Control) executed in the test area (PCA) of the optical disc 10 is obtained. The OPC is a process of recording test data on the PCA of the optical disc 10 by changing the recording power in a plurality of stages, reproducing the test data, evaluating the signal quality, and selecting a recording power that can obtain a desired signal quality. It is. For the signal quality, β value, γ value, modulation factor, jitter, etc. are used.

  When data recorded on the optical disk 10 is reproduced, a laser beam of reproduction power is irradiated from the LD of the optical pickup 16, and the reflected light is converted into an electric signal by the PD and output. A reproduction signal from the optical pickup 16 is supplied to the RF circuit 26. The RF circuit 26 generates a focus error signal and a tracking error signal from the reproduction signal and supplies them to the servo processor 30. The servo processor 30 servo-controls the optical pickup 16 based on these error signals, and maintains the optical pickup 16 in an on-focus state and an on-track state.

  The optical pickup 16 performs recording / reproduction with respect to the groove and land of the optical disc 10. The optical disk 10 is formed with a spiral groove. For example, data is recorded / reproduced alternately between the groove and the land, such as groove 1 → land 1 → groove 2 → land 2 → groove 3 → land 3 →. . Alternatively, the lands in the same zone may be recorded / reproduced after all the grooves in the zone have been recorded / reproduced for each zone, such as recording / reproduction of only the grooves for each zone and then recording / reproduction on the lands. Further, the RF circuit 26 supplies an address signal included in the reproduction signal to the address decoding circuit 28. The address decoding circuit 28 demodulates the address data of the optical disk 10 from the address signal and supplies it to the servo processor 30 and the system controller 32. The address data is embedded as wobbles in the groove and land of the optical disc 10. The optical disc 10 includes a segment address and a track address as address data. The address data is formed on the optical disc 10 as a gray code.

  The address format of the optical disc 10 is composed of two address systems as described above. The groove track address is always detected by one address system (G track address system), and the land track address is always detected by the other address system (L track address system). The G track address system and the L track address system are formed along the track direction in the groove track, and the G track address system and the L track address system are formed along the track direction also in the land track. In the G track address system in the groove track and the L track address system in the land track, the wobble is always adjusted to be in-phase wobble, so that the address can be detected from the wobble signal included in the reproduction signal.

  The RF circuit 26 supplies the reproduction RF signal to the binarization circuit 34. The binarization circuit 34 binarizes the reproduction signal and supplies the obtained signal to the encoding / decoding circuit 36. The encode / decode circuit 36 demodulates the binary signal and corrects errors to obtain reproduction data, and outputs the reproduction data to a host device such as a personal computer via the interface I / F 40. When the reproduction data is output to the host device, the encoding / decoding circuit 36 temporarily stores the reproduction data in the buffer memory 38 and outputs it.

  When recording data on the optical disk 10, data to be recorded from the host device is supplied to the encode / decode circuit 36 via the interface I / F 40. The encode / decode circuit 36 stores data to be recorded in the buffer memory 38, encodes the data to be recorded, and supplies the data to the write strategy circuit 42 as modulated data (ETM modulation (Eight to Twelve Modulation)). The write strategy circuit 42 converts the modulation data into a multi-pulse (pulse train) according to a predetermined recording strategy, and supplies it to the driver 22 as recording data. The recording strategy is composed of, for example, the pulse width of the first pulse, the pulse width of the subsequent pulse, and the pulse duty in the multi-pulse. Since the recording strategy affects the recording quality, it is usually fixed to a certain optimum strategy. A recording strategy may be set at the time of OPC. The laser light whose power is modulated by the recording data is irradiated from the LD of the optical pickup 16 and the data is recorded on the optical disk 10. After recording the data, the optical pickup 16 reproduces the recorded data by irradiating a laser beam with a reproduction power, and supplies it to the RF circuit 26. The RF circuit 26 supplies the reproduction signal to the binarization circuit 34, and the binarized data is supplied to the encode / decode circuit 36. The encode / decode circuit 36 decodes the modulated data and collates it with recorded data stored in the buffer memory 38. The result of the verification is supplied to the system controller 32. The system controller 32 determines whether to continue recording data or execute a replacement process according to the result of verification.

  In such a configuration, when the address is detected by tracing the groove track in order to record / reproduce data in the groove, the G track address system formed in the groove can be detected without any problem, but the L track address is detected. The system becomes reverse phase wobble and becomes undetectable (NG). In the present embodiment, a land address is also detected from the NG L track address system, and information that has not been used in the past is effectively utilized. That is, an address is detected from the L track address system that is inherently indefinite, and this address is compared with the groove address detected from the G track address system to verify the groove address.

  Similarly, when a land track is traced and an address is detected in order to record / reproduce data on the land, the land address is detected from the L track address system formed on the land, and the G track address system which becomes a reverse phase wobble The address is also detected, and this address is compared with the land address detected from the L track address system to verify the land address.

  FIG. 2 schematically shows the address detection process of the present embodiment. The optical disk 10 is formed with lands N−1, grooves N, lands N, and grooves N + 1... From the inner peripheral side toward the outer peripheral side. When tracing the groove N, the address value (N) is read from the G track address system. This is address X. At this time, it is unknown whether the address X is an accurate address. Next, in the same groove N, the address information of the L track address system is read. The L track address system includes a reverse-phase wobble, and the address cannot be determined uniquely. However, the address information is embedded with a gray code having an inter-code distance of 1, and the address information of the L track address system is Among them, since only one bit is a reverse phase wobble, its address is either N-1 or N. That is, the address is N-1 when the signal portion in the reverse phase wobble is read as 0, and the address is N when the signal portion in the reverse phase wobble is read as 1. The L track address system can take either N-1 or N as described above, and this address value is Y.

If the address value X read from the G track address system is correct, X = N
Considering that Y = N or N−1, the relationship is X = Y or X = Y + 1. On the other hand, if the address value X read from the G track address system is incorrect, for example, X = N−2 or N + 2, the relationship X = Y or X = Y + 1 is not satisfied, and this is It can be determined that this is a read error.

  However, if the address value X read from the G track address system is incorrect, for example, X = N−1, reading the address from the L track address system may result in Y = N−1. Since X = Y, an error in the address value X of the G track address system cannot be determined. That is, in the present embodiment, it is possible to detect a read error at address 2 or more of the G track address system.

  On the other hand, when the land N is traced, the address value (N) is read from the L track address system. This is address X. At this time, it is unknown whether the address X is an accurate address. Next, in the same land N, the G track address system address information is read. The G track address system includes a reverse-phase wobble, and the address cannot be uniquely determined. However, the address information is embedded with a gray code having a code distance of 1, and the address information of the G track address system is Among them, since only one bit is a reverse phase wobble, its address is either N or N + 1. That is, the address is N when the signal portion in the reverse phase wobble is read as 0, and the address is N + 1 when the signal portion in the reverse phase wobble is read as 1. The G track address system can take either N or N + 1 as described above, and this address value is Y.

If the address value X read from the L track address system is correct, X = N
Considering that Y = N or N + 1, there is a relationship of X = Y or X = Y−1. On the other hand, if the address value X read from the L track address system is incorrect, for example, X = N−2 or N + 2, the relationship X = Y or X = Y + 1 is not satisfied, and this is It can be determined that this is a read error.

However, if the address value X read from the L track address system is incorrect, for example X = N + 1, reading the address from the G track address system may result in Y = N + 1, so X = Y. The error of the address value X of the L track address system cannot be determined. That is, it is possible to detect a read error at address 2 or more in the L track address system.

  FIG. 3 shows a flowchart of an address information verification process when tracing a groove track.

  When tracing a groove track, segment information is acquired, a wobble signal is extracted from a reproduction signal of a G track address system, and demodulated to obtain an address value X (S101). Specifically, a component having a predetermined wobble frequency is extracted from the reproduction signal and binarized to obtain address information. The address value X is supplied from the address decoding circuit 28 to the system controller 32.

  Next, a wobble signal is similarly extracted from the reproduction signal of the L track address system formed by shifting along the track direction in the same groove track, and demodulated to obtain an address value Y (S102). Since the L track address system includes a reverse-phase wobble, the data value of that portion is indefinite, but is binarized with a threshold value and is read as 0 or 1 (forcedly). The address value Y is supplied from the address decoding circuit 28 to the system controller 32.

  After obtaining the address value X from the G track address system and the address value Y from the L track address system, the system controller 32 determines that the address value X and the address value Y have a predetermined relational expression, that is, X = Y or X = Y + 1. It is determined whether either one is satisfied (S103). For example, when X = N and Y = N−1, the address value X is normal, and the address value X is determined assuming that the address reading of the G track address system is normally performed (S104). On the other hand, if neither X = Y nor X = Y + 1 is satisfied, it is determined that the address value X is abnormal and an error has occurred in reading the G track address system (S105). If it is determined that there is a reading error, the system controller 32 executes predetermined error processing.

  FIG. 4 shows a flowchart of address information verification processing when tracing a land track.

  When tracing a land track, segment information is acquired, a wobble signal is extracted from an L-track address reproduction signal, and demodulated to obtain an address value X (S201). Specifically, a component having a predetermined wobble frequency is extracted from the reproduction signal and binarized to obtain address information. The address value X is supplied from the address decoding circuit 28 to the system controller 32.

  Next, a wobble signal is similarly extracted from the reproduction signal of the G track address system formed by shifting along the track direction in the same land track, and demodulated to obtain an address value Y (S202). Since the G track address system includes a reverse-phase wobble, the data value of that portion is indefinite, but it is binarized with a threshold value and is read as 0 or 1 (forcibly). The address value Y is supplied from the address decoding circuit 28 to the system controller 32.

  After obtaining the address value X from the L track address system and the address value Y from the G track address system, the system controller 32 determines that the address value X and the address value Y have a predetermined relational expression, that is, X = Y or X = Y−. It is determined whether any of 1 is satisfied (S203). For example, if X = N and Y = N + 1, the address value X is normal, and the address value X is determined assuming that the address reading of the L track address system has been performed normally (S204). On the other hand, when neither X = Y nor X = Y−1 is satisfied, it is determined that the address value X is abnormal and an error has occurred in reading the L track address system (S205). If it is determined that there is a reading error, the system controller 32 executes predetermined error processing.

  As described above, in this embodiment, when tracing the groove track, the address information read from the G track address system is verified using the L track address system information, and when tracing the land track, the G track is tracked. Since the address information read from the L track address system is verified using the address system information, the L track address system in the groove track and the G track address system in the land track are effectively used to improve the accuracy or reliability of the address information. Can be improved.

  When shifting to the processing of FIG. 3 or FIG. 4, it is necessary to determine whether the track currently being traced is a groove track or a land track. For example, it can be determined by the polarity of the tracking servo.

  In this embodiment, as indicated by S103 in FIG. 3, it is determined whether X = Y or X = Y + 1 during groove tracing. However, the system controller 32 determines that | X−Y | ≦ 1. If the condition is not satisfied, it may be determined as a reading error. Similarly, also in the processing at the time of land tracing (S203 in FIG. 4), it may be determined whether or not | X−Y | ≦ 1, and if this condition is not satisfied, it may be determined as a reading error. Of course, it may be determined whether or not | X−Y |> 1, and if this condition is satisfied, an error may be determined.

1 is an overall configuration diagram of an embodiment. It is track address explanatory drawing of embodiment. It is a processing flowchart at the time of groove track tracing. It is a processing flowchart at the time of land track tracing. It is wobble explanatory drawing of an optical disk (HD-DVD). It is track address explanatory drawing of an optical disk (HD-DVD).

Explanation of symbols

  10 optical disc (HD-DVD), 32 system controller, 36 encoding / decoding circuit.

Claims (3)

Address information is embedded by wobbling the groove and land, and the address information is converted into a gray code in which the encoding distance of two consecutive address values is 1, and data is recorded in the groove and land of the embedded optical disk. Alternatively, an optical disc device that performs playback,
The groove address information includes a groove track address system defined by in-phase wobbles having the same phase of the inner and outer wobbles forming the groove, and the inner and outer wobbles forming the groove. Including two address systems of a land track address system defined including a reverse phase wobble in which the phase of the wobble is inverted,
Means for demodulating first groove address information X from a wobble signal obtained by reproducing the groove track address system;
Means for demodulating second groove address information Y from a wobble signal obtained by reproducing the land track address system;
Means for determining an error in the first groove address information X when the second groove address information Y is not X = Y or X = Y + 1 with respect to the first groove address information X;
An optical disc apparatus comprising: Address information is embedded by wobbling the groove and land, and the address information is converted into a gray code in which the encoding distance of two consecutive address values is 1, and data is recorded in the groove and land of the embedded optical disk. Alternatively, an optical disc device that performs playback,
The land address information includes a land track address system defined by an in-phase wobble in which the phases of the inner and outer wobbles forming the land are the same, and the inner and outer wobbles and outer periphery forming the land. Including two address systems of a groove track address system defined by including a reverse phase wobble in which the phase of the wobble is inverted,
Means for demodulating first land address information X from a wobble signal obtained by reproducing the land track address system;
Means for demodulating second land address information Y from a wobble signal obtained by reproducing the groove track address system;
Means for determining an error in the first land address information X when the second land address information Y is not X = Y or X = Y−1 with respect to the first land address information X;
An optical disc apparatus comprising: Address information is embedded by wobbling the groove and land, and the address information is converted into a gray code in which the encoding distance of two consecutive address values is 1, and data is recorded in the groove and land of the embedded optical disk. Alternatively, an optical disc device that performs playback,
The groove address information includes a groove track address system defined by in-phase wobbles having the same phase of the inner and outer wobbles forming the groove, and the inner and outer wobbles forming the groove. The land track address system includes two address systems defined as including a reverse phase wobble in which the phase of the wobble is inverted, and the address information of the land includes an inner peripheral wobble and an outer peripheral wobble forming the land. 2 of a land track address system defined by in-phase wobbles having the same phase and a groove track address system defined by including reverse phase wobbles in which the phases of the inner and outer wobbles forming the land are reversed. Including one address system,
Means for demodulating the first address information X from a wobble signal obtained by reproducing the groove track address system at the time of the groove trace or a wobble signal obtained by reproducing the land track address system at the time of the land trace;
Means for demodulating second address information Y from a wobble signal obtained by reproducing the land track address system at the time of the groove trace or a wobble signal obtained by reproducing the groove track address system at the time of the land trace;
Means for determining an error in the first address information X when the second address information Y is | X−Y |> 1 with respect to the first address information X;
An optical disc apparatus comprising:

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