JP4054045B2 - Information storage medium, information recording method, information reproducing method, and information reproducing apparatus - Google Patents

Description

  The present invention relates to an improvement of a sync frame (synchronization frame) used in an information storage medium such as an optical disk. Specifically, the present invention relates to an information storage medium, an information recording method, an information reproducing method, and an information reproducing apparatus based on an information recording format (sync frame structure) using an improved sync frame. The present invention is compatible with next-generation optical discs (next-generation DVD-ROM standards, next-generation DVD-R standards, next-generation DVD-RAM standards, etc.).

  In a recordable optical disc, preformat information is recorded on the optical disc in advance. When data is recorded on an optical disk by the optical disk device, preformat information is detected, and the detection position of the data is determined by referring to the detected information.

  Usually, a recording track formed in a spiral shape on an optical disk is divided into address segments of a predetermined length, addresses indicating addresses are assigned to the respective segments, and the addresses are written as preformat data.

  In an optical disc having a CLV structure with a constant recording linear density, the address segment lengths are all the same. If the address segment is too long, the time for searching for address information by random access increases. Therefore, the length is selected so that one round consists of 10 to several tens of address segments.

  As a preformatting method, a prepit may be formed at the beginning of a segment, but this portion cannot be used as a data area, so in recent recording media, it is superimposed on a data recording track as a wobble signal due to meandering of a groove. There is also a method for recording format information.

  When recording format information in wobble, modulation such as phase inversion and frequency change is applied. In + R, such a method is used. On the other hand, a method for forming format information by discretely forming prepits in lands between grooves is used in DVD-R.

  On the other hand, for the data to be recorded, an error correction code is generated for the original data, and the data is further divided into fine synchronization frames. For example, in a DVD (digital versatile disk), an error correction code block (ECC block) is modulated, a synchronization code is added at a predetermined interval, a plurality of synchronization frames are generated, and the plurality of synchronization frames are used as recording data. Yes.

  The following documents are related to the present invention.

  Japanese Patent No. 2,786,810 (Reference 1)... Describes the technical contents related to the synchronization code used in the current DVD.

  In addition, there is US Pat. No. 5,587,991 as an equivalent to this document 1.

Japanese Patent Laid-Open No. 2002-373472 (Document 2)... Describes a method for discriminating the reproduction position in a sector in the order of arrangement of a plurality (three) of synchronization codes.
Patent 2,786,810 JP 2002-373472 A

  In the current DVD standard in which a synchronization code (SYNC Code) related to the contents described in Document 1 is adopted, there are 32 types of synchronization codes (SYNC Code). In order to detect the synchronization code position by the information reproducing apparatus or the information recording / reproducing apparatus, brute force pattern matching detection is performed on the 32 kinds of patterns with respect to reproduced data reproduced from the information storage medium. Since the detection of the position of the synchronization code is very time-consuming, the synchronization code detection circuit is complicated, and the price of the information reproducing apparatus or information recording / reproducing apparatus is increased.

  In addition, since the synchronization code detection algorithm is complicated (due to the presence of 32 types of synchronization codes), the detection reliability is low. In addition, since the number of code for pattern matching (the number of bits of the entire synchronization code) is as long as 32 bits, there is a problem that the reliability of position detection of the synchronization code due to a defect on the information storage medium is further reduced. .

  In addition, if a false detection is caused with respect to a reproduction pattern of a synchronization code (SYNC Code) due to a defect on the information storage medium, there is a problem that information immediately after that becomes an error.

  Document 2 describes a method for discriminating reproduction positions in a sector in the order of arrangement of a plurality (three) of synchronization codes. However, if a value of one of the plurality of synchronization codes is erroneously detected during reproduction due to a defect on the information storage medium or the like, the position in the ECC block of the information immediately after that is shifted and determined. Then, there arises a problem that the error correction capability of the entire ECC block is greatly reduced. However, Document 2 does not describe any countermeasures against erroneous detection of the synchronization code.

  An object of the present invention is to solve the above problems. In a narrow sense, simplification of the detection of the position of the synchronization code is made, and if one synchronization code is detected as an unscheduled value by devising the arrangement of the synchronization code, it is “simple detection error” or “frame”. It is an object of the present invention to improve the detection reliability of the synchronization code by adopting a structure capable of determining whether “shift has occurred” or “whether it has been out of track”. In particular, it is an object of the present invention to provide a sync frame structure that can solve the above problems, and an information storage medium, an information recording method, an information reproducing method, and an information reproducing apparatus based on this structure.

In one embodiment of the present invention,
A1] The arrangement method of the synchronization code (SYNC Code) in the same sector is devised, and the combination pattern of three consecutive synchronization codes (SYNC Code) is two or more synchronization codes compared with the combination pattern shifted by one It is arranged to change with. Or
A2] Compared to a combination pattern of a plurality of consecutive sync codes (SYNC Code) in the past, “A frame shift has occurred”, “An error in sync code (SYNC Code) has occurred”, or “Out of track has occurred Is determined. Or
A3] The number of types of synchronization code (SYNC Code) is greatly reduced (reduced to 4 types compared to 32 types of conventional DVDs) to facilitate detection of the synchronization code of the information reproducing apparatus or information recording / reproducing apparatus. The price of the information recording / reproducing apparatus is reduced and the detection reliability of the synchronization code is increased. Or
4) Enables rewriting (or additional writing) in units of ECC blocks, forms guard areas between ECC blocks, records a synchronization code (SYNC Code) at the head position of the guard area, and facilitates detection of the guard area ing.

In other words, in the practice of this invention,
B1) An information storage medium (221) having an area (401) divided by a plurality of sectors (230 to 241 in FIG. 19) is used. The sector (234) includes one or more sync frames (420 to 429), and the sync frame (422 in FIG. 19; Sync frame in FIG. 14; SYNC Code number in FIG. 16) includes a plurality of sync codes ( 19 includes 431; SY0 to SY3 in FIG. 14; sync code numbers “2”, “1”, “0”, etc. in the sync frame number “00” in FIG. 16). Here, with respect to the arrangement of the synchronization code in the same sector, in the first pattern (for example, SY0, SY1, SY1 in FIG. 14; or sync frame number “00” in FIG. 16) composed of a combination of three synchronization codes. The second pattern (for example, SY1, SY1, SY2 in FIG. 14; or FIG. 16), which is a combination of the sync code number “2”, “1”, “0”) and one synchronization code code arrangement shifted from the first pattern. When the sync code number “01” in the sync frame number “01” is compared with two or more sync codes (in the example of FIG. 14, the first SY0 → SY1 and the third sync code SY1 → SY2; in the example of FIG. 16, “2” → “1” “1” → “0” “0” → “1” (three locations) are configured to change.

  B2) An information storage medium having an area divided by a plurality of sectors is used. The sector includes one or more sync frames, and the sync frame includes a plurality of synchronization codes. Here, with respect to the arrangement of the synchronization codes in the same sector, based on a past pattern composed of a combination of a plurality of past consecutive synchronization codes (comparison at ST66 in FIG. 36; comparison at ST5 in FIG. 37 / see FIG. 18). ), Whether a frame shift has occurred in the sync frame (ST6), or whether an erroneous detection of the sync code has occurred (ST7).

  B3) An information storage medium having an area divided by a plurality of sectors is used. The sector includes one or more sync frames, and the sync frame includes a plurality of synchronization codes. Here, the area divided by the plurality of sectors includes an ECC block that can be used as a unit for rewriting or appending, and a plurality of ECC blocks (411 to 418 in FIG. 20) are formed on the information storage medium, Guard areas (441 to 448 in FIG. 20; or FIGS. 21 to 22) are provided between these ECC blocks, and the synchronization code (for example, SY1 in FIG. 21 or FIG. 22) is located at the head position of the guard area. (The guard area can be easily detected by the synchronization code at the head of the guard area).

  The detection reliability of the synchronization code can be improved while simplifying the position detection of the synchronization code.

  Embodiments of the present invention will be described below with reference to the drawings.

1] Description of video information recording format on information recording medium according to one embodiment of the present invention (A)
FIG. 1 shows an example of file arrangement on an information recording medium according to an embodiment of the present invention. Conventional SD (Standard Definition) Object File (existing SD specific title object (VTS1TT_VOBS) file) 216, management files 206, 208, 211, 123, and HD (High Definition) for high-quality video Object File (High-Definition HD Specific Title Object (VTS2TT_VOBS) File) 217 and management files 201, 209, 212, 214 are separated from each other and coexisting in the conventional DVD-Video dedicated directory 202 is doing.

  FIG. 2 shows another example of the file arrangement on the information recording medium according to the embodiment of the present invention. Here, a conventional SD (Standard Definition) Object File (existing SD specific title object (VTS1TT_VOBS) file) 216 and management files 206, 208, 211, 123, and HD (High Definition) corresponding to high-quality video. Object file (specific image object (VTS2TT_VOBS) file 217 for high image quality HD) and management files 201, 209, 212, and 214 are arranged separately under different directories 203 and 204, respectively. If the Object File and management file are separated for SD and HD, not only will file management be easier, but it will also be possible to prepare an SD or HD decoder in advance for playback of the Object File. The preparation time before starting is greatly shortened.

  FIG. 3 is a diagram for explaining a video information recording method for an information recording medium according to an embodiment of the present invention. As shown in FIG. 3, according to one embodiment of the present invention, information is recorded on an information recording medium in the form of a program stream in accordance with a multiplexing rule defined by MPEG layer 2. That is, the main video information in the video information is distributed and arranged in the video packs 252 to 254, and the audio information is distributed and arranged in the audio pack 255. In the system according to the embodiment of the present invention, although not shown, the navigation pack 251 is arranged at the head position of VOBU (Video Object Unit) which is the minimum unit of video information. In addition to the main video recorded in the video packs 252 to 254, sub-video information indicating subtitles and menus is defined. Sub-picture information is distributed in sub-picture packs 256-258. When reproducing video information from an information recording medium, sub-picture units 256 258 are collected and collected in the sub-picture packs 256 to 258 to form a sub-picture unit 259 and then processed by a video processor (not shown). Then, the processed sub-picture information is displayed to the user.

  In one embodiment of the present invention, sectors 231 to 238 having a size of 2048 bytes are management units for information recorded on the information recording medium 221. Therefore, the data size per pack 241 to 248 is also set to 2048 bytes according to the sector size.

  FIG. 4 is a diagram for explaining an example of compression rules for sub-pictures recorded on the information recording medium according to the embodiment of the present invention. This rule is described below.

2] Sub-picture information expression format and compression rule (B) in one embodiment of the present invention
(a) Run-length compression rule
Run-length compression is used to compress sub-pictures. Some of the compression rules are described here. Several run-length compression rules have been developed for SD and HD.

  1) A case where 4 bits are set as one unit (see sub-picture information compression rule (1) in FIG. 4). If pixel data (pixel data) having the same value is continued for 1 to 3, the first 2 bits indicate the number of pixels (pixel number), and the subsequent 2 bits represent specific pixel data.

  2) A case where 8 bits are set as one unit (see sub-picture information compression rule (2) in FIG. 4). If pixel data having the same value is continuously 4-15, the first 2 bits are set to 0. The next 4 bits indicate the number of pixels, and the next 2 bits represent specific pixel data.

  3) Case in which 12 bits are set as one unit (see sub-picture information compression rule (3) in FIG. 4). If pixel data having the same value continues for 16 to 63, the first 4 bits are set to 0. The next 6 bits indicate the number of pixels, and the next 2 bits represent specific pixel data.

  4) A case where 16 bits are set as one unit (see the compression rule explanatory diagram (4) of the sub-picture information in FIG. 4). If pixel data having the same value is continuously 64 to 255, the first 6 bits are set to 0. The next 8 bits indicate the number of pixels, and the next 2 bits represent specific pixel data.

  5) A case where 16 bits are set as one unit (see sub-picture information compression rule explanatory diagram (5) in FIG. 4). If pixel data of the same value continues to the end of one line, the first 14 bits are set to 0. Then, specific pixel data is represented by the following 2 bits.

  6) If byte alignment cannot be realized when pixels for one line are expressed, a 4-bit dummy ('0000b') is inserted for adjustment.

  The above is a rule used when compressing a sub-picture for SD, but a rule used when compressing a sub-picture for HD has also been developed.

  FIG. 5 is a diagram illustrating a processing procedure for generating a recording data field. As shown in FIG. 5, the data recorded in the data field of the information recording medium includes a data frame, a scrambled frame, a recording frame or a recording data field (Recording) according to the signal processing stage. frame or Recorded data field). The data frame is composed of 2048 bytes, and has main data, a 4-byte data ID, a 2-byte ID error detection code (IED), a 6-byte reserved byte, and a 4-byte error detection code (EDC).

  After the error detection code (EDC) is added, the main data is scrambled. Here, a cross-reed-Solomon error correction code (Cross Reed-Solomon error correction code) is applied to the 32 scrambled data frames (scrambled frames), and so-called ECC encoding processing is executed. Thereby, a recording frame is formed. This recording frame includes an outer parity code (Parity of Outer-code (PO)) and an inner parity code (Parity of Inner-code (PI)).

  PO and PI are error correction codes created for each ECC block composed of 32 scrambled frames. The recording data field is 4/6 modulated. A sync code (SYNC) is added to the head every 91 bytes to form a recording frame. Four recording data fields are recorded in one data field. FIG. 5 shows how data changes from the main data to the recording frame.

  FIG. 6 shows the form of the data frame. The data frame is 2064 bytes composed of 172 bytes × 2 × 6 rows, and includes 2048 bytes of main data.

  FIG. 7 shows the contents of the data ID of FIG. This data ID is composed of 4 bytes. The first 1 byte of bits b31 to b24 is data field information, and 3 bytes (bits b23 to b0) are data field numbers.

  The data field information in the embossed data zone is as follows. Information such as sector format type, tracking method, reflectivity, recording type, area type, data type, and layer number is included.

  Sector format type ... 1b zone format type, tracking method ... 0b pit tracking, reflectance ... 1b equal to or less than 40%, recording type ... 0b general, 1b real time information (defect management method with 0b and 1b Area type ... 01b, lead-in area, data type ... 0b, read-only data, layer number ... 0b, dual layer 0 or single layer disc, 1b, dual layer 1 .

  The data field information in the rewritable data zone is as follows.

  Sector format type ... 1b zone format type, tracking method ... 1b groove tracking, reflectance ... 1b less than or equal to 40%, recording type ... 0b general, 1b real time information (defect management method with 0b and 1b) Area type ... 00b, data area, 01b, lead-in area, 10b, lead-out area, data type ... 1b, rewritable data, layer number ... 0b, dual layer 0 or single layer disc 1b shows layer 1 of the dual layer. These bits must also be assigned according to the above rules.

  FIG. 8 shows the contents of the data field number in FIG. When the ECC block belongs to an embossed data zone, a defect management area, or a disc identification zone, a sector number is described in any case. When the ECC block belongs to the data area, the data field number is “logical sector number (LSN) + 031000h”. At this time, the ECC block includes user data.

  An ECC block belongs in the data area, but this ECC block does not include user data, that is, it may be an unused ECC block. In such a case, it is one of the following three. (1) Bits 0 to 3 of the first sector are 0, and a serially incremented field number is described in the succeeding sector. (2) A field number between 00 0000h and 00 000Fh is described. (3) Or nothing is described.

  FIG. 9 shows the definition of the recording type. That is, it is “reserved” when the ECC block is in the embossed data zone. When the ECC block is in the rewritable data zone and in the lead-in area or lead-out area, it is “reserved”. When the ECC block is in the rewritable data zone and in the data area, 0b means general data (General data) and 1b means real-time data.

In the case of general data, if a block is defective, a linear replacement algorithm is applied to the corresponding sector. In the case of real-time data, if a block is defective, the linear replacement algorithm is not applied to the corresponding sector.

  Next, an error detection code (IED) for data ID will be described.

Now, if each byte arranged in the matrix is Ci, j (i = 0 to 11, j = 0 to 171); and each byte for IED is C0, j (j = 0 to 4), the IED is Can be expressed as:

here,

  Next, 6-byte RSV will be described. The first byte of RSV is used as seed information for scrambling. The other 5 bytes are 0h and are reserved.

The error detection code (EDC) is a 4-byte check code and is attached to 2060 bytes of the data frame before scramble. Assume that the MSB of the first byte of the data ID is b16511 and the LSB of the last byte is b0. Then, each bit bi (i = 31 to 0) for EDC is

here,

  FIG. 10 is a diagram for explaining an example of the initial value of the shift register when the main data is scrambled and the shift register. FIG. 10A shows an example of an initial value given to the feedback shift register when creating a scrambled frame, and FIG. 10B shows a feedback shift register for creating a scramble byte. Yes. Here, 16 types of preset values are prepared.

  r7 (MSB) to r0 (LSB) are shifted by 8 bits and used as a scramble byte. The initial preset number in FIG. 10A is equal to 4 bits (b7 (MSB) to b4 (LSB)) of the data ID. At the start of data frame scrambling, the initial values r14 to r0 must be set to the initial preset values in the table of FIG.

  The same initial preset value is used for 16 consecutive data frames. Next, the initial preset values are switched, and the same switched preset values are used for 16 consecutive data frames.

The lower 8 bits of the initial values of r7 to r0 are taken out as a scramble byte S0. Thereafter, an 8-bit shift is performed, and then a scramble byte is taken out, and such an operation is repeated 2047 times. When scrambled bytes S0 to S2047 are extracted from r7 to r0, the data frame changes from the main byte Dk to the scrambled byte Dik.

となる。 This scrambled byte Dik is

It becomes.

  Next, the configuration of the ECC block will be described (D) and (E).

  FIG. 11 shows the ECC block. The ECC block is formed of 32 consecutive scrambled frames. 192 rows + 16 rows are arranged in the vertical direction, and (172 + 10) × 2 columns are arranged in the horizontal direction. B0, 0, B1, 0,... Are each 1 byte. PO is PI, error correction code, and outer parity and inner parity.

  In the ECC block of FIG. 11, the unit (6 rows × 172 bytes) is handled as one scrambled frame. FIG. 12 is a diagram rewritten as the scrambled frame arrangement in this way. That is, it consists of 32 consecutive scrambled frames. Further, in this system, (block 182 bytes × 207 bytes) is handled as a pair. When L is added to the number of each scrambled frame of the left ECC block and R is added to the number of each scrambled frame of the right ECC block, the scrambled frames are arranged as shown in FIG. That is, left and right scrambled frames exist alternately in the left block, and scrambled frames exist alternately in the right block.

  That is, the ECC block is formed from 32 consecutive scrambled frames. Each row in the left half of the odd sector is replaced with a row in the right half. 172 × 2 bytes × 192 rows is equal to 172 bytes × 12 rows × 32 scrambled frames and is an information field. A 16-byte PO is added to form an outer code of RS (208, 192, 17) in each 172 × 2 column. Also, 10-byte PI (RS (182, 172, 11)) is added to each 208 × 2 row of the left and right blocks. PI is also added to the PO line.

  The numbers in the frame indicate the scrambled frame number, and the suffixes R and L mean the right half and the left half of the scrambled frame. The PO and PI shown in FIG. 11 are generated according to the following procedure.

First, 16-byte Bi, j (i = 192 to 207) is added to the column j (j = 0 to 171 and j = 182 to 353). This Bi, j is defined by the following polynomial Rj (X), which forms the outer code RS (208, 192, 17) in 172 × 2 columns:

here,

Next, 10 bytes of Bi, j (j = 172 to 181, j = 354 to 363) are added to the row i (i = 0 to 207). This Bi, j is defined by the following polynomial Ri (X), which forms the inner code RS (182,172,11) in each row of (208 × 2) / 2:

here,

here,

FIG. 13 shows how the outer parity (PO) is interleaved into the left block and the right block in the ECC block. Bi, j, which is an element of each B matrix in FIG. 11, constitutes 208 rows × 182 × 2 columns. This B matrix is interleaved between the rows so that Bi, j is rearranged at Bm, n. This interleaving rule is expressed as:

  As a result, as shown in FIG. 13, the 16 parity rows are distributed one by one. That is, 16 parity rows are arranged one by one for every two recording frames. Accordingly, a recording frame consisting of 12 lines is 12 lines + 1 line. After this row interleaving is performed, 13 rows × 182 bytes are referred to as a recording frame. Therefore, the ECC block after row interleaving is 32 recording frames. In one recording frame, as described with reference to FIG. 12, there are six rows of blocks on the right side and the left side. The PO is arranged so that it is located in a different row between the left block (182 × 208 bytes) and the right block (182 × 208 bytes). In the figure, one complete ECC block is shown. However, during actual data reproduction, such ECC blocks continuously arrive at the error correction processing unit. In order to improve the correction capability of such error correction processing, an interleaving method as shown in FIG. 13 is adopted.

  FIG. 14 is a diagram for explaining a configuration example of recorded data fields (even field and odd field).

  In FIG. 14, both the Even Recorded data field and the Odd Recorded data field are the last two sync frames (that is, the last “SYNC code is SY3”, the immediately following “sync data” and “SYNC code is SY1”. And the information of PO (Parity Out) shown in FIG. 13 is inserted into the sync data area in the portion where “sync data” is arranged immediately thereafter.

  That is, the “part of the left PO” shown in FIG. 12 is inserted in the last two sync frame locations in the even recorded data field, and the last two sync frame locations in the odd recorded data field are shown in FIG. The “part of the right PO” shown is inserted. As shown in FIG. 12, each ECC block is composed of left and right “small ECC blocks”, and each sector is alternately different PO group (PO belonging to the left small ECC block or right small ECC block). Data belonging to PO) is inserted.

[Individual points in one embodiment of the present invention and explanation of unique effects for each individual point]
F) As shown in FIG. 14, if the sector number of the sector constituting one ECC block that defines a plurality of types of Sync frame structures depending on the sector constituting the ECC block is an even number or an odd number, There is a feature in changing. That is, the structure is such that different PO group data is inserted alternately for each sector (FIG. 13).

  [Effect] Since the data ID is arranged at the head position of the sector even after the ECC block is configured, the data position at the time of access can be confirmed at high speed. Further, the PO insertion method as shown in FIG. 13 is simpler than the case where POs belonging to different small ECC blocks are mixedly inserted in the same sector, and the structure of each sector after error correction processing in the information reproducing apparatus is simplified. Information extraction can be facilitated, and the assembly process of the ECC block data in the information recording / reproducing apparatus can be simplified.

○ PO interleave / insertion position is different on the left and right (Fig. 13)
... [Effect] Since the data ID is arranged at the head position of the sector even after the ECC block is configured, the data position at the time of access can be confirmed at high speed.

  FIG. 15 is a diagram for explaining a specific example of the contents of a sync code. Corresponding to the modulation rule in one embodiment of the present invention, there are two states, State0 and State1. Four types of SYNC Codes from “SY0” to “SY3” are set for each state. In the current DVD standard, 8/16 modulation (converting 8 bits to 16 channel bits) RLL (2, 10) (Run Length Limited: d = 2, k = 10: “0” is a continuous range The minimum value is 2 and the maximum value is 10). Four states from State 1 to State 4 and 8 types of SYNC Codes from “SY0” to “SY7” are set for modulation. In comparison, the number of types of SYNC codes in the embodiment of the present invention is drastically reduced. In the information recording / reproducing apparatus or the information reproducing apparatus, the type of SYNC Code is identified by a pattern matching method when reproducing information from the information storage medium. As in one embodiment of the present invention, the number of types of SYNC Code is greatly reduced to reduce the target pattern required for matching, simplify the processing required for pattern matching and improve processing efficiency, as well as recognition speed. Can be improved.

  As shown in FIG. 15, the SYNC code (synchronization code) according to the embodiment of the present invention comprises the following parts.

<1> Code part for synchronization position detection ... It has a common pattern for all SYNC Codes and forms a fixed code area. By detecting this code, the position of SYNC Code can be detected. Specifically, it means the last 17 channel bits “01000 000000 001001” in each SYNC Code of FIG.

<2> Conversion table selection code part at the time of modulation: A code that forms part of the variable code area and changes according to the State number at the time of modulation. This corresponds to the first one channel bit in FIG.

<3> Sync frame position identification code portion: A code for identifying each type from “SY0” to “SY3” in the SYNC Code, and forms a part of the variable code area. This corresponds to the second to seventh channel bit portions from the beginning in each SYNC Code in FIG. As will be described later, the relative position in the same sector can be detected from the connection pattern of three SYNC Codes detected successively.

  In one embodiment of the present invention, 4/6 modulation and RLL (1, 9) are employed as the modulation method. That is, 4 bits are converted to 6 channel bits during modulation, and the range in which the converted “0” continues is set so that the minimum value (d value) is 1 and the maximum value (k value) is 9. Yes. In one embodiment of the present invention, by setting d = 1, it is possible to achieve higher density than in the past, but it is difficult to obtain a sufficiently large reproduction signal amplitude at the closest mark.

  As shown in FIG. 33, an information recording / reproducing apparatus according to an embodiment of the present invention has a PR equalization circuit 130 and a Viterbi complex 156, and is very stable by using PRML (Pertiral Response Maximum Likelyhood) technology. Signal reproduction is possible. In addition, since k = 9 is set, 10 or more consecutive “0” s do not continue in the modulated general channel bit data. By using this modulation rule, the above-mentioned “synchronization position detection code part” has a pattern that does not appear in the modulated general channel bit data.

  That is, as shown in FIG. 15, in the “synchronization position detection code portion”, 11 (k + 2) “0” s are continuously continued. The information recording / reproducing apparatus or the information reproducing apparatus finds this portion and detects the position of the synchronization position detecting code portion. In addition, if “0” continues continuously for too long, a bit shift error is likely to occur. Therefore, in order to alleviate the adverse effect, a pattern with a small number of consecutive “0” s is placed immediately after that in the synchronization position detection code section. Yes.

  In one embodiment of the present invention, since d = 1, it is possible to set “101” as the corresponding pattern. However, as described above, a sufficiently large reproduction signal amplitude is obtained at “101” (the most dense pattern). Therefore, “1001” is arranged instead, and the “synchronous position detection code portion” pattern as shown in FIG. 15 is used.

  Of the four types of synchronization codes (SYNC Code) shown in FIG. 15, only “SY0” is arranged at the first sync frame position in the sector as shown in FIG. There is. As an effect, the head position in the sector can be determined immediately by simply detecting “SY0”, and the head position extraction process in the sector is greatly simplified. Also, there is a feature that the combination patterns of three consecutive synchronization codes are all different within the same sector.

  FIG. 16 is a diagram for explaining a comparative example 1 of continuous sync code combination patterns (column direction) (when moving between sectors). In the embodiment of FIG. 14, “SY0” appears at the sync frame position at the head of the sector in both the Even Recorded data field and the Odd Recorded data field, followed by “SY1” and “SY1”. In this case, the combination pattern of the three synchronization codes is (0, 1, 1) by arranging only the SYNC Code numbers. When this combination pattern is arranged vertically in the column direction, the pattern changes when the combinations are shifted one by one are arranged in the horizontal direction as shown in FIG. For example, in the column of the latest SYNC Frame number “02” in FIG. 16, SYNC Code numbers are arranged in the order of (0, 1, 1).

  In FIG. 14, the SYNC Frame position of “02” in the Even Recorded data field represents the third SYNC Frame position from the left in the top row. The synchronization code at this SYNC Frame position is “SY1”. When the data in the sector is reproduced continuously, the synchronization code at the SYNC Frame position arranged immediately before is “SY1”, and the previous two synchronization codes are “SY0” (the SYNC Code number is “ 0 ").

  As apparent from FIG. 16, the combination patterns of the three SYNC Code numbers arranged in the column direction in the range of the latest SYNC Frame number from “00” to “25” are all different combinations. Taking advantage of this feature, the position in the same sector can be determined from the combination pattern of three consecutive synchronization codes.

  The sixth line in FIG. 16 represents the number of changes in the SYNC Code number within the pattern change when the combination of three consecutive synchronization codes is shifted by one. For example, the column with the latest SYNC Frame number “02” has the SYNC Code numbers arranged in the order of (0, 1, 1). The combination pattern when this combination is shifted by one is described in a column with the latest SYNC Frame number “03” and is (1, 1, 2). When these two patterns are compared, the SYNC Code number is unchanged from “1 → 1” in the center, but the front changes from “0 → 1” and the rear changes from “1 → 2”. Therefore, the total “2 places” changes, and the code change number between adjacents becomes “2”.

  As is apparent from FIG. 16, the number of code changes between adjacent neighbors becomes 2 or more within the entire range from the latest SYNC frame number “00” to “25” (that is, three consecutive sync codes The combination pattern in which the combination is shifted by one is devised such that the SYNC code number changes at least two places), and the major feature of the present invention is that the SYNC code numbers in the sector are arranged.

  FIG. 17 is a diagram for explaining a comparative example 2 of continuous sync code combination patterns (column direction) (when straddling a guard area). As will be described later with reference to FIGS. 20 and 23, in one embodiment of the present invention, a specific data structure in a read-only information storage medium and an ECC block in a write-once information storage medium and a rewritable information storage medium And a synchronization code (SYNC Code) is arranged at the beginning of a PA (Postamble) area in the guard area, and “SY1” is set as the synchronization code in the guard area as shown in FIG. . By setting the SYNC Code number in this way, even when two sectors are arranged with the guard area in between, adjacent combinations when three consecutive sync code combinations are shifted one by one The code change number is always kept at “2 or more” as shown in FIG.

  The seventh line in FIGS. 16 and 17 represents the number of code changes when two consecutive combinations of three synchronization codes are shifted by two. For example, the latest SYNC frame number is “04” when the combination is shifted by 2 with respect to the column where the latest SYNC frame number is “02” in which the SYNC code numbers are arranged in the order of (0, 1, 1). SYNC Code numbers are arranged in the order of (1, 2, 1). At this time, the SYNC Code number in the back is “1 → 1” and the SYNC Code number is not changed, but the front is changed from “0 → 1” and the center is changed from “1 → 2”. The number of code changes when “2 places” change and the combination is shifted by 2 is “2”.

  When the information recorded on the information storage medium is played back continuously, the frame data is played back in the ideal case where there is no “defect on the information storage medium” and there is no “frame shift” or “off-track”. At the same time, the synchronization code data is also detected in sequence accurately. In this case, adjacent patterns shifted one by one are sequentially detected from the combination pattern of three consecutive synchronization codes.

  When the synchronization code arrangement according to the embodiment of the present invention as shown in FIG. 14 is performed, the combination pattern of three consecutive synchronization codes is always two or more as shown in FIGS. The SYNC Code number has changed. Therefore, if the SYNC Code number of only one combination pattern is changed between adjacent ones, there is a high possibility that a part of the synchronization code (number) is erroneously detected or a track is off.

  Even if the synchronization is lost for some reason during information reproduction on the information storage medium and the synchronization is shifted by 1 Sync Frame, it is the same depending on the combination pattern of the two preceding synchronization codes when the next synchronization code is detected. You can check the current playback position in the sector. As a result, it is possible to reset synchronization by shifting (by correcting the position) by one sync frame.

  When it is detected that the synchronization has been lost and shifted by one sync frame during continuous reproduction, a pattern change when two consecutive combinations of three synchronization codes are shifted appears. The number of places where the SYNC Code number changes in the pattern at this time is shown in the seventh line of FIGS.

When the frame shift occurs, the frame shift amount is “± 1 SYNC Frame” in the majority of cases, so that the majority of the frame shifts can be detected by grasping the pattern change situation when the frame is shifted by one sync frame. As can be seen from the seventh line of FIGS. 16 and 17, in the synchronization code arrangement method according to the embodiment of the present invention, when a frame shift of ± 1 SYNC Frame occurs,
B) In most cases, there are two or more places where the SYNC Code number changes in the pattern;
B) The only place where the SYNC Code number changes in the pattern is only the place near the beginning in the sector (the latest SYNC Frame number is “03” and “04” only);
C) The only place where the SYNC Code number changes in the pattern is that the detected combination pattern is (1, 1, 2) or (1, 2, 1) (the latest SYNC Frame number is “03” and “ 04 ”) and (1,2,2) or (2,1,2) (the latest SYNC Frame number is a position shifted by 1 Sync Frame from“ 03 ”and“ 04 ”) Only the place of the combination pattern) at the place shifted by 2);
There is a feature called.

  From the above characteristics, in many cases (even if a frame shift occurs, the shift amount is ± 1 Sync Frame), “the number of places where the SYNC Code number changes within the combination pattern of three consecutive sync codes. When there is only one location and the detected combination pattern does not correspond to any of (1, 1, 2), (1, 2, 1), (1, 2, 2), (2, 1, 2) It can be determined that “synchronous code error detection” or “track off” has occurred.

  When the track is off, it can be detected by the continuity of the Data ID shown in FIG. 6 or the continuity of the Wobble Address information described later (continuity is interrupted when the track is off).

  FIG. 18 is a diagram illustrating an example of the relationship between the detected pattern content and the abnormal phenomenon content when an unscheduled sync code combination pattern is detected. Using the characteristics of the synchronization code arrangement method according to the embodiment of the present invention shown in FIG. 14, the “frame shift”, “synchronization code misdetection”, “ Any of “track off” can be identified. The contents described above are collectively shown in FIG.

  A major feature of one embodiment of the present invention is that “frame shift” or “false detection of sync code / track off” can be identified based on whether or not the number of locations where the SYNC Code number changes in the pattern is only one. There is.

  In FIG. 18, the pattern change state in each Case is collectively shown in the column direction (vertical direction). For example, Case 1 is regarded as “frame shift” if it differs from the planned combination pattern by two or more places and matches a pattern shifted by ± 1 SYNC Frame with respect to the planned pattern. On the other hand, in Case 2, “differing in only one place from the scheduled pattern” “matches a pattern shifted by ± 1 SYNC Frame with respect to the scheduled pattern” “detected patterns are (1, 1, 2), (1, 2 , 1), (1, 2, 2), and (corresponding to any of (2, 1, 2)) unless the three situations overlap, it is not considered that a “frame shift” has occurred.

[Individual points of one embodiment of the present invention and explanation of unique effects for each individual point]
J) The arrangement is devised, and the number of code changes when the combination of three consecutive synchronous codes is shifted by one is set to 2 or more (FIGS. 16 to 18).
... [Effect] The synchronization code recorded due to dust or scratches attached to the surface of the information storage medium or a minute defect on the recording film (light reflecting film) cannot be read correctly and is erroneously recognized as another synchronization code number. (False positives) things often happen. In the conventional DVD sync code arrangement, there is a place where the SYNC Code number changes only at one location between adjacent sync code combination patterns. For this reason, if the SYNC Code number of the one-point synchronization code is misread (detected erroneously), it is erroneously determined that a frame shift has occurred, and resynchronization is performed (reset) at the wrong position. In this case, the remaining frame data excluding the synchronization code in the Sync Frame is assigned to an incorrect position in the ECC block shown in FIG. 13, for example, and is subjected to error correction processing.

  The amount of frame data for one sync frame corresponds to half a line in the left and right small ECC blocks constituting the ECC block shown in FIG. Therefore, if the allocation position in the ECC block for one sync frame is mistaken due to the above-described erroneous detection, the error correction capability is greatly reduced, and the influence affects all data in the ECC block.

  As in one embodiment of the present invention, the surface of the information storage medium is devised so that the number of code changes becomes 2 or more when the combination of three consecutive synchronous codes is shifted by one. Even if the synchronization code number is erroneously detected due to dust or scratches adhering to the recording medium, or a minute defect on the recording film (light reflection film), it is rarely erroneously determined that a frame shift has occurred, and error correction by the ECC block is performed. It is possible to prevent a significant deterioration in capacity.

  In addition, even if an unexpected SYNC Code number is detected in only one place in the synchronization code combination pattern, it is possible to determine “whether or not the synchronization code is erroneously detected”, so that the erroneous detection result is automatically correct. The “automatic correction process” (ST7 in FIG. 37) can be changed to the SYNC Code number. As a result, compared with a conventional DVD, the reliability of synchronization code detection and synchronization processing using the same is greatly improved.

○ Devise so that the number of code changes is 2 or more even when the sector structure that does not include the guard area repeats;
○ Even if the sector structure is placed across the guard area, the number of code changes is 2 or more;
[Effect] As shown in FIGS. 20 and 23, even when there are two types of data recording formats in the read-only information storage medium, the synchronization code is also applied to the write-once information storage medium and the record information storage medium regardless of the data recording format. Since the same detection method using an array can be used, it is possible to ensure compatibility with respect to the medium type and the data recording format (in the read-only information storage medium) viewed from the synchronization detection. As a result, the detection processing circuit / processing program using the synchronization code arrangement can be shared regardless of the medium type and recording format, and the information recording / reproducing apparatus can be simplified and reduced in price.

4] First example (C) in a read-only information storage medium (next-generation DVD-ROM) according to an embodiment of the present invention
In one embodiment of the present invention, two types of data structures of recorded data in a read-only information storage medium (next-generation DVD-ROM) are allowed, and the content provider can select one of them depending on the data content to be recorded.

4-1) Explanation of data structure in the first example of the read-only information storage medium (next-generation DVD-ROM) according to the embodiment of the present invention FIG. 19 shows the data unit of the recording data on the information storage medium. It is a figure explaining an example. The information storage medium 221 in FIG. 19 is configured such that digital information is recorded in an area 401 (ECC block) divided by a plurality of sectors using the sync frame structure in FIGS. 14 to 17.

  In one embodiment of the present invention, data recorded on the information storage medium 221 is recorded as shown in FIG. 19 regardless of the type of the information storage medium 221 (reproduction only / writable / rewritable). Has a hierarchical structure of data.

  That is, one ECC block 401 which is the largest data unit capable of detecting or correcting data errors is composed of 32 sectors 230 to 241. The sectors 230 to 241 shown in FIG. 19 have the same contents as the sectors 231 to 238 recorded in pack units shown in FIG. As already described with reference to FIG. 14 and again with reference to FIG. 19, each sector 230 to 241 includes 26 sync frames # 0 420 to # 25 429. In one sync frame, a sync code 431 and sync data 432 are formed as shown in FIG. One sync frame includes data of 1116 channel bits (24 + 1092) as shown in FIG. 14, and a sync frame length 433 which is a physical distance on the information storage medium 221 on which the one sync frame is recorded. Is almost constant everywhere (excluding changes in physical distance for intra-zone synchronization).

  In addition, there is a feature of the embodiment of the present invention in that a plurality of types of recording formats can be set in the read-only information storage medium (corresponding to the invention point (C)). Specifically, there are two types of recording formats shown in the first and second embodiments of the read-only information storage medium.

  FIG. 20 is a diagram for explaining the difference between the first embodiment and the second embodiment when the embodiment of the present invention is applied to a read-only information storage medium.

  FIG. 20A shows the first embodiment, where the ECC blocks # 1 411 to # 5 415 are physically packed and continuously recorded on the information storage medium 221. FIG. On the other hand, in the second embodiment, as shown in FIG. 20B, guard areas # 1 441 to # 8 448 are inserted and arranged between the ECC blocks # 1 411 to # 8 418, respectively. Corresponding to Invention Point (H)]. The physical lengths of the guard areas # 1 441 to # 8 448 coincide with the sync frame length 433.

  As can be seen from FIG. 14, since the physical distance of the data recorded on the information storage medium 221 is handled with the sync frame length 433 as a basic unit, the physical distance of each of the guard areas # 1 · 441 to # 8 · 448 By matching the target length to the sync frame length 433, it is possible to easily manage the physical arrangement of the data recorded on the information recording medium 221 and to control access to the data.

4-2) Common part of the read-only information storage medium (next-generation DVD-ROM) according to the embodiment of the present invention with the second embodiment
The Lead-in and Lead-out parts are data structures that are packed and recorded;
... [Effect] If the data structure is different across the entire area of the information storage medium, the playback device may be wondering which one to deal with when starting the playback of the information storage medium for the first time, and the playback start time is longer than necessary. End up. First, at the start-up (at the start of playback of the information playback device or information recording / playback device immediately after the information storage medium is mounted) by sharing the data structure of a part of the information storage medium (Lead-in and Lead-out) You can access that part first and play back the minimum required information in the same format. Therefore, it is possible to start playback stably and quickly at startup.
4-3) Recording location of identification information of two types of formats (corresponding to invention point (C))
○ Format is common within the same disk (format change is not possible from the middle of the disk);
As another example,
○ Two formats can be mixed in the same disc according to the content of the content to be recorded;
Also,
○ Record the DVD-ROM format identification flag information (whether or not two plans are included) on the disc;
☆ Record format identification flag information in a common format area;
Record in the Control Data Zone shown in FIG. 17;
☆ Record the format identification flag information in the recordable area;
For the rewritable information storage medium (not shown), the above identification flag is provided in the Disc identification zone in the Rewritable data zone.

5] Second example of read-only information storage medium (next-generation DVD-ROM) according to an embodiment of the present invention
5-1) Description of structure in which “ROM-compatible guard area” is arranged between ECC blocks The recording format shown in the second example in the read-only information storage medium according to the embodiment of the present invention is the same as that shown in FIG. ), The guard areas # 1 · 441 to # 8 · 448 are inserted between the ECC blocks # 1 411 to # 8 418 (corresponding to the invention point (C)).

5-2) Specific data structure description in the “ROM guard area” in the second embodiment (corresponding to the invention point (H))
In the conventional ROM media playback operation, it is necessary to first read the error correction block including the requested data block, and calculate the position where the specified block will exist from the current position from the block number difference, etc., and predict the position The seek operation is started. After seeking to the specified designated location, the readout clock is extracted from the information data, channel bit synchronization and frame synchronization signal detection and symbol synchronization are performed, the symbol data is read out, and then the block number is detected to designate the designated block. It will be confirmed.

  In other words, in general ROM media playback, there is only a detection signal for the RF signal from the information pits, so all of the disk rotation control, information linear velocity, and channel bit read clock generation, which is the data read clock, are left to the RF signal. It is done. In recording / playback media, in order to specify a recording location, address information, which is a target of one embodiment of the present invention, exists in a signal format different from the recording of data information. A PLL or the like can detect the linear velocity or the like using such a signal, and can control the oscillation frequency of the PLL in the vicinity of the correct channel bit clock frequency. For this reason, it is possible not only to shorten the lock-up time of the PLL but also to provide an optimal system that can prevent runaway.

  However, since such a signal cannot be used in ROM media, a similar control system cannot be used. Therefore, a system is constructed by using a maximum code length (Tmax) or shortest code length (Tmin) signal of a conventional information signal. It was. That is, in the ROM medium, it is important how the PLL can be brought into an early locked state, and it has been desired to provide a signal form for that purpose. However, since the data / track structure of the ROM media in existing CDs and DVDs is determined by focusing only on the recording density, and the data / track structure of the recording / reproducing media is subsequently constructed, a data stream that differs for each medium, etc. It has become.

  In developing a recording method for next-generation media while approximating data streams of recording / reproducing media such as ROM media and R / RAM, introduction of measures for improving recording density is being studied. As one of the recording density improvement techniques, there is an improvement in modulation efficiency, and introduction of a new modulation method is considered in which the shortest pit length (Tmin) with respect to the recording / reproducing beam diameter is reduced. When the shortest pit length is reduced with respect to the beam system, it is difficult to detect the phase of the channel bit clock generation PLL that performs channel bit separation even if the signal amplitude cannot be obtained and the data can be read out by the PRML technology. Become. As described above, the ease of PLL lock in ROM media that relies only on the pit signal becomes increasingly severe with the introduction of high-density technology, making high-speed seeks difficult, and the insertion of auxiliary signals for that becomes necessary. ing.

  The recording format shown in the second example of the read-only information storage medium according to the embodiment of the present invention is the same as that shown in FIG. 20 (b), and the ROM medium also includes the ECC blocks # 1, 411 to #. By adopting a structure in which guard areas # 1 and 441 to # 8 and 448 are inserted and placed between 8 and 418, by inserting signals necessary for the ease of seeking and the lockability of the PLL for generating the channel bit clock into the guard area, There is also an object to realize the same control as the playback processing of the recording / playback media.

  FIG. 21 is a diagram showing an example of a guard area in the ROM medium. The guard area is composed of SYNC Code: SY1 and Specific code: 1002. Specific code: 1002 includes an error correction ECC block number, Segment-NO, a copyright protection signal, and other control information signals. Specific code: 1002 can be used to arrange a special control signal that is not configured in the data area. For example, there are a copyright protection signal, a media specific information signal, and the like. By securing such a special information area, system expandability is also possible.

  FIG. 22 is a diagram showing another example. In the example of FIG. 22, the area of Specific code: 1002 in FIG. 21 is used for the arrangement of a random signal (Random code 1003) so that the channel bit clock generation PLL can easily enter the locked state.

  Conventionally, in a recording medium such as a DVD-RAM, a repetitive signal (VFO: Variable Frequency Oscillator) having a fixed code length is inserted so that the PLL can easily realize a locked state. In ROM media, the phase difference detection method is likely to be used as a tracking error signal detection method. In this phase difference detection method, if the signal pattern of the adjacent track continues to approximate the signal pattern of this track, the adjacent track A phenomenon occurs in which the tracking error signal cannot be detected due to crosstalk. For this reason, there is a problem in adopting a VFO signal composed of a signal with a fixed period used for a recording medium or the like. On the other hand, with the shortest code length when the PRML method or the like is used for high density, there are many signals that are difficult to detect the phase difference in the channel bit clock generation PLL. Of course, in order to facilitate the phase locking of the PLL, the detection sensitivity becomes higher as the number of phase detections is larger. Therefore, it is necessary to consider this point.

  Therefore, the portion of Random code 1003 in FIG. 22 is a limited code in which the partial code length on the shortest pit side where the PLL phase detection is not reliable and the partial code length on the longest pit side where the number of detections is reduced are deleted. It is configured to introduce a random signal with a combination of lengths. That is, a random signal using a code whose run length is limited is used.

  Note that the specific code: 1002 in FIG. 21 may be scrambled with a random signal from a random number generator whose initial value is specified by a segment number. When the scrambled data at this time is modulated into a recording signal, it is desirable to modify the modulation table so that the recording signal stream is limited in run length. By such processing, it is possible to prevent adjacent track pattern matching in the area of Specific code: 1002, similarly to the scramble processing function supported in the data area of the current DVD-ROM.

6] Description of relationship in format between recordable information storage medium according to one embodiment of the present invention and the above-mentioned read-only information storage medium (next-generation DVD-ROM) FIG. FIG. 6 is a diagram illustrating a comparison of data recording format examples for each of a write-once type and a rewritable type. The relationship on the recording format (format) in the recordable storage medium and the read-only information storage medium in one embodiment of the present invention will be described with reference to FIG. FIGS. 23 (a) and 23 (b) are the first and second embodiments of the read-only information storage medium shown in FIG. For a recordable information storage medium, a guard area having the same length as the sync frame length 433 between the ECC blocks # 1, 411 to # 8, 418, as in the second embodiment of the read-only information storage medium. Is provided. However, the patterns of data (record marks) recorded in the guard area are different between the read-only information storage medium and the guard areas # 2, 452 to # 8, 458 of the write-once information storage medium shown in FIG.

  Similarly, guard areas # 2 442 to # 8 448 of the read-only information storage medium shown in FIG. 23B and guard areas # 2 462 to # 8 of the rewritable information storage medium shown in FIG. In 468, the pattern of data (record mark) recorded in the header area is different. As a result, the type of the information storage medium 221 can be determined.

  According to one embodiment of the present invention, in both the write-once information storage medium and the rewritable information storage medium, information write-in and rewrite processing is performed in units of ECC blocks # 1, 411 to # 8, 418.

  In one embodiment of the present invention, a PA (Postamble) region is formed (not shown) at the start position of each guard region 442 to 468 in any of FIGS. 23 (a) to 23 (d). Furthermore, as shown in the PA column of FIG. 17, a SYNC Code (SY1) having a SYNC Code number “1” is arranged at the head position of the PA area.

  The method of using the guard area of the read-only information recording medium has been described in the above section [5]. Here, the method of using the guard area resulting from the difference between the read-only information recording medium and the recordable type information recording medium. Will be described with reference to FIGS. 23B, 23C, and 23D.

  Note that the write-once information recording medium shown here is a write-once recording medium in which the recording operation is performed only once. Usually, a continuous recording process is performed. Next, the method of recording the next data block by the write-once method is adopted. Therefore, in FIG. 23, it is read as a write-once information recording medium.

  Before explaining the difference in the guard structure of each medium, the difference between the data streams of the read-only information recording medium and the recording / reproducing medium will be explained. In the read-only information recording medium, the relationship between channel bits and symbol data is continuous in a specified relationship in all data blocks including the guard area. However, in the write-once information recording medium, at least the phase of the channel bit changes between the blocks where the recording operation is stopped. Since the rewritable information recording medium is rewritten in units of ECC blocks, there is a high possibility that the phase will change in units of ECC blocks. That is, in the read-only medium, the channel bit phase is continuous from the beginning to the end, but in the recording medium, the channel bit phase is largely changed in the guard area.

  On the other hand, in the recording medium, the recording track is physically formed with a recording track groove, and the groove is wobbled for the purpose of controlling the recording rate and inserting addressing information. From this, it is possible to control the transmission frequency of the channel bit clock generation PLL, and it is possible to prevent runaway of the transmission frequency even in processing operations such as variable speed reproduction. However, in the recordable information recording medium, since the medium after recording is used exclusively for reproduction, the adjacent track, which is a consideration when the phase difference method is introduced in the tracking error detection method described in the section [5], is used. I want to avoid recording signal pattern matching between the two.

  In a rewritable information recording medium, in general, when a phase difference method (DPD: Differential Phase Detection) is not used as a tracking error detection method, there is no problem with information signal pattern matching in adjacent tracks. The area is preferably structured so that the channel clock generation PLL can easily lock, that is, the Random code 1003 area in FIG. 22 is preferably a signal with a constant period such as VFO.

  Since these types of media have different properties, the structures of (b) guard region 442, (c) guard region 452, and (d) guard region 462 in FIG. 23 are optimal considering the characteristics of the medium. Data structure is introduced.

  In the header area of the read-only information recording medium, a pattern that facilitates linear velocity detection and a channel bit generation PLL lock facilitating signal based on a random signal are suitable.

  The header area of the write-once information recording medium is a channel based on a random signal that copes with phase fluctuations in the header area because the oscillation frequency of the PLL for generating the channel bit clock is prevented from runaway by wobbling detection and can be controlled in the vicinity. It may be configured with a lock generation signal of the bit generation PLL.

  In the rewritable information recording medium, it is possible to introduce a VFO pattern having a fixed period for facilitating PLL lock, and it is optimal that the rewritable information recording medium is composed of other header mark signals.

  Note that the media identification is facilitated by making the guard area different depending on the type of the information recording medium. Also, the copyright protection system also improves the protection capability due to the difference between read-only and recordable media.

[Individual points of one embodiment of the present invention and explanation of unique effects for each individual point]
H) Guard area arrangement structure between ECC blocks (FIG. 23)
... [Effect] Discrimination between read-only / write-once / rewritable types can be made quickly and easily;
○ Change the data contents between read-only / write-once / rewritable type (→ for use in identification);
○ Use random signals for DVD-ROM headers;
... [Effect] DPD signal can be detected stably at the DVD-ROM header position even if the positions of adjacent tracks match.

  FIG. 24 shows a zone structure of a rewritable information recording medium in one embodiment of the present invention.

7-1) Description of Zone Structure The rewritable information storage medium according to the embodiment of the present invention has a zone structure as shown in FIG. In one embodiment of the present invention,
Reproduction linear velocity: 5.6m / s
Channel length: 0.086μm
Track pitch: 0.34μm
Channel frequency: 64.8MHz
Recorded data (RF signal): (1,7) RLL
Wobble carrier frequency: about 700kHz (93T / Wobble)
Modulation phase difference [deg]: ± 90.0
Segment / track: 12-29 segments
Zone: About 18 zones.

7-2) Description of address information recording format in one embodiment of the present invention (phase modulation + wobble modulation by NRZ method)
In one embodiment of the present invention, address information in a recording information storage medium is recorded in advance using wobble modulation. As a wobble modulation method, phase modulation of ± 90 degrees (180 degrees) is used, and an NRZ (Non Reture to Zero) method is adopted. Also, an L / G (Land and Groove) recording method is used for a rewritable information storage medium. The fact that the wobble modulation method is adopted in the L / G recording method is also a major feature of one embodiment of the present invention.

  FIG. 25 is a diagram for explaining 180 ° phase modulation and NRZ method in wobble modulation. A specific description will be given with reference to FIG. In one embodiment of the present invention, one address bit (also referred to as an address symbol) area 511 is expressed by 8 wobbles or 12 wobbles, and the frequency, amplitude, and phase are consistent throughout the 1 address bit area 511. . In addition, when the same value as the address bit value continues, the same phase continues at the boundary portion of each address bit area 511 (the portion marked with “black triangle” in FIG. 25), and the address bit is inverted. In this case, inversion of the wobble pattern (180 degree phase shift) occurs.

[Individual points of one embodiment of the present invention and explanation of unique effects for each individual point]
O) Wobble phase modulation of 180 degrees (± 90 degrees) is employed in L / G recording (FIG. 25).
... [Effect] When an indefinite bit is generated on the land due to the change of the groove track number in "L / G recording + groove wobble modulation", the overall level of the reproduction signal from the recording mark recorded thereon changes. However, there is a problem that the error rate of the reproduction signal from the recording mark is locally deteriorated. However, by making the wobble modulation for the groove 180 degree (± 90 degrees) phase modulation as in the embodiment of the present invention, the land width is left-right symmetric at the indefinite bit position on the land and the sine wave shape is obtained. Therefore, the overall level change of the reproduction signal from the recording mark becomes a very straightforward shape close to a sine wave shape. Further, when tracking is stably performed, an indefinite bit position on the land can be predicted in advance. Therefore, according to the embodiment of the present invention, it is possible to realize a structure in which the reproduction signal quality is easily improved by performing correction processing on the reproduction signal from the recording mark in a circuit.

7-3) Description of L / G recording method and indefinite bit mixing by wobble modulation As information indicating the address on the information storage medium 221, the rewritable information storage medium according to the embodiment of the present invention uses zone identification information. It has three types of address information: certain zone number information, segment number information that is segment address information, and track number information that indicates track address information. The segment number means a number within one turn, and the track number means a number within a zone. When the zone structure shown in FIG. 24 is adopted, the zone identification information and the segment address information in the address information take the same value between adjacent tracks, but the track address information takes different address information between adjacent tracks. .

  FIG. 26 is a diagram for explaining the principle of indefinite bit generation when wobble modulation is performed in land (L) / groove (G) recording. As shown in FIG. 26, it is assumed that “... 0110...” Is recorded as the track address information in the groove area 501 and “... 0010 ...” is recorded as the track address information in the groove area 502. In this case, in the land area 503 sandwiched between “1” and “0” in the adjacent groove area, the land width periodically changes, and an area in which the address bit by wobble is not determined occurs. In one embodiment of the present invention, this area is referred to as “indefinite bit area 504”.

  When the condensing spot passes through the indefinite bit region 504, the land width periodically changes. Therefore, the total amount of light reflected from and returned through the objective lens (not shown) periodically changes. Since a recording mark is also formed in the indefinite bit area 504 in the land, the reproduction signal with respect to this recording mark periodically fluctuates due to the above-described influence, and the reproduction signal detection characteristics deteriorate (deterioration of the error rate of the reproduction signal). The problem of causing

7-4) Description of Gray code and special track code (one embodiment of the present invention) employed in an embodiment of the present invention In the embodiment of the present invention, the indefinite bit 504 region In order to reduce the frequency of occurrence of this problem, the existing “gray code” or the gray code is improved and the special track code newly devised in one embodiment of the present invention is used [Invention Point (O) Corresponding to].

  FIG. 27 shows an example of a Gray code. There is a feature of the Gray code where “only 1 bit changes” every time “1” changes in decimal (becomes alternating binary).

  FIG. 28 shows a special track code newly proposed in one embodiment of the present invention. This special track code changes “only 1 bit” every time the decimal value changes “2” (track numbers m and m + 2 become alternating binary), and 2n for the integer value n. Between 2n + 1, only the most significant bit changes, and all the other least significant bits match.

  The special track code according to the embodiment of the present invention is not limited to the above example, but changes by “1 bit” whenever the decimal value changes by “2” (track numbers m and m + 2 are alternating binary). It is also possible to set a code having a characteristic that the address bits change while “holding a specific relationship” between 2n and 2n + 1.

[Individual points of one embodiment of the present invention and explanation of unique effects for each individual point]
P) Gray code or special track code is adopted for the track address (FIGS. 27 and 28).
... [Effect] The frequency of indefinite bits on the land caused by the change of the groove track number in "L / G recording + groove wobble modulation" is suppressed. At an indefinite bit position on the land, the land width locally changes in a symmetrical manner. As a result, the wobble detection signal cannot be obtained from the indefinite bit position on the land, and the entire level of the reproduction signal from the recording mark recorded thereon changes, and the error of the reproduction signal from the recording mark there occurs. There is a problem that the rate deteriorates locally. In this way, by suppressing the occurrence frequency of indefinite bits on the land, the occurrence frequency of the above-mentioned problem portion can be suppressed, and the reproduction of the wobble detection signal and the reproduction signal from the recording mark can be stabilized.

8] Explanation of embodiment concerning wobble address format arrangement
8-1) Description of Example of Segment Format FIG. 29 is a diagram for explaining an example of a method for recording rewritable data recorded on a rewritable information storage medium. FIG. 29 shows a recording format of rewritable data recorded on the rewritable information storage medium. FIG. 29A shows the same content as FIG. 23D described above. In one embodiment of the present invention, rewritable data is rewritten for each ECC block. FIG. 29C shows a rewritable data structure in the rewrite unit. The rewritable data on the information storage medium is rewritten in the ECC block # 2 information rewrite unit 531. The data content of the rewritable data 525 in the ECC block # 2 is read-only information storage as shown in FIG. Regardless of the type of media such as media (FIGS. 23 (a) and 23 (b)) and write-once information storage media (FIG. 23 (c)), all have the same format data structure, and 9672 bytes of data are recorded respectively. It is possible. That is, the data content of the rewritable data 525 in the ECC block # 2 has a structure shown in FIG. Each sector data constituting the ECC block is composed of 26 sync frames as shown in FIG. 19 or FIG. 14 (data field structure).

  As shown in FIG. 29 (c), in the rewrite unit 531 of the ECC block # 2 information, 2 bytes are allocated to the copy information area 524 corresponding to the copy protection prior to the rewritable data 525 in the ECC block # 2. Before that, 3 bytes are set in the presync area 523 indicating the end position of the VFO area. A VFO (Variable Frequency Oscillator) area 522 set for 35 bytes is used to synchronize when rewritable data 525 is reproduced. Immediately after the rewritable data 525, a postamble area 526 indicating the end position of the rewritable data 525 is arranged.

  A front guard area 521 and a rear guard area 527 are arranged at the front end and rear end of the rewrite unit 531 of the ECC block # 2 information. The front guard area 521 is 30 bytes + J, and the rear guard area 527 is 22 bytes-J. By changing the value of “J”, the writing / writing end position of the rewriting unit 531 of the segment # 2 information is changed. “Random shift” is possible. In the case of a phase change recording film, there is a feature that the characteristic deterioration of the recording film is likely to occur remarkably at the writing start / write end position of rewritable data. In one embodiment of the present invention, as described above, By random shifting, it is possible to prevent the characteristic deterioration of the phase change recording film.

  In order to compare the physical range of the rewrite unit, a part 530 of the rewrite unit of the ECC block # 1 information is shown in FIG. 29B, and a part 532 of the rewrite unit of the ECC block # 3 information is shown in FIG. Is shown. The embodiment of the present invention is characterized in that rewriting is performed so that the front guard region 522 and the rear guard region 527 partially overlap at the overlapping portions 541 and 542 at the time of rewriting [corresponding to the invention point (I) ]. By rewriting in such a manner that a part of them is overlapped, it is possible to remove interlayer crosstalk in a recordable information storage medium having two recording layers on one side.

[Individual points of one embodiment of the present invention and explanation of unique effects for each individual point]
I) A guard area is partially recorded in a recording format for a recordable information storage medium;
As shown in FIG. 29, the front guard region 521 and the rear guard region 527 overlap, resulting in overlapping portions 541 and 542 at the time of rewriting;
... [Effect] When there is a gap (a part where no recording mark exists) between the front and rear guard areas between segments, there is a difference in light reflectivity depending on the presence or absence of the recording mark. A difference in light reflectance occurs. For this reason, when the single-sided, two-recording layer structure is used, the information reproduction signal from the other layer is disturbed due to the influence from that portion, and errors during reproduction frequently occur. By partially overlapping the guard area as in the embodiment of the present invention, it is possible to prevent the occurrence of a gap where no recording mark exists and to eliminate the influence of interlayer crosstalk from the already recorded area in the single-sided two-recording layer. A stable reproduction signal can be obtained.

  FIG. 30 is a view for explaining an example of a wobble address format on the information storage medium according to the embodiment of the present invention. Next, the address information recording format using wobble modulation in the recordable information storage medium according to the embodiment of the present invention will be described with reference to FIG. The address information setting method using wobble modulation in one embodiment of the present invention has a great feature in that “allocation is performed in units of sync frame length” shown in FIG.

  As shown in FIG. 14, one sector is composed of 26 sync frames, and as can be seen from FIG. 13, one ECC block is composed of 32 sectors. Therefore, one ECC block is composed of 26 × 32 = 832 sync frames. . As shown in FIG. 29, the length of the guard area existing between the ECC blocks coincides with the length of one sync frame. Therefore, the total length of the guard area and the ECC block is composed of 832 + 1 = 833 sync frames.

Where
833 = 7 × 17 × 7 (1)
Because it can be factored into a factor, it has a structural arrangement that takes advantage of this feature. That is, as shown in FIG. 30B, the area obtained by adding the guard area and the ECC block is divided into “7” wobble segments # 0 · 550 to # 6 · 556, and each wobble segment # 0 · 550 is divided. The wobble address information 610 is recorded in advance in the form of wobble modulation every .about. # 6,556. Further, each wobble segment # 0 · 550 to # 6 · 556 is divided into 17 wobble data units # 0 · 560 to # 16 · 576 (FIG. 30 (c)).

  From equation (1), it can be seen that seven sync frames are assigned to the length of one wobble data unit # 0 · 560 to # 16 · 576. Each wobble data unit # 0 · 560 to # 16 · 576 is composed of a modulation area for 16 wobbles and non-modulation areas 590 and 591 for 68 wobbles. One embodiment of the present invention is characterized in that the occupation ratio of the non-modulation areas 590 and 591 to the modulation area is greatly increased.

  Since the unmodulated areas 590 and 591 are always wobbled at a constant frequency, the recording marks recorded on the information storage medium by applying PLL (Phase Locked Loop) using the unmodulated areas 590 and 591 Thus, it is possible to stably extract (generate) a reference clock for reproducing the recording or a recording reference clock used for newly recording. As described above, in one embodiment of the present invention, the reproduction reference clock is extracted (generated) or the recording reference clock is extracted (generated) by greatly increasing the occupation ratio of the non-modulation areas 590 and 591 to the modulation area. ) Accuracy and extraction (generation) stability can be greatly improved.

  When moving from the non-modulation areas 590 and 591 to the modulation area, the modulation start marks 581 and 582 are set using four wobbles, and the wobble address areas 586 and 587 which are wobble modulated immediately after the detection of the modulation start marks 581 and 582 are performed. Are arranged to come. To actually extract the wobble address information 610, as shown in FIGS. 30D and 30E, the unmodulated areas 590 and 591 in the wobble segments # 0 and 550 to # 6 and 556 and the modulation start are performed. The wobble sync area 580 excluding the marks 581 and 582 and the wobble address areas 586 and 587 are collected and rearranged as shown in FIG.

  In the embodiment of the present invention, as shown in FIG. 25, the phase modulation of 180 degrees and the NRZ method (Non Return to Zero) are adopted, so that the address of the wobble phase is “0 degree” or “180 degrees”. Bit (address symbol) “0” or “1” is set.

  As shown in FIG. 30D, in the wobble address areas 586 and 587, 3 address bits are set in 12 wobbles. That is, one address bit is composed of four consecutive wobbles.

  Since one embodiment of the present invention employs the NRZ method as shown in FIG. 25, the phase does not change within four consecutive wobbles in the wobble address areas 586 and 587. The wobble pattern of the wobble sync area 580 and the modulation start marks 561 and 582 is set using this feature. That is, by setting a wobble pattern that cannot be generated in the wobble address areas 586 and 587 to the wobble sync area 580 and the modulation start marks 561 and 582, the wobble sync area 580 and the modulation start marks 561 and 582 are set. The arrangement position is easily identified.

  In one embodiment of the present invention, one address bit length is set to 4 at the modulation start marks 561 and 582 positions and the wobble sync area 580 positions with respect to the wobble address areas 586 and 587 which constitute one address bit by four consecutive wobbles. It is characterized by the fact that it is set to a length other than wobble. That is, at the positions of the modulation start marks 561 and 582, the 4 wobbles are further divided into two wobbles, and the wobble bits are set to change to “1” and “0” as shown in FIG. Yes. In the wobble sync area 580, the area where the wobble bit is “1” is set to “6 wobbles” different from 4 wobbles, and the modulation area within one wobble data unit # 0 · 560 ( All of (16 wobbles) are assigned to the wobble sync area 580, thereby improving the ease of detection of the start position of the wobble address information 610 (arrangement position of the wobble sync area 580).

The contents of the wobble address information 610 are as follows:
1. Track information 606, 607
This means the track number in the zone, and the address is fixed on the groove (not including the undefined bit → the undefined bit is generated on the land) and the address is fixed on the groove track information 606 and the land (including the undefined bit) No → Land track information 607 is recorded alternately (indefinite bits are generated on the groove). Also, track number information is recorded in the track information 606 and 607 only in the gray code shown in FIG. 27 or the special track code shown in FIG.

2. Segment address information 601
Information indicating the segment number in the track (within one revolution in the information storage medium 221). When the segment number is counted from “0” as the segment address information 601, a pattern “000000” in which 6 bits “0” continues in the segment address information 601 appears. In this case, it becomes difficult to detect the position of the boundary portion of the address bit area 511 (the “black triangle mark” portion) as shown in FIG. 25, and the bit shift is detected by shifting the position of the boundary portion of the address bit area 511. Is likely to occur. As a result, erroneous determination of wobble address information due to bit shift occurs.

  In order to avoid the above problem, the segment number is counted from “000001” in the embodiment of the present invention. This also has the characteristics of one embodiment of the present invention (corresponding to the invention point (K)).

3. Zone identification information 602
... indicates the zone number in the information storage medium 221, and the value "n" of "Zone (n)" shown in FIG. 24 is recorded.

4). Recording layer (layer) identification information 603
In the information storage medium 221 according to the embodiment of the present invention, each of the read-only type, the write-once type, and the rewritable type has a recording layer A • 222 and a recording layer B • 223 as shown in FIGS. Both have a “single-sided two-recording layer” structure capable of reproducing or recording / reproducing from the same surface side. Information indicating which recording layer A • 222 or recording layer B • 223 corresponds to the recording layer currently being reproduced or recorded is recording layer (layer) identification information 603, which is a recording layer number. Indicated.

5. Parity information 605
... is set for error detection during playback from wobble address information 610, and 17 address bits from segment information 601 to reservation information 604 are individually added. If the addition result is an even number, "0" is set. In the case of an odd number, “1” is set.

6). Monotone information 608
As described above, each wobble data unit # 0 · 560 to # 16 · 576 is set so as to be composed of a modulation area for 16 wobbles and non-modulation areas 590 and 591 for 68 wobbles. The occupation ratio of the non-modulation regions 590 and 591 is greatly increased. Further, the occupation ratio of the non-modulation regions 590 and 591 is expanded to further improve the accuracy and stability of extraction (generation) of the reproduction reference clock or recording reference clock.

  The location where the monotone information 608 shown in FIG. 30 (e) is included is the wobble data unit # 16 576 in FIG. 30 (c) and the wobble data unit # 15 immediately before (not shown). It corresponds exactly as it is. In the monotone information 608, all six address bits are “0”. Therefore, the modulation start marks 581 and 582 are not set in the wobble data unit # 16 576 including the monotone information 608 and the wobble data unit # 15 immediately before (not shown), and all of them are not set. It is a non-modulation region of uniform phase.

[Individual points of one embodiment of the present invention and explanation of unique effects for each individual point]
G) ECC block segment division structure (FIG. 30)
... [Effects] Format compatibility between read-only / write-once / rewritable is high, and it is possible to prevent a reduction in error correction capability of a reproduction signal from a recording mark, particularly in a rewritable information storage medium.

            Since the number of sectors 32 and the number of segments 7 in the ECC block are not divisible by each other (a non-multiple relationship), it is possible to prevent a reduction in error correction capability of a reproduction signal from a recording mark.

[Individual points of one embodiment of the present invention and explanation of unique effects for each individual point]
K) Add conditions to address numbering method for address information (especially segment address information) ... [Effect] Increase the frequency of polarity inversion in wobble symbol (address bit) unit, and change the boundary position of symbol (address bit) Increase detection accuracy;
O Address numbers start with “1”, not “0”, where all bits have the same value;
○ Missing address numbers where “1” or “0” appears three or more times in succession.

[Individual points of one embodiment of the present invention and explanation of unique effects for each individual point]
L) Address information is recorded by L / G recording + wobble modulation (Fig. 26)
... [Effect] Largest capacity possible. The recording efficiency is higher when the recording marks are formed on both the groove and the land than when the recording marks are formed only on the groove. Further, when the address is pre-recorded in the pre-pit state, a recording mark cannot be formed at the pre-pit position. However, as in the embodiment of the present invention, the wobble-modulated groove / land area is not recorded. In addition, since the recording mark can be recorded redundantly, the recording efficiency of the recording mark is higher in the address information recording method by wobble modulation than in the pre-pit address method. Therefore, the method employing both of the above methods is most suitable for increasing the capacity.

[Individual points of one embodiment of the present invention and explanation of unique effects for each individual point]
M) Indefinite bits are also distributed in the groove area (FIG. 30 (e) track information 606, 607).
[Effect] By providing an area in which the track address is determined without an indefinite bit even in the land portion, it is possible to detect the address with high accuracy in the land portion.

Track address detection accuracy is improved because an area where the track address is fixed can be predicted in advance without the indefinite bit in each of the land part and the groove part;
○ When creating a groove, locally change the groove width to create a constant land width area;
☆ Change the groove width by locally changing the exposure amount when creating the groove area;
☆ Use two exposure condensing spots when creating the groove area and change the groove width by changing the distance between them;
○ Change the wobble amplitude in the groove and place undefined bits in the groove area.

[Individual points of one embodiment of the present invention and explanation of unique effects for each individual point]
N) Indefinite bits are distributed and arranged in both Land and Groove by L / G recording + wobble modulation (FIG. 30 (e) track information 606, 607)
... [Effect] If indefinite bits are centrally arranged in either Land or Groove, the frequency of erroneous detection when address information is reproduced in a portion where indefinite bits are centrally arranged becomes very high. By distributing undefined bits to Land and Groove, it is possible to distribute the risk of false detection and provide a system that can easily detect address information stably as a whole.

○ When changing the groove width locally, control the groove width so that the land width of the adjacent part is constant;
In the groove width changing portion, an indefinite bit is obtained in the groove area, but the width is kept constant in the adjacent land area, so that the indefinite bit can be avoided in the land area.

  In contrast to the synchronization code arrangement method shown in FIG. 14, a method of determining the position in the physical sector of the data currently being reproduced using the sequence of information before and after three consecutive synchronization codes is shown in FIGS. Will be described.

  FIG. 31 is a diagram for explaining an example of a method for determining one sync frame in one physical sector from the arrangement order of sync frame identification codes in the synchronization code. FIG. 32 is a diagram illustrating a specific example (when the data field illustrated in FIG. 14 is employed) when the sync frame position is determined from the arrangement order of the sync frame identification codes. FIG. 33 is a diagram for explaining the configuration of an information recording / reproducing apparatus according to an embodiment of the present invention. FIG. 34 is a diagram illustrating a detailed configuration example of the synchronization code position extraction unit (detection unit) 145 and its peripheral elements in FIG.

  FIG. 33 shows the structure of an information reproducing apparatus or information recording / reproducing apparatus according to an embodiment of the present invention. In one embodiment of the present invention, the channel bit interval is shortened to near the limit in order to increase the density of the information storage medium. As a result, for example, when a pattern “10101010101010101010101010”, which is a repetition of the pattern of d = 1, is recorded on the information storage medium and the data is reproduced by the information recording / reproducing unit 141, the cutoff frequency of the MTF characteristic of the reproducing optical system is obtained. Since it is approaching, the signal amplitude of the reproduced raw signal is almost buried in noise. Therefore, in one embodiment of the present invention, a PRML (Partial Response Maximum Likely Hood) technique is used as a method of reproducing recorded marks or pits whose density is close to the limit (cutoff frequency) of the MTF characteristic.

  That is, the signal reproduced from the information recording / reproducing unit 141 is subjected to reproduction waveform correction by the PR equalization circuit 130. The AD converter 169 samples the signal after passing through the PR equalization circuit 130 in accordance with the timing of the reference clock 198 sent from the reference clock generation circuit 160 and converts it into a digital quantity, and the Viterbi decoder 156 performs Viterbi decoding. Get processed. The data after the Viterbi decoding process is processed as the same data as the binarized data at the conventional slice level. When the PRML technique is employed, the error rate of data after Viterbi decoding increases when the sampling timing in the AD converter 169 is shifted. Therefore, in order to increase the accuracy of the sampling timing, the information reproducing apparatus or information recording / reproducing apparatus according to the embodiment of the present invention particularly has a sampling timing extracting circuit (a combination of the Schmitt trigger binary circuit 155 and the PLL circuit 174). Yes.

  The information reproducing apparatus or information recording / reproducing apparatus according to the embodiment of the present invention is characterized in that a Schmitt trigger circuit is used as the binarization circuit. This Schmitt trigger circuit has a characteristic that the slice reference level for binarization has a specific width (actually the forward voltage value of the diode) and is binarized only when the specific width is exceeded. Yes. Therefore, for example, as described above, when the pattern “101010101010101010101010” is input, the signal amplitude is very small, so that binarization is not switched, and a sparser pattern such as “1001001001001001001001” is input. In this case, since the amplitude of the reproduced raw signal becomes large, the Schmitt trigger binarization circuit 155 switches the polarity of the binarized signal in accordance with the timing “1”.

  In one embodiment of the present invention, the NRZI (Non Return to Zero Invert) method is employed, and the position of “1” in the pattern coincides with the edge portion (boundary portion) of the recording mark or pit.

  The PLL circuit 174 detects a frequency and phase shift between the binarized signal output from the Schmitt trigger binarizing circuit 155 and the reference clock 198 signal sent from the reference clock generating circuit 160 to detect the PLL circuit 174. The frequency and phase of the output clock are changed. In the reference clock generation circuit 160, the output signal of the PLL circuit 174 and the decoding characteristic information of the Viterbi complex 156 (specifically, the convergence length in the path metric memory in the Viterbi complex 156 (distance to convergence). ) Is used to feed back the reference clock 198 (frequency and phase) so that the error rate after Viterbi decoding is lowered.

33, the ECC encoding circuit 161, the ECC decoding circuit 162, the scramble circuit 157, and the descramble circuit 159 all perform processing in units of 1 byte. When 1-byte data before modulation is modulated according to a (d, k; m, n) modulation rule (in the above-described method, it means RLL (d, k) of m / n modulation), the length after modulation becomes
8n ÷ m (11)
It becomes. Therefore, when the data processing unit in the above circuit is converted into the processing unit after the modulation, the processing unit of the sync frame data 106 after the modulation is given by the equation (11), so that the processing between the sync code and the sync frame data after the modulation is performed. When integration is aimed at, the data size (channel bit size) of the synchronization code needs to be set to an integral multiple of equation (11). Therefore, in one embodiment of the present invention, the size of the synchronization code 110 is
8Nn ÷ m (12)
Thus, the main feature of the embodiment of the present invention is that the integrity of processing between the sync code 110 and the modulated sync frame data 106 is ensured. (In formula (12), N means an integer value.)
Until now as an example of one embodiment of the present invention
d = 1, k = 9, m = 4, n = 6
Therefore, when the value is substituted into the equation (12), the total data size of the synchronization code 110 is
12N (13)
It becomes. Since the sync code size of the current DVD is 32 channel bits, in one embodiment of the present invention, the process is simplified and the reliability of position detection / information identification is improved by making the total data size of the sync code smaller than 32 channel bits. Improves. Therefore, in one embodiment of the present invention, the total data size of the synchronization code is 24 channel bits as shown in FIG.

  FIG. 34 is a detailed structural explanatory diagram relating to the periphery of the synchronization code position detection unit 145 shown in FIG.

  FIG. 35 is a flowchart for explaining an example of a method for determining the sync frame position in a sector from the sequence of three consecutive sync codes. The output data of the Viterbi decoder 156 of FIG. 33 (ST51 of FIG. 35) as shown in FIG. 31B is detected by the synchronization code position detector 145 (ST52 of FIG. 35). Thereafter, the information of the detected synchronization code 110 is sequentially stored in the memory unit 175 via the control unit 143 as shown in FIG. 31 (c) (ST53 in FIG. 35). If the position of the synchronization code 110 is known, only the sync frame data 106 after the modulation in the data output from the Viterbi decoder 156 can be extracted and transferred to the shift register circuit 170 (ST54 in FIG. 35). Next, the control unit 143 reads the history information of the synchronization code 110 recorded in the memory unit 175, identifies the arrangement order of the sync frame position identification codes (ST55 in FIG. 35), and temporarily stores it in the shift register circuit 170. The position of the modulated sync frame data 106 in the physical sector is determined (ST56 in FIG. 35).

For example, as shown in FIG. 31, if the sequence of synchronization codes stored in the memory unit 175 is “SY0 → SY1 → SY1”, the modulation arranged immediately after the latest SYNC Frame number 02 immediately after the last “SY0”. The later sync frame data ”
If “SY3 → SY1 → SY2”, “modulated sync frame data arranged immediately after the latest SYNC Frame number 12” exists immediately after the last “SY2”.
It becomes possible to determine.

  Thus, when the position in the sector is determined and it is confirmed that the modulated sync frame data 106 at the desired position has been input into the shift register circuit 170, the data is transferred to the demodulation circuit 152. Demodulation is started (ST57 in FIG. 35).

  FIG. 36 is a flowchart for explaining an example of a method for detecting an abnormality (such as an out-of-track) from the arrangement order of a plurality of synchronization codes in the information recording / reproducing apparatus according to one embodiment of the present invention. FIG. 37 is a flowchart for explaining an example of a method for determining an abnormal phenomenon and its adaptive processing when the detection result of the combination pattern of the synchronization code is different from the expected pattern.

  A description will be given of an abnormality detection method using synchronization code combination pattern detection during continuous reproduction with reference to FIG. When the combination pattern of the synchronization code to be detected next in the control unit 143 is predicted in advance as shown in ST64 and compared with the combination pattern of the actually detected synchronization code (ST66), the comparison result does not match Detects that an abnormality has occurred.

  FIG. 37 shows a phenomenon estimation method and a countermeasure method when the combination pattern of the detected synchronization codes is different from the prior prediction. In one embodiment of the present invention, this is inferred using the relationship explanatory diagram shown in FIG. The feature of the process of FIG. 37 is that it is determined (ST3) whether or not “there is a single place where the detected combination pattern of the synchronization code is different from the previous prediction”.

  When there is only one place that is different, if the detection pattern is (1, 1, 2), (1, 2, 1), (1, 2, 2), or (2, 1, 2) There is a high possibility that a “frame shift” has occurred, and if not, it can be considered that “a synchronization code has been erroneously detected”.

Based on the above judgment result,
・ If “frame shift” occurs, synchronize again (ST6)
If “synchronous code is erroneously detected”, a process (ST7) of automatically correcting the erroneously detected synchronous code in accordance with the prior prediction value is performed.

  In parallel, a data ID continuity check (ST8) and a Wobble Address continuity check (ST9) are performed, and a track outage detection and a response when a track outage occurs (ST10) are performed.

0] List of points of one embodiment of the present invention Prior to the description of one embodiment of the present invention, the points of one embodiment of the present invention in a broad sense for achieving the above-described object of the present invention, It is summarized below.

  In the following, the contents of big invention points are classified by alphabet numbers, and the contents for implementing each big invention point (one embodiment point of this invention at the intermediate level) are summarized with "○" and further realized The contents of the points of the invention are described in a hierarchical structure in such a manner that the details of the invention necessary for making are described with “*”.

  In the description of the embodiments in the future, the alphabetical numbers corresponding to the following invention points will be indicated in parentheses.

0-1) One embodiment of the present invention Point enumeration Point A) As shown in FIG. 1 and FIG. 2, a conventional SD (Standard Definition) Object File and management file are separated by file separation or directory (folder) separation. Enables separate management on an information storage medium for an object file and management file for HD (High Definition) corresponding to high-quality video;
Point B) 4-bit representation of sub-picture information and compression rules (FIG. 4);
Point C) A plurality of types of recording formats can be set in the read-only information storage medium (FIG. 20);
◇ In the case of content that can be freely copied as many times as possible (less important);
... As before, a structure that records data continuously by connecting (packing) each segment;
◇ For important content subject to copy restrictions;
... Separately arrange each segment on the information storage medium, and in the gap (between the previous and subsequent segments), "Identification information of read-only information storage medium", "Copy control information", "Encryption key related information", "Address information", etc. Is a recordable structure. This ensures content protection in the information storage medium and high speed access;
○ Format is common within the same disk (format change is not possible from the middle of the disk);
○ Two formats can be mixed in the same disc according to the content of the content to be recorded;
○ Both have a common format area (go to read there at startup);
○ Record the DVD-ROM format identification flag information (whether or not two plans are included) on the disc;
☆ Record format identification flag information in a common format area;
☆ Record the format identification flag information in the recordable area;
Point D) ECC block structure using product codes (FIGS. 11 and 12);
As shown in FIGS. 11 and 12, in one embodiment of the present invention, data to be recorded on an information storage medium is arranged two-dimensionally, and PI (Parity in) in the row direction as additional bits for error correction, It has a structure with PO (Parity out) added to the column direction;
○ 32 sectors constitute one error correction unit (ECC block);
As shown in FIG. 12, in one embodiment of the present invention, 32 sectors from “0 sector” to “31 sector” are sequentially arranged vertically to constitute an ECC block;
Point E) The same sector is divided into a plurality of parts, and a different product code (small ECC block) is formed for each divided part;
As shown in FIG. 12, intra-sector data are alternately arranged on the left and right sides every 172 bytes, and are grouped separately on the left and right sides (data belonging to the left and right groups are interleaved in a “nested” manner). . As shown in FIG. 12, the divided left and right groups are collected by 32 sectors to form small ECC blocks on the left and right. For example, the meaning of “2-R” in FIG. 12 represents a sector number and a left and right group identification symbol (for example, second right side data). (L in FIG. 12 represents Left.)
O Interleave within the same sector (alternately included in different groups at equal intervals) and make each group belong to a different small ECC block;
Point F) Multiple types of Sync frame structures are defined by the sectors that make up the ECC block;
It is characterized in that the Sync frame structure is changed as shown in FIG. 14 depending on whether the sector number of the sector constituting one ECC block is an even number or an odd number. That is, it has a structure (FIG. 13) in which different PO group data is inserted alternately for each sector;
○ PO interleaving / inserting position is different on the left and right (Fig. 13);
Point G) Segment division structure in ECC block (FIG. 30);
Point H) Guard area arrangement structure between ECC blocks (FIG. 23);
○ Change the data contents between read-only / write-once / rewritable type (→ for use in identification);
○ Use random signals for DVD-ROM headers;
Point I) The guard area is recorded partially overlapping in a recording format for a recordable information storage medium;
As shown in FIG. 29, the front guard region 521 and the rear guard region 527 overlap, resulting in overlapping portions 541 and 542 at the time of rewriting;
Point J) The arrangement is devised, and the number of code changes when the combination of three consecutive synchronous codes is shifted by one is set to 2 or more (FIGS. 16 to 18);
○ Devise so that the number of code changes is 2 or more even when the sector structure that does not include the guard area repeats;
○ Even if the sector structure is placed across the guard area, the number of code changes is 2 or more;
Point K) Add conditions to the address numbering method for address information (particularly segment address information);
O Address numbers start with “1”, not “0”, where all bits have the same value;
○ Missing address numbers where “1” or “0” appears three or more times in succession;
Point L) L / G recording + address information is recorded by wobble modulation (FIG. 26);
Point M) Distribute indefinite bits in the groove area;
Point N) Indefinite bits are distributed to both Land and Groove by L / G recording + wobble modulation;
Point O) Wobble phase modulation of 180 degrees (± 90 degrees) is employed in L / G recording (FIG. 25);
Point P) A gray code or a special track code is adopted for the track address (FIGS. 27 and 28).

<Effect A according to the embodiment of the invention>
<Guaranteed high capacity for high-quality video and improved access reliability to high-quality video>
(1) When an HD video is recorded on an information storage medium by file or folder separation with respect to a conventional SD video, the HD video has a high resolution, and thus the recording capacity of the information storage medium must be increased. Since the recording capacity can be increased in the L / G recording than in the groove recording, and the recording mark cannot be formed on the prepit address, the recording efficiency is higher in the address information recording by the wobble modulation than the prepit address. “/ G recording + wobble modulation” increases the recording capacity most. In this case, since the track pitch becomes dense, it is necessary to further improve the address detection performance and increase the reliability of access. Adopting gray code or special track code for the occurrence of indefinite bits that are a problem in “L / G recording + wobble modulation”, reducing the occurrence frequency of indefinite bits, and adding, subtracting, exclusive OR operation in bit units, etc. Thus, error detection code addition and scramble processing while maintaining the gray code characteristic or special track code characteristic are performed, and the address detection accuracy can be greatly increased.

  (2) Although the quality of the sub-picture needs to be improved in accordance with the improvement in the quality of the picture recorded on the information storage medium, the amount of data to be recorded increases if the sub-picture is expressed from 2 bits to 4 bits. Therefore, it is necessary to increase the capacity of the information storage medium for recording it. Since the recording capacity can be increased in the L / G recording than in the groove recording, and the recording mark cannot be formed on the prepit address, the recording efficiency is higher in the address information recording by the wobble modulation than the prepit address. “/ G recording + wobble modulation” increases the recording capacity most. In this case, since the track pitch becomes dense, it is necessary to further improve the address detection performance and increase the reliability of access. Adopting gray code or special track code for the occurrence of indefinite bits that are a problem in “L / G recording + wobble modulation”, reducing the occurrence frequency of indefinite bits, and adding, subtracting, exclusive OR operation in bit units, etc. Thus, error detection code addition and scramble processing while maintaining the gray code characteristic or special track code characteristic are performed, and the address detection accuracy can be greatly increased.

<Efficient zone division is possible to improve recording efficiency and guarantee large capacity according to high-quality video >>>
(3) When an HD video is recorded on an information storage medium by file or folder separation with respect to a conventional SD video, the HD video has a high resolution, and thus the recording capacity of the information storage medium must be increased. Since the recording capacity can be increased in the L / G recording than in the groove recording, and the recording mark cannot be formed on the prepit address, the recording efficiency is higher in the address information recording by the wobble modulation than the prepit address. “/ G recording + wobble modulation” increases the recording capacity most. Since the recording capacity can be increased in the L / G recording than in the groove recording, and the recording mark cannot be formed on the prepit address, the recording efficiency is higher in the address information recording by the wobble modulation than the prepit address. “/ G recording + wobble modulation” increases the recording capacity most. In the case of L / G recording, the zone structure shown in FIG. 24 is adopted. However, if the zones are arranged so that one round is an integral multiple of the ECC block, the recording efficiency becomes very poor. On the other hand, as in the embodiment of the present invention, one ECC block is divided into a plurality of segments (8 in the embodiment of the present invention), and one round on the information storage medium is made an integral multiple of the segments. If the setting is made so that the zones are arranged, the recording efficiency becomes very high.

  (4) Although it is necessary to improve the quality of the sub-picture in accordance with the improvement in the quality of the video recorded on the information storage medium, the amount of data to be recorded increases if the sub-picture is expressed from 2 bits to 4 bits. Therefore, it is necessary to increase the capacity of the information storage medium for recording it. Since the recording capacity can be increased in the L / G recording than in the groove recording, and the recording mark cannot be formed on the prepit address, the recording efficiency is higher in the address information recording by the wobble modulation than the prepit address. “/ G recording + wobble modulation” increases the recording capacity most. In the case of L / G recording, the zone structure shown in FIG. 24 is adopted. However, if the zones are arranged so that one round is an integral multiple of the ECC block, the recording efficiency becomes very poor. On the other hand, as in the embodiment of the present invention, one ECC block is divided into a plurality of segments (8 in the embodiment of the present invention), and one round on the information storage medium is made an integral multiple of the segments. If the setting is made so that the zones are arranged, the recording efficiency becomes very high.

<Protecting high-quality video, identifying media type, and ensuring access speed>
(5) When an HD video is recorded on an information storage medium by file or folder separation with respect to a conventional SD video, the HD video has a high resolution, and there is a high demand for enhancing protection against unauthorized copying. As in the embodiment of the present invention, the ECC block is divided into a plurality of segments, and there are two types of recording formats in the reproduction-only information storage unit. By providing a header, format compatibility among read-only / write-once / rewritable formats can be ensured, and the medium type can be easily identified. Further, in the write-once type / rewritable type, since the address information is recorded a plurality of times in the segment as a part of the identification information, a side effect of improving the access speed is exhibited at the same time.

  (6) It is necessary to improve the image quality of the sub-picture in accordance with the improvement of the image quality of the image recorded on the information storage medium. There is a high demand for enhancing the protection of unauthorized copying for high-quality sub-pictures that have been converted from conventional 2-bit to 4-bit representation. As in the embodiment of the present invention, the ECC block is divided into a plurality of segments, and there are two types of recording formats in the reproduction-only information storage unit. By providing a header between segments, format compatibility among read-only / write-once / rewritable formats can be ensured, and medium types can be easily identified. Further, in the write-once type / rewritable type, since the address information is recorded a plurality of times in the segment as a part of the identification information, a side effect of improving the access speed is exhibited at the same time.

<Guaranteed that the scratches on the surface will be the same length as the present even if the recording density is increased to match the high-quality video>
(7) When an HD video is recorded on an information storage medium by file or folder separation with respect to a conventional SD video, it is essential to increase the recording capacity of the information storage medium because the HD video has a high resolution. As the recording density increases, the range of influence on the recording data caused by the same length of scratches on the surface of the information storage medium becomes relatively large. In contrast to conventional DVDs, which consisted of 16 sectors in one ECC block, in the embodiment of the present invention, the recording density is increased in accordance with high-quality video by constructing one ECC block in twice as many as 32 sectors. However, it was guaranteed that the surface scratches would be the same length as the current one. Furthermore, one ECC block is composed of two small ECC blocks, and one sector is distributed in two ECC blocks, so that data in the same sector is substantially interleaved, resulting in longer scratches and The impact on burst errors can be reduced.

  (8) Although it is necessary to improve the quality of the sub-picture in accordance with the improvement of the quality of the video recorded on the information storage medium, the amount of data to be recorded increases if the sub-picture is expressed from the conventional 2-bit to 4-bit representation. Therefore, it is necessary to increase the capacity of the information storage medium for recording it. . As the recording density increases, the range of influence on the recording data caused by the same length of scratches on the surface of the information storage medium becomes relatively large. In contrast to conventional DVDs, which consisted of 16 sectors in one ECC block, in the embodiment of the present invention, the recording density is increased in accordance with high-quality video by constructing one ECC block in twice as many as 32 sectors. However, it was guaranteed that the surface scratches would be the same length as the current one. Furthermore, one ECC block is composed of two small ECC blocks, and one sector is distributed in two ECC blocks, so that data in the same sector is substantially interleaved, resulting in longer scratches and The impact on burst errors can be reduced.

  (9) When an HD video is recorded on an information storage medium by file or folder separation with respect to a conventional SD video, since the HD video has a high resolution, it is essential to increase the recording capacity of the information storage medium. As the recording density increases, the range of influence on the recording data caused by the same length of scratches on the surface of the information storage medium becomes relatively large. In contrast to conventional DVDs, which consisted of 16 sectors in one ECC block, in the embodiment of the present invention, the recording density is increased in accordance with high-quality video by constructing one ECC block in twice as many as 32 sectors. However, it was guaranteed that the surface scratches would be the same length as the current one. Furthermore, one ECC block is composed of two small ECC blocks, and in the embodiment of the present invention, PO data belonging to different small ECC blocks is inserted for each sector. Therefore, every one PO data in the small ECC block is placed. Since the interleaved arrangement (distributed arrangement) is performed within the sector, the reliability of the PO data is improved, and the error correction process can be performed with high accuracy.

  (10) Although the quality of the sub-picture needs to be improved in accordance with the improvement in the quality of the picture recorded on the information storage medium, the amount of data to be recorded increases if the sub-picture is expressed from the conventional 2-bit to 4-bit representation. Therefore, it is necessary to increase the capacity of the information storage medium for recording it. As the recording density increases, the range of influence on the recording data caused by the same length of scratches on the surface of the information storage medium becomes relatively large. In contrast to conventional DVDs, which consisted of 16 sectors in one ECC block, in the embodiment of the present invention, the recording density is increased in accordance with high-quality video by constructing one ECC block in twice as many as 32 sectors. However, it was guaranteed that the surface scratches would be the same length as the current one. Furthermore, one ECC block is composed of two small ECC blocks, and in the embodiment of the present invention, PO data belonging to different small ECC blocks is inserted for each sector. Therefore, every one PO data in the small ECC block is placed. Since the interleaved arrangement (distributed arrangement) is performed within the sector, the reliability of the PO data is improved, and the error correction process can be performed with high accuracy.

<Fully compatible with read-only and write-once types, and can be added in small units>
(11) In conventional DVD-R or DVD-RW, additional writing / rewriting in fine units is impossible, and if the Restricted Overwrite process is performed forcibly, part of the recorded information is destroyed. There was a problem that. As in the embodiment of the present invention, a plurality of types of recording formats can be set exclusively for reproduction, and a recording structure having a header between segments divided in the ECC block can be exclusively reserved for reproduction. Fully compatible with read-only and write-once. Furthermore, since additional writing / rewriting can be performed from the middle of the header portion, there is no risk of destroying information in the segment already recorded by the additional recording / rewriting process. At the same time, since the guard area is partially overlapped and recorded in the header portion during the additional recording / rewriting, the crosstalk between the two layers by the gap region is prevented in order to prevent the presence of a gap region in which no recording mark exists in the header portion. And the problem of interlayer crosstalk in the single-sided two-recording layer can be solved at the same time.

<Increase fixed address information allocation frequency and secure access speed>
(12) In the embodiment of the present invention, prediction determination of indefinite bits is possible using the even / odd identification information of the track number, but it is not surely determined within the prediction determination range. On the other hand, track information can be detected with very high accuracy in a portion having no indefinite bit and having an error detection code added thereto. Therefore, in the embodiment of the present invention, the indefinite bits are arranged in the groove area, and the indefinite bits are distributed in both the land area and the groove area so that the land area does not have indefinite bits, and the error detection code is The added part can be formed. However, since indefinite bits are distributed and arranged in both the land area and the groove area, the arrangement frequency of the track number information 611 and 612 having no indefinite bits is relatively lowered. On the other hand, in the embodiment of the present invention, by arranging the address information a plurality of times in the segment, the arrangement frequency of the part where the land area and the groove area have no indefinite bit and the error detection code is added. As a result, the accuracy of address information reproduction is improved and a high access speed is secured.

<Increase wobble address reading accuracy>
(13) As shown in FIG. 25, the wobble address reading accuracy is improved by increasing the wobble inversion frequency at the boundary position of the 1-address bit area 511 (the portion of “triangle”). Therefore, “000000” is excluded as a possible value of the segment address information to increase the wobble inversion frequency, and data scramble is applied to the wobble inversion frequency at the boundary position (“triangle mark” portion) of one address bit area 511. Is increasing. At this time, if “0” continues for a long time in the scramble seed information, the effect of increasing the frequency of wobble inversion when data scramble is applied hardly appears. Therefore, by excluding “000000” as a possible value of the segment address information and increasing the appearance frequency of “1” in the seed information, it works to promote the effect of increasing the wobble inversion frequency when data scramble is applied.

<Accurate track number playback on the land improves track number playback accuracy on the land>
(14) In the embodiment of the present invention, prediction determination of indefinite bits is possible using the even / odd identification information of the track number, but it is not surely determined within the prediction determination range. On the other hand, track information can be detected with very high accuracy in a portion having no indefinite bit and having an error detection code added thereto. For this reason, in the embodiment of the present invention, an indefinite bit is arranged in the groove area, and the indefinite bit is distributed in both the land area and the groove area, so that there is no indefinite bit in the land area, and the error detection code. It is possible to form a portion to which is added. As a result, the track number can be read with high reproduction accuracy even on the land, and the access stability and high access speed in the land portion can be ensured.

<Indefinite bits can be distributed in the groove area and land area in a very easy way>
(15) In the embodiment of the present invention, by adopting ± 90 degree wobble phase modulation, the exposure amount modulation of the condensing spot 3 for forming the groove region or the relative position change between the two condensing spots is extremely high. Indefinite bits can be distributed and arranged in the groove area and the land area by a simple method. Therefore, the present invention can be implemented with a conventional master recording apparatus for creating an information storage medium. Since it can be carried out with an existing apparatus, it is possible to manufacture an inexpensive information storage medium without requiring the introduction of new equipment.

<Reproduction accuracy (reliability) of wobble address information can be greatly improved>
(16) In the embodiment of the present invention, an EDC code within a range of any of “addition operation”, “subtraction operation”, “Exclusive OR” operation or combination thereof in bit units with arbitrary data. Since both generation and data scramble processing can be performed, the reproduction accuracy (reliability) of wobble address information can be greatly improved by a very simple method (error occurrence by EDC and appearance frequency of wobble inversion position by scramble can be increased). In addition, since a PLL can be easily applied in a reproduction system), and only a few additional circuits are required to implement it, an inexpensive information reproducing apparatus or information recording / reproducing apparatus can be provided.

<Prevents indefinite bits from being aligned vertically in the ECC block and ensures error correction capability>
(17) Since the wobble address arrangement area and the data arrangement of the track number information are very correctly recorded, the positions of the indefinite bits are aligned vertically in the ECC block shown in FIG. There arises a problem that the error correction capability in the block is greatly reduced. In the embodiment of the present invention, the arrangement of indefinite bits is shifted by various methods, the indefinite bits are prevented from being arranged vertically in the ECC block, and performance for error correction capability in the ECC block can be ensured. As a result, the error rate (after correction) of reproduction information from the recording mark recorded on the information storage medium is reduced, and high-precision reproduction is possible.

<Reproducibility of wobble address information reproduction is very simple and inexpensive>
(18) Data can be scrambled by a simple circuit, the frequency of wobble inversion at the boundary of the address bit area can be increased, the boundary position of the address bit area can be easily detected, and the reproduction reliability of wobble address information can be increased. . In addition, since the data scramble circuit to be used can be made very inexpensively, an inexpensive information reproducing apparatus or an inexpensive information recording / reproducing apparatus can be provided.

  (19) By changing the pattern contents in the two address areas, the wobble inversion frequency at the boundary part of the address bit area is increased as a result, so that the boundary position of the address bit area can be easily detected, and wobble address information is reproduced. Increased reliability.

<Even / odd identification information of track number can be arranged with high detection accuracy and does not affect the recording mark>
(20) Since the even / odd identification information of the track number is recorded not by the wobble modulation data structure but by a physical shape change, high detection accuracy for the even / odd identification information of the track number can be ensured. Further, since the even / odd identification information of the track number is arranged in the header area between the segments, there is no adverse effect on the recording information by the recording mark recorded in each segment. At the same time, this information can be used to identify the type of read-only / write-once / rewritable information storage media, making it easy to detect unauthorized copies of high-quality video information and high-quality sub-video information that you want to prevent unauthorized copying. It becomes.

<Predictive judgment of indefinite bits with high accuracy is possible>
(21) Since the even / odd identification information of the track number is recorded not by the wobble modulation data structure but by a physical shape change, high detection accuracy for the even / odd identification information of the track number can be ensured. For this reason, prediction determination of indefinite bits can be performed with reference to the even / odd identification information of the track number that can ensure this high detection accuracy, so that prediction determination can be performed with relatively high accuracy.

<The address number is determined accurately on the land area without having an indefinite bit in the groove area>
(22) In the embodiment of the present invention, prediction determination of indefinite bits is possible using the even / odd identification information of the track number, but it is not surely determined within the prediction determination range. On the other hand, track information can be detected with very high accuracy in a portion having no indefinite bit and having an error detection code added thereto. In the embodiment of the present invention, track number information is progressively set in a zigzag manner in the L / G recording method. By doing so, it is possible to set a location where an address number is accurately determined by adding an error detection code without having an indefinite bit on the land area without having an indefinite bit in the groove area. Thus, not only can the track number be determined with high accuracy even in the land area, but also a relatively high access speed can be secured (since the address number is determined earlier).

<Easy and fast address number determination for both land and groove>
(23) Since the location of the address determination / prediction determination area is determined in advance for both the land and the groove, the address determination area and the address prediction area can be immediately determined, and the address number information suitable for each can be determined and predicted. In addition to facilitating the address information reproduction processing method, the address number can be determined at a high speed, so that a relatively high speed access process is possible.

<Reproduction reliability of recorded mark in segment>
(24) In the present invention, the ECC block is divided into a plurality of segments, a header is arranged between the segments, and track address information is arranged in the header area. As a result, even when address information is recorded by wobble modulation in L / G recording, it is possible to prevent indefinite bits from being mixed into the segment area, and a high quality reproduction signal can be obtained from the recording mark in the segment area. High reproduction reliability can be ensured.

  In summary, high-definition main video, high-quality sub-video display, large capacity, high format compatibility, PC data addition or rewriting, high reliability for address information playback, wobble signal Provides an information recording medium that can improve the accuracy of extracting the reference clock from the image, guarantee high-speed access, and ensure extensibility to a single-sided two-recording layer structure, and information that can be stably reproduced from the information recording medium It is possible to provide a reproducing apparatus or an information recording / reproducing apparatus capable of stably recording data.

<Effect B according to the embodiment of the invention>
Next, referring to Table 1, effects obtained by various embodiments and / or combinations of configurations of the present invention will be described. In Table 1, a circle mark indicates a main unique effect, and Δ indicates an additional (secondary) effect. Also, <1> to <15> in Table 1 correspond to the following item numbers <1> to <15>.

《Ensured large capacity according to high-quality video and improved access reliability to high-quality video》
<1> When recording HD (High Definition) video on an information storage medium by separating files or folders from conventional SD (Standard Definition) video, the HD video has a high resolution, so the recording capacity of the information storage medium must be increased. It becomes. The recording capacity can be increased in the L / G recording than in the groove recording. Further, since a recording mark cannot be formed on the pre-pit address, the recording efficiency of address information recording by wobble modulation is higher than that of the pre-pit address. Therefore, “L / G recording + wobble modulation” is the most effective for increasing the recording capacity. In this case, since the track pitch becomes dense, it is necessary to further improve the address detection performance and improve the access reliability.

  For the occurrence of indefinite bits, which is a problem in "L / G recording + wobble modulation", use gray codes or special track codes to reduce the frequency of indefinite bits and greatly increase the address detection accuracy. Is possible. In addition, the combination of synchronization codes has been devised to enable automatic correction for false detection of synchronization codes. As a result, the accuracy of position detection within sectors using synchronization codes has been dramatically improved, resulting in reliable and fast access control. Can be increased.

  <2> Sub-picture quality needs to be improved in accordance with the improvement of the picture quality recorded on the information storage medium, but the amount of data to be recorded will increase if the sub-picture is changed from the conventional 2-bit to 4-bit representation. Therefore, it is necessary to increase the capacity of the information storage medium for recording it. The recording capacity can be increased in the L / G recording than in the groove recording. Further, since a recording mark cannot be formed on the pre-pit address, the recording efficiency of address information recording by wobble modulation is higher than that of the pre-pit address. Therefore, “L / G recording + wobble modulation” is the most effective for increasing the recording capacity. Also in this case, since the track pitch becomes dense, it is necessary to further improve the address detection performance and improve the access reliability.

  For the occurrence of indefinite bits, which is a problem in “L / G recording + wobble modulation”, the gray code or special track code can be used to greatly increase the frequency of indefinite bit generation and the accuracy of address detection. It becomes. In addition, as a result of dramatically improving the position detection accuracy in the sector using the synchronization code, it is possible to improve the reliability and high speed of access control.

《Efficient zone division is possible to improve recording efficiency and guarantee large capacity according to high quality image》
<3> When an HD video is recorded on an information storage medium by file or folder separation with respect to a conventional SD video, the HD video has a high resolution, so it is essential to increase the recording capacity of the information storage medium. The recording capacity can be increased in the L / G recording than in the groove recording. Further, since a recording mark cannot be formed on the pre-pit address, the recording efficiency of address information recording by wobble modulation is higher than that of the pre-pit address. Therefore, “L / G recording + wobble modulation” is the most effective for increasing the recording capacity. Here, in the case of L / G recording, the zone structure shown in FIG. 24 is adopted. However, if the zones are arranged so that one round is an integral multiple of the ECC block, the recording efficiency becomes very poor. On the other hand, as in the embodiment of the present invention, one ECC block is divided into a plurality of segments (7 in the embodiment of the present invention), and one round on the information storage medium is made an integral multiple of the segments. If the zone is set to be arranged as described above, the recording efficiency becomes very high.

  <4> Sub-picture quality needs to be improved in accordance with the high-quality picture recorded on the information storage medium, but the amount of data to be recorded increases if the sub-picture is changed from the conventional 2-bit to 4-bit representation. Therefore, it is necessary to increase the capacity of the information storage medium for recording it. The recording capacity can be increased in the L / G recording than in the groove recording. Further, since a recording mark cannot be formed on the pre-pit address, the recording efficiency of address information recording by wobble modulation is higher than that of the pre-pit address. Therefore, “L / G recording + wobble modulation” is the most effective for increasing the recording capacity. Here, in the case of L / G recording, the zone structure shown in FIG. 24 is adopted. However, if the zones are arranged so that one round is an integral multiple of the ECC block, the recording efficiency becomes very poor. On the other hand, as in the embodiment of the present invention, one ECC block is divided into a plurality of segments (7 in the embodiment of the present invention), and one round on the information storage medium is made an integral multiple of the segments. If the zone is set to be arranged as described above, the recording efficiency becomes very high.

《High-quality video protection and media type identification》
<5> When an HD video is recorded on an information storage medium by file or folder separation with respect to a conventional SD video, the HD video has a high resolution and there is a high demand for enhancing protection against unauthorized copying. As in the embodiment of the present invention, the ECC block is divided into a plurality of segments and has two types of recording formats in the read-only information storage medium. Have a guard area in between. In this way, format compatibility among the read-only / write-once / rewritable formats can be ensured, and the medium type can be easily identified.

  <6> The quality of sub-pictures needs to be improved in accordance with the improvement of the quality of pictures recorded on information storage media. There is a high demand for enhancing the protection of unauthorized copying for high-quality sub-pictures that have been converted from conventional 2-bit to 4-bit representation. As in the embodiment of the present invention, the ECC block is divided into a plurality of segments, and there are two types of recording formats in the read-only information storage medium. Provide guard area between blocks. In this way, format compatibility among the read-only / write-once / rewritable formats can be ensured, and the medium type can be easily identified.

《Guaranteed that the scratches on the surface will be the same length as the present even if the recording density is increased according to the high quality image》
<7> When an HD video is recorded on an information storage medium by file or folder separation with respect to a conventional SD video, the HD video has a high resolution, so it is essential to increase the recording capacity of the information storage medium. As the recording density increases, the range of influence on the recording data caused by the same length of scratches on the surface of the information storage medium becomes relatively large. In the conventional DVD, one ECC block is composed of 16 sectors, whereas in the embodiment of the present invention, one ECC block is composed of 32 sectors which is twice that. This guarantees that the scratches on the surface will be the same as the current length even if the recording density is increased to match the high-quality video. Furthermore, one ECC block is composed of two small ECC blocks and one sector is distributed over two ECC blocks, so that data in the same sector is substantially interleaved, resulting in a longer scratch. And the effect on burst errors can be reduced.

  Further, in the conventional DVD standard, when an error is detected in the synchronization code due to a scratch on the surface of the information storage medium, a frame shift occurs and the error correction capability in the ECC block is remarkably lowered. In contrast to this, in the embodiment of the present invention, when a false detection is generated for the synchronization code due to scratches on the surface of the information storage medium, it can be distinguished from the frame shift. In addition, as shown in ST7 of FIG. 37, erroneous detection of the synchronization code can be automatically corrected. For this reason, the detection accuracy and detection stability of the synchronization code are greatly improved. As a result, the error correction capability of the ECC block is prevented from being deteriorated, and error correction with high accuracy and reliability is possible.

  <8> Sub-picture quality needs to be improved in accordance with the high-quality picture recorded on the information storage medium, but the amount of data to be recorded increases if the sub-picture is expressed from 2 bits to 4 bits. Therefore, it is necessary to increase the capacity of the information storage medium for recording it. As the recording density increases, the range of influence on the recording data caused by the same length of scratches on the surface of the information storage medium becomes relatively large. In the conventional DVD, one ECC block is composed of 16 sectors, whereas in the embodiment of the present invention, one ECC block is composed of 32 sectors which is twice that. This guarantees that the scratches on the surface will be the same as the current length even if the recording density is increased to match the high-quality video. Furthermore, one ECC block is composed of two small ECC blocks and one sector is distributed over two ECC blocks, so that data in the same sector is substantially interleaved, resulting in a longer scratch. And the effect on burst errors can be reduced.

  Further, in the conventional DVD standard, when an error is detected in the synchronization code due to a scratch on the surface of the information storage medium, a frame shift occurs and the error correction capability in the ECC block is remarkably lowered. In contrast to this, in the embodiment of the present invention, when a false detection is generated for the synchronization code due to scratches on the surface of the information storage medium, it can be distinguished from the frame shift. In addition, as shown in ST7 of FIG. 37, erroneous detection of the synchronization code can be automatically corrected. For this reason, the detection accuracy and detection stability of the synchronization code are greatly improved. As a result, the error correction capability of the ECC block is prevented from being deteriorated, and error correction with high accuracy and reliability is possible.

  <9> When an HD video is recorded on an information storage medium by file or folder separation with respect to a conventional SD video, since the HD video has a high resolution, it is essential to increase the recording capacity of the information storage medium. As the recording density increases, the range of influence on the recording data caused by the same length of scratches on the surface of the information storage medium becomes relatively large. In the conventional DVD, one ECC block is composed of 16 sectors, whereas in the embodiment of the present invention, one ECC block is composed of 32 sectors which is twice that. This guarantees that the scratches on the surface will be the same as the current length even if the recording density is increased to match the high-quality video. Furthermore, one ECC block is composed of two small ECC blocks, and in the embodiment of the present invention, PO data belonging to different small ECC blocks is inserted for each sector. For this reason, the PO data in the small ECC block is interleaved (distributed) in every other sector, so that the reliability due to damage to the PO data is improved, and accurate error correction processing is possible.

  Further, in the conventional DVD standard, when an error is detected in the synchronization code due to a scratch on the surface of the information storage medium, a frame shift occurs and the error correction capability in the ECC block is remarkably lowered. In contrast to this, in the embodiment of the present invention, when a false detection is generated for the synchronization code due to scratches on the surface of the information storage medium, it can be distinguished from the frame shift. In addition, as shown in ST7 of FIG. 37, erroneous detection of the synchronization code can be automatically corrected. For this reason, the detection accuracy and detection stability of the synchronization code are greatly improved. As a result, the error correction capability of the ECC block is prevented from being deteriorated, and error correction with high accuracy and reliability is possible.

  <10> Sub-picture quality needs to be improved in accordance with the high-quality picture recorded on the information storage medium, but the amount of data to be recorded increases if the sub-picture is changed from the conventional 2-bit to 4-bit representation. Therefore, it is necessary to increase the capacity of the information storage medium for recording it. As the recording density increases, the range of influence on the recording data caused by the same length of scratches on the surface of the information storage medium becomes relatively large. In the conventional DVD, one ECC block is composed of 16 sectors, whereas in the embodiment of the present invention, one ECC block is composed of 32 sectors which is twice that. This guarantees that the scratches on the surface will be the same as the current length even if the recording density is increased to match the high-quality video. Furthermore, one ECC block is composed of two small ECC blocks, and in the embodiment of the present invention, PO data belonging to different small ECC blocks is inserted for each sector. For this reason, the PO data in the small ECC block is interleaved (distributed) in every other sector, so that the reliability due to damage to the PO data is improved, and accurate error correction processing is possible.

  Further, in the conventional DVD standard, when an error is detected in the synchronization code due to a scratch on the surface of the information storage medium, a frame shift occurs and the error correction capability in the ECC block is remarkably lowered. On the other hand, in the embodiment of the present invention, in the case where a false detection is caused for the synchronization code due to a scratch on the surface of the information storage medium, it is distinguished from the frame shift. As shown in ST7 of FIG. 37, erroneous detection of the synchronization code can be automatically corrected. For this reason, the detection accuracy and detection stability of the synchronization code are greatly improved. As a result, the error correction capability of the ECC block is prevented from being deteriorated, and error correction with high accuracy and reliability is possible.

《Fully compatible with read-only and write-once type and can be added in fine units》
<11> With conventional DVD-R or DVD-RW, additional writing / rewriting in fine units is impossible, and if you perform Restricted Overwrite processing to try to do so, some of the information already recorded is destroyed. There was a problem that. As in the embodiment of the present invention, a plurality of types of recording formats can be set exclusively for reproduction, and a recording structure having a guard area between ECCs can be provided exclusively for reproduction. Full compatibility is possible. Further, since additional writing / rewriting can be performed from the middle of the guard area, there is no risk of destroying information in the ECC block already recorded by the additional writing / rewriting process. At the same time, a part of the guard area is recorded in the guard area at the time of additional recording / rewriting. Therefore, in order to prevent the existence of a gap area in which no recording mark exists in the guard area, crossing between two layers by the gap area is performed. The influence of talk can be removed, and the problem of interlayer crosstalk in the single-sided two-recording layer can be solved at the same time.

<Enhancing the accuracy of address information determination and ensuring access speed>
<12> Track information can be detected with very high accuracy in the portion where an error detection code is added without having an indefinite bit. For this reason, in the embodiment of the present invention, indefinite bits are also arranged in the groove area, and indefinite bits are distributed in both the land area and the groove area. This makes it possible to form a portion to which an error detection code is added without having indefinite bits in the land area. As a result, the accuracy of determining address information can be improved and a constant access speed can be secured.

《Improve reading accuracy of wobble address》
<13> As shown in FIG. 25, increasing the wobble inversion frequency at the boundary position of the 1-address bit area 511 (the “black triangle” portion) improves the wobble address reading accuracy. Therefore, “000000” is excluded as a possible value of the segment address information to increase the wobble inversion frequency, and the wobble inversion frequency at the boundary position of the 1 address bit area 511 (the “black triangle mark” portion) is increased. Yes. As a result, the boundary position detection accuracy of the 1-address bit area 511 is improved, and the wobble address reading accuracy is improved.

《Track number playback accuracy on the land increases because the track number can be reliably played back on the land. >>
<14> Track information can be detected with very high accuracy in a portion having no indefinite bit and an error detection code added. For this reason, in the embodiment of the present invention, indefinite bits are also arranged in the groove area, and indefinite bits are distributed in both the land area and the groove area. This makes it possible to form a portion to which an error detection code is added without having indefinite bits in the land area. As a result, the track number can be read with high reproduction accuracy even on the land, and the access stability and high access speed in the land portion can be ensured.

<< Prevents indefinite bits from being lined up in the ECC block and ensures error correction capability >>
<15> In the embodiment of the present invention, since the number of sectors 32 and the number of segments 7 constituting the ECC block are not divisible by each other (non-multiple relationship), each ECC block shown in FIG. The start positions of the segments are arranged at different positions. In the wobble address format shown in FIG. 30, the indefinite bit 504 shown in FIG. 26 may be mixed in the groove track information 606 and the land track information 607. In this indefinite bit area 504, since the groove width or land width changes, the level of the reproduction signal from here changes, causing an error. As in the embodiment of the present invention, by making the number of sectors and the number of segments constituting the ECC block non-constant, the ECC block shown in FIG. This has the effect of preventing indefinite bits from being aligned vertically. As described above, the arrangement of the indefinite bits is shifted to prevent the indefinite bits from being arranged vertically in the ECC block, and it is possible to ensure the performance for the error correction capability in the ECC block. As a result, the error rate (after correction) of reproduction information from the recording mark recorded on the information storage medium is reduced, and high-precision reproduction is possible.

  Furthermore, in the embodiment of the present invention, when a false detection is generated for the synchronization code due to a defect in the information storage medium, it can be distinguished from the frame shift. Therefore, not only can the frame shift be prevented, but also erroneous detection of the synchronization code can be automatically corrected as shown in ST7 of FIG. For this reason, the detection accuracy and detection stability of the synchronization code are greatly improved. As a result, the error correction capability of the ECC block is prevented from being deteriorated, and error correction with high accuracy and reliability is possible. In this way, by preventing the indefinite bits from being aligned in a straight line in the ECC block, ensuring error correction capability, and increasing the accuracy of detecting the synchronization code to increase the placement location setting accuracy of the frame data in the ECC block. The error correction capability can be further increased (decrease in error correction capability can be prevented) by the superimposing action (synergistic effect) of both.

A summary of <1> to <15> above is shown in the table below:

The figure which shows the example of the file arrangement | positioning with respect to the information recording medium which concerns on one embodiment of this invention. The figure which shows the other example of the file arrangement | positioning with respect to the information recording medium which concerns on one embodiment of this invention. Explanatory drawing of the recording method of the video information with respect to the information recording medium which concerns on one embodiment of this invention. Explanatory drawing which shows the example of the compression rule of the subvideo recorded on the information recording medium based on one embodiment of this invention. Explanatory drawing which shows the process sequence which produces | generates a recording data field. Explanatory drawing which shows the structure of a data frame. Explanatory drawing which shows the content of data ID of FIG. Explanatory drawing which shows the content of the data field number of FIG. Explanatory drawing of a definition of a recording type. An example of an initial value of a shift register when scrambling main data and an explanatory diagram of the shift register. Explanatory drawing which shows the structure of an ECC block. Explanatory drawing which shows the example of arrangement | positioning of a scrambled frame. The figure which shows a mode that the outer parity (PO) was interleaved by the left block and the right block, respectively, in the ECC block. The figure explaining the structural example of the recorded data field (even field and odd field). The figure explaining the specific example of a content of a sync code. The figure explaining the comparative example 1 of the combination pattern (column direction) of a continuous sync code (when moving between sectors). The figure explaining the comparative example 2 of the combination pattern (column direction) of a continuous sync code (when straddling a guard area | region). The figure explaining the example of a relationship between the detection pattern content and the abnormal phenomenon content at the time of detecting the combination pattern of the unscheduled sync code. The figure explaining an example of the data unit of the recording data on an information storage medium. The figure explaining the 1st example of an embodiment compared with the 2nd example when the embodiment of this invention is applied to a read-only information storage medium. The figure explaining the data structure (example 1) in a guard area | region. The figure explaining the data structure (example 2) in a guard area | region. The figure which compares and demonstrates the example of a data recording format for various information storage media (reproduction-only, write-once type, rewritable type). The figure which shows the zone structure of the rewritable information recording medium in one embodiment of this invention. Explanatory drawing of 180 degree phase modulation and NRZ method in wobble modulation. FIG. 5 is a diagram illustrating the principle of indefinite bit generation when wobble modulation is performed in land (L) / groove (G) recording. The figure which shows the example of a gray code. Explanatory drawing of the special track code which concerns on one embodiment of this invention. The figure explaining the example of a recording method of the rewritable data recorded on a rewritable information storage medium. The figure explaining an example of the wobble address format on the information storage medium concerning one embodiment of this invention. The figure explaining an example of the method of calculating | requiring the sync frame one in one physical sector from the arrangement | sequence order of the sync frame identification code in a synchronous code. The figure which shows the specific example (when the data field illustrated in FIG. 14 is employ | adopted) when calculating | requiring a sync frame position from the arrangement | sequence order of a sync frame identification code. The figure explaining the structure of the information recording / reproducing apparatus which concerns on one embodiment of this invention. The figure explaining the detailed structural example of the synchronous code position extraction part (detection part) 145 of FIG. 33, and its peripheral element. The flowchart figure explaining an example of the method of calculating | requiring the sync frame position in a sector from the arrangement | sequence order of three continuous synchronous codes. The flowchart figure explaining an example of the method of detecting abnormality (out of track etc.) from the arrangement | sequence order of several synchronous code in the information recording / reproducing apparatus which concerns on one embodiment of this invention. The flowchart figure explaining an example of the method of the determination of an abnormal phenomenon, and its adaptive process when the detection result of the combination pattern of a synchronous code differs from the expected pattern.

Explanation of symbols

  221 ... Information storage medium (optical disc; next-generation DVD-ROM, R, RAM, etc.); 401, 411 to 418 ... ECC block; 230 to 241 ... sector; 420 to 429 ... sync frame; 431 ... sync code (synchronization code) 432: Sync data; 441-468: Guard area.

Claims (5)

An information storage medium having an area divided by a plurality of sectors,
The sector includes 26 sync frames, and the sync frame includes 4 types of synchronization codes.
Regarding the arrangement of the synchronization codes in the same sector, a first pattern composed of a combination of three consecutive synchronization codes is compared with a second pattern composed of a combination obtained by shifting the arrangement of the synchronization codes by one from the first pattern. In this case, digital information is recorded in an area delimited by the plurality of sectors using a sync frame structure configured such that two or more synchronization codes change , and the combination of the three consecutive synchronization codes. information storage medium configured to so that Do is possible to determine the position in the same sector by. An information storage medium having an area divided by a plurality of sectors,
The sector includes 26 sync frames, and the sync frame includes 4 types of synchronization codes.
The area divided by the plurality of sectors includes an ECC block that can be used as a unit for rewriting or appending. A plurality of ECC blocks are formed on the information storage medium, and a guard area is provided between the ECC blocks. Provided, the synchronization code is provided at the head position of the guard area,
Regarding the arrangement of the synchronization codes included in the guard area and the 26 sync frames, a first pattern composed of a combination of three consecutive synchronization codes and a combination obtained by shifting the arrangement of the synchronization codes by one from the first pattern when compared with a second pattern consisting of, by using a structure with sync frame structure as two or more sync codes are changed, are recorded in the area in which the digital information has been separated by the plurality of sectors, the continuous 3 by a combination of sync code configured to so that Do is possible to determine the position in the same sector information storage medium.   3. An information recording method configured to perform ECC encoding on digital information to be recorded on the information storage medium according to claim 1 and to record the digital information using the sync frame.   An information reproduction method configured to reproduce information recorded on the information storage medium according to claim 1 or 2 and to continue information reproduction based on the reproduced synchronization code.   A reproduction unit that reproduces information recorded therein from the information storage medium according to claim 1 or 2, and a synchronization code position extraction unit that detects a position of the synchronization code from the reproduced information, An information reproduction apparatus configured to continue information reproduction based on the detected synchronization code.

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