JP4209953B2 - Data recording / reproducing apparatus and method, and disk-shaped recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  This invention has different formatsDiskRecording media, especially of different sector sizesDiskData recording / reproducing apparatus and method capable of simplifying signal processing between recording media, and methodDiskThe present invention relates to a recording medium.
[0002]
[Prior art]
  As an external storage device of a computer, an optical disk drive has been attracting attention because of its advantages of large capacity and high-speed access. ) Drive adoption is expanding rapidly. In addition to these, MD (mini-disc; erasable disc) having a disc diameter of 2.5 inches has also been proposed. Furthermore, a DVD (Digital Video Disc) is being developed as a video storage medium.
[0003]
  A DVD is a recordable / reproducible optical disc that is a read-only disc having the same diameter as a CD, or an MO disc or a phase change disc, and can reproduce or record / reproduce video information compressed by MPEG or the like. It is. In DVD, the recording density is further improved by the progress of shortening the wavelength of the laser beam and the increase of NA of the objective lens, and the improvement of the digital modulation and error correction encoding process. Even in the case of a single layer disc, The data storage capacity is huge, about 3.7 Gbytes. CDs and MDs were originally developed as digital audio discs and then used as external storage media for computers, and it is expected that larger capacity DVDs will be used as external storage media for computers. ing.
[0004]
[Problems to be solved by the invention]
  As in the DVD example, the recording medium has been increased in density due to technological advances, and when it becomes more than a certain level, a new recording medium and a recording / reproducing apparatus are developed. Considering compatibility between existing recording media and new high-density recording media, if the signal format to be recorded / reproduced is the same, bytes of data errors caused by defects on the media (dust, scratches, etc.) There is a problem that the number increases and the reliability decreases.
[0005]
  With an existing optical disk such as a CD, a linear density of about 0.3 μm / bit is possible when the laser wavelength is 635 nm and the NA of the objective lens is 0.52. In this case, the track pitch is, for example, 0.84 μm. On the other hand, in a high-density optical disk that will be put to practical use in the near future, a linear density of about 0.18 μm / bit is possible if the wavelength of the laser is 440 nm of the blue laser and the NA of the objective lens is 0.6. is there. That is, the length on the 1-bit disk medium is reduced to about 60%. This means that a defect of a medium corresponding to 500 bytes in an existing optical disk becomes a defect corresponding to 833 bytes in a high-density optical disk. This has the effect of increasing the burst error length rather than increasing the error rate.
[0006]
  Therefore, it is conceivable that the error correction encoding and recording / reproducing signal format for high-density optical discs are different from existing ones. As a result, it becomes necessary to newly develop and design hardware, and compatibility Sexuality is impaired.
[0007]
  An object of the present invention is to provide a data recording device that has a small hardware scale and good accessibility to a plurality of data recording media having different recording densities, such as existing data recording media and high-density data recording media. / Reproduction apparatus and method, lineTo deDiscStatus recordTo provide a medium.
[0008]
[Means for Solving the Problems]
  The present invention relates to a data recording apparatus for recording digital data on a recording medium.
  First error correction encoding means for performing first error correction encoding;
  Interleaving means for interleaving the output data of the first error correction coding means;
  Second error correction coding means for performing second error correction coding on the output data of the interleave means;
  Of the second error correction coding meansConvolutionally codedRecording means for recording output data on a recording medium,
  The interleaving means is
  First interleave processing means for interleaving digital data with a first interleave length;
  Second interleave processing means for interleaving digital data with a second interleave length longer than the first interleave length;
  When the recording density information indicates the first recording density as the recording density of the digital data on the recording medium, the output of the first interleave processing means is selected, and the recording density information isHigher than the first recording densityAnd a selection means for selecting the output of the second interleave processing means for indicating the second recording density.
  This is a data recording apparatus characterized by the above. The present invention is also a recording method for recording digital data as described above.
[0009]
  In the present invention, the first error correction coding is performed, the data subjected to the first error correction coding is interleaved, and the second error correction coding is performed on the interleaved data.
  In interleaving, when the recording density information indicates the first recording density as the recording density of the digital data, the interleaving length is set to the first interleaving length, and the second recording density in which the recording density information is higher than the first recording density. When the interleave length is set to a second interleave length that is longer than the first interleave length,
  Second error correction encodingConvolutional coding obtained as outputIn a data reproducing apparatus for reproducing data from a recording medium on which data subjected to
  Reading means for reading digital data from the recording medium;
  Recording density information indicating the recording density of the read digital datadetectionRecording density detecting means for
  Second error correction means for decoding a second error correction code for the read digital data;
  Deinterleaving means for deinterleaving the output data of the second error correction means;
  First error correction means for decoding the first error correction coding on the output data of the deinterleave means,
  Deinterleaving means
  First deinterleave processing means for deinterleaving the digital data interleaved with the first interleave length;
  Second deinterleave processing means for deinterleaving the digital data interleaved with the second interleave length;
  When the recording density information indicates the first recording density, the output of the first deinterleave processing means is selected, and when the recording density information indicates the second recording density, the output of the second deinterleaving processing means. And selecting means for outputting digital data
  A data reproducing apparatus characterized by the above. The present invention is also a reproduction method for reproducing digital data as described above.
[0010]
  The present invention is a disc-shaped recording medium having a plurality of recording tracks and rotated at a constant angular velocity when accessing the plurality of recording tracks.
  The first error correction coding is performed, the data subjected to the first error correction coding is interleaved with the first interleave length, and the second error correction coding is performed on the interleaved data. Second error correction codingConvolutional coding obtained as outputA first recording track on which the first digital data is recorded;
  The first error correction coding is performed, the data subjected to the first error correction coding is interleaved with a second interleave length longer than the first interleave length, and the second data is interleaved with the second interleave data. Error correction codingConvolutional coding obtained as outputAnd a second recording track having a recording density higher than that of the first recording track. The second recording data is a disc-shaped recording medium.
[0011]
  The invention is divided into at least two recording areas defined by radial positions,
  In one recording area, the first error correction encoding is performed, the data subjected to the first error correction encoding is interleaved with the first interleave length, and the interleaved data is the second Error correction coding is performed, and the second error correction coding is performed.Convolutional coding obtained as outputThe first digital data is recorded,
  In the other recording area where the recording density is higher than that in one recording area, the first error correction encoding is performed, and the data subjected to the first error correction encoding is a second longer than the first interleave length. The second error correction coding is performed on the interleaved data with the interleave length ofConvolutional coding obtained as outputThe disc-shaped recording medium is characterized in that the second digital data subjected to is recorded.
[0012]
  The present invention has a plurality of recording layers,
  One recording layer is subjected to the first error correction coding, the data subjected to the first error correction coding is interleaved with the first interleave length, and the second data is subjected to the second interleaving. Error correction coding is performed, and the second error correction coding is performed.Convolutional coding obtained as outputThe first digital data is recorded,
  The other recording layer having a recording density higher than that of the one recording layer is subjected to the first error correction coding, and the second error data that has been subjected to the first error correction coding is longer than the first interleave length. The second error correction coding is performed on the interleaved data with the interleave length ofConvolutional coding obtained as outputThe disc-shaped recording medium is characterized in that the second digital data subjected to is recorded.
[0013]
  In the double encoding combining the first and second error correction encoding and the interleave processing, the burst error correction capability increases as the interleave length increases. Therefore, when recording on a data recording medium having a high recording density, the interleaving length is longer. Thereby, reliability can be improved.
[0014]
  When error correction encoding is performed in units of blocks, the correction capability for burst errors can be improved as the block size is increased. Therefore, when recording on a data recording medium having a high recording density, the block size is made larger. This can improve reliability.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of an embodiment of an optical disk recording / reproducing system according to the present invention. This system includes an optical disc recording system 54 and an optical disc playback system 55. Digital data to be recorded, such as computer data, is supplied from an input terminal 1. The input digital data is divided for each sector, which is a unit of data to be recorded / reproduced, and a data sync and header are added to the sector as necessary.
[0016]
  Input digital data is supplied to an error correction code encoder. In this example, convolutional double coding such as CIRC (Cross Interleave Reed-Solomon Code) in CD is adopted as the error correction code. The encoder includes a C2 encoder 2, interleavers 3a and 3b, a selection circuit 4, and a C1 encoder 5. In this encoder, error correction encoding is performed on a plurality of data symbols by the C2 encoder 2, and the code sequence of the parity generated in the data symbols and the C2 encoder 2 is changed by the interleave 3a or 3b, and a plurality of code sequences are changed. The C1 encoder 5 encodes the symbols.
[0017]
  Data subjected to error correction coding is supplied to the recording processing circuit 6, and recording data from the recording processing circuit 6 is supplied to an optical pickup via a drive circuit (not shown) and recorded on the optical disc 20. In the figure, an area indicated by TOC of the disk 20 is an area in which TOC (Table of Contents) information is recorded, and a disk ID described later is recorded therein. The cartridge 59 a in which the disk 20 is stored is for protecting the disk 20. The cartridge 59a is provided with a semiconductor memory 59b, and the previous disk ID may be stored therein.
[0018]
  As the optical disc 20, a recordable / reproducible optical disc such as WO (Write Once), MO, and phase change type is used. Further, the present invention can be applied not only to the drive device of the optical disk 20 but also to a mastering system for a read-only disk such as a CD-ROM. In one embodiment of the present invention, it is allowed to selectively use two types of optical disks 20 having different recording densities, or not only current disks but also high-density optical disks that are expected to appear in the future. It is possible to cope with.
[0019]
  Although not shown, the reproduction data read from the optical disk 20 is supplied to the reproduction processing circuit 11 via a reproduction amplifier, a clock extraction circuit, and the like. In addition, a focus servo, a tracking servo, and a feed servo related to the optical pickup are provided for the optical disc 20, and a spindle motor servo for driving the optical disc by CAV (Constant Angular Velocity) or CLV (Constant Linear Velocity). In addition, a circuit for controlling laser power and the like are provided. Since these are equivalent to those of the conventional circuit configuration, their description is omitted.
[0020]
  An error correction code decoder is connected to the reproduction processing circuit 11. The decoder includes a C1 decoder 12, deinterleavers 13a and 13b, a selection circuit 14, and a C2 decoder 15. The reproduction data of the optical disk 20 is extracted from the C2 decoder 15 to the output terminal 16.
[0021]
  The reason for providing the two interleavers 3a and 3b is to switch the interleave length in response to the recording density of the optical disc 20. Other configurations are basically the same even if the recording density of the optical disc 20 is different. Therefore, the format of data recorded on the optical disc 20 and reproduced from the optical disc 20 is the same regardless of the recording density of the disc. For example, similar to CD, the format of recording / playback data is subcode, data, parity P of C1 code and parity Q of C2 code within one transmission frame (sometimes referred to as EFM frame or C1 frame). Furthermore, these data are digitally modulated, and a sync (meaning a synchronization signal) is added to the head portion of each transmission frame.
[0022]
  Error correction coding in one embodiment of the present invention will be described with reference to FIG. In FIG. 2, m symbols are data to be subjected to error correction coding, r symbols are parity Q, and s symbols are parity P. The error correction code C1 is encoded with respect to m data symbols in parallel (same timing in time) and r parities Q, and s parities P are generated. Further, the error correction code C2 is encoded with respect to the data symbol at the position indicated by the diagonal line, and the parity Q is generated.
[0023]
  Here, the interleaver 3a is selected when the optical disc 20 has a standard recording density, and forms a code sequence indicated by C2a in FIG. On the other hand, the interleaver 3b is selected when the optical disk 20 has a high density, and forms a code sequence indicated by C2b in FIG. Generally, the maximum delay amount given by the interleaving process is referred to as an interleaving length (also referred to as an interleaving constraint length, an interleaving depth, an interleaving interval, etc.). As can be seen from FIG. 2, the relationship between the interleave length a for a standard recording density disk and the interleave length b for a high density disk is set to b> a.
[0024]
  A disk ID is generated from the CPU 57 by the input digital data and accompanying information, reading of the semiconductor memory 59b, or a user's key operation from the keyboard 56, and the selection circuit 4 is controlled by this disk ID, and the recording density of the optical disk 20 is increased. The corresponding interleaver 3a or 3b is selected. Alternatively, the reflectivity or the like may be detected from the reflected light returning from the disk, a disk ID may be generated, and the interleavers 3a and 3b may be automatically selected. Note that, when the disk ID information is not stored in the semiconductor memory 59b, the generated disk ID may be stored in the semiconductor memory 59b.
[0025]
  The reason why the interleave length is in the relationship (b> a) is that the longer the interleave length, the higher the burst error correction capability. As described above, a high-density optical disc tends to have a longer burst error length due to a defect such as a scratch on the disc than an optical disc with a standard recording density. Accordingly, the interleave length b for the high-density disk is set larger than the interleave length a for the standard density disc. On the other hand, when the interleaving length is increased, the area in which recording of other data is prohibited before and after the data of the rewriting unit also increases, and there is a demerit that the effective recording density is lowered. Therefore, the interleave length a in the case of standard density is shorter than b.
[0026]
  In the optical disk playback system 55, the error correction process using the C1 code is performed in the reverse order of the optical disk recording system 54, and then the deinterleave process for canceling the interleave process on the recording side is performed, and then the error correction process using the C2 code is performed. Do. When the optical disk 20 is a standard density optical disk, the deinterleaver 13a is selected. When this is a high density optical disk, the deinterleaver 13b is selected. As the disc ID for selection control, TOC information, directory information, and the like read prior to data reproduction are recorded in the CPU 58, and a corresponding interleaver is automatically selected. When the disk ID is stored in the semiconductor 59b, the disk ID is read from the memory access circuit 59c, and the corresponding interleaver is automatically selected. The recording CPU 57 and the reproduction CPU 58 are separate from each other, but may be shared by one CPU.
[0027]
  An example of the optical disk recording system 54 in FIG. 1 will be described with reference to FIG. The formatted data is written into the semiconductor memory (RAM) 21. A parity generation circuit 22 and a memory control circuit 23 are provided in association with the memory 21, and parity P and Q of error correction code are generated. The data to which the parity is added is supplied to the digital modulation circuit 26 through the switching circuit 24. The switching circuit 24 switches between the error correction encoded output and the TOC data from the TOC data generation circuit 25 and supplies it to the digital modulation circuit 26.
[0028]
  The disk ID is supplied to the memory control circuit 23 and the TOC data generation circuit 25. The memory 21, the parity generation circuit 22, and the memory control circuit 23 constitute the error correction code encoder (C2 encoder 2, interleavers 3a and 3b, selection circuit 4, and C1 encoder 5) in FIG. That is, the interleave processing can be realized by controlling the writing of data to the memory 21 and the reading of the data from the memory 21 by the memory control circuit 23. By switching the control of the memory 21 in response to the disk ID, two interleaving processes can be performed. More specifically, as described above, the interleave length b at the time of data recording on the high-density optical disc is made longer than the interleave length a at the time of data recording on the standard density optical disc.
[0029]
  The digital modulation circuit 26, for example, maps a 1-byte (8-bit) data symbol to a 16-bit code word according to a predetermined table, thereby generating a modulation output with a small amount of direct current. Of course, EFM on a CD, 8-15 modulation for converting an 8-bit data symbol into a 15-bit code word, etc. can be adopted as digital modulation. The output of the digital modulation circuit 26 is supplied to the sync adding circuit 27. The sync adding circuit 27 adds an additional sync, a C1 sync, a sector sync, and the like. The output of the sync adding circuit 27 is supplied to the optical pickup via the drive circuit and recorded on the optical disc 20. As these syncs, those having unique bit patterns that do not appear in the modulated data are used.
[0030]
  FIG. 4 is an example of the optical disc playback system 55. The reproduction data is supplied to the sync separation circuit 31, and although not shown, a sync detection signal corresponding to the sync is generated from the sync separation circuit 31, and these sync detection signals are supplied to the timing generation circuit and are synchronized with the reproduction data. Various timing signals such as pulses are generated.
[0031]
  A digital demodulation circuit 32 is connected to the sync separation circuit 31. Data in which the code word is returned to the data symbol is generated from the demodulating circuit 32 by the reverse process of the digital modulation circuit 26. Output data of the digital demodulation circuit 32 is written into the semiconductor memory (RAM) 35 via the TOC extraction circuit 33. The TOC extraction circuit 33 extracts the TOC data read in the initial state when the disc is loaded. The extracted TOC data is supplied to the TOC decoder 34. The TOC decoder 34 decodes the TOC data and supplies various control information to the CPU 58. One of them is the disk ID.
[0032]
  An error correction circuit 36 and a memory control circuit 37 are coupled to the memory 35. The error correction circuit 36 corrects errors in the reproduced data. The disk ID is supplied from the TOC decoder 34 to the memory control circuit 37 via the CPU 58. Data read from the memory 35 and subjected to error correction processing is taken out to the output terminal 16.
[0033]
  The memory 35, the error correction circuit 36, and the memory control circuit 37 constitute the error correction code decoder (C1 decoder 12, deinterleavers 13a and 13b, selection circuit 14, and C2 decoder 15) in FIG. That is, the deinterleaving process can be realized by controlling the writing of data to the memory 35 and the reading of data from the memory 35 by the memory control circuit 37. By switching the control of the memory 35 from the TOC decoder 34 via the CPU 58 in response to the disk ID, two deinterleaving processes corresponding to the standard density and high density optical disks can be performed.
[0034]
  FIG. 5 schematically shows another embodiment of the present invention. Similar to the first embodiment, the other embodiment is a convolutional double encoding, but is different in that it is a feedback type. The feedback type means a type in which C1 encoding targets not only data symbols but also parity Q, and C2 encoding targets not only data symbols but also parity P.
[0035]
  As shown in FIG. 5, the C1 encoder 5 encodes the data symbol from the input terminal 1 and the parity Q via the selection circuit 8, and the encoded output (data symbol, parity P, Q) is output from the C1 encoder 5. It is taken out. At the same time, the output (data symbol and parity P) of the C1 encoder 5 is supplied to the C2 encoder 2 via the interleavers 3a and 3b and the selection circuit 4, and C2 encoding is performed. The encoded output (data symbol and parity Q) of the C2 encoder 2 is supplied to the C1 encoder 5 via the interleavers 7a and 7b and the selection circuit 8.
[0036]
  In the feedback type double encoding, when the optical disk 20 has a standard density, it is input from the keyboard 62 by the user's key operation that the optical disk 20 is a standard density optical disk. Lever 3a, 7a is selected. On the other hand, if this is a high-density one, it is input from the keyboard 62 that the optical disk 20 is a high-density optical disk by the user's key operation, and the interleavers 3b and 7b are selected by the disk ID generated by the CPU 61. As in the case of one embodiment, the interleave length b in the case of a high-density optical disc is made larger than the interleave length a in the case of a standard-density disc, whereby the other embodiments also provide highly reliable recording. / Playback can be performed. When the disk ID is stored in the semiconductor memory 59b, the disk ID is read from the memory access circuit 59c, and the corresponding interleaver 3a, 7a or 3b, 7b is automatically selected.
[0037]
  The error correction code decoder provided on the reproduction side includes a C1 decoder 12, deinterleavers 13a and 13b, a selection circuit 14, a C2 decoder 15, deinterleavers 17a and 17b, a selection circuit 18, and a C1 decoder. 19. Deinterleavers 13a and 17a are provided for standard density optical discs, and deinterleavers 13b and 17b are provided for high density optical discs. In the case of the feedback type, efficient error correction can be performed by sequentially performing C1 decoding, C2 decoding, and C1 decoding.
[0038]
  A more specific example of error correction coding according to another embodiment of the present invention, that is, feedback type-convolution type-double coding will be described. FIG. 6 is a block diagram illustrating an error correction code encoding process when recording on a standard density optical disc. A 148-byte input symbol is supplied to the C1 encoder 105. The output (data symbol 148 bytes and 8-byte C1 parity P) of the C1 encoder 105 is supplied to the C2 encoder 102 via the interleave delay circuit group 103a.
[0039]
  In the C2 encoder 102, a 14-byte C2 parity Q is formed by encoding [170, 156, 15] Reed-Solomon code. Since the C1 encoder 105 C1 encodes not only data but also the C2 parity Q, the C2 parity Q is fed back to the C1 encoder 105 from the C2 encoder 102 via the interleave delay circuit group 107a. Accordingly, the C1 encoder 105 encodes [170, 162, 9] Reed-Solomon code. The delay circuit groups 103a and 107a constitute a standard density optical disc interleaver.
[0040]
  170 bytes (consisting of 148 bytes of data, 8 bytes of C1 parity P, and 14 bytes of C2 parity Q) from the C1 encoder 105 are extracted as an output symbol via the array changing circuit 100 including a delay circuit. This arrangement changing circuit 100 is provided in order to prevent an error at a symbol boundary from becoming a two-symbol error by separating the interval between adjacent symbols. The interleave length of this feedback-convolution-type double coding is 170 frames (the frame here is the length of the C1 code sequence) corresponding to the maximum delay amount in the delay circuit group 103a.
[0041]
  In the case of a high-density optical disc, the delay amount of each delay circuit is doubled as in the delay circuit groups indicated by reference numerals 103b and 107b in FIG. Processing other than interleaving is the same as in FIG. Therefore, the interleaving length of the interleaving processing by the delay circuit groups 103b and 107b is 340 frames. Therefore, the interleave length in the case of a high-density optical disc can be made twice the interleave length in the case of a standard density optical disc.
[0042]
  The processing of the standard density optical disk encoder shown in FIG. 6 and the corresponding decoder will be described with reference to FIG. An input symbol (170 bytes) from the reproduction processing circuit is supplied to the C1 decoder 112 via the array changing circuit 110. The array change circuit 110 performs the reverse process of the encoder array change circuit 100. The C1 decoder 112 decodes the [170, 162, 9] Reed-Solomon code.
[0043]
  The output of the C1 decoder 112 is supplied to the C2 decoder 115 via the deinterleaving delay circuit group 113a. The C2 decoder 115 decodes [170, 156, 15] Reed-Solomon code. Further, the decoded output of the C2 decoder 115 is supplied to the C1 decoder 119 via the deinterleave delay circuit group 117a. In this manner, the error-corrected 148-byte data symbol is extracted through the C1 decoding, C2 decoding, and C1 decoding processes.
[0044]
  FIG. 9 shows the processing of the decoder corresponding to the high-density optical disk encoder shown in FIG. In the case of a high-density optical disc, the delay amount of each interleave delay circuit in the encoder is doubled. Therefore, the delay amount of each delay circuit in the deinterleave processing delay circuit groups 113b and 117b is 2 respectively. Doubled. Processing other than deinterleaving is the same as in FIG.
[0045]
  In the above description, the interleave length is doubled, but the method is not limited to an integer multiple. For example, when the delay amount for interleaving processing with respect to a standard density optical disk changes by d, 2d, 3d,... By unit delay amount d, the delay amount for interleaving processing with respect to a high density optical disk is set to 2d, As in 3d, 5d, 6d, 8d,..., The difference between d and 2d may be alternately provided.
[0046]
  Furthermore, the present invention can also be applied to the case where areas having different recording densities are provided in the same optical disc. As shown in FIG. 13A, when the recording density of the outer peripheral area Rb is higher than the recording density of the inner peripheral area Ra of the disc, error correction coding interleaving of the area Ra is performed.LongIn contrast, error correction coding interleaving of region RbLongIt is made to enlarge.
[0047]
  Further, in a disk such as a CAV disk that is rotated at a constant angular velocity and digital data on the disk is accessed, the relative line between the inner track and the head that accesses the track is compared with the outer track. The speed is reduced and the recording density on the inner circumference side is inevitably increased. In such a case, interleaving on the inner circumference sideLongInterleaving on the outer circumferenceLongTo be bigger. In other words, since the recording density is higher on the inner circumference side, the burst error length on the outer circumference side is longer than the burst error length on the inner circumference side, but the interleave on the inner circumference side is increased.LongInterleaving on the outer circumferenceLongBy increasing the size, the burst error correction capability on the inner circumference side where the burst error length becomes longer can be enhanced. Also, on the outer peripheral side where the recording density is relatively low, the interleaving on the inner peripheral sideLong andCompared with interleaving on the outer circumference sideLongBy making it smaller, the area where recording of other data is prohibited before and after the data in the rewrite unit is shortened, and interleaving that matches the inner circumference side is performed.LongCompared with the use, the substantial recording density can be increased.
[0048]
  Furthermore, the present invention can be applied to a case where the recording density of each layer is different in a multilayer optical disc. As shown in FIG. 13B, in a multi-layer optical disk such as a two-layer optical disk, data recording layers La and Lb are formed in the thickness direction of the disk, and each layer can be recorded / reproduced by focusing the optical pickup OP on each recording layer. It is said. For example, when the recording layer Lb closer to the reading side has a higher recording density than the recording layer La, the error correction encoding process for each recording layer is switched as described above.
[0049]
【The invention's effect】
  When the data recording density is different, the present invention isInterleaveSince the length is increased as compared with the standard density, it is possible to perform burst error correction equivalent to the standard density even at high density, and the reliability as a data recording medium can be improved. . The present invention also makes it possible to realize a CAV disk and a disk drive capable of recording / reproducing two disks having different recording densities, a multi-session disk having two different recording density areas, and the like. it can.
[Brief description of the drawings]
FIG. 1 is an overall block diagram of an embodiment of a recording / reproducing circuit according to the present invention.
FIG. 2 is a schematic diagram for explaining error correction coding according to an embodiment of the present invention;
FIG. 3 is a block diagram of an example of a recording processing system in FIG.
4 is a block diagram of an example of a reproduction processing system in FIG. 1. FIG.
FIG. 5 is an overall block diagram of another embodiment of a recording / reproducing circuit according to the present invention.
FIG. 6 is a schematic diagram showing a specific example of an encoding process for error correction coding in another embodiment of the present invention.
FIG. 7 is a schematic diagram showing a specific example of an encoding process for error correction coding in another embodiment of the present invention.
FIG. 8 is a schematic diagram showing a specific example of decoding processing of error correction coding in another embodiment of the present invention.
FIG. 9 is a schematic diagram showing a specific example of decoding processing of error correction coding in another embodiment of the present invention.
FIG. 10It is a basic diagram for demonstrating the application example of this invention.
[Explanation of symbols]
2 C2 encoder
3a, 3b interleaver
4 Selection circuit
5 C1 encoder
6 Recording processing circuit
11 Reproduction processing circuit
12 C1 decoder
13a, 13b Deinterleaver
15 C2 decoder

Claims (11)

In a data recording apparatus for recording digital data on a recording medium,
First error correction encoding means for performing first error correction encoding;
Interleaving means for interleaving the output data of the first error correction coding means;
Second error correction coding means for performing second error correction coding on the output data of the interleaving means;
Recording means for recording the convolutionally encoded output data of the second error correction encoding means on a recording medium,
The interleaving means is
First interleave processing means for interleaving the digital data with a first interleave length;
Second interleave processing means for interleaving the digital data with a second interleave length longer than the first interleave length;
When the recording density information indicates the first recording density as the recording density of the digital data on the recording medium, the output of the first interleave processing means is selected, and the recording density information is higher than the first recording density . A data recording apparatus comprising: a selecting unit that selects an output of the second interleave processing unit when a recording density of 2 is indicated. The data recording apparatus according to claim 1, wherein
A data recording apparatus further comprising recording density input means for inputting the recording density information. The data recording apparatus according to claim 1, wherein
A data recording apparatus, further comprising recording density detecting means for detecting the recording density information from the recording medium. The first error correction coding is performed, the data subjected to the first error correction coding is interleaved, and the second error correction coding is performed on the interleaved data.
In the interleaving, when the recording density information indicates the first recording density as the recording density of the digital data, the interleaving length is set to the first interleaving length, and the recording density information is higher than the first recording density. The interleave length is set to a second interleave length that is longer than the first interleave length.
In a data reproducing apparatus for reproducing data from a recording medium on which data subjected to convolutional encoding obtained as the second error correction encoded output is recorded,
Reading means for reading digital data from the recording medium;
Recording density detecting means for detecting recording density information indicating the recording density of the read digital data;
Second error correction means for decoding the second error correction code for the read digital data;
Deinterleaving means for deinterleaving the output data of the second error correction means;
First error correction means for decoding the first error correction coding on the output data of the deinterleave means,
The deinterleaving means is
First deinterleaving processing means for deinterleaving the digital data interleaved with the first interleave length;
Second deinterleaving processing means for deinterleaving the digital data interleaved with the second interleave length;
When the recording density information indicates the first recording density, the output of the first deinterleave processing means is selected, and when the recording density information indicates the second recording density, the second recording density A data reproducing apparatus comprising: selecting means for selecting the output of the deinterleave processing means and outputting the digital data. The data reproducing apparatus according to claim 4, wherein
The data reproducing apparatus according to claim 1, wherein the recording density detecting means detects the recording density information from a storage means provided in the recording medium. The data reproducing apparatus according to claim 4, wherein
The data reproducing apparatus according to claim 1, wherein the recording density detecting means detects the recording density information from a reference information area included in the digital data of the recording medium. In a data recording method for recording digital data on a recording medium,
The first error correction coding is performed, the data subjected to the first error correction coding is interleaved, the second error correction coding is performed on the interleaved data, and the second error correction coding is performed. Record the convolutionally encoded data obtained as error correction encoded output on a recording medium,
One interleave length of the first interleave length and the second interleave length longer than the first interleave length can be set as the interleave.
When the recording density information indicates the first recording density as the recording density of the digital data on the recording medium, the interleave length is set to the first interleaving length, and the recording density information is higher than the first recording density. A data recording method, wherein when the recording density is 2, the interleave length is set to the second interleave length. The first error correction coding is performed, the data subjected to the first error correction coding is interleaved, and the second error correction coding is performed on the interleaved data.
In the interleaving, when the recording density information indicates the first recording density as the recording density of the digital data, the interleaving length is set to the first interleaving length, and the recording density information is higher than the first recording density. The interleave length is set to a second interleave length that is longer than the first interleave length.
In a data reproduction method for reproducing data from a recording medium on which data subjected to convolutional encoding obtained as the second error correction encoding output is recorded,
Read digital data from the recording medium,
Generating recording density information indicating the recording density of the read digital data;
Decoding the second error correction code for the read digital data, deinterleaving the output data of the second error correction means,
Decoding the first error correction coding on the deinterleaved data;
When the recording density information indicates the first recording density, deinterleaving corresponding to the first interleaving length is performed, and when the recording density information indicates the second recording density, the second interleaving length A data reproduction method comprising performing deinterleaving corresponding to the above. A disk-shaped recording medium having a plurality of recording tracks and rotated at a constant angular velocity when accessing the plurality of recording tracks,
The first error correction coding is performed, the data subjected to the first error correction coding is interleaved with the first interleave length, and the second error correction coding is performed on the interleaved data. A first recording track on which the first digital data subjected to the convolutional encoding obtained as the second error correction encoding output is recorded;
The data subjected to the first error correction coding and the data subjected to the first error correction coding are interleaved with a second interleave length longer than the first interleave length, and the interleaved data The second digital data subjected to the convolutional encoding obtained as the second error correction encoding output is recorded and has a second recording track having a recording density higher than that of the first recording track. A disc-shaped recording medium. Divided into at least two recording areas defined by radial positions;
In one recording area, the first error correction coding is performed, the data subjected to the first error correction coding is interleaved with the first interleave length, and the interleaved data is subjected to the first error correction coding. The first digital data subjected to the convolutional encoding obtained as the second error correction encoding output is recorded,
The other recording area having a higher recording density than the one recording area is subjected to the first error correction coding, and the first interleave length is applied to the data subjected to the first error correction coding. Interleaving is performed with a longer second interleaving length, and the convolutionally encoded second digital data obtained as the second error correction encoding output is recorded on the interleaved data. Disc-shaped recording medium. Having a plurality of recording layers,
One recording layer is subjected to the first error correction coding, the data subjected to the first error correction coding is interleaved with the first interleave length, and the interleaved data is subjected to the first error correction coding. The first digital data subjected to the convolutional encoding obtained as the second error correction encoding output is recorded,
The other recording layer having a recording density higher than that of the one recording layer is subjected to the first error correction coding, and the first interleave length is applied to the data subjected to the first error correction coding. Interleaving is performed with a longer second interleaving length, and the convolutionally encoded second digital data obtained as the second error correction encoding output is recorded on the interleaved data. Disc-shaped recording medium.

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