JP2006277857A - Recording device and method, reproducing device and method, recording medium, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce redundancy in error correction codes. <P>SOLUTION: When recording, the ECC encoder 41 adds error correction codes to every ECC block of predetermined units. The data divider 43 divides the data added with error correction codes into ECC blocks according to the recording layers of an optical disk 13, then shuffles the divided data and record the shuffled data by distributing to the layers of the optical disk 13. When reproducing, the data mixing section 44 restores the data distributed and recorded on the layers of the optical disk 13 to the state before distributing in every ECC block. Thus, the ECC decoder 42 can reduce the redundancy in the error correction codes by making error correction based on the error correction codes contained in the restored data. This invention is applicable to the recording format, recording device, and reproducing device of optical disks. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus and method, a reproducing apparatus and method, a recording medium, and a program, and more particularly, to a recording apparatus and method, a reproducing apparatus and method, a recording medium, and a program that can reduce redundancy of error correction codes. .

  In recent years, optical discs with a large storage capacity such as DVDs (Digital Versatile Discs) have become widespread. There is also a demand for further increase in storage capacity, and there are discs having recording layers on both the front and back sides of the disc and discs having two recording layers on one side. Specifically, a DVD is formed from a 1.2 (mm) disc by laminating two 0.6 mm (mm) disc substrates, and is divided into two layers on one side of the pasting. There are a recording method (dual layer) and a recording method (double side) in which one layer is recorded on each of the bonded surfaces. In the future, a method of recording in two layers on both sides (that is, four layers because there are two layers on both sides) in which both the dual layer and the double side are combined may be considered.

  In other words, DVDs have a physical disc format such as single-sided, single-sided, double-sided, or double-sided, single-sided (ie, two layers because there is one layer on each side), thereby increasing the capacity of the disc. ing.

  More specifically, the capacity of the disc by the single-sided single-layer recording method is 4.7 gigabytes (GB), and the capacity of the disc by the single-sided two-layer recording method is 8.5 (GB). Further, the capacity of the disc by the double-sided single-layer (two-layer) recording method is 9.4 (GB), and when the double-sided two-layer (four-layer) recording method is possible, the disc capacity is 17 (GB). In the case of two layers, the disc capacity is not doubled because of a margin for error. In the case of a two-layer disc, one recording surface is translucent, and signals from two layers are read by irradiating laser light from one side.

  Also, an optical disc using a single-sided four-layer recording method has been studied.

  Incidentally, recorded data may not be read due to dust or scratches attached to the surface of the optical disk. In rare cases, even if the recording layer itself of the optical disc is defective, or data that should have been recorded normally due to the temperature at the time of recording or the power supply of the recording device or reproducing device, etc. There is a possibility that an error will occur at random.

  In particular, in an optical disc having two or more layers on one side (hereinafter referred to as a multilayer disc), recording and reproduction are performed by focusing laser light on each layer for recording and reproducing data. The farther the recording layer is located, the more the reflected light from the recording layer present in the foreground becomes noise, the recording / reproduction quality deteriorates and the error rate increases, so there is a higher possibility of an error when reading data. .

  In general, when data is recorded on an optical disc as a method for dealing with such an error occurrence, an error correcting code (ECC) is added to the data to be recorded and recorded. When data is read, it is possible to correct data errors based on the error correction code, so that data can be reliably reproduced.

  Here, the error correction code refers to redundant data added separately from the original data for the purpose of correcting data errors when data is read from the optical disk.

  That is, an optical disc apparatus that performs recording and reproduction with an optical disc records data with an error correction code when recording data on the optical disc, adding an error correction code to the data to be recorded, and reading data from the optical disc. Is read out, the data error is corrected based on the error correction code.

  Further, in an optical disc, data to be recorded is recorded in a continuous spiral, and this spiral recording area is called a track. Furthermore, the track is composed of sectors which are the minimum recording units on the optical disc, and data is processed in units of sectors. However, if processing is performed in units of sectors, an area required for management increases, and therefore processing is generally performed in units of clusters in which a plurality of sectors are collected.

  Further, the optical disc apparatus executes processing on the optical disc in units of ECC blocks in which an error correction code is added to user data. Specifically, in the case of a DVD, the optical disc apparatus executes a process of writing data on an optical disc with 16 sectors as one ECC block (one ECC block). Hereinafter, an ECC block format (ECC format), which is a unit for writing data on an optical disc, will be described with reference to FIG.

  FIG. 1 is a diagram for explaining an example of a conventional ECC format. For the convenience of the present invention, there are some numerical values that are slightly different from those of a general DVD ECC format.

  The user data is divided into 172 bytes (bytes) in the order of writing or reading, and the first and last of the divided 172 bytes of data are arranged to match. Each of the divided 172-byte data is referred to as one line. An error correction code is added as user error correction unit of user data consisting of 198 lines of 172 bytes per line.

  The horizontal direction in FIG. 1 corresponds to the direction of the order in which user data is written or read. That is, the horizontal direction in FIG. 1 corresponds to the number of bytes of user data. The vertical direction in FIG. 1 corresponds to the direction of the number of rows.

  172 bytes x 198 rows of user data are appended with 172 bytes x 10 rows of PO (hereinafter referred to as PO parity) and 10 bytes x 208 rows of PI (hereinafter referred to as PI parity) as error correction codes. The The PO parity is redundant data for detecting and correcting user data errors in the row direction, that is, in the vertical direction (PO sequence) in FIG. The PI parity is redundant data for detecting and correcting user data errors in the direction in which user data is written or read, that is, in the horizontal direction (PI series) in FIG.

  In FIG. 1, the optical disc apparatus extracts the first 1-byte data from the data of each of 198 rows with respect to the user data stored in the internal memory, and extracts the extracted 198-byte data. On the other hand, 10 error correction codes of 10 bytes are generated and added, and then 1 byte data after 1 byte is extracted from the data of each of 198 lines and extracted. To generate and add 10 rows of error correction code of 10 bytes to 198 bytes of data, generate 10 rows of error correction code of 10 bytes to user data of 172 bytes × 198 rows By repeating the process of adding 172 times, a PO parity of 172 bytes × 10 rows is added. Data to which PO parity is added is stored in the memory.

  In addition, the optical disk device generates a 10-byte error correction code for the 172 bytes of data in each of the 1st to 208th rows for the user data added with the PO parity stored in the memory. Thus, a PI parity of 10 bytes × 208 rows is added.

  Furthermore, error correction codes (PO parity and PI parity) can correct errors more reliably as the amount of data increases. However, because redundant data for error correction increases, Since the recording density of user data is reduced, the data amount is set to an optimum amount by an error rate (error rate).

  Specifically, in the case of an optical disc using a four-layer recording method on one side, the error rates of the first layer, the second layer, the third layer, and the fourth layer are 0.00001 and 0.0001, respectively, as viewed from the surface of the disc. , 0.001, and 0.01, it is considered that the error correction code (ECC) is designed in accordance with the error rate of 0.01 in the fourth layer, which is the worst (highest) error rate.

  In other words, when designing an error correction code (ECC), there is a trade-off between the error correction capability and data redundancy of the optical disc, so the error rate target after correcting the error with the error correction code is set as the target. It is necessary to design while considering the value.

  FIG. 2 is a graph showing the relationship between the error rate before error correction and the error rate after error correction in the ECC format of FIG.

  The vertical axis of the graph in FIG. 2 indicates the error rate after error correction, and the larger the value of the vertical axis, the higher the probability that an error will occur. The horizontal axis indicates the error rate before error correction. The larger the value on the horizontal axis, the higher the probability that an error will occur.

  The curve in the figure is a curve showing the relationship between the error rate before error correction and the error rate after error correction in the ECC format of FIG. A curve indicating the relationship between the error rate before error correction and the error rate after error correction is determined by the error correction code (PO parity and PI parity) (data amount) added to the user data.

  That is, when a large number of error correction codes (PO parity and PI parity) are added to user data, the error occurrence rate after error correction decreases, so the curve becomes a steeper curve, whereas the user data When the number of error correction codes (PO parity and PI parity) to be added is reduced, the error occurrence rate after error correction becomes high, so the curve becomes a gentle curve.

Here, the error rate after correcting the error by the error correction code, if you want to less error rate is 1 × 10 ^-9, the error rate is 1 × 10 ^-9 of the vertical axis in FIG lines and curves In order to achieve the target error rate after error correction, the value of the horizontal axis at the point of intersection with the error, that is, the error rate of 0.014 is the limit error rate set before error correction. It becomes.

Therefore, if the error rate before error correction is equal to or lower than the recording / reproduction quality limit of 0.014, the error rate after error correction is equal to or lower than the error rate of 1 × 10 ⁻⁹ .

In this case, as described above, in the optical disc using the single-sided four-layer recording method, the error rates of the first layer, the second layer, the third layer, and the fourth layer are 0.00001, respectively, as viewed from the surface of the disc. , 0.0001, 0.001, and 0.01, the error correction code (ECC) is designed to match the error rate of 0.01 of the fourth layer, which is the worst (highest) error rate. However, since the error rate is less than the recording / reproduction quality limit of 0.014, the error rate after error correction is less than or equal to 1 × 10 ⁻⁹ in all layers.

  As described above, the error correction code (ECC) is designed in the conventional optical disc apparatus.

  In the type of single-layer disc and multilayer disc, the recording layer serving as the first layer has the same distance from the surface of the cover layer on which the laser beam is incident in the thickness direction of the disc. There is also a disc recording medium in which the second and subsequent recording layers are formed closer to the cover layer surface than the first layer (see, for example, Patent Document 1).

JP 2003-346379 A

  However, in multi-layer discs, the recording / reproduction quality changes depending on the recording layer, so if the ECC format is adopted in accordance with the error rate expected in the layer with the worst recording / reproduction quality, it will The ECC format is over-specification, and there is a problem that the recording density of user data is lowered.

  For example, the disc recording medium disclosed in Japanese Patent Application Laid-Open No. 2003-346379 can execute recording / reproduction of a multi-layer disc, but the difference in error rate between a layer having poor recording / reproduction quality and a layer having good quality can be obtained. Since the considered ECC format is not adopted, the recording density of user data may be reduced.

  In addition, a method of changing the ECC format used for each recording layer in accordance with the recording / reproduction quality of each recording layer of the optical disc is also conceivable, but in this case, it is possible to prevent a decrease in the recording density of user data. However, when considering the configuration of the optical disk apparatus, since different ECC formats are adopted for each recording layer, it is necessary to support a plurality of ECC formats, which complicates the processing, and the circuit of the optical disk apparatus There was also a problem that the configuration was complicated.

  The present invention has been made in view of such a situation, and in a disk for recording data on a plurality of layers, it is possible to reduce the data amount of an error correction code with a simpler configuration. It is.

  The recording apparatus of the present invention includes an adding means for adding an error correcting code for correcting an error to data, a dividing means for dividing the data to which the error correcting code is added into a number corresponding to the number of layers, It is characterized by comprising recording control means for controlling the recording of the divided data onto the disc so that each of the divided data divided from the data is recorded in different layers.

  The dividing means further shuffles the divided data so that unit data of a predetermined amount of the divided data is exchanged between the divided data divided from one data, and the recording control means is shuffled. It is characterized by controlling the recording of the divided data on the disk.

  The recording apparatus of the present invention includes storage means for storing the divided data, and the recording control means performs recording so that the stored divided data of a predetermined amount of data is collectively recorded on one layer of the disc. It is characterized by controlling.

  The adding means adds an error correction code to the data so as to be a product code.

  The recording method of the present invention includes an addition step of adding an error correction code for correcting an error to data, a division step of dividing the data to which the error correction code is added into a number corresponding to the number of layers, And a recording control step for controlling recording of the divided data on the disc so that each of the divided data which is data divided from the data is recorded in different layers.

  The program for controlling the recording apparatus of the recording medium of the present invention includes an adding step for adding an error correction code for correcting an error to data, and dividing the data with the error correction code into a number corresponding to the number of layers. And a recording control step for controlling the recording of the divided data on the disc so that each of the divided data divided from one data is recorded in a different layer. And

  The program for controlling the recording apparatus of the present invention includes an addition step of adding an error correction code for correcting an error to data, and a division step of dividing the data to which the error correction code is added into a number corresponding to the number of layers And a recording control step for controlling the recording of the divided data on the disc so that each of the divided data divided from one data is recorded in a different layer.

  The reproducing apparatus according to the present invention is divided data obtained by dividing data with an error correction code into a number corresponding to the number of layers, and each piece of divided data obtained by dividing one data is recorded in a different layer. Reproduction control means for controlling the reproduction of the divided data from each of the disc layers, a mixing means for mixing the data to which the error correction code is added from the reproduced divided data, and the mixed data. Correction means for correcting an error in the data based on the error correction code.

  The reproduction control means controls reproduction of the divided data so that divided data of a predetermined data amount is reproduced at a time from one layer of the disc.

  When the divided data is shuffled so that the unit data of a predetermined data amount of the divided data is exchanged between the divided data divided from one data, the mixing unit is configured to restore the unit data based on the arrangement of the unit data. In this case, the divided data is reverse shuffled so that the data with the error correction code added is mixed from the reverse shuffled divided data.

  The correction means corrects an error in the data based on an error correction code that is a product code added to the data.

  The reproduction method of the present invention is divided data obtained by dividing data with error correction codes added into a number corresponding to the number of layers, and each piece of divided data is recorded on a different layer. Added to the mixed data, a reproduction control step for controlling reproduction of the divided data from each of the disc layers, a mixing step for mixing the data with the error correction code added from the reproduced divided data, and the mixed data. And a correction step for correcting an error in the data based on the error correction code.

  A program for controlling a recording medium playback apparatus according to the present invention is divided data obtained by dividing data to which an error correction code is added into a number corresponding to the number of layers, and each piece of divided data obtained by dividing one piece of data. Is a reproduction control step for controlling the reproduction of the divided data from each of the layers of the disc recorded in different layers, and a mixing step for mixing the data with the error correction code added from the reproduced divided data, And a correction step of correcting an error of the data based on the error correction code added to the mixed data.

  The program for controlling the reproducing apparatus of the present invention is divided data obtained by dividing data with error correction codes into a number corresponding to the number of layers, and each piece of divided data obtained by dividing one data is mutually A reproduction control step for controlling reproduction of the divided data from each of the layers of the disc recorded in different layers, a mixing step for mixing the data with the error correction code added from the reproduced divided data, and And a correction step of correcting an error in the data based on an error correction code added to the data.

  The disc of the present invention is divided data obtained by dividing data with an error correction code into a number corresponding to the number of layers, and each piece of divided data is recorded on a different layer. It is characterized by.

  In the recording apparatus and method, the recording medium, and the program of the present invention, an error correction code for correcting an error is added to the data, and the data to which the error correction code is added is divided into a number corresponding to the number of layers. The recording of the divided data on the disc is controlled so that each of the divided data, which is data divided from one data, is recorded on different layers.

  In the reproducing apparatus and method, recording medium, and program of the present invention, divided data obtained by dividing data added with error correction codes into a number corresponding to the number of layers and dividing one data The reproduction of the divided data from each of the disk layers recorded in different layers is controlled, and the data obtained by adding the error correction code is mixed from the reproduced divided data. Data errors are corrected based on the added error correction code.

  According to the present invention, the redundancy of error correction codes can be kept low.

  Further, according to the present invention, the data amount of the error correction code can be further reduced with a simpler configuration in a disk for recording data on a plurality of layers.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode of the present invention will be described below. The correspondence relationship between the disclosed invention and the embodiments is exemplified as follows. Although there are embodiments which are described in this specification but are not described here as corresponding to the invention, the embodiments correspond to the invention. It does not mean that it is not a thing. Conversely, even if an embodiment is described herein as corresponding to an invention, that means that the embodiment does not correspond to an invention other than the invention. It is not a thing.

  Further, this description does not mean all the inventions described in the specification. In other words, this description is for the invention described in the specification and not claimed in this application, i.e., for the invention that will be applied for in the future or that will appear as a result of amendment and added. It does not deny existence.

  According to the present invention, a recording apparatus is provided. In this recording apparatus (for example, the optical disc apparatus 1 in FIG. 3), an adding means (for example, the ECC encoder 41 in FIG. 3) for adding an error correction code for correcting an error and the error correction code are added. Dividing means for dividing the data into the number corresponding to the number of layers (for example, the data dividing unit 43 in FIG. 3) and the divided data, which is the data divided from one data, are recorded in different layers. As described above, recording control means (for example, the recording control unit 51 in FIG. 3) for controlling the recording of the divided data on the disc is provided.

  The dividing means further shuffles the divided data so that unit data of a predetermined amount of the divided data is exchanged between the divided data divided from one data, and the recording control means is shuffled. It is possible to control the recording of the divided data on the disc.

  The recording apparatus includes storage means for storing the divided data (for example, the ECC memory 25 in FIG. 3). The recording control means collects the divided data stored in a predetermined amount in one layer of the disk. Recording can be controlled to be recorded.

  The adding means can add an error correction code to the data so as to be a product code.

  According to the present invention, a recording method is provided. In this recording method, an addition step (for example, processing in steps S15 to S18 in FIG. 6) for adding an error correction code for correcting an error to the data, and the data with the error correction code added to the number of layers. The division step (for example, the process of step S19 in FIG. 6) that divides the data into the appropriate number and the divided data that is the data divided from one data are recorded in different layers. And a recording control step (for example, the process of step S37 in FIG. 9) for controlling the recording of the divided data.

  According to the present invention, a program for controlling a recording apparatus is provided. This program adds an error correction code for correcting an error to the data (for example, processing in steps S15 to S18 in FIG. 6), and adds the error correction code to the data according to the number of layers. And dividing into discs so that each of the divided data, which is data divided from one data, is recorded in a different layer. A recording control step for controlling data recording (for example, the process of step S37 in FIG. 9) is executed.

  According to the present invention, a playback device is provided. This reproducing apparatus (for example, the optical disc apparatus 1 in FIG. 3) is divided data obtained by dividing the data to which the error correction code is added into the number corresponding to the number of layers, and the divided data obtained by dividing one data. Reproduction control means (for example, reproduction control unit 52 in FIG. 3) for controlling reproduction of divided data from each of the disk layers recorded in different layers, and error correction from the reproduced divided data A mixing unit (for example, the data mixing unit 44 in FIG. 3) for mixing the data with the added code, and a correcting unit (for example, for correcting an error in the data based on the error correction code added to the mixed data) ECC decoder 42) of FIG.

  The reproduction control means can control reproduction of the divided data so that divided data of a predetermined data amount is reproduced at a time from one layer of the disc.

  When the divided data is shuffled so that the unit data of a predetermined data amount of the divided data is exchanged between the divided data divided from one data, the mixing unit is configured to restore the unit data based on the arrangement of the unit data. In this way, it is possible to reverse shuffle the divided data and mix the data to which the error correction code is added from the reverse shuffled divided data.

  The correction means can correct an error in the data based on an error correction code that is a product code added to the data.

  According to the present invention, a reproduction method is provided. This reproduction method is divided data obtained by dividing data to which an error correction code is added into a number corresponding to the number of layers, and each divided data obtained by dividing one data is recorded in different layers. A reproduction control step (for example, the process of step S74 in FIG. 10) for controlling the reproduction of the divided data from each of the layers of the disc, and a mixing step for mixing the data with the error correction code added from the reproduced divided data (For example, the process of step S93 in FIG. 11) and the correction step for correcting the data error based on the error correction code added to the mixed data (for example, the process of step S95 to step S98 in FIG. 11) ).

  According to the present invention, a program for controlling a playback device is provided. This program is divided data obtained by dividing data added with error correction codes into a number corresponding to the number of layers, and each piece of divided data obtained by dividing one data is recorded in a different layer. A reproduction control step (for example, the process of step S74 in FIG. 10) for controlling the reproduction of the divided data from each of the layers of the disc, and a mixing step for mixing the data with the error correction code added from the reproduced divided data ( For example, the process in step S93 in FIG. 11) and a correction step for correcting an error in the data based on the error correction code added to the mixed data (for example, the process in steps S95 to S98 in FIG. 11). And execute.

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

  FIG. 3 is a block diagram showing a configuration of an embodiment of an optical disc apparatus 1 to which the present invention is applied.

  The optical disk device 1 is an example of a reproducing device or a recording device of the present invention. The optical disk apparatus 1 includes a signal processing unit 11, an optical pickup 12, a spindle motor 14, a servo controller 15, a control unit 16, and a memory 17, and an optical disk 13 that is a recording medium such as a DVD, which is an example of a disk, When it is mounted on a disk table mounted integrally with the spindle motor 14, it is driven to write data from the host computer 2 (or a video playback device (not shown), etc.) onto the optical disk 13. Alternatively, data is read from the optical disc 13 and the read data is supplied to the host computer 2 (or a video playback device or the like).

  In this embodiment, the optical disk 13 is described as an optical disk based on a single-sided four-layer recording method.

  The signal processing unit 11 performs predetermined signal processing such as processing for adding an error correction code, scrambling processing, and processing for modulating a signal on data supplied from the host computer 2 during recording, A signal obtained as a result of the processing is supplied to the optical pickup 12. Further, the signal processing unit 11 performs predetermined signal processing such as signal decoding processing, scramble processing, and error correction processing on the signal supplied from the optical pickup 12 during reproduction, and performs processing. Data obtained as a result of the application is supplied to the host computer 2.

  Further, the signal processing unit 11 generates a focus error signal that is a signal indicating a focus error of the laser light emitted from the optical pickup 12 based on a signal supplied from the optical pickup 12 and an error due to tracking deviation. A tracking error signal, which is a signal to be shown, is generated, and the generated focus error signal and tracking error signal are supplied to the control unit 16.

  The signal processing unit 11 includes an external interface 21, a memory controller 22, a buffer 23, an ECC processing unit 24, an ECC memory 25, a modulation unit 26, a driver 27, an equalizer 28, and a demodulation unit 29.

  The memory controller 22 stores, for example, data supplied from the host computer 2 in the buffer 23 via the external interface 21 compliant with a standard such as ATAPI (AT Attachment Packet Interface) or SCSI (Small Computer System Interface). The data stored temporarily and stored in the buffer 23 is supplied to the ECC processing unit 24 as appropriate.

  That is, the buffer 23 temporarily stores data to absorb the difference between the data transfer rate between the host computer 2 and the external interface 21 and the data transfer rate of the optical disc apparatus 1.

  Specifically, when the data transfer rate between the host computer 2 and the external interface 21 is slower than the data transfer rate of the optical disc apparatus 1, the memory controller 22 supplies the data from the host computer 2 via the external interface 21. The received data is stored until the buffer 23 is full, and the stored data is supplied to the ECC processing unit 24. Conversely, when the data transfer rate between the host computer 2 and the external interface 21 is faster than the data transfer rate of the optical disc apparatus 1, data transfer from the host computer 2 is awaited.

  At the time of recording, the ECC processing unit 24 performs shuffling (interleaving) by adding an error correction code to the data supplied from the memory controller 22, processing for dividing the data, or mixing the divided data. The data subjected to these processes are stored in the ECC memory 25. The ECC processing unit 24 reads data stored in the ECC memory 25 as appropriate, and supplies the read data to the modulation unit 26.

  Further, the ECC processing unit 24 stores the data supplied from the demodulation unit 29 in the ECC memory 25 during reproduction. The ECC processing unit 24 reads out data stored in the ECC memory 25 as appropriate, and performs reverse shuffling processing for returning the shuffled data to the original state and processing for combining the divided data with respect to the read data. Then, error correction processing is executed, and the data subjected to such processing is supplied to the memory controller 22.

  The ECC processing unit 24 includes an ECC encoder 41, an ECC decoder 42, a data dividing unit 43, and a data mixing unit 44.

  The ECC encoder 41 adds an error correction code for error correction to the data stored in the ECC memory 25 for each predetermined user data. The ECC encoder 41 stores the user data to which the error correction code is added in the ECC memory 25.

  Here, user data to which user data and an error correction code are added will be described below in units of ECC blocks. For example, data obtained by adding a predetermined error correction code to user data of one ECC block (one ECC block) will be referred to as 1 ECC block data to which an error correction code is added.

  For example, the ECC encoder 41 reads data of one ECC block from the data stored in the ECC memory 25, adds PO parity and PI parity to the read data, and ECC data with PO parity and PI parity added. Store in the memory 25.

  The data dividing unit 43 reads the data of one ECC block to which the PO parity and the PI parity are added, stored in the ECC memory 25, and divides the read data of the 1 ECC block to which the PO parity and the PI parity are added. The data dividing unit 43 stores the divided data in the ECC memory 25.

  For example, the data division unit 43 reads the data of one ECC block to which the PO parity and the PI parity are added, stored in the ECC memory 25, and reads the data of the 1 ECC block to which the read PO parity and the PI parity are added, The data is divided into four (four divisions) according to the four-layer type optical disc 13 and the data divided into four is stored in the ECC memory 25.

  Further, the data dividing unit 43 executes shuffling processing for mixing the data with the divided data. The data dividing unit 43 stores the shuffled data in the ECC memory 25. For example, the data dividing unit 43 shuffles the divided data so that the unit data of a predetermined data amount among the divided data is exchanged between the data divided from one ECC block. Data is stored in the ECC memory 25.

  The modulation unit 26 performs predetermined modulation such as 8/16 modulation (EFM (Eight to Fourteen Modulation) Plus) on the data supplied from the ECC processing unit 24, and supplies the modulated data to the driver 27.

  The driver 27 supplies a signal corresponding to the modulated data supplied from the modulation unit 26 to the optical pickup 12 and controls the optical pickup 12 to send a signal corresponding to the supplied modulated data to the optical disc 13. Let me record.

  The optical pickup 12 includes a laser diode, a collimator lens, an objective lens, and a photodetector (all not shown). In recording, the optical pickup 12 controls the output of the laser light and modulates supplied from the driver 27. A signal corresponding to the recorded data is recorded on the optical disc 13.

  Also, the optical pickup 12 changes the recording layer for focusing the laser beam irradiated to the optical disc 13 requested by the recording control unit 51 via the servo controller 15 during recording (hereinafter referred to as a focus jump). ) So that a signal can be recorded on a predetermined recording layer. At this time, the request for changing the recording layer to which the laser beam is focused, which is requested by the recording control unit 51, is hereinafter referred to as a recording layer change request.

During reproduction, the optical pickup 12 irradiates the optical disc 13 with laser light and photoelectrically converts the reflected light from the optical disc 13 to generate a signal. The optical pickup 12 supplies the generated signal to the equalizer 28.

  The optical pickup 12 can reproduce a signal from a predetermined recording layer by performing a focus jump based on the recording layer change request supplied from the recording control unit 51 via the servo controller 15 during reproduction. To do.

  Further, the optical pickup 12 supplies a signal obtained by photoelectrically converting reflected light (returned light) from the optical disk 13 to a servo signal generation block (not shown). The servo signal generation block generates a signal indicating a focus error of the laser light emitted from the optical pickup 12 and a signal indicating an error due to tracking deviation, and supplies the generated signals to the servo controller 15.

  An objective lens (not shown) of the optical pickup 12 is moved by an actuator driven by a tracking servo signal for tracking control or a focus servo signal for focus control, and is supplied from a servo controller 15. By being controlled by a servo signal such as a focus servo signal or a tracking servo signal, laser light irradiation by the optical pickup 12 can be performed accurately.

  The servo controller 15 controls the optical pickup 12 (an actuator that moves an objective lens (not shown) thereof) to apply focus servo and tracking servo. Specifically, the servo controller 15 controls the optical pickup 12 to move up and down based on a focus error signal and a tracking error signal supplied from a servo signal generation block (not shown) so as to match the focus. A focus servo signal that is a signal to be transmitted, or a tracking servo signal that is a signal for controlling the laser beam to return to a predetermined region of the pit row when the recording surface of the optical disc 13 is out of the predetermined region with respect to the pit row. The generated focus servo signal or tracking servo signal is supplied to the optical pickup 12.

  A disk table for mounting the optical disk 13 is integrally attached to the spindle motor 14. The spindle motor 14 has a constant linear velocity (CLV (Constant Linear Velocity)) and a constant angular velocity (CAV (Constant Angular Velocity)) based on a spindle motor drive signal for driving itself from the servo controller 15. ) Or the like to rotate the optical disk 13 mounted on the disk table at a predetermined rotational speed.

  The servo controller 15 generates a spindle motor drive signal for driving the spindle motor 14 and supplies the generated spindle motor drive signal to the spindle motor 14 so that the optical disk 13 is driven at a desired rotational speed. Apply the spindle servo to control. When the track of the optical disk 13 meanders at a fixed period, the signal that is the source of the spindle servo is detected by the return light from the optical pickup 12 so that the period becomes a desired period. This is done by controlling the drive pulse of the spindle motor.

  The equalizer 28 applies equalization processing such as amplifying the frequency component of the signal or cutting unnecessary frequency components to the signal supplied from the optical pickup 12. The equalizer 28 supplies the equalized signal to the demodulator 29.

  The demodulator 29 demodulates the equalized signal supplied from the equalizer 28 by a predetermined demodulation method such as demodulation according to 8/16 modulation, and supplies the data obtained by the demodulation to the ECC processor 24. .

  The data mixing unit 44 reads the data of one ECC block stored in the ECC memory 25, and executes the reverse shuffling process for returning the shuffled data to the original state with respect to the read data of the one ECC block. The data mixing unit 44 stores the mixed data in the ECC memory 25.

  For example, the data mixing unit 44 divides the data of one ECC block stored in the ECC memory 25 into four according to the four-layer type optical disc 13, and further shuffles the data divided into four. If the data is stored in the ECC memory 25, reverse shuffling is performed on the data, so that the data divided into four is mixed and stored in the ECC memory 25.

  The ECC decoder 42 executes error correction processing using an error correction code for each ECC block on the data stored in the ECC memory 25 and stores the data after the error correction processing in the ECC memory 25.

  For example, the ECC decoder 42 reads the data of one ECC block from the data stored in the ECC memory 25, executes error correction processing based on the PO parity and the PI parity added to the read data, The data after error correction is stored in the ECC memory 25.

  The memory controller 22 temporarily stores the data supplied from the ECC processing unit 24 in the buffer 23, and supplies the data stored in the buffer 23 to the host computer 2 via the external interface 21 as appropriate. .

  That is, as described above, the buffer 23 temporarily stores data to absorb the difference between the data transfer rate between the host computer 2 and the external interface 21 and the data transfer rate of the optical disc apparatus 1. ing.

  The control unit 16 controls each unit of the optical disc apparatus 1. In addition, the control unit 16 supplies data to the memory 17 or acquires data temporarily stored in the memory 17 as necessary.

  The control unit 16 is configured to include a recording control unit 51 and a reproduction control unit 52.

  The recording control unit 51 controls the optical pickup 12 via the servo controller 15 during recording to record a signal on each layer of the optical disc 13.

  For example, the recording control unit 51 indicates that the data stored in the ECC memory 25 supplied from the signal processing unit 11 is a predetermined ECC block (for example, 100 ECC blocks (100 ECC blocks) data). Based on the signal (hereinafter referred to as status notification), the optical pickup 12 generates a recording layer change request for changing the recording layer on which the laser beam is focused to the Nth layer by focus jump, and the generated recording layer change Information is supplied to the optical pickup 12 via the servo controller 15.

  Here, the recording layer N indicates one of a layer for recording data and a layer for reproducing data in a multilayer disc. For example, the recording layer N is controlled by storing a variable indicating the recording layer N in the memory 17. The unit 16 can acquire information indicating on which layer of the optical disc 13 data is recorded or from which layer of the optical disc 13 data is read as necessary. For example, when the value of the recording layer N stored in the memory 17 is 1 (recording layer N = 1), the optical disc apparatus 1 is the first layer to the fourth layer of the four-layer optical disc 13. Data is recorded (or reproduced) in the layer.

  During reproduction, the reproduction control unit 52 controls the optical pickup 12 via the servo controller 15 to read signals from each layer of the optical disc 13.

  For example, the reproduction control unit 52 requests the recording layer change to cause the optical pickup 12 to change the recording layer on which the laser beam is focused by the focus jump based on the state notification supplied from the signal processing unit 11. And the generated recording layer change request is supplied to the optical pickup 12 via the servo controller 15.

  The control unit 16 can read and execute a control program stored in the (nonvolatile) memory 17 in advance.

  By the way, as described above, generally, when data is recorded on the optical disc 13, an error correction code is added to the data to be recorded and the error is corrected when the data is read from the optical disc 13. This makes it possible to reproduce data reliably. Hereinafter, referring to FIG. 4 and FIG. 5, a unit of data to be processed when the optical disc apparatus 1 of the present invention executes processing for recording data on the optical disc 13 and processing for reproducing data from the optical disc 13. The ECC format in the ECC block (1 ECC block data to which an error correction code is added) will be described.

  FIG. 4 is a diagram for explaining the ECC format of the present invention. In the ECC format in FIG. 4, the description thereof is omitted as appropriate in the same case as in FIG.

  In FIG. 4, 2 bytes of PO parity and 10 bytes of PI parity are vertically (hereinafter referred to as PO series) and lateral (hereinafter referred to as PO series) for user data of 198 rows (bytes) × 172 bytes horizontally. In order to detect an error or correct an error, each byte of the data (referred to as a PI series) is added as parity, which is redundant data added to the original data.

  Also, by combining two error correction codes (PO parity and PI parity) into a product code, error correction can be performed more reliably. Further, for example, a Reed-Solomon code is used as the error correction code, and is added to the user data as parity.

  Here, for user data of 198 rows x 172 bytes horizontally, in the conventional ECC format (Fig. 1), 10 rows of PO parity and 10 bytes of PI parity are in the vertical direction (PO sequence) and horizontal direction. Although added to each byte of (PI sequence), in the ECC format of the present invention (FIG. 4), two rows of PO parity and 10 bytes of PI parity are in the vertical direction (PO sequence) and the horizontal direction. Since it is added to each byte of (PI sequence), the ECC format (FIG. 4) of the present invention has a smaller amount of data of the added error correction code (PO parity and PI parity). .

  In addition, although details will be described later, in the example shown in FIG. 4, the PO parity is set to 2 rows instead of 10 rows. The optical disk 13 has user data of 1 ECC block to which PO parity and PI parity are added. Since the disc is a four-layer type, it is divided into four in the horizontal direction (PI series), the divided data is shuffled (mixed data), and each shuffled data is transferred to the four-layer type optical disc 13. When data is reproduced from the optical disc 13 by sorting and recording the first layer, the second layer, the third layer, and the fourth layer, the number of errors in the PO sequence and PI sequence in the 1 ECC block is averaged. Since there is no bias, it is not necessary to match the highest error rate (4th layer error rate), so the amount of PO parity data added as an error correction code This is because it is possible to reduce.

  Specifically, since the optical disk 13 is a four-layer disk, user data of one ECC block to which PO parity and PI parity are added is divided by three dotted lines in the horizontal direction (PI series) in the figure. The data is divided into four data, and the data divided into four is shuffled and mixed.

  The example shown in FIG. 4 is data of one ECC block that is divided into four and shuffled in this way. In the data of this 1ECC block, when the four data divided by the three dotted lines are respectively data 1, data 2, data 3, and data 4 in order from the top, each of data 1 to data 4 is changed to the optical disk. Each of the first to fourth layers of 13 is distributed and recorded.

  Therefore, in the case of the conventional ECC format (FIG. 1), the ECC format is designed in accordance with the number of errors expected in the layer with the worst recording / reproducing quality (high error rate). For the layer having a low error rate, the ECC format is over-spec, and the recording density of user data has been reduced. However, in the case of the ECC format of the present invention (FIG. 4), an error correction code (for example, redundant data) , PO parity) is reduced, the user data recording density can be increased by increasing the amount of user data.

  FIG. 5 is a graph showing the relationship between the error rate before error correction and the error rate after error correction in the ECC format of FIG. The vertical axis and horizontal axis of the graph in FIG. 5 are the same as those shown in FIG.

  The curve in the figure is a curve showing the relationship between the error rate before error correction and the error rate after error correction in the ECC format of FIG. 4, but the error correction code (PO parity and PI added to the user data). (Parity), which is redundant compared to the curve in FIG. 2 (curve showing the relationship between the error rate before error correction and the error rate after error correction in the conventional ECC format (FIG. 1)). Since there are few error correction codes (PO parity and PI parity) as data, the curve is gentle.

Here, similarly to FIG. 2, the error rate after correcting the error by the error correction code, if you want to less error rate is 1 × 10 ^-9, is 1 × 10 ^-9 of the vertical axis in FIG. The value of the horizontal axis at the intersection of the error rate line and the curve, i.e., an error rate of 0.001, for example, is the limit set before error correction in order to achieve the target error rate after error correction. The recording / reproduction quality limit is an error rate.

Therefore, if the error rate before error correction is 0.001 or less than the recording / reproduction quality limit, the error rate after error correction is 1 × 10 ⁻⁹ or less.

In this case, for example, in the four-layer type optical disc 13, as described above, the error rates of the first layer, the second layer, the third layer, and the fourth layer are 0.00001 as seen from the surface of the disc. , 0.0001, 0.001, and 0.01, the error correction code (ECC) is not designed to match the error rate of 0.01 of the fourth layer, which is the worst (highest) error rate. By designing an error correction code (ECC) in accordance with the error rate of 0.001 of the eye, the error rate after error correction is equal to or lower than the error rate of 1 × 10 ⁻⁹ in all layers.

Although details will be described later, in this case, the fourth error layer, which is the worst error rate, has an error rate of 0.01, so that the error rate does not fall below the recording / reproduction quality limit of 0.001. In this graph, the error rate after error correction is not less than the error rate of 1 × 10 ^-9 , but in practice, the data to be recorded on each layer is mixed and shuffled and recorded. Even if the data was recorded on the fourth layer at the time of recording, when the data shuffled at the time of reproduction is returned to the original state, the number of errors in the PO series and PI series is averaged. By designing an error correction code (ECC) in accordance with the error rate of 0.001 of the eye, the error rate after error correction is equal to or lower than the error rate of 1 × 10 ⁻⁹ in all layers.

  That is, in the case of the conventional ECC format (FIG. 1), the error correction code (ECC) is designed in accordance with the error rate which is 0.01 of the fourth layer which is the worst (highest) error rate. In the case of the ECC format of the present invention (FIG. 4), an error correction code (ECC) can be designed in accordance with an error rate of 0.001 in the third layer, so that redundant data (for example, PO parity) is generated. In addition to the reduction, the recording density of user data can be increased.

  For example, data that does not add PI parity (PI sequence), such as LDC (Long Distance Code), which is used in BD (Blu-ray Disc), can be considered. In this case, data to be recorded on each layer of the optical disk may be shuffled and recorded on each layer of the optical disk 13 without shuffling.

  In other words, 1 ECC block data is allocated to each layer of the optical disc 13 and recorded, the number of PO sequence errors is averaged, and the data allocated to each layer of the optical disc 13 is shuffled to record the number of PI sequence errors. It can be said that is averaged.

  Next, processing (recording or reproduction processing) executed by the optical disc apparatus 1 when the above-described ECC format (FIG. 4) is adopted will be described with reference to FIGS. First, with reference to FIG. 6 to FIG. 9, a process at the time of data recording in which data is recorded on the optical disc 13 among processes executed by the optical disc apparatus 1 will be described.

  First, recording encoding processing will be described with reference to the flowchart of FIG.

  In step S <b> 11, the memory controller 22 stores the data supplied from the host computer 2 through the external interface 21 in the buffer 23.

  In step S12, the memory controller 22 determines whether or not the data stored in the buffer 23 has become a 100 ECC block.

  Here, the reason is that data of 100 ECC blocks (100 ECC blocks) is stored in the buffer 23. As described above, the optical disc apparatus 1 stores data with an error correction code added to the optical disc 13. Although processing is performed in units of ECC blocks, when the ECC format of the present invention (FIG. 4) is adopted, when data is recorded, it is necessary to allocate data to each layer of the optical disc 13 and record the data divided into each layer. In order to record, it is necessary to record between layers.

  Therefore, the optical pickup 12 records between the layers by focus jump. However, since it takes about 0.5 seconds to perform the focus jump, a plurality of ECC blocks are collected together. By recording, the number of focus jumps is reduced. For example, by recording 100 ECC blocks together, the number of focus jumps can be reduced to 1/100. Hereinafter, in this embodiment, description will be made assuming that processing is performed in units of 100 ECC blocks.

  As described above, when recording data by performing a focus jump, the optical pickup 12 records the ECC blocks after collecting them in a predetermined unit. Therefore, the number of focus jumps can be reduced, and the user data recording rate can be reduced. It is possible to record without dropping.

  In step S12, when the data stored in the buffer 23 does not become a 100 ECC block, that is, when the data is less than 100 ECC block, the process ends.

  That is, the recording encoding process of FIG. 6 ends in the process of step S12 until the data stored in the buffer 23 becomes 100 ECC blocks. Therefore, by repeating the processes of step S11 and step S12, the data is stored in the optical disk 13. In this case, since the host computer 2 sequentially supplies data to the buffer 23 via the external interface 21 and the memory controller 22, the buffer 23 stores 100 ECC block data.

  On the other hand, when the data stored in the buffer 23 becomes a 100 ECC block in step S12, the process proceeds to step S13, and the memory controller 22 reads the data of the 100 ECC block stored in the buffer 23 and reads the read 100 ECC block. Are transferred to the ECC processing unit 24.

  In step S <b> 14, the ECC processing unit 24 stores the 100 ECC block data transferred from the memory controller 22 in the ECC memory 25.

  In step S15, the ECC encoder 41 reads data of one ECC block among the data of 100 ECC blocks stored in the ECC memory 25, and adds PO parity to the read data of one ECC block.

  For example, in step S15, the ECC encoder 41 reads and reads one ECC block of user data (the data of 198 rows × 172 bytes in FIG. 4) among the user data of 100 ECC blocks stored in the ECC memory 25. In addition, two rows of PO parity are added to 198 rows of data in the vertical direction (PO sequence) of user data of one ECC block. Then, the ECC encoder 41 repeats the process of adding two rows of PO parity to the read user data of one ECC block 172 times (one byte becomes one time and repeats for 172 bytes).

  That is, by the process of step S15, data in which only the PO parity is added to the user data (data of 200 rows x 172 data excluding the PI parity in FIG. 4) is generated.

  In step S16, the ECC encoder 41 determines whether or not the process of adding the PO parity to the data of one ECC block has been looped 100 times (repeated 100 times).

  If it is determined in step S16 that the process of adding the PO parity to the data of one ECC block is not looped 100 times, the process returns to step S15 and the above-described process is repeated. That is, by repeating the processing of step S15 and step S16, PO parity is added to each ECC block in the data of 100 ECC blocks stored in the ECC memory 25.

  On the other hand, if it is determined in step S16 that the process of adding the PO parity to the data of one ECC block has been looped 100 times, the PO parity is added to the data of the 100 ECC block stored in the ECC memory 25. Therefore, the process proceeds to step S17, and the ECC encoder 41 reads out data of one ECC block among the data of 100 ECC blocks stored in the ECC memory 25, and adds PI parity to the read data.

  For example, in step S17, the ECC encoder 41, among the data of 100 ECC blocks stored in the ECC memory 25, data of 1 ECC block to which PO parity is added (vertical 200 rows excluding PI parity in FIG. 4 × 10-byte PI parity is added in the horizontal direction (PI sequence) to the data of one ECC block to which the read PO parity of the two rows is added.

  That is, by the processing in step S15 and step S17, as shown in the example shown in FIG. 4, the PO parity which is 2 rows and the PI parity which is 10 bytes are vertically (PO sequence) and horizontal with respect to the user data. It is added to each byte of direction (PI series).

  In step S18, the ECC encoder 41 determines whether or not the process of adding the PI parity to the data of one ECC block has been looped 100 times (repeated 100 times).

  If it is determined in step S18 that the process of adding the PI parity to the data of one ECC block is not looped 100 times, the process returns to step S17 and the above-described process is repeated. That is, by repeating the processing of step S17 and step S18, PO parity and PI parity are added to each ECC block in the data of 100 ECC blocks stored in the ECC memory 25.

  On the other hand, if it is determined in step S18 that the process of adding the PI parity to the data of one ECC block has looped 100 times, the PO parity and the PI parity are added to the data of the 100 ECC block stored in the ECC memory 25. Therefore, the process proceeds to step S19, and the data dividing unit 43 reads out the data of one ECC block from the data of the 100 ECC block to which the PO parity and the PI parity are added and stored in the ECC memory 25, and reads the read 1 ECC. Data division processing for dividing the block data into a predetermined number is executed.

  For example, in step S19, the data dividing unit 43 reads data of one ECC block (200 vertical rows × 182 horizontal rows in FIG. 4) stored in the ECC memory 25 to which the PO parity and the PI parity are added, The read 1-ECC block data to which the PO parity and PI parity are added is divided into four in accordance with the four-layer optical disk 13 (because the data is recorded in the first to fourth layers) (see FIG. (4 data divided by 3 dotted lines in 4 horizontal directions (PI series)) Data division processing is executed.

  When the optical disk 13 is loaded, the number of layers of the optical disk 13 is acquired, and the data may be divided based on the acquired number of layers of the optical disk 13.

  In step S20, the data dividing unit 43 performs a shuffling process for mixing the data divided by the process of step S19.

  Here, the details of the shuffling process will be described with reference to FIGS. First, shuffling processing in the ECC format of FIG. 4 will be described with reference to FIG. In the ECC format in FIG. 7, the description is omitted as appropriate when it is the same as that in FIG. 4.

  In FIG. 7, as in FIG. 4, two rows of PO parity and 10 bytes of PI parity are added to user data of length 198 rows × width 172 bytes.

  As described above, in the example shown in FIG. 7, the PO parity is not 10 rows but 2 rows because user data of 1 ECC block to which PO parity and PI parity are added is stored on the optical disc 13 in a four-layer system. Disc (because the data is recorded in the first layer to the fourth layer), it is divided into four in the horizontal direction (PI series), and the divided data is shuffled (mixed data), The number of errors in the PO sequence and PI sequence in one ECC block when data is reproduced from the optical disc 13 by recording each shuffled data on the first to fourth layers of the four-layer optical disc 13 Is averaged (no bias), so it is not necessary to match the highest error rate (the error rate of the fourth layer). This is because it is possible to reduce the data amount of PO parity.

  Specifically, in the example shown in FIG. 7, the data of 200 rows in length and 182 bytes in width with PO parity and PI parity added is divided into four in the horizontal direction (PI series) by three dotted lines in the figure. In the case of dividing the four divided data into data 1, data 2, data 3, and data 4 in order from the top, the data 1 to data 4 are shuffled and the shuffled data (hereinafter referred to as shuffling data). Are allocated to the first layer to the fourth layer of the four-layer type optical disc 13 for recording.

  In addition, as a shuffling method, for example, in the example shown in FIG. 7, data in the first row of data 1 (data indicated by a square with a left-downward oblique line in FIG. 7), data in the first row of data 2 Data (data indicated by a square with a downward slanted diagonal line in FIG. 7), data in the first row of data 3 (data indicated by a square with a diagonal grid in FIG. 7), and the first row of data 4 (Data indicated by squares with vertical and horizontal grids in FIG. 7) are extracted. The extracted data is shuffled and then recorded on each layer of the optical disc 13.

  FIG. 8 is a diagram for explaining shuffling processing. In the example shown in FIG. 8, the upper side of FIG. 8 shows the data before shuffling, and the lower side of FIG. 8 shows the data after shuffling.

  Here, for example, in the example shown in FIG. 7, when the data of the first row is extracted for each of the data 1 to data 4, the data before shuffling on the upper side in FIG. Data in the first row (data indicated by a square with a left-down diagonal line in FIG. 7), data in the first row in data 2 (data indicated by a square in a right-down diagonal line in FIG. 7), data 3 The data in the first row (data indicated by a square with a diagonal grid in FIG. 7) and the data in the first row in data 4 (data indicated by a square with a vertical and horizontal grid in FIG. 7).

  For easy understanding, for example, the data extracted from each layer in the data before and after shuffling will be described in units of 1 row (byte) × 1 byte data. That is, in the data before shuffling on the upper side of FIG. 8, for each of the extracted data of each layer, 1 row × 1 byte data is arranged in 4 rows (bytes) vertically and 182 columns (bytes) horizontally. It will be out. For example, the data surrounded by the thick line on the upper side in FIG. 8 is the data of one vertical row × one horizontal byte.

  In the following description, the data in the first row in the upper data 1 in FIG. 8 (the data indicated by the square with a left-down diagonal line in FIG. 7) is respectively displayed from the left side in the figure from the vertical 1 row × horizontal. The data will be described in the order of 1 byte, 1 column data, 1 row, 2 column data, 1 row, 3 column data,. Similarly, the data in the first row in the upper data 2 in FIG. 8 (data indicated by a square with a downward slanted diagonal line in FIG. 7) is respectively in units of 1 vertical row × 1 horizontal byte from the left side in the drawing. Will be described in the order of 2 rows and 1 column data, 2 rows and 2 columns data, 2 rows and 3 columns data,..., 2 rows and 182 columns data.

  Further, similarly, the data in the first row in the data 3 on the upper side in FIG. 8 (data indicated by squares with diagonal lattices in FIG. 7) are respectively expressed in units of 1 row × 1 byte horizontally from the left side in the drawing. The data will be described in the order of 3rd row, 1st column data, 3rd row, 2nd column data, 3rd row, 3rd column data,. Similarly, the data in the first row of the data 4 on the upper side of FIG. 8 (data indicated by squares with vertical and horizontal grids in FIG. 7) are respectively expressed in units of vertical 1 row × horizontal 1 byte from the left side in the figure. The data will be described in the order of 4 rows and 1 columns data, 4 rows and 2 columns data, 4 rows and 3 columns data,..., 4 rows and 182 columns data.

  Data obtained by shuffling the data in the first row (that is, the upper side in FIG. 8) in the data 1 to data 4 in FIG. 7 becomes the data after the shuffling in the lower side in FIG.

  In the example shown in FIG. 8, when the four shuffled data on the lower side are the shuffling data 1, the shuffling data 2, the shuffling data 3, and the shuffling data 4 in order from the top, the shuffling data 1 to the shuffling data 4 Each of them is allocated to the first layer to the fourth layer of the four-layer type optical disc 13 for recording.

  For example, the shuffling data 1 recorded in the first layer of the four-layer optical disc 13 includes data in the first row and the first column, data in the second row and the second column, data in the third row and the third column, and 4 rows and 4 columns. The eye data, the data in the first row and the fifth column, and so on are stored. Similarly, the shuffling data 2 recorded in the second layer includes data in the second row and the first column, data in the third row and the second column, data in the fourth row and the third column, data in the first row and the fourth column, Data in the second row and the fifth column,... Are stored.

  Further, similarly, the shuffling data 3 recorded in the third layer includes the data in the third row and the first column, the data in the second row and the second column, the data in the first row and the third column, the data in the second row and the fourth column, The data of the third row and the fifth column,... Are stored. Similarly, the shuffling data 4 recorded in the fourth layer includes 4th row, 1st column data, 1st row, 2nd column data, 2nd row, 3rd column data, 3rd row, 4th column data, The data of the 4th row and the 5th column, and so on are stored.

  The data in the second row in data 1 to data 4 in FIG. 7, the data in the third row in data 1 to data 4 in FIG. 7, the data in the fourth row in data 1 to data 4 in FIG. 7 is shuffled in the same manner as the data in the first row in the data 1 to data 4 in FIG. 7, and the shuffled data is distributed to the first layer to the fourth layer of the four-layer optical disc 13. To be recorded.

  In this way, the first layer data with the lowest error rate (data in the first row and the first column), the fourth layer data with the highest error rate (the data in the fourth row and the fourth column), and the first layer And shuffling by mixing the data of the second layer (data of the second row and the second column) and the data of the third layer (the data of the third row and the third column), which are error rates between the first layer and the fourth layer, Since the shuffled data is distributed and recorded on each of the first to fourth layers of the optical disc 13, the number of errors in the first to fourth layers is averaged (no bias is eliminated).

  Further, even when a large number of errors occur in a specific layer, the error blocks generated in one ECC block are not biased by the reverse shuffling process described later, and errors are arranged on average. .

  Therefore, since the number of errors in each layer of the optical disc 13 is averaged (no bias), it is not necessary to match the error rate of the highest fourth layer, so an error correction code (for example, PO parity) added to user data ) Data amount can be reduced.

  Returning to the flowchart of FIG. 6, in step S <b> 21, the data dividing unit 43 determines whether or not the shuffling process is looped 100 times (repeated 100 times).

  If it is determined in step S21 that the shuffling process is not looped 100 times, the process returns to step S19 and the above-described process is repeated. That is, by repeating the processing from step S19 to step S21, the data of 100 ECC blocks stored in the ECC memory 25 is divided and shuffled for each ECC block.

  On the other hand, if it is determined in step S21 that the shuffling process has been looped 100 times, the process proceeds to step S22, where the data dividing unit 43 stores the shuffled 100 ECC block data in the ECC memory 25, and then proceeds to step S11. Return and repeat the process described above.

  That is, at this time, the data of the 100 ECC block stored in the ECC memory 25 is the data to which the PO parity and the PI parity are added and further shuffled. Hereinafter, 100 ECC block data to which PO parity and PI parity are added and shuffled and stored in the ECC memory 25 will be referred to as recording data. For example, the ECC memory 25 stores shuffling data 1 to shuffling data 4 as recording data.

  In this way, by adopting the ECC format based on the error rate between the high error rate layer and the low error rate layer, the user data to which the error correction code is added is shuffled, and each of the shuffled data is transferred to the optical disc 13. By allocating corresponding to each layer, it is possible to reduce the data amount of the error correction code added to the user data and to prevent the user data recording density from being lowered.

  Next, disk recording processing will be described with reference to the flowchart of FIG.

  In step S <b> 31, the signal processing unit 11 determines whether or not 100 ECC block recording data is stored in the ECC memory 25.

  Further, when the recording data of a predetermined ECC block (for example, 100 ECC block) is stored in the ECC memory 25, the signal processing unit 11 confirms that the recording data stored in the ECC memory 25 has become a predetermined ECC block. The status notification shown is generated, and the generated status notification is supplied to the recording control unit 51.

  In step S31, when it is determined that the recording data of the 100 ECC block is not stored in the ECC memory 25, that is, when it is less than 100 ECC block, the process ends.

  That is, the disk recording process of FIG. 9 ends in the process of step S31 until the shuffling data stored in the ECC memory 25 becomes 100 ECC blocks. Therefore, the process of step S31 is repeated simultaneously (in parallel). ) Since the recording data is sequentially stored in the ECC memory 25 by the above-described recording encoding process (FIG. 6), 100 ECC block shuffling data is stored in the ECC memory 25.

  On the other hand, if it is determined in step S31 that the recording data of the 100 ECC block is stored in the ECC memory 25, the process proceeds to step S32, and the recording control unit 51, based on the status notification supplied from the signal processing unit 11, As an initial value of the recording layer N stored in the memory 17, the recording layer N = 1 is set.

  Further, since the recording control unit 51 has the recording layer N = 1 based on the state notification supplied from the signal processing unit 11, the optical pickup 12 sets a recording layer for focusing the laser beam by the focus jump. A recording layer change request to be changed to the first layer is generated, and the generated recording layer change request is supplied to the optical pickup 12 via the servo controller 15.

  In step S <b> 33, the optical pickup 12 seeks to a recording start address that is an address for starting recording of recording data on the optical disc 13. Further, the optical pickup 12 changes the recording layer on which the laser beam is focused to the first layer by focus jump based on the recording layer change request supplied from the recording control unit 51 via the servo controller 15. To do.

  In step S <b> 34, the ECC processing unit 24 reads the Nth layer recording data stored in the ECC memory 25 and supplies the read Nth layer recording data to the modulation unit 26. For example, in step S34, when the recording layer N = 1, the ECC processing unit 24 shuffles the first layer of the optical disc 13 stored in the ECC memory 25 as the recording data (for example, the first layer in FIG. 4). Data 1) to be recorded in the eye is read, and the read shuffling data is supplied to the modulation unit 26.

  In step S <b> 35, the modulation unit 26 performs predetermined modulation such as 8/16 modulation (EFM Plus) on the Nth layer recording data supplied from the ECC processing unit 24. For example, in step S35, when the recording layer N = 1, the modulation unit 26 applies predetermined modulation such as 8/16 modulation (EFM Plus) to the first layer of shuffling data supplied from the ECC processing unit 24. Apply.

  In step S36, the modulation unit 26 adds a sync pattern to the signal corresponding to the modulated recording data of the Nth layer, and sends a signal corresponding to the recording data of the Nth layer to which the sync pattern is added to the driver 27. Supply. For example, in step S36, when the recording layer N = 1, the modulation unit 26 adds a sync pattern to the signal corresponding to the modulated shuffling data of the first layer, and the first layer to which the sync pattern is added. A signal corresponding to the shuffling data is supplied to the driver 27.

  As will be described in detail later, the sync pattern is data added to divide data into a certain unit during data reproduction.

  In step S <b> 37, the optical pickup 12 controls the output of the laser light, and sends a signal corresponding to the Nth layer recording data to which the sync pattern is added, supplied from the driver 27, to the Nth layer of the optical disc 13. Let me record. For example, in step S 37, the optical pickup 12 controls the output of the laser beam, and sends a signal corresponding to the first layer of shuffling data to which the sync pattern is added, supplied from the driver 27, to 1 of the optical disc 13. Record in layer.

  In step S38, the recording control unit 51 determines whether or not 100-ECC block recording has been performed on the N-th recording data. For example, in step S38, the recording control unit 51 determines whether or not 100 ECC blocks of the first layer of shuffling data have been recorded.

  If it is determined in step S38 that the recording data of the Nth layer is not recorded in 100 ECC blocks, the process returns to step S34 and the above-described processing is repeated.

  That is, by repeating the processing from step S34 to step S38, the first layer of shuffling data (N) stored in the ECC memory 25 and stored in the ECC memory 25 by the recording encoding processing described in the flowchart of FIG. The shuffling data of the layer) is recorded on the first layer (Nth layer) of the optical disc 13.

  In this way, instead of changing the layer for recording shuffling data for each ECC block, the number of focus jumps described above can be reduced by collectively recording the shuffling data of 100 ECC blocks, so it is shorter. Shuffling data can be recorded on the optical disc 13 in time. For example, by recording 100 ECC blocks together, the number of focus jumps can be reduced to 1/100.

  On the other hand, if it is determined in step S38 that the recording data of the Nth layer has been recorded by 100 ECC blocks, the process proceeds to step S39, and the recording control unit 51 records the recording layer N = 4, that is, the recording data is recorded in the fourth layer. It is determined whether or not it has been done.

  If it is determined in step S39 that the recording data is not recorded in the fourth layer, the shuffling data still stored in the ECC memory 25 remains, so the process proceeds to step S40, where the recording control unit 51 Based on the recording change notification supplied from the processing unit 11, N = N + 1, that is, the recording layer N stored in the memory 17 is incremented by one. For example, in step S40, when the recording layer N = 1, the recording control unit 51 increments the recording layer N stored in the memory 17 by 1 and sets the recording layer N = 2.

  At this time, since the recording layer N = 2 on the basis of the recording change notification supplied from the signal processing unit 11, the recording control unit 51 causes the optical pickup 12 to focus the laser beam by the focus jump. A recording layer change request for changing the recording layer to be matched to the second layer is generated, and the generated recording layer change request is supplied to the optical pickup 12 via the servo controller 15.

  In step S41, the optical pickup 12 sets the layer on which the laser beam is focused to the Nth layer by focus jump based on the recording layer change request supplied from the recording control unit 51 via the servo controller 15. Then, the signal corresponding to the recording data can be recorded in the Nth layer of the optical disc 13, and the processing returns to step S33 and the above-described processing is repeated.

  For example, in step S41, the optical pickup 12 includes two layers for focusing the laser beam by focus jump based on the recording layer change request supplied from the recording control unit 51 via the servo controller 15. The eye is changed so that a signal corresponding to the recording data can be recorded on the second layer of the optical disc 13.

  In other words, by repeating the processing from step S33 to step S38, the second layer of shuffling data (for example, data 2 recorded in the second layer in FIG. 4) stored in the ECC memory 25 corresponds to the second layer. The signal is recorded on the second layer of the optical disc 13.

  In step S39, since the recording data is not recorded on the fourth layer, the process proceeds to step S40, and the recording control unit 51 stores the recording change notification in the memory 17 based on the recording change notification supplied from the signal processing unit 11. The recorded recording layer N = 2 is incremented by 1 to obtain a recording layer N = 3.

  At this time, since the recording layer N = 3 based on the recording change notification supplied from the signal processing unit 11, the recording control unit 51 performs recording in which the optical pickup 12 focuses the laser beam by a focus jump. A recording layer change request for changing the layer to the third layer is generated, and the generated recording layer change request is supplied to the optical pickup 12 via the servo controller 15.

  In step S41, the optical pickup 12 sets the third layer to which the laser beam is focused by focus jump based on the recording layer change request supplied from the recording control unit 51 via the servo controller 15. Then, the signal corresponding to the recording data can be recorded on the third layer of the optical disc 13, and the processing returns to step S33 and the above-described processing is repeated.

  That is, by repeating the processing from step S33 to step S38, the third layer of shuffling data (for example, data 3 recorded in the third layer in FIG. 4) stored in the ECC memory 25 corresponds to the third layer. The signal is recorded on the third layer of the optical disc 13.

  In step S39, since the recording data is not recorded in the fourth layer, the process proceeds to step S40, and the recording control unit 51 is stored in the memory 17 based on the recording change notification supplied from the signal processing unit 11. The recording layer N = 3 is incremented by 1 to obtain the recording layer N = 4.

  At this time, since the recording layer N = 4 based on the recording change notification supplied from the signal processing unit 11, the recording control unit 51 performs recording in which the optical pickup 12 focuses the laser beam by focus jump. A recording layer change request for changing the layer to the fourth layer is generated, and the generated recording layer change request is supplied to the optical pickup 12 via the servo controller 15.

  In step S41, the optical pickup 12 sets the fourth layer to which the laser beam is focused by focus jump based on the recording layer change request supplied from the recording control unit 51 via the servo controller 15. Then, the signal corresponding to the recording data can be recorded on the fourth layer of the optical disc 13, and the processing returns to step S33 and the above-described processing is repeated.

  That is, by repeating the processing from step S33 to step S38, the fourth layer of shuffling data (for example, data 4 recorded in the fourth layer in FIG. 4) stored in the ECC memory 25 corresponds to the fourth layer. The signal is recorded on the fourth layer of the optical disc 13.

  In step S39, the signal corresponding to the recording data is recorded in the fourth layer, so that all the 100 ECC block shuffling data stored in the ECC memory 25 has been recorded on the optical disc 13. Return and repeat the process described above.

  Thus, by recording each signal corresponding to the shuffled data in correspondence with each layer of the optical disc 13, the amount of error correction code added to the user data can be reduced, and the user data It is possible to prevent a decrease in recording density.

  Also, by repeating the recording encoding process (FIG. 6), predetermined processes (PO parity and PI parity adding process, data dividing process, shuffling process) are executed on 100 ECC block data. Thus, the shuffling data of 100 ECC blocks is sequentially stored in the ECC memory 25, and the shuffling data of 100 ECC blocks stored in the ECC memory 25 is sequentially recorded on each layer of the optical disc 13 by the disk recording process (FIG. 9). it can.

  That is, by repeating the recording encoding process (FIG. 6) and the disk recording process (FIG. 9) simultaneously (in parallel), the data supplied from the host computer 2 is stored in the optical disk 13 in units of 100 ECC blocks. Recording is performed sequentially on each layer.

  Therefore, the optical disc apparatus 1 can record all data supplied from the host computer 2 on the optical disc 13.

  Next, with reference to FIG. 10 and FIG. 11, a process at the time of data reproduction in which data recorded on the optical disk 13 is reproduced among the processes executed by the optical disc apparatus 1 will be described.

  Next, disk playback processing will be described with reference to the flowchart of FIG.

  In step S <b> 71, the signal processing unit 11 determines whether there is a reproduction data storage area in the ECC memory 25.

  In addition, when the ECC memory 25 has a reproduction data storage area of a predetermined ECC block (for example, 100 ECC block), the signal processing unit 11 notifies the ECC memory 25 that there is a reproduction data storage area. And the generated status notification is supplied to the recording control unit 51.

  If it is determined in step S71 that there is no storage area for reproduction data in the ECC memory 25, the reproduction data cannot be stored in the ECC memory 25, and the process ends.

  That is, when there is no area for storing the reproduction data in the ECC memory 25, the ECC memory 25 has already stored the reproduction data. Therefore, the disk reproduction process of FIG. 10 is performed simultaneously by repeating the process of step S71. Reproduction data stored in the ECC memory 25 is reduced by a reproduction decoding process (FIG. 11) to be described later (in parallel), so that an area for storing reproduction data can be secured in the ECC memory 25. become.

  In step S71, when it is determined that there is a reproduction data storage area in the ECC memory 25, the process proceeds to step S72, and the reproduction control unit 52 performs memory 17 based on the state notification supplied from the signal processing unit 11. As an initial value of the recording layer N stored in the recording layer N, the recording layer N = 1 is set.

  In addition, since the reproduction control unit 52 has the recording layer N = 1 based on the state notification supplied from the signal processing unit 11, the optical pickup 12 sets a recording layer for focusing the laser beam by the focus jump. A recording layer change request to be changed to the first layer is generated, and the generated recording layer change request is supplied to the optical pickup 12 via the servo controller 15.

  In step S73, the optical pickup 12 seeks to a reproduction start address that is an address for starting reproduction of the reproduction data recorded on the optical disc 13. Further, the optical pickup 12 changes the recording layer on which the laser beam is focused to the first layer by focus jump based on the recording layer change request supplied from the reproduction control unit 52 via the servo controller 15. To do.

  In step S74, the optical pickup 12 irradiates the optical disk 13 with laser light, photoelectrically converts the reflected light from the Nth layer of the optical disk 13 to generate a signal corresponding to the reproduction data, and reproduces the generated Nth layer. A signal corresponding to the data is supplied to the equalizer 28. For example, in step S74, the optical pickup 12 irradiates the optical disc 13 with laser light, photoelectrically converts the reflected light from the first layer of the optical disc 13, and shuffles the first layer (for example, the first layer in FIG. 4). A signal corresponding to the data 1) to be recorded is generated, and a signal corresponding to the generated first-layer shuffling data is supplied to the equalizer 28.

  In step S75, the equalizer 28 amplifies the frequency component of the signal corresponding to the reproduction data supplied from the optical pickup 12 or cuts unnecessary frequency components. The signal corresponding to the equalized reproduction data of the Nth layer is supplied to the demodulation unit 29. For example, in step S75, the equalizer 28 amplifies the signal corresponding to the first layer of shuffling data supplied from the optical pickup 12 or amplifies the frequency component of the signal corresponding to the first layer of shuffling data. The signal corresponding to the shuffling data of the first layer that is equalized by applying an equalization process such as cutting a frequency component is supplied to the demodulator 29.

  In step S76, the demodulator 29 extracts, from the signal corresponding to the equalized reproduction data supplied from the equalizer 28, a sync pattern added for the purpose of dividing the reproduction data for each row of the ECC block, and extracts the sync pattern. Based on the sync pattern, the signal corresponding to the equalized Nth layer reproduction data is divided for each row of the ECC block. For example, in step S76, the demodulator 29 extracts a sync pattern from the signal corresponding to the first layer of shuffling data supplied from the equalizer 28, and equalizes the first layer based on the extracted sync pattern. The signal corresponding to the shuffling data is divided for each line of the ECC block.

  In step S77, the demodulator 29 demodulates the signal corresponding to the reproduction data of the Nth layer divided by the sync pattern by a predetermined demodulation method such as demodulation according to 8/16 modulation, and is obtained by demodulation. The reproduction data of the Nth layer is supplied to the ECC processing unit 24. For example, in step S77, the demodulator 29 demodulates the signal corresponding to the first layer of shuffling data divided by the sync pattern by a predetermined demodulation method such as demodulation corresponding to 8/16 modulation, and obtains it by demodulation. The first layer of shuffling data is supplied to the ECC processing unit 24.

  In step S <b> 78, the ECC processing unit 24 stores the Nth layer reproduction data supplied from the demodulation unit 29 in the ECC memory 25. For example, in step S <b> 78, the ECC processing unit 24 stores the first layer of shuffling data supplied from the demodulation unit 29 in the ECC memory 25.

  In step S79, the reproduction control unit 52 determines whether or not the Nth layer reproduction data has been stored in 100 ECC blocks. For example, in step S79, the playback control unit 52 determines whether or not 100 ECC blocks of the first layer of shuffling data are stored.

  Here, as in the recording, the optical pickup 12 reproduces data across the layers by the focus jump at the time of reproduction. For the focus jump, for example, about 0.5 Since it takes 2 seconds, the number of focus jumps is reduced by reading a plurality of ECC blocks together. For example, by reading 100 ECC blocks in one focus jump, the number of focus jumps can be reduced to 1/100.

  In this way, when reading data by performing a focus jump, the ECC block is read in a predetermined unit, so the number of focus jumps can be reduced and playback can be performed without reducing the playback rate of user data. Become.

  If it is determined in step S79 that the reproduction data of the Nth layer is not stored in 100 ECC blocks, the process returns to step S74 and the above-described processing is repeated.

  That is, by repeating the processing from step S74 to step S79, the reproduction data of the Nth layer of 100 ECC blocks is stored in the ECC memory 25. For example, by repeating the processing from step S74 to step S79, the first layer of shuffling data of 100 ECC blocks is stored in the ECC memory 25.

  On the other hand, if it is determined in step S79 that the reproduction data of the Nth layer has been stored in 100 ECC blocks, the process proceeds to step S80, and the reproduction control unit 52 reproduces the recording layer N = 4, that is, the reproduction data is reproduced from the fourth layer. It is determined whether or not it has been done.

  If it is determined in step S80 that the reproduction data has not been reproduced from the fourth layer, the process proceeds to step S81, and the reproduction control unit 52 performs N = based on the recording change notification supplied from the signal processing unit 11. N + 1, that is, 1 is incremented to the recording layer N stored in the memory 17. For example, in step S81, when the recording layer N = 1, the reproduction control unit 52 increments the recording layer N stored in the memory 17 by 1 and sets the recording layer N = 2.

  At this time, the reproduction control unit 52 has the recording layer N = 2 based on the recording change notification supplied from the signal processing unit 11, so that the optical pickup 12 focuses the laser beam by the focus jump. A recording layer change request for changing the recording layer to be matched to the second layer is generated, and the generated recording layer change request is supplied to the optical pickup 12 via the servo controller 15.

  In step S82, the optical pickup 12 sets the layer on which the laser light is focused by the focus jump to the Nth layer based on the recording layer change request supplied from the reproduction control unit 52 via the servo controller 15. Then, the signal corresponding to the reproduction data can be reproduced from the Nth layer of the optical disc 13, and the process returns to step S72 to repeat the above-described process.

  For example, in step S82, the optical pickup 12 has two layers for focusing the laser beam by focus jump based on the recording layer change request supplied from the reproduction control unit 52 via the servo controller 15. The eye is changed so that a signal corresponding to the reproduction data can be reproduced from the second layer of the optical disc 13.

  That is, by repeating the processing from step S73 to step S79, the second layer of shuffling data (for example, data 2 recorded in the second layer in FIG. 4) of the 100 ECC block reproduced from the second layer of the optical disc 13 is obtained. It is stored in the ECC memory 25.

  In step S80, since the reproduction data has not been reproduced from the fourth layer, the process proceeds to step S81, and the reproduction control unit 52 stores in the memory 17 based on the recording change notification supplied from the signal processing unit 11. The stored recording layer N = 2 is incremented by 1 so that the recording layer N = 3.

  At this time, since the recording layer N = 3 based on the recording change notification supplied from the signal processing unit 11, the reproduction control unit 52 performs recording in which the optical pickup 12 focuses the laser beam by focus jump. A recording layer change request for changing the layer to the third layer is generated, and the generated recording layer change request is supplied to the optical pickup 12 via the servo controller 15.

  In step S82, the optical pickup 12 sets the third layer to which the laser beam is focused by focus jump based on the recording layer change request supplied from the reproduction control unit 52 via the servo controller 15. Then, the signal corresponding to the reproduction data can be reproduced from the third layer of the optical disc 13, and the process returns to step S73 to repeat the above-described process.

  That is, by repeating the processing from step S73 to step S79, the third layer of shuffling data of 100 ECC blocks reproduced from the third layer of the optical disc 13 (for example, data 3 recorded in the third layer in FIG. 4) It is stored in the ECC memory 25.

  In step S80, the reproduction data has not been reproduced from the fourth layer, so the process proceeds to step S81, and the reproduction control unit 52 is stored in the memory 17 based on the recording change notification supplied from the signal processing unit 11. The recording layer N = 3 is incremented by 1 to obtain the recording layer N = 4.

  At this time, the reproduction control unit 52 records the recording layer N = 4 based on the recording change notification supplied from the signal processing unit 11, so that the optical pickup 12 records the laser beam to be focused by the focus jump. A recording layer change request for changing the layer to the fourth layer is generated, and the generated recording layer change request is supplied to the optical pickup 12 via the servo controller 15.

  In step S82, the optical pickup 12 sets the fourth layer to which the laser beam is focused by focus jump based on the recording layer change request supplied from the reproduction control unit 52 via the servo controller 15. Then, the signal corresponding to the reproduction data can be reproduced from the fourth layer of the optical disc 13, and the process returns to step S73 to repeat the above-described process.

  That is, by repeating the processing from step S73 to step S79, the fourth layer of shuffling data (for example, data 4 recorded in the fourth layer in FIG. 4) of the 100 ECC block reproduced from the third layer of the optical disc 13 is obtained. It is stored in the ECC memory 25.

  In step S80, since the reproduction data is reproduced from the fourth layer, 100 ECC block shuffling data reproduced from each of the first to fourth layers of the optical disc 13 is stored in the ECC memory 25. Returning to step S71, the above-described processing is repeated.

  That is, by executing the disk reproduction process, the ECC memory 25 stores 100 ECC block shuffling data reproduced from each of the first to fourth layers of the optical disk 13.

  In this way, by reproducing each shuffled data recorded on each layer of the optical disc 13 from each layer of the optical disc 13, the number of errors in the shuffled data reproduced from each layer is averaged (biased). Therefore, when designing the ECC format of the ECC block, it is possible to adopt an ECC format based on an error rate between a layer having a bad error rate and a layer having a good error rate instead of the layer having the worst error rate. As a result, it is possible to reduce the data amount of the error correction code added to the user data and to prevent the recording density of the user data from being lowered.

  Next, playback decoding processing will be described with reference to the flowchart of FIG.

  In step S <b> 91, the signal processing unit 11 determines whether or not 100 ECC block reproduction data has been stored in the ECC memory 25.

  Further, when the reproduction data of a predetermined ECC block (for example, 100 ECC block) is stored in the ECC memory 25, the signal processing unit 11 confirms that the reproduction data stored in the ECC memory 25 has become the predetermined ECC block. The status notification shown is generated, and the generated status notification is supplied to the data mixing unit 44.

  If it is determined in step S91 that the reproduction data of the 100 ECC block is not stored in the ECC memory 25, that is, if it is less than 100 ECC block, the process ends.

  That is, the reproduction decoding process of FIG. 11 ends in the process of step S91 until the reproduction data stored in the ECC memory 25 becomes 100 ECC blocks. Therefore, the process of step S91 is repeated simultaneously (in parallel). ) Since the reproduction data is sequentially stored in the ECC memory 25 by the above-described disk reproduction processing (FIG. 10), the reproduction data of 100 ECC blocks is stored in the ECC memory 25.

  On the other hand, when it is determined that the reproduction data of 100 ECC blocks is stored in the ECC memory 25, the process proceeds to step S92, and the data mixing unit 44 stores the data in the ECC memory 25 based on the state notification supplied from the signal processing unit 11. Among the reproduced data of 100 ECC blocks, one ECC block is read, and reverse shuffling processing is executed on the read reproduced data of one ECC block.

  Here, the reverse shuffling process is the reverse process of the shuffling process executed by the data dividing unit 43 in the process of step S20 of FIG. Specifically, for example, this is processing for rearranging the shuffled data on the lower side of FIG. 8 to the data on the upper side of FIG.

  Therefore, even if a large number of errors occur in a specific layer due to the reverse shuffling process, the error blocks generated in one ECC block are not biased, and errors are arranged on average.

  In step S93, the data mixing unit 44 performs data composition processing on the reproduction data of each layer rearranged in the state before shuffling by the reverse shuffling processing to obtain data of one ECC block.

  For example, in step S93, the data mixing unit 44 performs shuffling data (for example, first to fourth layers) reproduced from each layer (first layer to fourth layer) of the optical disc 13 and stored in the ECC memory 25 (for example, The data on the lower layer in FIG. 8 is combined with the data in the first to fourth layers rearranged like the data before shuffling (for example, the upper data in FIG. 8) by reverse shuffling. 1 ECC block data (for example, 1 ECC block data in FIG. 7).

  In step S94, the data mixing unit 44 determines whether the reverse shuffling process and the data combining process are looped 100 times (repeated 100 times).

  If it is determined in step S94 that the reverse shuffling process and the data combining process are not looped 100 times, the process returns to step S92 and the above-described processes are repeated. That is, by repeating the processing from step S92 to step S94, the reverse shuffling process and the data composition process are executed for each ECC block in the 100 ECC block data stored in the ECC memory 25.

  On the other hand, if it is determined in step S94 that the reverse shuffling process and the data synthesis process are looped 100 times, the process proceeds to step S95, where the ECC decoder 42 stores the mixed 1 ECC block stored in the ECC memory 25. Data is read out, and PI correction processing is executed on the read data of one ECC block.

  For example, in step S95, the ECC decoder 42 reads the shuffled 1 ECC block data stored in the ECC memory 25, and the 10-byte data added in the horizontal direction to the read 1 ECC block data. Based on the PI parity, a PI correction process is executed on the read data of one ECC block.

  In step S96, the ECC decoder 42 determines whether or not the PI correction processing has been looped 100 times (repeated 100 times) for the data of one ECC block.

  If it is determined in step S96 that the PI correction process has not looped 100 times for the data of one ECC block, the process returns to step S95 and the above-described process is repeated. That is, by repeating the processing of step S95 and step S96, PI correction processing is executed for each ECC block in the mixed 100 ECC block data stored in the ECC memory 25.

  On the other hand, if it is determined in step S96 that the PI correction processing has been looped 100 times for the data of one ECC block, the process proceeds to step S97, and the ECC decoder 42 stores the PI correction stored in the ECC memory 25. The read data of one ECC block is read, and the PO correction processing is executed on the read data.

  For example, in step S97, the ECC decoder 42 reads the PI-corrected 1 ECC block data stored in the ECC memory 25, and the two rows added in the vertical direction to the read 1 ECC block data. Based on the PO parity, PO correction processing is executed on the read data of one ECC block.

  In step S98, the ECC decoder 42 determines whether or not the PO correction process has been looped 100 times (repeated 100 times) for the data of one ECC block.

  If it is determined in step S98 that the PO correction process is not looped 100 times for the data of one ECC block, the process returns to step S97 and the above-described process is repeated. That is, by repeating the processing of step S97 and step S98, the PO correction processing is executed for each ECC block in the data of the 100 corrected ECC block stored in the ECC memory 25.

  On the other hand, if it is determined in step S98 that the PO correction process has been looped 100 times for the data of one ECC block, the process proceeds to step S99, where the ECC decoder 42 performs the data of the 100 ECC block that has undergone PI correction and PO correction. Is supplied to the memory controller 22.

  Then, the memory controller 22 temporarily stores the data of the 100 ECC block subjected to PI correction and PO correction supplied from the ECC decoder 42 in the buffer 23, and appropriately stores the data stored in the buffer 23 as an external interface. The data is transferred to the host computer 2 via 21, and the process returns to step S91 to repeat the above-described processing.

  In this way, each of the shuffled data recorded on each layer of the optical disc 13 is subjected to the reverse shuffling process and the data synthesizing process, and the PI correction process and the PO correction process are executed on the mixed data. Thus, it is possible to reduce the data amount of the error correction code added to the user data, and to prevent the recording density of the user data from being lowered.

  Also, by repeating the disc playback process (FIG. 10), 100 ECC block shuffling data recorded on each layer of the optical disc 13 is played back, and the played shuffling data is sequentially stored in the ECC memory 25, and playback decoding processing is performed. (FIG. 11), predetermined processing (reverse shuffling processing, data synthesis processing, PI correction processing, and PO correction processing) is performed on the shuffling data of 100 ECC blocks stored in the ECC memory 25. As a result, reproduction data can be supplied to the host computer 2.

  That is, the reproduction data recorded on the optical disk 13 is sequentially reproduced in units of 100 ECC blocks by repeating the disk reproduction process (FIG. 10) and the reproduction decoding process (FIG. 11) simultaneously (in parallel). Can do.

  Accordingly, the optical disc apparatus 1 can reproduce (all) reproduction data recorded on each layer of the optical disc 13 and supply the reproduced data to the host computer 2.

  As described above, according to the present invention, the data amount of the error correction code can be further reduced with a simpler configuration in the disk for recording data on a plurality of layers.

  Further, according to the present invention, in a multi-layer disc, an ECC format based on an error rate between a layer with poor recording / reproduction quality and a layer with good quality is adopted, and data with an error correction code added to each layer of the optical disc. By recording, it is possible to prevent a decrease in the recording density of user data.

  Furthermore, according to the present invention, since recording and reproduction can be performed on all recording layers of an optical disc in a single ECC format, the recording apparatus or reproduction apparatus of the present invention can be realized with a simpler circuit configuration. can do.

  In the above example, the optical disk 13 is described as a four-layer disk. However, the present invention is not limited to this, and may be applied to an optical disk having a plurality of recording layers, such as a two-layer disk. Can do.

  In the above-described example, the processing such as the PO correction processing is executed for every 100 ECC blocks. However, the present invention is not limited to this, and the processing may be executed for each of one or a plurality of ECC blocks. In that case, the more the number of ECC blocks to be processed at a time, the smaller the number of focus jumps.

  Further, as described above, PI parity is not added without executing processing for adding PI parity (PI sequence) (steps S17 and S18 in FIG. 6) as in an error correction method such as LDC. Although data is also conceivable, in this case, the data of one ECC block is transferred to the optical disk 13 without performing the shuffling process (the process of step S20 in FIG. 6) on the data to be recorded on each layer of the optical disk at the time of recording. 1 ECC block data is reproduced without performing the reverse shuffling process (the process of step S92 in FIG. 11) on the data recorded on each layer of the optical disc 13 at the time of reproduction. You just have to do it.

  Further, even for data to which no PI parity (PI sequence) is added, shuffling processing may be executed during recording, and reverse shuffling processing may be executed during reproduction.

  Further, in the above-described example, when the data amount of the error correction code is reduced, it has been described that the data amount of the PO parity is reduced. However, the data amount of the PI parity is reduced, or the respective data amounts of the PO parity and the PI parity May be reduced.

  Further, the order of shuffling and the size of data (for example, one vertical row × one horizontal byte) described above are merely examples, and the present invention is not limited thereto. Further, the shuffling process may be performed in a predetermined row unit or column unit in the ECC block.

  Further, as described above, according to the present invention, the data amount of the error correction code can be reduced. Therefore, according to the reduced data amount, the data amount of the user data is increased to increase the recording density of the user data. Alternatively, for example, the user data can be recorded by extending the shortest pit length which is the length of the shortest pit recorded on the optical disc 13 without changing the data amount of the user data. You may make it raise the quality of reproduction | regeneration.

  Further, the control unit 16 reads out and executes a control program (controlling ECC processing corresponding to the multi-layer disk) stored in the (non-volatile) memory 17. The update may be performed by reading a different version of the control program from an external medium such as an optical disk, which is appropriately attached to a drive connected to the computer 2, and storing the read control program in the memory 17. Further, different versions of the control program may be acquired from a server connected to the Internet via an interface such as a router or a modem as necessary.

  In the present specification, the step of describing the program stored in the recording medium is not limited to the processing performed in chronological order according to the described order, but is not necessarily performed in chronological order. It also includes processes that are executed individually.

It is a figure explaining the conventional ECC format. 2 is a graph showing a relationship between an error rate before error correction and an error rate after error correction in the ECC format of FIG. 1. It is a block diagram which shows the structure of one Embodiment of the optical disk apparatus to which this invention is applied. It is a figure explaining the ECC format of this invention. 5 is a graph showing a relationship between an error rate before error correction and an error rate after error correction in the ECC format of FIG. It is a flowchart explaining the process of recording encoding. It is a figure explaining the shuffling process in ECC format. It is a figure explaining the process of shuffling. It is a flowchart explaining the process of disk recording. It is a flowchart explaining the process of disk reproduction | regeneration. It is a flowchart explaining the process of reproduction | regeneration decoding.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Optical disk apparatus, 11 Signal processing part, 12 Optical pick-up, 13 Optical disk, 14 Spindle motor, 15 Servo controller, 16 Control part, 17 Memory, 21 External interface, 22 Memory controller, 23 Buffer, 24 ECC processing part, 25 ECC memory , 26 modulation unit, 27 driver, 28 equalizer, 29 modulation unit, 41 ECC encoder, 42 ECC decoder, 43 data division unit, 44 data mixing unit, 51 recording control unit, 52 playback control unit, 61 drive, 71 magnetic disk, 72 optical disk, 73 magneto-optical disk, 74 semiconductor memory

Claims (15)

In a recording apparatus for recording the data on a disk on which data is recorded in each of a plurality of layers,
Adding means for adding an error correction code for correcting an error to the data;
Dividing means for dividing the data to which the error correction code is added into a number corresponding to the number of layers;
And recording control means for controlling recording of the divided data onto the disc so that each of the divided data divided from the one data is recorded on the different layers. Recording device. The dividing means further shuffles the divided data so that unit data of a predetermined amount of the divided data is exchanged between the divided data divided from one piece of the data,
The recording apparatus according to claim 1, wherein the recording control unit controls recording of the shuffled divided data onto the disk. Storage means for storing the divided data;
2. The recording control unit according to claim 1, wherein the recording control unit controls the recording so that the divided data having a predetermined amount of data stored is collectively recorded in one of the layers of the disc. Recording device. The recording apparatus according to claim 1, wherein the adding unit adds the error correction code to the data so as to be a product code. In a recording method of a recording apparatus for recording the data on a disk on which data is recorded on each of a plurality of layers,
An additional step of adding an error correction code for correcting an error to the data;
A division step of dividing the data to which the error correction code is added into a number corresponding to the number of layers;
And a recording control step for controlling recording of the divided data on the disc so that each of the divided data which is data divided from the one data is recorded on the different layers. Recording method. A recording processing program for recording the data on a disk on which data is recorded on each of the plurality of layers,
An additional step of adding an error correction code for correcting an error to the data;
A division step of dividing the data to which the error correction code is added into a number corresponding to the number of layers;
And a recording control step for controlling recording of the divided data on the disc so that each of the divided data which is data divided from the one data is recorded on the different layers. A recording medium on which a program to be recorded is recorded. In a program for causing a computer of a recording apparatus to record the data on a disk on which data is recorded in each of a plurality of layers to perform a recording process,
An additional step of adding an error correction code for correcting an error to the data;
A division step of dividing the data to which the error correction code is added into a number corresponding to the number of layers;
And a recording control step for controlling recording of the divided data on the disc so that each of the divided data which is data divided from the one data is recorded on the different layers. Program to do. In a playback apparatus for playing back the data recorded from a disk in which data is recorded in each of a plurality of layers,
The data to which the error correction code is added is divided data obtained by dividing the data into a number corresponding to the number of layers, and each of the divided data obtained by dividing one piece of the data is recorded in different layers. Playback control means for controlling playback of the divided data from each of the layers of the disc;
Mixing means for mixing the data to which the error correction code is added from the reproduced divided data;
A reproducing apparatus comprising: correction means for correcting an error in the data based on the error correction code added to the mixed data. The reproduction control means controls reproduction of the divided data so that the divided data of a predetermined data amount is reproduced at a time from one layer of the disc. The reproducing apparatus as described. When the divided data is shuffled so that the unit data of a predetermined data amount of the divided data is exchanged between the divided data divided from one piece of the data, 9. The data to which the error correction code is added is mixed from the deshuffled divided data by reverse shuffling so that the arrangement of unit data is restored. Playback device. The reproducing apparatus according to claim 8, wherein the correction unit corrects an error in the data based on the error correction code that is a product code added to the data. In a playback method of a playback device for playing back the data recorded from a disc in which data is recorded in each of a plurality of layers,
The data to which the error correction code is added is divided data obtained by dividing the data into a number corresponding to the number of layers, and each of the divided data obtained by dividing one piece of the data is recorded in different layers. A playback control step for controlling playback of the split data from each of the layers of the disc;
A mixing step of mixing the data to which the error correction code is added from the reproduced divided data;
And a correction step of correcting an error in the data based on the error correction code added to the mixed data. A reproduction processing program for reproducing the data recorded from a disc in which data is recorded in each of a plurality of layers,
The data to which the error correction code is added is divided data obtained by dividing the data into a number corresponding to the number of layers, and each of the divided data obtained by dividing one piece of the data is recorded in different layers. A playback control step for controlling playback of the split data from each of the layers of the disc;
A mixing step of mixing the data to which the error correction code is added from the reproduced divided data;
And a correction step of correcting an error of the data based on the error correction code added to the mixed data. A recording medium on which a program is recorded. In a program for causing a computer of a playback device to play back the data recorded from a disk in which data is recorded in each of a plurality of layers to perform playback processing,
The data to which the error correction code is added is divided data obtained by dividing the data into a number corresponding to the number of layers, and each of the divided data obtained by dividing one piece of the data is recorded in different layers. A playback control step for controlling playback of the split data from each of the layers of the disc;
A mixing step of mixing the data to which the error correction code is added from the reproduced divided data;
And a correction step of correcting an error of the data based on the error correction code added to the mixed data. In a disc in which data is recorded in each of a plurality of layers,
The data to which the error correction code is added is divided data obtained by dividing the data into a number corresponding to the number of layers, and each of the divided data obtained by dividing one piece of the data is recorded in different layers. A disc characterized by being.

Images