JP4315052B2 - Disc-shaped recording medium playback device - Google Patents

Description

  The present invention relates to a disk-shaped recording medium playback apparatus, and more particularly to a disk-shaped recording medium playback apparatus that is muted when there is unreadable data during playback of an audio signal from a disk-shaped recording medium.

  At present, a small-diameter optical disk having a diameter of about 64 mm and having a storage capacity that enables recording of, for example, a musical sound signal for 74 minutes or more has come to be widely known. This small-diameter optical disk is called a mini-disc MD (registered trademark), a read-only type in which data is recorded by pits, and a recording / reproduction in which data is recorded by a magneto-optical recording (MO) method and can be reproduced. There are two types of molds. The following description relates to a recording / reproducing small-diameter optical disk (hereinafter referred to as a magneto-optical disk). In order to increase the recording capacity of the magneto-optical disk, the track pitch, the recording wavelength of the recording laser light, the NA of the objective lens, and the like have been improved.

  As shown in FIG. 8, an initial magneto-optical disk in which groove recording is performed at a track pitch of 1.6 μm and the modulation method is EFM is referred to as a first generation MD. The physical format of the first generation MD is defined as follows. The track pitch is 1.6 μm and the bit length is 0.59 μm / bit. The laser wavelength λ is λ = 780 nm, and the aperture ratio of the optical head is NA = 0.45. As a recording system, a groove recording system that uses grooves (grooves on the disk board surface) as tracks for recording and reproduction is adopted. The address system employs a system using a wobbled groove in which a single spiral groove is formed on the disk surface and wobbles as address information are formed on both sides of the groove. In this specification, the absolute address recorded by wobbling is also referred to as ADIP (Address in Pregroove). This first generation MD employs an EFM (8-14 conversion) modulation system as a recording data modulation system. As an error correction method, ACIRC (Advanced Cross Interleave Reed-Solomon Code) is used. In addition, a convolution type is adopted for data interleaving. As a result, the data redundancy is 46.3%. The data detection method in the first generation MD is a bit-by-bit method, and CLV (Constant Linear Verocity) is adopted as the disk drive method. The linear velocity of CLV is 1.2 m / s. The standard data rate at the time of recording / reproducing is 133 kB / s, and the recording capacity is 164 MB (140 MB in MD-DATA). The minimum data rewrite unit (cluster) is composed of 36 sectors including 32 main sectors and 4 link sectors.

  Furthermore, in recent years, high-density MDs with higher recording capacity than the first generation MDs have been developed. First, while maintaining the conventional medium (disk or cartridge) as it is, the modulation method, logical structure, etc. are changed to double the user area and the like, and the recording capacity is increased to, for example, 300 MB (hereinafter referred to as high density MD-1). Developed). The physical specifications of the recording medium are the same, the track pitch is 1.6 μm, the laser wavelength λ is λ = 780 nm, and the aperture ratio of the optical head is NA = 0.45. As a recording method, a groove recording method is adopted. The address system uses ADIP. Thus, the configuration of the optical system, the ADIP address reading method, and the servo processing in the disk drive device are the same as those in the first generation MD. This high-density MD-1 is an RLL (1-7) PP modulation method (RLL: Run Length Limited, PP: Parity preserve / Prohibit rmtr (repeated minimum transition runlength)) suitable for high-density recording as a modulation method for recording data. ) Is adopted. Further, as an error correction method, an RS-LDC (Reed Solomon-Long Distance Code) method with BIS (Burst Indicator Subcode) having higher correction capability is used.

  Further, as a high-density disk, a high-density MD-3 having a recording capacity increased from that of the high-density MD-1 has a track pitch narrowed to 1.25 μm while maintaining the compatibility of the outer shape and the optical system. It was developed by a method of detecting a recording mark from a groove by domain wall displacement detection (DWDD). This high-density MD-3 is an RLL (1-7) PP modulation system (RLL: Run Length Limited, PP: Parity preserve / Prohibit rmtr (repeated minimum transition runlength)) suitable for high-density recording as a modulation system for recording data. ) Is adopted. Further, as an error correction method, an RS-LDC (Reed Solomon-Long Distance Code) method with BIS (Burst Indicator Subcode) having higher correction capability is used. Data interleaving is a block-complete type. As a result, the data redundancy becomes 20.50%. As a data detection method, a Viterbi decoding method based on PR (1, -1) ML is used. A cluster which is the minimum data rewrite unit is composed of 16 sectors and 64 kB. A ZCAV system is used as the disk drive system, and the linear velocity is 2.0 m / s. The standard data rate at the time of recording / reproducing is 9.8 MB / s. Therefore, in the high density MD-3, the total recording capacity can be reduced to 1 GB by adopting the DWDD method and this driving method.

  The first generation MD, high-density MD-1, and high-density MD-3 all store the recording data read from the disk in the buffer memory, reproduce the stored data from the buffer memory, decode it, and output it. It was. JP-A-2000-76800 and JP-A-2003-346420 disclose an information reproducing apparatus and a recording / reproducing apparatus configured to temporarily store recording data read from a disk in a buffer memory and reproduce the accumulated data from the buffer memory as described above. The configuration is disclosed.

  Of the first generation MD, the high density MD-1, and the high density MD-3, when the conventional first generation MD fails to read data from the disk, the portion is actually regarded as “captured”. It is not fetched and is flagged as an error. When the part was decoded and the sound was output, the error part was muted (MUTE) and played to prevent noise.

  This is because the conventional first generation MD recorded data without being encrypted on the disc, and it is guaranteed that the decoder will not abort or abort even if unexpected and undefined data is applied to the decoder. Furthermore, the unit of recording / reading data was 1 sector (about 2 Kbytes). In this way, in the first generation MD, there was no problem with any data applied to the decoder, and at most it was muted in a multiple of the smallest unit. The playback time of one sector (about 2Kbyte) is about 200msec to 250msec. Therefore, the multiple is 400 msec to 500 msec, which is within 1 second.

JP 2000-76800 A JP 2003-346420 A

  However, in the case of a high-density MD such as the above-described high-density MD-1 or high-density MD-3, the minimum unit of recording / reading data is as large as 64 Kbytes, and the compression rate of audio data is increased to compress it to a minimum of about 32 kbps. As a result, if there is a read failure at one location (error detection exceeding the ECC correction capability), 64Kbyte data is lost.

  When this is converted to time, it is about 8 seconds when the minimum bit rate is 64kbps, which can be recorded by high-density MD (Hi-MD Audio), and about 15 seconds when the minimum bit rate is 32kbps that can be played back by Hi-MD Audio. It becomes. Although it is impossible to play back this missing data, if “MUTE playback as it is” as in the past, the missing time will be long, leading to the user thinking that there is considerable discomfort = failure of the playback system. End up.

  Another possible method is to skip the error part without reading it, but it has proved difficult to handle for the following reasons. Whether the reading part is an error or not is not known without actually accessing the data on the disk. This complicates the system processing at the time of capture when the area to be captured is an error when attempting to process by the method of “not capturing missing portions”. In addition, as a result of repeated access and retry and many failures, if all errors occur, the user will not be able to issue any message.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a disc-shaped recording medium playback device that can recognize that the recording state is bad in a time that does not give the user a sense of incongruity. .

  In order to solve the above-described problem, the disk-shaped recording medium playback apparatus according to the present invention cannot read the block-unit data to be read when the data recorded on the disk-shaped recording medium is read in block units. Reading means for detecting whether there is an error, storage means for storing block-unit data read by the reading means, decoding means for decoding block-unit data stored in the storage means, When the number of sound frames per block is calculated and an unreadable error is detected in the block unit data that the reading means is trying to read while reproducing the disk-shaped recording medium, the unreadable error is detected. Fewer sound frames than the number of sound frames per block detected The data of the block unit in which the unreadable error is detected for the number of times of data reproduction is converted into the muted data through the decoding means, and then read out by the reading means and stored in the storage means. And control means for outputting a decoding result from the decoding means for the subsequent block unit data.

When the data recorded on the disk-shaped recording medium is read in block units, the reading unit detects whether there is an unreadable error in the block unit data to be read. The control means calculates the number of sound frames per block, and when the read means detects an unreadable error in the block unit data to be read, the number of sound frames per block in which the unreadable error is detected The data of the block unit in which an unreadable error is detected for the number of times of reproduction of data corresponding to the number of sound frames smaller than that is converted into the mute state data through the decoding means, and then read out by the reading means and stored in the storage means. The decoding result from the decoding means of the data of the succeeding block unit stored is output.

  In the disc-shaped recording medium reproducing apparatus according to the present invention, when the reading unit detects an unreadable error in the block-unit data that the reading unit attempts to read, the control unit detects a predetermined time shorter than the block-unit data reproducing time. Since the mute state is set only through the decoding means, it is possible to recognize that the recording state is bad in such a time that the user does not feel uncomfortable.

  In other words, when playing back compressed data recorded on high-density MD (Hi-MD Audio), if it is not read due to an error, if you play MUTE as usual, there will be a maximum of about 15 seconds of silence in the standard. However, by applying the present invention, it is possible to reduce the user's recognition that the reproduction function is broken, or to easily recognize that the recording state is bad.

  As a result, the playback elapsed time will fly up to about 15 seconds, but when compared to recognizing a regenerative malfunction when there is no sound for a long time of 15 seconds, it gives the user a little anxiety. I can do it.

  Hereinafter, the best mode for carrying out the present invention will be described. FIG. 1 is a diagram showing a schematic configuration of a magneto-optical disk reproducing apparatus 1 according to the embodiment. The magneto-optical disk reproducing apparatus 1 reproduces a high-density disk 2 such as a high-density MD-1 or a high-density MD-3.

  The magneto-optical disk reproducing apparatus 1 has a disk reading unit 3 for reading recording data recorded on the high-density disk 2 and a predetermined storage capacity, and the recording data read by the disk reading unit 3 is stored. For example, it comprises a DRAM 12 that is a ring buffer memory, a memory controller 15 that controls the DRAM 12, and an audio decoder 13 that decodes data reproduced from the DRAM 12.

  Of the high-density disk 2, for example, the high-density MD-3 handles a block of audio data as a block Block (16 Kbyte) and a minimum unit of sound data as a sound frame SF (Sound Frame). The playback time per SF varies depending on the compression method (Codec), and is 46.4 ms / SF for ATRAC3plus, 23.2 ms / SF for ATRAC3, and 0.36 ms / SF for LPCM. Further, since there are different code rates within one Codec, the number of SFs included per block (16 Kbyte) is different as SF / 1Block in FIG.

  As described above, although the number of SFs in one block varies depending on the bit rate, the magneto-optical disk reproducing device 1 of the present embodiment has a synchronization signal (hereinafter referred to as “SF Sync”) indicating completion of 1SF reproduction and a synchronization signal (hereinafter referred to as “SF Sync”). BLK Sync). FIG. 3 is a diagram showing the relationship between Block and SF. After the reproduction is started in FIG. 3A, the end of the SF can be recognized by the synchronization signal of the end of the 1SF reproduction as shown in FIG. 3B. Further, as shown in FIG. 3C, the end of the block can be recognized by the synchronization signal of the end of the 1 block reproduction. Therefore, the relationship between Block and SF is known by each synchronization signal.

  When reading the data recorded on the high-density disk 2 in units of blocks, the disk reading unit 3 detects whether or not there is an unreadable error in the data in units of blocks to be read. The disk reading unit 3 demodulates the modulation signal recorded with the error correction code added to the high-density disk 2, performs error correction processing, and reads an unreadable error in the block unit data to be read. Detect whether or not there is.

  FIG. 4 is a diagram showing a detailed configuration of the magneto-optical disk reproducing apparatus 1. The disk reading unit 3 includes a spindle motor 4 for rotating the high density disk 2, an optical pickup 5 for reading data recorded on the high density disk 2, an RF signal from data read by the optical pickup 5, An RF amplifier 6 that generates an ADIP signal, a tracking error signal, a focus error signal, and the like is provided. Further, the reproduction signal processing unit 9 which performs reproduction signal processing on the RF signal from the RF amplifier 6 and supplies it to the DRAM 12, the address decoder 10 which decodes the address from the ADIP, and the tracking servo signal based on each error signal. A servo circuit 7 that generates a servo signal such as a focus servo signal and supplies the servo signal to the motor driver 8, and a drive controller 11.

  The signal processing unit 9 performs demodulation corresponding to RLL (1-7) PP modulation during reproduction of the high-density disc 2 (PRL (1, -1) ML and RLL (1-7) based on data detection using Viterbi decoding). A demodulation unit and a part for performing RS-LDC decoding. As described above, the signal processing unit 9 demodulates the modulated signal recorded with the error correction code added to the high-density disk 2, performs error correction processing, and reads the block unit data to be read out. Whether or not there is an unreadable error is detected.

  Information (photocurrent obtained by detecting the laser reflected light by the photodetector) detected by the laser irradiation of the optical pickup 5 on the high-density disk 2 by laser irradiation is supplied to the RF amplifier 6. The RF amplifier 6 performs current-voltage conversion, amplification, matrix calculation, and the like on the input detection information, and reproduces a reproduction RF signal, a tracking error signal TE, a focus error signal FE, and groove information (high density disc) as reproduction information. 2) ADIP information recorded by track wobbling).

  At the time of reproduction of the high-density disk 2, the reproduction RF signal obtained by the RF amplifier 6 is RLL (1-7) via the A / D conversion circuit, equalizer, PLL circuit, and PRML circuit in the reproduction signal processing unit 9. Signal processing is performed by the PP demodulator and the RS-LDC decoder. The reproduction RF signal is obtained by the RLL (1-7) PP demodulating unit to obtain reproduction data as an RLL (1-7) code string by data detection using PR (1, -1) ML and Viterbi decoding. RLL (1-7) demodulation processing is performed on the RLL (1-7) code string. Further, error correction and deinterleaving are performed by the RS-LDC decoder. The demodulated data is output to the DRAM 12 as reproduced data (compressed data) from the high-density disk 2. At this time, the RS-LDC decoder detects whether there is an unreadable error in the block-unit data to be read.

  The tracking error signal TE and the focus error signal FE output from the RF amplifier 6 are supplied to the servo circuit 7, and the groove information is supplied to the address decoder 10.

  The address decoder 10 extracts a wobble component by band-limiting the groove information with a bandpass filter, and then performs FM demodulation and biphase demodulation to extract an ADIP address. The extracted ADIP address, which is absolute address information on the disk, is supplied to the drive controller 11 as a high-density disk 2 address.

  The drive controller 11 executes predetermined control processing based on the ADIP address. The groove information is returned to the servo circuit 7 for spindle servo control.

  The servo circuit 7 generates a spindle error signal for ZCAV servo control, for example, based on an error signal obtained by integrating a phase error with a reproduction clock (PLL clock at the time of decoding) with respect to groove information.

  Further, the servo circuit 7 responds to a spindle error signal, a tracking error signal supplied from the RF amplifier 6 as described above, a focus error signal, a track jump command from the system controller 16 via the drive controller 11, an access command, or the like. Based on this, various servo control signals (tracking control signal, focus control signal, thread control signal, spindle control signal, etc.) are generated and output to the motor driver 8. That is, various servo control signals are generated by performing necessary processing such as phase compensation processing, gain processing, and target value setting processing on the servo error signal and command.

  The motor driver 8 generates a predetermined servo drive signal based on the servo control signal supplied from the servo circuit 7. The servo drive signal here includes a biaxial drive signal for driving the biaxial mechanism (two types of focus direction and tracking direction), a sled motor drive signal for driving the sled mechanism, and a spindle motor drive signal for driving the spindle motor 4. It becomes. With such a servo drive signal, focus control, tracking control, and ZCAV control for the spindle motor 4 are performed for the high-density disk 2.

  The DRAM 12 holds the compressed data supplied from the disk reading unit 3 and buffers it. Then, the buffered compressed data is output to the audio decoder 13 under the control of the memory controller 15 that performs memory control by a command from the system controller 11.

  The audio decoder 13 generates digital audio data by performing a decompression process on the compressed data input from the DRAM 12. The digital audio data generated in this way is converted into an analog audio signal from the output terminal 14 via an A / D converter (not shown), and reproduced and output as an audio output.

  As described above, the magneto-optical disk reproducing apparatus 1 is configured to buffer the data read from the high-density disk 2 in the DRAM 12 and then reproduce and output the data.

  An operation unit 17 is connected to the system controller 11. The operation unit 17 includes a play key, a pause key, a stop key, a first forward FF key, and a first reverse FR key on the operation panel. Further, the operation panel of the operation unit 17 is provided with a liquid crystal display unit, which displays a battery remaining amount display and a display regarding AB repeat.

  In addition, when the system controller 16 detects an unreadable error in the block unit data that the disk reading unit 3 tried to read during reproduction of the high-density disk 2, it is shorter than the reproduction time of the block unit data. The audio decoder 13 is muted for a predetermined time.

  FIG. 5 is a flowchart showing a series of processing procedures of the magneto-optical disk reproducing apparatus 1. When reproduction is started, the signal processing unit 9 of the disk reading unit 3 determines whether or not there is an unreadable error in the first block in accordance with control of the system controller 16 via the drive controller 11 in step S1. Is detected. When the system controller 16 determines in step S2 that the signal processing unit 9 has not detected the unreadable error, the system controller 16 proceeds to step S3 to reproduce normal reproduction, that is, reproduce all SFs in the first block. On the other hand, when the system controller 16 determines that the unreadable error has been detected, it writes an error flag in the DRAM 12 via the memory controller 15. For blocks that cannot be read, the process proceeds to step S4 with the error flag set and error reproduction is performed. The error reproduction in step S4 is to mute the sound frame SF for a predetermined time shorter than the reproduction time of the block unit data.

  As described above, the playback time per 1SF differs depending on the compression method (Codec), and was 46.4ms / SF for ATRAC3plus and 23.2ms / SF for ATRAC3. When muted in units of blocks using the conventional method, as described above, the mute time is about 8 seconds at the minimum bit rate of 64 kbps that can be recorded by itself, and about 15 seconds at the minimum bit rate of 32 kbps that can be played back by Hi-MD Audio. It can be made a short time compared with becoming. This makes it possible to recognize that the recording state is bad in such a time that the user does not feel uncomfortable.

  In other words, when playing back compressed data recorded on high-density MD (Hi-MD Audio), if it is not read due to an error, if you play MUTE as usual, there will be a maximum of about 15 seconds of silence in the standard. However, by applying the present invention, it is possible to reduce the user's recognition that the reproduction function is broken, or to easily recognize that the recording state is bad.

  As a result, the playback elapsed time will fly up to about 15 seconds, but when compared to recognizing a regenerative malfunction when there is no sound for a long time of 15 seconds, it gives the user a little anxiety. I can do it.

  When the error reproduction in step S4 or the normal reproduction in step S3 ends, the system controller 16 causes the disk reading unit 3 to detect an error in the next block in step S5. Then, the processing from step S2 is repeated.

  The magneto-optical disk reproducing apparatus 1 was an apparatus for reproducing only the high-density disk 2. As described above, it was possible to recognize that the recording state was bad in such a time that the user did not feel uncomfortable.

  Furthermore, the present invention may be applied to a magneto-optical disk recording / reproducing apparatus for reproducing the first generation MD in addition to the high density MD-1 and the high density MD-3.

  FIG. 6 shows a configuration of a disk drive device 50 that records and reproduces the first generation MD in addition to the high density MD-1 and the high density MD-3. The disk drive device 500 can be connected to a personal computer (hereinafter referred to as a PC) 100, and the high-density disk 2 can be used as external storage such as a PC in addition to audio data.

  As shown in FIG. 6, the disk drive device 50 includes a media drive unit 20 incorporating an optical disk determination device, a memory transfer controller 51, a DRAM (buffer memory) 52, an auxiliary memory 53, a USB interface 54, 55, a USB hub 56, a system controller 57, and an audio processing unit 58.

  The media drive unit 20 performs recording / reproduction on the loaded first generation MD, high density MD-1, and high density MD-3 individual disks 90. The internal configuration of the media drive unit (optical disc recording / reproducing apparatus) 20 will be described later with reference to FIG.

  The memory transfer controller 51 performs transmission / reception control of reproduction data from the media drive unit 20 and recording data supplied to the media drive unit 20. The buffer memory 52 buffers data read by the media drive unit 20 from the data track of the disk 90 in units of high-density data clusters based on the control of the memory transfer controller 51. The auxiliary memory 53 stores various management information and special information such as UTOC data, CAT data, unique ID, and hash value read from the disk 90 by the media drive unit 20 based on the control of the memory transfer controller 51.

  The system controller 57 can communicate with the PC 100 connected via the USB interface 55 and the USB hub 56, and performs communication control with the PC 100 to execute commands such as a write request and a read request. It performs reception, status information, transmission of other necessary information, and the like, and performs overall control of the entire disk drive device 50.

  For example, when the disk 90 is loaded in the media drive unit 20, the system controller 57 instructs the media drive unit 20 to read management information from the disk 90, and the PTOC read by the memory transfer controller 51. Management information such as UTOC is stored in the auxiliary memory 53.

  The system controller 57 can grasp the track recording state of the disk 90 by reading the management information. Further, by reading the CAT, the high-density data cluster structure in the data track can be grasped, and the access request to the data track from the PC 100 can be handled.

  The disk authentication process and other processes are executed based on the unique ID and the hash value, or these values are transmitted to the PC 100, and the disk authentication process and other processes are executed on the PC 100.

  When there is a read request for a certain FAT sector from the PC 100, the system controller 57 gives a signal to the media drive unit 20 to execute reading of a high-density data cluster including this FAT sector. The read high-density data cluster is written into the buffer memory 52 by the memory transfer controller 51. However, when the data of the FAT sector has already been stored in the buffer memory 52, reading by the media drive unit 20 is not necessary.

  At this time, the system controller 57 gives a signal for reading out the requested FAT sector data from the data of the high-density data cluster written in the buffer memory 52, and sends it to the PC 100 via the USB interface 54 and the USB hub 56. Control to send.

  When there is a write request for a certain FAT sector from the PC 100, the system controller 57 causes the media drive unit 20 to execute reading of a high-density data cluster including this FAT sector. The read high-density data cluster is written into the buffer memory 52 by the memory transfer controller 51. However, when the data of the FAT sector has already been stored in the buffer memory 52, reading by the media drive unit 20 is not necessary.

  Further, the system controller 57 supplies the FAT sector data (recording data) transmitted from the PC 100 to the memory transfer controller 51 via the USB interface 54, and rewrites the corresponding FAT sector data on the buffer memory 52. Let

  The system controller 57 instructs the memory transfer controller 51 to transfer the data of the high-density data cluster stored in the buffer memory 52 with the necessary FAT sector being rewritten to the media drive unit 20 as recording data. At this time, the media drive unit 20 uses the EFM modulation method if the mounted medium is a conventional mini-disc, and uses the RLL (1-7) PP modulation method to generate a high-density data cluster if the medium is a next generation MD1 or next generation MD2. The recorded data is modulated and written.

  In the disk drive device 50, the above-described recording / reproduction control is control when recording / reproducing data tracks, and data transfer when recording / reproducing MD audio data (audio tracks) is performed via the audio processing unit 58. Done.

  The audio processing unit 58 includes, for example, an analog audio signal input unit such as a line input circuit / microphone input circuit, an A / D converter, and a digital audio data input unit as an input system. The audio processing unit 58 includes an ATRAC compression encoder / decoder and a compressed data buffer memory. Furthermore, the audio processing unit 58 includes an analog audio signal output unit such as a digital audio data output unit, a D / A converter, and a line output circuit / headphone output circuit as an output system.

  An audio track is recorded on the disk 90 when digital audio data (or an analog audio signal) is input to the audio processing unit 58. Linear PCM audio data that is input as linear PCM digital audio data or analog audio signals and then converted by an A / D converter is subjected to ATRAC compression encoding and stored in a buffer memory. Thereafter, the data is read from the buffer memory at a predetermined timing (data unit corresponding to the ADIP cluster) and transferred to the media drive unit 20.

  In the media drive unit 20, the transferred compressed data is modulated by the first modulation method EFM modulation method or RLL (1-7) PP modulation method and written on the disk 90 as an audio track.

  When reproducing an audio track from the disk 90, the media drive unit 20 demodulates the reproduction data into an ATRAC compressed data state and transfers it to the audio processing unit 58. The audio processing unit 58 performs ATRAC compression decoding to obtain linear PCM audio data, which is output from the digital audio data output unit. Alternatively, line output / headphone output is performed as an analog audio signal by a D / A converter.

  In FIG. 6, when the media drive unit 20 reads data recorded on the disk 90 in units of sectors (first generation MD) and blocks (high-density disk 2), the sector unit to be read is read out. Alternatively, it is detected whether there is an unreadable error in block unit data. Specifically, it is detected whether there is an unreadable error in the ACIRC decoder 28 or the RS--LDC decoder 36 in FIG. 7 described later.

  The buffer memory 52 stores data in units of sectors (first generation MD) and blocks (high density disk 2) read from the disk 90 by the media drive unit 20.

  Further, the personal computer 100 or the audio processing unit 58 decodes the data in the sector unit (first generation MD) and the block unit (high density disk 2) stored in the buffer memory 52.

  When the system controller 57 detects an unreadable error in the sector unit or block unit data that the media drive unit 20 tried to read during playback of the disk 90, the playback time of the upper sector unit or block unit data is detected. The mute state is established via the audio processing unit 58 or the personal computer 100 for a predetermined time shorter than the predetermined time.

  When the sector data is muted, as described above, it is about 200 msec to 250 msec. Further, if the block unit, which is a unit for reading the high density disk 2, is muted, as described above, the muting is performed for 8 seconds and 15 seconds. In this case, when the first generation MD and the high density MD are reproduced, when there is an unreadable error, the mute time is too different. Therefore, when reproducing a high-density MD, the user feels more uncomfortable.

  Therefore, even in the disk drive device 50, when the system controller 57 determines that the unreadable error has been detected in the high-density disk 2, it writes an error flag in the DRAM 52 via the memory transfer controller 51. For the unreadable block, the error reproduction shown in step S4 in FIG. 5 is performed with the error flag set. The error reproduction in step S4 is to mute the sound frame SF for a predetermined time shorter than the reproduction time of the block unit data.

  As described above, the playback time per 1SF differs depending on the compression method (Codec), and was 46.4ms / SF for ATRAC3plus and 23.2ms / SF for ATRAC3. When muted in units of blocks using the conventional method, as described above, the mute time is about 8 seconds at the minimum bit rate of 64 kbps that can be recorded by itself, and about 15 seconds at the minimum bit rate of 32 kbps that can be played back by Hi-MD Audio. It can be made a short time compared with becoming. This makes it possible to recognize that the recording state is bad in such a time that the user does not feel uncomfortable.

  FIG. 7 shows a configuration of a media drive unit 20 (a magneto-optical disk recording / reproducing apparatus) for recording / reproducing the first generation MD, the high density MD-1 and the high density disk 2. The media drive unit 20 discriminates the disc type by the disc discriminating technique disclosed in WO03 / 088228 by the applicant. This disc discrimination technology is a laser beam while moving an objective lens or an optical block (optical pickup) from an inner circumference side to an outer circumference side at a constant speed to, for example, a high-density MD-1 or high-density MD-3 that is rotationally driven. The type of each disk is determined by detecting the tracking error signal of the light and the total light quantity signal from the reflected light of the wobbled groove obtained with the focus on, and comparing the phases. The optical disc type is determined by comparing the phase of the binarized signal of the tracking error signal detected by the tracking error detecting means and the binarized signal of the total light quantity signal detected by the total light quantity signal detecting means. is there. Of course, the first generation MD and the high density disk can also be discriminated.

  In order to record and reproduce the first generation MD, high density MD-1, and high density MD-3, the media drive unit 20 performs EFM modulation and ACIRC encoding for recording on a conventional mini-disc, particularly as a recording processing system. It is characterized in that it comprises a configuration for executing, and a configuration for executing RLL (1-7) PP modulation / RS-LDC encoding for recording high density MD-1 and high density MD-3. As a playback processing system, a configuration for executing EFM demodulation and ACIRC decoding for playback of a conventional mini-disc, and PR (1, 2, 1) ML, PR (1, -1) for playback of the next generation MD1 and next generation MD2 ) It is characteristic that it has a configuration for executing RLL (1-7) demodulation and RS-LDC decoding based on data detection using ML and Viterbi decoding.

  The media drive unit 20 rotationally drives the loaded disk 90 by the spindle motor 21 by the CLV method or the ZCAV method. At the time of recording and reproduction, laser light is irradiated from the optical head 22 to the disk 90.

  The optical head 22 performs a high level laser output for heating the recording layer on the recording track to the Curie temperature during recording, and a relatively low level for detecting data from reflected light by the magnetic Kerr effect during reproduction. Perform laser output. For this reason, the optical head 22 is equipped with a laser diode as a laser output means, an optical system including a polarization beam splitter, an objective lens, and the like, and a detector for detecting reflected light. The objective lens provided in the optical head 22 is held so as to be displaceable in the radial direction of the disk and in the direction of contacting and separating from the disk by, for example, a biaxial mechanism. The optical head 22 is provided with a photodetector PD that supplies a light reception signal A and a light reception signal B to a built-in optical disc discrimination device. The objective lens or the entire optical head 22 is moved from the inner circumference to the outer circumference at a constant speed, which is necessary to determine the traveling direction when discriminating the optical disk. The received light signals A and B can be detected at a speed that overcomes the amount of movement due to eccentricity.

  In this specific example, in order to obtain the maximum reproduction characteristics for the first generation MD having different physical specifications on the medium surface and the high density MD-3, a phase compensator is provided in the reading optical path of the optical head 22. Is provided. This phase compensator can optimize the bit error rate during reading. The first generation MD and the high density MD-1 have the same physical specifications.

  A magnetic head 23 is disposed at a position facing the optical head 22 across the disk 90. The magnetic head 23 applies a magnetic field modulated by the recording data to the disk 90. Although not shown, a sled motor and a sled mechanism for moving the entire optical head 22 and the magnetic head 23 in the radial direction of the disk are provided. The sled motor and sled mechanism move the optical head 22 from the inner circumference to the outer circumference when the built-in optical disc discrimination device discriminates the optical disc.

  The media drive unit 20 includes a recording processing system, a playback processing system, a servo system, and the like in addition to a recording / reproducing head system using the optical head 22 and the magnetic head 23 and a disk rotation driving system using the spindle motor 21.

  The recording processing system includes a circuit unit that performs EFM modulation and ACIRC encoding at the time of recording on the first generation MD, RLL (1-7) PP modulation at the time of recording to the high-density MD-1 and high-density MD-3, and RS-LDC. And a circuit unit for encoding.

  As a reproduction processing system, a part for performing demodulation and ACIRC decoding corresponding to EFM modulation at the time of reproduction of the first generation MD, and RLL (1-7) PP modulation at the time of reproduction of the high density MD-1 and high density MD-3. Corresponding demodulation (RLL (1-7) demodulation based on data detection using PR (1, 2, 1) ML and Viterbi decoding) and a circuit unit for performing RS-LDC decoding are provided.

  Information detected as reflected light by the laser irradiation of the optical head 22 on the disk 90 (photocurrent obtained by detecting the laser reflected light with a photodetector) is supplied to the RF amplifier 24. The RF amplifier 24 performs current-voltage conversion, amplification, matrix calculation, and the like on the input detection information, and performs reproduction RF signal, tracking error signal TE, focus error signal FE, groove information (on the disc 90) as reproduction information. (ADIP information recorded by track wobbling) and the like are extracted.

  During reproduction of the first generation MD, the reproduction RF signal obtained by the RF amplifier 24 is processed by the EFM demodulator 27 and the ACIRC decoder 28 via the comparator 25 and the PLL circuit 26. The reproduced RF signal is binarized by the EFM demodulator 27 to form an EFM signal sequence, EFM demodulated, and further subjected to error correction and deinterleave processing by the ACIRC decoder 28. If it is audio data, it will be in the state of ATRAC compression data at this time. At this time, the first generation MD signal side of the selector 29 is selected, and the demodulated ATRAC compressed data is output to the data buffer 30 as reproduction data from the disc 90. In this case, the compressed data is supplied to an audio processing unit (not shown).

  On the other hand, at the time of reproducing the high density MD-1 or high density MD-3, the reproduction RF signal obtained by the RF amplifier 24 passes through the A / D conversion circuit 31, the equalizer 32, the PLL circuit 33, and the PRML circuit 34. The signal is processed by the RLL (1-7) PP demodulator 35 and the RS-LDC decoder 36. The reproduction RF signal is obtained by the RLL (1-7) PP demodulator 35 by obtaining reproduction data as an RLL (1-7) code string by data detection using PR (1, 2, 1) ML and Viterbi decoding. The RLL (1-7) demodulation process is performed on the RLL (1-7) code string. Further, the RS-LDC decoder 36 performs error correction and deinterleave processing. At this time, the RS-LDC decoder 36 detects whether or not there is an unreadable error in the block unit data to be read from the reproduction data (compressed data) from the high-density disk 2. The error detection result of the RS-LDC decoder 36 is supplied to the system controller 57 via the selector 29 and the data buffer 30. When the system controller 57 detects an unreadable error in the block unit data that the media drive unit 20 tried to read during reproduction of the high-density disk 2 (high-density MD-1 or high-density MD-3). The mute state is set, for example, through an audio decoder in the personal computer 100 for a predetermined time shorter than the reproduction time of block unit data.

  In this case, the selector 29 selects the high-density MD-1 / high-density MD-3 side, and the demodulated data is output to the data buffer 30 as reproduction data from the disk 90. At this time, the demodulated data is supplied to a memory transfer controller (not shown).

  The tracking error signal TE and the focus error signal FE output from the RF amplifier 24 are supplied to the servo circuit 37, and the groove information is supplied to the ADIP decoder 38.

  The ADIP decoder 38 limits the band of the groove information by a bandpass filter and extracts a wobble component, and then performs FM demodulation and biphase demodulation to extract an ADIP address. The extracted ADIP address, which is absolute address information on the disc, is passed through the MD address decoder 39 in the case of the conventional mini disc and the next generation MD1, and the next generation MD2 address decoder in the case of the next generation MD2. 40 to the drive controller 41.

  The drive controller 41 executes a predetermined control process based on each ADIP address. The groove information is returned to the servo circuit 37 for spindle servo control.

  The servo circuit 37, for example, based on an error signal obtained by integrating the phase error with the reproduction clock (PLL clock at the time of decoding) with respect to the groove information, the spindle error for the CLV servo control and the ZCAV servo control described above. Generate a signal.

  The servo circuit 37 performs various servo control signals (based on the spindle error signal, the tracking error signal supplied from the RF amplifier 24 as described above, the focus error signal, the track jump command from the drive controller 41, the access command, etc. Tracking control signal, focus control signal, thread control signal, spindle control signal, etc.) are generated and output to the motor driver 42. That is, various servo control signals are generated by performing necessary processing such as phase compensation processing, gain processing, and target value setting processing on the servo error signal and command.

  The motor driver 42 generates a predetermined servo drive signal based on the servo control signal supplied from the servo circuit 37. The servo drive signal here includes a biaxial drive signal for driving the biaxial mechanism (two types of focus direction and tracking direction), a sled motor drive signal for driving the sled mechanism, and a spindle motor drive signal for driving the spindle motor 21. It becomes. By such servo drive signals, focus control and tracking control for the disk 90 and CLV control or ZCAV control for the spindle motor 21 are performed.

  When a recording operation is performed on the disk 90, high-density data or normal ATRAC compressed data from an audio processing unit is supplied from a memory transfer controller 51 (not shown).

  At the time of recording on the first generation MD, the selector 43 is connected to the first generation MD side, and the ACIRC encoder 44 and the EFM modulation unit 45 function. In this case, if it is an audio signal, the compressed data from the audio processing unit 19 is interleaved and an error correction code added by the ACIRC encoder 44 and then EFM-modulated by the EFM modulating unit 45. The EFM modulation data is supplied to the magnetic head driver 46 via the selector 43, and the magnetic head 23 applies a magnetic field based on the EFM modulation data to the disk 90 to record the modulated data.

  At the time of recording on the high density disk 2 (high density MD-1 and high density MD-3), the selector 43 is connected to the high density MD-1 and high density MD-3 side, and the RS-LCD encoder 47 and RLL (1- 7) The PP modulator 48 functions. In this case, the high-density data sent from the memory transfer controller 51 is subjected to interleaving and RS-LDC error correction code addition by the RS-LCD encoder 47 and then to the RLL (1-7) PP modulation unit 48. RLL (1-7) modulation.

  The recording data modulated into the RLL (1-7) code string is supplied to the magnetic head driver 46 via the selector 43, and the magnetic head 23 applies the magnetic field to the disk 90 based on the modulation data. Is recorded.

  The laser driver / APC 49 causes the laser diode to perform a laser emission operation during reproduction and recording as described above, but also performs a so-called APC (Automatic Laser Power Control) operation. Specifically, although not shown, a detector for laser power monitoring is provided in the optical head 22, and this monitor signal is fed back to the laser driver / APC 49. The laser driver / APC 49 compares the current laser power obtained as the monitor signal with a preset laser power and reflects the error in the laser drive signal, thereby outputting the laser power output from the laser diode. Is controlled to be stabilized at the set value. Here, as the laser power, values as the reproduction laser power and the recording laser power are set in a register in the laser driver / APC 49 by the drive controller 41.

  Based on an instruction from the system controller 57, the drive controller 41 controls each component so that the above operations (access, various servos, data writing, and data reading operations) are executed. In addition, each part enclosed with the dashed-dotted line in FIG. 7 can also be comprised as a circuit of 1 chip | tip.

  When the disk drive device 50 including the media drive unit 20 having the configuration and operation described above determines that an unreadable error has been detected in the high-density disk 2, it writes an error flag in the DRAM 52 via the memory transfer controller 51. For blocks that cannot be read, error reproduction is performed with the error flag set. This error reproduction is to mute the sound frame SF for a predetermined time shorter than the data reproduction time of the block unit. As a result, even when an unreadable error occurs in the high-density disk 2, the disk drive device 50 can create a mute state that is not much different from the time when the unreadable error occurs in the first generation MD. Because it can, it does not give the user a sense of incongruity. That is, it is possible to recognize that the recording state is bad with a mute time that does not give the user a sense of incongruity.

1 is a diagram illustrating a schematic configuration of a magneto-optical disk reproducing device according to an embodiment. It is a figure which shows the compression information of a high-density disk. It is a figure which shows the relationship between a block and a sound frame. 1 is a diagram showing a detailed configuration of a magneto-optical disk reproducing device 1. FIG. 4 is a flowchart showing a series of processing procedures of the magneto-optical disk reproducing apparatus 1. It is a figure which shows the structure of the disk drive apparatus which makes 1st generation MD the object of recording / reproduction other than high density MD-1 and high density MD-3. 2 is a diagram showing a configuration of a media drive unit for recording / reproducing a first generation MD, a high density MD-1 and a high density disk 2. FIG. It is a figure which shows the disk specification of 1st generation MD, high density MD-1, and high density disk 2. FIG.

Explanation of symbols

  1 magneto-optical disk playback device, 2 high-density disk, 3 disk reading unit, 12 DRAM, 13 audio decoder, 15 memory controller, 16 system controller

Claims (2)

A reading means for detecting whether or not there is an unreadable error in the block unit data to be read when the data recorded on the disk-shaped recording medium is read in a block unit;
Storage means for storing block-unit data read by the reading means;
Decoding means for decoding block unit data stored in the storage means;
When the number of sound frames per block is calculated and an unreadable error is detected in the block unit data that the reading means is trying to read while reproducing the disk-shaped recording medium, the unreadable error is detected. The block unit data in which the unreadable error has been detected is muted through the decoding means for the reproduction time of data corresponding to the number of sound frames smaller than the number of sound frames detected per block, and then the reading means. And a control means for outputting a decoding result from the decoding means of the subsequent block unit data read out and stored in the storage means.   The reading means performs error correction processing after demodulating the modulated signal recorded with the error correction code added to the disk-shaped recording medium, and reads the block unit data to be read as an unreadable error. 2. The disc-shaped recording medium reproducing device according to claim 1, wherein it is detected whether or not there is.

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