JP3784889B2 - Multilevel recording medium and recording / reproducing apparatus thereof - Google Patents

Multilevel recording medium and recording / reproducing apparatus thereof Download PDF

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Publication number
JP3784889B2
JP3784889B2 JP18289996A JP18289996A JP3784889B2 JP 3784889 B2 JP3784889 B2 JP 3784889B2 JP 18289996 A JP18289996 A JP 18289996A JP 18289996 A JP18289996 A JP 18289996A JP 3784889 B2 JP3784889 B2 JP 3784889B2
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Japan
Prior art keywords
multi
information
value
recording
recording medium
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JP18289996A
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JPH1027396A (en
Inventor
奨 今井
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日立マクセル株式会社
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Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multi-value recording medium capable of multi-value recording and a recording / reproducing apparatus thereof, and more specifically, a multi-value recording medium capable of stable reproduction even when multi-value information and binary information are mixedly recorded. And a recording / reproducing apparatus thereof.
[0002]
[Prior art]
As a means for improving the recording density of a recording medium such as a magnetic disk or a magneto-optical disk, a multi-value recording method for recording multi-value information has attracted attention. For example, in Japanese Patent Application No. 7-109676, the present applicants apply a four-valued external magnetic field to a magneto-optical recording medium having two magnetic layers under light irradiation by applying four values. Shows how to record information and play it back.
[0003]
[Problems to be solved by the invention]
However, the above prior art has the following problems. That is, as the linear recording density increases, it becomes difficult to stably record and reproduce while maintaining compatibility between multi-level recording and binary recording. That is, it is not always stable that user data recorded by binary recording is reproduced by a multi-value recording reproducing device, and conversely, user data recorded by multi-value recording is reproduced by a binary recording reproducing device. I can't do it. This is because it is difficult to make the shape of the isolated waveform recorded in multiple values and the shape of the isolated waveform recorded in binary values the same. For this reason, when a portion recorded by multi-value recording and a portion recorded by binary recording coexist on the same multi-value recording medium, instability during reproduction becomes a particularly serious problem.
[0004]
An object of the present invention is to reduce the above inconveniences and to accurately reproduce user data recorded on a multi-value recording medium having compatibility between multi-value recording and binary recording, and It is to provide the recording / reproducing apparatus.
[0005]
Another object of the present invention is to stably reproduce user data even when a portion recorded by multi-value recording and a portion recorded by binary recording coexist on the same multi-value recording medium. It is an object of the present invention to provide a novel multi-value recording medium and a recording / reproducing apparatus thereof.
[0006]
[Means for Solving the Problems]
According to the first aspect of the present invention, when binary information is recorded at a boundary portion where information per mark recorded in a user data area in which user data can be recorded is switched between multi-value information and binary information. There is provided a multi-value recording medium characterized by providing a boundary region for recording a recording pattern that does not exist in a modulation recording pattern.
[0007]
As a recording pattern that does not exist in the recording pattern of the modulation method when recording binary information according to the first aspect of the present invention, for example, the RLL (2, 7) method is used as a modulation method when recording binary information. Can be used, a recording pattern with a run length of 1 such as 10101010 can be used. By using a device in which it is preset that the recording pattern in the boundary area is a pattern that is not used in the binary recording modulation scheme, the certainty of access to the boundary between binary recording and quaternary recording can be increased.
[0008]
According to the second aspect of the present invention, in a multi-value recording medium capable of reproducing user data using any of multi-value recording and binary recording, any of multi-value recording and binary recording is possible. There is provided a multi-value recording medium characterized in that auxiliary information capable of discriminating whether user data has been recorded using is stored in the multi-value recording medium.
[0009]
In the second aspect of the present invention, the auxiliary information that can determine whether user data is recorded using multi-level recording or binary recording includes an information sequence corresponding to the modulation and coding scheme at the time of recording. But you can. In addition, it is desirable to add redundant bits for error correction to the auxiliary information. The addition of redundant bits for error correction increases the reliability when reading auxiliary information.
[0010]
The auxiliary information of the second aspect of the present invention is recorded on a multi-value recording medium when user data is recorded. Since the auxiliary information includes identification information that makes it possible to determine whether the recording is multi-level recording or binary recording, adaptive processing can be performed when reproducing user data. That is, when it is determined that multi-value recording was performed at the time of user data recording and when it was determined that multi-value recording was performed at the time of user data recording, it is possible to execute reproduction processing by adaptively switching waveform equalization during reproduction. . Correction can be made using the characteristics of a signal obtained by reproducing an information sequence corresponding to the modulation and coding scheme included in the auxiliary information.
[0011]
Next, according to the third aspect of the present invention, when user data is recorded, the user data recorded by multi-value recording and the user data recorded by binary recording are the same multi-value recording medium. There is provided a multi-value recording medium characterized by being mixedly recorded above.
[0012]
In the third aspect of the present invention, the identification information in the auxiliary information that makes it possible to determine whether the recording is multi-value recording or binary recording can be associated with the physical address of the user data. For this reason, it is possible to determine whether the user data of the address desired to be reproduced was multi-value recording or binary recording at the time of recording by using the identification information at the time of user data reproduction. After discriminating between multi-value recording and binary recording at the time of recording, adaptive processing can be performed when user data is reproduced, as in the first aspect of the present invention. Further, it is preferable that information for determining the presence / absence of auxiliary information and information capable of designating a storage position of auxiliary information on a multi-value recording medium are contained in an SFP (Standard Formatted Part) area. This can be dealt with, for example, by using a portion reserved in the conventional SFP area.
[0013]
According to a fourth aspect of the present invention, there is provided a multilevel recording medium characterized in that a data area for recording information on defects of the multilevel recording medium is a data area different in multilevel recording and binary recording. Provided.
[0014]
A recording / reproducing apparatus for recording / reproducing a multilevel recording medium according to the first to fourth aspects of the present invention can determine whether user data is recorded using multilevel recording or binary recording. Auxiliary information is used to adaptively control waveform equalization during user data playback. At this time, it is desirable to perform error correction processing using redundant bits for error correction to control the tracking servo during user data reproduction. By performing error correction processing using redundant bits for error correction, auxiliary information can be generated accurately, and reliability at the time of reproducing user data is eventually increased.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments and examples of the multi-value recording medium and the recording / reproducing apparatus of the present invention will be described below with reference to the drawings.
[0016]
First, an example in which the binary recording area and the multi-value recording area are switched within one track on the multi-value recording medium of the present invention will be described with reference to FIG. FIG. 1 is a conceptual diagram for explaining the boundary region of the present invention. As shown in FIG. 1, a boundary area is provided at a boundary portion where a binary recording area and a multi-value recording area are switched within one track on a recording medium. A recording pattern that does not exist in the recording pattern of the modulation method used when recording binary information is recorded in the boundary area. As a recording pattern that does not exist in the recording pattern of the modulation method when recording binary information, for example, when the RLL (2, 7) method is used as the modulation method when recording binary information, 10101010 A recording pattern with a run length of 1 may be used.
[0017]
Next, using FIG. 2, the waveforms reproduced as MO signals from the multilevel recording medium of the present invention are compared in the multilevel recording area, binary recording area, and boundary area. FIG. 2 conceptually shows a reproduced waveform before waveform equalization. As can be seen from FIG. 2, since the waveform at the time of reproduction is different between the multilevel recording area and the binary recording area, it is preferable to perform waveform equalization adaptively. Further, since the boundary region reproduction waveform of FIG. 2 is a pattern that does not appear in the binary recording region, it can be seen that the boundary region can be easily detected on the apparatus side during reproduction. However, when the recording pattern of the multi-value recording area is regarded as a binary recording pattern, it may coincide with the pattern of the boundary area by chance. Therefore, it is preferable to use address management by a sample servo method, for example.
[0018]
Therefore, in order to enable address management, a multi-value / binary auxiliary information area is provided as shown in FIG. The multi-value / binary auxiliary information recorded in the multi-value / binary auxiliary information area is auxiliary information capable of determining whether multi-value recording or binary recording is used to record user data. As shown in FIG. 4, on the multi-value recording medium of the present invention, a reflection area, a control track PEP area, a transition area, a control track SFP area (SFP1), a manufacturer data area (Mnfctr1), a multivalue / Binary auxiliary information area (SUB1), user data area, multi-value / binary auxiliary information area (SUB2), manufacturer data area (Mnfctr2), control track SFP area (SFP2), lead-out area Has been. The control track PEP area includes information on the modulation method, error correction method, and the like. The control track SFP areas (SFP1) and (SFP2) contain the same information, medium information, system information, and reserve as the PEP. In the present invention, it is preferable to store information on the presence / absence and arrangement of the multilevel / binary auxiliary information areas (SUB1) and (SUB2) in the control track SFP areas (SFP1) and (SFP2). The manufacturer data area (Mnfctr1) and (Mnfctr2) are configured so that the manufacturer test area is sandwiched between guard bands. In FIG. 4, the user data area is sandwiched between the multi-value / binary auxiliary information area (SUB1) and the multi-value / binary auxiliary information area (SUB2). It is desirable to construct an application system in which a normal user cannot access the multi-value / binary auxiliary information area (SUB1) and the multi-value / binary auxiliary information area (SUB2).
[0019]
Next, an example of the data structure recorded in the multi-value / binary auxiliary information area (SUB1) and the multi-value / binary auxiliary information area (SUB2) will be described. An example of the data structure in the case of recording in the multi-value / binary auxiliary information area (SUB1) and the multi-value / binary auxiliary information area (SUB2) of the present invention is shown in FIG. The multi-value / binary auxiliary information itself is recorded by binary recording. In FIG. 5, the same data starts to be recorded from START1 and START2 in the figure in each of the multilevel / binary auxiliary information area (SUB1) and the multilevel / binary auxiliary information area (SUB2). That is, since the multi-value / binary auxiliary information is located in two areas at the start and end of the user data area, the same multi-value / binary auxiliary information is recorded at four locations on the multi-value recording medium. Become. This increases the certainty in reproducing the multi-value / binary auxiliary information. The track address and the sector address of START1 and START2 are preferably arranged so that START2 is arranged exactly in the middle of the multi-value / binary auxiliary information area as shown in FIG. This is because if the track address and the sector address of START1 and START2 are too close, there is a high possibility that both will become erroneous information if there is a defect near one of them. A binary sequence of a specific pattern is stored in START1 and START2, and the start position of the multi-value / binary auxiliary information area is reliably detected.
[0020]
Next, the information included in the multi-value / binary auxiliary information will be further described. The multi-value / binary auxiliary information described above preferably includes identification information that makes it possible to determine whether multi-value recording or binary recording has been selected during recording, and is capable of corresponding to the physical address of the recorded user data. For example, 1 bit is allocated to all sectors of the multi-level recording medium, 1 is recorded for the bit corresponding to the sector accessed during multi-level recording, and it corresponds to the sector accessed during recording in binary recording. It is sufficient to record 0 as the bit to be performed. Alternatively, the address in which user data is recorded in FAT (File Allocation Table) format, and discrimination information between multilevel recording and binary recording may be used as multilevel / binary auxiliary information. The multilevel / binary auxiliary information may include an information sequence corresponding to the modulation and coding scheme at the time of recording. Further, redundant bits for error correction may be added to the multilevel / binary auxiliary information.
[0021]
Note that a normal DDS (Disk Definition Structure) is arranged at the start and end of the user data area. The DDS is used to indicate the position of a DMA (Defect Management Area). The DMA is an area for recording information relating to defects on the disk that cannot be corrected for errors. Conventionally, two areas are located at the start and end of the user data area. A DDS is arranged in the first sector of the DMA, and the DDS has information on a PDL (Primary Defect List) and an SDL (Secondary Defect List). Here, in the SDL, information related to defects in the multilevel recording medium may be recorded in different data areas in the multilevel recording and the binary recording. In this way, adaptive defect management can be performed depending on whether reproduction is multi-level recording or binary recording. However, in this case, it is necessary to consider that there is a risk that the data capacity that can be recorded by the user is reduced.
[0022]
Next, the configuration of the multilevel recording medium recording / reproducing apparatus of the present invention will be described. FIG. 3 is a configuration diagram for explaining the configuration of the multilevel recording medium recording / reproducing apparatus of the present invention. As shown in FIG. 3, the multi-value recording medium recording / reproducing apparatus of the present invention includes a turntable for rotationally driving the multi-value recording medium, and a laser beam for irradiating the multi-value recording medium with recording / reproducing laser light. An optical system, an external magnetic field applying coil for applying an external magnetic field for magneto-optical recording, and a detection system for detecting an MO signal and an RF signal by detecting a polarization component from the reproduction light The multi-value / binary correction circuit is used to stably maintain compatibility between multi-value recording and binary recording reproduction. Here, the external magnetic field application coil is connected to a magnetic field control device including a power source and a driver. The laser controls the irradiation timing and output by the driver, and the magnetic field control device and driver are controlled by a main controller (not shown) so that an external magnetic field is applied in synchronization with the laser beam irradiation timing from the laser. The In the present invention, since the multi-value / binary auxiliary information is recorded on the multi-value recording medium in order to improve the reproduction stability of the multi-value recording and the binary recording as described above, the external magnetic field applying coil is used. Both the connected driver and the driver connected to the laser connect with the multi-value / binary auxiliary information generation part. The detection system for the MO signal and the RF signal includes a detector for detecting a focus error of recording light or reproducing light, a λ / 2 wavelength plate, a phase plate, and a polarization beam splitter for separating P-polarized light and S-polarized light. And a detector for detecting each polarization component, and a MO signal / RF signal detection portion for obtaining an MO signal and an RF signal from the output of the polarization component detector.
[0023]
At the time of recording, the laser beam adjusted to the recording laser output by the driver is irradiated from the laser to the multi-value recording medium through the beam splitter. At this time, an external magnetic field is applied to the recording portion from the external magnetic field application coil in synchronism with the irradiation of the laser light, and magneto-optical recording is executed. The direction of magnetization of the portion that is locally heated by the recording laser light and exceeds the Curie temperature of the recording layer is controlled by an external magnetic field applied based on a recording signal from the main controller. At the time of user data recording, the driver connected to the external magnetic field application coil and the driver connected to the laser have already explained the multi-value / binary auxiliary information generated from the connected multi-value / binary auxiliary information generation part. Record in the multi-value / binary auxiliary information area.
[0024]
When reproducing the recorded data, the laser beam adjusted to the reproduction laser beam intensity by the driver is irradiated from the laser to the multi-value recording medium through the beam splitter. The reflected light from the multi-value recording medium is reflected by the beam splitter and enters the polarization beam splitter through the wave plate and the phase plate. In the polarization beam splitter, it is separated into two orthogonally polarized components and each detected by a corresponding detector. From the detected P deflection component and S deflection component, the MO signal / RF signal detection portion obtains an MO signal and an RF signal. The MO signal is input to a multi-value / binary adaptive waveform equalization circuit, A / D converted in parallel with the clock generation using the RF signal, and the reproduced data is generated using the generated clock. Decrypt. When an address in the user data area including the boundary area is accessed, the reproduction signal is confirmed by confirming that the A / D converted reproduction pattern includes the boundary area reproduction pattern at the time of decoding. Increase the stability of the.
[0025]
At this time, before reproducing user data recorded in the user data area, the multi-value / binary auxiliary information area is necessarily reproduced. As already described, in the multi-value / binary auxiliary information area, the same data is recorded at four locations on the multi-value recording medium, and error correction is possible, so that reliable data reproduction is possible. Therefore, first, multi-value / binary auxiliary information is detected in the multi-value / binary auxiliary information detection portion and input to the multi-value / binary adaptive waveform equalization circuit. The multi-value / binary adaptive waveform equalization circuit adaptively performs waveform equalization based on multi-value / binary auxiliary information when reproducing user data. That is, waveform equalization for multilevel recording is performed for reproduction of the multilevel recording area, and waveform equalization for binary recording is performed for reproduction of the binary recording area. The MO signal and the RF signal that are adaptively waveform-equalized in this way are A / D converted in parallel with the clock generation, and are decoded into reproduced data using the generated clock, thereby providing stable user data. Can be played.
[0026]
【The invention's effect】
According to the present invention, a modulation system recording pattern for recording binary information is recorded at a boundary portion where information per mark recorded in a user data area where user data can be recorded switches between multi-value information and binary information. Has a configuration in which a boundary area for recording a non-existing recording pattern is provided. Therefore, binary recording and four-value recording are performed by a device that sets in advance that the recording pattern in the boundary area is a pattern that is not used in the binary recording modulation method. It becomes possible to improve the stability of access to the boundary of recording.
[0027]
In addition, since the multi-value / binary auxiliary information is configured to store identification information that allows the user data of the address desired to be reproduced to be recorded as multi-valued recording or binary recording, Adaptive waveform equalization becomes possible, and stability during reproduction can be further enhanced. Thereby, user data recorded by multi-value recording and binary recording on the same multi-value recording medium can be mixed.
[0028]
Furthermore, since redundant bits for error correction are added to the multi-value / binary auxiliary information, error correction processing becomes possible, and the auxiliary information can be read accurately with high reliability. Unstable user data reproduction can be avoided by using accurate auxiliary information.
[0029]
In addition, the multi-value recording medium is characterized in that the data area for recording information on defects in the multi-value recording medium is different in multi-value recording and binary recording. To do.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an example in which a boundary region is arranged in one track on a multi-value recording medium of the present invention.
FIG. 2 is an example of a reproduction waveform using the recording medium of the present invention.
FIG. 3 is a configuration diagram for explaining a configuration of a multi-value recording medium recording / reproducing apparatus of the present invention.
FIG. 4 is a conceptual diagram showing an example of each data area arrangement on the multilevel recording medium of the present invention.
FIG. 5 is a conceptual diagram showing an example of a data structure of multi-value / binary auxiliary information on the multi-value recording medium of the present invention.

Claims (11)

  1. In a multi-value recording medium capable of recording multi-value information by applying an external magnetic field, information per mark recorded in a user data area where user data can be recorded is switched between multi-value information and binary information. A boundary area for recording a recording pattern that does not exist in the recording pattern of the modulation method when recording binary information is provided at the boundary, and the binary information is a value obtained by selecting a part of the multi-value information. A multi-value recording medium characterized by the above.
  2. In a multi-value recording medium capable of recording multi-value information by applying an external magnetic field, whether the information per mark recorded in the user data area where user data can be recorded is multi-value information or binary information The multi-value recording medium is characterized in that auxiliary information that can be discriminated is stored in the multi-value recording medium, and the binary information is a value obtained by selecting a part of the multi-value information .
  3.   Auxiliary information capable of determining whether the information per mark recorded in the user data area is multi-value information or binary information is stored in a data area different from the user data area The multi-value recording medium according to claim 1 or 2.
  4.   2. A redundant bit for error correction is added to auxiliary information capable of determining whether the information per mark recorded in the user data area is multi-value information or binary information. Or the multi-value recording medium of 2.
  5.   The user data in which multi-value information is recorded and user data in which binary information is recorded are mixedly recorded in the user data area on the same multi-value recording medium. Or the multi-value recording medium of 2.
  6.   2. The auxiliary information capable of determining whether the information per mark recorded in the user data area is multi-value information or binary information can correspond to a physical address of user data. The multi-value recording medium according to any one of?
  7.   That the SFP area contains information for determining the presence or absence of auxiliary information capable of determining whether the information per mark recorded in the user data area is multi-value information or binary information. The multi-value recording medium according to any one of claims 1 to 6, wherein
  8.   Information that can specify the storage position on the multi-value recording medium of auxiliary information that can determine whether the information per mark recorded in the user data area is multi-value information or binary information is the SFP area. The multi-value recording medium according to claim 1, wherein the multi-value recording medium is contained in the multi-value recording medium.
  9.   9. The multi-value recording medium according to claim 1, wherein the data area for recording information relating to defects in the multi-value recording medium is a data area different in multi-value recording and binary recording.
  10.   The waveform equalization during user data playback is adaptively controlled using auxiliary information capable of determining whether the information per mark recorded in the user data area is multi-value information or binary information. 10. A recording / reproducing apparatus for recording / reproducing information on / from a multi-value recording medium according to claim 1.
  11.   An error correction process is performed using the redundant bits for error correction, and it is determined whether the information per mark recorded in the user data area is multi-value information or binary information. The recording / reproducing apparatus according to claim 10.
JP18289996A 1996-07-12 1996-07-12 Multilevel recording medium and recording / reproducing apparatus thereof Expired - Fee Related JP3784889B2 (en)

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JP18289996A JP3784889B2 (en) 1996-07-12 1996-07-12 Multilevel recording medium and recording / reproducing apparatus thereof

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KR100429179B1 (en) 1998-07-01 2004-06-16 엘지전자 주식회사 Apparatus for managing defect area of optical recording medium and method for managing defect area using the same
DE69927345T2 (en) 1998-07-28 2006-07-13 Lg Electronics Inc. Data recording method and device on optical recording medium
KR100407931B1 (en) 1998-07-29 2004-03-30 엘지전자 주식회사 Real time recording / reproduction file management method, and real-time data recording method and geugwang recording / reproducing medium,
EP1246174A2 (en) 2001-03-30 2002-10-02 TDK Corporation Optical recording method, optical recording medium and optical irradiating time controlling device
EP1246176A2 (en) 2001-03-30 2002-10-02 TDK Corporation Optical recording medium and optical recording method
US6754166B2 (en) 2001-03-30 2004-06-22 Tdk Corporation Optical recording medium and optical recording method
US6699557B2 (en) 2001-03-30 2004-03-02 Tdk Corporation Optical recording medium and optical recording method

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