JPH1027396A - Multi-valued recording medium and recording/ reproducing device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a multi-valued recording/reproducing capable of a stable reproducing by providing a device in which it is preset that a recording pattern in a boundary area is not used in a binary-recording modulation system. SOLUTION: When recorded data are reproduced, a multi-valued recording medium is irradiated with a laser beam adjusted to a laser light intensity for reproduction by a driver through a beam splitter. Reflected light from the multi- valued recording medium is reflected by the beam splitter and is made incident on a polarized light beam splitter through a wave plate and a phase plate. The beam splitter separates the light into two orthogonal polarized components, which are detected by corresponding detectors respectively. From the detected P-polarized light component and S-polarized light component, MO signal and RF signal are obtained at MO/RF signal detection parts respectively. The MO signal is inputted to multi-/binary valued adaptive type wave equalization circuit, and is A/D converted paralleling the clock generation by using RF signal, and is reproduced by using the generated clock.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-level recording medium capable of multi-level recording and a recording / reproducing apparatus for the same, and more particularly, to a stable reproduction even when multi-level information and binary information are recorded in a mixed manner. And a recording / reproducing apparatus for the same.

[0002]

2. Description of the Related 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, the present applicants disclosed in Japanese Patent Application No. Hei 7-109676 a quaternary value by applying an external magnetic field having four types of modulation intensities to a magneto-optical recording medium having two magnetic layers under light irradiation. It shows how to record information and play it back.

[0003]

However, the above prior art has the following problems. That is, as the linear recording density increases, it is difficult to stably perform recording and reproduction while maintaining compatibility between multi-level recording and binary recording. That is, it is not always stable to reproduce user data recorded by binary recording with a multi-level recording playback device, or conversely, to reproduce user data recorded by multi-level recording with a binary recording playback device. I can't. This is because it is difficult to make the shape of the multi-value recorded isolated waveform the same as that of the binary recorded isolated waveform. For this reason, when a part recorded by multi-value recording and a part recorded by binary recording are mixed on the same multi-value recording medium,
Instability during playback is a particularly serious problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a multi-valued recording medium for accurately reproducing user data recorded on a multi-valued recording medium having compatibility between multi-value recording and binary recording. An object of the present invention is to provide a recording medium and a recording / reproducing apparatus therefor.

Another object of the present invention is to stabilize user data even when a portion recorded by multi-value recording and a portion recorded by binary recording are mixed on the same multi-value recording medium. It is an object of the present invention to provide a novel multi-valued recording medium capable of reproducing by using the same, and a recording and reproducing apparatus for the same.

[0006]

According to a first aspect of the present invention, information per mark recorded in a user data area in which user data can be recorded is provided at a boundary where the information is switched between multi-value information and binary information. (2) A multi-level recording medium is provided in which a boundary area for recording a recording pattern that does not exist in a modulation pattern recording pattern when recording binary information is provided.

As a recording pattern which does not exist in the modulation pattern for recording binary information according to the first aspect of the present invention, for example, RLL (2,2) is used as a modulation method for recording binary information. 7) When the method is used, 101
A recording pattern having a run length of 1, such as 01010, can be used. The recording pattern of the boundary area is 2
By using a device in which a pattern that is not used in the value recording modulation method is set in advance, it is possible to increase the reliability of access to the boundary between binary recording and quaternary recording.

According to a second aspect of the present invention, a multi-level recording medium capable of reproducing user data by using either a multi-level recording or a binary recording is provided. A multi-value recording medium is provided, in which auxiliary information capable of determining which of the recordings is used to record the user data is stored in the multi-value recording medium.

The auxiliary information according to the second aspect of the present invention, which can determine whether the user data is recorded by using multi-level recording or binary recording, includes information corresponding to a modulation and coding method at the time of recording. A sequence may be included. 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.

The auxiliary information according to the second aspect of the present invention is recorded on a multi-value recording medium when recording user data. Since the auxiliary information includes identification information that can determine whether the recording is multi-value recording or binary recording,
Adaptive processing becomes possible when reproducing user data. That is, when it is determined that multi-level recording is performed when recording user data, and when it is determined that multi-level recording is performed when recording user data, reproduction processing can be executed by adaptively switching waveform equalization during reproduction. . The correction can be performed by using the characteristics of the signal obtained by reproducing the information sequence corresponding to the modulation and coding method included in the auxiliary information.

Next, according to a third aspect of the present invention, when the user data is recorded, the user data recorded in the multi-level recording and the user data recorded in the binary recording have the same number. A multi-value recording medium characterized by being recorded on a value recording medium in a mixed manner is provided.

According to a third aspect of the present invention, the identification information in the auxiliary information, which can determine whether the recording is multi-value recording or binary recording, can correspond to the physical address of the user data. . Therefore, when the user data is reproduced, the identification information is used to determine whether the user data at the address desired to be reproduced is multi-valued at the time of recording.
It can be determined whether or not the value was recorded. When recording, whether multi-level recording
After the determination of binary recording, adaptive processing can be performed when user data is reproduced, as in the first embodiment of the present invention. Further, it is preferable that information for determining the presence or absence of the auxiliary information and information for specifying the storage position of the auxiliary information on the multi-value recording medium are included in an SFP (Standard Formatted Part) area. This can be dealt with, for example, by using a reserved portion in the conventional SFP area.

According to a fourth aspect of the present invention, a data area for recording information relating to a defect of a multi-level recording medium is a different data area between multi-level recording and binary recording. A recording medium is provided.

A recording / reproducing apparatus for recording / reproducing a multi-value recording medium according to the first to fourth aspects of the present invention determines whether the user data is recorded using multi-value recording or binary recording. Waveform equalization at the time of user data reproduction is adaptively controlled using the distinguishable auxiliary information. At this time, it is desirable to perform error correction processing using redundant bits for error correction to control the tracking servo at the time of user data reproduction. By performing error correction processing using redundant bits for error correction, auxiliary information can be accurately generated, and the reliability at the time of reproducing user data is increased.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments and examples of a multi-value recording medium and a recording / reproducing apparatus for the same according to the present invention will be described with reference to the drawings.

First, an example in which a binary recording area and a multi-level recording area are switched within one track on the multi-level recording medium of the present invention will be described with reference to FIG. FIG. 1 is a conceptual diagram for explaining a boundary region according to the present invention. As shown in FIG. 1, a boundary area is provided at a boundary where a binary recording area and a multi-value recording area are switched within one track on a recording medium. 2 in the border area
A recording pattern that does not exist in the recording pattern of the modulation method when recording the value information is recorded. 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 the binary information, 10101
A recording pattern having a run length of 1, such as 010, may be used.

Next, referring to FIG. 2, a waveform reproduced as an MO signal from the multi-value recording medium of the present invention is represented by a multi-value recording area,
The comparison is made in the binary recording area and the boundary area. FIG. 2 conceptually shows a reproduced waveform before waveform equalization. From FIG. 2, it can be seen that the waveforms at the time of reproduction are different between the multi-valued recording area and the binary recording area, so that it is preferable to adaptively perform waveform equalization. Also, since the reproduced waveform of the boundary region in 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 device side during reproduction. However,
When the recording pattern in the multi-valued recording area is regarded as a binary recording pattern, there is a possibility that the pattern becomes accidentally equal to the pattern in the boundary area. Therefore, for example, it is preferable to use address management by a sample servo method.

Therefore, in order to enable address management, a multi-value / binary auxiliary information area is provided as shown in FIG. The multi-valued / binary auxiliary information recorded in the multi-valued / binary auxiliary information area is auxiliary information that can determine whether user data is recorded using multi-value recording or binary recording. As shown in FIG. 4, on the multi-value recording medium of the present invention,
Reflection area, control track PEP area, transition area, control track SFP area (SFP1),
Manufacturer data area (Mncttr1), multi-valued / binary auxiliary information area (SUB1), user data area, multi-valued / binary auxiliary information area (SUB2), manufacturer data area (Mncttr2), control track SFP An area (SFP2) and a lead-out area are arranged. The control track PEP area includes information on a modulation method, an error correction method, and the like. Control track SFP area (SFP1), (SFP
2) includes the same information as PEP, medium information, system information, and reserve. In the present invention, multi-value / 2
It is preferable to store information on the presence / absence and arrangement of the value auxiliary information areas (SUB1) and (SUB2) in the control track SFP areas (SFP1) and (SFP2). Manufacturer data area (Mnfctr1), (Mnf
ctr2) has a configuration in which a manufacturer test region is sandwiched between guard bands. In FIG. 4, the user data area is sandwiched between a multi-valued / binary auxiliary information area (SUB1) and a multi-valued / binary auxiliary information area (SUB2). It is desirable to construct an application system in which ordinary users cannot access the multi-valued / binary auxiliary information area (SUB1) and the multi-valued / binary auxiliary information area (SUB2).

Next, a multi-valued / binary auxiliary information area (SUB
An example of the data structure recorded in 1) and the multi-value / binary auxiliary information area (SUB2) will be described. FIG. 5 shows an example of the data structure when recording in the multi-valued / binary auxiliary information area (SUB1) and the multi-valued / binary auxiliary information area (SUB2) of the present invention. The multi-valued / binary auxiliary information itself is recorded by binary recording. In FIG. 5, the multi-valued / binary auxiliary information area (SUB1) and the multi-valued / binary auxiliary information area (SUB2)
, The same data is started to be recorded from START1 and START2 in the figure. That is, since the multi-valued / binary auxiliary information is located in two regions at the beginning and the end of the user data area, the same multi-valued / binary auxiliary information is recorded at four places on the multi-valued recording medium. Become. This increases the certainty in reproducing the multi-valued / binary auxiliary information. As shown in FIG. 5, the track address and the sector address of START1 and START2 are located just in the middle of the multi-valued / binary auxiliary information area.
Is preferably arranged. This is STAR
This is because if the track address and the sector address of T1 and START2 are too close, if there is a defect near one of them, the possibility that both will be erroneous information increases. In START1 and START2, a binary sequence of a specific pattern is stored to ensure detection of the start position of the multi-value / binary auxiliary information area.

Next, the information of the multi-valued / binary auxiliary information will be further described. It is desirable that the above-mentioned multi-value / binary auxiliary information includes identification information that enables discrimination between multi-value recording and binary recording at the time of recording, and can correspond to the physical address of the recorded user data. To this end, for example, one bit is allocated to all sectors of the multi-level recording medium, and the bit corresponding to the sector accessed at the time of recording in the multi-level recording is set to 1, and the bit corresponding to the sector accessed at the time of recording in the binary recording is recorded. The bit to be recorded may be recorded as 0. Alternatively, FAT (File Alloca
An address in which user data is recorded, and information for discriminating between multi-valued recording and binary recording may be used as multi-valued / binary auxiliary information. The multi-level / binary auxiliary information may include an information sequence corresponding to the modulation and coding method at the time of recording. Further, redundant bits for error correction may be added to the multi-valued / binary auxiliary information.

The start and end portions of the user data area usually include a DDS (Disk Definition Structure).
To place. DDS is DMA (Defect Management Area)
Is used to indicate the position of The DMA is an area for recording information on an error-correctable defect on a disk. Conventionally, two areas are located at the start and end of the user data area. In the first sector of the DMA, a DDS is arranged, and information on a PDL (Primary Defect List) and an SDL (Secondary Defect List) is stored in the DD.
S has. Here, information on defects of the multi-level recording medium may be recorded in the SDL in different data areas for multi-level recording and binary recording. This makes it possible to perform adaptive defect management in accordance with either multi-valued 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.

Next, the configuration of the multi-level recording medium recording / reproducing apparatus of the present invention will be described. FIG. 3 is a configuration diagram for explaining the configuration of the multi-level recording medium recording / reproducing apparatus of the present invention. As shown in FIG. 3, the multi-level recording medium recording / reproducing device of the present invention includes a turntable for rotating and driving the multi-level recording medium, and a laser beam for irradiating the multi-level recording medium with laser light for recording / reproduction. 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 a component of a polarization component from the reproduction light to detect an MO signal and an RF signal. And a multi-level / binary correction circuit for stably maintaining compatibility between multi-level recording and binary recording reproduction.
Here, the external magnetic field applying coil is connected to a magnetic field control device and a driver including a power supply therein. The irradiation timing and output of the laser are controlled by its driver,
The magnetic field control device and the driver are collectively controlled by a main controller (not shown) so that an external magnetic field is applied in synchronization with the timing of irradiating a laser beam from a laser. In the present invention, since the multi-value / binary auxiliary information is recorded on the multi-value recording medium in order to enhance the stability of the multi-value recording and the reproduction of the binary recording as described above, the external magnetic field applying coil is Both the connected driver and the driver connected to the laser are connected to 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 the recording light or the reproduction light, a λ / 2 wavelength plate and 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 outputs of the polarization component detectors.

At the time of recording, a laser beam adjusted to a recording laser output by a driver is emitted from a laser to a multilevel recording medium via a beam splitter. At this time, an external magnetic field is applied to the recording unit from the external magnetic field applying coil in synchronization with the irradiation of the laser light, and magneto-optical recording is performed. The direction of magnetization of a portion of the recording layer, which has been locally heated by the recording laser beam and has exceeded the Curie temperature, is controlled by an external magnetic field applied based on a recording signal from the main controller. In recording user data, the driver connected to the external magnetic field applying coil and the driver connected to the laser have already explained the multi-valued / binary auxiliary information generated from the connected multi-valued / binary auxiliary information generation part. It is recorded in the multi-valued / binary auxiliary information area.

When reproducing recorded data, a laser beam adjusted to a reproducing laser beam intensity by a driver is emitted from a laser to a multilevel recording medium via a beam splitter. The reflected light from the multilevel recording medium is
The light is reflected by the beam splitter, and enters the polarization beam splitter via the wave plate and the phase plate. In the polarization beam splitter, the light is separated into two orthogonal polarization components and detected by the corresponding detectors. From the detected P deflection component and S deflection component, the MO signal / RF signal is obtained in the MO signal / RF signal detection section. The MO signal is input to a multi-level / binary adaptive waveform equalization circuit,
A / D conversion is performed in parallel with generation of a clock using a signal, and decoding into reproduced data is performed using the generated clock. When an address in the user data area including the boundary area is accessed, it is necessary to confirm that the A / D-converted reproduction pattern includes the reproduction pattern of the boundary area at the time of decoding. Increase stability.

At this time, before reproducing the user data recorded in the user data area, the multi-value / binary auxiliary information area is always reproduced. As described above, 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 also possible, so that reliable data reproduction is possible. Therefore, first, the multi-valued / binary auxiliary information is detected in the multi-valued / binary auxiliary information detection portion and input to the multi-valued / binary adaptive waveform equalizer. The multi-level / binary adaptive waveform equalization circuit adaptively performs waveform equalization based on the multi-level / binary auxiliary information when reproducing user data. That is, waveform equalization for multi-level recording is performed for reproduction of the multi-value recording area, and waveform equalization for binary recording is performed for reproduction of the binary recording area. MO adaptively equalized in this way
The signal and the RF signal are A / D
The converted data is decoded into reproduction data using the generated clock, and stable reproduction of user data becomes possible.

[0026]

According to the present invention, 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 is provided.
Since a boundary area for recording a recording pattern that does not exist in the modulation pattern when recording the value information is provided, the recording pattern in the boundary area is a pattern not used in the binary recording modulation method. It is possible to improve the stability of access to the boundary between binary recording and quaternary recording by using a device in which is set in advance.

[0027] Further, since multi-value / binary auxiliary information is stored with identification information capable of discriminating whether user data at an address desired to be reproduced is multi-value recording or binary recording. In addition, adaptive waveform equalization can be performed during reproduction, and the stability during reproduction can be further improved. This makes it possible to mix user data recorded by multi-level recording and binary recording on the same multi-level recording medium.

Further, since redundant bits for error correction are added to the multi-valued / binary auxiliary information, error correction can be performed, and the auxiliary information can be accurately read out with high reliability. By using accurate auxiliary information, unstable user data reproduction can be avoided.

Further, the data area for recording information relating to the defect of the multi-level recording medium is a different data area between the multi-level recording and the binary recording. Management is stable.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example in which a boundary area is arranged within one track on a multilevel recording medium according to the present invention.

FIG. 2 is an example of a reproduced waveform using the recording medium of the present invention.

FIG. 3 is a configuration diagram for explaining a configuration of a multi-level recording medium recording / reproducing apparatus of the present invention.

FIG. 4 is a conceptual diagram showing an example of an arrangement of each data area on a multi-value 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 a multi-value recording medium of the present invention.

Claims (11)

[Claims] 1. A multi-valued recording medium capable of recording multi-valued information by applying an external magnetic field, wherein information per mark recorded in a user data area in which user data can be recorded is multi-valued information. A multi-valued recording medium characterized by providing a boundary area for recording a recording pattern that does not exist in a modulation pattern recording pattern for recording binary information, at a boundary portion that switches to binary information. 2. A multi-valued recording medium capable of recording multi-valued information by applying an external magnetic field, wherein information per mark recorded in a user data area in which user data can be recorded is multi-valued information. A multi-value recording medium, characterized in that auxiliary information capable of determining whether the information is present or binary information is stored in the multi-value recording medium. 3. An auxiliary information which can determine whether 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, wherein: 4. A redundant bit for error correction is added to auxiliary information capable of determining whether information per mark recorded in the user data area is multi-valued information or binary information. The multi-value recording medium according to claim 1 or 2, wherein 5. The user data area, wherein user data on which multi-value information is recorded and user data on which binary information is recorded are mixedly recorded on the same multi-value recording medium. The multi-value recording medium according to claim 1 or 2, wherein 6. An auxiliary information capable of determining whether information per mark recorded in the user data area is multi-valued information or binary information can correspond to a physical address of user data. The multi-value recording medium according to claim 1. 7. Information for discriminating presence / absence of auxiliary information capable of discriminating whether information per mark recorded in the user data area is multi-value information or binary information is provided.
2. The composition according to claim 1, wherein the compound is contained in an SFP region.
7. The multivalued recording medium according to any one of items 1 to 6, 8. A storage position on a multi-level recording medium of auxiliary information capable of determining whether information per mark recorded in the user data area is multi-level information or binary information can be designated. 8. The multi-value recording medium according to claim 1, wherein the information is contained in an SFP area. 9. The multi-level recording medium according to claim 1, wherein a data area for recording information relating to a defect of the multi-level recording medium is a different data area between multi-level recording and binary recording. Multi-value recording medium. 10. A waveform equalizer at the time of reproducing user data is adapted by using auxiliary information capable of determining whether information per mark recorded in the user data area is multi-value information or binary information. The recording / reproducing apparatus for recording / reproducing on / from a multi-value recording medium according to any one of claims 1 to 9, wherein the recording / reproducing apparatus performs the control. 11. An error correction process is performed using the redundant bits for error correction to determine whether information per mark recorded in the user data area is multi-level information or binary information. The recording / reproducing apparatus according to claim 10, wherein: