WO2011118070A1

WO2011118070A1 - Optical disc and optical disc device

Info

Publication number: WO2011118070A1
Application number: PCT/JP2010/068383
Authority: WO
Inventors: 育則久保
Original assignee: 日立コンシューマエレクトロニクス株式会社
Priority date: 2010-03-24
Filing date: 2010-10-19
Publication date: 2011-09-29
Also published as: JP2011198444A

Abstract

When manufacturing multi-layer optical discs and high density optical discs, it is assumed that the reflectance and plate thickness etcetera of each recording disc will need to be more rigorously managed than has previously been the case, creating an excessive burden on disc makers. Furthermore, even if reproduction conditions are recorded on a disc, an optical disc device cannot carry out reproduction under suitable conditions at the point of reading out those conditions, and there are concerns that the device might not be able to read the recorded reproduction conditions. In order to resolve the above problems, in the disclosed optical disc, optimum reproduction conditions for the disc (for example, the reproduction laser power etcetera) are recorded in a region on the disc wherein reproduction is possible under the unambiguously prescribed reproduction conditions. An optical disc device reads the recorded reproduction conditions under the unambiguously prescribed reproduction conditions, and reproduction becomes possible through setting to data reproduction time.

Description

Optical disc and optical disc apparatus

The present invention relates to an optical disc and an optical disc apparatus for recording and reproducing data.

Patent Document 1 below describes that an optimum gain value of a limit equalizer obtained by analyzing an information carrier in advance is stored on the information carrier, and this value is set when the disk device reads and reproduces the value. Has been.

Special table 2008-521155

In general, the conditions for reproducing data properly for optical disks are defined by the disk standards. For example, in a single-layer, write-once Blu-ray Disc (BD-R) having one recording layer on which data is recorded, the laser emission power irradiated when reading data from the disc is 0.35 mW, The disc standard stipulates that data is appropriately reproduced when the gain value of the equalizer that processes the read reproduction signal is 7 dB.

Therefore, when producing a BD-R, a disc manufacturer needs to produce a disc having characteristics that allow data to be properly reproduced under the reproduction conditions defined in the disc standard.

Since the disc is manufactured in accordance with the disc standard in this manner, the optical disc apparatus can reproduce data properly by applying the reproduction conditions defined in the disc standard when reproducing the BD-R disc. Will be able to.

However, as the capacity of optical discs increases in the future and the recording layers become multi-layered / densified, it is considered that the influence of the reflectivity and plate thickness error of each recording layer on the reproduction performance is further increased. In order to minimize this effect, the quality of each recording layer must be strictly controlled, and it is expected that an excessive load will be generated on the disc manufacturer.

Further, when data is reproduced from a multilayer disc or a high density disc that makes quality control difficult as described above, even if the reproduction conditions are recorded on the disc as described in Patent Document 1, for example, At the time of reading out, there is a concern that it cannot be reproduced under appropriate conditions, and the recorded reproduction condition itself cannot be read.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical disc that solves the above-described problems, can reduce a load generated when a disc manufacturer manufactures a disc, and can read data recorded on the disc with high quality. And

The above problem is solved by the invention described in the scope of claims as an example.

According to the present invention, the above-mentioned problems are solved, and the disk manufacturer can relax the specifications of the disk by the present invention, and can easily manufacture a multilayer disk and a high-density disk. Further, the optical disk device can read out the data recorded on each recording layer with high quality by reading the optimum reproduction condition from the disk.

It is a figure which shows an example of the reproduction | regeneration quality characteristic of the optical disk with respect to reproduction | regeneration laser power. It is a figure which shows the structural example of the optical disk of this invention. It is a figure which shows the example of the power management area | region of the optical disk of this invention. It is a block diagram which shows the structural example of the optical disk apparatus for reproducing | regenerating the optical disk of this invention. 5 is a flowchart showing a setup process of the optical disc apparatus. 5 is a flowchart showing a reproduction process of the optical disc apparatus.

First, an embodiment of an optical disc according to the present invention will be described with reference to FIG.

FIG. 1 shows an example of reproduction quality characteristics of an optical disc with respect to reproduction laser power. In FIG. 1, the horizontal axis 101 represents the reproduction laser power set when reading data. A vertical axis 102 represents a quality index value (for example, the number of reproduction errors) when the data recorded on the optical disk is reproduced, and indicates that the reproduction quality is good as it goes downward. A straight line 103 represents a reference value of a reproduction quality index at which recorded data can be reproduced, and indicates that data can be read from the disc if this reference value is satisfied.

Curves

104 and 105 represent the reproduction quality characteristics of the optical disk. The reproduction quality is the best at reproduction laser power P0 in characteristic 104 and reproduction laser power P1 in characteristic 105. Hereinafter, the reproduction laser power with the best reproduction quality such as P0 and P1 is referred to as the optimum power.

The optical disk of the present embodiment records the optimum power P0 on the disk if the characteristic of the optical disk has 104, for example, and records the optimum power P1 on the disk if the characteristic of the optical disk has 105, for example. It is a feature to keep. In addition, the area where the optimum power is recorded is an area where reproduction is possible with a uniquely determined reproduction laser power. Hereinafter, the area for recording the optimum power is referred to as a power management area, and the laser power for reproducing the uniquely determined area is referred to as management data power.

A disk manufacturer that manufactures the disk of the present invention analyzes the reproduction quality characteristics of the disk to determine the optimum power, and records the power in the power management area in advance. On the other hand, when the disc of the present invention is inserted, the optical disc apparatus reads the optimum power information recorded in the power management area using the management data power, and reproduces the read optimum power in each area on the disc. Set to to play data.
According to the present invention, since the optimum power is recorded on the disc as the specification of the disc, the disc manufacturer does not need to uniquely define the disc characteristics, and the restrictions on the disc characteristic variations that occur during disc manufacture are relaxed. Thus, the disk can be easily manufactured. In addition, the optical disk apparatus can read the optimum power from the disk by reproducing the area where the optimum power is recorded with the management data power so that the optimum power can be reliably read regardless of the characteristics of the disk. Problems that cannot be solved.

Also, the tolerance to reproduction laser power (reproduction light resistance) varies depending on the disc manufacturer or the difference in the composition of the recording film for each layer of the multi-layer disc. By setting the power higher than the standard value at which playback is possible as the optimum power, the playback quality can be improved and the reliability can be improved.

Note that the reference value 103 in FIG. 1 may be a level at which an error can be sufficiently corrected by, for example, an error correction code recorded together with data. As a method for measuring the reproduction quality characteristic of the disc, an error rate, jitter, etc. of reproduction data generally used in the conventional optical disc apparatus may be measured.

In the present embodiment, the features of the optical disk of the present invention have been described by taking the reproduction laser power as an example. However, this is only an example, and an equalizer gain value used for reproduction signal processing may be used. Alternatively, it may be a reference level value (for example, PR (1, 2, 2, 2, 1)) of a Viterbi decoder included in PRML (Partial-Response Maximum-Likelihood) which is a reproduction signal detection method obtained from a disc. Since PRML is a known technique, description thereof is omitted here.

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

The optical disc of the present invention can be realized with the configuration of an optical disc as shown in FIG.

FIG. 2 is a diagram showing a configuration example of the optical disc of the present invention having three recording layers. Let each recording layer be L0, L1, L2 from the disk surface side. The optical disc 201 has a BCA (Burst Cutting Area) area 202, a first management data area 203, a user data area 204, and a second management data area 205 from the inner periphery side.

The BCA area 202 is an area for recording data immediately after manufacture of the disk, and for example, identification data of the disk is recorded. The user data area 204 is an area in which user data is written, and audio / video data and the like are recorded. The

management data areas

203 and 205 are areas in which data managed by the optical disc apparatus is written, and record data recording conditions, disc defect management information, and the like.

In the BCA area 202, data is generally described by a barcode, and the recording density is independent of other areas. These are recorded by burning off the reflective film with a powerful infrared laser called YAG laser after manufacturing the disk. This area has a low data recording density and a format that can be easily reproduced by the optical disc apparatus. When the optical disk apparatus performs focusing servo to the recording layer at the BCA radial position, the reflected light level from the optical disk becomes bar code data that repeats strength. This bar code data is a BCA code. Thus, in order to read out the BCA code, only the focusing servo needs to be performed, and the tracking servo is unnecessary.

Thus, the BCA area 202 has playback conditions independent of other areas, and it can be said that the playback conditions are uniquely determined regardless of the characteristics of the disc. Therefore, in the optical disc of the present invention, for example, the BCA area 202 is used as a power management area, and the optimum powers of L0, L1, and L2 are recorded in this area.

Note that it is preferable that the optimum power recorded on the disc includes all optimum powers corresponding to the respective recording areas of all the recording layers. In addition, it is efficient in terms of access that only one recording layer exists in the power management area, but this is an example, and the power management area may be provided in each of a plurality of layers. Further, it may be provided anywhere from the inner periphery to the outer periphery of the disk.

FIG. 3 shows an example of the power management area in the optical disc of this embodiment. For example, in a conventional disk configuration such as BD-R, (a) BCA area or (b) PIC (Permanent Information & Control Information) area may be mentioned. The BCA area (a) is an area where disc identification data and the like are recorded with a barcode as described above. The PIC area (b) is a management data area in the BD-R, and is formed of, for example, a high-frequency groove (a rectangular wave groove). This area is formed in the same manner as the wobbled groove in the data area by a stamper or the like at the time of manufacturing the disk, and recording conditions and the like determined in advance at the time of manufacturing the disk are recorded. Like these areas (a) and (b), it is desirable that the power management area be an area where the recording density is lower than other areas and reproduction is easy. Alternatively, as shown in (c), a data density may be made lower than that of the other region by providing a region formed by a groove having a lower wobble frequency than the other region. Further, as shown in (d), even if the density is the same as the data area, it may be an area having a higher reflectance than the other areas. If the area as shown in (d) is used as the power management area, a good S / N ratio can be obtained even when the optical disc apparatus reads out the optimum power when reproducing a multi-layer disc having 10 or more recording layers, for example. Can do.

When reproducing the optical disk according to the present invention, it is not necessary to add a special function to a general optical disk apparatus. For example, with the configuration of a conventional optical disk apparatus as shown in FIG. It can be played back by devising.

4, 401 is an optical disk, 402 is an optical pickup, 403 is a laser control unit, 404 is a reproduction signal processing unit, 405 is a spindle control unit, 406 is a servo control unit, 407 is a system control unit, and 408 is a storage unit. An optical disc 401 represents an optical disc according to the present invention, and reference numeral 409 shown in the optical disc 401 represents a power management area in which the optimum power of the optical disc 401 is recorded in advance. For the storage unit 408, for example, a memory is used.

First, basic playback processing of the optical disc apparatus will be described with reference to FIG.

When the data reproduction process of the optical disc 401 is started, the system control unit 407 controls the spindle control unit 405 and the servo control unit 406 to rotate the optical disc 401 and position the optical pickup 402 at the reproduction start position, and then the optical pickup 402. The laser controller 403 is controlled so that the laser on the optical head above emits light with a desired reproduction power. The laser control unit 403 emits a laser beam that emits light with a desired reproduction power. The light spot of the irradiated laser beam is focused on the position where data is to be reproduced from the optical disc 401. The reflected light of the laser beam irradiated on the optical disc 401 is converted into an electric signal by the light receiving element of the optical pickup 402 or the like. The electrical signal output from the optical pickup 402 is sent to the reproduction signal processing unit 404, subjected to analog signal processing such as signal amplitude adjustment, digital signal processing such as binarization processing, and the like. It is converted into digital data that is a bit string. In this way, data reproduction processing is performed.

In this embodiment, the optimum power is read from the power management area on the disk using the management data power during the setup process for the inserted disk, and the read optimum power is applied when reproducing each area. Good reproduction quality can be obtained.

FIG. 5 is a flowchart showing a part of the flow of the setup process in the present embodiment. When the setup process of the optical disc 401 is started, the system control unit 407 first sets the management data power for reproducing the power management area 409 by controlling the laser control unit 403 (S501). Then, the area 409 is reproduced by the reproduction process described above (S502). The data read from the area 409 includes the optimum power for reproducing the optical disc 401, and the system control unit 407 stores the acquired data in the storage unit 408 (S503).

The processing described above is included in the setup processing in this embodiment.

FIG. 6 is a flowchart showing the flow of the reproduction process in this embodiment. When the data reproduction process is started, the system control unit 407 first reads the optimum power of the reproduction target area stored in the storage unit 408, for example, and controls the laser control unit 403 to obtain the read optimum power. Setting is made (S601). Then, the data recorded in the reproduction target area is reproduced under the optimum power (S602).
Thus, according to the present invention, good reproduction performance can be obtained by setting the optimum power in each recording area in the reproduction operation. And since this optimal power is acquired from the data read at the time of setup, it is not necessary to perform a useless process and is efficient.

For example, even when a multi-layer disc composed of two or more recording layers or a disc having the same recording layer and different recording density in each area, the optimum power for each recording layer and each density is recorded on the disc in advance. However, by performing the processing as shown in FIGS. 5 and 6, it is possible to perform the optimal reproduction processing for each region.

Note that FIG. 4 shows only parts necessary for explaining the present embodiment. Further, each part shown in FIG. 4 is a part provided in a normal optical disc apparatus. Therefore, the storage unit 408 in FIG. 4 does not need to be individual, and may actually be allocated to a partial area of the rewritable nonvolatile memory used by the system control unit 407, for example.

As described above, when this embodiment is used, even when the optimum power is unknown when reproducing the data recorded on the disc, the optimum power is recorded in the power management area in advance, and the optimum power is recorded as the management data power. Since the data can be read by performing the reproduction process after reading and setting, the optical disc apparatus can execute an appropriate reproduction process.

In the present embodiment, the above description has been made with reference to the physical structure of a general optical disc. However, the format of the disc does not have to be a conventional method, and the structure itself does not have to be a structure like an optical disc. . That is, in the above description, the reproduction process on the optical disk is taken as an example. However, if the reproduction condition is recorded on the data recording medium and the condition is read and set, the recorded data can be read out. This is effective not only for optical disks. That is, the present invention records not only the optical disc but also other data recording media, by recording the reproduction conditions of each recording area on the medium, and manufacturing a data recording medium having a recording area that can be reproduced under those conditions. It can also be implemented in a hologram memory or the like.

In addition, this invention is not limited to the above-mentioned Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

In addition, each of the above-described configurations may be configured such that a part or all of the configuration is configured by hardware, or is realized by executing a program by a processor. Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

101 ... Reproduction laser power, 102 ... Reproduction quality index value,
103: reproduction quality reference value, 104, 105: reproduction quality characteristics of the optical disc,
201: optical disc, 202: BCA area,
203 ... first management data area, 204 ... user data area,
205 ... second management data area,
401: optical disk, 402: optical pickup,
403 ... Laser control unit, 404 ... Reproduction signal processing unit,
405 ... Spindle control unit, 406 ... Servo control unit,
407 ... System control unit, 408 ... Storage unit 409 ... Power management area.

Claims

An optical disc comprising one or more recording layers,
A first data recording area which can be reproduced under a uniquely defined first reproduction condition;
A second data recording area that can be reproduced under the second reproduction condition;
An optical disc, wherein the second reproduction condition is recorded in the first data recording area.
The optical disc according to claim 1,
The optical disk characterized in that the reproduction condition is a light emission power of a laser.
The optical disc according to claim 1,
The playback conditions are:
An optical disc characterized in that it is an equalizer gain value used when processing a reproduction signal read from the optical disc.
The optical disc according to claim 1,
The playback conditions are:
An optical disc characterized in that it is a reference level value for Viterbi decoding of PRML (Partial-Response Maximum-Likelihood) which is a reproduction signal detecting means.
The optical disc according to claim 1,
An optical disc characterized in that a BCA (Burst Cutting Area) area or a PIC (Permanent Information & Control data) area is used as the first data recording area.
The optical disc according to claim 1,
The optical disk according to claim 1, wherein the first data recording area is an area having a higher reflectance than the second data area.
The optical disc according to claim 1,
The optical disk according to claim 1, wherein the first data recording area is an area having a recording density lower than that of the second data area.
The optical disc according to claim 1,
The second data recording area has a plurality of data recording areas with different reproduction conditions,
An optical disc, wherein a plurality of the second reproduction conditions respectively corresponding to the plurality of data recording areas are recorded in the first data recording area.
An optical disk device capable of reproducing an optical disk,
An optical pickup that emits laser light toward the optical disc;
A laser controller for controlling the laser light emitted from the optical pickup;
A reproduction signal processing unit for processing a reproduction signal obtained from the optical disc;
A system control unit for controlling the optical pickup, the laser control unit, and the reproduction signal processing unit;
With
The optical disc includes a first data recording area that can be reproduced under a uniquely defined first reproduction condition, and a second data recording area that can be reproduced under a second reproduction condition. The second reproduction condition is recorded in the data recording area,
The system control unit reads the second reproduction condition recorded in the first data recording area by using the first reproduction condition, and reads the read second reproduction condition to the laser processing unit. And / or controlling to set to the reproduction signal processing unit.