JP2004178650A - Information recording method and disk apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure reliability in reproduction compatibility in a DVD player by correcting a recording start position for recording according to the amount of eccentricity in an optical disk so that a gap section that has not yet been recorded is not formed at a linking section in DVD-R recording. <P>SOLUTION: A means for measuring the amount of eccentricity in the optical disk is provided, recording timing, where a recording start position is corrected, is generated according to the amount of eccentricity, and additional recording is started. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an information recording method and a disk device, and particularly, when additionally recording data on a disk, a gap portion where data is not recorded is formed between an end portion of recorded data and a start end of data to be additionally recorded. The present invention relates to a technique related to a recording method in which data is continuously recorded so as not to be formed.
[0002]
[Prior art]
An optical disc can store a relatively large amount of information. Among such optical discs, a DVD that can handle a large amount of information such as computer data, video data, and music data on a common recording medium is used for a PC, an AV device, or the like. It is attracting attention as a new large-capacity storage medium, and the market is rapidly expanding due to the spread of DVD players and the emergence of DVD recorders.
[0003]
Also, with the spread of recordable optical disks, compatibility of optical disk media is regarded as important as a user's request. However, many DVD players that are already widely used are not compatible because they do not support the rewritable formats (DVD-RAM, DVD-RW, etc.) employed in DVD recorders. Therefore, with the establishment of DVD-R for General Ver 2.0 conforming to the DVD-Video format, DVD players will also support DVD-R media, which are recordable optical disks, to ensure high compatibility. There is a trend.
[0004]
In the DVD-Video format used for a read-only optical disc, video information and the like are recorded continuously from the inner circumference. Therefore, in order to allow information recorded on a DVD-R disc to be compatiblely reproduced by a DVD player, the information is recorded continuously from the inner periphery without including any unrecorded portions or the like, similarly to a read-only DVD-Video disc. This is necessary due to the characteristics of a read-only DVD player device.
[0005]
The recording methods described in the above-mentioned known DVD-R for General Ver. 2.0 are divided into disc-at-once recording from the start to end of recording at a stroke, and incremental recording which can be additionally recorded in plurals. The former is a recording method suitable for non-linear recording by a PC or the like, and the latter is suitable for recording information by linear recording with a video camera or the like.
[0006]
In the case where the recording is divided into a plurality of parts by the above-described incremental recording, a joint called linking always occurs between the data.
[0007]
FIG. 7A is a schematic diagram illustrating a linking unit when video data is divided into a plurality of video scenes and recorded by incremental recording in incremental recording. The ending part 4 of the recording data 1 up to the previous time (Nth) and the starting part where the additional recording data 2 starts to be recorded when the recording of the video data (N + 1) is started are the linking shown in FIG. Recorded as shown in part 3.
[0008]
Ideally, linking as shown in FIG. 7 (c) is required to ensure high reliability in reproduction compatibility with DVD players and the like. However, the operation at the time of actually recording the additional write data is such that an unrecorded gap 7 occurs as shown in FIG. 7B, and conversely, as shown in FIG. Data may be recorded while being overlapped with each other.
[0009]
In a write-once recording medium such as a DVD-R, the overlapped data portion may be destroyed and the correction capability by ECC may be reduced. If the data destruction section becomes long, the servo control is also affected. . On the other hand, if an attempt is made to reduce the overlap 8 portion as much as possible without deteriorating the correction capability by the ECC and not affecting the servo control, an unrecorded gap 7 portion is likely to occur.
[0010]
The reason that the recording start position of the additional recording data fluctuates back and forth is mainly due to the eccentric component of the recording medium described below.
[0011]
The eccentric component of the optical disc is obtained by extracting a wobble signal (described in the above-mentioned known DVD-R for General Ver 2.0) embedded in the medium, generating a synchronization signal by PLL, and suppressing the eccentric component. ing. The suppression of the eccentric component by the PLL increases the suppression effect when the gain of the PLL is high. However, the PLL response excessively acts on a decrease in the SN of the wobble signal or a defect due to contamination of the recording medium, and the synchronization signal is appropriately controlled. May not be generated. Therefore, the gain is suppressed and set to an optimum value so as to obtain an appropriate response to the characteristics of the recording apparatus. For this reason, a residual suppression of the eccentric component occurs, which causes the recording start position to fluctuate as described above.
[0012]
In the case where the data is recorded with the overlap 8 in the case of a write-at-once recording medium such as a DVD-R, both the information originally recorded and the information overwritten at the time of additional recording are destroyed. Would. For this reason, there is a method of minimizing information loss by skipping an ECC (Error Correcting Code) block including linking as dummy data and skipping the dummy data only in the vicinity of the linking section (Patent Document 1). reference).
[0013]
If there is no unrecorded gap 7 between the data, the original data and the data to be additionally written are not destroyed, but in the case of a DVD player of a read-only device, the recording mark is used. Since the servo control of the DPD (Differential Phase Detection) method is adopted, servo cannot be applied to the unrecorded portion, and the recorded information cannot be read out normally. For this reason, in order to reproduce a recordable optical disk with a DVD player, there is a method of recording so that a start end portion of data to be additionally written at a data end portion of a pre-recorded portion is overlapped so that an unrecorded gap does not occur. (See Patent Document 2).
[0014]
As described above, the fluctuation of the recording start position generated in the linking section becomes a problem during reproduction. Particularly, when an unrecorded gap 7 is generated, in the worst case of a DVD player, the reproduction cannot be performed at all. May be. For such a reason, a recording method of offsetting the recording start position so as to slightly overlap 8 so as not to generate the unrecorded gap 7 is performed.
[0015]
[Patent Document 1]
JP-A-9-270171
[Patent Document 2]
JP-A-11-25459
[Problems to be solved by the invention]
However, the recording start position in the linking unit depends on various factors such as residual eccentricity suppression of the disk medium, SN degradation of the wobble signal due to contamination of the recording medium, and rotation fluctuation of the disk medium, as described above. , And the amount of change is not constant. For this reason, if a large overlap amount is fixedly set so that an unrecorded gap 7 is never generated even when recording on a medium having a large eccentric amount, the linking unit greatly consumes the correction capability by ECC. In some cases, the ability to correct the original defect is reduced.
[0018]
As described above, in the conventional method of setting the amount of overlap with a fixed value, if a sufficient margin is secured for the eccentric variation of the disk medium, the ability to correct stains and defects on the recording medium is reduced. There has been a problem that block noise is generated and reproduction becomes impossible in reproduction of video and the like.
[0019]
Therefore, it is desirable to perform recording while adaptively changing the optimal overlap amount at the time of recording without lowering the reliability of the data and generating the unrecorded gap 7.
[0020]
The present invention adaptively corrects the recording start timing based on the detected eccentricity of the disc-shaped recording medium, thereby eliminating the occurrence of the unrecorded gap 7 occurring at the link portion regardless of the eccentricity variation, and as much as possible. It is an object of the present invention to provide a recording method capable of minimizing the eight overlapping portions of data.
[0021]
[Means for Solving the Problems]
The present invention solves the above-mentioned problem by, when additionally recording on a recordable disc-shaped recording medium, a gap where data is not recorded between the end of recorded data and the start of additionally recorded data. In the information recording method of continuously recording data so that no part is formed, the eccentricity of the disk-shaped recording medium is measured, and the variation of the recording start position is calculated from the measured eccentricity, and the eccentricity is calculated. A recording start timing is generated in accordance with the amount corresponding to the variation of the recording start position thus performed, and control is performed to vary the recording start position of the recording data.
In other words, at the time of additional recording of information on a recording medium of a standard that does not have a physical gap portion in a link portion by additional recording or the like represented by a DVD-R medium, recording starts according to the eccentricity measured for each recording medium. Based on the correction value corresponding to the position variation, the timing to advance the recording start position is adaptively generated, and the recording start position of the first data is adaptively variably controlled (the recording data length of the first data is adaptively adjusted). Thus, regardless of the eccentric variation, the occurrence of a gap in the link portion is suppressed, and the data overlap 8 minutes is minimized.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The disc-shaped recording medium to which the present invention is applied is a recording medium of a standard represented by a DVD-R disc that does not have a physical gap at a joint between data (that is, a DVD-RAM or a DVD-R disc). This is a non-standard recording medium in which a physical ID is embedded in advance in a state where data is not recorded, such as an MO, and data is always separated by the physical ID.)
[0023]
FIG. 1 is a block diagram showing a configuration of an optical disk device according to one embodiment of the present invention. In FIG. 1, reference numeral 9 denotes a high-order controller, 10 denotes a modulation unit, 11 denotes a recording data generation unit, 12 denotes a timing generation unit, 13 denotes a recording unit, 14 denotes a reproduction unit, 15 denotes an eccentricity detection unit, 16 denotes a data discrimination unit, 17 is a demodulation unit.
[0024]
The host controller 9 is responsible for overall control of the entire apparatus, and takes in recording information from an information source (information source is not limited to this) of recording information (user data) such as a camera, a recorder, and a tuner. Also, the reproduction information is output to an appropriate external device. At the time of recording, the upper controller 9 sends recording information to the modulation unit 10. The modulation unit 10 performs addition of an error correction code (ECC) and 8/16 conversion for converting recording information into a recording mark format, and the recording data generation unit 11 binarizes a Hi-level and Lo-level NRZI format. Recording data is generated as a recording pulse which is a signal. The NRZI signal, which is recording data, is sent to the recording unit 13 in synchronization with the recording timing generated by the timing generation unit 12. The timing generation unit 12 generates various recording timings based on the synchronization signal from the data discrimination unit 16. Further, based on the information of the measured value of the eccentricity performed by the eccentricity detecting unit 15 at the time of loading, a shift processing of the recording timing corresponding to the correction amount of the recording start position is performed. The recording data synchronized with the SYNC signal (described in the well-known DVD-R for General Ver 2.0) by the timing generation unit 12 is sequentially sent to the recording unit 13. The recording unit 13 includes an optical head including a semiconductor laser driving circuit, a semiconductor laser, an optical system, and a moving mechanism. The recording data is sent to the semiconductor laser driving circuit, and drives the semiconductor laser to emit laser light. The laser light beam emitted from the optical head is irradiated on the recording film surface of the optical disk, and a recording mark is formed.
[0025]
Reading of data recorded on the optical disc is performed by the reproducing unit 14. The reproducing unit 14 is the same optical head as the recording unit 13, and focuses a laser beam that is weaker than at the time of recording on a recorded optical disk, and detects reflected light modulated by a recording mark. The playback unit 14 outputs playback data, which is information recorded on the optical disc, and servo signals and the like necessary for tracking and focus control. The reproduced data is discriminated by the data discriminating section 16 into SYNC pattern detection indicating a data demodulation start point and user data such as video information. The user data is demodulated by the demodulation unit 17 and sent to the host controller 9.
[0026]
In the present embodiment, at the time of the additional recording operation, the eccentricity detecting unit 15 uses a tracking error signal, which is a servo signal obtained from the reproducing unit 14 at the time of loading the disc, and the track pitch of the optical disc by the eccentricity detecting unit 15 for each medium. The amount is measured, and the measured amount is used in a recording timing shift operation as a reference for calculating a correction value. The measurement of the amount of eccentricity will be described later.
[0027]
FIG. 2 is a diagram showing a histogram 18 of the fluctuation of the SYNC position obtained from the recording data according to the amount of eccentricity of the optical disk, and the relationship between the fluctuation of the recording start position assumed thereby. The fluctuation of the SYNC position is substantially proportional to the amount of eccentricity of the optical disk. This is because the distribution of the histogram is determined by the amount of residual eccentricity suppression by the above-mentioned PLL setting value, and once the PLL setting value is determined, the relationship between the eccentricity of the optical disk and the recording position is always proportional. Is supported.
[0028]
As shown in FIG. 2, if additional recording is simply performed, when the eccentricity is 80 μm, the recording start position is up to 10T on the side overlapping with the end of the previously recorded data 1, and unrecorded. In the direction in which the gap occurs, a fluctuation 19 of a maximum of 10T is made. When the amount of eccentricity is 160 μm, the eccentricity is enlarged 20 to a maximum of 20T. As described above, the unrecorded gap portion that occurs stochastically interferes with the reproduction by the DVD player, and therefore, in the present embodiment (the present invention), the correction 21 is performed so that the unrecorded portion does not occur due to the eccentricity. .
[0029]
Next, an example of a method of measuring the amount of eccentricity and an example of adaptively generating a timing for making the recording start position earlier will be described with reference to FIGS.
[0030]
When the optical disk rotates without performing the tracking control, a laser spot crosses a track on the disk due to the eccentricity of the optical disk. The eccentricity detecting unit 15 counts the number of traversed tracks by detecting a tracking error signal obtained when the reproducing unit 14 crosses a track, and calculates the eccentricity based on the relationship between the count value and the track pitch of the disk. Is converted.
[0031]
When converting the amount of eccentricity to the amount of correction of the recording start position, the conversion table shown in FIG. 3 is used. As described above, this conversion table is determined by the eccentricity suppression residual by the PLL setting of the optical disk device, and does not depend on the device, but only on the amount of eccentricity of the optical disk. Therefore, a conversion table as shown in FIG. 3 can be prepared in advance.
[0032]
The correction amount converted into the correction value by the conversion table is sent to the timing generation unit 12, and a recording timing in which the recording start position is shifted by the correction is generated. The correction process in the timing generation unit 12 will be described with reference to FIG.
[0033]
In FIG. 4, the reference clock in 1T increments is denoted by 22, the NRZI-format recording pulse as recording data is denoted by 23a, 23b, 23c, and the recording control signals for controlling the recording start position are denoted by 24a, 24b, 24c. Here, a case where the correction value obtained from the eccentricity detection unit 15 is 10 T when the eccentricity is 80 μm and 20 T when the eccentricity is 160 μm will be described as an example. When there is no correction, the timing of each signal at the time of additionally writing to the end part 4 of the previous recording data is indicated by the recording data 23a and the recording control signal 24a. When the recording control signal 24a is at the Hi level, the recording pulse of the NRZI of the recording data 23a is masked, and the laser does not emit light. When the recording control signal becomes Lo level, the recording data 23a is output, and the laser is emitted and recording is started.
[0034]
When the correction of the recording start position is 10T, the recording control signal 24b is controlled to be at the Lo level 10 clocks earlier than the end portion 4 of the previous recording data, and the recording data 23b becomes shorter by that amount. Is output. Similarly, when the correction amount is 20T, the recording control signal 24c is controlled to be at the Lo level 20 clocks earlier, and the recording data 23c is output at an earlier point in time. By performing such control, the recording start position can be shifted without the absolute position of the recording data being shifted (there is no influence of shifting the SYNC position).
[0035]
FIG. 5 is a schematic diagram of a linking unit when the present invention is applied to an optical disk with a large eccentricity, and FIG. 6 is a schematic diagram of a linking unit when the present invention is applied to an optical disk with a small eccentricity. Even in a case where an unrecorded gap having a large eccentric amount is vacant, an unrecorded gap does not occur because the correction value 21 corresponding to the optical disc is used. In this case, the amount of overlap is also large. However, due to the characteristics of the DVD player device, when the data portion is not recorded, the playback compatibility is extremely deteriorated, whereas the overlap side is relatively poor. It is known that the margin 25 for reproduction compatibility is wide. For this reason, there is a possibility that the correction capability by ECC may be slightly reduced, but the reproduction compatibility is not maintained. In the case of a recording medium having a small eccentricity shown in FIG. 6, there is no occurrence of unrecorded gaps, the amount of overlap is small, and the ECC correction capability is not deteriorated. Therefore, the reproduction margin 25 can be improved as compared with the case where the amount of overlap is determined by a fixed value.
[0036]
On the other hand, in a conventional optical disc which cannot be reproduced as a result of overlappingly recording using a fixed amount (correction value corresponding to eccentricity of 100 μm), the recording method using the same optical disc and applying the present invention is not applicable. As a result of recording, it could be reproduced without any problem.
[0037]
In the above description, the eccentricity of the optical disc (residual eccentricity suppression) is treated as being constant irrespective of the radial position of the disc at which additional recording is started. ) Is empirically found to be larger on the inner circumference side of the disk than on the outer circumference side of the disk. Therefore, after measuring the eccentricity without performing tracking control at a predetermined position of the disk, the measured eccentricity is corrected and calculated according to the disk radial position at which additional recording is started, and the corrected eccentricity is calculated based on the corrected eccentricity. Based on this, the above-described correction of the recording start position (generation of the timing to make the recording start position earlier) may be performed. In this way, more reliable recording control can be achieved.
[0038]
【The invention's effect】
As described above, according to the present invention, at the time of additional recording on a disc, so that a gap portion where data is not recorded is not formed between the end portion of recorded data and the start end of data to be additionally recorded, In an information recording method for continuously recording data, it is possible to suppress the occurrence of a gap in a link portion and to minimize the overlap of data. Thus, for example, in DVD-R recording, the reliability of DVD player reproduction compatibility can be ensured.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an optical disc device according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a variation of a recording start position according to an eccentric amount of an optical disc.
FIG. 3 is an explanatory diagram showing a relationship between an eccentric amount and a correction amount of a recording start position.
FIG. 4 is an explanatory diagram showing a relationship between a correction value and a recording timing.
FIG. 5 is an explanatory diagram showing a case where the present invention is applied to an optical disk having a large eccentricity.
FIG. 6 is an explanatory diagram showing a case where the present invention is applied to an optical disk having a small eccentricity.
FIG. 7 is an explanatory diagram showing an influence generated in a linking unit by an eccentric component of the optical disc.
[Explanation of symbols]
1 Previously recorded data 2 Newly added data 3 Linking unit 4 End of previously recorded data 5 Recording start position when overlapping 6 Recording start position when gap exists 7 Unrecorded gap 8 Over Wrap unit 9 Host controller 10 Modulation unit 11 Record data generation unit 12 Timing generation unit 13 Recording unit 14 Reproduction unit 15 Eccentricity detection unit 16 Data discrimination unit 17 Demodulation unit 18 Histogram 19 Variation range of recording start position (Small eccentricity)
20 Variation range of recording start position (large eccentricity)
21 Correction amount 22 Reference clocks 23a, 23b, 23c Recording data 24a, 24b, 24c Recording control signal 25 Range compatible with reproduction

Claims (4)

When additional recording is performed on a recordable disc-shaped recording medium, data is continuously recorded so that a gap where data is not recorded is not formed between the end of recorded data and the beginning of additionally recorded data. The information recording method for recording
Measuring the amount of eccentricity of the disk-shaped recording medium;
Calculating the variation of the recording start position from the measured eccentricity;
Generating a recording start timing according to the amount corresponding to the variation of the recording start position calculated from the eccentric amount, and performing a control to vary the recording start position of the recording data,
An information recording method, characterized in that: In claim 1,
An information recording method, wherein the measured eccentricity is corrected and calculated according to a radial position of the disk-shaped recording medium at which additional recording starts. When additional recording is performed on a recordable disc-shaped recording medium, data is continuously recorded so that a gap where data is not recorded is not formed between the end of recorded data and the beginning of additionally recorded data. In a disk device for recording
Means for measuring the amount of eccentricity of the disk-shaped recording medium,
Means for calculating the variation of the recording start position from the measured eccentricity,
Means for generating a recording start timing according to the amount corresponding to the variation of the recording start position calculated from the eccentricity, and means for performing control to vary the recording start position of the recording data,
A disk device characterized by the above-mentioned. In claim 3,
A disk device, comprising: means for correcting and calculating the measured eccentricity according to the radial position of the disk-shaped recording medium at which additional recording is started.

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