JP4111807B2 - Information recording method, disk device, and information recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information recording method, a disk device, and an information recording device , and in particular, when additional recording is performed on a disk, data is not recorded between the end portion of recorded data and the start end portion of additionally recorded data. The present invention relates to a technique related to a recording method in which data is continuously recorded so that no gap portion is formed.
[0002]
[Prior art]
An optical disc can store a relatively large amount of information. Among such optical discs, a DVD capable of handling a large amount of information such as computer data, video data, and music data on a common recording medium is used for PCs, AV devices, and the like. It attracts attention as a new large-capacity storage medium, and the market is rapidly expanding with the advent of DVD recorders in addition to the widespread use of DVD players.
[0003]
Further, with the widespread use of recordable optical disks, compatibility of optical disk media is regarded as important by users. However, many DVD players that are already widely used do not support rewritable formats (DVD-RAM, DVD-RW, etc.) employed in DVD recorders, and thus are not compatible. Therefore, with the establishment of DVD-R for General Ver2.0 that complies with the DVD-Video format, DVD players will also support DVD-R media that are recordable optical discs to ensure high compatibility. There is a trend.
[0004]
In the DVD-Video format used in a reproduction-only optical disc, video information and the like are continuously recorded from the inner periphery. For this reason, in order to reproduce information recorded on a DVD-R disc in a compatible manner with a DVD player, recording is continuously performed from the inner circumference without including an unrecorded portion or the like, as in a reproduction-only DVD-Video disc. This is necessary due to the characteristics of the reproduction-only DVD player device.
[0005]
The recording methods described in the above-mentioned known DVD-R for General Ver. 2.0 can be divided into disc-at-once recording from the start to the end of recording at once and incremental recording that can be additionally recorded in a plurality. 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 by a video camera or the like.
[0006]
When recording by dividing into a plurality of pieces by the above-described incremental recording, a joint called linking always occurs between data.
[0007]
FIG. 7A is a schematic diagram showing a linking unit in a case where video data is divided into a plurality of video scenes by incremental recording by incremental recording. The ending portion 4 of the recording data 1 up to the previous (Nth) and the starting end portion where the additional recording data 2 starts to be recorded when the recording of the video data (N + 1) is started are the linking in FIG. Recorded as shown in part 3.
[0008]
In reproduction compatibility with a DVD player or the like, in order to ensure high reliability, linking as shown in FIG. 7C is ideally required. However, as shown in FIG. 7 (b), the operation for recording the actual additional recording data is caused by an unrecorded gap 7 portion, and conversely, as shown in FIG. 7 (d), Data may be recorded with overlap 8.
[0009]
In a write-once recording medium such as a DVD-R, the overlapped data portion may be destroyed and the correction ability by ECC may be reduced. If the data destruction section becomes longer, servo control is also affected. . On the other hand, if the overlap 8 portion is reduced as much as possible so as not to reduce the correction capability by ECC and affect the servo control, an unrecorded gap 7 portion tends to occur.
[0010]
The factors that cause the recording start position of these additional data to fluctuate back and forth are largely due to the eccentric components of the recording medium described below.
[0011]
As the eccentric component of the optical disc, a wobble signal embedded in the medium (described in the above-mentioned well-known DVD-R for General Ver. 2.0) is extracted, a synchronization signal is generated by PLL, and the eccentric component is suppressed. ing. Suppression of the eccentric component by the PLL increases the suppression effect when the gain of the PLL is high, but the PLL response works excessively with respect to a decrease in SN of the wobble signal or defects due to contamination of the recording medium, etc. May not be generated. Therefore, the optimum gain is set so as to have an appropriate response to the characteristics of the recording apparatus. For this reason, an amount of residual suppression of the eccentric component occurs, which causes the recording start position to fluctuate as described above.
[0012]
In the case of a write-at-once recording medium such as a DVD-R, where the data and the data are overlapped 8 are recorded, both the information that was originally recorded and the information that was overwritten at the time of additional recording are destroyed. End up. For this reason, there is a method of skipping the error correction code (ECC) block including linking as dummy data, or inserting dummy data only in the vicinity of the linking unit to minimize information loss (Patent Document 1). reference).
[0013]
If there is no unrecorded gap 7 between the data, the original data and the data to be added are not destroyed. However, in the case of a DVD player for playback only, a recording mark is used. Since the DPD (Differential Phase Detection) servo control is employed, the servo cannot be applied to the unrecorded portion and the recorded information cannot be read normally. For this reason, in order to reproduce a recordable optical disc with a DVD player, there is a method of recording so that the start end portion of data to be additionally recorded overlaps with the data end portion of the previous recording portion so that an unrecorded gap does not occur. Yes (see Patent Document 2).
[0014]
As described above, the fluctuation of the recording start position that occurs in the linking section becomes a problem during reproduction. In particular, when an unrecorded gap 7 occurs, the DVD player cannot reproduce at all in the worst case. There is a case. For this reason, a recording method in which the recording start position is offset so as to slightly overlap 8 so as not to generate an unrecorded gap 7 is performed.
[0015]
[Patent Document 1]
JP-A-9-270171 [0016]
[Patent Document 2]
Japanese Patent Laid-Open No. 11-25459
[Problems to be solved by the invention]
However, as described above, the recording start position in the linking section is caused by various factors such as the residual eccentricity of the disk medium, the SN degradation of the wobble signal due to the dirt on the recording medium, and the rotational fluctuation of the disk medium. The amount of fluctuation is not constant. For this reason, if a large overlap amount is fixedly set so that an unrecorded gap 7 does not occur even when a medium having a large eccentricity is recorded, the correction capability by ECC is greatly consumed in the linking portion. In some cases, the ability to correct the original defect is reduced.
[0018]
As described above, in the conventional method of setting the overlap amount with a fixed value, if a sufficient margin is secured for the eccentric variation of the disk medium, the correction capability for the dirt and defects of the recording medium decreases. There are problems such as generation of block noise and inability to reproduce video images.
[0019]
Therefore, it is desirable to perform recording by adaptively changing the optimum overlap amount that does not reduce the reliability of the data and does not generate the unrecorded gap 7 at the time of recording.
[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. The present invention provides a recording method capable of minimizing the overlap 8 portion of data.
[0021]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention continuously records data so that the end of recorded data and the start of recorded data are connected when additional recording is performed on a recordable disc-shaped recording medium. In the information recording method for additional recording, the amount of eccentricity of the disc-shaped recording medium is measured, and the larger the measured amount of eccentricity , the overlapping portion of the recorded data end portion and the start end portion of the additional recording start area. as increases, the additional recording to calculate the variation of the recording start position that is a position for starting to generate a recording start timing in accordance with the amount corresponding to the variation of the recording start position calculated from the eccentricity, Control is performed to vary the recording start position in the circumferential direction of the recording data.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The disc-shaped recording medium targeted by the present invention is a standard recording medium represented by a DVD-R disc and having no physical gap at the junction between data (that is, DVD-RAM or (This is a non-standard recording medium in which a physical ID is embedded in advance with no data recorded, such as MO, and the data is always separated by this physical ID).
[0023]
FIG. 1 is a block diagram showing a configuration of an optical disc apparatus according to an embodiment of the present invention. In FIG. 1, 9 is a host controller, 10 is a modulation unit, 11 is a recording data generation unit, 12 is a timing generation unit, 13 is a recording unit, 14 is a reproduction unit, 15 is an eccentricity detection unit, 16 is a data discrimination unit, Reference numeral 17 denotes a demodulation unit.
[0024]
The host controller 9 is responsible for overall control of the entire apparatus, for example, captures 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 host controller 9 sends recording information to the modulation unit 10. The modulation unit 10 adds an error correction code (ECC) and performs 8/16 conversion to convert the recording information into a recording mark format. The recording data generation unit 11 binarizes the Hi-level and Lo-level NRZI formats. Recording data is generated as a recording pulse as a signal. The NRZI signal that 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 generator 12 generates various recording timings based on the synchronization signal from the data discriminator 16. Further, based on the information on the measured value of the eccentric amount performed at the time of loading by the eccentric amount detector 15, the recording timing shift process 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 Ver2.0) 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. Recording data is sent to the semiconductor laser driving circuit, and the semiconductor laser is driven to emit laser light. The laser light beam emitted from the optical head is irradiated onto the recording film surface of the optical disc to form a recording mark.
[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, collects a laser beam weaker than that at the time of recording on the recorded optical disc, and detects reflected light modulated by the recording mark. The reproduction unit 14 outputs reproduction data that is information recorded on the optical disc, servo signals necessary for tracking and focus control, and the like. The reproduced data is discriminated by the data discriminating unit 16 into user data such as SYNC pattern detection indicating the data demodulation start point and video information. User data is demodulated by the demodulator 17 and sent to the host controller 9.
[0026]
In the present embodiment, during the write-once recording operation, the eccentricity detection unit 15 performs eccentricity for each medium based on the tracking error signal, which is a servo signal obtained from the reproducing unit 14 during disk loading, and the track pitch of the optical disk. An amount is measured, and the measured amount is used as a reference for calculating a correction value for a recording timing shift operation. The measurement of the eccentricity will be described later.
[0027]
FIG. 2 is a diagram showing the SYNC position fluctuation histogram 18 obtained from the recording data depending on the amount of eccentricity of the optical disc, and the relation of the fluctuation of the recording start position assumed thereby. The change in the SYNC position is substantially proportional to the amount of eccentricity of the optical disk. This is because the histogram distribution is determined by the amount of residual eccentricity suppression due to the PLL setting value described above, and if the PLL setting value is determined, the relationship between the eccentricity of the optical disk and the recording position is always proportional. Is backed up.
[0028]
As shown in FIG. 2, when additional recording is simply performed, when the amount of eccentricity is 80 μm, the recording start position is a maximum of 10 T on the side overlapping with the end of the last recorded data 1, and unrecorded In the direction in which the gap is generated, a variation 19 of 10T at maximum is also made. Further, when the amount of eccentricity is 160 μm, each is enlarged 20 to a maximum of 20T. As described above, since the unrecorded gap portion that occurs stochastically hinders reproduction on a DVD player, in this embodiment (the present invention), correction 21 is performed so that an unrecorded portion does not occur due to the amount of eccentricity. .
[0029]
Next, an example of a method of measuring the amount of eccentricity and an example of adaptively generating the timing for increasing the recording start position will be described with reference to FIGS.
[0030]
When the optical disk rotates without tracking control, the laser spot crosses the track on the disk due to the eccentricity of the optical disk. The eccentricity detector 15 counts the number of crossed tracks by detecting the tracking error signal obtained when the reproducing unit 14 crosses the track, and determines the amount of eccentricity from the relationship between the count value and the track pitch of the disk. Is converted.
[0031]
When converting the amount of eccentricity into the correction amount of the recording start position, the conversion table shown in FIG. 3 is used. As described above, this conversion table is determined by the residual amount of eccentricity suppression by the PLL setting of the optical disk apparatus, and does not depend on the apparatus but depends only on the eccentricity amount 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 generator 12, and the recording timing is generated by shifting the recording start position by the correction amount. The correction process in the timing generation unit 12 will be described with reference to FIG.
[0033]
In FIG. 4, a reference clock in increments of 1T, 22 NRZI format recording pulses as recording data, 23a, 23b, 23c, and recording control signals for controlling the recording start position are represented by 24a, 24b, 24c, respectively. Here, the case where the correction value obtained from the eccentricity detection unit 15 is 10T when the eccentricity is 80 μm and 20T when the eccentricity is 160 μm will be described as an example. When there is no correction, the timing of each signal when additional recording is performed on the end portion 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 Hi level, the NRZI recording pulse 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 a recording start state is reached in which the laser emits light and is recorded.
[0034]
When the correction of the recording start position is 10T, the recording control signal 24b is controlled to become Lo level earlier by 10 clocks from the end portion 4 of the previous recording data, and the recording data 23b is earlier by that amount. Is output. Similarly, when the correction amount is 20T, the recording control signal 24c is controlled to become Lo level earlier by 20 clocks, and the recording data 23c is also output at an earlier time. By performing such control, the recording start position can be shifted without shifting the absolute position of the recording data (not affected by the shifting of the SYNC position).
[0035]
FIG. 5 shows a schematic diagram of the linking portion when the present invention is applied to an optical disc with a large amount of eccentricity, and FIG. 6 shows a schematic diagram of the linking portion when the present invention is applied to an optical disc with a small amount of eccentricity. Even in a case where an unrecorded gap having a large eccentricity is large, 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 reproduction compatibility is extremely deteriorated. 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 is somewhat reduced, but there is no possibility that reproduction compatibility is not maintained. In the case of the recording medium having a small eccentricity shown in FIG. 6, there is no occurrence of an unrecorded gap, the overlap amount is small, and the ECC correction capability is not deteriorated. For this reason, 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, with the conventional fixed amount (correction value corresponding to the eccentricity of 100 μm), the recording method using the same optical disk and the present invention applied to the optical disk that cannot be reproduced as a result of overlapping recording. As a result of recording, it was possible to reproduce without problems.
[0037]
In the above description, the amount of eccentricity of the optical disk (residual amount of eccentricity suppression) is assumed to be constant regardless of the position in the radial direction of the disk where additional recording starts. ) Has been empirically found that the inner circumference of the disc is larger than the outer circumference of the disc. Therefore, after measuring the amount of eccentricity without performing tracking control at a predetermined position of the disk, the calculated amount of eccentricity is corrected according to the position in the radial direction of the disk where additional recording is started, and the corrected amount of eccentricity is calculated. Based on this, the above-described correction of the recording start position (generation of timing for making the recording start position earlier) may be performed. In this way, more reliable recording control can be achieved.
As described above, in the present embodiment, measurement was performed for each recording medium at the time of additional recording of information with respect to a recording medium of a standard that does not have a physical gap portion in a link portion such as additional recording represented by a DVD-R medium. Based on the correction value for the change in the recording start position according to the amount of eccentricity, the timing to advance the recording start position is adaptively generated, and the recording start position of the top data is adaptively variably controlled (recording of the top data). The data length is adaptively variably controlled), thereby suppressing the occurrence of a gap in the link section and minimizing the overlap of data regardless of the eccentricity variation.
[0038]
【The invention's effect】
According to the present invention as described above, when the additional recording on the disc, the continuous information recording method for additional recording of data as the starting end of data to be additionally recorded and end of the recorded data will lead , suppress the occurrence of a gap at the link portion, the overlap of data it is possible to suppress obtain. As a result, for example, it is possible to ensure the reliability of DVD player playback compatibility in DVD-R recording.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an optical disc apparatus according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing variations in the recording start position according to the amount of eccentricity of the 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 recording timing.
FIG. 5 is an explanatory diagram showing a case where the present invention is applied to an optical disc having a large amount of eccentricity.
FIG. 6 is an explanatory diagram showing a case where the present invention is applied to an optical disc with a small amount of eccentricity.
FIG. 7 is an explanatory diagram showing an influence generated in the linking portion by the eccentric component of the optical disc.
[Explanation of symbols]
1 Previously recorded data 2 Newly added data 3 Linking part 4 Last recorded data end part 5 Recording start position when overlapping 6 Recording start position when there is a gap 7 Unrecorded gap part 8 Over Lapping unit 9 Host controller 10 Modulating unit 11 Recording data generating unit 12 Timing generating unit 13 Recording unit 14 Reproducing unit 15 Eccentricity detecting unit 16 Data discriminating unit 17 Demodulating unit 18 Histogram 19 Recording start position variation range (small eccentricity)
20 Recording start position variation range (large eccentricity)
21 Correction amount 22 Reference clock 23a, 23b, 23c Recording data 24a, 24b, 24c Recording control signal 25 Reproducible compatibility range

Claims (5)

In the information recording method of additionally recording data continuously so that the end of recorded data and the beginning of data to be additionally recorded are connected when additionally recording to a recordable disc-shaped recording medium,
Measuring the amount of eccentricity of the disc-shaped recording medium;
As the measured amount of eccentricity is larger, the amount of change in the recording start position, which is the position at which the additional recording is started , is increased so that the overlapping portion between the end portion of the recorded data and the start end portion of the additionally recorded data becomes larger. A calculating step;
Generating a recording start timing according to an amount corresponding to a change in the recording start position calculated from the amount of eccentricity, and performing a control to vary the recording start position in the circumferential direction of the recording data.
An information recording method characterized by the above. The information recording method according to claim 1,
An information recording method, wherein the measured eccentricity is corrected according to a radial position of the disk-shaped recording medium on which additional recording is started. In a disk device that additionally records data so that the end of recorded data and the start of recorded data are connected when performing additional recording on a recordable disc-shaped recording medium,
Means for measuring the amount of eccentricity of the disc-shaped recording medium;
As the measured amount of eccentricity is larger, the amount of change in the recording start position, which is the position at which the additional recording is started, is increased so that the overlapping portion between the end portion of the recorded data and the start end portion of the additionally recorded data becomes larger. Means for calculating;
Control means for generating a recording start timing in accordance with an amount corresponding to a change in the recording start position calculated from the amount of eccentricity, and performing control to vary the recording start position in the circumferential direction of the recording data,
A disk device characterized by the above. The disk device according to claim 3, wherein
A disk apparatus comprising: means for correcting and calculating the measured eccentricity in accordance with a radial position direction of the disk-shaped recording medium on which additional recording starts. In the information recording apparatus for additionally recording data continuously so that the end portion of the recorded data and the start end portion of the data to be additionally recorded are connected when additionally recording to a recordable disc-shaped recording medium,
A data generation unit for generating recording data;
A timing generator for generating a recording timing signal;
A data recording unit for recording the recording data based on the recording timing signal generated by the timing generation unit;
Control means for controlling each of the components,
The control means records the recorded data to be additionally recorded such that the larger the amount of eccentricity of the disc-shaped recording medium, the larger the overlapping portion between the end of the recorded data and the start end of the additionally recorded data. Controlling the data recording unit to change the recording start position in the circumferential direction of
An information recording apparatus characterized by that.

Images