JP2011187160A - Information recording device, information recording method, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent degradation in recording compatibility and playback compatibility due to a difference in recording quality when recording quality is different with respect to a threshold of switch processing due to a difference in a reproducing means, and to secure compatibility of a device especially between drives of PRML correspondence/non-correspondence, and between drives having different recording speeds/reading speeds. <P>SOLUTION: This information recording device for recording information in a recording medium provided with a first recording area for recording information and a second recording area being a spare area for the first recording area is provided with a recording part for writing information in the recording area of the recording medium, and a control part for controlling the recording part, and a reference value to be used in the case of changing a recording area for writing the information therein from the first recording area to the second recording area, is made different between when processed by a first signal processing method and when processed by a second signal processing method. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an information recording apparatus, an information recording method, and a recording medium.

  In DVD-RAM, which is a kind of rewritable optical disc, when there is a defective area on the disc, a replacement process is performed to secure a spare area, which is an area different from the user area, as an alternative area ( For example, Patent Document 1, paragraphs 0001 to 0016).

Japanese Unexamined Patent Publication No. 2000-113643

  The replacement process is performed in order to prevent recording failure due to scratches, dust, etc. on the disk and to ensure high reliability of data recording. Specifically, when the number of errors in the area to be recorded is equal to or greater than a certain threshold value, the area is determined as an inappropriate area as a recording area, and a process for setting another area as the recording area is performed. That is, whether or not to perform the replacement process is determined depending on whether or not the number of errors exceeds a preset threshold value.

  However, since the number of detected errors varies depending on the method for reading information from the disk or the reading speed of the disk, the replacement process cannot be performed properly if the threshold value is uniformly determined.

  For example, the ability to read information from a disc is greatly different between when PRML (Partial Response Most Likelihood, details will be described later) is used and when it is not used. FIG. 4 shows the bit error rate of the data read from the disk. Compared to the case where PRML is not used (401), the bit error rate is significantly improved when PRML is used (PRML). It is shown. In such a case, if the threshold value is uniformly determined, it becomes difficult to achieve reproduction compatibility between recording apparatuses. In other words, in the recording device that can use PRML, the replacement process is not performed because the number of errors detected is small. On the other hand, when this disk is recorded / reproduced on a device that cannot use PRML, the number of errors increases, so the recording failure・ Reproduction failure may occur.

  Also, the number of detected errors varies depending on the disk reading speed. In general, the number of errors tends to be small at a low speed, and the number of errors tends to be large at a high speed. If the threshold value is uniformly determined, it becomes difficult to achieve reproduction compatibility between recording apparatuses. For example, a disk recorded with a 2 × speed recording device has a small number of errors and therefore no replacement processing is performed. On the other hand, when recording / playback is performed with a 16 × speed device, the number of errors increases, resulting in recording failure / playback failure. there is a possibility.

  As described above, since the number of detected errors differs among apparatuses, there is a possibility that a recording compatibility defect and a reproduction compatibility defect may occur between the apparatuses.

  An object of the present invention is to provide an information recording apparatus, an information recording method, and a recording medium that can solve the above-described problems and improve reliability.

  To achieve the above object, the present invention provides an information recording apparatus for recording information on a recording medium comprising a first recording area for recording information and a second recording area that is a spare area of the first recording area. A recording unit that writes information to a recording area of the recording medium, and a control unit that controls the recording unit, wherein the recording area for writing the information is changed from the first recording area to the second recording area. It is characterized in that the reference value used in the case of changing is different between the case of processing by the first signal processing method and the case of processing by the second signal processing method.

  Further, in an information recording apparatus for recording information on a recording medium having a first recording area for recording information and a second recording area which is a spare area of the first recording area, the information is recorded on the recording area of the recording medium. A recording unit for writing information, and a control unit for controlling the recording unit, and a reference value used when changing the recording area for writing the information from the first recording area to the second recording area, It is characterized in that the recording is different between the case of recording at the first recording speed and the case of recording at the second recording speed.

  According to the present invention, it is possible to provide an information recording apparatus, an information recording method, and a recording medium that can improve reliability.

The figure which shows the relationship between the drive and disk in a 1st Example. Schematic diagram of optical frequency characteristics (MTF) at 6.8x speed and 16x speed playback. The figure which shows an example of the state transition diagram and trellis diagram in ML. The figure which shows an example of the output bit Error Rate with respect to input S / N. The schematic diagram which shows the replacement process in DVD-RAM. The figure which shows the process sequence of a 1st Example. The figure which shows the relationship between Zone of DVD-RAM in 1st Example, and a replacement process threshold value. The figure which shows the process sequence of a 2nd Example. The figure which shows the relationship between Zone of DVD-RAM in 1st Example, and a replacement process threshold value.

  In recent years, the speed of rewritable optical disks such as DVD-RAM, DVD-RW, and CD-RW, and recordable optical disks such as DVD-R and CD-R has been increased. Of these, rewritable optical discs using phase change films, such as DVD-RAM and DVD-RW, differ from mark recording by pit formation on optical discs that can be additionally written with dye films, because they are recorded by crystallization. Therefore, the reproduction CN at the time of high-speed reproduction cannot be obtained sufficiently. In particular, in the case of a DVD system, a playback signal with a minimum mark length of 3T (T is a channel clock unit) is played back using normal binarization means, for example, the recording waveform is 50% duty due to a decrease in amplitude during high-speed playback. The signal binarization means increases the possibility of binarization errors. As one of the means to solve this problem, the sampling result of the reproduced signal by the channel clock is added before and after according to a certain rule, the degree of probability of the obtained sample sequence is calculated, and the result is the highest. A method for specifying a sample sequence of a reproduction signal has been proposed. Of these, the part that creates the sample sequence is called a partial response (hereinafter referred to as PR), the portion that characterizes the sample sequence from the certainty is called maximum likelihood composite (hereinafter referred to as ML), and both are collectively called PRML. Let the obtained sample sequence be a binary sequence. On the other hand, a conventional binarization method using Duty or the like of a reproduced waveform is called a binary slice.

  However, as described above, it may be impossible to achieve reproduction compatibility between a recording device that uses PRML and a recording device that does not use it depending on the presence / absence of a replacement process. This needs to be solved. In addition to the use / nonuse of PRML, there may be cases where playback compatibility cannot be achieved between recording devices depending on the recording speed. Hereinafter, a technique for achieving reproduction compatibility regardless of recording speed in the first embodiment, and a technique for achieving reproduction compatibility regardless of use of PRML will be described in the second embodiment.

  There are two types of replacement processing: replacement processing during disk formatting and replacement processing during disk recording. In the former, the corresponding area of the frame error is removed and remapping of the logical address to the physical address is performed. In the latter, the logical address of the disk is mapped to the physical address of another area specified in advance. Is done. Here, the physical address indicates an address provided through the entire area of the disk, and the logical address indicates an address provided through the user management area. These processes are hereinafter collectively referred to as a replacement process.

(First embodiment)
First, a first embodiment of the present invention will be described using a DVD-RAM as an example. In FIG. 1, 101 is a DVD-RAM disc compatible with high-speed recording / reproducing, for example, 16 × recording, and 102 is an optical disc drive compatible with 16 × recording of the disc 101. Reference numeral 103 denotes an optical disc drive that supports playback at medium speed, for example, up to 5 times speed. In this case, 16 × speed recording in the drive 102 is CAV recording, and the inner peripheral recording speed in that case is 6.8 × speed.

  When recording on a DVD-RAM disc with the drive 102, recording is performed while performing verification, and if the signal quality during verification is degraded, recording is performed in the spare area in addition to the area as shown in FIG. Perform replacement processing. In this example, there is an error where information should originally be recorded in ZONE2, so that an alternate process is performed and information is recorded in the spare area.

  As a condition for performing the replacement process, for example, the recommended number of frame errors is defined in the DVD-RAM standard. The number of frame errors is the number of byte errors in one frame when signal correction processing is performed, and is closely related to the bit error rate shown in the previous description of RPML. For areas with disc-related recording defects such as scratches on the disc, fingerprints, etc., and drive-related recording failures due to recording condition errors during recording, the replacement process is performed in this manner, and recorded in the spare area. Is assigned to the spare area. Thereby, the spare area is directly reproduced at the time of reproduction, thereby preventing the reproduction defect due to the recording defect.

  FIG. 2 is a schematic diagram of optical frequency characteristics (MTF) at 6.8 times speed and 16 times speed reproduction. In the figure, 201 is a 6.8 × MTF, and 202 is a 16 × MTF. 203 is a noise component at 6.8 times speed, and 204 is a noise component at 16 times speed. As shown in FIG. 2, when the disc playback speed is increased, for example, even if the frequency characteristics of the drive playback circuit are infinite, the noise band increases, and the signal S / N decreases. Furthermore, since the reproduction circuit also has frequency characteristics, the signal amplitude deteriorates with high-speed reproduction, and the signal S / N also decreases. Therefore, compensation for signal S / N degradation is performed by using PRML in which partial response (PR) and maximum likelihood decoding (ML) are combined. The PR outputs a series obtained by adding the sample values before and after the reproduction signal sampled with a clock having a fixed period, for example, a channel clock, according to a predetermined rule. In contrast, in ML, the expected value of the obtained sample value is set as a target value in advance, the rule of the sample sequence is represented by a state transition as shown in FIG. 3A, and the obtained sample sequence is shown in FIG. 3B according to the state transition. As shown, a transition diagram (called a trellis) is divided, and the most probable trellis is selected by selecting the most probable trellis from the sum of errors from the sample values at the end of each trellis. As a result, even when a signal with a reduced S / N is input, a correct waveform sample series can be reproduced by correction by state transition. FIG. 4 shows an example of an output bit error rate with respect to input S / N when binarization using conventional bit by bit and binarization using PRML are performed. In the figure, 401 is a bit by bit, and 402 is a graph when PRML is used. As shown in the figure, it can be seen that by using PRML, a significant improvement in bit error rate can be seen compared to conventional bit-by-bit binarization. This compensates for the decrease in signal S / N due to the increase in reproduction speed described above. The drive 102 supports 16-times speed recording and playback, and includes the PRML decoding process. Since the drive 103 only supports playback up to 5 × speed, it does not have a decoding process by PRML.

  In a drive using PRML processing for decoding a reproduction signal like the drive 102 described above, having two or more decoding processing is disadvantageous in terms of cost and circuit scale. Use PRML. In such a case, the threshold value for performing the replacement process, for example, the threshold value of the frame error in DVD-RAM, must be guaranteed to be reproduced when the same double speed is reproduced by binarization with the conventional bit by bit. There is. Therefore, in the case of the drive 102, it is necessary that the recording quality with respect to the disc 101 does not cause a reproduction failure when the drive 103 performs 5x reproduction. However, the recording speed at the innermost periphery of the drive 102 is 6.8 times speed, which is close to the reproduction speed 5 times speed at the drive 103. Therefore, when performing replacement processing based on the number of frame errors obtained using PRML during 6.8x speed recording with the drive 102, unlike the replacement conditions obtained with bit by bit, the recording quality deteriorates and the disc scratches. The allowable expansion for. As a result, the drive 103 may cause a reproduction failure during the above-described area reproduction. In order to prevent this, the following adjustment shown in FIG. 6 is performed when the drive is shipped.

  1. Let A be the frame error threshold value for replacement processing described in the DVD-RAM standard or recommended by the standard.

2. Prepare a disc with a recording area where the number of frame errors is A by performing 5x playback using a bit-by-bit binarization process on a disc that supports 16x recording. One or more of these areas are provided near the innermost circumference and the outermost circumference of the lowest disk. This disk is hereinafter referred to as a replacement processing reference disk, and of the recording areas, the inner circumference side is designated as area B and the outer circumference side is designated as area C. (602)
3. The area 102 of the replacement processing reference disk is reproduced by the drive 102 (the drive having the PRML for adjustment), the number of frame errors is measured, and the number of frame errors is set to D. The reproduction speed at this time is substantially the same as the recording speed of the area. (603)
4. In area C, perform the same operation as 3 above, and let E be the number of frame errors obtained. (604)
5. Storing drive 102 EEPROM, etc., with D as the threshold value for the number of frame errors that perform the replacement process at the innermost circumference of drive 102 and E as the threshold value for the number of frame errors that perform the replacement process at the outermost circumference. Register in the area. Further, as shown in FIG. 7 from the values of D and E, the threshold value of the frame error number for performing the replacement process in each Zone is obtained by an interpolation method such as linear interpolation, and similarly, the EEPROM of the drive 103 or the like Register in the storage area. (605)
6. Remove the reference disk from the drive 102 and finish the factory adjustment. (606)
By performing the above adjustment, even if a disc that has been recorded at a double speed G in a drive using PRML and including a replacement process is played back at double speed H close to double speed G on a drive that does not use PRML, the replacement Since the processing thresholds appear to be almost equal, it is possible to reduce reproduction failures due to recording / reproduction compatibility between drives.

  In the above example, the threshold values of the zones are linearly interpolated using the replacement threshold values at the inner and outer circumferences. However, it is not always necessary to use linear interpolation. It is conceivable to create various interpolation tables such as shape interpolation.

  In this embodiment, the replacement processing threshold value is obtained at two points, the inner periphery and the outer periphery. However, the frame error used as the replacement processing threshold value in this example is an S / N deterioration due to higher speed. Since it is determined by the interaction with the improvement in reproduction performance by PRML, it may be possible to obtain the interpolation table with higher accuracy by obtaining replacement processing threshold values at a plurality of points on the middle circumference other than the inner circumference.

  Further, the replacement processing reference disk in this embodiment can be used for adjusting a plurality of drives as long as there is no deterioration of the recording data.

  In the above example, the threshold values of the zones are linearly interpolated using the replacement threshold values at the inner and outer circumferences. However, it is not always necessary to use linear interpolation. It is conceivable to create various interpolation tables such as shape interpolation. Further, regarding the method of setting the threshold values of the zones between the inner circumference and the outer circumference with different values by using an interpolation method such as linear interpolation, the maximum likelihood such as PRML as in this embodiment is used. When the decoding process is not used, for example, a technique using a bit-by-bit slice can be used, and an appropriate replacement process threshold value can be set according to the recording and reproduction speeds of each zone by this technique.

(Second embodiment)
Next, a second embodiment of the present invention will be shown. The drive 802 is a drive having the same performance as that of the drive 102 of the first embodiment, and includes a decoding processing means by binarization by bit by bit. The disk 801 and the drive 803 are the same as the disk 101 and the drive 103 in the first embodiment, and unless otherwise specified, the device configuration, device operation, flowchart, and other conditions are the same as those in the first embodiment. When the disk 101 is inserted into the drive 802 (803), the following adjustment shown in FIG.

  1. Set a recording condition in which the number of frame errors when using decoding by bit-by-bit binarization on the inner circumference of the disc is larger than the frame error threshold A described in the first embodiment (This condition is defined as condition J) (802).

  2. Record data on the inner circumference under the above conditions. This recorded area is designated as area K (803).

  3. Region K is reproduced by a decoding process that does not use PRML, and the number L of frame errors is acquired (804).

  4. Regenerate region K using a decoding process using PRML. Let M be the number of frame errors.

  5. ΔEr = LM is calculated, and the threshold frame error number of the replacement process when the disk 801 is recorded by the drive 802 is A ′ = A−ΔEr.

  6. Using the threshold value A 'for the inner circumference obtained above and the threshold value A described in the disc standard or recommended by the standard as the threshold value for the outer circumference, The threshold value is obtained using an interpolation method such as linear interpolation shown in FIG.

  According to the present embodiment, it is possible to set a threshold value for replacement processing in consideration of a change in ambient conditions at the time of drive setup, and in addition to the first embodiment, it is possible to further reduce reproduction failure due to recording / playback compatibility between drives. it can.

  Further, even when adjustment cannot be performed due to shortened shipping time or the like, by using the method of this embodiment, it is possible to reduce reproduction failure due to recording / reproduction compatibility between drives.

  Also, in this embodiment, CAV is assumed, and correction of the threshold value of the alternation process is performed in the low-speed playback area where the effect of improving the playback conditions in PRML is large with respect to the playback performance deterioration, that is, the inner periphery of the disc. Although the setup time is shortened, if there is a margin in the sequence time, the same threshold correction as above is performed on the outer circumference of the disk, and the corrected replacement threshold values on the inner and outer circumferences of the disk are set. By using and expanding to the threshold value of each zone in the middle of the disk, it is possible to perform a more accurate replacement threshold value control and to ensure stable performance even in low-speed playback compatibility.

  As an area where the number of frame errors is large, for example, it is conceivable to reduce the number of recording operations and reduce the drive setup time by using recording data at the time of recording power adjustment.

  In addition, by preparing an area where the replacement threshold can be adjusted in advance for a commercially available disc, for example, an area recorded so that the number of frame errors in the case of DVD-RAM is increased, drive setup can be performed. The recording operation at the time can be skipped, and the setup time can be shortened.

  The first embodiment and the second embodiment of the present invention are both DVD-RAM disc embodiments, but stable recording device compatibility can be obtained even in other media that perform replacement processing. .

  According to the embodiment of the present invention described above, when recording on an optical disk that performs a replacement process at the time of recording, the recording by the optical disk recording apparatus using the maximum likelihood decoding process for verifying the replacement process and the maximum likelihood decoding process are used. In recording by a non-optical disk recording apparatus, it is ensured that the recording quality for performing the replacement process is equal, so that recording compatibility can be ensured. In particular, when recording at low speed with little degradation in playback quality, it is possible to eliminate the difference in recording quality by performing alternate processing depending on the presence or absence of maximum likelihood decoding, and stable even at variable speed recording from low to high speed. Record compatibility can be ensured.

  Also, by specifying these in the disc standard or the like, recording / reproducing compatibility including variable speed recording can be ensured among a plurality of recording medium manufacturers and optical disc drive manufacturers.

  DESCRIPTION OF SYMBOLS 101 ... High-speed writable RAM disk, 102 ... DVD-RAM drive provided with PRML processing means for high-speed recording / reproduction, 103 ... DVD-RAM drive not provided with PRML processing means, 201, 202 ... Optical frequency characteristics ( MTF), 203 · 204, noise spectrum.

Claims (15)

In an information recording apparatus for recording information on a recording medium comprising a first recording area for recording information and a second recording area which is a spare area of the first recording area,
A recording unit for writing information in a recording area of the recording medium;
A control unit for controlling the recording unit,
The reference value used when changing the recording area in which the information is written from the first recording area to the second recording area is processed by the first signal processing method and by the second signal processing method. An information recording apparatus, wherein the information recording apparatus is different depending on the case. In an information recording apparatus for recording information on a recording medium comprising a first recording area for recording information and a second recording area which is a spare area of the first recording area,
A recording unit for writing information in a recording area of the recording medium;
A control unit for controlling the recording unit,
When recording at the first recording speed and at the second recording speed, the reference value used when the recording area in which the information is written is changed from the first recording area to the second recording area And an information recording device characterized in that it is different for each. The information recording apparatus according to claim 1,
The information recording apparatus according to claim 1, wherein the first signal processing method is a PRML method, and a reference value when processing by the PRML method is smaller than a reference value when processing by the second signal processing method. The information recording apparatus according to claim 2, wherein
The first recording speed is slower than the second recording speed, and the reference value when recording at the first recording speed is higher than the reference value when recording at the second recording speed. An information recording apparatus characterized by being small. The information recording apparatus according to claim 1 or 2,
The information recording apparatus according to claim 1, wherein the first recording area is a user area, and the second recording area is a spare area. The information recording apparatus according to claim 1, wherein the reference value is a value related to a recording quality of information in a recording area of a recording medium. The information recording apparatus according to claim 1, wherein the reference value is a value related to the number of errors obtained by reading information from a recording area of a recording medium and performing error correction processing. The information recording apparatus according to claim 1 or 2,
When the value indicating the recording quality of the recording area in which the information is written exceeds the reference value, the recording area in which the information is written is changed from the first recording area to the second recording area. Information recording device. The information recording apparatus according to claim 1, wherein the recording medium is a DVD-RAM. In an information recording apparatus for recording information on a recording medium comprising a first recording area for recording information and a second recording area which is a spare area of the first recording area,
A reference value for changing the recording area for recording information from the first recording area to the second recording area is provided. When processing is performed by the first signal processing method, the recording area is changed by the first reference value. In the information recording apparatus, the recording area is changed by the second reference value when processing is performed by the second signal processing method. In an information recording apparatus for recording information on a recording medium comprising a first recording area for recording information and a second recording area which is a spare area of the first recording area,
A reference value for changing the recording area for recording information from the first recording area to the second recording area is provided, and when recording at the first recording speed, the recording area is changed by the first reference value. An information recording apparatus wherein the recording area is changed according to the second reference value when recording at the second recording speed. In an information recording method for recording information on a recording medium comprising a first recording area for recording information and a second recording area that is a spare area of the first recording area,
A reference value for changing the recording area for recording information from the first recording area to the second recording area is provided. When processing is performed by the first signal processing method, the recording area is changed by the first reference value. In the information recording method, the recording area is changed by the second reference value when processing is performed by the second signal processing method. In an information recording method for recording information on a recording medium comprising a first recording area for recording information and a second recording area that is a spare area of the first recording area,
A reference value for changing the recording area for recording information from the first recording area to the second recording area is provided, and when recording at the first recording speed, the recording area is changed by the first reference value. An information recording method comprising: changing a recording area according to a second reference value when recording at a second recording speed. In a recording medium comprising a first recording area for recording information and a second recording area that is a spare area of the first recording area,
A reference value for changing the recording area for recording information from the first recording area to the second recording area is provided. When processing is performed by the first signal processing method, the recording area is changed by the first reference value. In the case of processing by the second signal processing method, the recording area is changed by the second reference value. In a recording medium comprising a first recording area for recording information and a second recording area that is a spare area of the first recording area,
A reference value for changing the recording area for recording information from the first recording area to the second recording area is provided, and when recording at the first recording speed, the recording area is changed by the first reference value. The recording medium is characterized in that the recording area is changed according to the second reference value when recording at the second recording speed.

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