DE19936840A1 - Defect management method e.g. for data recording for an optical disk - Google Patents

Abstract

A criteria for the detection of defects is initially generated, either manually or for a predefined list of criteria, depending on what type of data is to be analyzed. Once this is defined, any defects can be detected when data is recorded on or reproduced from the disk. Defect detection when data is being reproduced provides a verification that the data was initially recorded. Independent claims are included for: (1) a disk device for accessing data on an optical disk; (2) an optical disk for recording data; and (3) a method of recording from or reproducing from an optical medium.

Description

The present invention relates to a Procedure for handling errors in one Disc recording medium, an optical one Disk device on the optical disk Data is recorded using such Procedure for handling errors and on a optical disc that can store information that relate to an error criterion that is to replace a defective area of the plate by a not faulty area is used.  

A disk used to record computer data requires a very high level of reliability, which in the worst case is less than 10 ^-12 . So far, error handling systems have been used to deal with the fact that errors in recording sectors that lead to errors, albeit very rarely, are inevitable in the current plate making processes.

Disk media are subjected to error management to ensure data security even if Dirt, scratches or loss of quality due to repeated rewrite operations occurs. Primary defects at the time of manufacture Plate occur, using a test procedure found that at the time of the plate initialization tion and secondary defects that occur after the plate is put into operation have been found through an exam that is to Date of writing or the like becomes. Sectors where an error is found are replaced by using sectors that are arranged in a replacement area on a Part of a plate is formed which is not a User area is. When handling errors, a Pair of a user area and a replacement area called a group.

In an example of an arrangement of user names range and replacement areas on a plate the data area from a single group. There are however, many optical disks where one data area is divided into a large number of groups. If a faulty group is found in a group is tried first, the faulty  Sectors using sectors in one Replacement area to replace the same group. In many Cases, an optical disk is configured so that the recording capacity of a spare area is several% of a user area. The Standard for 90 mm magneto-optical disks that pass through ECMA-154 or ECMA-201 is defined, and the DVD-RAM standard, which is defined by ECMA-272 Examples of such configurations.

By the way, ECMA is short for "European Computer Manufacturers Association", DVD is is an abbreviation for "digital video disc" and RAM an abbreviation for "random access memory".

The presence or absence of a defect in a sector can be caused by an error in one ID signal can be determined which is a physical Represents the address of the sector due to an error in a signal of the recorded data or by a Servo error signal.

If in the header area for each sector A large number of IDs are recorded considered the sector in question as if it had one Malpractice, if not less than one before specific number of IDs for each sector Kehler contains. For example, in the DVD-RAM Standard each sector with four IDs, and it an error can be recorded for each ID. Everyone who Sectors are considered to have none Intentional error if it does not have more than two ID errors comprises: a sector with three or more ID errors is considered as having a premature defect, there its reliability is poor.  

Furthermore, the presence or absence of a Error in a signal from recorded data through the use of an error correcting Codes added to them are detected. If more than a predetermined number of errors per Recording unit occurs, the data signal considered as if it had a data error. The "Recording unit" can be a sector or a block be made up of a variety of sectors is, depending on the width of an error map rigorous codes (ECC).

In the DVD-RAM standard, data is broken down into sectors a record and an error correction coding in units of 16 sectors subject, also referred to as the ECC block become. The data of 32 KB, which is an ECC block form are in the form of a matrix of 172 × 192 Bytes (or 172 columns × 192 rows), and Reed-Solomon codes (inner code PI, outer code PO) of 10 bytes and 16 bytes in Column direction or row direction added to generate a product code.

The inner code PI is arranged so that it within a sector is complete. With the inner code PI can count the number of error bytes in each line of the data reproduced become. In accordance with the number recorded from errors becomes the reliability of each line determined, and based on the number can be determined whether each sector or block is one Has data errors. For example, a sector of four or more lines with four or more Includes error bytes, considered as if it had one Data defect, or it becomes a block that is six or  has more such lines, considered as if it had a data defect.

With regard to the detection of errors due to of a servo error signal becomes a sector in question considered as having a servo error when the Size of the servo error signal, such as a tracking error signal, a predetermined one Value so that it becomes difficult for those a servo control stabilizer required for data recording guarantee quality.

If a sector is found to have a header error, a data error or a servo error it is determined that it is faulty.

In general, error management different procedures applied to one sector replace. One is a sliding replacement, and that another is a linear replacement.

The sliding replacement is based on primary defects applied. If a bad sector at the time If a plate is found, the next sector instead of the bad sector used. In a disk drive device to access a sector that contains data, a logical address converted into a physical address changes and a sector is accessed of IDs that has the physical address represent. When the sliding replacement is done the physical address numbers that correspond to the logical addresses by one ben or "glided".  

The sliding replacement will be within each group carried out. For example, if two different Replacement of m-sectors and n-sectors in one User area will occur, the end of User area of the group in the head of the replacement range shifted by (m + n) sectors. If the like sliding replacements are made, the connecting relationship between the physi calic addresses and the logical addresses around the Number of sectors replaced for all sectors replaced replaced sectors, postponed. Primary defective, for which the sliding replacement is carried out are in a PDL (primary error list) registered. This list contains the physical ones Addresses of the bad sectors in each entry.

Linking the physical addresses with the logical addresses can only be carried out then when a disk is initialized, and therefore, the sliding replacement is just up Primary error applied.

The linear replacement is based on secondary errors applied. If a bad sector is found will be replaced by Replacement sectors used in a replacement area become. If an ECC block is found (formed from 16 sectors) a bad sector contains, the entire EEC block is represented by 16 Sectors replaced in a replacement area. It can also the case occur that a block in a reserve area that has replaced another block in the following is replaced by another block. Spare sectors are given the same logical address as the original sectors.  

The linear replacement is within the same group done first. For example, if two linear Replacement of m-blocks or n-blocks in one User area occur, m blocks and n blocks at the beginning of the unused part of the Replacement area used. This can be set up this way that the spare area in a different group is used when the spare area of the same Group has been used up. Secondary errors that have been subjected to a linear replacement, are in an SDL (secondary error list) registered. This List contains the physical addresses of the errors stick sectors and the replacement sectors in each Entry.

If such a linear replacement is done has to be used every time an access is used a logical address is carried out which denotes a replacement sector, access to the Replacement sector carried out with subsequent return become. Therefore, the average data is about wear rate significantly reduced when it Secondary errors there.

A set of the error lists PDL and SDL is in one Defect management area within a tax information mation range in each of the outer and inner Perimeter areas saved. You are in a lot number of places and are arranged together with Information about the structure of a plate is given draws.

Generally used in recorders Criteria for recording primary and secondary errors set in the following way.  

A record is in its best condition, though Primary errors are recorded and registered. The number the error on the disk increases over time or Use due to scratches and dirt and resulting deterioration. Therefore primary errors are recorded and replaced by managed using a criterion that is stricter than that to capture the Secondary defects, so that some additional scratches or dirt does not result in an error according to the criterion for the detection of secondary errors Is found.

Although the secondary errors are recorded with one criterion that is less strict than that for them Primary error, there will be a safety margin between the criterion for the detection of secondary faults and the error correction ability left to one To ensure error correction during playback Afford. In this case, different ones Criteria for the detection of primary faults and the Secondary fault detection used.

Conventionally, optical disks are mainly used Lich used for the recording of computer data det, and so the first concern was data improve reliability and it became a mistake management that is essentially based on the Replacement using replacement sectors stands to deal with the errors in the record sectors that cause errors.

With increasing capacity of optical disks expands their use in recent years out on the field of video recording like for example with DVD.  

Data files for recording computer data (Pc files) are said to be completely error-free, and it is high reliability of the recording is required Lich. In contrast, it is open for data files drawing of audio or video data (AV files) required that the data to be recorded be continuous must be entered in real time. In some Errors are permitted as long as the fault of the Played images or sounds not found becomes, so the data reliability is not as high must be like the recording of computer data. Instead, the non-stop is the record important.

That is, with respect to storage devices for the recording of computer data casualness rather than the recording time first Has importance while for storage devices for the video recording the continuous Recording performance is of primary importance. in the If the same type of plate is used for opening drawing of both audio and video data and Computer data, it is therefore necessary, the ver reliability and the recording speed ensure that the requirements of the correspond corresponding records. In the same way error management must be performed on both types of recording customizable.

The conventional error handling for optical Disks have the following disadvantages.

To perform a replacement to secondary a disk at the time of recording to deal with, data from the recorded part  reproduced for testing, and if errors above a prescribed criterion or an error part that cannot be reproduced, are found, are listed in this part recorded data again in replacement sectors a reserve area is recorded, and the data be checked again by the replacement sectors reproduced. When a secondary fault is detected and replacement is as follows the time required four times more than the time which is required for the one-time recording of data becomes. In the case of playback of audio or Real-time video data is likely to be Recording is interrupted when an error is detected.

One solution to this problem is Secondary errors during the recording of audio and video data not to be recorded. In this case can the reproduced pictures or the like Have faults in those parts that Have secondary errors, but they are considered considered less unpleasant than an interruption the record. The underlying assumption is that once primary defects to Removed the time the disk was initialized any secondary errors that could occur will only be minor. If the measure of secondary errors lies beyond the prediction, the disturbance of the reproduced image will be unbearable and consequently this solution fail.

Where the optical disks for recording Audio or video data is used, it is considered considered unnecessary, errors with a criterion too grasp that is as strict as the one at  the recording of computer data is used. This is because if that's overly strict Criterion is used sectors used for audio or video data are allowed to be found to be erroneous be put and the video recording under will break if the time-consuming replacement is carried out. Since the conventional method for Handling errors the intended use the optical disc is not taken into account the criterion used is the same level, regardless from the intended use of the optical Plate, and therefore there was no idea about that Use the best error detection technique.

The present invention has been made to accomplish the above overcome the problems presented, and their goal is to apply error management to the data type fit that recorded on an optical disc or the intended use of the Plate.

Another goal is to ensure interchangeability improve optical disc.

Another goal is the usability of optical discs for recording audio or Improve video data.

According to a first aspect of the invention, there is provided a method of handling errors on an optical disk used to record data, comprising the steps of:
Determining a criterion for recording said errors according to the data type for which errors are to be recorded; and
Detection of said errors using said criterion when data is recorded on or reproduced from said disk.

With the above arrangement, it is possible to use one Criterion to use that for each data type for which the specified errors are recorded should be suitable.

The said step of capturing the said Errors can occur with reference to the data on the Disk are recorded.

In this case, the errors can be detected if the data are recorded on the disc or if the data to check the data that is recorded net were reproduced. If the mistakes be captured when the data is recorded can be a determination of presence or absence of servo errors and deliberate errors be a determination of presence or absence However, data errors cannot be performed become. If the errors occur during playback Examination can be recorded, the presence or Ab presence of data errors as well as servo errors and Intentional errors can be determined.

The said step of capturing the said Alternatively, errors can be made if the Data are played back. If in one If errors are detected, the reproduction of the Data tried again. The decision whether the Playback will be tried again  using a different criterion performed that by the type of data that again be given depends.

The process can continue to use the step not faulty areas on the optical Plate instead of faulty areas on the include optical disc.

With the above arrangement, the result of the Error detection can be used to make a decision to make sure that the areas that are considered faulty were found through non-faulty areas to be replaced.

The step of determining a criterion can include:
Provide a variety of criteria; and
Selection of one of the plurality of criteria mentioned according to the type of data for which errors are to be recorded.

With the above arrangement, the error criterion be determined simply by sending a signal to the Is made available that one of the multitude of criteria that are available in advance were selected instead of the values that form the criterion, be specified.

The stated variety of criteria can at least a first criterion and a second criterion include, said second criterion less is strict than the first criterion mentioned, and the mentioned step of selection can be the selection of mentioned first criterion if the data,  for which errors are to be recorded, are for which has a time limit on data drawing or reproduction is less stringent, and the selection of the second criterion mentioned when the data for which errors are recorded should be those for which there is a time limit with regard to data recording or playback is stricter.

An example of data for which a time limit regarding data recording or playback less strict is computer data. An example for dates for which a time limit is related more strict on data recording or playback is audio or video data.

When using a less stringent criterion for the audio or video data becomes an interruption Avoid recording audio or video data unless the fault has one Extent that the resulting disturbance in the sound or the picture is intolerable.

The process can continue the sending step of tax information specifying the genann criteria from a means of ver processing of data to be recorded, to a means of recording the said data.

The above means of processing data, for example, is to be recorded a host device. The above means of For example, the data is recorded Disk device.  

With the above arrangement, the host device can be one Set the criterion exactly for the type of Data recorded on the disc should be optimized.

The data can be recorded in recording units be recorded, and the said step of sending of control information can control information for send each recording unit.

With the above structure, it is possible to dynamically Set criterion that exactly for each record unit (e.g. sector or ECC block) optimized is, depending on the type of data that to be recorded in each recording unit. That is, even if different dates types, e.g. B. audio or video data and computer data, can be recorded on the same disc Error management can be achieved using the best criterion for the respective data, since the Host device the criteria control information in Link to the data being recorded should send.

The tax information mentioned, which is the criterion determined, can be one of a variety of criteria choose.

With the above arrangement, the amount of tax is information is low, since it is only one from one Must determine a large number of predetermined criteria instead of determining values that meet the criterion educate yourself.

The data can be recorded in recording units can be drawn, and the method mentioned  continue the step of recording tax include information that is the criterion for each Represents recording unit on the optical Plate in connection with the mentioned respective Recording unit.

In the above arrangement, the criterion for the Error detection for each recording unit (sector or ECC block) is to be used by reading the tax information is known and can be used be to maintain the data on the disk are recorded.

According to a second aspect of the invention there is provided a disk device for accessing the data on an optical disk, comprising:
means for determining a criterion for the detection of said errors according to the type of data for which the errors are to be detected;
means for detecting said errors using said criterion when the data is recorded on or reproduced from said disk.

With the above arrangement, it is possible that Criterion to use that for each type the data is suitable for which errors are recorded should.

The said detection device can be the said Record errors taking into account the data that are recorded on the disc.  

In this case, the errors can be detected if the data are recorded on the disc or if the data to check the data that is recorded net were reproduced. If the errors in the recording of the data can be recorded Servo errors and delays are detected, data however, errors cannot be recorded. If the Errors are detected during playback Testing, data errors as well as servo errors and Intentional errors are recorded.

Alternatively, the detection device may fail capture when the data is played back. If in such a case, errors will be detected tried to play the data again. The Decide whether to try playback again will be using different Criteria depending on the type of data that are reproduced, taken.

Said device can be a device for Handling errors on the optical disk include using non-defective areas the optical disk instead of faulty loading pass.

With the above arrangement, the result of the Error detection can be used to make a decision to make sure that the areas that are considered faulty were found through non-faulty areas to be replaced.

Said determination device can comprise:
a device for storing a plurality of criteria; and
a device for selecting one of the plurality of criteria mentioned according to the type of data for which errors are to be recorded.

With the above arrangement, the error criterion can be determined simply by applying a signal to choose one from the variety of criteria that were made available in advance instead of Determination of the values that form the criterion.

The stated variety of criteria can at least a first criterion and a second criterion include, said second criterion less is strict as the first criterion mentioned and where said selector said first Criterion can select if the data for which Errors to be recorded are those for which Time limits on data logging or playback are less stringent, and that selects said second criterion if the data, for which errors are to be recorded, are for the time constraints on data logging or playback are stricter.

An example of data, of time limits regarding data recording or playback Computer data is less strict. An example for data, for the time limit regarding the Data recording or playback are stricter, are audio or video data.

By using a less strict criterion for the audio and video data the interruption Avoid recording audio or video data unless the mistake is such an end  possesses that the resulting sound or that resulting image are intolerable.

The said determination device can Determine criterion according to a control signal that is from provided outside the device becomes.

The control signal can be sent from a host device to the Be provided with the plate direction is connected.

With the above arrangement, the host device can be one Set the criterion for the type or the Contents of the data for which errors are recorded should be optimized.

The apparatus may further comprise an apparatus for recording data in recording units on the disc, wherein
said determination device can determine the criterion for each of said recording units and
said recording apparatus can also record the criteria control information which controls the criterion for each recording unit in connection with each of said recording units.

With the above arrangement, the criterion that is for the error detection for the data of each record unit (e.g. sector or ECC block) is used become known by reading the tax information tion and can be used to care for the Data recorded on the disc respectively.  

According to a third aspect of the invention, a optical disk for recording data for ver added that covers an area that Criteria control information stores the criteria determined to capture errors for data, those recorded on or from the disc are reproduced, should be used.

With the above arrangement, the criterion is known to be used to record errors, when the disk is accessed by the Criteria tax information on the disc is recorded, is read. Accordingly the maintenance of the data on the disk is facilitated, and the interchangeability of the plate is improved because the criteria control information through each panel device can be read.

The data mentioned can be in recording units be recorded and the criteria mentioned tax information indicating the criterion that to be used to correct errors related to each of the to record said recording units can then in conjunction with each of the records mentioned units are recorded.

With the above arrangement, the criterion that is for each recording unit, e.g. B. sector or ECC block to be used, known by the Criteria control information is read and it can used to maintain the data on recorded on the disc.

The mentioned information can meet the mentioned criterion  from a variety of predetermined criteria choose.

With this arrangement, the amount of tax information mation low, since this is only one of the Determine a variety of predetermined criteria must instead of determining the values themselves, which the Form criterion.

In the accompanying figures

Fig. 1 is a block diagram of an optical disk device of an embodiment of the present invention;

Fig. 2 is a block diagram of a failure determination device used in the optical disk device of Fig. 1;

Fig. 3a is a schematic diagram showing examples of the deformation of a groove forming a track;

Fig. 3b is a timing chart showing a tracking signal obtained when the light spot follows the track shown in Fig. 3a;

Fig. 4a is a diagram showing the arrangement of a sector on a DVD-RAM;

Fig. 4b is a schematic diagram showing the signal obtained when the light spot follows the sector shown in Fig. 4a;

Figure 5 is a diagram showing an example of a fault in an error-correcting block.

Figure 6 is a table summarizing two sets of error criteria.

Figure 7 is a table summarizing three sets of error criteria.

Fig. 8 is a block diagram of a fault-determining device a further embodiment;

Fig. 9 is a diagram showing an example of a process performed for setting an error criterion;

Fig. 10 is a diagram showing another example of a process performed for setting an error criterion;

FIG. 11 is a diagram showing the arrangement of an example of a Fehlerkriterien- control information; and

Fig. 12 is a view showing the arrangement of information for controlling an error criterion on an optical disk.

There are now embodiments of the invention Be described with reference to the attached figures, in which similar parts with similar reference numerals are designated.  

Fig. 1 is a block diagram of an optical disk device used to perform the error management method according to the invention. A disk rotating device 4 controls the rotation of an optical disk 2 for recording and reproducing data. An optical head servo device 22 performs position control via an optical head 6 such that a light spot formed by a light beam and focused by the optical head 6 follows the track of the disk 2 .

The light reflected from the optical disc 2 and representing the data recorded on the disc 2 is converted into an electrical signal in the optical head 6 , which is given to an address reproducing device 8 and a signal reproducing device 10 becomes. On the basis of an ID signal in the header, the address reproducing device 8 reproduces the address of a sector which is currently being accessed. The detected address is sent to a drive control device. The signal reproducing device 10 reproduces the signals from the signals provided by the optical head 6 in accordance with the recording format. A data reproducing device 16 corrects errors in the reproduced signal to generate information and outputs information to a host device (not shown) as reproduced data of the desired logical block.

At this moment, the data reproducing device 16 can recognize a sector in which the desired data is recorded based on control signals which it receives from the drive control device 14 . At the same time, the drive control device 14 sends a command to the disk rotating device 4 to control the rotating speed of the disk 2 . Furthermore, the drive control device 14 determines the position of the sector on the disc containing the information to be reproduced and sends commands to the optical head access device 20 to move the optical head 6 to the position of the sector. The drive control device 14 also sends commands to control the operation of the servo system. The optical head access device 20 and the optical head servo device 22 control the position of the optical head 6 in accordance with the received commands.

An error handling control information acquisition device 18 reads control information necessary to perform the error handling from the reproduced data and obtains information related to the error management such as the error handling method applied to the disk, the arrangement of spare areas and user areas, the status of use of the spare sectors and the error criteria. The information thus obtained is sent to the drive control device 14 and used to control devices involved in error handling at the time of recording or reproducing data.

Incidentally, all sectors are on the disk consecutive addresses from the inner margin numbered to the outer edge of the plate. The Addresses of sectors for recording users however, data is not consecutive. This  is because the physical addresses are not only sectors for user recording data, but also the sectors in replacement areas, intended for error replacement, and Sectors in the protected areas in zone boundaries in Case are assigned to a zone format plate.

At the time of access from the host device through an interface, logical block numbers of a file system are used. Therefore, the disk device needs to perform a conversion between a logical block number and a sector address. The conversion is performed by the drive control device 14 in accordance with the received error management information.

In the write mode, data sent from the host device is first input to a data recording device 24 . The data recorder 24 performs error correction encoding on the data in accordance with a format and outputs the data as signals to be recorded with timing relationships controlled in accordance with the sector addresses on the disk by the control signals were detected by the drive control device 14 .

A signal recording device 26 modulates the received signals in accordance with a recording format and sends them to the optical head 6 .

The optical head 6 writes the signals into the optical disc 2 by operating a laser.

At this time, the optical head 6 is controlled so that a light spot passes over the sector in which the data is recorded by the optical head access device 20 and the optical head servo device 22 .

The drive control device 14 stores the error management control information acquired by the error management control information detection device 18 when the disk is loaded. The logical block number of the block to be accessed is given by an interface control signal provided by the host device, which is not shown. More specifically, the host device sends a record command specifying the logical block number of the block in which the data is to be written and the like to the disk device along with the data to be recorded, or sends a playback command specifying the logical block number of the one Block from which the data is to be read and the like to the disk device.

The drive controller 14 converts the logical block number of the block to be accessed into physical addresses using the error management information and sends a command to the optical head access device 20 and the data recorder 24 or data reproducer 16 which is the physical address of the sectors determined to be accessed. The physical address of the sectors that are currently being accessed are reproduced by the address reproducing device 8 and input to the drive control device 14 . The drive control operation, such as control over the optical head access device 20 and the data recording device 24 or the data reproducing device 16 , is performed based on the detected current address and the destination address.

A fault determining device 12 makes a judgment as to whether a sector is faulty and should be replaced. The error determining device 12 receives the information necessary for error determination in each sector from the optical head servo device 22 , the address reproducing device 8 and the data reproducing device 16 and determines the presence or absence of an error in accordance with a defect criterion, that has been set by the drive control device 14 and reports the results of the determination to the drive control device 14 . If the sector that was accessed was determined to be the bad sector, the drive control device performs the necessary procedure. During the recording, the drive control device 14 interrupts the recording operation and causes the data of the block to be recorded again in spare sectors. During the Prüfwiedergabe the drive control device 14 causes the data of the block that has been recorded are recorded again in alternate sectors. During playback, drive controller 14 causes playback to be tried again. These modes of operation are pre-programmed into the drive control device 14 .

Fig. 2 shows the structure of the fault-determining device 12. It receives servo error signals such as a tracking error signal and a focus error signal from the servo device 22 for the optical head. It also receives a header error signal, which represents the number of errors in the IDs represented for each sector, from the address reproducing device 8 . It also receives a data error signal representing the number of errors in the reproduced data from the data reproducing device 16 .

In this embodiment, the error determining device 12 includes two error criteria storage devices 34 and 36 for storing different error criteria A and B. The two error criteria A and B are input to an error criteria selector 38 that is one of the two criteria A and B. selects and outputs CS in accordance with an error criteria setting signal. There are three outputs Rs, Rd and Rh. A reference signal Rs for detecting a servo error is input to a servo error detecting device 28 , a reference signal Rh for detecting a header error is input to a header error detecting device 32 , and a reference signal Rd for detecting a data error is shown in FIG entered a data error detecting device 30 . These are compared with a servo error signal Es, a prefix error signal Eh and a data error signal Ed in the corresponding error detection device 28 , 32 and 30 to detect the presence or absence of a servo error, a prefix error and a data error. An error detection device 40 receives the output signals of the error detection devices 28 , 32 and 30 and outputs an error detection signal DF when at least one of the errors has been detected.

Referring to Fig. 3A and Fig. 3B is the detection of a servo error will be described. To record data, a track is used that has a substantially uniform width Wt (the track is actually circular or spiral, but the short part of the track shown can be treated as straight). The track is formed from a continuous guide groove or the like. Consider the case where the track is deformed at points X and Y. Such deformations can be caused by dirt, which is produced during the production of a master plate or a substrate, by irregular operation of a manufacturing device, unevenness of a formed substrate or other minor irregularities. The tracking control is performed such that a light spot of the center line 42 follows c, which is represented by a dot-dash line in Fig. 3A, and it is a tracking error signal Et which is shown in Fig. 3B is obtained. The tracking error signal Et is zero when the light spot of the center line 42 c follows the track. If the light spot deviates from the center line 42 c, the tracking error signal Et deviates either positively or negatively depending on the direction and the size of the deviation. If there is a deformation of the track and the center line 42 c of the track is suddenly bent, the light spot deviates from the center line 42 c since the light spot cannot follow the sudden bend.

At point X, there is a deviation in the tracking error signal Et due to the deformation of the track. At point Y, there is also a deviation in the tracking error signal Et due to the meandering of the track. If the tolerance limit Rtb of the tracking error, which is shown as a broken line in FIG. 3B, is given as a reference for determining a servo error, a servo error at point Y is detected. If a stricter tolerance limit Rta of the tracking error, which is shown by the dash-dotted line in the figure, is specified, servo errors are detected at both points X and Y.

The tolerance limit Rta of the tracking error ent speaks the value of the tracking signal Et when the Deviation of the light spot a quarter of the track width Wt is, and the tolerance limit Rtb of the tracking error corresponds to the value of the tracking signal Et, if the deviation of the light spot is one eighth of the Track width Wt is.

For example, if the Rta level at the dash dotted line used as error criterion A. and the level Rtb on the dashed line in the figure is given as error criterion B it is possible the determination process for servo defects perform at two different levels. in the otherwise the recording track does not have to be continuous be a nutty groove. With a plate, such as as a DVD-RAM, in the recording areas are formed for the user data from webs and grooves and in the intent area, which is only from previous ver depressions is formed, no groove is formed, it is sufficient to single servo error detection to be carried out for the areas in which extends a groove.  

The servo error detection can be done with reference to a Focus error signal in the same way as that Tracking error signal can be performed.

Fig. 4A shows the formation of a sector in a groove track in a DVD-RAM, and Fig. 4B shows the waveform of the signal reproduced by the sector shown in Fig. 4A. These figures are used to describe the detection of intent errors. A recording sector of a DVD-RAM contains a header area with a sector address and the like at the beginning, followed by a data area for recording user data. The header area contains four IDs, referred to as ID1 through ID4, each containing address information representing a sector address. In the sector shown in Fig. 4A, ID1 and ID2 are offset by one half of the track width Wt toward the outer periphery of the disk and are shared with a sector in the outer adjacent land track, while ID3 and ID4 are offset by half the track width Wt toward of the inner circumference of the plate are offset and shared with a sector in the inwardly adjacent web track.

In a land track, not shown, ID1 and ID2 are offset by one half of the track width Wt toward the inner periphery of the plate and are divided by a sector in the inner adjacent groove track, and ID3 and ID4 are separated by half the track width Wt toward the outer Perimeter of the plate offset and are shared with a sector in the groove track adjacent to the outside. The waveform of the signal represented by the header area and the data area in one sector in a land track is also shown in Fig. 4B.

The data area that follows the header is located itself in a groove or in a web and contains a Synchronous signal (SYNC), control information (CI), User data and an error correcting code and a buffer one after the other in that order to be recorded. The tax information CI consists of a small amount of information (like for example, the number of data in the sector), by the user data is different.

The size of the user data, along with the Tax information, is 2 KB in one sector (Kilobytes) and it becomes an error correcting Coding performed, the user data and the control information of 32 KB in sixteen other sectors used as a unit error correcting codes are added to form an ECC block.

The error-correcting codes are over sixteen Sectors distributed.

The sector address can be obtained even if only one of the four IDs in a header is correct will read. For criterion B, if none of the four If the IDs are read correctly, it is found that the Sector has an intentional error, and if befun is that two or more sectors within one ECC blocks have an intentional error, be found that the ECC block encountered a header error points. For criterion A, if not more than one of the If four IDs are read correctly, it is found that the Sector has an intentional error, and if  it is found that one or more sectors an intentional error within an ECC block , it is found that the ECC block has a Has deliberate errors.

A sector that is not considered defective according to criterion A is found to have at least two correct readable IDs. This makes it more likely that at least one ID remains legible, even if the plate becomes dirty or deteriorates later tert or to another disk device will wear.

In this way it is possible to determine Delayed errors with two different levels perform.

Fig. 5 shows the structure of an ECC block in a DVD-RAM. This figure is used to describe the data error detection. In the data recorder 24 , the thirty-two KB data for sixteen sectors are arranged in the form of a matrix of 172 bytes in the row direction by 192 bytes in the column direction. An outer parity code PO with sixteen bytes in the column direction is added to each column, and then an inner parity code PI with ten bytes in the row direction is added to each row.

So a product code that is a Reed-Solomon code is formed from 182 bytes by 208 bytes.

When the data is recorded on the optical disc 2 , the PO lines are interleaved with the other lines so that the bytes of the error correcting code are evenly distributed over all sixteen sectors of the ECC block.

At the time of playback, the data playback device 16 arranges the reproduced signal in a matrix of 182 bytes by 208 bytes and first detects and corrects any errors of each row by means of the inner code PI with 10 bytes. The inner code PI can correct errors up to five bytes per line and detect errors up to ten bytes per line.

Next, the outer code PO is 16 bytes used to remove any remaining errors record and correct. The outer code PO can Correct errors in up to 8 bytes per column and Record errors up to 16 bytes per column. This Failure detection and correction skills can be improved by the process of PI-PO- Error correction is repeated even if the additional repetitions additional circuits and need additional time.

If a large number of errors are detected and corrected is greeded, it is likely that some of the Corrections are wrong, with the corrected data deviate from the original data. Therefore criteria A and B, for example, as follows set. With criterion A one row is considered as if it had a data error when errors in little at least 4 bytes are captured, which is close to the error cor rectification limit of the PI code, and an ECC block is considered to have a data error if he has at least eight lines with a data error having. With the less strict criterion B  looks at a line as if it had data errors if errors are recorded in at least 8 bytes be what is repeated close to the limit of Error correction of the PI code and an ECC block is considered faulty if at least eight lines with a data error. When a ECC block is considered to have one Data error, every sixteen of his will visual sectors replaced.

In this way it is possible to determine the Data errors at two different levels to lead.

In Fig. 5, line 3 has four byte errors denoted by X. This line is considered to have a data error under criterion A but not under criterion B.

In this way, the presence or absence of errors in each sector can be determined with respect to the servo error, the header error, and the data error depending on the error criterion that is provided to each error detection device. Fig. 6 summarizes the error criteria A and B, which have been described above, as examples of the corre sponding errors. The set of criterion A is stored in the criteria storage device 34 , while the set of criterion B is stored in the criteria storage device 36 . It is then possible to switch the signal CS between the two levels of the criteria (identifier) A and B by means of the criteria selection device 38 in accordance with the criteria setting.

In the case of recording computer data, a high reliability required, so the data when they are recorded, not lost or be changed. For this reason, often one checking playback at the time of recording carried out.

Accordingly, during the recording and during the testing rendering the strict Criterion A applied to ensure that the correct data is recorded.

This is in contrast in the case of audio or video data a continuous record with a high Transfer rate necessary. Accordingly, often omitted the checking playback, being data errors are ignored. Even if there are some mistakes it should be preferred during the recording drag with the recording operation under ignoring the error continues as long as the appearance of the Error has such a degree that the error corrected later at the time of playback or can be hidden as this is the performance and the Operability as a recording device improved. For this reason, the criteria for Servo errors and delays are set to set a less stringent level at which corrected or hidden the recorded data can be.

If the two different error criteria A and B are available, the strict criterion A used for the recording of computer data, while the less stringent criterion B for the Recording of audio or video data used becomes.  

There are situations in which more than two different levels of reliability are required depending on the type of data to be recorded. For example, there is a situation where three different levels are required, one for recording computer data, another for recording important audio or video data, and the last for recording normal audio or video data. In such a situation, as shown in Fig. 7, provision is made that it is possible to switch between three different error criteria A, B and C. Criteria A and B are the same as those described with reference to FIG. 6 and are used for the recording of computer data and for the recording of normal audio or video data.

Criterion C becomes more important for the recording Uses audio or video data and therefore owns it an average severity between criteria A and B. The permissible deviation in criterion C is of the tracking error one sixth of the track width Wt, and an ECC block is found to have a Has a header error if all four IDs are in are illegible in any sector. Regarding data errors, criteria C and A are the same.

To use the three different sets of error criteria, the error determining device 12 should have an additional criteria storing device in addition to the elements shown in FIG. 2, and the criteria selecting device 38 should be between criteria A, B and C. may select that are provided by the additional criteria storage device mentioned above as well as by the criteria storage devices 34 and 36 in FIG. 2, in accordance with the criteria-replacing signal CS.

Fig. 8 shows a further embodiment of the fault-determining device 12. The arrangement of FIG. 8 is different from the arrangement of FIG. 2 in that the criteria storage devices 34 and 36 and the criteria selection device 38 , which makes the selection depending on the criteria selection signal CS, are replaced, as shown in FIG. 2 are by an error-setting and storing device 46 which carries out the adjustment in accordance with the criteria-selecting signal CS.

The error criterion that is applied is provided by a host device (not shown) to the drive control device 14 via an interface. In response to this, the drive control device 14 generates a criteria-setting signal CS that determines the criterion.

In the error-determining device 12 from FIG. 2, the error criteria that are stored in the corresponding criteria-storing devices are defined. In practice, however, it may be desirable that the host device that controls the disk device (recording device) can flexibly vary the criteria so that reliability and transfer rate are dependent on the nature, type, characteristic and degree the importance of the data to be recorded is optimized. For example, a countermeasure against errors in the application software or the file system can be provided. That is, error correcting encodings can be applied prior to transferring the data to the disk device at a predetermined rate. In this case, error processing in the disk device is not so important, and the ability to continuously record in real time with a high data transfer rate can be important.

The embodiment described above can do this Meet requirements.

With reference to Fig. 9, an embodiment of the method will be described, which is followed when setting an error criterion. In the first place, the host device sets the error criterion to be used according to the type or content of the data to be recorded. A command to set the criterion is then sent from the host device to the disk device (drive). The disk device selects or sets the criterion accordingly upon receipt of the command. In the system shown in FIG. 2, the command sent from the host device to the disk device is a command only to determine the selection between criteria A and B. In the system shown in FIG the error criterion can be set, the system is configured so that the error criterion can be arbitrarily set in the host device, and the command denotes the error criterion that has been set in the host device. The details of the error criteria setting command may be as described later with reference to FIG. 11, in which the error criteria control information independently selects one of a variety of criteria for the servo error, the header error, and the data error can.

The host device then sends a record command along with the data to be recorded. Once the disk device receives the command it records the data in the specific sectors and performs error handling using the error criterion described in the above Way was set and reported the result error handling to the host device. The Host device ends a series of recordings when confirmed that the record was completely correct. If the record is not has been carried out correctly, a predetermined one Process (rewriting or information of the User) to deal with the incorrectness leads.

According to the method of FIG. 9, the host device, which knows the content of the data to be recorded, sets the error criterion which has been optimized precisely according to the type or content of the data. It is therefore possible to provide flexibility in obtaining an optimal combination of reliability and transmission rate according to the intended use of the data.

Fig. 10 shows another embodiment of a method that is performed for setting an error criterion. In this embodiment, a command is sent that sets an error criterion and instructs data recording. First, the host device determines an error criterion to be used in accordance with the type or content of the data to be recorded, and then prepares the data to be recorded. This order can also be reversed.

The host device then sends the record command, which also sets the error criterion the disk device. In accordance with that certain error criterion is determined by the plate direction selected or set the criterion. The determination of the setting by the host device has been sent to the disk device, can make a determination to determine the selection below a variety of preset criteria (for example between criteria A and B) or one for setting an arbitrary criterion his.

The disk device records the received data along with the command on the plate while they handle errors in accordance with the Error criterion that, as described above has been set and informs the host direction of the result. According to this Aus the best possible combination tion of reliability and transmission rate Depends on the intended use of the Plate as described in the others earlier Embodiments. Because the number at Instructions that are transmitted are reduced on top of that, the overhead is reduced, and the possibility speed that the transmission rate is lowered decreased.

A way of recording control information is now described, which is the error criterion determined at the time of data recording. Fig. 11 shows the configuration of a control information for error criteria. With this configuration, one of four different criteria for the servo error, the header error and the data error can be determined independently using one byte.

The most significant bit b7 denotes the mode of the Determination of the error criterion. If the value of the Bits b7 is "1", the mode used by denotes other bits of the control information byte , while if the value is "0", the Standard criterion is used, which is the Has disk device, the other bits of the control information byte are neglected.

The next bit b6 indicates the area within of which the error criterion is to be applied. When the value of bit b6 is "1", for each Recording unit, e.g. B. each sector or block, the mode applied by other bits in the Control information byte is set. If the value of the Bits b6 is "0", the same criterion is applied over the entire surface of the plate applied.

The next two bits (b5 and b4) denote the Criteria among the four criteria for the Servo errors are applied. If the combined Value of bits b5 and b4 is "11", the Tracking error tolerance, above the one Servo error is detected, a quarter of the track width Wt. If the combined value is "10", is the tolerance is one sixth of the track width Wt. If the combined value is "01", the tolerance is on Eighth of the track width Wt. If the combined value  "00", the tolerance is one tenth of the Track width Wt.

The next two bits b3 and b2 denote this Error criterion among the four error criteria, the is used for the intent errors. If the combined value of bits b3 and b2 is "11", the ECC block is found to have a header error if all four IDs are illegible in two or are more of its sectors. If the combined value Is "10", the ECC block is found to be a Has a header error when there are three or more IDs in two or more of its sectors are illegible. If the combined value is "0", it is found that the ECC block has a header error if all four IDs in one or more of its sectors are illegible are. If the combined value is "00", will found that the ECC block was a header error if there are three or more IDs in one or more of its sectors are illegible.

The last two bits b1 and b0 denote this Defect criterion among the four criteria, the is used for data errors. If the combined Value of bits b1 and b0 is "11", it is found that the ECC block has a data error if at least sixteen of its lines errors in each have at least eight bytes. If the combined Value is "10", it is found that the ECC block has a data error if at least eight of its lines errors in at least eight bytes each to have. If the combined value is "01", will found that the ECC block has a data defect indicates if at least eight of its lines contain errors in each have at least four bytes. If the  combined value is "00", it is found that the ECC block has a data error, if at least six of his lines errors in at least four each Have bytes.

The control information for error criteria described above can be arranged in any sector constituting a minimum recording unit. In a DVD-RAM, a 1-byte area can be reserved in the control information area located at the beginning of the data area as shown in Fig. 4. The criterion can be set separately for each sector. The same control information for error criteria can be set in all sectors within the same ECC block or in predetermined sectors so that the control information for error criteria is recorded repeatedly and the area within which the same error criterion is to be applied can be used with the unit the error correction (ECC block) match.

The precaution to optimize the setting of the exactly Enabling this criterion improves the usefulness Possibility for the user in multimedia application where the audio or video data and Computer data are mixed together. It should it should be noted that the error criterion used for the respective data is to be applied in the System (host device) depending on the Content of the data can be switched and it is possible flexibility to get the optimal Combination of reliability and transfer rate to achieve.  

It is possible to preselect an error criterion to be used when recording on a disc and to record the criterion as control information for error criteria on the disc before using the disc. Fig. 12 shows an example of an array of control information areas and a data recording area including user areas and replacement areas, and an array of control information for error criteria in the control areas. The data recording area is divided into groups, each containing a user area and a spare area. The control information areas are located near the inner and outer peripheries of the disk, and the same control information is recorded on the respective control information areas.

In a known example, error management ment procedure in a tax information area recorded. In contrast, according to this Embodiment control information for errors criteria in a tax information area saved. At the time of starting a disk the disk device reads the control information for error criteria to get the error criteria know. If the error criterion that for the intended use, for example as Computer data, audio or video data or the like, is suitable, can be recorded the error determination according to the error criterion be performed.

If a bit is provided in the control information area for recording the control information for error criteria, then it is possible to record two sets of error criteria and use them selectively. To record three or four sets of error criteria and to use them optionally, two bits should be provided in the control information area. When a bit is provided in the control information area, it is possible to select one of the criteria for the servo error, the data error and the header error, respectively, and a combination of specific error criteria for the respective types, as described with reference to FIG. 11 determine.

With such a device, the error criterion if the information once at the time the initialization of the disk is recorded, then applied to all data on the Plate were recorded. It is therefore possible the need to eliminate the error criterion set each time data is recorded become. Accordingly, the recording can be done with at a high speed and in a simple way and Way.

Claims (20)

1. A method for handling errors on an optical disk used for recording data, comprising the steps of:
Determination of a criterion for the detection of said errors according to the data type for which the errors are to be recorded; and
Detecting said errors using said criterion when the data is recorded on or reproduced from said disk. 2. The method according to claim 1, said step of capturing the errors mentioned taking into account Data is carried out on the disk are recorded. 3. The method according to claim 2, said step of capturing the mentioned error is carried out when the Data for the purpose of checking data that recorded. 4. The method of claim 1, further comprising the steps of:
using non-defective areas on the optical disk instead of defective areas on the optical disk. 5. The method of claim 1, wherein said step of determining a criteria comprises:
Provide a variety of criteria; and
Selection of one of the numerous criteria mentioned according to the type of data for which the errors are to be recorded. 6. The method of claim 5, wherein said plurality of criteria comprises at least a first criterion and a second criterion, said second criterion being less stringent than said first criterion, and
said step of selection comprising selecting said first criterion if the data for which the errors are to be detected are those for which the time limit or playback is less stringent with respect to the data recording and the selection of said The second criterion includes when the data for which the errors are to be detected is those for which the time limit for data recording or playback is more stringent. 7. The method according to claim 2, continue comprehensively the step of sending a control information for determining the mentioned criterion, from a device for Processing of data that is recorded to a device for recording of the mentioned data. 8. The method according to claim 7, where the data is in recording units are recorded, and wherein said Step of sending control information Control information for each recording unit sends. 9. The method according to claim 7, said control information being the Criterion determines to choose one from one Variety of criteria there is. 10. The method according to claim 2, where the data is in recording units be recorded and the above procedure includes the step of recording tax information that is the criterion for each Recording unit represents on the optical Plate in connection with any of the above Recording units. 11. A disk device for accessing data on an optical disk, comprising:
a device for determining a criterion for detecting errors according to the data type for which the errors are to be recorded; and
means for detecting said errors using said criterion when data is recorded on or reproduced from said disk. 12. The device according to claim 11, said detection device being the mentioned errors with reference to data based on the disc are recorded. 13. The apparatus of claim 11, further comprising a device for Handling errors on the optical disk using non-faulty Areas on the optical disc instead of faulty areas. 14. The apparatus of claim 11, wherein said determining device comprises:
a device for storing a plurality of criteria; and
a device for selecting one of the plurality of criteria mentioned according to the data type for which the errors are to be recorded. 15. The apparatus of claim 14, wherein said plurality of criteria comprises at least a first criterion and a second criterion,
said second criterion being less stringent than said first criterion, and
said selector selecting said first criterion if the data for which errors are to be detected are those for which the time limit on data recording or playback is less stringent, and selecting said second criterion if the data is for the errors to be detected are those for which the time limit on data recording or playback is more stringent. 16. The apparatus of claim 12, said determining device said Criterion determined according to a control signal that available from outside the device is provided. 17. The apparatus of claim 12, further comprising:
a device for recording data in recording units on the disk,
said determining means determining the criteria for each of said recording units and
said recording device also records criteria control information that controls the criterion for each recording unit in association with each of said recording units. 18. Optical disc for recording data, comprehensively an area, the criteria tax information that stores the criterion intended to detect errors for Data to be used on the disk recorded or reproduced from the disc become. 19. An optical disc according to claim 18, said data being in record units are recorded and the above Criteria tax information that the criterion referred to that for the detection of errors regarding each of the above records units should be used in Link to any of the above records units is recorded. 20. An optical disc according to claim 18, said information being said Criterion from a variety of previously certain criteria.