JP3281063B2 - Optical disk certification method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for certifying an optical disk, and more particularly, to a method for certifying an optical disk drive or a media inspection device.

[0002]

2. Description of the Related Art As a document describing the prior art according to the present invention, for example, "90 mm rewritable / reproduction-only format and data input / output actuality" (Hideki Segawa, Information Processing, J.
an. 1992, pp. 48-54). This document describes the contents of a 90 mm MO (Magneto-Optics; magneto-optical) optical disk, mainly focusing on the layout and how to handle defective sectors. Hereinafter, a conventional replacement processing method will be described based on the above-mentioned document. An MO optical disk is used as an external memory of a computer like a floppy disk or a hard disk, and user data is recorded as a digital signal. The data area of the MO optical disk is divided into units called "sectors". As shown in FIG. 4, there are 10,000 tracks in the data area with a radius of 24 mm to 40 mm, and 2 tracks per track.
Since 5 sectors are included, 250,000 sectors are the data area. However, since the data area has the types of sectors as shown in FIG. 5, the user cannot freely record and reproduce data in all of the 250,000 sectors.

[0003] A ROM (Read Only Memory) area is a read-only area. The data in the ROM area is formed of uneven pits as in the music CD (the data in the rewritable area is formed by magnetization marks on a magnetic material).
Since data in the ROM area cannot be replaced, a special sector called "Parity Sector" is arranged instead. The parity sector of one sector is generated from data for 25 sectors. If any of the 25 sectors has a defect or the like, an ECC (Error Co
Even if there is data that cannot be corrected even by rrection code, it can be corrected by using Parity Sector.
Information on the layout of the ROM area as described above is recorded in a control track DDS (Disk Definition Sector).

[0004] A feature of the Rewritable area is that "alternative processing" is performed. "Replacement processing" is the aforementioned Parity Sec
Rather than adding a sector having a correction capability like tor, this refers to an operation of transferring data of a sector with many errors to another sector as it is. There are the following two methods of the "replacement processing". Linear replacement method Slipping method

[0005] Linear replacement method When a user actually records and reproduces data, the processing is replaced by this method. If the sector that has been subjected to the replacement process is referred to as the “original sector” and the replacement sector is referred to as the “alternate sector”, first, immediately after the user has recorded the desired data in the “original sector”, The original sector is read to check whether the recording result is correct.
As a result, if the error is below a certain value, that is, ECC
If it is possible to correct the error sufficiently, the recording operation is terminated as "OK". However, if the error exceeds a certain value, that is, if the error cannot be corrected even by using the ECC with a slight increase in the error, " The original sector is not used and is re-recorded in the “alternate sector” (the sector whose error exceeds a certain value and needs to be alternately processed is called “Bad sector”).
If this “replacement sector” is also a bad sector, it is recorded again in the next replacement sector.

The "alternate sector" is laid out collectively in an area called an "alternate processing area". In addition, the PBA (Physical Block A)
ddress; physical address) is SDL (Secondary Defect)
List), and the drive reads the SDL,
It is possible to know the “original sector” that has not been used and the “alternate sector” on which the recording has been performed properly. Originally, LBA (Logica
l Block Address (logical address) is replaced by an “alternate sector”.

[0007] Slipping method This method is, at the same time takes place when you certify the disk. The certification is an operation of performing "test recording / reproduction" on the entire surface of an MO optical disc before using the MO optical disc to extract a bad secter. The PBA (physical address) of the bad secter generated by the certification is registered in a PDL (Primary Defect List). In the above-described Linear replacement method, only two PBAs of the “original sector” and “alternate sector” are registered in the SDL.
Register only BA in PDL. LBA (logical address) to be allocated to a sector registered in the PDL
Is replaced by the sector immediately after this sector. That is, L
BA slips after one sector.

[0008] The Rewritable area is divided into units called "groups". Each group has a “user data area” and a “replacement processing area”. When the number of groups is small, the number of sectors in one user data area is large. Therefore, when the use of the replacement processing area is small, that is, when the bad sector is small, the LBA is continuously
, The transfer rate is high. Conversely, when the number of groups is large, the distance between the “user data area” and the “alternate processing area” is short, so that even when the alternate processing area is frequently used, the moving distance of the laser beam, that is, the pickup, can be reduced. Therefore, the transfer rate does not significantly deteriorate.

As described above, grouping and bad sector
All information such as the position of the DMA (Defect Management Ar
ea). The DMA is provided with three tracks each near the innermost circumference and the outermost circumference of the disk. The DMA includes a DDS (Disk Definition Secter) PDL registration sector and an SDL registration sector. Grouping information is provided in the DDS,
The position of the bad sector and the position of the replacement sector are recorded in the PDL registration sector and the SDL registration sector. The drive sends this information to the DM before recording / reproducing on the disc.
Read from A. The above is the method defined as a standard for the alternation processing described in the above document. As described above, there are DDS, PDL registered as the slippeng method, and SDL registered as the linear replacement as the group division.

A first problem of the prior art is a criterion for determining a Bad sector for creating a PDL. Conventionally, certification has been performed over the entire surface of the disc using the same criteria. However, the use of a so-called DMA area in which DDS, PDL, SDL, etc. are written, and an area in which general data is written are different. The DMA area is an area where replacement processing is not performed. Therefore, as a manufacturer, it is necessary to increase the reliability by eliminating the occurrence of Badsectors compared to general data areas. Also, among the general data areas, for example, information (IPL, FA) for managing the area of the DOS data.
The area in which (T, root directory) is written is an important area for managing the entire data area, and is a part that is always read when trying to use this disk. As a user, we also want this part to reduce the occurrence of bad sectors and increase trust. It is required that these areas do not cause an error or increase not only when performing the certification but also when reading them out. In general,
Where an error first occurs, then the error is not small but tends to increase.

Next, the second problem of the prior art relates to a specific pattern for performing certification. conventionally,
The certification was performed in the same pattern all over the disk. Various patterns can be considered as the pattern. For example, what is referred to as 8T is good at finding relatively long errors, but can be missed or even more than small in the case of small errors. Conversely, 3T
What is called is better at finding small errors, but may miss larger errors or be fewer than they actually are. In general, the degree of occurrence of a defect is different between the inner circumference, the outer circumference, and the middle circumference of the disk. For example, the inner and outer circumferences tend to be generated irrespective of their size due to dust of the manufacturing apparatus, material impurities, and the like, and the middle circumference has fewer defects and a more stable shape than other portions. Therefore, the error occurrence mode may differ depending on the location. Therefore, in order to increase the reliability, it is necessary to select a specific pattern suitable for each use method and place.

Generally, when a user uses an optical disk, a data area is managed by software called DOS. This can be used only after performing the certify operation and then performing the format operation. The format operation is to write information (IPL, FAT, root directory) for managing the data area in a part of the logical address based on the information written in the DDS. Therefore, when performing the certify operation, the write area may not be known in advance.

[0013]

The present invention has been made in view of the above-mentioned circumstances, and in order to enhance the reliability of a disk, it is necessary to quickly remove a defective sector which is used for a replacement process and shorten the time for the replacement process. Depending on the importance of the area to be written
To remove in advance any bad sectors that are more severe than the bad sector criteria and are going to be bad sectors
Also, to provide the importance the certification process of the optical disk was Unishi by you removed in advance what you would bad sectors around the replacement process to select a specific pattern area to be written has been made for the purpose is there.

[0014]

To achieve the above object, the present invention provides (1)
In a method of certifying an optical disk for writing a specific pattern on an optical disk, verifying the defective sector to detect the defective sector, and registering that the defective sector is not used, the criterion of the defective sector is determined based on an area in which replacement processing is not performed, a data area, Change depending on the area where the management information is written, the replacement processing area, the user data area, or
(2) In the optical disk certification method of writing a specific pattern on the optical disk, verifying the defective sector to detect the defective sector, and registering that the defective sector is not used, the specific pattern to be written is replaced by an alternate process.
Area, data area management information is written,
It is characterized by being changed depending on the substitute processing area and the user data area . Hereinafter, a description will be given based on examples of the present invention.

First, the definition of a bad sector (bad sector) is as follows.
(Sector mark) is not recognized, and a data field has a defect of 3 bytes or more. Next, an area to be written will be described. Optical discs are generally connected in a spiral,
One round is composed of a track, which is further divided into so-called sectors. The contents written in one sector are 9
As shown in FIG. 1 for a 0 mm disk. Figure, SM is a sector _{mark, VFO 1, VFO 2, VFO} 3 are continuous data pattern for PLL locking, AM is an address mark, ID
Is address, CRC (Cyclic Redundancy Code) is ID
Part error detection code, PA is postamble, ODF
(Offset Detection Flag) is a mark for offset detection in tracking error detection using a push-pull method, GAP is a gap, SYN is a periodic signal of a data part, DATA Field is an area for writing user data,
BUF is an area for a disc rotation fluctuation margin.

An I in which a track number and a sector number are recorded
High reliability is required in the D region. Further, depending on the state of occurrence of the defect, it may become impossible to reproduce the information of the entire one sector, and the effective rate usable by the user decreases. For this reason, the ID area has a CRC (Cyclic Redundanc) for error detection.
y Code) is added, triple writing is performed, a VFO for pulling in the PLL is arranged in front of each ID area, and S
Even when the M (sector mark) cannot be detected due to a defect or the like, the ID is detected from the AM by setting the AM (address mark) to an irregular pattern not conforming to the modulation rule. The ODF is a one-byte area without a guide groove, and is used for detecting a tracking offset amount.

Since the header portion of one sector is already formed by embossing, it is the recording portion that is read / written by the optical disk drive. The actual data portion in the recording portion is an additional 512 bytes of 639 bytes of the data field shown in FIG.
ECC and CRC for error correction are added.
FIG. 4 shows the radial position and the area. Among them, the data zone is related to the replacement process. In the certify operation, in the case of a 90-mm disk, write verification is performed on the above data zone with specific pattern data, and the data corresponding to the above bad sector is checked. If it becomes a bad sector, the corresponding track and sector number are registered in the PDL. The method of skipping the bad sectors registered here without using them is called the Slipping method.

After that, a DDS is written which describes how to use the REWRITEBIE ZONE. After this,
Write data to and read data from the REWRITEBIE ZONE. At this time, if there is a write verify or read data that corresponds to the above bad sector,
The data that is to be written or read into the defective sector is written to the replacement processing area (designated by DDS), and the track and sector number of the defective sector and the track and sector number of the replacement processing area are registered in the SDL. This method is called Linear replacement.

An address expressed by such a continuous track and sector number is called a physical address. Also, R
D explaining how to use EWRITEBIE ZONE
An address expressed in the DS excluding the replacement processing area is called a logical address. It is in the area determined by the logical address that the user writes the actual data. The user
When an optical disk is used, a format operation generally conforms to DOS. The format operation divides the area determined by the logical address as shown in FIG. 3 and writes necessary data. The reserved area is a boot sector of the DOS, in which the initial program loader of the system is inserted. FAT
The area indicates the status of connection, use, failure, and the like of the cluster (the logical sector of a certain number of units to be written) constituting the data area. The root directory area stores data relating to the file such as the file name, directory name, file attribute, and FAT registration number. The data area stores file data. The format operation of the user writes data necessary for the DOS into at least the reserved area, the FAT area, and the root directory area. Then, the data of the file in the data area is read and written. At this time, the FAT area and the root directory area are always read and written.

As described above, according to the description of the area to be written, it is roughly divided into four according to the significance of the information. Those that have high Read / Write frequency and cannot be replaced. Immediately after the optical disk is inserted into the drive, it is absolutely necessary to read and write data, and is always read and written if there is a bad sector in another area. It is required that errors are much lower. Bad sectors are bad. DMA area. Read / Write frequency is high and can be replaced. It is absolutely necessary for the user to read and write data (by file), always read and always written when writing user data (by file). Low errors are required. FAT area, root directory area. Read / Write frequency is lower than other areas,
Things you do not want to be replaced. Low errors are required. Alternation processing area. Read / write frequency is much lower than other areas. User data (file unit) area.

Next, the occurrence of an error will be described. Excluding the insufficient writing, poor reading by the drive itself, the intentional intention of the user, and the dust, the occurrence of the error is that which is present in or contained in the optical disk itself. It is a material that constitutes an optical disc in the manufacturing process,
The cause is that impurities, dust, and moisture contained in the chemical film are entrained and adhere to the substrate and each film, or the shape thereof is deformed or deteriorated. In addition, an error may occur immediately after manufacturing, and various types of devices may take a long time, such as moisture, or may be repeatedly erased, written, and read.
Basically, where there is an error, there is something that causes it, and it increases but hardly decreases. Therefore, in order to improve the reliability of the data on the optical disk, it is necessary to remove the defective sector or the future sector as quickly as possible.

Hereinafter, embodiments of the present invention will be described.
The common component of each claim is that the defective sector or the future
This is to remove by the slipping method (certify first and use it to register a bad sector), and then perform grouping by DDS to take the linear replacement method. Also, it is to determine the write can written as or used the way (described in severity of written to information), what likely ones or future that is a bad sector.

The first aspect of the present invention is obtained by adding, to the above-mentioned two components, a strict definition of a bad sector for judging a defective sector or a likely one in the future. For example, the number of unreadable IDs is one out of three, or the data field has a defect of 2 bytes or more. A second aspect of the present invention is a device in which a specific pattern for judging a defective sector or a likely future sector is devised in the above two constituent requirements. It is, for example, a combination of 3T pattern and 8T pattern or a characteristic pattern,
Another characteristic is performed several times depending on a random pattern or a region.

[0024]

[0025]

[0026]

As apparent from the above description, the present invention has the following effects. (1) Effect corresponding to claim 1: A bad sector is determined by a certifying operation by changing (selecting) a criterion for judging a bad sector or a future sector as a bad sector according to the importance of information to be written. What is PD
By registering in L, the number of times of replacement processing by the Linear replacement method is reduced, thereby shortening the read / write time and obtaining reliability. (2) Effect corresponding to claim 2: A specific pattern used for a certify operation is selected based on the importance of information to be written as a defective sector or a likely sector in the future, and becomes a defective sector in the certify operation. Is registered in the PDL, thereby reducing the number of times of replacement processing by the Linear replacement method, thereby shortening the read / write time and obtaining reliability .

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a method for certifying an optical disk according to the present invention, and is a diagram showing contents written in one sector.

FIG. 2 is a diagram showing a data field of an optical disc according to the present invention.

FIG. 3 is a diagram showing an area determined by a logical address of the optical disc according to the present invention.

FIG. 4 is a diagram showing a layout of a conventional optical disc.

FIG. 5 is a diagram showing a data area of a conventional optical disc.

Claims (2)

(57) [Claims] A specific pattern is written on an optical disc,
In an optical disk certifying method for verifying and detecting a bad sector and registering that the bad sector is not used, a criterion of the bad sector is set to an area where replacement processing is not performed and an area where data area management information is written. Certifying method for an optical disc, wherein the certifying method is changed depending on a replacement processing area and a user data area. 2. A specific pattern is written on an optical disk,
In a certification method for an optical disk for verifying and detecting a bad sector and registering that the bad sector is not used, the specific pattern to be written is replaced
The management information of the unprocessed area and data area is written
A method for certifying an optical disk, wherein the method is changed depending on an area, a replacement area, and a user data area .