JP2002117546A - Recording erasure control method for optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that portions of old recording points remain as the sizes of a beam spot does not change with the conventional device of recording and reproducing information by utilizing the intensity modulation of the single laser beam and utilizing the reflectivity of the crystalline state (erasing state) and amorphous state (recording state) of a medium relating to the erasure of the recorded parts of the optical disk. SOLUTION: This recording control method for optical disks makes control possible in such a manner that arbitrary arrays can be written to a specific range by checking the recorded parts to be managed by a filing system by an application, then inputting a specific command to an NVRAM to invalidate overwriting protection. Since the space parts are provided with marks larger at a ratio of 1:3 than the marks of the recorded parts by a laser beam, the perfect erasure may be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for erasing data stored on an optical disk, and more particularly, to a method for erasing data stored by incorporating a specific command into control unit software so that the data cannot be decoded by a third party. It is intended to provide a control method capable of performing erasure.

[0002]

2. Description of the Related Art Heretofore, as an optical information recording / reproducing apparatus capable of overwriting, an apparatus using a phase change medium as an information recording medium and utilizing the intensity modulation of a single laser beam is known. Information is recorded / reproduced by utilizing a difference in reflectance between a crystalline state (erased state) and an amorphous state (recorded state) of the medium as a phase change medium.

However, in the case of this overwriting, since the size of the beam spot does not change even if the intensity is modulated from the optical disk of the semiconductor laser, a part of the old recording point remains, causing a deterioration in the error rate. was there.

As one means for solving these problems, Japanese Patent Application Laid-Open No. Hei 5-94621, entitled "Information Recording / Erasing Method for Optical Information Recording / Reproducing Apparatus", synchronizes with intensity modulation of a laser light source corresponding to erasing / writing of recording. By overwriting the light intensity or phase near the center of the cross section of the light beam emitted from the laser light source, the overwriting width is made larger than the recording width so that the old recording points remain unerased. .

Japanese Patent Application Laid-Open No. Hei 5-290381, "Data erasing device for write-once optical disc," discloses that data recorded on a conventional optical disc is hardly destroyed both magnetically and optically, and the data is reflected on the optical disc surface. Because there is a synthetic resin layer etc. to protect the surface from rust or corrosion,
When discarding these optical discs, it is disclosed that most data can be read even if the optical disc surface is damaged.

As a means for solving these problems, Japanese Patent Application Laid-Open Publication No. H10-15064 discloses a recording apparatus for a write-once optical disc, which is provided with an input section for inputting data erasure, and specific data, for example, " A technique is disclosed in which “1” and “0” are redundantly recorded so that recorded data cannot be read.

Japanese Unexamined Patent Publication No. Hei 8-124158 discloses an erasing device for erasing data from an optical disk which stores data in spiral tracks. A larger output, for example, a laser output of 250 mV or more, and an elliptical shape extending over a plurality of tracks, for example, about 50 μm to 150 μm in a disk circumferential direction and 2 μm to 2 μm in a track direction.
The data is erased at a high speed by irradiating an optical disk with a 4 μm elliptical laser spot light.

[0008] Similarly, Japanese Patent Application Laid-Open No. 10-293942, "Optical information recording medium and engineering information recording / reproducing method"
Form a phase-change optical recording medium on which recording and reproduction of information is performed by irradiating a laser beam with a recording film phase change on a transparent rigid substrate, and form a plurality of phase-change optical recording media through a transparent spacer. It discloses that information is recorded, reproduced, and erased in each layer of the transparent phase change type recording medium by using an engineering information recording medium on which is laminated.

Further, as described in Japanese Patent Application Laid-Open No. 11-185256, "Optical disk erasing device", the output setting of the laser beam emitted from the laser beam irradiating means is used for the period of erasing the optical signal recorded on the track. Can be set intermittently at a predetermined cycle, and the heat accumulation state on the disk can be improved.
It is disclosed that the control of the range for raising the temperature is excellent.

[0010]

However, most of the optical discs disclosed in the above-mentioned publications have a size of about 3.5 inches or about 5 inches, and have recently developed a large capacity of 12 inches. Non-rewritable WORM (Write with excellent data storage and high speed)
Once Read Many), the above erasing device could not be used.

Particularly, in a drive and a library apparatus which are most suitable for multi-users who require permanent data storage and high-speed connection to important and large-capacity data, the 12-inch non-rewritable WORM (Write Once Read Many) )
However, there is a problem that it is difficult to erase the data at the time of discarding. Therefore, when a secret sentence is included in the data, there is a problem in concealment.

[0012]

SUMMARY OF THE INVENTION The present invention is directed to a conventionally known device.
2-inch non-rewritable WORM (Write Once Read)
Many) write devices are used, but by incorporating special commands into the RAM (Random Access Memory) built in this device, the overwrite protection of the control unit is invalidated and an arbitrary array is set in the extent (range). An object of the present invention is to provide a method capable of erasing a desired sector (area) at a location where writing can be performed.

That is, a first aspect of the present invention is to provide a method for recording and erasing an optical disk, in which a specific command is incorporated in a RAM of the optical disk control device, thereby invalidating overwrite protection of the control device and arranging an arbitrary array in an extent of the optical disk. A method for controlling the recording and erasing of an optical disc, characterized by erasing data in a specific sector so that data can be written.

According to a second aspect of the present invention, as a means for erasing the data of the specific sector, a specific sector portion specified by a specific command is input to a delete symbol, and the output of a head installed in a driver is increased. 2. The recording / erasing control method for an optical disk according to claim 1, wherein the recording and erasing are performed by burning.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The feature of the present invention is that after an erased portion is specified by a specific command, a wider area than the storage portion of that portion is burned so that data cannot be read.

For this reason, the following overwrite extent SCSI command is incorporated in the control unit in order to invalidate the overwrite protection of the control device (not shown) and write an arbitrary array in a specific range.

One of the commands is a 10-byte vendor-unique SCSI overwrite command, xOPx00xS1xS2xS3xS4x00xT1x
It is added in the format of T2x00.

These symbols are: xOP = vendor unique operation code xS1 = start LBA most significant byte xS2 = start LBA next byte xS3 = start LBA next byte xS4 = start LBA least significant byte xT1 = transfer length most significant byte xT2 = transfer Indicates the least significant byte.

With this command, the overwrite protection of the LD6000 controller (not shown) is invalidated, and (xS1S2S3S4) to (xS1S2S3S4)
+ XT1T2) to write an arbitrary sequence in the extent (range).

In this case, the ECC byte is overwritten together with arbitrary data, and for the transferred sector, both the initial sector and the replacement sector are overwritten.

In the apparatus according to the present invention, an arbitrary array is created internally by the control device instead of the host (upper computer), so that the drive does not proceed to the data transfer stage. Specifically, the drive is disconnected from the host while the above-mentioned overwrite command is being input, and upon completion of this command, the host is selected again and its status (status) is reported. I have.

The drive performs verification processing (verify) on all overwritten sectors as described above to determine whether the sectors are completely overwritten. In this processing, the drive performs: The overwritten sector is read to confirm that the overwritten sector cannot be decoded (decoded).

If a readable sector is found in this verification process, a "hardware error-media write failure" (request sense byte 2 / x12 / x13)
= 04/03/00) The status is checked, and the faulty LBA is put in the request sense information byte.

Another command used in the apparatus of the present invention, a 6-byte vendor-unique SCSI "overwrite disk" command, is added in the format of xOPx00x00x00x00x00.

These symbols indicate xOP = vendor unique operation code.

With this command, LD6000 / L
The overwrite protection of the D8000 controller is invalidated, and an arbitrary array can be written to all disks (0..MAXLBA).

In this case, the ECC byte is overwritten together with arbitrary data, and for the transferred sector, both the initial sector and the replacement sector are overwritten.

In the method of the present invention, the drive does not proceed to the data transfer stage because an arbitrary array is created internally by the control unit instead of the host (upper computer). Specifically, the drive is disconnected from the host while the above-mentioned overwrite command is being input, and upon completion of this command, the host is selected again and its status (status) is reported. I have.

The drive performs a verifying process on all overwritten sectors as to whether the sector has been completely overwritten. In this process, the drive performs: The overwritten sector is read to confirm that the overwritten sector cannot be decoded (decoded).

If a readable sector is found in this verification process, a "hardware error-media write failure" (request sense byte 2 / x12 / x13)
= 04/03/00) The status is checked, and the faulty LBA is put in the request sense information byte.

As the overwritable drive used in the method of the present invention, the drive can be overwritten by adding the special values of the above equations (1) and (2) to the NVRAM at the production factory. I have.

On the other hand, the conventional control device which does not have these special values in the NVRAM responds to the vendor unique overwrite command by "illegal request-invalid operation code" (request sense byte 2 / x12 / x13 = 5). / 20
/ 0) Since the check state based on the status is repeated, it cannot be used in the method of the present invention.

In general, on Philips LMS WORM media, the written sector contains a series of marks and spaces of various lengths (strings), and the RLL 1,7
Usually follows the code rules for codes.

However, when this sector is overwritten on a WORM medium with a different data arrangement, the original mark remains as a mark, but most of the original space is changed to a mark.

In this case, a mark substantially larger than the space is written by the LMS drive, and the ratio is typically 1: 3.

The LMS drive also handles this asymmetry by adjusting the slice level at the time of reading. However, the fact that the mark is so large is that most of the space is overwritten when overwriting. Indicates that it has been changed.

When the original mark and the new mark are combined, most of the data fields consist only of marks, thus producing an almost incorrect RLL1,7 array,
This results in unpredictable data bytes after decoding the channel bits.

Furthermore, since the original data is overwritten by any data, for example, even if a given byte can be overwritten with a second given byte to form a valid code, The value of the second byte (byte to be overwritten) is unknown.

Hereinafter, the present invention will be described in detail with reference to examples.

As a device used in the method of the present invention, a 12-inch optical library device (not shown) manufactured by Plasmon, UK was used. Since this apparatus uses a dual head drive, it can access data of up to 30 GB per disk at a high speed.

Also, this dual head has front and back 30 GB.
In addition to being able to read and write on the board at the same time, unlike other libraries, there is no need to flip the disk, so that the data access time is very short.

The optical disk used in the method of the present invention comprises:
Since a highly reliable, large-capacity, and non-rewritable WORM is used because of glass quality, the frequency of media exchange can be reduced, and unlike other devices, a cache is not required.

The OS (O) of the apparatus used in the method of the present invention
TracerXFS (UNIX)
(Registered trademark) version) and MicroHSM (Windows NT version) software, but other systems may be used.

The NV RAM (Random Access M) of the above device
emory) as a 10-byte vendor-unique SCSI "overwrite" command in the format of xOPx00xS1xS2xS3xS4x00xT1xT2x00 (1).

Similarly, a 6-byte vendor unique S
A CSI "overwrite disk" command was added in the format of xOPx00x00x00x00x00 (2).

Since the management of the sector of the optical disk used in the present invention is performed by a file system, the location of the sector to be erased is confirmed by an application separately attached to the apparatus in order to first select the sector to be erased.
For example, we specified Delete A (the range of the retirement sector).

In this case, by overwriting the erasure, a new mark is provided in the space portion at a ratio of 1: 3 from the top of the previously recorded mark portion to the space portion including the surrounding space portion as described above ( The corresponding numerical value in the range of Delete A in the expressions 1) and (2) was input to the NVRAM.

As a result, the overwrite protection of the control unit is invalidated, and a new mark is overwritten in the sector range to be erased, and the previously stored data is completely erased.

[0049]

According to the method of the present invention, a specific sector which is a cancellation range is confirmed by an application, and then the NVRA
By inputting an overwrite command or overwrite disc command to M, the sector to be erased is specified.
Since this is a method of erasing the recording portion in the range by inputting the delete symbol, it is possible to provide a new erasing method that can solve the problem that it was conventionally impossible to completely erase the recording portion.

In the present invention, if the overwritten area is in a decrypted state, it is possible to check by a hardware error-medium write failure status. It is.

Claims (2)

[Claims] In an optical disk recording and erasing method, a specific command is incorporated in a RAM of an optical disk control device, so that overwriting protection of the control device is invalidated and an arbitrary array can be written in an extent of the optical disk. A method for controlling recording and erasing of an optical disc, comprising erasing data of a specific sector. 2. The method according to claim 1, wherein the means for erasing the data of the specific sector burns off a specific sector portion specified by a specific command by receiving an input of a delete symbol and increasing an output of a head installed in a driver. 2. The recording / erasing control method for an optical disk according to claim 1, wherein: