JPH07161145A - Data recording for optical disc - Google Patents

Abstract

PURPOSE:To surely perform an overwriting by recording a data to an optical disk in the CD-ROM format and also recording another overwriting data by the recording unit where connecting blocks are arranged before and after data block. CONSTITUTION:Recording is conducted by the recording unit WU where connecting blocks BF, BB are additionally arranged before and after the data block BD on which overwriting is to be conducted and when the overwriting is to be conducted, the recording is also performed in this recording unit WU. Here, PC designates a connecting point, PS designates an overwriting start point and PE designates an overwriting end point. According to this recording method, the overwriting is first conducted on the block BF for connection arranged before the data block BD to be overwritten and thereafter the overwriting is conducted continuously on the data block BD. Thereby, since a certain period is assured until the data block BD from detection of period of the block BF for the first connection, deviation of the recording timing of the EFM frame is never generated in the data block BD and the overwriting is conducted reliably.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc recording method applicable to compact disc related equipment and capable of rewriting information.

[0002]

2. Description of the Related Art CD-ROMs are becoming widespread as optical discs capable of recording large-capacity data, applications, OS, etc., and capable of being mass-produced at low cost, forming a very large market as read-only optical discs. There is. The advantage of such a CD-ROM is that it can be produced at a large capacity and at a low cost, but it has a major drawback that the contents cannot be rewritten. The fact that existing data cannot be rewritten can be an advantage in certain application fields, but we want to record large amounts of data.
There is a great demand for a recordable CD-ROM.

Therefore, a write-once CD that can be recorded only once
-ROM has emerged and is becoming popular as CD-R (CD-Recordable). However, even with this CD-R, the number of times it can be recorded is limited to once, and it is not possible to rewrite the data once recorded. Therefore, even if it is a CD-R, the usable range of application is limited, and since the CD-R is not sufficient, an optical disk having a CD-ROM format that allows rewritable recording any number of times is desired. ing.

By the way, as one of optical memory media capable of recording, reproducing and erasing information by irradiating electromagnetic waves, especially laser beams, a so-called phase which utilizes a transition between a crystal-amorphous phase or a crystal-crystalline phase is used. Changeable recording media are well known. With this phase-change recording medium, overwriting with a single beam, which is particularly difficult with magneto-optical memory, is possible, and the optical system on the drive side is simpler.
For that reason, research and development have recently become active. In particular, because of the advantage that the same optical system can be used, the present invention can be applied as a rewritable CD-ROM having characteristics such as high reflectance and high contrast.

[0005]

Regarding the recording method of the write-once type CD-ROM, etc., the document "Recordable Compact D" is used.
isk Part II ”. First, since the CD-R is a write-once type, new data is always updated by adding it to the final block. Rewritable type CD-R
In the case of the OM, similar to the case of the write-once type, in addition to adding new data to the final block, the data can be updated by overwriting the existing data block with the new data. However, no method has been proposed for overwriting data on a CD-ROM format optical disc.

This point will be described in more detail with reference to FIG. First, recording in the CD-ROM format is performed by EFM (Eight to Fourteen Modulation) modulation. Here, one block of the CD-ROM consists of 98 EFM frames, and the content of one block is 9
It consists of the entire signal of 8 EFM frames and is recorded. When adding data to a CD-R, the above-mentioned document "R
According to "ecordable Compact Disk Part II", recording is started after shifting by 26 ± 1 EFM frames from the sync signal. It is possible to rewrite the contents of existing data with a rewritable optical disc of such a CD-ROM format. Consider Figure 3. Blocks of recorded data and E
It shows a relationship with an FM frame. In the figure,
For example, in order to rewrite the block 2, it is necessary to detect the synchronization pattern (synchronization frame) and simultaneously rewrite the subsequent EFM frame, but this is electrically difficult. Therefore, when considering such a time shift of the EFM frame, it is difficult to rewrite only the block 2, and it is actually necessary to devise some means.

[0007]

According to a first aspect of the present invention, recording on an optical disk in the CD-ROM format and recording of new overwrite data are performed in a recording unit in which connection blocks are arranged before and after a data block. I decided to do it.

According to the second aspect of the invention, the entire data area is recorded as a recording unit of the same size in which connection blocks are arranged before and after the data block, and recording on an optical disk in the CD-ROM format and a new recording unit are performed. Overwriting data was recorded.

According to the third aspect of the present invention, in these inventions, the number of connecting blocks arranged on the front side of the data block is three or more, and the number of connecting blocks arranged on the rear side of the data block is two or more. .

In this case, in the invention described in claim 4, the number of data blocks forming each recording unit is set to 8 or more.

According to a fifth aspect of the present invention, in regard to these aspects of the invention, recording is performed so that a blank portion on a data block caused by overwriting is filled with specific data indicating that the host computer side is blank. did.

[0012]

According to the invention of claim 1, a CD-ROM is provided.
Since the recording unit has a connection block provided before and after the data block from the time of recording by the format, the time difference of the recording timing of the EFM frame does not occur in the data block. Overwriting is possible without overlapping.

According to the second aspect of the invention, since the entire data area is recorded or overwritten as a recording unit in which the same number of connected blocks are positioned before and after the data block, the same is applied to any data area. It can be handled by overwriting.

In these cases, in the invention according to claim 3, since the number of connection blocks to be arranged on the front side and the rear side of the data block is 3 or more and 2 or more, the data is surely protected. You will get it.

In this case, according to the fourth aspect of the invention, since the number of data blocks forming each recording unit is eight or more, it is possible to secure at least half or more as an area usable by the user.

Further, when a certain data block is overwritten with the data of a file smaller than that, there is a possibility that the data before rewriting remains in the portion where there should be no data. However, in the invention of claim 5, this Since such a blank portion is recorded by being filled with specific data in order to indicate to the host computer side that it is empty, overwriting can be performed without a data error even if the data length is different.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. In this embodiment, a rewritable optical disk such as a phase change recording medium is recorded in a format reproducible by a CD-ROM player so that it can be applied as a rewritable CD-ROM. Basically. First, as a premise, recording in the CD-ROM format used also in this embodiment is performed by EFM modulation as described with reference to FIG. An existing data block formatted and recorded by such a CD-ROM format is in a state as shown in FIG. 1, for example,
Consider the case where B _D is a data block to be overwritten. In such a case, if rewriting is performed as it is for only the corresponding data block B _D , as described above,
The time shift of the EFM frame cannot be absorbed and an error may occur.

Therefore, in this embodiment, as shown in FIG. 2A, a recording unit W _U in which extra connection blocks B _F and B _B are arranged before and after the data block B _D to be overwritten.
The recording unit W _{U is used} for recording even when overwriting is performed (corresponding to the invention described in claim 1). In FIG. 2B, P _C indicates a connection point, P _S indicates an overwrite start point, and P _E indicates an overwrite end point.

According to the recording method of the present embodiment, the connection block B _F arranged before the data block B _D to be overwritten is first overwritten, and then the data block B _{D is} overwritten.
Overwrite. Therefore, since there is a certain period from the first synchronization detection of the connection block B _F to the data block B _D , the recording timing deviation of the EFM frame does not occur in the data block B _D , and overwriting is reliably performed.

By arranging the connection block B _B after the data block B _D , the overwriting of data becomes more reliable.

Particularly, the entire data area is set to the data block B.
Connection block B _F around and _D, if B _B so as to record and recording for overwriting the recording unit W _U which is the same becomes size was located (corresponding to the invention of claim 2 wherein) The same method can be used to overwrite any data area.

By the way, when recording is performed in such a recording unit W _U , if the number of data blocks B _D occupying the recording unit W _U is too small, all the connecting blocks B _F and B _{B in} the front and rear are completely. The ratio occupied in the data area becomes large, and the data area usable by the user becomes small. For example, assuming that the number of data blocks B _D forming the recording unit W _U is 1, the number of front-side connection blocks B _F is 5, and the number of rear-side connection blocks B _B is 2,
The number of data blocks B _D becomes 1 with respect to 8 blocks forming the entire recording unit W _U, and only 1/8 can be used by the user. Therefore, the recording unit W _U
It can be said that a certain number is required as the number of data blocks B _D forming the. For example, if the number of data blocks B _D is eight, in the above example, the user-usable ratio is eight.
/ 15, and if the number of data blocks B _D is 16, the ratio usable by the user is 16/23. In order to secure at least half of the entire data area, at least the number of data blocks B _D needs to be 8 or more (corresponding to the invention of claim 4). On the contrary, the smaller the number of connection blocks B _F and B _B is, the larger the user area can be. However, for data protection, the number of front connection blocks B _F is 3 or more, and the number of rear connection blocks B _F is large. Two or more B _B are required (corresponding to the invention of claim 3).

CD-ROM according to the method of the present invention
In a rewritable optical disc according to the format, since it is necessary to make the data block B _D large, it is appropriate to use it for recording a large file. In particular,
The file size of image / sound data etc. becomes large,
Since the size of 100 kB or more increases, it is suitable for recording such a file.

When a file is overwritten with a smaller file, the file before rewriting may remain in a portion where there should be no data, which causes a data error. Therefore, such a remaining portion (empty portion of data) is overwritten with specific data, for example, "0", to indicate to the host computer side that there is no data (empty). (Corresponding to the invention of claim 5).

Specific examples 1 and 2 of the present invention based on such an idea will be illustrated below.

Concrete Example 1 16 data blocks B _D , connection blocks B _F , B
Recording was performed on a rewritable optical disc in a CD-ROM format using recording units W _U (= 23 blocks) in which 5 and 2 _Bs were respectively arranged. Here, since one block is 2048 B, the size of the recording unit W _U is 32 kB. When any one recording unit W _{U in the} thus recorded optical disk was overwritten with another data, the data could be rewritten accurately without causing an error in the data.

Concrete Example 2 16 data blocks B _D , connection blocks B _F , B
Recording was performed on a rewritable optical disc in a CD-ROM format using recording units W _U (= 23 blocks) in which 5 and 2 _Bs were respectively arranged. The recorded file is data having an average size of 100 kB. When any one file in the optical disc recorded in this way was overwritten with another file, it was possible to rewrite correctly without any data error.

In the present embodiment, an example of application to overwrite recording has been described, but it is obvious that the present invention can also be applied to a normal recording method of recording after erasing. Also,
The present invention can be applied not only to the phase change recording medium but also to a magneto-optical recording medium.

[0029]

According to the first aspect of the present invention, recording is performed on the optical disc in the CD-ROM format and new overwrite data is recorded in a recording unit in which connection blocks are arranged before and after the data block. Therefore, since the time difference of the recording timing of the EFM frame does not occur in the data block, the overwriting can be surely performed.

According to the second aspect of the invention, since the entire data area is recorded or overwritten as a recording unit in which the same number of connection blocks are positioned before and after the data block, which data area is used. The same overwriting process can be applied to the above.

According to the third aspect of the present invention, in these inventions, the number of connecting blocks arranged on the front side of the data block is three or more, and the number of connecting blocks arranged on the rear side of the data block is two or more. Therefore, the data to be overwritten can be surely protected.

In this case, according to the fourth aspect of the invention, since the number of data blocks forming each recording unit is eight or more, it is possible to secure at least half or more as an area usable by the user.

According to the fifth aspect of the present invention, with respect to these aspects of the invention, recording is performed so that the empty portion on the data block caused by the overwriting is filled with specific data indicating that the host computer side is empty. Therefore, when overwriting a certain data block with the data of a file smaller than that, it is possible to eliminate the possibility that the data before rewriting remains in the part where there should be no data, even if the data length is different. Error-free overwriting can be done.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a state of an existing data block.

2A and 2B show an embodiment of the present invention, FIG. 2A is a schematic diagram of a recording unit, and FIG. 2B is a schematic diagram of a state of a data block that has been overwritten and updated.

FIG. 3 is a schematic explanatory diagram showing a relationship between an EFM frame of a general CD-ROM format and each block.

[Explanation of symbols]

B _D Data block B _F Front side connection block B _B Rear side connection block

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukio Ide 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (5)

[Claims] 1. An optical disk recording method, wherein recording is performed on an optical disk in a CD-ROM format and new overwrite data is recorded in a recording unit in which connection blocks are arranged before and after a data block. . 2. The entire data area is used as a recording unit of the same size in which connecting blocks are arranged before and after the data block, and recording on the optical disc in the CD-ROM format and recording of new overwrite data are performed. An optical disk recording method characterized by the above. 3. The number of connecting blocks arranged on the front side of the data block is three or more, and the number of connecting blocks arranged on the rear side of the data block is two or more. Optical disc recording method. 4. The optical disk recording method according to claim 3, wherein the number of data blocks forming each recording unit is 8 or more. 5. The recording is performed by filling the empty portion on the data block generated by the overwriting with specific data indicating that the host computer is empty. , 3 or 4, the optical disc recording method.