JPH0778969B2 - Final recording sector detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a final recording sector detection method suitable for a write-once type optical disk device.

[Background technology]

FIG. 4 is a diagram conceptually showing an area in a conventional write-once optical disc. The disk is generally divided into an index area and a data area. The user can record a desired data file in each sector (D _{1 to} D ₅ ) of the data area. When a predetermined file is recorded, index information about the file is sequentially recorded in each sector (I ₁ , I ₂ ) of the index area. Therefore, the latest index information of the data recorded on the disc can be obtained by reading the tail of the last recording sector (I _{2 in the} figure) of the index area.

Conventionally, in order to detect the last recorded sector, the amplitude of the RF signal obtained while sequentially reproducing the index area is monitored. When the level of the RF signal falls below a predetermined reference value, the sector immediately before that is detected as the last recorded sector.

[Problems to be solved by the invention]

Since the conventional method detects the last recorded sector depending on the presence or absence of the RF signal in this way, it is easily affected by noise in the unrecorded sector, and the final recorded sector may be erroneously detected. Further, even if the data in the last recording sector has an error, it cannot be recognized, and there is a risk of reading the wrong index information. As a result, new data may be overwritten on the already recorded sector, and the original data may be destroyed.

Therefore, the present invention more accurately detects the final recording sector and prevents reading of erroneous index information.

[Means for solving problems]

In order to solve the above problems, the present invention reproduces a recording medium in which the same data to which an error code such as an error correction code or an error detection code is added is recorded in corresponding sectors of a plurality of areas, Sector for each sector belonging to any one of the areas, the error status is sequentially detected for the data recorded in the sector using the error code, and the error status satisfies a predetermined criterion. Then, n sectors in which the error situation does not satisfy the predetermined criterion are continuously detected, and n sectors in other areas corresponding to the n sectors all satisfy the predetermined criterion. If not satisfied, a sector immediately before the n sectors that do not satisfy the predetermined criterion in any one of the plurality of regions is detected as a final recording sector.

[Action]

According to the present invention, the same data to which an error code is added is reproduced on a recording medium in which corresponding sectors of a plurality of areas are recorded, and an error is generated for each sector belonging to any one of the plurality of areas. An error situation is sequentially detected with respect to the data recorded in the sector using a code, and n sectors in which the error situation does not satisfy the predetermined criterion are successively detected following the sector whose error situation satisfies the predetermined criterion. In addition, when all the n sectors in the other areas corresponding to the n sectors do not satisfy the predetermined criterion, the n sectors that do not satisfy the predetermined criterion in any one of the plurality of areas The immediately preceding sector is detected as the last recorded sector.

Therefore, in any one of the plurality of areas, n sectors whose error status does not satisfy the predetermined criterion are consecutive, and n sectors in other areas corresponding to the n sectors are Only if all the prescribed criteria are not met,
Since the sector immediately before n sectors that do not satisfy the predetermined criterion is detected as the final recording sector, the detection accuracy of the final recording sector can be improved.

〔Example〕

FIG. 3 is a block diagram when the final recording sector detection method of the present invention is applied to a write-once type optical disc device. When recording is commanded by the input means 9, the control circuit 8 including a microcomputer controls the servo circuit 10 to rotate the disk 1 via the spindle motor 2. Further, the pickup 3 is moved to the index area via the servo circuit 10, the final recording sector is detected and the data is read as will be described later, and the address of the data area to be recorded next is calculated from the data.

On the other hand, the recording data signal input from the terminal 7 is corrected by the correction circuit 6.
Then, processing such as interleaving and addition of error correction code is performed, and the result is supplied to the modulation / demodulation circuit 5. The modulation / demodulation circuit 5 modulates the input signal by, for example, M ² and outputs it. This output signal is amplified by the amplifier circuit 4 and supplied to the pickup 3. The pickup 3 controls a laser beam or the like that irradiates the disc 1 in response to an input signal. As a result, data is recorded in a predetermined sector of the data area of the disc 1.

The control circuit 8 immediately executes the verify read after the recording is completed. That is, the position of the pickup 3 is controlled via the servo circuit 10 to reproduce the signal just recorded. The reproduced signal output from the pickup 3 is amplified by the amplifier circuit 4, and further demodulated by M ² by the modulator / demodulator circuit 5.
The demodulated signal is input to the correction circuit 6 and subjected to processing such as error correction and deinterleaving. When the error of the reproduced signal cannot be corrected or the number of errors is equal to or larger than the predetermined reference value, the control circuit 8 re-records the same data in the spare area in the data area.

When the predetermined data is recorded in the data area (including the replacement area) in this way, the control circuit 8 controls the servo circuit 10 to move the pickup 3 to the sector next to the last recording sector in the index area, Control the correction circuit 6,
An index signal corresponding to recording data is generated and recorded.

As shown in FIG. 1, the index area of the disc 1 is divided into a plurality of areas (two areas A and B in the embodiment). The 'assuming that the index signal has already been recorded up to ₄ (sector I _4, I' sector I in the region B and its corresponding sector I ₄ now for example the area A when ₄ is assumed to be the last recording sector) , A new index signal is recorded in the following sectors I ₅ and I ′ ₅ . Incidentally, the correspondence here means the positions from the first sectors I ₁ and I ′ ₁ of the areas A and B.

When the index signal i ₅ is recorded in the sector I _{5 in the} area A and the sector I ′ ₅ in the area B, the control circuit 8 immediately causes the recorded data to be verify-read as in the case described above. Like the data signal, the index signal i ₅ is provided with an error correction code such as a Reed-Solomon code or an error code such as an error detection code such as CRC for each sector. The correction circuit 6 detects the error status of the reproduction index signal i ₅ using this error correction code or the like. Eg sector
If the standard for read-verify (which may be stricter than the standard for normal playback) is not satisfied, such as when the error reproduced at I ₅ cannot be corrected or the number of errors is large, the next sector I _The same index signal i ₅ is recorded in ₆ and I ′ ₆ .

The index signal i ₅ recorded in the sectors I ₆ and I ′ ₆ is also immediately verified and read, and the recording operation of the index signal is terminated when both error conditions satisfy the criteria.

For example, the index signal I ₇ recorded in the sector I _{7 of the} area A
Although satisfied the criteria of the verify read, the corresponding region same index signal i ₇ recorded in the sector I _'7 of B
Area does not satisfy the verify read criteria, area A
The same index signal i ₇ is recorded again in the sectors I ₈ and I ′ ₈ next to the sectors B and B, respectively. Thus all areas A,
The recording operation of the same index signal is repeated until the verify read standard is satisfied in the corresponding sector of B.

Note that the areas A and B do not necessarily need to be concentratedly provided at different positions, for example, I ₁ , I ′ ₁ , I ₂ , I ′ ₂
It is also possible to set the sector of the odd address as the area A and the sector of the even address as the area B as in.

In this way, since the same indenx signal is recorded in a plurality of corresponding sectors, when the index signal of one area is deteriorated, the index signal of the other area can be used.

When the same index signal is recorded in the corresponding sectors of a plurality of areas, the final recording sector can be detected by the following method.

That is, when detecting the last recorded sector of the index area, the control circuit 8 controls the servo circuit 10 to cause the pickup 3 to sequentially reproduce each sector of one area (for example, area A) from the beginning. At this time, the control circuit 8 monitors the error status of each sector from the output of the correction circuit 6 and determines whether the error status satisfies a predetermined standard.

In the sector where the index signal is not recorded, the error cannot be corrected (when the error correction code is used) or the error is detected (when the error detection signal is used). Therefore, for example, on the basis of whether error correction is possible or no error is detected, it is possible to detect a sector in which no index signal is recorded. The last recorded sector is detected as the sector immediately before it.

Alternatively, if information about the length of the index area is recorded in a predetermined sector of the index area, the information is first read. Then, the pickup 3 is moved to the middle of the index area, and it is determined whether or not the sector in the vicinity thereof is already recorded. The recording state is detected in a sector that is half the distance between the position and the end portion when the recording has been completed, and in a sector that is half the front distance when the recording is not performed. The same operation is repeated thereafter to detect the final recording sector. By doing so, the final recording sector can be detected in a shorter time than in the case described above.

Next, examples according to the present invention will be described in detail.

According to the final recording sector detection method described so far,
Even if the index signal is recorded, the sector may be erroneously detected as a sector not satisfying the standard (unrecorded sector) due to noise or the like. Therefore, in order to avoid such a case, as shown in FIG. 2, a sector which does not satisfy the standard (indicated by X in the figure) satisfies a sector (○ in the figure)
The area A is reproduced until n (two in the embodiment) are detected successively after (shown by the mark). Sector I that does not meet the criteria
_{When N + 1} and I _{N + 2} are detected two times in a row, then the area B
Of the two corresponding sectors _{I'N + 1} and _{I'N + 2} .
For example, in the case of an apparatus that does not record data in a sector whose sector address cannot be read during recording, the probability that n consecutive sectors whose sector address cannot be read is set to a value that is sufficiently small.

If the two sectors _{I'N + 1} and _{I'N + 2} do not satisfy the criteria (B _{1 in} the figure), the immediately preceding sector
Detecting I _N, the I _'N as a final recording sector. When the probability of detecting a recorded sector as an unrecorded sector is P, the sectors I _N and I ′ _N are actually recorded even though the testers I _{N + 1} and I ′ _{N + 1} are the last recorded sectors. The probability of erroneous detection as the final recording sector is P ² , which is considerably small.

When one of the corresponding sectors I ′ _{N + 1} and I ′ _{N + 2 in} the area B satisfies the criterion (B ₂ or B _{3 in} the figure), the sector (the value of n is set to 3 or more) In this case, the rearmost sector (the recording direction of the area, not the rotation direction) is detected as the last recording sector.

As described above, since the last recorded sector is recorded so as to satisfy the reference condition in all (two) areas A and B, unless both sectors are detected as not satisfying the reference, the last recorded sector is the last recorded sector. The recording sector is correctly detected.

The present invention can also be applied to a recording medium that can be erased and re-recorded.

〔effect〕

As described above, according to the present invention, in a plurality of areas, when the error statuses of consecutive n sectors having a corresponding relationship do not satisfy a predetermined criterion, immediately before the n sectors. Since it is detected as the last recorded sector of the sector, the detection accuracy of the last recorded sector can be improved, and the data in the sector in one of the plurality of areas is deteriorated and an error occurs or the error occurs. Even when the correction of is impossible, the sector of the other area corresponding to the sector of the one area can be detected as the final recording sector.

[Brief description of drawings]

1 and 2 are schematic explanatory views of an index area of a disc when the final recording sector detection method of the present invention is applied, and FIG. 3 is a block diagram of the optical disc device, and FIG.
The figure is a schematic explanatory view of a region of a conventional disc. 1 ... Disk 2 ... Spindle motor 3 ... Pickup 4 ... Amplification circuit 5 ... Modulation / demodulation circuit 6 ... Correction circuit 7 ... Terminal 8 ... Control circuit 9 ... Input means 10 ... Servo circuit

Claims (1)

[Claims] 1. A recording medium in which the same data to which an error code is added is recorded in corresponding sectors of a plurality of areas is reproduced, and for each of the sectors belonging to any one of the plurality of areas, The error status is sequentially detected for the data recorded in the sector using the error code, and the sector where the error status does not meet the predetermined standard is followed by the sector where the error status satisfies a predetermined standard. If n sectors are continuously detected and all n sectors of the other areas corresponding to the n sectors do not satisfy the predetermined criterion, the area in any one of the plurality of areas is A method of detecting a final recording sector, characterized in that a sector immediately before n sectors which do not satisfy a predetermined criterion is detected as a final recording sector.