JPS6318524A - Defect detection system for additional description type optical disk - Google Patents

Abstract

PURPOSE:To automatically execute a defect check while a user does not notice by loading an additional description type optical disk onto a recorder and checking a defect as to a recording area not in use. CONSTITUTION:A pickup 5 supplies an output based on a reflected light from an area not recorded yet to a level detector 8 and when the level exceeds a predetermined level, a defect detection signal is fed to a write signal generator 9 and a disk driver 4, an error flag is written in a sector having a defect so as to project a laser light of the luminous quantity of the write mode and the sector having a defect is stored in a memory 10. Then when a write request comes from a host processor 11, the data to be written are written in the recording area not in use having no defect as the result of the check of the disk 1 under the control of the write signal generator 9 and the disk driver 4. When the write is finished, the defect check is conducted similarly from the sector next to that stored in the memory 10 to assure the recording area not in use after checking thereby enabling the next write.

Description

[Detailed Description of the Invention] [Summary] The recording area of a write-once optical disc is divided immediately after it is loaded into a recording device, immediately after data is written, or when a host processor accesses another peripheral device. The present invention automatically inspects the recorded portion for defects without being aware of the time required to inspect the write-once optical disk for defects.

[Industrial application field]

The present invention relates to a defect detection method for a write-once optical disc, which inspects a recording area for defects before recording data on the write-once optical disc.

[Conventional technology]

FIG. 2 is a diagram showing a state before data is recorded on an example of a write-once optical disc, and a data recording section provided subsequent to an ID section (sector identification section) indicating a sector address etc. has a section for tracking control. Pre-group (guide groove)
is preformed and data is recorded at the bottom of this pregroup.

(in Fig. 2) is the line of the pregroup P shown in Fig. 2 (a).
This is a diagram showing a cross section at -■, where the area marked A is not coated with the recording film, and the area marked B is coated with a thick recording film, both of which are defective parts. Data is not recorded correctly in the defective area.

Conventionally, one method for accurately recording data is to read the recorded data immediately after recording the data, compare the read data with the recorded data, and check whether there is any error. However, if an error is found in the middle of multiple recorded sectors, recording must be performed again in a pre-prepared replacement sector, and a replacement sector must be prepared. Not only is it necessary to store data, but also data equivalent to the storage capacity of the data buffer used for recording is recorded at one time, so if this storage capacity is for 20 sectors, for example, from the sector where recording started, from these 20 sectors It is necessary to provide this replacement sector later, and even if recording is performed in this way, as shown in Figure 3 (al), the recorded data is not arranged in the correct order, so it is difficult to read the data. This method has disadvantages such as requiring extra access time or adding unnecessary processing to the processing of read data.

In order to eliminate such defects, write-once optical discs are inspected for defects before recording.
One method is to irradiate the recorded area with a laser beam in read mode while rotating the disk to be inspected and detect the reflected light as shown in Figure 2 (C), and the output based on the reflected light is A'. As shown, it decreases in the area where the recording film was not applied, and as shown in B', it increases in the area where the recording film was thickly applied, and when these values exceed predetermined values, the recording area Detecting the presence of defects is being carried out.

In this way, for sectors in which a defect is detected in the recording part before recording, an error flag is written in the ID section of the corresponding sector to prevent writing to that sector when data is recorded. By doing this, it is possible to skip the defective sector and write to each sector in sequence as shown in Figure 3 (bl). When executed, the write processing time becomes extremely long, and if the entire surface of the optical disk is inspected before it is used, a long inspection time is required.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, the method of first recording and then reading this record for inspection is undesirable as it requires preparation of replacement sectors in advance and unnecessary processing, as described above. In addition, if an inspection is performed before recording, the user must consciously command the execution of the defect inspection, and furthermore, the process of accessing the optical disc cannot be performed during this inspection time, which is wasteful. requires a long waiting time.

The present invention eliminates the above-mentioned drawbacks of the prior art by automatically performing a defect inspection of a write-once optical disc during a time when the user is not aware of it, and by preventing any hindrance to the process of accessing the optical disc. This is an attempt to provide a defect inspection method.

(Means for solving the problem) By loading a write-once optical disc into a recording device, or furthermore, immediately after data writing is completed or when a host processor accesses another terminal device, the unrecorded area of this disc is By dividing the data into parts so that the inspection can be performed in a short period of time that the user is not aware of, and inspecting the unrecorded portion for defects, the processing time for defect inspection of write-once optical discs can be done without the user being aware of it.
I made it run automatically.

This recording area can be divided in advance into an area where the user is not aware of the time required for inspection, or if the writing has just finished, an area corresponding to the amount of writing has been done, or if the host processor The test can be performed continuously while the input/output device is being accessed.

[For production]

As shown in FIG. 1 (1), by loading a write-once optical disc into a recording device, a predetermined inspection area is created so that the inspection can be completed in such a time that the user is not aware that a defect inspection is being carried out. CKi is automatically inspected for defects in unrecorded areas.

In this way, if a write-once optical disc is automatically inspected when it is loaded into a recording device, the inspection of the portion of the optical disc that should be recorded will be completed without the user being aware of it. Regarding the conventional example, the second
As explained with reference to the figures, data can be recorded sequentially by skipping sectors having defective parts.

In addition, as shown in Figure 1 (2) and (3), if the optical disc is inspected immediately after the data write W is completed, it will be possible to inspect the next time the data is written. The next write can be executed without waiting time, but the inspection area at that time is (2) in the same figure.
As shown in , a predetermined recording area CK2 that allows the inspection to be completed during a time when the user is not aware of it, or data of a fixed length, such as when recording image data frame by frame, is recorded. When doing so, it is possible to perform the inspection on the recording area CKW which is equal to the amount of written data as shown in FIG. 3(3).

Furthermore, as shown in FIG. 1 (4), this optical disk recording device is normally not accessed during the period when the host processor is accessing other peripheral devices other than the optical disk recording device, so during this period T. Defect inspection CKs can be performed on write-once optical discs in optical disc recording devices. In this case, the area that can be inspected changes depending on the access period to the peripheral device, but depending on the type of peripheral device or access mode. This has the advantage that a large unrecorded area can be inspected.

In any of the above cases, if an access request to the optical disk is generated from the host processor during the inspection, it is desirable to interrupt the inspection so that the request from the host processor can be responded to.

In addition, if the amount of data written after checking the unrecorded area as described above is larger than the checked recording area, at least an area sufficient to write the data that cannot be recorded in the checked area It is desirable to write this data after inspecting for defects.

Note that the length of the horizontal axis corresponding to the passage of time in FIG. 1 is arbitrary.

〔Example〕

FIG. 4 is a block diagram of a first embodiment in which the present invention is applied to an optical disc recording/reproducing apparatus. When the write-once optical disc 1 is loaded into this optical disc recording/reproducing apparatus,
The disk sensor 2 sends a signal indicating that this optical disk is present at a predetermined position to the disk loading detector 3, and when this detector detects that loading of the disk is completed and sends out a loading completion signal, this signal is output. The disk driver 4 receives the data and sends a light intensity switching signal to the pink-up 5 so that the laser beam of the read mode intensity is projected onto the optical disk, and at the same time starts the motor 6 to rotate the write-once optical disk, detects the next sector of the recording area in which is recorded and starts defect inspection from this sector.

In addition, by the laser light in the readout mode as mentioned above,
By reading the directory information recorded on this disk, recorded sectors or unrecorded sectors can be identified.

The pickup 5 supplies an output based on the reflected light reflected from the unrecorded area to the level detector 8, and the level detector 8 generates a defect detection signal based on the reflected light (if the output exceeds a predetermined value). A write signal is supplied to the write signal generator 9 and the disk driver 4, and in response to this defect detection signal, the disk driver 4 outputs a light intensity switching signal so that the laser beam of the light intensity of the write mode is projected onto the pink-up 5. An error flag is written in the ID section of the sector in which a defect is detected based on the output from the signal generator 9, and the disk driver 4
The system stores sectors in which defects have been detected in the memory 10 connected to this disk driver 4. Furthermore, sectors in which defects have been detected, sectors for which inspection has been completed, sectors that have been recorded, etc., are stored in the memory 10 connected to this disk driver 4. If the memory 10 for storing data is provided in the recording/reproducing apparatus, there is no need to access the host processor each time processing is performed, so that the processing speed can be improved.

Thereafter, when a data write request is received from the host processor 11, the disk driver 4 outputs a light intensity switching signal so that the laser beam of the light intensity of the write mode is projected onto the pickup 5, and the data to be written is transferred to the write-once optical disc. Under the control of the write signal generator 9 and the disk driver 4, data is written to unused recording areas (sectors) in which no defects were detected as a result of the first inspection.

Immediately after writing of data to the disk is completed, the disk driver 4 inspects the next sector stored in the memory 10 for defects in the same manner as described above, and stores the inspected unused record so that the next write can be made. Secure the area.

In reading from the optical disc 1, the disc driver 4 sets the laser beam from the pink-up 5 to the light intensity of the read mode, and after shaping the read signal from the pink-up by the slice circuit 12, the data reproducing unit 13
This is done by reproducing the data and transferring it to the host processor 11.

To explain this more specifically, taking as an example a case in which the host processor imports image data from the outside in the above device and records the data on an optical disk, in this case, the image data for one page is, for example, 32 sectors. The number of sectors is a fixed number, and since there is a limit to the reading speed of the scanner on the host processor side, a large number of pages are not written to the disk at once, and usually only a fixed number of pages are written. Image data will be generated, so it will be recorded that the inspection has been completed and it is ready for writing! ! The area always needs to be several pages long.

Now, if the image data is 32 sectors, which corresponds to one page, and the host processor takes in the image data for lθ pages at once, the data is always written in units of 320 sectors, so defect inspection is difficult. In the meantime, the disk driver 4 counts the number of sectors in which no defects were detected, and when the number of sectors in which no defects were detected reaches 320 sectors, it ends the inspection and waits until write data is generated. Just do it.

In addition, write data may occur during defect inspection, or the amount of written data may be inconsistent outside of the above-mentioned stripping, and the amount of written data may be unused records where the inspection is completed and no defects are detected. If the area exceeds the range, it is possible to check the range corresponding to the shortage immediately before writing the data. Even in such a case, the range of inspection performed immediately before data writing is sufficient to cover the shortage, so that the waiting time for inspection can be reduced compared to the conventional method.

Next, a case will be explained as a second example.

FIG. 5 shows an implementation of a recording and reproducing device in which a write-once optical disc is inspected for defects while the host processor is accessing peripheral devices 20s, 202, -, -, -, -, other than this recording and reproducing device. This is a block diagram showing an example, in which a bus decoder 21 is provided to decode addresses and input/output commands of peripheral devices on the bus from a host processor 11, and the output of this bus decoder 21 is supplied to a disk driver 4. This embodiment differs from the embodiment shown in FIG. 4 in this respect, but other configurations and operations are substantially the same as the embodiment shown in FIG. Indicated.

With this configuration, the disk driver 4 can identify from the output of the bus decoder 21 that the host processor 11 is accessing another peripheral device, and the fourth
In the same way as described for the illustrated embodiment, the optical disc 1 can be inspected for defects under the control of the disc driver 4.

Furthermore, when processing such as data writing is completed, the inspection should be performed from the next recording area of the recording area that has already been inspected, and the inspection range in this case is as explained above. Thus, the defect inspection can be performed in a range that can be completed within a time that the user is not aware of, or in a range that corresponds to the amount of written data.

〔Effect of the invention〕

Since the write-once optical disc is automatically inspected by loading it into a recording/playback device, the user does not have to consciously inspect the write-once optical disc, and the waiting time for this inspection is reduced. This effect can be further enhanced by performing defect inspection when writing to the optical disk is finished or while the host processor is accessing other peripheral devices. can do.

[Brief explanation of the drawing]

Fig. 1 is a diagram explaining the present invention in detail, Fig. 2 is a diagram showing a data recording surface of a write-once optical disc, a cross section of a pre-group, and an example of a defective part, and Fig. 3 is a conceptual diagram showing the data recording state. FIG. 4 is a block diagram showing the main parts of the first embodiment, and FIG. 5 is a block diagram showing the main parts of the second embodiment. Figure 1 (b) on the explanatory page of the shield raccoon at the end of Egu. figure

Claims (6)

[Claims] (1) Defects in a write-once optical disc characterized in that by loading the write-once optical disc into a recording device, a predetermined range of unused recording areas of the write-once optical disc is inspected for defects. Detection method. (2) The defect detection method for a write-once optical disc according to claim 1, wherein after the writing is completed, a predetermined range of unused recording areas is further inspected for defects. (3) A defect detection method for a write-once optical disc according to claim 1, wherein after completion of writing, an unused recording area in an area equal to the amount of writing is inspected for defects. (4) While the host processor is accessing other peripheral devices, the unused recording area of the write-once optical disk is further inspected for defects. Defect detection method for the write-once optical disc described. (5) The inspection for defects in the unused recording area is terminated when there is an access request from the host processor to the write-once optical disk during execution of the inspection. 4. A defect detection method for a write-once optical disc according to item 4. (6) If the amount of data to be recorded on the write-once optical disc is such that it is necessary to record the data in an area that exceeds the area that has been previously inspected for defects, the above defect inspection is performed immediately before the recording operation. The write-once type according to any one of claims 1 to 5, characterized in that recording of all data is started after inspecting for defects in an area in which data exceeding the area is to be recorded. Optical disc defect detection method.