JP3885538B2 - Optical disk device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disk device, and more particularly, to a return process in the case where tracking or out of focus occurs.
[0002]
[Prior art]
Conventionally, various processes have been proposed for recovering an error that occurs during a recording operation in a CD-R drive or the like. For example, the so-called buffer underrun, in which the transfer rate of input data from the personal computer is lower than the transfer rate of transferring data to the optical disk due to higher recording speed and multitask processing in the personal computer. A technique has been proposed in which the recording operation is temporarily interrupted when a (Buffer under run) condition occurs, and when data is input and the buffer underrun condition is resolved, the data recording is resumed from the point where the recording was interrupted. ing. Hereinafter, this buffer underrun function will be described.
[0003]
FIG. 5 is a block diagram showing the configuration of a conventional optical disc apparatus disclosed in Japanese Patent Laid-Open No. 2000-40302.
[0004]
The optical head 1 emits a laser beam that traces the disk, and writes and reads recording data to and from the disk. The RF amplifier 2 amplifies an RF signal (high frequency signal) obtained by reading the recording data on the disc with the optical head 1, binarizes the RF signal, and outputs it as digital data. The head servo circuit 3 feeds back the output of the optical head 1 via the RF amplifier 2 and performs focusing control for focusing the laser beam on the signal surface of the disk and tracking control for tracking the laser beam to the signal track of the disk. Thread feeding control is performed to feed the optical head 1 itself in the radial direction of the disk. The decoder 4 performs signal processing for demodulating the digital data output from the RF amplifier 2, and the subcode demodulating circuit 5 demodulates the separated subcode. The wobble decoder 6 extracts a 22.05 kHz wobble component from the pre-groove signal of the disc obtained via the RF amplifier 2, generates a component necessary for disc rotation control, and demodulates the ATIP from the wobble component. The ATIP demodulating circuit 7 is provided.
[0005]
The interface 8 controls data transfer with a personal computer 10 serving as a host connected to the outside via the connection terminal 9, and the encoder 11 records the input data input via the interface 8 on the disc. Modulate to data. In addition, when performing modulation based on the CD-ROM standard, the encoder 11 adds a sync, a header, an EDC of an error detection code for CD-ROM data, and an ECC of an error correction code to input data, and then performs a CD method. CIRC processing, which is an error correction code, is added, a subcode is added, EFM processing is applied, and a synchronization signal is added. The RAM 12 stores input data modulated by the encoder 11.
[0006]
The internal RAM 13 is provided in the encoder 11 and is used for modulation processing by the encoder 11. The laser driving circuit 14 drives the laser light source of the optical head 1 to perform recording on the disk based on the recording data of the EFM data output from the encoder 11. The system control circuit 15 performs system control related to recording and reproduction of the disc. The subcode address of the absolute time information in the subcode (subQ data) demodulated by the subcode demodulation circuit 5 and the ATIP demodulation circuit 7 The access control unit 16 that selectively controls the access by selectively referring to the ATIP address of the absolute time information demodulated by ATIP and the data capacity stored in the input data RAM 12 and records the recording data on the disk A buffer underrun determination unit 17 for determining that a buffer underrun in which the data transfer rate of input data is slower than a data transfer rate to be generated and a state in which the buffer underrun occurs is avoided, and a buffer Depending on the determination by the underrun determination unit 17 A recording control unit 18 for controlling the recording of the recording data on the recording medium, and a recording start position where the recording control unit 18 detects the beginning of the unrecorded area where no recording data is recorded on the disc and starts recording the recording data. Recording data to be newly recorded on the disk is already recorded on the disk using the recording start position detection unit 19 to be detected, the sub-code synchronization signal extracted by the decoder 4 and the sub-Q data demodulated by the sub-code demodulation circuit 5. And a signal synchronizer 20 that synchronizes with the recorded data.
[0007]
The system clock generation circuit 21 is a general operation related to recording and reproduction of a disk by two PLL circuits that selectively synchronize with a reproduction clock obtained by reproducing EFM data output from the RF amplifier 2 and a reference clock having crystal oscillation accuracy. An operation clock used for system control of the system is generated.
[0008]
In such a configuration, when a command is generated from the personal computer 10 and recognized by the system control circuit 15 via the interface 8, a recording operation is executed. When the recording operation is executed, the optical head 1 is controlled to read the pre-groove signal of the disk by the laser output for reproducing the disk, and the pre-groove signal read from the optical head 1 is shaped by the RF amplifier 2. Thereafter, the wobble component is extracted by the wobble decoder 6, and the ATIP demodulation circuit 7 demodulates the ATIP from the wobble component.
[0009]
Data output from the personal computer 10 to be recorded on the disk is supplied to the encoder 11 via the interface 8 and is modulated by the encoder 11 into recording data in a form to be recorded on the disk. When the position traced by the laser beam of the optical head 1 comes to the writing position of the disk, the recording data is sequentially output from the encoder 11 in units of EFM frames, and the address data indicating the address corresponding to the output recording data is the system. The address memory 15a provided in the control circuit 15 is sequentially updated and stored. The laser driving circuit 14 drives the laser light source of the optical head 1 based on the recording data output from the encoder 11, and the recording data is recorded on the disk.
[0010]
During data recording, the transfer speed of data output from the personal computer 10 cannot keep up with the writing speed of recorded data recorded on the disk, and is input to the encoder 11 compared to the data transfer rate output to the encoder 11. As the data transfer rate decreases, the data capacity stored in the RAM 12 decreases. If this state continues, the data capacity stored in the RAM 12 will eventually become empty, and when this empty occurs, the buffer underrun determination unit 17 determines that a buffer underrun has occurred, and a determination output to that effect. Is generated. Then, the recording control unit 18 determines to interrupt the recording on the disk, the recording data output from the encoder 11 is interrupted, and the writing beam is stopped from being emitted from the optical head 1. Recording on the disc is interrupted. When the recording data output from the encoder 11 is interrupted, the address data corresponding to the address of the last frame of the recording data output from the encoder 11 immediately before the recording interruption is stored in the address memory 15a in the system control circuit 15. The stored address data is the time information of the sub-code Q channel data (sub Q data) and the address information indicating the number of the EFM frame in the time information. The signal synchronizer 20 uses the address data stored in the address memory 15a to record the address of the last frame recorded data on the disk, and the time information in the sub-Q data indicates what time and how many frames, and what number in the time information. It manages whether it is an EFM frame.
[0011]
When the next data is input from the personal computer 10, the access control unit 16 accesses the recorded data recorded on the disc immediately before the interruption by the ATIP demodulated by the ATIP demodulation circuit 7, and traces by the optical head 1. To start. When the recording data is recorded during the trace, the pit signal formed on the disk is simultaneously read, and when the EFM data is obtained from the pit signal, the system clock generation circuit 21 uses the signal synchronization unit 20 to set the reference clock. 1 is switched to a state in which a recovered clock synchronized with EFM data is generated, and each circuit of FIG. 1 is operated in synchronization with the recovered clock, and the modulation processing by the encoder 11 is also synchronized with the recovered clock. Will be performed.
[0012]
On the other hand, the encoder 11 is provided with an internal RAM for performing a modulation process, and the internal RAM records recording data in order to secure a CIRC interleave length necessary for newly input data. When data is interrupted, data necessary for CIRC processing is secured. When the modulation processing by the encoder 11 is performed in synchronization with the reproduction clock, the signal synchronization unit 20 uses the subcode synchronization signal extracted by the decoder 4 and the subQ data demodulated by the subcode demodulation circuit 5. The recording data output from the encoder 11 is synchronized with the recording data already recorded on the disc. The encoder 11 refers to the address data stored in the address memory 15a and immediately before the recording interruption by the recording control unit 18. In this state, the recording data of the next frame of the last frame recorded on the disc is output. When the encoder 11 enters a standby state, the address data stored in the address memory 15a is referred to, and the start position of the unrecorded area immediately after the recorded area where the recording data has already been recorded on the disk by the recording start position detector 19 is determined. Detection is performed. The detection of the start position of the unrecorded area is performed based on the time information of the sub-Q data and the number of the EFM frame in the time information. The sub-code frame unit is searched using the sub-Q data, and the EFM frame is searched. The unit is determined by determining the end of the last frame of the recorded data recorded on the disk by counting channel bits with reference to the synchronization signal.
[0013]
When the start position of the unrecorded area is detected, the system clock generation circuit 21 is switched from the state of generating the reproduction clock synchronized with the EFM data by the signal synchronization unit 20 to the state of generating the reference clock. This is an operation clock for the encoder 11. When the reproduction clock is switched to a state in which the reference clock is generated, the recording data is output from the encoder 11 at the same time by the recording control unit 18, and recording on the disk is resumed.
[0014]
[Problems to be solved by the invention]
As described above, in the conventional optical disk apparatus, when a buffer underrun occurs, recording of the recording data to the disk is interrupted, and when the buffer underrun is resolved, the final recording data at the time of the recording interruption is seamless. It operates to resume recording from the following position, but on the other hand, when recording or playback operations to the optical disc, vibration or impact is applied from the outside to the drive and abnormal tracking or focus occurs. There was a problem that normal recording could not be performed.
[0015]
In other words, even when such tracking or out-of-focus occurs, the position where the out-of-track or out-of-focus has occurred is stored in the memory using the buffer underrun function as described above or a similar technique. However, it is difficult to detect exactly where the track is out of focus or out of focus, and there is no guarantee that the recording will always be resumed seamlessly. There was a case where the data could not be reproduced due to discontinuity in the data.
[0016]
Even when data cannot be recorded seamlessly, recording on the optical disk is normally completed in the conventional optical disk apparatus, and the user knows that data recording is not normal until the optical disk is reproduced. As a result, there is a problem that the recording operation is wasted.
[0017]
The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to reliably record data even when tracking or focus abnormality occurs during a recording operation. It is an object of the present invention to provide an optical disc apparatus capable of reliably reproducing the image.
[0018]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has a function of interrupting data recording when an error occurs in the data recording operation and then restarting data recording from the beginning of an unrecorded area where no data is recorded. An optical disc apparatus having a tracking or focus abnormality detecting unit, and when the abnormality is detected, data recording is interrupted using the function, and the beginning of an unrecorded area where no data is recorded Means for trial writing the data by a predetermined amount, means for determining whether or not the trial written data can be reproduced, and trial writing if the trial written data can be reproduced. Interrupted Data recording is restarted from the beginning of an unrecorded area immediately after that and no data is recorded, and when the test-written data cannot be reproduced, there is provided means for executing a predetermined error process.
[0019]
Here, the means for detecting the tracking or focus abnormality can be constituted by a sensor for detecting the vibration applied to the drive (optical disc apparatus). Alternatively, it is possible to detect an abnormality by detecting the level of a well-known tracking error signal or focus error signal for applying tracking servo or focus servo, and comparing this level with a predetermined threshold value.
[0020]
The error processing of the present invention can be, for example, stopping the data recording. Further, the error processing may be retrial writing in which the start address of the trial writing is shifted by a predetermined amount.
[0021]
As described above, the optical disk apparatus according to the present invention can cope with tracking abnormality and focus abnormality by skillfully utilizing the conventional recovery function such as the recovery function at the time of buffer underrun error. In other words, when a buffer underrun occurs when a tracking error or focus error occurs due to external force application (when tracking servo or focus servo cannot be followed and a detrack or defocus condition occurs) Recording is interrupted in the same manner as described above, and data recording is resumed from the beginning of an unrecorded area in which no data is recorded. When this data recording is resumed, a predetermined amount of data is written on a trial basis. After trial writing the data, the data recording is interrupted again, the data recorded from the address position immediately before the first interruption to the end of the trial writing is read, and whether the data can be reproduced, that is, the data is seamless Check whether it is recorded (verify). If it is determined that the data can be recorded and reproduced seamlessly, the data recording is resumed immediately after the trial writing is completed.
[0022]
When data recording is forcibly interrupted due to an unexpected situation such as off-track or out-of-focus conditions, it is possible to accurately detect the state of data at the time of recording interruption unlike when a buffer underrun occurs. Although it is not guaranteed that even if the buffer underrun recovery function is used, it is not guaranteed whether or not data has been recorded seamlessly, but recording should be continued after verifying whether or not data has been recorded seamlessly as in the present invention. With this, data continuity can be secured and data can be recorded reliably.
[0023]
On the other hand, when the test writing data cannot be reproduced as a result of the verification, predetermined error processing is executed. As the error processing, for example, it is conceivable to stop data recording at that time, and it is possible to prevent the useless recording operation from continuing and generating an unreproducible optical disc. In the case of a rewritable optical disc, the recording resume position can be adjusted by shifting the trial writing position by a predetermined amount and performing the trial writing again when it cannot be reproduced. Data can be recorded.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, since the buffer underrun function is used as the recovery function, the same or corresponding members as those in FIG. 5 are denoted by the same reference numerals, and the description thereof is omitted.
[0025]
FIG. 1 is a block diagram showing the configuration of the optical disc apparatus according to this embodiment. The difference from the conventional optical disk apparatus shown in FIG. 5 is that a verify control unit 22 is further provided in the system control circuit 15, and a vibration detection sensor 100 is provided at a predetermined position of the optical disk apparatus, for example, near the optical head. The detection signal from the vibration detection sensor 100 is supplied to the system control circuit 15.
[0026]
The buffer underrun determination unit in the present embodiment determines whether or not the buffer underrun has occurred and is eliminated as in the conventional case. Furthermore, based on the detection signal from the vibration detection sensor 100, the optical disc apparatus is subjected to vibration or impact from the outside. It is determined that a predetermined amount or more has been applied and a state has occurred in which tracking or defocusing occurs. When the tracking or the out-of-focus state occurs, a signal is output to the recording control unit 18 as when the buffer underrun occurs, and the recording operation is forcibly interrupted at that time. The address at the time of interruption is stored in the address memory 15a.
[0027]
On the other hand, the verify unit 22 is an address stored in the address memory 15a by the recording start position detection unit 19 when vibration is detected by the vibration detection sensor 100 and recording is interrupted by the recording control unit 18. When the head address of the unrecorded area is detected with reference to the value, and the recording control unit 18 restarts recording from this position again, the remaining data is recorded after the recording is restarted as in the case of the conventional buffer underrun process. Instead of recording all, trial writing of data by a predetermined amount or a predetermined frame (or predetermined sector) is performed, data recording is interrupted again, test writing data is read, and the number of errors is counted. Then, the counted number of errors is compared with a predetermined allowable value, and if it is equal to or smaller than the allowable value, it is determined that data is continuously recorded continuously, that is, trial writing is successful, and the recording control unit 18 and the recording Data recording is resumed from the start address of the unrecorded area immediately after the trial position is interrupted by controlling the start position detector 19. On the other hand, if the counted number of errors is equal to or greater than the allowable value, it is determined that the data is not recorded seamlessly, and the resumption of data recording is stopped.
[0028]
FIG. 2 shows a process flowchart of the system control circuit 15 in the present embodiment. First, the buffer underrun determination unit 17 determines whether or not vibration is detected by the vibration detection sensor 100 (S101). When vibration is detected and it is determined that tracking abnormality or focus abnormality has occurred, the recording control unit 18 instructs the encoder 11 to stop encoding, and also causes the laser driving circuit 14 to stop irradiation of recording power laser light. The data recording is interrupted (S102). At this time, address data corresponding to the address of the last frame of the recording data output from the encoder 11 immediately before the recording interruption is stored in the address memory 15a.
[0029]
When data is input in a state where the storage is interrupted and accumulated in the RAM 12 (S103), the recording start position detecting unit 19 detects the leading address of the data unrecorded area with reference to the address value stored in the address memory 15a. Then, the access control unit 16 moves the optical head 1 to the position and writes data for several frames on a trial basis (S104). After trial writing the data for several frames, the verify unit 22 instructs the recording control unit 18 to issue a command to interrupt data recording, and the recording control unit 18 stops the operation of the encoder 11 and the operation of the laser drive circuit 14. Let The final address of the interrupted test write data is stored in the address memory 15a in the same manner as when the buffer underrun occurs. The address memory 15a stores two addresses: an address that was interrupted when vibration was detected, and a test writing interrupt address.
[0030]
After the test writing is interrupted, the verify unit 22 instructs the access control unit 16 to move the optical head 1 to the address position immediately before the interrupt. This movement is executed based on the vibration detection address stored in the address memory 15a. Then, the recorded data from this position to the test write data interruption position is read (S105), and the number of errors in the read data is counted by the error correction circuit in the decoder 4. The count value is supplied from the error correction circuit to the verify unit 22. The verify unit 22 compares the number of input errors with a predetermined allowable value (S106). If the number of errors is equal to or smaller than the predetermined allowable value, the verify unit 22 recorded normally after vibration detection, that is, continuously without a seam. It is determined that the data has been trial-written, and recording is resumed from the address immediately after the trial-writing is interrupted (S107). Specifically, the start position of the unrecorded area is detected by the recording start position detection unit 19 with reference to the address data at the time of the trial writing data interruption stored in the address memory 15a, and the access control unit 16 reaches the position. The optical head 1 is moved and the encoded data is supplied to the laser driving circuit 14 to record the data.
[0031]
On the other hand, if NO in S106, that is, if the counted number of errors exceeds a predetermined allowable value, data is not normally recorded after vibration detection, that is, data is not recorded seamlessly (between recorded data). Data recording is stopped at that time, and an error message is output to the personal computer 10 via the interface 8 (S108). As a result, it is possible to prevent the creation of an optical disc in which data is recorded but cannot be reproduced, and the user confirms the error message output to the personal computer 10 so that the data is reproduced before the data is actually reproduced. You can know that it is not recorded normally.
[0032]
FIG. 3 schematically shows the above-described process (verify process). FIG. 3A shows a state in which the recording is interrupted at the position P1 due to the occurrence of vibration. In the figure, the hatched portion indicates that data has already been recorded. The address of the position P1 is stored in the address memory 15a.
[0033]
FIG. 3B shows a state in which data is trial-written for a predetermined frame (or a predetermined number of blocks) after recording is interrupted. The trial writing is performed from the beginning of the unrecorded area immediately after the position P1, and is interrupted at the position P2. The address of the position P2 is also stored in the address memory 15a.
[0034]
In FIG. 3C, after the trial writing is interrupted, the optical head 1 is sought to the position P0 immediately before the position P1, the recorded data existing at P0 to P2 is read, and the number of errors in the data is counted. The process to do is shown. If the number of errors counted in this process is less than or equal to a predetermined allowable value, data recording is resumed again immediately after the position P2 where test writing is interrupted as shown in FIG. To go. On the other hand, as a result of the verification in FIG. 3C, when the number of errors exceeds a predetermined allowable value, the data recording is not resumed from the position P2 as shown in FIG. The recording ends when the data is recorded up to the time point, that is, the position P2. Conventionally, even if a “gap” or “jump” occurs at the position P1, data recording is resumed as it is. However, in this embodiment, after trial writing, the “gap” becomes “ When it is determined that data cannot be reproduced due to the occurrence of “jumping”, data recording is not resumed, so that useless data recording can be prevented.
[0035]
In this embodiment, when it is determined that there is an error as a result of verification, data recording is stopped and an error message is output at that time (see FIG. 2), but data rewriting is performed like a CD-RW. In the case of an optical disc that can be read, if it is determined that there is an error as a result of verification, an error message is not output, but the trial writing is shifted to the front and back, and trial writing is performed again. You can repeat the verification and trial writing process until you run out.
[0036]
FIG. 4 shows an error processing flowchart in this case. This process is executed when NO in S106 of FIG. 2, that is, when it is determined that the number of errors exceeds a predetermined allowable value. That is, if it is determined that there is an error, the trial writing start address is shifted forward by several addresses, and the data is overwritten by several frames (S1081). Then, verification is executed again (S1082), the number of errors is counted and compared with an allowable value (S1083). If the number of errors still exceeds the allowable value, the process returns to S1081 again, and the data is overwritten by shifting the start address of the trial writing by a few more addresses before verifying again. On the other hand, if the number of errors becomes equal to or smaller than the predetermined allowable value as a result of the trial writing again, it is determined that the data has been normally recorded, and the process proceeds to S107 in FIG. Resume data recording from the address.
[0037]
By utilizing the characteristics of the rewritable optical disc in this manner, data can be recorded reliably by executing trial data writing a plurality of times in the event of tracking abnormality or focus abnormality and finally recording the data seamlessly. .
[0038]
As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various change is possible.
[0039]
For example, in the present embodiment, description has been made taking CD-R or CD-RW as an example, but the present invention can be similarly applied to DVD-R or DVD-RW.
[0040]
In the present embodiment, the vibration is detected by the vibration detection sensor 100, but the tracking error signal and the focus error signal of the servo 3 for maintaining the optical head 1 in the on-track state or the on-focus state are at a predetermined level. The recording operation may be interrupted by determining that an abnormality has occurred when the threshold value is exceeded and the threshold value is exceeded. In this case, a tracking error signal or a focus error signal is supplied from the head servo 3 to the system control circuit 15, and the buffer underrun determination unit 17 compares the level with a predetermined threshold value to determine whether the threshold value is exceeded. It may be determined whether or not.
[0041]
Furthermore, in the present embodiment, the recovery function of the buffer underrun error has been described as the recovery function, but the present invention can be similarly applied to the case of using another recovery function. That is, it is only necessary to test-write data using the function, and then interrupt and verify the test writing, and resume data recording after confirming that there is no problem.
[0042]
【The invention's effect】
As described above, according to the present invention, even when tracking abnormality or focus abnormality occurs, data can be recorded seamlessly, and thereby an optical disk capable of reproducing data can be created.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an optical disc apparatus according to an embodiment.
FIG. 2 is a processing flowchart of the embodiment.
FIG. 3 is a process explanatory diagram of the embodiment.
FIG. 4 is a processing flowchart of another embodiment.
FIG. 5 is a block diagram showing the configuration of a conventional optical disc apparatus.
[Explanation of symbols]
1 optical head, 4 decoder, 8 interface, 11 encoder, 14 laser drive circuit, 15 system control circuit, 16 access control unit, 17 buffer underrun judgment unit, 18 recording control unit, 19 recording start position detection unit, 20 signal synchronization Part, 21 system clock generation circuit, 22 verify part.

Claims (6)

An optical disc apparatus having a function of suspending data recording when an error occurs in a data recording operation and restarting data recording from the beginning of an unrecorded area where data is not recorded,
Means for detecting tracking or focus abnormalities;
Means for interrupting data recording using the function when the abnormality is detected, and for trial writing data by a predetermined amount from the beginning of an unrecorded area in which no data is recorded;
Means for determining whether the test-written data can be reproduced;
If the test-written data can be reproduced, data recording is restarted from the beginning of an unrecorded area where data has not been recorded immediately after the trial write is interrupted. Means for performing the error handling of
An optical disc apparatus comprising: The apparatus of claim 1.
The function is a function of interrupting data recording when a buffer underrun occurs, and resuming data recording from the beginning of an unrecorded area where no data is recorded when the buffer underrun is resolved. Optical disk device to perform. The apparatus according to claim 1,
The optical disc apparatus characterized in that the means for detecting is a vibration sensor for detecting vibration applied to the apparatus. The apparatus according to claim 1, further comprising:
A means for outputting the tracking deviation amount or the focus deviation amount as an error signal;
The optical disc apparatus characterized in that the detecting means includes means for comparing the level of the error signal with a predetermined threshold value. In the apparatus in any one of Claims 1-4,
The optical disc apparatus characterized in that the error processing is a stop of the data recording. In the apparatus in any one of Claims 1-4,
The optical disk apparatus according to claim 1, wherein the error processing is retrial writing in which a start address of the trial writing is shifted by a predetermined amount.

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