JP3831655B2 - Recording control method for optical disc recording / reproducing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disk recording system configured to record a signal on a disk by a light beam emitted from a laser element incorporated in an optical pickup and perform a reproduction operation of the signal recorded on the disk by the light beam. The present invention relates to a playback device.
[0002]
[Prior art]
Disc players that use optical pickups to read signals recorded on discs have become widespread, but recently, in addition to the playback function, the light emitted from the laser elements incorporated in the optical pickups An optical disc recording / reproducing apparatus configured to record a signal on a disc by a beam has been commercialized.
[0003]
Such an optical disc recording / reproducing apparatus is configured to perform a recording operation based on a synchronization signal obtained from a wobble signal obtained from a groove called a wobble provided on the disc and a reference signal for recording.
[0004]
[Problems to be solved by the invention]
An optical disc recording / reproducing apparatus is configured to perform a signal recording operation in accordance with a recording command from a computer device that is a host device. In such a recording operation, a signal to be recorded on a disc is temporarily stored in a buffer RAM. The signal recording operation to the disk is performed by reading the signal stored in the buffer RAM.
[0005]
In a state where the signal recording operation to the disk is normally performed, the recording signal output from the computer device is written to the buffer RAM, the signal is read from the buffer RAM, and the read operation is performed. The recording operation of the signal on the disc is performed in accordance with the amount of the recording signal and the recording state on the disc.
[0006]
In a state where the signal recording operation is being performed, if the amount of the recording signal stored in the buffer RAM is insufficient, a state in which the signal recording operation cannot be performed on the disk, that is, a so-called buffer underrun state occurs. As a method for solving such a problem, when the amount of the recording signal stored in the buffer RAM becomes less than a predetermined value, that is, the interruption set value, the recording operation to the disk is temporarily stopped and stored in the buffer RAM. A technique has been developed in which the recording operation on the disc is resumed when the amount of the recorded signal exceeds a predetermined value, that is, a restart setting value.
[0007]
As a method for solving the problem of buffer underrun, there is a method of performing a recording interruption operation and a recording resumption operation. The recording resumption operation reproduces a signal recorded on the disc before the recording interruption, The synchronization signal and the recording reference signal included are synchronized, and the recording operation is resumed when the synchronization is performed. However, the recording operation is not resumed immediately when the synchronization signal and the recording reference signal are synchronized, and the recording operation is resumed when the number of frames constituting the recording signal after synchronization reaches a predetermined number. It is configured as follows.
[0008]
The technique for performing the recording interruption / resuming operation described above has been developed to prevent a buffer underrun. However, such a technique can be used when the recording operation is interrupted by a shock.
[0009]
The above-described recording resumption operation after the recording interruption operation is performed when the synchronization signal included in the signal reproduced from the disc is synchronized with the recording reference signal. In order to perform such synchronization processing, Requires a reproduction signal of 10 blocks, for example, as a reproduction signal. If the recording operation is interrupted immediately after starting the signal recording operation in the first part of the recording area of the disc, that is, if the recording operation is interrupted without recording 10 blocks of signals, the recording operation is resumed. Since the synchronization process cannot be performed, there is a problem that it is determined as an error and the signal recording operation to the disk cannot be performed.
[0010]
The present invention is intended to provide a recording control method for an optical disc recording / reproducing apparatus capable of solving such a problem.
[0011]
[Action]
The present invention interrupts the recording operation to the disc when the amount of the signal stored in the buffer RAM in which the recording signal is temporarily stored becomes less than the set interruption value when performing the recording operation to the disc. When the amount of the signal stored in the buffer RAM increases to the restart setting value, the signal recorded on the disc before the interruption is reproduced, and the synchronization signal obtained from the reproduced signal and the recording reference signal are synchronized. In the optical disk recording / reproducing apparatus configured to resume the recording operation from the recording interruption position based on the processing, when the recording interruption operation is performed before the signal amount recorded on the disk reaches a predetermined amount after the recording operation starts. The recording operation is resumed based on the synchronization processing of the synchronization signal obtained from the wobble signal of the disk and the recording reference signal.
[0012]
【Example】
FIG. 1 is a block circuit diagram showing an embodiment of an optical disk recording / reproducing apparatus according to the present invention, and FIG. 2 is an operation explanatory diagram for explaining a recording control method of the present invention.
[0013]
In FIG. 1, reference numeral 1 denotes a disk placed on a turntable (not shown) that is rotationally driven by a spindle motor, and is configured to be rotationally driven by the rotation of the turntable. Also. On the disc 1, position information data is recorded by a groove called a wobble, and a signal recording / reproducing operation is performed based on a wobble signal obtained from the groove. Reference numeral 2 denotes a laser element (not shown) for irradiating the disk 1 with a light beam, and a monitoring diode for monitoring the level of the light beam emitted from the laser element, and reflected from the signal surface of the disk 1. It is an optical pickup incorporating a photodetector that receives a light beam, and is configured to be moved in the radial direction of the disk 1 by a pickup feed motor (not shown).
[0014]
Reference numeral 3 denotes an RF signal amplifier circuit for amplifying an RF signal obtained from a photodetector incorporated in the optical pickup 2 and shaping the waveform. Reference numeral 4 denotes a signal obtained via the RF signal amplifier circuit 3 or the like. A focus control operation for focusing the light beam output from the optical pickup 2 on the signal surface of the disk 1 and a tracking control operation for tracking the light beam on the signal track of the signal surface; A servo circuit and a tracking servo circuit are incorporated.
[0015]
Reference numeral 5 denotes a digital signal processing circuit that performs digital signal processing of signals output from the RF signal amplification circuit 3 and performs demodulation operations of various signals. Reference numeral 6 denotes a digital signal that is processed by the digital signal processing circuit 5. If the information recorded on the disc 1 is an audio signal, it is converted to an analog signal and then output to an amplifier or the like. In the case of a data signal such as computer software, it is digital. The signal is output to the computer device 7 provided as a host device as a signal.
[0016]
A system control circuit 8 receives a signal demodulated by the digital signal processing circuit 5 and performs various control operations in accordance with a command signal output from the computer device 7. 9 is a signal recording circuit for recording a data signal or the like on the disk 1 by inputting a recording signal such as a test signal or an information signal and controlling the laser irradiation operation by the laser driving circuit 10 in response to the recording signal. It is. The laser driving circuit 10 incorporates a laser servo circuit that controls the laser output based on a signal obtained from a monitoring diode incorporated in the optical pickup 2.
[0017]
Reference numeral 11 denotes a buffer RAM in which a signal recorded on the disk 1 is temporarily stored. A signal output from the computer device 7 is written and a signal storing operation and a reading operation are controlled by a control operation of the system control circuit 8. It is configured to be. The signal stored in the buffer RAM 11 is still stored after being read out to be recorded on the disk 1, and then a new signal output from the computer device 7 is stored at that position. In this way, the information is sequentially overwritten and erased.
[0018]
Reference numeral 12 denotes a spindle motor drive circuit whose operation is controlled by the system control circuit 8, which has a function of rotationally controlling the spindle motor that rotationally drives the disk 1 at a speed for performing recording and reproduction operations. . Reference signal generating circuit 13 generates a recording reference signal used for recording a signal on the disk 1. Reference numeral 14 denotes a synchronization signal reproduced from the disk 1 and a recording reference generated by the reference signal generating circuit 13. It is a synchronization detection circuit that detects whether or not the signal is synchronized. A servo error detection circuit 15 detects a level change of a servo signal obtained from a servo circuit incorporated in the pickup control circuit 4 and detects whether the level exceeds a predetermined level, that is, an error detection level. Yes, the detection output is output to the system control circuit 8.
[0019]
In such a configuration, during the recording operation of the signal to the disk 1, the signal output from the computer device 7 is stored in the buffer RAM 11, and the reading operation of the stored signal is controlled to control the signal to the disk 1. The signal recording operation is controlled. When the signal recording operation on the disk 1 is interrupted and the recording operation is resumed, the signal stored in the buffer RAM 11 and the signal recorded on the disk 1 before the interruption are The comparison operation is performed so that the signal is recorded continuously with the signal recorded before the interruption, that is, the signal is recorded by a method called seamless.
[0020]
Further, while the signal recording operation to the disk 1 is being performed, the memory circuit provided in the system control circuit 8 is configured to store the final address of the position where the normal recording operation has been performed. Yes. When the recording operation is interrupted due to a buffer underrun state in which the amount of recording signal stored in the buffer RAM is insufficient during the recording operation, the operation is interrupted based on the final address stored in the memory circuit. The recording operation can be performed seamlessly from the position.
[0021]
Further, when a signal recording operation to the disk 1 is started, the recording signal amount from the start of recording is measured by counting the number of blocks of the signal. Then, when the recording interruption operation is performed, if the amount of the recording signal is larger than a predetermined amount, the synchronization signal obtained by reproducing the signal recorded on the disk is synchronized with the recording process when resuming the recording. When the amount of the recording signal is smaller than a predetermined amount, the synchronization processing at the time of resuming recording is performed by the synchronization signal obtained from the wobble signal and the recording reference signal.
[0022]
As described above, the optical disk recording / reproducing apparatus according to the present invention is configured. Next, the reproducing operation in the circuit configured as described above will be described. When a command signal for performing a reproduction operation is output from the computer device 7 to the system control circuit 8 constituting the drive device, the control operation for the reproduction operation by the system control circuit 8 is started. When such a reproduction operation is performed, the laser drive circuit 10 is supplied with a drive current for obtaining a laser output for performing a signal read operation to the laser element incorporated in the optical pickup 2. Is set to
[0023]
When the control operation for such a reproduction operation is started, the spindle motor drive circuit 12 performs a spindle motor rotation control operation. The spindle motor rotation control operation is obtained by decoding a wobble signal. The disk 1 is rotated at a constant linear velocity by comparing the synchronization signal with a reference signal output from a reference signal generation circuit (not shown) provided in the system control circuit 8. Such rotation control operation of the spindle motor is similarly performed during a signal recording operation which will be described later.
[0024]
The rotation control operation of the spindle motor is performed as described above. In the optical pickup 2 that performs the signal reading operation, the focusing control operation and the tracking control operation by the pickup control circuit 4 are started, and the disk by the optical pickup 2 is started. The read operation of the signal from 1 is started, but the read operation of the TOC data recorded in the lead-in area constituting the first session of the disc 1 is performed prior to the reproduction operation.
[0025]
The reading / reproducing operation of the signal recorded in the signal recording area of the first session recorded on the disc 1 is performed based on the TOC data recorded in the lead-in area. The signal read out by the optical pickup 2 is amplified and waveform-shaped through the RF signal amplifier circuit 3, and then input to the digital signal processing circuit 5, where the signal is demodulated. When signal processing is performed by the digital signal processing circuit 5 and information data is extracted, the information data is subjected to signal processing such as error correction and then applied to the signal reproduction circuit 6.
[0026]
When the information data read from the disk 1 is an audio signal, the signal reproducing circuit 6 converts the information data into an analog signal and outputs it to an amplifier or the like. Is output to the computer device 7 as a digital signal.
[0027]
As described above, the reproduction operation in this embodiment is performed. Next, the signal recording operation on the disk 1 will be described.
[0028]
The operation of recording a signal on the disc 1 is performed by first setting a laser output most suitable for the characteristics of the disc 1 by recording a test signal in a test writing area provided on the disc 1. Such a setting operation is performed by recording the test signal while changing the laser output and reproducing the recorded signal. However, since this operation is well known, the description thereof is omitted.
[0029]
When such a laser output setting operation is performed, an operation of reading information data recorded in an area called a buffer of the disk 1, that is, position information of a signal recorded in the signal recording area is performed. Based on the information data read out in this way, it is possible to recognize whether a data signal recording operation is possible in the signal recording area provided on the disc 1 and where the recording operation is performed. Operation is performed.
[0030]
When such a recognition processing operation is completed, the optical pickup 2 is moved to a position where the recording operation on the disk 1 is started, and a recording signal writing operation to the buffer RAM 11 is performed. When a signal writing operation to the buffer RAM 11 is performed, the storage amount of the signal stored in the buffer RAM 11 gradually increases. When the storage amount exceeds a predetermined amount, the signal stored in the buffer RAM 11 is read, and the read signal is input to the signal recording circuit 9. As a result, the control operation of the laser drive circuit 10 by the signal recording circuit 9 is performed, and a signal is recorded on the disk 1.
[0031]
By such an operation, a signal recording operation to the disk 1 is performed, but a signal writing operation to the buffer RAM 11 is performed in accordance with a signal reading operation from the buffer RAM 11. . In a state where the recording operation is normally performed, an operation for storing an address indicating the position, that is, a final address in the memory circuit is performed every time a signal recording operation to the disk 1 is performed.
[0032]
Then, in a state where the signal recording operation to the disk 1 is being performed, the amount of the signal output from the computer device 7 and written to the buffer RAM 11 is compared with the amount of the signal read out for recording on the disk 1. If the number of recording signals decreases, the amount of recording signals stored in the buffer RAM 11 gradually decreases. When the amount of the recording signal stored in the buffer RAM 11 decreases to a predetermined amount, that is, when the buffer underrun state is entered, a control operation for interrupting the recording operation on the disk 1 is performed. When such an interruption operation is performed, the signal reading operation from the buffer RAM 11 is also interrupted.
[0033]
In this state, when a recording signal is output from the computer device 7, a control operation for writing the recording signal to the buffer RAM 11 is performed, and the amount of the recording signal stored in the buffer RAM 11 is reduced. It will gradually increase. When the amount of the recording signal stored in the buffer RAM 11 increases and the amount reaches a predetermined amount, a control operation for resuming the recording operation is performed.
[0034]
Such a recording restart operation is performed by first displacing the optical pickup 2 to a position where the recording operation is started, that is, a position retracted from the position where the recording operation was interrupted, and then performing a reproducing operation from that position. . The position where the recording is interrupted can be easily recognized from the final address stored in the memory circuit every time the normal recording operation is performed, and the optical pickup 2 can be moved to a desired position.
[0035]
A signal reproduced by such a reproduction operation is a signal recorded immediately before the recording operation is interrupted, and a comparison operation between the reproduction signal and a signal stored and held in the buffer RAM 11 is performed. When it is determined by such a comparison operation that both are the same signal, reading of the signal stored in the buffer RAM 11 and subsequent to the signal subjected to the comparison operation described above is read. As the operation is performed, the signal is input to the signal recording circuit 9 and the recording operation of the signal on the disk 1 is started. By the above-described operation, the recording interruption operation and the recording resumption operation of the signal to the disc 1 can be performed. By performing such an operation, the signal is continuously supplied to the disc 1 even though the recording operation is interrupted. Recording operation, so-called seamless recording operation can be performed.
[0036]
As described above, the signal control operation during the recording interruption resuming operation is performed. Next, a control operation for resuming the recording operation from the recording interruption position will be described. In such a control operation, a signal recorded on the disk 1 is read before interruption, and a synchronization signal, which is a reference signal, is detected from the read signals. On the other hand, the synchronization processing operation of the recording reference signal generated by the reference signal generation circuit 13 and the synchronization signal obtained from the disk 1 is performed. Then, the synchronization detection circuit 14 performs an operation for detecting whether or not the two reference signals are synchronized with each other in the synchronization processing operation.
[0037]
When the synchronization detection circuit 14 detects that the two reference signals are synchronized, the recording operation to the disk 1 is started when the number of frames constituting the synchronized recording signal reaches a predetermined number. The number of frames is set in consideration of the recording interruption position and the time required to complete the processing operation for starting recording. In the present invention, after the synchronization, the synchronization detection circuit 14 detects whether or not a synchronization shift between the recording reference signal generated by the reference signal generation circuit 13 and the reference signal obtained from the disk 1 occurs. In this case, the recording operation is resumed when no synchronization shift occurs.
[0038]
The recording interruption / resuming operation performed when the buffer underrun state in which the amount of the recording signal stored in the buffer RAM 11 is insufficient is performed as described above. A description will be given with reference to FIG. In the figure, the recording operation is interrupted when it is detected that the point T0 is in a buffer underrun state. The point t0 is a point where the signal reading operation is started by the processing operation for resuming the recording operation, and the comparison operation between the read signal and the signal stored in the buffer RAM 11 and the comparison with the synchronization signal This is the point where the action starts. Such a comparison processing operation or the like is performed, and the recording operation is resumed at the point T0. As a result of such a recording resuming operation, the above-described seamless recording operation can be performed.
[0039]
As described above, the recording interruption restart operation is performed when the buffer underrun occurs. In FIG. 2A, the period from the t0 point to the T0 point is a period during which synchronization processing is performed. For example, it is set to 10 blocks.
[0040]
As described above, the recording operation in the present embodiment is performed. Next, the operation when a shock is applied will be described. When the optical disk recording / reproducing apparatus receives a shock from the outside during the recording operation, the level of the tracking servo signal becomes abnormally high with the servo operation by the pickup control circuit 4. Such a signal is called a tracking error signal, and a change in the signal level is detected by the servo error detection circuit 15.
[0041]
When the servo error detection circuit 15 detects that the servo signal level exceeds the error detection level, the detection output is input to the system control circuit 8. When the detection output from the servo error detection circuit 15 is input to the system control circuit 8, the system control circuit 8 determines that the recording operation cannot be continued normally, and the recording operation is interrupted. I do.
[0042]
When the recording interruption operation is performed in this manner, a control operation for resuming the recording is started. This control operation is performed after the optical pickup 2 is first displaced to a position retracted from the recording interruption position. The playback operation is started from that position. The position where the recording is interrupted can be easily recognized from the final address stored in the memory circuit every time the normal recording operation is performed, so that the optical pickup 2 can be moved to a desired position. Further, when the optical pickup 2 is moved to a desired position, the control operation by the pickup control circuit 4 is performed, and the signal recorded on the disk 1 can be reproduced.
[0043]
A signal reproduced by such a reproduction operation is a signal recorded immediately before the recording operation is interrupted, and a comparison operation between the reproduction signal and a signal stored and held in the buffer RAM 11 is performed. When it is determined by such a comparison operation that both are the same signal, reading of the signal stored in the buffer RAM 11 and subsequent to the signal subjected to the comparison operation described above is read. As the operation is performed, the signal is input to the signal recording circuit 9 and the recording operation of the signal on the disk 1 is started. By the above-described operation, the recording interruption operation and the recording resumption operation of the signal to the disc 1 can be performed. By performing such an operation, the signal is continuously supplied to the disc 1 even though the recording operation is interrupted. Recording operation, so-called seamless recording operation can be performed.
[0044]
As described above, the recording restart operation is performed when the recording operation is interrupted by the shock, and the synchronization processing operation in such a case is also performed in the period from the point t0 to the point T0 shown in FIG.
[0045]
As described above, the recording interruption resumption operation is performed when a buffer underrun occurs and when a shock is received. Next, the gist of the present invention will be described.
[0046]
In FIG. 2A, when the point R is the start point of the recording area provided on the disc 1, the recording signal amount between the point T0 and the point R, which is the recording interruption position, performs a synchronization process. Since there are 10 blocks or more necessary for the above, the above-described synchronization processing operation can be performed normally.
[0047]
The present invention solves the problem in the case where the recording operation is interrupted due to a shock or the like when an amount of signals that cannot be synchronized after the signal recording operation is started is recorded. This is intended, and will be described with reference to FIG.
[0048]
In FIG. 2B, point R is the start point of the recording area provided on the disc 1, and point T1 is the point at which the recording operation is interrupted. In this case, since the amount of signals recorded between the R point and the T1 point is less than 10 blocks necessary for performing the synchronization process at the time of resuming the recording, the synchronization processing operation cannot be performed and the recording interruption position The recording operation cannot be started from the T1 point. In addition, since no signal is recorded before the point T1, a synchronization signal cannot be obtained and synchronization processing cannot be performed.
[0049]
In the present invention, when the recording operation is started from the point R, the amount of the recording signal is measured by counting the number of blocks. Therefore, when the recording operation is interrupted at the point T1, it can be recognized that the synchronization process cannot be performed. In such a case, the synchronization process for resuming the recording operation is performed by synchronizing the synchronization signal obtained from the wobble signal with the reference signal for recording, not the synchronization signal obtained from the signal recorded on the disk 1. A processing operation for starting the recording operation is performed.
[0050]
The signal recording operation is started by such a synchronization processing operation. In this case, the synchronization processing operation is also performed based on the synchronization signals for 10 blocks. Since the wobble signal described above can be obtained from the point T1 that is the position where the recording interruption operation has been performed, the synchronization processing operation can also be performed beyond the point T1. When the synchronization process is performed, the recording operation is resumed. In this case, a deviation occurs between the recording interruption position and the recording start position.
[0051]
In the CD standard, an area called a pregap is formed by a signal output from the computer device 7 between a recording start point and a position where a data signal that is a recording signal is recorded. The recording time length of this pregap is defined as 2 seconds (corresponding to the length of 150 blocks), and the length is longer than the gap between the recording restart position and the recording interruption position. The reproduction operation of the data signal recorded on the recording medium can be performed without any trouble.
[0052]
In this embodiment, the starting point of the recording area of the disk 1 is the first recording signal area of the disk 1 in a recording system in which an audio signal is recorded from the inner circumference side to the outer circumference side, that is, a recording system called disc at once. In the recording method for recording signals for each track, that is, the recording method called track-at-once, this is the first region of each track.
[0053]
【The invention's effect】
The present invention interrupts the recording operation to the disc when the amount of the signal stored in the buffer RAM in which the recording signal is temporarily stored becomes less than the set interruption value when performing the recording operation to the disc. When the amount of the signal stored in the buffer RAM increases to the restart setting value, the signal recorded on the disc before the interruption is reproduced, and the synchronization signal obtained from the reproduced signal and the recording reference signal are synchronized. In the optical disk recording / reproducing apparatus configured to resume the recording operation from the recording interruption position based on the processing, when the recording interruption operation is performed before the signal amount recorded on the disk reaches a predetermined amount after the recording operation starts. Since the recording operation is resumed based on the synchronization process between the synchronization signal obtained from the wobble signal of the disk and the recording reference signal, the synchronization process is confirmed. It can be carried out in. Therefore, according to the present invention, there is no error processing as in the prior art, and the recording operation can be performed without any trouble.
[0054]
In the present invention, the recording signal amount is measured by the number of blocks of the recording signal. Therefore, when performing the synchronization process using the synchronization signal obtained for each block, whether or not the synchronization process can be performed accurately is determined. It has the advantage that it can be recognized.
[Brief description of the drawings]
FIG. 1 is a block circuit diagram showing an embodiment of an optical disc recording / reproducing apparatus according to the present invention.
FIG. 2 is an operation explanatory diagram for explaining a recording control method of the present invention.
[Explanation of symbols]
1 Disc 2 Optical Pickup 4 Pickup Control Circuit 5 Digital Signal Processing Circuit 7 Computer Device 8 System Control Circuit 11 Buffer RAM
15 Servo error detection circuit

Claims (2)

When the amount of the signal stored in the buffer RAM in which the recording signal is temporarily stored is less than the set interruption value when performing the recording operation to the disk, the recording operation to the disk is interrupted and the buffer RAM When the amount of the signal stored in the disc increases to the restart setting value, the signal recorded on the disc before the interruption is reproduced, and based on the synchronization processing between the synchronization signal obtained from the reproduced signal and the recording reference signal In an optical disc recording / reproducing apparatus configured to resume the recording operation from the recording interruption position, when the recording interruption operation is performed before the signal amount recorded on the disc reaches a predetermined amount after the recording operation starts, the wobble of the disc An optical disc recording apparatus is characterized in that the recording operation is resumed based on a synchronization process between the synchronization signal obtained from the signal and the recording reference signal. Recording control method of a playback device. 2. The recording control method according to claim 1, wherein the amount of signal recorded on the disk is measured by the number of blocks of the recording signal.

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