JP3634714B2 - 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]
Also, recently, signals can be recorded in a state in which the disk is rotationally controlled at a constant high linear velocity such as 2 times, 4 times, 6 times, 8 times and 12 times the prescribed recording linear velocity. An optical disc recording / reproducing apparatus configured to be able to be developed has been developed.
[0004]
[Problems to be solved by the invention]
The optical disk recording / reproducing apparatus is configured to perform a signal recording operation in accordance with a recording command from the computer device side which is a host. Such a recording operation temporarily stores a signal to be recorded on the disk in a buffer RAM, A signal recording operation is performed on the disk by reading a 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 a predetermined amount or less, the recording operation to the disk is temporarily stopped and the amount of the recording signal stored in the buffer RAM is reached. A technique has been developed in which the recording operation on the disc is resumed when the value exceeds a predetermined amount.
[0007]
In an optical disc recording / reproducing apparatus incorporating such a technique, it is necessary to record a signal after the signal recorded on the disc before the recording operation is interrupted, and therefore an operation for recording a new signal following the recorded signal. However, the timing of recording on the disc is shifted due to the difference in the rising characteristics of the laser elements constituting the optical pickup, and there is a problem that a gap is generated between signals.
[0008]
The present invention is intended to provide an optical disc recording / reproducing apparatus that can solve such a problem.
[0009]
[Means for Solving the Problems]
The present invention relates to an optical disk recording / reproducing apparatus configured to read a signal once stored in a buffer RAM and to record the signal on a disk by a light beam emitted from a laser element incorporated in an optical pickup. After the signal read from the buffer RAM is recorded on the disk during the signal recording operation, it is stored and held in the buffer RAM until a new signal is written in place of the signal recorded on the disk. When the recording operation is interrupted, the signal is recorded continuously to the signal recorded on the disk before the interruption based on the last address of the signal normally recorded and the signal stored and held in the buffer RAM. At the same time, the start writing start time of the laser element when recording is restarted is a test writing area provided on the disc It is configured to set the recording characteristics of the test signal to.
[0010]
【Example】
FIG. 1 is a block circuit diagram showing an embodiment of an optical disk recording / reproducing apparatus according to the present invention. In the figure, reference numeral 1 denotes a disk placed on a turntable (not shown) that is rotationally driven by a spindle motor (not shown), 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).
[0011]
Reference numeral 3 denotes an RF signal amplifying circuit for amplifying an RF signal obtained from a photodetector incorporated in the optical pickup 2 and shaping the waveform, and reference numeral 4 denotes the signal based on the signal obtained via the RF signal amplifying circuit 3. A pickup control circuit for performing focusing control for focusing the light beam output from the optical pickup 2 on the signal surface of the disc 1 and tracking control for causing the light beam to follow the signal track of the signal surface; a focus servo circuit; A tracking servo circuit is incorporated.
[0012]
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 as a signal.
[0013]
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.
[0014]
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.
[0015]
Reference numeral 12 denotes a spindle motor drive circuit whose operation is controlled by the system control circuit 8 and has a function of controlling the rotational drive of a spindle motor that rotationally drives the disk 1. Such rotational drive control operation is to rotate at a constant linear velocity such as twice, four times, six times, eight times and twelve times the prescribed speed as well as the prescribed linear speed. It is configured to be able to.
[0016]
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.
[0017]
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.
[0018]
The operation of resuming the recording operation after the signal recording operation on the disk 1 is interrupted is a comparison operation between the signal stored in the buffer RAM 11 and the signal recorded on the disk 1 before the interruption. However, the driving operation of the laser element by the laser driving circuit 10 is set in consideration of the rising characteristics of the laser element. That is, even when a command signal for outputting a signal for driving the laser element to the laser driving circuit 10 is applied from the system control circuit 8, the laser element is in an operating state and the light beam level is transmitted to the disk 1. Although it takes a short time before recording can be performed, a time that cannot be ignored is required, and the time is set in consideration of the delay time.
[0019]
The timing for supplying a drive signal to such a laser element is recorded when an operation for setting a laser output value by recording a test signal in a test writing area provided on the inner peripheral side of the disk 1 is performed. It is configured to be set according to the characteristics of the received signal. A synchronization signal is recorded on the disk 1 by a groove called a wobble. Based on the synchronization signal, an operation for controlling the rotational speed of the disk 1 and a recording operation for a test signal are performed. A synchronization signal is also incorporated in the signal recorded on the disk 1, and it is necessary to start up the laser element by detecting a time difference between this synchronization signal and the synchronization signal recorded on the disk 1. Can recognize time. The timing of the command signal output from the system control circuit 8 to the laser driving circuit 10 is set in accordance with the time difference detected in this way.
[0020]
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
[0021]
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 driven to rotate at a constant linear velocity by comparing the synchronization signal with a reference signal output from a reference signal generation circuit (not shown). Such a control operation is similarly performed during a signal recording operation described later.
[0022]
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 are started, and the signal from the disc 1 by the optical pickup 2 is started. Although the read operation is started, 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.
[0023]
The read / play operation of the signal recorded in the signal recording area of the first session of 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.
[0024]
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.
[0025]
As described above, the reproduction operation in this embodiment is performed. Next, the signal recording operation on the disk 1 will be described.
[0026]
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. In such setting operation, the test signal is recorded while changing the laser output, and the recorded signal is reproduced, and the setting operation of the drive current that can obtain the optimum laser output for the recording operation is performed. The operation for detecting the time difference between the synchronization signal obtained from the wobble signal and the synchronization signal obtained from the signal recorded on the disk 1 is performed during the reproduction operation of the test signal. And the timing which outputs a control signal from the system control circuit 8 to the laser drive circuit 10 is set based on the time difference detected by such detection operation.
[0027]
When such a laser output setting operation and a timing setting operation for outputting a control signal from the system control circuit 8 to the laser driving circuit 10 are performed, information data recorded in an area called a buffer of the disk 1, that is, signal recording An operation of reading position information of a signal recorded in the area is performed.
[0028]
Based on the information data read out in this manner, a data signal recording operation can be performed in the signal recording area provided on the disc 1, and a recognition operation such as where the recording operation is performed is performed. Done.
[0029]
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.
[0030]
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.
[0031]
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.
[0032]
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.
[0033]
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.
[0034]
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 transmitted to the disc 1 despite the recording operation being interrupted. Recording operation, so-called seamless recording operation can be performed.
[0035]
As described above, the signal recording operation in this embodiment is performed, but when recording is resumed, in order to record the signal so that it is continuous with the signal recorded before the recording is interrupted, the signal recording starts. It is necessary to supply a drive signal output from the laser drive circuit 10 to the laser element in consideration of the relationship between the timing of the laser beam and the rising characteristic of the laser element. In consideration of the relationship between the start timing of signal recording and the rise characteristics of the laser element, the laser is sent from the system control circuit 8 at a timing when the laser drive circuit 10 is put into an operation state for supplying a drive signal for performing a recording operation to the laser element. A command signal is output to the drive circuit 10, and this timing is performed at a timing set when a test signal recording operation is performed in the test writing area. Such timing is set by recording the test signal in the test writing area and reproducing the signal, so that the gap between the signal recorded before the interruption and the signal recorded at the time of restart is set. It can be as close to zero as possible, and a recording operation called seamless can be performed satisfactorily.
[0036]
【The invention's effect】
The present invention relates to an optical disk recording / reproducing apparatus configured to read a signal once stored in a buffer RAM and to record the signal on a disk by a light beam emitted from a laser element incorporated in an optical pickup. After the signal read from the buffer RAM is recorded on the disk during the signal recording operation, it is stored and held in the buffer RAM until a new signal is written in place of the signal recorded on the disk. When the recording operation is interrupted, the signal is recorded continuously to the signal recorded on the disk before the interruption based on the last address of the signal normally recorded and the signal stored and held in the buffer RAM. At the same time, the start writing start time of the laser element when recording is restarted is a test writing area provided on the disc Since so as to set the recording characteristics of the test signal to, it is possible to start the recording operation at an accurate timing. Therefore, according to the present invention, the gap between the signal recorded before interruption of recording and the signal recorded at the time of resumption can be brought to zero as much as possible, and a recording operation called seamless is performed favorably. I can do it.
[0037]
The present invention also detects a time difference between the synchronization signal included in the test signal recorded in the test writing area and the synchronization signal recorded on the disc, and based on the detected time difference, Since the start operation start time of the laser element is set, the timing at the time of resuming recording can be set accurately.
[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.
[Explanation of symbols]
1 Disk 2 Optical Pickup 4 Pickup Control Circuit 5 Digital Signal Processing Circuit 7 Computer Device 8 System Control Circuit 9 Signal Recording Circuit 10 Laser Drive Circuit 11 Buffer RAM

Claims (2)

Signal recording operation in an optical disc recording / reproducing apparatus configured to read a signal once stored in a buffer RAM and record the signal on a disc by a light beam irradiated from a laser element incorporated in an optical pickup After the signal read from the buffer RAM is recorded on the disk, it is stored and held in the buffer RAM until a new signal is written in place of the signal recorded on the disk. When interrupted, based on the last address of the signal recorded normally and the signal stored and held in the buffer RAM, the signal is recorded continuously to the signal recorded on the disk before the interruption and when recording is resumed. Test start time of the laser element in the test writing area provided on the disc Optical disc recording and reproducing apparatus being characterized in that so as to set the recording characteristics of the signals. The time difference between the synchronization signal included in the test signal recorded in the test writing area and the synchronization signal recorded on the disc is detected, and the start-up operation of the laser element is started when recording is resumed based on the detected time difference. 2. The optical disc recording / reproducing apparatus according to claim 1, wherein the time is set.

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