JP2003132539A - Optical disc recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that it is hard to correctly read the data recorded on a disc when reading the data signals using the sub-beam delayed in time from the main beam formed by diffraction because the read signal levels largely change following the change in the light output of the optical head depending on the condition of recording. SOLUTION: The level adjuster circuit 11 changes the light output of the optical head 1 which changes its level in recording and in pause depending on the condition of recording, and adjusts the level of the output of the sub- beam which is behind in time the main beam formed by diffraction. The data signals recorded by the main beam are read by the sub-beam using the adjusted light output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an optical head that diffracts a light beam from a light source and emits a main beam and a sub-beam positioned temporally behind the main beam. The present invention relates to an optical disc recording device that reads a recorded data signal.

[0002]

2. Description of the Related Art As an optical disk recording apparatus for recording a digital data signal on a disk by using a light beam from an optical head, a CD (Compact Disc) family CD is used.
CD-R / RW drives compatible with -R (Recordable) and CD-RW (ReWritable) are well known.

Discs recorded by such an optical disc recording apparatus have different recording sensitivities due to different manufacturers due to different materials, different recording sensitivities due to individual differences due to variations, or the same due to unevenness. There is a difference in recording sensitivity within the disc.

Therefore, in the optical disc recording apparatus,
It is necessary to control the light emission output emitted from the optical head during recording so as to compensate for the difference in recording sensitivity, and to set the light emission output of the optical head to an optimum recording level optimum for recording on the disc.

The emission output of the optical head is set mainly by detecting the β value (recording depth) using the peak value and bottom value of the HF signal read from the disk.

In the CD-R, since the recording speed is increased to 20 times the rated speed, it is necessary to strictly set the recording conditions. It is necessary to perform so-called running OPC (Optimum Power Control), which detects the recording state of the recorded recording signal and controls the light emission output of the optical head.

Further, even if the light emission output of the optical head is set to the optimum recording level suitable for the recording of the disk according to the recording speed as described above, the disk does not correspond to the set recording speed or the disk of poor quality. In such a case, the amount of jitter of the HF signal (high frequency signal) read from the disc on which recording has been completed is large, and the disc recording may fail because the reproduction cannot be performed.

Therefore, during the disk recording operation,
This jitter amount is detected in order to determine whether the jitter amount of the HF signal interferes with disk reproduction.

[0009]

By the way, in order to perform the above-mentioned running OPC and the amount of jitter, it is necessary to detect the recording state of the recording signal recorded on the disk. It is difficult to detect the recording state of.

In order to execute the running OPC, a method of detecting the recording level by detecting the reflection level of the recording pulse for recording the recording signal is implemented, but this actually detects the recording state. However, there is a problem that the light emission output of the optical head that is set does not match the actual optimum recording level, and the amount of jitter cannot be detected.

Therefore, in addition to the main beam actually used for recording as a light beam emitted from the optical head to the disc, a sub-beam positioned rearward in time is formed,
It is conceivable to detect the recording state of the disc by reading the data signal recorded by the main beam with this sub beam.

By the way, in the case of an optical disk recording apparatus, a differential push-pull method is generally adopted for tracking control,
The 0th order beam of the diffracted light of the optical head is used as the main beam for recording and reproducing on the disc, and the ± 1st order beams of the diffracted light are used as the front and rear sub-beams for tracking control.

Therefore, when the light emission output of the optical head is changed between the recording level and the recording pause level (for example, the reproduction level) in order to record the recording mark corresponding to the data signal to be recorded on the disk, the main disk recording is performed. Not only the beam but also the sub-beam simultaneously changes in light quantity according to the recording level and the recording pause level.

Therefore, when the data signal recorded on the disc is read from the sub-beam which is temporally backward in the recording state of the disc, the read data signal (HF signal) has a large level due to the change in the light emission output of the optical head. Due to the disturbance, the recording state of the disc could not be detected.

[0015]

According to the present invention, in a recording state on a disc, a light reception output based on reflected light on a disc in a sub beam temporally behind a main beam formed by diffraction is emitted from an optical head. Adjusts the level by a level adjusting circuit to eliminate the level difference between the recording level and the recording pause level, and reads the data signal recorded by the main beam by the sub beam using the light reception output after the level adjustment. There is. In this case, the level difference between the received light output after the level adjustment is eliminated between the recording level period and the recording pause level period.
It becomes possible to read the data signal recorded by the main beam by the sub beam whose light amount is changed in accordance with the change in the light emission output of the optical head.

[0016]

1 is a circuit block diagram of a CD-R / RW drive showing an example of an optical disk recording apparatus according to the present invention.

In FIG. 1, reference numeral 1 denotes an optical head which emits a laser beam tracing a signal track of a disc and writes and reads a data signal on the disc.

The optical head 1 diffracts a laser beam emitted from a laser light source (not shown) by a diffraction grating (not shown) to form a main beam for writing a data signal. In addition, the disc is irradiated with ± first-order beams of diffracted light which are sub-beams, and as shown in FIG. 2, a main beam is irradiated to form a main light spot Sm, and each sub-beam is irradiated to each sub-light spot. Ss1 and Ss2 are formed.

Each of these sub-light spots Ss1 and Ss
2 indicates that, in a state where the main light spot Sm is correctly arranged on the signal track n of the disc, the sub light spot Ss1 on the outer peripheral side of the disc has the inner half of the signal track n and the outer half of the signal track n. n and the adjacent signal track (n + 1) on the outer circumference side are arranged so as to be projected respectively, and the sub-light spot Ss on the inner circumference side of the disc is arranged.
In FIG. 2, the outer half is the signal track n and the inner half is the signal track n and the inner adjacent track (n-1).
And so that they are projected respectively.

The optical head 1 is provided with a photodetector for receiving the reflected light in which the main beam and the subbeams are reflected by the disk. As shown in FIG. 2, the photodetector includes the main beam and the subbeams. A main light receiving area A for receiving each reflected light and a pair of sub light receiving areas B,
Equipped with C.

The main light receiving area A and the pair of sub light receiving areas B and C are each divided at least into two by a dividing line in a direction corresponding to the direction of the signal track of the disk, and the divided main light receiving area A. And each of the divided areas of the pair of sub-light-receiving areas B and C generate a light-receiving output corresponding to the amount of light received.

Reference numeral 2 is a binary value generated by amplifying and amplifying an HF signal (high frequency signal) of a data signal recorded on a disk by using a light receiving output generated from a predetermined light receiving area of a photodetector of the optical head 1. Head amplifier 3 for generating a focus error signal between the main beam from the optical head 1 and the signal surface of the disk and a tracking error signal between the main beam from the optical head 1 and the signal track of the disk. Focus control for focusing the main beam on the signal surface of the disk according to the error signal and tracking control for tracking the main beam to the signal track of the disk according to the tracking error signal are performed, and the optical head 1 itself It is a head servo circuit that controls the thread feeding in the radial direction.

Reference numeral 4 is a decoder for demodulating the binarized data of the HF signal output from the head amplifier 2 in synchronization with the bit clock. The decoder 4 receives the input H
E according to EFM (Eight to Fourteen Modulation), which is a modulation code on the CD standard, from binary data of the F signal
Along with FM demodulation, various data are demodulated according to the data structure.

Reference numeral 5 denotes an interface for controlling data transfer with a higher-level device such as a personal computer connected through the connection terminal 6, and 7 has a data structure for recording input data input through the interface 5 on a disk. E that corresponds to the CD standard modulation code
An encoder that modulates an FM signal.

Reference numeral 8 caches the input data input by the interface 5, and is used when the encoder 7 modulates the recording data to be recorded on the disc. The data read from the disc is cached by the decoder 4. This is a buffer RAM used when demodulating data.

Reference numeral 9 is an EF output from the encoder 7.
A head output control circuit 10 for generating a control output for controlling a laser beam generated from the optical head 1 on the basis of the M data is an optical head for recording on a disk according to the control output from the head output control circuit 9. 1 is a laser drive circuit for driving the first laser light source.

Reference numeral 11 denotes a recording level and a recording mark at which a light emission output of the optical head forms a recording mark for an HF signal (details will be described later) obtained by a sub-beam that is temporally rearward (inner side of the disc from the main beam). A recording pause level that is not formed, in this embodiment, a level adjustment circuit that adjusts the level to eliminate the level difference from the reproduction level, and 12 is a level-adjusted H obtained via the level adjustment circuit 11.
The selection circuit selectively switches the F signal between a recording level period in which the light emission output of the optical head is at the recording level and a reproduction level period in which the light emission output of the optical head is at the reproduction level, and selectively supplies it to the subsequent stage.

The level adjusting circuit 11 switches the input signal path selected between the recording level period and the reproduction level period of the light emission output of the optical head according to the EFM recording signal output from the head output control circuit 9.

Reference numeral 13 denotes H obtained through the selection circuit 12.
It is a β value detection circuit that detects the peak value and the bottom value of the F signal and detects the β value from those values. The β value detection circuit 13 controls the head output control circuit 9 based on the detected β value to set the light emission output by the optical head 1 during recording.

Reference numeral 14 is an HF obtained through the selection circuit 12.
This is a jitter amount detection circuit that extracts a jitter component from a signal, detects the time width of the jitter component, and detects the amount of jitter. This jitter amount detection circuit 14 is HF by a PLL circuit.
The jitter component is extracted by the phase difference output between the clock reproduced from the signal and the reference clock, and the jitter amount is detected by the pulse width of the phase difference output.

Reference numeral 15 demodulates a 22.05 kHz wobble signal included in the pre-groove of the disc from the push-pull signal generated by the head amplifier 2 by the push-pull method, and also outputs time information from the wobble signal. Address ATIP (Absolute Time In Pre-g
roove) A wobble decoder for demodulating addresses.

Reference numeral 16 is a spindle motor for rotating the disk, 17 is a motor drive circuit for driving the spindle motor 16, and 18 is a motor control circuit for controlling the motor drive circuit 17. The motor control circuit 18 uses the sync signal and the reproduction clock extracted from the data signal recorded on the disc, or the wobble decoder 15
Rotation can be controlled by a constant linear velocity method using a wobble signal demodulated by the. A pulse signal from a frequency generator (FG) 19 that generates a pulse signal according to the rotation of the spindle motor 16 is used. The rotation can be controlled by a fixed method.

Reference numeral 20 is a speed setting circuit for controlling the motor control circuit 18 based on the recording speed and the reproduction speed required by the host device connected to the connection terminal 6 to set the rotation speed of the disk. When the rotation speed of the disc is set by the speed setting circuit 20, the operation clocks of the circuits for performing the reproduction process and the recording process change based on the rotation speed of the disc, and the head servo and the head output also change the rotation speed of the disc. The reproduction process and the recording process according to the set rotation speed of the disc are performed according to the above.

When the rotation speed of the disk is set by the speed setting circuit 20 during recording, the operations of the encoder 7 and the head output control circuit 9 are switched according to the rotation speed.

First, the generation of the tracking error signal and the HF signal related to the gist of the present invention will be described with reference to FIG.
Will be described in detail. When the astigmatism method is used for focus control, at least the main light-receiving area A of the photodetector is divided into four in a cross shape, but the description of the focus error signal generation is omitted, so the description will be simplified. In order to make it, it shows like FIG.

The divided areas of the main light receiving area A of the photodetector generate the light receiving outputs a1 and a2, respectively, and the divided areas of the sub light receiving area B generate the light receiving outputs b1 and b2, respectively. Each of the divided areas generates light reception outputs c1 and c2, respectively.

The respective light receiving outputs a1 and a2 generated from each divided area of the main light receiving area A are output by the first differential amplifier 21 as a difference output (a1) of the light receiving outputs a1 and a2.
-A2) is obtained, and the respective light receiving outputs b1 and b2 generated from each divided area of the sub light receiving area B are obtained by the second differential amplifier 22 as a differential output (b1-b2) of the light receiving outputs b1 and b2. And the respective light receiving outputs c1 and c2 generated from each divided area of the sub light receiving area C are the third
The differential amplifier 23 obtains a difference output (c1-c2) between the light receiving outputs c1 and c2.

The differential output (b1 by the second differential amplifier 22)
-B2) and the differential output (c1-
c2) is the differential output of one differential amplifier, in this case the differential output (c
1-c2) is level-adjusted by the gain g1 by the level adjustment amplifier 24, and then added by the adder 25. The addition output (b1−b1) obtained by adding the difference output (b1−b2) of the second differential amplifier 22 obtained by the adder 25 and the difference output g1 (c1−c2) of the level-adjusted third differential amplifier 23. b2) + g1 (c1-c2)
Is further level-adjusted by the gain g2 by the level adjustment amplifier 26 and level-adjusted with the differential output (a1-a2) by the first differential amplifier 21, and then input to the fourth differential amplifier 27.

Therefore, the fourth differential amplifier 27 outputs the addition output g2 ((b1-b2) + g1 (c1-c) of the adder 25 whose level is adjusted by the level adjustment amplifier 26.
2)) and the differential output by the first differential amplifier 21 (a1-a
2) difference output {(a1-a2) -g2 ((b1-b
2) + g1 (c1-c2))} is generated.

The output signal from the fourth differential amplifier 27 corresponds to a tracking error in which the output level and the polarity change depending on the amount and direction of deviation between the main beam from the optical head 1 and the signal track of the disk. Becomes a tracking error signal (TE signal).

In this case, when the respective light spots are arranged as shown in FIG. 2, the tracking error signal is changed to the sub light spot S.
It has been confirmed that the maximum sensitivity of the tracking error signal obtained when s1 and Ss2 are respectively arranged in the center between the signal tracks is about half, but the main beam tracking control can be performed without any problem.

Next, extraction of the HF signal (high frequency signal) obtained by reading the recording signal recorded on the signal track of the disk with the optical head 1 will be described.

The light receiving outputs a1 and a2 output from the respective divided areas of the main light receiving area A are summed by the summing amplifier 28 (a1 + a2).

The addition output (a1
+ A2) is the reflected light of the main beam over the entire main spot Sm, the addition output (a1 + a2) by the addition amplifier 28 is the HF signal corresponding to the recording signal recorded on the signal track, and this HF signal is the main H signal.
The signal is reproduced by the decoder 4 provided at the subsequent stage after being amplified by the F amplifier 29.

On the other hand, the sub-light spot Ss2 corresponding to the sub-beam temporally behind the main beam is irradiated to the signal track n at approximately half of the outer peripheral side of the disk, and half of the sub-spot Ss2 irradiated to this signal track n. The light receiving output c2 generated from one of the divided areas of the sub light receiving area C corresponding to the side is directly guided to the first sub HF amplifier 30 and the second sub HF amplifier 31 without being calculated.

Since the reflected light of the sub beam temporally behind the main beam includes the recording signal component recorded by the main beam, in this case, the recording signal component of the signal track n, the sub light receiving area C The light reception output c2 generated from one of the divided areas is an HF signal corresponding to the recording signal of the signal track n. Therefore, the HF signal corresponding to the recording signal of the signal track n is input to the first and second sub HF amplifiers 30 and 31 from the position temporally behind the position where the main beam is irradiated.

The HF signals amplified by the first and second sub HF amplifiers 30 and 31, respectively, are selected by the selection circuit 1.
2 are selected in the recording level period of the light emission output of the optical head 1 and the reproduction level period of the light emission output of the optical head 1, and are supplied to the subsequent stage.

That is, the HF signal input to the first sub-HF amplifier 30 selected during the recording level period of the light emission output of the optical head 1 is obtained during the period when the light emission output of the optical head 1 is at the recording level. On the other hand, the HF signal input to the second sub HF amplifier 31 selected during the reproduction level period of the light emission output of the optical head 1 is the light emission output of the optical head 1 at the reproduction level. The received light output c2 is obtained during the period.

Then, the first and second sub-HF amplifiers 30 and 31 are arranged so that when the light emission output of the optical head 1 changes between the recording level and the reproduction level, the first and second sub-HF amplifiers 30 and 31 operate.
The respective gains are set to eliminate the level difference between the HF signals output from the F amplifiers 30 and 31, respectively.

Therefore, the selection circuit 12 outputs the HF signal in which the level difference between the light reception output c2 obtained during the recording level period and the reproduction level period of the light emission output of the optical head 1 is eliminated and recorded on the disc. An HF signal having a correct level according to the data signal can be obtained.

Therefore, from the selection circuit 12, the HF signal obtained by reading the data signal recorded by the main beam by the rear sub-beam is obtained.

By the way, as described above, in the on-track state of the main beam, the half of the sub-spot Ss2 on the outer peripheral side is arranged on the signal track n.
Light reception output c2 in one divided area of the sub light receiving area C
HF signal having the maximum amplitude is obtained from the above, and conversely, when the position of the sub-spot Ss2 is set, the received light output c2
Is monitored and the maximum amplitude is set.

Incidentally, when the angle of each sub beam is changed and the main beam is on-track, the sub light spot Ss is
2 is arranged such that the inner half of the light spot Ss2 is arranged in the signal track (n-1) adjacent to the inner circumference, and the light receiving output c from the divided area in the sub light receiving area C
It is also possible to read the HF signal of the signal track (n-1) adjacent to the inner peripheral side by 1.

Next, the recording operation of the optical disk recording apparatus configured as shown in FIG. 1 will be described.

When recording on the disc is requested by the host device connected to the connection terminal 6, each circuit is controlled so that the recording operation is performed according to the request. In this case, the motor control circuit 18 controls the motor drive circuit 17 to drive the disc at the rotation speed corresponding to the recording speed required by the speed setting circuit 20.

Before the recording on the disc is started, at the set recording speed, the light emission output of the optical head 1 is optimally recorded on the disc so that the record data having the minimum error rate when reproduced is recorded. Is set to the optimum recording level. The setting of the optimum recording level is performed by changing the light emission output stepwise in the calibration area provided on the innermost circumference of the disc and performing trial writing.

When data requesting recording is transmitted from the host device connected to the connection terminal 6, the data is received by the interface 5 and written in the buffer RAM 8.

When the storage amount of the data written in the buffer RAM 8 reaches the data capacity at which the encoder 7 starts the encoding process, the data is read from the buffer RAM 8 and recorded by the encoder 7 on the disc in EFM frame units. Is modulated into the EFM signal.

The head output control circuit 9 generates an EFM recording signal obtained by converting the EFM signal output from the encoder 7 according to the β value detected by the β value detecting circuit 13 so that the disk recording can be performed at the optimum recording level. To do. This E
The FM recording signal is composed of a recording level "H" signal that forms a recording mark on the disc and a recording pause level that does not form a recording mark, and a reproduction level "L" signal in this embodiment. The laser light source of the optical head 1 is driven in accordance with the EFM recording signal, whereby a recording mark is formed in accordance with the EFM recording signal and recording is performed on the disc.

By the way, the light emission output emitted from the optical head 1 is set by the head output control circuit 9 to the optimum recording level optimum for recording on the disk, and the setting is based on the β value detected by the β value detection circuit 13. Is done.

The β value detection circuit 13 detects the β value by using the HF signal read from the main beam at the start of recording the disc, and the HF read from the rear sub-beam at the time of actual recording in the program area of the disc. The β value is detected using the signal.

At the time of actual recording in the program area of the disc, in order to change the light emission output of the optical head 1 according to the EFM recording signal to be recorded on the disc, the laser light amount of the rear sub-beam also depends on the EFM recording signal. Change. Therefore, the HF signal cannot be correctly obtained by simply extracting the reflected light amount of the rear sub-beam from the light receiving region corresponding to the sub-beam.

In this state, in order to correctly obtain the HF signal from the disc by the rear sub-beam, in the present invention, when the light emission output of the optical head 1 changes to the recording level and the reproducing level during the disc recording, respectively. The level adjustment circuit 11 eliminates the level difference of the HF signal during the period.

Therefore, at the time of recording in the program area of the disc, the optical head 1 is controlled by the head output control circuit 9 according to the β value based on the HF signal read from the EFM recording signal actually recorded by the main beam.
The emission output emitted from is set, and the setting becomes the optimum recording level optimum for recording on the disc.

By the way, the HF signal selected by the selection circuit 12 is also supplied to the jitter amount detection circuit 14, and this jitter amount detection circuit 14 outputs the HF signal read from the rear sub-beam during actual recording in the program area of the disc. Detect the amount of jitter.

When the jitter amount detected by the jitter amount detection circuit 14 falls outside the allowable range, the recorded EFM recording signal cannot be correctly read from the disc, resulting in a recording failure. The rotation speed of the disk is lowered by the speed setting circuit 20 in order to lower the rotation speed. The decrease of the disk rotation may be continuous, which changes linearly, or may be decreased step by step within the prepared rotation speed.

When the recording speed is reduced in this way,
The ratio of the jitter component to the recording mark decreases as the rotation speed of the disk decreases, and eventually the jitter amount detection circuit 1
The recording speed is such that the amount of jitter detected by 4 is within the allowable range, and recording is continued at this recording speed.

By the way, in the present embodiment, a disc rotation system in which the highest recording speed is constant angular velocity is adopted, and a disc rotation system in which the lowest recording speed is constant linear velocity is adopted.

The disk rotation method specified in the CD method has a constant linear velocity, and the disk rotation method with the constant linear velocity can be used to perform recording in a circuit-free manner. This is also the case when a disk rotation system with a constant zone linear velocity is adopted instead of a constant angular velocity.

Therefore, when recording is performed by the disk rotation method with a constant angular velocity, when it is detected that the detected jitter amount is outside the preset allowable range, the disk rotation method with a constant linear velocity is selected. In contrast, recording is performed, which changes the condition of the recording operation and slows the recording speed to reduce the jitter amount of the data signal recorded on the disc.

Further, when recording is performed by the disc rotation system with a constant linear velocity, when it is detected that the detected jitter amount is outside the preset allowable range, the disc rotation system is not switched but the linear rotation method is used. Recording is performed by moving to a slower recording speed at a constant speed, thereby reducing the amount of jitter of the data signal recorded on the disc.

In the above embodiment, the sub-beam for reading the HF signal is a ± 1st-order beam of diffracted light. However, although the beam light amount is reduced, it may be a beam of ± 2nd-order or later of the diffracted light. In this case, The ± first-order beams can be arranged with priority given to the tracking control, and a high-quality tracking error signal can be obtained.

[0073]

As described above, according to the present invention, the light receiving output based on the light reflected by the disk in the sub beam temporally rearward of the main beam formed by diffraction is the light emitting output of the optical head at the recording level and the recording pause level. Since the level is adjusted by the level adjusting circuit in order to eliminate the level difference, the data signal recorded by the main beam can be read by the sub beam at the time of recording in the program area of the disc.

In this case, the level adjusting circuit is composed of independent first and second amplifiers having different gains, and the output signals respectively output from the first amplifier and the second amplifier are set to the recording level period and the recording pause. Since the selection is performed by switching between the level period and the recording period, the transition characteristic at the time of switching between the recording level period and the recording suspension level period is good, and the level difference between the recording level and the recording suspension level can be reliably eliminated. .

Further, since the recording state of the data signal actually recorded immediately before is detected, the light emission output of the optical head can be set to the optimum recording level optimum for recording on the disc.

Further, the jitter amount of the data signal actually recorded immediately before is detected, and the recording speed is switched based on the detected jitter amount. When the high-speed rotation recording is set so that the recording can only be performed, the recording can be continued by automatically switching to the recording speed in which the amount of jitter is within the allowable range.

In this case, the disc recording can be continued at a predetermined recording speed that ensures the recording quality by confirming that the recording quality becomes the predetermined recording quality while gradually decreasing the recording speed.

Further, in the photodetector of the optical head corresponding to the differential push-pull method, the sub light-receiving area corresponding to the ± first-order beams of diffracted light is divided into two in the signal track direction, When the corresponding light spot is on-track, half of the light spot corresponding to the rear sub-beam is arranged on the adjacent signal track, so that a high-quality data signal can be obtained from one divided area of the sub light-receiving area. I can.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of a CD-R / RW drive that realizes an optical head emission output control method for an optical disc recording apparatus according to the present invention.

FIG. 2 is a circuit diagram showing details of a portion for extracting various signals from each beam of the optical head 1.

[Explanation of symbols]

1 Optical head 2 head amplifier 4 decoder 7 encoder 9 Head output control circuit 11 Level adjustment circuit 12 Selection circuit 13 β value detection circuit 14 Jitter amount detection circuit 18 Motor control circuit 20 speed setting circuit 30 First Sub HF Amplifier (First Amplifier) 31 Second Sub HF Amplifier (Second Amplifier)

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5D090 AA01 BB04 CC01 CC05 EE02                       HH01 KK03 LL08                 5D118 AA13 BA01 BB02 BF03 CA13                       CC12 CF03 CG03 DA35                 5D119 AA28 BA01 DA01 DA09 EA02                       EC39 KA17                 5D789 AA28 BA01 DA01 DA09 EA02                       EC39 KA17

Claims (6)

[Claims] 1. An optical disk recording comprising an optical head that diffracts a light beam from a light source and emits a main beam and a sub-beam positioned temporally behind the main beam, and performs recording on a disk by the main beam. In a recording state on a disc, a level adjustment circuit adjusts a light receiving output based on the reflected light of the sub beam of the disc by a level adjusting circuit so as to eliminate a level difference between an emission output of an optical head and a recording pause level. An optical disk recording apparatus, wherein the data signal recorded by the main beam is read by the sub beam by using the received light output after the adjustment. 2. The level adjusting circuit is composed of a first amplifier and a second amplifier for amplifying received light outputs based on reflected light of the sub-beam on the disk by different gains, respectively, and the first amplifier and the second amplifier. The output signals respectively output from the switch are selected by the selection circuit by switching between a recording level period in which the light emission output of the optical head is at the recording level and a recording pause level period in which the light emission output of the optical head is at the recording pause level. The optical disk recording device according to claim 1, wherein 3. The data signal read by the sub beam is used to detect the recording state of the data signal recorded on the disk, and the light emission output of the optical head is controlled according to the detection. The optical disk recording device described. 4. An optical disk recording apparatus capable of recording on a disk and capable of switching a recording speed, detects a jitter amount of a data signal recorded on the disk by using a data signal read by the sub beam, and detects the jitter amount. The optical disc recording apparatus according to claim 1, wherein the recording speed is switched based on the amount of jitter. 5. The optical disk recording according to claim 4, wherein when the detected jitter amount is detected to be outside a preset allowable range, the recording speed is gradually decreased each time recording is performed. apparatus. 6. The main beam is a 0th-order beam of diffracted light, and a differential push-pull method is used for tracking control using the 0th-order beam and ± 1st-order beams of the diffracted light. Each sub-light-receiving area for receiving light is 2
In an optical disk recording apparatus provided with an optical head having a divided photodetector, one of the sub-light-receiving regions, one of the sub-light-receiving regions, which receives reflected light obtained from a sub-beam positioned rearward in time. 2. The optical disc recording apparatus according to claim 1, wherein a data signal is read from the disc by using a light reception output output from the divided area.