JP2003208714A - Optical recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further improve accuracy of a test write power and to secure an optimum power margin by producing an optimum recording mark in a whole zone area of a disk, without being affected to the utmost by the thermal interference due to a linear velocity for every zone while unnecessitating a complicated algorithm or special constitution. <P>SOLUTION: By an amplitude detecting circuit 12, a wave height value of an output signal of a PD 7 amplified by a head amplifier 9 is detected. In a recording power arithmetic circuit 13, the decision of the test write power for the trial writing in a test track of a magneto-optical disk 2 and the calculation of the actual recording power in each zone of the magneto-optical disk 2 based on the test write power are carried out by the control of a drive controller 11. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording / reproducing apparatus, and more particularly to an optical recording / reproducing apparatus characterized by a recording power setting portion.

[0002]

2. Description of the Related Art Optical discs have been attracting attention as a storage medium which is the core of multimedia which has been rapidly developing in recent years. For example, in a 3.5-inch magneto-optical disc, in recent years, 540 MB, 640 MB, 1 .3 GB and 3.
High-density recording media such as 3 GB are being provided.

By the way, in a 3.5-inch magneto-optical disc, for example, ZCAV recording (zone constant angular velocity recording) in which the medium track is divided into zones and the number of sectors in each zone is the same is adopted. The number of zones of the magneto-optical medium is
The conventional 128MB medium was limited to 1 zone, and the 230MB medium was limited to 10 zones.
In a high-density recording medium such as 0 MB or 640 MB, the track pitch of the medium is narrowed and the number of zones is greatly increased as the recording density is improved.

That is, the 640 MB medium has 11 zones and the number of zones is relatively small, whereas the 540 MB medium has 18 zones and the number of zones nearly double that of the conventional case. Normally, in the case of a magneto-optical disk, there is a difference in the optimum recording power for each medium. Therefore, when the medium is loaded, trial writing is performed for each zone to perform emission adjustment for adjusting the optimum recording power. .

For example, as shown in Japanese Patent Laid-Open No. 9-293259, trial writing is performed in the inner zone and the outer zone, and the recording power in the zone between them is obtained by linear approximation to adjust the light emission. It can be carried out.

Further, in the conventional 230 MB medium, recording is performed by pit position modulation (PPM), and the light emission power may be changed in two steps of erase power and recording power, but in the 540 MB and 640 MB medium, in order to increase the recording density. Recording by pulse radiation modulation (PWM) is adopted. In this PWM recording, it is necessary to change the light emission power in three stages of the 1st write power, the 2nd write power, and the 3rd write power (erase power).

As an example, recording on a 540/640 MB capacity magneto-optical disk defined by ISO / IEC15041 will be given. In the 540/640 MB capacity magneto-optical recording, unlike the conventional magneto-optical recording, "0" and "1"
In the binary recording, the recording value “1” is represented not by the recording signal itself but by the writing start and writing end (hereinafter referred to as edge) of the recording signal. In edge recording, good jitter characteristics at the edge portion of the recording signal are required.

Therefore, in the 540 / 640MB magneto-optical disk, as shown in FIG. 10, preheat power (hereinafter referred to as P1) for raising the medium temperature before signal recording and independent recording power for the front and rear edges are used. A certain front edge recording power (hereinafter referred to as P2) and a rear edge recording power (hereinafter referred to as P3) are provided, and P1
To prevent thermal interference between the front and rear edges,
A signal is recorded by pulse train recording with so-called ternary power in which 2 and P3 are arranged in a comb shape.

As described above, in the case of a magneto-optical disk,
Since there is a difference in the optimum recording power for each temperature and each medium, it is necessary to determine the recording power for each zone by trial writing.

[0010]

In the future, when the density of the disk medium and various disk rotation speeds are taken into consideration, thermal interference of the mark edge recording pattern may occur in the prior art such as Japanese Patent Laid-Open No. 2000-20956. In view of this, setting the optimum peak power value for each zone of the disk medium is taken into consideration, but the write pulse profile is not taken into consideration, so that accuracy deterioration due to test writing and variations in test write power are absorbed. It is expected that the optimum recordable power range (hereinafter referred to as power margin) cannot be secured.

The present invention has been made in view of the above circumstances, and does not require a complicated algorithm or a special configuration.
Provided is an optical recording / reproducing device that is not affected by thermal interference due to the linear velocity of each zone as much as possible and further improves the accuracy of test write power and generates an optimum recording mark in the entire zone of the disc to secure an optimum power margin. The purpose is to do.

[0012]

An optical recording / reproducing apparatus of the present invention is an optical recording / reproducing apparatus for setting a recording power of laser light during data recording in a test area on a recording medium, and a semiconductor emitting the laser light. A laser, a laser control means for irradiating an information recording medium with a light beam from the semiconductor laser through a converging lens, and arbitrarily controlling a light beam of power emitted from the semiconductor laser, and recording with the power. Information reproducing means for reading and reproducing recorded information on the recording medium, amplitude measuring means for measuring the amplitude of the reproduced signal reproduced by the information reproducing means, and the laser control means in the test area on the recording medium. A test power means for writing data by sequentially varying the power, and a swing of the reproduction signal of the data in the test area by the amplitude measuring means. Recording power calculation means for calculating the recording power based on the test power which is the power when the measurement is performed and the amplitude measurement result falls within a predetermined range determined in advance, and the power is sequentially varied in the test area. And a profile processing means for processing the recording pattern at that time with a predetermined pulse profile.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1 to 9 relate to an embodiment of the present invention. FIG. 1 is a block diagram showing the structure of a magneto-optical disk device, and FIG. 2 is a magneto-optical disk mounted in the magneto-optical disk device of FIG. 2 is a block diagram showing the structure of the recording area of FIG.
Of the test track and buffer track of FIG. 4, FIG. 4 is a view showing an example of the recording power, FIG. 5 is a first explanatory view for explaining the coefficient by which the test write power is multiplied, and FIG. FIG. 7 is a flow chart for explaining the operation of the magneto-optical disk device, FIG. 7 is a diagram showing a write pattern for amplitude measurement, FIG. 8 is a diagram showing a pulse waveform in write pulse train recording, and FIG. It is the 2nd explanatory view explaining.

As shown in FIG. 1, in the magneto-optical disk device 1 of this embodiment, a magneto-optical disk 2 for magneto-optically recording information is inserted, and the magneto-optical disk 2 is loaded on the spindle motor 3 by a loading mechanism (not shown). It is attached and is designed to rotate. An optical pickup 4 as an optical head is installed in the vicinity of the spindle motor 3 so as to be movable in the radial direction of the magneto-optical disc 2, and a laser beam 5 for recording and reproduction is directed toward the magneto-optical disc 2. It is designed to irradiate.

The optical pickup 4 is provided with a laser diode (hereinafter referred to as LD) 6 that emits a laser beam 5, and a photodetector (hereinafter referred to as PD) 7 that receives the reflected light from the magneto-optical disk 2. , The laser beam 5 from the LD 6 is emitted into a small spot and emitted, and the PD 7 is irradiated with the reflected light from the magneto-optical disk 2 (not shown).

An LD driver 8 is connected to the LD 6, and a driving current is supplied to the LD 6 by the LD driver 8. On the other hand, the analog signal processing circuit 10 is connected to the PD 7 through the head amplifier 9, and the output signal of the PD 7 is amplified by the head amplifier 9 and then binarized by the analog signal processing circuit 10. There is.

The binarized signal binarized by the analog signal processing circuit 10 is sent to the drive controller 11 and demodulated and error-corrected by the drive controller 11 to obtain the data recorded on the magneto-optical disk 2. Read out. The read data is sent to, for example, a host computer (not shown) for various processing.

Further, the amplitude detection circuit 12 is a head amplifier 9
The peak value of the output signal of the PD 7 amplified by is detected. The crest value detected by the amplitude detection circuit 12 is read into the drive controller 11 and is compared with a target value suitable for binarizing the detection signal, for example, to adjust the gain of a variable gain amplifier (not shown), and an analog signal processing circuit In 10, the binarization process can be stably performed.

A recording power calculation circuit 13 and a storage circuit 14 are connected to the drive controller 11, and the recording power calculation circuit 13 is controlled by the drive controller 11 so that the test writing on a test track of the magneto-optical disk 2 will be described later. The determination of the test write power for recording and the calculation of the actual recording power in each zone of the magneto-optical disk 2 based on this test write power are executed. On the other hand, the storage circuit 14 stores a sector in which test writing on the test track is prohibited.

The magneto-optical disk device 1 is provided with focusing means and tracking means (not shown).

The magneto-optical disk 2 is, for example, a 540 MB medium, and as shown in FIG.
18 zones of 7 (ISO / IEC1
5041). Further, in each zone, a buffer track is provided between the user area for recording data and an adjacent zone, and a test track is provided between the outermost peripheral portion of the user area and the buffer track. ing. Generally, test writing is performed on this test track to determine the recording power of the magneto-optical disk. However, in the present embodiment, test writing is first performed on the test track of zone 0, which is the inner peripheral zone, and the recording power in zone 0 is set. Then, test writing is performed on the test track of the zone 16 which is the outer peripheral side zone to determine the recording power in the zone 16, and linear approximation is performed using the recording power in the zone 0 and the recording power in the zone 16. As a result, the recording power of other zones is determined.

Here, as shown in FIG. 3, sectors are radially provided in the same zone (zone 0 or zone 16) and sector ID portions are provided at the same radial position, but they are adjacent to each other. In the zone (zone 1 or zone 17), since the sector configuration is different, the radial position of the ID part is different. Therefore, in the test writing on the test track, depending on the sector, the signal of the ID part of the adjacent zone may be different. Since the birefringence causes leakage, spike noise or the like is generated, so that there is a problem that the signal amplitude cannot be accurately measured by the amplitude detection circuit 12.

Therefore, in this embodiment, the test-write-prohibited sector in the test track in zone 0 shown in Table 1 and the test-write-prohibited sector in the test track in zone 16 shown in Table 2 are stored in the memory circuit 14. Has been done.

[0025]

[Table 1]

[Table 2] As described above, in the present embodiment, the trial writing is performed in the zone 0 and the zone 16, but the present invention is not limited to this, the trial writing is performed only in one zone, for example, the zone 0, and the determined recording power is set. The recording power of the other zones may be determined by linear approximation based on this, in which case the setting time of the recording power can be shortened, and one or a plurality of zones other than the two zones of zone 0 and zone 16 can be determined. The test writing may be performed on the zones, and in this case, the recording power of each zone can be accurately determined.

Here, in the case of multi-value recording by a pulse train as shown in FIG. 4, each peak power (P1,
The test write power Pt determined for P2, P3, ..., Pn) is multiplied by a coefficient (α1, α2, α3, ..., αn). The coefficients α1, α2, α3, ..., αn are
It is stored in the recording power calculation circuit 13 in advance.

A first example of setting the coefficient αi (i = 1 to n) will be described by taking as an example the case where a signal is recorded by pulse train recording with three-valued power (P1, P2, P3).

Generally, in the signal judgment of the optical disk recording,
Judgment based on error rate is used. Although the error rate fluctuates when the above three values are made variable, error correction (hereinafter referred to as ECC) is performed in the signal reading of the optical disk drive, and a recording signal having an error rate characteristic up to a certain level. If so, the signal can be read normally. The variation of the error rate characteristic when the power of P3 is made variable while the ratio of P1, P2 and P3 is kept constant is shown in the graph of FIG. At this time, assuming that the error rate indicated by a black line is an error rate limit that can be corrected by ECC, a good recording area in FIG. 5 is defined by Pmin ≦ P3 ≦ Pmax (hereinafter, this recording area Pmax -Pmin
Is described as a power margin).

The operation of this embodiment will be described below. As shown in FIG. 6, when the magneto-optical disk 2 is loaded in the magneto-optical disk device 1 in step S1, the drive controller 11 moves the optical pickup 4 to a test track for trial writing. In this case, the test track is the Zone 0 test track.

In step S2, writing is performed on a predetermined sector of the test track for trial writing, and the amplitude of the written data is measured by monitoring the output from the amplitude detection circuit 12, and within a predetermined window. The test write power Pt0 is changed so as to converge to

Since the data pattern to be written measures the amplitude, it is desirable to repeat a single pattern. In this embodiment, a 2T repeating pattern as shown in FIG. 7 is used. The preheat power Pt1 at that time is Pt10 which is the preheat power in zone 0, and P is the preheat power which is used in the trial writing performed later in the test track of zone 16.
Assuming t 116, Pt 10 and P t 116 are values proportional to the linear velocity of disk rotation. By appropriately setting the preheat power, the amplitude with respect to the test write power Pt has an appropriate sensitivity and the accuracy of the test write is improved.

In step S3, the write power for actually writing data is set. First, the peak power P3 is set by multiplying the test write power Pt0 by the recording power coefficient α0.

At this time, α0 is a level range (power margin) in which the error rate is error-correctable (ECC) based on the error rate characteristics when the power of P3 is varied while the ratio of P1, P2, and P3 is fixed. ) Is obtained, and α0 is set so that the target value estimated by using the detection error of the test write power Pt0 and the error of the drive electric system as a margin is P3.

Regarding P2 and P1, as shown in Table 3, the power ratio k1: k of the recording pulse train in the zone 0 prepared in advance, which is obtained by the method described later.
2: Multiply k3 by P3 set above to set each. The recording power coefficient and the power ratio of the recording pulse train are stored in the recording power calculation circuit 13.

[0035]

[Table 3] In step S4, a predetermined sector is written with the set write power to determine whether the writing is normal (no error occurs during verification). If not, error processing is performed in step S10 to end the processing. If so, move to the next action.

In step S5, the drive controller 1
In step 1, the optical pickup 4 is moved to a test track for trial writing in the zone 16.

In step S6, trial writing is performed as in step S3. At that time, as described in step S3, the preheat power is set to P t 116.

In step S7, the data is actually obtained by multiplying the test write power P t 116 by the recording power coefficient α 16 and the recording pulse train power ratio k1: k2: k3 in the zone 16 prepared in advance as in step S3. Set the recording power to write.

In step S8, writing is performed in a predetermined sector with the recording power set in step S7, and it is determined whether the writing is normal (no error occurs during verification).
If not, error processing is performed in step S10 and the processing is terminated. If succeeded, the next operation is performed.

In step S9, P3 for each zone is obtained by linear approximation from the values of P3 in zone 0 and zone 16,
The value is multiplied by the power ratio of the recording pulse train in Table 3 to determine the recording power for each zone, and the process is terminated.

Step S3, Step S7, Step S
The power ratio of the recording pulse train shown in Table 3 for obtaining the recording power for actually writing data used in No. 9 is P1, P2, P3 of the pulse waveform in the write pulse train recording used in the present embodiment shown in FIG. The error rates of zone 0 and zone 17 when P3 is varied by changing the respective ratios are measured, and the power margin for each ratio is calculated according to FIG.

In zone 0, P1: P2: P3 is 0.06:
1: 1 (FIG. 9A), 0.14 in zone 17:
It can be seen that the power margin is optimum when 0.9: 1 (FIG. 9B). Table 3 shows the recording power coefficient in each zone obtained by linear approximation based on this result.

These methods are 640 MB, 1.3 GB,
The same method can be applied to direct overwrite (DOW). Further, even in 2.3 GB in which land / groove recording is performed, since the medium sensitivity differs between the land and the group, it can be applied to setting the recording pulse power ratio separately for the land and the group.

[0044]

As described above, according to the present invention, the thermal interference due to the linear velocity in each zone is not received as much as possible without requiring a complicated algorithm and a special configuration, and the accuracy of the test write power is further improved. Further, there is an effect that an optimum recording mark can be generated in the entire zone of the disc and an optimum power margin can be secured.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a magneto-optical disk device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a configuration of a recording area of a magneto-optical disc mounted in the magneto-optical disc device of FIG.

FIG. 3 is a configuration diagram showing configurations of a test track and a buffer track of FIG.

FIG. 4 is a diagram showing an example of recording power.

FIG. 5 is a first explanatory diagram illustrating a coefficient by which a test write power is multiplied.

FIG. 6 is a flowchart explaining the operation of the magneto-optical disk device of FIG.

FIG. 7 is a diagram showing a light pattern for performing amplitude measurement.

FIG. 8 is a diagram showing a pulse waveform in write pulse train recording.

FIG. 9 is a second explanatory diagram illustrating a coefficient by which the test write power is multiplied.

FIG. 10 is a diagram showing a waveform of recording power in conventional pulse train recording.

[Explanation of symbols] 1 ... Magneto-optical disk device 2 ... Magneto-optical disk 3 ... Spindle motor 4 ... Optical pickup 6 ... LD 7 ... PD 8 ... LD driver 9 ... Head amp 10 ... Analog signal processing circuit 11 ... Drive controller 12 ... Amplitude detection circuit 13 ... Recording power calculation circuit 14 ... Memory circuit

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Claims (2)

[Claims] 1. An optical recording / reproducing apparatus for setting a recording power of laser light during data recording in a test area on a recording medium, wherein a semiconductor laser emitting the laser light and a converging lens for converging a light beam from the semiconductor laser. A laser control means for irradiating an information recording medium through the laser beam, and arbitrarily controlling a light beam of the power emitted from the semiconductor laser; and information for reading and reproducing recorded information recorded on the recording medium with the power. Reproducing means, amplitude measuring means for measuring the amplitude of the reproduced signal reproduced by the information reproducing means, and test power means for writing data by sequentially varying the power in a test area on the recording medium by the laser control means. And the amplitude measurement means measures the amplitude of the reproduction signal of the data in the test area, and the amplitude measurement result is predetermined. A recording power calculation means for calculating the recording power based on a test power which is the power when the power is within a predetermined range, and a recording pattern for sequentially varying the power in the test area is predetermined. And a profile processing means for processing with a pulse profile. 2. The light according to claim 1, further comprising arithmetic processing means having a coefficient of a power ratio of a predetermined recording pulse train when the recording power is calculated based on the test power means. Recording / playback device.