JP2000020954A - Optical disc device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set up an erase power with accuracy for preventing cross erase due to a narrow track width of a high-density medium. SOLUTION: An amplitude detection circuit 12 detects a peak value of an output signal of PD7 amplified by a head amplifier 9. The peak value detected by the amplitude detecting circuit 12 is read into a drive controller 11, and it is, for example, compared with a suitable target value to binarize the detected signal and adjusts the gain of a variable gain amplifier, and stably binarized in an analog signal processing circuit 10. Determination of a test light power for trial writing in a test track of a magneto-optical disk 2 and operation of an actual elimination power in each zone of the magneto-optical disk 2, based on the test light power are executed by the control of the drive controller 11 in a power operation circuit 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device, and more particularly, to an optical disk device characterized by a setting portion for erasing power.

[0002]

2. Description of the Related Art An optical disk has been attracting attention as a storage medium serving as a core of multimedia which has been rapidly developing in recent years. For example, in a 3.5-inch magneto-optical disk, in addition to the conventional 128 MB and 230 MB, it has recently been increasing. , 54
High-density recording media such as 0 MB and 640 MB are also being provided.

[0003] For example, a 3.5-inch magneto-optical disk employs ZCAV recording (zone constant angular velocity recording) in which a medium track is divided into zones and the number of sectors in each zone is the same. The number of zones of the magneto-optical medium is
The conventional 128 MB medium is limited to one zone, and the 230 MB medium is limited to 10 zones.
In a high-density recording medium such as 0 MB or 640 MB, the track pitch of the medium has been narrowed and the number of zones has been greatly increased with an increase in the recording density.

That is, the 640 MB medium has 11 zones and the number of zones is relatively small, while the 540 MB medium has 18 zones and the number of zones has almost doubled compared to the conventional one. Normally, in the case of a magneto-optical disk, there is a difference in the optimum erasing power and recording power for each medium. Therefore, when the medium is loaded, light emission adjustment for adjusting to the optimum erasing power and recording power is performed.

[0005] For example, in Japanese Patent Application Laid-Open No. 63-108539, a part of a cartridge for storing an optical recording medium is provided.
A magnetic information recording unit that records optical recording conditions is provided, and the magnetic information is read at the time of loading, thereby determining the recording, reproducing, and erasing conditions of the optical recording medium.

In Japanese Patent Application Laid-Open No. Hei 2-308425, recording conditions matched in advance for each disk are stored in a recording means, and information on disk control tracks at the time of loading, for example, information on disk manufacturing conditions such as vendor unique information. Is read, and recording, reproduction, and erasing conditions for the inserted disc are selected from among the stored recording conditions, and light emission adjustment is performed.

Further, there is a method in which, when a medium is loaded, test writing is performed, and light emission adjustment for adjusting to optimum erasing power and recording power is performed.
In Japanese Patent No. 5258, standard data is stored in a ROM or the like in advance, an environmental temperature is measured first, and a drive current value for each radius of the magneto-optical disk corresponding to the environmental temperature is read from the standard data. A semiconductor laser is driven by a square wave having a duty ratio of 50% to perform test writing on a magneto-optical disk. Then, the data recorded by trial writing is reproduced using the light receiving element and the secondary distortion detecting circuit. At this time, the drive current value of the semiconductor laser is varied so that the duty ratio of the reproduction signal is 50%, that is, the output of the secondary distortion detection circuit becomes zero, and the recording / reproduction is repeated to determine the power for each zone. ing.

[0008]

However, the duty ratio of the reproduced signal in the above-mentioned Japanese Patent Application Laid-Open No. 62-285258 varies due to unevenness in sensitivity or rotation deviation of the magneto-optical disk. The conventional method has a problem that the power cannot be determined accurately.

In a next-generation magneto-optical recording medium in which the recording track is expected to be further narrowed, the spot diameter of the laser beam regulated by the wavelength of the laser beam and the NA of the optical system may be larger than the track pitch. Thought,
In such a case, if an erasing operation is performed on the track with the erasing power of DC emission from the semiconductor laser as in the related art,
There is a possibility that a so-called cross-erase occurs in which a recording signal of an adjacent track is erased by heat generated by a laser spot having an erasing power, that is, appropriate storage of data becomes difficult.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an optical disk apparatus capable of accurately setting an erasing power for preventing a cross erase due to a narrow track width of a high-density medium. I have.

[0011]

According to a first aspect of the present invention, there is provided an optical disk apparatus for setting the power of a laser beam in a test area on a recording medium. Means, information reproducing means for reading and reproducing the recorded information on the recording medium recorded with the power, amplitude measuring means for measuring the amplitude of a reproduced signal reproduced by the information reproducing means, and the laser control means The power is sequentially varied in the test area on the recording medium to write data, 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 a predetermined predetermined value. And an erasing power calculating means for calculating an erasing power based on the test power which is the power when the power falls within the range. It is.

In the optical disk device according to the first aspect of the present invention,
The power is sequentially varied in the test area on the recording medium by the laser control means to write data, and the amplitude measurement means measures the amplitude of the reproduction signal of the data in the test area. The erase power calculation means calculates the erase power based on the test power which is the power when the power falls within a predetermined range, thereby preventing cross-erase due to the narrow track width of the high-density medium. It is possible to accurately set the erasing power.

According to a second aspect of the present invention, there is provided an optical disk device for setting the power of a laser beam in a test area on a recording medium, a laser control means for arbitrarily controlling the power of the laser beam, Information reproducing means for reading and reproducing recorded information recorded on the recording medium; amplitude measuring means for measuring the amplitude of a reproduced signal reproduced by the information reproducing means; and the test on the recording medium by the laser control means. When the power is sequentially varied in the area to erase data, the amplitude measuring means measures the amplitude of the reproduced signal of the data in the test area, and the amplitude measurement result falls within a predetermined range. And an erasing power calculating means for calculating an erasing power based on the test power.

According to the optical disk device of the second aspect of the present invention,
The laser control means sequentially varies the power in the test area on the recording medium to erase data, and the amplitude measurement means measures the amplitude of the reproduction signal of the data in the test area, and the amplitude measurement result The erase power calculating means calculates the erase power based on the test power which is the power when the power falls within a predetermined range, thereby preventing the cross erase due to the narrow track width of the high-density medium. It is possible to accurately set the power.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 7 relate to an embodiment of the present invention. FIG. 1 is a configuration diagram showing a configuration of a magneto-optical disk device, and FIG. 2 is a magneto-optical disk mounted on the magneto-optical disk device of FIG. FIG. 3 is a configuration diagram showing a configuration of a recording area of FIG.
FIG. 4 is a second flowchart illustrating the operation of the magneto-optical disk device of FIG. 1, and FIG. 5 is an example of the recording power calculated by the flowchart of FIG. FIG. 6 is a first flowchart illustrating a modified example of the operation of the magneto-optical disk device of FIG. 1, and FIG. 7 is a second flowchart illustrating a modified example of the operation of the magneto-optical disk device of FIG. is there.

As shown in FIG. 1, in the magneto-optical disk drive 1 of this embodiment, a magneto-optical disk 2 for recording information magneto-optically is inserted, and the magneto-optical disk 2 is connected to a spindle motor 3 by a loading mechanism (not shown). It is mounted and driven to rotate. An optical pickup 4 as an optical head is installed near the spindle motor 3 so as to be movable in the radial direction of the magneto-optical disk 2, and a laser beam 5 for recording and reproduction is directed toward the magneto-optical disk 2. Irradiation.

The optical pickup 4 is provided with a laser diode (hereinafter, referred to as LD) 6 for emitting laser light 5 and a photodetector (hereinafter, referred to as PD) 7 for receiving light reflected from the magneto-optical disk 2. An optical system (not shown) for irradiating the laser beam 5 from the LD 6 to a minute spot and irradiating the PD 7 with reflected light from the magneto-optical disk 2 is provided.

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, an analog signal processing circuit 10 is connected to the PD 7 via a head amplifier 9. The output signal of the PD 7 is amplified by the head amplifier 9 and then binarized by the analog signal processing circuit 10. I have.

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

The amplitude detection circuit 12 is a head amplifier 9
The peak value of the output signal of the PD 7 amplified by the above is detected. The peak value detected by the amplitude detection circuit 12 is read by the drive controller 11, and is compared with, for example, a target value appropriate for binarizing the detection signal, and the gain of a variable gain amplifier (not shown) is adjusted. At 10, the binarization process can be stably performed. Also,
A power operation circuit 13 is connected to the drive controller 11. Under the control of the drive controller 11, the power operation circuit 13 determines a test write power for test writing on a test track of the magneto-optical disk 2 described later, For example, calculation of the actual erase power in each zone of the magneto-optical disk 2 based on the write power is executed.

The magneto-optical disk drive 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.
7 and 18 zones are provided (ISO / IEC1
5041). In each zone, a buffer track is provided between an adjacent zone in addition to a user area for recording data, 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. In this embodiment, first, test writing is performed on the test track of zone 0, which is the inner peripheral zone, and the erasing power on zone 0 is determined. Then, test writing is performed on the test track of the zone 16 which is the outer peripheral zone, the erase power in the zone 16 is determined, and a linear approximation is performed using the erase power in the zone 0 and the erase power in the zone 16. Thus, the erasing power of another zone is determined.

As described above, in the present embodiment, the test writing is performed in the zone 0 and the zone 16; however, the present invention is not limited to this. The erasing power of another zone may be determined by linear approximation based on the erasing power. In this case, the setting time of the erasing power can be shortened. Alternatively, test writing may be performed on a plurality of zones, and in this case, the erasing power of each zone can be determined accurately.

Next, the operation of the embodiment constructed as described above will be described. That is, a method of determining the erasing power by trial writing in the magneto-optical disk device 1 of the present embodiment will be described.

First, when the magneto-optical disk 2 is loaded on the magneto-optical disk device 1, as shown in FIG. 3, the drive controller 11 moves the optical pickup to a test track where test writing is performed in step S1. The test track in this case is the test track in zone 0 (see FIG. 2).

Next, in step S2, a predetermined initial value is set as the test write power Pt, and in step S3, the test write power Pt is written to a predetermined sector of a test track where test writing is to be performed.

Here, since the amplitude of the data pattern to be written is measured in a later operation, it is desirable to repeat a single pattern.

Then, in step S4, the drive controller 11 measures the amplitude of the data written in step S3 by monitoring the output from the amplitude detection circuit 12. In step S5, the amplitude value monitored in step S4 is determined in advance. It is determined whether it is smaller than the prescribed lower limit. If smaller, the test write power Pt is increased in step S6, and the increased test write power Pt reaches the actual upper limit Pmax of the erase power in step S7. It is determined whether or not the upper limit value Pma
If the number has reached x, error processing is performed and the processing is terminated. If the number has not reached the upper limit value Pmax, the flow returns to step S3 to perform writing again.

If it is determined in step S5 that the monitored amplitude value is equal to or larger than the predetermined lower limit, in step S8, it is determined whether the monitored amplitude value is within the predetermined upper limit value. In step S9, if the test write power P
t, and the test write power Pt further reduced in step S10 becomes the lower limit value Pmi of the actual erase power.
n is determined, and if the lower limit value Pmin is reached, error processing is performed and the process is terminated.
If not, the process returns to step S3 to perform writing again. By repeating this operation, the test write power Pt in which the amplitude value of the written data falls within a specified range.
To determine.

If the target value of the amplitude (the center of the specified range) is too small, an error in amplitude measurement due to noise increases, which is not preferable. On the other hand, if the target value of the amplitude is too large, the amplitude of the written data becomes saturated, so that the fluctuation of the amplitude with respect to the fluctuation of the write power becomes small and the error of the amplitude measurement becomes large, which is not preferable.

If it is determined in step S8 that the monitored amplitude value is within the predetermined upper limit value, as shown in FIG. 4, the test track power is determined by the test write power determined in step S11. The write is performed in the sector No. and the amplitude of the data written in step S12 is monitored. Then, in step S13, it is determined whether or not the amplitude value monitored in the separate sector is within a range of a specified value defined by a specified upper limit value and a specified lower limit value. If not, the process moves to another sector in step S14. Then, the process returns to step S2 in FIG. 3 to repeat the process.

If the amplitude value is within the specified value range in step S13, the data is actually erased by the power arithmetic circuit 13 at step S15 by multiplying the test write power Pt determined in the above processing by a factor by a factor. Power when erasing.

In the present embodiment, the erasing power for actually erasing data is, as shown in FIG.
This is performed by binary erasure using a 0% pulse train, and the base power P1 and the peak power P2 are obtained by multiplying the determined test write power Pt by a factor (α1, α2). The coefficients α1 and α2 are stored in the power calculation circuit 13 in advance.

Subsequently, returning to FIG. 4, in step S16, it is determined whether or not the test track is the zone 16. If the test track is the zone 16, the linear approximation is performed based on the erasing power in the zones 0 and 16 to erase other zones. The power is determined and the process ends.

In the above description, the test track is zone 0
Therefore, the process returns from step S16 to step S1 in FIG. 3, moves to the test track of zone 16 in step S1, repeats the above processing, determines the erasing power in zone 16, and in step S16, determines the erasing power in zone 0 and zone 16. The linear approximation is performed based on the erasing power to determine the erasing power of another zone, and the process is terminated. Zone 16
, The test write power Pt in step S2
Is the test write power P determined in zone 0
It is calculated and set based on t.

As described above, in the present embodiment, the amplitude of the reproduced signal of the written information is measured, the test write power Pt is determined based on the measured value, and a predetermined coefficient is added to the determined test write power Pt. The erasing power is set by multiplication, and the amplitude measurement is not affected by sensitivity unevenness or rotational deviation of the magneto-optical disk, so that the erasing power of each zone can be set with high accuracy.

Since the erasing power is executed by binary erasing using a pulse train, the erasing power can be accurately controlled so as to prevent cross-erase on a high-density track.

Although the erasure is determined by the flowcharts of FIGS. 3 and 4, it is not limited to this, and may be as shown in FIGS. 6 and 7.

That is, as shown in FIG. 6, the drive controller 11 moves the optical pickup to a test track where test writing is performed in step S31. The test track in this case is the test track in zone 0 (see FIG. 2).

Next, at step S32,
Alternatively, writing is performed on a sector determined by the recording power determined by trial writing. In step S33, a predetermined initial value is set as the test erase power Pe, and in step S34, the sector written with the recording power is erased.

Then, in step S35, the drive controller 11 measures the amplitude of the data erased in step S34 by monitoring the output from the amplitude detection circuit 12. In step S36, the drive controller 11 measures the amplitude of the data erased.
It is determined whether the monitored amplitude value is smaller than a predetermined lower limit value in 35. If the monitored amplitude value is smaller, the test erase power Pe is too large. Therefore, the test erase power Pe is reduced in step S37.
It is determined whether the test erase power Pe reduced in step 8 is equal to or lower than the lower limit value Pemin of the actual erase power. If the test erase power Pe is lower than the lower limit value Pemin, error processing is performed and the processing is terminated. Returns to step S34 to perform erasure again.

If it is determined in step S36 that the monitored amplitude value is equal to or larger than the predetermined lower limit value, in step S39, it is determined whether the monitored amplitude value is within the predetermined upper limit value. If it exceeds the specified upper limit, the test erase power Pe is too small, so the test erase power Pe is increased in step S40, and the test erase power Pe reduced in step S41 is equal to the actual upper limit of the erase power. Pema
x is determined, and if the upper limit value Pemax is reached, error processing is performed and the process is terminated, and the upper limit value Pem is reached.
If it has not reached ax, the process returns to step S34 to perform erasing again. By repeating this operation, the test erase power Pe in which the amplitude value of the erased data falls within the specified range is determined.

When it is determined in step S39 that the monitored amplitude value is within the predetermined upper limit value, as shown in FIG. 7, the test track power of the test track is determined by the test erase power Pe determined in step S42. The data written to another sector is erased, and the amplitude of the erased data is monitored in step S43. Then, in step S44, it is determined whether or not the amplitude value monitored by the separate sector is within a range of a specified value defined by a specified upper limit value and a specified lower limit value. Then, the process returns to step S33 in FIG. 6 to repeat the process.

If the amplitude value is within the specified value range in step S44, the data is actually written by the power operation circuit 13 at step S46 by multiplying the test erase power Pe determined in the above processing by a coefficient by a factor. Power when erasing.

Subsequently, in step S47, it is determined whether or not the test track is the zone 16. If the test track is the zone 16, linear approximation is performed based on the erasing powers in the zones 0 and 16, and the erasing powers in other zones are determined. The process ends.

In the above description, the test track is zone 0
Therefore, from step S47 to step S31 in FIG.
Returning to step S31, the process moves to the test track in zone 16 and the above processing is repeated to determine the erasing power in zone 16, and in step S16 zone 0 and zone 1 are determined.
A linear approximation is performed on the basis of the erasing power in step 6 to determine the erasing power of another zone, and the process is terminated. Note that the initial value of the test erase power Pe in step S33 in the zone 16 is calculated and set based on the test erase power Pe determined in the zone 0.

[0048]

As described above, according to the optical disk apparatus of the first aspect of the present invention, data is written by sequentially varying the power in the test area on the recording medium by the laser control means, and is written by the amplitude measurement means. Since the amplitude of the reproduced signal of the data in the test area is measured, and the erase power calculating means calculates the erase power based on the test power which is the power when the amplitude measurement result falls within a predetermined range, the erase power is high. There is an effect that the erasing power for preventing the cross erase due to the narrow track width of the density medium can be set with high accuracy.

According to the optical disk apparatus of the present invention, the data is erased by sequentially varying the power in the test area on the recording medium by the laser control means, and the reproduced signal of the data in the test area is obtained by the amplitude measuring means. And the erasing power calculating means calculates the erasing power based on the test power, which is the power when the amplitude measurement result falls within a predetermined range. There is an effect that the erasing power for preventing the cross erase can be set with high accuracy.

[Brief description of the 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 disk mounted on the magneto-optical disk device of FIG. 1;

FIG. 3 is a first flowchart for explaining the operation of the magneto-optical disk device of FIG. 1;

FIG. 4 is a second flowchart for explaining the operation of the magneto-optical disk device of FIG. 1;

FIG. 5 is a diagram showing an example of a recording power calculated according to the flowchart of FIG.

FIG. 6 is a first flowchart illustrating a modification of the operation of the magneto-optical disk device of FIG. 1;

FIG. 7 is a second flowchart illustrating a modification of the operation of the magneto-optical disk device of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Magneto-optical disk device 2 ... Magneto-optical disk 3 ... Spindle motor 4 ... Optical pick-up 6 ... LD 7 ... PD 8 ... LD driver 9 ... Head amplifier 10 ... Analog signal processing circuit 11 ... Drive controller 12 ... Amplitude detection circuit 13 ... Power operation circuit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D090 AA01 BB04 CC01 CC04 CC06 CC18 DD03 DD05 EE06 FF11 HH01 JJ12 KK03 5D119 AA26 BA01 BB03 DA09 FA02 HA19 HA37 HA44

Claims (3)

[Claims] 1. An optical disc apparatus for setting the power of laser light in a test area on a recording medium, a laser control means for arbitrarily controlling the power of the laser light, and recording on the recording medium recorded with the power. Information reproducing means for reading and reproducing information; amplitude measuring means for measuring the amplitude of a reproduced signal reproduced by the information reproducing means; and the laser control means for sequentially varying the power in the test area on the recording medium. Write data, measure the amplitude of the reproduced signal of the data in the test area by the amplitude measuring means, and, based on the test power which is the power when the amplitude measurement result falls within a predetermined range. And an erasing power calculating means for calculating an erasing power by using the optical disk device. 2. An optical disc apparatus for setting the power of a laser beam in a test area on a recording medium, a laser control means for arbitrarily controlling the power of the laser beam, and recording on the recording medium recorded with the power. Information reproducing means for reading and reproducing information; amplitude measuring means for measuring the amplitude of a reproduced signal reproduced by the information reproducing means; and the laser control means for sequentially varying the power in the test area on the recording medium. The data is erased, the amplitude measuring means measures the amplitude of the reproduction signal of the data in the test area, and the amplitude measurement result is based on the test power which is the power when the amplitude falls within a predetermined range. And an erasing power calculating means for calculating an erasing power by using the optical disk device. 3. The erasing power calculator according to claim 1, wherein the erasing power calculator multiplies the test power by one or more predetermined coefficients to calculate the erasing power composed of a pulse train. Optical disk device.