JP2002342930A - Laser power setting method and optical disk unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a laser power most suitable for every zone at the time of recording data. SOLUTION: Zone information indicating one zone and reference laser power corresponding to the zone information are acquired from an optical disk 1. Data based on a maximum recording mark and a minimum recording mark are continuously recorded on a trial writing area provided in the one zone over three tracks on the basis of the reference laser power corresponding to the zone information. Then, the maximum laser power is obtained from the amplitude ratio of each reproduction signal of a second track and third track among the three recorded tracks in the trial writing area. The minimum laser power is obtained from the asymmetry value generated by the deviation of the center of the amplitude between the maximum recording mark and the minimum recording mark of the reproduction signal of the third recorded track. The mean value between the maximum laser power and the minimum laser power is set as optimum laser power to the one zone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser power setting method for setting an optimum laser power at the time of data recording when data is satisfactorily recorded on a track on the optical disk using a rewritable optical disk. It concerns the device.

[0002]

2. Description of the Related Art In general, a disk-shaped optical disk can record and / or reproduce digital data such as video data, audio data, and computer data on a spiral or concentric track at a high density. It is often used because of its high speed access to trucks.

[0003] This type of optical disc includes a read-only type and a recordable / reproducible type. Further, the recordable / reproducible type includes a type capable of recording once and a type capable of recording / reproducing repeatedly a plurality of times. is there.

[0004] Among the above optical disks, an optical disk of a phase change type having a phase change recording layer or the like can be repeatedly recorded and reproduced a plurality of times, without erasing already recorded data. On top of this, data can be rewritten (also called overwriting, overwriting, and overwriting).

Here, when data is rewritten on a phase change recording layer or the like formed on an optical disk with a laser beam (laser light) emitted from an optical pickup (not shown), the power of the laser beam applied to the optical disk is changed. It greatly affects the accuracy of the data to be recorded. For example, if the power of the laser beam is weak, the already recorded data will remain unerased. On the other hand, if the power of the laser beam is high, a cross-erase to an adjacent track occurs. For this reason, in an optical disk of a phase change type or the like, an optimum condition value at the time of laser beam irradiation is recorded in advance in a ROM area (control track) provided at the innermost or outermost part. Then, at the time of data recording, the laser beam power is set to an optimal value based on the previously recorded optimal condition value at the time of laser beam irradiation.

However, as the capacity and density of rewritable optical disks have been increased, developments have been made in the direction of shortening the wavelength of laser beams and increasing the NA of objective lenses. There is a need for more accurate laser power control. Further, laser power control corresponding to changes in the environment of the optical disk, the inherent characteristics of the optical disk device, and the like is required.

In response to this, Japanese Patent Laid-Open Publication No. Hei 11-25491 discloses a method of setting a laser power and a recording / reproducing apparatus as an example of a conventional improvement plan for setting an optimum laser power for data recording. ing.

That is, according to the method for setting a laser power and the recording / reproducing apparatus disclosed in Japanese Patent Application Laid-Open No. H11-25491, as shown in FIGS. When recording is performed, first, the initial setting laser power Po is obtained from the control track provided on the optical disk, and the data pattern "00" is written on the test track provided on the optical disk by the obtained initial setting laser power Po. Deletes the data recorded on the test track. Subsequently, increment data such that the data value simply increases is written in the test track by the initial setting laser power Po. Thereafter, when the random data is overwritten on the test track on which the increment data has been written with a laser power smaller than the initially set laser power Po and the random data is reproduced, an error rate of the random data is detected. If the error rate is larger than the predetermined value, the laser power is increased and the process of writing random data is repeated again. On the other hand, when the error rate reaches a predetermined value, the laser power Pow at this time is multiplied by, for example, 1.2 and set as the laser power Pset for writing data in the data recording area of the optical disk. This discloses that data can be recorded with an optimal laser power even if the influence of the recording environment on the optical disc differs, and the error rate of the recorded data can be reduced.

On the other hand, as another example of an improvement plan for solving the cross-erase due to the narrowing of the track in the rewritable optical disk, Japanese Patent Laid-Open No. Hei 10-241163 discloses a method for preventing a side erase of a rewritable optical disk. ing.

That is, the above-mentioned Japanese Patent Application Laid-Open No. 10-241163.
In the method for preventing side erasure of a rewritable optical disk disclosed in Japanese Patent Application Laid-Open Publication No. H10-260, as shown in FIG. 18, every time a data signal is recorded on an arbitrary recording track (Ti) on the optical disk, that recording track (Ti ) Predetermined area (S)
And the recording track (Ti-1, Ti +) adjacent to the recording track (Ti).
1) is detected, and if this difference exceeds a preset number, the adjacent recording track (Ti-
1, (Ti + 1) is re-recorded. It is disclosed that the cross erase accompanying the narrowing of the track can be solved by this.

[0011]

However, FIG.
Examples of improvement proposals shown in FIGS.
No. 5,491) discloses a laser power Pset at the time of detecting and writing an error rate to random data overwritten on a test track on an optical disk.
In this improved example, the laser power Pset at the time of writing is set to be the same over the entire surface of the optical disk. However, recently, the development of an optical disc capable of recording / reproducing an ultra-high density recording / reproducing which has a recording capacity on a rewritable optical disc of 20 giga or more has been actively performed. The data recording area is divided into a plurality of zones in the radial direction of the disk substrate, and the number of revolutions is switched stepwise at a substantially constant linear velocity for each zone, and further, the rotation is controlled at a constant angular velocity within each zone. Therefore, the recording condition changes for each zone, so that the laser power P
If the set is set to be the same over the entire surface of the optical disc, there is a problem since data cannot be recorded well in each zone.

On the other hand, in another example of the improvement shown in FIG. 18 (JP-A-10-241163), the number of rewrites of a recording track is recorded in a predetermined area, and the difference between the number of rewrites with an adjacent track is detected. When the difference in the number of rewrites exceeds a preset number, the data on the adjacent track can be re-recorded to eliminate the effects of cross-erase. The effect of cross-erase becomes a big problem because the difference in the number of rewrites between adjacent tracks becomes large, so this improvement plan is effective.However, for optical discs such as video applications where continuous recording is mainly performed, The difference in the number of rewrites between adjacent tracks does not increase, and when the number of rewrites increases, Not only the influence of the contact tracks, such as the characteristic deterioration of the recording track unerased data is also a serious problem. Therefore, in such an optical disc, it is not sufficient to simply re-record adjacent tracks to eliminate the influence of cross-erase, and it is necessary to perform highly accurate recording in accordance with or to prevent deterioration of characteristics. is there. Also in this case, similarly to the above, it is desired that an optimum laser power at the time of data recording can be set for each zone with respect to an optical disk capable of recording and reproducing at a very high density under development.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. According to a first invention, a rewritable data recording area is divided into a plurality of zones in a radial direction of a disk substrate, and A test writing area is provided near the head of each zone, and a reference laser power at the time of data recording set for each zone is pre-recorded in a predetermined area of the disk substrate. The number of revolutions is switched stepwise to a substantially constant linear velocity, and an optical disc whose rotation is controlled at a constant angular velocity in each zone is used to set the optimum laser power for each zone during data recording. A power setting method, comprising: zone information indicating one zone; and a reference laser power corresponding to the zone information. The data by the maximum recording mark and the minimum recording mark are continuously recorded over three tracks in the test writing area provided in the one zone based on the reference laser power corresponding to the zone information. After this, the maximum laser power that does not cause cross-erase is obtained from the amplitude ratio of the reproduction signals of the second track and the third track among the three tracks recorded in the test writing area, Obtain a minimum laser power that does not cause any remaining erasure from an asymmetry value due to a deviation of the amplitude center between the maximum recording mark and the minimum recording mark of the reproduction signal of the third track, and calculate the maximum laser power and the minimum laser power. Setting an intermediate value between them as an optimum laser power to said one zone. Setup is a method.

According to a second aspect of the present invention, the rewritable data recording area is divided into a plurality of zones in the radial direction of the disk substrate, and the rewritable data is written near the head of each zone or near the head of an ECC block in each zone. A rewrite number recording area for recording the number data is provided,
In addition, the laser power at the time of data recording, which is set stepwise in accordance with the rewrite frequency data for each zone, is previously recorded in a predetermined area of the disk substrate, and the number of revolutions for each zone is stepwise. A laser power setting method for setting an optimum laser power for each zone at the time of data recording using an optical disc which is switched at a substantially constant linear velocity and which is rotationally controlled at a constant angular velocity in each zone. The zone information indicating one zone, the number of times of rewriting recorded in the number of rewriting times recording area in the one zone corresponding to the zone information, and the optimum number of times for the one zone corresponding to the number of times of rewriting. And obtaining a proper laser power from the optical disc.

According to a third aspect of the present invention, the rewritable data recording area is divided into a plurality of zones in a radial direction of the disk substrate, and a test writing area is provided near the head of each zone. A rewrite frequency recording area for recording the rewrite frequency data is provided near the head of the ECC block or near the head of the ECC block in each zone. Further, the reference laser power for data recording set for each zone and A correction data table for correcting the reference laser power in accordance with the result of the test writing to the data recorded in the test writing area when the number-of-times data has reached a predetermined number is recorded in a predetermined area of the disk substrate in advance. In addition, the rotation speed is switched stepwise to a substantially constant linear velocity in each zone, and further, the angular velocity in each zone is changed. This is a laser power setting method for setting an optimum laser power for each zone at the time of data recording using an optical disc that is controlled to rotate constantly, and the zone information indicating one zone and the zone information corresponding to this zone information are provided. The optical disc includes a reference laser power, a rewrite frequency data recorded in a rewrite frequency recording area in the one zone, and a correction data table for correcting the reference laser power when the rewrite frequency data reaches a predetermined number. When the rewrite frequency data reaches a predetermined number, data is trial-written in the trial write area provided in the one zone based on the reference laser power, and thereafter, the recorded trial write is performed. An error from the proper recording state is detected from the reproduction signal that reproduces the area, and the error A laser power setting method and setting as the optimum laser power to the correction data table by correcting the reference laser power by the one zone.

According to a fourth aspect of the present invention, the rewritable data recording area is divided into a plurality of zones in the radial direction of the disk substrate, and a test writing area is provided near the head of each zone. The reference laser power at the time of data recording set for each zone is previously recorded in a predetermined area of the disk substrate, and the rotation speed is switched stepwise to a substantially constant linear speed for each zone. An optical disc device configured to use an optical disc whose rotation is controlled at a constant angular velocity in a zone and to set an optimum laser power for each zone at the time of data recording, wherein zone information indicating one zone, Means for acquiring a reference laser power corresponding to information from the optical disc, and the test laser provided in the one zone. Means for continuously recording data by a maximum recording mark and a minimum recording mark over three tracks in the recording area based on the reference laser power corresponding to the zone information; and three recorded tracks in the test writing area. Among them, the maximum laser power that does not cause cross-erase is obtained from the amplitude ratio of each reproduction signal of the second track and the third track, and the maximum recording mark and the minimum of the reproduction signal of the recorded third track are obtained. Obtain the minimum laser power that does not cause unerased from the asymmetry value due to the deviation of the amplitude center from the recording mark, and set the intermediate value between the maximum laser power and the minimum laser power to the optimum laser power for the one zone. Means for setting as an optical disk.

According to a fifth aspect of the present invention, the rewritable data recording area is divided into a plurality of zones in the radial direction of the disk substrate, and the rewritable data is written near the head of each zone or near the head of an ECC block in each zone. A rewrite number recording area for recording the number data is provided,
In addition, the laser power at the time of data recording, which is set stepwise in accordance with the rewrite frequency data for each zone, is previously recorded in a predetermined area of the disk substrate, and the number of revolutions for each zone is stepwise. An optical disc device configured to use an optical disc that is switched to a substantially constant linear velocity and that is controlled to rotate at a constant angular velocity in each zone, and that an optimum laser power is set for each zone during data recording. The zone information indicating one zone, the number of times of rewriting recorded in the number of rewriting times recording area in the one zone corresponding to the zone information, and the optimum number of times for the one zone corresponding to the number of times of rewriting. An optical disk device, comprising: means for obtaining a high laser power from the optical disk. .

According to a sixth aspect of the present invention, the rewritable data recording area is divided into a plurality of zones in the radial direction of the disk substrate, and a test writing area is provided near the head of each zone. A rewrite frequency recording area for recording the rewrite frequency data is provided near the head of the ECC block or near the head of the ECC block in each zone. Further, the reference laser power for data recording set for each zone and A correction data table for correcting the reference laser power in accordance with the result of the test writing to the data recorded in the test writing area when the number-of-times data has reached a predetermined number is recorded in a predetermined area of the disk substrate in advance. In addition, the rotation speed is switched stepwise to a substantially constant linear velocity in each zone, and further, the angular velocity in each zone is changed. An optical disc device configured to use an optical disc whose rotation is constantly controlled and to set an optimum laser power for each zone during data recording, wherein zone information indicating one zone and zone information corresponding to this zone information are provided. The optical disc includes a reference laser power, a rewrite frequency data recorded in a rewrite frequency recording area in the one zone, and a correction data table for correcting the reference laser power when the rewrite frequency data reaches a predetermined number. Means for obtaining data from the memory, the means for trial-writing data on the basis of the reference laser power in the trial writing area provided in the one zone when the number of times of rewriting data reaches a predetermined number of times, An error from a proper recording state is detected from a reproduction signal obtained by reproducing the writing area, and the detection result is obtained. An optical disk apparatus characterized by comprising a means for setting the corresponding said corrected by the data table by correcting the reference laser power as the optimum laser power to said one zone.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a laser power setting method and an optical disk apparatus according to the present invention will be described below in detail in the order of items with reference to FIGS.

Before describing the laser power setting method and the optical disk apparatus according to the present invention, the rewritable optical disk applied here will be described first.

<Optical Disk> FIG. 1 is a perspective view for explaining a rewritable optical disk applied to the laser power setting method and the optical disk apparatus according to the present invention, and FIG. 2 is a configuration of a zone in the optical disk shown in FIG. FIG. 3 is a diagram schematically showing the wobble cycle of the wobbled groove in the optical disc shown in FIGS. 1 and 2 by dividing the wobble cycle into an inner circumference side and an outer circumference side.

As shown in FIG. 1, an optical disk 1 applied to an optical disk apparatus according to the present invention is formed by forming a transparent disk substrate 2 having a thickness of, for example, about 0.6 mm in a disk shape. A groove 3 wobbled in a sine curve or a cosine curve shape on one surface side of the groove 3 and a land 4 located between adjacent grooves 3
Are formed spirally or concentrically from the innermost circumference to the outermost circumference on the disk substrate 2 and address information (zone information) for data to be recorded on the groove 3 is formed on the land 4. Auxiliary information such as address information and track address information) and parity for correction is formed in advance as land prepits 5.

The shapes of the groove 3 and the land 4 are generally such that the groove 3 is formed in a concave shape and the land 4 is formed in a convex shape. In order for the relationship between the concavities and convexities to be reversed, one of the concave and convex shapes of the groove 3 and the land 4 may be formed in a concave shape and the other may be formed in a convex shape.

Further, as described later, a recording block unit (E) corresponding to a predetermined number of land pre-pits 5 is recorded in the data.
CC block) is allocated.

At this time, the groove 3 is a recording track for recording data. On the other hand, the land prepits 5 formed on the lands 4 are in the form of pits in which address information, correction parity and the like are auxiliary information. It is recorded in advance.

On the groove 3 and the land 4, a phase change recording layer 6 using a phase change material, a metal reflection layer 7 using Al (aluminum), Au (gold), and the like, and a protective layer 8 Are sequentially formed, and a reinforcing substrate 9 having a thickness of about 0.6 mm is attached to the protective layer 8 side by using an adhesive to form the optical disc 1 having a total thickness of 1.2 mm. .

Therefore, the optical disc 1 can rewrite (overwrite, overwrite, overwrite) data by the phase change recording layer 6 formed on the groove 3.

Then, a beam spot B is applied to one groove 3 from the other surface side of the transparent disk substrate 2 and lands 4 and 4 adjacent to both sides of the groove 3.
The returning reflected light from which the beam spot B is reflected by the metal reflective layer 7 through the disk substrate 2 and the phase-change recording layer 6 is used for the optical disk devices 20A to 20A to 1 to 3 described later.
20C (FIGS. 9, 15, and 16), a four-division photodetector 23 in an optical pickup 23 provided respectively.
d (FIGS. 9, 10, 15, and 16) is detected by the push-pull method.

Incidentally, when it is necessary to reduce the thickness of the disk substrate 2 located on the data reading side in order to further improve the recording density on the optical disk 1, though not shown, the thickness is reduced to 0. Tracks having pairs of grooves 3 and lands 4 are formed spirally or concentrically on a thick disk substrate 2 having a thickness of about 0.5 mm to 1.1 mm.
After the metal reflection layer 7 and the phase change recording layer 6 are sequentially formed on the lands 4, the thickness of the metal reflection layer 7 and the phase change
There is also a method in which a thin transparent film of about 0.2 mm is adhered with a transparent adhesive, and the optical disc 1 is formed so that the beam spot B is irradiated from the thin transparent film side.

As shown in FIG. 2, in the optical disk 1 according to the present invention, the data recording area for recording data is concentric with the center hole 2a of the disk substrate 2 along the radial direction of the optical disk 1. Is divided into multiple zones. At this time, as an example, when the diameter of the optical disc 1 is formed to be 12 cm and the data recording area is divided into N from zone 0 to zone N-1, the number of zones N is, for example, 83, and Inside is, for example, 1024
It is composed of book tracks. Further, a ROM area is provided on the innermost circumference of the optical disc 1, and in this ROM area, recording conditions such as laser power when recording data on the groove 3 are recorded in advance in a state where the recording conditions are set for each zone. Here, the recording conditions are first to third
The optical disk devices 20A to 20C of the embodiment (FIGS. 9 and 1)
5 and FIG. 16), which will be described in each embodiment.

The rotation control method for the optical disk 1 is as follows.
ZCLV (Zone Constant) in which the rotation speed of the optical disc 1 is sequentially switched stepwise from zone 0 to zone N-1 for each zone and the rotation is controlled to be substantially constant in linear velocity.
A Linear Constant Angular (ZCAV) system in which the rotation speed is constantly controlled at a constant rotation speed set for each zone by a ZCLV in each zone while a linear velocity (ZVV) method is employed.
r Velocity) method is employed.

In accordance with the above-described rotation control method for the optical disk 1, as shown in FIG. 3, the rotation speed of the optical disk 1 is sequentially switched stepwise for each zone by the ZCLV method. Is high, the rotation speed on the outer circumference side is set low, and the wavelength of the wobble of the groove 3 is shorter on the inner circumference side and longer on the outer circumference side in the same zone.

In each zone, the 1024 grooves 3 are rotated at a constant rotation speed by the ZCAV system, so that the phases of the wobbles are all formed in the same phase. Since the phenomena such as the phases of the grooves 3 being opposite to each other do not occur, the crosstalk from the adjacent track caused by the narrow interval between the grooves 3 does not occur.

Next, a description will be given of the land prepits 5 formed on the lands 4 in one appropriate zone on the optical disk 1 with reference to FIGS.

FIGS. 4A and 4B are views for explaining land prepits formed on lands in an optical disk applied to the optical disk apparatus according to the present invention. FIG. 4A schematically shows the shape of land prepits. FIG. 5B is a diagram showing a waveform of a land pre-pit signal when a land pre-pit is detected, FIG. 5 is a diagram showing a signal form in a groove synchronization frame, and FIG. FIG. 7 is a diagram for explaining the types of the formed land prepits, FIG. 7 is a diagram showing a plurality of land prepits provided corresponding to one sector, and FIG. 8A is a diagram showing one land prepit in one ECC block. FIG. 3B shows land prepit blocks of a sector, and FIG. 4B shows a land prepit block corresponding to one ECC block.

As shown in FIG. 4A, in one appropriate zone on the optical disk 1, a plurality of grooves 3 are wobbled along the disk circumferential direction with the same phase. One of three synchronization frame periods is set to, for example, three wobble periods. FIG. 4 (a)
Is wobbled on both sides, but the invention is not limited to this, and only one side of the groove 3 may be wobbled.

When scanning while tracking one groove 3 with the beam spot B, land pre-pits 5 and 5 formed on lands 4 and 4 located on both sides of one groove 3 are divided into four divided types. The land pre-pit signal detected from the reproduced signal by the push-pull method using the photodetector 23d (FIGS. 9, 10, 15, and 16) has a synchronous frame period as shown in FIG. Each time the polarity is reproduced in reverse. That is, in the detection of the land pre-pit signal by the push-pull method, for example, the land pre-pit signal from the land pre-pit 5a connected to the outer side (the peak side of the waveform of the groove 3) becomes a positive output, while the inner side ( (Valley side of groove 3)
The land pre-pit signal from the land pre-pit 5b connected to the terminal is an output of negative polarity.

Here, when scanning while tracking one groove 3 with the beam spot B, the land pre-pits 5a on the outer peripheral side with respect to one groove 3 being scanned.
Indicates the address information of the groove 3 currently being scanned, on the other hand, the land pre-pit 5b on the inner circumference side has the address for the groove 3 on the inner circumference side one track before the groove 3 currently being scanned. Since the information indicates information, if the track pitch is wide, only the land pre-pits 5a on the outer periphery need to be detected. If the track pitch is narrow, the land pre-pits 5a and 5b on both sides are detected in order to increase the detection accuracy. By detecting, even if the land pre-pits 5a on the outer peripheral side cannot be detected and the address information of the groove 3 being scanned by the beam spot B cannot be read,
By detecting the land pre-pits 5b on the inner peripheral side, the address information of the groove 3 being scanned by the beam spot B can be obtained.

As shown in FIG. 5, a synchronization signal SY and data D are recorded in one synchronization frame corresponding to one synchronization frame period of the groove 3.

The data format of the data recorded in the groove 3 is a well-known DVD (Digital
Similarly to the Versatile Disc, one sector (recording sector) is composed of 26 synchronization frames (sync frames) and one EC
A C (Error Correcting Code) block is composed of 32 sectors, twice as large as a DVD.

Returning to FIG. 4A, land prepits 5 formed on the lands 4 between the grooves 3 are provided corresponding to the wobble period and the synchronous frame period of the groove 3. More specifically, the land pre-pits 5 are provided every other as a predetermined interval with respect to one synchronization frame period of the groove 3, and each land pre-pit 5
Land pre-pits 5a formed on lands 4 and 4 located on both sides of one groove 3 are provided at predetermined positions with respect to the wobble period and the synchronization frame period.
5b, the outer peripheral side is connected to the peak side of the waveform of the groove 3 and the inner peripheral side is connected to the valley side of the waveform of the groove 3 so that the two are shifted from each other so as not to coincide with each other while maintaining a predetermined interval, and do not overlap. It is provided as follows.

That is, the land pre-pits 5a formed on the outer lands 4 for one groove 3 are provided corresponding to the odd-numbered synchronous frames, and formed on the inner lands 4. Since the land pre-pits 5b are provided corresponding to the even-numbered synchronous frames, the land pre-pits 5a and 5b do not overlap on both sides of one groove 3.

In the land pre-pit 5, as shown in FIG. 6, four types of code data are set by a combination using three bits (b2, b1, b0).
An array of 3 bits (b2, b1, b0) is set at a predetermined position of each of the wobbles synchronized with the wobble cycle in three consecutive wobbles in total.

At this time, the arrangement of the three bits (b2, b1, b0) of the land pre-pit 5 corresponds to the pre-pit synchronization signal 1
Is (1,1,1), and the pre-pit synchronization signal 2 is (1,1,1).
(1, 0), the pre-pit data is set to (1, 0, 1), and the pre-pit data = 0 is set to (1, 0, 0).

Therefore, each land pre-pit 5 is always provided with any one of the four types.
Bit b2 is set to “1” in common for the types of land prepits 5, and both bits b1 of the prepit synchronization signal 1 and prepit synchronization signal 2 are “1”.
By recognizing that the bit b0 is "1" or "0", it can be handled as 1-bit data.

Accordingly, as described above, since one sector is composed of 26 synchronization frames, every other land pre-pit 5 is provided for every synchronization frame period of the synchronization frame. Thirteen sectors are provided corresponding to one sector, and are arranged as shown in FIG.

As shown in FIG. 8A, one E
The CC block is composed of 32 sectors, and 13 land prepits 5 provided corresponding to each sector are composed of one prepit synchronization signal (1 or 2) and 12 prepit data (12 bits). ).

Further, the land pre-pit block shown in FIG. 8B combines the land pre-pits 5 provided in one sector shown in FIG. 8A for 32 sectors into one ECC block. It is made to correspond.

Here, the contents to be recorded in the land prepit for one sector are a prepit synchronization signal, a relative sector address in the block, and disk information such as an ECC block address and a zone number. At this time, since 8 bits are allocated to the disc information, the remaining 5 bits must indicate the pre-pit synchronization signal and the relative sector address. But,
To represent the address of 32 sectors in one ECC block, all 5 bits are required. Therefore, the pre-pit synchronization signal is 1 bit, the relative sector address is 4 bits, and the pre-pit synchronization signal uses two code patterns of the pre-pit synchronization signal 1 and the pre-pit synchronization signal 2 as described above. Thus, by combining the synchronization signal pattern information of the two types of pre-pit synchronization signals 1 and 2 using 1 bit and the 4-bit relative address information in the pre-pit data, combined address information of a total of 5 bits is obtained. Thus, address information for 32 sectors constituting one ECC block can be obtained from the combination address information. In other words, 1
By using part of the relative address information in the pre-pit data with the synchronizing signal pattern information based on the two types of pre-pit synchronizing signals 1 and 2 using bits, the amount of address information in the ECC block can be increased.

Further, the two pre-pit synchronization signals 1 and 2 are used as the most significant bit of the relative sector address, and in one ECC block, the pre-pit synchronization signal 1 is synchronized with the first half 16 sectors. The pre-pit synchronization signal 2 is a synchronization code of the latter 16 sectors. However, the present invention is not limited to this. For example, the pre-pit synchronization signal 1
It is also possible to assign the pre-pit synchronization signal 2 to even-numbered sectors.

According to the present invention, not limited to the example as shown in FIG. 8B, the pre-pit synchronization signal in the land pre-pits 5 also serves as address information, so that it has n pieces of synchronization signal pattern information. a pre-pit synchronization signal, the combination address data of a combination of a m-bit address bits in pre-pit data, in the conventional a place that can not be represented only 2 ^m sectors, can represent the relative address of the n × 2 ^m sectors, one Even when the number of sectors is large in one ECC block, the optical disk devices 20A to 20C (FIGS. 9, 15, and 16) of the first to third embodiments described below can perform appropriate recording and reduce the number of sectors per ECC block. It is possible to improve the error correction capability by increasing the number of optical discs, and to obtain a high-density optical disc 1 with higher accuracy.

<First Embodiment> FIG. 9 is a block diagram showing the structure of an optical disk apparatus according to a first embodiment of the present invention.
FIG. 11 schematically shows a state in which, in the optical disk device of the first embodiment according to the present invention, reflected light from the optical disk by a beam spot irradiated on the optical disk is detected by a four-division type photodetector. FIG. 12 is a schematic diagram for explaining a case where data is continuously recorded over three tracks in a test writing area in a zone in the optical disc apparatus of the first embodiment according to the present invention.
FIG. 13 is a diagram showing characteristics of the amplitude ratio of each reproduction signal and the recording laser power in the second and third tracks in the test-recorded zone in the optical disk device of the embodiment, and FIG.
In the optical disc device of the first embodiment according to the present invention,
FIG. 14 is a diagram showing a relationship between an asymmetry value and a jitter value of a reproduced signal of a third track in a test-recorded zone. FIG. 14 shows a third track in a test-recorded zone in the optical disc apparatus according to the first embodiment of the present invention. FIG. 4 is a diagram showing characteristics of an asymmetry value of a reproduction signal and a recording laser power by a track of FIG.

As shown in FIG. 9, the optical disc apparatus 20A of the first embodiment according to the present invention uses the rewritable optical disc 1 described above to record and / or record data on the groove 3 formed on the optical disc 1. It is configured to be reproducible.

The optical disk device 20 of the first embodiment described above
In A, the optical disc 1 is rotatably mounted on a turntable 22 fixed to a shaft of a spindle motor 21. Further, an optical pickup 23 is provided movably in the radial direction of the optical disk 1 so as to face the optical disk 1. The optical pickup 23 has a groove 3 (FIG. 1) and a land 4 (FIG. 1) in which a laser beam from a semiconductor laser 23 a installed therein is narrowed down by an objective lens 23 c via a beam splitter 23 b to form a beam spot B on the optical disc 1. 1) A beam spot B irradiated on the optical disc 1 while being reflected on the optical disc 1 is returned to the metal reflection layer 7 (FIG. 1) of the optical disc 1 and the returned reflected light is divided into four by the objective lens 23c and the beam splitter 23b. It is detected by the photo detector 23d of the type.

Here, as shown in FIG.
The split photodetector 23d is formed in a substantially rectangular shape, and the entire light receiving area is divided into four equal parts by a straight line along the radial direction of the optical disc 1 and a straight line along the groove direction (track direction). However, when the return beam spot B formed on the photodetector 23d is photoelectrically converted, a set of two light receiving areas A and B on the outer circumference of the optical disc 1 and two The light receiving area C and the light receiving area D are divided into two sets, and are divided into two with respect to a straight line along the recording track direction of the optical disc 1.

Returning to FIG. 9, when data is recorded on the phase change recording layer 6 (FIG. 1) formed on the groove 3 of the optical disc 1, data to be recorded is inputted to the pulse generating circuit 24, and The recording pulse generated by the pulse generating circuit 24 is input to a laser driving circuit 25, and a recording signal corresponding to the recording pulse is generated by the laser driving circuit 25. The laser driving circuit 25 increases the laser power from the semiconductor laser 23a. The recording beam spot B is irradiated on the phase change recording layer 6 of the optical disc 1.

On the other hand, when reproducing the data recorded on the phase change recording layer 6 of the optical disc 1, the reproducing beam spot B having a weak laser power output from the semiconductor laser 23a by the laser drive circuit 24 is used. The change recording layer 6 is irradiated.

Here, Z between the zones on the optical disc 1
In the case where the CLV system is adopted and the data is recorded by employing the ZCAV system in each zone, it is necessary to set the optimum laser power at the time of data recording to the semiconductor laser 23a for each zone on the optical disc 1. This will be described below.

First, the optical disc 1 is rotated, and the ROM area (FIG. 2) provided on the innermost circumference of the optical disc 1 is read by the optical pickup 23. At this time, the optical pickup 23
Are input to a reproduction signal detection circuit 26, a wobble detection circuit 27, and a land pre-pit detection circuit 28, respectively.

At this time, the optical disc 1 applied to the first embodiment has a reference laser power for data recording set for each of zone 0 to zone N-1 and an amplitude ratio / recording laser for test recording described later. The power characteristic and the asymmetry / recording laser power characteristic have the R
It is recorded in advance in the OM area (FIG. 2). When the ROM area is reproduced, a reproduction signal from the photodetector 23d in the optical pickup 23 is input to the reproduction signal detection circuit 26.

In the reproduction signal detection circuit 26 described above, FIG.
The light-receiving outputs of the light-receiving regions A to D are all added by the four-division photodetector 23d shown in FIG.
+ B + C + D) signal. (A +
The (B + C + D) signal is a signal obtained by reproducing data recorded on the optical disc 1 and is output from the output terminal OUT during normal data reproduction. The reference laser power at the time of data recording and the amplitude ratio / recording laser power characteristic and the asymmetry / recording laser power characteristic at the time of test recording, which are set for each of zone 0 to zone N-1, are reproduced. Ra
nd Access Memory) 29.

Next, in the first embodiment, it is necessary to obtain the zone information of each zone in order to set the optimum laser power at the time of data recording for each zone of the optical disc 1, so that the optical pickup 23 is set to the zone information. Is moved to one zone where it is desired to obtain, and the wobble detection circuit 27 and the land pre-pit detection circuit 28 are operated to obtain zone information from one zone.

The wobble detection circuit 27 detects the wobble of the groove 3 formed on the optical disk 1, and calculates the sum of the light receiving areas A and B of the photodetector 23d from the sum of the light receiving areas C and D. To obtain a radial push-pull signal {(A + B)-(C + D)},
The {(A + B)-(C + D)} signal is removed through a band-pass filter (not shown) to remove the influence of the land pre-pit 5 to obtain a wobble signal, and the wobble signal is output to the land pre-pit detection circuit 28. I have.

The above-mentioned land pre-pit detection circuit 28
Detects the land pre-pits 5 on the lands 4 formed on the optical disk 1. At this time, the land pre-pits 5 have zone address information, block address information, etc. as described above. In the land pre-pit detection circuit 28, a radial push-pull signal {(A + B)-(C + D)} is obtained by subtracting the added value of the light receiving regions C and D from the added value of the light receiving regions A and B of the photo detector 23d.
And the {(A + B)-(C + D)} signal is sliced with a predetermined value larger than the amplitude value of the wobble signal to obtain a land pre-pit signal. Then, of the land pre-pit signals obtained here, zone information (zone address information) indicating one zone to be recorded is stored in RA.
M29 and the laser power setting circuit 30.

In the laser power setting circuit 30, the zone information from the land pre-pit detection circuit 28 and the reference laser power at the time of data recording of the zone corresponding to the zone information from the RAM 29 are obtained, and one zone to be recorded is obtained. Test recording conditions (test recording strategy)
And the test recording conditions are input to the pulse generation circuit 24 and the laser drive circuit 25. At this time, the test recording conditions are such that the pulse peak value, the pulse width of the shortest recording mark, and the pulse width of the longest recording mark are determined based on the reference laser power.

Here, a test writing area is set near each head of zone 0 to zone N-1 on the optical disc 1, and after the test recording condition for one zone to be recorded is set, Driving the semiconductor laser 23a in accordance with the test recording conditions from the laser drive circuit 25,
As shown in FIG. 11, continuous recording is performed according to test recording conditions over three tracks in a test writing area of one zone to be recorded. At this time, the three tracks record the shortest recording mark and the longest recording mark separately in the first half and the second half of each track, but the beam spot B from the optical pickup 23 is tracked along the center of the groove 3. The adjacent lands 4 and 4 are also irradiated, and if the cross-erase occurs due to the temperature diffusion by the beam spot B, the recording mark of the first track recorded by the beam spot B records the second track. Partially erased at the beam spot B, and the recording mark of the second track is partially erased at the beam spot B recording the third track, and the third track is shortest without cross-erase. A recording mark and a longest recording mark are recorded.

Then, after test recording is continuously performed over three tracks in a test writing area in one zone to be recorded, the three tracks are reproduced by the optical pickup 23. Here, the reproduction signal from the optical pickup 23 is input to the reproduction signal detection circuit 26 described above.

First, the reproduction signal detection circuit 26 uses the obtained first to third tracks (A + B + C +
D) Of signals, (A) of each of the second and third tracks
+ B + C + D) signal to the amplitude detection circuit 31.

In the amplitude detection circuit 31, the (A + B + C + D) signal of each of the second and third tracks is passed through a filter (not shown) to obtain (A + B + C + D).
The amplitude waveform (envelope) of the signal is taken out, and the amplitude value of each of the second and third tracks is measured. At this time, since a part of the recording mark of the second track has been erased,
The amplitude value of the second track is smaller than the amplitude value of the third track without cross erase.

Therefore, as a method of obtaining the maximum recording laser power Pmax in order to eliminate the influence of the cross erase, one of the shortest recording mark and the longest recording mark recorded on each of the second and third tracks is used. Is measured, the amplitude ratio α based on the two amplitude values is calculated, and this amplitude ratio α is input to the laser power correction circuit 33.

More specifically, as shown in FIG. 12A, assuming that the amplitude value of the second track is w2 and the amplitude value of the third track is w3, the obtained amplitude ratio α is α = w3 / w
2. On the other hand, the laser power correction circuit 33 has R
The amplitude ratio / recording laser power characteristic at the time of test recording as shown in FIG.
According to the amplitude ratio / recording laser power characteristics, when the amplitude ratio α is 1.0 or less, there is no cross-erase, and when the amplitude ratio α = 1, the maximum recording laser power Pmax is equal to the cross-erase. Is the maximum value that does not occur. On the other hand, when the amplitude ratio α becomes larger than 1.0, there is a state where cross erase occurs.

Here, the recording laser power Pact is:
The recording laser power Ps is an actual value recorded at the time of test recording, and the recording laser power Ps is a value corresponding to the amplitude ratio α at the time of measurement plotted on the amplitude ratio / recording laser power characteristic.
Recording laser power Pact> Recording laser power Ps
It is.

Since the amplitude value w3 of the third track is larger than the amplitude value w2 of the second track, the measured amplitude ratio α is larger than 1. Therefore, the laser power correction circuit 33 calculates the recording laser power Ps and the maximum recording laser power Pmax corresponding to the amplitude ratio α.
And a difference value is obtained as a correction amount γ.

Thereafter, as shown in FIG. 12B, the actual recording laser power Pact recorded during the test recording was obtained.
Is the actual maximum recording laser power Pmax to be obtained without cross-erase.
obtained as act. Thus, from the correlation between the amplitude ratio α and the recording laser power, the two amplitude values w2 and w3
Are substantially equal, and a maximum recording laser power Pmax act that does not cause cross erase is obtained.

Further, the reproduction signal detection circuit 26 calculates (A + B + C +) based on each of the first to third tracks obtained here.
D) Of the signals, (A + B + C +) of the third track
D) The signal is sent to the asymmetry detection circuit 32.

In the above asymmetry detection circuit 32,
The asymmetry value (=) under the test recording condition is obtained from the waveform of the input reproduction signal of the third track.
The deviation of the amplitude center between the shortest recording mark and the longest recording mark) is obtained, and the asymmetry value is used as the laser power correction circuit
3 At this time, as shown in FIG. 13, the asymmetry value has a relationship with the jitter value. If the jitter value is equal to or less than a predetermined value, the recording characteristics are good. The minimum value of Ami
n.

On the other hand, the laser power correction circuit 33 includes:
Asymmetry values and recording laser power characteristics at the time of test recording as shown in FIG. Further, the minimum recording laser power Pmin with no remaining erase corresponds to the minimum asymmetry value Amin.

Here, the recording laser power Pact is:
As described above, the recording laser power Pa is an actual value recorded at the time of test recording, and the recording laser power Pa is a value corresponding to the asymmetry value at the time of measurement plotted on the asymmetry value / recording laser power characteristic. Pact> recording laser power Pa.

Then, a difference between the recording laser power Pa and the minimum recording laser power Pmin corresponding to the asymmetry value measured from the third track is calculated, and the difference value is obtained as a correction amount δ. Thereafter, as shown in FIG. 14B, a value obtained by subtracting the correction amount δ from the actual recording laser power Pact recorded during the test recording is the actual minimum recording laser power Pm to be obtained without jitter.
Obtained as in act. As described above, the minimum recording laser power Pmin act that eliminates the unerased residue is obtained from the correlation between the asymmetry value and the recording laser power.

After that, the laser power correction circuit 33
Actual maximum recording laser power P without cross erase
Calculate an intermediate value between max act and the actual minimum recording laser power Pmin act that has no remaining erase and has no jitter, and sets the intermediate value recording laser power as the optimum recording laser power for data recording. By notifying this to the laser power setting circuit 30, the data recording condition (data recording strategy) is set in the laser power setting circuit 30 based on the optimum recording laser power at the time of data recording. By supplying the pulse to the pulse generation circuit 24 and the laser drive circuit 25, the semiconductor laser 23a is driven according to the data, and the data is recorded in one zone to be recorded.

In the above description, one zone in which data is desired to be recorded has been described. However, before data recording, the optimum laser power at the time of data recording in all zones 0 to N-1 is determined by the above method. The optimum laser power at the time of data recording corresponding to each zone is temporarily stored in the RAM 29, and the optimum laser power at the time of data recording corresponding to one zone to be recorded from the RAM 29 at the time of data recording is obtained. Laser power may be called.

In the first embodiment described above, the reference laser power at the time of data recording for each of zone 0 to zone N-1 is recorded in the ROM area of the optical disc 1 in advance. A method of pre-recording the reference laser power at the time of data recording using the land pre-pits 5 in the zone is also conceivable. In this case, the land pre-pit detection circuit 28 controls the reference laser power at data recording corresponding to each zone. May be detected and supplied directly to the laser power setting circuit 30.

As described above, in the first embodiment, the rotation speed is switched to a substantially constant linear velocity for each zone, and the angular velocity is controlled to be constant in each zone. By setting the optimal laser power when recording data in one zone in accordance with the result of the test writing to the data recorded in the test writing area, for each zone you want to record while reducing the effects of cross-erase and remaining unerased data Data can be rewritten satisfactorily, and
Data can be recorded and reproduced at an ultra high density.

<Second Embodiment> FIG. 15 shows a second embodiment according to the present invention.
FIG. 2 is a block diagram illustrating a configuration of the optical disc device of the embodiment.

The optical disk device 20B of the second embodiment shown in FIG. 15 has the same configuration as that of the optical disk device 20A of the first embodiment described above except for a part thereof. The same components as those described above are denoted by the same reference numerals, and the components described above are appropriately described as needed. Components different from the first embodiment are denoted by new reference numerals. explain.

In the second embodiment, as in the first embodiment, the ZCLV system is used between the zones on the rewritable optical disk 1 and the ZCAV system is used to record data in each zone. In this case, it is necessary to set an optimum laser power at the time of data recording for each zone on the optical disc 1 with respect to the semiconductor laser 23a. In the second embodiment, the recording characteristics change depending on the number of times of rewriting to the optical disc 1. Therefore, the optimum laser power at the time of data recording is set for each zone according to the number of times of rewriting. This will be described below.

At this time, the optical disc 1 applied to the second embodiment has a rewrite frequency recording area for recording the rewrite frequency near the head of each zone or near the head of an ECC block in each zone. I have. In the rewrite frequency recording area, information indicating that the initial is performed is recorded in advance at the time of initializing, or there is no data.

The optimum laser power at the time of data recording, which is set stepwise according to the number of rewrites for each of zone 0 to zone N-1 on the optical disc 1, is set at the innermost circumference.
It is recorded in advance in the OM area (FIG. 2). For example, the number of times of rewriting is 1000 times, 3000 times for one zone.
, 5000 times,..., And the optimum laser power at the time of data recording is set stepwise according to the number of times of rewriting.

First, in the reproduction signal detecting circuit 26, when the ROM area on the optical disk 1 is reproduced, when the data is recorded step by step according to the number of rewrites for each of zone 0 to zone N-1 on the optical disk 1 Since the optimum laser power is reproduced, these are temporarily stored in the RAM 29.

Next, in the second embodiment, it is necessary to obtain zone information of each zone in order to set the optimum laser power at the time of data recording according to the number of rewrites for each zone of the optical disk 1. The pickup 23 is moved to one zone for which zone information is desired to be obtained, and the wobble detection circuit 27 and the land pre-pit detection circuit 28 are operated to obtain zone information from one zone. It is supplied to the setting circuit 30.

The reproduction signal detecting circuit 26 reproduces a rewrite frequency recording area provided near the head of one zone to be recorded or near the head of an ECC block in one zone to be recorded, and reads the rewrite frequency recording area. 41
Send to The rewriting number reading circuit 41 reads rewriting number data recorded in the rewriting number recording area, and sends the rewriting number data to the RAM 29 and the laser power setting circuit 30.

Thereafter, the laser power setting circuit 30 sets the data recording condition (based on the optimum laser power at the time of data recording read from the RAM corresponding to the zone information of one zone to be recorded and the rewrite frequency data). A data recording strategy is set, and the data recording conditions are supplied to the pulse generating circuit 24 and the laser driving circuit 25, so that the semiconductor laser 23a is driven according to the data, and the data is recorded in one zone to be recorded. I have. At the time of data recording, the above-mentioned rewrite count recording area is updated and recorded with rewrite count data obtained by adding 1 to the count.

As described above, in the second embodiment, the rotation speed is switched to a substantially constant linear velocity for each zone, and the angular velocity is controlled to be constant within each zone. By setting the optimum laser power for one zone at the time of data recording according to the number of times of rewriting, data can be satisfactorily rewritten for each zone to be recorded, and data is recorded and reproduced at an ultra high density be able to.

<Third Embodiment> FIG. 16 shows a third embodiment according to the present invention.
FIG. 2 is a block diagram illustrating a configuration of the optical disc device of the embodiment.

The optical disk device 20C of the third embodiment shown in FIG. 16 has the same configuration as that of the optical disk device 20A of the first embodiment described above, except for a part thereof. The same components as those described above are denoted by the same reference numerals, and the components described above are appropriately described as needed. Components different from the first embodiment are denoted by new reference numerals. explain.

In the third embodiment, as in the first embodiment, the ZCLV system is used between the zones on the rewritable optical disk 1 and the ZCAV system is used to record data in each zone. In this case, it is necessary to set an optimum laser power at the time of data recording for each zone on the optical disc 1 with respect to the semiconductor laser 23a. Therefore, when the predetermined number of rewrites is reached, test writing of data is performed based on the reference laser power in the test writing area in one zone to be recorded, and the reference laser power is set in accordance with the reproduction result of the test written data. By making corrections using the correction data table,
This is for setting an optimum laser power to one zone at the time of data recording, which will be described below.

At this time, the optical disc 1 applied to the third embodiment has a rewrite frequency recording area for recording the rewrite frequency near the head of each zone or near the head of an ECC block in each zone. I have. In the rewrite frequency recording area, information indicating that the initial is performed is recorded in advance at the time of initializing, or there is no data. A test writing area is provided near the head position of each zone on the optical disc 1.

Further, the optical disc 1 has a reference laser power for data recording set for each of zone 0 to zone N-1 and a test for the data recorded in the test writing area when the number of rewriting data reaches a predetermined number. A correction data table for correcting the reference laser power at the time of data recording according to the writing result is recorded in advance in the ROM area (FIG. 2) provided at the innermost circumference. At this time, it is assumed that the correction data table stores a plurality of correction data corresponding to the test writing result.

First, in the reproduction signal detecting circuit 26, when reproducing the ROM area on the optical disk 1, the reference laser power for data recording set for each of zone 0 to zone N-1 on the optical disk 1 and a predetermined rewriting When the number of times is reached, a correction data table for correcting the reference laser power at the time of data recording is reproduced.
It is temporarily stored in M29.

Next, in the third embodiment as well, it is necessary to obtain zone information of each zone in order to set the optimum laser power for data recording according to the number of rewrites for each zone of the optical disk 1. The pickup 23 is moved to one zone for which zone information is desired to be obtained, and the wobble detection circuit 27 and the land pre-pit detection circuit 28 are operated to obtain zone information from one zone. It is input to the setting circuit 30.

The reproduction signal detection circuit 26 reproduces a rewrite number recording area provided near the head of one zone to be recorded or near the head of an ECC block in one zone to be recorded, and reads this area by a rewrite number read circuit. 51
Send to The rewriting number reading circuit 51 reads the rewriting number data recorded in the rewriting number recording area, and sends the rewriting number data to the RAM 29, the laser power setting circuit 30, and the laser power correction circuit 53.

Thereafter, the laser power setting circuit 30 determines whether or not the rewrite frequency data has reached a predetermined number based on the zone information of one zone to be recorded and the rewrite frequency data in the one zone. If the number of times of rewriting has not reached the predetermined number, the reference laser power at the time of data recording corresponding to one zone read from the RAM 29 is set as the optimum laser power, and this optimum laser power is pulsed. By supplying the data to the circuit 24 and the laser driving circuit 25, data is recorded on a track in one zone where data is to be recorded.

On the other hand, when the number of times of rewriting reaches a predetermined number, data is trial-written based on the reference laser power in a trial writing area in one zone, and thereafter, the trial-written data is detected by a reproduction signal detection. The signal is reproduced by the unit 26 and a reproduced signal is sent to the recording state detection circuit 52.

The above-mentioned recording state detecting circuit 52 detects an error from the proper recording condition from the reproduction signal waveform of the test-written data, and sends this detection result to the laser power correction circuit 53. At this time, the operation of detecting an error from the proper recording condition from the reproduction signal waveform of the test-written data is performed as follows.
For example, an asymmetry value or the like due to a shift in the amplitude center between the shortest recording mark and the longest recording mark as described in the first embodiment may be detected.

Next, the above-described laser power correction circuit 5
3, the RA from the detection result from the recording state detection circuit 52
The optimum correction data is selected from the correction data table sent from M29, the correction power value is sent to the laser power setting circuit 30, and the laser power setting circuit 30 sets a reference for data recording corresponding to one zone to be recorded. The laser power is corrected in consideration of the correction power value,
The optimum laser power for data recording is obtained. Then, by supplying the corrected optimal laser power to the pulse generation circuit 24 and the laser drive circuit 25, the semiconductor laser 23a is driven according to the data, and the data is recorded in one zone to be recorded. At the time of data recording, the above-mentioned rewrite count recording area is updated and recorded with rewrite count data obtained by adding 1 to the count.

When performing trial writing, for example, ECC
There is also a method for each block, but this method causes a large loss in the user data area and lowers the recording capacity,
In continuous recording of video data and the like, it is more effective to perform test writing for each zone.

As described above, in the third embodiment as well, the rotation speed is switched to a substantially constant linear velocity for each zone, and the angular velocity is controlled to be constant within each zone. By setting the optimum laser power to one zone at the time of data recording according to the result of trial writing to the data recorded in the trial writing area when the number of times of rewriting reaches the predetermined number of times, for each zone to be recorded Data can be satisfactorily rewritten, and data can be recorded and reproduced at an ultra high density.

[0108]

In the laser power setting method and the optical disk apparatus according to the present invention described in detail above, according to the first and fourth aspects, in particular, zone information indicating one zone and a reference corresponding to the zone information are provided. The laser power is obtained from the optical disk, and the data by the maximum recording mark and the minimum recording mark are continuously recorded over three tracks in the test writing area provided in one zone based on the reference laser power corresponding to the zone information. Thereafter, the maximum laser power that does not cause cross-erase is obtained from the amplitude ratio of the reproduction signals of the second track and the third track among the three tracks recorded in the test writing area, and the recorded laser is obtained. Erase from the asymmetry value due to the deviation of the amplitude center between the maximum recording mark and the minimum recording mark of the reproduction signal of the third track Obtain the minimum laser power that does not produce a residue, and set the intermediate value between the maximum laser power and the minimum laser power as the optimum laser power for one zone, so the rotation speed for each zone is approximately linear speed On an optical disc that is switched to a constant and controlled to have a constant angular velocity in each zone, data can be satisfactorily rewritten for each zone to be recorded while reducing the effects of cross-erase and unerased data. Recording and reproduction can be performed at a very high density.

According to the second and fifth aspects, in particular, zone information indicating one zone, rewrite frequency data recorded in a rewrite frequency recording area in one zone corresponding to this zone information, Since the optimum laser power for one zone corresponding to the rewrite frequency data is obtained from the optical disc, the rotation speed is switched to a substantially constant linear velocity for each zone, and the angular velocity is controlled to be constant within each zone. Data can be satisfactorily rewritten for each zone to be recorded on the optical disc
In addition, data can be recorded and reproduced at a very high density.

According to the third and sixth aspects, in particular, the zone information indicating one zone, the reference laser power corresponding to this zone information, and the number of rewrites recorded in one zone are recorded. Obtain the rewrite frequency data and a correction data table for correcting the reference laser power when the rewrite frequency data reaches a predetermined number from the optical disc, and provide them in one zone when the rewrite frequency data reaches the predetermined number. Writes data based on the reference laser power to the trial write area, and then detects an error from the reproduction signal from the recorded trial write area from the reproduced signal, and corrects the error according to this detection result. Since the reference laser power is corrected by the data table and set as the optimal laser power for one zone, The number of revolutions is switched to a substantially constant linear velocity in each zone, and the data can be satisfactorily rewritten for each zone to be recorded on an optical disc whose angular velocity is controlled to be constant in each zone. Recording and reproduction can be performed at high density.

[Brief description of the drawings]

FIG. 1 is a perspective view for explaining a rewritable optical disk applied to a laser power setting method and an optical disk device according to the present invention.

FIG. 2 is a plan view showing a configuration of a zone in the optical disc shown in FIG.

FIG. 3 is a diagram schematically showing a wobble cycle of a wobbled groove divided into an inner peripheral side and an outer peripheral side in the optical disc shown in FIGS. 1 and 2;

FIG. 4 is a diagram for explaining land pre-pits formed on lands in an optical disc applied to the optical disc apparatus according to the present invention, and FIG. 4 (a) schematically shows the shape of land pre-pits; (B) is a diagram showing a waveform of a land pre-pit signal when a land pre-pit is detected.

FIG. 5 is a diagram showing a signal form in a groove synchronization frame.

FIG. 6 is a diagram for explaining types of land prepits formed on lands.

FIG. 7 is a diagram showing a plurality of land prepits provided corresponding to one sector.

FIG. 8A is a diagram showing land pre-pit blocks of one sector in one ECC block, and FIG. 8B is a diagram showing land pre-pit blocks corresponding to one ECC block.

FIG. 9 is a block diagram showing a configuration of the optical disc device of the first embodiment according to the present invention.

FIG. 10 is a diagram schematically showing a state in which, in the optical disk device according to the first embodiment of the present invention, light reflected from the optical disk by a beam spot irradiated on the optical disk is detected by a four-division type photodetector. is there.

FIG. 11 is a schematic diagram for explaining a case where data is continuously recorded over three tracks in a test writing area in a zone in the optical disc device of the first embodiment according to the present invention.

FIG. 12 is a diagram showing characteristics of the amplitude ratio of each reproduction signal and the recording laser power on the second and third tracks in the test-recorded zone in the optical disc device of the first embodiment according to the present invention. .

FIG. 13 is a diagram showing a relationship between an asymmetry value and a jitter value of a reproduction signal from a third track in a test-recorded zone in the optical disc device according to the first embodiment of the present invention.

FIG. 14 is a diagram illustrating characteristics of an asymmetry value of a reproduced signal and a recording laser power of a third track in a test-recorded zone in the optical disc device according to the first embodiment of the present invention.

FIG. 15 is a block diagram showing a configuration of an optical disc device of a second embodiment according to the present invention.

FIG. 16 is a block diagram showing a configuration of an optical disc device of a third embodiment according to the present invention.

FIG. 17 is a diagram for explaining an example of a conventional improvement plan.

FIG. 18 is a diagram for explaining another example of a conventional improvement plan.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk, 2 ... Disk board, 3 ... Groove, 4
... land, 5 ... land pre-pit, 6 ... phase change recording layer,
20A to 20C... Optical disk devices of first to third embodiments;
21: spindle motor, 22: turntable, 23
... Optical pickup, 23a ... Semiconductor laser, 23d ... Photo detector, 24 ... Pulse generation circuit, 25 ... Laser drive circuit, 26 ... Reproduction signal detection circuit, 27 ... Wobble detection circuit, 28 ... Land pre-pit detection circuit, 29 ... R
AM, 30: laser power setting circuit, 31: amplitude detection circuit, 32: asymmetry detection circuit, 33: laser power correction circuit, 41: rewrite count reading circuit, 51 ...
Circuit for reading the number of rewrites, 52: Recording state detection circuit, 5
3: laser power correction circuit, B: beam spot.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D090 AA01 BB04 CC01 DD03 EE02 GG27 JJ12 KK03 5D119 AA23 BA01 BB03 DA01 HA19 HA20 HA45

Claims (6)

[Claims] 1. A rewritable data recording area is divided into a plurality of zones in a radial direction of a disk substrate, and a test writing area is provided near a head of each zone.
In addition, the reference laser power at the time of data recording set for each zone is previously recorded in a predetermined area of the disk substrate, and the number of revolutions is switched stepwise to a substantially constant linear velocity for each zone, Furthermore, a laser power setting method for setting an optimum laser power for each zone at the time of data recording using an optical disc that is controlled to rotate at a constant angular velocity in each zone, comprising: zone information indicating one zone; Acquiring a reference laser power corresponding to the zone information from the optical disc, and recording a maximum recording mark and a minimum recording in the test writing area provided in the one zone based on the reference laser power corresponding to the zone information. The data by the mark is recorded continuously over three tracks, and thereafter, the recording in the test writing area is performed. The maximum laser power that does not cause cross-erase is obtained from the amplitude ratio of the reproduction signals of the second track and the third track among the already recorded three tracks, and the maximum recording of the reproduction signal of the recorded third track is performed. From the asymmetry value due to the deviation of the amplitude center between the mark and the minimum recording mark, obtain the minimum laser power that does not cause erasure, and set the intermediate value between the maximum laser power and the minimum laser power to the one zone. A laser power setting method characterized by setting the optimum laser power. 2. A rewritable data recording area is divided into a plurality of zones in a radial direction of a disk substrate, and rewrite frequency data is recorded near a head of each zone or near a head of an ECC block in each zone. And the laser power at the time of data recording set stepwise in accordance with the rewrite frequency data for each zone is previously recorded in a predetermined area of the disk substrate. At the same time, the number of revolutions is switched stepwise to a substantially constant linear velocity in each zone, and furthermore, an optical disc whose rotation is controlled to a constant angular velocity in each zone is used. A laser power setting method for setting, comprising: zone information indicating one zone; and the zone information. The rewriting frequency data recorded in the rewriting frequency recording area in the corresponding one zone and the optimum laser power for the one zone corresponding to the rewriting frequency data are obtained from the optical disc. Laser power setting method. 3. A rewritable data recording area is divided into a plurality of zones in a radial direction of a disk substrate, a test writing area is provided near a head of each zone, and a test writing area is provided near a head of each zone or each zone. A rewrite frequency recording area for recording rewrite frequency data is provided in the vicinity of the head of the ECC block within the zone. Further, the reference laser power for data recording set for each zone and the rewrite frequency data are set to a predetermined number of times. And a correction data table for correcting the reference laser power in accordance with the result of the test writing to the data recorded in the test writing area when the test writing area is reached. The number of revolutions is switched stepwise to a substantially constant linear velocity in each zone, and furthermore, the rotation is controlled to a constant angular velocity in each zone. A laser power setting method for setting an optimum laser power for each zone at the time of data recording using an optical disc, comprising: zone information indicating one zone; a reference laser power corresponding to the zone information; Obtaining, from the optical disc, rewriting frequency data recorded in a rewriting frequency recording area in one zone and a correction data table for correcting the reference laser power when the rewriting frequency data reaches a predetermined number. When the number-of-times data reaches a predetermined number, a test signal is written in the test writing area provided in the one zone based on the reference laser power, and thereafter, a reproduction signal obtained by reproducing the recorded test writing area. An error from the proper recording state is detected from the A laser power setting method, wherein the reference laser power is corrected by a bull and the laser power is set as an optimum laser power for the one zone. 4. A rewritable data recording area is divided into a plurality of zones in a radial direction of a disk substrate, and a test writing area is provided near a head of each zone.
In addition, the reference laser power at the time of data recording set for each zone is previously recorded in a predetermined area of the disk substrate, and the number of revolutions is switched stepwise to a substantially constant linear velocity for each zone, Furthermore, an optical disk device configured to use an optical disk that is controlled to rotate at a constant angular velocity in each zone and to set an optimal laser power for each zone during data recording, wherein zone information indicating one zone and Means for acquiring a reference laser power corresponding to the zone information from the optical disc; and a maximum recording mark based on the reference laser power corresponding to the zone information in the test writing area provided in the one zone. Means for continuously recording data by a minimum recording mark over three tracks; 2 Of recorded three tracks of the inner
The maximum laser power that does not cause cross-erase is obtained from the amplitude ratio of the reproduction signals of the third track and the third track, and the maximum recording mark and the minimum recording mark of the recorded reproduction signal of the third track are obtained. Means for obtaining a minimum laser power that does not cause unerased from an asymmetry value due to a deviation of the center of amplitude, and setting an intermediate value between the maximum laser power and the minimum laser power as an optimum laser power for the one zone. An optical disk device comprising: 5. A rewritable data recording area is divided into a plurality of zones in a radial direction of a disk substrate, and rewrite count data is recorded near a head of each zone or near a head of an ECC block in each zone. And the laser power at the time of data recording set stepwise in accordance with the rewrite frequency data for each zone is previously recorded in a predetermined area of the disk substrate. At the same time, the number of revolutions is switched stepwise to a substantially constant linear velocity in each zone, and furthermore, an optical disc whose rotation is controlled to a constant angular velocity in each zone is used. An optical disk device configured to be set, comprising: zone information indicating one zone; Means for acquiring, from the optical disc, the number of times of rewriting recorded in the number-of-times-of-rewriting recording area in the corresponding one zone and the optimum laser power for the one zone corresponding to the number of times of rewriting. An optical disc device characterized by the above-mentioned. 6. A rewritable data recording area is divided into a plurality of zones in a radial direction of a disk substrate, a test writing area is provided near a head of each zone, and a test writing area is provided near a head of each zone or each zone. A rewrite frequency recording area for recording rewrite frequency data is provided in the vicinity of the head of the ECC block within the zone. Further, the reference laser power for data recording set for each zone and the rewrite frequency data are set to a predetermined number of times. And a correction data table for correcting the reference laser power in accordance with the result of the test writing to the data recorded in the test writing area when the test writing area is reached. The number of revolutions is switched stepwise to a substantially constant linear velocity in each zone, and furthermore, the rotation is controlled to a constant angular velocity in each zone. An optical disc device configured to set an optimum laser power for each zone at the time of data recording using an optical disc, wherein zone information indicating one zone, a reference laser power corresponding to the zone information, and Means for obtaining, from the optical disc, a rewrite frequency data recorded in a rewrite frequency recording area in one zone, and a correction data table for correcting the reference laser power when the rewrite frequency data reaches a predetermined number. Means for trial-writing data based on the reference laser power in the trial writing area provided in the one zone when the number of times of rewriting reaches a predetermined number of times; and reproducing the recorded trial writing area. An error from the proper recording state is detected from the signal, and the correction corresponding to the detection result is performed. Optical disk apparatus characterized by comprising a means for setting as the optimum laser power by correcting the reference laser power to zone the one by Tateburu.