JP2001110053A - Information recording method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information recording method which can record information over the entire surface of an optical disk medium with even signal characteristic by means of a simple method that revolves the optical disk medium by a CAV system while keeping compatibility with a recording format of the conventional media that is used only for reproduction. SOLUTION: The width of the head cooling pulse of a recording pulse string is increased in response to a recording linear velocity to vary the front edge position of the cooling pulse and to secure the pulse width that is different from a cooling pulse of a subsequent multi-pulse part. The width of the head cooling pulse set at the highest recording linear velocity to the lowest recording linear velocity of an optical disk medium is set within a range of 0.2 T-0.5 T that does not exceed the width of a subsequent cooling pulse in terms of the cumulative increment of width of the head cooling pulse, and the width of the head cooling pulse is updated at a prescribed interval in response to a desired recording linear velocity. Thus, the information can be recorded over the entire surface of the optical disk medium with even signal characteristic even when the recording linear velocity is varied by the CAV control that fixes the disk rotational frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video DVD (D
digital Video or Versatile Disk) or DVD-RO
DVD-R (Recodable) or DVD-R having format compatibility with read-only DVD media such as M
The present invention relates to a method and apparatus for recording information on an optical disk medium such as a W (ReWritable) disk.

[0002]

2. Description of the Related Art With the spread of multimedia, video D
Information recording media such as read-only media such as VD and DVD-ROM, and write-once DVD-R using a dye material as a recording layer and rewritable DVD-RW using a phase change material have been developed.

Information (sectors in this example) recorded on these DVD media has a format as shown in FIG. In such a format, as shown in FIG. 8D, data (sectors) are continuously recorded at a constant linear density on all tracks of the medium.

In order to provide an information recording medium having a format compatible with the read-only medium, a conventional method for controlling the rotation speed of the information recording medium (media) is shown in FIG.
As shown in (b), CLV (Constant Linear Velocit)
y: constant linear velocity) method, controlling the rotational speed of the media so that the rotational speed becomes inversely proportional to the track radius, and keeping the linear velocity of the track constant while maintaining the information at a constant recording channel clock frequency. We are recording.

However, in order to control the rotational speed by the CLV method, it is necessary to change the rotational speed of the medium in order to keep the track linear velocity constant. That is, since the rotation of the spindle motor for rotating the medium is accompanied, a large rotation torque is required, and a large-sized and high-cost motor is required. Also, at the time of seeking, it takes a long time to complete the shifting of the spindle motor, so compared to HDDs and MO drives,
There is a disadvantage that it takes a lot of access time.

[0006] In view of the above, in order to perform recording on the medium while keeping the rotation speed of the medium constant without controlling the shift, the format of the information recorded on the medium is as shown in FIG. It is also considered. That is, as shown in FIG. 9C, the frequency of the channel clock to be recorded on the medium is made smaller on the inner circumference side and increased on the outer circumference side in proportion to the radial position of the track. In this case, since the recording linear velocity becomes smaller on the inner peripheral side and increases on the outer peripheral side, the recording linear density is constant as shown in FIG. In addition, it is possible to record information on the medium by keeping the number of rotations (rotation speed) of the medium constant as shown in FIG. 9B, that is, by the CAV (Constant Angular Velocity) method. .

[0007] This eliminates the need for rotational speed change control of the spindle motor that rotationally drives the medium.
A low-rotation torque is sufficient, and a small and low-cost motor can be used. Further, since no shift is performed, a shift waiting time during seeking is not required, and the access time can be greatly reduced.

However, dye-based DVD-Rs in which pits (marks) are generally formed in a heat mode
Media and phase-change type RW media optimize the pulse width and recording power of a recording pulse train generated by laser emission at the time of recording at a specific recording linear velocity, and the state of marks and spaces formed at different recording linear velocities is reduced. Change. In other words, a shortage of heat capacity occurs due to the top heating pulse necessary for forming a mark, the heating temperature reaching the optimum decomposition temperature varies, the average length of the mark varies, and the duty ratio of the optimum heating pulse decreases. A different and uniform mark width cannot be obtained, and a thicker or thinner (a so-called tear-shaped mark) occurs depending on the mark length, thereby deteriorating jitter characteristics.

In this respect, for example, according to Japanese Patent Application Laid-Open No. 5-225570, at least two test recording areas are required in order to determine the optimum recording light amount corresponding to the entire recordable area of each optical disc in a relatively short time. The optimum recording light amount is obtained at a recording linear velocity equal to the position, and the optimum recording light amount is obtained by an interpolation routine.
By performing an interpolation process or an extrapolation process on the optimum recording light quantity at one recording linear velocity, the optimum recording light quantity at all the recording linear velocities is obtained.

According to Japanese Patent Application Laid-Open No. Hei 5-274678, in order to reduce the laser power required for recording without deteriorating the jitter characteristics, the optical disk is rotated at a constant number of rotations, and is different depending on the area. In a method of recording information at a higher frequency in an outer peripheral region than in an inner peripheral region by irradiating a light beam intensity-modulated according to an information signal based on a reference clock, the light beam is referred to in each region. A light beam that periodically emits pulses at a frequency that is an integral multiple of the clock frequency, and
When the light beam is applied to the outer peripheral region, the duty ratio of the pulse emission is set to be larger than when the light beam is applied to the inner peripheral region.

According to Japanese Patent Application Laid-Open No. 10-106008, an optical disk, an optical head, a synchronizing signal generation means, a VCO, a phase comparison means, A controller and a recording signal generating means are provided, and by changing the pulse height and width of the recording signal in accordance with the recording linear velocity, recording can always be performed under the best recording conditions.

[0012]

That is, in the case of these publications, in the CAV system, control is performed such that the set value of any element of the recording pulse train such as the duty ratio of pulse emission is varied according to the recording linear velocity. But
It is a qualitative effect on optical disc media, especially DV
It is insufficient for the recording medium of D. That is, since a plurality of factors interact with each other on the characteristic fluctuation of the recording information (RF signal) such as the jitter characteristic, the recording method described in these publications is inadequate and not necessarily over the entire surface of the optical disk medium. Recording cannot be performed with uniform signal characteristics, and a desired effect is not always obtained. Even if the set value of the recording pulse train is changed, how to change the set value has not been quantitatively studied.

Also, when the set value of the recording pulse train is changed, the modulation level and asymmetry of the reproduced signal change before and after the setting is changed, so that the slice level for binarization cannot be followed and the jitter deteriorates. Will occur.

Accordingly, the present invention provides a method of recording information while rotating an optical disk medium without controlling the rotational speed of the optical disk medium and maintaining compatibility with the recording format of a conventional read-only medium. It is another object of the present invention to provide an information recording method and an information recording apparatus capable of recording information with uniform signal characteristics over the entire surface of an optical disk medium using a simple method.

It is another object of the present invention to provide an information recording method which suppresses fluctuations in binarization with respect to a slice level, prevents deterioration of jitter characteristics, and stably operates a PLL of a reproduced clock. .

Further, according to the present invention, even when recording is performed by CAV control, the edge shift of a mark due to the effect of heat storage is corrected for all recording linear velocities, and recording with low jitter is performed over the entire optical disk medium. An object of the present invention is to provide an information recording method that can be performed.

[0017]

According to a first aspect of the present invention, there is provided an information recording method for recording information on an optical disk medium having a recording layer in which information is formed in pits by a recording pulse train of a laser beam emitted from a laser light source. At this time, the recording is performed so that the recording linear density becomes substantially constant by changing the recording clock cycle T according to the change in the recording linear velocity, and the leading edge position of the leading cooling pulse in the recording pulse train is changed. Then, the set value of the pulse width of the leading cooling pulse is updated at predetermined intervals according to a desired recording linear velocity so that the pulse width is different from the cooling pulse of the subsequent multi-pulse portion.

Therefore, the CA for keeping the disk rotation speed constant
Even if the recording linear velocity changes due to the V control, an optimal recording pulse train can be set for each recording linear velocity, and uniform characteristics can be recorded over the entire surface of the optical disk medium.

According to a second aspect of the present invention, in the information recording method according to the first aspect, according to the increase in the recording linear velocity,
The pulse width of the leading cooling pulse is increased.

Therefore, the CA for keeping the disk rotation speed constant
Even if the linear velocity at the time of recording changes due to V control, an optimal recording pulse train can be set continuously from the innermost circumference to the outermost circumference, and uniform characteristics can be recorded over the entire surface of the optical disk medium. .

According to a third aspect of the present invention, there is provided the information recording method according to the first or second aspect, wherein each of the set values at the minimum recording linear velocity at the innermost peripheral position of the optical disk medium is set.
The pulse width of the leading cooling pulse at the maximum recording linear velocity at the outermost peripheral position of the optical disk medium exceeds the pulse width of the subsequent cooling pulse within the range of 0.2T to 0.5T as the cumulative increase. There is no pulse width set.

Therefore, the CA for keeping the disk rotation speed constant
Even if the linear velocity at the time of recording changes due to V control, inappropriate settings can be prevented for various optical disk media, and an optimum recording pulse train can be set continuously from the innermost circumference to the outermost circumference.

According to a fourth aspect of the present invention, in the information recording method of the first, second or third aspect, the ratio Ttop of the pulse width of the first heating pulse to the recording clock cycle T and the duty of the heating pulse of the subsequent multi-pulse portion are set. The ratio Tmp,
Ratio of recording power Pw at desired recording linear velocity to optimum recording power Pwmin at minimum recording linear velocity ρ = Pw / Pwmin
Is set to the set value at the minimum recording linear velocity at the innermost position of the optical disc medium, as the cumulative increase of each set value at the maximum recording linear velocity at the outermost position of the optical disc medium. , The ratio Ttop is 0.3T
0.7T, the duty ratio Tmp is 0.03T
０．０0.07T and the ratio ρ is in the range of 0.3０．３0.6 in accordance with an increase in the recording linear velocity.

Accordingly, it is possible to set an optimum recording pulse train especially for a dye-based optical disk medium, to prevent a setting that causes a recording failure in the range of the cumulative increase, and to obtain a recording in which uniform reproduction characteristics can be obtained. Becomes possible.

[0025] The fifth aspect of the present invention provides the first to fourth aspects.
In the information recording method according to any one of the above, the difference between the asymmetry of the longest data and the shortest data of the recorded information to be reproduced is the set value of the ratio Ttop, the duty ratio Tmp, and the ratio ρ of the recording pulse train. 10 before and after updating
The change amount or the update interval of each set value is set so as to be within%.

Therefore, it is possible to suppress the fluctuation of the binarization with respect to the slice level, to perform recording without deteriorating the jitter characteristic and to improve the stability of the PLL of the reproduction clock.

The invention according to claim 6 is the invention according to claims 1 to 4
In the information recording method according to any one of the above, when the space length immediately before the mark to be formed is the shortest length, the leading edge of the leading heating pulse of the recording pulse train forming the mark, the leading edge of the leading heating pulse In order to shorten the pulse width, the same correction amount is set in the range of -0.02T to -0.07T with respect to the change of the recording linear velocity in the constant rotation angle method, and the recording is performed.

Therefore, even when the recording is performed by the CAV control in which the number of rotations of the optical disk medium is different with respect to the type of the dye material and the groove configuration, the mark due to the effect of the heat storage is obtained for all the recording linear velocities. Edge shift can be corrected, and recording with low jitter can be performed over the entire surface of the optical disk medium.

[0029] The invention according to claim 7 is the invention according to claims 1 to 6.
In the information recording method according to any one of the above, the setting value of the recording pulse train preformatted on the optical disc medium, or the setting of the recording pulse train included in disc information previously recorded in a predetermined area. The change amount or the gradient to be updated at the predetermined interval is calculated based on any one of the values, the optimum setting value for each of the plurality of recording linear velocities.

Therefore, it is possible to perform recording with uniform characteristics over the entire surface of the optical disk medium by a simple method without updating the set values more than necessary.

The invention described in claim 8 is the first invention to the seventh invention.
In the information recording method according to any one of the above, detecting the address information preformatted on the optical disk medium, from the change amount to be updated at the predetermined interval, the set value of the recording pulse train corresponding to the address information Calculated, and the predetermined interval is associated with the address range.

Accordingly, it is possible to easily recognize the update interval of the set value so as not to deviate from the optimum set value of the recording pulse train even during recording. Therefore, it is possible to update the set value of the recording pulse train in the CAV system in which the disk rotation speed is constant, with high accuracy.

According to a ninth aspect of the present invention, there is provided an information recording apparatus on an optical disk medium having a recording layer in which information is formed in pits by a recording pulse train composed of a heating pulse and a cooling pulse. An information recording apparatus for performing recording by changing a recording clock cycle T according to a change in a recording linear velocity so as to make a recording linear density substantially constant, wherein the heating pulse in the recording pulse train is recorded. A multi-stage edge signal generation circuit for changing the leading edge and the trailing edge of the head, and changing the leading edge position of the leading cooling pulse in the recording pulse train to have a pulse width different from the cooling pulse of the subsequent multi-pulse portion. In accordance with a desired recording linear velocity, a set value of the pulse width of the head cooling pulse is set before the head cooling pulse in the recording pulse train. In accordance with a desired recording linear velocity, the set value of the pulse width of the leading cooling pulse and the recording clock cycle T are changed so that the pulse position is changed so as to have a pulse width different from the cooling pulse of the subsequent multi-pulse portion. And the ratio ρ of the duty ratio Tmp of the heating pulse in the subsequent multi-pulse portion to the optimum recording power Pwmin at the minimum recording linear velocity of the recording power Pw at the desired recording linear velocity. A controller that calculates each set value of Pw / Pwmin and updates it as needed, and a controller that calculates and updates the set value as needed, and a multi-stage edge signal output from the edge signal generation circuit, based on the set values, A selector for selecting a predetermined edge signal corresponding to each of the first heating pulse and the subsequent heating pulse, and a driver for updating the amount of light emitted from the laser light source as needed. And an inverter circuit.

Therefore, it is possible to perform recording by CAV control using the information recording method according to the first to eighth aspects with a simple and small-scale circuit configuration.

[0035]

FIG. 1 shows a first embodiment of the present invention.
A description will be given with reference to FIG. First, as a setting of a basic recording pulse train used in a dye-based optical disk which is an optical disk medium, as shown in FIG. 1, the number of pulses nx constituting a recording pulse train for each mark data length nT is set.
(X is 1 or 2), the ratio Ttop of the pulse width of the head heating pulse to the recording clock cycle T, and the duty ratio Tmp of the heating pulse of the subsequent multi-pulse portion. The setting of the recording power includes a recording power Pw and a bias power Pb. Regarding the recording power, since the state of mark formation has a strong correlation with the recording linear velocity Lv, a desired radial position (recording linear velocity) with respect to the innermost circumferential position, that is, the optimum recording power Pwmin at the minimum recording linear velocity.
Ρ = Pw / Pwmin is set. In the present embodiment, the ratio T
More detailed settings are made for top, duty ratio Tmp, and ratio ρ. In addition, in the present embodiment, in addition to these, more detailed settings are made for the ratio Tcptop of the pulse width of the leading cooling pulse to the recording clock period T.

When recording control is performed on a dye-based DVD disk having a diameter of 120 mm by the CAV method, the recording linear velocity is about 3.5 m / s at the innermost position and about 8.4 m / s at the outermost position. The recording clock frequency is 26.2 MHz at the innermost position of the disk and 63.000 at the outermost position.
3 MHz. When such a recording requiring a change in recording linear velocity of about 2.4 times is performed on a dye-based DVD disk, if the same set of recording pulse train and recording power is used over the entire area, a high recording linear velocity is used. , The preheating by the top heating pulse becomes excessive or insufficient, and the modulation degree of the RF signal varies,
Variations in signal symmetry (asymmetry) increase. Further, a deviation occurs in the optimum value of the duty ratio of the heating pulse in the subsequent multi-pulse portion, and the recording mark width becomes non-uniform. In the present embodiment, as described below, uniform signal characteristics are provided from the innermost circumference to the outermost circumference of an optical disk medium, and low jitter recording is enabled.

First, as shown in FIG. 2, at the minimum recording linear velocity at the innermost position, the number of pulses constituting the recording pulse train is n-1 (n is the mark data length), the ratio Ttop is 0.80T, the duty is The ratio Tmp is set to 0.60T, the optimum recording power Pwmin is set to 10 mW, and the pulse width of the head cooling pulse is set to 0.05T. These setting values are typical numerical values of a dye-based recording disk, and are different optimum values depending on various tunings and types of recording materials.
Then, as shown in FIG. 2, the set values of the ratio Ttop and the duty ratio Tmp, the ratio ρ = Pw / Pwmin with the recording power Pw, and the ratio Tcptop are all increased in accordance with the increase in the recording linear velocity. In this way, it is possible to add an optimal amount of heat to the head of the mark and to perform recording with the optimal recording power, so that the mark width can be formed uniformly, thus maintaining good jitter characteristics. Can be.

As described above, when recording is performed by the CAV method in which the recording linear velocity changes depending on the radial position, these set values can be updated as follows. As a specific example of the set value, as shown in FIG. 3 or FIG. 4, the ratio T of the pulse width of the head heating pulse to the recording clock cycle T is used.
The top is changed from 0.8T (≒ 30.6 ns) at the innermost position to 1.3T (≒ 20.5 ns) at the outermost position, and is 0 with respect to the recording clock cycle T as the cumulative increase. .5
The set value is updated and changed so that T becomes longer. Also,
The interval for updating the set value of the ratio Ttop is updated stepwise in steps of about 0.35 m / s in the width of the recording linear velocity.

Similarly, the duty ratio Tmp of the heating pulse of the subsequent multi-pulse section is 0.60 T at the innermost position.
(≒ 22.9 ns), 0.65T at the outermost position
(≒ 10.3 ns).
The set value is updated and changed so as to be 05T longer. Further, the interval at which the set value of the duty ratio Tmp is updated is also set to the ratio T.
Same as top.

The recording power Pw is 1 at the innermost position.
It is changed from 0 mW to 14 mW at the outermost peripheral position. Therefore, the set value is updated and changed so that the ratio ρ of the innermost position at the outermost position to the optimum recording power Pwmin is from 1 to 1.4, that is, 0.4 which is increased by the cumulative increase. Also, the interval at which the set value of the ratio ρ is updated is determined by the ratio Ttop
Is the same as

The ratio Tcptop of the head cooling pulse to the recording clock cycle T is 0.05 T (≒) at the innermost position.
From 1.9 ns) to 0.35T at the outermost position (≒ 5.6
ns), and the set value is updated and changed so that the cumulative increase becomes 0.30 T longer than the recording clock cycle T in total. At this time, in order to change the position of the leading edge of the leading cooling pulse, the leading heating pulse has such a timing as to shift forward with respect to the edge of the recording clock.

As described above, all the set values of the ratio Ttop, the duty ratio Tmp, the ratio ρ, and the ratio Tcptop are updated and changed so as to increase toward the outer peripheral side of the disk. 14T modulation and 3T
A signal with little change in the degree of modulation or asymmetry and little increase in jitter can be recorded.

The above set values are typical values for a disk having a specific dye material and groove configuration. However, dye-based recording disks generate optical changes due to thermal decomposition due to laser beam irradiation and accompanying substrate deformation, and information is recorded by forming marks based on the changes. When a mark is formed by such a heat mode, the present embodiment is well suited.
Examples of typical organic dyes include polymethine dyes, cyanine-based, naphthalocyanine-based, phthalocyanine-based, squarylium-based, pyrylium-based, naphthoquinone-based, anthraquinone-based (indanthrene-based), xanthene-based, triphenylmethane-based, and azulene-based. And phenanthrene-based, triphenothiazine-based dyes and azo-based metal complex compounds. These dyes have optical properties, recording sensitivity,
It may be used by mixing or laminating it with another organic dye, a metal, or a metal compound for the purpose of improving signal characteristics and the like. Examples of metals and metal compounds include In, Te, Bi, Se,
Sb, Ge, Sn, Al, Be, TeO ₂ , SnO, A
s, Cd, etc., each of which can be used in the form of dispersion mixing or lamination. The recording layer can be formed by ordinary means such as vapor deposition, sputtering, CVD, or solvent application. When the coating method is used, the above-mentioned dye or the like is dissolved in an organic solvent, and the coating can be performed by a conventional coating method such as spraying, roller coating, dipping and spin coating.

In these various dye-based recording disks, the optimum set values are different. However, when performing recording by the CAV method, the set values of the head heating pulse and the heating pulse of the subsequent multi-pulse part and the set values of the recording power (set values of the ratio Ttop, the duty ratio Tmp, and the ratio ρ) are as follows. The same optimization can be applied to the recording linear velocity Lv for any recording disk. Also, a phase change type recording disk shows similar recording characteristics with respect to the recording linear velocity, and can be adapted by optimizing each set value.

In the optical disk medium having such a configuration, the increment of each set value at the outermost position with respect to the innermost position is:
The ratio Ttop of the top heating pulse to the recording clock period T
Is in the range of 0.3T to 0.7T, and the duty ratio Tmp of the heating pulse of the subsequent multi-pulse part is 0.03T to
0.07T and the recording power ratio ρ is 0.3
By increasing the ratio Tcptop of the leading cooling pulse to the recording clock period T in the range of 0.6 to 0.6 so as to be in the range of 0.2T to 0.5T, various dyes having a diameter of 120 mm can be obtained. It becomes possible to perform recording on a recordable DVD disc by the CAV method.

Hereinafter, each set value will be described in detail. Generally, when recording is performed on a dye-based recording disk at different recording linear velocities, it is known that the recording power is substantially proportional to the square root of the recording linear velocity (for example, Japanese Patent Application Laid-Open No. H10-106008 described above). reference). That is, assuming that the recording power is Pw, the recording linear velocity is Lv, and the constant is Klv, the recording power is calculated as Pw = Klv√Lv. However, as described above, when all the set values including the ratio Ttop of the first heating pulse and the duty ratio Tmp of the heating pulse of the multi-pulse portion are optimized according to the recording linear velocity Lv, the above-described recording is performed. Assuming that the power ratio is ρ and the constant Kpw, the optimum recording power at the minimum and maximum recording linear velocities is the recording power calculated by linear approximation ρ = Klv × Lv + Kpw, It shows an appropriate value. Similarly, by using the set values calculated by linear approximation for the ratio Ttop, the duty ratio Tmp, and the ratio Tcptop, it is possible to obtain optimum set values for the recording linear velocity over the entire area. In the set values of the present embodiment, Ttop = 0.10 × Lv + 0.44 Tmp = 0.01 × Lv + 0.56 Pw = Pwmin × (0.08 × Lv + 0.72) Tcptop = 0.06 × Lv− The approximate expression of 0.16 is used. By using such a setting method of updating the set value, it is possible to calculate an optimum set value for an arbitrary recording linear velocity by a simple calculation.

In response to the increase in the recording linear velocity Lv,
As described above, the interval at which each set value is updated is preferably as small as possible in view of the characteristics of the RF signal, but the load on the controller increases. However, a difference in asymmetry between the longest data and the shortest data of the RF signal before and after updating the set value has a great influence on an error rate of reproduced information and the like. As shown in FIG. 5, when the asymmetry difference before and after the update of the set value becomes close to ± 10%, the jitter characteristic rapidly deteriorates. Therefore, the difference in asymmetry needs to be within ± 10%. In addition, since the slice circuit for binarizing the RF signal does not have a time constant that follows this difference in asymmetry, accurate binarization cannot be performed, and a large edge shift occurs in the RF signal. In some cases, the PLL for generating the reproduced clock may be disconnected. According to a more detailed study, it is desirable to update the above set values so that the asymmetry difference is within ± 5% in consideration of jitter characteristics and PLL stability.

The above four setting values (the setting values of the heating pulse ratio Ttop, the duty ratio Tmp, the recording power ratio ρ, and the cooling pulse ratio Tcptop) each have some effect, but the characteristics of the RF signal can be recognized. Since the fluctuations have an interaction, it is desirable to implement at least two set values. Note that, as in the present embodiment, four set values (ratio T
Needless to say, this is most effective when all of the top, the duty ratio Tmp and the setting value of the ratio ρ are updated and set.

Next, a second embodiment of the present invention will be described. In order to perform recording with lower jitter on a dye-based recording disk, it is effective to correct the leading edge of the ratio Ttop to the recording clock cycle T of the first heating pulse according to the data length to be recorded. Generally, when a dye material is used for the recording layer, the amount of heat accumulated differs depending on the space length immediately before the mark to be recorded, and the leading edge of the mark is shifted. Since this phenomenon becomes remarkable at the shortest space length, the above correction is particularly effective. More specifically, by performing recording with the correction amount of the pulse width of the head heating pulse as shown in Table 1, recording with even lower jitter can be realized.

[0050]

[Table 1]

In this embodiment, since the recording data subjected to the EFM modulation is used, when the immediately preceding space length is 3T and the mark length is 4T to 14T, the pulse width of the first heating pulse is shortened by -0.05T. The front edge is corrected so as to be as follows. Also, the immediately preceding space length is 3T and the mark length is 3T.
In the case of, -0.02T
Only amended. These corrections are particularly effective in all combinations of the immediately preceding space length and the mark length, and the effect of reducing the jitter by the correction amounts of the other combinations shown in Table 1 is small.

Even when recording is performed by the CAV method as shown in the first embodiment, the correction of this embodiment is applied to all recording linear velocities Lv. That is, the correction amount at the minimum recording linear velocity at the innermost position is
When the combination of the immediately preceding space length and the mark length is 3T-3T, -0.02T (about -0.75 ns) and 3T-4 to 1T
At 4T, it is -0.05T (about -1.9ns). The correction amount at the maximum recording linear velocity at the outermost peripheral position is
The same correction amount may be used for the clock period T. When a similar combination is 3T-3T, the correction amount is about -0.3 ns,
It is about -0.8 ns at T-4 to 14T. As described above, when the space length immediately before the mark to be formed is the shortest, the leading edge of the head heating pulse of the recording pulse train forming the pit is set so that the leading edge of the head heating pulse is shortened in CAV recording. By performing recording with the same correction amount for a change in the recording linear velocity, recording with low jitter can be performed over the entire recording disk.

The correction amount is set by setting the correction amount in the range of -0.02T to -0.07T, even if the recording disk is different depending on the type of the dye material and the tuning of the groove configuration. It becomes possible.

A third embodiment of the present invention will be described with reference to FIG. Generally, a recording disk such as a CD or a DVD is formed with a groove for obtaining a tracking error signal (push-pull signal), and a wobble signal obtained by meandering the groove is superimposed. At a recording linear velocity of, the information encoded by frequency modulation or phase modulation is detected by a programmable BPF and demodulated so that address information and disc information unique to the disc can be obtained even for an unrecorded disc. ing. It is also known that such information is generated by cutting intermittent pits (Land-PrePit signal) in the land portion. In such disk information, recording of the optimal head heating pulse at a plurality of recording linear velocities such as a minimum (innermost) recording linear velocity, a maximum (outermost) recording linear velocity, and an intermediate (middle) recording linear velocity. Ratio Tto to clock period T
p, the duty ratio Tmp of the heating pulse of the subsequent multi-pulse part, and the recording power Pw are embedded in advance.
In the present embodiment, the pulse width ratio Tcptop of the leading cooling pulse, which is particularly effective when performing CAV recording, is also set. By setting these by reading them out from the medium or by setting them newly in the recording device (step S1), the optimum set values are obtained, and the change amount of the set values linearly approximated to the recording linear velocity (or ,
The gradient is calculated (S2).

The change amount and the gradient may be calculated in accordance with the characteristics of the optical disk medium, and may be calculated with high accuracy by linear approximation or other polynomial approximation. Next, C
An appropriate set value update interval is calculated from the range of the recording linear velocity in the AV control (S3) (in the present embodiment, about 0.35 m / s).

The amount of change in the set value obtained in this way is relative to the recording linear velocity, and in fact, it is necessary to recognize it using address information obtained by demodulating the above-described wobble signal or PLL signal. A specific address is determined from the innermost position to the outermost position, and can be associated with the recording linear velocity. Next, by assigning an interval for updating the set value and a range of addresses corresponding to the interval (S4), the set value can be updated when the address to be updated is reached (S5). During recording by the actual CAV control, the current address is read (S
6) It is determined whether the set value is within the range of updating, that is, within the address range (S7). If the set value is out of the range, the set value is updated to the newly calculated set value (S4, S5), and continuous. Can be recorded. If it is within the address range, recording is performed by CAV control as described above (S
8) The same process is repeated until the recording end address is reached (S9). With such a configuration, it is possible to greatly reduce the load on the controller for controlling the recording pulse train.

The recording power Pw is determined by an optimum value by trial writing (OPC) at at least two kinds of recording linear velocities corresponding to the innermost position and the outermost position, or the recording power obtained from the wobble signal. By replacing or correcting the information described above, it is possible to perform more accurate setting.

A fourth embodiment of the present invention will be described with reference to FIG. The present embodiment relates to an information recording apparatus for recording on an optical disk medium using the above-described information recording method (while updating the setting values of the pulse ratio Ttop, the duty ratio Tmp, the ratio ρ, and the pulse ratio Tcptop).

First, a rotating mechanism 3 including a spindle motor 2 for rotating the optical disc medium 1 is provided for the optical disc medium 1, and an objective lens for condensing and irradiating the optical disc medium 1 with laser light. An optical head 4 having a light source such as a laser and a semiconductor laser is provided so as to be able to move in a seek direction in the disk radial direction. Optical head 4
Servo mechanism 5 for the objective lens driving device and output system
Is connected. A wobble detector 7 including a programmable BPF 6 is connected to the servo mechanism 5.
An address demodulation circuit 8 for demodulating an address from the detected wobble signal is connected to the wobble detection unit 7.
The address demodulation circuit 8 includes a PLL synthesizer circuit 9
Is connected. PL
The drive controller 11 is connected to the L synthesizer circuit 9. The drive controller 11 connected to the system controller 12 includes a rotation mechanism 3, a servo mechanism 5, a wobble detection unit 7, and an address demodulation circuit 8.
Is also connected. An EFM encoder 13 and a recording pulse train control unit 14 are connected to the system controller 12. The recording pulse train control unit 14 includes a recording pulse train generation unit 15 that generates a heating pulse control signal including a head heating pulse and a heating pulse of a subsequent multi-pulse part, and an edge selector 16 that is a selector described later.
And an edge signal generation unit 17. The output side of the recording pulse train control unit 14 has the recording power Pw and the bias power Pb
An LD driver 19 which is a driver circuit for driving the semiconductor laser in the optical head 4 by switching the respective drive current sources 18 is connected.

In such a configuration, the center frequency of the BPF corresponding to the recording linear velocity is
And the address demodulation circuit 8 demodulates the address from the wobble signal detected by the wobble detection unit 7 and the PLL synthesizer circuit 9 in which the basic clock frequency is changed by the drive controller 11, and the arbitrary recording linear velocity Is generated and output to the recording pulse train control unit 14.

Next, in order to generate a recording pulse train by the semiconductor laser, a recording channel clock and EFM data as recording information are input from the recording pulse train control unit 14 and the EFM encoder 13 to the recording pulse train control unit 14, respectively. The generation unit 15 generates a heating pulse control signal including a head heating pulse and a heating pulse of a subsequent multi-pulse part. Then, the LD driver 19 switches the drive current sources 18 for the recording power Pw and the bias power Pb. At the time of recording, the bias current source steadily causes the semiconductor laser to emit light at the bias power Pb equivalent to the reproduction power, and the recording pulse train generation unit 15 described above.
The laser emission waveform of the recording pulse train as shown in FIG. 1 can be obtained by the heating pulse control signal generated in step (1).

In this embodiment, a multi-stage delay circuit using a gate element and having a delay of about 0.5 ns is arranged as the edge signal generator 17 of the head heating pulse generator in the recording pulse train generator 15. After being input to the multiplexer-configured edge selector 16, a leading heating pulse control signal that changes the leading edge and the trailing edge is generated by the edge pulse selected by the system controller 12. Similarly, in the edge signal generation unit 17 of the heating multi-pulse generation unit in the recording pulse train generation unit 15 that varies the leading edge of the heating pulse of the subsequent multi-pulse unit, the delay amount using the gate element is about 0.5 ns. After the multi-stage delay elements are arranged and input to the edge selector 16, a heating multi-pulse control signal is generated by an edge pulse selected by the system controller 12.

With such a configuration, each set value is determined as in the inventions of claims 1 to 4 and 6, an optimum edge pulse is selected at a desired recording linear velocity, and a desired multi-pulse train is generated. Is working to be. Also,
When the recording pulse train generated by such a configuration is updated at predetermined intervals, each set value changes as shown in FIG. Therefore, when the multi-stage delay element is used, each pulse width becomes a fixed value during the update period, and the pulse width ratio and the duty are set so as to change according to the change of the recording channel clock.

Next, as another embodiment of the present invention, instead of a multistage delay element, a phase comparator, a loop filter and a VCO
A pulse edge generation unit having a PLL configuration using a (voltage controlled oscillator) and a frequency divider may be used. In this configuration, a high-resolution clock obtained by multiplying the recording channel clock by 32 is used as a PLL.
And a pulse edge signal of 0.03
T, that is, a resolution of about 1.1 ns to 0.5 ns. After such multi-stage pulse edge signals are input to the edge selector 16 having a multiplexer configuration, a leading heating pulse control signal that changes the leading edge and the trailing edge is generated by the edge pulse selected by the system controller 12. Similarly, in the heating multi-pulse generation circuit in the recording pulse train generation unit 15 that varies the leading edge of the heating pulse of the succeeding multi-pulse unit, P
A pulse edge generator having an LL configuration is arranged, and after being input to the edge selector 16, a heating multi-pulse control signal is generated by an edge pulse selected by the system controller 12. With such a configuration, each set value is determined as in the first to fourth and sixth aspects of the present invention, so that an optimum edge pulse is selected at a desired recording linear velocity and a desired multi-pulse train is generated. It is working.

When the recording pulse train generated in such a configuration is updated at predetermined intervals, each set value changes to a value as shown in FIG. Therefore, PLL
When the edge pulse generator having the above configuration is used, the pulse width ratio and the duty are set to be constant values with respect to the change of the recording channel clock during the update period.

It should be noted that the present invention enables uniform recording at the time of CAV recording for any of these configurations,
Various circuit systems can be used as the recording pulse train generator.

Therefore, according to the information recording apparatus of this embodiment, the pulse ratio Ttop, the duty ratio Tmp, the power ratio ρ, and the pulse ratio T
Recording by CAV control using an information recording method involving update setting of the setting value of cptop becomes possible.

[0068]

According to the information recording method of the present invention, the leading edge position of the leading cooling pulse in the recording pulse train is changed so as to have a pulse width different from the cooling pulse of the subsequent multi-pulse portion. Since the pulse width of the head cooling pulse is updated at predetermined intervals in accordance with a desired recording linear velocity, the CA which keeps the disk rotation speed constant
Even if the linear velocity at the time of recording changes due to V control, it is possible to record with uniform characteristics over the entire surface of the optical disk medium.

According to the information recording method of the second and third aspects of the present invention, even if the linear velocity at the time of recording changes due to CAV control for keeping the disk rotation speed constant, the optical disk medium moves from the innermost circumference to the outermost circumference. Recording of uniform characteristics over the entire surface becomes possible.

According to the information recording method of the present invention, a recording pulse train corresponding to the entire surface of the optical disk medium can be obtained even when recording is performed on various dye-based optical disk media by CAV control in which the number of rotations is constant. Can be approximated, and a setting that causes a recording failure can be prevented, and recording with uniform reproduction characteristics can be achieved.

According to the information recording method of the present invention, the variation of the binarization with respect to the slice level can be suppressed, the jitter characteristic does not deteriorate, and the stability of the reproduction clock PLL is also good. Becomes possible.

According to the information recording method of the present invention, even when the recording is performed by the CAV control in which the disk rotation speed is kept constant, the edge shift of the mark due to the effect of the heat storage for all the recording linear velocities. Can be corrected, and recording with low jitter can be performed over the entire surface of the optical disk medium.

According to the information recording method of the present invention, even when recording is performed by CAV control for keeping the disk rotation speed constant for optical disk media having different types of dye materials, groove configurations, and the like. The edge shift of the mark due to the heat accumulation can be corrected for the recording linear velocity, and recording with low jitter can be performed over the entire surface of the optical disk medium.

According to the information recording method of the present invention, it is possible to perform recording with uniform characteristics over the entire surface of the optical disk medium by a simple method without updating the set values more than necessary. Become.

According to the information recording method of the present invention, it is possible to easily recognize the update interval of the set value so as not to deviate from the optimum set value of the recording pulse train even during recording. Therefore, the set value of the recording pulse train in the CAV method in which the disk rotation speed is constant can be updated with high accuracy.

According to the information recording apparatus of the ninth aspect, it is possible to perform recording by CAV control using the information recording method according to the first to eighth aspects with a simple and small circuit configuration.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a recording pulse train and the like showing a first embodiment of the present invention.

FIG. 2 is a characteristic diagram of a recording linear velocity-heating pulse ratio, a power ratio, and the like.

FIG. 3 is a characteristic diagram showing a method of updating.

FIG. 4 is a characteristic diagram showing a method of updating.

FIG. 5 is an asymmetry-jitter characteristic diagram.

FIG. 6 is a flowchart illustrating a third embodiment of the present invention.

FIG. 7 is a block diagram showing a fourth embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a conventional example of the CLV method.

FIG. 9 is an explanatory diagram showing a conventional example of the CAV method.

[Explanation of symbols]

 Reference Signs List 1 optical disk medium 12 controller 16 selector 17 edge signal generation circuit 19 driver circuit

Claims (9)

[Claims] When a laser beam emitted from a laser light source is recorded on an optical disk medium having a recording layer in which information is formed in pits by a recording pulse train composed of a heating pulse and a cooling pulse, a change in recording linear velocity occurs. The recording is performed so that the recording linear density becomes substantially constant by changing the recording clock cycle T in accordance with the following, and by changing the front edge position of the leading cooling pulse in the recording pulse train, An information recording method in which the set value of the pulse width of the leading cooling pulse is updated at predetermined intervals according to a desired recording linear velocity so that the pulse width is different from the cooling pulse. 2. The information recording method according to claim 1, wherein a pulse width of said head cooling pulse is increased in accordance with an increase in said recording linear velocity. 3. The pulse width of the head cooling pulse at the maximum recording linear velocity at the outermost peripheral position of the optical disk medium with respect to each set value at the minimum recording linear velocity at the innermost peripheral position of the optical disk medium is the accumulated value. As an increase,
3. The information recording method according to claim 1, wherein the pulse width is set within a range of 0.2T to 0.5T so as not to exceed a pulse width of a subsequent cooling pulse. 4. A ratio Ttop of a pulse width of a head heating pulse to a recording clock cycle T, a duty ratio Tmp of a heating pulse of a subsequent multi-pulse part, and a recording power Pw at a desired recording linear velocity at a minimum recording linear velocity. The respective set values of the ratio ρ = Pw / Pwmin with the optimum recording power Pwmin are the maximum recording at the outermost peripheral position of the optical disk medium with respect to the respective set values at the minimum recording linear velocity at the innermost peripheral position of the optical disk medium. The ratio Ttop is in the range of 0.3T to 0.7T as an increment of accumulation of each set value in the linear velocity,
The duty ratio Tmp is set in the range of 0.03T to 0.07T and the ratio ρ is set in the range of 0.3 to 0.6 in accordance with an increase in the recording linear velocity. Item 1. The information recording method according to Item 1, 2 or 3. 5. A difference in asymmetry between the longest data and the shortest data of recorded information to be reproduced is 10% before and after updating all set values including the pulse width of the head cooling pulse.
The information recording method according to any one of claims 1 to 5, wherein a change amount or an update interval of each set value is set so as to be within. 6. When the space length immediately before a mark to be formed is the shortest, the leading edge of the head heating pulse of the recording pulse train forming the mark is formed so that the pulse width of the head heating pulse is reduced. The same correction amount for the change in the recording linear velocity in the constant rotation angle method.
The information recording method according to any one of claims 1 to 5, wherein recording is performed by setting a value in a range of 0.02T to -0.07T. 7. A plurality of set values of the recording pulse train preformatted on the optical disc medium or set values of the recording pulse train included in disc information previously recorded in a predetermined area. 7. The information recording method according to claim 1, wherein a change amount or a gradient to be updated at the predetermined interval is calculated based on the optimum setting value for each recording linear velocity. 8. A method of detecting address information preformatted on the optical disk medium, calculating a set value of the recording pulse train corresponding to the address information from a change amount updated at the predetermined interval, 8. The information recording method according to claim 1, wherein the information is associated with a range of an address. 9. When a laser beam emitted from a laser light source is recorded on an optical disk medium having a recording layer in which information is formed in pits by a recording pulse train composed of a heating pulse and a cooling pulse, a change in a recording linear velocity occurs. An information recording apparatus that performs recording by changing the recording clock cycle T according to the following so that the recording linear density becomes substantially constant, and for changing a leading edge and a trailing edge of the heating pulse in the recording pulse train. A multi-stage edge signal generation circuit, by changing the leading edge position of the leading cooling pulse in the recording pulse train, so as to have a pulse width different from the cooling pulse of the subsequent multi-pulse portion, to a desired recording linear velocity Accordingly, the set value of the pulse width of the head cooling pulse, the ratio Ttop of the pulse width of the head heating pulse to the recording clock cycle T, and the following value And the duty ratio Tmp heating pulse of Ruchiparusu portion, the optimum recording power at the minimum recording linear velocity of the recording power Pw in a desired recording linear velocity Pwmi
a controller that calculates each set value of the ratio ρ = Pw / Pwmin to n and updates the set value at any time; and a head heating based on the set values from a multi-stage edge signal output from the edge signal generation circuit. An information recording apparatus, comprising: a selector for selecting a predetermined edge signal corresponding to each of a pulse and a subsequent heating pulse; and a driver circuit for updating the amount of light emitted from the laser light source as needed.