JP2001076341A - Information recording method and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information recording method capable of performing recording with uniform signal recording characteristics over the entire surface of an optical disk medium by using a simple method rotatingly driving the medium with a CAV(constant angluar velocity) system while maintaining the compatibility with the recording formats of reproduction-only media. SOLUTION: All setting values with the ratio Ttop of a leading heating pulse width to a recording clock period T, the duty ratio Tmp of heating pulses of a succeeding multi-pulse part, and a ratio ρ=Pw/Pw min between a recording power Pw at a desired recording linear velocity to the optimum recording power Pw min at the minimum recording linear velocity are updated at prescribed intervals in accordance with a desired recording linear velocity. Thus, even when the recording linear velocity is changed by a CAV control making the number of revolution of an optical disk constant, recording having a uniform recording characteristics is made possible over the entire surface of the optical recording medium.

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.

The 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. 7D, 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 method of controlling the rotation speed of the information recording medium (media) has conventionally been used as 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. Further, at the time of seeking, it takes a long time to complete the shifting of the spindle motor, so that there is a disadvantage that a large access time is required as compared with an HDD or an MO drive.

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 speed change, the format of information recorded on the medium is as shown in FIG. It is also considered. That is, as shown in FIG. 8C, 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, the recording linear velocity is small on the inner peripheral side and increases on the outer peripheral side, so that the recording linear density is constant as shown in FIG. Further, 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. 8B, 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, a dye-based medium in a heat mode such as a DVD-R generally has a different recording power at a specific recording linear velocity because the pulse width and recording power of a recording pulse train due to laser emission during recording are optimized. At the recording linear velocity, the state of the formed mark or space changes. 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 on an optical disk medium having a recording layer in which information is formed in pits in a heat mode by a recording pulse train of a laser beam emitted from a laser light source. At the time of recording, the recording clock cycle T is changed in accordance with the change of the recording linear velocity to perform the recording so that the recording linear density becomes substantially constant, and the leading edge of the heating pulse in the recording pulse train is changed. The ratio Ttop of the head heating pulse width to the recording clock cycle T, the duty ratio Tmp of the heating pulse of the subsequent multi-pulse part in the recording pulse train, and the minimum recording line of the recording power Pw at a desired recording linear velocity Recording power at speed Pwmin
All the set values of the ratio ρ = Pw / Pwmin are updated at predetermined intervals according to a desired recording linear velocity.

Accordingly, the ratio Ttop of the head heating pulse width to the recording clock cycle T, the duty ratio Tmp of the heating pulse of the subsequent multi-pulse portion, and the optimum recording power Pw at the desired recording linear velocity at the minimum recording linear velocity. By updating all the set values of the ratio ρ = Pw / Pwmin to the recording power Pwmin at predetermined intervals according to the desired recording linear velocity, the recording linear velocity can be reduced by the CAV control for keeping the disk rotation speed constant. Even if it changes, it is possible to record uniform characteristics 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 amount of change of each set value is updated so that the ratio Ttop, the duty ratio Tmp, and the ratio ρ are all increased.

Therefore, the CA for keeping the disk rotation speed constant
Even if the linear velocity at the time of recording changes due to the V control, it is possible to record uniform characteristics over the entire area from the innermost circumference to the outermost circumference of the optical disk medium.

According to a third aspect of the present invention, in the information recording method according to the first or second aspect, a difference in asymmetry between the longest data and the shortest data of the recorded information to be reproduced is determined by the ratio Ttop of the recording pulse train and the ratio Ttop. The amount of change of each set value or the update interval is set so as to be within 10% before and after updating the set values of the duty ratio Tmp and the ratio ρ.

Accordingly, it is possible to suppress the variation 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.

According to a fourth aspect of the present invention, in the information recording method according to the first, second or third aspect, the maximum value 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. As the increment of each set value at the maximum recording linear velocity at the outer peripheral position, the ratio Ttop is in the range of 0.3T to 0.7T, the duty ratio Tmp is in the range of 0.05T to 0.2T, and the ratio ρ is 0.3-0.
5, respectively.

Accordingly, even when recording is performed on various dye-based optical disk media by the CAV control in which the number of rotations is kept constant, it is possible to approximate the set value of the recording pulse train corresponding to the entire surface of the optical disk medium. Such a setting can be prevented, and recording with uniform reproduction characteristics can be performed.

[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, when the space length immediately before the mark to be formed is the shortest, the leading edge of the leading heating pulse of the recording pulse train forming the mark is the leading heating pulse width. So that
Recording is performed with the same correction amount with respect to a change in the recording linear velocity in the constant rotation angle method.

Therefore, the CA for keeping the disk rotation speed constant
Even when recording is performed by V control, the edge shift of the mark due to the effect of heat storage can be corrected for all recording linear velocities, and low jitter recording can be performed over the entire optical disk medium.

According to a sixth aspect of the present invention, in the information recording method of the fifth aspect, the correction amount is from -0.02T to -0.02T.
It is set in the range of 0.07T.

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

An information recording apparatus according to a ninth aspect of the present invention is an information recording apparatus for recording on an optical disk medium by the information recording method according to any one of the first to eighth aspects, wherein A multi-stage edge signal generation circuit for changing the leading edge of the first heating pulse and the leading edge of the subsequent multi-pulse heating pulse;
A controller that calculates each of the set values and updates as needed, a selector that selects a predetermined edge signal based on each of the set values from a multi-stage edge signal output from the edge signal generation circuit, and a laser light source. A driver circuit that updates the amount of emitted light as needed.

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 head heating pulse width to the recording clock period T, and the duty ratio Tmp of the heating pulse of the subsequent multi-pulse portion. The recording power is set as a recording power Pw and a bias power Pb.
There is. Regarding the recording power, since the state of the mark formation has a strong correlation with the recording linear velocity Lv, the recording power at the innermost circumferential position, that is, at any desired radial position (recording linear velocity) with respect to the optimum recording power Pwmin at the minimum recording linear velocity. The ratio ρ = Pw / Pwmin of the recording power Pw is set. In the present embodiment, among these set values, the ratio Ttop, the duty ratio Tmp, and the ratio ρ are set in more detail.

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-2 (n is the mark data length), the ratio Ttop is 1.20 T, the duty is The ratio Tmp is set to 0.60 T, and the optimum recording power Pwmin is set to 10 mW. These setting values are typical numerical values of a dye-based recording disc,
The optimum value differs 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 and the ratio ρ = Pw / Pwmin of the recording power Pw change so as to increase in accordance with the increase of the recording linear velocity. By doing so, it becomes possible to apply an optimal amount of heat to the head of the mark and to perform recording with an optimal recording power, so that the mark width can be formed uniformly, so that the jitter characteristics can be maintained satisfactorily.

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 set value example, as shown in FIG. 3, the ratio Ttop of the head heating pulse to the recording clock cycle T is from 1.2T (≒ 46 nsec) at the innermost position to 1.T at the outermost position. 7T
(≒ 27 nsec), and the set value is updated and changed so as to be 0.5 T longer than the recording clock cycle T in total. The interval at which the set value of the ratio Ttop is updated 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.
(≒ 23nsec), 0.7T at the outermost position (最 11n
sec), and the set value is updated and changed so as to be 0.1 T longer in total. Also, the duty ratio Tmp
Is updated in the same manner as the ratio Ttop.

The recording power Pw is 1 at the innermost position.
It is changed from 0 mW to 14 mW at the outermost peripheral position. Accordingly, 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 increases from 1 to 1.4 (0.4 in increments).
The interval at which the set value of the ratio ρ is updated is the same as that of the ratio Ttop.

As described above, all the set values of the ratio Ttop, the duty ratio Tmp, and the ratio ρ are updated and changed so as to increase as they become closer to the outer periphery of the disk.
The reproduced RF signal is a signal with little deterioration of the modulation degree, asymmetry and jitter, and enables good recording.

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.

As described above, the increment of each set value at the outermost position relative to the innermost position is such that the ratio Ttop of the head 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 in the range of 0.05T to 0.2T, and
By increasing the recording power ratio ρ in the range of 0.3 to 0.5, various dye-based recordable DVD disks having a diameter of 120 mm can be used.
Recording can be performed by the V 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 ratio of the power is ρ and the constant Kpw, based on the optimum recording power at the minimum and maximum recording linear velocities, ρ = Klv × Lv + Kp
The recording power calculated by linear approximation with w indicates an appropriate value for the recording linear velocity over the entire area. Also, the ratio Ttop,
Similarly, by using the set value calculated by linear approximation for the duty ratio Tmp, it is possible to obtain the optimum set value for the recording linear velocity over the entire area. In the set values of this embodiment, the following approximate expressions are used: Ttop = 0.1 × Lv + 0.85 Tmp = 0.02 × Lv + 0.53 Pw = Pwmin × (0.08 × Lv + 0.72) By using such a setting value update setting method, it is possible to calculate an optimum setting 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, the difference in asymmetry between the longest data and the shortest data, which greatly affects the error rate of the reproduced information, needs to be within ± 10%. As shown in FIG. 4, when the asymmetry difference before and after the update of the set value becomes close to ± 10%, the jitter characteristic rapidly deteriorates. With a time constant that is followed by a slice circuit for binarizing an RF signal, 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. In more detail, in consideration of jitter characteristics and PLL stability, it is desirable to update the above set values so that the asymmetry difference is within ± 5%.

In addition, the above three set values (ratio Ttop,
Although the respective effects of the duty ratio Tmp and the setting value of the ratio ρ) are recognized, it is desirable to perform the operation with at least two setting values because the characteristic fluctuation of the RF signal has an interaction. Note that, as in the present embodiment, three 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. For a dye-based recording disk, it is effective to correct the ratio Ttop of the top heating pulse to the recording clock cycle T according to the data length to be recorded in order to perform recording with lower jitter. 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 correction is particularly effective. Specifically, by performing recording with the correction amount of the head heating pulse width as shown in Table 1, recording with even lower jitter can be realized.

[0049]

[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 peripheral position is determined by the combination of the preceding space length and the mark length being 3T-3T.
About -0.75nsec for 3T-4 to 14T about-
1.9 nsec. The correction amount at the maximum recording linear velocity at the outermost peripheral position is about -0.3 nsec when the same combination is 3T-3T, and is about -0.3 nsec when the combination is 3T-4 to 14T.
0.8 nsec. As described above, when the space length immediately before the mark to be formed is the shortest, the leading edge of the leading heating pulse of the recording pulse train forming the pit is formed by the recording line in CAV recording so that the leading heating pulse width becomes shorter. By performing recording with the same correction amount for a change in speed, 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. In general, a groove groove for obtaining a tracking error signal (push-pull signal) is formed on a dye-based recording disk, and a wobble signal obtained by meandering the groove groove is superimposed thereon. At linear velocity, by detecting by a programmable BPF and demodulating information encoded by frequency modulation or phase modulation, disc-specific address information and disc information can be obtained even for an unrecorded disc. .
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. The ratio Ttop to the clock period T and the duty ratio Tmp of the heating pulse of the subsequent multi-pulse portion
And the recording power Pw are embedded in advance, and by reading them out (step S1), an optimum set value is obtained, and a change amount (or a gradient thereof) of the linearly approximated set value with respect to the recording linear velocity is calculated. (S2).

The amount of change and the gradient may be calculated according to the characteristics of the optical disk medium, and may be calculated by an approximate expression other than the linear approximation. Next, an appropriate set value update interval is calculated from the range of the recording linear velocity in the CAV control (S3) (in the present embodiment, every 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 by 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 obtained from the wobble signal by obtaining an optimum value by trial writing (OPC) at at least two types of recording linear velocities corresponding to the innermost position and the outermost position. By replacing or correcting the power information, it is also 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 by using the above-described information recording method (while setting and updating the set values of the ratio Ttop, the duty ratio Tmp, and the ratio ρ).

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 a multi-stage delay element 17 using a gate element constituting an edge signal generation circuit. The output side of the recording pulse train control unit 14 switches the drive current sources 18 of the recording power Pw and the bias power Pb to switch the optical head 4.
LD as a driver circuit for driving the semiconductor laser inside
The driver 19 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 to the recording pulse train control unit 14 from the recording pulse train control unit 14 and the EFM encoder 13, 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 constantly causes the semiconductor laser to emit light with the bias power Pb corresponding to the reproduction power, and the recording pulse train generation unit 1 described above.
By the heating pulse control signal generated in step 5, a laser emission waveform of a recording pulse train as shown in FIG. 1 can be obtained.

In this embodiment, the head heating pulse generator in the recording pulse train generator 15 has a delay of 0.5 ns.
A multi-stage delay element 17 of the order of ec is arranged, and after being input to an edge selector 16 having a multiplexer configuration, a head heating pulse control signal for varying the leading edge by an edge pulse selected by the system controller 12 is generated. Similarly, a multi-stage delay element 17 having a delay amount of about 0.5 nsec is also arranged in the heating multi-pulse generation circuit in the recording pulse train generation section 15 for changing the leading edge of the heating pulse of the subsequent multi-pulse section. After the input, the heating multi-pulse control signal is generated by the edge pulse selected by the system controller 12.

Therefore, according to the information recording apparatus of the present embodiment, the ratio Tto
Recording by CAV control using an information recording method involving update setting of the set values of p, duty ratio Tmp, and ratio ρ can be performed.

[0063]

According to the information recording method of the present invention, the ratio Ttop of the head heating pulse width to the recording clock cycle T, the duty ratio Tmp of the heating pulse of the subsequent multi-pulse portion, and the desired recording All the setting values of the ratio ρ = Pw / Pwmin of the recording power Pw at the linear velocity to the optimum recording power Pwmin at the minimum recording linear velocity are updated at predetermined intervals according to the desired recording linear velocity. So
Even if the recording linear velocity changes due to the CAV control that keeps the disk rotation speed constant, 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 present invention, even if the linear velocity at the time of recording changes due to the CAV control for keeping the disk rotation speed constant, the information is recorded from the innermost circumference to the outermost circumference of the optical disk medium. Recording of uniform characteristics over the entire surface becomes possible.

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 characteristics do not deteriorate, and the stability of the PLL of the reproduction clock is good. 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 if the recording is performed by CAV control with a constant rotation speed on various dye-based optical disk media. 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, 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 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 the CAV control for keeping the disk rotation speed constant for optical disk media having different types of dye materials, groove configurations, and the like, all the information is recorded. 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. It becomes possible.

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 of the present invention, it is possible to perform recording by CAV control using the information recording method of 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 an asymmetry-jitter characteristic diagram.

FIG. 5 is a flowchart illustrating a third embodiment of the present invention.

FIG. 6 is a block diagram showing a fourth embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a conventional example of the CLV method.

FIG. 8 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 recording information on an optical disk medium having a recording layer in which pits are formed in a heat mode by a recording pulse train of a laser beam emitted from a laser light source, a recording clock according to a change in a recording linear velocity. The recording is performed such that the recording linear density becomes substantially constant by changing the period T, and the leading heating pulse width with respect to the recording clock period T is set so as to change the leading edge of the heating pulse in the recording pulse train. The ratio ρ = Pw of the ratio Ttop and the duty ratio Tmp of the heating pulse of the subsequent multi-pulse portion in the recording pulse train to the optimum recording power Pwmin at the minimum recording linear velocity of the recording power Pw at the desired recording linear velocity.
An information recording method in which all set values of / Pwmin are updated at predetermined intervals according to a desired recording linear velocity. 2. The amount of change of each set value is updated so that all of the ratio Ttop, the duty ratio Tmp, and the ratio ρ increase in accordance with the increase in the recording linear velocity. 1. The information recording method according to 1. 3. The difference in asymmetry between the longest data and the shortest data of the recorded information to be reproduced is within 10% before and after updating the set values of the ratio Ttop, the duty ratio Tmp and the ratio ρ of the recording pulse train. The information recording method according to claim 1 or 2, wherein a change amount of each set value or an update interval is set so that 4. The ratio Ttop as an increment of each set value at a maximum recording linear velocity at an outermost peripheral position of the optical disk medium with respect to each set value at a minimum recording linear velocity at an innermost peripheral position of the optical disk medium. Is 0.3T to 0.7T
And the duty ratio Tmp is 0.05T to 0.2T.
4. The information recording method according to claim 1, wherein the ratio is set in a range of 0.3 to 0.5. 5. When the space length immediately before a mark to be formed is the shortest, the leading edge of the leading heating pulse of the recording pulse train forming the mark is rotated so that the leading heating pulse width becomes shorter. 5. The information recording method according to claim 1, wherein recording is performed with the same correction amount with respect to a change in the recording linear velocity in the constant angle method. 6. The correction amount is -0.02T to -0.07.
The information recording method according to claim 5, wherein the information is set within a range of T. 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. An information recording apparatus for recording on an optical disk medium by the information recording method according to claim 1, wherein a front edge of the head heating pulse in the recording pulse train and a subsequent multi-pulse are recorded. A multi-stage edge signal generation circuit for changing the leading edge of the heating pulse in the pulse portion; a controller for calculating and updating the set values as needed; and 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 from the controller based on each of the set values; and a driver circuit for updating the emitted light amount of the laser light source as needed.