JP2001118245A - Information recording method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use a simple method of rotating and driving a phase change type optical disk medium by a CAV method while maintaining compatibility with a recording format of a conventional read-only medium, and to cover the entire surface of the optical disk medium. Provided is an information recording method capable of recording with uniform signal characteristics throughout. SOLUTION: A head heating pulse duty ratio Tto in which a front edge of a head heating pulse in a recording pulse train is changed.
p, the final cooling pulse duty ratio Tecp obtained by changing the trailing edge of the final cooling pulse in the recording pulse train, and the erasing power ratio E of the erasing power Pe to the heating power Pw.
By updating at least two or more of the set values at predetermined intervals, the disk rotation speed is kept constant.
Even if the recording linear velocity changes due to the AV control, it is possible to record uniform characteristics over the entire surface of the phase change type optical disk 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
Information recording on a phase-change type optical disk medium having a recording layer that reversibly changes between a crystalline phase and an amorphous phase, such as a DVD-RW (ReWritable) disk having format compatibility with a read-only DVD medium such as M A method and an apparatus therefor.

[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. 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.

In view of the above, in order to perform recording on the medium while keeping the rotational 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. 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, in general, a phase-change type optical disk medium is optimized at a specific recording linear velocity by optimizing the ratio of the pulse width of a recording pulse train due to laser emission at the time of recording to the heating power and the erasing power. The speed changes the state of the formed marks and spaces. That is, excess or deficiency of the heat capacity due to the top heating pulse necessary for forming the mark occurs, the average length of the mark varies due to a change in the cooling rate, and erasure failure or deterioration of the recording film occurs due to excess or deficiency of the erasing power. As a result, the jitter of the reproduced signal deteriorates and the number of overwrites decreases.

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 degree and asymmetry of the reproduced signal change before and after the setting is changed, so that the slice level for binarization is different and jitter is deteriorated. Will occur.

Therefore, the present invention provides a method for recording information while driving a phase-change type optical disk medium having a recording layer reversibly changing between a crystalline phase and an amorphous phase while rotating the optical disk medium.
Recording with uniform signal characteristics over the entire surface of the optical disk medium using a simple method without controlling the rotation speed of the optical disk medium and maintaining compatibility with the recording format of conventional read-only media. It is an object of the present invention to provide an information recording method and an information recording apparatus capable of performing the same.

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. .

[0016]

According to a first aspect of the present invention, there is provided an information recording method, comprising: a step of irradiating a laser beam from a laser light source onto an optical disc medium having a recording layer which reversibly changes between a crystalline phase and an amorphous phase. When light is used to record information by a recording pulse train composed of a heating pulse and a cooling pulse, recording is performed by changing the recording clock cycle T according to a change in the recording linear velocity so that the recording linear density becomes substantially constant. And a leading heating pulse duty ratio Ttop obtained by changing the leading edge of the leading heating pulse in the recording pulse train.
And a final cooling pulse duty ratio Tecp obtained by changing the trailing edge of the final cooling pulse in the recording pulse train,
At least two or more set values in the set value of the recording pulse train with the erase power ratio E to the heating power Pw of the erase power Pe are updated at predetermined intervals.

Accordingly, the leading heating pulse duty ratio Ttop in which the leading edge of the leading heating pulse in the recording pulse train is changed, and the final cooling pulse duty ratio Tecp in which the trailing edge of the last cooling pulse in the recording pulse train is varied.
And at least two or more of the setting values of the erasing power Pe and the erasing power ratio E to the heating power Pw,
By updating at predetermined intervals, even if the recording linear velocity changes due to the CAV control that keeps the disk rotation speed constant, it is possible to record uniform characteristics over the entire surface of the phase change type 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 head heating pulse duty ratio Ttop is increased, the final cooling pulse duty ratio Tecp is reduced, and the erasing power ratio E 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 the V control, it is possible to perform recording with uniform characteristics over the entire range from the innermost circumference to the outermost circumference of the phase change type optical disk medium.

According to a third aspect of the present invention, in the information recording method of the first or second aspect, a difference in asymmetry between the longest data and the shortest data of the recorded information to be reproduced causes the set value of the recording pulse train to be updated. A change amount or an update interval of each set value is set so as to be within 10% before and after.

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.

According to a fourth aspect of the present invention, in the information recording method of the first, second or third aspect, the head heating pulse duty ratio Ttop is set to 0.2T to 1.0T in accordance with an increase in the recording linear velocity. , The final cooling pulse duty ratio Tecp is in the range of 1.0T to 0.2T, and the erasing power ratio E is in the range of 0.3 to 0.7. did.

Therefore, even when recording is performed on a phase-change type optical disk medium by CAV control with a constant rotation speed, it is possible to approximate the set value of the recording pulse train corresponding to the entire surface of the optical disk medium and cause a recording failure. By preventing such a setting, it becomes possible to perform recording with uniform reproduction characteristics.

The invention according to claim 5 is the invention according to claims 1 to 4.
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 according to claim 6 is the invention according to claims 1 to 5
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.

Therefore, 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 the 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.

[0028] The invention according to claim 7 provides the invention according to claims 1 to 6.
In the information recording method according to any one of the above, the recording layer of the optical disc medium is made of an AgInSbTe-based recording material.

Therefore, when performing recording by CAV control, it is possible to set a recording pulse train with high accuracy at all recording linear velocities.

In the information recording apparatus according to the present invention, a laser beam irradiated from a laser light source emits a heating pulse and a cooling beam onto an optical disk medium having a recording layer that reversibly changes between a crystalline phase and an amorphous phase. An information recording apparatus which performs recording by changing a recording clock cycle T according to a change in a recording linear velocity when recording information by a recording pulse train composed of pulses so that the recording linear density becomes substantially constant. A multi-stage edge signal generation circuit for changing the leading edge of the leading heating pulse and the trailing edge of the final cooling pulse in the recording pulse train; and leading heating by varying the leading edge of the leading heating pulse in the recording pulse train. A pulse duty ratio, a final cooling pulse duty ratio obtained by changing a trailing edge of the final cooling pulse in the recording pulse train, and erasing. A controller that calculates each set value of the erasing power ratio E with respect to the heating power Pw of the power Pe and updates the set value at any time; and a predetermined value based on the set values from a multi-stage edge signal output from the edge signal generation circuit. A selector for selecting an edge signal; and a driver circuit for updating the amount of light emitted from the laser light source as needed.

Therefore, recording by CAV control using the information recording method according to the first to seventh aspects can be performed with a simple and small circuit configuration.

[0032]

FIG. 1 shows a first embodiment of the present invention.
A description will be given with reference to FIG. First, as shown in FIG. 1, a basic recording pulse train used in a phase-change type optical disk as an optical disk medium has a pulse width set as follows.
There are a leading heating pulse duty ratio Ttop of the leading heating pulse forming the recording pulse train, a duty ratio Tmp of the heating pulse of the subsequent multi-pulse part, and a final cooling pulse duty ratio Tecp of the final cooling pulse. The setting of the recording power includes a heating power Pw, an erasing power Pe, and a bias power Pb. Regarding the recording power, since the mark formation state is not the erasing power Pe alone but has a correlation with the heating power Pw, the erasing power ratio E (= Pe / Pw) of the erasing power Pe to the heating power Pw is set. In the present embodiment, among these setting values, more detailed settings are made for the first heating pulse duty ratio Ttop, the last cooling pulse duty ratio Tecp, and the erasing power ratio E.

When recording control is performed on a phase change 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 of the disk and about 8.4 m / s at the outermost position. Becomes Therefore, it is difficult for the phase change type optical disk medium to perform uniform recording when the same set value of the recording pulse train is used for a wide range of recording linear velocities. Here, as the linear velocity becomes higher, the preliminary heating by the head heating pulse duty ratio Ptop becomes insufficient,
Since the modulation degree of the RF signal becomes lower and the asymmetry becomes smaller, as shown in FIG. 2, by updating the set value of the head heating pulse duty ratio Ptop in accordance with the increase of the recording linear velocity, A sufficient amount of heat can be applied, and good mark formation can be maintained.

Further, as the linear velocity becomes higher, the erasing power required at the time of overwriting becomes insufficient due to an increase in the cooling rate, and the jitter is deteriorated due to an erasing failure. Therefore, by updating the setting value of the erasing power ratio E so as to increase in accordance with the increase in the recording linear velocity, a sufficient erasing power can be applied, and the formation of a good space can be maintained.

On the other hand, since the cooling rate increases as the linear velocity increases, the average length of the formed marks increases,
The asymmetry of the F signal increases. Therefore, by decreasing the final cooling pulse duty ratio Pecp as the linear velocity increases, the characteristics of the RF signal can be kept constant even at different recording linear velocities.

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 values, as shown in FIG. 3, the top heating pulse duty ratio Ttop is 0.5T (≒ 1
9.1 ns) to 0.8T at the outermost position (≒ 12.6)
ns), and the set value is updated and changed so as to be 0.3 T longer in total. The interval at which the set value of the top heating pulse duty 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 final cooling pulse duty ratio Tec
p is changed from 0.7T (≒ 26.7 ns) at the innermost position to 0.4T (≒ 6.3 ns) at the outermost position, and the set value is reduced by 0.3T in total. Update has changed. Also, the final cooling pulse duty ratio Tec
The interval at which the set value of p is updated is the same as the head heating pulse duty ratio Ttop.

As for the erasing power Pe, by controlling the erasing power set value of the semiconductor laser driving current source, the erasing power ratio E of the erasing power Pe to the heating power Pw is also reduced to 0.4 at the innermost peripheral position. The set value is updated and changed so as to be increased by 0.2 from to the outermost peripheral position by 0.6. The interval at which the set value of the erasing power ratio E is updated is the same as the head heating pulse duty ratio Ttop.

As described above, the set values of the leading heating pulse duty ratio Ttop and the erasing power ratio E are increased toward the outer periphery of the disk, and the final cooling pulse duty ratio Tecp is decreased toward the outer periphery of the disk. By changing this, the reproduced RF signal is less likely to deteriorate in the degree of modulation, asymmetry and jitter, and can be recorded with a good number of overwrites.

It should be noted that the heating power Pw is determined by the test writing (OP
The optimum value is determined by C), and may be different depending on the recording linear velocity.

By the way, each set value described above is based on AgIn
This is a representative value for an SbTe-based phase change optical disc, and can be different depending on various tunings and material compositions. That is, GeSbTe is used as a recording layer of a conventionally used phase change type optical disk medium.
System, GeTeSbS system, TeGeSnAu system, GeTe
Sn system, SbSe system, SbSeTe system, SnSeTe
System, GaSeTe system, GaSeTeGe system, InSe
System, InSeTe system, AgInSbTe system, etc.
In the present embodiment, as described above, AgInSbTe
System recording material is used. When recording data on a phase-change type optical disk medium of this recording material, it is highly dependent on amorphous formation with respect to changes in the rapid cooling conditions from heating to cooling due to changes in the recording linear velocity. The shape of the edge portion and the size of the mark depend on the leading heating pulse duty ratio Ttop, the final cooling pulse duty ratio Tecp, and the erasing power ratio E. Therefore, the shape and size of the front and rear edge portions of the mark can be controlled with high precision. Further, the above-mentioned optimum value of the set value of the recording pulse train tends to be almost linearly approximated, which indicates that the recording material of the AgInSbTe system easily controls the mark length. However, even with other recording materials, the relationship between the emission power and the jitter characteristic and the overwrite characteristic, and the relationship between the recording pulse width and the mark length are basically the same, and it goes without saying that this recording method is effective. No.

In any case, in order to perform the recording by the CAV control, the setting range of the heating portion, the cooling portion, and the erasing portion is limited, so that the leading heating pulse duty ratio Ttop is 0.2T to 1.0T. , The final cooling pulse duty ratio Tecp is in the range of 1.0T to 0.2T, and the erasing power ratio E is in the range of 0.3 to 0.7. is there.

In accordance with the increase in the recording linear velocity, as described above, the interval for updating each set value 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 that greatly affects the jitter characteristics needs to be within ± 10%. As shown in FIG. 4, when the difference between the asymmetry before and after the update of the set value is 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 difference in asymmetry is within ± 5%.

The above three setting values (the setting values of the top heating pulse duty ratio Ttop, the last cooling pulse duty ratio Tecp, and the erasing power ratio E) have their respective effects. In order to have an effect, it is desirable to carry out with at least two set values. It should be noted that the most effect is obtained when all three set values (set values of the top heating pulse duty ratio Ttop, the last cooling pulse duty ratio Tecp, and the erasing power ratio E) are updated as in the present embodiment. Needless to say.

A second embodiment of the present invention will be described with reference to FIG. Generally, a groove groove for obtaining a tracking error signal (push-pull signal) is formed on a phase change type optical disk medium, and a wobble signal obtained by meandering the groove groove is superimposed. At the recording linear velocity, detected by the programmable BPF,
By demodulating the address information encoded by frequency modulation or phase modulation, address information and disk information unique to the disk can be obtained even for an unrecorded disk. It is also known that such information is generated by cutting intermittent pits (Land-PrePit signal) in the land portion. Such disc information includes 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 optimum head heating pulse duty ratio Ttop, final cooling pulse duty ratio Tecp, and erasing power ratio E are embedded in advance and read out (step S
1) The optimum set value is obtained, and the amount of change (or gradient) of the set value linearly approximated 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 LPP 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). Recording can be performed continuously. 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.

A third embodiment of the present invention will be described with reference to FIG. In the present embodiment, the information to be recorded on the optical disk medium by using the above-described information recording method (while setting and updating the set values of the head heating pulse duty ratio Ttop, the final cooling pulse duty ratio Tecp, and the erasing power ratio E). It relates to a recording device.

First, the optical disc medium 1 is provided with a rotation mechanism 3 including a spindle motor 2 for driving the optical disc medium 1 to rotate, 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.
The wobble detector 7 is connected to an address demodulation circuit 8 for demodulating an address from the detected wobble signal.
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. On the output side of the recording pulse train control unit 14, an LD driver as a driver circuit for driving the semiconductor laser in the optical head 4 by switching the respective drive current sources 18 of the heating power Pw, the erasing power Pe, and the bias power Pb. 19 are 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. An erasing pulse control signal, which is an erasing portion, is also generated.
The respective drive current sources 18 of w, erase power Pe, and bias power Pb are switched. During recording, an erasing power Pe equivalent to cooling power is constantly supplied by a bias current source.
Then, the semiconductor laser emits light, and the laser emission waveform of the recording pulse train as shown in FIG. 1 can be obtained by the heating pulse control signal and the erasing pulse control signal generated by the recording pulse train generator 15 described above.

In this embodiment, the head heating pulse generator in the recording pulse train generator 15 has a delay amount of 0.5 n.
A multi-stage delay (gate delay) element 17 of about s is provided, and after being input to an edge selector 16 having a multiplexer configuration, a head heating pulse control signal for changing a leading edge by an edge pulse selected by the system controller 12 is provided. Generated. Similarly, in the erase pulse generation circuit in the recording pulse train generation unit 15 corresponding to the trailing edge of the final cooling pulse, a multi-stage delay element 17 having a delay amount of about 0.5 ns is arranged. The erase pulse control signal is generated by the edge pulse selected by the controller 12.

Therefore, according to the information recording apparatus of the present embodiment, the set values of the head heating pulse duty ratio Ttop, the final cooling pulse duty ratio Tecp, and the erasing power ratio E as described above can be obtained with a simple and small circuit configuration. Recording by CAV control using an information recording method with an update setting of.

[0054]

According to the information recording method of the present invention, the leading heating pulse duty ratio Ttop obtained by changing the leading edge of the leading heating pulse in the recording pulse train and the trailing edge of the last cooling pulse in the recording pulse train are determined. At least two or more of the set values of the changed final cooling pulse duty ratio Tecp and the erase power ratio E of the erase power Pe with respect to the heating power Pw are updated at predetermined intervals. Even if the recording linear velocity changes due to the CAV control in which the number of revolutions is kept constant, it is possible to record uniform characteristics over the entire surface of the phase change type 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 phase change type optical disk medium has the maximum innermost position. Recording of uniform characteristics over the entire outer periphery becomes possible.

According to the information recording method of the present invention, it is possible to suppress the variation of the binarization with respect to the slice level, without deteriorating the jitter characteristic, and improving the stability of the PLL of the reproduced clock. Becomes possible.

According to the information recording method of the present invention, even if recording is performed on a phase change type optical disk medium by CAV control with a constant rotation speed, a recording pulse train corresponding to the entire optical disk medium can be recorded. The set value can be approximated, and a setting that causes a recording failure can be prevented, thereby enabling recording with uniform reproduction characteristics.

According to the information recording method of the present invention, recording is performed with uniform characteristics over the entire surface of the phase change type optical disk medium by a simple method without updating the set value 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 method of the present invention, when performing recording by CAV control, it is possible to set a recording pulse train with high accuracy at all recording linear velocities.

According to the information recording apparatus of the present invention, it is possible to perform recording by CAV control using the information recording method of the present invention 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-pulse duty ratio and an erasing pulse ratio.

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

FIG. 4 is an asymmetry difference-jitter characteristic diagram.

FIG. 5 is a flowchart showing a second embodiment of the present invention.

FIG. 6 is a block diagram showing a third 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 (8)

[Claims] 1. A laser beam emitted from a laser light source records information on an optical disk medium having a recording layer that reversibly changes between a crystalline phase and an amorphous phase by a recording pulse train including a heating pulse and a cooling pulse. When performing the recording, the recording clock cycle T is changed in accordance with the change in the recording linear velocity, recording is performed so that the recording linear density becomes substantially constant, and the leading edge of the head heating pulse in the recording pulse train is changed. Setting of the recording pulse train including a first heating pulse duty ratio Ttop, a final cooling pulse duty ratio Tecp obtained by changing a trailing edge of the last cooling pulse in the recording pulse train, and an erasing power ratio E of the erasing power Pe to the heating power Pw. An information recording method in which at least two or more set values are updated at predetermined intervals. 2. In accordance with an increase in the recording linear velocity, the head heating pulse duty ratio Ttop is increased, the final cooling pulse duty ratio Tecp is decreased, and the erasing power ratio E is increased. 2. The information recording method according to claim 1, wherein a change amount of the set value is updated. 3. The amount of change of each set value or the amount of 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 value of the recording pulse train. Claim 1 in which an update interval is set.
Or the information recording method according to 2. 4. The head heating pulse duty ratio Ttop is set to 0.2T to 1.0T in accordance with an increase in the recording linear velocity.
, The final cooling pulse duty ratio Tecp is set to 1.
0T to 0.2T, and the erasing power ratio E is 0.3 to
4. The information recording method according to claim 1, wherein the amount of change of each set value is increased or decreased within a range of 0.7. 5. The method according to claim 1, wherein the setting value of the recording pulse train preformatted on the optical disc medium or the setting value of the recording pulse train included in disc information previously recorded in a predetermined area. 5. 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. 6. A method for 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 to be updated at the predetermined interval, and The information recording method according to any one of claims 1 to 5, wherein the information is associated with a range of an address. 7. The optical disc medium according to claim 7, wherein the recording layer is
7. A recording material comprising gInSbTe-based recording material.
The information recording method according to any one of the above. 8. A laser beam emitted from a laser light source records information on an optical disk medium having a recording layer that reversibly changes between a crystalline phase and an amorphous phase by a recording pulse train composed of a heating pulse and a cooling pulse. An information recording apparatus that changes the recording clock cycle T in accordance with a change in the recording linear velocity to perform recording so that the recording linear density becomes substantially constant. A multi-stage edge signal generation circuit for changing the leading edge and the trailing edge of the final cooling pulse, a leading heating pulse duty ratio in which the leading edge of the leading heating pulse in the recording pulse train is changed, and The final cooling pulse duty ratio in which the trailing edge of the final cooling pulse is changed, and the erasing power P
e, a controller that calculates each set value of the erasing power ratio E with respect to the heating power Pw and updates the set value at any time; and a predetermined edge based on the set values from a multi-stage edge signal output from the edge signal generation circuit. An information recording device, comprising: a selector for selecting a signal; and a driver circuit for updating the amount of light emitted from the laser light source as needed.