JP2002183954A - Optical information recording method, optical information recorded and trial recording method of optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-valued recording system which obtains stable recoding marks in multi-valued recording. SOLUTION: A phase transition material changes from an amorphous state to a crystallized state by the recording laser power set at Pe. Overwrititing recording (recording while erasing) is made possible by this effect. The ratio of the amorphous state and the crystallized state of the recording marks is changed by changing this Pe, by which the value of a pit level is regulated. The change in the pit level when Pe is changed is shown in Figure 5. The abscissa ε in the graph of Figure 5 is defined by ε=Pe/Pw1 (=Pw2). The recording conditions at this point are Pw1=Pw2=13, 2 mW, Ttop=0.9 T, Tmp=0.45 T and they are the results of the recording with a mark length 4 T. The experimental results indicate that the pit level can be changed in a range from 0.3 to 0.6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording / reproducing method which controls the signal level of a recording pit to a binary value or more.

[0002]

2. Description of the Related Art Hitherto, various information reproducing apparatuses for reproducing information recorded on an information recording medium by multi-value recording have been proposed. (1) JP-A-4-111230 (2829)
No. 108) discloses a light beam output means for outputting a light beam, an optical system for condensing the light beam output from the light beam output means on a recording portion of the information recording medium, Optical property detecting means for receiving the reflected light beam and outputting an electric signal corresponding to the optical property of the recording portion; and differentiating the signal waveform of the electric signal output by the optical property detecting means by differentiating the signal waveform. Differentiating means for outputting a waveform, clock generating means for detecting a zero crossing of the differentiated waveform input from the differentiating means to generate a demodulated clock, and synchronizing with the demodulated clock obtained by the clock generating means. There has been disclosed an information reproducing apparatus including a reproduction signal generating means for detecting a signal level of the electric signal.

Further, (2) Japanese Patent Application Laid-Open No. 11-39656 discloses that two states having different crystal states are generated in an irradiation area depending on whether a recording medium is irradiated with a light beam. An optical information recording method for recording information based on a difference in optical characteristics is characterized in that the method is performed as follows. The light beam irradiation frequency is made to correspond to a pulse signal. The irradiation area is irradiated with a light beam according to the number of the pulse signals. There is disclosed a technique for recording multi-valued information in the irradiation area by making a plurality of intermediate states exist between two states having different crystal states. Further, (3) JP-A-1-154321 (second
No. 6,348,27) discloses a method in which a signal having a step-like waveform test pattern is recorded on an optical disk surface, a reproduction signal corresponding to the set test pattern is accurately detected, and a reproduction test pattern as a result of the detection is described above. Optimizing the recording conditions by controlling the modulation circuit 4 and setting the recording power or recording pulse width of the laser light so that the two test patterns, which are the results of the comparison, are accurately compared with the set test pattern. A technique for performing this is disclosed.

Here, a recording laser power control system which is a conventional multi-value recording system will be described. FIG. 1 shows a recording pulse waveform. Top pulse
And a subsequent multi-pulse sequence, and the recording laser power (Recording power) can be adjusted independently of Pw1 and Pw2. In order to overwrite, the erase laser power (Erase Power) Pe is biased. In order to perform multi-level recording, there is a method of changing the recording laser power. FIG. 2 shows that Pw1 = Pw2, ε = P
e / Pw1 = 0.58, head pulse length Ttop = 0.9
T (T is the width of the reference clock), multi-pulse length Tmp
= 0.45T, and a result of recording with a mark length of 4T (T = 38 ns).

As a recording material, AgInSbT is used.
The phase change material of e is used. The recording device has a recording laser wavelength of 635 nm, the NA of the objective lens is 0.6, and the recording medium has a track pitch (an interval between grooves).
TP = 0.47 μm and recording linear velocity V = 3.5 m / s. Under these conditions, around Pw1 = 13 mW,
The jitter of the recorded mark (the deviation of the mark interval was represented by σ, the reference clock was represented by Tw, and the jitter was represented by σ / Tw) was minimized. As shown in FIG. 2, when Pw1 is reduced, FIG.
The pit level of the recording mark shown in (1) increases (the value of the pit level increases), and as a result of the experiment, the pit level can be changed in the range of 0.5 to 0.9. However, since the recording state is not optimal, that is, the recording mark is not properly amorphized, the formation of the recording mark is insufficient and the mark formation is uneven. As shown in FIG. 4, there is a problem that the recorded information cannot be reproduced accurately because the jitter increases depending on the pit level change.

[0006]

By the way, (1) In the technology described in Japanese Patent Application Laid-Open No. 4-111230 (No. 2829108), a recording material (a magneto-optical recording material or a recording medium) used for an erasable so-called rewritable optical disk is used. In general, the pit level of the reproduction signal is not proportional to the light irradiation energy at the time of recording and becomes non-linear, and the recording characteristics are changed by the laser power (see FIG. 2). In this case, the higher the recording laser power, the lower the pit level of the recording mark (see FIG. 3) tends to be. This change in pit level enables multi-valued recording. However, as the recording laser power is lower (the pit level is larger), the recording mark length deviates from the ideal length (Bo).
(totJitter: numerical value obtained by dividing the standard deviation σ by the reference clock time width Tw) tends to increase (see FIG. 4). This is because when the recording laser power is low, the formation of the recording mark is insufficient and the recording mark becomes unstable. In the recording marks in such an insufficient state, the mark lengths are not uniform, which causes a problem in signal quality. (2) In the technique described in JP-A-11-39656, the number of light beam irradiations is made to correspond to a pulse signal, and the light beam is irradiated to the irradiation area according to the number of pulse signals. As a result, multi-level recording becomes possible by providing a plurality of intermediate states between two states having different crystal states. However, since a recording laser optical system requires a plurality of beams (multi beams), the optical system becomes complicated,
In addition, the configuration of the recording apparatus is complicated in that light quantity control and pulse control of each multi-beam are required. Also,
Since an intermediate medium in which the recording state is amorphous and crystallized is used, it is impossible to avoid the problem of insufficient recording mark variation as described in Japanese Patent Laid-Open No. 4-111230.

(3) JP-A-1-154321 (No. 263)
No. 4827), the principle of multilevel recording is realized by adjusting the recording power and the pulse length. Even in this method, a multi-value recording method using recording power is basically employed.
There is a problem that the pit level at which multi-value recording is performed is liable to fluctuate due to the recording mark in an insufficient state as described in JP-A-1230.

Therefore, a first object of the present invention is to provide a multi-level recording method for obtaining a stable recording mark in multi-level recording. A second object of the present invention is to provide a multi-level recording apparatus for obtaining stable recording marks in multi-level recording. A third object of the present invention is to provide a test recording method for obtaining a stable recording mark in multi-value recording.

[0009]

According to the first aspect of the present invention,
In the optical information recording method of determining the presence or absence of light beam irradiation on the recording medium, generating two states having different crystal states with respect to the irradiation area, and recording information by a difference in optical characteristics in each state, When the number of pit levels for multi-level recording is n, erasing laser powers for n pit levels for different pit levels detected from the recording marks are arranged, and the value of the erasing laser power is adjusted according to the information to be recorded. The first object is achieved by recording and recording multi-valued information in the irradiation area by modulating and making n intermediate states exist between the two crystal states different from each other.

According to a second aspect of the present invention, there is provided an optical information recording apparatus using an optical information recording method for performing recording by irradiating an optical information recording medium with a light beam according to the first aspect of the present invention. Converting means for converting the erasing laser power into a bias value for controlling the laser output, and irradiating the light beam converted by the converting means by modulating the erasing laser power of the light beam, and performing crystallization in accordance with multi-value information. The second object is achieved by providing a plurality of states having different degrees.

According to a third aspect of the present invention, in the optical information recording method according to the first aspect, the focused laser beam diameter B
The relationship between D and the length PL in the circumferential direction of a multi-value recorded recording mark is PL / BD = 0.63 to 0.94, and a plurality of states in which the degree of crystallization varies according to the multi-value information. Is characterized by being present. According to the fourth aspect of the present invention, it is determined whether the recording medium is irradiated with the light beam, and two states having different crystal states are generated in the irradiation area, and information is obtained by a difference in optical characteristics in each state. In the optical information recording method of changing the radial mark width of a recording mark to a different pit level when recording a recording mark, a recording laser pulse is composed of a leading pulse and a succeeding pulse train, and the laser power Pw1 of the leading pulse is used. The width of the recording mark is determined in the radial direction, the individual pulse lengths Tmp of the subsequent pulse trains are adjusted to make the mark width of the recording mark uniform, and the combination of Pw1 and Tmp of these recording pulses is adjusted according to the information to be recorded. It is characterized in that multi-value information is recorded in the illuminated area by the presence of recording marks having different mark widths. To. According to a fifth aspect of the present invention, there is provided an optical information recording apparatus using the optical information recording method according to the fourth aspect, wherein n combinations of Pw1 and Tmp are prepared corresponding to multi-valued information, and
A conversion means for converting a combination of recording conditions into a laser pulse signal for recording, and irradiating an optical information recording medium with a light beam optically modulated by the laser pulse signal converted by the conversion means, and in accordance with the multi-valued information. A plurality of states having different recording mark widths are present.

According to the present invention, it is determined whether or not the recording medium is irradiated with the light beam, and two states having different crystal states are generated in the irradiation area, and a difference in optical characteristics between the respective states is obtained. When information is recorded by, in the optical information recording method of changing the radial mark width of the recording mark to different pit levels, the recording laser pulse is
It is composed of a leading pulse and a succeeding pulse train, and determines the radial mark width of the recording mark length by the leading pulse length Ttop,
By adjusting the individual pulse lengths Tmp of the subsequent pulse trains, the mark width of the recording mark is made uniform, and modulated in accordance with the information to be recorded by a combination of Ttop and Tmp of these recording pulses, so that the mark width of the recording mark differs. It is characterized in that multi-value information is recorded in the irradiation area by the presence of a recording mark. According to a seventh aspect of the present invention, there is provided an optical information recording apparatus using the optical information recording method according to the sixth aspect, wherein Ttop and Tmp correspond to multilevel information.
Conversion means for preparing n combinations of the above, and converting the n combination recording conditions into a laser pulse signal for recording; and an optical information recording medium which optically modulates the light beam with the laser pulse signal converted by the conversion means. And a plurality of states having different recording mark widths according to the multi-valued information are present.

According to the present invention, it is determined whether or not the recording medium is irradiated with the light beam, and two states having different crystal states are generated in the irradiated area, and a difference in optical characteristics between the respective states is obtained. When information is recorded by, in the optical information recording method of changing the radial mark width of the recording mark to different pit levels, the recording laser pulse is
It is composed of a leading pulse and a succeeding pulse train, and determines the radial mark width of the recording mark length by the leading pulse length Ttop,
The mark width of the recording mark is made uniform by adjusting the individual laser power Pw2 of the subsequent pulse train, and modulated according to the combination of Ttop and Pw2 of these recording pulses according to the information to be recorded. It is characterized in that multi-value information is recorded in the irradiation area by the presence of a recording mark. According to a ninth aspect of the present invention, there is provided an optical information recording apparatus using the optical information recording method according to the eighth aspect, wherein Rrop and Pw correspond to multilevel information.
A conversion means for preparing n combinations of 2 and converting the n combination recording conditions into a laser pulse signal for recording; and optically recording the light beam with the laser pulse signal converted by the conversion means. It is characterized in that a plurality of states having different recording mark widths according to the multi-valued information exist by irradiating the medium.

According to the tenth aspect of the present invention, the presence or absence of light beam irradiation on the recording medium is determined, and two states having different crystal states are generated in the irradiation area, and the difference in optical characteristics between the respective states is determined. In the optical information recording method of changing the radial mark width of the recording mark to different pit levels when information is recorded by using the recording laser pulse, the recording laser pulse is composed of a head pulse and a subsequent pulse train, and has a head pulse length Ttop. The mark width in the radial direction of the recording mark length is determined by adjustment, the mark width of the recording mark is made uniform by adjusting the individual pulse length Tmp of the subsequent pulse train, and the Ttop and T of these recording pulses are adjusted in accordance with the information to be recorded.
It is characterized in that multi-value information is recorded in the irradiation area by modulating with a combination of mp and causing recording marks having different recording mark widths. According to an eleventh aspect of the present invention, in the optical information recording apparatus according to the eighth aspect, n combinations of Ttop and Tmp are prepared corresponding to the multilevel information,
A conversion means for converting the n combination recording conditions into a laser pulse signal for recording; and a light beam which is light-modulated with the laser pulse signal converted by the conversion means and irradiates an optical information recording medium to convert the multi-valued information into multi-value information. A plurality of states having different recording mark widths corresponding thereto are provided. According to the twelfth aspect of the present invention, in the optical information recording apparatus according to the second aspect, when performing the test recording for calculating the optimum recording condition, the test recording is performed using the erasing laser power as a variable parameter, and each of the erasing laser power values and the pits are determined. The third object is achieved by regressing the level correlation and calculating an erasing laser power condition that results in a desired pit level.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. First, an erasing laser power control method (first embodiment) will be described. As described in the background art, Pe bias power is added to a recording pulse to enable overwriting. With the recording laser power set to this Pe, the phase change material changes from an amorphous state to a crystallized state. With this effect, overwrite recording (recording while erasing) becomes possible. In the present embodiment, by changing this Pe, the ratio between the amorphous state and the crystallized state of the recording mark is changed, and the value of the pit level is adjusted. FIG. 5 shows the change in the pit level when Pe is changed. The horizontal axis ε in the graph of FIG. 5 is ε = Pe / Pw1 (=
Pw2). The recording condition at this time is Pw1 = P
w2 = 13.2 mW, Ttop = 0.9T, Tmp =
This is the result of recording with a mark length of 4T at 0.45T. Experimental results show that the pit level can be changed in the range of 0.3 to 0.6.

As described in the background art, the recording laser power method has a problem that the jitter of a recorded mark increases. However, as shown in FIG. 6, in this embodiment in which ε is changed, The increase with respect to the optimum recorded jitter is small. For this reason, the irregularity of the multi-value recorded recording marks is small, and the recorded information can be reproduced accurately.

FIG. 7 shows a recording pulse waveform according to the present embodiment. For each recording pit, erase laser power Pe
Is changed, multi-level recording having different pit levels can be performed. In FIG. 7, the erasing laser power Pe1 and Pe2 for erasing the recording mark of Pe0 are erasing laser powers for setting different pit levels. When the number of levels to be multi-valued is n, erase laser powers for different pit levels are arranged from Pe1 to Pen, and multilevel recording is possible by modulating the value of Pen according to the information to be recorded. Becomes

Next, a Pw1 or Ttop length × Tmp control method (second embodiment) will be described. Ratio of recording mark area to reproduction beam diameter (contrast)
The pit level changes. In order to stably perform multi-value recording using this principle, a method that requires less fluctuation due to recording conditions is required. The recording mark width can be changed by changing the recording laser power Pw1 (see FIG. 2).
It is also possible to change with p length or a combination of Ttop length and Tmp length. This is because the surface area of a certain recording mark substantially contributes as the total of the recording laser pulses represented by the pulse train. The role of the leading pulse and the subsequent pulse train is such that the leading width of the recording mark formed by changing the Pw1 or Ttop length changes, and the Pw2 or Tmp length of the succeeding recording pulse train is changed to the width of the leading mark. If adjusted together, there is a characteristic that the width of the recording mark can be made uniform to an arbitrary value.

(Results with Ttop Length) Although it is possible to change the recording laser power Pw1 of Ttop, as described in the section of the conventional method, in the pit level adjustment by the recording laser power, jitter increases due to recording mark fluctuation. Tend to. FIG. 8 shows a change in the pit level when the Ttop length is changed. The recording condition at this time is P
w1 = Pw2 = 13.2 mW, ε = 0.300, Tmp
= 0.45T. The recording pulse waveform at this time is shown in FIG. When the Ttop length is 0.8T or more, the change in the pit level is small, and it can be expected that the change due to the recording condition is small. When the Ttop length is 0.6T or more, jitter fluctuation is small, and stable multi-value recording can be performed. From this result, in the multi-value recording aiming at the pit level 0.45, it can be said that Ttop ≧ 0.8T is a combination of the stabilization conditions (see FIG. 9).

However, in the region of Ttop <0.6, since the recording conditions of the first pulse and the pulse train are not in an appropriate combination, the recording mark shape becomes “tear-shaped” as shown in FIG.
It is considered that the recording mark tends to fluctuate depending on the recording conditions and the jitter increases because the recording head has a narrow head and a wide rear end. (Combination control method of Ttop length and Tmp length) The above result is a result of adjusting the pulse train recording condition of Pw2 = 13.2 mW and Tmp = 0.45T and the Ttop condition to an appropriate range. Therefore, an example in which the recording condition of the succeeding pit train is optimized to the condition of the leading pulse train, that is, an example in which Tmp is adjusted in accordance with Ttop will be described. FIG. 11 shows a change in the pit level when the Tmp length is changed. The recording condition at this time is Pw1
= Pw2 = 13.2 mW, ε = 0.30, Ttop =
0.90T. The recording pulse waveform at this time is shown in FIG. In the range of Tmp ≦ 0.5, the change of the pit level is small, and it can be expected that the change due to the recording condition is small. Also, it can be seen that the jitter in this region is a combination of favorable conditions of 4% or less (see FIG. 12).
In this way, by controlling the Ttop length and the Tmp length in combination, stable multi-value recording can be performed.

Next, a Ttop length × Pw2 control system according to a third embodiment will be described. Even if the laser power Pw2 of the pulse train is adjusted instead of adjusting the Tmp length, stable multi-value recording can be performed. FIG. 14 shows a change in the pit level when Pw2 is changed. The recording conditions at this time were: Pw1 = 13.2 mW, ε = 0.30, Tto
p = 0.90T and Tmp = 0.45T. The recording pulse waveform at this time is shown in FIG. 0.3 ≦
In the range of Pw2 / Pw2 ≦ 0.9, the change of the pit level is small, and it can be expected that the change due to the recording condition is small. Also, it can be seen that the jitter in this region is a combination of favorable conditions of 4% or less (see FIG. 15). Like this
By controlling the combination of the Ttop length and Pw2, stable multi-value recording can be performed.

The relationship between the recording mark length and the recording / reproducing laser beam diameter in the erasing laser power control system will be described. FIG. 17 shows the relationship between the recording mark length and the pit level in the erasing laser power control multilevel recording system (notes are also added in 3T to 8T in the graph), and FIG. 1 shows the relationship between the recording mark length and the jitter.
It is shown in FIG. From FIG. 17, as the recording mark length is longer,
It can be seen that the rate of change of the pit level with respect to ε is low. This is related to the recording / reproducing laser beam diameter and the size of the recording mark. The tendency in FIG. 17 is that when the recording mark length is smaller than the beam diameter, the contrast caused by the recording mark appears as a change in the pit level as it is, and when the recording mark length is larger than the beam diameter, the recording mark becomes larger. , The change in the pit level is small and the change rate is saturated. For this reason, the longer the recording mark length, the lower the rate of change of the pit level with respect to ε.

On the other hand, it can be seen from FIG. 18 that the shorter the recording mark length, the higher the pit level change rate with respect to ε. However, the shorter the recording mark, the narrower the margin with respect to ε. In particular, when the recording mark length is 3T, ε =
If it deviates from around 0.25, the jitter rapidly increases, so that multi-level recording in which the pit level is changed is possible, but the recorded information cannot be accurately reproduced due to the increase in the jitter. From the consideration of FIGS. 17 and 18, it is possible to derive the range of the recording mark length in which recording and reproduction can be performed stably. When the recording mark length is around 3T, the jitter increases, and when the recording mark length is 6T or more, the change rate is saturated.
Can be said to be an appropriate range. In FIG. 17, the recording / reproducing laser beam diameter is about 0.85 μm, and the recording mark is 1
Since T is about 0.13 μm, in nT, the recording mark length is calculated as 0.13 × n. If this range is expressed by the ratio of the beam diameter to the recording mark length, 4T recording mark length / beam diameter (BD) = 0.53 / 0.85 = 0.
From around 63, 6T recording mark length / beam diameter (BD) =
0.80 / 0.85 = 00.94.

Next, a multi-value recording embodiment will be described. (1) Embodiment Using Erase Laser Power Control System An embodiment using the erase laser power control system will be described with reference to FIGS. In the example of FIG. 19, the binary-represented Data (11001001111001) is multi-valued, divided in 2-bit units, and multi-valued information Data '
(3021321) and multi-level recording. The four-level multi-level code has a pit level of 100%, 5
They correspond to 5%, 45% and 35%. Each pit level corresponds to a 100% multi-level code (1), a 45% multi-level code (2), and a 35% multi-level code (3). With this four-value recording, the recording capacity can be doubled as compared with the case where the conventional binary code is recorded as it is.

The recording conditions of this embodiment are as shown in FIG.
e Power (ε = Pe / Pw) and pit level ”, set the value of ε for each pit level, when pit level is 100% ε = 0.58, when pit level is 55% ε = 0.5, when pit level is 45% ε =
0.3 and ε = 0.2 when the pit level is 35%. Other recording conditions are Pw1 = Pw2 = 13.2 mW,
Ttop = 0.9T, Tmp = 0.45T, and the mark length was 4T. (T = 38 ns) The recording pulse waveform is shown in FIG. According to each pit level,
When the pit level is 100%, Pe0 (ε
= Pe1 / Pw1 = 0.58), pit level 55%
Pe2 (ε = Pe2 / Pw1 = 0.5) when the pit level is 45%, and Pe2 (ε = Pe2 / Pw1 = 0.
3) When the pit level is 35%, Pe3 (ε = Pe3 /
Pw1 = 0.2).

When the fluctuation (jitter value BJ) of the pit rise and rise interval at each pit level was measured, BJ = 3.9% when the pit level was 55% and BJ = 45% when the pit level was 45%. = 4.2%, pit level 3
At 5%, BJ = 4.5%, which is a range in which signal reproduction can be stably performed. In this embodiment, four-valued other value recording is performed. However, if the pit level is set to eight values by adjusting ε, the recording capacity can be quadrupled as compared with the case where the conventional binary code is recorded as it is. It is.

Ttop length × Tmp length Control method In the same manner as in the example of FIG.
In this example, multi-valued data is converted into multi-valued information Data '(3021321), and multi-valued data is recorded. The pit level is 100%, 55%, 45%, 35%
It corresponds to. Each pit level corresponds to a 1000% multi-level code (1), a 45% multi-level code (2), and a 35% multi-level code (3). With this four-value recording, the recording capacity can be doubled as compared with the case where the conventional binary code is recorded as it is. The recording conditions of the present embodiment are such that the pit level is 55% for each pit level with reference to the results of FIGS.
When Ttop = 0.5T and Tmp = 0.2T, when the pit level is 45%, Ttop = 0.8T and Tmp = 0.4
T, when the pit level is 35%, Ttop = 0.9T and T
mp = 0.55T.

Other recording conditions are Pw1 = pw2 = 13.
The mark length was 4T at 2 mW and ε = 0.30. (T =
38 ns) The recording pulse waveform is shown in FIG. The fluctuation (jitter value BJ) of the interval between the rising and falling of the pits at each pit level was measured. When the pit level was 55%, BJ = 4.5%, and when the pit level was 45%, BJ = 3. When the pit level was 8% and the pit level was 35%, BJ was 3.8%, which was a range in which the signal could be stably reproduced.

Calibration method for optimum recording conditions There is a problem that the optimum recording laser power and the above-mentioned ε value are shifted from the optimum recording conditions due to the difference between the surfaces of the optical information recording medium and the difference between the optical information recording devices. In particular, in the case of multi-level recording, when a pit level is recorded with a deviation from a target value, a fatal problem that recorded information cannot be reproduced occurs. For this reason, it is important to maintain a state in which recording is performed under optimum recording conditions in a combination of the target optical information recording medium and the optical information recording device. In the present embodiment, a method is employed in which a test recording area is provided in a system area other than the user area (the area for recording user information), and before the information is recorded in the user area, an optimum recording condition is determined in this test recording area. did. FIG. 23 shows the layout of the test recording area according to the present embodiment. Test recording area PCA (Power Calibir)
area for recording a plurality of tracks in the user recording area and a start address and an end address of each track PMA (Program Me).
memory area), an area PA (Program Area) for recording user information in track units, an area Lin for recording the content of each track, an area Lou which is an end area of each track and a connection area for the next track.
It is composed of a t region.

The PCA is designed so that test recording can be performed a plurality of times.
It is divided into a plurality of frames.
Each frame can be trial-recorded, and each frame can be trial-recorded under 16 types of recording conditions. Also, the default condition is recorded in advance in the system area of the optical information recording medium so as to be superimposed on the address information,
This default condition was read by an optical information recording device and a test recording was performed. In this embodiment, the default condition is
Pw1 = Pw2, ε0 (erasing laser power), Tto
p, Tmp, the pit level of multi-level recording is four, and the erasing laser power control method used in the first embodiment is adopted. As shown in FIG. 22, the default recording condition recorded in the system area in advance is reproduced (steps 10 to 12), and a table of ε for trial multi-value recording is created based on this condition (step 1).
3). After the test recording (step 14), a correlation equation with the pit level for each ε is calculated (step 15).
Based on this calculation formula, ε at which a target pit level can be recorded is calculated (step 16), and if it is used when recording in user information (step 17), the pit level is recorded with a deviation from the target value. Problems can be solved.

The regression equation calculated by the trial recording is represented by Y =
0.22 * LnX + 0.70 (X: ε, Y: pit level), and when the pit level is 55%, ε = 0.51
(Pe1 = 13.2 * 0.51 = 6.68 mW), and when the pit level is 45%, ε2 = 0.32.
2 * 0.32 = 4.24mW), pit level 35%
Ε3 = 0.20 (Pe3 = 13.2 * 0.20 =
2.69 mW).

[0032]

According to the present invention, a stable recording mark having a different pit level can be obtained only by changing the erasing laser power, so that the recording pulse control is easy. The second aspect of the invention is the same as the first aspect. Claim 3: Since the relationship between the recording laser beam diameter and the recording mark length on which a multi-value recording mark can be formed is limited, stable multi-value recording can be recorded and reproduced. Claims 4 to 1
According to the first aspect of the present invention, in a method of performing multi-level recording using a difference in radial width of a recording mark, a recording method in which the radial width of a recording mark is uniform is provided. Can be recorded and reproduced. According to the twelfth aspect of the present invention, a test recording method for obtaining a stable recording mark in multi-value recording can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a model of a recording pulse waveform.

FIG. 2 is a diagram showing a relationship between recording power and a pit level.

FIG. 3 is an explanatory diagram of a multi-level recording pit level.

FIG. 4 Recording power and jitter (σ / Tw)
FIG.

FIG. 5 is a diagram showing a relationship between an erasing laser power (ε = Pe / Pw) and a pit level.

FIG. 6 is a diagram showing a relationship between an erasing laser power (ε = Pe / Pw) and a jitter (σ / Tw).

FIG. 7 is a diagram showing an example of a pulse waveform according to the embodiment of the present invention.

FIG. 8 is a diagram showing a relationship between a Ttop length and a pit level.

FIG. 9 is a diagram showing a relationship between Ttop and jitter (σ / Tw).

FIG. 10 is a diagram showing an example of a recording pulse waveform of Ttop length control according to the embodiment of the present invention.

FIG. 11 is a diagram showing a relationship between a Tmp length and a pit level.

FIG. 12 is a diagram showing a relationship between Tmp and jitter (σ / Tw).

FIG. 13 shows Ttop length and Tm according to the embodiment of the present invention.
FIG. 7 is a diagram illustrating an example of a recording pulse waveform of p-length combination control.

FIG. 14 is a diagram showing a relationship between Pw2 and a pit level.

FIG. 15 is a diagram showing a relationship between Pw2 and jitter (σ / Tw).

FIG. 16 shows Ttop length and Pw according to the embodiment of the present invention.
FIG. 4 is a diagram showing an example of a recording pulse waveform of two-combination control.

FIG. 17 is a diagram showing a relationship between ε and a pit level.

FIG. 18 is a diagram showing a relationship between ε and jitter.

FIG. 19 is a diagram illustrating multi-level recording by the erasing laser power control method according to the present embodiment.

FIG. 20 is a diagram illustrating a multilevel recording pulse waveform according to the erasing laser power control method according to the present embodiment.

FIG. 21 is a diagram illustrating a multilevel recording pulse waveform according to the Ttop and Tmp control methods according to the present embodiment.

FIG. 22 is a flowchart illustrating a test recording procedure.

FIG. 23 is a diagram illustrating a test recording area layout.

Claims (12)

[Claims] 1. A method for judging whether a recording medium is irradiated with a light beam, generating two states having different crystal states in an irradiation area, and recording information by a difference in optical characteristics in each state. In the information recording method, when the number of pit levels to be multi-valued is n, n erasing laser powers for different pit levels detected from the recording mark are arranged, and the erasing is performed in accordance with the information to be recorded. Modulating the value of the laser power so that n intermediate states exist between the two different crystal states, thereby recording multi-valued information in the irradiation area; Information recording method. 2. An optical information recording apparatus using an optical information recording method for performing recording by irradiating an optical beam onto an optical information recording medium according to claim 1, wherein the erasing laser power is adjusted in accordance with multi-value information. A converting means for converting the laser beam into a bias value for controlling the laser output; and a plurality of states in which the erasing laser power of the light beam converted by the converting means is modulated and irradiated, and the degree of crystallization varies according to multi-value information. An optical information recording device, characterized by having the following. 3. The optical information recording method according to claim 1, wherein the relationship between the converging beam diameter BD of the recording laser and the circumferential length PL of the multi-value recorded recording mark is PL / BD = 3.
An optical information recording method for an optical information recording medium, wherein a plurality of states having different degrees of crystallization according to multi-valued information are present. 4. A method for determining whether a recording medium is irradiated with a light beam, generating two states having different crystal states in an irradiation area, and recording information based on a difference in optical characteristics between the states. In the optical information recording method in which the mark width in the radial direction of the recording mark is changed to make the pit level different, the recording laser pulse is composed of a leading pulse and a succeeding pulse train, and the recording mark length is determined by the laser power Pw1 of the leading pulse. Is determined, the mark width of the recording mark is made uniform by adjusting the individual pulse lengths Tmp of the succeeding pulse trains, and modulated by a combination of Pw1 and Tmp of these recording pulses in accordance with the information to be recorded. Recording multi-valued information in the irradiation area by making recording marks having different mark widths of the recording marks exist. The optical information recording method of the broadcast recording medium. 5. An optical information recording apparatus using the optical information recording method according to claim 4, wherein n combinations of Pw1 and Tmp are prepared corresponding to the multilevel information, and the n combination recording conditions are prepared. Means for converting a laser beam into a laser pulse signal for recording, and irradiating the optical beam with an optical information recording medium by optically modulating the light beam with the laser pulse signal converted by the converting means, and the recording mark width varies according to the multilevel information. An optical information recording device, wherein a plurality of states exist. 6. A method for judging whether or not a recording medium is irradiated with a light beam, generating two states having different crystal states in an irradiation area, and recording information by a difference in optical characteristics in each state. In the optical information recording method in which the mark width in the radial direction of the recording mark is changed to have a different pit level, the recording laser pulse is composed of a leading pulse and a succeeding pulse train, and the leading pulse length Ttop is the radial direction of the recording mark length. Determine the mark width and determine the individual pulse length T of the subsequent pulse train
By adjusting mp, the mark width of the recording mark is made uniform, and the T of these recording pulses is adjusted in accordance with the information to be recorded.
An optical information recording method for an optical information recording medium, wherein modulation is performed by a combination of top and Tmp, and multi-valued information is recorded in the irradiation area by causing recording marks having different mark widths to be present. 7. An optical information recording apparatus using the optical information recording method according to claim 6, wherein n combinations of Ttop and Tmp are prepared corresponding to the multi-valued information, and the n combination recording conditions are prepared. Conversion means for converting a laser beam into a laser pulse signal for recording, and irradiating an optical information recording medium by optically modulating a light beam with the laser pulse signal converted by the conversion means, and a recording mark width differs according to multi-valued information. An optical information recording device, wherein a plurality of states exist. 8. A method for judging whether or not a recording medium is irradiated with a light beam, generating two states having different crystal states in an irradiation area, and recording information based on a difference in optical characteristics between the respective states. In the optical information recording method in which the mark width in the radial direction of the recording mark is changed to have a different pit level, the recording laser pulse is composed of a leading pulse and a succeeding pulse train, and the leading pulse length Ttop is the radial direction of the recording mark length. The mark width is determined, and the individual laser power Pw2 of the subsequent pulse train is adjusted to make the mark width of the recording mark uniform, and modulated according to the information to be recorded by the combination of Ttop and Pw2 of these recording pulses. Optical information recording wherein multi-valued information is recorded in the irradiation area by the presence of recording marks having different mark widths. The optical information recording method of the medium. 9. An optical information recording apparatus using the optical information recording method according to claim 8, wherein n combinations of Rrop and Pw2 are prepared corresponding to the multilevel information, and the n combination recording conditions are prepared. Conversion means for converting a laser beam into a laser pulse signal for recording, and irradiating an optical information recording medium by optically modulating a light beam with the laser pulse signal converted by the conversion means, and a recording mark width differs according to multi-valued information. An optical information recording device, wherein a plurality of states exist. 10. A method for judging whether or not a recording medium is irradiated with a light beam, generating two states having different crystal states in an irradiation area, and recording information based on a difference in optical characteristics in each state. In the optical information recording method of changing the radial mark width of a recording mark to a different pit level, the recording laser pulse is composed of a leading pulse and a succeeding pulse train, and the recording mark length is adjusted by adjusting the leading pulse length Ttop. By determining the radial mark width and adjusting the individual pulse length Tmp of the subsequent pulse train, the mark width of the recording mark is made uniform, and modulated according to the combination of Ttop and Tmp of these recording pulses according to the information to be recorded. An optical information recording medium, wherein multi-valued information is recorded in the irradiation area by the presence of recording marks having different recording mark widths. Optical information recording method. 11. The optical information recording apparatus according to claim 8, wherein n combinations of Ttop and Tmp are prepared corresponding to the multi-value information, and a laser pulse signal for recording the n combination recording conditions is provided. Converting means for converting, and irradiating the optical beam with an optical information recording medium by optically modulating the light beam with the laser pulse signal converted by the converting means, and causing a plurality of states having different recording mark widths according to the multi-valued information to exist. An optical information recording device characterized by the above-mentioned. 12. The optical information recording apparatus according to claim 2, wherein when test recording for calculating an optimum recording condition is performed, test recording is performed using an erasing laser power as a variable parameter, and a correlation between each erasing laser power value and a pit level. And calculating an erasing laser power condition at which a desired pit level is obtained.