JP2003030836A - Information recording method, information recording medium, and information recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that the recording mark cannot be formed well because the period of one channel clock is shortened to be approximately equal to the rise time and the fall time for laser light emission by recording information on a phase change optical recording medium at a higher recording linear speed. SOLUTION: The power of radiated laser light is set to at least a recording power and a bias power, and a higher power level than the bias power is given to the recording power, and a recording mark having a length (3n-2)T where T is the length of one channel clock, a recording mark having a length (3n-1)T, and a recording mark having a length (3n)T are formed by n recording pulses, and a method for changing intervals of recording pulses is adopted to solve the problem.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to recording of information for recording / reproducing / erasing information by irradiation of an energy beam, and particularly to an information recording method, an information recording medium and information suitable for a phase change optical recording medium. Recording device

[0002]

2. Description of the Related Art In recent years, with the diversification of information, large-capacity, high-speed optical information recording media have been attracting attention. The optical information recording medium includes a read-only information recording medium, a write-once information recording medium capable of additional recording, and a rewritable information recording medium capable of rewriting information. Among them, some of the rewritable information recording media use a phase change material for the recording layer. Information recording on this phase change optical recording medium is a method of recording information by utilizing the difference in reflectance between a crystalline state and an amorphous state. Here, the crystalline state is obtained by raising the temperature of the recording layer above the crystallization temperature and holding it for a predetermined time, and the amorphous state is obtained by raising the temperature of the recording layer above the melting point and rapidly cooling. . Both the crystalline state and the amorphous state can be realized by irradiation with a laser beam. Various information recording methods have been proposed as a laser beam irradiation method, and for example, a method using multi-pulse recording has been put to practical use in DVD-RW. The method that has been put to practical use in DVD-RW is that the laser power is set to three levels, and the laser pulse with the highest power that melts the recording layer is used for the number of points that match the length of the recording signal. After irradiating the laser beam, the laser power is lowered to a low laser power to cool it to form an amorphous mark, and a laser having an intermediate power is irradiated to a portion where the mark is not formed to bring the recording layer into a crystalline state.
This method allows you to erase old information and then
Instead of overwriting new information, it is possible to overwrite new information directly on top of old information.

The 3T mark, which is the shortest recording mark, is recorded by one head pulse and one subsequent multi-pulse and one cooling pulse, and a longer mark is recorded from 3T to 1T.
It is formed by increasing the number of multi-pulses by one for each increase. The multi-pulse is emitted once per 1T. The pulse width is around T / 2. Here, T is the length of one channel clock, and is 38.2 ns for DVD-RW.
Hereinafter, the head pulse and the multi-pulse will be collectively referred to as a recording pulse train.

[0004]

However, when the recording linear velocity is increased to record information on the phase-change optical recording medium, there has been encountered a problem that the above-mentioned prior art cannot form a recording mark well. The cause can be estimated as follows. That is, when the recording speed is increased, the cycle of the one-channel clock becomes shorter, and the time is about the same as the rise and fall times when the laser is emitted. Therefore, even if an attempt is made to emit a predetermined pulse width with a predetermined power, it is not possible to reduce the laser power to a sufficiently low level, and it is not possible to perform the rapid cooling necessary for amorphization. Will happen. For example, if the recording linear velocity in DVD-RW is 4 times, T is 9.55.
The pulse rise and fall times are around 2 ns, which is not negligible. There is also a method of recording recorded marks of different lengths with one pulse according to their length, but this is because the recrystallization of the mark front end is considerably large and it is possible to control the mark length accurately. Can not.

In order to solve this problem, 2T is set as one cycle, n recording pulses are used to form a recording mark having a length of 2nT, and the head pulse of a 2nT pulse train is used in the case of (2n + 1) T. Is lengthened by 0.5T, and each length is lengthened by 0.5T immediately after the first pulse and immediately before the last pulse. However, when recording is performed using this method, there is a problem in that the front edge is recrystallized particularly at a long mark, so that the jitter at the front edge is bad.

An object of the present invention is to solve the above drawbacks of the prior art and to provide an information recording method, an information recording medium, and an information recording apparatus capable of accurately forming a mark even at a high recording speed. is there.

[0007]

In order to achieve this object, the inventors of the present invention have made various studies and found that the recording pulses are sufficiently opened to minimize the influence of heat between the recording pulses, thereby making the amorphous state amorphous. It has been found important to provide rapid cooling for qualification. In particular, when recording a long mark, the number of recording pulses should be reduced as much as possible because it is easily affected by the recording pulse train that follows at the front end of the mark. Therefore, when forming recording marks of at least two different lengths, for example, when forming a mark of length aT, the time 2T following the recording pulse train forming the length of (a-2) T.
Instead of adding two pulses of width less than T between
2) With the same number of recording pulses as T, the mark length may be controlled by changing the interval between recording pulses in the recording pulse train.

Specifically, (i) the power of the emitted laser light is set to at least the recording power and the bias power, the recording power is set to a power level higher than the bias power, and when the 1-channel clock T is set, (3n-2) T recording marks, length (3n-1) T recording marks and length (3n) T recording marks are formed by n recording pulses, and the width between the recording pulses is Can be changed depending on each recording mark length.

Alternatively, (ii) recording marks of length (3n-1), recording marks of length (3n) T, and recording marks of length (3n + 1) T are formed by n recording pulses. It is possible to adopt a method in which the width between the recording pulses is changed depending on the length of each recording mark.

Further, (iii) a recording mark of length (3n) T and a length (3n)
The formation of (n + 1) T recording marks and (3n + 2) T recording marks is performed by n recording pulses, and the width between the recording pulses is changed according to each recording mark length. You can Which method among (i), (ii) and (iii) is adopted can be appropriately selected according to the signal modulation method, the disc structure, the disc rotation speed, the linear velocity and the like.

Therefore, the first aspect of the present invention is a method for recording or rewriting information on an information recording medium by irradiating a laser beam, in which the power of the radiated laser beam is set to at least a recording power and a bias power, and recording is performed. When the power is set to a power level higher than the bias power, recording marks are recorded by a recording pulse train having a recording power level, and the number of recording pulses is changed when forming recording marks of at least two different lengths. Instead, it is performed by changing the width between the recording pulses.

Among them, when one channel clock T is used, a recording mark of length (3n-2) T, a recording mark of length (3n-1) T and a recording mark of length (3n) T are formed. In the case of performing n recording pulses at the recording power level, the width between the recording pulses may be changed according to each recording mark length.

A recording mark having a length (3n-1) T and a length (3n-1) T
When the recording marks of n) T and the recording marks of length (3n + 1) T are formed by n recording pulses of the recording power level, the width between the recording pulses is changed by each recording mark length. Just do it.

When the 1-channel clock T is used, the formation of the recording mark of length (3n) T, the recording mark of length (3n + 1) T and the recording mark of length (3n + 2) T is recorded. When the recording is performed with n power level recording pulses, the width between the recording pulses may be changed according to each recording mark length.

In the first aspect of the present invention, in order to reduce the difference in thermal history of the recording film due to the difference in recording mark length, it is preferable to increase the recording pulse width as the width between the recording pulses is increased.

The power between a plurality of recording pulses is
It can be set to any power lower than the recording power.

In order to align the shapes of the rear end portions of the marks, it is preferable to irradiate n recording pulses and then 1 cooling pulse having a cooling power level lower than the recording power.

Further, it is more preferable that the width of the cooling pulse is changed according to the recording mark length.

The recording pulse interval may include a case where the interval between the first pulse and the next pulse is 0.

In the first aspect of the present invention, the optimum number of recording pulses for recording a recording mark of a predetermined length, recording pulse width, recording pulse interval, cooling pulse width, start position, end position of each pulse, recording When these parameters are read from an information recording medium on which one or more parameters of the recording method such as power, bias power, erasing power, and cooling power are recorded in advance, and recording is performed based on these parameters. Good.

The second aspect of the present invention is an information recording medium which comprises at least a substrate and a recording layer, and which records information by irradiating laser light, records information, and records at least the power of the irradiated laser light. When the recording power is set to the power and bias power and the recording power is set to a power level higher than the bias power, the recording mark is formed by recording with a recording pulse train having the recording power level,
When the recording marks having three different lengths are formed, the width of the recording pulses is changed without changing the number of recording pulses.

Among them, when one channel clock T is used, a recording mark of length (3n-2) T, a recording mark of length (3n-1) T and a recording mark of length (3n) T are formed. When n recording pulses are used, the information recording medium may be formed by changing the width between the recording pulses according to each recording mark length.

Information is recorded by forming recording marks of length (3n-1) T, recording marks of length (3n) T and recording marks of length (3n + 1) T by n recording pulses. In the case of performing the information recording medium, the width between the recording pulses may be changed according to the length of each recording mark.

A recording mark having a length (3n) T and a length (3n +
1) When the recording mark of T and the recording mark of length (3n + 2) T are formed by n recording pulses, the information performed by changing the width between the recording pulses according to each recording mark length. A recording medium may be used.

In the second aspect of the present invention, it is preferable that the recording of the information is performed by making the recording pulse width longer as the width between the recording pulses becomes longer.

In the second aspect of the present invention, particularly when a phase change material is used for the recording layer, information is recorded by irradiation with one cooling pulse having a cooling power level lower than the recording power immediately after irradiation with n recording pulses. It is preferable to carry out.

Further, it is more preferable that the width of the cooling pulse is changed according to the recording mark length.

In the information recording medium of the second aspect of the present invention, the optimum number of recording pulses, recording pulse width, recording pulse width, cooling pulse width, for recording a recording mark of a predetermined length,
It is preferable that one or more parameters of the recording position such as the start position and end position of each pulse, recording power, bias power, erasing power, and cooling power are recorded in advance.

According to a third aspect of the present invention, in an information recording apparatus which comprises at least a substrate and a recording layer and records information on an information recording medium for recording information by irradiating laser light, the information recording is irradiated. When the power of the laser light is set to at least the recording power and the bias power, and the recording power is set to a power level higher than the bias power, the recording mark is formed by recording with a recording pulse train having the recording power level and at least 2 When the recording marks having three different lengths are formed, the width of the recording pulses is changed without changing the number of recording pulses.

Among them, when one channel clock T is used, a recording mark of length (3n-2) T, a recording mark of length (3n-1) T and a recording mark of length (3n) T are formed. In the case of performing n recording pulses, the width between the recording pulses may be changed according to each recording mark length.

A recording mark having a length (3n-1) T and a length (3n-1) T
n) T recording marks and recording marks of length (3n + 1) T are formed by n recording pulses, the width between the recording pulses is changed by each recording mark length. If

A recording mark having a length (3n) T and a length (3n +
1) When the recording mark of T and the recording mark of length (3n + 2) T are formed by n recording pulses, the width between the recording pulses may be changed by changing the length of each recording mark. Good.

In the third aspect of the present invention, when recording information, it is preferable that the recording pulse width be made longer as the width between the recording pulses is made longer.

In the third aspect of the present invention, when information is recorded, it is performed by irradiating one cooling pulse having a cooling power level lower than the recording power immediately after the irradiation of n recording pulses. preferable.

Further, it is more preferable that the width of the cooling pulse is changed according to the recording mark length.

In the third aspect of the present invention, the optimum number of recording pulses for recording a recording mark of a predetermined length, recording pulse width, recording pulse width, cooling pulse width, start position and end position of each pulse, These parameters are read from an information recording medium on which one or more of the recording method parameters such as recording power, bias power, erasing power, and cooling power are recorded in advance, and information is recorded based on these parameters. It is preferable that the information recording apparatus performs

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1 and 4 are explanatory diagrams related to the conventional recording method, and FIGS. 2, 3, and 5 are explanatory diagrams related to the recording method according to the embodiment of the present invention.

These are for performing recording / reproducing / erasing with one beam, where Pw is the recordable laser power, Pe is the erasable laser power, and Pb is the cooling power level.

First, a conventional recording method will be described.
Here, the recording layer of the phase change optical recording medium is Ag-In-Sb-Te.
Described below is the case where information is recorded / reproduced by the mark edge method such that the shortest mark is 0.4 μm on the system recording layer.

The phase change optical recording medium was composed of a polycarbonate substrate, (ZnS) ₈₀ (SiO ₂ ) ₂₀ (mol%) of 80 nm, and a recording layer of A
g _3.5 In _6.5 Sb ₇₀ Te ₂₀ (at%) 20 nm, as intermediate layer (ZnS)
Initially crystallized, ₈₀ (SiO ₂ ) ₂₀ (mol%) of 20 nm, Ag 100 nm as a heat dissipation layer, and 7 μm of an ultraviolet curable resin as a protective layer were sequentially laminated.

Semiconductor laser on recording layer in crystalline state
(Wavelength 635nm, numerical aperture 0.6), recording linear velocity 14m / s, 1
With the channel clock T set to 9.55 ns, the first pulse 0.5T
The multi pulse was set to 0.4 T and the cooling pulse was 0.6 T, and the multi pulse recording as shown in FIG. 1 was performed. Pw is 15mW, Pe is 5m
W and Pb were set to 0.5 mW, and a 14T single pattern was used as the recording pattern. When the information recorded in this way was reproduced, the front edge jitter after waveform equalization was 15.5%,
The rear edge jitter was 14.3%. Information is recorded using a random pattern, and the wavelength is 648 nm and the numerical aperture is
When reproduced with a semiconductor laser of 0.6 at a linear velocity of 3.5 m / s, the jitter was 18% and the modulation was 50%.

Therefore, as Example 1, in a multi-pulse train as shown in FIG. 2, a recording mark of length (3n-2) T and length (3n-2) T
-1) T recording marks and n (3n) T recording marks are used to form n recording pulses.The recording pulse width is 1T, and the inter-pulse width is set at positions where recording pulses are even Width For example, in the case of 7T, pulse interval 1T,
In case of 8T, it was 1.5T, and in case of 9T, it was 2T. Cooling pulse width 1.
Other than 5T, multi-pulse recording was performed in the same manner as the conventional method.

The front edge jitter of 14T single pattern is 9.7
%, And the trailing edge jitter was 8.5%. When information was recorded using a random pattern and reproduced in the same manner, the jitter was 8% and the modulation was 69%.
Compared with the conventional method, it was found that the recording film layer was properly rapidly cooled, the recrystallization of the mark portion was small, and the mark was accurately formed, so that the jitter was improved and the modulation degree was considerably increased.

As a second embodiment, a recording mark of length (3n-1) T, a recording mark of length (3n) T and a recording of length (3n + 1) T are recorded in a multi-pulse train as shown in FIG. The number of recording pulses is used to form the marks, and the recording pulse width is (3n-1) T, (3n) T is 1T, and (3n + 1) T is 1.5T. Information was recorded in the same manner as the conventional method by multi-pulse recording with a width of 1.5 T for cooling pulse width so as to be evenly arranged.

The front edge jitter of a 14T single pattern is 10.
It was 5% and the trailing edge jitter was 8.5%. When information was recorded using a random pattern and reproduced in the same manner, the jitter was 8.7% and the degree of modulation was 69%. Also in Example 2, as in Example 1, good results could be obtained.

As a comparative example, in a multi-pulse train as shown in FIG. 4, 2T is one cycle, and n recording pulses are used to form a recording mark having a length of 2nT and (2n + 1) T. (2n + 1) T
In the case of, the length is adjusted by adding 0.5T each between the first and last pulses or pulses, and the recording pulse width is 1T, the cooling pulse width is 1T, and other multipulse recording is performed as in the conventional method. It was

The front edge jitter of the 14T single pattern is 12.
7% and the back edge jitter was 8.7%. When information was recorded using a random pattern and reproduced in the same manner, the jitter was 10.5% and the modulation was 62%. Compared with the conventional method, although the jitter and the modulation degree are improved by the quenching effect by opening the pulse, compared to the example, the front edge jitter of the 14T single pattern is worse and the jitter of the random pattern is also worse. It was getting worse with it. Since the degree of modulation is small, it is considered that recrystallization is occurring due to the narrow pulse interval.

Table 1 shows a comparison of the respective jitters and modulations of the example of the present invention, the conventional method and the comparative example. As is clear from this table, it is understood that the present invention has a low jitter under each condition and a high modulation degree.

[0049]

[Table 1]

Although the width of the recording pulse is constant in the first embodiment, better jitter can be obtained by optimizing the recording pulse width for each mark length. The optimization of the recording pulse width can be appropriately changed depending on the medium structure and the recording film composition.

In this embodiment, the width of the cooling pulse was constant, but when the width of the cooling pulse was optimized for each mark length, better jitter was obtained.

Although the recording linear velocity was set to 14 m / s in this embodiment, similar results were obtained when the recording velocity was further increased.

Further, when T is further shortened, for example, when the speed is further increased or when the modulation method is changed, a recording mark of length (3n) T and a length of (3n) T are formed in a multi-pulse train as shown in FIG. Good results were obtained by recording using n recording pulses to form a recording mark of (3n + 1) T and a recording mark of length (3n + 2) T.

In this embodiment, the number of recording pulses is the same for three consecutive recording mark lengths. However, when T is further shortened, the number of recording pulses is the same for four or more consecutive recording mark lengths. Also, good results can be obtained by changing the recording pulse interval.

In this embodiment, the case where the recording layer composition of the information recording medium is Ag _3.5 In _6.5 Sb ₇₀ Te ₂₀ (at%) was described, but the composition is not limited to this, and the composition ratio is When it is changed, or when the constituent elements are changed, for example, Ge ₁₀ Sb
Good results were also obtained with ₇₀ Te ₂₀ (at%) and the like.

Further, in the present embodiment, the recording pulses were adjusted so that the recording pulses were at uniform positions between the recording pulses, but good results could be obtained even when the recording pulses were different.

In this embodiment, the phase change material is used for the recording layer, but other recording layer materials such as dyes and magneto-optical materials can also be used.

Although the 8-16 modulation method is used in this embodiment, other modulation methods such as RLL (1,7), RLL (2,7), NRZI are used.
Etc. can also be used.

Although a laser having a wavelength of 635 nm was used in this example, similar results were obtained by using a laser having a longer wavelength, for example, a laser having a wavelength near 650 nm, a wavelength near 780 nm or a wavelength near 830 nm. Similar results were obtained by using a short wavelength laser, for example, one having a wavelength of around 405 nm or less.

Further, in the present embodiment, the one having the numerical aperture of 0.6 was used, but the same result was obtained even when the one having the numerical aperture of 0.45 to 0.7 was used. Similar results were also obtained when two or more lenses were combined and a numerical aperture of 0.7 or more was used. High-speed and high-density recording became possible by using a lens with NA = 0.85 and a laser with a wavelength of 405 nm in combination. Further, in combination with SIL (Solid Immersion Lens), etc., the effective NA was set to 1 or more, and similar effects were obtained even in near-field recording using evanescent light.

[0061]

According to the present invention, even when the recording speed is high and the cycle of one channel clock is short, the number of recording pulses is minimized when forming a long recording mark,
By sufficiently setting the width between recording pulses, it is possible to form marks accurately.

[Brief description of drawings]

FIG. 1 is a recording waveform diagram in a conventional method.

FIG. 2 is a recording waveform diagram for explaining the form of the first embodiment of the present invention.

FIG. 3 is a recording waveform diagram for explaining a mode of a second embodiment of the present invention.

FIG. 4 is a recording waveform diagram for explaining a mode of a comparative example of the present invention.

FIG. 5 is a recording waveform diagram for explaining an embodiment of the present invention.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Shirai             Hitachima, 1-88, Torora, Ibaraki City, Osaka Prefecture             Within Kucsel Co., Ltd. (72) Inventor Makoto Iimura             Hitachima, 1-88, Torora, Ibaraki City, Osaka Prefecture             Within Kucsel Co., Ltd. F-term (reference) 5D090 AA01 BB05 CC01 DD03 EE02                       KK05                 5D119 AA23 BA01 BB04 HA60

Claims (18)

[Claims] 1. In an information recording method for recording or rewriting information on an information recording medium by irradiating a laser beam, the power of the radiated laser beam is set to at least a recording power and a bias power, and the recording power is a bias. When the power level is higher than the power, the recording marks are formed by recording with a recording pulse train having a recording power level, and when forming recording marks of at least two different lengths, the number of recording pulses is not changed. A method for recording information, which is performed by changing a width between recording pulses. 2. The information recording method according to claim 1, wherein a recording mark having a length (3n-2) T, a recording mark having a length (3n-1) T, and a length when one channel clock T is used. A recording mark of (3n) T is formed by n recording pulses having a recording power level, and the width between the recording pulses is changed by each recording mark length. 3. The information recording method according to claim 1, wherein when one channel clock T is used, a recording mark of length (3n-1) T, a recording mark of length (3n) T and a length ( The recording mark of 3n + 1) T is formed by n recording pulses having a recording power level, and the width between the recording pulses is changed by each recording mark length. 4. The information recording method according to claim 1, wherein when one channel clock T is used, a recording mark of length (3n) T, a recording mark of length (3n + 1) T, and a length ( 3n + 2) T recording marks are formed by n recording pulses having a recording power level, and the width between the recording pulses is changed by each recording mark length. 5. The information recording method according to claim 2, wherein the recording pulse width is made longer as the width between the recording pulses is made longer. 6. The information recording method according to claim 2, wherein one cooling pulse having a cooling power level lower than the recording power is irradiated immediately after irradiation of n recording pulses. How to record information to be recorded. 7. The information recording method according to claim 6, wherein the width of the cooling pulse is changed according to each mark length. 8. The information recording method according to claim 2, wherein the optimum number of recording pulses, recording pulse width, recording pulse width, and cooling are optimum for recording a recording mark having a predetermined length. These parameters are recorded from an information recording medium in which one or more parameters of the recording method such as the pulse width, the start position and the end position of each pulse, the recording power, the bias power, the erasing power, and the cooling power are recorded in advance. Is read and recording is performed based on these parameters. 9. An information recording medium comprising at least a substrate and a recording layer, wherein information is recorded by irradiating a laser beam, the information is recorded, and the power of the radiated laser beam is set to at least a recording power and a bias power. However, when the recording power is set to a power level higher than the bias power, the recording marks are formed by recording a recording pulse train having the recording power level, and at least two recording marks having different lengths are formed. Is performed by changing the width between the recording pulses without changing the information recording medium. 10. The information recording medium according to claim 9, wherein when recording information on one channel clock T, a recording mark having a length (3n-2) T and a recording mark having a length (3n-1) T are used. The information recording medium is characterized in that the recording mark and the recording mark having a length (3n) T are formed by n recording pulses, and the width between the recording pulses is changed by each recording mark length. 11. The information recording medium according to claim 9, wherein when recording information, a recording mark having a length (3n-1) T and a recording mark having a length (3n) T are used when one channel clock T is used. The information recording medium is characterized in that the recording mark having the length (3n + 1) T is formed by n recording pulses, and the width between the recording pulses is changed by each recording mark length. 12. The information recording medium according to claim 9, wherein when recording information, a recording mark having a length (3n) T and a recording mark having a length (3n + 1) T are used when one channel clock T is used. And an information recording medium characterized in that a recording mark having a length (3n + 2) T is formed by n recording pulses, and a width between the recording pulses is changed by each recording mark length. 13. The information recording medium according to claim 10, wherein the optimum number of recording pulses, recording pulse width, recording pulse width, cooling pulse for recording a recording mark of a predetermined length. Width, start position, end position of each pulse,
An information recording medium, wherein one or more parameters of a recording method such as recording power, bias power, erasing power, and cooling power are recorded in advance. 14. An information recording apparatus, comprising at least a substrate and a recording layer, for recording information on an information recording medium for recording information by irradiating a laser beam.
When the power of the irradiated laser light is set to at least the recording power and the bias power, and the recording power is set to a power level higher than the bias power, the recording mark is formed by recording with a recording pulse train having the recording power level, An information recording apparatus, characterized in that at least two recording marks having different lengths are formed by changing the width between the recording pulses without changing the number of recording pulses. 15. The information recording apparatus according to claim 14, wherein when recording information, a recording mark having a length (3n-2) T and a length (3n- 1) Recording marks of T and recording marks of length (3n) T are formed by n recording pulses, and the width between the recording pulses is changed by each recording mark length. Information recording device. 16. The information recording apparatus according to claim 14, wherein when recording information, a recording mark having a length (3n-1) T and a length (3n) when one channel clock T is used. The recording mark of T and the recording mark of length (3n + 1) T are formed by n recording pulses, and the width between the recording pulses is changed by each recording mark length. Information recording device. 17. The information recording apparatus according to claim 14, wherein when recording information, a recording mark having a length (3n) T and a length (3n + 1) when one channel clock T is set. An information recording apparatus characterized in that the recording mark of T and the recording mark of length (3n + 2) T are formed by n recording pulses, and the width between the recording pulses is changed by each recording mark length. . 18. The information recording apparatus according to claim 15, wherein the optimum number of recording pulses, recording pulse width, recording pulse width, and cooling pulse are optimum for recording a recording mark having a predetermined length. These parameters are recorded from an information recording medium in which one or more parameters of the recording method such as the width, the start position and the end position of each pulse, the recording power, the bias power, the erasing power, and the cooling power are recorded in advance. An information recording device characterized by reading and recording information based on these parameters.