JP2009070491A - Optical information recording medium and information recording method to optical information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information recording method in consideration of shelf characteristics when recording data at high speed to an information recording medium having a large capacity and to provide an optical information recording medium suitable for the information recording method. <P>SOLUTION: In the information recording method, power of laser light is controlled in at least three values corresponding to each pulse of a heating pulse, a cooling pulse and an erasure pulse and prescribed information is recorded by a plurality of recording marks formed by alternately irradiating the optical information recording medium with the heating pulse and the cooling pulse and having lengths different from each other and spaces formed between the recording marks by irradiation with the erasure pulse, a pre-heating pulse having power equal to the erasure pulse or more and equal to the heating pulse or less is provided before the first heating pulse when the recording mark is formed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a recordable optical information recording medium, in particular, a large-capacity optical information recording medium such as BD-RE and HD DVD-RW, and an information recording method suitable for the optical information recording medium.

  In recent years, digitalization and multimediaization of information are rapidly progressing, and a demand for a recording medium capable of recording and reproducing a large amount of information at high speed is increasing. In particular, it is represented by DVD-R, DVD-RW, DVD + R, DVD + RW, CD-R, and CD-RW that can be recorded while ensuring reproduction compatibility with DVD-ROM and CD-ROM that are read-only memories. The demand for recordable optical discs is increasing because they are highly versatile and convenient. Recently, in order to achieve higher capacity recording, Blu-ray Disc (BD) and HD DVD, which are systems using a blue LD with a wavelength of 405 nm, have been put into practical use with respect to ROM, write once and rewritable media, respectively. ing. Since these have large capacities, recording takes time and recording at higher speed is required.

  When recording on a high-capacity optical information recording medium such as a Blu-ray Disc (BD) or HD DVD at a high speed, the recording is more than when recording on a relatively small optical information recording medium such as a conventional CD or DVD. It is considered that the strategy greatly affects the reproduction characteristics after recording. Here, the recording strategy is a laser emission pattern for writing a recording mark of a predetermined length on an optical information recording medium in an accurate shape. The number of pulses, pulse width, pulse interval, pulse start position, pulse Set by parameters such as power.

  As shown in FIG. 19, a conventionally used recording strategy is that a heating pulse with a laser power of Pw and a cooling pulse with a laser power of Pb (bottom power) are set to 1 according to the recording mark length. Recording marks (amorphous phase) are formed by alternately irradiating from one to a plurality of pulses, and the erasing power with a laser power of Pe is irradiated as continuous light between the recording marks, that is, the space (crystal phase) portion. There is a method of forming by doing. In this method, the number of heating pulses is (n-1) to (n-2) with respect to the recording mark length nT, and (n-1) when the shortest mark length includes 2T. is there. The power of the last cooling pulse may be different from the power Pb of other cooling pulses. This method is used in CD-RW, DVD-RW, DVD + RW, BD-RE, etc., which are rewritable optical information recording media.

  In addition, as shown in FIG. 20, by irradiating a plurality of pulses from one of the powers that is not continuous light but smaller than the power Pe of the erasing pulse and smaller than the power Pw of the heating pulse as shown in FIG. A recording strategy has been proposed that suppresses deterioration of the recording film caused by irradiating continuous light to the space portion during repeated overwriting 1000 times, and does not deteriorate characteristics even when overwritten (for example, Patent Document 1).

  However, when performing high-speed recording on a large-capacity rewritable optical information recording medium such as a Blu-ray disc (BD) or HD DVD, a recording strategy that fully considers shelf characteristics is required. Here, the shelf characteristic means that when an optical information recording medium is stored in a high temperature and high humidity environment and recorded in that environment, or after the optical information recording medium is stored in a high temperature and high humidity environment and returned to room temperature. This refers to characteristics such as jitter value after recording.

In a conventional optical information recording medium having a relatively small capacity such as a CD or DVD, a power margin at the time of recording (relation between a laser power at the time of recording and a jitter value after recording) is sufficiently secured. Even if the shelf characteristics are deteriorated, a predetermined reference value provided in the jitter value or the like can be sufficiently satisfied, and there is no problem. However, when recording at a high speed on a large-capacity optical information recording medium such as a Blu-ray Disc (BD) or HD DVD, it is difficult to secure a sufficient power margin during recording, so deterioration of shelf characteristics becomes a problem. Become.
JP 2006-286194 A

  However, various recording strategies have heretofore been proposed. An information recording method based on a recording strategy in consideration of shelf characteristics when recording on a high-capacity optical information recording medium such as a Blu-ray disc (BD) or HD DVD at high speed. There was a problem that was not established.

  The present invention has been made in view of the above, and provides an information recording method considering shelf characteristics when recording on a high-capacity optical information recording medium at high speed, and an optical information recording medium suitable for the information recording method. For the purpose.

  In order to achieve the above object, according to a first aspect of the present invention, the power of laser light is controlled to at least three values corresponding to each of a heating pulse, a cooling pulse, and an erasing pulse, and the heating pulse and the cooling are applied to an optical information recording medium. Predetermined information is recorded by a plurality of types of recording marks having different lengths formed by alternately irradiating pulses and spaces formed between the recording marks by irradiating the erasing pulse. In the information recording method, when forming the recording mark, before the first heating pulse, a preheating pulse having a power not less than the power of the erasing pulse and not more than the power of the heating pulse is provided. Features.

  According to a second aspect of the present invention, in the information recording method according to the first aspect of the present invention, a power that is greater than or equal to the power of the cooling pulse and less than or equal to the power of the preheat pulse between the preheat pulse and the first heating pulse. A pre-erasure pulse is provided.

  According to a third aspect of the present invention, in the information recording method according to the second aspect of the present invention, the power between the preheating pulse and the pre-erasing pulse is higher than the power of the cooling pulse and lower than the power of the pre-erasing pulse. A precooling pulse is provided.

  According to a fourth aspect of the present invention, in the information recording method according to any one of the first to third aspects, the plurality of types of recording marks are a plurality of types corresponding to a natural number times the basic clock period T. The plurality of types of recording marks formed by alternately irradiating the heating pulse and the cooling pulse are the heating marks for forming the recording marks corresponding to a length of 2T. The number of pulses is one, and thereafter, the recording strategy is formed using a recording strategy in which the number of heating pulses increases by one every time the length of the recording mark increases by 2T.

  According to a fifth aspect of the present invention, in the information recording method according to any one of the first to third aspects, the plurality of types of recording marks have a length that is n times (n is a natural number) the basic clock period T. Corresponding plural kinds of recording marks, which are formed by alternately irradiating the heating pulse and the cooling pulse, form the recording marks corresponding to the length of nT. In this case, the number of the heating pulses is (n-1) and the recording strategy is used.

  A sixth invention is the information recording method according to any one of the first to fifth inventions, wherein a ratio of the power of the erasing pulse and the power of the heating pulse (the power of the erasing pulse / the power of the heating pulse). (Power) is 0.2 or more and 0.5 or less.

  According to a seventh invention, in the information recording method according to any one of the first to sixth inventions, the predetermined information is recorded at a linear velocity of 15 m / s or more.

  According to an eighth aspect of the present invention, in the information recording method according to any one of the first to seventh aspects, the wavelength of the laser beam is in a 400 nm band.

  The ninth invention is formed by controlling the power of the laser beam to at least three values corresponding to each of the heating pulse, the cooling pulse and the erasing pulse, and alternately irradiating the heating pulse and the cooling pulse. An optical information recording medium on which predetermined information is recorded by a plurality of types of recording marks having different lengths and a space formed between the recording marks by irradiation of the erasing pulse, Is formed in advance, before the first heating pulse, information for providing a preheating pulse that is equal to or higher than the power of the erasing pulse and lower than the power of the heating pulse is written. To do.

  According to a tenth aspect of the present invention, in the optical information recording medium according to the ninth aspect of the present invention, the power of the cooling pulse is equal to or higher than the power of the cooling pulse between the preheating pulse and the first heating pulse. Information for providing a pre-erasing pulse as power is written in advance.

  An eleventh aspect of the invention is the optical information recording medium according to the tenth aspect of the present invention, wherein the power is not less than the power of the cooling pulse and not more than the power of the pre-erase pulse between the preheating pulse and the pre-erase pulse. Information for providing a pre-cooling pulse is previously written.

  A twelfth aspect of the present invention is the optical information recording medium according to any one of the ninth to eleventh aspects, wherein the plurality of types of recording marks are a plurality corresponding to a natural number times the basic clock period T. The plurality of types of recording marks formed by alternately irradiating the heating pulse and the cooling pulse are the types of recording marks when the recording marks corresponding to a length of 2T are formed. The number of heating pulses is one, and each time the recording mark length increases by 2T, the recording pulse is formed by using a recording strategy in which the number of heating pulses increases by one.

  A thirteenth aspect of the present invention is the optical information recording medium according to any one of the ninth to eleventh aspects, wherein the plurality of types of recording marks have a length n times (n is a natural number) the basic clock period T. A plurality of types of recording marks that are formed by alternately irradiating the heating pulse and the cooling pulse, forming the recording marks corresponding to a length of nT. In this case, the number of the heating pulses is (n-1) and the recording strategy is used.

  A fourteenth invention is the optical information recording medium according to any one of the ninth to thirteenth inventions, wherein the ratio of the power of the erasing pulse and the power of the heating pulse (the power of the erasing pulse / the heating pulse). Power) of 0.2 or more and 0.5 or less.

  According to a fifteenth aspect, in the optical information recording medium according to any one of the ninth to fourteenth aspects, the predetermined information is recorded at a linear velocity of 15 m / s or more.

  A sixteenth aspect of the present invention is the optical information recording medium according to any one of the ninth to fifteenth aspects, wherein the wavelength of the laser beam is in a 400 nm band.

  ADVANTAGE OF THE INVENTION According to this invention, the optical information recording medium suitable for the information recording method and the information recording method which considered the shelf characteristic at the time of recording on a high capacity | capacitance optical information recording medium at high speed can be provided.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[Optical information recording medium]
The optical information recording medium according to the present invention has a structure in which at least a reflective layer, a protective layer, a recording layer, a protective layer, and a light transmission layer (ultraviolet curable resin layer) are laminated in this order on the substrate, or at least a protective layer on the substrate. A layer, a recording layer, a protective layer, a reflective layer, an ultraviolet curable resin layer, and a substrate. The former structure is that of a Blu-ray disc in which the NA of the objective lens is 0.85, the thickness of the substrate is 1.1 mm, and the thickness of the light transmission layer is 0.1 mm. The latter structure is for an HD DVD disc having an objective lens NA of 0.65 and a substrate thickness of 0.6 mm.

  For the substrate, materials such as glass, ceramics, or resin are usually used. Moreover, what was shape | molded so that it may have a magnitude | size, thickness, and groove | channel shape suitable for the standards to which it conforms is used. For example, in the Blu-ray disc standard, the diameter is 12 cm, the thickness is 1.1 mm, the track pitch is 0.32 μm, and a guide groove having a width of 0.14 to 0.18 μm and a depth of 20 to 35 nm is usually provided. The so-called on-groove recording, which is recorded in the groove of the convex portion as viewed from the incident direction, is employed. This guide groove is usually a meandering groove (wobble) for the information recording device to sample the frequency during recording. The wobble phase is reversed or the frequency is changed in a predetermined area. In this way, it is possible to input addresses and information necessary for recording.

  For the recording layer, materials such as AgInSbTe, GeAgInSbTe, GeSb, GeSbSn, InSb, InSbGe, GaSb, and GaGeSb are used. Since Sb or Sb, Te occupies 50% or more, these may be called Sb-based and SbTe-based.

  For the protective layer, materials such as oxides such as ZnS.SiO2, TiOx, TaOx, ZrOx, InOx, SnOx, ZnOx, and mixtures thereof are used.

  A material such as Ag, Ag—Nd—Cu, Ag—Cu, Ag—Bi, or Al—Ti is used for the reflective layer.

  Particularly important factors affecting the shelf characteristics are the material of the recording layer and the material of the protective layer above and below the recording layer, but the material of the ultraviolet curable resin layer is also important in consideration of the moisture resistance.

  Further, for example, in the innermost peripheral portion (lead-in area) of the optical information recording medium according to the present invention, recording optimization information such as optimum recording strategy information and optimum recording power information related to the information recording method according to the present invention is stored. For example, it is written using wobbles or pits. The recording optimization information includes information necessary for selecting an optimum recording strategy stored in advance on the information recording apparatus side. The information recording apparatus to be described later reads the recording optimization information written on the optical information recording medium according to the present invention, and performs recording under the optimal recording conditions such as the optimal recording strategy and the optimal recording power condition, Even when high-speed recording is performed on a large-capacity optical information recording medium, it is possible to perform favorable recording with little deterioration in shelf characteristics.

  Further, the optical information recording medium according to the present invention is in a crystalline state by irradiating a laser beam of about 1 to 2 mW at room temperature with an initialization device while the recording layer after the medium production is in an amorphous phase. (Initialization) is necessary, and recording is possible after the initialization.

[Information recording method]
An object of the present invention is to provide an information recording method in consideration of shelf characteristics when recording at a high linear velocity on a large-capacity optical information recording medium and an optical information recording medium suitable for the information recording method. As described above, the shelf characteristic means that when an optical information recording medium is stored in a high temperature and high humidity environment and recorded in that environment, or the optical information recording medium is stored in a high temperature and high humidity environment and returned to room temperature. This refers to characteristics such as jitter when recording after recording. In addition, the shelf characteristics are the characteristics when recording for the first time in a high-temperature and high-humidity environment, and after recording at least once at room temperature, leave it in a high-temperature and high-humidity environment and overwrite it on it (overwrite). ) Including the characteristics of the case.

  “Recording at a high linear velocity” means recording information on the optical information recording medium at a recording linear velocity of 15 m / s or more and having a minimum mark length and width of 0.1 μm or more. Recording on a Blu-ray disc (19.8 m / s) is at least four times the reference linear velocity, and recording on a HD DVD disc at three times the reference linear velocity corresponds to “recording at a high linear velocity”. The case of recording on an optical information recording medium under conditions other than this is called “recording at a low linear velocity”.

  When recording on the optical information recording medium at a low linear velocity, the ratio of the erasing pulse power Pe and the heating pulse power Pw in FIG. 19 (erasing pulse power Pe / heating pulse power Pw) is 0.5. If it is larger than, it can be recorded. The optical information recording medium crystallized by initialization is allowed to stand for several hundred hours or more under a high temperature and high humidity condition of 70 ° C. or higher and a relative humidity of about 85%, returned to room temperature condition and Pe at a low linear velocity (10 m / s). When recording is performed once under the condition of /Pw>0.5 (recorded for the first time on the unrecorded portion), the same characteristics as when recording at room temperature before leaving under high temperature and high humidity conditions can be obtained. That is, shelf characteristics are not a problem. Furthermore, after being overwritten once to 10 times at room temperature and then left again in a high-temperature and high-humidity environment, even after recording (overwriting) the information recorded in advance at room temperature, there is some degradation. However, it is possible to obtain characteristics within a predetermined reference value such as a jitter value. That is, shelf characteristics are not a problem.

  In the case of high linear velocity recording, if recording is performed under the condition of Pe / Pw> 0.5, recrystallization at the rear end of the recording mark proceeds faster than in the case of low linear velocity recording, and the recording mark becomes shorter. Although the characteristics deteriorate, if recording is performed under the condition of Pe / Pw ≦ 0.5, preferably Pe / Pw = 0.3, sufficient repetitive overwriting characteristics can be obtained. Further, when 0.2> Pe / Pw, it is necessary to satisfy 0.2 ≦ Pe / Pw because the recording mark already recorded at the time of overwriting cannot be erased. That is, when recording on a large-capacity optical information recording medium at a high linear velocity, 0.2 ≦ Pe / Pw ≦ 0.5 is preferable, and Pe / Pw = 0.3 is more preferable.

  However, under these conditions alone, the shelf characteristics deteriorate, and the deterioration increases as the jitter value exceeds the reference value. In order to solve this problem under the medium conditions, the recording layer material and the protective layer material have been mainly studied. However, at present, sufficient measures have not been found.

  One of the reasons that the shelf characteristics did not become a problem when recording at a low linear velocity is that a material having a low crystallization rate is used as the material of the recording layer. However, the crystal state in a high temperature and high humidity environment is changed to a state different from the crystal state at room temperature, and the changed crystal state has a high Pe / Pw ratio (Pe / Pw> 0.5), that is, a high erase power. It is considered that a major factor is that the material is recrystallized after melting and returned to a state equivalent to the crystalline state at room temperature before standing. However, the configuration conditions of a highly reliable optical information recording medium capable of high linear velocity recording with high Pe / Pw have not been found at present.

  From the above situation, as a method of recording at a high linear velocity on a large-capacity optical information recording medium without deteriorating shelf characteristics, a condition of low Pe / Pw ratio (0.2 ≦ Pe / Pw ≦ 0.5) is used. However, even when recording at a high linear velocity, the crystalline state changed in a high-temperature and high-humidity environment is recrystallized after melting before recording, and returned to a state equivalent to the crystalline state at room temperature before standing. It is considered necessary to propose such a laser emission waveform (recording strategy).

  In a test under a high temperature and high humidity environment, when the crystal state changes, it becomes difficult to form an amorphous phase after the change. Also, the recording sensitivity tends to deteriorate. Assuming that the thermal conductivity of the recording layer increases after the change, it can be expected that the recording sensitivity will deteriorate, but if the sensitivity simply deteriorates, if recording is performed with a higher recording power, the recording characteristics of the recording mark The jitter value should be the same value as before the sensitivity was lowered. However, even when recording is actually performed with a high recording power, the jitter value is not equal to that when recording before storage at high temperature and high humidity (under room temperature conditions) and deteriorates. Therefore, the sensitivity is not simply deteriorated.

  When the jitter value of a recording mark is further measured by dividing it into a leading portion (Leading edge jitter, abbreviated as LEJ) and a trailing end portion (Trailing edge jitter, abbreviated as TEJ), the deterioration of LEJ is larger. know. Furthermore, it is also known that the recording signal amplitude (the crystal of the longest mark of the recorded mark, the reflectance difference of the amorphous phase) is small, and from these, at least unrecorded and recorded crystal state, Changes when left in a high-temperature and high-humidity environment, especially the area of the amorphous phase at the beginning of the recording mark is expected to be small, and the recording mark length that is originally recorded is expected to be short or the recording mark area to be small Is done.

  In the crystal state after the change, when erasing power of 50% or more of the optimum recording power is continuously irradiated for one track and then recording, the jitter characteristics after recording are restored to the same values as those recorded before storage at high temperature and high humidity. I found out that Therefore, in view of this result, the power at which the recording layer is in a molten state before irradiation of the original power at the head of the recording mark (before the first heating pulse when forming the recording mark). It is considered that shelf characteristics can be improved if recording is performed after irradiating a pulse (preheating pulse, pre-erasing pulse, pre-cooling pulse) to obtain the same crystal state as before the change. A recording strategy based on this idea is shown in FIGS.

  FIG. 1 is a diagram showing an example of a laser light emission waveform in the information recording method according to the present invention. In FIG. 1, the horizontal axis represents time, and the vertical axis represents laser power. The upper side is a data signal, and the lower side is a light emission waveform of the laser beam. In the laser light emission waveform, a pulse with laser power Pw is a heating pulse, a pulse with laser power Pb is a cooling pulse, a pulse with laser power Pe is an erasing pulse, and a pulse with laser power Pm is a preheating pulse. It is. A feature is that a preheating pulse having a power Pm that is equal to or higher than the erase pulse power Pe and equal to or lower than the heating pulse power Pw is provided before the first heating pulse. An interval between adjacent dotted lines is a basic clock period T.

  FIG. 2 is a diagram showing another example of the emission waveform of laser light in the information recording method according to the present invention. In FIG. 2, the horizontal axis represents time, and the vertical axis represents laser power. The upper side is a data signal, and the lower side is a light emission waveform of the laser beam. In the laser light emission waveform, a pulse with laser power Pw is a heating pulse, a pulse with laser power Pb is a cooling pulse, a pulse with laser power Pe is an erasing pulse, and a pulse with laser power Pm is a preheating pulse. A pulse having a laser power of Pe2 provided after the preheating pulse is a pre-erasing pulse. Before the first heating pulse, a preheating pulse having a power Pm that is greater than or equal to the power Pe of the erase pulse and less than or equal to the power Pw of the heating pulse is provided, and between the preheating pulse and the first heating pulse, It is characterized in that a pre-erase pulse having a power Pe2 which is equal to or higher than the power Pb and equal to or lower than the power Pm of the preheating pulse is provided. An interval between adjacent dotted lines is a basic clock period T. In FIG. 2, the power Pe2 of the pre-erase pulse may be set to the same value as the power Pe of the erase pulse.

  The area irradiated with the recording power (the area conventionally irradiated with the heating pulse) is irradiated with a higher power than the preheating pulse, and the recording layer is sufficiently melted. . Although a method of making only the recording power of the first heating pulse higher than the recording power of the subsequent heating pulse is also conceivable, the peak power becomes high, which is not preferable in terms of heat generation of the laser.

  In the case of FIG. 1, if the power Pm of the preheating pulse is the same as the power Pw of the first heating pulse, it is equivalent to simply increasing the pulse width of the first heating pulse. However, simply spreading the first heating pulse may improve the shelf characteristics, but the pre-test characteristics (recording characteristics under normal room temperature conditions) deteriorate, especially over 1000 times. Write characteristics are deteriorated, which is not preferable.

  The power Pm of the preheating pulse is higher than the power Pe of the erasing pulse and sufficient for melting, and is preferably lower than the power Pw of the heating pulse. Pe <Pm <Pw, and Pm is 0.8 × Pw> Pm ≧ 0.5 × Pw, and the irradiation time of Pm ranges from 0.2 × T to T with respect to the clock period T. Is preferred.

  The rise and fall times of a laser having a wavelength of 405 nm are preferably about 1.5 nsec or less, and should be 3 nsec or less at worst. If the length is longer than this, the influence of thermal interference on the previous recording mark becomes large, and the characteristics before the test (recording characteristics under normal room temperature conditions) deteriorate. When the recording linear velocity becomes higher, it is preferable to record using the information recording method of FIG. 2 rather than FIG. This is because when the recording linear velocity becomes higher, the preheating pulse cannot reach the required temperature just before the first heating pulse as shown in FIG. Because there is a fear. Thus, the melt recrystallization can be performed by increasing the temperature sufficiently by increasing the start time of the preheating pulse. However, if the start time is set too early, the characteristics deteriorate due to thermal interference with the previous recording mark. Further, if the preheating time is too long, the overwrite characteristics are deteriorated. Therefore, it is preferable to start from about 2T before the start time of the data signal (the rising edge of the data signal in FIG. 2). The irradiation time is preferably 2 nsec or more.

  In the BD-RE (Blu-ray Rewritable) standard, at 4 × speed (recording linear velocity 19.68 m / s), T is about 3.8 nsec, and when T is used as a reference, 0.5T is about 2 nsec. The upper limit of the preheating time is preferably 8 nsec or less. Since a slow cooling time is required after the preheating pulse irradiation, a pre-erasing pulse having a power Pe2 that is not less than the power Pb of the cooling pulse and not more than the power Pm of the preheating pulse is provided between the preheating pulse and the first heating pulse. However, it is preferable to secure a pre-erasing pulse irradiation time of 2 nsec or more.

  FIG. 3 is a diagram showing another example of the emission waveform of the laser beam in the information recording method according to the present invention. In FIG. 3, the horizontal axis represents time, and the vertical axis represents laser power. The upper side is a data signal, and the lower side is a light emission waveform of the laser beam. In the laser light emission waveform, a pulse with laser power Pw is a heating pulse, a pulse with laser power Pb is a cooling pulse, a pulse with laser power Pe is an erasing pulse, and a pulse with laser power Pm is a preheating pulse. The pulse with the laser power Pb2 provided after the preheating pulse is a pre-cooling pulse, and the pulse with the laser power Pe2 provided after the pre-cooling pulse is a pre-erasing pulse.

  Before the first heating pulse, a preheating pulse having a power Pm that is equal to or higher than the erase pulse power Pe and equal to or lower than the heating pulse power Pw is provided, and after the preheating pulse, the pre-erasing pulse is equal to or higher than the cooling pulse power Pb. A pre-cooling pulse having a power Pb2 equal to or lower than the power Pe2 is provided, and a pre-erasing pulse having a power Pe2 equal to or higher than the power Pb of the cooling pulse and lower than the power Pm of the preheating pulse is provided after the pre-cooling pulse. is there. An interval between adjacent dotted lines is a basic clock period T. In FIG. 3, the power Pe2 of the pre-erase pulse may be set to the same value as the power Pe of the erase pulse. Further, the power Pb2 of the pre-cooling pulse may be set to the same value as the power Pb of the cooling pulse.

  FIG. 3 shows a pre-cooling pulse having a power Pb2 that is greater than or equal to the power Pb of the cooling pulse and less than or equal to the power Pe2 of the pre-erasing pulse, between the preheating pulse and the pre-erasing pulse, in order to promote cooling than in FIG. It is characteristic that it is provided. By providing the pre-cooling pulse, the melt recrystallized state is formed immediately before the recording mark is formed, the mark at the head of the recording mark can be formed reliably, and the deterioration of the recording characteristics before and after the test can be reduced. That is, shelf characteristics can be improved.

  FIG. 4 is a schematic diagram showing an example of recording marks recorded on an optical information recording medium stored in a high temperature and high humidity environment. Arrows indicate the track direction, with the left side of the figure being the leading portion and the right side being the trailing end. The recording mark including the dotted line portion in FIG. 4 is a recording mark when recorded by the information recording method according to the present invention, and the recording mark excluding the dotted line portion is a recording mark when recorded by the conventional information recording method. As shown in FIG. 4, according to the information recording method of the present invention, a molten recrystallized state is formed immediately before the recording mark is formed even on an optical information recording medium stored in a high temperature and high humidity environment. Thus, the mark at the beginning of the recording mark can be reliably formed.

[Information recording device]
Next, a configuration example of an information recording apparatus for realizing the information recording method (recording strategy) according to the present invention will be described. FIG. 5 is a diagram schematically illustrating a main part of the information recording apparatus 100 that realizes the information recording method according to the present invention.

  Reference numeral 10 denotes an optical information recording medium according to the present invention. As described above, in a predetermined area such as a lead-in area of the optical information recording medium according to the present invention, recording strategy information and recording power information necessary for realizing the information recording method according to the present invention are provided. Record optimization information is written.

  An information recording apparatus 100 that records data on the optical information recording medium 10 mainly includes a spindle motor 20, a laser light irradiation means 30, a preamplifier 40, a servo drive circuit 50, a control means 60, and the like. The laser beam irradiation means 30 is composed of an optical pickup 31 and a laser driving means 32. The control means 60 is mainly composed of focus servo means 61, tracking servo means 62, laser power control means 63, and the like.

  In FIG. 5, a spindle motor 20 is a motor for rotating the optical information recording medium 10 at a predetermined rotational speed. The laser light irradiation means 30 is means for irradiating the optical information recording medium 10 with laser light, and the optical pickup 31 in the laser light irradiation means 30 has a desired lens of the optical information recording medium 10 by a movable lens (not shown). In this device, the laser beam is made to follow the track, and the reflected light from the optical information recording medium 10 is received and converted into an electric signal. The laser drive means 32 in the laser light irradiation means 30 receives a laser drive signal generated by the laser power control means 63 and applies a laser (not shown) mounted on the optical pickup 31 to a desired power and a desired timing. This is a means for emitting light.

  The preamplifier 40 is a circuit that generates a focus error signal from the electrical signal input from the optical pickup 31. The servo drive circuit 50 is a circuit that drives the spindle motor 20 and the lens (not shown) of the optical pickup 31. The control means 60 emits a servo executed by the focus servo means 61 such as a focus servo or a tracking servo executed by the tracking servo means 62, or a laser executed by the laser power control means 63 at a desired power or desired timing. It is means for performing overall control of the information recording apparatus 100 including laser power control for generating a laser drive signal for generating the laser drive signal.

  A recording strategy for realizing a recording method according to the present invention using a laser (not shown) mounted on the optical pickup 31 by means of the laser beam irradiation means 30 and the laser power control means 63 which are constituted by the optical pickup 31 and the laser driving means 32. Can emit light.

  When laser power control or servo control is performed according to the command of the control means 60, the focus servo and tracking servo are applied to the desired track on the recording surface of the optical information recording medium 10 rotated by the spindle motor 20, and the desired The laser beam spot automatically follows the track.

  When data is recorded on the optical information recording medium 10 according to the present invention using the information recording apparatus 100, the record optimization information written in a predetermined area of the optical information recording medium 10 is read out. The optimum recording strategy and the optimum recording power are determined based on the above. In order to realize the determined optimum recording strategy, optimum recording power, etc., the laser power control means 63 in the control means 60 generates a laser drive signal to be output to the laser drive means 32 in the laser light irradiation means 30. . For example, the laser power control means 63 counts the recording mark length and generates a laser drive signal such that one set of heating pulse and cooling pulse is generated every time the count value increases by 2T.

  The laser drive unit 32 in the laser beam irradiation unit 30 determines the optimum recording in which a laser (not shown) mounted on the optical pickup 31 in the laser beam irradiation unit 30 is determined based on the input laser drive signal. Light is emitted by a strategy (recording strategy according to the present invention) or the like, and information is recorded on the optical information recording medium 10.

  Hereinafter, description will be made based on specific examples.

<Example 1, Comparative Example 1>
A polycarbonate substrate for BD-RE to which a spiral continuous groove is transferred, a reflective layer, a second protective layer, a phase change recording layer, a first protective layer, and a cover layer are sequentially laminated, and the recording layer is initially crystallized. Used as a sample. Ag-0.5 wt% Bi alloy as reflective layer, film thickness 140 nm, ZnO-2 wt% Al2O3 as second protective layer, film thickness 8 nm, In18Sb77Ge3Zn2 (atomic%) as phase change recording layer, film thickness 11 nm, first protective layer As a film, ZnS-20 mol% SiO 2 and a film thickness of 33 nm were formed by a sputtering apparatus manufactured by Unaxis and a DVD printer. An adhesive made of an ultraviolet curable resin was applied thereto by a spin coat method, and a Teijin polycarbonate film having a thickness of 0.75 μm was bonded to form a cover layer. Subsequently, the recording layer was initially crystallized with a large aperture LD.

  Information was recorded on the thus obtained sample using a recording / reproduction signal evaluation apparatus ODU-1000 manufactured by Pulstec Industrial Co., Ltd. The wavelength of the laser beam used for recording is 405 nm. Similarly, the channel clock (basic clock period) corresponding to the quadruple speed of 25 GB BD was set to 264 MHz (T = 3.79 sec) corresponding to the quadruple speed. The shortest recording mark length 2T at this time corresponds to 0.149 μm. The information to be recorded was a random pattern conforming to 1-7PP which is a BD modulation method.

  As a recording strategy, the number of heating pulses when forming a recording mark corresponding to a length of 2T among a plurality of types of recording marks is one, and heating is performed every time the recording mark length increases by 2T. An N / 2 recording strategy was used in which the number of pulses was increased by one. FIG. 6 is a diagram showing an example of a conventional N / 2 recording strategy. FIG. 7 is a diagram showing a recording strategy according to the present invention used in the first embodiment. In the first embodiment, the conventional recording strategy (N / 2 recording strategy) shown in FIG. 6 includes the preheating pulse shown in FIG. 1 and the recording strategy shown in FIG. 7 (improvement of the N / 2 recording strategy). And recorded.

  6 and 7, the interval between adjacent dotted lines is the basic clock period T, and the top indicates the rising position of the data signal. Below that, in order, a recording strategy for forming a recording mark corresponding to a length of 2T, which is twice the basic clock period T, corresponds to a length of 3T, which is three times the basic clock period T. A recording strategy for forming a recording mark, and similarly a recording strategy for forming a recording mark corresponding to a length of 4T to 9T are shown below. Here, the recording strategy is a laser emission pattern for writing a recording mark of a predetermined length on an optical information recording medium in an accurate shape. The number of pulses, pulse width, pulse interval, pulse start position, pulse Set by parameters such as power. FIG. 8 is a diagram showing light emission waveform conditions (parameter settings) of the recording strategy according to the present invention shown in FIG.

  The start time of the pulse according to the type of space length before the target recording mark so as to reduce the influence of the thermal interference on the recording mark formation at the head or rear end of the recording mark, that is, the influence of intersymbol interference Adjust. The heating pulse power Pw = 8.5 mW, the erase pulse power Pe = 2.72 mW (Pe / Pw = 0.32), the preheating pulse power Pm = 6 mW, and the cooling pulse power Pb = 0.1 mW.

  FIG. 9 is a diagram showing the recording power dependence of jitter at the head portion (LEJ) and the rear end portion (TEJ) of the recording mark when the first recording is performed before the high temperature and high humidity test. FIG. 10 shows the recording power dependence of the jitter at the head portion (LEJ) and rear end portion (TEJ) of the recording mark when the first recording is performed after being left at 80 ° C. and 85% RH for 100 hours in an unrecorded state. It is a figure which shows sex. Further, assuming that the recording power that minimizes the jitter value after 10 overwrites of this optical information recording medium is the optimum recording power, the power is 8.5 mW. When the jitter reference value is set to 7%, the optimum recording power 8.5 mW jitter is 7% or less in FIGS. 9 and 10, and the recording according to the present invention shown in FIG. It was found that good shelf characteristics can be obtained when recording with a strategy.

  As Comparative Example 1, the result of recording on the same optical information recording medium as in Example 1 using the conventional N / 2 recording strategy of FIG. 6 without irradiating the preheating pulse Pm is shown. Other recording conditions are the same as those in the first embodiment. FIG. 11 is a diagram showing the recording power dependence of jitter at the head portion (LEJ) and the rear end portion (TEJ) of the recording mark when the first recording is performed before the high temperature and high humidity test. FIG. 12 shows the recording power dependence of the jitter at the head portion (LEJ) and rear end portion (TEJ) of the recording mark when the first recording is performed after being left at 80 ° C. and 85% RH for 100 hours in an unrecorded state. It is a figure which shows sex. In FIG. 11, the jitter with the optimum recording power of 8.5 mW is 7% or less, which is the reference value. In FIG. 12, the jitter (LEJ) with the optimum recording power of 8.5 mW exceeds the reference value of 7%. ing. That is, the jitter value when recording after storage at high temperature and high humidity has deteriorated, and the shelf characteristics have deteriorated.

<Example 2>
In Example 2, recording was performed on the same optical information recording medium as in Example 1 with a recording strategy different from that in Example 1. In Example 2, the conventional recording strategy shown in FIG. 6 was recorded by including a preheating pulse and a pre-erasing pulse as shown in FIG. In Example 2, the power of the pre-erase pulse was set to the same value as the power Pe of the erase pulse. Heat pulse power Pw = 8.5 mW, erase pulse power (pre-erasure pulse power) Pe = 2.72 mW (Pe / Pw = 0.32), preheating pulse power Pm = 6 mW, cooling pulse power Pb = 0.1 mW.

  FIG. 13 is a diagram representatively showing the recording strategy according to the present invention used in the second embodiment in the case of a 2T mark. Although only the 2T mark is shown in FIG. 13, the same strategy is applied to a mark longer than the 3T mark. FIG. 14 is a diagram showing light emission waveform conditions (parameter settings) of the recording strategy according to the present invention shown in FIG. The parameter of the preheating pulse indicates the time before that with reference to the start position (rise position) of the data signal.

  After recording on the same optical information recording medium as in Example 1 with the recording strategy shown in FIG. 13, the jitter values before and after the test were measured under the same conditions as in Example 1.

  FIG. 15 is a diagram showing the recording power dependence of jitter at the head portion (LEJ) and the rear end portion (TEJ) of the recording mark when the first recording is performed before the high temperature and high humidity test. FIG. 16 shows the recording power dependence of the jitter at the head portion (LEJ) and the rear end portion (TEJ) of the recording mark when the first recording is performed after leaving for 100 hours at 80 ° C. and 85% RH in an unrecorded state. It is a figure which shows sex. 15 and 16, the jitter with the optimum recording power of 8.5 mW is 7% or less, which is the reference value. When recording is performed with the recording strategy according to the present invention shown in FIG. Was found to be obtained. In Example 2, the jitter value at the optimum recording power of 8.5 mW at the time of reproduction after recording before and after storage at high temperature and high humidity is further improved compared to Example 1, and the recording strategy shown in FIG. It was found to be very effective for improvement.

<Example 3>
In Example 3, recording was performed on the same optical information recording medium as in Example 1 and Example 2 with a recording strategy different from that in Example 1 and Example 2. In Example 3, pre-heating pulses, pre-erasing pulses, and pre-cooling pulses as shown in FIG. 3 were included in the conventional recording strategy shown in FIG. In order to reduce the effects of slow cooling and preheating, a precooling pulse is provided after preheating pulse irradiation. The power of the pre-cooling pulse was set to the same power Pb as that of the cooling pulse. Heat pulse power Pw = 8.5 mW, erase pulse power (pre-erasure pulse power) Pe = 2.72 mW (Pe / Pw = 0.32), preheat pulse power Pm = 6 mW, cooling pulse power (pre- Cooling pulse power) Pb = 0.1 mW.

  FIG. 17 is a diagram representatively showing the recording strategy according to the present invention used in Example 3 in the case of a 2T mark. In FIG. 17, only the 2T mark is illustrated, but the same strategy is applied to a mark longer than the 3T mark. FIG. 18 shows light emission waveform conditions (parameter settings) of the recording strategy according to the present invention shown in FIG. The parameter of the preheating pulse indicates the time before that with reference to the start position (rise position) of the data signal.

  In Example 3, when the first recording before the high-temperature and high-humidity test was recorded at the optimum recording power of 8.5 mW, the jitter at the head portion (LEJ) and the rear end portion (TEJ) of the recording mark and unrecorded In this state, after left at 80 ° C. and 85% RH for 100 hours, the jitter at the beginning (LEJ) and rear end (TEJ) of the recording mark when the first recording was recorded at 8.5 mW which is the optimum recording power. Was measured. As a result, the jitter values before the high temperature and high humidity test were LEJ 6.1% and TEJ 5.9%, and the jitter values after the high temperature and high humidity test were LEJ 6.5% and TEJ 6.1%. It was. In both cases, the jitter with the optimum recording power of 8.5 mW is 7% or less, which is the reference value. Like the first and second embodiments, the recording strategy shown in FIG. I found out.

<Example 4, comparative example 2>
In Example 4, using the same recording method (recording strategy) shown in FIG. 17 as Example 3 on the same optical information recording medium as in Examples 1 to 3, overwriting was performed 10 times at room temperature, and recording after recording was performed. Jitter at the head portion (LEJ) and rear end portion (TEJ) of the mark was measured. As a result, LEJ was 6.7% and TEJ was 6.5%. Furthermore, after this optical information recording medium was left in a high temperature and high humidity environment of 80 ° C. and 85% RH for 100 hours, overwriting was performed once under the same recording conditions, and the recording mark head (LEJ) after recording was recorded. Jitter at the rear end (TEJ) was measured. As a result, LEJ was 7.5% and TEJ was 6.9%.

  On the other hand, as Comparative Example 2, the same optical information recording medium as in Examples 1 to 3 was overwritten ten times at room temperature by the same recording method (recording strategy) shown in FIG. Jitter at the head portion (LEJ) and the rear end portion (TEJ) of the mark was measured (however, Pw was 8.45 mW). As a result, they were LEJ 6.5% and TEJ 6.3%. Furthermore, after this optical information recording medium was left in a high temperature and high humidity environment of 80 ° C. and 85% RH for 100 hours, overwriting was performed once under the same recording conditions, and the recording mark head (LEJ) after recording was recorded. The jitter at the rear end (TEJ) was measured. As a result, LEJ was 10.4% and TEJ was 7.6%.

  Since the conditions of the test of Example 4 are stricter than those of Examples 1 to 3, the reference value of the jitter value in Example 4 was set to 8.5%. Therefore, it has been found that by using the recording method according to the present invention, the deterioration can be suppressed even if the recorded mark is left in a high temperature environment after recording a plurality of times at room temperature and then recorded again.

<Example 5, Comparative example 3>
In Example 5, recording was performed on the same optical information recording medium as in Examples 1 to 4 with a recording strategy different from that in Examples 1 to 4. In Example 5, a light emission pulse (n-1 recording strategy) of a type having (n-1) pulses is used for the nT mark shown in FIG. A recording strategy for setting a preheating pulse, a pre-erasing pulse, and a pre-cooling pulse was used in the same manner as in FIG.

  Heat pulse power Pw = 10.5 mW, erase pulse power (pre-erasure pulse power) Pe = 2.95 mW (Pe / Pw = 0.28), preheat pulse power Pm = 6 mW, cooling pulse power (pre- Cooling pulse power) Pb = 0.1 mW. A laser having a fast rise time of 0.8 nsec is used. Other recording conditions are the same as those in Examples 1 to 4. After being left unrecorded in an environment of 80 ° C. and 85% RH, recording was performed once, and the jitter at the head portion (LEJ) and rear end portion (TEJ) of the recorded mark after recording was measured.

  As a result of the measurement, the jitter values before the high temperature test were LEJ 6.2% and TEJ 6.0%, and the jitter values after the high temperature and high humidity test were LEJ 6.7% and TEJ 6.2%. . In all cases, the jitter with the optimum recording power of 8.5 mW is 7% or less, which is the reference value. In the case of the n-1 recording strategy as in the fifth embodiment, it is possible to add a preheating pulse or the like. It was found to be very effective in improving the characteristics.

  On the other hand, in Comparative Example 3, recording was performed on the same optical information recording medium as in Example 5 with a recording strategy different from that in Example 5. In Comparative Example 3, a recording strategy for setting a light emission pulse of a type having (n−1) pulses for the nT mark shown in FIG. 19 was used (a preheating pulse and a precooling before the first pulse). Pulse and pre-erase pulse are not set). After being left unrecorded in an environment of 80 ° C. and 85% RH, recording was performed once, and the jitter at the head portion (LEJ) and rear end portion (TEJ) of the recorded mark after recording was measured. Other recording conditions are the same as those in the fifth embodiment.

  As a result of the measurement, the jitter values before the high-temperature test are LEJ 6.2% and TEJ 6.0%, and the jitter values after the high-temperature and high-humidity test are greatly degraded to LEJ 9.4% and TEJ 7.5%. Was. The jitter reference value in this test was 7.0%.

  As described above, as shown in Examples 1 to 5 and Comparative Examples 1 to 3, if the information recording method according to the present invention is used, a high capacity recording medium such as a Blu-ray disc (BD-RE) can be used. Even when recording is performed at a linear velocity, it is possible to perform suitable recording without deteriorating shelf characteristics.

  Further, by reading and recording information such as a recording strategy preliminarily written in the optical information recording medium according to the present invention in an information recording apparatus, it is possible to perform suitable recording without deteriorating shelf characteristics.

  The preferred embodiments and examples of the present invention have been described in detail above. However, the present invention is not limited to the above-described examples, and various modifications can be made to the above-described examples without departing from the scope of the present invention. And substitutions can be added.

  For example, in the embodiments and examples of the present invention, an example of recording on one optical information recording medium has been shown, but the present invention can be similarly applied to an optical information recording medium having two or more layers. it can.

  In the embodiments and examples of the present invention, an example of recording on a Blu-ray disc (BD-RE) has been shown. However, the present invention is similarly applied to other optical information recording media such as HD DVDs. can do.

  In the embodiments and examples of the present invention, an example of recording using a modulation method of 1-7PP has been shown, but other modulation methods may be used.

It is a figure which shows the example of the light emission waveform of the laser beam in the information recording method which concerns on this invention. It is a figure which shows the other example of the light emission waveform of the laser beam in the information recording method which concerns on this invention. It is a figure which shows the other example of the light emission waveform of the laser beam in the information recording method which concerns on this invention. It is a schematic diagram which shows the example of the recording mark recorded on the optical information recording medium preserve | saved in a high temperature, high humidity environment. It is a figure which illustrates roughly the principal part of the information recording device 100 which implement | achieves the information recording method which concerns on this invention. It is a figure which shows the example of the conventional N / 2 recording strategy. It is a figure which shows the recording strategy based on this invention used in Example 1. FIG. It is a figure which shows the light emission waveform conditions (parameter setting) of the recording strategy which concerns on this invention shown in FIG. It is a figure which shows the recording power dependence of the jitter of the head part (LEJ) of a recording mark and the rear end part (TEJ) at the time of the first recording before a high temperature, high humidity test. FIG. 6 is a diagram showing the recording power dependence of jitter at the head portion (LEJ) and the rear end portion (TEJ) of a recording mark when the first recording is performed after being left at 80 ° C. and 85% RH for 100 hours in an unrecorded state. is there. It is a figure which shows the recording power dependence of the jitter of the head part (LEJ) of a recording mark and the rear end part (TEJ) at the time of the first recording before a high temperature, high humidity test. FIG. 6 is a diagram showing the recording power dependence of jitter at the head portion (LEJ) and the rear end portion (TEJ) of a recording mark when the first recording is performed after being left at 80 ° C. and 85% RH for 100 hours in an unrecorded state. is there. It is a figure which shows the recording strategy which concerns on this invention used in Example 2 in the case of a 2T mark. It is a figure which shows the light emission waveform conditions (parameter setting) of the recording strategy which concerns on this invention shown in FIG. It is a figure which shows the recording power dependence of the jitter of the head part (LEJ) of a recording mark and the rear end part (TEJ) at the time of the first recording before a high temperature, high humidity test. FIG. 6 is a diagram showing the recording power dependence of jitter at the head portion (LEJ) and the rear end portion (TEJ) of a recording mark when the first recording is performed after being left at 80 ° C. and 85% RH for 100 hours in an unrecorded state. is there. It is a figure which shows the recording strategy which concerns on this invention used in Example 3 in the case of 2T mark as a representative. It is a figure which shows the light emission waveform conditions (parameter setting) of the recording strategy which concerns on this invention shown in FIG. It is a figure which shows the example of the conventional recording strategy. It is a figure which shows the other example of the conventional recording strategy.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Optical information recording medium 20 Spindle motor 30 Laser light irradiation means 31 Optical pick-up 32 Laser drive means 40 Preamplifier 50 Servo drive circuit 60 Control means 61 Focus servo means 62 Tracking servo means 63 Laser power control means 100 Information recording apparatus Pw of heating pulse Power Pb Cooling pulse power Pe Erase pulse power Pm Preheating pulse power Pb2 Precooling pulse power Pe2 Preerase pulse power T Basic clock period 2T to 9T Recording mark Tmp, Tspt, Tesp, Tlp, ΔTlc, Tm, Te Recording strategy parameters

Claims (16)

The laser beam power is controlled to at least three values corresponding to each of a heating pulse, a cooling pulse, and an erasing pulse, and the optical information recording medium is irradiated with the heating pulse and the cooling pulse alternately. An information recording method in which predetermined information is recorded by a plurality of types of recording marks having different sizes and a space formed between the recording marks by irradiation with the erasing pulse,
An information recording method, wherein when the recording mark is formed, a preheating pulse having a power higher than that of the erasing pulse and lower than that of the heating pulse is provided before the first heating pulse.   2. The pre-erasing pulse having a power not less than the power of the cooling pulse and not greater than the power of the pre-heating pulse is provided between the pre-heating pulse and the first heating pulse. Information recording method.   3. The information according to claim 2, further comprising a pre-cooling pulse having a power that is greater than or equal to the power of the cooling pulse and less than or equal to the power of the pre-erase pulse between the preheat pulse and the pre-erase pulse. Recording method.   The plurality of types of recording marks are a plurality of types of recording marks corresponding to a natural number times the basic clock period T, and are formed by alternately irradiating the heating pulse and the cooling pulse. The plurality of types of recording marks has one heating pulse when forming the recording mark corresponding to a length of 2T, and then the number of heating pulses increases each time the recording mark length increases by 2T. 4. The information recording method according to claim 1, wherein the information recording method is formed using a recording strategy that increases one by one.   The plurality of types of recording marks are a plurality of types of recording marks corresponding to a length n times (n is a natural number) the basic clock period T, and the heating pulse and the cooling pulse are alternately irradiated. The plurality of types of recording marks to be formed are formed using a recording strategy in which the number of heating pulses when forming the recording marks corresponding to the length of nT is (n-1). The information recording method according to any one of claims 1 to 3, wherein the information recording method is characterized in that:   6. The ratio of the erase pulse power to the heating pulse power (the erase pulse power / the heating pulse power) is 0.2 or more and 0.5 or less. The information recording method according to one item.   7. The information recording method according to claim 1, wherein the predetermined information is recorded at a linear velocity of 15 m / s or more.   8. The information recording method according to claim 1, wherein a wavelength of the laser beam is in a 400 nm band. Laser light power is controlled to at least three values corresponding to each of a heating pulse, a cooling pulse, and an erasing pulse, and a plurality of types having different lengths formed by alternately irradiating the heating pulse and the cooling pulse An optical information recording medium on which predetermined information is recorded by the recording mark and a space formed between the recording marks by irradiation of the erasing pulse,
When forming the recording mark, information for providing a preheating pulse that is higher than the power of the erase pulse and lower than the power of the heating pulse is written in advance before the first heating pulse. An optical information recording medium characterized by the above.   Furthermore, information for providing a pre-erasing pulse that is higher than the power of the cooling pulse and lower than the power of the preheating pulse is written in advance between the preheating pulse and the first heating pulse. The optical information recording medium according to claim 9.   Further, information for providing a pre-cooling pulse that is greater than or equal to the power of the cooling pulse and less than or equal to the power of the pre-erase pulse is written in advance between the preheat pulse and the pre-erase pulse. The optical information recording medium according to claim 10.   The plurality of types of recording marks are a plurality of types of recording marks corresponding to a natural number times the basic clock period T, and are formed by alternately irradiating the heating pulse and the cooling pulse. The plurality of types of recording marks has one heating pulse when forming the recording mark corresponding to a length of 2T, and then the number of heating pulses increases each time the recording mark length increases by 2T. 12. The optical information recording medium according to claim 9, wherein the optical information recording medium is formed using a recording strategy that increases one by one.   The plurality of types of recording marks are a plurality of types of recording marks corresponding to a length n times (n is a natural number) the basic clock period T, and the heating pulse and the cooling pulse are alternately irradiated. The plurality of types of recording marks to be formed are formed using a recording strategy in which the number of heating pulses when forming the recording marks corresponding to the length of nT is (n-1). The optical information recording medium according to claim 9, wherein the optical information recording medium is a recording medium.   14. The ratio of the erase pulse power and the heating pulse power (the erase pulse power / the heating pulse power) is 0.2 or more and 0.5 or less. The optical information recording medium according to one item.   15. The optical information recording medium according to claim 9, wherein the predetermined information is recorded at a linear velocity of 15 m / s or more.   The optical information recording medium according to claim 9, wherein the wavelength of the laser beam is in a 400 nm band.

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