JP2008226391A - Optical recording medium, optical recording device and recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording method to an optical recording medium by which satisfactory recording can be performed by adopting a method for setting a recording condition to the optical recording medium with an easy method, and to provide an optical recording device and the optical recording medium. <P>SOLUTION: The recording method includes steps of: acquiring an index for recording related to the optimum recording power of a laser beam in a test recording region of the optical recording medium; setting the optimum recording power based on the acquired index for recording in the test recording region; acquiring the index for recording in each recording region into which a recording area of the optical recording medium is divided; correcting the set optimum recording power based on the acquired index for recording in each recording region; and performing recording in each recording region by the corrected optimum recording power. The optical recording device is also provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical recording medium, an optical recording apparatus, and a recording method, and in particular, recording with good quality can be performed by adopting a method for setting recording conditions on an optical recording medium by an easy method. The present invention relates to an optical recording medium, an optical recording apparatus, and a recording method.

Conventionally, when recording on an optical recording medium is performed by an optical recording apparatus, a test recording method (OptimumPower) is used.
In many cases, the recording power is determined by Control (OPC). Since the test area where the OPC is performed is set outside the data recording area, it is usually set at the innermost or outermost part of the disc (see Patent Documents 1 and 2).

Japanese Patent No. 3085551 Japanese Patent No. 3124721

By the way, optical recording media are not necessarily uniform in film thickness of each layer and optical characteristics of the recording layer, and many of them have in-plane variation (difference due to radial position). The in-plane variation of the film thickness of each layer is attributed to, for example, that the film thickness tends to be thin at the outer periphery when each layer is formed by sputtering. Further, the in-plane variation of the optical characteristics of the recording layer is caused by, for example, that the transmittance tends to increase due to the saturation of oxygen in the outer peripheral portion of the recording layer.
As described above, when in-plane variation occurs in the film thickness of each layer and the optical characteristics of the recording layer, the optimum recording power for the test recording area set in the innermost peripheral part or the outermost peripheral part and the optimum recording in the recording area Power will be different. In this case, since the optimum recording power set by the OPC performed in the test recording area is not the “optimal” recording power for the recording area, the recording area cannot be appropriately recorded. As a result, there is a case where recording is performed with a quality that cannot be read and reproduced after recording.
The present invention has been made in view of the above problems, and the problem is that even when the optimum recording power for the test recording area and the optimum recording power for the recording area are different, the quality of the recording area is good. It is to provide a recording method, an optical recording apparatus, and an optical recording medium on an optical recording medium that can perform the above recording.

Said subject is solved by the following means (1)-(5).
(1) In the test recording area of the optical recording medium, obtaining the recording-related index related to the optimum recording power of the laser beam, and setting the optimum recording power based on the acquired recording-related index of the test recording area And correcting the set optimum recording power based on the acquired recording-related index in each recording area, and acquiring the recording-related index in each recording area that divides the recording area of the optical recording medium. And a recording method for recording on each recording area with the corrected optimum recording power.
(2) The recording method on the optical recording medium according to (1), wherein the recording-related index is a reflected light intensity of the laser beam.
(3) An optical recording medium used in the recording method described in (2) above, wherein the material of the recording layer contains an inorganic material that causes an irreversible change when irradiated with laser light. recoding media.
(4) The wavelength of the laser beam is 390 to 420 nm, the main components of the recording layer are Bi and oxygen, and in addition, Mg, Al, Cr, Mn, Co, Fe, Cu, Zn, Li, Si , Ge, Zr, Ti, Hf, Sn, Mo, V, Nb, Y, Ta, Te, Sb, In, Ga, Ni, B, a recording mark on which information is recorded The optical recording medium according to (3), wherein the portion includes a crystal of an element contained in the recording layer and / or a crystal of an oxide of the contained element.
(5) Irradiation means for irradiating the optical recording medium with laser light, acquisition means for acquiring a recording-related index related to the optimal recording power of the laser light, and the optimum recording power based on the acquired recording-related index Setting means for setting, and drive means for driving the irradiating means based on the set optimum recording power, wherein the setting means is the recording-related index acquired in the test recording area of the optical recording medium. And correcting the optimum recording power set on the basis of the recording-related index acquired in each recording area obtained by dividing the recording area of the optical recording medium.

  According to the recording method of the present invention, the optimum recording power set based on the recording related index acquired in the test recording area is corrected based on the recording related index acquired in each recording area, and each of the corrected optimum recording power is Recording is performed on the recording area. Therefore, even when the optimum recording power for the test recording area is different from the optimum recording power for each recording area (recording area), the optimum recording power for each recording area can be corrected in consideration of the difference. Therefore, it is possible to appropriately record in each recording area.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. . The following description is an example of the best mode of the present invention and does not limit the scope of the claims.

One embodiment of the layer structure of the optical recording medium according to the present invention is shown in FIG.
The basic configuration of this optical recording medium is that a lower protective layer 2, a recording layer 3, an upper protective layer 4, a reflective layer 6, and an organic resin material are used on a substrate 1 having guide grooves (not shown). It has a layer (overcoat layer) 7.
The above layer configuration is an example, and if necessary, either the lower protective layer 2 or the upper protective layer 4 is not formed, or if an Ag-based reflective layer is used, a barrier is provided between the upper protective layer and the upper protective layer. A layer 5 (anti-sulfurization layer or anti-oxidation layer) is provided, a hard coat layer 8 is provided on the mirror side of the substrate (opposite the surface where the guide groove is formed), or on the overcoat layer 7 May be provided with a printing layer 9. Further, the above single plate disk may have a laminated structure with the adhesive layer 10 interposed therebetween. In this case, the overcoat layer 7 is not formed, and the function may be shared by the adhesive layer 10. The disc on the opposite side to be bonded may be a similar single plate disc or only a transparent substrate. Alternatively, the single-layer disc may be bonded without forming the print layer 9, and after the bonding, the print layer 9 ′ may be formed on the opposite surface side.

The material used for the substrate 1 is usually glass, ceramics or resin, and a resin substrate is preferable in terms of moldability and cost. Examples of the resin include polycarbonate resin, acrylic resin, epoxy resin, polystyrene resin, acrylonitrile-styrene copolymer resin, polyethylene resin, polypropylene resin, silicone resin, fluorine resin, ABS resin, and urethane resin. Polycarbonate resins and acrylic resins that are excellent in terms of moldability, optical properties, and cost are preferred.
Further, when the optical recording medium of the present invention is applied to an HD DVD-R disc (DVD-R disc capable of high-density recording) or an HD DVD-RW disc, the following specific conditions are given. It is desirable. That is, the width of the guide groove formed on the substrate 1 is 0.1 to 0.3 μm, preferably 0.17 to 0.23 μm, and the depth of the guide groove is 18 to 40 nm, preferably 23 to 33 nm. It is that. One period of the meandering period of the guide groove is 9.5 μm. The thickness of the substrate 1 is preferably 0.57 to 0.63 mm, and the thickness of the disk after bonding is preferably 1.1 to 1.3 mm. These substrate grooves improve reproduction compatibility with the HD DVD-ROM drive.

For the recording layer 3, for example, a recording material used for a write-once optical recording medium made of an inorganic material is used.
As a write-once type optical recording medium using an inorganic material as a recording layer material, a method of recording information by forming pits (holes) in a medium by laser light irradiation as described in JP-A-2003-145934 Alternatively, a method of recording information by changing the reflectivity by causing a structural change due to phase change or alloying has been proposed. However, in the case of the pit method, it becomes difficult to obtain uniform pits as the recording density increases, and this deteriorates signal characteristics and recording sensitivity, which is not desirable. In the case of the phase change recording method, there is a risk that the recording mark may be erased depending on the case of using the phase transition between the crystal and the amorphous state. That is, although there is a problem that the contrast of the reproduction signal of the recording mark is small, in order to control the size of the recording mark, these methods using the structural change are desirable.

In particular, as a recording material used in the present invention, an optical recording medium using a laser beam in a red laser wavelength region (approximately 630 nm to 670 nm) used in a DVD, or an infrared laser wavelength region (approximately 760 nm) used in a CD. When used for an optical recording medium using a laser beam of ˜830 nm), a metal or metalloid material for absorbing the irradiated laser beam and raising the temperature, an oxide, a sulfide for suppressing deformation, Ceramics such as carbides or mixtures of similar materials are desirable.
Specifically, at least one element of S, Se, Te, Sb, Ge, Sn, Bi, Ga, and In is used as the metal or semimetal, and the ceramic material includes CaO, SiO ₂ , Al ₂ O. ₃ , Fe ₂ O ₃ , Bi ₂ O ₃ , CuO, PbO, BaO, TiO ₂ , Sb ₂ O ₃ , CeO ₂ , ZnO, CdO, In ₂ O ₃ , SnO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅ , V ₂ O ₅ , MgO, BeO, ZrO ₂ , MoO ₃ , WO ₃ , NiO, CoO ₂ , TeO ₂ , MnO and other oxides, sulfides such as ZnS, CdS, and MoS ₂ ; Si ₃ N ₄ , A nitride such as AlN, BN, or TiN, or a carbonized material such as SiC, B4C, TiC, WC, amorphous carbon, graphite, or diamond can be used. In particular, it is more preferable to use a ceramic having a small energy band gap because it can assist light absorption.

  In the case of an optical recording medium using a laser beam in a blue laser wavelength region (approximately 390 nm to 420 nm) used in HD DVD and BD, Bi and the like disclosed in JP-A-2006-116948 are used. In addition to O, at least one of Mg, Al, Cr, Mn, Co, Fe, Cu, Zn, Li, Si, Ge, Zr, Ti, Hf, Sn, Mo, V, Nb, Y, Ta The recording mark portion that contains the element and in which the information is recorded can use a recording material containing an element crystal and / or an oxide crystal of the element contained in the recording layer. In addition, for a recording material in which one or more elements are added to Bi and O, Te, Sb, In, Ga, Ni, and B can also be used as elements to be added.

  About the thickness of the recording layer 3, although the optimal value changes with conditions of the optical information recording medium to be used, it is desirable to exist in the range of about 10-25 nm. If the film thickness is less than 10 nm, the degree of modulation of the recording mark decreases, and if it exceeds 25 nm, the formation accuracy of the recording mark at the time of recording decreases.

An inorganic protective layer (upper protective layer 4 and lower protective layer 2) for protecting the recording layer 3 is formed on at least one of the upper layer and the lower layer of the recording layer 3. _{Specifically, SiO, SiO 2, ZnO,} SnO 2, Al 2 O 3, TiO 2, In 2 O 3, MgO, oxides such as _{ZrO 2, Ta 2 O 5,} Nb 2 O 5; Si 3 N _4, AlN, TiN, BN, nitride or ZnS such as ZrN, sulfides or SiC, such _{TaS 4, TaC, B4C, WC} , TiC, carbide or diamond-like carbon, such as ZrC, or a mixture thereof is used.
Further, when a material that reacts with sulfur to produce sulfide, such as Ag, is used as the reflective layer material, the upper protective layer 4 is composed of two or more layers and is in contact with the reflective layer 6. In some cases, a layer containing no sulfide is formed as the barrier layer 5.
As for the film thickness of the inorganic protective layer (upper protective layer 4 and lower protective layer 2), a range in which recording / reproducing signals such as recording sensitivity and reflectance are good may be set, but the function of protecting the recording layer 3 Is required, a film thickness of at least 4 nm or more is required.

The material of the reflective layer 6 is preferably a substance having a high reflectance with respect to the wavelength of the laser beam. Examples thereof include Au, Ag, Cu, Al, Ti, V, Cr, Ni, Nd, Mg, Pd, Zr, and Pt. , Ta, W, Si, Zn, and In, and at least one metal and semimetal. Among them, one of Au, Ag, and Cu is the main component, and Au, Ag, Cu, Al, Ti, V, Cr, Ni, Nd, Mg, Pd, Zr, Pt, Ta, W, Si, Zn, In An alloy to which at least one selected from 0.1% to 10% by weight is added is preferable, and In is particularly preferable (since it is an alloy, the combination of Au and Au, Ag and Ag, and Cu and Cu is naturally except). By adding 0.1% by weight or more of the above metal or metalloid, a thin film having fine crystal grains and excellent corrosion resistance can be obtained.
However, it is not preferable to add more than 10% by weight of the above metal or metalloid because the reflectance decreases. The base material is most preferably Ag capable of increasing the film forming rate, and the additive is particularly preferably Au, Cu, Mg, or In having a small refractive index n and a large absorption coefficient k.
The thickness of the reflective layer 6 is 30 nm to 200 nm, preferably 35 to 160 nm. In addition, the reflective layer can be multi-layered. Even in the case of multiple layers, it is preferable that the total thickness of the multi-layered film is in the same range as that of one layer. When the film thickness is less than 30 nm, it is difficult to ensure the reflectance. If it is thicker than 200 nm, it takes too much time to form a film, so that deformation due to stress on the substrate during film formation occurs. Also, the production efficiency is lowered.

As a method for forming the recording layer 3, the lower protective layer 2, the upper protective layer 4, and the reflective layer 6 in the optical recording medium of the present invention, film forming methods such as plasma CVD, plasma treatment, ion plating, and photo CVD can be used. A sputtering film forming method widely used in the production of optical recording media is effective. Typical film forming conditions are a pressure of 10 ⁻² hPa to 10 ⁻⁴ hPa, a sputtering power of 0.1 kW / 200 mmφ to 5.0 kW / 200 mmφ, and a film forming speed of 0.1 nm / s to 50 nm / s.

An overcoat layer 7 made of an organic resin is formed on the reflective layer 6 in contact with the reflective layer 6. The overcoat layer 7 is preferably formed by spin coating in order to form a uniform film.
The material of the overcoat layer 7 needs to be selected in consideration of the fact that it does not contain corrosive components in the reflective layer material to be used and that it is a highly curable material that is difficult to become uncured. is there. Examples of such materials include anaerobic curable resins such as ultraviolet curable resins and silicone resins. However, ultraviolet curable resins that can be cured without taking a long time are advantageous for improving productivity. Even more preferred. Regarding the selection of materials, the constituent conditions of the overcoat layer 7, and the preparation conditions, it is necessary to consider the adhesion with the reflective layer 6. In the case of a bonded optical recording medium, the adhesive layer 10 can also serve as the overcoat layer 7 without forming the overcoat layer 7.
The thickness of the overcoat layer 7 is suitably 3 to 15 μm. If the thickness is less than 3 μm, an increase in error may be observed when the printing layer 9 is provided on the overcoat layer 7. Moreover, storage deterioration may occur and the role as a protective layer may not be fulfilled. On the other hand, if it is thicker than 15 μm, the internal stress increases, which greatly affects the mechanical properties of the disk.

  When the hard coat layer 8 is provided, an ultraviolet curable resin layer produced by spin coating is generally used. The thickness is suitably 2 to 6 μm. If it is thinner than 2 μm, sufficient scratch resistance cannot be obtained. If it is thicker than 6 μm, the internal stress increases, which greatly affects the mechanical properties of the disk. The hardness needs to be not less than the pencil hardness H that does not cause a large scratch even when rubbed with a cloth. It is also effective to mix a conductive material as necessary to prevent electrification by preventing electrification.

  The printing layers 9 and 9 ′ are for the purpose of ensuring scratch resistance, label printing of brand names, etc., and forming an ink receiving layer for inkjet printers, and it is preferable to form an ultraviolet curable resin by a screen printing method. is there. The thickness is suitably 3 to 50 μm. If the thickness is less than 3 μm, unevenness occurs when forming the layer, and if the thickness is more than 50 μm, the internal stress increases, which greatly affects the mechanical properties of the disk.

For the adhesive layer 10, an adhesive such as an ultraviolet curable resin, a hot melt adhesive, or a silicone resin can be used. These materials are applied on the resin protective layer or the printing layer 9 by a method such as spin coating, roll coating, or screen printing according to the material, and subjected to treatment such as ultraviolet irradiation, heating, and pressurization, so that the opposite surface Affix to the disc. The disc on the opposite surface may be a similar single plate disc or a transparent substrate alone, and the adhesive layer material may or may not be applied to the bonding surface of the opposite disc. In addition, as the adhesive layer 10, an adhesive sheet can be used.
The film thickness of the adhesive layer 10 is not particularly limited, but is 5 to 100 μm, preferably 7 to 80 μm, considering the effects of material applicability, curability, and disk mechanical properties. The range of the adhesive surface is not particularly limited, but when applied to a rewritable disc that is compatible with DVD and / or HD DVD, in order to ensure high-speed recording, it is necessary to secure the adhesive strength. It is desirable that the position of the peripheral end is φ15 to 40 mm, preferably φ15 to 30 mm.

As shown in FIG. 2, the optical recording apparatus includes a driving unit that rotates and drives an optical recording medium by a driving unit including a spindle motor, a pickup (irradiating unit) that irradiates the optical recording medium with laser light, and reflection of the laser light. Detection unit (acquisition means) for detecting light intensity, setting unit for setting the optimum recording power of laser light based on the detected reflected light intensity, and laser drive for driving the pickup based on the set optimum recording power Circuit. Then, a semiconductor laser light source is driven by a laser driving circuit of a recording / reproducing pickup, and a pulse pattern having a front pulse portion, a multi-pulse portion, and an end pulse portion as shown in FIG. 3 is provided on an optical recording medium via an optical system. The recording layer of the optical recording medium is optically changed by irradiating the laser beam, and the reflected light from the optical information recording medium is received by a recording / reproducing pickup, and information is recorded and reproduced on the optical recording medium. Is to do.
The recording means uses a so-called PWM recording (mark edge recording) system in which a signal is recorded as a mark width on the recording layer of the optical information recording medium of the present invention. In this case, for example, when a signal having a signal width of nT (n is a predetermined value and T is a clock time: a time corresponding to a clock period used for signal modulation) is high as shown in FIG. A pulse pattern including a power level Pw and a low power level Pb is used.
For recording / reproducing on / from the optical recording medium of the present invention, laser light having a wavelength corresponding to the type of the optical recording medium described above is irradiated.

By the way, even in the same optical recording medium, if the appropriate recording power differs depending on the radial position, when recording is performed at a position away from the area where OPC is performed, recording is performed with the recording power set by OPC. In some cases, recording with good quality may not be possible.
In such a case, it is necessary to correct the recording power in accordance with the recording area and perform recording with the optimum recording power. The optimum recording power targets not only maximum and minimum values such as jitter, PRSNR (Partial Response Signal to Noise Ratio), and data errors, but also a specific value such as modulation degree and β. There are also things.

As a method for setting the recording power Pw, the above-described technique such as OPC is used. Here, a case where the reflected light intensity is selected as the recording-related index will be described.
The reflected light intensity varies depending on the recording area (the reflected light intensity increases at the outer periphery) due to in-plane variation of the film thickness of each layer (difference depending on the radial position) and in-plane variation of the optical characteristics of the recording layer. to cause. In-plane variation of the film pressure of each layer, in the case of sputtering film formation, the film thickness tends to be thin at the outer periphery, and in the optical recording medium described in the examples, when the film thickness is thin in a layer other than the reflective layer, The reflected light intensity tends to increase. Further, the in-plane variation of the optical characteristics of the recording layer is due to the fact that the composition of the recording layer varies depending on the radial position. More specifically, oxygen tends to be saturated at the outer peripheral portion, thereby transmitting. It is considered that the rate increases (the reflectance intensity increases as an optical recording medium) (see FIG. 5).

  In the optical recording medium of the present invention, it has been found that the optimum recording power and the reflected light intensity (unrecorded portion) have a substantially proportional relationship (see FIG. 4). Therefore, the recording method of the present invention includes (a step) a step of acquiring a recording-related index related to the optimum recording power of the laser beam for the test recording area of the optical recording medium, and (b step) the test acquired in step a. A step of setting the optimum recording power based on a recording-related index of the recording area; and (c step) obtaining a recording-related index of the step a for each recording area dividing the recording area of the optical recording medium; (D step) A step of correcting the set optimum recording power based on the acquired recording-related index of each recording region, and (e step) recording on each recording region with the corrected optimum recording power. Through the processes, the optimum recording power in the recording area can be estimated.

The “recording related index” here is, for example, reflected light intensity, focus error signal, tracking error signal, wobble error signal, address error signal as an index before recording, and as an index after recording, for example, , Β (asymmetry), modulation degree, jitter, and data error signal.
In addition, as “a method for obtaining a recording-related index for each recording area”, the reflected light intensity or the like may be measured by actually irradiating a laser beam, or the medium information (manufacturer name) recorded on the optical disc , Media type, etc.) may be read to refer to information (recorded in advance in the apparatus) that associates the medium information with the recording-related index of each recording area.

To explain with a schematic example, in setting the optimum recording power in the test recording area (r = 23.8 mm), the recording power at which the PRSNR is minimized is selected. In this schematic example, the recording area is divided by a radius of 1 mm, the optimum recording power is corrected at r = 24.0 mm (test recording area), and r = 24.0-24. Recording is performed in a recording area of 999... Mm, the optimum recording power is corrected at r = 25 mm, and correction is performed in a recording area of r = 25.0 to 25.999. Repeatedly.

Therefore, in the present invention, the reflected light intensity is obtained by OPC of the test recording area (r = 23.8 mm) (step a), and the optimum recording power of the test recording area is set based on this reflected light intensity ( b process). On the other hand, the reflected light intensity in each of the divided recording areas is obtained (step c), and the value of the ratio of the reflected light intensity in each recording area to the reflected light intensity in step a is set to the optimum recording power of the test recording area. By multiplying the value, the optimum recording power of each of the divided recording areas is corrected (step d). Then, recording is performed in each recording area with the optimum recording power corrected in step d (step e). That is, in the optical recording apparatus, the setting unit is based on the reflected light intensity detected in the test recording region. The set optimum recording power is corrected based on the reflected light intensity detected in each recording area. Then, the drive unit drives the pickup based on the corrected optimum recording power. For this reason, the laser beam of the optimal recording power corrected appropriately is irradiated from the pickup.
By this method, even when recording is performed at a position away from the OPC area, it is possible to record with good characteristics. In addition, this method can be said to be a preferable method because it is possible to set an appropriate power without actually performing test recording in the recording area, and the data area is not impaired. In addition, according to the recording method of the present invention, even when the outermost part is recorded after a large part of the recording capacity is used after a large part of the recording capacity is used, for example, in a DVD recorder, it is satisfactory. You can record with good quality.

  The above calculates the optimum recording power in the recording area using the reflected light intensity as a recording-related index, but instead of the reflected light intensity, the intensity of a focus error signal, tracking error signal, wobble error signal, address error signal, etc. is recorded before recording. As an index related to recording, the intensity of β, modulation degree, jitter, data error signal, etc. is used as an index related to recording after recording, and the optimum recording power in the recording area is obtained in the same manner as in the case of reflected light intensity. You can ask for it.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In addition, a part here is a weight part.

(Example 1)
On a polycarbonate substrate having a diameter of 120 mm and a thickness of 0.6 mm made of a guide groove having a depth of about 25 nm, a groove width of about 0.20 μm, and a track pitch of 0.40 μm, a ZnS film having a thickness of about 60 nm is formed as a lower protective layer by sputtering. -SiO ₂ (80:20 _{mol%), Bi 2 O 3 -Fe} 2 O 3 (70:30 mol%) with a thickness of about 15nm as a recording layer, having a thickness of about 20nm as an upper protective layer _ZnS-SiO 2 ( 80:20 mol%), and a reflective layer was formed by sequentially laminating about 40 nm of Al—Ti (99: 1 wt%).
An ultraviolet curable resin material (Diabeam MH-7617N, manufactured by Mitsubishi Rayon Co., Ltd.) is spin-coated on the reflective layer to form a resin protective layer having an average film thickness of 6 μm, and then spin coated on the resin protective layer. A 0.6 mm thick polycarbonate substrate is pasted through an adhesive layer made of an ultraviolet curable resin material (KAYARADDVD-802 manufactured by Nippon Kayaku Co., Ltd.) having an average film thickness of 50 μm formed by coating, and about 1.2 mm. An optical recording medium (disc A) compliant with the 1X-SPEED HD DVD-R standard (DVD Specification for High Density Recordable Disc Part 1 (Ver. 1.0)) was produced.

The optical information recording medium thus obtained was recorded on an HD DVD-ROM using a recording / reproduction evaluation device (ODU-1000 / Pickup laser light wavelength 405 nm, NA 0.65 manufactured by Pulstec Industrial Co., Ltd.) compatible with HD DVD. Recording and reproduction signal evaluation at a linear velocity equivalent to 1 × speed (6.61 m / s) was performed.
Recording / reproduction evaluation was performed at a radial position of 23.8 mm (test recording area), 40 mm, 55 mm, 57 mm, and 58 mm. The optimum recording power at this radial position is as shown in FIG. The recording power is obtained by multiplying the value of the optimum recording power at the radius of 23.8 mm (test recording area) by the ratio of the reflected light intensity at the radius position to the reflected light intensity at the radius of 23.8 mm. Recording is performed with the corrected power.
The results are as shown in Table 1 and FIGS. 6 and 7, and it was confirmed that recording was performed with sufficiently good recording characteristics at any evaluation position. In addition, SbER described in Table 1 is an abbreviation for Simulated bit Error Rate (the same applies to Table 2).

(Comparative Example 1)
For the optical recording medium manufactured in the same manner as in Example 1, the optimum recording power value at a recording power radius of 23.8 mm (test recording area) is used, and the radial position is 23.8 mm. , 40 mm, 55 mm, 57 mm, and 58 mm, and the same reproduction evaluation as in Example 1 was performed.
The results are as shown in Table 1 and FIGS. 6 and 7. In the evaluation of the outer peripheral radii of 57 mm and 58 mm, it was confirmed that the recording characteristics were out of the standard and recording with good characteristics was not possible. It was done.

(Example 2)
When producing an optical recording medium by the same method as in Example 1, the production was carried out by adjusting the sputtering conditions so as to change the radial distribution of each film thickness of the recording layer, the upper protective layer, and the lower protective layer. An optical recording medium (disc B) conforming to the 1X-SPEED HD DVD-R standard in which the radial distribution of recording sensitivity was changed from the optical recording medium of Example 1 was produced. The variation in the radial direction of the optimum recording power of this optical recording medium is as shown in FIG. Recording / reproduction evaluation was performed on the optical recording medium thus obtained in the same manner as in Example 1. The results are as shown in Table 2 and FIGS. 6 and 7, and it was confirmed that recording was performed with sufficiently good recording characteristics at any evaluation position.

(Comparative Example 2)
The same recording / reproduction evaluation as in Comparative Example 1 was performed on the optical recording medium produced in the same manner as in Example 2. The results are as shown in Table 2, FIG. 6, and FIG. 7. In the evaluation of the outer peripheral radius of 55 mm, it was confirmed that the recording characteristics were out of the standard and recording with good characteristics was not possible. .

It is a figure which shows the layer structure of the optical recording medium of this invention. It is a figure which shows a mode that recording / reproduction | regeneration is performed to an optical recording medium. It is a figure which shows a pulse pattern at the time of recording of the optical recording medium of this invention. It is a figure which shows the correlation with optimal recording power and reflected light intensity. It is a figure which shows the radial direction fluctuation | variation of optimal recording power. It is a figure which shows the result of PRSNR of an Example and a comparative example. It is a figure which shows the result of SbER of an Example and a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Lower protective layer 3 Recording layer 4 Upper protective layer 5 Barrier layer 6 Reflective layer 7 Overcoat layer 8 Hard coat layer 9 Print layer 9 ′ Print layer 10 Adhesive layer

Claims (5)

Obtaining a recording-related index related to the optimum recording power of the laser beam in the test recording area of the optical recording medium;
Setting the optimum recording power based on the obtained recording-related index of the test recording area;
Obtaining each recording-related index in each recording area into which the recording area of the optical recording medium is divided;
Correcting the set optimum recording power based on the obtained recording-related index of each recording area;
Recording on each recording area with the corrected optimum recording power; and
A method for recording on an optical recording medium.   The method for recording on an optical recording medium according to claim 1, wherein the recording-related index is a reflected light intensity of the laser beam.   3. An optical recording medium for use in the recording method according to claim 2, wherein the material of the recording layer contains an inorganic material that causes an irreversible change when irradiated with laser light.   The wavelength of the laser beam is 390 to 420 nm, and the main components of the recording layer are Bi and oxygen, and in addition, Mg, Al, Cr, Mn, Co, Fe, Cu, Zn, Li, Si, Ge, A recording mark portion that contains at least one element of Zr, Ti, Hf, Sn, Mo, V, Nb, Y, Ta, Te, Sb, In, Ga, Ni, and B, and in which information is recorded, 4. The optical recording medium according to claim 3, comprising crystals of elements contained in the recording layer and / or crystals of oxides of the contained elements. An irradiation means for irradiating the optical recording medium with laser light;
An acquisition means for acquiring a recording-related index related to the optimum recording power of the laser beam;
Setting means for setting the optimum recording power based on the acquired recording-related index;
Driving means for driving the irradiation means based on the set optimum recording power, and
The setting means is configured to acquire the optimum recording power set based on the recording-related index acquired in the test recording area of the optical recording medium, in the recording areas obtained by dividing the recording area of the optical recording medium. An optical recording apparatus that performs correction based on a recording-related index.