JPH09138971A - Optical information recording medium and recording method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical information recording medium for obtaining a reproduced signal having high modulation degree. SOLUTION: The optical information recording medium is formed with a light absorbing layer 2 for absorbing laser light directly or via an other layer on a translucent substrate 1, a light reflecting layer 3 for reflecting the laser light directly or via an other layer on the light absorbing layer 2 and pits 5 for reproducing data by irradiating it with the laser light. A layer on the translucent substrate 1 side adjacent to the light absorbing layer 2 in the pit 5 sections deforms and sections of the light absorbing layer 2 irradiated with the laser light decompose and the pits are formed in positions irradiated with the laser light. The light absorbing layer 2 generates heat by absorbing the laser light and simultaneously fuses, evaporates, sublimates, deforms or is changed in property. Or a portion of compositions constituting the light absorbing layer 2 diffuses or viscously flows to the layer adjacent to the light absorbing layer 2 and is mixed with or is partially compounded with components of the layer on the translucent substrate 1 side adjacent to the light absorbing layer 2. Or the boundary between the light absorbing layer 2 and the other layer adjacent thereto peels, gap parts are formed therein or air bubbles are generated in the light absorbing layer 2 and are remained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium having pits recorded by laser light and a recording method therefor.

[0002]

2. Description of the Related Art An optical information recording medium capable of recording data by irradiating a laser beam has a recording layer including a metal layer such as Te, Bi and Mn and a dye layer such as cyanine, merocyanine and phthalocyanine. In addition, by irradiating the laser beam, the recording layer is deformed, sublimated, evaporated or modified to form pits, and data is recorded. In an optical information recording medium having this recording layer, a gap is generally provided behind the recording layer to facilitate deformation, sublimation, evaporation or denaturation of the recording layer when forming pits. . Specifically, for example, a laminated structure called an air sandwich structure in which two substrates are laminated with a space portion interposed therebetween is employed. In this optical information recording medium, laser light is irradiated from the transparent substrate 1 side to form pits. And when playing back the recorded data,
A laser beam having a weaker power than that at the time of recording is emitted from the substrate 1 side, and a signal is read according to a difference in reflected light between the pit and other portions.

On the other hand, a so-called ROM type optical information recording medium in which data is recorded in advance and data cannot be written or erased thereafter has already been widely put to practical use in the information processing and acoustic departments. This type of optical information recording medium does not have the recording layer as described above, but pits for reproducing recorded data are formed in advance on a polycarbonate substrate by means of a press or the like, and Au, Ag are formed on the pit. A reflective layer made of a metal film of Cu, Al, or the like is formed and further covered with a protective layer.

The most typical one of the ROM type optical information recording media is a so-called CD, which is a compact disk widely put into practical use in the acoustic department, the information processing department and the like.
The specification of the recording and reproduction signals of D is standardized as a so-called CD format, and a reproduction apparatus conforming to this is very widely used as a compact disk player (CD player).

[0005]

It is strongly desired that the optical information recording medium has compatibility with, for example, a widely spread CD when being reproduced and can be reproduced by a CD player. For that purpose, an optical information recording medium capable of obtaining a reproduction signal having a large modulation degree is required. However, the above-mentioned optical information recording medium has a recording layer which is not found in a CD, and means for forming pits in the recording layer, not on the substrate, is used for recording. Further, since the recording layer has a void layer or the like for facilitating the formation of pits, the reproduction signal differs from the CD in terms of the reflectance of the laser beam, the modulation degree of the reproduction signal, and the like. In particular, a pit formed by irradiating a laser beam is not as clear as a pit formed mechanically like a press, so that it is difficult to obtain a large degree of modulation. For this reason, it is difficult to satisfy the above-mentioned CD format that defines the so-called CD standard, and it is not possible to provide an optical disc that can be played back by a CD player.
The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide an optical information recording medium from which a reproduction signal having a high modulation degree can be obtained.

[0006]

In the present invention, firstly, a light absorbing layer which absorbs laser light directly on a transparent substrate or through another layer, and a light absorbing layer directly on the light absorbing layer. Alternatively, in an optical information recording medium in which a light reflection layer that reflects laser light through another layer and a pit for reproducing data by irradiation of the laser light are formed, the pit portion is adjacent to the light absorption layer. The layer on the substrate side to be deformed is deformed, the portion of the light absorption layer irradiated with the laser light is decomposed, and a pit is formed at the position irradiated with the laser light. Further, the light absorption layer of such an optical information recording medium is irradiated with laser light to form the pits as described above.

Here, by irradiating the light absorption layer with laser light, the light absorption layer absorbs the laser light to generate heat, and is also melted, evaporated, sublimated, deformed or modified. Alternatively, a part of the components constituting the light absorption layer diffuses or viscously flows into a layer adjacent to the same layer, and this mixes with the components of the layer on the transparent substrate side adjacent to the light absorption layer, or Are partially compounded. Or, the interface between the light absorbing layer and another layer adjacent thereto is separated and a void is formed therein, or bubbles are generated in the light absorbing layer and remain. ing.

In such an optical information recording medium, in the pit, the layer on the substrate side adjacent to the light absorption layer is locally deformed, so that the phase difference between the pit portion and the portion other than the pit portion. The generated laser spot is scattered, and a large difference occurs in the amount of reflected laser light. Therefore, the modulation degree of the reproduced signal can be increased.

In this case, the deformation of the pit portion on the substrate side is substantially the same regardless of whether it is convex, concave or wavy on the light absorption layer side. Further, in addition to the above-described deformation in the pit portion, the layer on the substrate side has an optical property modification portion in which the optical property is locally changed, or the light absorption layer and another layer adjacent to the same layer. If voids are formed at the interface of the pits or fine bubbles are dispersed in the light absorption layer at the pits, the action of phase difference, absorption, scattering, etc. of the laser spot by these causes the pits and the pits A large difference is caused by the reflected light amount of the laser light with respect to other portions, and the degree of modulation of the reproduction signal can be increased.

Further, the layer on the substrate side adjacent to the light absorption layer in the pit portion has an optical characteristic modification portion in which the optical characteristics are locally changed, so that the incident laser light is distributed at the optical characteristic modification portion. Due to the effects of phase difference, absorption, scattering, etc., a large difference occurs in the optical condition between the part other than the pit and the part of the pit, especially the reflection of the laser beam. Can be large.
In this way, in the optical information recording medium in which the pit is formed by deforming or changing the layer on the substrate side adjacent to the light absorption layer, the reflection layer can be provided in close contact with the back of the light absorption layer.
It is possible to easily obtain a recordable optical information recording medium in which a reproduction signal for reading data conforms to, for example, the CD format.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described specifically and in detail with reference to the drawings. An example of a schematic structure of an optical information recording medium according to the present invention is shown in FIG.
3 to FIG. In the figure, 1 is a transparent substrate, and 2 is a light absorbing layer formed thereon, which absorbs irradiated laser light to generate heat, as will be described later.
It is a layer for melting, vaporizing, sublimating, deforming or modifying and forming pits 5 at the positions irradiated with the laser spots. FIG. 2 shows a state before recording with laser light, and FIG.
In the state after recording, that is, when the laser beam 7 is converged and irradiated from the optical pickup 8 onto the light absorption layer 2, the surface of the transparent substrate 1 is partially deformed and / or changed, and pits 5 are formed. The state is schematically shown.

When the light absorption layer 2 is irradiated with laser light 7,
The irradiated part absorbs the laser beam 7 and generates heat,
The irradiated portion melts and decomposes, and at the same time, the layer adjacent thereto also softens and melts. Then, a part of the components forming the light absorbing layer 2 diffuses or viscously flows into a layer adjacent to the same layer, and this mixes with the components of the layer on the transparent substrate 1 side adjacent to the light absorbing layer 2. , Partially combined. Along with this, the light absorption layer 2
A convex deformed portion 6 is formed on the surface of the layer adjacent to.
Such a phenomenon is mainly caused when, for example, one layer adjacent to the light absorption layer 2 is the light reflecting layer 3 made of a metal layer and the other adjacent layer is the transparent substrate 1 made of a resin layer. Although it is likely to occur on the transparent substrate 1 side, the deformation on the interface with the light absorbing layer 2 may also occur on the light reflecting layer 3 side. The deformed portion 6 may be wavy or concave on the side of the light absorption layer 2 in some cases.

The translucent substrate 1 is made of a material having high transparency to laser light and is mainly made of a resin having excellent impact resistance, such as a polycarbonate plate, an acrylic plate or an epoxy plate. The light absorption layer 2 absorbs the laser light incident from the transparent substrate 1 side to generate heat, and also melts and decomposes. For example, a cyanine dye such as indodicarbocyanine is formed on the substrate 1. Alternatively, it is formed by a spin coating method or the like via another layer formed thereon. The reflection layer 3 is formed of a metal film, for example, gold, silver, copper, aluminum, or an alloy film containing them. The protective layer 4 is the transparent substrate 1
It is formed of a resin having the same excellent impact resistance as described in 1., and most commonly, it is formed by applying an ultraviolet curable resin by a spin coating method and irradiating it with ultraviolet rays to cure it. In addition, epoxy resins, acrylic resins, silicone-based hard coat resins, and the like are generally used.

In the optical information recording medium according to the present invention, ρ = n given by the real part n _abs of the complex refractive index of the light absorption layer 2, its film thickness d _abs and the wavelength λ of the reproduction light.
It is preferable that _abs d _abs / λ is 0.05 ≦ ρ ≦ 0.6, and the imaginary part k _abs of the complex refractive index is 0.3 or less. This is to increase the reflectance with respect to the reproduction light, and when the above conditions are satisfied, a high reflectance is obtained, and the reflectance of 70% or more is sufficiently secured as the standard characteristic defined in the CD format and the like. it can.

FIGS. 4 to 8 schematically show examples of the above-mentioned pit 5 formed by irradiating laser light. FIG. 4 schematically shows a state in which deformation 6 occurs in the substrate 1 adjacent to the light absorption layer 2 by irradiating the light absorption layer 2 with a spot of the laser light 7 in the pit 5.

This will be described more specifically with reference to FIG.
(A) shows that when the light absorption layer 2 is irradiated with a laser spot, the components of the same layer 2 are melted and decomposed, and the interface side of the light transmissive substrate 1 with the light absorption layer 2 is softened. The case where the deformation 6 is formed by the components of the light absorption layer 2 diffusing or viscous flowing to the transparent substrate 1 side is schematically shown. At the same time, the portion of this modification 6 is the light absorption layer 2
The component (1) is locally mixed with the material forming the transparent substrate 1 and partially compounded, so that the optical characteristics of the light absorbing layer 2 and the transparent substrate 1 become different from those of the optical characteristics. It may be part 12.

When the light absorption layer 2 is irradiated with a laser spot to form the pits 5, the components forming the light absorption layer 2 locally generate heat at that portion, and are melted and decomposed, so that the light absorption layer 2 is exposed. It is customary that the optical characteristics also change locally. Furthermore, as a result of such a phenomenon, physically
As shown in (b), the interface between the light absorption layer 2 and another layer adjacent to the light absorption layer 2, for example, the light reflection layer 3 is peeled off to form a void portion 10 therein, or Bubbles may be generated inside and remain after cooling.

In the void 10 as described above, the layer adjacent to the side of the light absorption layer 2 on which the laser light 7 is incident, for example, the substrate 1 side, is the layer behind the light absorption layer 2, for example, the light reflection layer 3 and the protective layer. It can be formed when the latter is poorer in binding property with the light absorption layer 2 than the former, because it is relatively easily thermally deformed from the layer 4 side. That is, in such an optical information recording medium, when the laser beam 7 of the light absorbing layer 2 is irradiated, energy is generated in the light absorbing layer 2 as described above, and the substrate 1 is deformed 6 at the same time. It is considered that gas is generated in the light absorbing layer 2, whereby the interface between the light absorbing layer 2 having poor binding properties and the light reflecting layer 3 adjacent thereto is separated, and the gas is accumulated there. . Further, the gas generated inside the light absorption layer 2 remains as bubbles 11.

4C and 4D show another shape of the deformation 6 on the transparent substrate 1 side, and in FIG. 4C, the top of the convex deformation 6 is split into two. Shows the state, (d) is
A wavy deformation 6 in which unevenness is alternately repeated is shown.
Also in these cases, the voids 10 and the bubbles 1 as described above.
1. The optically modified portion 12 may be formed. In FIG. 8, since the pits 5 are formed along the pre-groove 13 which is a tracking means formed on the surface of the transparent substrate 1, the light absorption layer 2 is irradiated with the laser spot along the pre-groove 13. After that, the protective layer 4 and the light reflection layer 3 are peeled from the translucent substrate 1, and the light absorption layer 2 is removed from the surface of the substrate 1 schematically.

Furthermore, STM (Scanning Tunneling Mic
FIG. 9 shows an example of observing the state of the surface of the transparent substrate 1 along the pre-groove 13 using a roscope). In the same figure, the horizontal axis represents the movement distance of the tip (probe) 14 along the pre-groove 13, that is, the tracking direction, and the vertical axis represents the height of the surface of the transparent substrate 1. FIG. 7A shows a case where the pit distance is relatively short, 10000 angstrom, and here, the height is about 20.
It can be seen that a convex and clear deformation 6 of 0 angstrom is formed. Further, FIG. 6B shows the case where the pit distance is relatively long as 40,000 angstroms, and a convex deformation 6 having a height of about 200 angstroms is recognized here, but the intermediate portion of this deformation is slightly low. It can be seen that the peak of Modification 6 is divided into two.

FIG. 5 schematically shows a case where the deformation 6 of the transparent substrate 1 adjacent to the light absorbing layer 2 in the pit 5 is formed in a concave shape with respect to the light absorbing layer 2. FIG.
(A) shows a void 10 at the boundary between the light absorption layer 2 and the light reflection layer 3.
In the same figure (b), the voids 10 are formed, and at the same time as the voids 10 are formed, fine bubbles 11, 11, ... The decomposed component of the light absorption layer 2 is diffused into the formed transparent substrate 1, and this component and the component of the transparent substrate 1 are mixed and partially combined to form the optical property modification portion 12. It shows the case where is formed. Further, FIG.
The figure shows the case where the void 10 ′ is formed between the substrate 1 and the light absorption layer 2 at the same time when the film is formed.

FIG. 6 shows deformations 6 and 6'in the pit 5.
Shows the case where it extends to both layers adjacent to the light absorption layer 2. Such pits are often formed when the layers on both sides of the light absorption layer 2, for example, the substrate 1 and the light reflection layer 2 and the protective layer 4 have substantially the same thermal deformation temperature or hardness. In FIG. 6A, in the pit 5, a space 10 ′ is formed between the light absorption layer 2 and the substrate 1, and in FIG. In the case where voids 10 and 10 'are formed on both sides of the light reflection layer 3, the figure (c) shows the case where fine bubbles 11, 11 ... Are dispersed in the light absorption layer 2. Are shown respectively. In FIG. 6D, the deformation 6 on the transparent substrate 1 and the light reflection layer 3 side,
6'indicates a state of being formed in a convex shape toward the light absorbing layer 2 side.

Further, in FIG. 7, an optical characteristic modification portion 13 having an optical characteristic different from that of other portions in the pit 5 portion is provided in the layer on the side where the laser light 7 is incident with respect to the light absorption layer 2. This is the case. This modified portion 13 must be the laser light 7
Of the light absorption layer 2 and often extends to the inside of the light absorption layer 2. In this case, the deformation 6 of the layer adjacent to the light absorption layer 2 may be observed, but the deformation is generally unclear due to the presence of the optical property modification portion 13.

FIG. 7A shows a state in which the optical characteristic modifying portion 13 is formed adjacent to the light absorption layer 2, for example, the portion of the substrate 1, and FIG. It shows a state in which the optical characteristics gradually change to the layer 2 in the thickness direction. Such denaturation of each layer is formed by the action of heat generated when the light absorbing layer 2 is irradiated with the laser beam 7, whereby the light absorbing layer 2 and other layers are decomposed, reacted, and mutually diffused. Therefore, such pits 5 are formed when a material having such an action is selected for the light absorbing layer 2 and the layer adjacent thereto.

Further, specific examples of the present invention will be described below. (Example 1) Width 0.8 μm, depth 0.08 μm on the surface,
Spiral pregroove 8 with a pitch of 1.6 μm, thickness 1.2 mm, outer diameter 120 mmφ, inner diameter 15
The mmφ polycarbonate substrate 1 was molded by an injection molding method. Rockwell hardness ASTM D785 of this polycarbonate substrate 1 is M75 (equivalent to pencil hardness HB), and heat distortion temperature ASTM D648 is 4.6.
It was kg / cm ² and 121 ° C.

As an organic dye for forming the light absorption layer 2, 0.65 g of 1,1'dibutyl 3,3,3 ', 3'
Tetramethyl 4,5,4 ', 5' dibenzoindodicarbocyanine perchlorate (manufactured by Japan Photosensitive Dye Research Institute, product number NK3219) was added to diacetone alcohol solvent 10c.
It was dissolved in c and applied on the surface of the substrate 1 by a spin coating method to form a light absorption layer 2 having a film thickness of 130 nm.

Next, the diameter of this disk is 45 to 118 m.
A film thickness of 80 is formed on the entire surface of the mφ area by the sputtering method.
An Au film having a thickness of 3 nm was formed, and the reflective layer 3 was formed. further,
An ultraviolet curable resin was spin-coated on the reflective layer 3 and irradiated with ultraviolet light to be cured, thereby forming a protective layer 4 having a thickness of 10 μm. Rockwell hardness ASTM D785 after curing of the protective layer 4 is M90, and heat distortion temperature ASTM D648 is 4.6 kg / cm ² , 135 ° C.
Met.

The optical disc thus obtained has a wavelength of 78
A 0 nm semiconductor laser was irradiated at a linear velocity of 1.2 m / sec and a recording power of 6.0 mW to record an EFM signal. After that, this optical disk is put into a commercially available CD player (Aure
x XR-V73, reproduction light wavelength λ = 780 nm), the semiconductor laser reflectance was 72%, I ₁₁ /
I _top was 0.68, I ₃ / I _top was 0.35, and the block error rate BLER was 1.2 × 10 ^-2 .

According to the CD standard, the reflectance is 70% or more and I ₁₁
/ I _top is 0.6 or more, I ₃ / I _top is 0.3 to 0.7,
The block error rate BLER is defined to be 3 × 10 ⁻² or less, and the optical disc according to this embodiment satisfies this standard. Further, the protective layer 4 and the light reflection layer 3 of the optical disc after this recording are peeled off, the light absorption layer 2 is washed and removed with a solvent, and the surface of the light-transmissive substrate 1 is STM (scanned).
When observed with an ng Tunneling Microscope), a convex deformation was observed in the pit portion.

(Example 2) In Example 1, except that the epoxy resin was spin-coated between the light absorption layer 2 and the light reflection layer 3 to form a hard layer having a film thickness of 100 nm.
An optical disk was manufactured in the same manner as in Example 1. Rockwell hardness AST after curing this epoxy resin
M D785 is M90, heat distortion temperature ASTM D
648 was 4.6 kg / cm ² and 135 ° C.

An EFM signal was recorded on the thus-obtained optical disc in the same manner as in Example 1, and the optical disc was reproduced by a commercially available CD player. As a result, a semiconductor laser reflection similar to that in Example 1 was performed. Rate, reproduced signal output characteristics, and block error rate BLER
Was 3.0 × 10 ⁻³ . Further, when the surface of the transparent substrate 1 of the optical disc after recording was observed with an STM (Scanning Tunneling Microscope) in the same manner as in Example 1, a convex deformed portion 6 was recognized. The middle of the deformed portion 6 was slightly low, and it was confirmed that the peak of deformation was divided into two.

(Example 3) In Example 1, in place of the epoxy resin formed on the upper surface of the light absorbing layer 2 between the light absorbing layer 2 and the light reflecting layer 3, a silicon acrylic film having a thick film of 100 nm was used. An optical disk was manufactured in the same manner as in Example 1 except that a hard layer of resin was provided and a 20 nm binder layer made of epoxy resin was formed on the upper surface of the hard layer by spin coating. The Rockwell hardness ASTM D after curing the silicone acrylic resin layer
785 is M100, heat distortion temperature ASTM D64
8 was 4.6 kg / cm ² and 100 ° C.

An EFM signal was recorded on the thus obtained optical disk with a recording power of 7.0 mW in the same manner as in Example 1, and then this optical disk was recorded in the same CD player (Aurex XR-V73, When reproduction was performed at a wavelength of 780 nm, the semiconductor laser had a reflectance of 75%, I ₁₁ / I _top was 0.63, and I ₃ / I _top was 0.
35, the block error rate BLER is 2.5 × 10 ^-3
Met. In addition, in the same manner as in Example 1, the STM (Scanning T
When observed with an unneling microscope), the same state as in Example 1 was confirmed.

Example 4 In Example 1, an alloy film of gold and antimony in a ratio of 9: 1 was formed as a light reflection layer 3 on the light absorption layer 2 by a vacuum evaporation method, and 20 nm made of epoxy resin on the reflective layer 3
An optical disk was manufactured in the same manner as in Example 1 except that the protective layer 4 made of an ultraviolet curable resin was formed via the binding layer of 1. The light reflection layer 3 has a pencil hardness of “H” or higher.

An EFM signal was recorded on the thus-obtained optical disc at a recording power of 6.2 mW in the same manner as in Example 1, and then this optical disc was reproduced by the same CD player as in Example 1, and a semiconductor was obtained. The laser reflectance is 72%, I ₁₁ / I _top is 0.62, and I ₃ / I _top is 0.
32, block error rate BLER is 3.5 × 10 ^-3
Met. In addition, in the same manner as in Example 1, the STM (Scanning T
When observed with an unneling microscope), the same state as in Example 1 was confirmed.

(Example 5) In Example 1, the surface of the polycarbonate substrate 1 on which the UV-curable hard coat resin is spin-coated on the light-incident side is provided with a substrate protective layer having a thickness of 1 µm and a pre-groove is provided. Except that the light absorption layer 2 is formed on the light absorption layer 2 and an alloy film of iridium and gold in the ratio of 3: 1 is formed on the light absorption layer 2 as the light reflection layer 3 by the sputtering method. An optical disk was manufactured in the same manner as in Example 1. The light reflection layer 3 has a pencil hardness of “5H” or more.

An EFM signal was recorded on the thus-obtained optical disc in the same manner as in the first embodiment, and then this optical disc was reproduced by the same CD player as in the first embodiment, and the reflectance of the semiconductor laser was 70. %, I ₁₁ / I
_{The top} was 0.62, I ₃ / I _top was 0.37, and the block error rate BLER was 3.7 × 10 ⁻³ . Further, in the same manner as in Example 1, the surface of the translucent substrate 1 of the optical disc after recording was subjected to STM (Scanning Tunneling Microscoping).
When observed in e), the same state as in Example 1 was confirmed.

(Example 6) In Example 1, the light reflection layer 3 was formed of a silver film having a thickness of 60 nm, and a silicone hard coat agent was spin-coated on the silver film and heated and cured. An optical disk was manufactured in the same manner as in Example 1 except that the hard protective layer 4 having a thickness of 3 μm was formed. The protective layer 4 has a pencil hardness of "HB".
It has the above hardness.

An EFM signal was recorded on the thus-obtained optical disc in the same manner as in Example 1, and thereafter the optical disc was reproduced by the same CD player as in Example 1. The reflectance of the semiconductor laser was 71%. , I ₁₁ / I _top was 0.63, I ₃ / I _top was 0.35, and the block error rate BLER was 2.8 × 10 ^-3 . Further, in the same manner as in Example 1, the transparent substrate 1 of the optical disc after recording is performed.
When the surface of the sample was observed with an STM (Scanning Tunneling Microscope), the same state as in Example 1 was confirmed.

(Embodiment 7) In Embodiment 1, the light-reflecting layer 3 is formed by vacuum-depositing an Au film having a thickness of 50 nm on the light-reflecting layer 3 and spin-coated with a polysulfide-added epoxy resin diluted with diglycidyl ether. An optical disk was manufactured in the same manner as in Example 1 except that a silicone-based hard coat agent was spin-coated through a 30 nm binder layer, and this was heated and cured to form a hard protective layer 4 having a thickness of 3 μm. did.

An EFM signal was recorded on the thus-obtained optical disc in the same manner as in Example 1, and thereafter the optical disc was reproduced by the same CD player as in Example 1. The reflectance of the semiconductor laser was 72%. , I ₁₁ / I _top was 0.65, I ₃ / I _top was 0.35, and the block error rate BLER was 2.5 × 10 ⁻³ . Further, in the same manner as in Example 1, the transparent substrate 1 of the optical disc after recording is performed.
When the surface of the sample was observed with an STM (Scanning Tunneling Microscope), the same state as in Example 1 was confirmed.

Example 8 In the above Example 1, 1,
1'dibutyl 3,3,3 ', 3' tetramethyl 5,5 '
The light absorption layer 2 was formed using diethoxyindodicarbocyanine iodide, a 100 nm hard layer made of an epoxy resin was formed on the light reflection layer 3, and a UV curable resin was further provided thereon to a thickness of 10 μm. An optical disk was manufactured in the same manner as in Example 1 except that the protective layer 4 was formed.

An EFM signal was recorded on the thus-obtained optical disc in the same manner as in Example 1, and thereafter the optical disc was reproduced by the same CD player as in Example 1. The reflectance of the semiconductor laser was 74%. , I ₁₁ / I _top was 0.68, I ₃ / I _top was 0.34, and the block error rate BLER was 8.3 × 10 ^-3 . Further, in the same manner as in Example 1, the transparent substrate 1 of the optical disc after recording is performed.
When the surface of the sample was observed with an STM (Scanning Tunneling Microscope), the same state as in Example 1 was confirmed.

(Embodiment 9) The same operation as in the above Embodiment 1 except that an ultraviolet curable hard coat resin was spin-coated on the light incident side of the polycarbonate substrate 1 to form a substrate protective layer having a thickness of 1 μm. An optical disk was manufactured in the same manner as in Example 1. An EFM signal was recorded on the thus-obtained optical disc in the same manner as in Example 1, and thereafter,
When this optical disc was reproduced by the same CD player as in Example 1, the semiconductor laser reflectance was 70% and I ₁₁
/ I _top was 0.62, I ₃ / I _top was 0.37, and the block error rate BLER was 1.3 × 10 ^-2 . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording is subjected to STM (Scanning Tunneling Mic).
Observation with a roscope) confirmed the same state as in Example 1.

Example 10 In Example 1, a polybutadiene resin dissolved in cyclohexane was spin-coated between the light absorption layer 2 and the reflection layer 3 to give a thickness of 10 nm.
An optical disk was manufactured in the same manner as in Example 1 except that the polybutadiene resin layer of 1 was provided. The optical disc obtained in this manner is processed by EFM in the same manner as in the first embodiment.
When a signal was recorded and then this optical disk was reproduced by the same CD player as in Example 1, the semiconductor laser reflectance was 72%, I ₁₁ / I _top was 0.65, and I ₃ / I.
_top is 0.35, block error rate BLER is 8.
It was 6 × 10 ⁻³ . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM.
Observation with a (Scanning Tunneling Microscope) confirmed the same state as in Example 1.

Example 11 The same polycarbonate substrate 1 used in Example 1 was spin-coated with an acrylic resin dissolved in diisobutyl ketone,
A resin layer (not shown) having a thickness of 40 nm was formed. The Rockwell hardness ASTM D785 of this resin layer is M85.
And the heat distortion temperature ASTM D648 is 4.6 kg.
/ Cm ² and 100 ° C.

As an organic dye for forming the light absorption layer 2, 0.6 g of 1,1'dipropyl, 3,3,3 ',
3'tetramethyl 5,5 'dimethoxy indodicarbocyanine iodide and isopropyl alcohol solvent 1
It was dissolved in 0 cc, and this was applied onto the surface of the substrate 1 by a spin coating method to form a light absorption layer 2 having a film thickness of 120 nm. The real part n _abs of the complex refractive index of the light absorption layer 2
And its film thickness d _abs and the wavelength λ of the reproduction light, ρ =
n _abs d _abs / λ was 0.41 and the imaginary part k _abs of the complex refractive index was 0.02.

Next, a silicon acrylic resin dissolved in cyclohexane was spin-coated on the above to give a thickness of 100 n.
m hard layer was formed. This hard layer has a pencil hardness of 2H,
Heat distortion temperature ASTM D648 4.6 kg / cm ² , 1
20 ° C. An Au film having a film thickness of 50 nm was formed on the hard layer by a sputtering method to form the reflective layer 3. Further, an ultraviolet curable resin was spin-coated on the reflective layer 3 and was irradiated with ultraviolet rays to be cured to form a protective layer 4 having a film thickness of 10 μm. The Rockwell hardness ASTM D785 after curing of the protective layer 4 is M90, and the heat distortion temperature ASTM D648 is 4.6 kg / c.
m was ^2, 135 ° C..

The optical disc thus obtained has a wavelength of 78
A 0 nm semiconductor laser was irradiated at a linear velocity of 1.2 m / sec and a recording power of 7.5 mW to record an EFM signal. Then, when this optical disk was reproduced by the same CD player as in Example 1, the reflectance of the semiconductor laser was 74% and I ₁₁
/ I _top was 0.62, I ₃ / I _top was 0.31, and the block error rate BLER was 4.0 × 10 ⁻³ . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording is subjected to STM (Scanning Tunneling Mic).
Observation with a roscope) confirmed the same state as in Example 1.

(Twelfth Embodiment) In the eleventh embodiment,
Spin coat a silicon coating agent on the resin layer,
An optical disc was manufactured in the same manner as in Example 11 except that a silicate layer having a thickness of 0.01 μm was provided and the light absorption layer 2 was formed thereon. The optical disk thus obtained was recorded with a recording power of 7.8 in the same manner as in Example 11.
When an EFM signal was recorded at mW and then this optical disc was reproduced by the same CD player as in Example 11,
The reflectivity of the semiconductor laser is 73%, and I ₁₁ / I _top is 0.6.
2, I ₃ / I _top is 0.31, block error rate BL
The ER was 3.4 × 10 ^-3 . Further, when the surface of the transparent substrate 1 of the optical disc after recording was observed by an STM (Scanning Tunneling Microscope) in the same manner as in Example 1, the same state as in Example 1 was confirmed.

(Embodiment 13) In the embodiment 11,
A glass substrate was used as the substrate 1, and a 20 nm-thick binder layer formed by spin coating an isocyanate resin dissolved in a 1: 1 solvent of toluene and methyl ethyl ketone was formed on the reflective layer. An optical disc was produced in the same manner as in Example 11 except for the above. An EFM signal was recorded on the thus-obtained optical disc with a recording power of 7.2 mW in the same manner as in Example 11, and then the optical disc was reproduced by the same CD player as in Example 11, and the reflection of the semiconductor laser was reflected. 72%, I
₁₁ / I _top was 0.65, I ₃ / I _top was 0.33, and the block error rate BLER was 3.6 × 10 ⁻³ . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording is subjected to STM (Scanning Tunneling Mic).
Observation with a roscope) confirmed the same state as in Example 1.

(Embodiment 14) In the embodiment 11,
Spin coat a silicon coating agent on the resin layer,
A silicate layer having a thickness of 0.01 μm was provided, and the light absorption layer 2 was formed on the silicate layer, and a binding layer having a thickness of 20 nm formed by spin coating polybutadiene was formed on the light reflection layer 3. An optical disc was produced in the same manner as in Example 11 except for the above.

An EFM signal was recorded on the thus-obtained optical disc with a recording power of 7.2 mW in the same manner as in Example 11, and the optical disc was reproduced by the same CD player as in Example 11, and the semiconductor was obtained. Laser reflectance is 72%, I ₁₁ / I _top is 0.66, I ₃ / I _top is 0.35, and block error rate BLER is 3.5 × 1.
It was 0 ^-3 . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanni
ng Tunneling Microscope), the same state as in Example 1 was confirmed.

(Fifteenth Embodiment) In the eleventh embodiment,
Example 11 except that the thickness of the resin layer was set to 20 nm, the silicon acrylic resin layer was not provided, and an alloy film of iridium and gold in the ratio of 1: 9 was formed as the reflective layer 3 by the sputtering method. An optical disk was manufactured in the same manner as in. The pencil hardness of the alloy film is 2
H.

An EFM signal was recorded on the thus-obtained optical disc at a recording power of 7.0 mW in the same manner as in Example 11, and then this optical disc was reproduced by the same CD player as in Example 11. Laser reflectance is 71%, I ₁₁ / I _top is 0.63, I ₃ / I _top is 0.32, and block error rate BLER is 3.3 × 1.
It was 0 ^-3 . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanni
ng Tunneling Microscope), the same state as in Example 1 was confirmed.

(Example 16) In Example 11,
Spin coat a silicon coating agent on the resin layer,
A silicate layer having a thickness of 0.01 μm was provided, and the light absorption layer 2 was formed thereon, a silicon acrylic resin layer was not provided, and the reflective layer 3 was made of iridium and gold of 1: 9.
An optical disk was manufactured in the same manner as in Example 11 except that the alloy film having the ratio of 1 was formed by the sputtering method.

An EFM signal was recorded on the thus-obtained optical disc at a recording power of 7.8 mW in the same manner as in Example 11, and then this optical disc was reproduced by the same CD player as in Example 11. Laser reflectance is 71%, I ₁₁ / I _top is 0.64, I ₃ / I _top is 0.32, and block error rate BLER is 2.8 × 1.
It was 0 ^-3 . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanni
ng Tunneling Microscope), the same state as in Example 1 was confirmed.

(Embodiment 17) In the embodiment 11,
No silicon acrylic resin layer is provided, an alloy film of iridium and gold in a ratio of 1: 9 is formed as the reflective layer 3 by a sputtering method, and on the light reflective layer,
Polyisoprene is spin-coated to form a binder layer having a thickness of 20 nm, and a protective layer 4 made of an ultraviolet curable resin is formed on the binder layer.
In the same manner as in Example 11 except that
An optical disk was manufactured.

An EFM signal was recorded on the thus-obtained optical disc at a recording power of 7.4 mW in the same manner as in Example 11, and then this optical disc was reproduced by the same CD player as in Example 11, and a semiconductor was obtained. Laser reflectance is 72%, I ₁₁ / I _top is 0.64, I ₃ / I _top is 0.32, and block error rate BLER is 4.1 × 1.
It was 0 ^-3 . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanni
ng Tunneling Microscope), the same state as in Example 1 was confirmed.

(Embodiment 18) In Embodiment 11,
No silicon acrylic resin layer was provided, a copper film having a thickness of 50 nm was formed as the reflective layer 3, and the protective layer 4
As a bisphenol-curable epoxy resin diluted with diglycidyl ether solvent as a spin coat to a thickness of 5 μm
Example 1 except that the epoxy resin layer of No. 1 was formed.
An optical disc was manufactured in the same manner as in 1. The protective layer has a Rockwell hardness of ASTM D785 of M110.
Therefore, it has a function as a hard layer.

An EFM signal was recorded on the thus-obtained optical disc at a recording power of 7.0 mW in the same manner as in Example 11, and then this optical disc was reproduced by the same CD player as in Example 11, and a semiconductor was obtained. Laser reflectance is 75%, I ₁₁ / I _top is 0.64, I ₃ / I _top is 0.33, and block error rate BLER is 2.9 × 1.
It was 0 ^-3 . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanni
ng Tunneling Microscope), the same state as in Example 1 was confirmed.

Example 19 In the above Example 11,
Spin coat a silicon coating agent on the resin layer,
A silicate layer having a thickness of 0.01 μm was provided, a light absorbing layer 2 was formed thereon, a silicon acrylic resin layer was not provided, and a copper film having a thickness of 50 nm was formed as the reflecting layer 3, and a protective layer 4 An optical disk was manufactured in the same manner as in Example 11 except that a bisphenol-curable epoxy resin diluted with a diglycidyl ether solvent was spin-coated to form an epoxy resin layer having a thickness of 5 μm.

An EFM signal was recorded on the thus-obtained optical disc at a recording power of 7.0 mW in the same manner as in Example 11, and then this optical disc was reproduced by the same CD player as in Example 11, and a semiconductor was obtained. Laser reflectance is 74%, I ₁₁ / I _top is 0.64, I ₃ / I _top is 0.33, and block error rate BLER is 3.5 × 1.
It was 0 ^-3 . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanni
ng Tunneling Microscope), the same state as in Example 1 was confirmed.

(Embodiment 20) In the embodiment 11,
A foaming agent was mixed in the acrylic resin, a silicon acrylic resin layer was not provided, and a copper film having a thickness of 50 nm was formed as the reflective layer 3 by a vacuum deposition method. Toluene and methyl ethyl ketone 6: 4 were formed on the reflective layer. 20 nm thickness formed by spin coating polyvinyl acetate resin dissolved in the solvent
The protective layer 4 was formed via the tie layer, and the protective layer 4 was spin-coated with a bisphenol-curable epoxy resin diluted in a diglycidyl ether solvent to a thickness of 5 μm.
An optical disk was manufactured in the same manner as in Example 11 except that the epoxy resin layer of m was formed.

An EFM signal was recorded on the thus-obtained optical disc at a recording power of 7.4 mW in the same manner as in Example 11, and then this optical disc was reproduced by the same CD player as in Example 11, and a semiconductor was obtained. Laser reflectivity is 74%, I ₁₁ / I _top is 0.64, I ₃ / I _top is 0.33, and block error rate BLER is 3.6 × 1.
It was 0 ^-3 . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanni
ng Tunneling Microscope), the same state as in Example 1 was confirmed.

(Example 21) A spiral pregroove 8 having a width of 0.8 μm, a depth of 0.08 μm, and a pitch of 1.6 μm was formed on the surface, the thickness was 1.2 mm, and the outer diameter was 120 m.
As an organic dye for forming the light absorption layer 2 on the glass substrate 1 having mφ and an inner diameter of 15 mmφ, 0.5 g of 1,
1 ', dipropyl 3,3,3', 3 'tetramethyl 5,
5'diethoxyindodicarbocyanine perchlorate was dissolved in 10 cc of dichloroethane solvent, and this was coated on the surface of the substrate 1 by spin coating to form a light absorbing layer 2 having a thickness of 100 nm.

Next, the diameter of this disc is 45 to 118 m.
A film thickness of 50 m
An Au film having a thickness of 3 nm was formed, and the reflective layer 3 was formed. further,
A urethane resin dissolved in methyl ethyl ketone was spin-coated on the reflective layer 3 to a thickness of 100 nm to form a buffer layer, and an ultraviolet-curable resin was spin-coated on the buffer layer, which was irradiated with ultraviolet rays to be cured. A protective layer 4 having a film thickness of 10 μm was formed.

The optical disc thus obtained has a wavelength of 78
A 0 nm semiconductor laser was irradiated at a linear velocity of 1.2 m / sec and a recording power of 7.2 mW to record an EFM signal. After that, this optical disk is put into a commercially available CD player (Aure
x XR-V73, reproduction light wavelength λ = 780 nm), the semiconductor laser reflectivity was 77%, I ₁₁ /
I _top was 0.65, I ₃ / I _top was 0.33, and the block error rate BLER was 3.0 × 10 ⁻³ . Also,
In the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanning Tunneling Microsc
As a result, the same state as in Example 1 was confirmed.

(Embodiment 22) A spiral pre-groove 8 having a width of 0.8 μm, a depth of 0.08 μm and a pitch of 1.6 μm is formed on the surface, a thickness of 1.2 mm and an outer diameter of 120 m.
A polycarbonate substrate 1 having an mφ and an inner diameter of 15 mmφ was injection molded. As an organic dye for forming the light absorption layer 2, 0.5 g of 1,1 ′, dipropyl 3,3,3 ′,
3'tetramethyl 5,5 'diethoxy indodicarbocyanine perchlorate was dissolved in 10 cc of isopropyl alcohol solvent, and this was applied on the surface of the substrate 1 by spin coating to form a light absorption layer having a thickness of 100 nm. Two
Was formed. Further, a SiO ₂ film having a thickness of 40 nm was formed thereon by a sputtering method.

Next, the diameter of this disc is 45 to 118 m.
A film thickness of 50 m
An Au film having a thickness of 3 nm was formed, and the reflective layer 3 was formed. further,
A urethane resin dissolved in methyl ethyl ketone was spin-coated on the reflective layer 3 to a thickness of 100 nm to form a buffer layer, and an ultraviolet curable resin was spin coated on the buffer layer, which was irradiated with ultraviolet rays to be cured. A protective layer 4 having a film thickness of 10 μm was formed.

A wavelength of 78
An EFM signal was recorded by irradiating a 0 nm semiconductor laser with a linear velocity of 1.2 m / sec and a recording power of 6.8 mW. After that, this optical disk is put into a commercially available CD player (Aure
x XR-V73, reproduction light wavelength λ = 780 nm), the semiconductor laser reflectivity was 77%, I ₁₁ /
I _top was 0.66, I ₃ / I _top was 0.36, and the block error rate BLER was 3.5 × 10 ⁻³ . Also,
In the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanning Tunneling Microsc
ope), the same state as in Example 2 was confirmed.

(Example 23) In Example 22,
An optical disc was produced in the same manner as in Example 22 except that the SiO ₂ film was formed by the LPD method and that the dioxane solvent was used as the solvent of the coating agent when forming the light absorption layer 2. The optical disc thus obtained was recorded with a recording power of 7.2 in the same manner as in Example 22.
When an EFM signal was recorded at mW and then this optical disc was reproduced by the same CD player as in Example 22,
Semiconductor laser reflectance is 77%, I ₁₁ / I _top is 0.6
6, I ₃ / I _top is 0.35, block error rate BL
The ER was 4.0 × 10 ^-3 . Further, when the surface of the transparent substrate 1 of the optical disc after recording was observed by an STM (Scanning Tunneling Microscope) in the same manner as in Example 1, the same state as in Example 1 was confirmed.

(Embodiment 24) In the embodiment 22,
In place of the SiO ₂ film, an epoxy resin dissolved in diglycidyl ether was spin-coated to form an epoxy resin layer having a thickness of 100 nm, and as the reflection layer 3, an alloy thin film layer of gold and titanium in a ratio of 9: 1 And a polybutadiene resin dissolved in cyclohexane was spin-coated between the light absorption layer 2 and the reflection layer 3 to give a thickness of 12
An optical disk was manufactured in the same manner as in Example 22 except that a 0 nm polybutadiene resin layer was provided.

An EFM signal was recorded on the thus-obtained optical disc at a recording power of 7.0 mW in the same manner as in Example 22, and then this optical disc was reproduced by the same CD player as in Example 22, and a semiconductor was obtained. Laser reflectivity is 74%, I ₁₁ / I _top is 0.64, I ₃ / I _top is 0.33, and block error rate BLER is 2.5 × 1.
It was 0 ^-3 . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanni
ng Tunneling Microscope), the same state as in Example 1 was confirmed.

(Example 25) In the above Example 22,
In place of the SiO ₂ film, an epoxy resin dissolved in diglycidyl ether was spin-coated to form an epoxy resin layer having a thickness of 100 nm, and as the reflection layer 3, an alloy thin film layer of gold and titanium in a ratio of 9: 1 Is formed, a polybutadiene resin dissolved in cyclohexane is spin-coated between the light absorption layer 2 and the reflection layer 3 to give a thickness of 120 n.
m of the above Example 22 except that a polybutadiene resin layer having a thickness of m is provided and a bisphenol-curable epoxy resin is spin-coated to a thickness of 20 nm between the light reflecting layer and the protective layer 4 in order to enhance the binding property. An optical disk was manufactured in the same manner as in.

An EFM signal was recorded on the thus obtained optical disc at a recording power of 7.2 mW in the same manner as in Example 22, and then this optical disc was reproduced by the same CD player as in Example 22, and a semiconductor was obtained. Laser reflectivity is 74%, I ₁₁ / I _top is 0.64, I ₃ / I _top is 0.33, and block error rate BLER is 3.0 × 1.
It was 0 ^-3 . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanni
ng Tunneling Microscope), the same state as in Example 1 was confirmed.

(Example 26) In Example 22,
Instead of the SiO ₂ film, an epoxy resin dissolved in diglycidyl ether was spin-coated to form an epoxy resin layer having a thickness of 100 nm. The epoxy resin layer was dissolved between the epoxy resin layer and the reflective layer 3 in cyclohexane. A polybutadiene resin layer was spin-coated with a polybutadiene resin layer having a thickness of 120 nm, and the thickness of the protective layer was 5 μm.
An optical disc was manufactured in the same manner as in Example 22 except that the above was adopted.

An EFM signal was recorded on the thus obtained optical disc at a recording power of 7.2 mW in the same manner as in Example 22, and then this optical disc was reproduced by the same CD player as in Example 22 to obtain a semiconductor. Laser reflectance is 74%, I ₁₁ / I _top is 0.64, I ₃ / I _top is 0.32, and block error rate BLER is 3.3 × 1.
It was 0 ^-3 . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanni
ng Tunneling Microscope), the same state as in Example 1 was confirmed.

(Twenty-seventh Embodiment) In the twenty-second embodiment,
No SiO ₂ film was formed, a polybutadiene resin dissolved in cyclohexane was spin-coated between the light absorption layer 2 and the reflection layer 3 to provide a polybutadiene resin layer having a thickness of 120 nm, the reflection layer and the protection layer 4. An optical disc was prepared in the same manner as in Example 22 except that a bisphenol-curable epoxy resin was spin-coated to a thickness of 20 nm and the protective layer had a thickness of 5 μm in order to enhance the binding property with the optical disc. Was produced.

An EFM signal was recorded on the thus obtained optical disc at a recording power of 7.2 mW in the same manner as in Example 22, and then this optical disc was reproduced by the same CD player as in Example 22 to obtain a semiconductor. Laser reflectance is 74%, I ₁₁ / I _top is 0.63, I ₃ / I _top is 0.32, and block error rate BLER is 2.8 × 1.
It was 0 ^-3 . Further, in the same manner as in Example 1, the surface of the transparent substrate 1 of the optical disc after recording was subjected to STM (Scanni
ng Tunneling Microscope), the same state as in Example 1 was confirmed.

Example 28 In the above Example 22,
Example 2 except that the SiO ₂ film is not formed
An optical disc was manufactured in the same manner as in 2. An EFM signal was recorded on the thus-obtained optical disc at a recording power of 7.2 mW in the same manner as in Example 22, and the optical disc was reproduced by the same CD player as in Example 22, and the reflection of the semiconductor laser was observed. 77%, I ₁₁ / I
_{The top} was 0.66, the I ₃ / I _top was 0.35, and the block error rate BLER was 1.0 × 10 ^-2 . Further, in the same manner as in Example 1, the surface of the translucent substrate 1 of the optical disc after recording was subjected to STM (Scanning Tunneling Microscoping).
When observed in e), the same state as in Example 1 was confirmed.

(Example 29) A spiral pre-groove 8 having a width of 0.4 μm, a depth of 0.1 μm and a pitch of 0.8 μm was formed on the surface, a thickness of 1.2 mm, and an outer diameter of 120 mm.
A polycarbonate substrate 1 having a diameter of 15 mm and an inner diameter of 15 mm was molded by an injection molding method. Rockwell hardness ASTM D785 of this polycarbonate substrate 1 is M75 (equivalent to pencil hardness HB), and heat distortion temperature ASTM D648.
Was 4.6 kg / cm ² and 121 ° C.

As an organic dye for forming the light absorption layer 2, 0.65 g of 1,1'dibutyl 3,3,3 ', 3'
Tetramethyl 4,5,4 ', 5' dibenzoindomonocarbocyanine perchlorate was dissolved in 10 cc of diacetone alcohol solvent, and this was dissolved on the surface of the substrate 1,
The light absorption layer 2 having a film thickness of 100 nm was formed by applying by a spin coating method.

Next, the diameter of this disc is 45 to 118 m.
A film thickness of 80 is formed on the entire surface of the mφ area by the sputtering method.
An Au film having a thickness of 3 nm was formed, and the reflective layer 3 was formed. further,
An ultraviolet curable resin was spin-coated on the reflective layer 3 and irradiated with ultraviolet light to be cured, thereby forming a protective layer 4 having a thickness of 10 μm. Rockwell hardness ASTM D785 after curing of the protective layer 4 is M90, and heat distortion temperature ASTM D648 is 4.6 kg / cm ² , 135 ° C.
Met.

The optical disc thus obtained has a wavelength of 67
A 0 nm semiconductor laser was irradiated at a linear velocity of 2.0 m / sec and a recording power of 8.0 mW to record an EFM signal. After that, when this optical disk was reproduced, the reflectance of the semiconductor laser was 70%, I ₁₁ / I _top was 0.70, and I ₃ / I _top.
Was 0.32.

The optical disc according to this example could be recorded with a large degree of modulation. Further, the protective layer 4 and the light reflecting layer 3 of the optical disc after this recording were peeled off, the light absorbing layer 2 was washed and removed with a solvent, and the surface of the transparent substrate 1 was analyzed. Decomposition was confirmed. Further, when the surface was observed with an STM (Scanning Tunneling Microscope), convex deformation was observed in the pit portion.

[0087]

As described above, according to the optical information recording medium of the present invention, it is possible to form pits from which a reproduction signal having a high degree of modulation can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic half sectional perspective view showing an example of the structure of an optical information recording medium.

FIG. 2 is a partially enlarged view of the optical information recording medium of FIG. 1 taken along a track before optical recording.

3 is a partially enlarged view of the optical information recording medium of FIG. 1 taken along a track after optical recording.

FIG. 4 is an enlarged cross-sectional view of a main part taken along a track to show an example of an optical information recording medium pit.

FIG. 5 is an enlarged cross-sectional view of a main part taken along a track to show another example of the optical information recording medium pit.

FIG. 6 is an enlarged cross-sectional view of a main part taken along a track to show another example of the optical information recording medium pit.

FIG. 7 is an enlarged cross-sectional view of a main part taken along a track to show another example of an optical information recording medium pit.

FIG. 8 is an enlarged perspective view of an essential part showing the surface of a transparent substrate of an optical information recording medium after recording.

FIG. 9 shows an STM (Scanning Tun) on the surface of the transparent substrate.
It is an example of a graph showing the relationship between the moving distance along the tracking direction of the chip and the altitude when observed with a neling Microscope).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Light absorption layer 3 Light reflection layer 4 Protective layer 5 Pit 6 Deformation part 6'Deformation part 10 Void part 10 'Void part 11 Fine air bubble 12 Optical modification part 13 Optical property modification part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Ishiguro 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Induction Co., Ltd.

Claims (14)

[Claims] 1. A light absorbing layer that absorbs laser light directly or through another layer on a transparent substrate, and a laser beam that reflects laser light directly or through another layer on the light absorbing layer. In an optical information recording medium in which a light reflecting layer and a pit for reproducing data by laser light irradiation are formed, a layer on the substrate side adjacent to the light absorbing layer in the pit portion is deformed and The part of the layer irradiated with laser light decomposes,
An optical information recording medium having a pit formed at a position irradiated with a laser spot. 2. A light absorbing layer that absorbs laser light directly or through another layer on a transparent substrate, and a laser beam that reflects laser light directly or through another layer on the light absorbing layer. In an optical information recording medium in which a light reflecting layer and a pit for reproducing data by irradiation of laser light are formed, the light absorbing layer absorbs laser light and generates heat, and melting,
An optical information recording medium, characterized in that a pit is formed at a position irradiated with a laser spot by evaporation, sublimation, deformation or modification. 3. A light absorbing layer that absorbs laser light directly or through another layer on the transparent substrate, and a laser beam that reflects laser light directly or through another layer on the light absorbing layer. In an optical information recording medium having a light reflecting layer and pits for reproducing data by irradiating a laser beam, a part of components constituting the light absorbing layer is diffused or spread to a layer adjacent to the same layer. It is characterized by viscous flow, which mixes with or partially combines with the components of the layer on the transparent substrate side adjacent to the light absorption layer, and pits are formed at the position where the laser spot is irradiated. Optical recording medium. 4. A light absorbing layer that absorbs laser light directly or through another layer on a transparent substrate, and a laser beam that reflects laser light directly or through another layer on the light absorbing layer. In an optical information recording medium in which a light reflecting layer and pits for reproducing data by laser light irradiation are formed, an interface between the light absorbing layer and another layer adjacent to the light absorbing layer is separated, and a void is formed therein. The optical information recording medium is characterized in that a pit is formed at a position where a laser spot is irradiated, or a bubble is generated in the light absorption layer and the bubble remains in the light absorption layer. . 5. The light absorbing layer according to claim 1, wherein the light absorbing layer absorbs a laser beam applied to the layer to generate heat, and is melted, evaporated, sublimated, deformed or modified. Optical information recording medium. 6. The light absorbing layer according to claim 1 or 2, wherein a part of the components constituting the light absorbing layer diffuses or viscously flows into a layer adjacent to the same layer, and this diffuses into the light absorbing layer. An optical information recording medium, characterized in that it is mixed with or partially combined with components of a layer on the side of an adjacent transparent substrate. 7. The interface according to claim 1, wherein the interface between the light absorption layer and another layer adjacent to the light absorption layer is separated, and a void is formed therein. Alternatively, the optical information recording medium is characterized in that bubbles are generated in the light absorbing layer and remain. 8. A light absorbing layer that absorbs laser light directly or through another layer on the transparent substrate, and a laser beam that reflects laser light directly or through another layer on the light absorbing layer. In a recording method of an optical information recording medium in which a light reflecting layer and pits for reproducing data by laser light irradiation are formed, in the recording medium, a pit portion on the side of the substrate adjacent to the light absorbing layer is irradiated by laser light. A recording method for an optical information recording medium, which comprises deforming a layer and decomposing a portion of the light absorption layer irradiated with laser light to form a pit at a position irradiated with a laser spot. 9. A light absorbing layer that absorbs laser light directly or through another layer on a transparent substrate, and a laser beam that reflects laser light directly or through another layer on the light absorbing layer. In a recording method of an optical information recording medium having a light reflecting layer and pits for reproducing data by irradiating laser light, the light absorbing layer absorbs the laser light to generate heat while being irradiated with the laser light. A method for recording an optical information recording medium, characterized in that pits are formed at positions irradiated with a laser spot by melting, evaporating, subliming, deforming or modifying. 10. A light absorbing layer that absorbs laser light directly or through another layer on a transparent substrate, and a laser beam that reflects laser light directly or through another layer on the light absorbing layer. In a recording method of an optical information recording medium in which a light reflecting layer and a pit for reproducing data by laser light irradiation are formed, a part of components constituting the light absorbing layer by laser light irradiation is formed in the same layer. And diffuse or viscous flow into a layer adjacent to the layer, and mix or partially combine the components with the layer on the side of the transparent substrate adjacent to the light absorption layer, and at the position where the laser spot is irradiated. A recording method for an optical information recording medium characterized by forming pits. 11. A light absorbing layer that absorbs laser light directly or through another layer on a transparent substrate, and a laser light that reflects laser light directly or through another layer on the light absorbing layer. In a recording method of an optical information recording medium in which a light reflecting layer and pits for reproducing data by laser light irradiation are formed, the light absorbing layer and other layers adjacent to the light absorbing layer are irradiated by laser light irradiation. Optical information recording, characterized in that the interface is peeled off and a void is formed therein or a bubble is generated in the light absorption layer to form a pit at a position irradiated with a laser spot. Media recording method. 12. The light absorbing layer according to claim 8, wherein the light absorbing layer absorbs the laser light irradiated thereon to generate heat and is melted, evaporated, sublimated, deformed or modified. Recording method for optical information recording medium. 13. The light absorbing layer according to claim 8 or 9, wherein a part of the components constituting the light absorbing layer diffuses or viscously flows into a layer adjacent to the same layer, and this diffuses into the light absorbing layer. A recording method for an optical information recording medium, characterized in that it is mixed with or partially combined with components of a layer on the side of an adjacent transparent substrate. 14. The interface according to claim 8, wherein the interface between the light absorption layer and another layer adjacent to the light absorption layer is separated, and a void is formed therein. Alternatively, a recording method of an optical information recording medium, characterized in that bubbles are generated in the light absorption layer and the bubbles remain.