JPH10162429A - Optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a medium which attains reproduction of signals with not only laser light of reproducing wavelengths for a CD-R but laser light in a shorter wavelength range for reproducing of a DVD by forming an interference layer having a dye layer the optical conditions of which are easily controlled on a light-transmitting substrate. SOLUTION: A first dye having absorption for laser light of 770 to 830nm reproducing wavelengths and a second dye which is transparent for laser light in a longer wavelength region over 630 to 680nm and does not damage the recording property of the first dye are applied by spin coating to form a dye layer. As for the dyes, org. dyes such as phthalocyanine, carbocyanine and azo dyes are preferable. Due to the wavelength dependence of the optical consts. of the first and second dyes, the optical path for the first and second reproducing wavelengths can be matched, and absorption of light in the second reproducing wavelength can be decreased while the reflectance is increased and modulation degree can be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium capable of recording / reproducing with a laser beam, and enables reproduction with a laser beam in a short wavelength region as well as a reproduction wavelength region of an ordinary compact disc. The present invention relates to an optical information recording medium.

[0002]

2. Description of the Related Art Optical recording media such as CD-Rs have been used as means for recording and reproducing data such as images such as characters and figures or sound. This CD-R is provided, for example, by providing a recording layer made of an organic dye on a light-transmitting substrate, irradiating the recording layer with a laser beam based on a data signal, and elevating the temperature of the organic dye and melting the organic dye. The data is recorded by forming a pit by disassembling the substrate and deforming the substrate, and the data is recorded, and the data is read and reproduced by a difference in reflected light from the pit and other portions by irradiating a laser beam. A laser beam having a wavelength of 770 to 830 nm has been used for such a CD-R. Recently, a DVD, which is a high-density optical medium using a laser beam having a shorter wavelength of 630 to 680 nm, has appeared. It has come to be used as a media for the next era.

[0003]

In such a situation, in order to enhance the utility value of the CD-R, it is desirable that the reproduction can be performed by a reproducing apparatus used for a DVD. The dye in the R recording layer is
When reproduction is performed with a laser beam having a wavelength of 630 to 680 nm, the absorption is too large, and hence the reflectivity is insufficient, the focus signal is insufficient, and the focus cannot be focused on the recording surface, or the modulation degree which is practically satisfactory. However, there is a problem that the electric signal cannot be obtained and the reproduction cannot be performed.

A first object of the present invention is to provide an optical information recording medium capable of reproducing not only a laser beam having a reproduction wavelength of a CD-R but also a laser beam for reproducing a DVD having a shorter wavelength. is there. A second object of the present invention is to provide an optical information recording medium capable of easily adjusting optical conditions. A third object of the present invention is to provide a digital signal reproducing apparatus which reproduces the characteristics of an electric signal such as the degree of modulation and the jitter even when reproduced by a CD player.
An object of the present invention is to provide an optical information recording medium which is comparable to a VD player.

[0005]

According to the present invention, there is provided an optical information recording medium having at least a light interference layer having a dye layer and a reflection layer on a light transmitting substrate. Therefore, recording / reproduction with a first reproduction wavelength laser light selected from a wavelength of 770 to 830 nm is possible, and a wavelength of 6 shorter than the first reproduction wavelength laser light.
It is an object of the present invention to provide an optical information recording medium capable of reproducing with a laser beam having a second reproducing wavelength selected from 30 to 680 nm. Further, the present invention provides (2) the sum of all the layers of the light interference layer where ρ = kd given by the imaginary part k and the thickness d (nm) of the optical constant of each layer constituting the light interference layer. The optical information recording medium of (1) above, wherein Σρ is not larger than 30 for the first reproduction wavelength laser beam and not larger than 60 for the second reproduction wavelength laser beam, (3) the optical interference layer is the first reproduction mode. A mixture of a first dye having an absorption peak between the laser light of the second reproduction wavelength and a second dye having an absorption peak at a shorter wavelength than the laser light of the second reproduction wavelength is contained. Having a dye layer, the first
The real part of the optical constant of the first dye at the first reproduction wavelength laser light is n ₁₁ , the imaginary part is k ₁₁ , the real part of the optical constant of the first dye at the second reproduction wavelength laser light is n ₁₂ , The imaginary part is k ₁₂ , the real part of the optical constant of the second dye at the first reproduction wavelength laser light is n ₂₁ , the imaginary part is k ₂₁ , and the optics of the second dye at the second reproduction wavelength laser light. The real part of the constant is n ₂₂ , the imaginary part is k ₂₂ , the real part of the optical constant of the entire optical interference layer in the first reproduction wavelength laser light is n ₁ , the imaginary part is k ₁ , and the second reproduction wavelength laser When the real part of the optical constant of light is n ₂ and the imaginary part is k ₂ ,
The first dye has n ₁₁ and n ₁₂ of 1.5 to 3.5, k ₁₁ and k ₁₂ of 0.05 to 0.4, and the second dye has n ₂₁ and n ₂₂ of 1.5 to 3.5. 3.0, k ₂₁ and k ₂₂ are not larger than 0.05, and n ₂ / n ₁ is 0.6-1.
The optical information recording medium according to the above (2), wherein 0 and k ₁ are smaller than 0.1 and k ₂ is smaller than 0.4,
Having a second dye layer containing a second dye having an absorption peak at a shorter wavelength than the reproduction wavelength laser light on the transparent substrate, the first reproduction wavelength laser light and the second reproduction wavelength laser A first dye layer containing a first dye having an absorption peak between light is provided on the second dye layer, and the first dye layer has an optical constant of the first reproduction wavelength laser light at the first reproduction wavelength laser beam. The real part is n
₁₁ , the imaginary part is k ₁₁ , the real part of the optical constant of the first dye at the second reproduction wavelength laser light is n ₁₂ , the imaginary part is k ₁₂ , and the second reproduction light is the first reproduction wavelength laser light. When the real part of the optical constant is n ₂₁ , the imaginary part is k ₂₁ , the real part of the optical constant of the second dye at the second reproduction wavelength laser beam is n ₂₂ , and the imaginary part is k ₂₂ , The dyes have n ₁₁ and n ₁₂ of 1.6 to 4.0, and k ₁₁
There 0.01~0.2, k ₁₂ is 0.05 to 1.5,
The optical information recording according to the above (2), wherein the second dye has n ₂₁ and n ₂₂ of 1.6 to 4.0, n ₂₁ is smaller than n ₂₂ and k ₂₁ and k ₂₂ are not larger than 0.1. Medium, (5) In the optical information recording medium of (4), the first dye layer and the second dye layer
An optical information recording medium in which a first dye layer is formed on a light-transmitting substrate, and a second dye layer is formed on the first dye layer; 6) The light interference layer is the first
Between the first dye layer and the second dye layer, where k is 0.1 for the first reproduction wavelength laser light and the second reproduction wavelength laser light.
(4) or (5), wherein the optical information recording medium has an intermediate layer smaller than 01,
The optical information recording medium according to any one of the above (3) to (6), which has an intermediate layer in which k is smaller than 0.01 for the reproduction wavelength laser light and the second reproduction wavelength laser light.
(8) The above (3) to (3) to wherein the light interference layer has an intermediate layer between the translucent substrate and the dye layer, where k is smaller than 0.01 for the first reproduction wavelength laser light and the second reproduction wavelength laser light. (7) An optical information recording medium according to any of (7).

In the above (3), “the first dye and the second dye”
The mixed dye layer containing a mixture of the dyes of the above, "a mixed dye layer obtained by applying a solution containing the first dye and the second dye dissolved together in the same solvent of a single or mixed solvent" In the above (4) and (5), “... Is a dye layer” is replaced by “... Dyes, and the first dye and the second dye are opposite to each other. It may not be dissolved by the application of the dye solution of the solvent on the side '', and in each of the above-mentioned other inventions, the `` optical recording medium '' is referred to as the `` method for producing an optical recording medium '',
An expression similar to this may be used.

In the present invention, “having at least a light interference layer having a dye layer and a reflective layer on a light-transmitting substrate” means “a light interference layer having a dye layer”, and “reflection layer” is an essential component. But also a protective layer on the reflective layer,
Furthermore, it shows that a hydrophilic resin layer or the like may be provided thereon, or a protective layer may be provided on the substrate surface (on the side where laser light is incident). Further, the "light interference layer having a dye layer",
It has a dye layer as an essential configuration, and the dye layer may be either a single layer or a plurality of layers, but indicates that an intermediate layer described below may be provided on either or both of the upper and lower sides of the dye layer . With this “light interference layer having a dye layer”, recording / reproduction is possible with a laser beam having a first reproduction wavelength selected from a wavelength of 770 to 830 nm, and recording / reproduction is possible in the same manner as a general CD-R. On the other hand, 630 to 68 on the shorter wavelength side than the first reproduction wavelength laser light
Reproduction with a second reproduction wavelength laser beam selected from 0 nm is possible, and reproduction with a so-called DVD reproduction device becomes possible. This can be realized by changing the optical interference condition by adjusting the optical characteristics of the optical interference layer when the laser light is irradiated. The optical characteristics can be represented by the wavelength of the laser light, the number of light interference layers, the optical constant of each layer, and the thickness of each layer. First, in order to sufficiently secure the reflected light, ρ = k of each layer given by the imaginary part k and the thickness d (nm) of the optical constant of each layer constituting the light interference layer.
The sum Σρ of all the light interference layers of d is not larger than 30 (30 or less) for the first reproduction wavelength laser beam, that is, the laser beam selected from λ ₁ = 770 to 830 nm, and the second Reproduction wavelength laser light, ie, λ
_The above can be realized when the value is not larger than 60 (60 or less) for a laser beam selected from ₂ = 630 to 680 nm. In addition, the optical interference conditions can be more finely adjusted by designing the dye layer in the light interference layer, but the dye layer can change the number of layers and the type of dye used for each layer. In the case of using two kinds of dyes, there are a case where the dye layer is formed as one layer and a case where the dye layer is provided in two layers.
The above can be realized by adjusting the optical constant of the invention of (4). When one dye layer is provided, for example, a mixed solution obtained by applying a solution containing a first dye and a second dye that are dissolved together in the same solvent of a single or mixed solvent described below by spin coating or the like is used. A dye layer can be mentioned, and the dye layer becomes a recording layer. In the case where two dye layers are provided, the first dye and the second dye are dye layers in which the respective dye layers are not dissolved by the application of a dye solution of a solvent described later on the other side, that is, the first dye layer and the second dye layer. The solubility of the dye 1 in solvent 1 is μ ₁₁ ,
When the solubility of the second dye in the solvent 1 is μ ₁₂ , the solubility of the second dye in the solvent 1 is μ ₂₁ , and the solubility of the second dye in the solvent 2 is μ ₂₂ , the first dye layer satisfying μ ₁₁ ≫μ ₂₁ and μ ₁₂ ≪μ ₂₂ A dye layer obtained by laminating a second dye layer can be mentioned. The first dye layer serves as a recording layer, and the second dye layer also has a role as the recording layer. It can also serve to match the optical path lengths of the first reproduction wavelength laser light and the second reproduction wavelength laser light. When the first dye layer is formed on a light-transmitting substrate, the substrate tends to be deformed, which is one of recording factors,
Further, the enhancement effect of the second dye layer on the first dye layer is also obtained, whereby the predetermined recording can be performed even when the first dye layer is thinned, and the predetermined reflectance and modulation degree can be obtained. The occurrence of jitter can be further suppressed.

In the present invention, the first dye layer and the second dye layer may be disposed between the light-transmitting substrate and the dye layer (or a dye layer in which the first dye layer and the second dye layer are combined if both are provided). An intermediate layer can be provided between the dye layers and between the dye layer and the reflective layer. These intermediate layers are made of a material other than a resin or an inorganic dye that has an optical constant k of almost 0, specifically, less than 0.01, with respect to the first reproduction wavelength laser light and the second reproduction wavelength laser light. Configure. In the above case, even when the substrate is attacked by a solvent when applying the dye solution, by providing a solvent-resistant intermediate layer that is not attacked by the solvent, the solvent selectivity at the time of forming the dye layer can be increased. . In the above case, when an intermediate layer is provided between the first dye layer and the second dye layer, each dye is coated using a solution of a solvent having a similar solubility to form each dye layer. Even if this is done, the effect on the dye of the dye layer previously applied by the dye solution applied later can be blocked by the intermediate layer, so that the dye can be prevented from dissolving, and the dye on both sides of the intermediate layer can be prevented. It is possible to suppress minute movement of the dyes of the layers with respect to the dye layers on the other side. By increasing the selectivity of the two dye layers as described above, it is possible to optimally perform recording / reproduction by an optimum combination of the dyes, and to suppress the occurrence of jitter. In the case described above, a so-called enhancement effect is obtained in which interference is performed at the time of reproduction with the first or second reproduction laser beam so as to increase the reflectance.

In the present invention, the first dye has absorptivity to a laser beam having a first reproduction wavelength of 770 to 830 nm for recording.
A material that is transparent to laser light in a wavelength region longer than 0 to 680 nm and does not impair the recording properties of the first dye is preferable. When these are represented by optical constants, the first dye has a wavelength of 77.
In the first reproduction wavelength laser light of 0 to 830 nm,
n = 1.5-4.0, k = 0.05-1.5, wavelength 63
In the second reproduction wavelength laser light of 0 to 680 nm,
It is preferable that n = 1.5 to 4.0 and k = 0.05 to 1.0, and the second dye is 630-680 nm and 77.
In laser light in a wavelength region of 0 to 830 nm, n =
It is preferable that 1.5 to 4.0 and k = 0 to 0.05. In particular, when a single dye layer is used, the real part of the optical constant of the first dye is n = 1.5 to 3.5 and the wavelength 6 in the first reproduction wavelength laser light having a wavelength of 770 to 830 nm.
In the second reproducing laser beam of 30 to 680 nm, n
= 1.5 to 3.0, and in the case where the number of dye layers is two, the real part of the optical constant of the first dye is such that, in the first reproduction laser light having a wavelength of 770 to 830 nm,
It is preferable that n = 1.6 to 4.0. 1st, 2nd
Any of the phthalocyanine dyes corresponding to these,
Organic dyes such as carbocyanine dyes and azo dyes are preferred.

The dye layer includes a coating layer obtained by applying a solution of a commonly used solvent of an organic dye by a spin coating method and drying the solution. In this case, the total thickness of the dye layer after drying is the same as that of a conventional dye layer. What is being applied is applicable. The dye layer may contain other compounds such as a singlet oxygen quencher, a light absorber, and a stabilizer for improving weather resistance. For the dye solution, a fluorine-based solvent such as chloroform, dichloroethane, and fluorinated alcohol, methyl ethyl ketone, dimethylformamide, methanol, toluene, cyclohexanone, acetylacetone, diacetone alcohol, cellosolves such as methyl cellosolve, dioxane, and the like can be used. In this case, the mixing ratio of a dye such as a cyanine dye is preferably 1% by weight to 20% by weight, more preferably 2% by weight to 10% by weight. Au, A formed by vapor deposition, sputtering, etc. as the reflective layer
l, Ag, high reflectance material films such as metal films of each of these and other alloys, and the like. The protective layer is made of an ultraviolet curable resin or the like for the purpose of protecting the optical information recording medium and improving weather resistance. A coating layer formed by applying a solution of a radiation-curable resin by a spin coating method and drying the applied solution. Examples of the substrate used in the present invention include glass and plastics such as epoxy resin, methacrylic resin, polycarbonate resin, polyester resin, and polyvinyl chloride resin. Grooves or pits for tracking may be formed on the main surface of the substrate on which the dye layer is formed.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be described with reference to the following examples. When the first dye is a blue dye and the second dye is a red dye, for example, as shown in FIG. While the blue dye has an absorption peak (absorption curve a) between the first reproduction wavelength and the second reproduction wavelength, the absorption of the laser light absorption curve b due to the wavelength of the red dye as the second dye is shown. Since the peak is on the shorter wavelength side than the second reproduction wavelength, the optical path lengths of the first reproduction wavelength and the second reproduction wavelength of, for example, 780 nm can be matched due to the wavelength dependence of both optical constants. At the reproduction wavelength of 2, light absorptivity is reduced, its reflectance is increased, and the degree of modulation can be secured. When the blue dye of the first dye and the red dye of the second dye are mixed, the absorption curves a and b of FIG. 1 are combined and shown in FIG. Also, the first
The optical constants n and k of the blue dye of the dye and the red dye of the second dye are shown in, for example, FIG. 3 for the former and FIG. 4 for the latter, and the optical constants n and k when both are mixed are shown in FIG. Indicated at 5. FIG. 6 shows ideal optical constants n and k of the entire light interference layer having a dye layer using both dyes. 3 to 6, the solid line indicates n and the dotted line indicates k.

[0012]

Embodiments will be described below. Example 1 0.5 μm width, 0.2 μm depth, 1.6 μm pitch on the surface
m formed into a spiral groove having a thickness of 1.2
mm, an outer diameter of 120 mmφ and an inner diameter of 15 mmφ were molded by an injection molding method. In order to form a dye layer as a light interference layer, 70 parts by weight of a phthalocyanine represented by the following [Chemical Formula 1] and 30 parts by weight of a cyanine dye (product number: NK-4284, manufactured by Japan Photosensitive Dye Laboratories) are dissolved in a cellosolve solvent. This was applied to the surface of the substrate by spin coating to form a mixed dye layer having a thickness of 150 nm.

[0013]

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At this time, the product ρ = kd of the imaginary part k of the optical constant of the dye layer and the film thickness d there is converted into a laser beam (λ ₁ ) having a wavelength of 780 nm and a laser beam (λ ₂ ) having a wavelength of 635 nm.
Are shown in Table 1 together with the values obtained for the other optical constants. Next, an Au reflective film having a thickness of 80 nm was formed on the dye layer by a sputtering method to form a reflective layer. Further, an ultraviolet curable resin was applied on the reflective layer by a spin coating method, and was irradiated with ultraviolet light to be cured, thereby forming a protective layer having a thickness of 5 μm. An optical disk was thus obtained. The optical disk was irradiated with a semiconductor laser having a wavelength of 780 nm similar to the above-mentioned λ ₁ at a linear velocity of 1.2 m / s and a recording power of 7 mW.
The EFM signal was recorded. Thereafter, when this optical disk was reproduced by a commercially available CD player (a reproduction light of a laser beam having a wavelength of 780 nm similar to the above λ ₁ ), the reflectance (R
_top ), the degree of modulation (I ₁₁ / I _top ), and the average 3T jitter were as shown in Table 5. In the Orange Book standard,
The reflectance is set to 65% or more and I ₁₁ / I _top is set to 0.6 or more, and the optical disk in this embodiment satisfies this standard. On the other hand, when the optical disk recorded with a laser beam having a wavelength of 780 nm was reproduced at a linear velocity of 1.2 m / s (reproduced light of a laser beam having a wavelength of 635 nm similar to the above λ ₂ ), the reflectance (R _top ) Degree of modulation (I ₁₁ /
I _top ) is as shown in Table 5, and a value sufficient for regeneration was obtained.

Example 2 On the surface of a substrate molded in the same manner as in Example 1, a cyanine dye (manufactured by Japan Photographic Dye Laboratories, product number:
NK-4270) dissolved in fluorinated alcohol is applied by spin coating to form a second 100-nm thick film.
Was formed. Next, a solution obtained by dissolving phthalocyanine in an ether solvent as a first dye represented by the following formula (2) (iPr of R = iPr represents an isopropyl group) is applied on the second dye layer by spin coating. Then, a first dye layer having a thickness of 80 nm was formed.

[0016]

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Next, an Au reflective film having a film thickness of 80 nm was formed on the dye layer by sputtering to form a reflective layer. Further, an ultraviolet curable resin was applied on the reflective layer by a spin coating method, and was irradiated with ultraviolet light to be cured, thereby forming a protective layer having a thickness of 5 μm, thereby completing an optical disk. The respective optical constants obtained in the same manner as in Example 1 are shown in Table 1, and recording and reproduction were performed on this optical disk in the same manner as in Example 1 except that the recording power was set to the value shown in Table 5. Table 5 shows the results.

Embodiment 3 In Embodiment 2, the first dye layer and the second dye layer are provided in reverse, that is, the first dye layer is provided on a light-transmitting substrate, and An optical disk was manufactured in the same manner except that the second dye layer was provided. The respective optical constants obtained in the same manner as in Example 1 are shown in Table 1, and recording and reproduction were performed on this optical disk in the same manner as in Example 1 except that the recording power was set to the value shown in Table 5. Table 5 shows the results.

Example 4 A solution obtained by dissolving a cyanine dye (manufactured by Nippon Kogaku Dye Laboratories, product number: NK-4284) in cellosolve as a second dye was spin-coated on the surface of the substrate 1 formed in the same manner as in Example 1 above. Coating was performed by a coating method to form a second dye layer having a thickness of 100 nm. Next, a 50 nm-thick SiO film was formed on the second dye layer by a vacuum evaporation method, and an intermediate layer was provided. Further, phthalocyanine as a first dye represented by the above formula (1) is dissolved in a cellosolve solvent, and the solution is applied on the intermediate layer by a spin coating method.
A first dye layer of 0 nm was formed. Next, an Au reflective film having a thickness of 80 nm was formed on the first dye layer by a sputtering method, thereby forming a reflective layer. Further, an ultraviolet curable resin was applied on the reflective layer by a spin coating method, and was irradiated with ultraviolet light to be cured, thereby forming a protective layer having a thickness of 5 μm, thereby completing an optical disk. The respective optical constants obtained in the same manner as in Example 1 are shown in Table 1, and recording and reproduction were performed on this optical disk in the same manner as in Example 1 except that the recording power was set to the value shown in Table 5. Table 5 shows the results.

Embodiment 5 In Embodiment 4, the first dye layer and the second dye layer are provided in reverse, that is, the first dye layer is provided on a light-transmitting substrate, and An optical disk was manufactured in the same manner except that the second dye layer was provided. The respective optical constants obtained in the same manner as in Example 1 are shown in Table 1, and recording and reproduction were performed on this optical disk in the same manner as in Example 1 except that the recording power was set to the value shown in Table 5. Table 5 shows the results.

Example 6 In the above-mentioned Example 1, a 200 nm-thick SiO film was formed on the mixed dye layer by a vacuum evaporation method in order to provide an intermediate layer between the mixed dye layer and the reflective layer. An optical disk was manufactured in the same manner except that a reflective layer was similarly provided. The respective optical constants obtained in the same manner as in Example 1 are shown in Table 1, and recording and reproduction were performed on this optical disk in the same manner as in Example 1 except that the recording power was set to the value shown in Table 5. Table 5 shows the results.

Examples 7 to 10 In each of Examples 2 to 5, optical disks were manufactured in the same manner as in Example 6, except that an intermediate layer was provided between the dye layer and the reflective layer. The optical constants obtained in the same manner as in Example 1 are shown in Table 2, and recording and reproduction were performed on this optical disk in the same manner as in Example 1 except that the recording power was set to the value shown in Table 5. Table 5 shows the results.

Example 11 An intermediate layer made of a 50-nm-thick SiO film was formed on the surface of a substrate formed in the same manner as in Example 1 by a vacuum evaporation method. Next, on this intermediate layer, a solution prepared by dissolving 70 parts by weight of phthalocyanine represented by the following Chemical Formula 3 and 30 parts by weight of cyanine (manufactured by Nippon Kosaku Dye Laboratories, product number: NK-4284) in chloroform was spun. The mixture was applied by a coating method to form a mixed dye layer having a thickness of 150 nm. further,
A film thickness of 80 n is formed on the first dye layer by a sputtering method.
A reflective film of Au was formed to form a reflective layer. Thereafter, an ultraviolet-curable resin was applied on the reflective layer by spin coating, and the applied resin was cured by irradiating ultraviolet rays to form a protective layer having a thickness of 5 μm, thereby completing an optical disk.

[0024]

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Table 2 shows the respective optical constants obtained in the same manner as in Example 1.
Recording and reproduction were performed in the same manner as in Example 1 except that the recording power was set to the value shown in Table 5, and the results are shown in Table 5.

Example 12 A second dye layer was formed in the same manner as in Example 2 except that an azo dye represented by the following chemical formula 4 was used as the second dye and chloroform was used as a solvent. An optical disc was manufactured in the same manner as in Example 11, except that an intermediate layer similar to that of Example 11 was provided between the second dye layer and the substrate. The optical constants obtained in the same manner as in Example 1 are shown in Table 2, and recording and reproduction were performed on this optical disk in the same manner as in Example 1 except that the recording power was set to the value shown in Table 5. Table 5 shows the results.

[0027]

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Example 13 A first dye layer was formed in the same manner as in Example 3, except that the dye represented by the above formula (3) was used as the first dye and chloroform was used as a solvent. An optical disk was manufactured in the same manner as in Example 11, except that the same intermediate layer was provided between the first dye layer and the substrate. The optical constants obtained in the same manner as in Example 1 are shown in Table 3, and the recording power of this optical disk is shown in Table 5.
Recording and reproduction were performed in the same manner as in Example 1, except that the values shown in Table 5 were used. The results are shown in Table 5.

Example 14 In Example 4, the dye represented by the above formula [Chemical Formula 3] was used as the first dye, and the dye represented by the above Chemical Formula 4 was used as the second dye, and chloroform was used as a solvent. Optical disks were produced in the same manner except that first and second dye layers were formed, respectively, and that an intermediate layer similar to that of Example 11 was provided between the second dye layer and the substrate. The optical constants obtained in the same manner as in Example 1 are shown in Table 3, and the recording power of this optical disk is shown in Table 5.
Recording and reproduction were performed in the same manner as in Example 1, except that the values shown in Table 5 were used. The results are shown in Table 5.

Example 15 In Example 5, the dye represented by the above formula [Chemical Formula 3] was used as the first dye, and the dye represented by the above Chemical Formula 4 was used as the second dye, and chloroform was used as the solvent. Optical disks were manufactured in the same manner except that first and second dye layers were formed, respectively, and that an intermediate layer similar to that in Example 11 was provided between the first dye layer and the substrate. The optical constants obtained in the same manner as in Example 1 are shown in Table 3, and the recording power of this optical disk is shown in Table 5.
Recording and reproduction were performed in the same manner as in Example 1, except that the values shown in Table 5 were used. The results are shown in Table 5.

Example 16 In Example 6, a mixed dye layer was formed by using the dye represented by the above formula [1] as the first dye and chloroform as a solvent. An optical disc was manufactured in the same manner except that a suitable intermediate layer was provided between the mixed dye layer and the substrate. The respective optical constants obtained in the same manner as in Example 1 are shown in Table 3, and recording and reproduction were performed on this optical disc in the same manner as in Example 1 except that the recording power was set to the value shown in Table 5. Table 5 shows the results.

Example 17 In Example 7, the second dye layer was formed by using the dye represented by the above formula (4) as the second dye and chloroform as the solvent. An optical disc was manufactured in the same manner except that the same intermediate layer was provided between the second dye layer and the substrate. The respective optical constants obtained in the same manner as in Example 1 are shown in Table 3, and recording and reproduction were performed on this optical disc in the same manner as in Example 1 except that the recording power was set to the value shown in Table 5. Table 5 shows the results.

Example 18 The same procedure as in Example 8 was carried out except that the dye represented by the above formula (3) was used as the first dye and chloroform was used as the solvent to form the first dye layer. An optical disc was manufactured in the same manner except that an intermediate layer similar to that described above was provided between the first dye layer and the substrate. The optical constants obtained in the same manner as in Example 1 are shown in Table 4, and recording and reproduction were performed on this optical disk in the same manner as in Example 1 except that the recording power was changed to the value shown in Table 5. Table 5 shows the results.

Example 19 In Example 9, the dye represented by the above formula [3] was used as the first dye, the dye represented by the above formula [4] was used as the second dye, and chloroform was used as the solvent. Optical disks were produced in the same manner except that first and second dye layers were formed, respectively, and that an intermediate layer similar to that of Example 11 was provided between the second dye layer and the substrate. Table 4 shows the respective optical constants obtained in the same manner as in Example 1. Table 5 shows the recording power of this optical disk.
Recording and reproduction were performed in the same manner as in Example 1, except that the values shown in Table 5 were used. The results are shown in Table 5.

Example 20 In Example 10, the dye represented by the above formula [Chemical Formula 3] was used as the first dye, and the dye represented by the above Chemical Formula 4 was used as the second dye, and chloroform was used as a solvent. Forming first and second dye layers, respectively;
An optical disc was produced in the same manner as in Example 11, except that an intermediate layer was provided between the first dye layer and the substrate. The optical constants obtained in the same manner as in Example 1 are shown in Table 4, and recording and reproduction were performed on this optical disk in the same manner as in Example 1 except that the recording power was changed to the value shown in Table 5. Table 5 shows the results.

Comparative Example 1 A substrate obtained by dissolving a cyanine dye (manufactured by Japan Photographic Dye Laboratories, product number: NK-3219) in diacetone alcohol was applied to a substrate formed in the same manner as in Example 1 by spin coating. A dye layer having a thickness of 100 nm was formed. Next, a film thickness of 80 nm is formed on the dye layer by a sputtering method.
A reflective film of Au was formed to form a reflective layer. further,
An ultraviolet-curable resin is applied on the reflective layer by spin coating, and is cured by irradiating ultraviolet rays onto the reflective layer.
A protective layer having a thickness of μm was formed, and an optical disk was completed. Table 4 shows the respective optical constants obtained in the same manner as in Example 1. Table 5 shows the recording power of this optical disk.
Recording and reproduction were performed in the same manner as in Example 1, except that the values shown in Table 5 were used. The results are shown in Table 5.

Comparative Example 2 An optical disk was prepared in the same manner as in Comparative Example 1, except that an ether solution of a phthalocyanine dye represented by the above formula [2] was used instead of the diacetone alcohol solution of the cyanine dye. The optical constants obtained in the same manner as in Example 1 are shown in Table 4, and recording and reproduction were performed on this optical disk in the same manner as in Example 1 except that the recording power was changed to the value shown in Table 5. Table 5 shows the results.

From the results shown in the table, the optical discs of Examples 1 to 20 and Comparative Examples 1 and 2 have a reflectance of 65% or more and an I ₁₁ / I _top of 0.6 as defined by the Orange Book standard.
Satisfies the above standards. On the other hand, the above-mentioned optical disk recorded with a laser beam having a wavelength of 780 nm was moved at a linear velocity of 1.2 m.
/ Playback s when obtained by (laser beam of reproducing light of the same wavelength 635nm and the lambda _2), the optical disc of Example 20 is at least 33% (33% or higher) reflectivity, preferably at least 40 % (40% or more), and I ₁₁ /
I _top is at least 0.68 (0.68 or more), preferably at least 0.70 (0.70 or more), whereas the optical disks of Comparative Examples 1 and 2 have a reflectance of less than 12% or 10%, _It can be seen that ₁₁ / I _top is very small and cannot be measured. In the present invention, these limiting conditions can be added. The intermediate layer enhances the enhancing effect particularly on the laser light on the short wavelength side, and the optical path length can be adjusted by the difference in the enhancing effect. In addition, the dye 2
When layering, even if each dye layer is formed using each dye solution in which each of a plurality of dyes is dissolved by a solvent having mutual solubility, each dye is formed by interposing an intermediate layer in the dye layer. Does not need to be dissolved, and the solvent selectivity can be improved accordingly, and as a result, the dye selectivity can also be improved.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

[Table 4]

[0043]

[Table 5]

[0044]

According to the present invention, by providing an optical interference layer for easily adjusting the optical conditions, not only the laser beam of the reproduction wavelength of the CD-R but also the laser beam of the DVD of the shorter wavelength side can be reproduced. However, it is possible to provide an optical information recording medium that can be reproduced, and furthermore, the electric signal characteristics such as the degree of modulation and the jitter
It is possible to provide an optical information recording medium that is comparable to a D player and a DVD player.

[Brief description of the drawings]

FIG. 1 is a graph showing absorption curves of a blue dye and a red dye.

FIG. 2 is a graph showing an absorption curve when both dyes are mixed.

FIG. 3 is a graph showing optical constants n and k of a blue dye.

FIG. 4 is a graph showing optical constants n and k of a red dye.

FIG. 5 is a graph showing optical constants n and k when both dyes are mixed.

FIG. 6 is a graph showing an ideal type of optical constants n and k of the entire light interference layer.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Emiko Hamada 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Denki Co., Ltd.

Claims (8)

[Claims] 1. An optical information recording medium having at least a light interference layer having a dye layer and a reflective layer on a light transmitting substrate, wherein recording is performed by using a laser beam having a first reproduction wavelength selected from a wavelength of 770 to 830 nm. · Reproducible and 630-68 shorter in wavelength than the first reproduced wavelength laser light
An optical information recording medium that can be reproduced by a laser beam having a second reproduction wavelength selected from 0 nm. 2. The sum Σρ of all the layers of the light interference layer, where ρ = kd of each layer given by the imaginary part k and the thickness d (nm) of the optical constant of each layer constituting the light interference layer, is the first. 2. The optical information recording medium according to claim 1, wherein the laser light having a reproduction wavelength is not larger than 30 and the laser light having a second reproduction wavelength is not larger than 60. 3. The light interference layer absorbs a first dye having an absorption peak between the first reproduction wavelength laser light and the second reproduction wavelength laser light and a wavelength shorter than the second reproduction wavelength laser light. A dye layer containing a mixture with a second dye having a peak, wherein the real part of the optical constant of the first dye at the first reproduction wavelength laser light is n ₁₁ , the imaginary part is k ₁₁ , and the first is The real part of the optical constant of the dye of the second reproduction wavelength laser light is n ₁₂ ,
The imaginary part is k ₁₂ , the real part of the optical constant of the second dye at the first reproduction wavelength laser light is n ₂₁ , the imaginary part is k ₂₁ , and the optics of the second dye at the second reproduction wavelength laser light. The real part of the constant is n ₂₂ , the imaginary part is k ₂₂ , the real part of the optical constant of the entire optical interference layer at the first reproduction wavelength laser light is n ₁ , the imaginary part is k ₁ , and the second is
When the real part and the imaginary part of the optical constant in the reproduction wavelength laser light are n ₂ and k ₂ , respectively, the first dye has n ₁₁ and n ₁₂ of 1.5.
３3.5, k ₁₁ and k ₁₂ are 0.05-0.4, and the second dye has n ₂₁ and n ₂₂ of 1.5-3.0, k ₂₁ and k
₂₂ is not greater than 0.05, and n ₂ / n
₁ is 0.6 to 1.0, k ₁ is less than 0.1, k ₂ is an optical information recording medium according to less than 0.4 claim 2. 4. The light interference layer has a second dye layer containing a second dye having an absorption peak at a shorter wavelength than the second reproduction wavelength laser light on a light transmitting substrate, Forming a first dye layer containing a first dye having an absorption peak between the reproduction wavelength laser light and the second reproduction wavelength laser light as the second dye layer;
, The real part of the optical constant of the first dye at the first reproduction wavelength laser light is n ₁₁ , the imaginary part is k ₁₁ , and the second reproduction wavelength laser light of the first dye is Is the real part of the optical constant at n ₁₂ , the imaginary part is k ₁₂ , the real part of the optical constant of the second dye at the first reproduction wavelength laser beam is n ₂₁ , the imaginary part is k ₂₁ , and the second dye is The real part of the optical constant of the second reproduction wavelength laser light
₂₂ and the imaginary part is k ₂₂ , the first dyes are n ₁₁ and n ₁₂
But 1.6 to 4.0, k ₁₁ is 0.01 to 0.2, k ₁₂ is 0.05 to 1.5, the second dye is n ₂₁ and n ₂₂ is from 1.6 to 4. 0 and n ₂₁ is smaller than n ₂₂ , k
The optical information recording medium according to claim 2 ₂₁ and k ₂₂ is not greater than 0.1. 5. The optical information recording medium according to claim 4, wherein the first dye layer and the second dye layer are provided in reverse, and the first dye layer is formed on a light transmitting substrate. An optical information recording medium in which a second dye layer is formed on one dye layer. 6. An intermediate layer in which the light interference layer has a k of less than 0.01 for the first reproduction wavelength laser light and the second reproduction wavelength laser light between the first dye layer and the second dye layer. The optical information recording medium according to claim 4, comprising: 7. The light interference layer according to claim 3, wherein k is smaller than 0.01 for the first reproduction wavelength laser light and the second reproduction wavelength laser light on the dye layer. The optical information recording medium according to the above. 8. The light interference layer has an intermediate layer having a k of less than 0.01 for the first reproduction wavelength laser light and the second reproduction wavelength laser light between the translucent substrate and the dye layer. 8. The optical information recording medium according to any one of 7.