JPH08283263A - Metal complex compound and optical recording medium using the same - Google Patents

Abstract

PURPOSE: To obtain the subject compound having a light molar light absorption coefficient as a pigment excellent in light fastness and capable of giving an optical recording medium having stable recording and reproducing characteristics with excellent light fastness. CONSTITUTION: This metal complex compound is a compound of formula I [Y is a heterocyclic ring having N, S or O atom next to its substituted position; X is a halogen, an alkyl, an alkoxy or an unsubstituted acylamino; Z is an aryl having a substituting group such as hydroxyl at the para position or a heterocyclic ring; R<1> to R<4> are each H, a halogen, an alkyl, an alkoxy, etc.; M1 is the salt of Ni, Cu, Co, Zn, Fe, etc.; (n) is 2, 3], preferably a compound of formula II (R<8> to R<10> are each same as R<1> , etc.; R<5> to R<7> are each H or an alkyl; M2 is the salt of Ni, Cu). Further, it is preferable e.g. to synthesize an imidazole derivative to which a substituent capable of binding to M is introduced, further conduct an oxidative coupling reaction with para-aminophenol, etc., dissolve the obtained azomethine pigment in a solvent, and add a metal salt such as Ni acetate to obtain the objective compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel metal complex compound having excellent properties as a dye and an optical recording medium using the compound as a light absorbing substance.

[0002]

2. Description of the Related Art Pigments known as dyes and pigments are
It is widely used in various applications such as dyeing materials for fibers, coloring materials for resins and paints, image forming materials for photography, printing, copying machines and printers, and light absorbing materials for color filters. Common problems of these dyes include optimization of absorption wavelength and waveform, improvement of molar absorption coefficient, and improvement of storage stability such as light resistance and heat resistance. In order to form a full color or three primary colors, three kinds of dyes of yellow, magenta and cyan are required, and a cyan dye having particularly good absorption characteristics and storage stability is desired.

On the other hand, with the rapid increase in the amount of information in recent years,
Large-capacity optical recording media are in the spotlight. A long-wavelength absorption dye that absorbs light in the red to near-infrared region is used for an organic optical recording medium that can easily and highly densely record information with an inexpensive semiconductor laser. Conventionally, cyanine dyes, which have excellent absorption and reflection properties, have been used for this purpose from various dyes, but they have the drawbacks of loss of information over time and inability to write because of poor storage stability such as light resistance. It was

In order to solve such a problem, for example, US Pat. Nos. 3,432,300 and 4,050,938, published patent publications Sho 60-118748, Sho 63-199248 and Shohei 2-300288 are light-stabilized. Agent, or photostabilization method is described,
It has not been possible to obtain sufficient storage stability.

Further, Japanese Patent Laid-Open Publication Nos. 64-44786 and 2-hei.
Nos. 76884 and 5-17701 describe metal chelate dyes having excellent storage stability, but their absorption wavelengths are too long to be used for optical recording media.

[0006]

SUMMARY OF THE INVENTION A first object of the present invention is to provide a subject of the above dye, especially a dye having a high molar extinction coefficient and excellent light resistance. The second object of the present invention is to obtain optical recording characteristics and storage stability by using a dye having an absorption suitable for a semiconductor laser used in an optical recording device, a high molar extinction coefficient, and excellent light resistance. To provide an excellent optical recording medium.

[0007]

The above object can be achieved by the following constitutions.

1. A metal complex compound represented by the following general formula I.

[0009]

Embedded image

In the formula, Y is a nitrogen atom adjacent to the substitution position,
A heterocyclic group having a sulfur atom or an oxygen atom, X represents a halogen atom, an alkyl group, an alkoxy group, or an unsubstituted acylamino group. Z represents an aryl group or a heterocyclic group having a substituent selected from the hydroxyl group, amino group, alkylamino group and alkoxy group at the para position. R
₁ , R ₂ , R ₃ and R ₄ are each a hydrogen atom, a halogen atom,
It represents a group selected from an alkyl group, an alkoxy group, an acylamino group, and an alkylsulfonamide group. M ₁ is Ni,
It represents a salt of Cu, Co, Zn, Fe, Pd, or Pt. n represents 2 or 3.

2. The metal complex compound according to the above item 1, wherein the compound represented by the general formula I is represented by the following general formula II.

[0012]

[Chemical 4]

In the formula, X represents a halogen atom, an alkyl group or an alkoxy group, or an unsubstituted acylamino group. R ₁ , R ₂ , R ₃ , R ₄ , R ₈ , R ₉ and R ₁₀ each represent a group selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an acylamino group and an alkylsulfonamide group. R ₅ , R ₆ and R ₇ each represent a hydrogen atom or an alkyl group. M ₂ represents a salt of Ni or Cu.

3. An optical recording medium comprising a substrate and at least one metal complex compound represented by the general formula I or II as a recording layer.

4. 4. The optical recording medium as described in 3 above, wherein writing and reading are performed through a substrate by using a semiconductor laser as a light source.

The metal complex compound of the present invention will be described in detail below.

The metal complex compound of the present invention is formed by binding two to three dye molecules and one divalent metal salt. Although the details of the bond are not always clear, the general formula I
In the main ring, the lone electron pair of the N atom in the imidazole ring of the main ring and 2 to 3 coordination bonds by M ₁ , and further 2 to 3 between the nitrogen atom, the sulfur atom or the oxygen atom in the heterocyclic group and M _1. It is considered that three coordination bonds form a tetra- or hexa-dentate metal complex.

In Japanese Patent Application Laid-Open No. 7-33746 by the present inventors, an ionic bond between a phenyl group having a similar structure and a dissociative substituent such as a sulfonamide group at the ortho position and a metal atom, and other groups. A hexadentate dye having a coordination bond between a metal atom and a metal atom is described. However, the present invention eliminates the dissociative substituent and introduces an appropriate substituent into X, so that the absorption maximum has a shorter wavelength. And a dye having a higher molar extinction coefficient is obtained.

In the above general formula I, examples of the heterocyclic group represented by Y having a nitrogen atom, a sulfur atom or an oxygen atom adjacent to the substitution position include 1-pyrazolyl group, 2-pyridyl group and 2 -Benzthiazolyl group, 2-imidazolyl group,
A 2-piperazyl group, a 2-benzimidazolyl group, a 2-oxazolyl group and the like can be mentioned. Y is preferably a 1-pyrazolyl group or a 2-pyridyl group.

When the group represented by X is a halogen atom, examples thereof include a chlorine atom and a fluorine atom, and when it is an alkyl group, examples include a methyl group, an ethyl group and a propyl group. , I-propyl group, i-butyl group, t-butyl group, etc., and examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, etc. Examples at certain times include acetamide groups, benzamide groups and the like.

Examples of Z include 4-hydroxyphenyl group, 3,5-dichloro-4-hydroxyphenyl group, 4-aminophenyl group, 4- (N-methylamino) phenyl group and 4- (N-ethyl group. Amino) phenyl group, 4- (N-hexylamino) phenyl group, 4- (N-dodecylamino) phenyl group, 4- (N, N-dimethylamino) phenyl group, 4- (N, N-diethylamino) phenyl Group, 4- (N, N-dihexylamino) phenyl group, 4- (N-
Ethyl-N-methylsulfonamidoethylamino) phenyl group, 4- (N, N-diethylamino) -2-methylphenyl group, 4-
(N, N-dihexylamino) -2-methylphenyl group, 4- (N-ethyl-N-methanesulfonamidoethylamino) -2-methylphenyl group, 4- (N-ethyl-N-hydroxyethylamino) -
2-methylphenyl group, 4- (N-ethyl-N-methoxyethylamino) -2-methylphenyl group, 4- (N, N-dimethoxyethylamino) -2-methylphenyl group, 4-methoxyphenyl group,
3,5-dichloro-4-methoxyphenyl group, 3,5-dichloro-4-
Octyloxyphenyl group, 4-anilinophenyl group, 4-
Acetamidophenyl group, 4-isopropylamidophenyl group, 4-benzamidophenyl group, 4-methylsulfonamidophenyl group, 4-octylsulfonamidophenyl group, 2- (3-methyl-5-N, N-diethylamino) pyridyl group Etc. can be mentioned. Z is preferably 4- (N, N-diethylamino) -2-methylphenyl group, 4- (N-ethyl-N-methanesulfonamidoethylamino) -2-methylphenyl group,
It has a para-phenylenediamine derivative structure such as 4- (N-ethyl-N-methoxyethylamino) -2-methylphenyl group.

When the group represented by R ₁ , R ₂ , R ₃ and R ₄ is a halogen atom, examples thereof include a chlorine atom and a fluorine atom, and when the group is an alkyl group. Is a methyl group, an ethyl group, a propyl group, an i-propyl group,
Examples thereof include an i-butyl group and a t-butyl group, examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group, and examples of the acylamino group include an example. , Acetamido group, benzamido group and the like, and examples of the alkylsulfonamide group include methylsulfonamide group, ethylsulfonamide group, trifluoromethylsulfonamide group and the like.

The above X, Y and Z may further have other substituents if necessary.

M ₁ is Ni, Cu, Co, Zn, Fe, P
Examples of the salt of a metal atom selected from d and Pt include acetate, perchlorate, halogen salt, borofluoride salt, fluorophosphorus salt, acetylacetone salt, benzenesulfonate salt of the above metal atom. , Benzoate and the like. n is preferably 2.

Among the metal complex compounds of the present invention, the structure represented by the general formula II is more preferable in terms of absorption / reflection properties as a dye, storage stability, easiness of complex formation and the like.

Examples of the group represented by X in the general formula II include the same examples as the group represented by X in the general formula I. X is preferably a halogen atom, an alkyl group or an alkoxy group. More preferably, it is a halogen atom.

The group represented by R ₁ , R ₂ , R ₃ , R ₄ , R ₈ , R ₉ and R ₁₀ is a group selected from a halogen atom, an alkyl group, an alkoxy group, an acylamino group and an alkylsulfonamide group. As an example when represented, R ₁ in the general formula I,
The same examples as the groups represented by R ₂ , R ₃ and R ₄ can be given. The groups represented by R ₁ , R ₂ , R ₃ and R ₄ are preferably all hydrogen atoms, or when any one of them is a halogen atom, an alkyl group or an alkoxy group and the other is a hydrogen atom. And more preferably when R ₂ is a halogen atom and the other is a hydrogen atom.

[0028] R _8, R _9, and preferably groups represented by R _10, when all of R _8, R ₉ and R ₁₀ is an alkyl group,
Alternatively, R ₈ and R ₁₀ are alkyl groups, and R ₉ is a hydrogen atom. More preferably, R ₈ and R ₁₀ are alkyl groups and R ₉ is a hydrogen atom. When the groups represented by R ₅ , R ₆ and R ₇ are alkyl groups, examples thereof include a methyl group, an ethyl group, a propyl group, an i-propyl group, an i-butyl group and a t-butyl group. be able to. Furthermore, as an example of the case where they have a substituent, a methoxyethyl group,
Examples thereof include a methylsulfonamidoethyl group. R ₅ is preferably a methyl group. R ₆ and R ₇ are preferably an ethyl group or an ethyl group further having a substituent.

Examples of the Ni or Cu salt represented by M ₂ include acetate, perchlorate, halogen salt, borofluoride salt,
Examples thereof include phosphorous fluoride salts, acetylacetone salts, benzenesulfonate salts, benzoate salts and the like. Perchlorates, borofluoride salts, phosphorus fluoride salts, and acetylacetone salts are preferable, and Ni salts are more preferable.

Since the metal complex compound of the present invention is advantageous in that it has a high absorbance per molecular weight, the molecular weight is 15
It is preferably 00 or less, more preferably 1300 or less.

Specific examples of the metal complex compound of the present invention are shown below.

[0032]

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[0033]

[Chemical 6]

[0034]

[Chemical 7]

[0035]

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[0036]

[Chemical 9]

[0037]

[Chemical 10]

[0038]

[Chemical 11]

[0039]

[Chemical 12]

[0040]

[Chemical 13]

[0041]

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The compounds of the present invention are, for example, Beilstein 2
3, 24, 25, and Berichte 34, 639, 29
Vol. 2103, Vol. 92, 550, etc., the imidazole derivative introduced with a substituent capable of binding to M was synthesized with reference to the imidazole synthesis method, and further para-aminophenol, para-phenylenediamine derivative, etc. An azomethine dye is obtained by, for example, an oxidative coupling reaction with.

The azomethine dye is dissolved in a suitable solvent to prepare a metal salt such as Ni acetate, Cu acetate, Ni chloride, C chloride.
The metal complex compound of the present invention can be obtained by adding u or an inorganic salt such as Ni salt of acetylacetone or an organic salt.

The metal complex compound of the present invention can be made into a polymer by introducing a polymerizable substituent, if necessary. In addition, by introducing oil-soluble groups and hydrophilic groups into the structural formula, it is possible to process dye solutions, LB (Langmuir-Blodgett) film formation, dispersion using oil, or various forms such as microcapsules. is there.

The compounds of the present invention may be used alone or in combination, or in combination with other dyes, optical recording media, dyes for fibers,
It can be used for various purposes such as coloring materials for resins and paints, printing inks, color copying machines, color printers, image forming materials for heat-sensitive recording materials, solid-state image pickup tubes and filter dyes for color liquid crystals.

It is possible to further improve the storability by adding various storability improvers to the metal complex compound of the present invention.
For example, ultraviolet absorbers such as benztriazolylphenol derivatives, β-carotene, tocopherol derivatives, hydroquinone derivatives, spiroindane derivatives, phenol derivatives, amine derivatives, thioether derivatives, Ni dithiol derivatives, Ni phenanthroline derivatives, Ni benzylidene aniline derivatives And antioxidants and light stabilizers, and may be added alone or in admixture of two or more.

Next, an optical recording medium using the metal complex compound of the present invention will be described.

As the substrate constituting the optical recording medium of the present invention, the wavelength region of laser light used for recording / reproducing (700 to 900) is used.
(nm) is required to be substantially transparent (transmittance of 80% or more). As for the shape of the substrate, it is 1.2mm thick when used as a normal compact disc.
The diameter is about 80 to 120 mm. Examples of the material forming the substrate include polymethylmethacrylate resin, acrylic resin, polycarbonate resin, epoxy resin, polysulfone resin, transparent resin such as methylpentene polymer, and glass.

If necessary, an oxygen barrier coating may be formed on the outer surface, inner surface and inner / outer peripheral surface of the substrate.

Further, it is preferable that a tracking groove is formed on the substrate on which the recording layer is formed.

The recording layer using the metal complex compound of the present invention has an extinction coefficient k in the wavelength region of laser light that is preferable as a recording layer of an optical recording medium, and has a light absorption property suitable for recording and reproduction. Therefore, it has a suitable reflectance. Here, if the extinction coefficient k of the recording layer in the wavelength region of the laser light is excessively large, the reflectance is lowered, and the reproduction by the reflected light cannot be sufficiently performed. If the extinction coefficient k is too small, it becomes difficult to perform recording with normal recording power. The extinction coefficient k is preferably 0.01 to 0.1.

On the other hand, the refractive index n (real part of complex refractive index) of the recording layer in the wavelength region of laser light is preferably 1.8 to 4.0.

The recording layer constituting the optical recording medium of the present invention contains other kinds of dye compounds, various resins, surfactants, antistatic agents, dispersants, antioxidants, crosslinking agents and the like. May be.

The recording layer may be formed on one surface of the substrate or may be formed on both surfaces of the substrate. Also,
Generally, the thickness of the recording layer is preferably 500 to 3000Å.

The method for forming the recording layer on the substrate is not particularly limited, and examples thereof include spin coating method, dip coating method, spray coating method, blade coating method, roller coating method, bead coating method and Meyer. Coating method,
Various methods such as a curtain coating method can be applied.

The solvent used for forming the recording layer is, for example, a ketone solvent such as cyclohexanone,
Examples thereof include ester solvents such as butyl acetate, ether solvents such as ethyl cellosolve, alcohol solvents, aromatic solvents such as toluene, and alkyl halide solvents.

A reflective layer may be formed on the recording layer. Examples of the reflective layer include Au, Al-Mg alloy, A
It can be formed by means of vapor deposition, sputtering or the like, using a metal having a high reflectance such as 1-Ni alloy, Ag, Pt and Cu. The thickness of the reflective layer is preferably 500Å or more.

A protective film made of, for example, an ultraviolet curable resin may be formed on the reflective layer. The thickness of the protective film is about 0.1 to 100 μm and its hardness is 25
The pencil hardness at C is preferably H to 8H.

An adhesive layer may be provided between the recording layer and the reflective layer to bring them into close contact with each other. The thickness of the adhesive layer is preferably 10-300Å.

Solid-state lasers, gas lasers, dye lasers, and semiconductor lasers are conceivable as light sources for recording and reproducing data on the optical recording medium of the present invention. However, as seen in compact discs, they are inexpensive, compact, and have low power consumption. From the viewpoint, a semiconductor laser is preferable.

Since the compound of the present invention has a particularly high recording sensitivity, a semiconductor laser of 630 nm to 830 nm is suitable.

[0062]

EXAMPLES Synthesis examples of the metal complex compound of the present invention and examples of using the compound of the present invention in an optical recording medium are shown below.
The present invention is not limited to these.

Example 1 Synthesis Example 1 (Synthesis of Exemplified Compound (12)) (Reaction Scheme)

[0064]

[Chemical 15]

80 g of raw material amidine (1) and 40 g of bromacetophenone (2) were dissolved in 100 ml of chloroform and heated under reflux for 2 hours. After washing with water and drying, the solvent was distilled off, and recrystallization from a mixed solvent of ethyl acetate and hexane was carried out to obtain 22 g of the intended intermediate (3). It was confirmed to be the desired product by NMR and MASS spectra. 20 g of intermediate (3) and 20 g of 4- (N, N-diethylamino) -2-methylaniline were dissolved in 200 ml of ethyl acetate. A solution of 40 g of potassium carbonate dissolved in 100 ml of water was added thereto, and then 50 ml of an aqueous solution containing 20 g of ammonium persulfate was added dropwise. After reacting for 1 hour, the precipitated crystals were filtered under reduced pressure, washed with water, washed with methanol and dried to obtain 9 g of the objective dye (4). NMR, MAS
It was confirmed to be the desired product by S spectrum. Dissolve 5 g of dye (4) in 30 ml of methanol, and further dissolve 1.
After adding 7 g of Ni acetate tetrahydrate, another 0.8 g of sodium tetrafluoroborate salt was added. After distilling off the solvent, recrystallization from methanol was performed to obtain 4 g of Exemplified Compound (12) of the target metal complex. From IR and elemental analysis values, it was confirmed to be the target product.

The spectral absorption characteristics of the metal complex compound of the present invention are shown below.

(Spectral Absorption Property) The metal complex compounds (1), (5) and (12) of the present invention and the acetone of the imidazole metal complex dye (A) described in JP-A-7-33746 below for comparison. Table 1 shows the spectral absorption characteristics.

[0068]

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[0069]

[Table 1]

As is clear from Table 1, all of the exemplified compounds of the present invention are excellent dyes having a maximum absorption in a wavelength range more preferable as a cyan dye and a large ε, as compared with the comparison.

Example 2 (Evaluation as an optical recording medium) The absorption maximum in a thin film, light resistance, optical recording characteristics, etc. were evaluated by the following procedure.

(1) Formation of Recording Layer 1 g of each of the exemplified compounds (1), (5) and (12) of the present invention and the following comparative compounds (B) and (C) was weighed, and 50
It was dissolved in ml of cyclohexanone. The coating liquid was applied onto a glass substrate (thickness: 1.1 mm, diameter: 80 mm) by a spin coating method and dried at 80 ° C. for 30 minutes to form a recording layer having a thickness of about 1000 Å on the glass substrate.

[0073]

[Chemical 17]

(2) Light resistance test A xenon fade meter (manufactured by Suga Test Instruments Co., Ltd.) was used to irradiate the recording layer of each sample with xenon light, and the dye residual ratio after irradiation was measured. Here, as the irradiation conditions, the illuminance on the recording layer surface was 70,000 lux, the temperature during irradiation was 43 ° C., and the irradiation time was 30 hours. Further, the dye residual ratio was obtained from the following formula by measuring the light transmittance of the dye at the maximum absorption wavelength before and after irradiation with xenon light.

Formula) Percentage of remaining dye = (100-T) /
(100−T ₀ ) [where, T ₀ represents the transmittance before irradiation with xenon light, and T represents the transmittance after irradiation with xenon light. The results are shown in Table 2.

[0076]

[Table 2]

As is clear from the results in Table 2, sample No. 1 which is a recording medium using the metal complex compound of the present invention. It can be seen that Nos. 1 to 3 have an absorption maximum equivalent to that of the comparative sample 4 using the cyanine dye, and have a higher residual ratio of the dye than the comparative sample, and excellent light resistance.

On the other hand, it is understood that the sample 5 using the metal complex compound different from the present invention has an absorption maximum of too long wavelength and is not suitable as an optical recording medium.

Example 3 (Production and Evaluation of Optical Recording Medium) A recording layer was coated on a polycarbonate substrate with a groove having a diameter of 5 inches by using the metal complex compound (12) of the present invention, and a reflective layer (Au, thickness). 1000Å), protective film (UV curable resin, thickness 5μ
m) were sequentially formed according to a standard method to produce the optical recording medium (6) of the present invention.

For comparison, an optical recording medium (7) was similarly prepared using the comparative compound (B) in the recording layer. When the reflectance was measured, both of the optical recording media (6) and (7) showed 70% or more. 780 nm for these samples
Information is recorded by changing the power with the semiconductor laser of
Regeneration was performed at 0.8 mW. Further, using the xenon fade meter used in Example 2, the same recording / reproducing experiment was conducted after performing light exposure for 70,000 lux for 30 hours.

The results are shown in Table 3.

[0082]

[Table 3]

As is clear from the results, the optical recording medium (6) of the present invention was able to perform good recording / reproducing satisfying the CD standard, and particularly stable recording having excellent light resistance.
It has become clear that it has reproduction characteristics.

On the other hand, in the comparative optical recording medium (7), the reflectance was lowered by the reproduction light of the laser, the reproduction failure was caused, and the phenomenon that the optical recording medium (7) could not be recorded even by the light irradiation by the xenon fade meter was observed.

[0085]

INDUSTRIAL APPLICABILITY The metal complex compound of the present invention is a dye having a high molar extinction coefficient and excellent light resistance, and when these are used in an optical recording medium, they have absorption suitable for the semiconductor laser used. It was possible to perform good recording / reproducing, and particularly stable recording / reproducing characteristics excellent in light resistance were obtained.

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Claims (4)

[Claims] 1. A metal complex compound represented by the following general formula I: Embedded image [In the formula, Y is a heterocyclic group having a nitrogen atom, a sulfur atom or an oxygen atom adjacent to the substitution position, X is a halogen atom,
It represents an alkyl group, an alkoxy group, or an unsubstituted acylamino group. Z represents an aryl group or a heterocyclic group having a substituent selected from the hydroxyl group, amino group, alkylamino group and alkoxy group at the para position. R ₁ , R ₂ , R ₃
And R ₄ each represents a group selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an acylamino group and an alkylsulfonamide group. M ₁ is Ni, Cu, C
It represents a salt of o, Zn, Fe, Pd, and Pt. n represents 2 or 3. ] 2. The metal complex compound according to claim 1, wherein the compound represented by the general formula I is represented by the following general formula II. Embedded image [In the formula, X represents a halogen atom, an alkyl group or an alkoxy group, or an unsubstituted acylamino group. R ₁ ,
R ₂ , R ₃ , R ₄ , R ₈ , R ₉ and R ₁₀ each represent a group selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an acylamino group and an alkylsulfonamide group.
R ₅ , R ₆ and R ₇ each represent a hydrogen atom or an alkyl group. M ₂ represents a salt of Ni or Cu. ] 3. An optical recording medium comprising a substrate and at least one metal complex compound represented by the general formula I or II as a recording layer. 4. The optical recording medium according to claim 3, wherein writing and reading are performed through a substrate by using a semiconductor laser as a light source.