JP2002279637A - Optical recording and reproducing method and optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording and reproducing method of an optical recording medium improved in high-speed recording and a reproducible optical recording medium forming a data pit by the recording and reproducing method. SOLUTION: In the recording and reproducing method, when the thermal decomposition temperature of a recording layer is 400 deg.C or lower and a pit-length-modulated recording mark is to be formed in the recording layer, the shortest signal recording pulse length is changed between at a disk inner peripheral part and an outer peripheral part. In the recording and reproducing method, when the thermal decomposition temperature of the recording layer is 400 deg.C or lower and the pit-length-modulated recording mark is to be formed in the recording layer, the second shortest signal recording pulse length in signals is changed between at the disk inner peripheral part and the outer peripheral part. The optical recording medium forming the data pit by the recording and reproducing method is provided. Recording signals are CD signals, the shortest signal recording pulse (3T pulse) length is turned to (3-X)*231.4 ns and recording is performed. The recording signals are the CD signals, the second shortest signal recording pulse (4T pulse) length of the CD signals is turned to (4-X)*231.4 ns and recording is performed. Provided that 0.25<=0.08*Vw/Vr+X<=1.25 where a recording speed is Vw and the standard playing-back speed (1.2 m/s to 1.4 m/s) of a compact disk is Vr.

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,
The present invention relates to a method for recording and reproducing data on and from an optical recording disk such as a CD-R and a DVD-R, and an optical recording medium therefor.

[0002]

2. Description of the Related Art In recent years, in addition to optical recording media such as read-only CDs (compact disks), recordable CDs have been added.
(CD-R, CD-RW) have been put to practical use. CD-
Unlike conventional CDs, R and CD-RW allow a user to record information, and the signal after recording is a conventional CD.
Satisfies the standard, and can be reproduced on a commercial CD player. One of the methods for realizing such media is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-42 for CD-R.
No. 652 proposes that a dye is spin-coated on a substrate to provide a light absorbing layer, and a metal reflective layer is provided behind the light absorbing layer. On the other hand, as recording drives, recording speed has recently been increased from conventional constant speed (about 1.3 m / s) recording, and higher performance 4 to 12 times speed (about 15.6 times) has been achieved.
m / s) Recording models are prevalent.

[0003] However, the conventional CD-R media, when recorded at a high speed such as 12-times speed, has a higher speed than a constant speed recording.
The signal quality was poor. That is, when recording is performed at a high speed, there is a problem that a characteristic margin with respect to a recording power is narrow, and a reproduction error occurs depending on a combination of a recording device and a reproducing device.

Japanese Patent No. 2858067 discloses (n + P) 23
The EFM signal is recorded on the CD-R with a pulse width of 1.4 ns · Vr / Vw, where n = 3.4.5.6.7.8.9.10.11 -0.5 <P <-0.2,
As the recording speed increases, the pulse width can be shortened.
Japanese Patent Application Laid-Open No. 10-64065 proposes that as the recording speed increases, the value of the bottom power of the recording pulse decreases.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording / reproducing method for an optical recording medium excellent in high-speed recording and a reproducible optical recording medium in which data pits are formed by the recording / reproducing method. is there.

The reason why the margin for the recording power becomes narrow when recording at high speed is presumed to be as follows. That is, when recording is performed at a high speed, the formation speed of the recording pits formed in the light absorbing layer is faster than at a constant speed, the thermal interference before and after the recording pits and adjacent tracks becomes large, and the recording pits have a desired length. It is considered that the signal jitter is increased due to the deviation. In this case, the influence of the thermal interference increases as the recording power increases.
This effect differs between the inner and outer peripheral portions of the medium.
This is because the dye recording layer is generally formed by spin coating. In the spin coating method, it is difficult to control the thickness of the dye and the degree of filling of the dye in the guide groove formed in the substrate, and a difference in the inner and outer circumferences occurs in the state of forming the dye film, thereby changing the influence of thermal interference. Further, the shape of the guide groove formed on the substrate also affects the heat interference. The deeper the groove and / or the narrower the groove, the more easily the effect of preventing thermal interference is obtained, and the influence of thermal interference changes due to the difference between the inner and outer circumferences of the groove shape. Therefore, the present invention solves the above-mentioned problem by adjusting the thermal decomposition characteristics of the recording layer, the difference between the inside and outside of the medium, and the recording pulse pattern to characteristics suitable for high-speed recording conditions.

[0007]

According to the present invention, the above object has been attained by a combination of a recording material having a specific thermal decomposition characteristic and a recording pulse pattern. That is, the invention of the optical recording / reproducing method according to the first aspect of the present invention provides a recording layer made of a dye material having a thermal decomposition temperature of 400 ° C. or less, at least on a substrate having a guide groove on the surface, directly or via another layer. Using a recordable optical recording medium having a reflective layer directly or via another layer on the front side of the recording layer, and irradiating recording light from the back side of the substrate, the pit length on the recording layer An optical recording / reproducing method for forming a modulated recording mark, wherein the shortest signal recording pulse length is changed between an inner peripheral portion and an outer peripheral portion of a disk.

According to a second aspect of the present invention, there is provided an optical recording / reproducing method.
At least a recording layer made of a dye material having a thermal decomposition temperature of 400 ° C. or less, directly or through another layer, on a substrate having a guide groove on the surface, and the recording layer is directly or other layered on the surface side. Using a recordable optical recording medium having a reflective layer through, by irradiating recording light from the back side of the substrate, an optical recording and reproduction method for forming a pit length modulated recording mark on the recording layer, It is characterized in that the signal recording pulse length which is the second shortest in the signal is changed between the inner peripheral portion and the outer peripheral portion of the disk.

According to a third aspect of the present invention, in the optical recording / reproducing method of the first aspect, the recording signal is a CD signal and the shortest signal recording pulse (3T pulse) is recorded as (3-X) * 231.4 ns. It is characterized by the following. However, 0.25 ≦ 0.08 * Vw / Vr + X ≦ 1.25 Vw is the recording speed, Vr is the standard playback speed of a compact disc
(1.2m / s to 1.4m / s).

According to a fourth aspect of the present invention, in the optical recording / reproducing method of the second aspect, the recording signal is a CD signal,
Set the second shortest signal recording pulse (4T pulse) length to (4-X) *
It is recorded as 231.4 ns. However, 0.25 ≦ 0.08 * Vw / Vr + X ≦ 1.25 Vw is the recording speed, Vr is the standard playback speed of a compact disc
(1.2m / s to 1.4m / s).

The invention according to claim 5 is the first or second invention.
In the optical recording / reproducing method, the dye material is a phthalocyanine-based compound represented by the following general formula (1).

[0012]

Embedded image

(Wherein M is a divalent metal atom, monosubstituted 3
A ¹ and A ² , A ³ and A ⁴ , A ⁵ and A ^6, and A ⁷ and A
⁸ , one of each is independently an alkyl group, an alkoxy group, a phenyl group, an alkylthio group,
Or a phenylthio group, and the other represents a halogen, a nitro group, a CN group, or a hydrogen atom. )

According to a sixth aspect of the present invention, in the optical recording / reproducing method according to any one of the first to fifth aspects, the thermal decomposition temperature of the coloring material is not less than 250 ° C. and not more than 400 ° C. I do.

The invention of an optical recording medium according to a seventh aspect is characterized in that data pits are formed by the optical recording / reproducing method according to the first to sixth aspects.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. The optical recording / reproducing method according to the present invention comprises at least a recording layer made of a dye material having a thermal decomposition temperature of 400 ° C. or less, directly or via another layer, on a substrate having a guide groove on the surface. Using a recordable optical recording medium having a reflective layer directly or via another layer on the front side of the substrate, irradiating recording light from the back side of the substrate to form a pit-length modulated recording mark on the recording layer An optical recording / reproducing method according to claim 1, wherein the shortest signal recording pulse length is changed between an inner peripheral portion and an outer peripheral portion of the disk.
The present invention provides the optical recording / reproducing method, wherein the recording signal is a CD.
Signal, and the shortest signal recording pulse (3T pulse) length is (3-
X) * Recorded as 231.4 ns. However, 0.25 ≦ 0.08 * Vw / Vr + X ≦ 1.25, Vw is the recording speed, Vr is the standard playback speed of a compact disc (1.2m / s to 1.4m / s)
It is.

Further, the optical recording / reproducing method according to the present invention is characterized in that at least a recording layer made of a dye material having a thermal decomposition temperature of 400 ° C. or less is provided directly or via another layer on a substrate having a guide groove on the surface. Using a recordable optical recording medium having a reflective layer directly or via another layer on the front side of the recording layer, and irradiating recording light from the back side of the substrate, pit length modulation on the recording layer An optical recording / reproducing method for forming a recorded mark, characterized in that a signal recording pulse length, which is the second shortest in a signal, is changed between an inner peripheral portion and an outer peripheral portion of a disk.

In the above optical recording / reproducing method, the recording signal may be a CD signal, and the recording may be performed with the second shortest signal recording pulse (4T pulse) of the CD signal being (4-X) * 231.4 ns. . However, 0.25 ≦ 0.08 * Vw / Vr + X ≦ 1.25, Vw is the recording speed, Vr is the standard playback speed of the compact disc (1.2m /
s to 1.4 m / s).

In the above optical recording / reproducing method, the dye material may be a phthalocyanine compound represented by the following general formula (1).

[0020]

Embedded image

(Wherein M is a divalent metal atom, monosubstituted 3
A ¹ and A ² , A ³ and A ⁴ , A ⁵ and A ^6, and A ⁷ and A
⁸ , one of each is independently an alkyl group, an alkoxy group, a phenyl group, an alkylthio group,
Or a phenylthio group, and the other represents a halogen, a nitro group, a CN group, or a hydrogen atom. )

In the above optical recording / reproducing method, it is preferable that the thermal decomposition temperature of the coloring material is from 250 ° C. to 400 ° C.

Further, the optical recording medium is characterized in that data pits are formed by the optical recording / reproducing method.

Here, the thermal decomposition temperature of the dye material constituting the recording layer of the optical recording medium in the optical recording / reproducing method is as follows.
This is the calorific value (DSC) change peak temperature or weight change (Tg) start temperature when the temperature is raised at 10 ° C./min with a thermobalance.

When the recording signal is a CD signal, the shortest signal recording pulse (3T pulse) length of the CD signal is preferably in the following condition range. Minimum signal recording pulse (3T pulse) Length = (3-X) * 231.4ns where 0.25 ≤ 0.08 * Vw / Vr + X ≤ 1.25 Vw is the recording speed, Vr is the standard playback speed of a compact disc
(1.2m / s to 1.4m / s). The higher the recording speed and the shorter the recording signal pulse, the more likely thermal interference of the recording pits occurs. Therefore, the shortest 3T pulse length in the EFM which is a CD signal is controlled in accordance with the recording speed. In the above formula, by controlling the recording pulse to be longer as the recording speed is higher, there is an effect of suppressing the spread of the recording pit on the recording film.

Further, the difference between the inside and outside of the disk is adjusted by changing the length of the recording pulse (3T pulse) between the inner and outer circumferences of the disk. 5% change in pulse length
It is preferable that the change in the recording pulse be longer in the outer peripheral portion than in the inner peripheral portion. Generally, in spin coating film formation, the thickness of the dye is more likely to be greater at the outer periphery than at the inner periphery, and the degree of filling of the dye in the guide grooves is also more likely to be buried at the outer periphery. In such a case, the recording pulse length is increased in the outer peripheral portion according to the amount of increase in the dye film thickness.

Further, a similar effect can be obtained by controlling the second shortest signal recording pulse length 4T of the pulse CD signal as follows. Second shortest signal recording pulse (4T pulse) Length = (4-X) *
231.4ns However, 0.25 ≦ 0.08 * Vw / Vr + X ≦ 1.25 Vw is recording speed, Vr is standard playback speed of compact disc
(1.2m / s to 1.4m / s).

Examples of the dye material used in the present invention include cyanine dyes, phthalocyanine dyes, pyrylium / thiopyrylium dyes, azurenium dyes,
Squarylium dyes, metal complex salt dyes such as Ni and Cr, naphthoquinone / anthraquinone dyes, indophenol dyes, indoaniline dyes, triphenylmethane dyes, triallylmethane dyes, aminium / diimmonium dyes and Although a nitroso compound can be mentioned, phthalocyanine of the above general formula (1) is preferable. In the above formula 1, M represents a divalent metal atom, a monosubstituted trivalent metal atom, a disubstituted tetravalent metal atom or an oxymetal;
¹ and A ² , A ³ and A ⁴ , A ⁵ and A ⁶ and A ⁷ and A ⁸ are
One of each independently represents an alkyl group, an alkoxy group, a phenyl group, an alkylthio group, or a phenylthio group, and the other is a halogen, a nitro group,
Represents a CN group or a hydrogen atom.

The phthalocyanine is excellent in durability against light and heat and easily obtains a thermal decomposition temperature of 400 ° C. or less. Further, it is easy to obtain a thermal decomposition temperature of 250 ° C or more and 400 ° C or less. If the thermal decomposition temperature is 400 ° C. or higher, it is difficult to obtain good recording sensitivity under high-speed recording conditions. On the other hand, the thermal decomposition temperature is 250 ℃
In the following, the recording pits are liable to undergo thermal interference, and it is difficult to control the recording pits using the recording pulse pattern.

The specific structure of phthalocyanine is as follows:
Can be mentioned. As the central metal M, a divalent metal: Cu²⁺, Zn²⁺, Fe²⁺, Co²⁺, N
i²⁺, Ru²⁺, Rh²⁺, Pd ²⁺, Pt²⁺, Mn²⁺, Mg
²⁺, Ti²⁺, Be²⁺, Ca²⁺, Ba²⁺, Cd²⁺, H
g ²⁺, Pb²⁺, Sn²⁺Such. Monosubstituted trivalent metal: Al-Cl, Al-Br, Al-F,
Al-I, Ga-Cl, Ga-F, Ga-I, Ga-B
r, In-Cl, In-Br, In-I, In-F, T
l-Cl, Tl-Br, Tl-I, Tl-F, Al-C
₆H_Five, Al-C ₆H_Four(CH_Three), In-C₆H_Five,
In-C₆H_Four(CH_Three), In-C_TenH ₇, Mn (O
H), Mn (OC₆H_Five), Mn (OSi (C
H_Three)_Three), FeCl, RuCl, etc. Disubstituted tetravalent metal: CrCl_Two, SiCl_Two, SiB
r_Two, SiF_Two, SiI_Two, ZrCl_Two, GeCl_Two,
GeBr_Two, GeI_Two, GeF_Two, SnCl_Two, SnB
r_Two, SnI_Two, SnF_Two, TiCl_Two, TiBr_Two,
TiF_Two, Si (OH)_Two, Ge (OH)_Two, Zr (O
H)_Two, Mn (OH)_Two, Sn (OH)_Two, TiR_Two,
CrR_Two, SiR_Two, SnR_Two, GeR_Two[R is alk
Phenyl, naphthyl and its derivatives
], Si (OR ')_Two, Sn (OR ') _Two, Ge (O
R ')_Two, Ti (OR ')_Two, Cr (OR ')_Two[R '
Is an alkyl group, phenyl group, naphthyl group, trialkyl
Silyl group, dialkylalkoxysilyl group and derivatives thereof
Represents the body], Sn (SR ~)_Two, Ge (SR ~)
_Two[R is an alkyl group, a phenyl group, a naphthyl group and
Represents a derivative of). Oxy substitution: VO, MnO, TiO, etc. Among them, one selected from Zn, Ni, Cu, Pd, VO, TiO
Metal atoms or metal oxides are preferred. Conversion of these M
The compound is easy to manufacture and has good light absorption properties.
I do. As the substituents A1 to A8, straight-chain having 1 to 10 carbon atoms
Chain, branched or cyclic alkyl or alkoxy group
Or an alkylthio group, an aryl group having 6 to 20 carbon atoms,
Reeloxy group or arylthio group, halogen source
Preferred is a nitro group, a nitro group, a CN group or a hydrogen atom.

Specific examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, an n-butyl group, an iso-butyl group, a tert-butyl group and a sec-butyl group.
Butyl group, n-pentyl group, iso-pentyl group, ne
o-pentyl group, 1-methylbutyl group, 2-methylbutyl group, n-hexyl group, 2-ethylbutyl group, 3-methylpentyl group, 2,3-dimethylbutyl group, n-heptyl group, n-octyl group, 2 -Ethylhexyl group, n-nonyl group, 2,5,5-trimethylhexyl group, n-decyl group, 4-ethyloctyl group, 4-ethyl-4,5 dimethylhexyl group, n-undecyl group, n-dodecyl group ,
1,3,5,7-tetramethyloctyl group, 4-butyloctyl group, 6,6-diethyloctyl group, n-tridecyl group, 6-methyl-4-butyloctyl group, n-tetradecyl group, n-pentadecyl Group, cyclohexyl group,
An adamantyl group, a norbornyl group, a 2-chlorobutyl group and the like can be mentioned.

Specific examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a propyloxy group,
iso-propyloxy group, n-butyloxy group, is
o-butyloxy group, tert-butyloxy group, se
c-butyloxy group, n-pentyloxy group, neo-
Pentyloxy group, iso-pentyloxy group, ter
t-pentyloxy group, 1-methylbutyloxy group, 2
-Methylbutyloxy group, n-hexyloxy group, cyclohexyloxy group, adamantyloxy group, norbornyloxy group, 2-chlorobutyloxy group and the like.

Specific examples of the alkylthio group having 1 to 10 carbon atoms include methylthio, ethylthio, n-propylthio, iso-propylthio, n-butylthio,
iso-butylthio group, tert-butylthio group, se
c-butylthio group, n-pentylthio group, iso-pentylthio group, neo-pentylthio group, 1,2-dimethylpropylthio group, n-hexylthio group, 1-ethyl-
2-methylpropylthio group, 2-ethylbutylthio group,
Cyclohexylthio, 2-methyl-1-iso-propylthio, n-heptylthio, 2-methylhexylthio, 1-ethylpentylthio, n-octylthio, 2-ethylhexylthio, 3-methyl-1 −is
o-propylbutylthio group, n-nonylthio group, 3-methyl-1-iso-butylbutylthio group, 3,5,5-
Trimethylhexylthio group, 2-chlorobutylthio group,
4-tert-butylcyclohexylthio group and the like.

Specific examples of the aryl group having 6 to 20 carbon atoms include phenyl, 2-methylphenyl, 2,4-dimethylphenyl, 2,4,6-trimethylphenyl, and 2-iso-propylphenyl. Group, 4-bromophenyl group, 2,6-dichlorophenyl group, naphthyl group, and the like. Specific examples of the aryloxy group having 6 to 20 carbon atoms include a phenoxy group, a 2-methylphenoxy group,
2,4-dimethylphenoxy group, 2,4,6-trimethylphenoxy group, 2-iso-propylphenoxy group,
A 4-bromophenoxy group, a 2,6-dichlorophenoxy group, a naphthyloxy group and the like;
Specific examples of the arylthio group of 20 include a phenylthio group, a 2-methylphenylthio group, a 2,4-dimethylphenylthio group, a 2,4,6-trimethylphenylthio group,
Examples thereof include a 2-iso-propylphenylthio group, a 4-bromophenylthio group, a 2,6-dichlorophenylthio group, and a naphthylthio group.

Specific examples of the halogen atom include F and C
l, Br and I atoms.

Among the above substituents, particularly preferred are linear or branched alkyl, alkoxy, and alkylthio groups having 4 to 10 carbon atoms, and aryloxy and arylthio groups having 6 to 15 carbon atoms. . Compounds having these groups have excellent solubility and are easy to apply and form. On the other hand, if the number of carbon atoms is larger than these, the absorbance per unit film of the light absorbing layer decreases, and it becomes difficult to obtain appropriate optical characteristics (complex refractive index), which is not preferable.

Other groups may be added to A ^{1 to} A ⁸ for reasons such as improving the recording sensitivity, adjusting the absorption wavelength of the light absorbing layer, and improving the solubility in the coating solvent. ,
Examples of such a group include a sulfonic acid group, a sulfonic acid amine, a carboxyl group, an amide group, and an imide group. Further, the most preferable structures of A ^{1 to} A ⁸ are the following groups. A ¹ and A ^2, A ³ and A ^4, A ⁵ and A ⁶ and A ⁷ and A ^8:
One of each is independently -OC (
R ¹ ) (R ³ ) -R ² , and the other is a hydrogen atom. R ¹ and R ³ are an alkyl group, a fluorine-substituted alkyl group or a hydrogen atom. R ^{2 is} an alkyl group, a substituted phenyl group or an unsubstituted phenyl group. Specific examples of R ¹ and R ³ include methyl, ethyl, propyl, isopropyl, n-propyl, butyl, n-butyl, sec-butyl, tert-butyl, -CF ₃ , —C ₂ F ₅ , —CF (CF ₃ ) ₂ and a hydrogen atom.

In particular, it is preferred that both the substituents R ¹ and R ³ are —CF ₃ . The use of _three CFs lowers the thermal decomposition temperature (T2) and improves the recording sensitivity and jitter characteristics. Specific examples of R ² include a phenyl group, a naphthyl group, a 2-methylphenyl group, a 2.4-dimethylphenyl group, a 2.4.6-trimethylphenyl group, a 2-isopropylphenyl group, a 2.5-dimethylphenyl group, and a 2.6-dimethylphenyl group. Group, 2-ethylphenyl group and the like. The alkyl group provided to the phenyl group preferably has 1 to 4 carbon atoms. If the number of carbon atoms is larger than this, the absorbance per unit film thickness of the light absorbing layer tends to decrease, and it becomes difficult to obtain a favorable complex refractive index.

The phthalocyanine compound represented by the general formula (1) can be easily synthesized by a cyclization reaction of the corresponding phthalonitrile mixture. That is, phthalonitrile of the general formula (2) can be easily synthesized by reacting a metal derivative with an alcohol in the presence of, for example, 1,8-diazabicyclo [5,4,0] -7-undecene.

[0040]

Embedded image

Recording layer comprising the phthalocyanine compound
Dissolves the compound in a solvent and coats it on the substrate as a coating solution.
Can be obtained easily by Furthermore, the central metal M is
Fe ²⁺, Co²⁺, Zn²⁺, Cd²⁺, Mn²⁺If it is
It is preferable to add an amino compound.

When M is one of these metals, the amino compound is easily coordinated with M, and the coordination results in solubility in a solvent,
This is because the coating film forming property is improved. Examples of the amino compound include, but are not limited to, the following compounds.

Amino compounds: n-butylamine, n-hexylamine, tert-butylamine, pyrrole, pyrrolidine, pyridine, piperidine, purine, imidazole, benzimidazole, 5,6-dimethylbenzimidazole, 2,5,6-trimethylbenz Imidazole, naphthoimidazole, 2-methylnaphthoimidazole, quinoline, isoquinoline, quinoxaline, benzquinoline, phenanthridine, indoline, carbazole, norharman, thiazole, benzthiazole, benzoxazole, benztriazole, 7-azaindole, tetrahydroquinoline, tri Phenylimidazole, phthalimide, benzoisoquinoline-5,10-
Dione, triazine, perimidine, 5-chlorotriazole, ethylenediamine, azobenzene, trimethylamine, N, N-dimethylformamide, 1 (2H) phthalazinone, phthalhydrazide, 1,3-diiminoisoindoline, oxazole, polyimidazole, polybenzimidazole , Polythiazole and the like.

Among these, the effect of preventing the association of the phthalocyanine compound is high, and the durability (heat resistance, light resistance) is high.
In view of the fact that the compound is excellent in the above, a compound containing an N atom in a heterocyclic ring is preferable. Further, from the viewpoint of maintaining the thermal stability of the light absorbing layer, the amino compound preferably has a melting point of 150 ° C. or higher. When the melting point is lower than 150 ° C., the characteristics (particularly, optical characteristics) of the light absorbing layer under a high temperature and high humidity environment
Is likely to change. Among them, particularly preferred is
Imidazole, benzimidazole and thiazole derivatives.

As the organic dye material, the general formula (1)
In addition to the phthalocyanine-based compound represented by the formula, other third components such as a binder and a stabilizer can be contained as necessary. The thickness of the light absorbing layer is 10
It is preferably from 0 to 5000 °, more preferably from 500 to 3000 °. This is because if the thickness of the light absorbing layer is smaller than this range, the recording sensitivity is reduced, and if the thickness is larger, the reflectance is reduced.

The substrate used in the present invention can be arbitrarily selected from various materials used as substrates for conventional information recording media. Examples of substrate materials include:
Examples include acrylic resins such as polymethyl methacrylate, polyvinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer, epoxy resins, polycarbonate resins, amorphous polyolefins, polyesters, glasses such as soda-lime glass, and ceramics. In particular, polymethyl methacrylate, polycarbonate resin, epoxy resin, amorphous polyolefin, polyester, glass, and the like are preferable in terms of dimensional stability, transparency, and planarity.

On the substrate surface on the side where the light absorbing layer is provided,
Improvement of flatness, improvement of adhesive strength and prevention of deterioration of light absorption layer
An undercoat layer may be provided for the purpose of. With the material of the undercoat layer
For example, polymethyl methacrylate, acrylic
Acid / methacrylic acid copolymer, styrene / maleic anhydride
Copolymer, polyvinyl alcohol, N-methylol
Rilamide, styrene / sulfonic acid copolymer, styrene
/ Vinyltoluene copolymer, chlorosulfonated polyethylene
Ren, nitrocellulose, polyvinyl chloride, chlorinated poly
Olefin, polyester, polyimide, vinyl acetate /
Vinyl chloride copolymer, ethylene / vinyl acetate copolymer,
Polyethylene, polypropylene, polycarbonate, etc.
Polymeric substances: Organic substances such as silane coupling agents:
And inorganic oxides (SiO_Two, Al_TwoO_ThreeEtc.), inorganic fluorination
Object (MgF _TwoAnd the like.
The thickness of the undercoat layer is generally in the range of 0.005 to 20 μm.
And preferably in the range of 0.01 to 10 μm.
You.

Further, a reflective layer is provided on the light absorbing layer for the purpose of improving the S / N ratio, the reflectance, and the sensitivity during recording. The light-reflective substance that is the material of the reflection layer is a substance having a high reflectance to laser light, and examples thereof include Mg, Se, Y, Ti, Zr, Hf, V, Nb,
Ta, Cr, Mo, W, Mn, Re, Fe, Co, N
i, Ru, Rh, Pd, Ir, Pt, Cu, Ag, A
u, Zn, Cd, Al, Ca, In, Si, Ge, T
Metals and semimetals such as e, Pb, Po, Sn, and Si can be mentioned. Of these, preferred is A
u, Al and Ag. These substances may be used alone or in combination of two or more kinds or as an alloy. The thickness of the reflective layer is generally 100 to 30.
It is in the range of $ 00.

On the light absorbing layer (or reflecting layer),
A protective layer may be provided for the purpose of physically and chemically protecting the light absorbing layer and the like. This protective layer may be provided on the side of the substrate where the light absorbing layer is not provided, for the purpose of improving the scratch resistance and the moisture resistance. Examples of the material used for the protective layer include inorganic substances such as Si, O, SiO ₂ , MgF ₂ , and SnO ₂ , thermoplastic resins, thermosetting resins, and UV curable resins. The thickness of the protective layer is generally in the range of 500 ° to 50 μm.

Next, a method for manufacturing the optical recording medium of the present invention will be described. The manufacturing method of the optical recording medium of the present invention, on a substrate having a guide groove formed on the surface thereof, a recording layer containing an organic dye material as a main component directly or through another layer provided by a coating film forming means, A light reflection layer is provided thereon by a vacuum film forming means directly or via another layer, and a protective layer is further provided thereon. That is, the production method of the present invention includes the following steps. (A) a step of providing a recording layer containing an organic dye material as a main component directly or through another layer on a substrate having a guide groove formed on a surface thereof by a coating film forming means; A step of providing a light reflecting layer by vacuum film forming means directly or via another layer; and (c) a step of providing a protective layer on the light absorbing layer.

(Recording Layer Forming Step) In the method of the present invention, first, a recording layer mainly composed of an organic dye material is formed on a substrate having a guide groove formed on its surface, directly or through another layer. It is provided by a coating film forming means. That is, a recording layer is formed by dissolving an organic dye material having a thermal decomposition property in a solvent and coating it on a substrate as a liquid coating solution. As a solvent for preparing this coating liquid, a known organic solvent (for example, alcohol, cellosolve, halogenated carbon, ketone, ether, etc.) can be used. Further, as a coating method, a spin coating method is preferable because the layer thickness can be controlled by adjusting the concentration, viscosity and drying temperature of the solvent of the light absorbing layer.

The provision of an undercoat layer on the surface of the substrate on which the recording layer is provided is performed for the purpose of improving the flatness of the substrate surface, improving the adhesive strength, preventing the recording layer from being altered, and the like. In this case, the undercoat layer is prepared, for example, by dissolving or dispersing the aforementioned undercoat layer material in an appropriate solvent to prepare a coating solution, and then applying the coating solution by spin coating, dip coating, extrusion coating, or the like. It can be formed by applying to the substrate surface by a method.

(Light Reflecting Layer Forming Step) In the method of the present invention, a light reflecting layer is then provided on the recording layer directly or via another layer by vacuum film forming means. That is, the light reflecting layer is formed on the recording layer by, for example, vapor deposition, sputtering, or ion plating of the light reflecting substance described above.

(Protective Layer Forming Step) In the method of the present invention, a protective layer is provided on the light reflecting layer. That is, the protective layer material is formed by vacuum film formation or coating film formation of the above-mentioned material for the protective layer made of the above-mentioned inorganic substance and various resins. In particular, UV
It is preferable to use a curable resin, and the resin is formed by spin-coating and then curing the resin by irradiation with ultraviolet rays.

(Examples) Hereinafter, the present invention will be described based on examples, but the present invention is not limited to these examples.

(Example 1) Diameter 120 mm, thickness 1.2 mm
Prepare a substrate with a depth of about 1500 mm, a track pitch of 1.6 μm, and a 1.2 m / s reproduction linear velocity / guide groove uneven pattern on the surface of a polycarbonate disk.
The recording material was provided by dissolving the material of the dye material (phthalocyanine) (A) in Table 1 in a mixed solvent of tetrahydrofuran, 2-methoxyethanol and methylcyclohexane and spin-coating as a coating solution. The thickness of the light-absorbing layer is as follows: disc radius = 25 mm approx. 1500 A, disc radius = 55 mm approx. 16
It was 50A. The thermal decomposition temperature of A by a thermobalance is 250
° C.

Next, Ag was applied to a thickness of about 1400 ° on the recording layer by sputtering using Ar as a sputtering gas to form a reflective layer. Furthermore, an ultraviolet curable resin (SD1700
An optical recording medium (1) of the present invention was obtained by providing a protective layer made of Dainippon Ink) at a thickness of about 5 μm.

Using a signal evaluation device (DUU Pulstec Co.), this medium was used at a wavelength of 790 nm, NA of 0.5, and a linear velocity of 14.4 m / s.
The audio data EFM signal was recorded and reproduced under the following conditions, and the jitter was measured with a jitter meter (LJM-1851 LEADER). EFM recording signal pulse is (nX) * 231.4ns,
n is the signal pattern (T) 3.4.5.6.7.8.9.10.11, and the disc radius: X = 0 for 25 to 50 mm, and X = -0.5 for 50 to 58 mm.

The results are as shown in Table 2. Good characteristics satisfying the standard value (35 ns or less) were obtained at β = 4%.
The recording laser power at 25 mm was 19.3 mW.
Further, this optical recording medium could be reproduced by a commercially available CD player.

Example 2 A recording medium (2) of the present invention was prepared in the same manner as in Example 1 except that the dye material (A) in Table 1 was changed to the dye material (B). ) created.
The thermal decomposition temperature of (B) was 340 ° C. For these, the recording characteristics were evaluated in the same manner as in Example 1. The results of the jitter characteristics are shown in Table 2, and good characteristics satisfying the standard values were obtained as in Example 1. In addition, commercial CD
Playback on the player was possible.

(Examples 3 to 10) In Example 1, the jitter margin with respect to the recording power was measured by changing the recording linear velocity and the X of the EFM recording signal pulse as shown in Table 3.
The results are shown in FIGS.

(Comparative Examples 1 and 2) In Example 1, the jitter margin with respect to the recording power was measured by changing the recording linear velocity and the X of the EFM recording signal pulse as shown in Table 3.
The results are shown in FIGS. In Examples 1 to 10 and Comparative Examples 1 and 2, as can be seen from FIGS. 1 to 4, under the recording pulse conditions of claims 3 and 4, good jitter was obtained over a wide β range. Other than pulse conditions,
The good jitter range was significantly narrowed.

(Comparative Example 3) In Example 1, the recording pulse length was not changed between the inner and outer peripheral portions of the disk.
5858 mm was recorded as X = 0. The results are as shown in Table 2, and the standard value (35 ns or less) could not be satisfied at the outer peripheral portion (55 mm).

Comparative Example 4 In Example 1, Solvent Blue (Cu phthalocyanine dye) was used as an organic dye material.
Was prepared in the same manner as in Example 1 except that 2.2.3.3.- was spin-coated with tetrafluoropropanol. The thermal decomposition temperature of this dye was 450 ° C. or higher. This medium was evaluated in the same manner as in Example 1, but recording could not be performed with a laser power of 25 mW or less due to insufficient sensitivity.

(Experimental Example 1 (Comparative Example)) In Example 1, except that the dye material (A) was changed to the dye material (C),
A recording medium of the present invention was prepared in the same manner as in Example 1.
The thermal decomposition temperature of (C) was 190 ° C. For these, the recording characteristics were evaluated in the same manner as in Example 1. The results of jitter characteristics are shown in Table 2, and the standard values could not be satisfied.

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

[Table 3]

[0069]

According to the recording / reproducing method for an optical information recording medium of the present invention, the thermal decomposition temperature of the recording layer is 400 ° C. or less,
When forming a recording mark with pit length modulation on the recording layer,
Since the shortest signal recording pulse length is changed between the inner and outer peripheral portions of the disc to record with the shortest signal recording pulse suitable for the thermal decomposition characteristics of the recording layer, good recording / reproducing signal characteristics can be obtained even under high-speed recording conditions. .

In the recording / reproducing method for the optical information recording medium according to the present invention, the thermal decomposition temperature of the recording layer is 400 ° C. or less, and when forming a pit-length modulated recording mark on the recording layer, the second shortest signal in the signal is used. Since the signal recording pulse length is changed at the inner and outer peripheral portions of the disc and recording is performed with a recording pulse suitable for the thermal decomposition characteristics of the recording layer, good recording and reproducing signal characteristics can be obtained even under high-speed recording conditions.

Further, since the optical information recording medium of the present invention is recorded with a recording signal pulse suitable for the thermal decomposition characteristics, it is possible to form data pits which can be reproduced under high-speed recording conditions. Therefore, a recorded disk can be manufactured quickly and easily.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a relationship between a β range and jitter in Examples 3 and 4.

FIG. 2 is a diagram illustrating a relationship between a β range and jitter in Examples 5 and 6.

FIG. 3 is a diagram illustrating a relationship between a β range and jitter in Examples 7 and 8 and Comparative Example 1.

FIG. 4 is a diagram showing a relationship between β range and jitter in Examples 9 and 10 and Comparative Example 2.

Claims (7)

[Claims] 1. A thermal decomposition temperature of at least 400 ° C., directly or through another layer, on a substrate having a guide groove on the surface.
Using a recordable optical recording medium having a recording layer made of the following dye material and having a reflective layer directly or via another layer on the front side of the recording layer, irradiating recording light from the back side of the substrate. An optical recording / reproducing method for forming a pit-length-modulated recording mark on a recording layer, wherein the shortest signal recording pulse length is changed between an inner peripheral portion and an outer peripheral portion of the disk. 2. Thermal decomposition temperature of at least 400 ° C., directly or via another layer, on a substrate having a guide groove on the surface.
Using a recordable optical recording medium having a recording layer made of the following dye material and having a reflective layer directly or via another layer on the front side of the recording layer, irradiating recording light from the back side of the substrate. An optical recording and reproducing method for forming a pit-length-modulated recording mark on a recording layer, wherein a signal recording pulse length, which is the second shortest in a signal, is changed between an inner peripheral portion and an outer peripheral portion of a disc. Recording and playback method. 3. The optical recording / reproducing method according to claim 1, wherein the recording signal is a CD signal, and the shortest signal recording pulse (3T pulse) is recorded as (3-X) * 231.4 ns. However, 0.25 ≦ 0.08 * Vw / Vr + X ≦ 1.25 Vw is the recording speed, Vr is the standard playback speed of a compact disc
(1.2m / s to 1.4m / s). 4. The recording signal is a CD signal, and the second shortest signal recording pulse (4T pulse) of the CD signal is (4-X) * 231.
The optical recording / reproducing method according to claim 2, wherein recording is performed at 4 ns. However, 0.25 ≦ 0.08 * Vw / Vr + X ≦ 1.25 Vw is the recording speed, Vr is the standard playback speed of a compact disc
(1.2m / s to 1.4m / s). 5. The optical recording / reproducing method according to claim 1, wherein the dye material is a phthalocyanine compound represented by the following general formula (1). Embedded image (Wherein M is a divalent metal atom, a monosubstituted trivalent metal atom,
Represents a disubstituted tetravalent metal atom or an oxymetal, and A ¹ and A ² , A ³ and A ⁴ , A ⁵ and A ^6, and A ⁷ and A ⁸ are each independently an alkyl group, Represents an alkoxy group, a phenyl group, an alkylthio group, or a phenylthio group, the other being a halogen, a nitro group, a CN group,
Or represents a hydrogen atom. ) 6. The optical recording / reproducing method according to claim 1, wherein a thermal decomposition temperature of the coloring material is 250 ° C. or more and 400 ° C. or less. 7. The optical recording / reproducing method according to claim 1,
An optical recording medium characterized by forming data pits.