JPH0287341A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To obtain the reproduction signal having the high modulation degree complying with the format of a compact disk CD by specifying the thermal deformation temp. of an intermediate layer 6 to be interposed between a light absorption layer 2 contg. a material which causes heat generation and pressure increase when subjected to irradiation of light and a light transparent substrate 1. CONSTITUTION:The light absorption layer 2 generates heat by absorbing the laser light and causes melting, evaporating, sublimating, reacting, decomposing or modifying when the absorption layer 2 is irradiated with the laser light. The local energy conversion by the heat and pressure increase is then executed. The thermal deformation temp. of the intermediate layer 6 interposed between the light transparent substrate 1 and the absorption layer 2 is in a 50 to 150 deg.C range under ASTM D649 4.6kg/cm<2> and, therefore, the energy generated in the absorption layer 2 is absorbed by the local deformation on the surface of the intermediate layer 6. The pits 5 by the deformation are, therefore, formed on the layer 6. The reproduction signal of the large modulation degree complying with the CD format is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical information recording medium that is irradiated with a laser beam and reproduces recorded data using the reflected light.

[Prior Art] Optical information recording media on which data can be recorded by irradiation with laser light include gold 1i [such as Te1 BiX Mn].
A recording layer consisting of a pigment layer such as cyanine, merocyanine, phthalocyanine, etc. is formed, and bits are formed by deforming, sublimating, evaporating, or denaturing the recording layer by irradiation with laser light. Record. In optical information recording media having such a recording layer, a void is generally provided behind the recording layer in order to facilitate deformation, sublimation, evaporation, denaturation, etc. of the recording layer when forming bits. ing. Specifically, for example, a stacked structure called an air sandwich t+'4 iM, in which two substrates are stacked with a space between them, is used.

In this optical information recording medium, bits are formed by irradiating laser light from the side of the transparent substrate l. When reproducing the recorded data, a laser beam with a lower power than during recording is irradiated from the substrate 1 side, and the signal is read based on the difference in reflected light between the bit and other parts.

On the other hand, so-called ROM type optical information recording media, on which data is recorded in advance and cannot be subsequently written or erased, have already been widely put into practical use in the information processing and audio sectors. This type of optical information recording medium does not have a recording layer as described above, but bits for reproducing recorded data are formed in advance on a polycarbonate substrate by means such as pressing, and Auz Ags Cu A reflective layer made of gold BH such as A1 is formed, and this is further covered with a protective layer.

The most typical ROMIJA optical information recording medium is the compact disc, or so-called CD, which is widely used in the audio and information processing sectors.The specifications of the recording and playback signals of this CD are the so-called CD format. A playback device that is standardized and conforms to this standard is extremely widely used as a compact disc player (CD player).

[Problems to be Solved by the Invention] Since the above-mentioned optical information recording medium is a recording and reproducing means that uses the same laser beam as a CD, it must be possible to reproduce it with a CD player whose reproduction device is already widely used, that is, the CD format. Compliance with the above is strongly (desired).

However, the above-mentioned optical information recording medium has a recording layer that is not present in a CD, and means to form and record bits on this recording layer instead of on the substrate. Furthermore, since the recording layer has voids and the like to facilitate the formation of bits, the reproduced signal naturally differs from that of a CD. For this reason, the above-mentioned CD, which has established standards for so-called CDs,
It was difficult to satisfy the format. especially,
Currently, due to the low degree of modulation of the reproduced signal, it is not possible to obtain a reproduced signal conforming to the CD format.

The present invention has been made to solve the above-mentioned conventional problems, and its purpose is to provide a writable optical information recording medium that can obtain a reproduced signal with a high degree of modulation that complies with the CD format. .

[Means for Solving the Problems] That is, the gist of the first means adopted in the present invention in order to achieve the above object is to absorb laser light through another layer on the transparent substrate l. The light absorption layer 2 and the light absorption layer 2
In an optical information recording medium having a light reflecting layer 3 that reflects laser light provided directly or through another layer thereon, the light absorbing layer 2 is made of a material that generates heat and increases pressure when irradiated with laser light. This light absorption layer 2 and a transparent substrate l
an intermediate layer 6 is interposed between the
This is an optical information recording medium characterized by a temperature of 150°C.

The gist of the second means is that a light absorption layer 2 that absorbs laser light is provided on a transparent substrate 1 via another layer, and a light absorption layer 2 is provided on the light absorption layer 2 directly or via another layer. In an optical information recording medium that has a light-reflecting layer 3 that reflects laser light, the light-absorbing layer 2 contains a material that generates heat and increases pressure when irradiated with laser light, and the light-absorbing layer 2 and the light-transmitting This optical information recording medium is characterized in that an intermediate layer 6 is interposed between the optical information recording medium and the magnetic substrate 1, and the intermediate layer 6 has a Rockwell hardness of M100 to 50 according to ASTM D758.

The gist of the third means is that a light absorption layer 2 that absorbs laser light is provided on a transparent substrate l, and a light absorption layer 2 that is provided on the light absorption layer 2 directly or through another layer reflects the laser light. In an optical information recording medium having a light reflecting layer 3, the light absorbing layer 2 contains a material that generates heat and increases pressure upon irradiation with a laser beam,
An intermediate layer 6 is interposed between the light absorption layer 2 and the light reflection layer 3, and the heat deformation temperature of the intermediate layer 6 meets ASTM D64.
8 4.6Kg/cm2, 50-150°C, and Rockwell hardness is M100 according to ASTM D758.
It is an optical/oral recording medium in the range of ~50.

[Function] In the above optical information recording medium, when the light absorption layer 2 is irradiated with laser light, the light absorption layer 2 absorbs the laser light and generates heat,
Through melting, evaporation, sublimation, reaction, decomposition, or denaturation, local energy conversion occurs as heat and pressure increase. The heat distortion temperature of the interposed intermediate layer 6 is ASTM D648.
4.6Kg/cm2 in the range of 50-150°C,
Or Rockwell hardness is M according to ASTM D758.
Since it is in the range of 100 to 50, the energy generated in the light absorption layer 2 is absorbed by local deformation of the surface of the intermediate layer 6. Therefore, the bit 5 is formed in the same layer 6 by the above deformation.

In this way, the bits 5 formed in the intermediate layer 6 are formed in the recording layer by means such as perforations, and are similar to the bits previously formed on the surface layer of the transparent substrate by means such as pressing. It is something to do. Further, another layer, for example, a light reflecting layer 3 made of a Kanazawa layer, can be provided behind the light absorbing layer 2. Therefore, an optical information recording medium similar in form to a CD can be obtained, and a recordable optical information recording medium conforming to the CD format can be easily obtained.

Here, the reason why the heat deformation temperature or hardness of the intermediate layer 6 is limited to the above range is as follows.

That is, when the thermal deformation temperature of the intermediate layer is less than the above range, the bits 5 that have been formed are easily deformed by the heat received thereafter, resulting in poor stability of recorded data. Moreover, when the thermal deformation temperature of the intermediate layer 6 exceeds the above range, it is difficult to absorb the energy generated in the light absorption layer 2 in the form of deformation of the intermediate layer 6, so that the clear bit 5
cannot be formed, and a reproduced signal with a large degree of modulation cannot be obtained.

The same goes for the hardness; if the hardness of the intermediate layer 6 is less than the above range, the once-formed bit 5 will be easily deformed by a small external force, resulting in poor stability of recorded data. Further, when the hardness of the intermediate layer 6 exceeds the above range, it is difficult to absorb the energy generated in the light absorption layer 2 in the form of deformation of the intermediate layer 6, so that the clear bit 5
cannot be formed, and the reproduced signal with a large degree of modulation becomes i! I can't get 1.

[Example] Next, see the drawings! ! ? ! From now on, embodiments of the present invention will be described in detail.

A typical example of the ()η structure of the optical information recording medium according to the present invention is shown in FIGS. 1 to 3. In the figure, ``■'' is a transparent substrate, 6 is an intermediate layer made of resin or the like formed thereon, 2 is a light absorption layer further formed thereon, 11. ? This layer absorbs the emitted laser beam, generates heat, melts, evaporates, sublimates, deforms or denatures, locally deforms the intermediate layer 6, and forms a bit.

As already mentioned, in the present invention, the heat distortion temperature of the intermediate layer 6 is in accordance with ASTM D648 4°6Kg/cm2.
50~150°C1 or O-7 hardness is AST
It is necessary to have an MD of 758 and a range of M100 to 50. On the other hand, the back side of the light absorbing layer 2, for example, the protective layer 4, preferably has a higher thermal deformation temperature and higher hardness than the intermediate layer 6. Reference numeral 3 indicates a light reflection layer formed on the light absorption layer 2 to reflect laser light, and reference numeral 4 indicates a protective layer provided outside of the light reflection layer.

Note that FIGS. 2 and 4 show the state before recording with laser light, and FIGS. 3 and 5 show the state after recording, that is, the local state of the light absorption layer 2 when irradiated with laser light. A state in which the intermediate B6 is partially deformed due to thermal deformation and a bit 5 is formed is schematically shown. FIG. 3 shows a state in which deformation due to heat generation and pressure increase in the light absorption layer 2 due to j1rA laser beam irradiation substantially only affects the intermediate layer 6, and hardly affects the transparent substrate 1. ing. On the other hand, FIG. 5 shows a case where the deformation extends not only to the intermediate layer 6 but also to the transparent substrate I, and the bit 5 is formed from the intermediate layer 6 to the transparent substrate I. Generally, when the intermediate layer is thin, such as 30 nm or less, the heat distortion temperature of the transparent substrate 1 is 85 to 200°C at ASTM D648 4.6 kg/cm2, and the Rockwell hardness is ASTM D
758 and about M2O0-75, bit 5 like the latter is formed.

In the present invention, the bit 5 may be formed in either of the forms shown in FIG. 3 and FIG. 5.

A specific example of this optical information recording medium will be described below.

(The translucent substrate l in this example was formed using an injection molding method and had a diameter of 46 to 117 mmφ, and a width of 0°8 u rrh.
Depth 0.08 μl Th Thickness 1, 2 mm 5 with spiral pre-groove 8 with pitch 1.6 μm
A polycarbonate disk (manufactured by Teijin Kasei, trade name: Panlite) with an outer diameter of 120 mmφ and an inner diameter of 15 mmφ was used. The Rockwell hardness ASTM of this polycarbonate substrate 1 is D785 and M75, and it is not subject to thermal deformation. Temperature AS
TM is D648, 4. 135 at 6kg/cm2
It is °C.

On this transparent substrate l, an acrylic resin is formed as an intermediate layer 6 to a thickness of 70 nm using a spin cord, and on top of this, Ff [1 of 65 g of N O as 1 dye] is added to form a light absorbing IVJ2. .1' dipropyl3. 3.
3', 3' tetramethyl 5°5' dimethoxy indodicarbocyanine iodide was dissolved in 10 cc of diacetone alcohol solvent, and this was applied to the surface of the above substrate 1 by a spin coating method to a film thickness of 90 nm. A light absorption layer 2 was formed. Heat distortion temperature AST of the intermediate layer 6
M is D 648.4. 6kg/cm2
At 100°C1 Rockwell hardness ASTM D78
5 is MB2.

Next, silicon acrylic resin is formed on the light absorption layer 2 with a thickness of 50 nm using a spin cord, and then an Au film with a thickness of 50 nm is formed on the entire surface of the disk with a diameter of 45 to 118 mmφ by a sputtering method. Then, a light reflecting layer 3 was formed.

Furthermore, this light reflection F! Apply ultraviolet curable (M resin) on top of I3, irradiate it with ultraviolet rays and cure it.
A protective layer 4 having a thickness of 10 μm was formed.

The thus obtained optical disk was coated with a semiconductor with a wavelength of 780 nm and a linear velocity of 1.2 m/5ees, recording power of 6,
It was irradiated with OmW and the EFM signal was recorded. This optical disc is then inserted into a commercially available CD player (Aurex).
When reproducing with XR-V73 (reproduction light wavelength λ = 780 nm), Iz/ obtained from the eye pattern of the reproduced signal
1. , was 0.63, and I3/Lo was 0.32.

In the CD standard, I++/It. . is 0.6 or more, ■3/
Itap is defined as 0.3 to 0.6, and the optical disc according to this embodiment satisfies this standard.

Furthermore, when the protective layer 4, light reflective layer 3 and light absorbing layer 2 of the optical disc after recording were peeled off and the surface of the intermediate lff 16 was observed, it was confirmed that a recessed bit 5 was formed there. Ta.

(Example 2) In the above Example 1, the intermediate layer 6 has a heat distortion temperature of A
STM D648 is 4.6kg/cm2 and 80°C%
C' Tsukwell hardness ASTM is D785 and M95
An optical disc was manufactured in the same manner as in Example 1 above, except that it was formed to a thickness of 60 nm using a vinyl chloride copolymer.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1, and then this optical disc was
When played on a commercially available CD player, Iz/Ito obtained from the eye pattern of the playback signal is O, Ei6, I
3/It. - was 0°35.

Furthermore, in the same manner as in Example 1, the intermediate layer 6 after recording was
When the surface was observed, it was confirmed that depression-shaped pits 5 were formed there.

(Example 3) In the above Example 1, the intermediate layer 6 has a heat distortion temperature of A
STM D648 is 4.6kg/cm2 and 90°CM
It was made of Mloo acrylic resin with a Rockwell hardness ASTM of D785, the thickness of the light absorption layer 2 was 130 nm, and a silicone acrylic resin layer was not formed between the light absorption layer 2 and the light reflection layer 3. An optical disk was fabricated in the same manner as in Example 1, except that the reflective surface 3 was made of a 9:1 alloy of Au and 1R.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1, and then this optical disc was
When playing i1T on a commercially available CD player, the eye pattern of the playback signal shows [z/It. - is 0. 63
．． 13/l1o- was 0°32.

Furthermore, when the surface of the intermediate layer 6 after recording was observed in the same manner as in Example 1, it was found that there were pit-like pits there.・5
It was clear that a bruise had formed.

(Example 4) In the above Example 1, the intermediate layer 6 has a J1 deformation degree ASTM D648 of 4.61<g/cm2 and 66°.
C% D Tsukwell hardness ASTM is D785 and M2
An optical disc was manufactured in the same manner as in Example 1 above, except that it was formed from a vinylidene chloride copolymer of O to a thickness of 60 nm.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1, and then this optical disc was
r++/It obtained from the eye pattern of the playback signal when played back with a commercially available CD player. - is 0.67, I
3/Ito- was 0136.

Furthermore, in the same manner as in Example 1, the intermediate layer 6 after recording was
When the surface was observed, it was confirmed that depression-shaped pits 5 were formed there.

(Example 5) In the above Example 1, the intermediate layer 6 has a heat distortion temperature of A
STM D648 is 1. -85°C at 6kg/cm2
An optical disk was prepared in the same manner as in Example 1 above, except that the %5°C% Rho/Furanyl TM was made of D785 and M2O polystyrene.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1, and then this optical disc was
After playing with a commercially available CD player for one time, Iz/Ito, which is detected from the eye pattern of the playback signal, was 0.65.
13/l-0- was region 34.

Furthermore, in the same manner as in Example 1, the intermediate layer 6 after recording was
When the surface was observed, it was confirmed that depression-shaped pits 5 were formed there.

(Example 6) In the above Example 1, the intermediate layer 6 has a heat distortion temperature of A
STM D648 is 4.6kg/cm2 and 55°C%
An optical disk was fabricated in the same manner as in Example 1, except that it was made of polyvinyl acetate of M2O with a Rockwell hardness of D785 to a thickness of 60 nm, and that 10 nm of isonoanate was spin-coded on top of the silicone acrylic resin. Manufactured.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1, and then this optical disc was
lz/It obtained from the eye pattern of the playback signal when played back with a commercially available CD player. , is 0.86.13
/I,. , was 0°32.

Furthermore, in the same manner as in Example 1, the intermediate layer 6 after recording was
When the surface was observed, it was confirmed that pit-shaped pits 1-5 were formed there.

(Example 7) In the above Example 1, the intermediate layer 6 has a heat distortion temperature of A
STM D648 is 4.6 kg/cm2, 70°C, Rockwell hardness ASTM is D785, and it is made of M2O polyester, and as a dye for forming the light absorption layer 2, 1.1' diptyl 3.3.3'3' Tetramethyl 4.5.4'5' Dibenzoindodicarbocyanine perchlorate was used, silicone resin was formed on the light absorption layer 2 by coating instead of silicone acrylic resin, and light An optical disc was manufactured in the same manner as in Example 1 above, except that a 20 nm thick bisphenol-curable epoxy resin layer was formed on the reflective layer 3.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1, and then this optical disc was
I++/It obtained from the eye pattern of the playback signal when played back with a commercially available CD player. , is 0.61%I
s/It. , was 0°31.

Furthermore, in the same manner as in Example 1 above, the intermediate B after recording
When I observed the surface of 6, I found a pit-shaped pit there.
5 was confirmed to be formed.

(Example 8) In the above Example 1, the intermediate layer 6 has a heat distortion temperature of A
STM D648 is 4.6kg/cm2 and 50°C1
The intermediate layer 6 was formed with a polyurethane resin of M2O to a thickness of 50 nm with an ASTM hardness of D785, and a silicone resin was formed on the intermediate layer 6 with a thickness of 15 nm using a spin cord, and after being subjected to solvent-resistant treatment, Dibutyl 3.3
．． 3′ 3′ Tetramethyl 4.5.4″ 5′ The light absorption layer 2 with a thickness of 130 nm was formed using dibenzoindodicarbocyanine perchlorate, and between the light absorption layer 2 and the light reflection layer 3. 9: No silicone acrylic resin was coated, and the reflective layer 3 was made of Au and Ir.
Example 1 above except that the alloy film was formed using the alloy film of
An optical disc was produced in the same manner.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1, and then this optical disc was
lz/It obtained from the eye pattern of the playback signal when played back with a commercially available CD player. , is 0.66, I3
/L. , was 0°33.

Furthermore, in the same manner as in Example 1, the intermediate layer 6 after recording was
When the surface was observed, it was confirmed that depression-shaped pits 5 were formed there.

(Example 9) In the above Example 1, the intermediate layer 6 has a heat distortion temperature of A
STM D648 is 4.6 kg/cm2 at 50°C, Rockwell hardness ASTM is D785, it is formed with M2O polyurethane resin to a thickness of 50 nm, and a silicone coating agent is formed on the intermediate layer 6 with a thickness of 15 nm using a spin cord. After solvent-resistant treatment, 1.1" dibutyl 3.
3.3' 31 Tetramethyl 4.5.45' The light absorption layer 2 was formed using dibenzoindodicarbocyanine perchlorate, and silicone resin was formed on this light absorption layer 2 instead of silicone acrylic resin. An optical disc was manufactured in the same manner as in Example 1, except that a 20 nm coating of polysulfide-added epoxy resin was formed on the light reflective layer 3, and then a protective layer 4 was provided.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1, and then this optical disc was
When played on a commercially available CD player, I++/Ito11 obtained from the eye pattern of the playback signal was 0.66.
Is/It. p was 0°33.

Furthermore, in the same manner as in Example I, the intermediate layer 6 after recording was
When the surface was observed, it was confirmed that a recessed bit 5 was formed there.

(Example 10) In the above Example 1, as the intermediate layer 6, the octopus deformation temperature A
STM D648 is 4.8kg/cm2 and 60°C%
The organic dye forming the light absorbing layer 2 was as follows: 1' dibutyl 3.3.3
'3'Tetramethyl 4.5.4'5'' dibenzoindodicarbocyanine perchlorate was used, and the light absorption layer 2 was coated with silicone resin instead of silicone acrylic resin. An optical disc was manufactured in the same manner as in Example 1.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1 above, and then this optical disc was played back on a commercially available CD player. / I top is 0
．． 65. I3/It. , was 0°32.

Furthermore, in the same manner as in Example 1, the intermediate layer 6 after recording was
When the surface was observed, it was confirmed that a recessed bit 5 was formed there.

(Example 11) In the above Example 1, the intermediate layer 6 has a heat distortion temperature of A
STM D648 is 4.6kg/cm2 at 50℃, o
The intermediate layer 6 was formed to have a thickness of 50 nm using a urethane-based pJ1 plastic resin with a Tsukwell hardness of D785 and M2O, and a silicon-based coating agent was formed on the intermediate layer 6 to a thickness of 15 nm using a spin cord and treated with solvent resistance. 1
11'dibutyl3.3.3'3'tetramethyl4.
Example 1 above, except that the light absorption layer 2 was formed using 5.4'5' dibenzoindodicarbocyanine barchloride) and that a silicone resin was coated instead of the silicone acrylic resin. An optical disc was produced in the same manner.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1, and the disc was then played back on a commercially available CD player.Iz/It obtained from the eye pattern of the playback signal, , is 0.67, I
a/It. . was 0.34.

Furthermore, in the same manner as in Example 1, the intermediate layer 6 after recording was
When the surface was observed, it was confirmed that a recessed bit 5 was formed there.

(Example 1.2) In the above Example 1, the intermediate layer 6 had a deformation temperature ASTM D648 of 4.6 kg/cm2 and 70°C.
It is made of M2O acrylic resin with an ASTM hardness of D785, and the organic pigment is 1,1
' Dipropyl 5.7.5.7 Dime I xylindica - film thickness 130 nm using posidianine fluoroborate
Except for forming the light absorption layer 2 of 2, the light reflection layer 3 of Co1, and the protection layer 4 of 5 μm thick of silicon-based Bartco-1.
An optical disc was manufactured in the same manner as in Example 1 above.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1, and then this optical disc was
When I played 11f on a commercially available CD player, I++/[to, obtained from the eye pattern of the playback signal was 0.63.
, 13/IL. - was 0°32.

Furthermore, in the same manner as in Example 1, the intermediate layer 6 after recording was
When the surface of the ball was observed, it was confirmed that a concave bit 5 was formed there.

(Example 13) In the above Example 1, the intermediate layer 6 has a heat distortion temperature of A
STM D648 is 4.6kg/cm2 and 50°C%
Cff Tsukwell hardness ASTM is D785, it is made of M2O polyurethane resin, and the organic dye forming the light absorption FJ2 is ■, 1' dipropyl 5.7.
5.7 Using dimethoxy indodicarbocyanine fluoroborate, 30 nm thick S on the light absorption layer 2
The light reflection layer 3 was formed of a Cu film, and the protective layer 4 was formed on the light reflection layer 3 by spin coating an epoxy resin with a thickness of 20 nm. The protective layer 4 is made of silicon-based bar coat.
1. An optical disc was manufactured in the same manner as in Example 1 above, except that it was formed to have a thickness of 5 μm.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1, and then this optical disc was
When played on a commercially available CD player, Iz/It0. which can be obtained from the eye pattern of the playback signal. is 0.66, I3
/It. , was 0°33.

Furthermore, in the same manner as in Example 1, the intermediate layer 6 after recording was
When the surface was observed, it was confirmed that depression-shaped pits 5 were formed there.

(Example 14) In the above Example 1, a glass disk was used as the transparent substrate 1, and the intermediate layer 6 had a μi deformation temperature ASTM
D648 is 4.6kg/cm2 and 70°Cs C
' 2p method (photo poly-ma) was applied to the surface of M9O with Tsukwell hardness ASTM-hCD785.
The film was formed using an acrylic resin with pregrooves formed using a method (resolution a+method), and 1.1' dipropyl 5.7.5.7 dimethoxyindodicarbocyanine fluoroborate was used as the organic dye forming the light absorption layer 2. The light absorption layer 2 with a thickness of 130 nm was formed, the light reflection layer 3 was formed with a Cu film, and the protective layer 4 was formed with a silicon-based hard coating agent to a thickness of 5 nm.
An optical disc was manufactured in the same manner as in Example 1 above, except that the thickness was formed in μm.

EFM signals were recorded on the thus obtained optical disc in the same manner as in Example 1, and then this optical disc was
When played on a commercially available CD player, the eye pattern obtained from the eye pattern of the playback signal was 1/1. . , is 0.83, Is
/It. , was 0°32.

Furthermore, in the same manner as in Example 1, the intermediate layer 6 after recording was
When the surface was observed, it was confirmed that depression-shaped pits 5 were formed there.

(Comparative Example) In Example 1, the intermediate layer 6 has a heat distortion temperature of A
STM D648 is 4.6kg/cm2 and 180℃,
An optical disc was manufactured in the same manner as in Example 1 above, except that it had a Rockwell hardness ASTM of D785 and was made of Mloo silicone 1M resin.

EFM signals were recorded on the optical disc thus obtained in the same manner as in Example 2 above, and then this optical disc was
When played on a commercially available CD player, I++/It is obtained from the eye pattern of the playback signal. , is 0.28.1
1/It. . was 0°05.

This optical disc cannot satisfy the above CD format.

[Effects of the Invention] As explained above, according to the optical information recording medium and the recording method of the present invention, by irradiation with laser light, the intermediate layer 6 formed on the transparent substrate l has a structure similar to that of a CD. Since concave pits can be formed and the reflective layer 3 can be formed in close contact behind the light absorbing layer 2, a pit shape and layer structure similar to a CD can be obtained.

In particular, if the heat deformation temperature is relatively low on the transparent substrate l,
Alternatively, since the intermediate layer 6 with low hardness is formed, clear pits can be formed in the intermediate layer 6 by the energy generated in the light absorption layer 2 by irradiation with laser light, thereby increasing the modulation degree. A high reproduction signal can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic half-sectional perspective view showing an example of the structure of an optical information recording medium, FIG. 2 is an enlarged view of part A in FIG. 1 before optical recording,
Figure 3 is an enlarged view of part A in Figure 1 after optical recording, and Figure 4 is
An enlarged sectional view of a main part of an optical disc before optical recording showing another example,
FIG. 5 is an enlarged sectional view of the main part of the same optical disc after optical recording. ■...Substrate 2...Light absorption layer 3...Reflection layer 4
...protective layer

Claims (1)

[Claims] (1) A light absorption layer 2 that absorbs laser light through another layer on the transparent substrate 1, and a light absorption layer 2 that is provided on the light absorption layer 2 directly or through another layer. In an optical information recording medium having a light reflection layer 3 that reflects the laser light emitted, the light absorption layer 2 contains a material that generates heat and pressure increases when irradiated with the laser light, and the light absorption layer 2 and the transparent An optical information recording medium characterized in that an intermediate layer 6 is interposed between the optical substrate 1 and the intermediate layer 6 has a thermal deformation temperature of 50 to 150° C. according to ASTM D648 4.6 Kg/cm^2. (2) A light absorption layer 2 that absorbs laser light through another layer on the transparent substrate 1, and a light absorption layer 2 provided on the light absorption layer 2 directly or through another layer that reflects the laser light. In an optical information recording medium having a light-reflecting layer 3, the light-absorbing layer 2 contains a material that generates heat and increases pressure when irradiated with laser light, and the light-absorbing layer 2 and the transparent substrate 1 An intermediate layer 6 is interposed in between, and the Rockwell hardness of this intermediate layer 6 is M according to ASTM D758.
100-50. (3) A light absorption layer 2 that absorbs laser light through another layer on the transparent substrate 1, and a light absorption layer 2 that reflects the laser light provided on the light absorption layer 2 directly or through another layer. In an optical information recording medium having a light-reflecting layer 3, the light-absorbing layer 2 contains a material that generates heat and increases pressure when irradiated with laser light, and the light-absorbing layer 2 and the transparent substrate 1 An intermediate layer 6 is interposed in between, and the intermediate layer 6 has a heat deformation temperature of 50 to 150°C according to ASTM D648 4.6 Kg/cm^2, and a Rockwell hardness of M100 to 50 according to ASTM D758. Characteristic optical information recording media.