JPH05120729A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To enhance a recording sensitivity and to prevent reproducing light from being affected by a recording layer by adopting the structure constituted by laminating a transparent substrate and a transparent resin layer which melts at the temp. below the m. p. of a radiation reflection layer. CONSTITUTION:A radiation absorption heat converting layer 9 is provided between the 1st resin layer 3 side and the radiation reflection layer 2a and the 2nd resin layer 4. The guide groove 7 part of the radiation reflection layer 2a is irradiated with a recording beam, such as laser beam, from the 2nd resin layer side to form recording pits 8 of information on the guide grooves. The thermal conversion is executed by absorbing the recording beam, such as laser beam, near the guide groove part of the radiation reflection layer in such a case and, therefore, only the 1st and 2nd resin layers on both sides of the radiation reflection layer 2a are melted and the deformation of the guide groove parts of the radiation reflection layer 2a is facilitated without thermally deforming the transparent substrate 1. Then, the deformation is generated in the radiation guide groove parts and the distinct recording elements (recording pits) are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a guide groove for optical tracking or the above guide groove and information prepits such as user information signals and address signals on a transparent substrate, and at least a radiation reflection layer for light or the like is provided. In particular, the present invention relates to a write-once type optical information recording medium which is suitable for newly forming an additional optical information element (recording pit) on the reflective layer and has excellent recording and reproducing sensitivity.

[0002]

2. Description of the Related Art Conventional optical discs such as laser discs and CDs (compact discs) have been read-only optical discs that are played back by a playback player. There is a demand for an optical disc that can be reproduced by a CD player. Generally, in a read-only optical disc, a reflective film made of a metal such as Al is provided on the side of the prepit signal forming surface of a transparent substrate on which prepit signals are formed, and further, a protective film made of various resin materials is provided on the reflective film. The structure is such that a film is formed, and the pre-pits and the like are provided in a convex shape on the transparent substrate side. In a CD or a laser disc on which a user can record information, for example, Au or the like is used as a reflective film made of metal, and a recording material, such as an organic dye recording film, is additionally writable between the transparent substrate and the reflective film. There has been proposed a write-once optical disc in which a hole (recording pit) is provided in the recording film to additionally record information. In addition, a guide groove such as a pre-groove is formed on the transparent substrate in a concentric circle shape or a spiral shape, and the recording film is irradiated with recording light while tracking the guide groove to form a heat-deformable recording element (recording pit) on the transparent substrate. Write-once information writable CD
Optical disks have also been proposed. However, in an optical disc using a recording film such as the above organic dye, the recording film or the information recording pit is deteriorated over time due to the corrosion of the disc, the fading of the dye, and the like, and the reproduction sensitivity of the recorded information is low. There was a problem to realize. As conventional techniques relating to this type of optical information recording medium, there are, for example, JP-A-2-42652, JP-A-59-55795 and JP-A-60-204394.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems in the prior art,
In an optical information recording medium having a recording layer made of a material that absorbs light and converts heat, between the transparent substrate and a radiation reflecting layer such as light, or in the radiation reflecting layer itself, corrosion of the recording film or fading of dye An object of the present invention is to provide a highly reliable optical information recording medium excellent in recording sensitivity and reproduction sensitivity by preventing deterioration of a recording film or information recording pits of an optical disk due to time and deterioration of reproduction sensitivity of recorded information. .. Further, the present invention modifies a portion such as the above-mentioned guide groove or prepit of the thermoplastic material layer in which a guide groove such as a pre-groove or a prepit is formed in an area where information for users is not recorded, or a flat portion. By doing so, an optical information recording medium such as a write-once optical disc, which allows a user to record information desired to be recorded with high sensitivity, is provided. Further, according to the present invention, information is recorded with high sensitivity and high reproduction sensitivity of recorded information is obtained by deforming a radiation reflection layer for light or the like in which guide grooves such as pregrooves and prepits are formed. An optical information recording medium such as an optical disc is provided.
Then, the present invention provides an optical information recording medium such as an optical disc on which information which the user needs at any time can be additionally recorded and which can be reproduced by a CD player.

[0004]

In order to achieve the above object, the present invention provides an optical information recording medium comprising at least a transparent substrate and a radiation reflecting layer, on one side of the transparent substrate, a spiral guide groove or a concentric circle. A first material layer made of a transparent resin material or the like that is formed at least at a temperature equal to or lower than the melting point of the radiation reflecting layer for light and the like, and an optical guide groove having a concave shape or a convex shape on the transparent substrate side. A radiation reflecting layer having a shaped optical guide groove and a second material layer that melts at a temperature at which the first material layer melts are sequentially laminated, and the radiation reflecting layer and the first material layer and the first material layer melt together. The two material layers form an optical information recording medium having a sandwich structure. The second material layer and the first material layer may be made of the same material. The radiation absorption heat conversion layer that absorbs the information recording light and converts it into heat, which is necessary for the optical information recording medium of the present invention, may be the radiation reflection layer itself having the function, but the radiation reflection layer. And the first material layer or the second material layer can be formed and used. In addition, a first material made of a material that melts at a temperature not lower than the melting point of at least the radiation reflection layer
The material layer and the second material layer may be layers made of a material having a function of absorbing information recording light and converting it into heat. Then, between the radiation absorption heat conversion layer that absorbs the information recording light and converts it into heat and the first material layer, or the second material layer.
In order to improve recording sensitivity, interposing a film layer such as a resin layer containing a heat explosive substance such as nitrocellulose between the above-mentioned material layer and between the radiation absorption heat conversion layer and the radiation reflection layer. preferable. In particular, the first material layer and the second material layer melt at a temperature not higher than the initiation temperature of the film layer containing a heat explosive substance and at a temperature not higher than the melting, sublimation, decomposition, etc. temperature of the radiation absorption heat conversion layer. Is preferred. In the usual case, it is most preferable to use a resin that melts at a temperature of 200 ° C. or lower for the first material layer and the second material layer. In the optical information recording medium of the present invention, on the surface of the second resin layer,
A protective film made of a light transmissive resin may be provided. Then, the transparent substrate side of the radiation reflecting layer is concavely or convexly formed on the optically guideable groove, and recording light is irradiated from a direction opposite to that of the transparent substrate side of the radiation reflecting layer to record information. The information is preferably reproduced by irradiating reproduction light from the transparent substrate side of the radiation reflection layer. As a preferred embodiment of the optical information recording medium of the present invention in which recording light is irradiated from a direction opposite to the transparent substrate side of the radiation reflecting layer, a spiral guide groove is provided on at least one surface of the transparent substrate. Alternatively, at least a first resin layer made of a transparent resin material that melts at a temperature equal to or lower than the melting point of the radiation reflection layer and a heat explosive substance such as nitrocellulose are provided on a transparent substrate on which concentric guide grooves are formed. A resin layer, a radiation reflection layer having a convex or concave optical guide groove on the transparent substrate side, a radiation absorption heat conversion layer that absorbs information recording light and converts it into heat, and the first resin layer A second resin layer made of the same material is preferably laminated in that order, and if necessary, a protective film made of various transparent resin materials is provided on the second resin layer. .. That is, the film layer of the heat explosive substance in the optical information recording medium of the present invention is disposed on the side of the radiation reflection layer opposite to the recording light irradiation side, and the radiation absorption heat conversion layer is the recording of the radiation reflection layer. The present invention relates to an optical information recording medium arranged on the light irradiation surface side. Further, the film layer of the heat explosive substance in the optical information recording medium of the present invention relates to the optical information recording medium having a structure arranged on the convex side of the guide groove of the radiation reflecting layer.

[0005]

A first resin layer having a guide groove made of a transparent resin material that melts at a temperature lower than the melting point of the radiation reflection layer on a transparent substrate, and a laser beam having an optical guide groove shape Information is obtained by irradiating a recording light such as a laser beam on an optical information recording medium formed by sequentially laminating a radiation reflecting layer and a second resin layer made of a material that melts at the melting temperature of the first resin layer. When recording is performed, a radiation absorption heat conversion layer is provided between the first resin layer side and the radiation reflection layer and the second resin layer, and recording light is emitted from the transparent substrate side which is the reproduction light irradiation side. A method of irradiating and recording information may be used, but a radiation absorption heat conversion layer is provided between the radiation reflection layer and the second resin layer, and recording light such as laser light is emitted from the second resin layer side. Irradiate the guide groove of the reflective layer to form information recording pits on the guide groove. Method is most preferable. In the optical disc having the configuration of the present invention, recording light such as laser light is absorbed in the vicinity of the guide groove portion of the radiation reflection layer to perform heat conversion, so that the transparent substrate is not thermally deformed and the radiation reflection layer Only the first and second resin layers on both sides are melted, and the guide groove portion of the radiation reflecting layer is easily deformed. Therefore,
Deformation occurs in the guide groove portion of the radiation reflecting layer, and a clear recording element (recording pit) can be formed. Further, between the radiation reflecting layer and the first or second resin layer, a substance that absorbs laser light or the like and is heated by heat generated by heat conversion to explode, for example, a heat explosive substance such as nitrocellulose (NC). By providing the resin layer containing γ, it is possible to form a recording element (recording pit) having extremely high recording sensitivity and a clear shape deformation, and thus an optical disc having high reproduction sensitivity can be obtained. Further, since there is no film layer of a radiation absorption heat conversion substance such as an organic dye that reduces the amount of reproduction light between the transparent substrate on the reproduction light incident side and the radiation reflection layer, the reproduction sensitivity of recorded information is further improved. Can be improved.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the present invention will be given below to explain in more detail with reference to the drawings. Generally, light or a laser beam or the like is generally used as the radiation used for recording / reproducing information on an optical disc or the like. As a material used for the radiation reflection layer, a substance that absorbs a part of recording light such as a laser beam to convert it into heat and reflects a part of the laser beam is preferable. For example, Au—Sn alloy, Ag—Sn alloy. , Pt-
Sn alloy, Pd-Sn alloy, Rh-Sn alloy, Ti-S
n alloy, Al-Sn alloy, Al-Ti-Sn alloy, In
-Sn alloy, In-Sn-O alloy, Mn-Bi alloy,
Tb-Fe-Co alloy, Gd-Tb-Fe-Co alloy,
A Tb-Fe-Co-Nb alloy is a particularly preferable material. When a film layer provided separately, for example, a resin layer made of a transparent resin material having a melting temperature equal to or lower than that of a transparent substrate has a heat conversion function for recording light, a magnetic substance such as a magnetic metal or A non-magnetic material such as a non-magnetic metal, which is excellent in light reflection performance, such as Al,
Au, Ag, Pt, Pd, Rh, Co, Cr, Ni, C
Metals such as u, Ti, Si, W, Te and Bi, and alloys thereof such as Al-Ti, Pt-Co, Fe-Cr and Fe.
An alloy such as -Cr-Ni, Fe-Cr-Ti, Te-Pb-Se is used. In general, the material of the radiation reflecting layer has a low thermal conductivity, for example, 50 W / m · K or less, and a high light reflectance, for example, a material that simultaneously retains the property of reflecting 70% or more of the irradiation light. Is preferred. Usually, Au, Ag, Al, Cu or the like, which has a high reflectance with respect to the reproduction light of recorded information, is used as the radiation reflection layer, but it has low light reflectivity with respect to the recording light of information and absorbs light. It must be a material with a high rate, for example 15% or more, and a low thermal conductivity. For this reason, one surface of the radiation reflection layer is a reflection surface for reproducing light of Al, Au, Ag or the like, and the surface opposite to the above surface is made of an oxide of aluminum such as Al ₂ O ₃ or Au. Oxide, Ag oxide, Cu
Oxide, Al-Sn alloy, Au-Sn alloy, Ag-S
It is preferably used in a structure in which a film layer made of a material having a high absorptivity for information recording light such as an n alloy and a low thermal conductivity is provided. In addition, examples of the substance used for the absorbed light-heat conversion layer include Te, Te-Pb-Se alloy, Bi and Bi.
-Sb alloy, chalcogen element, chalcogen element compound,
Alloys containing chalcogen elements, organic dye compounds such as cyanine dyes, and the like are used. The thickness of the radiation reflection layer is 10
The range of ~ 5000Å (angstrom) is preferable,
A more preferred range is 50 to 600Å, and a most preferred range is 60 to 200Å. As a transparent substrate material that transmits radiation, ceramics such as glass and plastic materials such as PC resin (polycarbonate), acrylic resin, PMMA resin (polymethylmethacrylate), epoxy resin, and radiation curable resin are preferably used. .. An epoxy resin, a radiation curable resin, or the like is used as the protective film. The optical information recording medium of the present invention includes a laser disc, a writable compact disc (writable CD), a write-once optical disc, a phase change optical disc,
It can be applied to magneto-optical disks, etc., but in particular, it has a reflectance of 70% or more for reproducing light and a signal modulation of 1
It is applied to 60% or more of 1T signal and 30 to 70% of 3T signal. The first and second resin layers made of a transparent resin material having a melting temperature equal to or lower than the melting point of the radiation reflecting layer or the melting point of the transparent substrate material are film layers having a function of absorbing radiation and converting heat. preferable. The transparent resin material may be an organic dye compound, a polymer of a polymer compound and an organic dye compound, a polymer of an organic dye compound, an organic dye-added polymer compound, or the like.
A thermoplastic resin such as (polyvinyl alcohol), PMMA (polymethylmethacrylate), polyethylene, polypropylene, polyacrylate, polyvinyl chloride, polystyrene, polycarbonate, or a thermoplastic polymer is preferably used. A resin layer containing nitrocellulose is the most preferable material for the film layer containing the heat explosive substance. A protective film made of a resin material having a melting temperature higher than that of the second resin layer may be provided on the outer surface of the laminated second resin layer. In the optical information recording medium of the present invention, a recording element (recording pit) which is optically deformed to the side opposite to the transparent substrate side or the transparent substrate side is formed in the guide groove portion formed in the radiation reflection layer, and the guide is formed. A characteristic is that the recorded information is reproduced by detecting the optical contrast from the optically undeformed portion of the groove. That is, by irradiating the optical information recording medium with recording light,
By thermally melting the first and second resin layers provided on both sides of the radiation reflecting layer, the convex guide groove portions of the radiation reflecting layer are dented, so that the optically deformed recording pits are formed. It is an optical information recording medium of a system for forming and recording information. The drive device for the optical information recording medium of the present invention irradiates the recording light while optically tracking the guide groove of the optical information recording medium to provide the first and second layers provided on both sides of the radiation reflecting layer. Use a recording / reproducing apparatus equipped with means for recording information by optically deforming the convex guide groove portion of the radiation reflecting layer by thermally melting the resin layer and reproducing the recorded information. You can

[Embodiment 1] FIG. 1 is a schematic view showing an example of the structure of an optical information recording medium of the present invention in which information can be recorded only on one side, and a spindle hole 1 at the center of rotation is provided.
An example of the configuration of an optical disc recording medium with 0 is shown. On the surface 1a side having the pre-format pattern formed of the pre-groove (guide groove) or the pre-pit (recording information element) of the transparent substrate 1, the transparent substrate 1 is melted at a temperature equal to or lower than the melting point of the recording layer 2 including the radiation reflecting layer. A first resin layer 3 made of a resin material is formed, a recording layer 2 including a radiation reflecting layer is formed on the first resin layer 3, and the recording layer 2 is further formed.
A second resin layer 4 that melts at substantially the same temperature as the first resin layer 3 is formed on the upper surface of the first resin layer 3, and the outer surface of the recording layer 2 including the radiation reflection layer on the first resin layer 3 is formed on the outer surface of the second resin layer 4. In addition to being completely covered, the inner peripheral portion and the outer peripheral portion of the first resin layer 3 are directly adhered to the first resin layer 3 to form a protective film for the recording layer 2 including a radiation reflection layer. Provided in the form.
The first resin layer 3 and the second resin layer 4 may use the same material. The information recording light is irradiated onto the radiation reflecting layer from the surface side where the radiation absorbing and heat converting layer is provided to record information, and the information reproducing light is irradiated from both sides of the radiation reflecting layer to reproduce the information. It is possible to do.

[Embodiment 2] FIG. 2 shows a case where the outer surface of the second resin layer 4 in FIG. 1 is covered with a protective film 5 made of another high melting point resin material, and the guide groove has a trapezoidal shape. This is an example of the case where the recording layer 2 including the radiation reflecting layer and the recording layer 2 including the radiation reflecting layer is composed of the radiation absorbing and heat converting layer 9 and the radiation reflecting layer 2a in combination, and the other points are almost the same as in the first embodiment. .. In the disk recording media of Examples 1 and 2, the recording layer can be configured so that information can be recorded or reproduced by irradiating light from the transparent substrate 1 side, but especially the second resin layer. It is preferable that the recording layer 11 is irradiated with the recording light 11 from the 4 side to record information, and the reproducing light 12 can reproduce the information from the transparent substrate 1 side. As shown in FIGS. 3 (a) and 4 (a), it is possible to record information by irradiating the recording light 11 from the side of the second resin layer 4 made of this transparent resin material, and recording including a radiation reflection film. It is most preferable to record information in the guide groove portion formed in a convex shape toward the second resin layer 4 side in the uneven portion such as the prepit and the pregroove (guide groove) formed in the layer 2. When information is recorded in a portion formed in a convex shape on the second resin layer 4 side, the convex portion is deformed, and the information is recorded in FIGS.
A recording element (recording pit) 8 is formed at the position shown in (b). The shape of the recording pit 8 is preferably the same as the recording pit 8 shown in FIG. In order to form the recording pits 8, the recording layer 2 including the radiation reflecting layer has a photothermal conversion function of absorbing the recording light 11 and converting the recording light 11 into heat, and this occurs in the recording layer 2 including the radiation reflecting layer. Due to the conversion heat of the recording light 11, the first and second resin layers 3 and 4 provided on both sides of the recording layer are melted together to be thermoplastic, and the guide groove convex portion side of the radiation reflecting layer 2a. It is necessary to have three elements such as the phenomenon of volume expansion. The photothermal conversion function of converting the recording light 11 of the recording layer 2 including the radiation reflecting layer into heat has, for example, an organic dye such as a cyanine dye or a radiation such as an alloy such as Te-Se-Pb at a position shown in FIG. It is obtained by forming the absorption heat conversion layer 9. On the convex side of the pre-groove (guide groove) 7 of the radiation reflecting layer 2a, a resin layer 6 containing a material having a property of exploding by the conversion heat of the recording light 11, for example, nitrocellulose (NC), is provided in FIG. When formed as shown in FIG. 4 (a), the shape of the recording pit 8 can be sharp or remarkable as shown in FIG. However, basically, the information recording light is irradiated from the side of the radiation reflecting layer 2a on which the radiation absorbing and heat converting layer 9 is provided to record information, and the information reproducing light is emitted from either side of the radiation reflecting layer 2a. However, it is possible to irradiate and reproduce.

[Example 3] A material having a property of exploding by conversion heat of recording light 11, for example, nitro, on the convex side of the pre-groove (guide groove) 7 of the radiation reflecting layer 2a made of metal such as Al or Au. Resin layer 6 containing cellulose (NC)
The pre-groove (guide groove) 7 of the radiation reflection layer 2a.
FIG. 6 shows an optical recording medium having a structure in which the radiation absorption heat conversion layer 9 for generating the conversion heat of the recording light 11 is formed on the concave side of. Irradiating the recording light 11 from the radiation absorption heat conversion layer 9 side,
The conversion heat generated in the portion of the radiation reflection layer 2a causes the nitrocellulose (N
The resin layer 6 containing C) explodes, and the pre-groove (guide groove) 7 of the radiation reflection layer 2a is deformed to the concave side to form the recording pit 8. Note that FIG. 6 shows an example of the configuration of an optical disc in which convex recording pits 8 are formed on the irradiation side of the recording light 11.

[Embodiment 4] FIG. 7 shows a radiation reflection having a function of absorbing a part of irradiation light made of Au-Sn alloy or the like to generate conversion heat and a function of reflecting a part of the light. By using the layer 2b, a resin layer 6 containing a material having a property of exploding by conversion heat of the recording light 11, for example, nitrocellulose (NC) is provided on the convex side of the pre-groove (guide groove) 7 of the radiation reflecting layer 2b, This is an example of irradiating recording light 11 from the resin layer 6 side containing nitrocellulose (NC) to form convex recording pits 8 on the transparent substrate 1 side. Prepits, clock pits, pregrooves, etc. for tracking are formed on the tracking surface of the optical information recording medium. In addition to these, header pits such as sector addresses or track numbers, prepits, etc. are also formed as necessary. It Pregrooves, prepits, etc. are generally formed in an uneven shape on the film surface of the radiation reflecting layer. The recorded information, which is recorded on the film surface of the radiation reflection layer 2b and is composed of uneven prepits and pregrooves, is the film surface of the radiation reflection layer 2b generated by diffraction or scattering of light reflected from the film surface of the radiation reflection layer 2b. It is reproduced and output as a signal of light and dark from.

[Embodiment 5] FIG. 8 shows a typical embodiment of the present invention. That is, an uneven pre-groove (guide groove) is formed on a transparent substrate 1 made of PC resin or the like, which is formed with an uneven pre-groove (guide groove) on one surface, and a pre-format pattern including a pre-pit such as a sector address or a track number is formed if necessary. On the surface on which the groove is formed,
A first resin layer 3 made of a transparent resin material that melts at a temperature equal to or lower than the melting point of the recording layer 2 including the radiation reflection film 2a and the radiation absorption heat conversion layer 9 is formed, and the first resin layer 3 is formed on the first resin layer 3. ,
A material that explodes due to the conversion heat of the recording light 11,
For example, a resin layer 6 containing nitrocellulose (NC) is provided, and Al, Au or Al is formed on the resin layer 6 containing NC.
A radiation reflection layer 2a selected from a —Ti alloy, an Au—Sn alloy, or the like is provided, and an organic dye such as a cyanine dye or Te or Te—Se— is provided on the radiation reflection layer 2a.
Forming the radiation absorption heat conversion layer 9 made of Pb alloy or the like,
The second resin layer 4 made of the same material as the first resin layer is formed on the radiation absorption heat conversion layer 9, and a protective film 5 made of an ultraviolet curable resin or the like is further formed if necessary. This is an information recording medium. This optical information recording medium has a recording light 1
1 is incident from the protective film 5 or the second resin layer 4 side to record information, and reproduced from the transparent substrate 1 side by incidence of reproducing light 12. The feature of the optical information recording medium illustrated in the present embodiment is that the radiation absorbing heat converting layer 9 required only for recording is provided on the second resin layer 4 side of the radiation reflecting layer 2a. Radiation reflection layer 2a
The first resin layer 3 side is a film layer dedicated to the reproduction of recorded information, and there is no obstacle to the information reproduction of the radiation absorption heat conversion layer 9. Therefore, for the radiation absorption heat conversion layer 9, it is possible to select and use a material having high recording sensitivity and excellent recording characteristics. As a result, an optical information recording medium having excellent recording and reproducing characteristics and a high S / N ratio can be obtained. Even if an organic dye such as a cyanine dye, or a material such as Te or Te-Se-Pb alloy that deteriorates with time due to sunlight or oxygen in the air is used for the radiation-absorption heat conversion layer 9, the radiation-absorption heat is not used except during recording. On the conversion layer 9 side, it is possible to provide a treatment for blocking sunlight and oxygen in the air, and it is possible to obtain the effect of significantly reducing deterioration with time and prolonging the life. The optical recording medium in which the information of the present embodiment is recorded can be reproduced not only by a commercially available CD type optical disc player, but also by recording information on one side of the medium while simultaneously reproducing information from the opposite side. There are also features that can be used by players.

[Sixth Embodiment] FIG. 9 shows a typical embodiment of the present invention. That is, a transparent substrate (thickness 1) having a concave-convex guide groove (pre-groove) formed on one surface and a pre-format pattern including a pre-pit such as a sector address or a track number is also formed on the surface, if the radiation-curable resin or glass is used. .2 ± 0.1 mm) 1 on the surface of the concave-convex pregroove forming side, a transparent first resin layer (thickness 0.1
10 μm, optimal thickness 0.2-0.6 μm) 3 is formed, and a silicon nitride compound layer (thickness 8 is formed on the first resin layer 3).
00 to 1000Å) 15, and a magneto-optical recording layer (thicknesses 320 to 6) made of a rare earth element such as Tb and a transition element such as Fe or Co is further provided on the silicon nitride compound layer 15.
00Å) 14 is provided on the magneto-optical recording layer 14 via a silicon nitride compound layer (thickness 150 to 350Å) 15 or directly, such as a perpendicular magnetization film made of Pt—Co alloy or an in-plane magnetization film. Radiation reflection layer (thickness 100 to 20
0Å) 2a is formed, and an organic dye such as a cyanine dye or Te or Te-Se-P is formed on the radiation reflection layer 2a.
A radiation absorbing heat converting layer 9 such as an alloy b is formed, and on the radiation absorbing heat converting layer 9, a material having a property of exploding due to conversion heat of recording light, for example, a resin layer containing nitrocellulose (NC) (thickness 0.1-10 μm, optimal thickness 0.2
˜2.0 μm) 6 and further includes the resin layer 6 containing the NC.
A second resin layer made of the same material as the transparent first resin layer 3 made of the PC (polycarbonate) resin (thickness 0.1 to 10 μm, optimal thickness 0.2 to 0.6 μm).
4 is an optical information recording medium in which a protective film 5 made of an ultraviolet curable resin or the like is further formed. [Embodiment 7] As shown in FIG. 10, a transparent substrate (thickness) having an uneven guide groove (pre-groove) formed on one surface and, if necessary, a pre-format pattern including pre-pits such as sector addresses or track numbers 1.2 ± 0.1 mm) 1. A silicon nitride compound layer (thickness 800 to 1000 Å) is formed on the surface of the concave and convex pregroove formation side of 1.
15 is provided, and Tb is further formed on the silicon nitride compound layer 15.
A magneto-optical recording layer (thickness 320 to 600 Å) 14 made of a rare earth element such as Fe and Co and a transition element such as Fe or Co is provided, and a silicon nitride compound layer (thickness 150 to 3) is formed on the magneto-optical recording layer 14.
50 Å) 15 or directly through the transparent first resin layer (thickness 0.1 to 10 μm) made of a plasma-polymerized resin.
m, an optimum thickness of 0.2 to 0.6 μm) 3 is formed, and a perpendicular magnetization film made of a Pt—Co alloy or the like, or an in-plane magnetization film, or Al, Al− is formed on the first resin layer 3. Radiation reflection layer (thickness 100 to 200Å) made of Ti alloy, etc. 2
a, and a resin layer (thickness 0.1 to 10 μm, optimal thickness 0.2 to 2) containing a material having a property of exploding by light conversion heat, such as nitrocellulose (NC), on the radiation reflecting film 2a. 0.0 μm) 6 and further, on the resin layer 6 containing the nitrocellulose (NC), an organic dye such as a cyanine dye, or a radiation absorption heat conversion layer 9 such as Te or Te-Se-Pb alloy is formed, A second resin layer (thickness: 0.1 to 10 μm, optimal thickness: 0.2 to 10 μm) made of the same material as the transparent first resin layer 3 made of the plasma-polymerized resin is formed on the radiation absorption heat conversion layer 9. 0.6 μm) 4
And an optional protective film 5 made of an ultraviolet curable resin or the like. In the optical information recording media described in Examples 6 and 7, the recording light 11 is incident from the protective film 5 or the second resin layer 4 side to record information, and is reproduced by the reproduction light 12 incident from the transparent substrate 1 side. To be done. In addition, as the material of the magnetic reflection film such as the perpendicular magnetization film or the in-plane magnetization film used for the radiation reflection layer 2a in the above-mentioned Examples 6 and 7, Pt, AuAg,
It is preferable to use an alloy thin film of at least one element selected from the group of elements such as Au, Cu and Rh and at least one element selected from the group of elements such as Fe, Co and Ni. The characteristics of the optical information recording medium illustrated in the embodiment of the present invention are as follows. First, the second resin layer 4 of the radiation reflecting layer 2a.
Since the radiation absorption / heat conversion layer 9 necessary only for recording is provided on the side, the first resin layer 3 side of the radiation reflection layer 2a becomes a film dedicated to reproduction of recorded information, and the radiation absorption / heat conversion layer. The obstacle to the information reproduction of 9 is eliminated. On the other hand, a material having high recording sensitivity and excellent recording characteristics can be selected and used for the radiation absorption heat conversion layer 9. As a result, it is possible to obtain an optical information recording medium which can be configured under conditions excellent in recording characteristics and reproducing characteristics and which has a high S / N ratio. In addition, an organic dye such as a cyanine dye or Te, Te-Se-Pb is used for the radiation absorption heat conversion layer 9.
Even if a material such as an alloy that deteriorates with time due to sunlight or oxygen in the air is used, it is possible to take measures to shield the radiation absorption / heat conversion layer 9 side from sunlight or oxygen in the air except during recording. There is an effect that the deterioration of the life of the optical disk can be remarkably reduced. The optical disc medium in which the information of the present embodiment is recorded can be reproduced not only by a commercially available CD type optical disc player, but also information can be simultaneously reproduced from the opposite side while recording the information on one side of the medium. There is a feature that it can be used even with an optical disk player that can.

[0013]

The optical information recording medium of the present invention includes a transparent substrate on which a radiation reflecting layer having a preformat pattern such as guide grooves and prepits, and a radiation absorbing heat converting layer or a layer containing a heat explosive substance are sandwiched. Then, since the transparent substrate and the transparent resin layer that melts at a temperature equal to or lower than the melting point of the radiation reflecting layer are laminated, by irradiating the recording light from the radiation absorbing heat converting layer side, both sides of the radiation reflecting layer Since the resin layer provided on the substrate melts at the same time, the guide groove forming part of the radiation reflecting layer is easily deformed, so that a well-formed recording pit can be easily formed in the guide groove part of the radiation reflecting layer without deforming the substrate. The recording sensitivity is extremely high because it can be formed on the transparent substrate, and the reproduction light is irradiated from the transparent substrate side that is not affected by the recording layer such as the radiation absorption heat conversion layer. Because the reproduction characteristics of the recorded information is good, high light information recording medium S / N ratio can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of the configuration of an optical disc recording medium exemplified in a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing an example of a configuration of an optical disc recording medium exemplified in a second embodiment of the present invention.

FIG. 3 is a schematic diagram showing an example of a recording pit forming process in the optical disc recording medium exemplified in the second embodiment of the present invention.

FIG. 4 is a schematic diagram showing an example of a process of forming recording pits in the optical disc recording medium illustrated in the second embodiment of the present invention.

FIG. 5 is a schematic diagram showing an example of the shape of a recording pit exemplified in the second embodiment of the present invention.

FIG. 6 is a schematic diagram showing the shape of recording pits of the optical disk recording medium exemplified in Example 3 of the present invention.

FIG. 7 is a schematic diagram showing the form of recording pits in the optical disc recording medium illustrated in Example 4 of the present invention.

FIG. 8 is a schematic diagram showing an example of a configuration of an optical disc recording medium exemplified in a fifth embodiment of the present invention.

FIG. 9 is a schematic diagram showing an example of the configuration of the optical disc recording medium illustrated in Example 6 of the present invention.

FIG. 10 is a schematic diagram showing an example of the configuration of the optical disc recording medium illustrated in Example 7 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 1a ... Surface with preformat pattern formed 2 ... Recording layer including radiation reflection layer 2a ... Radiation reflection layer 2b ... Radiation reflection layer 3 ... First resin layer 4 ... Second resin layer 5 ... Protective film 6 ... Resin layer containing nitrocellulose (NC) 7 ... Pre-groove (guide groove) 8 ... Recording pit 9 ... Radiation absorption heat conversion layer 10 ... Spindle hole 11 ... Recording light 12 ... Reproducing light 13 ... Lens 14 ... Magneto-optical recording Layer 15 ... Silicon nitride compound layer

Claims (7)

[Claims] 1. An optical information recording medium comprising at least a transparent substrate and a radiation reflecting layer, wherein the radiation reflecting layer has an optical guide groove selected from a spiral guide groove and a concentric guide groove on the transparent substrate side. A first material layer made of a material having a concave shape or a convex shape, the melting point of the transparent substrate being lower than the melting point of the radiation reflecting layer, and melting at least at a temperature not higher than the melting point of the radiation reflecting layer; An optical information recording medium, characterized in that it is laminated in a sandwich shape with a second material layer that melts at a temperature at which the first material layer melts. 2. The thermal explosion from the side of the radiation reflecting layer to at least one of the two boundaries formed between the radiation reflecting layer and the first material layer and the second material layer according to claim 1. An optical information recording medium comprising a layer containing a functional substance and a radiation absorption heat conversion layer which absorbs information recording light and converts it into heat in this order. 3. The optical information recording medium according to claim 1, wherein a protective film made of a light transmissive resin is formed on the surface of the second material layer. 4. The side of the radiation reflecting layer opposite to the transparent substrate side of the radiation reflecting layer on the optically guide groove having a concave shape on the transparent substrate side of the radiation reflecting layer. An optical information recording medium, wherein a layer containing a heat explosive substance and a radiation absorption heat conversion layer that absorbs information recording light and converts it into heat are arranged. 5. A transparent material which melts at least at a temperature equal to or lower than the melting point of a radiation reflecting layer on a guide groove forming surface of a transparent substrate on which an optical guide groove selected from at least a spiral guide groove and a concentric circular guide groove is formed. First resin layer made of a different resin material, a layer containing a heat explosive substance, a radiation reflecting layer having a convex optically guideable groove on the transparent substrate side, and absorbing information recording light to heat. A radiation absorption heat conversion layer for conversion,
An optical information recording medium, which is configured by sequentially laminating a second resin layer made of the same material as the first resin layer. 6. An optical information recording medium according to claim 5, wherein a protective film made of a light transmissive resin is formed on the surface of the second resin layer. 7. The radiation according to claim 1, wherein the first material layer and the second material layer made of a material that melts at least at a temperature equal to or lower than the melting point of the radiation reflection layer have a property of converting information recording light into heat. An optical information recording medium characterized by being an absorption heat conversion layer.