JP2000339768A - Optical recording medium and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Problem] It has two functions of a read-only type and a recordable type. SOLUTION: A first information recording medium having a transparent first substrate in which pits corresponding to information are formed on one surface, and a translucent layer formed on the first substrate, A second information recording body including a second substrate having a groove formed on a surface thereof, a light reflecting layer formed on the second substrate, and a recording layer made of a light absorbing material; Information recording medium and the second
The information recording medium is bonded via an optically transparent adhesive layer, and information is optically recorded / reproduced by the incidence of laser light from the first substrate side.

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 in which information can be written in advance and a new recording can be performed only once, and a method of manufacturing the same.

[0002]

2. Description of the Related Art As a conventional optical recording medium, a CD (Comp
There are a read-only type, such as an act disc) and a CD-ROM, in which information is written in advance at the time of manufacture, and only a reproduction, and a recordable type, in which a user can freely write or read information. Furthermore, as a recordable type, 1
There are a write-once type that can be written only once and an erasable type that can be written or erased any number of times.

[0003]

In a read-only optical recording medium, information is written and recorded in advance, and the information recorded in advance can be reproduced, but new information cannot be written. . In a write-once optical recording medium,
Information is written and not recorded in advance. In a write-once optical recording medium, new information can be written only once.

As described above, there is an optical recording medium having a read-only type or a write-once type function independently, but no optical recording medium having both functions of a read-only type and a write-once type.

The present invention has been proposed in view of the above-described conventional situation, and has as its object to provide an optical recording medium having both functions of a read-only type and a recordable type. .

[0006]

The optical recording medium of the present invention comprises:
Transparent first pits with pits according to information formed on one side
A first information recording medium having a substrate, a translucent layer formed on the surface of the first substrate on which the pits are formed, and a second substrate having a groove formed on one surface. A second information recording body comprising: a light reflecting layer formed on the surface of the second substrate on which the groove is formed; and a recording layer made of a light absorbing material formed on the light reflecting layer. Wherein the first information recording body and the second information recording body are bonded via an optically transparent adhesive layer with the sides on which the pits or grooves are formed facing each other. The recording and reproduction of information is performed optically by the incidence of laser light from the first substrate side.

[0007] In the optical recording medium according to the present invention as described above, the first information recording medium having the read-only area and the second information recording medium having the additional recordable area are attached to each other. In addition to the stored information, the user can write information as needed. This optical recording medium has a recording capacity equivalent to that of an optical recording medium having two recording layers.

[0008] The method of manufacturing an optical recording medium according to the present invention comprises:
A first substrate forming step of forming an optically transparent first substrate and forming pits corresponding to an information signal on one surface integrally with the first substrate; and the first substrate forming step A first information recording body manufacturing step of forming a first information recording body by forming at least a translucent layer on a surface of the first substrate formed with the pits, on which the pits are formed, and a second substrate And forming a groove on one surface integrally with the second substrate; and forming the groove of the second substrate formed in the second substrate forming step. A second information recording body manufacturing step in which at least a light reflection layer and a recording layer made of a light absorbing material are sequentially formed on the formed surface to form a second information recording body; The first information recording body produced in the body producing step and the second information recording body A laminating step of laminating the second information recording body produced in the recording body producing step with an optically transparent adhesive layer facing the side where the groove or pit is formed. It is characterized by.

In the method for manufacturing an optical recording medium according to the present invention as described above, the first information recording medium having a read-only area and the second information recording medium having a recordable area are attached to each other. In addition to the pre-recorded information, the user can write information as needed,
An optical recording medium having the same recording capacity as an optical recording medium having two recording layers can be obtained.

[0010]

Embodiments of the present invention will be described below.

FIG. 1 shows an example of the configuration of an optical disk 1 according to the present embodiment. This optical disc 1 has a first disc 3 having a read-only first information recording section 2 on one side.
And a second disk 5 having a recordable second information recording section 4 on one side, so that the first information recording section 2 and the second information recording section 4 face each other. 6 and joined by the adhesive layer 6.

The first disk 3 is a light-transmissive first disk.
A pit 8 corresponding to information is provided on one surface of the first substrate 7 and a translucent layer 9 is formed on the surface of the first substrate 7 where the pit 8 is formed to constitute the first information recording section 2. are doing.

The first substrate 7 is made of an optically transparent resin. As a material of the first substrate 7, a known material usually used for a substrate of this type of optical disc, such as polycarbonate or polymethyl methacrylate, can be used.

On one surface of the first substrate 7, pits 8 corresponding to digital information recorded on the first disk 3 are formed in a spiral shape. These pits 8 are formed integrally with the first substrate 7 by transferring information from a stamper when the resin material as described above is formed into the first substrate 7. The first information recording section 2 is a reproduction-only area, and is an area where information cannot be written after the first substrate 7 is formed.

As a material of the translucent layer 9, a metal, a metal oxide or the like can be used.

The second disk 5 has a second substrate 1
0, a tracking groove 11 is provided on one surface of the second substrate 10, and a light reflection layer 12 and a recording layer 13 are sequentially laminated on the surface of the second substrate 10 on which the groove 11 is formed to form a second information recording section. 4.

For the second substrate 10, a known material such as polycarbonate and polymethyl methacrylate which is generally used for a substrate of this type of optical recording medium can be used.

On one surface of the second substrate 10, a groove 11 is formed in a spiral shape. The groove 11 is transferred from a stamper and is formed integrally with the second substrate 10 when the resin material as described above is formed into the second substrate 10.

Here, the second information recording portion 4 in which the groove 11 is formed on the second disk 5 is made recordable, and when the second substrate 10 is formed, the information is stored in this area. Is not input, and information can be written after the molding of the second substrate 10. The groove 11 is for tracking a laser beam when recording information. In the second information recording section 4, information can be written only once in one place.

As a material of the light reflection layer 12, a metal, a metal oxide or the like can be used.

The recording layer 13 is made of a light absorbing material. Examples of the light-absorbing material constituting the recording layer 13 include organic dyes such as cyanine dyes and phthalocyanine dyes.

Then, the optical disc 1 according to the present embodiment
The first disk 3 and the second disk 5 as described above are opposed to each other on the side on which the first information recording unit 2 or the second information recording unit 4 is formed, with the adhesive layer 6 interposed therebetween. And they are stuck together. An adhesive sheet, a photocurable resin, or the like can be used for the adhesive layer 6.

Recording and reproduction of information with respect to the optical disk 1 having the above-described configuration is performed by irradiating a laser beam from the substrate side of the first disk 3, as shown in FIGS. An optical system 20 for recording / reproducing information on / from the optical disc 1 includes a laser beam generating unit 21, a half mirror 22, an objective lens 23, and a return light detecting unit 24.
And The laser light emitted from the laser light generator 21 passes through the half mirror 22 and enters the objective lens 23. The laser light incident on the objective lens 23 is focused by the objective lens 23 and focused on the optical disc 1.

At this time, when reproducing information from the first disk 3, as shown in FIG. 2, a laser beam is focused on the translucent layer 9 of the first disk 3. The return light from the first optical disc 1 is
3 and enters the half mirror 22. The laser light that has entered the half mirror 22 is reflected by the half mirror 22 and enters the return light detection unit 24, where an information signal is detected. At this time, the power of the laser light to be irradiated is weaker than during recording.

When information is recorded on the second disk 5, a laser beam is focused on the recording layer 13 on the second disk 5, as shown in FIG. Then, the portion of the recording layer 13 irradiated with the laser beam is deformed by heating, causing a difference in reflectance from the portion not irradiated with the laser beam, and a pit corresponding to information is formed.

The optical disc 1 according to the present embodiment having the above-described configuration is formed by laminating two discs each having a recording section, so that the optical disc 1 has a larger capacity than an optical recording medium composed of one disc. Will have. Further, since the optical disc 1 has a read-only area and a write-once area, the disc can be configured according to the purpose of use.

The optical disk 1 as described above is
For example, it is produced as follows.

First, the first disk 3 is manufactured as described below.

First, a transparent first substrate 7 in which pits 8 corresponding to information signals are formed in a spiral shape by injection molding a thermoplastic resin using a stamper. As the thermoplastic resin constituting the first substrate 7,
Examples include polycarbonate and polymethyl methacrylate.

Next, a translucent layer 9 is formed on the surface of the first substrate 7 on which the pits 8 are formed. Examples of the material constituting the translucent layer 9 include metals and metal oxides. Examples of the method for forming the translucent layer 9 include a sputtering method and a vacuum evaporation method.

As described above, the first disk 3 having the read-only type first information recording section 2 is manufactured.

Further, the second disk 5 is manufactured as follows.

First, a second substrate 10 having the grooves 11 formed in a spiral shape is formed by injection molding a thermoplastic resin using a stamper. Examples of the thermoplastic resin constituting the second substrate 10 include polycarbonate and polymethyl methacrylate.

Next, the second groove 11 is formed.
The light reflection layer 12 is formed on the surface of the substrate 10 on which the grooves 11 are formed. Examples of the material forming the light reflecting layer 12 include a metal and a metal oxide. Examples of a method of forming the light reflecting layer 12 include a sputtering method and a vacuum evaporation method.

Next, a recording layer 13 made of a light absorbing material is formed on the light reflecting layer 12. Examples of the light-absorbing material constituting the recording layer 13 include organic dyes such as cyanine dyes and phthalocyanine dyes.

The recording layer 13 is formed by dissolving the above-described organic dye in a solvent such as hydroxymethylbutanone or tetrafluoropropanol to form a solution, and then forming the second layer on which the light reflecting layer 12 is formed. Substrate 10
The solution is dropped onto the light reflecting layer 12 while rotating the light reflecting layer 12, and the solution is stretch-coated on the light reflecting layer 12 by a spin coating method, or the organic dye is sublimated in a vacuum to form the light reflecting layer 12
Vacuum evaporation method of depositing on top is mentioned.

As described above, the second disk 5 having the write-once second information recording section 4 is manufactured.

The first disk 3 and the second disk 5 manufactured as described above are opposed to each other on the side on which the first information recording section 2 or the second information recording section 4 is formed. Then, the first disk 3 and the second disk 5 are stuck together by an ordinary method using an optically transparent ultraviolet curable resin, and the optical disk 1 is completed. Here, it is preferable that the thickness of the ultraviolet curable resin layer is 40 μm to 60 μm.

In the above-described method, the case where the first substrate 7 and the second substrate 10 are manufactured by injection molding has been described as an example. However, the present invention is not limited to this. In addition to molding, the first substrate 7 or the first substrate 7 may be applied by applying a UV-curable resin onto a glass plate or the like, and irradiating UV rays while pressing a stamper against the UV-curable resin to cure the UV-curable resin. Two substrates 10 may be manufactured.

As shown in FIG. 4, the recording layer 1 on the semi-transparent layer 9 of the first disk 3 or the recording layer 1 of the second disk 5
A protective layer 14 may be provided on the third layer 3. This protective layer 1
4 is provided for the purpose of protecting the recording layer 13 and the translucent layer 9. As a material for forming the protective layer 14, for example, an organic polymer material, a metal or a metal oxide is used. The means for forming the protective layer 14 includes, for example, a spin coating method, a sputtering method, and a vacuum evaporation method.

In the above-described embodiment, when the first disk 3 and the second disk 5 are bonded together, the first disk 3 and the second disk 5 are bonded using an ultraviolet curing resin. However, the present invention is not limited to this, and the first disk 3 and the second disk 5 are laminated using an optically transparent double-sided adhesive film. Is also good.

[0042]

According to the present invention, a read-only first information recording medium on which information has been written in advance and a recordable second information recording medium on which new recording can be performed only once are used. An optical recording medium that can be used properly according to the purpose can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one configuration example of an optical disc according to the present embodiment.

FIG. 2 is a schematic diagram showing an example of an optical system for reproducing information from a first disk.

FIG. 3 is a schematic diagram illustrating an example of an optical system that records information on a second disk.

FIG. 4 is a sectional view showing another configuration example of the optical disc according to the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Optical disk, 2 1st information recording part, 3 1st
Disk, 4 second information recording section, 5 second disk, 6 adhesive layer, 7 first substrate, 8 pits, 9 translucent layer, 10 second substrate, 11 groove, 12 light reflecting layer, 13 Recording layer, 14 protective layer

Continuation of the front page (72) Inventor Shinichiro Tamura 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5D029 JA04 JB09 JC03 RA05 RA16 RA44 5D121 AA01 AA04 AA05 AA07 EE02 EE03 EE22 FF01

Claims (6)

[Claims] A first substrate having a pit corresponding to information formed on one surface thereof; and a translucent layer formed on a surface of the first substrate having the pit formed thereon. First
An information recording medium, a second substrate having a groove formed on one surface thereof, a light reflecting layer formed on the surface of the second substrate having the groove formed thereon, and a light reflecting layer formed on the light reflecting layer. A second information recording body having a recording layer formed of a light-absorbing material, wherein the first information recording body and the second information recording body have the pits or grooves formed thereon. The first and second substrates are bonded to each other with an optically transparent adhesive layer interposed therebetween, and the recording and reproduction of information is performed optically by laser light incident from the first substrate side. Optical recording medium. 2. The optical recording medium according to claim 1, wherein said light absorbing material is an organic dye. 3. The optical recording according to claim 1, wherein a protective layer is formed on the translucent layer of the first information recording medium or the recording layer of the second information recording medium. Medium. 4. An optically transparent first substrate is formed, and a pit corresponding to an information signal is formed on one surface of the first substrate.
A first substrate forming step integrally formed with the substrate, and forming at least a translucent layer on a surface of the first substrate formed in the first substrate forming step, on which the pits are formed. A first information recording body manufacturing step of forming a first information recording body, and a second substrate molding step of molding a second substrate and forming a groove on one surface integrally with the second substrate. Forming at least a light-reflective layer and a recording layer made of a light-absorbing material on the surface of the second substrate formed in the second substrate forming step, on which the groove is formed, in order to form a second substrate; A second information recording body producing step of forming the information recording medium, the first information recording body produced in the first information recording body producing step, and a second information recording body producing step produced in the second information recording body producing step The groove or pit is formed between the second information recording medium and the second information recording medium. And a bonding step of bonding the optical recording media with the sides facing each other via an optically transparent adhesive layer. 5. The method for manufacturing an optical recording medium according to claim 4, wherein an organic dye is used as said light absorbing material in said second information recording body manufacturing step. 6. The method according to claim 4, further comprising a step of forming a protective layer on the translucent layer of the first information recording medium or the recording layer of the second information recording medium. A method for manufacturing an optical recording medium.