JPH09180260A - Pasted type optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute one side recording and reproducing while attaining the compatibility of transferability with optical characteristics by reproducing information from the information recording surface of a first disk surface through a second disk substrate and a translucent adhesive layer. SOLUTION: The first disk substrate 21 is light transmissible and has the information recording surface having pits carrying information formed on one surface which is coated with a reflection layer 22 of a metallic film. Further, the reflection layer 22 is spin-coated with a UV curing resin to form a translucent protective film 24 of a prescribed thickness. On the other hand, the light transparent second disk substrate 31 is pasted to the first disk substrate 21 with the translucent adhesive layer 25 consisting of a UV curing type adhesive in such a manner that the information recording surfaces face each other, and thereby the sticking type optical disk is constituted. A light beam is, therefore, converged through the second disk substrate 31 and the translucent adhesive layer 25 to the information recording surface of the first disk substrate 21 and the information is reproduced by the reflected light. As a result, the one side recording and reproducing are made possible while the compatibility of the transferability with the optical characteristics is attained.

Description

Detailed Description of the Invention

[0001]

[0001]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated optical disk.

[0003]

[0002]

[0004]

2. Description of the Related Art Conventionally, so-called video discs, compact discs, etc. have been known as optical discs for reproduction.

FIG. 2 is a sectional view of a conventional bonded optical disk.

In FIG. 2, the first disk substrate 21 is
It is a translucent substrate molded with a synthetic resin such as polycarbonate or acrylic resin, and has an information recording surface on one side of which a pit for carrying a signal is formed, and a metal film to cover it. A reflective layer 22 made of is formed. An ultraviolet curable resin is spin-coated on the reflective layer 22 to form a protective layer 23 having a predetermined thickness.

[0007]

Reference numeral 31 is a second disk substrate used for mechanical reinforcement, and is made of a light-transmissive substrate molded of synthetic resin such as polycarbonate or acrylic resin. The first and second disk substrates are bonded by an adhesive layer made of an ultraviolet curable adhesive or a hot melt adhesive to form a bonded optical disk.

The bonded type optical disc constructed as described above is constructed so that the light beam is focused on the information recording surface through the first disc substrate as shown in the figure and the information is reproduced by the reflected light. There is.

[0009]

[0004]

[0010]

By the way, in the above-mentioned bonded optical disk for single-sided reproduction, an information signal is transferred to one surface of one disk substrate, and a reproducing laser beam is radiated through this disk substrate. The disk substrate must satisfy the requirements of transferability and optical characteristics. However, when molding a disk substrate with a synthetic resin by injection molding, the two tend to conflict with each other in terms of molding conditions. For example, in terms of mold clamping pressure during molding,
The higher the mold clamping pressure is, the better the transferability is, but the optical characteristics are deteriorated due to the increase of stress, and the smaller the mold clamping pressure is, the better the optical characteristics are, but the transferability is deteriorated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a single-sided reproducing or single-sided recording / reproducing laminated optical disk which has both transferability and optical characteristics.

[0012]

[0005]

[0013]

The present invention has been made in view of the above-mentioned problems, and the laminated optical disk according to claim 1 is molded by injection molding, and an information recording surface is formed on one surface thereof. The first disk substrate having the same and the light-transmissive second disk substrate molded by injection molding are bonded together with the information recording surface inside by a light-transmissive adhesive layer,
The information is reproduced or recorded through the disc substrate and the adhesive layer.

[0014]

In the bonded optical disk according to the second aspect, the second disk substrate is a flat plate.

[0015]

Further, in the bonded optical disk according to the third aspect, the second disk substrate is formed in a state in which the mold clamping pressure or the mold temperature is lower than that of the first disk substrate. To do.

[0016]

[0008]

[0017]

The bonded optical disk according to the present invention is made of a synthetic resin by injection molding, and has a first disk substrate having an information recording surface on one side thereof and a second transparent optical disk formed of the synthetic resin. The disc substrate and the information recording surface are attached to each other by a translucent adhesive layer, and information is reproduced or recorded through the second disc substrate and the adhesive layer. Therefore, the first disc substrate is transferred. Injection molding can be performed under molding conditions that place importance on the property, and the second disk substrate can be injection molded under molding conditions that place importance on optical characteristics.

[0018]

[0009]

[0019]

1 is a cross-sectional view of a bonded optical disk substrate according to an embodiment of the present invention. The same parts as those of the conventional example are designated by the same reference numerals.

The information signal board 21 has a thickness of 0.4 to 0.8.
mm, for example, 0.6 mm, which is made of a synthetic resin such as polycarbonate or acrylic resin and is a light-transmissive first disk substrate molded by injection molding, and has a pit for carrying information formed on one surface thereof. A reflective layer 22 having an information recording surface and made of a metal film so as to cover the information recording surface.
Are formed. An ultraviolet curable resin is spin-coated on the reflective layer 22 to form a translucent protective layer 24 having a predetermined thickness.

[0021]

Reference numeral 31 is made of a synthetic resin such as polycarbonate or acrylic resin used to increase mechanical strength, and has a thickness of 0.4 to 0.8 mm, for example, 0.
It is a light-transmissive second disk substrate 31 molded by 6 mm injection molding.

The first and second disc substrates are laminated with a translucent adhesive layer 25 made of an ultraviolet curable adhesive or the like, with the information recording surface inside, to form a laminated optical disc.

In the laminated optical disk constructed as described above, a light beam is focused on the information recording surface of the first disk substrate through the second disk substrate 31 and the adhesive layer 25, and information is reproduced by the reflected light. To be configured.

Therefore, since the reproducing light beam does not pass through the first disk substrate having the information recording surface, the mold clamping pressure or the mold temperature can be increased to perform injection molding to improve the transferability. it can.

On the other hand, since the second disk substrate through which the reproducing light beam passes does not have an information recording surface, the mold clamping pressure or the mold temperature is lowered to perform injection molding to improve the optical characteristics. You can

[0026]

In the above-mentioned embodiment, the optical disk of the reproducing substrate is illustrated, but a guide groove is formed on the information recording surface of the first disk substrate, and the reflective layer 22 is formed on the guide groove.
It is also possible to form a dye film, a magneto-optical material thin film, and a phase change material thin film to form a writable optical disc. Also,
The protective layer 24 may not be formed, and the adhesive layer may be used for direct bonding. Furthermore, the first disk substrate does not have to be light transmissive, and may be a colored substrate.

[0027]

[0012]

[0028]

According to the present invention, in an optical disk in which a first disk substrate having an information recording surface and a second disk substrate are bonded with the information recording surface inside, a second optical disk substrate is used. Since the information recording surface of the disc substrate 1 is used for reproducing information or recording information on the information recording surface, a single-sided reproducing or single-sided recording / reproducing laminated optical disk having both transferability and optical characteristics. Can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a bonded optical disk substrate according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a bonded optical disc in a conventional example.

[Explanation of symbols]

 21, first disk substrate 22, reflective layer 23, 24, protective layer 25, 26, adhesive layer 31, second disk substrate

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[Procedure amendment]

[Submission date] December 16, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Detailed description of the invention

[Correction method] Change

[Correction contents]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated optical disk.

[0002]

2. Description of the Related Art Conventionally, so-called video discs, compact discs, etc. have been known as optical discs for reproduction.
FIG. 2 is a cross-sectional view of a conventional bonded type optical disc. FIG.
In, the first disk substrate 21 is a translucent substrate molded of a synthetic resin such as polycarbonate or acrylic resin, and has an information recording surface on one side of which a pit for carrying a signal is formed, A reflective layer 22 made of a metal film is formed so as to cover this. An ultraviolet curable resin is spin-coated on the reflective layer 22 to form a protective layer 23 having a predetermined thickness.

Reference numeral 31 is a second disk substrate used for mechanical reinforcement, and is made of a light-transmissive substrate molded of synthetic resin such as polycarbonate or acrylic resin. The first and second disk substrates are bonded by an adhesive layer made of an ultraviolet curable adhesive or a hot melt adhesive to form a bonded optical disk. The bonded type optical disc configured as described above is configured to focus a light beam on an information recording surface through a first disc substrate as shown in the figure and reproduce information by reflected light.

[0004]

By the way, in the above-mentioned bonded optical disk for single-sided reproduction, an information signal is transferred to one surface of one disk substrate, and a reproducing laser beam is radiated through this disk substrate. The disk substrate must satisfy the requirements of transferability and optical characteristics. However, when molding a disk substrate with a synthetic resin by injection molding, the two tend to conflict with each other in terms of molding conditions. For example, in terms of mold clamping pressure during molding,
The higher the mold clamping pressure is, the better the transferability is, but the optical characteristics are deteriorated due to the increase of stress, and the smaller the mold clamping pressure is, the better the optical characteristics are, but the transferability is deteriorated. The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a single-sided reproducing or single-sided recording / reproducing laminated optical disk which has both transferability and optical characteristics.

[0005]

The present invention has been made in view of the above-mentioned problems, and the laminated optical disk according to claim 1 is molded by injection molding, and an information recording surface is formed on one surface thereof. The first disk substrate having the same and the light-transmissive second disk substrate formed by injection molding are bonded together with the information recording surface inside by a light-transmissive adhesive layer, and the second
The information is reproduced or recorded through the disc substrate and the adhesive layer.

In the bonded optical disk according to the second aspect, the second disk substrate is a flat plate.

Further, in the bonded optical disk according to the third aspect, the second disk substrate is formed in a state in which the mold clamping pressure or the mold temperature is lower than that of the first disk substrate. To do.

[0008]

The bonded optical disk according to the present invention is made of a synthetic resin by injection molding, and has a first disk substrate having an information recording surface on one side thereof and a second transparent optical disk formed of the synthetic resin. The disc substrate and the information recording surface are attached to each other by a translucent adhesive layer, and information is reproduced or recorded through the second disc substrate and the adhesive layer. Therefore, the first disc substrate is transferred. Injection molding can be performed under molding conditions that place importance on the property, and the second disk substrate can be injection molded under molding conditions that place importance on optical characteristics.

[0009]

1 is a cross-sectional view of a bonded optical disk substrate according to an embodiment of the present invention. The same parts as those of the conventional example are designated by the same reference numerals. The information signal board 21 has a thickness of 0.4 to 0.8 mm, for example, 0.6 mm, is made of a synthetic resin such as polycarbonate or acrylic resin, and is a light transmissive first disk board formed by injection molding. An information recording surface having pits for carrying information is formed on one surface thereof, and a reflective layer 22 made of a metal film is formed so as to cover the information recording surface. In addition, this reflective layer 22
An ultraviolet-curable resin is spin-coated on the upper surface of the substrate to form a transparent protective layer 24 having a predetermined thickness.

Reference numeral 31 is made of a synthetic resin such as polycarbonate or acrylic resin used to increase mechanical strength, and has a thickness of 0.4 to 0.8 mm, for example, 0.
It is a light-transmissive second disk substrate 31 molded by 6 mm injection molding. The first and second disk substrates are bonded together with the information recording surface inside by a translucent adhesive layer 25 made of an ultraviolet curable adhesive or the like to form a bonded optical disk. The bonded type optical disc configured as described above has the second disc substrate 31 and the adhesive layer 25.
A light beam is focused on the information recording surface of the first disk substrate through the light beam and information is reproduced by the reflected light. Therefore, since the reproduction light beam does not pass through the first disk substrate having the information recording surface, the mold clamping pressure or the mold temperature can be increased and injection molding can be performed to improve the transferability. On the other hand, since the second disk substrate through which the reproducing light beam passes does not have an information recording surface, it is possible to improve the optical characteristics by injection molding while lowering the mold clamping pressure or the mold temperature.

In the above-mentioned embodiment, the optical disk of the reproducing substrate is illustrated, but a guide groove is formed on the information recording surface of the first disk substrate, and the reflective layer 22 is formed on the guide groove.
It is also possible to form a dye film, a magneto-optical material thin film, and a phase change material thin film to form a writable optical disc. Also,
The protective layer 24 may not be formed, and the adhesive layer may be used for direct bonding. Furthermore, the first disk substrate does not have to be light transmissive, and may be a colored substrate.

[0012]

According to the present invention, in an optical disk in which a first disk substrate having an information recording surface and a second disk substrate are bonded with the information recording surface inside, a second optical disk substrate is used. Since the information recording surface of the disc substrate 1 is used for reproducing information or recording information on the information recording surface, a single-sided reproducing or single-sided recording / reproducing laminated optical disk having both transferability and optical characteristics. Can be provided.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichi Hanzawa 2680 Nishihanawa, Tatomi-cho, Nakakoma-gun, Yamanashi Prefecture Pioneer Video Corporation

Claims (3)

[Claims] 1. A first disk substrate molded by injection molding and having an information recording surface on one surface thereof, and a light-transmissive second disk substrate molded by injection molding, the information recording surface being A laminated optical disk, which is laminated on the inside with a translucent adhesive layer, and information is reproduced or recorded through the second disk substrate and the adhesive layer. 2. The bonded optical disk according to claim 1, wherein the second disk substrate is a flat plate. 3. The second disk substrate is formed in a state where the mold clamping pressure or the mold temperature is lower than that of the first disk substrate.
The bonded type optical disk described in.