JPH09180256A - Optical information recording medium and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the boundary peeling at the outer peripheral end of a recording medium and near the part by constituting the outer peripheral end of only the second information recording layer and providing the recording medium with engageably fixing parts for engageably fixing the first and second information recording layers. SOLUTION: The optical disk 100 is composed of a two-layered structure obtd. by laminating and tightly adhering a substrate 1 which is the first information recording layer and a UV resin layer 2 which is the second information recording layer. The substrate 1 is molded to have a circular truncated conical shape by injection molding and the UV resin layer 2 is molded to include the outer periphery of the substrate 1. The outer peripheral part 11 of the substrate 1 has a slope 12 which is provided with rugged parts 3 as the engageably fixing parts, the outer peripheral end 14 of the UV resin layer 2 is also treated to round. The outer peripheral end of the optical information recording medium is composed of only the second information recording layer in such a manner and, therefore, the boundary does not occur at the outer periphery end and the peeling of the boundary is prevented. Since the recording medium is provided with the engageably fixing parts for engageably fixing the first information recording layer and the second information recording layer, the boundary peeling at the outer peripheral end and near the part is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium and a method for manufacturing the same, and more particularly to an optical information recording medium having a two-layer structure in which two information recording media are in close contact with each other and a method for manufacturing the same.

[0002]

2. Description of the Related Art FIG. 10 is a sectional structural view showing an example of a conventional optical disc.

This optical disk 1000 has a substrate 1001 serving as a first information recording layer and an ultraviolet curable resin (hereinafter referred to as "UV resin") layer 1002 serving as a second information recording layer.
And a two-layer structure. The substrate 1001 is formed by injection molding.

FIG. 11 is an explanatory view showing a method of manufacturing the optical disc 1000.

First, as shown in FIG. 1A, a required amount of the UV resin 1002 'in a fluid state is dropped onto a stamper S provided on the surface of a base (not shown).

Next, as shown in FIG.
The substrate 1001 is pressed from above the resin. This pressing is performed until the UV resin 1002 ′ has a predetermined film thickness. Subsequently, the UV resin 1002 ′ is cured by irradiating ultraviolet rays from the ultraviolet lamp L, and the substrate 100
Adhere to 1. The substrate 1001 is made of translucent resin.

Finally, as shown in FIG. 3C, the substrate 1001 and the cured UV resin layer 1002 are removed from the stamper S. From this, the optical disk 1000 is completed.

[0008]

In the above-mentioned conventional optical disc 1000, when the substrate 1001 is pressed against the UV resin 1002 ', as shown in FIG.
UV resin 1002 'was protruding from the end portion of (1) (the protruding portion 1002a). Therefore, there were the following problems.

(1) When the UV resin 1002 'is cured and removed from the stamper S, the protruding portion 1002a is missing as shown in FIG. 12 (b).
This causes the interface separation between the substrate 1001 and the UV resin layer 1002. In addition, the interfacial peeling means that the substrate 1001 and U
It means that the contact surface (interface) with the V resin layer 1002 is peeled off.

(2) Missing protruding portion 1002
a is scattered and adheres to the information area of the optical disc 1000,
Cause defects.

(3) Missing protrusion 1002
a remains on the stamper S and interferes with the manufacturing of the next optical disk 1000.

(4) When removing the protruding portion 1002a, it is necessary to add a manufacturing process, which complicates the manufacturing process.

On the other hand, as shown in FIG.
When pressing 001 against the UV resin 1002 ', the substrate 10
There is a method of limiting the dropping amount of the UV resin 1002 ′ so that the UV resin 1002 ′ does not protrude from the end of 01. However, this method also has a problem that interface separation occurs when the optical disc 1000 is removed from the stamper S, as shown in FIG. 13B.

Further, the optical disc 10 is mounted on the substrate 1001.
An inner hole serving as a central hole of 00 is formed (not shown). Therefore, UV should not be adversely affected to this inner hole.
It is necessary to control the flow of the resin 1002 '. Therefore, there is a problem in that the control becomes complicated.

Therefore, the present invention has been made in view of the above, and it is a first object of the present invention to provide an optical disk of good quality by preventing the interface separation between the substrate and the UV resin layer.
The purpose of.

The present invention has been made in view of the above, and a second object thereof is to realize continuous and stable manufacture of optical disks.

The present invention has been made in view of the above, and a third object thereof is to simplify the manufacturing process of an optical disk and the control contents in the manufacturing.

[0018]

An optical information recording medium according to claim 1 has a two-layer structure composed of a first information recording medium and a second information recording medium, and can read, write or erase information. An optical information recording medium that is optically performed is characterized in that the outer peripheral end portion of the optical information recording medium is composed of only the second information recording medium.

Conventionally, the interface peeling between the first information recording medium and the second information recording medium has occurred from the outer peripheral edge of the optical information recording medium. Therefore, this outer peripheral end is connected to the second
The information recording medium is used only so that no interface is generated at the outer peripheral edge. Therefore, no interfacial peeling occurs and a high quality optical information recording medium can be provided.

An optical information recording medium according to a second aspect of the present invention is the optical information recording medium according to the first aspect, wherein the first information recording medium and the second information recording medium are provided at an outer peripheral end portion of the first information recording medium. The constitutional feature is that an engaging portion for engaging with the information recording medium is provided.

The interface peeling often occurs not only in the outer peripheral edge of the optical information recording medium but also in the vicinity thereof. For this reason,
If the engaging portion is provided in this vicinity (specifically, the outer peripheral end portion of the first information recording medium), the first information recording medium and the second information recording medium can be firmly adhered to each other, and the interface peeling occurs. Can be further prevented.

An optical information recording medium according to a third aspect of the present invention is the same as the optical information recording medium, wherein the diameter of the outer peripheral end face of the first information recording medium differs in the thickness direction of the first information recording medium. The structural feature is that at least the second information recording medium side has a large diameter portion.

That is, if the engaging portion is one form and has at least a portion having a large diameter on the side of the second information recording medium, the second information recording medium is attached to the portion. It Therefore, the first information recording medium and the second information recording medium can be firmly adhered to each other, and interface separation can be further prevented.

An optical information recording medium according to a fourth aspect is characterized in that, in the optical information recording medium according to the second aspect, convex and concave portions are provided on an outer peripheral end surface of the first information recording medium. It is a thing.

The convex and concave portions are also a form of the engaging portion, and the second information recording medium is engaged with the convex and concave portions. Therefore, the first information recording medium and the second information recording medium can be firmly adhered to each other, and interface separation can be further prevented.

An optical information recording medium according to a fifth aspect of the present invention is characterized in that, in the optical information recording medium, the outer peripheral edge of the second information recording medium is rounded.

If the outer peripheral edge portion of the second information recording medium is formed into a corner, the corner portion will be fixed to the molding die and chipped or scattered when the optical information recording medium is removed from the molding die.
Therefore, the second outer peripheral edge portion is provided with a rounded shape to prevent chipping and scattering. As a result, the optical information recording medium can be smoothly removed and can be manufactured continuously and stably.

According to a sixth aspect of the present invention, there is provided a method of manufacturing an optical information recording medium, in which a fluidized second information recording medium is pressed against a molded first information recording medium to spread it, and the second information recording medium is cured. In the method for manufacturing an optical information recording medium having a two-layer structure, the first information recording medium is molded so that there is no protruding portion on the side of the second information recording medium before the gate cut. It is a feature of the above.

Since there is no protruding portion in the mold for pouring the fluid, the UV resin easily flows into the entire surface of the first information recording medium, and the control in the inner peripheral portion of the optical information recording medium becomes unnecessary.

According to a seventh aspect of the present invention, there is provided a method of manufacturing an optical information recording medium according to the above-mentioned method of manufacturing an optical information recording medium, wherein a second fluid state is provided in a mold in which the first information recording medium is set.
When the information recording medium (1) is poured, the air inside the mold is exhausted.

This makes it possible to prevent bubbles from entering the second information recording medium.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below in the order of Embodiment 1 and other embodiments with reference to the drawings. The present invention is not limited to these examples.

(Embodiment 1) FIG. 1 is a cross-sectional configuration diagram showing an optical disk which is Embodiment 1 of the present invention.

This optical disc 100 has a two-layer structure in which a substrate 1 which serves as a first information recording layer and a UV resin layer 2 which serves as a second information recording layer are laminated and adhered. Reference numeral 101 is a center hole for attaching the center hub. The substrate 1 has a truncated cone shape and is formed by injection molding.
Further, the UV resin 2 is molded so as to cover the outer periphery of the substrate 1.

FIG. 2 is an enlarged view of the outer peripheral edge portion 102 of the optical disc 100.

As described above, since the substrate 1 has the truncated cone shape, the outer peripheral end 11 of the substrate 1 has the slope 12. Further, the slope 12 is provided with an uneven portion 13. Further, the outer peripheral edge portion 14 of the UV resin 2 is rounded.

Next, a method of manufacturing the optical disc 100 will be described.

First, the substrate 1 is molded by injection molding. In the substrate 1, as shown in FIG. 3, the sprue lock portion 1b is formed inside the sprue 1a. 1c is a gate part. Further, as described above, the convex and concave portions 13 are formed on the slope 12 of the substrate 1.

Next, as shown in FIG. 4, the substrate 1 is held at a predetermined position of the molding die M. Here, the molding die M
Are an upper case M1 for holding the substrate 1, a lower case M2 (including a stamper and its base) united with the upper case M1, and a base M3 having a stamper M31 on the surface for supporting the lower case M2. , The substrate 1
It is mainly composed of a punch M4 and a center piston M5 for cutting the gate portion 1c. The upper case M1 and the lower case M2 are made of quartz glass, and are portions M12 and M22 corresponding to the outer peripheral edge 14 of the optical disc 100.
Is rounded.

The substrate 1 is held by the upper case M1.
This is performed by the negative pressure generated in the groove M11 provided in the. A plunger or the like (not shown) for injecting the UV resin 2 ′ is connected to the molding die M.

Next, as shown in FIG. 5, the upper case M1
And the lower case M2 are united and the mold is clamped. Then, the UV resin 2'which is in a fluidized state by heating is injected and filled into the molding die M. At the time of injection, the air in the mold M is exhausted. By this injection filling, the slope 12 of the substrate 1 is covered by the UV resin 2 '. As a result, the outer peripheral edge portion 102 of the optical disc 100 is composed only of the UV resin 2 '. Also, the sprue lock portion 1
UV resin 2'also flows into b. As described above, since the sprue lock portion 1b is provided in the sprue 1a, it does not hinder the flow of the UV resin 2 '. Therefore, the flow control is not necessary, and the UV resin 2 ′ easily flows into the entire surface of the substrate 1.

Subsequently, ultraviolet rays are irradiated (not shown) from above the upper case M1 to cure the UV resin 2 '. When the UV resin 2'is cured, the slope 12 of the substrate 1
The UV resin layer 2 bites into the convex and concave portions 13 and the substrate 1
And the UV resin layer 2 are firmly fixed.

Next, the punch M4 is lowered by a predetermined stroke to cut from the gate portion 1c portion of the substrate 1 to remove the sprue 1a and the like. As a result, the central hole 101 is opened. The center piston M5
Descends according to the punch M4.

Next, as shown in FIG. 6, the upper case M1 is moved upward while holding the substrate 1 and the UV resin layer 2 so that the substrate 1 and the UV resin layer 2 are removed from the lower case M2. Remove. To remove the punch M
It is accelerated by the air jet from 3 (not shown).

Next, the negative pressure of the upper case M1 is changed to a positive pressure. Then, the substrate 1 and the UV resin layer 2 are removed from the upper case M1 to complete the optical disc 100.

As described above, according to the optical disc 100, the outer peripheral edge portion 102 (see FIG. 1) of the optical disc 100 is U-shaped.
Since it is composed of only the V resin layer 2, an interface does not occur at the outer peripheral end portion 102. Therefore, the interface peeling between the substrate 1 and the UV resin layer 2 can be prevented.

Next, the substrate 1 and the UV resin layer 2 are attached to each other by the slope 12 and the projections 13 of the substrate 1. Therefore, the substrate 1 and the UV resin layer 2 are firmly fixed to each other, and interface peeling can be further prevented.

Further, since the outer peripheral edge portion 14 of the UV resin 2 is rounded, it is possible to prevent the UV resin layer 2 from being dropped or scattered when the optical disc 100 is removed from the mold M. As a result, the optical disc 100 can be smoothly removed, so that the optical disc 100 can be manufactured continuously and stably. In addition, it is possible to prevent adverse effects on the optical disc 100 (such as adhesion to the information area).

Further, in the substrate 1, since the sprue lock portion 1b is provided in the sprue 1a, the UV resin layer 2
There is no protruding part on the side. For this reason, the UV resin 2 ′ easily flows into the entire surface of the substrate 1, and flow control becomes unnecessary. Further, when the UV resin 2'is poured, the air in the mold M is exhausted, so that it is possible to prevent bubbles from being mixed into the UV resin layer 2.

(Other Embodiments) In the above embodiment, the outer peripheral end portion 11 of the substrate 1 is provided with the slope 12 and the unevenness 13 and the substrate 1 and the UV resin layer 2 are fixed to each other. I can't.

For example, as shown in FIG. 7, the outer peripheral end portion 11 may be provided with a groove 71 having a V-shaped cross section. Also,
As shown in FIG. 8, a convex portion 81 may be provided on the outer peripheral end portion 11. Further, as shown in FIG.
It is also possible to provide a plurality of grooves 91 without providing an inclination.

[0052]

As described above, according to the optical information recording medium of the present invention (Claim 1), the outer peripheral edge portion of the optical information recording medium is composed of only the second information recording medium.
No interface is generated at the outer peripheral edge. Therefore, interface peeling can be prevented and the quality of the optical information recording medium is improved.

According to the optical information recording medium of the present invention (Claim 2), at the outer peripheral end of the first information recording medium,
An engaging portion for engaging the first information recording medium and the second information recording medium is provided. Therefore, it is possible to prevent interfacial peeling at the outer peripheral edge of the optical information recording medium and its vicinity.

Further, according to the optical information recording medium of the present invention (claims 3 and 4), as one form of the engaging portion,
A portion having a large diameter is provided at least on the side of the second information recording medium. Alternatively, a convex / concave portion is provided on the outer peripheral end surface of the first information recording medium. For example, as in the above-described embodiment, the outer peripheral edge of the first information recording medium is provided with an inclination or an unevenness. By doing so, the second information recording medium is attached to such a portion, and the first information recording medium and the second information recording medium can be firmly adhered. As a result, interface peeling can be further prevented.

Further, according to the optical information recording medium of the present invention (Claim 5), since the outer peripheral edge of the second information recording medium is provided with the roundness, when the optical information recording medium is removed from the molding die, the chipping or scattering occurs. Absent. Therefore, the optical information recording medium can be continuously and stably manufactured. In addition, it does not adversely affect the quality of the optical information recording medium.

Further, according to the method of manufacturing an optical information recording medium of the present invention (claim 6), the first information recording medium is projected to the side of the second information recording medium in the state before gate cutting. Mold so that there is no For this reason, the UV resin easily flows into the entire surface of the first information recording medium, and control in the inner peripheral portion of the optical information recording medium becomes unnecessary.

Further, according to the method for manufacturing an optical information recording medium of the present invention (claim 7), when the second information recording medium in a fluid state is poured into the molding die in which the first information recording medium is set. The air inside the mold was exhausted. Therefore, it is possible to prevent bubbles from entering the second information recording medium.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram showing an optical disc that is Embodiment 1 of the present invention.

FIG. 2 is an enlarged view showing an outer peripheral end portion of the optical disc of FIG.

FIG. 3 is a cross-sectional view showing a substrate before gate cutting.

FIG. 4 is an explanatory diagram showing a method of manufacturing an optical disc.

FIG. 5 is an explanatory diagram showing a method of manufacturing an optical disc.

FIG. 6 is an explanatory diagram showing a method for manufacturing an optical disc.

FIG. 7 is a cross-sectional configuration diagram showing an optical disc which is another embodiment of the present invention.

FIG. 8 is a cross-sectional configuration diagram showing an optical disc which is another embodiment of the present invention.

FIG. 9 is a cross-sectional configuration diagram showing an optical disc which is another embodiment of the present invention.

FIG. 10 is a sectional structural view showing an example of a conventional optical disc.

FIG. 11 is an explanatory diagram showing a method of manufacturing the optical disc of FIG.

12 is an enlarged cross-sectional view showing an outer peripheral end portion of the optical disc of FIG.

FIG. 13 is an enlarged cross-sectional view showing the outer peripheral edge of the optical disc.

[Explanation of symbols]

 100 Optical Disc 1 Substrate 11 Outer Edge 12 Slope 13 Concavo-convex 14 Outer Edge 1a Sprue 1b Sprue Lock 1c Gate 2 UV Resin Layer 101 Center Hole 102 Outer Edge

Claims (7)

[Claims] 1. An optical information recording medium having a two-layer structure comprising a first information recording medium and a second information recording medium and optically reading, writing or erasing information, said optical information recording medium. An optical information recording medium, characterized in that the outer peripheral edge portion thereof is constituted only by the second information recording medium. 2. The optical information recording medium according to claim 1, wherein the first information recording medium and the second information recording medium are attached to an outer peripheral end portion of the first information recording medium. An optical information recording medium having a fastening portion. 3. The optical information recording medium according to claim 2, wherein the diameter of the outer peripheral end surface of the first information recording medium differs in the thickness direction of the first information recording medium, and at least the first information recording medium. 2. An optical information recording medium having a large diameter portion on the side of the second information recording medium. 4. The optical information recording medium according to claim 2, wherein the first information recording medium is provided with convex and concave portions on an outer peripheral end surface thereof. 5. The optical information recording medium according to claim 1, wherein the outer peripheral edge of the second information recording medium is rounded. . 6. A method for producing an optical information recording medium having a two-layer structure by pressing and spreading a second information recording medium in a fluid state onto a molded first information recording medium to cure the second information recording medium. In the method, the first information recording medium is molded such that there is no protruding portion on the side of the second information recording medium before the gate cutting, and a method for manufacturing an optical information recording medium. 7. The method for manufacturing an optical information recording medium according to claim 6, wherein when the second information recording medium in a fluid state is poured into a molding die in which the first information recording medium is set, the molding is performed. A method for manufacturing an optical information recording medium, which comprises exhausting air in a mold.