JPH04341944A - Production of optical disk - Google Patents

Abstract

PURPOSE:To provide the process for producing the optical disk of a double-sided type which solves the damage to the optical disk and the misalignment thereof by a photopolymer method by the change of the shape of a radiation transmittable substrate and the shaping using a laser beam machine and can prevent the oxidation of a reflection layer in the process for producing the optical disk to be used as various kinds of information apparatus. CONSTITUTION:A radiation curing resin 2 and an optical master disk 3 are damaged by a spatula for peeling at the time of peeling the radiation curing resin 2 cured by irradiation with radiations together with the radiation transmittable substrate 1a from the optical master disk 3 but if the damaged part is within the range of the removed part 7 in the outer peripheral part, this part is the removed part and, therefore, there is no damage on the optical disk. The center of the optical disk is determined from the outermost peripheral part or innermost peripheral part of the information recording range 5 transferred from the optical master disk 3 at the time of shaping of the optical disk by the fusion cutting using the laser beam machine, by which the misalignment is confined within 0.01. Since the cut part is cut by fusion cutting, the upper and lower radiation transmittable substrates 1a, 11a are welded and the radiation curing resin 2 and the reflection layer 8 are put into a hermetically sealed state. The double-sided type optical disk with which the oxidation of the reflection layer 8 can be prevented is obtd. in this way.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an optical disc, and more particularly to a method of manufacturing an optical disc using a radiation-transparent substrate having a wider area at the outer periphery than the prescribed shape of the optical disc.

0002

[Prior Art] In the method of manufacturing optical discs using fluid molding resin, the photopolymer method prepares a plastic substrate with good optical properties, and hardens it with radiation such as ultraviolet rays between this and an optical disc master that serves as a mold. This is a method of manufacturing optical discs by filling resin, irradiating radiation from the plastic substrate side to harden the resin, and peeling the plastic substrate and hardened resin together from the mold.This method produces high-density disks with excellent transferability. Suitable for small quantity production of information recording media.

[0003] A conventional method of manufacturing an optical disc will be explained below with reference to the drawings. In FIGS. 2 and 3, 1b is a radiation-transparent substrate having a prescribed shape for an optical disc, 2 is a radiation curing resin, 3 is an optical disc master, 4 is an information recording range on the surface of the optical disc master 3, and 10 is a positioning pin.

[0004] A method of manufacturing the optical disc configured as described above will be explained below with reference to FIGS. 2 and 3.

[0005] First, the radiation-curable resin 2 is cured by radiation irradiation, and is then peeled off from the optical disk master 3 together with the radiation-transparent substrate 1b using a peeling spatula (not shown). At this time, a peeling spatula is inserted between the radiation-cured resin 2 and the optical disk master 3 from the outer circumferential side.

[0006]

[Problems to be Solved by the Invention] However, in the above-mentioned conventional method, since the radiation-transparent substrate 1b itself becomes the completed optical disk, the damaged portion that occurs on the radiation-transparent substrate 1b is not damaged in the completed optical disk. Become. Therefore, inserting the peeling spatula between the radiation-cured resin 2 and the optical disk master 3 itself damages the radiation-transparent substrate 1b, the radiation-curable resin 2, and the optical disk master 3.

Moreover, during the peeling operation, the peeling spatula not only damages the radiation-transparent substrate 1b, the radiation-cured resin 2, and the optical disc master 3, but also damages the information recording range 4 on the surface of the optical disc master 3. many.

Furthermore, due to the dimensional accuracy and concentricity of the inner peripheral hole of the radiation-transparent substrate 1b, the amount of misalignment of the optical disk is 0.0.
3, which had the problem of large variations.

The present invention solves the above-mentioned conventional problems, and provides a method for manufacturing an optical disc that suppresses damage to completed optical discs and optical disc masters, and reduces misalignment and concentricity to within 0.01. The purpose is to

0010

[Means for Solving the Problems] In order to achieve this object, the method for manufacturing an optical disc of the present invention uses a radiation-transparent substrate having a larger area on the outer peripheral side than the prescribed shape of the optical disc,
In addition, two optical disks on which different types of information have been recorded are placed one on top of the other, with the sides of the radiation-transparent substrates having a wider area on the outer periphery than the prescribed shape facing each other, and the outer periphery is cut by a laser processing machine. The optical disc is then shaped into the prescribed shape.

[0011]

With this structure, in the optical disc manufacturing method of the present invention, a radiation-transparent substrate whose outer peripheral area is wider than the prescribed shape of the optical disc has removed portions at the inner and outer peripheral parts. This removed portion can be used as a contact portion for a peeling spatula, so that damage to the completed optical disc and optical disc master can be suppressed.

[0012] Furthermore, the center of the optical disc is determined from the information recording range transferred to the radiation-cured resin, and the outer circumference is cut by a laser processing machine to shape the optical disc into a prescribed shape, thereby reducing the misalignment and concentricity by 0.01. It will be possible to do it within.

[0013]

【Example】

(Embodiment 1) A first embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1(a), 1a is a radiation-transparent substrate whose outer peripheral area is wider than the prescribed shape of the optical disc, 2 is a radiation-curable resin, 3 is an optical disc master, 4 is an information recording range on the surface of the optical disc master 3, 6 is the inner peripheral side removed part, 7
is the removed portion on the outer circumferential side.

The operation of the method for manufacturing the optical disc constructed as above will be explained below with reference to FIGS. 1(a) and 1(c).

First, since the area of the outer periphery of the radiation-transparent substrate 1a is wider than the prescribed shape of the optical disc, the removed portions are divided into the inner periphery (inner periphery removed portion 6) and the outer periphery (outer periphery removed portion 7).
It is set up in

When peeling the radiation-cured resin 2, which has been cured by irradiation with radiation such as ultraviolet rays, from the optical disk master 3 together with the radiation-transparent substrate 1a, a peeling spatula (not shown) is used to separate the radiation-curable resin 2 and the optical disk master 3. By inserting the resin between the radiation cured resin 2 and the optical disc master 3, the part outside the information recording range will be damaged, but if it is within the range of the outer peripheral side removed part 7, it is the removed part, so there will be no damage to the completed optical disc. None.

Further, if the range of the outer peripheral side removal portion 7 is sufficient, the peeling operation can be easily performed without the peeling spatula reaching the information recording range 4 on the surface of the master optical disk.

As described above, according to this embodiment, by making the area of the radiation-transparent substrate larger than the prescribed shape of the optical disc, it is possible not only to eliminate damage to the completed optical disc, but also to facilitate the peeling operation itself. can do.

(Embodiment 2) A second embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1(b), 1a is a radiation-transparent substrate, 2 is a radiation-curable resin, 5 is an information recording range on the radiation-transparent substrate transferred from the optical disc master 3, 7 is a removed portion on the outer peripheral side, and 8 is a radiation-curable resin. The reflective layer 9 is the tip of the laser processing machine nozzle.

The operation of the method for manufacturing the optical disc constructed as described above will be explained below with reference to FIG. 1(b).

First, the radiation-curable resin 2 of the radiation-transparent substrate 1a to which the radiation-curable resin 2 peeled off in Example 1 is attached is removed.
A reflective layer 8 made of aluminum or the like is formed on the side. On this reflective layer 8, a radiation-transparent substrate 1a with the radiation-curable resin 2 attached and a radiation-transparent substrate 11a on which different types of information are recorded are stacked, fixed at a prescribed thickness of the optical disc, and irradiated with radiation such as ultraviolet rays. The radiation curing resin 2 is cured to complete an optical disc having a wider area than the prescribed shape of the optical disc.

[0024]Finally, the outer periphery is fused with a laser processing machine,
A double-sided optical disc can be completed by shaping the optical disc into a prescribed shape.

Before performing the laser processing, the center of the optical disc is determined from the outermost or innermost part of the information recording range transferred from the optical disc master 3. Even including the error when determining the center of the optical disc from the four points on the outermost or innermost periphery and the error of the laser processing machine itself, the amount of misalignment can be kept within 0.01, improving quality. .

[0026] Furthermore, the part cut by the laser processing machine is
Since it is fused, the upper radiation-transparent substrate 1a and the lower radiation-transparent substrate 11a are welded together and the radiation-cured resin 2
Then, the reflective layer 8 is in a sealed state. This allows the reflective layer 8 to be prevented from oxidizing.

As described above, according to this embodiment, by cutting the outer periphery with a laser processing machine and shaping the optical disc into the prescribed shape, the amount of misalignment can be suppressed to within 0.01, and at the same time, the oxidation of the reflective layer 8 can be prevented. It can be carried out.

[0028]

Effects of the Invention As is clear from the description of the above embodiments, according to the method of manufacturing an optical disk of the present invention, the radiation-transparent substrate can be made into a substrate whose outer peripheral area is larger than the prescribed shape of the optical disk; By cutting the outer periphery using a processing machine and shaping the optical disc into the specified shape, damage to the optical disc and optical disc master is suppressed, and the amount of misalignment is reduced to 0.01.
Therefore, it is possible to realize an excellent method for manufacturing an optical disc that can prevent oxidation of the reflective layer while at the same time preventing the oxidation of the reflective layer.

[Brief explanation of the drawing]

FIG. 1: (a) A cross-sectional view showing the state during a peeling operation to explain the structure and operation in the optical disc manufacturing method of the first embodiment of the present invention; (b) A cross-sectional view of the double-sided disc of the second embodiment. Cross-sectional view showing an enlarged view of the state during shaping by a laser processing machine for explaining the structure and operation in the optical disk manufacturing method (c) A plan view of the same radiation-transparent substrate

[Fig. 2] A cross-sectional view showing the state during peeling work to explain the structure and operation in a conventional optical disc manufacturing method.

[Figure 3
] Plan view of a radiation-transparent substrate in a conventional optical disc manufacturing method

[Explanation of symbols]

1a Radiation transparent substrate 2 Radiation curing resin 3 Optical disc master 4 Information recording range on optical disc master 5
Information recording range 6 on the radiation transparent substrate
Inner periphery removal range 7 Outer periphery removal range 8 Reflection layer 9 Laser processing machine nozzle tip 11a Radiation transparent substrate on which information different from the radiation transparent substrate 1a is recorded

Claims (2)

[Claims] 1. A method for manufacturing an optical disk by a casting method using a radiation-curable resin, using a radiation-transparent substrate having a wider area at the outer periphery than the prescribed shape of the optical disk. 2. Two optical disks on which different types of information have been recorded are stacked with the sides of the radiation-transparent substrates having a wider area on the outer periphery than the prescribed shape, with the surfaces on which the information is recorded facing each other, and a laser processing machine is used to stack them. A method for manufacturing a double-sided optical disc, wherein the outer peripheral portion is cut by melting and the optical disc is shaped into a prescribed shape.