JPS6124167B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a disk-shaped information recording carrier (hereinafter referred to as a disk).

2. Description of the Related Art Conventionally, disks have been considered that have concave and convex grooves on their surfaces corresponding to recorded information and concentric or spiral guide grooves along recording tracks to be recorded.

There is a method shown in FIG. 1 as a method for manufacturing a disk having predetermined irregularities formed on its surface.

In FIG. 1, reference numeral 1 denotes a disk-shaped disk base material, which is often made of cast acrylic resin, vinyl chloride resin, or the like. A stamp board 2 has a predetermined unevenness on its surface and is held with a gap 3 between it and the disk base material 1 (the holding method is not shown). The stamp board 2 has an injection port 4 and an introduction pipe 5 in the center thereof for discharging a viscous liquid ultraviolet curable resin (UV resin). A pipe 6 is connected to the introduction pipe 5, and the UV resin flows from the center toward the outer periphery of the disk base material 1 as shown by the arrow 7 through the pipe 6 and the introduction pipe 5, filling the gap 3. After that, the UV resin is cured together with the disk base material 1 by irradiating ultraviolet rays from the A direction, and the stamp disk 2 is
This is a method of transferring the unevenness of the disk onto the disk base material 1.

This method has the following drawbacks in actual use.

1 In the initial state of UV resin discharge, air inside the pipe is easily drawn in and air bubbles are likely to be mixed in.

2. Only low-viscosity UV resin can be used because it needs to be poured into the narrow gap between the disc base material and the stamp board. In other words, it has poor adhesion to the disc base material made of cast acrylic resin.
Only UV resin can be used.

3 In order to fill the entire circumference uniformly, it is necessary to discharge extra UV resin, and the post-processing of the protruding UV resin causes foreign matter to be generated during clean room work, making extra UV resin necessary.

4. A hardened lump of UV resin appears in the center and needs to be removed every time. Furthermore, even if a shielding plate or the like is provided to prevent the UV resin inside the pipe from solidifying, for example, the movement of the shielding plate will generate foreign matter, causing quality deterioration.

As mentioned above, many defects occur due to the inclusion of air bubbles, foreign objects, etc., and disks used for applications where defects are noticeable such as still image files, and applications where information errors are a problem such as document files. This can be said to be inappropriate as a manufacturing method.

The present invention eliminates these drawbacks and uses a cast acrylic board, which is ideal as a base material for optical disks because it has the least internal foreign matter, has excellent transparency, and has excellent mechanical strength among resin base materials. Even if
The present invention provides a manufacturing method for producing high-quality, highly reliable optical discs by filling and curing UV resin without air bubbles or foreign matter, thereby transferring guide grooves and information irregularities with high precision. be.

An embodiment of the method for manufacturing an optical disk according to the present invention will be described below with reference to the drawings.

FIG. 2 shows the state in which UV resin is applied to a disk base material, and 1 is a transparent disk base material having a center hole 8 in the center. This disk base material 1 is supported by a support body (not shown) so as to rotate at a constant speed in the direction of an arrow 9 about a center hole 8 . The method of rotating the disk base material 1 is not essential; it is sufficient to rotate the disk base material 1 at a constant speed around the center hole.

Reference numeral 10 denotes a nozzle of a fixed-quantity dispensing device for dispensing a fixed amount of UV resin, and the diameter for applying the UV resin is set by the fixed position of the nozzle 10. Reference numeral 11 denotes a UV resin discharged from a nozzle 10 and applied in an annular manner on the concentric circle of the center hole 8 of the disk base material 1;
The amount No. 1 is applied by adjusting the rotation speed of the disk base material 1 or the discharge amount of the metering dispensing device, etc. to apply a set amount. A UV resin with a viscosity of 3300 CPS (25°C) was used in this example.

FIG. 3 is a cross-sectional perspective view showing a state in which UV resin 11 is coated concentrically and annularly on the disk base material 1.
The cross section 12 of the applied UV resin is in a raised state due to the viscosity of the UV resin. Figure 4~
FIG. 7 shows a state in which the disk base materials are overlapped. Reference numeral 13 denotes a stamp board having guide grooves or signal irregularities on its surface, and is installed on a base 15 with a metal fitting 14 at the center. This metal fitting 14 is fitted into the center hole 8 of the disc base material 1 to position the stamp board 13 and the disc base material 1.

The stamp disc 13 is manufactured by a manufacturing method that is normally used for video discs, etc., for example, by coating a glass master with photoresist to the required thickness and then cutting it with a laser to produce the master disc.
Although the stamp board is made of metal using an electroforming method from a master disc, there is no difference even if the stamp board is made of silicone rubber or the like, which is simply made.

The base material 1 of the disk, on which the UV resin has been applied in an annular manner on the concentric circle of the center hole 8 using the quantitative dispensing device, is turned upside down from the applied state as shown in Fig. 4, and the UV resin 11 is applied as shown in Fig. 5. One point of the stamp board 13 is brought into contact with the stamp board 13. The stamp board 13 starts from the contact point 16 between the UV resin 11 and the stamp board 13.
In order for the contact part of the UV resin 11 to spread along the annular UV resin 11, use the arrow 1 at the contact point 16 as a fulcrum.
By gradually overlapping the disk base material 1 and the stamp board 13 in the direction 7, the UV resin 11 is brought into contact with the entire circumference of the stamp board 13. 6th
After contacting the UV resin 11 all around the circumference as shown in the figure, by pressing the disc base material 1 against the stamp board 13, the UV resin 11 is applied to the disc base material 1.
The stamp board 13 is filled with no air bubbles between the disc base material 1 and the stamp board 13. As shown in FIG. 7, the UV resin 11 is cured by irradiating ultraviolet rays from the side of the disc base 1 with the UV resin 11 filled between the disc base 1 and the stamp board 13.

At the same time as the UV resin is cured, the disk base material 1
By peeling off the disc base material 1 and the stamp board 13, the unevenness of the stamp board 13 is transferred to the UV resin, that is, the disc base material 1, and it has guide grooves or signal irregularities, thereby preventing air bubbles from entering. It is possible to obtain a disc base material of high quality. Furthermore, if the metal fitting 14 of the stamp board 13 and the center hole 8 of the disk base material 1 are fitted with high precision, a disk with good concentricity between the center hole 8 and the stamp board 13 can be obtained. This center hole 8 thus serves as a reference during the process. In addition, as a method of overlapping the disc base material and the stamp board with UV resin interposed, the disc base material coated with UV resin is held in the direction of application, that is, with the UV resin on the upper side of the disc base material, and the stamp is applied from above. It is also possible to stack the discs in the same way, but as shown in Figure 8, as time passes, the UV resin coated in a circular shape becomes less raised due to its own weight than the initial coated state 18. 19, and when it comes into contact with the stamp board, it comes into contact with a wide area, making it easy for air bubbles to get mixed in. Conversely, as explained in Figures 4 to 7, by flipping the disk base coated with UV resin upside down,
Due to its own weight, the UV resin changes to a more raised state than when it was applied, and comes into contact with the stamp board 13 at points, making it difficult for air bubbles to get mixed in. Of course, if the disk base material coated with UV resin is left upside down for a long period of time, the UV resin will fall off and cause bubbles, but the time it takes for it to fall off depends on the viscosity of the UV resin, but it is about 30 seconds. ~60
Seconds can be maintained without falling, and it is quite possible to complete the superposition within this time. 9 and 10 show an embodiment of the jig for overlapping as described above, in which 20 is a base for fixing the stamp board 13, and 21 is a spacer fixed at four locations on the outer periphery of the stamp board 13. The thickness of the UV resin is regulated according to the height from the base 20. 22 is a holding plate that holds the disk base material 1 and holds the disk base material 1 by vacuum suction (not shown).
is held. Reference numeral 23 denotes a positioning shaft between the presser plate 22 and the disk base material 1, which is positioned by the center hole 8 of the disk base material 1 and the hole 24 provided in the center of the presser plate 22, and is configured to be removed when overlapping. It's summery. Reference numeral 25 denotes a bearing fixed to the base 20 so that the holding plate 22 rotates around a pin 26. After setting the disk base material 1 coated with the UV resin 11 in an annular shape using the jig roughly constructed as described above, the presser plate 22 is set in the direction indicated by the arrow 27.
The disk substrates 1 are rotated in the direction of , and the disk substrates 1 are turned upside down and gradually overlapped.

Note that in order to obtain a recordable information carrier, the surface of the disk on which the guide grooves have been formed as described above is
It is sufficient to provide a recording layer whose unevenness or density changes depending on the light beam or the like.

As explained above, according to the present invention, the following effects can be obtained.

By applying resin concentrically and annularly to the disk base material and overlapping them, it is possible to transfer video information and the like using the minimum amount of resin necessary. That is, it is economical because the amount of resin used is small, and post-treatment of the resin protruding from the disk after transfer is facilitated.

Further, in the manufacturing process of the disk, it is possible to use a disk base material in which a center hole is previously provided as a reference for positioning.

Furthermore, by stacking the UV resin-coated disk base material on a stamp board with the resin-coated side facing down, a highly reliable optical disk without air bubbles can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing a conventional UV resin filling method, Fig. 2 is a perspective view showing a UV resin coating method according to an embodiment of the present invention, and Fig. 3 is a disk base coated with UV resin. 4 to 7 are diagrams showing the process of the UV resin filling method according to the present invention, FIG. 8 is a side sectional view showing the state of application of the UV resin, and FIG. 9 is a cross-sectional perspective view of the material. By example
A plan view of the UV resin filling jig, and FIG. 10 is a side view of the same. 1... Disk base material, 11... UV resin, 13... Stamp board.

Claims (1)

[Scope of Claims] 1. A viscous resin is applied in an annular manner concentrically to the center of a disk-shaped disk base material, and then placed on a stamp board having predetermined unevenness and pressed,
The resin is filled between the stamp board and the disc base material to form a resin layer, and then the resin is cured integrally with the disc base material, so that the unevenness of the stamp disc is transferred to the disc base material. A method for manufacturing an information carrier. 2. The method for manufacturing an information carrier according to claim 1, characterized in that an ultraviolet curable resin is used as the resin. 3 With the resin-coated side of the disc base material coated with resin facing downward, tilt the disc base material slightly against the stamp board held horizontally, and stamp one point on the annular resin on the lower side of the disc base material. The disc base material is brought into contact with the disc, and the resin is filled by gradually overlapping the disc base materials diagonally so that the contact part between the stamp disc and the resin spreads along an annular shape starting from the contact part. A method for producing an information carrier according to scope 1.