JPH07201086A - Method for preproducing optical disk stamper and reproducing device therefor - Google Patents

Abstract

PURPOSE:To reproduce a stamper and to make reproduction possible without giving any effects on the information signal part thereof by polishing the back surface of the optical disk stamper after being used for a specified number of times. CONSTITUTION:With the information signal surface of an optical disk stamper 2 used by about fifty thousand times downward, positioning is performed by inserting a positioning pillar body 10 into a center hole 2a thereof and the stamper is disposed on a stamper mounting base 15. In this case, the inner circumference of an optical disk stamber 2 is positioned in an inner circumferenc supporting part 12 and the information signal part of the optical disk stamper 2 is made to correspond to a recessed part 13. Then, making the inside of the recessed part 13 a negative pressure, this optical disk stamper 2 is vacuum- sucked and fixed on the mounting base 15. Then, this positioning pillar body 10 is removed and the back surface of the optical disk stamper 2 is ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing method and reproducing apparatus for an optical disk stamper for obtaining an optical disk such as a magneto-optical disk.

[0002]

2. Description of the Related Art Magneto-optical disks are generally formed by thermoplastic injection molding. In this thermoplastic injection molding, as shown in FIG. 3, for example, a stamper 2 for an optical disk having a desired information signal is provided in a movable mold 1a, and an information signal surface is fixed to a mold 1b.
Set as the side.

When performing the thermoplastic injection molding, first, the movable mold 1a is moved to clamp the movable mold 1a and the fixed mold 1b, and thereafter, the movable mold 1a is preliminarily set to, for example, 3
A thermoplastic resin 3 such as polycarbonate heated to 00 ° C. is injected (injected) at high pressure through the fixed mold 1b,
After that, it is cooled and solidified, and then the mold 1a is opened to take out the product.

In this case, the optical disk stamper 2 set in the movable mold 1a receives the thermoplastic resin 3 heated at a high pressure, transfers the information signal of fine unevenness to the optical disk, and then the optical disk is cooled and the product is taken out. However, the series of operations of this thermoplastic injection molding is, so to speak, accompanied by a shocking repetition of pressure and a shocking repetition of heat.

Therefore, for example, a moving mold 1 made of carbon steel is used.
a and the optical disk stamper 2 made of, for example, a nickel alloy, are rubbed by the relative difference in thermal expansion, and the back surface of the optical disk stamper 2 is gradually roughened.
After using 10,000 times (shots), the optical disk 4 of the product appears as polarization abnormality as shown in FIG. 4, so the life of the optical disk stamper 2 is about 50,000 times (shots) as a guide, and the rough surface of this back surface is rough. The optical disk stamper 2 was discontinued even if there was no defect in the information signal surface.

[0006]

However, it takes a relatively long time and labor to form the stamper 2 for an optical disk, and this material uses, for example, an expensive nickel alloy, and in order to provide the user with an inexpensive product. It is required to extend the life of the optical disk stamper 2.

In view of the above, the present invention provides a method and apparatus for reproducing an optical disk stamper for extending the life of the optical disk stamper.

[0008]

The present invention is a method of reproducing an optical disk stamper for forming an optical disk 4 by injection molding, in which the back surface of the optical disk stamper 2 is used after being used a predetermined number of times, for example, 50,000 times (shots). It is designed to be polished.

As shown in FIGS. 1 and 2, for example, the reproducing apparatus of the optical disk stamper of the present invention has a center hole 2a of the optical disk stamper 2 inserted therein, and the optical disk stamper 2 is positioned so as to be detachable. Means 10, inner circumference support means 11 for supporting the inner circumference of the optical disk stamper 2 provided along the outer circumference of the positioning means 10, and outer circumference support means 12 for supporting the outer circumference of the optical disk stamper 2, A recess 13 provided between the peripheral support means 11 and the peripheral support means 12, and the recess 1
3 and a negative pressure supply means 14 for supplying a negative pressure.

[0010]

According to the present invention, since the back surface of the optical disk stamper 2 having a rough back surface after being used for a predetermined number of times (shot) for example, 50,000 times is polished, the back surface of the optical disk stamper 2 is not roughened. The stamper 2 for optical disk can be used like a new product.

Further, according to the present invention, since the inner circumference and the outer circumference of the optical disk stamper 2 are supported and polished, the information can be reproduced without affecting the information signal portion of the optical disk stamper 2.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a reproducing method and reproducing apparatus for an optical disk stamper of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, reference numeral 15 denotes a disk-shaped stamper mounting table. The stamper mounting table 15 has a center portion formed of a substantially conical body having an outer diameter of the bottom substantially equal to the inner diameter of the central hole 2a of the optical disk stamper 2. The bottom side of the positioning column 10 is detachably inserted and fixed.

An O-ring made of, for example, rubber is arranged along the outer periphery of the positioning column 10 of the stamper mounting table 15 to form the inner peripheral support portion 11, and the stamper mounting table 15 is provided with the optical disk stamper 2. When this is done, an O-ring made of, for example, rubber is arranged at a portion corresponding to the outer circumference of the optical disk stamper 2 to provide the outer circumference support 12
To form.

The inner peripheral support 11 and the outer peripheral support 12 are also provided.
A toroidal concave portion 13 is formed between and, and the concave portion 13 is made to have a negative pressure by a vacuum pump 14. In this case, the vacuum pump 14 has a suction port 14a in the recess 13.
Through 5 to 10 mmHg.

Next, a case where the back surface of the optical disk stamper 2 is polished by using the reproducing apparatus for the optical disk stamper as shown in FIGS. 1 and 2 will be described. For example, as shown in FIG. 1, the optical disk stamper 2 that has been used for molding about 50,000 times (shots) has the information signal surface of the optical disk stamper 2 as the lower side, and the positioning column 10 is inserted into the center hole 2a. It is positioned and placed on the stamper mounting table 15.

In this case, as shown in FIG. 2, the inner circumference of the optical disk stamper 2 is located on the inner circumference support portion 11 and the outer circumference thereof is located on the outer circumference support portion 12, and the information signal portion of the optical disk stamper 2 is recessed. It corresponds to 13.

After that, the inside of the recess 13 is set to a negative pressure, and the optical disk stamper 2 is vacuum-adsorbed and fixed on the mounting table 15. Then, the positioning column 10 is removed and the back surface of the optical disk stamper 2 is polished.

This polishing is performed by hand, for example, with emery paper 8
Use No. 00 and polish it by turning it in the circumferential direction. This polishing is carried out until there is no visible stain and it is smooth by touching with a finger. The polishing is performed so that the thickness is reduced to about 2 μm by this one polishing.

After this polishing, the vacuum adsorption is released, and the polishing surface of the optical disk stamper 2 is washed with liquid such as acetone and air, and the process is completed.

In this case, the roughness of the back surface of the new optical disk stamper 2 in the radial direction is Rz =
Although it is 0.3 μm or less, the radial roughness of the back surface of the optical disk stamper 2 after using about 50,000 times (shots) is about Rz = 1 μm as shown in FIG. The optical disc 4 of the product molded by use showed polarization anomaly as shown in FIG.

However, the rough surface of the back surface of the optical disk stamper 2 after the use of about 50,000 times (shots) is subjected to the rotational polishing in the circumferential direction as described above, and the radius of the back surface of the optical disk stamper 2 after the completion. The roughness in the direction was similar to that of a new product with Rz = 0.3 μm or less as shown in FIG.

The optical disk 4 of the product molded by using the stamped optical disk stamper 2 after polishing did not show any polarization abnormality as shown in FIG. 8 and could be molded and used about 50,000 times (shot).

As described above, according to this example, the stamper 2 for an optical disk after being molded and used about 50,000 times can be further molded and used about 50,000 times, so that the productivity is improved and the user can be provided with an inexpensive product. There is.

Further, since the optical disk stamper 2 can be reused, not only the time and effort for molding the optical disk stamper 2 can be saved, but also the expensive nickel alloy, which is the material of the optical disk stamper 2, can be saved. There is a profit that can be achieved.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0026]

According to the present invention, since the back surface of the optical disk stamper 2 having a rough back surface after being used a predetermined number of times (for example, 50,000 shots) has been polished, the back surface of the optical disk stamper 2 is roughened. And the optical disk stamper 2 can be reused, and according to the present invention,
Since the inner and outer peripheries of the optical disk stamper 2 are supported and polished, it is possible to reproduce without affecting the information signal portion of the optical disk stamper 2. Therefore, according to the present invention, for example, the stamper 2 for an optical disk that has been molded and used for about 50,000 times can be molded and used for about 50,000 times more, so that there is an advantage that productivity is improved and an inexpensive product can be provided to the user.

Further, according to the present invention, since the optical disk stamper 2 can be reused, not only the labor and labor for molding the optical disk stamper 2 can be saved, but also the material for the optical disk stamper 2 is expensive. There is a benefit to save consumption of various nickel alloys.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a reproducing device for an optical disk stamper of the present invention.

FIG. 2 is a sectional view of a main part of FIG.

FIG. 3 is a cross-sectional view showing an example of a thermoplastic injection molding device.

FIG. 4 is a plan view showing an example of an optical disc.

FIG. 5 is a diagram for explaining the present invention.

FIG. 6 is a diagram used for explaining the present invention.

FIG. 7 is a diagram used for explaining the present invention.

FIG. 8 is a plan view showing an example of an optical disc.

[Explanation of symbols]

 2 Optical disk stamper 10 Positioning column 11 Inner peripheral support 12 Outer peripheral support 13 Recess 14 Vacuum pump 15 Stamper mounting table

Claims (2)

[Claims] 1. A method of reproducing an optical disk stamper for forming an optical disk by injection molding, wherein the back surface of the optical disk stamper is polished after being used a predetermined number of times. 2. A centering hole of an optical disk stamper is inserted to removably provide positioning means for positioning the optical disk stamper, and an inner circumference of the optical disk stamper provided along the outer circumference of the positioning means. Inner peripheral supporting means for supporting, outer peripheral supporting means for supporting the outer periphery of the optical disk stamper, a concave portion provided between the inner peripheral supporting means and the outer peripheral supporting means, and a negative pressure for supplying negative pressure to the concave portion. A reproducing apparatus for an optical disc stamper, comprising: a supply unit.