JPH05285992A - Holding structure for disk molding stamper - Google Patents

Abstract

PURPOSE:To make uniform heat conductivity by eliminating irregularity in tight contact between a stamper and a mold. CONSTITUTION:At a fixed side mirror face 16, an annular air intake port 16a is formed so as to eliminate irregular adhesion of a stamper S and obtain a temperature adjusting function under an excellent heat conductive state. Reference character 16b represents an air intake hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to molding of a disc as a disc-shaped recording medium such as a video disc or an audio disc, and more particularly to a base material for transferring a pit pattern as an information track surface onto the disc. The present invention relates to a stamper holding structure.

[0002]

2. Description of the Related Art In this type of disk molding, a stamper having a pit pattern is attached to either or both of a fixed-side mold plate and a movable-side mold plate of a mold. Is mounted so that the inner peripheral part is pressed by the inner peripheral presser member and the outer peripheral part is pressed by the ring-shaped outer peripheral presser member.The outer peripheral presser member is mounted between the stamper to allow expansion due to resin heat. It is provided with clearance.

[0003]

By the way, in this type of disc molding, the condition for obtaining high precision of the product is as follows.
Proper temperature control by uniform heat conduction between the stamper and the mold can be raised as one of them, but in the conventional configuration as described above, since it is a structure that simply presses the inner peripheral portion and the outer peripheral portion of the stamper, Further, since the stamper originally does not have a perfect flatness, an air layer 72 is formed between the template 70 and the back surface of the stamper S as shown in FIG. The current situation is that the accuracy of the product is reduced.

Since the stamper mounting surface of the template is mirror-finished and the stamper is an ultra-thin member, it was generally thought that no contact unevenness would occur. As a result of an experimental observation assuming the presence of unevenness, it was found that the uneven contact was actually present.

Therefore, the present invention provides a holding structure for a disk molding stamper, which can eliminate the unevenness of contact between the stamper and the mold plate and uniformize the thermal conductivity, thus improving the molding accuracy. To aim.

[0006]

The present invention was devised to achieve the above object, and is characterized in that a template to which the stamper is attached is formed with an annular air suction port for closely contacting the stamper. It is in the configuration.

[0007]

According to the present invention, the stamper is attached to the template with its inner circumference being held by the inner circumference pressing member and its outer circumference being held by the outer circumference pressing member. The air between the stamper and the template is sucked through the annular air suction port, whereby the stamper is attracted to the template without any uneven contact.

[0008]

1 to 3 show an embodiment of the present invention.
The mold 2 is provided with a fixed-side mold plate 4 and a movable-side mold plate 6 so that the mold 2 can be directly supported and opened / closed by two guide rods 8 also having a tie bar function without using a die plate. It has become. The guide rod 8 can directly use, for example, a rod of a mold clamping cylinder (not shown), and can be held by the bearing member 10 on the fixed-side mold plate 4 so as to be slidable smoothly. The nozzle 12 is inserted into the nozzle guide hole 4a formed in the fixed-side mold plate 4 for injection.

The sprue bush 1 is provided at the center of the fixed-side template 4.
4 is attached, and a cavity 13 is provided on the mold facing surface.
The fixed-side mirror surface portion 16 forming one of the components of (1) is fitted into the sprue bushing 14 and the outer peripheral portion is fixed by a bolt 17 and attached. Although not explicitly shown in the drawing, a stamper as a transfer base material is attached to the fixed-side mirror surface portion 16, and the stamper S is held by the inner peripheral pressing member 15 and the outer peripheral pressing member 18. Is becoming

The outer peripheral pressing member 18 is composed of a ring member 20 which also serves as a spacer between the molds and seals the outer peripheral region of the cavity 13, and a stamper holding portion 22 which is integrally formed on the inner periphery of the ring member 20. ing. Also,
Threaded holes 20a are formed on both sides of the ring member 20, and the fixed-side mold plate 4 and the movable-side mold plate 4 and the movable-side mold plate 4 do not need to be held manually by a through bolt 24 penetrating the fixed-side mold plate 4 or the movable-side mold plate 6. Any of the template 6 can be attached and converted.

As a result, the labor required for replacing the stamper can be reduced, and the replacement work can be performed easily and smoothly. That is, in the conventional structure, since it is configured to be attached to and detached from only one of the template plates, it is necessary to hold the outer peripheral pressing member 18, which is a heavy object, during replacement of the stamper, but it is possible to move by replacing the through bolt 24. It can be temporarily temporarily fixed to the side mold plate 6 side, and can be reattached to the fixed side mold plate 4 side without a holding operation by replacing the through bolt 24 again and tightening it in the mold closed state. .. Reference numerals 4b and 6a denote through bolts 2.
4 shows the insertion hole.

On the other hand, a gate cut member 26 is attached to the central portion of the movable side mold plate 6, and a movable side mirror surface portion 28 which is the other component of the cavity 13 is attached to the mold facing surface. The gate cut member 26 is composed of a cylinder member 30 fixed to the movable side mold plate 6 and a cut pin 34 having a sprue ejector pin and capable of advancing and retracting in the cylinder member 30.
The movable side mirror surface portion 28 is fitted in the cylinder member 30, and the outer peripheral portion is fixed by bolts 29.

An annular air suction port 16a is formed in the fixed-side mirror surface portion 16 so as to eliminate uneven contact of the stamper S and to obtain a temperature control function by a good heat conduction state. Reference numeral 16b indicates a suction hole communicating with the air suction port 16a.

As shown in FIG. 3, the stamper holding portion 22 is provided in a non-contact state having a clearance C with the outer peripheral portion of the stamper S, and the clearance C serves as a gas vent path. The clearance C is adjusted according to the thickness of each stamper S by sandwiching a shim plate between the stationary mold plate 4 and the ring member 20.

Next, the holding operation of the stamper S will be described. First, the stamper S is applied to the fixed-side mirror surface portion 16, the inner peripheral side pressing member 15 presses the inner peripheral side, the outer peripheral pressing member 18 holds the outer peripheral side, and air is sucked from the air suction port 16a. By this air suction, a vacuum state is created between the stamper S and the fixed mirror surface portion 16, and the stamper S is brought into close contact with the fixed mirror surface portion 16 without unevenness.

Even if the stamper S does not have perfect flatness, it is forcibly brought into close contact by air suction, so that the heat conductivity between the stamper S and the fixed-side mirror surface portion 16 becomes uniform, and the temperature unevenness occurs. It is possible to prevent the deterioration of the molding accuracy due to.

Further, since the outer peripheral side of the stamper S is held in a non-contact state, expansion of the stamper S in the radial direction due to resin heat is allowed, and deterioration of molding accuracy due to expansion inhibition is prevented.

[0018]

According to the present invention, even if the stamper does not have perfect flatness, it can be forcibly brought into close contact with the template by air suction, so that the entire stamper has uniform thermal conductivity and uneven temperature. It is possible to perform high-precision molding without

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a holding structure for a disk molding stamper according to the present invention.

FIG. 2 is an enlarged cross-sectional view around a fixed-side mirror surface portion.

FIG. 3 is an enlarged cross-sectional view showing a holding state of the outer peripheral portion of the stamper.

FIG. 4 is a schematic cross-sectional view showing conventional contact unevenness of a stamper.

[Explanation of symbols]

 2 Mold 4 Fixed-side mold plate 6 Movable-side mold plate 15 Inner circumference pressing member 16a Air suction port 18 Outer circumference pressing member C Clearance S Stamper

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // B29L 17:00 4F

Claims (1)

[Claims] 1. A stamper attached to a fixed-side mold plate and / or a movable-side mold plate of a mold, a ring-shaped outer-periphery pressing member that holds the outer circumference of the stamper, and an inner-periphery presser that presses the inner circumference of the stamper. In the holding structure of the disk molding stamper in which the outer peripheral pressing member is provided with a clearance between the member and the stamper, an annular air suction port for closely contacting the stamper with the template to which the stamper is attached. A holding structure for a stamper for molding a disc, wherein: