JPH0948045A - Mold device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate a highly accurate registering by setting and positioning a stamper as being mounted on the mold movable side in the peripheral direction and at an arbitrary angle with reference to the start or completion of recording area of the stamper mounted on the stationary side. SOLUTION: A movable side mirror surface block 2 is fitted in a movable side base 1 and a stamper 3 is held between an outer periphery holding rotation ring 4 and an inner peripheral holder 5, and a stationary side mirror surface 13 is fitted in a stationary side base 12, and a stamper 14 is held between an outer periphery holding rotation ring 15 and an inner peripheral holder 17. Into the cavity 19 formed with the bases 1, 12 and stampers 31, 14 molten resin is injected and filled up through a sprue 18 so as to transfer information signals on both surfaces of the substrate. A tooth wheel set on the outer periphery of the outer periphery holding rotation ring 4 is meshed with a screw tooth wheel 6 in order to conduct the shaft 7 of the tooth wheel outward via a bearing buried in the base 1 with a rotational fine dimension measuring tool equipped on its outer wall surface. Thus, peripheral directional angles of the disk substrate table and recording area starting position can be arbitrarily positioned highly accurately.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a mold device.

[0002]

2. Description of the Related Art As information recording disk substrates have been miniaturized from optical video disks to CDs and MDs, the recording capacity has been remarkably increased. Further, the application to the field of magnetic disks is also remarkable. Due to the increase in recording capacity, both sides of the substrate are being used. In order to efficiently record, reproduce, and erase information on an information recording disk using such a double-sided information recording disk substrate, a plurality of optical heads or magnetic heads and a recording area start position in a recording / reproducing apparatus must be located at the disk. It is desirable to be in a position synchronized with each of the front and back surfaces of the.

A mold apparatus for obtaining a double-sided information recording disk substrate generally has a structure in which stampers can be mounted on both the fixed side and the movable side, as shown in FIG.
Japanese Patent No. 25311 discloses a mold of a type in which a movable side mirror surface plate holds a second stamper with a flange of an outer peripheral ring by clamping. However, it is difficult for such a mold to satisfy the above-mentioned requirements.

[0004]

That is, the double-sided information recording disk loaded in the information processing apparatus is recorded and reproduced by a plurality of optical heads or magnetic heads corresponding to the front surface and the back surface, respectively. It is often used, but there is information that the allowable deviation between the head position where the mounting position in the device is almost fixed and the start position of the recording area in the disk circumferential direction is close to zero on both the front and back sides. This is useful in processing, and in order to satisfy this, control to match the head position of the information processing device with the circumferential recording area starting position on the substrate to be molded is an indispensable technique. Double-sided information recording disk substrate Regarding the alignment of the recording area starting position in the circumferential direction of the information recording part, it is common to align the position of the stamper attached to the movable side with reference to the stamper attached to the fixed side. However, with the conventional mold structure shown in FIG. 9, this work is extremely difficult because there is no way to do this except by visual examination. When the stamper is attached, the mold is generally in an open state, and even if a stamper is marked, it can be said that it is almost impossible to align the stamper on the order of, for example, 10 μm. Further, in the mold structure of the type in which the second stamper is clamped and supported by the flange of the outer peripheral ring on the movable side mirror surface plate disclosed in Japanese Unexamined Patent Publication No. 2-25311, control to match the head position of each information processing device is required. Not only is it impossible, but it is difficult to perform high-precision positioning considering the manufacturing precision of the mold.

An object of the present invention is to solve such a problem,
An object of the present invention is to provide a device that enables easy high-precision alignment.

[0006]

In order to achieve the above object, the present invention rotates the second stamper mounted on the mold movable side with respect to the first stamper mounted on the fixed side with high precision as necessary. According to the present invention, the stamper holding ring on the mold working side, which is conventionally attached by screw fixing, is rotated about the center of the mold, and the second stamper is also rotatable about the same center as the stamper holding ring. Close.

[0007]

According to the molding apparatus of the present invention, the second position is obtained by roughly visually locating the recording area starting position on the movable side with reference to the recording area starting position of the first stamper mounted on the fixed side.
Attach the stamper, start molding, measure the amount of deviation on the front and back sides of the recording area starting position of the information recording part of the double-sided information recording disk substrate taken out, quantify it, and then operate the above mechanism Then, by rotating the second stamper by a required angle, the optimum recording area starting position on both sides can be set with high accuracy.

[0008]

Embodiments of the present invention will be described below in detail with reference to FIGS. 1 to 8.

(Embodiment 1) FIGS. 1 and 2 are schematic views of a mold used for carrying out the present invention. In FIG.
A movable side mirror surface block 2 is fitted in the movable side base 1, a second stamper 3 is provided on the mirror surface, a stamper outer peripheral holding rotary ring 4 at the outer peripheral portion and a stamper inner peripheral holder 5 at the mold center portion.
It is pinched by. The fixed mirror surface 13 is fitted into the fixed base 12, and the stamper 14 is held on the mirror surface by the stamper outer peripheral holding ring 15 at the outer peripheral portion and the stamper inner peripheral holder 17 at the mold central portion. When both are mounted on a mold clamping unit (not shown) of the injection molding machine and the movable side base 1 and the fixed side base 12 are closed, a space (cavity) 19 surrounded by the stamper 3 and the stamper 14 is formed, and the space 19 is sprued. When the molten resin is injected and filled through 18, a double-sided information recording disk substrate having information signals transferred to both surfaces of the substrate is obtained. The present embodiment is characterized in that the stamper outer peripheral holding rotary ring 4 rotates unlike the screw fixing method of the stamper outer peripheral holding ring 34 in the conventional mold shown in FIG. That is, as shown in FIG. 2, a gear 22 is provided on a part of the outer circumference of the stamper outer circumference holding / rotating ring 4 (the lower part is preferable in consideration of preventing the dust from adhering to the substrate as much as possible). The gears 6 are engaged with each other, and the gear shaft 7 is guided to the outside of the movable side base 1 via the bearing 8 embedded in the movable side base 1. On the wall surface of the movable side base 1, a rotating device 8 equipped with a rotating minute dimension measuring machine capable of dividing and dividing the circumference into 360 equal parts was attached. By rotating the handle of this rotating device, the rotational force is transmitted from the screw gear 6 to the gear of the stamper outer peripheral holding rotary ring 4, and the ring holding pin passed through the ring rotary guides 21 provided at four positions of the stamper outer peripheral holding rotary ring 4. Rotate with 10 as a guide. In this embodiment, the start position of the stamper in the circumferential recording area can be moved by 0.6 mm with one rotation of the handle, and by rotating the handle once, about 0.00
It can be moved by 17 mm. Ring holding pin 10
Is connected to a direct acting cylinder 11 embedded in the movable side base 1, and when rotating the stamper outer peripheral holding rotary ring 4, the ring holding pin 10 is moved from the surface of the stamper outer peripheral holding rotary ring 4 to 0.1 to 0. It is lifted up by 2 mm to release the restraining force of the stamper outer peripheral holding rotation ring 4 on the movable side mirror surface block 2. When the adjustment work is completed, the direct acting cylinder 11 and the ring holding pin 10 are operated in the pulling direction to restrain the stamper outer circumference holding rotary ring 4.

The detailed structure of the stamper outer peripheral holding rotary ring 4a used in this embodiment and the stamper 3a to be combined is shown in FIGS. The stamper is fitted into the central step portion of the stamper outer circumference holding and rotating ring 4a so that the mold fixed side becomes the information recording surface, and the linear portion 20 is formed at two opposing locations on this step portion. The shape is a rotation stop for the stamper ring described below. Linear portions 2 are provided at two opposing locations on the outer peripheral portion of the stamper 3a shown in FIG.
3 is provided and is fitted to the linear portion 20 of the stamper outer peripheral holding rotary ring 4a. Using the mold device according to the embodiment,
As a result of a molding experiment, the deviation amount of the recording area starting position on the front surface and the back surface of the 2.5-inch information recording disk substrate was set to 10 μm or less, and the result satisfying this target value was obtained.

(Embodiment 2) With respect to the stamper outer periphery holding rotary ring and the stamper of the mold apparatus used in the experiment of Embodiment 1, the shaped products shown in FIGS. 5 and 6 were devised and manufactured, and the same experiment as in Embodiment 1 was conducted. went. The stamper is fitted into the central step portion of the stamper outer peripheral holding rotary ring 4b so that the mold fixed side becomes the information recording portion surface. In this step portion, there are two protrusions 25 having the same height as the stamper thickness at two opposing positions. It is made, and the shape of this protrusion serves as a rotation stopper for the ring of the stamper described below. The stamper 3b shown in FIG. 6 is provided with recesses 26 at two opposing locations on the outer periphery of the stamper 3b, and the recesses 26 are fitted to the protrusions 25 of the stamper outer periphery holding rotary ring 4a.
As a result of performing a molding experiment by using the mold apparatus according to the embodiment with a target deviation of 10 μm or less between the recording area starting position on the front surface and the back surface of the 2.5-inch information recording disk substrate, this target value is satisfied. Results were obtained.

(Embodiment 3) With respect to the stamper outer circumference holding rotary ring and the stamper of the mold apparatus used in the experiment of Embodiment 1, the shaped products shown in FIGS. 7 and 8 were devised and manufactured, and the same experiment as in Embodiment 1 was conducted. went. The stamper is fitted into the central step portion of the stamper outer circumference holding and rotating ring 4c so that the mold fixed side becomes the information recording surface, and the cylindrical protrusions 27 having the same height as the stamper thickness are provided at two opposing portions of this step portion. Is formed, and the shape of the protrusion serves as a rotation stop for the ring of the stamper described below. Stamper 3c shown in FIG.
Circular holes 28 are provided at two opposite positions on the outer peripheral portion of the stamper, and they are fitted to the cylindrical protrusions 27 of the stamper outer peripheral holding rotary ring 4a. As a result of performing a molding experiment by using the mold apparatus according to the embodiment with a target deviation of 10 μm or less between the recording area starting position on the front surface and the back surface of the 2.5-inch information recording disk substrate, this target value is satisfied. Results were obtained.

The embodiment discloses a typical example of the present invention. For example, regarding the co-rotating mechanism of the stamper and the outer peripheral ring, a worm and a worm wheel may be used, and the outer peripheral ring can be rotated. For example, a chain or a belt may be used as long as it is a mechanism that does. The mounting position of the gear mechanism is not limited and is free. The restraint means for the outer peripheral ring is also effective for both the air cylinder and the hydraulic cylinder. The rotation stopping mechanism for the outer peripheral ring and the stamper is not limited to two opposite positions, but may be one position or a plurality of positions. Moreover, the shape is not limited to the embodiment,
All shapes that stop the rotation of the stamper relative to the ring are valid. Further, all of this mechanism may be used on the die fixed side.

[0014]

By using the mold apparatus according to the present invention, it is possible to obtain a double-sided information recording disk substrate which can be positioned with high accuracy at any angle in the circumferential direction of the recording area starting position on the front and back surfaces of the disk substrate. I can.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an injection molding die apparatus showing an embodiment of the present invention.

FIG. 2 is a front view of the working side of the injection molding mold apparatus according to the embodiment of the present invention.

FIG. 3 is an explanatory view of an outer peripheral holding and rotating ring of the working side stamper of the injection molding mold apparatus according to the embodiment of the present invention.

FIG. 4 is an explanatory view of a stamper showing an embodiment of the present invention.

FIG. 5 is an explanatory view of an outer peripheral holding and rotating ring of an active side stamper which is an injection molding mold apparatus according to an embodiment of the present invention.

FIG. 6 is an explanatory view of a stamper showing an embodiment of the present invention.

FIG. 7 is an explanatory view of an outer periphery holding and rotating ring of an active side stamper which is an injection molding mold apparatus according to an embodiment of the present invention.

FIG. 8 is an explanatory view of a stamper showing an embodiment of the present invention.

FIG. 9 is a cross-sectional view of an injection molding die apparatus showing an example in the related art.

[Explanation of reference numerals] 1 ... movable side base, 2 ... movable side mirror surface block, 3 ... movable side stamper, 4 ... movable side stamper outer peripheral holding rotary ring, 5 ... stamper inner peripheral holding ring, 6 ... screw gear, 7 ... Gear shaft, 10 ... Ring holding pin, 11 ... Direct acting cylinder, 12 ... Fixed side base, 13 ... Mirror surface block, 14 ... Stamper, 15 ... Fixed side stamper holding outer ring, 16 ... Ring fixing screw, 17 ... Inside stamper Circumferential retaining ring, 18 ... Sprue bush, 19 ... Cavity space.

Front page continuation (72) Inventor Masaki Yoshii, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd. Inside the Hitachi, Ltd. Institute of Industrial Science (72) Inventor Norio Ohta, 1-20 Hitachi Kinodadai, Taniwahara-mura, Tsukuba-gun, Ibaraki Hitachi Maxell Co., Ltd.

Claims (2)

[Claims] 1. An injection molding machine, a mold comprising a fixed side and a movable side facing each other, and two stampers mounted on each of the fixed side and movable side mirror surface block surfaces of the mold. In a molding machine to obtain a double-sided information recording disk substrate by injecting and filling a mold device with a melt mainly made of thermoplastic material, the recording area starting position or recording area ending position of the information recording disk substrate is set to the front and back surfaces. In the information recording disk substrate molding apparatus that can be freely set in, the stamper mounted on the movable side of the mold is mounted on the fixed side without being removed, and the recording area starting position of the stamper is mounted on the fixed side. , Or a mold apparatus capable of being set and positioned at an arbitrary angle in the circumferential direction with reference to the end position of the recording area. 2. The stamper outer peripheral holding rotary ring, which is connected to the stamper and has a shape that rotates together with a center shared by the stamper and the mold as a rotation center, or the stamper connected to the stamper. A ring rotation mechanism that configures a stamper holding inner peripheral rotation ring that is given a shape that co-rotates about a center shared by the mold and the mold, and that allows the stamper holding rotation ring to be rotated from outside the mold. A die assembly in which a ring fitting shape is provided at a position outside the information recording area on the outer peripheral portion or the inner peripheral portion of the stamper in order to be provided and connected with the stamper holding ring to rotate together.