JPH08309804A - Disk mold - Google Patents

Abstract

PURPOSE: To provide a disk mold that facilitates changing of the cavity thickness. CONSTITUTION: In a disk mold, a cavity 4 for forming a disk is formed in mirror-surface plates that face each other and are disposed between a stationary mold 2 and a movable mold 3, and at least one of the mirror-surface plates 12, 23 is provided with a stamper 5 for transferring recorded information to the disk. The disk mold comprises a guide fixture frame 13, 25 that is disposed a first one side mirror-surface plates 12, 23 not provided with the stamper 5 and that faces a fixture frame 13, 25 disposed on the periphery of the mirror- surface plates 23, 12 of one side and engages with the fixture frame 25, 13 when the mold is closed, and a support plate 11, 22 to which the mirror-surface plates of the one side is fixed. A thickness adjust plate 10 for adjusting the thickness of the cavity 4 is provided between the facing surfaces of the guide fixture frame 13, 25 and the support plate 11, 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk mold for injection molding a disk substrate for a recording medium such as a commonly used video disk, CD, and DVD (digital video disk).

[0002]

2. Description of the Related Art In general, a disk substrate is manufactured by injection molding using a disk mold, and includes a pair of mirror surface plates arranged so as to face the mating surfaces of a fixed side mold and a movable side mold. A molten resin injected from a nozzle of an injection device into a cavity formed between one of these mirror surface plates and a stamper attached through an outer peripheral pressing ring, and the other mirror surface plate facing the stamper. Is molded through a sprue hole.

Products such as compact discs molded by this disc mold are normally standardized to have a thickness of 1.2 mm, but recently DVDs have been receiving attention.
However, since the recorded information is read from both sides of the disc, a structure having two 0.6-mm thick discs bonded together has been standardized.

Therefore, it has been made to form discs having the same diameter and different thicknesses. For such disc forming, individual molds are manufactured or one mold is used. When shared, it is necessary to adjust the thickness dimension of the mold cavity.

[0005]

In this case, according to the conventional method, in order to change the thickness of the disk substrate, the cavity thickness is changed by processing or replacing the back plate arranged on the back surface of the mirror plate. Have changed. However, with this adjusting method, it is necessary to remodel the insert bush and the ejector sleeve to the same size at the same time.

In order to eliminate such annoyance, the present invention provides a disk mold in which the cavity thickness can be easily changed only by disposing one thickness adjusting plate at a predetermined position. Is intended.

[0007]

In order to achieve the above object, the present invention provides a cavity for molding a disk in a mirror plate placed between a fixed mold and a movable mold to face each other. In a disc mold having a stamper for transferring recording information to a disc on at least one of the mirror plates, the stamper is placed on the outer periphery of one mirror plate and the outer periphery of the other mirror plate. A guide mounting frame that is engaged with the mounting frame when the mold is closed, and a receiving plate that fixes the one mirror surface plate, and a cavity thickness is provided on a mating surface between the guide mounting frame and the receiving plate. It is characterized in that a thickness adjusting plate for adjusting the height is provided.

[0008]

With such a structure, when the stamper is attached to the movable side mirror surface plate, the thickness adjusting plate is provided between the mounting frame of the fixed side mirror surface plate and the fixed plate which is the receiving plate. Only the abutting surface of the mounting frame becomes higher, and the mounting frames facing each other are engaged by this plate thickness to close the mold, so that the cavity thickness is expanded. Further, when the stamper is attached to the fixed-side mirror surface plate, a thickness adjusting plate is provided between the mounting frame of the movable-side mirror surface plate and the movable plate which is the receiving plate, so that the cavity thickness is similarly expanded. A disc having a desired thickness can be obtained by inserting or removing the thickness adjusting plate with one mold.

[0009]

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing the structure of a disk mold according to the present invention.

In FIG. 1, a disk mold 1 for molding a disk substrate is composed of a fixed side mold 2 and a movable side mold 3 which is slidably movable toward and away from the fixed side mold 2. In addition, a cavity 4 for forming a disc is provided on the mating surface of both, and a stamper 5 for transferring recording information to the disc is arranged on the mirror surface plate of the movable mold 3.

The fixed side mold 2 includes a fixed plate 11 attached to a fixed plate, a fixed side mirror surface plate 12 detachably attached to the fixed plate 11, and a fixed side mirror surface plate 1.
A mounting frame 13 is provided on the outer periphery of the mirror 2 to hold the mirror plate 12 at a predetermined position. Mounting frame 1
3 is fixed to the stepped portion 11a of the fixed plate 11 as a receiving plate of the fixed-side mirror surface plate 12 with a bolt (not shown) or the like.

Further, a mescatter 15 and a sprue bush 16 carried by the mescatter 15 are inserted into the through hole at the center of the fixed side mold 2, and the sprue bush 16 is further inserted.
A locate ring 17 that determines the mounting position of the fixed-side mold is arranged on the top.

The fixed-side mirror surface plate 12 has an upper surface serving as a cavity surface 12a forming the back surface of the disk, and a groove 18 is provided at the bottom portion on the opposite side. This groove is covered with a back plate 19 inserted between the fixed-side mirror surface plate 12 and the fixed plate 11, and is sealed by O-rings 20 fitted in several places of the fixed-side mirror surface plate 12.

The movable die 3 on one side is moved closer to the fixed die 2 so as to be separated from the fixed die 2, and a movable plate 22 attached to the movable plate 22 and a movable mirror plate 23 detachably attached to the movable plate 22. And a mounting frame 25 for holding the movable side mirror surface plate 23 at a predetermined position, which is arranged on the outer periphery of the mirror surface plate, and for fixing the outer peripheral stamper retainer 24. The mounting frame 25 is provided on the step portion 22 of the movable plate 22 as a receiving plate for the movable side mirror surface plate 23.
It is fixed to a with a bolt (not shown) or the like. The movable plate 22 that serves as the receiving plate constitutes a retainer plate that is a mirror surface plate.

Further, in the through hole at the center of the movable side mold 3,
The ejector pin 26, the punch 27, and the ejector sleeve 28 are fitted and inserted in the insert member 29 so as to be coaxially arranged. The punch 27 is for punching the inner diameter of the disc to separate the sprue 14 from the disc substrate, the ejector pin 26 is for ejecting the punched sprue 14, and the ejector sleeve 28 is for punching the punched disc substrate. It is for detaching from the movable mold.

The movable side mirror surface plate 23 has the stamper 5 mounted on the upper surface thereof, and the fixed side mirror surface plate 12 on the bottom portion on the opposite side.
Similarly to the above, a groove 30 that forms a temperature control flow path of the mold is provided, and this groove is covered with a back plate 31 inserted between the movable side mirror surface plate 23 and the movable plate 22, and the movable side mirror surface plate 23. It is sealed by O-rings 20 fitted in several places. Then, the fixed-side and movable-side mirror plate 1
2, 23 grooves 18, 30 and the concave portion 1 of the mescatter 15
A temperature control medium is circulated and supplied from a temperature controller to 5a in order to keep the temperature of the mold constant.

The outer peripheral edge of the stamper 5 is fixed by the outer peripheral stamper retainer 24, and the inner peripheral edge is held by the flange portion 32a of the stamper holder 32 arranged on the outer periphery of the insert member 29. The outer peripheral stamper retainer 24 is fixed by a bolt 33 to a mounting frame 25 arranged on the outer periphery of the mirror surface plate 23 of the movable mold 3.

As shown in FIG. 3, the outer peripheral stamper retainer 24
The front end portion of has a substantially vertical rising surface 24a instead of the inclined surface as in the conventional case. This is because even when the thickness adjusting plate 10 is added to increase the cavity thickness A, the gap N with the mirror surface plate is 2 as described below.
This is to maintain it at about 0 micron. This gap N is provided for degassing to the extent that burr does not occur on the disk surface.

The tip of the outer peripheral stamper retainer 24 and the stamper 5 are not in contact with each other on the entire peripheral surface, but a part thereof is in contact with the other part, and the other part forms a gas vent passage as shown in the drawing. A gap for degassing is also formed between the upper surface of the outer peripheral stamper retainer 24 and the fixed mirror surface plate 12 and the mounting frame 13.

On the other hand, in the stamper holder 32 which presses the inner peripheral edge of the stamper 5, the collar portion 32a causes the inner peripheral edge of the stamper 5 to move on the movable side mirror surface plate by screwing the screw portion 32b into the female screw of the stamper holder holding device 35. By holding it so that it is pressed against 23, and conversely by loosening the screw engagement,
The stamper 5 can be removed from the movable mold 3.

A movable side mounting frame 25 for holding the outer peripheral stamper retainer 24, and a fixed side mounting frame 13 facing the mounting frame 25.
Is provided with a step portion 36 that is engaged when the mold is closed.
Has an inclined surface and forms a guide surface when the movable mold 3 approaches the fixed mold 2. Here, the mounting frame 13,
One of the 25 is a mounting frame arranged on the outer periphery of the mirror surface plate on which the stamper 5 is not placed, and this mounting frame will be referred to as a guide mounting frame in order to distinguish it from the other mounting frame. In this embodiment, the mounting frame 1
3 is the guide mounting frame.

The disk mold of the present invention has a cavity thickness A.
In order to change the thickness, the thickness adjusting plate 10 is arranged between the guide mounting frame 13 on the side where the stamper is not arranged (fixed side in FIG. 1) and the fixed plate 11. By sandwiching the thickness adjusting plate 10, the guide mounting frame 13 is raised by the thickness of the thickness adjusting plate 10 and the engaging position of the mounting frame is moved to the front, so that the cavity thickness A when the mold is closed is increased. It will be. For example, by using a thickness adjusting plate of 0.6 mm, it is possible to change the disk mold for 0.6 mm thickness to a disk mold for 1.2 mm thickness.

Since the thickness adjusting plate 10 is made of a material such as stainless steel or brass and is placed on the outer peripheral step portion 11a of the fixed plate 11 as the receiving plate of the fixed side mirror surface plate 12, its positioning is easy. Can be done.

In this embodiment, the stamper 5 is attached to the movable mold 3
However, there is also a type of disc die in which the stamper 5 is placed on the fixed side die 2.
An example of such a disk mold is shown in FIG.

In FIG. 2, the same members and functions as those in FIG. 1 are designated by the same reference numerals. In this figure, the stamper 5 is placed on the mirror surface plate 12 of the stationary mold 2, the outer peripheral edge of which is held by the outer peripheral stamper retainer 24, and the inner peripheral edge of which is held by the stamper holder 32.

A sprue bush 16 is provided at the center of the stationary mold 2, and a mescatter 15 is arranged on the outer periphery of the sprue bush 16.
Further, a stamper holder 32 is arranged outside the meskatter 15. On the other hand, an ejector pin 26, a punch 27, and an ejector sleeve 28 are coaxially arranged in the central portion of the movable side mold 3, and an insert member 29 is further arranged outside thereof.

A mounting frame 2 is provided on the outer periphery of the movable side mirror surface plate 23.
5 is arranged, and the thickness adjusting plate 10 is arranged between the movable side mounting frame 25 as a guide mounting frame and the movable plate 22 as a receiving plate holding the movable side mirror surface plate 23. This thickness adjusting plate 10 operates in the same manner as the thickness adjusting plate 10 shown in FIG. 1, and by inserting the thickness adjusting plate 10, the guide mounting frame 25 is raised by the thickness of the thickness adjusting plate 10. Since the engaging position of the mounting frame is moved to the front, the cavity thickness A at the time of mold closing is increased.

As described above, in the present invention, the thickness adjusting plate 10 is provided between the guide mounting frame provided on the outer periphery of the one mirror surface plate on which the stamper 5 is not mounted and the receiving plate of the one mirror surface plate. It is possible to change the thickness dimension of a disk having the same diameter simply by disposing the disk.

[0029]

As is apparent from the above description,
In the disk mold of the present invention, the thickness of the cavity is provided on the mating surface of the guide mounting frame arranged on the outer periphery of the one mirror surface plate on which the stamper is not mounted and the receiving plate for fixing the one mirror surface plate. Since a thickness adjustment plate for adjustment is provided,
By changing only the thickness adjusting plate without changing the length of the insert bush or the ejector sleeve, it is possible to construct a mold for molding a disk having a desired thickness.

As a result, for discs of the same diameter,
Since it is possible to manufacture discs having different cavity thicknesses with one mold, it is possible to reduce the number of molds to be held and to reduce the mold cost for products.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment of a disk mold according to the present invention.

FIG. 2 is a sectional view of a second embodiment of a disk mold according to the present invention.

FIG. 3 is an enlarged sectional view showing an outer peripheral stamper retainer of a disc mold according to the present invention.

[Explanation of symbols]

 1 Disc Mold 2 Fixed Side Mold 3 Movable Side Mold 4 Cavity 5 Stamper 10 Thickness Adjusting Plate 11 Fixed Plate 12 Fixed Side Mirror Plate 13 Mounting Frame 22 Movable Plate 23 Movable Side Mirror Plate 25 Mounting Frame

Claims (6)

[Claims] 1. A cavity for forming a disk is formed in a mirror surface plate that is disposed between a fixed side mold and a movable side mold so as to face each other, and recording information is transferred to the disk on at least one of the mirror surface plates. In a disk mold having a stamper arranged, the stamper is arranged on the outer periphery of one mirror surface plate on which the stamper is not mounted, and faces the mounting frame arranged on the outer periphery of the other mirror surface plate to engage when the mold is closed. And a receiving plate for fixing the one mirror surface plate, and a thickness adjusting plate for adjusting the thickness of the cavity is provided on a mating surface between the guide mounting frame and the receiving plate. And disk mold. 2. A tip portion of an outer peripheral stamper retainer for holding a stamper has a substantially vertical rising surface, and a slight gap is provided between the vertical rising surface and a facing mirror surface plate. The disk mold according to claim 1. 3. The disk mold according to claim 1, wherein the thickness adjusting plate is arranged in the movable mold. 4. The disk mold according to claim 1, wherein the thickness adjusting plate is arranged on the fixed side mold. 5. The disk mold according to claim 1, wherein the receiving plate is a retainer plate having a back plate disposed between the receiving plate and the mirror plate. 6. The disk mold according to claim 1, wherein the receiving plate has a step portion on an outer peripheral surface facing the guide mounting frame.