JPS6111211A - Optical disk forming mold - Google Patents

Abstract

PURPOSE:To enable a stamper to be stuck forcibly to the resin part in a molding and cooling time and to contrive to improve transferring properties with a simple structure by giving force to the lower surface of a disc plate by compressed air when molds are clamped. CONSTITUTION:A gap 113 with size more than the cooling contraction of the resin having the thickness of the cavity 20 at the least is provided between the upper surface of the stamper 1 and the lower surface of the holding ring 10 in order to remove the air and gas generated from the resin in injection molding. The compressed air supplied from the inlet 113 of the retainer plate 16 on the movable side flows into several grooves 111, 112 on the die insert 3 on the movable side through a circuit 110 to enable the stamper 1 to be pushed by the air pressure from the lower surface of the disc plate 2 toward the cavity 20 after the contraction of cooling resin. Hereby, it is made possible to form an optical disc excellent in transferring properties without peeling contracting resin from the stamper surface and structure can be simplified as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a stamper in the form of a thin disk having information bits.
This invention relates to an optical disc molding mold for manufacturing replicas of optical discs such as video discs, compact discs, and information file discs by installing the disc into the mold.

Structure of the conventional example and its problems As shown in Figs. 1 and 2, in the conventional optical disc mold, the molded product part of the information bit of the stamper 21 (41-) is removed during molding (mold clamping). 40 (60) There is no structure in which compressive force is forcibly applied from the stamper side (movable mold side) in order to improve the transferability.In order to improve the transferability, the mold and molding conditions must be By simply relying on the fine-tuning of
It was very unstable in terms of productivity, and there were problems in molding work and molded product quality control.

OBJECTS OF THE INVENTION The present invention is intended to eliminate the above-mentioned conventional drawbacks and to simplify the configuration.

Composition of the Invention The optical disc molding die of the present invention includes a movable mold insert having a plurality of radial and concentric grooves on the upper surface, and a disk having a stepped portion on the outer periphery and a stamper installed on the upper surface. plate and
a holding push that holds the peripheral portion of the center hole of the stamper and is fixed to the center of the disk plate; an outer ring having a convex portion on an inner diameter portion for receiving a stepped portion of the outer circumference of the disk plate; It consists of a retaining ring fixed to the outer ring so as to be sandwiched together with the disc plate and a convex part of the outer ring, and a compressed air circuit leading from the movable mold plate to a plurality of grooves on the upper surface of the movable insert, When the mold is clamped, compressed air is used to apply force to the lower part of the disc plate, and the stamper on the disc plate can be forcibly brought into close contact with the resin part that is being molded and cooled. This is extremely advantageous in terms of work and molded product quality control.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. 1 is a disc plate on which 1 is placed, and 3 is a movable side plate having a plurality of radial grooves 112 and concentric grooves 111 on its upper surface. A mold insert, 4, holds the peripheral part of the hole on the upper surface of the disk plate through the center hole of the stamper, and a holding push fixed on the lower surface with a nut 13, 6, installed at the center of the movable mold insert. The retaining pusher outer ring 10 is fixed by sandwiching the stamper 1 together with the disk plate between the outer ring and the retaining ring 110. The retaining pusher outer ring 110 supplies compressed air from the inlet 114 of the movable mold plate 16 to the plurality of molds on the upper surface of the movable insert. This is the circuit hole that leads to the grooves 111 and 112.

Then, the upper surface of the stamper 51 and the retaining ring 10
The lower surface refers to at least the movable mold plate 1 in order to remove the air and gas generated in the cavity 20 during molding injection.
The compressed air sent from the inlet 113 of circuit 1
10, the plurality of grooves 111.1 of the i-side insert 3
12, and by air pressure, the stamper 1 can be pressed from the lower surface of the disk plate 2 toward the cavity 20 by following the contraction of the resin during cooling.

Effects of the Invention As described above, in the present invention, since molding is performed by forcibly pressing the stamper surface having a large amount of minute information bits onto the resin that is being molded and cooled, the stamper is compressed when the resin contracts.
It is possible to mold optical discs with good transferability without causing separation from the surface, greatly reducing the need for fine adjustment of molds and molding conditions, simplifying the overall configuration, and improving the molding process. This is extremely advantageous in terms of quality control.

[Brief explanation of drawings]

1 and 2 are partial sectional views of a conventional optical disc molding die, FIG. 3 is a partial sectional view of an optical disc molding die according to an embodiment of the present invention, and FIG. 4 is an enlarged sectional view of the same part. It is. 1... Stamper 12... Disc plate, 3... Movable side mold insert, 4... Holding push, 6... Positioning push, 9...
...Outer ring, 10...Retaining ring.

Claims (1)

[Claims] A thin disk-shaped stamper having a large amount of information bits, a movable mold insert having a plurality of radial and concentric grooves on the upper surface, and a stepped portion on the outer periphery, and the stamper is installed on the upper surface. a disc plate; a holding pusher that holds the peripheral portion of the center hole of the stamper and is fixed to the center portion of the disc plate; and an outer ring having a convex portion on an inner diameter portion and receiving a stepped portion on the outer periphery of the disc plate; A retaining ring fixed to the outer ring such that the stamper is sandwiched between the disc plate and the convex portion of the outer ring, and compressed air and vacuum exhaust that communicate from the movable mold plate to the plurality of grooves on the upper surface of the movable insert. An optical disc mold with a circuit.