JP3242230B2 - Method and apparatus for taking out optical disk substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for taking out an optical disk substrate made of an injection-molded resin from a mold.

[0002]

2. Description of the Related Art An optical disk substrate injects molten resin into a cavity formed between a fixed mold and a movable mold.
After filling and cooling and solidifying, the movable mold is separated from the fixed mold, and the optical disk substrate held by the movable mold is removed from the movable mold with the separation.

[0003] By the way, a conventionally known apparatus for taking out an optical disk substrate has been configured as shown in FIG. In FIG. 2, a stamper 3 for forming a predetermined pattern on the surface of the optical disk substrate P is fixed to a mirror surface 1a of the movable mold 1 by a mounting mold 2, and the movable mold 1 is fixed. Is provided with a gate cut piston 4 for forming a through hole Pa in the center of the optical disk substrate P to be injection-molded. On the outer periphery of the gate cut piston 4, an optical disc substrate P
A cylindrical substrate protruding member 5 that presses the outer peripheral portion of the central through hole Pa to protrude the optical disk substrate P outward from the mold 1 is provided to be able to advance and retreat via a cylinder (not shown). ing. Further, a pressurized air A is blown out between the stamper 3 and the optical disk substrate P on the outer peripheral portion of the substrate protruding member 5 to release the optical disk substrate P with a releasing force (to the right in FIG. 2). An annular pressurized air passage 6 for applying the extrusion pressure is formed.

On the other hand, an annular handling plate 7 attached to a hand (not shown) of a robot is provided at a central portion on the take-out side of the optical disk substrate P in an opposed manner. The handling plate 7 is provided with a plurality of suction pads 8 as suction tools which are in close contact with the substrate protruding member 5 and the optical disk substrate P protruded by the pressurized air A, and suction the optical disk substrate P by negative pressure. These suction pads 8 are communicated with a vacuum suction device (not shown) via an intake passage 8 a formed inside the handling plate 7.

Next, a description will be given of a method of taking out the optical disk substrate having the above-described structure by the take-out apparatus. After the injection molding of the optical disk substrate P, the movable mold 1 is separated from a fixed mold (not shown). At this time, the gate cut piston 4 is also separated from the fixed mold. Then, the robot operates to bring the handling plate 7 close to the central portion of the take-out side of the optical disk substrate P in an opposed manner as shown in FIG. Then, the stamper 3 of the movable mold 1 is passed through the pressurized air passage 6.
A pressurized air A is blown out between the optical disk substrate P and the substrate protruding member 5 is advanced to the robot side (substrate unloading side) by a cylinder (not shown) to press the outer peripheral portion of the central through hole Pa of the optical disk substrate P. I do. The optical disc substrate P is peeled from the stamper 3 by the pressing force, the releasing force by the pressurized air A, and the outward pushing pressure, and is protruded outward from the mold 1.

[0006] With the outward movement of the optical disk substrate P, the suction pad 8 is attached to the outer surface of the optical disk substrate P.
And the optical disk substrate P is suction-held on the handling plate 7 side by the negative pressure. In this suction state, the robot moves the handling plate 7 to the right side in FIG. 2 so that the optical disk substrate P is taken out of the movable mold 1.

[0007]

By the way, in the above-mentioned conventional method for removing the optical disk substrate P, when the optical disk substrate P is removed from the mold 1, the center through hole Pa of the substrate P is formed. Rubbing occurs between the gate-cut piston 4 and the inner peripheral surface of the central through-hole Pa, causing scattering of resin pieces Q such as variss, which may adhere to the surface of the optical disk substrate P. When the resin pieces Q such as burrs adhere to the surface of the optical disk substrate P, they may cause pinhole defects during the formation of the reflective film and the recording film, which are the steps after the removal, and may cause the protective film and the cuvette. -It may be a cause of a projection defect at the time of application of an ultraviolet curable resin such as a coating, which leads to a decrease in yield.

Usually, the above-mentioned deposits are removed by a static elimination air blow or the like before the film-forming or coating process. However, in this method, the deposits can be completely removed. Due to the difficulty, the decrease in yield cannot be sufficiently suppressed, and the quality of the optical disc is improved (good error).
Rate).

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has an object to remove an optical disk substrate in which resin pieces, such as burrs, generated when the optical disk substrate is removed are prevented from adhering to the surface of the optical disk substrate. It is intended to provide a method and apparatus.

[0010]

To achieve the above object, according to the solution to ## extraction method of the optical disc substrate according to the present invention, the medium
Projecting an optical disc substrate having a through-hole in central portion toward the outside from the mold side, and at the same time adsorbing the extruded come optical disk substrate in extraction side, said by sucking air in the vicinity of the center portion of the optical disc substrate Fly through the central through hole
Remove the scattered burrs.

An apparatus for removing an optical disk substrate according to the present invention is provided in a mold, and presses an outer peripheral portion of a central through hole of the optical disk substrate to project the optical disk substrate outward from the mold. Attached to the protruding member and the hand part that advances to the take-out side of the optical disk substrate
A suction tool for sucking the protruding optical disc substrate by a negative pressure; and a suction device attached to the hand portion for sucking air near the center through hole of the optical disc substrate to remove the air from the center through hole.
And an air inlet for removing the flying varieties .

[0012]

According to the present invention, when the molded resin optical disk substrate is pushed outward from the mold side and the ejected optical disk substrate is sucked and taken out at the take-out side, the central portion of the optical disk substrate is taken out. By sucking the air in the vicinity, resin pieces such as burrs generated at the center of the optical disk substrate are sucked and removed together with the air due to the protrusion. Therefore, it is possible to prevent resin pieces such as burrs from adhering to the surface of the optical disk substrate.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration of an optical disk substrate take-out apparatus according to the present invention. In FIG. 1, a robot hand (not shown) advances to the take-out side of the optical disc substrate P held by the movable mold 1, and the handling plate 7 attached to the hand holds the suction pad 8. In addition, an intake port 9 for sucking air near the center through hole Pa of the optical disc substrate P is fixed. Like the suction pad 8, the suction port 9 is communicated with a vacuum suction device (not shown) through an intake passage 8a formed inside the handling plate 7. The other configuration is the same as that of the conventional example shown in FIG. 2, and the same or corresponding parts are denoted by the same reference numerals and detailed description thereof will be omitted.

The method of taking out the optical disk substrate by the above-structured apparatus is basically the same as that of the conventional example, and the difference is as follows. That is, when the optical disk substrate P is taken out of the mold 1, friction occurs between the gate cut piston 4 for forming the central through hole Pa of the substrate P and the inner peripheral surface of the central through hole Pa. At this time, air near the center through hole Pa of the optical disc substrate P is sucked from the air inlet 9 fixed to the handling plate 7. Resin pieces Q such as burrs scattered from the central through-hole Pa are sucked into the above-described intake port 9 and removed. Therefore, it is possible to prevent the resin pieces Q such as burrs from adhering to the surface of the optical disk substrate P. Therefore, a pinhole defect does not occur when a reflective film or a recording film is formed on the optical disk substrate P after being taken out, and a protrusion defect occurs when an ultraviolet curable resin such as a protective film or a hard coat is applied. As a result, the quality and yield of the optical disk can be improved.

Hereinafter, a test performed by the present inventors will be briefly described. Using the optical disk substrate take-out apparatus shown in the above embodiment, the conditions of resin temperature of 320 to 360 ° C., mold temperature of 110 to 120 ° C., and cooling time of 3 to 6 seconds are appropriately selected, and the diameter is 3.5 inches. Was molded by injection molding. The pinhole defect rate when a recording film is formed as a post-process is 5% or less on the optical disk substrate taken out of the mold after molding, and when a protective film made of an ultraviolet curable resin is applied. The projection defect rate was also 5% or less. Further, the BYER (byte error rate) of the optical disk as the final product was about 3 × 10 ⁻⁶ , which was extremely good.

On the other hand, using the conventional optical disk substrate take-out apparatus shown in FIG.
A 5-inch optical disk substrate was injection molded. Then, when a similar post-process was performed on the optical disk substrate thus formed, the pinhole defect rate at the time of film formation was about 1%.
0%, and the percentage of defective protrusions at the time of application of the protective film was 10% or more.
The ER (byte error rate) was about 3 × 10 ⁻⁵ , and it was found that the yield was significantly inferior to that of the above example.

[0017]

As described above, according to the present invention, at the time of taking out an optical disk substrate, it is possible to suck and remove resin pieces such as varicuses generated and scattered in the vicinity of the central through hole. In addition, the pinhole defect rate at the time of film formation as a post-process and the protrusion defect rate at the time of applying the protective film are reduced, so that the process yield can be remarkably improved and the quality can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an optical disk substrate take-out apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional optical disk substrate take-out apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... (movable side) metal mold, 5 ... board protruding member, 6 ... pressurized air passage, 7 ... handling plate (hand part), 8 ... suction pad (suction unit), 9 ... suction port, P ... light Disk substrate, Pa: central through hole, A: pressurized air.

Claims (2)

(57) [Claims] 1. A method for removing an optical disk substrate having a through hole at a center portion thereof from a mold, comprising: projecting the optical disk substrate outward from the mold side; At the same time, the coming optical disk substrate is sucked on the take-out side, and at the same time, air near the center of the optical disk substrate is sucked to remove the burrs scattered from the central through hole.
How to remove the optical disk substrate to be removed. 2. An apparatus for removing an optical disk substrate made of a resin having a through hole in a central portion from a mold, wherein the device is disposed in the mold and presses an outer peripheral portion of the central through hole of the optical disk substrate. A substrate projecting member for projecting the optical disk substrate outward from the mold, and a suction device attached to a hand portion which advances to the take-out side of the optical disk substrate, for suctioning the projected optical disk substrate by negative pressure. Attached to the hand portion, sucks air near the center through hole of the optical disc substrate and scatters from the center through hole.
An apparatus for taking out an optical disk substrate, comprising an intake port for removing burrs .