JPS6231047A - Air sandwich type optical disk with vent hole - Google Patents

Abstract

PURPOSE:To prevent a disk from swelling and to eliminate the waving of its surface by forming an air vent hole discontinuously at a position (ED) where fusion begins in ultrasonic welding. CONSTITUTION:A vent hole is formed in the optical disk in air sandwich structure stuck by ultrasonic welding by making an energy director discontinuous. The vent hole is formed in a dummy plate 3 with a spacer used for the optical disk by making the ED part 4 of the dummy plate discontinuous. For example, when recording layers are formed on both surfaces, the vent hole is provided at least one place of the ED part 4 of an inner peripheral spacer 7 and/or inner peripheral spacer 8. Consequently, boring operation is performed not in a different process, but simultaneously with the welding and the vent hole of optional size is formed at an optional position of the optical disk. Further, the vent hole is blocked as necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to optical discs. More specifically, the present invention relates to an optical disc having an air sandwich structure bonded together by ultrasonic welding.

[Conventional technology and problems]

Conventionally, when manufacturing optical discs by ultrasonic welding,
For example, as shown in FIG. 13(a), when the disk substrate 1 is placed on the dummy plate 3 with the spacer 2 and the horn 5 of the ultrasonic device is pressed to apply ultrasonic vibration, the energy director ( The part where welding starts during ultrasonic welding, hereinafter abbreviated as HD) 4 (height 0.3~0.
5 mm) is melted, and the disk substrate 1 and spacer 2 are welded together as shown in FIG. 13(b). At this time, when the disk substrate 1 is pressed by the horn 5 before welding, the air layer 6 becomes sealed. Therefore, when welding is completed by ultrasonic waves, the air layer becomes pressurized, causing bulges on the disk as shown in FIG. 13 (C1), causing surface waviness.

[Means for solving problems]

As a result of extensive research, the present inventors discovered that the above problems could be solved by providing air vent holes (vent holes) in the HD to prevent pressurization of the air layer. The invention was completed.

That is, the present invention provides an optical disc having an air sandwich structure bonded together by ultrasonic welding, characterized in that vent holes are provided by making the HD discontinuous.

〔Example〕

Hereinafter, embodiments of the present invention will be described in more detail based on the drawings.

FIG. 1 is a sectional view showing an example of a dummy plate 3 with a spacer used in the optical disc of the present invention, and vent holes are provided by making the ED portion 4 of the dummy plate discontinuous. Note that the dummy plate is a simple plate used for a disk without a recording layer (a disk that uses only one side). FIG. 2 is a sectional view showing another embodiment of the optical disc of the present invention,
This is an example in which both surfaces are recording layers, and in this case, a vent hole is provided at at least one location in the HD portion 4 of the inner circumferential spacer 7 and/or outer circumferential spacer 8.

Specific examples of the shape of the HD in the present invention are shown in FIGS. 3 to 12.

3 to 12 are perspective views of a portion of a spacer ring having an ED, FIG. 3 is an example of a discontinuous HD in which a portion of ED4 is simply removed, and FIG. 4 is a perspective view of a portion of a spacer ring having an ED. This is an example in which a flat portion 9 whose height is lower than ED4 is provided,
FIG. 5 is an improvement on FIG. 3, in which a recess 10 extending in the opposite direction to the ED 4 is provided in the removed discontinuous portion, and FIG. 6 is a modification of FIG. 4, in place of the flat portion 9. This is an example in which a thin linear portion 11 is provided in the E.
An example in which a plurality of small protrusions 12 are provided in the discontinuous portion of D4, FIG. 8 is an example in which a filter or an elastic body (pressure fluctuation absorbing material, e.g. rubber) 13 is provided in the discontinuous portion of ED4, and FIG. This is a combination of FIG. 8 and FIG. 6, and is an example in which a thin linear portion 11 and a filter or elastic body 13 are provided, FIG. 10 is an example in which a groove 14 is provided in the same as in FIG. In the modified example shown in Fig. 5, the width of the recess 10'' is expanded to the full width of the spacer 2, and Fig. 12 shows a zigzag passage 15 for obstructing the passage of dirt.
The member 16 having the
This is an example of integral molding. Of these examples, 3.5,
In the example shown in Figure 7.11.12, the passage remains even after bonding by ultrasonic welding, but in the example shown in Figure 4.6゜8.9.10, the passage is blocked or removed after bonding. blocked by a filter.

In the present invention, when bonding by ultrasonic welding, air is allowed to escape, and when welding is completed, H
A D shape is preferred. Also, when transporting by air, it is preferable to have ventilation holes because the air pressure will drop, but to prevent dust from getting in, it is especially recommended to have a filter installed at the discontinuous part of the HD, or a zigzag passage. preferable.

〔Effect of the invention〕

In the optical disk of the present invention, the drilling and welding operations can be performed at the same time as welding, rather than as a separate process, and vent holes of any size can be formed at any position. Further, the vent hole of the present invention can be closed as necessary.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a dummy plate with a spacer used in the optical disk of the present invention, FIG. 2 is a cross-sectional view showing another embodiment of the optical disk of the present invention, and FIGS. A perspective view showing the shape of such an ED, and FIG. 13 are cross-sectional views showing the manufacturing process of a conventional optical disc. l: Disk board 2 spacer - 3: dummy board
4: HD 5: Horn 6: Air layer 7: Inner spacer 8: Outer spacer 9: Flat part 1o: Recessed part 11: Linear part 12: Small protrusion 13: Filter or elastic body 14: Groove 15: Zigzag passage 16 :Element

Claims (1)

[Claims] 1. An optical disc having an air sandwich structure bonded together by ultrasonic welding, wherein a vent hole is provided by discontinuing an energy director.