JPS62243145A - Manufacture of optical disk - Google Patents

Abstract

PURPOSE:To obtain a junction being uniform and strong extending over the whole periphery of a junction part without using a special device, by simple equipment and process, by joining two pieces of disks by performing a specific working to both joint surface sides. CONSTITUTION:Ring-shaped projections 3, 3'; 4, 4' are provided on the inside and outside peripheral parts of both joint surface sides of two pieces of disks 1, 1', a ring shape being a little smaller than the outside periphery of the inside peripheral part projections 3, 3' is stored, and thereafter, working is executed and a ring 5 made of a shape memory material being larger than the outside periphery of the inside peripheral part projections 3, 3', and a ring shape being a little larger than the inside periphery of the outside peripheral part projections 4, 4' are stored. Thereafter, working is executed and a ring 6 made of a shape memory material being smaller than inside periphery of the outside peripheral part projections 4, 4' is placed and superposed on the joint surface side of two pieces of optical disks 1, 1', and joined by making the rings 5, 6 execute a shape recovery. In such a way, a uniform and storing junction is obtained by simple equipment and process, and also, a metallic mold used for forming a disk can also be formed into a simple shape.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for playing a two-ply optical disc QJfA in which information signals are read and written using optical means such as laser light.

[Conventional technology]

Conventionally, a method has been known in which two disks are bonded together by an ultrasonic lamination method, as shown in @Kokai No. 115346/1983.

[Problem that the invention seeks to solve]

However, with conventional bonding methods, ultrasonic vibrations occur l! I need a pupil, 1t, the part that melts due to the ultrasonic waves absorbs the ultrasonic vibration, and not only can weld over a wide range not be possible, but the ultrasonic vibration has directionality. Therefore, the present invention has a problem in that it is difficult to bond uniformly. Therefore, the present invention is an attempt to solve this problem with the conventional method, and it is possible to bond uniformly around the entire circumference of the joint without using any special coating. The aim is to obtain uniform and strong joints using simple 11L equipment and processes.

[Means for solving problems]

The optical disk manufacturing method of the present invention is particularly suitable for I11 of a two-piece optical disk on which information is read and written.
! In the i method, ring-shaped protrusions are provided on the inner and outer peripheries of the joint surfaces of both the two disks, and after memorizing a ring shape that is slightly smaller than the outer periphery of the inner periphery protrusions, 7JO
A ring made of a fixed shape memory material is machined to be larger than the outer circumference of the inner circumference protrusion, and a ring shape slightly larger than the inner circumference of the outer circumference protrusion is memorized, and then the inner circumference of the outer circumference protrusion is machined. A ring made of a shape-memory material and made smaller than the circumference is placed on the joint surface side of the two optical discs to be joined, the two discs are overlapped, and the ring made of the shape-based material recovers the shape. It is characterized by joining two discs.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. 1 [F] is an air sandwich type optical disc in which recording layers face each other and has a hollow space between the recording layers, using an uninvented joining method; 1 and 1' are made of polymethylmethacrylate; -) (PMMA) or other transparent sweet acid resin disc base, 2 and 2' are 1 and 1°
'Information record formed on @+1. s and 3' are inner peripheral projections, and 4 and 4' are outer peripheral projections. Rings 5 and 6 are made of shape memory material and are engaged with 5 and 5' and 4 and 4', respectively, to join 1 and 1' by restoring their shape.

FIG. 3 shows the state of the rings 5 and 6 before their shape has been restored, and they are simply stacked on the disk IFi disk 1'. If the rings 5 and 6 are made of shape memory alloy such as Ni-Ti, if the shape recovery temperature of the rings 5 and 6 is set lower than the operating temperature of the optical disk, the rings 5 and 6 will be within the operating temperature range of the optical disk. The elastic modulus is the largest at this point, and the bond between the disks 1 and 1' becomes strong. To this end, the assembly shown in FIG. 2 is performed at a temperature lower than the operating temperature of the optical disk.

FIG. 3 shows another example of the present invention.

7 and 8 are tacky adhesives, which make the bonds between the rings 5 and 6 and the protrusions 3 and 4 more complete.

It works to improve the airtightness of the hollow space between recording layers.

9 and 9' are grooves provided on the inner protrusion, IQ and 10' are provided on the outer protrusion, and rings 5 and 6 are provided respectively.
and joins the discs 1 and 1'. To join the disks, adhesive adhesive is applied to the outer periphery of the inner periphery protrusion and the inner periphery of the outer periphery protrusion of the disks 1 and 1', and the rings 5 and 6, which have not yet recovered their shape, are set between the two disks. , by causing the rings 5 and 6 to recover their shapes.

In the above examples, the cross-sectional shapes of the rings 5 and 6 are V-shaped and U-shaped.
Any shape may be used as long as it can connect 11 and 11. It goes without saying that the present invention can also be applied to the original disk of a two-layer optical disk other than the air sandwich type.

〔Effect of the invention〕

As explained above, according to the present invention, not only can uniform and strong bonding be obtained with simple equipment and processes without using special equipment such as ultrasonic generation electric manufacturing, but also the shape of the bonded part can be Since the degree of freedom is large, the mold used for manufacturing the disc can also be made into a simple shape, which has the effect of making it economically advantageous.

[Brief explanation of drawings]

The first factor is 1. Fig. 2 is a longitudinal sectional view showing an embodiment of optical disc joining and purchasing according to the present invention. Fig. 2 is a longitudinal sectional view showing the state before shape recovery of the ring used for joining the discs. Fig. 5 is , a longitudinal sectional view showing another embodiment of the invention. 1... Disc base 2... Information recording 1-5... Ring made of shape memory material 7... Adhesive adhesive or more

Claims (1)

[Claims] In a manufacturing method for a two-disk bonded optical disk in which information is read and written using light, ring-shaped protrusions are provided on the inner and outer peripheries of the joint surfaces of both disks, and a ring-shaped protrusion is provided on the outer periphery of the inner periphery protrusion. After storing a slightly smaller ring shape, a ring made of a shape memory material was processed to be larger than the outer circumference of the inner protrusion, and a ring shape slightly larger than the inner circumference of the outer protrusion was memorized. After that, a shape-memory material ring that has been processed to be smaller than the inner periphery of the outer peripheral protrusion is placed on the joining surface side of the two optical discs to be joined, and the optical discs are overlapped, and the shape-memory material ring is A method for manufacturing an optical disc, characterized by joining two discs by performing shape recovery.