JPH0447380B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides two optical discs that can be used as information recording surfaces on both the upper and lower surfaces.
The present invention relates to an optical information recording medium that is laminated in an air sandwich type in which an air layer is formed between the two optical disks by a spacer.

[Conventional technology]

Two examples of how to bond an optical disk and a spacer in a conventional optical information recording carrier of this type are shown in FIGS. 7 and 8.

In FIG. 7, two optical disks 1 and 2 are bonded to spacers 3 and 4 at the outer periphery and center using an adhesive 5.
A, 2a are formed on one surface of transparent plastic substrates 1b, 2b.

The optical disks 1 and 2 are arranged on the information recording surface 1a,
The spacers 3 and 4 are bonded to each other with adhesive 5 so that 2a is the inner surface, and an air layer 6 is formed between the information recording surfaces 1a and 2a to form an air sandwich type.

Further, FIG. 8 shows the optical information recording carrier shown in FIG. 7 in which the outer periphery is sandwiched between bands 7.

[Problem that the invention seeks to solve]

The conventional optical information recording medium shown in FIG.
Since the two optical disks 1 and 2 are bonded to the spacers 3 and 4 only by the adhesive strength of the adhesive 5, the mechanical strength of the bond is weakened and there is a risk of them peeling off.

If the plastic substrates 1b, 2b of the optical disks 1, 2 and the spacers 3, 4 have different coefficients of thermal expansion, this tendency will be exacerbated by temperature changes.

Furthermore, in the optical information recording carrier shown in FIG.
Although there is no risk of peeling as described above, a step of winding the band 7 is required, which has the drawback of increasing costs.

[Purpose of the invention]

The present invention is intended to eliminate the above-mentioned drawbacks of the conventional optical information recording carrier with information recording surfaces on both sides. It is an object of the present invention to provide an optical information recording carrier that does not require a troublesome sandwiching process and causes less cost increase.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention interposes a spacer between the upper surface, the lower surface, and the optical disk forming the information recording surface, respectively, and separates these three from each other.
The gist is that at least both the upper and lower ends of the pin are melted and fixed using ultrasonic vibration.

[Embodiments of the invention]

One example of implementing the invention will be described below with reference to FIGS. 1 and 2.

Reference numerals 1 and 2 denote two optical disks for forming information recording surfaces on both the upper and lower surfaces, and information recording surfaces 1a and 2 are formed on one surface of transparent plastic substrates 1b and 2b.
a is formed in the same manner as before.

The optical disks 1 and 2 are provided with holes 1 having the same diameter as plastic pins 8, which will be described later, at equal intervals along the outer periphery.
c, 2c are formed.

3 is a spacer that is the same as the spacer on the outer periphery of a conventional optical information recording carrier, and a hole 3a is formed at the same interval as the holes 1c and 2c, and the diameter of this hole 3a is as follows.
The diameter of the pin 8 is larger than that of the pin 8.

The pin 8 is made of plastic whose surface can be melted by ultrasonic vibration, and the optical disk 1, spacer 3, and optical disk 2 are stacked in this order so that the information recording surfaces 1a and 2a are the inner surfaces. Together,
Insert pins 8 into holes 1c, 2c, and 3a.

For example, as shown in FIG. 2, this pin 8 has small cones 8a formed on both upper and lower end surfaces.

Then, when the head piece 9 having the small conical recess 9a is placed on the small cone 8a and ultrasonic vibration is applied while pressurizing the head piece 9, the small conical recess 9a and the small conical recess are The portion 9a is melted and welded to form a caulked shape as shown in FIG.

In this way, the optical disks 1 and 2 and the spacer 3 are fixed, forming a sanderch type structure in which an air layer 6 is formed between the information recording surfaces 1a and 2a.

In this embodiment, even if the thermal expansion coefficients of the optical disks 1, 2 and the spacer 3 are different, a gap is created between the hole 3a and the pin 8, so the difference in expansion and contraction of the spacer 3 due to temperature changes is absorbed. Therefore, no cracks are generated in the holes 1c and 2c of the optical disks 1 and 2.

Further, the spacers 3 of the optical disks 1 and 2 may be bonded together using an adhesive 5.

Furthermore, the pin 8 may not use the head piece 9, but the outer periphery of the pin 8 and the holes 1c, 2c may be welded.

Next, another embodiment of the present invention will be described with reference to FIG.

In this embodiment, it is not necessary to provide the holes 1c and 2c in the optical disks 1 and 2, the height of the pin 8 is the same as the thickness of the spacer 3, and small cones 8a are formed on both the upper and lower end surfaces. There is.

A hole 3a similar to the previous embodiment is formed in the spacer 3. A pin 8 is inserted into the hole 3a, the optical disks 1 and 2 are placed on the upper and lower surfaces of the spacer 3, and ultrasonic vibration is applied while applying pressure. When a
are welded, and the optical disks 1 and 2 and the spacer 3 are fixed.

Even in this case, optical disks 1 and 2 and spacer 3
The difference in thermal expansion coefficient is absorbed by the gap between the pin 8 and the hole 3a.

Furthermore, it is also possible to use an adhesive to fix the optical disks 1, 2 and the spacer 3, as in the previous embodiment.

FIG. 4 shows a third embodiment of the present invention.
A pin 8 is previously integrally molded onto the optical disk 1 or welded using ultrasonic waves.

Then, the spacer 3 has holes 3 as in the previous embodiment.
After inserting the pin 8 into this, a small cone 8a on the end surface of the pin 8 is brought into contact with the optical disk 2, and this is welded by ultrasonic vibration.

The height of the pin 8 in this case is the same as the thickness of the spacer 3 as in the previous embodiment.

FIG. 5 shows a fourth embodiment of the present invention, in which pins 10 and 11 are integrally molded or ultrasonically welded in advance to optical disks 1 and 2, respectively.
0 and the height of the pin 11 is the same as the thickness of the spacer 3.

Then, the pins 10 and 11 are inserted into the holes 3a of the spacer 3, which are the same as in the previous embodiment, butted against each other, and the small cone 10a on the end face of the pin 10 is welded to the end face of the pin 11 by ultrasonic vibration.

FIG. 6 shows a fifth embodiment of the present invention, in which the spacer 3
The pin 12 is the same height as the thickness of the optical disks 1 and 2.
are integrally molded or ultrasonically welded on both the top and bottom.

Holes 1d and 2d with a larger diameter than the pin 12 are bored at positions facing the pin 12 of the optical disks 1 and 2, and the pin 12 is inserted into the hole 1d and 2d. The head piece 9 shown in FIG. 2 is brought into contact with the head piece 9, and the small cone 12a and the head piece 9 are welded together by ultrasonic vibration.

The difference in expansion and contraction due to the difference in thermal expansion coefficient between the optical disks 1 and 2 and the spacer 3 in this embodiment is
This is absorbed by the gap between d and the pin 12.

Further, in each of the above embodiments, the optical disks 1 and 2
It is also possible to fix the spacer 3 and the spacer 3 in the same manner as in the past by using an adhesive in combination.

〔Effect of the invention〕

As described above, in the present invention, by welding at least one end of the pin using ultrasonic vibration, it is possible to obtain an optical information recording carrier whose upper and lower surfaces are composed of optical disks.

This welding of pins using ultrasonic waves is much stronger than conventional adhesive bonding because the pins are integrated with the welded object, and there is no risk of the optical disk peeling off from the spacer as in the conventional case.

If the diameter of the hole into which this pin is inserted is made larger than the outer diameter of the pin, the gap between the pin and the hole will absorb the difference in expansion and contraction between the optical disk and the spacer due to the difference in coefficient of thermal expansion, and this difference will cause peeling. This can prevent cracks in optical discs from occurring.

Alternatively, if an adhesive is used in combination to bond the spacer and the optical disk, the spacer and the optical disk can be fixed even more firmly.

Further, since there is no need to use a band as in the conventional case, the troublesome process and band are no longer necessary, and the cost increase due to the band is reduced, so that it can be provided at low cost.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of one embodiment of the present invention, FIG. 2 is an enlarged view of one example of the pin, FIGS. 3 to 6 are cross-sectional views showing other embodiments of the present invention, and FIG. figure,
FIG. 8 is a sectional view of each conventional example. 1, 2... Optical disk, 1a, 2a... Information recording surface, 1b, 2b... Plastic substrate, 1c,
2c, 1d, 2d...hole, 3...spacer, 3a
...hole, 6 ... air layer, 8 ... pin, 8a ... small cone, 9 ... head piece, 9a ... small conical recess, 1
0, 11, 12...pin, 10a, 12a...small cone.

Claims (1)

[Claims] 1. A spacer is interposed between two optical disks each forming an information recording surface on the upper surface and the lower surface,
An optical information recording carrier characterized in that these three members are fixed by melting at least one end of the pin using ultrasonic vibration.