JPH0240581Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a recording disk having a structure in which two single-sided disks are bonded together. Conventional laminated recording disks of this type, such as optical video disks, have hardened and sometimes relatively soft disks on opposing surfaces of two upper and lower single-sided resin disks A and B, as shown in Figure 1. It is constructed by applying an adhesive layer C and bonding them together, and D indicates the center hole. However, when playing by supporting the vicinity of the center hole D of a recording disk with this structure with the clamp of the player, if the atmosphere around the recording disk becomes high temperature, the single-sided disks A and B will soften and
Due to the disk's own weight, a soft adhesive layer C
Lateral slip occurs, causing deformation in which the outer peripheral edge hangs downward. If the disc is reproduced in such a deformed state, adverse effects such as a large amount of crosstalk occur during normal reproduction, and in severe cases, the outer peripheral edge of the recording disk comes into contact with the player. Moreover, even if the recording disk deformed in this way is cooled and returned to room temperature, it will not recover and will remain permanently deformed. Therefore, in order to prevent this deformation, if a hard adhesive is used in the adhesive layer,
The disadvantage was that the deformation due to molding distortion of the two single-sided disks A and B could not be absorbed, and the entire recording disk was distorted due to temperature and humidity.

The present invention attempts to solve the above-mentioned drawbacks, and includes a pair of opposing disks, a soft adhesive layer provided between the opposing surfaces of the pair of disks, and an outer periphery of the pair of disks. By providing an adhesive layer which is provided at the end and is harder after curing than the soft adhesive layer 4, it is possible to prevent the adhesive layer between disks from sliding sideways, and to prevent the adhesive layer from sliding in a high-temperature, high-humidity environment. It is an object of the present invention to provide a recording disk which prevents deformation at the bottom and also prevents a soft adhesive layer from extruding from the outer peripheral edge of the disk.

Hereinafter, the present invention will be described in detail with reference to the drawings. Fig. 2 is a partial sectional view of a recording disk according to the present invention, and in the figure, 1 and 2 are single-sided disks made of resin and having the same diameter. These two single-sided disks 1 and 2 are bonded together using an adhesive. Then, the outer peripheral ends 1a and 2a of the disks 1 and 2 are bonded using an adhesive layer 3 having hard properties after curing, and the other entire internal surfaces are bonded using a relatively soft adhesive as in the conventional example. Glue using layer 4. in this case,
The hard adhesive layer 3 becomes harder than the soft adhesive layer 4 after curing. In some cases, the inner peripheral ends 1b and 2b of the disks 1 and 2 may be
The portion may also be bonded with a hard adhesive layer 3. In this case, the deformation of the disk can be more effectively prevented, and the soft adhesive layer 4 can be more completely prevented from extruding. 5 is a clamp hole.

As described above, the present invention includes a pair of opposing disks 1 and 2, a soft adhesive layer 4 provided between opposing surfaces of the pair of disks, and an outer periphery of the pair of disks 1 and 2. Provided at the ends 1a and 2a,
The adhesive layer 3 is harder than the soft adhesive layer 4 after curing.

Therefore, the relatively soft adhesive layer 4 absorbs the deformation caused by the molding strain of the two single-sided disks 1 and 2, and the outer peripheral edges 1a and 2a of the disks are bonded to the hard adhesive layer 3 so that the entire disk is fixed. deformation can be prevented. Also, the outer peripheral edge 1 of the disk
Since a and 2a are bonded with a hard adhesive layer 3, the relatively soft adhesive layer 4 is prevented from protruding, and the soft adhesive layer 4 is prevented from shifting laterally under high temperature and high humidity. Deformation of the recording disk can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing a conventional recording disk, and FIG. 2 is a partial sectional view of a recording disk according to the present invention. 1, 2... Single-sided disk, 1a, 2a... Outer peripheral edge, 3... Hard adhesive layer, 4... Soft adhesive layer.

Claims (1)

[Scope of utility model registration request] a pair of opposing disks; a soft adhesive layer provided between opposing surfaces of the pair of disks; A recording disk with an adhesive layer that is later hardened.