JPH02128334A - optical recording medium - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical recording medium having a hollow structure and on which information is recorded, reproduced, erased, etc. using a laser beam or the like.

[Prior Art] Optical recording media such as optical disks have excellent features such as high recording density, large capacity, low cost, and high access and transfer speeds. It is attracting attention as a recording medium that can replace discs.

Conventionally, optical disks have a hollow structure from the viewpoint of recording sensitivity and the like. The structure of a typical optical disc is shown in FIG. That is, it has a configuration in which a recording layer 2 is formed on a substrate 1, and a backing material 3 is joined to the substrate 1 from the recording layer 2 side with spacers 6 disposed on the inner diameter part and the outer diameter part being sandwiched. However, it has a hollow structure in which a space is formed between the backing material 3 and the substrate 1 by the spacer 6. Here, the substrate 1, the spacer 6, the backing material 3 and the spacer 6 are UV rays.
It is bonded with an adhesive such as a binder. The spacers are aligned independently for the inner and outer diameter parts.

[Problem to be solved by the invention]

However, in the case of the above conventional example, the backing material and the substrate are bonded by applying a solvent-free liquid photosensitive resin using a dispenser, etc., and curing it after bonding and positioning. etc. may affect the recording material.

■A certain amount of space is required for adhesion.

■It is necessary to UV cure with alignment.
A jig is required.

■Stress may cause distortion in the substrate, which may increase birefringence or cause unevenness.

The present invention has been made in view of the above-mentioned problems, and provides an optical recording medium in which the backing material and the substrate can be easily bonded together without adversely affecting the recording layer by improving the structure of the optical recording medium. It is something to do.

[Means for Solving the Problems] According to the present invention, a backing material and a transparent substrate are joined with a predetermined gap therebetween via a spacer, and a recording layer for recording information is provided on the transparent substrate on the backing material side. In the formed optical recording medium, the spacer or the backing material has a joint portion inscribed with the top and bottom surfaces of the outer peripheral portion of the transparent substrate, and the fitting between the joint portion and the top and bottom surfaces of the outer peripheral portion causes the spacer or the backing material to bond with the backing material. By bonding with the transparent substrate, an optical recording medium that can be easily assembled without using an adhesive or using only a small amount of adhesive can be obtained without adversely affecting the recording material.

The present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing one embodiment of the optical recording medium of the present invention, and FIG.

In FIGS. 1 and 2, the backing material joining portion 4 is arranged over almost the entire outer circumference so as to cover the transparent substrate 1. The backing material 3 has a step on its inside, the spacer in the conventional example is integrally injection molded, and the backing material joining portion 4 is also integrally formed. The joint is made of a thin plastic material, and has a cutout 5, which has the characteristic of expanding slightly in the outer circumferential direction.Using this, as shown in FIG. can be expanded in the outer circumferential direction, and the transparent substrate 1 can be fitted into the backing material 3.

The backing material joining part is in the shape of a key, and is designed to fix the outer periphery of the transparent substrate vertically, and fixes and holds the upper and lower surfaces of the transparent substrate in a sandwiching manner. In this case, although there may be a gap in the outer circumferential direction between the transparent substrate 1 and the backing material joint 4, the transparent substrate must not come off without any stress. That is, the inner diameter of the key-shaped tip of the backing material joint must be smaller than the outer diameter of the transparent substrate. In this case, the center hole 7 of the backing material 3 is sufficiently larger than the center hole 8 of the transparent substrate, and is large enough not to block the center hole 8 when the backing material and the transparent substrate are misaligned. This is desirable.

In the present invention, the first transparent substrate may be any material that is transparent to light irradiated during recording, reproduction, etc., such as polycarbonate (PC).

Plastics such as polymethyl methacrylate (PMMA),
Glass or the like can be used. The recording layer may be made of organic materials such as cyanine, naphthoquinone, or polymethine, or Te.

Inorganic materials such as In, Se, and Te alloys may also be used. 3
The backing material may be transparent or opaque to the light irradiated during recording, reproduction, etc., and may be made of any material such as plastic or metal.

Next, another aspect of the optical recording medium of the present invention will be explained.

FIG. 3 is a part of a schematic sectional view in the diametrical direction, and shows that the spacer and backing material are also fitted into each other in the same way as the transparent substrate by the spacer bonding member 6.
has the same function as the backing material bonding material 4 described above.

Furthermore, it becomes possible to print on the backing material.

〔Example〕

The present invention will be further explained below with reference to Examples.

A recording layer (organic dye thin film) was provided on the top surface of a transparent substrate (diameter 84 mm, thickness 1.2 mm, made of polycarbonate), and then an integrally molded back surface with bonding members and spacers as shown in Figure 2 was provided. When the transparent substrate was fitted and fixed into a material (outer diameter 86 mm, inner diameter 17 mm, joint end inner diameter 83 mm, 4 notches, made of polycarbonate) with the surface on which the recording layer was formed inside, the optical recording obtained The medium was excellent in that the initial performance of the recording layer showed little deterioration over time.

〔Effect of the invention〕

As explained above, the backing material or spacer has a joint part inscribed with the top and bottom surfaces of the outer periphery of the transparent substrate, and by fitting the joint part and the top and bottom surfaces of the outer periphery, Since this is not necessary, there is no erosion of the recording material due to the gas generated by the adhesive or the overflow of the recording material, and even if the recording material overflows, it will not be chemically eroded by the adhesive, etc., so the initial stage of the recording layer performance can be maintained.

■No adhesive space is required, and the spacer-equivalent portion of the backing material is only about 1 mm, allowing for a wide recording area.

■In addition to the stress and strain caused by adhesion, since only the force of the bonding member is applied in the thickness direction of the substrate, there is no stress on the transparent substrate at all, and there is no stress or birefringence change due to bonding.

■Assembling is a snap-in type, making it very easy to assemble.
A very inexpensive optical disc can be obtained.

■It also has the advantage of not requiring positioning.

■ Furthermore, by having a protrusion from the surface of the transparent substrate,
It also has the effect of surface protection.

The optical recording medium having the structure of the present invention is very useful.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the optical recording medium of the present invention, FIG. 2 is a schematic cross-sectional view in the diameter direction from the center hole to the outer circumference of the optical recording medium shown in FIG. 1, and FIG. A fourth schematic cross-sectional view of the outer circumference in the diametrical direction of an optical recording medium showing another embodiment of the present invention.
The figure is an explanatory diagram showing a state in which the backing material according to the present invention is fitted into a transparent substrate, and FIG. 5 is a schematic cross-sectional view of the main part of a conventional optical recording medium. 1. Transparent substrate 2. Recording layer 3, backing material 4. Backing material joint 5, joint notch 6. Spacer joint member 7, backing material center hole 8. Transparent substrate center hole Figure 4 Hanging diagram Figure 4

Claims (1)

[Claims] In an optical recording medium in which a backing material and a transparent substrate are joined with a predetermined gap between them via a spacer, and a recording layer for recording information is formed on the transparent substrate on the backing material side, the spacer or the backing material is transparent. A light comprising a joint part inscribed with the upper and lower surfaces of the outer peripheral part of the substrate, and the backing material and the transparent substrate are joined by fitting the joint part and the upper and lower surfaces of the outer peripheral part. recoding media.