JPS62239444A - Optical recording medium - Google Patents

Abstract

PURPOSE:To improve the assembling workability and strength of the titled medium by fixing both surface of a spacer obtained by integrating the three parts, namely an annular part to be adhered to the inner periphery of a substrate, an annular part to be adhered to the outer periphery of the substrate, and a bridge part for bridging both parts, to respective substrates. CONSTITUTION:The spacer 1 is formed by integrating the three parts, namely the annular part 1a to be adhered to the inner periphery of the substrate, the annular part 1b to be adhered to the outer periphery of the substrate, and six bridge parts 1c for bridging both parts. Discoid substrates 3a and 3b laminated with recording layer 2a and 2b and having two central holes are stuck on both surfaces of the spacer 1 through an adhesive layer 4 so that both recording layers are opposed to each other to form the optical recording medium of the spacer 1. The frequency of positionings at the time of assembling and sticking operations can be reduced, and the assembling workability is improved. The strength of the optical recording medium is enhanced by the bridge part 1c of the spacer 1, and the substrate is difficult to deform.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical recording medium on which recording can be performed using a light beam.

[Conventional technology]

Conventionally, magneto-optical effects, photochromism,
An optical recording medium with an air sandwich structure is proposed, in which two recording media made of layered optical memory materials that utilize phase transition from amorphous to crystalline, pore formation, etc. are placed facing each other with an internal space in between. has been done.

The two recording media in a donut-shaped optical recording medium with an air sandwich structure constitute an internal space by two spacers (an outer circumferential spacer and an inner circumferential spacer) provided on the outer circumferential part and the inner circumferential part. There is.

[Problem that the invention seeks to solve]

Conventionally, as a method for assembling such optical recording media, generally the surfaces to be adhered near the outer periphery (outer periphery) and the inner periphery (inner periphery) of the two recording media as described above, or the outer periphery and the inner periphery, are bonded. After applying adhesive to the adhesive surfaces of the two peripheral spacers, the four parts (the two recording media, the outer spacer, and the inner spacer) are aligned, stacked, and fixed with adhesive. However, there were some problems in the assembly process, such as the time it took to apply the adhesive and the difficulty in aligning the recording medium and spacer.

Furthermore, since the conventional air sandwich structure optical recording medium only has its inner and outer peripheries glued together by spacers, it lacks strength and is susceptible to distortion and deformation of the substrate. There were drawbacks.

The present invention has been made in view of the above-mentioned problems, and its object is to provide an optical recording medium having an air sandwich structure that has excellent assembly workability and strength, and in which the substrate is difficult to deform.

(Means for Solving the Problems) The present invention, which can achieve the above-mentioned object, provides a disk-shaped substrate having a central hole with a recording layer provided on at least one side,
In an optical recording medium having an air sandwich structure, in which the spacer is attached to the inner periphery of the J and C plates, the ring-shaped portion attached to the inner periphery of the J and C plates, and the substrate. A spacer that is made up of three parts: a link-shaped part attached to the outer periphery and a bridging part that bridges both parts, and is fixed to each of the above-mentioned substrates on each of both sides of the spacer. An optical recording medium characterized by:

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view of an example of a spacer used for producing the optical recording medium of the present invention. This spacer 1 consists of three parts: a ring-shaped part 1a attached to the inner periphery of the substrate, a ring-shaped part tb attached to the outer periphery of the substrate, and six bridging parts 1c bridging these two parts. It is formed by integrating two parts.

FIG. 2 is a cross-sectional view of an embodiment of the optical recording medium of the present invention using the spacer described above, taken along line AB of the spacer 1 (dotted chain line in FIG. 1). In this optical recording medium, a disk-shaped substrate 3a, 3b having two central holes on which a recording layer 2a or 2b is laminated is attached to each spacer 1 by an adhesive layer 4, with the recording layers facing each other. It is pasted together.

Since the optical recording medium according to the present invention has an integrated spacer 1, the number of times of positioning and bonding operations during assembly can be reduced, and assembly workability is improved. Furthermore, the bridge portion 1c of the spacer 1 increases the strength of the optical recording medium and makes the substrate less likely to deform. Note that with some types of optical recording media (such as those that record by forming holes), if a spacer is attached to the recording part of the recording layer, the heat used for recording will escape to the adhesive layer.
In some cases, the recording sensitivity may decrease in that area, but in that case, if the structure of the spacer is selected so that the crosslinked part of the spacer is adhered to the preformat part of the recording layer, the optical A transparent recording medium is preferable because the recording sensitivity does not decrease. That is, in the case of a recording layer consisting of a preformat section 5a and a data section 5b as shown in FIG. If an optical recording medium is produced by bonding them together, the sensitivity will not be reduced. There is no problem in terms of strength as long as there are at least three bridges.

In the present invention, it is preferred that the overall thickness of the spacer is also uniform so that the spacer adheres to the substrate with an adhesive layer of uniform thickness and provides strength to the optical recording medium. The number of crosslinked portions of the spacer (5) is arbitrary, and may be appropriately selected in consideration of the balance of the optical recording medium after manufacturing, the surface shape of the preformat portion of the recording layer, etc.

(As the adhesive that is a component of the board, recording layer, and adhesive layer, any known adhesive can be used without restriction. For example, the substrate may be made of polycarbonate, epoxy, acrylic resin, or glass.
The recording layer 2 includes GdFc, TbFc, and Gd.
Transition total bending of FeGo, GdTbFcCo, etc. - Rare earth amorphous thin II! 2. Polycrystalline thin film such as MnBi,
Thin II made of pigment compounds! 2. As the adhesive, hot-melt adhesives, solution-type adhesives such as rubber adhesives, vinyl-based adhesives, silicone-based adhesives, emulsion-type adhesives, etc. can be used.

The optical recording medium of the present invention may be provided with various auxiliary layers such as a layer for protecting the recording layer and an antireflection layer for effectively utilizing recording light and reproduction light.

〔Example〕

The optical recording medium shown in FIG. 2 was produced as follows. A cyanine dye was applied to each of the two substrates 3a and 3b made of polycarbonate resin to a thickness of 700 mm using a spin coater as the recording layers 2a and 2b. Next, each of the substrates 3a and 3b was fixed to both sides of the spacer 1 so that the preformat thereof was aligned with the bridge portion 1c of the spacer 1.

A hot melt adhesive (company name: CI Sheapan, trade name: PS-15) was used as the adhesive for fixing.

〔Effect of the invention〕

Since the optical recording medium of the present invention described in detail above has integrated spacers, the number of times of positioning is reduced, and it is excellent in assembly workability, and the positioning accuracy of the spacers is also improved, resulting in good balance. became. Also,
Since the spacer has a crosslinked portion, the strength of the optical recording medium is increased and deformation of the substrate can be reduced.

[Brief explanation of drawings]

FIG. 1 is a plan view of an example of a spacer used for producing the optical recording medium of the present invention. FIG. 2 shows an embodiment of the optical recording medium of the present invention using an F spacer.
FIG. 2 is a cross-sectional view along the line AB (dotted chain line 11 in FIG. 1) of the spacer 1. FIG. FIG. 3 is a plan view of one embodiment of a recording layer having a preformat section and a data section. 1 Ni spacer-5lc: crosslinking part, 2a, 2b: recording layer, 3a, 3b: substrate, 4: adhesive layer, 5a nib pho- mat part, 5b nibrator part.

Claims (1)

[Claims] 1) An air sandwich structure in which disk-shaped substrates having a central hole and having a recording layer provided on at least one side are bonded together with an internal space interposed therebetween via a spacer. In the optical recording medium, the spacer has three parts: a ring-shaped part bonded to the inner circumference of the substrate, a ring-shaped part bonded to the outer circumference of the substrate, and a bridging part bridging both of these parts. An optical recording medium characterized in that the spacer is an integrated spacer, and both surfaces of the spacer are fixed to each of the substrates. 2) The optical recording medium according to claim 1, wherein the bridge portion of the spacer is fixed in alignment with the preformat portion of the recording layer.