JPH02146117A - Optical disk - Google Patents

Abstract

PURPOSE:To minimize the use amount of an adhesive, to reduce damages on a recording layer and to make positioning easy by providing sawtooth-like parts on the outside wall of an inner spacer and the inside wall of an outer spacer for two disk substrates. CONSTITUTION:A recording layer 2 is formed on the substrate 1 having a center hole 8. The outside wall 6 of the inner spacer 4 and the inside wall 7 of the outer spacer 5, four walls in all, are shaped into sawtooth-like parts 4a and 5a. The substrate 1 is made contact to the sawtooth-like parts 4a and 5a to be supported. The back substrate 3 is also fitted to the sawtooth-like parts 4a and 5a with a space on the layer 2 to be unified with the substrate 1. Thereby, the amount of the adhesive to be used for stacking the substrates is minimized, which reduces damages caused by the adhesive on the recording layer. Moreover, positioning of the substrates can be easily and accurately performed without using tools.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical disc, and particularly to an optical disc in which bonding of disc-shaped substrates is improved.

[Prior Art] A recently reported example of a conventional method for bonding disc-shaped substrates for optical discs is the method disclosed in Japanese Patent Application Laid-open No. 63
In Japanese Patent No. 31042, the protrusion of the first substrate and the peripheral end of the second substrate are fixed with an adhesive to strengthen the adhesive force. Furthermore, in JP-A No. 63-94446, the inner and outer peripheries of the disk are ultrasonically fused under reduced pressure, while in JP-A-63-96753, the adhesive layer is bonded by spray coating. The constructed optical disc was published in Japanese Patent Application Laid-Open No. 63-8
No. 76:11 discloses a method of manufacturing a disk with little deformation using a microencapsulated adhesive. As shown in these examples, various methods for bonding disc-shaped substrates of optical discs have been studied and are diverse.

Next, the following reports have been made regarding positioning methods when bonding disc-shaped substrates of optical discs. First, in Japanese Patent Application Laid-open No. 63-58323, annular groups are provided on both sides of a spacer, and when the tracking group is formed on a substrate with ultraviolet curing resin, a burr is formed, and the burr is formed on the spacer. A method of positioning by grouping, a method of positioning by inserting the shaft in the center hole as in Japanese Patent Application Laid-Open No. 6:1-71955 and Japanese Patent Application Laid-Open No. 63-71951i, or a method of positioning by placing the shaft in the center hole, or a method of positioning at the outer periphery. JP-A-63-76126 discloses a method using an engagement positioning member.

[Issue 8 to be solved by the invention] However, although many of the above conventional examples are based on the premise of using an adhesive, it is not necessarily suitable depending on the recording layer of the optical disc. In the case of dyes, adhesives can cause considerable damage, and for this reason, adhesives must be selected for each dye used, and the cost and time required for this is enormous.

Furthermore, as shown in the above-mentioned conventional example, the positioning method used when bonding disc-shaped substrates of optical discs is often time-consuming and time-consuming, and there has been a demand for a method that can easily perform positioning using a minimum number of jigs.

The present invention has been made in order to improve the drawbacks of the conventional examples.The present invention minimizes the use of adhesive, reduces damage to the recording layer caused by adhesive, and uses a jig for positioning. It is an object of the present invention to provide an optical disc that can be easily and accurately performed without the need for a computer.

[Means for Solving the Problems] In other words, one aspect of the present invention is to integrate two disc-shaped substrates each having a center hole and having a recording layer on at least one of them via an inner circumferential spacer and an outer circumferential spacer. There is an optical disc characterized in that a serrated portion is provided on at least one of the outer surface of the inner circumferential spacer or the inner surface of the outer circumferential spacer facing the disk-shaped substrate.

[Function] The optical disc of the present invention has two disc-shaped substrates (hereinafter referred to as substrates) each having a center hole and a recording layer on at least one of them, which are integrated via an inner spacer and an outer spacer. In the optical disc, the serrated portion is provided on at least one of the outer surface of the inner circumferential spacer facing the disk-shaped substrate or the inner surface of the outer circumferential spacer, so that alignment can be easily performed without using a jig. In addition, the outer surface of the inner circumferential spacer having serrated portions or the inner surface of the outer circumferential spacer and the substrate are fixed together by fitting, and the minimum area required is the use of adhesive. Damage to the recording layer caused by the agent can be reduced.

[Example] Hereinafter, an example of the present invention will be described in detail based on one drawing.

FIG. 1 is a plan view showing an embodiment of the optical disc of the present invention, and FIG. 2 is a sectional view taken along line AA'. . In the same figure,
In the optical disc of the present invention, a recording layer 2 is provided on a substrate 1 having a center hole 8, and serrated portions 4a are provided at four locations on an outer surface 6 of an inner circumferential spacer 4 and an inner surface 7 of an outer circumferential spacer 5, respectively. . A gap is provided above and the back substrate 3 is similarly fitted and supported in the sawtoothed portions 4a and 5a,
It is fixed and integrated without using adhesive.

The substrate 1 used is a disk-shaped substrate made of polycarbonate resin, acrylic resin, epoxy resin, or the like. The thickness does not need to be particularly limited, but in this example, a thickness of 1.2 mm was used.

As the recording layer, any layer commonly used in recording media can be used, and among these, a water-insoluble dye-based recording layer is particularly preferred. In this example, a cyanine dye represented by the following structural formula (I) was used.

(I) 'A,? ! The board is made of not only the resin used for the substrate, but also
In addition, opaque resin 9 synthetic paper and the like can also be used. In this example, 0.3 mm polycarbonate was used.

The materials of the inner circumferential spacer and the outer circumferential spacer are not particularly limited, but resin, rubber, easily moldable metal, etc. are preferable.

The width of the serrated portion of the spacer needs to be shaped to match the thickness of the air gap, the thickness of the back substrate, etc.

Preferably, the serrations are not provided on the entire spacer, but at several locations, usually 3 to 4 locations, as shown in FIG.

Next, a method of assembling the optical disc of this embodiment will be explained. When both the outer circumferential spacer and the inner circumferential spacer have serrated portions, the assembly of the optical disc is performed in the following order.9 In Figure 1.2, first insert the substrate 1 into the outer circumferential spacer 5, then insert the back substrate 3. The outer circumferential spacer 5 is inserted, and finally the inner circumferential spacer 4 is inserted into the center hole from the substrate 1 side.

Further, an adhesive or adhesive may be applied to the serrated portion of the spacer or the contact position with the substrate.

In addition, the method for assembling an optical disk in which two substrates both have recording layers is to first insert one substrate into the outer circumferential spacer, then insert the other substrate into the outer circumferential spacer,
Finally, the inner circumferential spacer may be inserted into the center hole from one of the knob plates.

[Effects of the Invention] As described above, according to the optical disc of the present invention, a serrated portion is provided on at least one of the outer surface of the inner circumferential spacer or the inner surface of the outer circumferential spacer facing the disk-shaped substrate. This minimizes the use of adhesive to bond the substrates together, reduces damage to the recording layer caused by the adhesive, and allows for easy and accurate positioning without the need for a jig.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the optical disc of the present invention, and FIG. 2 is a sectional view taken along line AA'. l...Substrate 2...Recording layer 3...Back substrate 4...Inner spacer 4a, 5a=
・Serrated portion 5...Outer periphery spacer 6...Outer surface 7...Inner surface 8...Center hole Fig. 1

Claims (1)

[Claims] In an optical disc formed by integrating two disc-shaped substrates each having a center hole and having a recording layer on at least one of them via an inner circumferential spacer and an outer circumferential spacer,
An optical disc characterized in that a serrated portion is provided on at least one of the outer surface of the inner circumferential spacer or the inner surface of the outer circumferential spacer facing a disk-shaped substrate.