JPS60129948A - Optical recording medium - Google Patents

Abstract

PURPOSE:To obtain an optical recording medium which is easily produced by forming projected parts in a body at one side of a supporter and a transparent substrate respectively to set a gap to be formed between these supporter and substrate, therefore forming a prescribed gap between the supporter and the substrate. CONSTITUTION:Projected parts 11a and 11b of the prescribed height are formed in a body at the outer and inner circumferential parts of a supporter 11. Then a circular transparent substrate 12 made of a transparent acrylic material, etc. is set opposite to the supporter 11. A recording layer 13 is formed on the substrate 12. The supporter 11 and the substrate 12 are adhered to each other at the parts 11a and 11b by an adhesive 14 with the layer 13 set inside. Thus a prescribed gap 15 is formed between the supporter 11 and the subsrate 12. Thus a gas is set between the supporter 11 and the substrate 12 by means of the parts 11a and 11b formed in a body to the supporter 11. This can omit a spacer requiring the highly accurate processing. Furthermore the labor is also greatly reduced for positioning, etc. needed at assembling the optical recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an optical recording medium, and more particularly to an optical recording medium having a predetermined gap between a support and a transparent substrate on which a recording layer is formed.

[Technical background of the invention and its problems] Optical recording media are capable of recording large amounts of information, can store information permanently or semi-permanently, and can be accessed online. Because of its unique features, it is attracting a lot of attention as a large-capacity disk memory.

Optical recording media usually have a structure as shown in FIG. That is, a support 1 and a transparent substrate 2 having a recording layer 3 formed on one side are placed facing each other with the recording layer 3 inside, and spacers 4a are placed between the support 1 and the substrate 2 on the outer and inner peripheries.
, '4b, respectively, with a gap 5 between them.
This is the structure that formed the . Here, the recording layer 3 is the transparent substrate 2
By being irradiated with light such as a laser beam from the side, information is recorded as optically readable state changes such as unevenness or bit formation.

Incidentally, since such an optical recording medium requires a high level of flatness and uniform thickness, the spacers 4a, 4b, as well as the support 1 and the substrate 2, have good flatness and a uniform thickness. Something is needed. However, spacers that require such sophisticated processing are not only expensive, but also require highly accurate positioning during media assembly, complicating the media manufacturing process.

[Object of the Invention] An object of the invention is to provide an optical recording medium in which a predetermined gap is formed between a support and a transparent substrate, and which is easy to manufacture at low cost.

[Summary of the Invention] The optical recording medium according to the present invention is characterized in that a protrusion for setting a gap to be formed between the support and the transparent substrate is integrally formed on at least one of the support and the transparent substrate.

[Effects of the Invention] According to the present invention, the protrusion integrally formed on at least one of the support and the transparent substrate plays the role of a spacer for setting a gap, and the protrusion is formed on at least one of the support and the transparent substrate. Since it can be formed at the same time as the substrate is manufactured, the processing cost is significantly reduced compared to the case where spacers are provided separately, and there is no need for troublesome work such as positioning the spacers when assembling the media. Therefore, overall manufacturing costs are significantly reduced, and there are fewer adhesive points than when using spacers that require adhesive to be applied on both sides.
Improvement in mechanical strength can also be expected.

Embodiment of the Invention FIG. 2 is a sectional view for explaining the structure and manufacturing process of an optical recording medium according to an embodiment of the invention.

In the figure, a support 11 is formed of a resin such as acrylic into a circular shape, and protrusions 11a and 11b of a predetermined height are integrally formed on the outer and inner circumferences thereof.

A circular transparent substrate 12 made of, for example, transparent acrylic is provided opposite to this support 11.
A recording layer 13 is formed on 2. The recording layer 13 causes an optically readable state change, such as unevenness or a bit string, by irradiation with light such as a laser beam, and specific examples include Te-c, TeOx, and the like.

The support 11 and the transparent substrate 12 are bonded together with the adhesive 14 at the protrusions 11a and 11b with the recording layer 13 facing inside. As a result, a predetermined gap 15 is formed between the support body 11 and the transparent substrate 12. As the adhesive 14, conventionally used epoxy or rubber adhesives require a long time for bonding. A photosensitive resin adhesive is used because there are problems such as deformation of the support or substrate due to heating during curing. Examples of photosensitive resin adhesives that can be used include solvent-free liquid photosensitive resins mainly based on vinyl ester resins, such as APR (trade name, manufactured by Asahi Kasei Corporation) and Tevistar (trade name, manufactured by Teijin Corporation). These photosensitive resins are cured by irradiation with ultraviolet rays, have excellent adhesive properties, and can be used satisfactorily as adhesives.

Next, the manufacturing process of the optical recording medium of this example will be explained.

First, the support body 11 is molded together with the protrusions 11a and 11b by injection molding or the like, and then the protrusions 1
A photosensitive resin 14 is applied on 1a and 11b. Next, as shown in FIG. 2(b), a transparent substrate 12 on which a recording layer 13 is formed on one side by sputtering, vapor deposition, etc. is placed opposite to the support 11 so that the recording layer 13 is located on the support 11 side. After stacking and pressing, the photosensitive resin adhesive 14 is cured by irradiating ultraviolet rays 16 from the transparent substrate 12 side. As a result, the support 11 and the transparent substrate 12 are firmly adhered, and at the same time, a gap 15 is formed between them. In this case, the size of the gap 15 is equal to the height of the protrusions 11a and 11b formed on the support 11.

In this way, according to the above embodiment, since the gap between the support and the transparent substrate is set by the protrusion formed integrally on the support, there is no need for a spacer that requires high-precision processing, and optical The effort required for positioning and the like when assembling the recording medium is also greatly reduced. Further, in the above embodiment, since a photosensitive resin having a fast effect rate is used as the adhesive, the bonding time can be shortened, and furthermore, there is an advantage that deformation of the support and the transparent substrate due to heating can be prevented.

FIG. 3 shows another embodiment of the present invention, which is the same as the embodiment shown in FIG. 2 except for the point that similar protrusions 12a and 12b are integrally formed on the transparent substrate 12, and has the same effect. is (q).

This invention can be modified in various ways without departing from the scope of the invention. For example, both the support and the transparent substrate may be
A protrusion may be formed to set a gap between these. Furthermore, when the support is made of a material that transmits ultraviolet rays, irradiation with ultraviolet rays for curing the photosensitive resin adhesive may be performed from the support side. Further, although the embodiments show cases in which the transparent substrate and recording layer are provided on only one side of the support, it goes without saying that the present invention can be similarly applied to cases in which the transparent substrate and recording layer are provided on both sides.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of a conventional optical recording medium, FIGS. 2(a) and 2(b) are sectional views at various steps of an optical recording medium according to an embodiment of the present invention, and FIG. 3 is a sectional view of the present invention. FIG. 3 is a cross-sectional view of an optical recording medium according to another example. 11...Support body, 11a, 11b...Protrusion, 12.
...Transparent substrate, 12a, 12b...Protrusion, 13...
Recording layer, 14... Photosensitive resin adhesive, 15... Gap, 16... Ultraviolet light. Applicant's agent Patent attorney Takehiko Suzue

Claims (3)

[Claims] (1) A support, a transparent substrate facing the support with a predetermined gap therebetween, and a recording layer formed on the surface of the transparent substrate on the support side and recording information by irradiation with light. An optical recording medium, characterized in that a projection for setting the gap is integrally formed on at least one of the support and the transparent substrate. (2) The support body and the transparent substrate are circular, and the protrusion is formed on the outer and inner circumferences of at least one of the support body and the transparent substrate. Optical recording medium described in Section 1. (3) The optical recording medium according to claim 1 or 2, wherein the support and the transparent substrate are bonded to each other at the protrusions using a photosensitive resin adhesive.