JPS61104345A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To improve the scratching resistance of an optical recording layer and to obtain an optical information recording medium which is of a single sheet construction and can be easily produced by forming the recording layer of a thin film consisting of a metal (alloy), an org. dye, etc. on a transparent substrate and fixing a protective plate or sheet to the entire recording surface. CONSTITUTION:The optical recording layer 2 which consists of a metal such as Te, Bi or Al, the alloy thereof, metallic oxide such as TeO2 or an org. dye such as phthalocyanine and has 200-2,000Angstrom film thickness is formed on the substrate (disk having a central hole 5 in the embodiment) 1 consisting of transparent plastic, glass, etc. A material 6 such as acrylic resin, polycarbonate or polyimide which has physical and chemical resistance is provided over the entire substrate surface including the layer 2. More specifically, the substrate ends 7, 8 around the layer 2 are also fixed with the above-mentioned material by a method such as adhering or baking. For example, a beam of laser light 9 is irradiated to the layer 2 from the substrate 1 side by which recording and reproducing are executed. The recording medium having the excellent scratching resistance is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical information recording medium having a single-plate structure used in an optical disk memory device.

[Prior art]

Conventionally, metals,
Vapor-deposited films of semimetals and nonmetals, organic dye films, and the like are known. However, these recording layers have a problem in that they are affected by scratches, outside air, light, etc., resulting in decreased storage stability. Various proposals have thus far been made as solutions to this problem. One method is to provide a protective layer on the surface of the recording layer, but this method has the disadvantage that the recording sensitivity decreases to about 1%. Maku, another one is Special Public Service 1986-5.
As described in Japanese Patent No. 241'5, it has been proposed to use a so-called air sandwich structure (see Figure 1) in which an annular space layer is formed between opposing surfaces of recording media, but there is an annular space layer. As a result, the recording medium floats, is difficult to handle, and the manufacturing process is complicated, resulting in poor productivity and high costs.

〔the purpose〕

The present invention was made in view of the above drawbacks, and its purpose is to reduce the protection of the information recording layer from physical and chemical damage (scratches caused by mechanical contact, chemical changes caused by contact with reactive gas). It is easy to perform at low cost and improves media manufacturability.
The goal is to make the recording medium thinner and more compact.

[groove formation]

In order to achieve the above object, the present invention is to apply force to the recording layer using a protective plate or a protective sheet member.

Specifically, the optical information recording medium of the present invention is characterized in that a recording layer is provided on a transparent substrate provided with a guide groove, and the recording layer is cut with a retaining plate or a protective sheet member. be.

The protective plate or protective sheet member in the present invention includes:
Acrylic resin, vinyl chloride resin, nylon resin, polycarbonate resin, polyester resin, vinyl acetate-vinyl chloride copolymer, Teflon, cellulose acetate, polybutadiene resin, polyvinylidene chloride resin, polyimide resin, polyethylene resin, polystyrene resin, silicone resin, Polypropylene resin and other plastics are preferred, and paper, metal, ceramics, glass, fur, cloth, etc. are also used. Of course, these materials must be selected so that they do not damage the optical recording layer or cause chemical reactions upon contact.

Next, a conventional optical information recording medium and an optical information recording medium of the present invention will be compared and explained with reference to the accompanying drawings.

In the recording layer of the present invention, pores are formed or some kind of optical change is caused by laser beam irradiation, and information can be recorded based on the change.

This recording layer is made of Te, Bi, In, Sn, Al, Se.
, As.

Metal matrix such as Cd%TeO2, SnO, etc. is a thin film made of alloy, organic dye, etc., and the film thickness is 200λ~2
It is preferably in the range of 00OX. Also.

The recording layer contains binders, stabilizers, dispersants, flame retardants,
A lubricant, an antistatic agent, a surfactant, a plasticizer, etc. may be contained. Examples of organic pigments include 7-thalocyanine, nato-2-hydrocholine, dioxazine, triphetchiazine, phenanthrene, cyanine (merocyanine), anthraquinone (indanthrene), xanthine, triphenylmethane, and croconium. Examples include pyrillicum-based pigments, pyrillicum-based pigments, and azulene-based pigments.

FIG. 1 is a cross-sectional view of a conventionally known air sun structure. This recording medium is a single-sided disc that can record from the direction of the arrow.

1 is a transparent substrate made of glass, plastic, etc., and 2 is a recording layer in which optical characteristics such as hole formation are formed by a focused laser beam.

and 6 is a protective cover. 4 is a spacer for providing an air gap between the recording layer 2 and the protective cover 3. Reference numeral 5 denotes a center hole, which is a jig for attaching the disk-shaped recording medium to the turntable without eccentricity. Although this configuration prevents mechanical damage to the recording layer and deterioration of characteristics due to chemical action, the above-mentioned problems still exist.

FIG. 2 is a sectional view showing an example of the optical information recording medium of the present invention, and shows a disk-shaped medium. Here, the same reference numerals as in FIG. 1 indicate common components.

The transparent substrate 1 is made of glass or plastic such as polycarbonate resin, acrylic resin, or polyvinyl chloride resin. The recording layer 2 is a thin film made of a metal or alloy such as Te or Bi, or an organic dye, and has a thickness of 200 mm or more.
Hole formation by irradiation with a focused laser beam at 2000 m
Information can be recorded by changing optical properties. A protective plate or a storage sheet 6 is provided to cover the recording layer 2, and in order to prevent the surface of the recording layer 2 from falling off, the protective plate or storage sheet 6 covers the transparent substrate at parts other than the recording layer on the substrate, for example, at the edges 7 and 8 as shown in the figure. 1. Glue, sew, bake, wrap with adhesive tape,
It can be fixed with pins, nails, etc.

FIG. 6 is a sectional view showing another example of the optical information recording medium of the present invention, and shows the positional relationship between the protective sheet 6 and the recording layer 2 when the recording layer 2 has uneven guide grooves. This shows that. The depth of the guide groove is 200A, which is suitable for generating tracking error signals and preformat signals.
-1500 or preferably 600 or -1300 is appropriate. As shown in the figure, recording is performed by irradiating the open portion with a focused laser beam 9. If the depth of the opening on the surface of the recording layer is 600 Å or more, even if the protective sheet 6 is in contact with the opening, there will be a gap of at least 300 Å in the opening, making it difficult for the heat from the recording layer 2 to diffuse, which will reduce the recording sensitivity. No deterioration occurs.

FIG. 2 shows the configuration of a disk-shaped recording medium that is one example of the present invention. ζ Here, the same reference numerals as in FIG. 1 mean common constituent members. The protective plate or protective sheet 6 according to the present invention must be provided to cover the recording layer 2. In order to prevent the recording layer 6 from falling off the surface of the recording layer 2, the recording layer 6 is fixed to a portion other than the recording layer on the substrate, for example, to the ends 7 and 8 as shown in the figure. The protection plate or the coefficient sheet can be fixed by any means. Examples include gluing,
It can be sewn, baked, wrapped with adhesive tape, pinned, nailed, etc.

FIG. 3 shows the most preferred example of the present invention, in which uneven guide grooves are formed in the recording layer 2. The appropriate depth of the guide groove is 200 to 1,500, preferably 500 to 1,300, which is suitable for generating tracking error signals and preformat signals. 150
If it becomes larger than 0^, it becomes difficult to track, which is not preferable. The depth of the opening (groove) on the surface of the recording layer is 30
If it is 0^ or more, there will be a gap of at least 300^ in the open part even if the protective sheet 6 is in contact with it, so that the heat from the recording layer 2 will be difficult to diffuse, so that no decrease in recording sensitivity will occur. As shown in the figure, information can be recorded by irradiating the open portion with a focused laser beam 9.

Next, taking as an example the most preferred recording medium of the present invention as shown in FIG. 3, the relationship between the depth of the grooves in the recording layer and the recording sensitivity (recording laser power) was examined.

A solution of a cyanine dye of the following formula dissolved in dichloroethane was applied onto guide grooves formed by photopolymerization on an acrylic substrate to form a recording layer with a film thickness of 5ooX. The width of the guide groove was cL8 μm, and the interval between the grooves was 2.0 μm. An acrylic sheet with a thickness of Q and 2sI was used as the protective sheet. When the recording sensitivity was measured by changing the depth of the grooves and the microbial density on the surface of the recording layer, the following results 2>r were obtained.

Note that information is recorded using a semiconductor laser beam with a wavelength of 79 Dnm from the substrate side at a half-value dome diameter of α9 μm and a linear velocity of 1.
．． The speed was 237 m/sec.

Groove depth Required recording laser power □ 200A 2.8mW 300A 2.5mW 500A 2.5mW 700A 2.2mW 900A 2.2mW 1100A 2.2mW Groove depth
Required recording laser power 1300A 2
．． 2mW 1500A 2.2mW Up to now, in explaining the present invention, the case where the recording layer 2 is provided on only one side of the substrate 1 has been illustrated, but the protection according to the present invention can also be applied to the case where the recording layer is provided on both sides of the substrate. A plate or device sheet can be applied to achieve the same purpose.

〔effect〕

According to the above-described configuration of the present invention, the recording medium can be made thin, making it easy to handle and easily manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an optical information recording medium having a conventional air sandwich structure, and FIGS. 2 and 3 are cross-sectional views showing an embodiment of the optical information recording medium according to the present invention. DESCRIPTION OF SYMBOLS 1... Transparent substrate, 2... Recording layer, 6... Protective cover, 4... Splice, 5... Center hole, 6... Protective plate or protective sheet member, 7, 8... end, 9...
Laser focused beam.

Claims (1)

[Claims] 1. An optical information recording medium, comprising a recording layer provided on a transparent substrate, and the recording layer covered with a protective plate or a protective sheet member.