JPH023120A - Information recording medium, method of reproducing recorded information of information recording medium and method of restoring information recording medium - Google Patents

Abstract

PURPOSE:To allow reading out with reading-out light from the side opposite to a transparent substrate when a coating member is partly or wholly removed by providing the coating member in a removable state to the above medium. CONSTITUTION:The coating member 3 is formed of three layers; a protective substrate 5, an adhesive layer 6 and a protective member 7. The coating member 3 is cut at the boundary between a recording region 8 and a non-recording region and the member 3 in the part where the recording layer 2 is not adhered to the region 8 is removed. Otherwise, the entire member 3 or the protective member 7 is removed in the strippable adhesive layer 4 or 6. The protective member 7 may be otherwise removed by melting. The medium which is damaged to the unreadable state can be restored if the recorded information is reproduced by the reading-out light from the side opposite to the transparent substrate 1 consisting of polymethyl methacrylate after the removal of a part or the whole of the member 3 from the region 8 and is recorded on another fresh medium. The member 7 is a PVC resin, polyester ink, Al foil, etc., and the adhesive layer 6 is a vinyl acetate adhesive agent, etc. The adhesive layer 4 is not particularly limited. The protective substrate may be PVC, etc.

Description

[Detailed Description of the Invention] [Prior Art] Conventionally, optical recording media such as optical disks, magneto-optical disks,
In optical cards, information is usually recorded by irradiating a recording layer with a light beam from the side of a transparent substrate, and read out by detecting reflected light from the recorded portion.

The recorded information is extremely small because it is formed by a laser beam focused by an optical system into a minute spot with a diameter of about 1 μm.

By the way, for optical recording media, scratches on the surface irradiated with recording/reading light can cause changes in optical characteristics, leading to recording/playback errors and noise in playback signals, so it is necessary to prevent the occurrence of extreme scratches. something is needed.

For this reason, optical recording media are provided with a hard coat layer made of acrylic modified resin or the like on the surface of a transparent substrate. However, when handling optical recording media or during storage, /%-
Even if a hard coat is provided, there is a problem in that scratches and irremovable stains adhere to the surface of the hard coat layer, making it impossible not only to record but also to reproduce the recorded information.

[Problems to be Solved by the Invention] An object of the present invention is to provide an information recording medium that makes it possible to reproduce an information recording medium that has become unreproducible.

Another object of the present invention is to provide a method for reproducing information recorded on an information recording medium that makes it possible to reproduce information from an information recording medium that has become unreproducible due to damage to the incident surface of recording and reproducing light. It is.

Another object of the present invention is to provide a method for restoring an information recording medium whose incident surface for recording and reproducing light has been damaged and cannot be reproduced.

[Means for solving problems]

The information recording medium of the present invention is an information recording medium that has a basic structure of a covering member, a recording layer, and a transparent substrate that is irradiated with recording or reading light. The covering member is provided in a removable state so that it can be read by reading light from the opposite side.

Further, a method for reproducing recorded information on an information recording medium according to the present invention is a method for reproducing recorded information on an information recording medium that basically includes a coating member, a recording layer, and a transparent substrate that is irradiated with recording or reading light. When the substrate is damaged, part or all of the covering member is removed and reading light is irradiated from the side opposite to the transparent substrate to read the recorded information in the recording layer. .

Hereinafter, the present invention will be explained in detail using the drawings.

In FIG. 1, the covering member 3 includes a protective substrate 5, an adhesive layer 6,
It consists of three layers of a protective member 7, and a part or all of this covering member 3 is configured to be removable from the recording area 8. That is, the protective substrate 5 of the covering member 3 is adhered to the transparent substrate having the recording layer via the adhesive layer 4 in a portion other than the recording area 8, or the adhesive layer 4 or the adhesive layer 6 is made of a removable adhesive. There is. The method for removing the covering member 3 from the recording area 8 is to cut the covering member 3 at the boundary between the recording area 8 and the non-recording area, thereby removing the covering member that is not adhered to the recording area 8 of the recording layer 2. Can be removed. Further, if the adhesive layer 4 or 6 is made of a removable adhesive, it can be removed by peeling off the entire covering member 3 or the protective member 7. Furthermore, if the protective member 7 is made of a material that can be eluted, it can be removed by dissolving the protective member 7.

In this embodiment, the covering member consists of three layers: the protective substrate 5, the adhesive layer 6, and the protective member 7, but the present invention is not limited to this, and may be a single layer as shown in FIG. .

Further, at least one layer of the covering member 3 is desirably opaque to the extent that recording and/or reproduction is substantially impossible in order to prevent diffused reflection.

Further, when the covering member 3 is composed of multiple layers, any of the layers may be opaque, but the part of the covering member 3 remaining in the recording area 8 must be transparent to the recording/reproducing light. It won't happen.

Further, when the covering member 3 is composed of a plurality of layers or more, it may be configured to be removable from any layer.

In the present invention, the thickness of the covering member is 50 μm to 600 μm.
1, particularly preferably 100 μm to 400 μm.

In this embodiment, the material of the protective member 7 is not particularly limited, and includes, for example, vinyl chloride resin, polyethylene resin, acrylic resin, polycarbonate resin, stainless steel,
Examples include aluminum. Furthermore, examples of materials that can be eluted include polyester-based and polyurethane-based inks.

Next, as the adhesive layer 6, for example, vinyl acetate type, vinyl acetate acrylic type, vinyl acetate copolymer type, vinyl acetate emulsion type, acrylic type, acrylate type, acrylic copolymer type, ethylene type, ethylene vinyl acetate type, ethylene acetic acid type, etc. Vinyl copolymer, polyethylene, methylene chloride,
Polyamide-based, polyamide-amine-based, polyimide-based,
Urea type, epoxy type, epoxy urethane type, epoxy acrylate type, urethane acrylate type, polyester type, chloroprene type, chloroprene rubber type, nitrile type, nitrile rubber type, urethane type, vinyl urethane type,
Polyurethane type, olefin type, cyanoacrylate type, alkyl acrylate type, vinyl chloride type, phenol type, SBR type (styrene butadiene rubber), polyol type, silica alumina type, synthetic rubber type, emulsion type,
Oligoester-based adhesives, cellulose-based adhesives, formaldehyde-based adhesives, ultraviolet curable adhesives, organic solvents, styrene-butadiene-based adhesives, Freon TA-based adhesives, etc. can be used. Bonding methods that require energy such as heat, light, and electron beams are also effective as long as the energy does not deteriorate the function of the optical recording material.

In addition, as a removable adhesive, the adhesive strength is 1000g/2
It is preferably 5 mm or less, more preferably 750 g/25 mm or less.

Furthermore, by performing a treatment to lower the surface tension of the surface of the covering member 3 such as fluoridation treatment or applying a release agent, the covering member 3 can be peeled off even if a material with strong adhesive force is used as the adhesive layer. It is possible to configure

In this embodiment, the transparent substrate l is preferably one that is less inconvenient in optical recording and reproduction, and examples thereof include acrylic resin, polyester resin, and carbonate resin.

Further, the transparent substrate 1 may be provided with an uneven preformat, and the molding method may be any commonly used method, such as compression molding, cast molding, 2P molding, etc.
It is done by law etc.

As the recording layer 2, a wide range of materials can be used as long as information can be recorded using light energy. For example, organic dyes include polymethine dyes such as cyanine,
Examples include naphthoquinone dyes and phthalocyanine pigments.

As unstructured materials, metals and semimetals include Bi and Sn.

A low melting point substance such as Te or As, Se, S
, O.

Recordable T due to complex compounds combining C, etc. and phase change
Examples include e-TeO2 system and silver halide capable of recording by changing optical density.

Further, the thickness of the optical recording medium layer is usually 200 to 1000
0 people, preferably 1000 to 2000 people.

As the protective substrate 5, it is preferable to use a material that causes few inconveniences in optical recording and reproducing when remaining on the recording area 8, and any material that has high transmittance for the recording and reproducing light used is sufficient, such as acrylic. Examples include polyester resins, polyester resins, polycarbonate resins, vinyl resins, and polysulfone resins.

Further, the adhesive layer 4 is not particularly limited, and any of the adhesives described above can be used. When a peelable adhesive is used for the adhesive layer 4, it may be peeled off from this part and reproduced by the readout light 9 from the side opposite to the transparent substrate. In this case, the protective substrate 6 does not need to have a high transmittance to the recording/reproducing light as described above, and any material can be used as long as it can be used as a normal protective substrate. , specifically polyvinyl chloride, fluorine-substituted ethylene polymer, vinyl chloride-vinyl acetate copolymer, polyvinylidene chloride, acrylic polymer such as polymethyl methacrylate, polystyrene, polyvinyl butyral, acetyl cellulose, styrene-butadiene copolymer. Polyethylene, polypropylene, polycarbonate, epoxy acrylonitrile-butadiene-styrene copolymer, etc. are used.

In some cases, iron, stainless steel, aluminum, tin,
A wide variety of materials can be used depending on the purpose, such as metal sheets such as copper or zinc, synthetic paper, paper, fiber-reinforced plastics, composites of metal powders such as magnetic materials and plastics, and ceramics.

Next, as a method for reproducing information recorded on an information recording medium according to the present invention, as described above, after removing a part or all of the covering member 3 from the recording area, reading light is emitted from the side opposite to the transparent substrate. Recorded information is played back. By recording the reproduced recorded information on another new information recording medium, it is possible to restore the damaged information recording medium from which the recorded information cannot be read.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Track grooves were formed by heat press molding on a transparent substrate of Bot methyl methacrylate measuring 85 mm long, 6 mm wide, 54 mm wide, 0 mm thick, and 4 mm thick, and then recording was performed on the track grooves. A polymethine dye having the following structural formula (I) was applied as a layer using a spinner coat so that the thickness of the track portion was 1000 mm, and the layer was dried. A polycarbonate protective substrate having a thickness of 0.3 mm was attached onto the recording layer using an ethylene-vinyl acetate copolymer adhesive. A vinyl chloride resin sheet having a thickness of 0.1 mm was used as the covering member, and an adhesive was applied to the non-recording area of the protective substrate to adhere the covering member to form an information recording medium. As the adhesive, an acrylic adhesive (manufactured by Sony Chemical, trade name 5C820) was used. Next, after recording information by irradiating a light beam from the transparent substrate side, the outside of the recording area of the covering member of this information recording medium is cut and removed, and the recorded information is irradiated from the protective substrate side. I read it out.

At this time, the C/N measured from the transparent substrate side was 45 dB, but when measured from the opposite side to the transparent substrate, it was 37 dB.
It was B. Furthermore, although the error rate increased from I x 10-' to about 3 x 10-', it was possible to reproduce recorded information.

Example 2 A track groove was formed on a polymethyl methacrylate substrate measuring 85.6 mm long, 54 mm wide, and 0.4 mm thick by hot press molding, and then the recording layer used in Example 1 was formed on the track groove. The same dye as the one previously used was applied using a bar code so that the film thickness on the track part was 1,000 mm, and then dried. A transparent protective member made of polymethyl methacrylate with a thickness of 0.3 mm is pasted on the recording layer via an ethylene-vinyl acetate copolymer adhesive, and an antireflection film of SiO is further deposited with a thickness of 1 μm. Established. Next, as an opaque protective member, a styrene-butadiene copolymer rubber adhesive (
After coating the entire surface of the antireflection film with 5C308 (manufactured by Sonic Chemical Co., Ltd.), an information recording medium having a coating member consisting of three pasted layers was formed.

Next, the transparent substrate side was irradiated with light to record information, and then the opaque protective member that was the outermost layer of the coating member was peeled off, and the recorded information was read out by irradiating readout light onto the antireflection film side.

At this time, the C/N measured from the transparent substrate side was 45 dB,
When measured from the opposite side of the transparent substrate, it is 34 dB,
Although the error rate increased from I.times.10-' to 5.times.10=, there was no problem in reproducing recorded information.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to perform at least reproduction of information recording media that cannot be recorded and/or reproduced due to scratches or stains on the surface irradiated with recording and/or reproduction light.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention. FIG. 2 is a plan view of one embodiment of the invention shown in FIG. 1. FIG. 3 is a cross-sectional view of another embodiment of the invention. Explanation of symbols representing main parts of the drawings 1...Transparent substrate 2...Recording layer 3...Coating member 4...Adhesive layer 5...Protective substrate
6... Adhesive layer 7... Protective member 8... No recording area A Penalty 20

Claims (7)

[Claims] (1) In an information recording medium that basically consists of a covering member, a recording layer, and a transparent substrate that is irradiated with recording or reading light, when a part or all of the covering member is removed, from the side opposite to the transparent substrate. An information recording medium characterized in that part or all of the covering member is provided in a removable state so as to be readable by the reading light of the information recording medium. (2) The information recording medium according to claim 1, wherein the covering member is composed of a plurality of layers or more. (3) The information recording medium according to claim 1, wherein at least one layer of the covering member has a transparency that makes recording and/or reproduction substantially impossible. (4) In a method for reproducing recorded information on an information recording medium that basically consists of a covering member, a recording layer, and a transparent substrate that is irradiated with recording or reading light, when the transparent substrate is damaged, a part of the covering member Alternatively, a method for reproducing information recorded on an information recording medium, comprising removing the entire transparent substrate and irradiating readout light from the side opposite to the transparent substrate to read the recorded information on the recording layer. (5) A method for reproducing information recorded on an information recording medium according to claim 4, wherein the covering member is composed of a plurality of layers or more. (6) A method for reproducing information recorded on an information recording medium according to claim 4, wherein at least one layer of the covering member has a transparency that makes recording and/or reproduction substantially impossible. (7) In a method for restoring an information recording medium that basically consists of a covering member, a recording layer, and a transparent substrate that is irradiated with recording or reading light, when the transparent substrate is damaged, part or all of the covering member is removed. 1. A method for restoring an information recording medium, which comprises removing the transparent substrate, irradiating readout light from the opposite side of the transparent substrate, and recording the information on another information recording medium based on the read recorded information.