JPH0196862A - Reproducing method for flexible laser disk - Google Patents

Abstract

PURPOSE:To suppress the warp and the deformation of a flexible laser disk and to accurately and stably read recording information by providing an adapter composed of a transparent material which has an approximately identical shape with that of the flexible laser disk on the upper and lower sides of the flexible laser disk and reproducing the recording information. CONSTITUTION:A flexible laser disk 10 is layer-composed of a base material file 2, a resin layer 3 in which unevenness information is formed, a reflecting film layer 7, and a protecting layer 8, and its whole thickness is made into approximately 100mu. When the recording information of the disk 10 is read, by an optical system 20, laser beams are converged on the disk 10. At this time, adapters 30 and 40 are prepared, which are composed of the transparent material having the approximately identical shape with that of the disk 10 and the thickness of approximately 1.4mm and 0.3mm, and by providing these adapters 30 and 40 so as to sandwich the disk 10, the information in the disk 10 is read. Thus, the warp and the deformation of the disk 10 can be suppressed, and the recording information can be read accurately and stably.

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention relates to a method for playing back a flexible laser disc.
More specifically, the present invention relates to a method for reproducing flexible laser discs that significantly simplifies the duplication process and enables mass production.

(Technical background and problems to be solved) Laser discs (optical discs) meet the demand for large-capacity memory in an information society supported by the rapid development of computers, and the demand for video discs as a featured product for post-color televisions. It has been supported by passionate attention and advances in laser technology. Storage capacity of laser disc.

The storage density is overwhelmingly higher than that of magnetic memory,
This is the purpose of using light. However, at present, optical memory has no choice but to be a ROM type dedicated memory, and in this respect it is complementary to magnetic memory, which can be repeatedly recorded and reproduced, and each has its own suitable application field.

The advantages of the optical method are as follows.

(2) It has a high recording density and can increase the carrier frequency, and the track width of a VTR is 58μ, whereas the track width of a laser disk is less than 2μ.

■It is a non-contact playback method and is resistant to dropout noise caused by scratches and dust. In the contact-type recycling method, the recycling needle pulls even the smallest dust particles, so the apparent size of the dust becomes very large.

■Excellent operability and maintainability. Contact-type products require special dust-free envelopes, and special care must be taken when handling them to protect hands from oil and fat.

■There is no wear and tear on the disc or pickup, so it has a long life.

■Various playback modes.

As mentioned above, one of the most anticipated features of laser discs is inexpensive large capacity memory, which is expected due to the ease of manufacturing laser discs. For read-only laser discs as well as recordable laser discs with pre-format and pre-group, it is possible to easily produce large-capacity discs by making a single master mold and making a replica of the large disc that will be used in the future. .

However, since conventional laser discs have a rigid shape, the process of duplicating laser discs is complicated, and it is difficult to easily transport and sell laser discs by attaching or storing them to books, articles, etc. was impossible.

For this reason, there is a strong desire to develop a flexible laser disk of the sonosheet type that is convenient for transportation and sale, as well as to establish a method for reliably and easily reproducing the recorded information.

(Object of the invention) This invention was made under the above circumstances,
SUMMARY OF THE INVENTION An object of the present invention is to provide a reproduction method for easily and accurately reading recorded information while suppressing warping and deformation of a flexible laser disk of the sonosheet type, which is convenient for transportation.

(Means for Solving the Problems) The present invention relates to a method for playing back a flexible laser disc, and the above object of the present invention is to provide the flexible laser disc above and below the flexible laser disc. This is achieved by disposing and recycling an adapter made of a transparent material having approximately the same shape.

(Function of the Invention) This invention reads recorded information by disposing two adapters made of a transparent material and having almost the same shape as the flexible laser disc above and below the flexible laser disc. is performed accurately and stably.

(Embodiments of the Invention) First, a flexible laser disk used in the present invention will be explained.

FIG. 1 shows the manufacturing process of a flexible laser disc, in which a laser disc forming film 1 with a thickness of about 100 μm is coated on a base film 2 with thermoformable ultraviolet curable resin or electron beam curable resin. The resin 3 is arranged in layers. As the base film 2, any film-shaped material can be used. Specifically, polyethylene,
Polypropylene, polyethylene terephthalate, polyvinyl chloride, vinyl chloride/vinyl acetate copolymer, polyvinylidene chloride, polymethyl methacrylate, polystyrene,
Polymer films such as polyvinyl notyral and polycarbonate, paper, synthetic paper, and gold scrap films such as iron can be used. Further, the thermoformable ultraviolet curable resin or electron beam curable resin 3 is solid at room temperature, and when provided on the base film 2, it can be rolled up without the surface becoming sticky. Therefore, since the laser disc forming film 1 comprising the resin provided on the base film 2 can be rolled up and stored, it is brought into contact with a laser disc master plate (master mold or resin thickness rm) for duplication. There is no need to provide the resin layer on the base film 2 immediately before. Further, materials that can be used for the laser disk layer are thermoformable objects having radically polymerizable unsaturated groups, and there are the following two types.

(1) A polymer having a glass transition temperature of 0 to 250t and having a radically polymerizable unsaturated group. More specifically, the following methods (a) to (d) are used to polymerize or copolymerize the following compounds (1) to (2).
It is possible to use those into which radically polymerizable unsaturated groups have been introduced.

■ Monomers with hydroxyl groups: N-methylol acrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-
Hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 2-hydroxyn, 3-phenoxypropyl methacrylate, 2-hydroxyn, 3-phenoxypropyl acrylate, etc.

■ Monomers with carboxyl groups: acrylic acid, methacrylic acid, acryloyloxyethyl monosuccinate, etc.

■Nigericidyl methacrylate, etc., which has an epoxy group.

(2) Monomers having an aziridinyl group: 2-aziridinyl edyl methacrylate, allyl 2-aziridinyl propionate, etc.

■One with an amino group! lim-niacrylamide, methacrylamide diaseptone acrylamide, diethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc.

■ Monomer with sulfone group: 2-acrylamide-
2-methylpropanesulfone etc.

(2) Monomer having an isocyanate group: an adduct of a diisocyanate and a radially polymerizable -QLffi substance having active hydrogen, such as a 1 mol to 1 mol adduct of 2,4-)-luene diisocyanate and 2-hydroxyethyl acrylate.

■Furthermore, the glass transition point of the above copolymer can be adjusted,
In order to adjust the physical properties of the cured film, the above compound and
The following -Q'-ffi which can be copolymerized with this compound
It can also be copolymerized with the body. Examples of such copolymerizable monomers include methyl methacrylate, methyl acrylate, edyl acrylate, ethyl methacrylate, pro-acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate,
Isobutyl acrylate, isoamyl acrylate, t
-butyl acrylate, -butyl methacrylate, isoamyl acrylate, isoamyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and the like.

Next, a desired material can be obtained by reacting the polymer obtained as described above by methods (a) to (ii) described below to introduce a radically polymerizable unsaturated group.

(a) A polymer of a monomer having a hydroxyl group, or in the case of a copolymer, a monomer having a carboxyl group such as acrylic acid or methacrylic acid is subjected to a condensation reaction.

([17 1-f with carboxyl group and sulfone group
In the case of a fi polymer or a copolymer, the aforementioned monomers having hydroxyl groups are subjected to a condensation reaction.

(8) In the case of a polymer or copolymer of a monomer having an epoxy group, an isocyanate group, or an aziridinyl group, the above-mentioned monoQLi substance having a hydroxyl group or a monomer having a carboxyl group is subjected to an addition reaction.

(2) In the case of a polymer or copolymer of a monomer having a hydroxyl group or a carboxyl group, a monomer having an epoxy group or an Atmer having an aziridinyl group, or a diisocyanate compound and a hydroxyl group-containing acrylic acid ester monomer. A 1:1 molar adduct of the polymers is subjected to an addition reaction.

In order to carry out the above reaction, it is preferable to add a polymerization inhibitor such as FIFR hydroquinone and carry out the reaction while blowing dry air.

(2) A compound having a melting point of 0 to 250°C and having a radically polymerizable unsaturated group. Specific examples include stearyl acrylate, stearyl methacrylate, triacryl isocyanurate, cyclohexanediol diacrylate, cyclohexanediol dimethacrylate, spiroglycol diacrylate, and spiroglycol dimethacrylate.

This radically polymerizable unsaturated monomer improves crosslinking density and heat resistance when irradiated with ionizing radiation, and in addition to the above-mentioned -Qlffi form, ethylene glycol diacrylate, ethylene glycol dimethacrylate,
Polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, hexanediol diacrylate, hexanediol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimedylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol tetraacrylate, Pentaerythritol tetramethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate,
Ethylene glycol diglycidyl ether diacrylate, ethylene glycol diglycidyl ether dimethacrylate, polyethylene glycol diglycidyl ether diacrylate, polyethylene glycol diglycidyl ether diacrylate, propylene glycol diglycidyl ether diacrylate, propylene glycol diglycidyl ether dimethacrylate , polypropylene glycol diglycidyl ether diacrylate,
Polypropylene glycol diglycidyl ether dimethacrylate, sorbitol tetraglycidyl ether tetraacrylate, sorbitol tetraglycidyl ether tetramethacrylate, etc. can be used, and based on 100 parts by weight of the solid content of the above copolymer mixture,
It is preferable to use it in a range of 0.1 to +00 fig. In addition, although the above materials can be sufficiently cured by electron beams, when curing by ultraviolet irradiation, benzoin ethers such as benzoquinone, benzoin, and benzoin methyl ether, halogenated acetophenones, and piatil neck sensitizers may be used. It is also possible to use materials that generate radicals when irradiated with ultraviolet rays, such as.

The laser disk original plate 4 has irregularities formed on its surface that correspond to electrical signals such as audio and image signals. This laser disk original plate 4 can be produced by a conventionally known method, and the laser disk formed on the laser disk original plate 4 is of a type that can record information by using unevenness on the surface of the material.

The above-described laser disc forming film 1 and laser disc original plate 4 are bonded together through a heat pressure welding roller 5a, which is a heat pressure welding means such as a heating roller, so that the ultraviolet curing resin or electron beam curing resin 3 of the film 1 forms a laser disc. The concavo-convex pattern of the laser disc original plate 4 is replicated on the surface of the ultraviolet curing resin or electron beam curing resin 3 of the laser disc forming film 1 by heating and pressurizing it so as to make contact with the original plate 4.

At this time, the temperature of the heating roller varies greatly depending on the type of resin 3 used, but is preferably 50 to 300°C, preferably 100 to 200°C. Further, it is preferable that the laser disc forming film 1 and the laser disc original plate 4 are pressed together under a pressure of 0.1 kg/7 cm or more, preferably 1 kg/cm or more.

In this way, an uneven pattern corresponding to electrical signals such as audio and images is formed on the surface of the ultraviolet curable resin or electron beam curable resin 3 of the laser disc forming film 1, and the surface is brought into pressure contact with the laser disc original plate 4. Then, the resin 3 is cured by irradiating the laser disk forming film 1 with ultraviolet rays if it is an ultraviolet curable resin, or with an electron beam if it is an electron beam curable resin. The irradiation of ultraviolet rays or electron beams onto the laser disc forming film 1 may be performed using the irradiation light source 6.

At this time, the irradiation with ultraviolet rays or electron beams may be carried out again after the film on which the unevenness of the laser disk original plate 4 has been formed is peeled off by a plate, and it is preferable that the resin is sufficiently cured. The irradiation amount of ultraviolet rays or electron beams needs to be adjusted appropriately depending on the resin used.

In this way, with the surface of the ultraviolet curable resin or electron beam curable resin of the laser disc forming film 1 having irregularities formed, the resin is cured by irradiation with ultraviolet rays or electron beams, thereby immediately producing a laser disc original plate. It becomes possible to release the pressure between the film and the film for forming the laser disc and cool the film.

This is because the resin is immediately cured by irradiation with ultraviolet rays or electron beams, and the formed irregularities do not disappear even when the pressure applied between the laser disc original plate 4 and the laser disc forming film 1 is released. Furthermore, since the resin is three-dimensionally crosslinked and cured by irradiation with ultraviolet rays or electron beams, heat and solvent resistance are imparted. Although the laser disc original plate 4 and the laser disc forming film 1 may be forcibly cooled before or after irradiation with ultraviolet rays or electron beams, it is usually sufficient to cool them naturally. Further, if necessary, by further irradiating the resin with ultraviolet rays or electron beams after peeling, the resin can be sufficiently cured, and the hardness, heat resistance, solvent resistance, etc. can also be improved.

Next, the uneven patterned surface of the laser disk forming film 1 having an uneven pattern formed thereon is deposited, sputtered, scoured, plated, plated, etc. to a thickness of about 5 mm as shown in FIG.
A reflective film layer 7 of QO~1000 aluminum, aluminum, etc. is formed. Thereafter, as shown in FIG. 3, a protective layer 8 of transparent resin may be further provided by coating. In this way, the reflective film layer 7 is formed, and if necessary, a "protective layer" 8 is further layered on the laser disc forming film 1.
This is punched into a predetermined shape and size using a punching die to obtain a flexible laser disk 1O as shown in FIG.

By the way, in the above-mentioned example, the flexible laser is formed using the laser disc forming film 1 in which the ultraviolet curable resin or electron beam curable resin layer 3 having thermoformability is layered on the base film 2. When creating a disc IO, there is a gap between the base film 2 and the laser disc original plate 4 which are arranged at a predetermined interval (for example, 1 mm).
After filling a resin liquid that can be cured with ultraviolet rays or electron beams, the resin liquid may be cured and shaped by irradiation with ultraviolet rays or electron beams. In this case, methods for filling or applying the resin liquid include roll coating, knife coating, and jabber coating. Known methods such as gravure coating, screen printing, and pouring can be used, and the thickness may be appropriately determined in consideration of the resin strength after curing. Further, although the irradiation with ultraviolet rays or electron beams may be performed directly on the coated surface, it is also possible to irradiate through the laser disk original plate 4 if the laser disk original plate 4 is made of a material that allows ultraviolet rays or electron beams to pass through. Furthermore, as the resin liquid that is cured by ultraviolet rays or electron beams, monomers, oligomers, prepolymers, etc. having unsaturated bonds in the molecule can be used, and if a mixture of an epoxy compound and a Lewis acid is required, It may be used by adding a sensitizing agent.

Flexible laser disc 1 manufactured as described above
0, as shown in cross section No. 13 in FIG. It has a structure in which a protective layer 8 is layered, and the total thickness is 1.
Approximately 00μ is considered flexible. Here, when reading the recorded information on the flexible laser disk 10, as shown in the figure, the laser beam is focused on the laser disk 10 by the optical system 20, so that no dust is generated on the laser disk 10. , dust, dirt, and other deposits 21 will block the light, making it impossible to read the information recorded on the laser disc IO.

Therefore, in the present invention, an adapter 30.40 made of a transparent material and having a thickness of about 1.4 mm and 0.3 mm, which has almost the same shape as the flexible laser disk 10 as described above, is prepared. 30 and 40 are arranged so as to sandwich the flexible laser disc io as shown in FIG. ) The recorded information is read out in the following manner.

FIGS. 7(8) and 7(B) show examples of drawing the adapters 30 and 40, and FIG. 8 shows a cross-sectional view of how to use them.

The adapter 40 has a circular shape (outer diameter of about 110 mm, inner diameter of about 35 n+m) as shown in FIG. 41A and 42A are provided. The adapter 30 has a circular shape (outer diameter approximately 1
2 On+m 2 and an inner diameter of 15 mm), and an insertion section 33 for inserting the flexible laser disk 10 is provided at the center of the circle. Insertion grooves 31 are provided on the inner and outer peripheries of the insertion portion 33 for fixing the attachment portion of the adapter 40.
B, 32B are provided. In such a configuration, it is placed on the adapter 30°33. Then, install the adapter 40 on top of it so that the mounting members 41^ and 428 of the adapter 40 are inserted into the insertion shelves 31A and 32A of the adapter 30, and rotate in the E direction while applying pressure from the top with your fingers. and insert the mounting members 418 and 42A into the grooves 31.
[Insert at 1°320 and secure. In this way, the flexible laser disc IO is fixed between the adapters 30 and 40, allowing the flexible laser disc 10 to be used.

A flexible laser disc 10 (outer diameter of approximately 110+++ m, inner diameter of approximately 351 m) on which music information is recorded with the above-mentioned configuration is prepared, the adapters 30 and 40 are arranged above and below, and fixed as described above, and a commercially available disc is manufactured. When played back on a CD player (for example, Sony's DP-M2O), the same sound quality as commercially available CD software recorded with the same audio information was obtained.

In this way, the thickness of the visible laser disc 10 (10
When a laser beam is focused onto the flexible laser disk 10 through an adapter 30 made of a transparent material that is considerably thicker (about 1.4+nm) than the thickness of the adapter 30 (approximately 0 μm), even if the deposit 21 adheres to the adapter 30, Since light can be focused on the flexible laser disk 10, reading of information will not be impossible due to adhesion of dirt or other deposits.

Furthermore, in this invention, since an adapter 40 similar to that described above is disposed above the flexible laser disk 1O, the surface of the flexible laser disk 1O may be uneven or eccentric during playback.
The information pits cannot be reproduced, and the dimensional stability of the flexible laser disk 10 and the adhesion with the adapter 30 are not affected.

Note that the shape of the adapter 30, 40 does not have to be the same as the shape described above, and the thickness is not limited to 1.4 mm or 0.3 mm. , glass, polycarbonate,
A transparent material such as epoxy is suitable.

When reading information from the flexible laser disc 10,
The act of disposing the adapter 30, 40 on the surface may be performed automatically or manually.

(Effects of the Invention) As described above, according to the reproducing method of the present invention, since recorded information is read from a thin flexible laser disc using an adapter, there is no possibility of deposits such as dust. There is an advantage that information can be read accurately even if the film is attached.

In addition, the warpage, deformation, etc. that are characteristic of flexible laser discs are corrected by the adapter placed below the disc, which prevents surface wobbling, eccentricity, etc. during playback, and improves the dimensional stability of the flexible laser disc and the adhesion with the adapter. It has the advantage of not being influenced by gender.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the manufacturing process of a flexible laser disk used in the present invention, FIGS. 2 and 3 are cross-sectional structural views showing an example of the flexible laser disk of the present invention, and FIG. FIG. 5 is a perspective view showing an example of a flexible laser disk, FIG. 5 is a view showing a state of reading information recorded on the flexible laser disk, and FIGS. 6 and 8 are cross sections showing examples of use of the adapter used in the present invention. Figure, Figure 7 (A), (B)
FIG. 1 is a diagram showing an example of the configuration of an adapter used in the present invention. DESCRIPTION OF SYMBOLS 1... Film for laser disc formation, 2... Base film, 3... Ultraviolet curable resin or electron beam curing resin, 4... Laser disc original plate, 5a. 5b...Heat pressure welding roller, 6...Irradiation light source, 7...
- Reflective film layer, 8... Protective layer, 10... Flexible laser disk, 20... Optical system, 30.40... Adapter, 318. 328... Closet shelf, 31 [1,328... Insertion groove, 41^. 42Δ...Mounting member. Applicant's agent Miyu Yasugata Ogi'＼ $ 2 Figure 3 Early 4 Figure 5 Figure 6 (B) (,4) Brown? ! 5a $6 Figure

Claims (2)

[Claims] (1) Playback of a flexible laser disc characterized in that adapters made of a transparent material having substantially the same shape as the flexible laser disc are disposed above and below the flexible laser disc for playback. Method. (2) When the adapter is installed, the thickness of the adapter on the laser light transmitting surface side is approximately 0.8 to 1.4 mm, and the thickness of the adapter on the opposite side to the laser light transmitting surface side is approximately 0.8 to 1.4 mm. Approximately 0
．． The method for reproducing a flexible laser disc according to claim 1, wherein the thickness is 1 to 0.5 mm.