JPH01220238A - Optical information recording card - Google Patents

Abstract

PURPOSE:To obtain a reproduction signal of high C/N by applying an antireflection means which prevents reflection of laser light onto a protective layer thereby preventing the reflection of the laser beam transmitted through an optical recording layer, the transmission of said beam again through pits and the detection thereof on a pickup side. CONSTITUTION:An optical recording part 14 consists of the optical recording layer 12 formed on a substrate 11. Said recording layer 12 is covered by the protective layer 13. The antireflection means which prevents the reflection of the laser light is applied on this protective layer 13. The reflection of the light transmitted through the pits formed on the optical recording layer 12 to the optical recording layer 12 side is, therefore, prevented by the antireflection means at the time of reading the recorded data by projecting the laser beam from the pickup to the optical recording layer 12 through the substrate 11 in the case of the optical information recording card of the system consisting in providing the pits to the optical recording layer 12 by boring holes thereto particularly by means of the laser beam. The optical information recording card which allows protection of the optical recording layer by the protective layer while having the high recording sensitivity and reproducing characteristic is thereby obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical information recording card in which an optical recording layer is covered with a protective layer.

[Prior Art] Write-once type optical information recording cards have a large recording capacity and excellent storage stability, and therefore attempts have been made to use them in various fields. Typical examples include recording methods that replace hospital medical records and bank passbooks.

Conventionally, as an optical recording means used in this type of optical information recording card, a method has been proposed in which silver particles are diffused into a gelatin layer by heat.

(Japanese Unexamined Patent Publication No. 58-188346) However, in this method, the pit size reaches as much as 5 um, high recording density cannot be obtained, and it is not practical.

On the other hand, as an optical recording means applied to a disk-shaped optical information recording medium, a T
Using an optical recording layer consisting of a metal layer such as e, Bi, or Mn, or a dye layer such as cyanine, merocyanine, or phthalocyanine, the optical recording layer is irradiated with a laser beam. There is a method of partially evaporating or sublimating and forming a pit 4 with a diameter of about 1 um in its wake. Furthermore, in addition to this, there is also a disk-shaped optical information recording medium in which an optical recording layer is formed using a dye polymer or a metal carbide, and the optical recording layer is partially deformed by irradiation with a laser beam to form pits. has also been developed. In this case, in either method, the optical recording layer is covered with a protective layer to protect the optical recording layer from stains, scratches, etc.

In both of the above optical recording means, after the laser beam irradiated onto the pit during reproduction passes through the pit, a part of it is reflected by the protective layer covering the optical recording layer, passes through the pit again, and is picked up. detected. Therefore, there was a problem that the difference between the amount of light detected at the pit and the amount of light detected at other parts was small, and the C/N of the obtained reproduced signal was small. In addition, especially in the latter type of optical recording means, when a protective layer is brought into close contact with the surface of the optical recording layer,
The surface of the optical recording layer is not sufficiently deformed, and the recording sensitivity itself becomes low.

For this reason, conventional optical information recording disks have a laminated structure called the so-called air sandwich method, in which two substrates are stacked with a spacer in between to create a gap between the optical recording layers 2. It has been adopted.

[Problems to be Solved by the Invention] However, the air sandwich structure as described above has the disadvantage that the disk becomes considerably thick, making it unsuitable for use as a card. Furthermore, optical information recording carts are characterized by their flexibility and are often used without being housed in a case, so external forces such as large impacts and pressures are often applied to the board surface. In such a case, there is a concern that various types of scratches may occur in the optical recording layer of the optical recording means, which may adversely affect optical recording and reproduction.

In view of the above problems, the first object of the present invention is to provide an optical information recording card in which the optical recording layer can be protected by a protective layer while obtaining high recording sensitivity and reproduction characteristics. The second objective is to provide an optical information recording card that can be made thinner while still achieving the first objective. Furthermore, the third purpose is to prevent scratches from occurring in the optical recording layer due to external force.

[Means for solving the problem] That is, the means adopted in the present invention to achieve the above object are as follows.

That is, first, in an optical information recording card in which an optical recording section 14 is formed on a card-shaped substrate 11, the optical recording section 14 is composed of an optical recording layer 12 formed on the substrate 11, and the optical recording section 14 is formed on the substrate 11. The optical information recording card is characterized in that an optical recording layer 12 is covered with a protective layer 13, and the protective layer 13 is provided with an anti-reflection means for preventing reflection of the light.

Second, in an optical information recording card in which an optical recording section 14 is formed on a card-shaped substrate 11, the optical recording section 14 is composed of an optical recording layer 12 formed on the substrate 11, and the optical recording section 14 is composed of an optical recording layer 12 formed on the substrate 11. The optical information recording card is characterized in that the layer 12 is covered with a protective layer 13, and a deformable buffer layer 17 is provided between the protective layer 13 and the optical recording layer 12.

Thirdly, in an optical information recording card in which an optical recording section 14 is formed on a card-shaped substrate 11, the optical recording section 14 is composed of an optical recording layer 12 formed on the substrate 11, and the optical recording section 14 is formed on the substrate 11. An optical information recording card characterized in that a layer 12 is covered with a protective layer 13, and an external force absorbing layer 19 that is softer than the optical recording layer 12 is formed on the side of the protective layer 13 facing the optical recording layer 12. It is in.

Fourthly, in an optical information recording card in which an optical recording section 14 is formed on a card-shaped substrate 11, the optical recording section 14 is composed of an optical recording layer 12 formed on the substrate 11, and the optical recording section 14 is formed on the substrate 11. The layer 12 is covered with a protective layer 13, a deformable buffer layer 17 is provided between the protective layer 13 and the optical recording layer 12, and the protective layer 13 or the buffer layer 17 has an anti-reflection layer for preventing reflection of laser light. There is an optical information recording card characterized in that the means is applied.

Fifth, in an optical information recording card in which an optical recording section 14 is formed on a card-shaped substrate 11, the optical recording section 14 is composed of an optical recording layer 12 formed on the substrate 11, and the optical recording section 14 is formed on the substrate 11. The layer 12 is covered with a protective layer 13, and an external force absorbing layer 19 that is softer than the optical recording layer 12 is formed on the side of the protective layer 13 facing the optical recording layer 12. This optical information recording card is characterized by being provided with an anti-reflection means for preventing reflection.

[Function] In the optical information recording card according to the first invention B, in particular, in the optical information recording card of the type in which bits are provided by making holes in the optical recording layer 12 using a laser beam, the optical information recording card according to the first invention When the laser beam hv is irradiated onto the optical recording layer 12 through the optical recording layer 12 and the recorded data is read, the anti-reflection means prevents the light that has passed through the bits formed on the optical recording layer 12 from being reflected toward the optical recording layer 12 side. is prevented.

Therefore, the difference between the bits of the optical recording layer 12 and the non-abrasive light detected in the other parts becomes large, and a reproduced signal with a high C/N can be obtained.

Furthermore, even in an optical information recording card in which bits are provided by deforming the surface of the optical recording layer 12, the laser beam that has passed through the optical recording layer 12 may damage the protective layer 13 during recording or reproduction.
A reproduced signal with low noise can be obtained.

Further, according to the optical information recording card of the second invention, when forming a bit by immediately peeling off the laser beam h on the optical recording layer 12 and locally deforming its surface, the buffer layer 1
7 absorbs the deformation of the surface of the optical recording layer 12, so it does not interfere with the formation of bits and high recording sensitivity can be obtained. Furthermore, since the protective layer 13 can be superimposed on the surface of the optical recording layer 12 via the buffer layer 17, the thickness of the optical recording section 14 can be significantly reduced compared to the conventional air-sun-toy-ner system.

Further, in the optical information recording medium according to the third invention, when the protective layer 13 is pressed from the outside, the pressing force is dispersed over a wide range on the relatively hard surface side of the protective layer 13. . This dispersed compressive force is absorbed by the softer external force absorbing layer 19 facing the optical recording layer 12, and the pressure applied to the optical recording layer 12 is greatly reduced.

This makes it difficult for the optical recording layer 12 to be scratched.

Further, according to the fourth and fifth inventions, as in the first invention, a signal with a high C/N can be obtained, and at the same time, the thickness of the card can be reduced, or the optical recording layer 1 can be reduced by external force.
The effects of the first and third inventions described above, such as being able to avoid the influence on 2.

[Example] Next, please refer to Figures 1 to 4. To describe an embodiment of the present invention, as shown in FIG. 1, an optical recording section 14 is formed on the negative part of the surface of a transparent card-shaped substrate 11, and this is covered with a protective layer 13.

2 to 4 show examples of specific layer structures of this optical recording section 14. The second bolt forms an optical recording layer 12 on the card-shaped substrate 1 using metal or organic dye,
When covering this surface side with protection + gta, this protective layer 1
A buffer layer 17 is interposed between the optical recording layer 3 and the optical recording layer.

Further, in FIG. 3, when the buffer layer 17 is inserted, an antireflection means is provided on the side of the protective layer 13 facing the optical recording layer 12. Note that when the buffer layer 17 is difficult to transmit light, the optical recording layer 12 of the buffer layer 17
Provide anti-reflection means on the side facing the Roughly speaking, Figure 4 is
A slight gap is provided between the optical recording layer 12 and the protective layer 13 as a buffer layer 17, and an external force absorbing layer 19 is provided on the side of the protective layer 13 facing the optical recording layer 12.

For the substrate 11, a transparent card-like tentan body such as a polycarbonate plate, a polymethyl methacrylate plate, an epoxy plate, etc. is used. Further, for the protective layer 13, polycarbonate, polymethyl methacrylate polyethylene terephthalate, etc. are generally used.

The buffer layer 17 is made of fluid gas, liquid, powder, etc.
A solid that can be elastically deformed or plastically deformed is used. Examples include gelatin, rubber, elastomer, nitrocellulose, cellulose peroxide, polyvinyl alcohol, collodion, acrylic resin, polyvinyl formal, polyvinyl butyral, foamed urethane, metal powder with a particle size of 1 to 20 Bm, and particle size of 1 to 20 Bm. /lrn ceramic powder, particle size 1-20t
, t m resin powder, porous polymer material, and combination thereof, as well as freon gas, air, nitrogen gas, argon gas, etc. In any case, it is stable and fluid,
It is best to use one that can be easily deformed.

When a solid material is used as the buffer layer 17, the buffer layer 1 is provided between the substrate 11 on which the optical recording layer 12 is formed and the protective layer 13.
7 can be inserted and brought into close contact. On the other hand, the buffer layer 17
When a fluid or powder is used, the optical recording section 14 of the substrate 11 is sealed with a protective layer 13.

The external force absorbing layer 19 is made of a material that is capable of elastic deformation and plastic deformation and is softer than the optical recording layer. For example, examples of elastic materials include acrylic rubber, acrylic resin, chloroprene rubber,
EVA, urethane, etc. are suitable. In addition, in plastic bodies,
A suitable material is one in which rod fibers are bound together with a binder such as resin. Furthermore, it is also possible to combine these to form a so-called composite layer, for example, the surface of the above-mentioned plastic body is thinly coated with an elastic body.

The anti-reflection means prevents the laser beam hν that passes from the substrate 11 through the optical recording layer 12 to the buffer layer 17 and the protective layer 13.
The light is absorbed into the interior of the film, scattered, or transmitted into the protective layer 13.

When the loose heel j layer 17 is provided, this warp prevention means is applied to the buffer layer 17, and when it is not provided, the protective layer 13 is applied.
In the former case, if the buffer layer 17 has translucency,
It is also possible to apply anti-reflection means to both the buffer layer 17 and the protective layer 13, or only to the protective layer 13. In general, this anti-reflection means may be applied to the entire protective layer 13 (or buffer layer 17), depending on the characteristics of the anti-reflection means, or may be applied to the entire protective layer 13 (or buffer layer 17).
3 (or the buffer layer 17) facing the optical recording layer 12.

For example, when forming an antireflection means that absorbs laser light only on the surface of the buffer layer 17 and the protective layer 13 as an antireflection layer, the buffer layer 17 and the protective layer 13 can be coated with velvet coating paint, carbon black paint, etc. The side of the layer 13 facing the optical recording layer 12 is coated with an anti-reflection coating, or a film subjected to an anti-reflection treatment such as black electrostatic flocking is used as the buffer layer 1.
7 or the protective layer 13 on the side facing the optical recording layer 12. When the buffer layer 17 or the entire protective layer 13 is used as an antireflection layer, a dye such as carbon black, cyanine dye, phthalocyanine, naphthoquinone, titanium black, etc. that has light absorption properties in the semiconductor laser wavelength band is used as the antireflection layer for the protective layer 13. This can be done by means of dispersion in the medium.

Further, as a means for forming an antireflection layer that scatters laser light on the buffer layer 17 and the protective layer 13, for example, means for roughening the surfaces of these layers facing the optical recording layer 12 side can be adopted. .

Furthermore, as a means for forming an antireflection layer that transmits the laser beam into the buffer layer 17 and the protective layer 13, refraction is applied from the side facing the optical recording layer 12 of these layers toward the other side. It is possible to employ means for forming a gradient or change in the refractive index such that the index increases continuously or intermittently. These changes in refractive index can be easily achieved by bonding layers of materials with different refractive indexes, layered growth, or partial addition of metal compounds commonly used to adjust the refractive index of optical glasses. . Note that the buffer layer 17
The ratio of the refractive index of the surface layer and the deeper layer of the protective layer 13 is around 1/l/:, and the thickness of the surface layer is about 1/4n(
n: refractive index of the surface layer, λ: wavelength of the semiconductor laser).

The means for absorbing, scattering and transmitting the laser light can be combined as appropriate as possible. For example, the surface of the buffer layer 17 or the protective layer 13 provided with a laser light absorption means may be roughened and an anti-reflection means for scattering light on the surface, or the surface side of the buffer layer 17 or the protective layer 13 may be For example, a means for transmitting laser light is provided, a means for absorbing laser light is provided in the deep part of the protective layer 13, and the laser light transmitted through the surface is absorbed in the deep part of the protective layer 13.

Next, specific examples of the present invention will be described.

(Example 1) 3-Methyl-2-[7-(
3'-methyl-2'-benzothiazoline)-1-3-5
-Hebutatrienyl]-benzothiazole verchlorate was dissolved at 2% by weight in methanol. This solution was prepared using a spinner method into a size of 55 mm long, 85 mm long, and 50 mm thick.
It is coated on a 0 um card-shaped polymethyl methacrylate substrate 11 with pre-groups and dried to a thickness of about 60 nm.
An optical recording layer 12 was formed.

Furthermore, the length is 55mm, the length is 85mm, and the thickness is 1100Ji.
Optical recording section 14 of polyethylene terephthalate film
A velvet coating film (manufactured by Sumitomo 3M Co., Ltd., 2010) was gravure-coated on one side of the portion corresponding to (see FIG. 1) to form an antireflection layer. Then, this anti-reflection layer is placed on top of the recording layer 12 so that the first side faces the optical recording layer 12 side, and the portion other than the optical recording section 14 is placed on the substrate 1.
1 to form a protective layer 13. In this way, an optical information recording card having the structure of the optical recording section 14 as shown in FIG. 1 was manufactured.

This optical information recording card has an antireflection layer 18 of a protective layer 13.
The side is not in close contact with the optical recording layer 12, but is merely in contact with it, and the slight air layer between them becomes the buffer layer 17. In addition, the anti-feeding layer 18 measured by a spectrophotometer
The integrated reflectance was 1%.

The optical information recording card uses a semiconductor laser with a wavelength of 780 nm, a linear velocity of 2.0 m/Se (:', and a recording frequency of 50 nm).
The OkHz laser beam is applied to the optical recording layer 12 from the substrate 11 side! Bits were formed on the same layer 12 and recording was performed. At this time, the optimum recording power of the laser beam hv measured and confirmed on the recording surface was 4.0 mW.

After recording, the optical recording layer 12 was irradiated with a laser beam h, ν with an output of 0.3 mW, and the C/N of the recording surface was measured.
It was 43dB.

(Example 2) The same procedure as in Example 1 was carried out, except that instead of forming the antireflection layer using a velvet coating film in one day, a paste consisting of carbon black and acrylic resin was applied by a spray method. An optical information recording card was made using the same method and conditions as in Example 1. The integrated reflectance of the antireflection layer for one day was 4% as measured by a spectrophotometer.

Further, when recording and reproduction were performed on the optical information recording card in the same manner as in Example 1, the recording power was 4.0.
mW, and the C/N of the reproduced signal was 42 dB.

(Example 3) The same 3-methyl- as used in Example 1 above was used as the dye.
2-[7-(3'-methyl-2'-benzothiazoline)
-1-3-5-hebutatrienyl]-benzothiazole verchlorate was used, and 3% by weight of this was dissolved in ethanol.

Further, as the substrate 11, a card-shaped pre-grooved polycarbonate substrate 11 having the same dimensions as in the above embodiment was used, and one side of this was coated with a thickness of about 60 nm by the same means as in the above embodiment 1.
An optical recording layer 12 of m thickness was formed.

Roughly, an antireflection layer 18 was formed by spray coating an antireflection acrylic paint (manufactured by Asahipen Co., Ltd.) on one side of a polyethylene terephthalate film having the same shape as the card and having a thickness of 150 um. A protective layer 13 was formed to cover the optical recording layer 12. Note that the integrated reflectance of the antireflection layer 18 measured by a spectrophotometer is 1%.
Met.

The optical recording layer 12 of the optical information recording card was coated in the same manner as in Example 1 (however, the linear velocity of the laser beam was 2.2 m/sec).
, recording frequency was 450 kHz), and recording was performed. At this time, the optimum recording power of the laser beam hv measured and confirmed on the recording surface was 4.0 mW. After recording, the C/N of the recording surface was similarly measured and found to be 45 dB.

(Example 4) Using the same type of substrate 11 as in Example 3, a Te alloy was vacuum-deposited on the optical recording section 14 on the surface to form an optical recording layer 12 with a thickness of 45 nm.

An elastomer paint in which carbon black was dispersed was sprayed onto the surface of the optical recording layer 12 to form a buffer layer 17 with a thickness of about 20 mm. Velvet coating (manufactured by Sumitomo 3M Co., Ltd. 2010) is spray-coated on this buffer layer 17 to form an anti-reflection layer 18 in advance, and then an aluminum layer is applied by vacuum deposition, and an acrylic hard coating is further applied to form a protective layer 13. Formed. In this way, an optical information recording card was manufactured.

Recording and reproduction were performed on the optical information recording card in the same manner as in Example 3. The optimal recording power at this time is 5
．． 5 mW, and the C/N of the reproduced signal was 48 dB.

(Example 5) In Example 3, an optical information recording card was manufactured by using an alumina ceramic sheet with black electrostatic flocking as an antireflection layer instead of the polyethylene terephthalate film forming the protective layer 13. . Incidentally, the integral rate of interest for one day of the antireflection layer was 1.2%.

Recording and reproduction were performed on the optical information recording card in the same manner as in Sales Example 3. The optimal recording power at this time is 4
．． 1 mW, and the C/N of the reproduced signal was 42 dB.

(Example 6) In Example 4, a porous anti-reflection acrylic paint spray film containing titanium black and silica gel as main components was used instead of the velvet coating film forming the anti-reflection layer 18, and an optical information recording card was prepared. was manufactured.

Recording and reproduction were performed on the optical information recording card in the same manner as in Example 3. @Appropriate recording power at this time is 5
, 0 +nW, and the C/N of the reproduced signal was 46 dB.

(Example 7) An epoxy resin dyed with naphthol green dye was applied using a spinner method onto a polycarbonate substrate 11 with a thickness of 700 um that was pre-grouped to a thickness of about 50 nm.
An optical recording layer 12 was formed.

Furthermore, Mg with a refractive index of 1.38 was added to a transparent polycarbonate film with a thickness of about 2001 tm and a refractive index of 1.59.
F2 was formed into a film with a thickness of 130 nm by vacuum evaporation method, and Mg
The F2 film side was placed on the optical recording layer 12, and the peripheral part of the optical recording section 14 was fixed to the substrate 11. Through the above steps, an optical information recording card was produced.

This optical information recording card uses a semiconductor laser with a wavelength of 780 nm, a linear velocity of 2.2 m/sec, and a recording frequency of 5.
Recording was performed by irradiating the optical recording layer 12 with a laser beam hv of 00 kHz from the substrate 11 side. The optimized recording laser power at this time was 4.3n+W.

After that, a laser beam h with an output of 0.3 m was applied to the optical recording layer 12, and the C/N of the recording surface was measured.
It was B.

(Example 8) Te alloy was vacuum-deposited to a thickness of 50 nm on the surface of a 5001 Lm thick epoxy substrate on which fine irregularities had been formed in advance to form an optical recording layer 12. Further, an acrylic hard coat is applied on polyvinyl alcohol in which carbon black is dispersed, and a buffer layer 1 is formed on the optical recording layer 12.
7 and a protective layer 13 were formed to produce an optical information recording card.

When recording and reproduction were performed on this optical information recording card in the same manner as in Example 1, the C/N of the reproduced signal was 46 dB, and the optimized recording power was 5.4 mW.

(Example 9) 1-1'-dibutyl-3- which is one of the cyanine dyes
3% by weight of 3-3'-3'tetramethyl 4-5-4'-5'dibenzoindodicarbocyanine verchlorate;
and 0.6% by weight of Ni-bis(trichloropensenosithionolitetra(1,-butyl)ammonium (PA-1006' manufactured by Mitsui Toatsu Fine Co., Ltd.) were dissolved in methyl ethyl ketone.Transparent acrylic UV curing. After the resin was applied, it was cured. The solution was applied by a spinner method onto a card-shaped polycarbonate substrate 11 with pre-groups measuring 55 mm in length and width, 85 mm in width and 500 mm in thickness, and dried to form an optical recording layer with a thickness of about 70 nm. Layer 12 was formed.

Furthermore, a urethane-based paint containing carbon dispersed therein was spray-coated on one side of a polycarbonate film laminated with heat sealant and aluminum, measuring 55 mm in length and width, 85 mm in width, and 200 J1 m in thickness, in a portion corresponding to the optical recording layer 12, and this was applied to the coating layer. It was placed so that its surface faced the optical recording layer 12 side, and the portion excluding the optical recording section 14 was heat-sealed to the substrate 11. As a result, an optical information recording card having the protective layer 13 and the antireflection layer 18 was manufactured. Incidentally, the integrated reflectance of the antireflection layer for one day measured by a spectrophotometer was 1%.

Data was recorded on this optical information recording card by irradiating the optical recording layer 12 with a laser beam from the substrate 11 side at a linear velocity of 2.2 m/sec using a semiconductor laser with a wavelength of 780 nm. After recording, the above signal was reproduced by applying a 0.3 mW laser beam to the optical recording layer 12, and the reproduced signal was 4.
It was 7dB.

(Example 10) 1-1'-diethyl 3- which is a cyanine dye
3-3'-3'tetramethylindotricarpodianine iodide was dissolved in 4% by weight ethanol. The solution was applied using a spinner method onto a card-shaped substrate 11 with dimensions of 55 mm x 85 mm and a thickness of 5001 Jm, which was made of a transparent acrylic plate pre-grouped with rJV curing resin, and dried to form a substrate with a thickness of about 70 nm. An optical recording layer 12 was formed.

Furthermore, a film having the same shape as the substrate is prepared by sandblasting the surface of an acrylic film in which carbon black is dispersed to give an appropriate surface roughness, and the center is aligned so that the sandblasted surface faces the optical recording layer 12 side. Place them together on the substrate 11, and attach the substrate 1 with a high-temperature melting adhesive.
Glued to 1. As a result, an optical recording card having a thickness of 80 cm and having a protective layer 13 subjected to anti-reflection treatment was manufactured.

(Comparative Example 1) A substrate 1 was prepared in the same manner as in Example 1 in a solution in which nitrocellulose corresponding to 3% of the weight of carbon tetrachloride was dissolved.
The optical recording layer 2 formed thereon is immersed, and a protective layer made of a porous nitrocellulose film is formed on the optical recording layer 2,
I made an optical information recording card.

When the optical information recording card was tested using the same method and conditions as in Example 1, the optimum recording power was 4.2 mW.
The C/N of the reproduced signal was 32 dB.

(Comparative Example 2) In Example 3, an optical information recording card was produced without applying antireflection treatment to the polyethylene terephthalate film forming the protective layer.

When the optical information recording card was tested using the same method and conditions as in Example 3, the optimum recording power was 4.0 mW.
The C/N of the reproduced signal was 34 dB.

(Comparative Example 3) In Example 3, an optical information recording card was made using a glossy black paint instead of the antireflection acrylic paint forming the antireflection layer 18. In this case, the integral reflectance of the protective layer on the interface side with the optical recording layer was 6.2%.

When the optical information recording card was tested using the same method and conditions as in Example 3, the optimum recording power was 3.8 mW.
The C/N of the reproduced signal was 36 dB.

(Comparative Example 4) In Example 6, an optical information recording card was produced without adding titanium black to the porous antireflection acrylic paint.

When the optical information recording card was tested using the same method and conditions as in Example 3, the optimum recording power was 5.0 mW.
The C/N of the reproduced signal was 34 dB.

(Comparative Example 5) In Example 7, M g F was formed on the optical recording layer 12.
Recording layer 12 formed on substrate 11 without providing two layers
A polycarbonate film having a thickness of about 200 ttm was superimposed thereon, and its inner and outer edges were fixed to the substrate 11 to produce an optical information recording card.

Regarding this optical information recording card, using a semiconductor laser with a wavelength of 780 nm, a laser beam hv with a linear velocity of 2.2 mm/sec and a recording frequency of 500 kHz is directed from the substrate 11 side to the optical recording layer 12, and recording is performed on the same layer 12. When I tried,
The optimum recording power is 4.5 W, and the C/N of the reproduction signal is 3.
It was 5 dB.

(Comparative Example 6) An optical information recording card was produced in the same manner as in Example 9 except that the urethane paint in which carbon was dispersed was not applied to the surface of the protective layer.

Regarding this, when the same test as in Example 9 was conducted, the C/N was 38 dB.

(Example 11) On a card-shaped polycarbonate substrate 11 with a thickness of 500 μm provided with pre-groups and pre-pits, an epoxy resin dyed with naphthol green dye is applied by a spinner method to form an optical recording layer 12 with a thickness of about 1100 nm. did.

Urethane foam was sprayed onto the surface of this optical recording layer 12 to form a buffer layer 17 with a thickness of about 30 um. Furthermore, on top of this buffer layer 17, a protective layer with a thickness of approximately 200 mm is provided.
A μm polycarbonate film was adhered to the entire surface.

Through the above steps, a card-shaped optical information recording card was produced.

For this optical information recording card, a semiconductor laser with a wavelength of 780 nm is used, and a linear velocity of 2. Om/secC, recording frequency 5
A laser beam h of 00 ktLz is applied to the optical recording layer 12 from the substrate 11 side. ? I took advantage of it and recorded it. The optimized recording laser power at this time was 4.3 mW. Thereafter, a laser beam 11ν with an output of 0.3 mW was applied to the optical recording layer 12, and the C/N of the recording surface was measured at the same linear velocity as during recording, and it was found to be 41 dB.

(Example 12) A Te alloy was vacuum-deposited to a thickness of 50 nm on the surface of a card-shaped epoxy substrate with a thickness of 500 μm on which fine irregularities had been formed in advance to form an optical recording layer 12. Polyvinyl alcohol was applied onto the optical recording layer 12 by a spray method to form a buffer layer 17. Then, an acrylic hard coat was applied on the buffer layer 12 as a protective layer.

When recording and reproducing were performed on this optical information recording card in the same manner as in Example 1, the C/N of the reproduced signal was 40 dB, and the optimized recording power was 5.4 mW.

(Comparative Example 7) In Example 11, a polycarbonate film with a thickness of about 200 Jim was directly adhered to the entire surface of the optical recording layer 12 using an adhesive, without spraying urethane foam onto the surface of the optical recording layer 12. , created an optical information recording card.

For this optical information recording card, a semiconductor laser with a wavelength of 7800 was used, a linear velocity of 1.4 m/sec, and a recording frequency of 5.
An attempt was made to record on the optical recording layer 12 by irradiating the optical recording layer 12 with a laser beam hv of 00 kHz from the substrate 11 side, but complete recording was not possible even with a recording power of 8 mW.

(Example 13) One of the cyanine dyes, 1,1'diethyl 3,3.
3", 3'tetramethyl4,5.4',5'dibenzoindodicarbocyanine iodide in ethanol.
wt% dissolved.

This solution was prepared using a spinner method to form a piece with a length of 55 mm and a length of 85 mm.
mm, thickness 500 u... on a card-shaped polymethyl methacrylate substrate 11 with ant groups, and dried.
An optical recording layer 12 having a thickness of about 60 nm was formed.

Furthermore, an external force absorbing layer 19 was formed by gravure coating acrylic rubber in which carbon was dispersed on one side of a polyethylene terephthalate film having the same shape as the substrate 11 and having a thickness of 75 μm and forming the optical recording portion 14 . This is placed over the recording layer 12 so that the external force absorbing layer 19 faces the optical recording layer 12 side, and the portion excluding the optical recording section 14 is fixed to the substrate 11 to serve as a protective layer 13 and optical information A recording card was produced.

This optical information recording card has an external force absorbing layer 19 of the protective layer 13.
The sides are not in close contact with the optical recording layer 12, but are merely in contact, and there is a slight gap between them.

In the optical information recording card, a semiconductor laser with a wavelength of 780 nm is used to irradiate the optical recording layer 12 with a laser beam at a linear velocity of 2.2 m/sec from the substrate 11 side, forming bits on the same layer 12, and recording. I did it. After that, the peripheral part of the card is fixed, and the center part is fixed by ±5m at a cycle of 0.7 times/sec.
When a bending test was conducted in which the sample was repeatedly warped 104 times to cause m deformation, the C/N deterioration was 0.5 dB.

(Example 14) In the above Example 13, instead of the 1501 tm thick polycarbonate film as the sheet forming the protective layer 13, a 1100 tt thick polycarbonate film containing carbon black was used, and carbon was dispersed therein. An optical recording card was manufactured in the same manner as in Example 1, except that the urethane paint prepared above was applied by a spray method to form the external force absorbing layer 19.

In this case, a bending test was performed after recording in the same manner as in the above example, and the C/N deterioration was 1.0 dB.

(Example 15) As a dye, 3-methyl-2-[7-(3'-methyl-
2'-Benzothiazoline)-1-3-5-hebutatrienyl]-benzothiazole perchlorate was used and dissolved at 3% by weight in ethanol. Further, as the substrate 11, a polycarbonate substrate 11 with pregrooves having the same shape as in Example 13 was used, and an optical recording layer 112 having a thickness of about 60 nm was formed on one side of the substrate by the same means as in Example 1.

Furthermore, a paint in which urethane cellulose single fibers' are dispersed is spray-coated on the recording part 14 on one side of a polyethylene terephthalate film having a thickness of 125 μm and having the same shape as the substrate 1, and on top of this, urethane in which carbon is dispersed is applied in a similar manner. The external force absorbing layer 19 was formed by coating using the following method. Then, in the same manner as in the above embodiment, the optical recording layer 1
2 was covered to form a protective layer 13.

In this case, a bending test was performed after recording in the same manner as in the above example, and the C/N deterioration was 0.8 dB.

(Comparative Example Day) In Example 13, a 125 μm thick polycarbonate film containing carbon black was used instead of the 150 μm thick polycarbonate film as the sheet forming the protective layer 13, and the same example An optical recording card was manufactured in the same manner as in the same Example except that the external force absorbing layer 19 was not formed.

In this case, a bending test was performed after recording in the same manner as in the above example, and the C/N deterioration was 5.2 dB.

As is clear from these Examples and Comparative Examples, Examples 13 to 1
5, the C/N deterioration before and after the bending test was 1. Od
8 or less, whereas in the comparative example, the C/
Deterioration of N was observed.

[Effects of the Invention] As explained above, according to the first invention, the protective layer 13
Due to the anti-reflection means applied to the optical recording layer 12, the laser beam that has passed through the optical recording layer 12 is reflected, passes through the pits again, and is not detected by the pickup side, so that a reproduced signal with a high C/N can be obtained.

According to the second invention, in an optical information recording medium in which recording is performed by locally deforming the optical recording layer 12 by irradiating the laser beam, the buffer layer 17 is attached to the optical recording layer 12.
In order to facilitate the deformation of the
The optical recording layer 12 is protected by the protective layer 13, and an optical information recording medium that is thinner than the conventional one of the same type can be obtained.

According to the third invention, it is possible to prevent damage to the optical recording layer 12 that would cause significant deterioration of recording and reproducing characteristics due to external force, thereby providing an optical information recording medium that is resistant to impact and pressure. can.

According to the fourth invention, the effects of the first invention and the second invention can be obtained by the buffer layer 17 and the antireflection layer 18.

According to the fifth invention, the external force absorbing layer 19 and the antireflection layer 18
Accordingly, the effects of the first invention and the third invention can be obtained together.

[Brief explanation of the drawing]

FIG. 1 is a partially vertical perspective view of an optical information recording card showing an embodiment of the present invention, and FIGS. 2 to 4 are section A in FIG. 1 showing embodiments of the optical recording section of the card. FIG. 11... Substrate 12... Optical recording layer 13... Protective layer 17... Buffer layer 1st... Antireflection layer 19...
・External force absorption layer

Claims (5)

[Claims] (1) In an optical information recording card in which an optical recording section 14 is formed on a card-shaped substrate 11, the optical recording section 14 is
It consists of an optical recording layer 12 formed on a substrate 11, the optical recording layer 12 is covered with a protective layer 13, and the protective layer 13 is provided with anti-reflection means for preventing reflection of laser light. Optical information recording card. (2) In an optical information recording card in which an optical recording section 14 is formed on a card-shaped substrate 11, the optical recording section 14 is
It consists of an optical recording layer 12 formed on a substrate 11, the optical recording layer 12 is covered with a protective layer 13, and a deformable buffer layer 17 is provided between the protective layer 13 and the optical recording layer 12. An optical information recording card characterized by: (3) In an optical information recording card in which an optical recording section 14 is formed on a card-shaped substrate 11, the optical recording section 14 is
Consisting of an optical recording layer 12 formed on a substrate 11, the optical recording layer 12 is covered with a protective layer 13, and a layer softer than the optical recording layer 12 is provided on the side of the protective layer 13 facing the optical recording layer 12. An optical information recording card characterized in that an external force absorbing layer 19 is formed. (4) In an optical information recording card in which an optical recording section 14 is formed on a card-shaped substrate 11, the optical recording section 14 is
It consists of an optical recording layer 12 formed on a substrate 11, the optical recording layer 12 is covered with a protective layer 13, and a deformable buffer layer 17 is provided between the protective layer 13 and the optical recording layer 12, An optical information recording card characterized in that the buffer layer 17 or the protective layer 13 is provided with anti-reflection means for preventing reflection of laser light. (5) In an optical information recording card in which an optical recording section 14 is formed on a card-shaped substrate 11, the optical recording section 14 is
Consisting of an optical recording layer 12 formed on a substrate 11, the optical recording layer 12 is covered with a protective layer 13, and a layer softer than the optical recording layer 12 is provided on the side of the protective layer 13 facing the optical recording layer 12. An optical information recording card characterized in that an external force absorbing layer 19 is formed, and the external force absorbing layer 19 is provided with antireflection means for preventing reflection of laser light.