JPH08212597A - Optical information medium, production of optical information medium and apparatus for producing optical information medium - Google Patents

Abstract

PURPOSE: To obtain a stuck disk of high-density thin type substrates having high environmental resistance at a low cost, a process for producing this disk, and an apparatus for production thereof. CONSTITUTION: A first reflection film is formed on the first information signal surface formed on one surface of a first substrate 1, and a second reflection film is formed on the second information signal surface formed on one surface of a second substrate 5. The first reflection film and the second reflection film are disposed to face each other and a layer of a UV-curing resin 10 is formed between the first and second reflection films. This UV-curing resin 10 is cured by UV rays transmitting the second substrate 5 and the second reflection film and the first and second substrates are integratedly stuck to produce the stuck disk.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information medium having two optical information substrates attached to each other, a manufacturing method thereof, and a manufacturing apparatus thereof. The present invention also relates to an optical information medium having two information surfaces for recording or reproducing information by irradiating a laser with a narrowed beam, a manufacturing method and a manufacturing apparatus thereof.

[0002]

2. Description of the Related Art Practical application of optical information media such as optical cards and optical discs is in progress. Among them, compact discs (hereinafter referred to as "CDs") have become very popular. In particular,
Since it has become possible to easily handle video and audio information recorded as digital signals on a CD-ROM with a computer, the utility value of a CD in the information industry field has significantly increased. In order to record and reproduce high-density information on such an optical disc, it is necessary to shorten the wavelength of laser light used for recording and reproduction and to increase the numerical aperture (NA) of the objective lens.

Recent advances in semiconductor lasers, image compression technology, and various peripheral technologies have made it possible to record video / audio information on one side of a disk having a diameter of 120 mm for a long time.
For example, an objective lens with NA (numerical aperture) of 0.6 and a wavelength of 65
If a 0 nm red semiconductor laser is used, signal pits having a track pitch of 0.74 μm and a shortest pit length of 0.40 μm can be reproduced with high quality. When the 8-15 method is used as the modulation method, the 1-bit length is 0.25 μm. Therefore,
If you can achieve a density more than 5 times that of a CD, and if you increase the degree of redundancy to 15%, you will be able to record about 5 GB of information on a disk with a diameter of 120 mm. A video / audio signal of 4.7 Mbps can be recorded for about 142 minutes.

However, with a high NA objective lens, the disc tilt that can be tolerated is very small. For example, 1.2 m, which is the same as a compact disc (hereinafter abbreviated as CD)
If a substrate with a thickness of m is used, the tilt allowable for an objective lens with NA 0.6 is about 0.25 degree, which is comparable to the error of mounting the optical head on the player, and the tilt due to the change in the shape of the disc is It becomes unacceptable and practical.

By reducing the thickness of the substrate, a high NA objective lens can be used, and a high density of a practical optical disk can be achieved. For example, if the thickness of the substrate is set to 0.6 mm, which is half the CD, the tilt that can be allowed for an objective lens with NA 0.6 is expanded to about 0.75 degrees, and even if the optical head mounting error is 0.25 degrees. The tilt due to the actual disc shape change has a margin of up to 0.5 degree.

First, a method of manufacturing a CD will be briefly described for comparison. Using a stamper on which audio signals are recorded, the thickness 1.2 with audio signals provided on one side by injection molding.
Make a mm substrate. A CD can be formed by forming a reflection film of aluminum or the like on the audio signal surface by a sputtering method, applying an ultraviolet curing resin on the reflection film, and forming a protective film by irradiating the ultraviolet light.

In the case of an optical disk having a thin substrate, a single plate will hang down by its own weight, so two substrates are bonded together. By bonding the two substrates, not only the mechanical strength is increased, but also the capacity is doubled by using both surfaces.

A conventional manufacturing method for the laminated disk of the thin substrate will be described. A first thin substrate having an information signal provided on one side is manufactured by an injection molding method using a stamper on which an information signal such as video and audio is recorded.

A reflection film of aluminum or the like is formed on the information signal surface by a sputtering method, an ultraviolet curing resin is applied on the reflection film, and ultraviolet rays are irradiated to form a protective film. Further, a second thin substrate is manufactured using a stamper on which another information signal is recorded, and the reflection film and the protective film are formed in the same manner as above.

A hot melt adhesive is applied on the protective film of these two substrates by a roll coater, and the two substrates are bonded and pressed so that the hot melt adhesives are aligned, thereby forming a first A laminated disk having the second substrate integrated is produced. This hot melt laminating method is the same as the laser disk.

The disk thus manufactured has a structure in which the protective films of two substrates are made to face each other, and a layer of hot melt adhesive is formed between the protective films to integrate the two substrates. Have

The structure of this conventional laminated disk is shown in FIG.
Will be explained. A first substrate 101 has an information signal surface 102 provided on one side thereof. The information signal side 1
A reflective film 103 made of a metal such as aluminum as a main component is formed on 02, and a protective film 104 is formed thereon. The second substrate 105 has an information signal surface 106 provided on one surface thereof. A reflective film 107 and a protective film 108 are similarly formed on the information signal surface 106. Then, a layer 109 of a hot melt adhesive is provided between the protective film 104 and the protective film 108 facing each other, and the first and second substrates 101 and 105 are integrally bonded.

As another optical information medium, a method of forming a two-layer information surface for recording or reproducing information by squeezing a laser from the same direction and irradiating it has been proposed (JP-A-3-209642). , USP 5,134,60
4). By reducing the reflectance of the information surface near the laser incident side, the laser can reach the information surface far from the laser incident side sufficiently so that the information surface of each layer can be read independently, and light of the same size can be read. Even in the information medium, the area of the recording area can be doubled and the recording capacity can be dramatically improved.

With respect to such a conventional example, the principle in the case where the two layers of information surfaces are read-only will be described. FIG. 9 shows a case where the laser is focused on the information surface farther from the laser incident side of the two layers. 151 is a transparent substrate made of glass or resin, and an information surface 152 is formed on one surface thereof. A semitransparent thin film 153 is formed on the information surface 152 so that only a part of the incident laser is reflected. An information surface 180 is further formed of a transparent material 154 on the semi-transparent thin film 153. The reflective film 181 on the information surface 180 is preferably formed of a metal such as aluminum because it should reflect most of the laser. Further, a protective film 182 is formed on the reflective film 181 with an ultraviolet curable resin or the like. 171 is an information surface 180
It is a laser that is focused and incident on.

When the laser is focused on the information surface 180, the information signal on the information surface 180 can be reproduced, but a part of the laser is also reflected on the information surface 152 on the way. 17
Reference numeral 2 is a part of the reflected light. In this case, the transparent substance 15
If the thickness of 4 is sufficient, the diameter of the laser beam on the information surface 152 is sufficiently large, the signal on the information surface 152 cannot be reproduced, and the reproduced signal on the information surface 180 is not adversely affected. If the semitransparent thin film 153 on the information surface 152 is formed to have a uniform thickness, the incident laser does not undergo a local phase change, so that a diffraction phenomenon unsuitable for signal reproduction can be almost ignored. Information surface 1 near the laser incident side of the two layers
Even when the laser is focused on 52, the semi-transparent thin film 15
Although the laser passes through 3, the laser beam diameter on the information surface 180 is sufficiently large, the signal on the information surface 180 cannot be reproduced, and the reproduced signal on the information surface 152 is not adversely affected.

FIG. 10 shows a method of manufacturing this two-layer optical information medium. Reference numeral 151 denotes a transparent substrate having the information surface 152 formed on one side thereof, which is manufactured by the injection method or the like similarly to the CD substrate. The information surface 152
A semitransparent thin film 153 is formed on the upper surface of the substrate by a sputtering method or a vacuum evaporation method using a target 161 as shown in FIG. The target 161 is a substance that forms the semitransparent thin film 153, and is a metal such as gold or aluminum, or Zn.
It is a dielectric such as S. Next, as shown in FIG.
Stamper 162 and information surface 15 for making information surface 180
Transparent material 1 between the semi-transparent thin film 153 formed on
An ultraviolet curable resin 154 to be 54 is inserted and pressed to have a predetermined thickness, so that the transparent substance 151 and the semitransparent thin film 1 are
Ultraviolet rays 164 are emitted via 53.

Next, as shown in FIG. 10C, the stamper 1
Target 1 on the information surface 180 formed by peeling 62
The reflective film 181 is formed by using a sputtering method or a vacuum evaporation method. For the target 165, a metal such as aluminum is used for reproduction only, and a phase change material or a magneto-optical material is used for recording / reproduction. On this manufacturing method,
It is necessary that the transparent substrate 151 and the semitransparent thin film 153 transmit ultraviolet rays. Finally, a protective film 182 is formed on the reflective film 181 with an ultraviolet curable resin.

[0018]

Since the conventional laminating disk uses the hot-melt method, new equipment such as a hot-melt adhesive roll coater and a pressure machine is required in addition to the CD manufacturing method. And the cost will be significantly higher. In addition, future disks will need to be considered for in-vehicle use, so they must withstand a temperature of 80 ° C and 85% for a long time. However, the hot melt adhesive softens at high temperature and high humidity, and the disk deforms more than the allowable disk tilt. According to the conventional method for manufacturing a two-layer optical information medium, an ultraviolet curable resin is provided between a stamper on which information is formed and a semitransparent thin film on the information surface near the laser incident side when forming an information surface far from the laser incident side. Since the ultraviolet rays are radiated through the information surface close to the laser incident side while inserting and pressing, a step of curing the resin with the ultraviolet rays and a step of peeling the resin from the stamper are required for each disk. Further, it takes a certain amount of time to separate the cured resin from the stamper, and dust easily adheres, resulting in poor productivity, high cost of the optical information medium, and many defects. .

The present invention has been made to solve the above problems, and an object of the present invention is to provide an optical information medium having high productivity, low cost and few defects, and a manufacturing method and manufacturing apparatus thereof. To do.

[0020]

The optical information medium of the present invention comprises:
A first substrate having a first information signal surface, a first reflective film formed on the first information signal surface of the first substrate,
A second substrate having a second information signal surface, and a second reflective film formed on the second information signal surface of the second substrate,
The above-described object is achieved by including a photocurable resin layer provided between the first reflective film and the second reflective film and connecting the first and second substrates.

The first and second reflective films are preferably formed of a metal containing aluminum as a main component.

At least one of the first and second reflective films preferably has a thickness of 0.1 μm or less.

The first and second substrates may have substantially equal thicknesses.

[0024] In one embodiment, the first and second substrates have a thickness of 0.57 mm or more and 0.63 mm or less.

Pit art may be formed on at least one of the first signal information surface and the second signal information surface.

A recording material film may be provided on at least one of the first substrate and the first reflective film and the second substrate and the second reflective film. .

The method of manufacturing an optical information medium of the present invention comprises a step of forming a first substrate having a first information signal surface on one side, and a step of forming a first substrate on the first information signal surface of the first substrate. A step of forming a first reflective film, a step of forming a second substrate having a second information signal surface on one surface, and a second reflective film on the second information signal surface of the second substrate. And a step of superimposing the first substrate and the second substrate such that the first reflective film and the second reflective film face each other with a photo-curing resin interposed therebetween. , At least said second substrate and second
By irradiating the photocurable resin with light through the reflective film, the part of the light is multiply reflected between the first reflective film and the second reflective film, and the photocurable resin is Cure it first
And the step of bonding the second substrate to the second substrate, whereby the above object is achieved.

In one embodiment, the step of superimposing the first substrate and the second substrate includes the step of applying the photocurable resin in a donut shape while rotating the first substrate, and the step of applying the photocurable resin. The first reflective film and the second reflective film through a cured resin.
Overlapping the second substrate on the first substrate so that the reflection films of the first substrate and the second substrate face each other, and integrally rotating the first substrate and the second substrate.

In one embodiment, the second substrate is superposed on the first substrate, the first substrate and the second substrate are integrally rotated, and then the second substrate is placed on the second substrate. The method further includes the step of disposing a transparent plate on the substrate and pressing the second substrate by the transparent plate.

The first reflective film and the second reflective film are
It is preferably formed of a metal containing aluminum as a main component.

An apparatus for manufacturing an optical information medium according to the present invention comprises a first substrate having a first reflective film formed on a first information signal surface and a second reflective film on a second information signal surface. A device for manufacturing an optical information medium by combining with a second substrate having a film formed thereon, wherein the first substrate is rotated at a low speed to apply a photocurable resin onto the first reflective film. Device, a device for stacking the second substrate on the photocurable resin so that the first reflective film and the second reflective film face each other, the first substrate and the second substrate. It is provided with a device for integrally rotating the substrate and the substrate at a high speed, and a device for irradiating light, thereby achieving the above object.

An apparatus for manufacturing an optical information medium of the present invention comprises a first substrate having a first reflective film formed on a first information signal surface and a second reflective film on a second information signal surface. A device for manufacturing an optical information medium by combining with a second substrate having a film formed thereon, wherein the first substrate is rotated at a low speed to apply a photocurable resin onto the first reflective film. Device, a device for stacking the second substrate on the photocurable resin so that the first reflective film and the second reflective film face each other, the first substrate and the second substrate. And a device for integrally rotating the substrate of
The device is provided with a device for pressing the substrate with a transparent plate, and a device for irradiating light, thereby achieving the above object.

An apparatus for producing an optical information medium of the present invention comprises a first molding machine for producing a first substrate having a first information signal surface, and the first information signal surface of the first substrate. A first manufacturing block including a first sputtering device for forming a first reflective film thereon; a second molding machine for manufacturing a second substrate having a second information signal surface; and a second molding machine for manufacturing the second substrate. Second manufacturing block including a second sputtering device for forming a second reflective film on the second information signal surface of the first substrate, and the second substrate of the first substrate through a photo-curable resin layer. No. 1 reflection film and the second substrate of the second substrate
Of the second substrate and the second substrate.
From the third manufacturing block that irradiates the photocurable resin with light through the reflective film, and the first manufacturing block and the second manufacturing block, respectively, to form the first substrate and the second substrate, respectively. And a transfer device for moving to the third block, whereby the above object is achieved.

The optical information medium of the present invention comprises a first substrate having a first information signal surface, a semitransparent film formed on the first information signal surface of the first substrate, and a second substrate. A second substrate having an information signal surface, a reflective film formed on the second information signal surface of the second substrate, and provided between the semitransparent film and the reflective film. And a photocurable resin layer for bonding the first and second substrates, whereby the above object is achieved.

The reflective film may include a recording material film.

The thickness of the first substrate is preferably 0.55 mm or more and 0.61 mm or less.

The photocurable resin layer has a thickness of 30 μm or more and 60
It preferably has a thickness of not more than μm.

Pit art may be formed on at least one of the first signal information surface and the second signal information surface.

The method of manufacturing an optical information medium of the present invention comprises a step of forming a first substrate having a first information signal surface on one side, and a step of forming a half on the first information signal surface of the first substrate. A step of forming a transparent film, and a second step having a second information signal surface on one side
The step of forming the substrate, the step of forming the reflective film on the second information signal surface of the second substrate, and the semitransparent film and the reflective film facing each other through the photocurable resin. As described above, the step of superimposing the first substrate and the second substrate, and irradiating the photocurable resin with light through the first substrate and the semitransparent film, thereby forming the reflective film Multiple reflection of a part of the light between the reflective film and the reflective film, thereby curing the photocurable resin to bond the first substrate and the second substrate, By doing so, the above object is achieved.

The optical information medium manufacturing apparatus of the present invention comprises a first molding machine for manufacturing a first substrate having a first information signal surface, and a first information signal surface of the first substrate. A first manufacturing block including a first sputtering device for forming a semi-transparent film on the substrate, a second molding machine for manufacturing a second substrate having a second information signal surface, and a second molding machine for the second substrate. A second sputtering device for forming a reflection film on the second information signal surface,
After the production block and the semitransparent film of the first substrate and the reflective film of the second substrate are opposed to each other via the photocurable resin layer, the first substrate and the semitransparent film are interposed. From the third manufacturing block that irradiates the photocurable resin with light, and the first manufacturing block and the second manufacturing block, respectively, and the first substrate and the second substrate are respectively connected to the third block. And a transfer device for moving the same to the above-mentioned object.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to examples.

(Embodiment 1) An embodiment of an optical information medium according to the present invention will be described with reference to FIGS. 1, 2 and 3A to 3D.

First, referring to FIG. The optical information medium of the present embodiment includes a first substrate (thickness: about 0.6 mm) 1 having a first information signal surface 2 and a first reflection formed on the first information signal surface 2. A film 3, a second substrate (thickness: about 0.6 mm) 5 having a second information signal surface 6, and a second reflective film 7 formed on the second information signal surface 6. And
The first substrate 1 and the second substrate 5 are formed by the ultraviolet curable resin layer 10 provided between the first reflective film and the second reflective film.
And are combined.

On the information signal surfaces 2 and 6 of this embodiment, a plurality of pits having a size corresponding to the wavelengths of the signal reproducing lights 21 and 23 are formed. When the substrates 1 and 5 are disc-shaped, the pits are arranged concentrically or spirally. On the information signal surfaces 2 and 6, apart from the pits,
A guide groove may be provided for tracking. However, in the present invention, the specific form of the information signal surfaces 2 and 6 is not limited to a specific one. For example, a macroscopically formed image using pits or grooves (referred to as "pit art") may be formed on all or part of the information signal surfaces 2 and 6.

The information recorded on the first information signal surface 2 is reproduced by the signal reproducing light 21 incident through the substrate 1. The light 21 that has entered through the substrate 1 is reflected by the reflective film 3 and becomes reflected light 22. The recorded information is reproduced by detecting the intensity change of the reflected light 22. On the other hand, the information recorded on the second information signal surface 6 is reproduced by the light 23 incident through the substrate 5. The light 23 that has entered through the substrate 5 is reflected by the reflective film 7 and becomes reflected light 24. The formation of the lights 21, 23 and the detection of the lights 22, 24 are performed by known techniques. When the light 21 and 23 are formed and the light 22 and 24 are detected by one optical head, in order to continuously reproduce information from different information signal surfaces, it is necessary to turn over the optical information medium halfway. There is. The first reflective film 3 and the second reflective film 7 are preferably formed of a metal containing aluminum as a main component, and have a thickness of 0.05 μm in this embodiment.
At least one of the first and second reflective films 3 and 7 preferably has a thickness of 0.1 μm or less for reasons of a manufacturing method described later. However, depending on the material of the reflective film, it may be possible to exceed 0.1 μm.

According to this embodiment, since the UV curable resin is used instead of the hot melt adhesive, the temperature is 80 ° C. and the temperature is 8 ° C.
It can withstand an environment of about 5% for a long time, and the disc will not be deformed beyond the allowable disc tilt. Therefore, an optical information medium suitable for vehicle use and excellent in environmental resistance is provided. In this specification, an optical information medium as shown in FIG. 1 is referred to as a “thin substrate bonded disc”.
Called. Such a disc usually has a disc shape, but may have a card shape.

Next, a method of manufacturing the above optical information medium will be described with reference to FIGS. 1 and 3A to 3D.

First, the substrate 1 shown in FIG. 1 is manufactured by an injection molding (injection) method or the like. In the case of the injection molding method, it is preferable to use a transparent resin such as polycarbonate as the material of the substrate 1. In this example, a disk-shaped substrate 1 having a thickness of 0.6 ± 0.03 mm, an outer diameter of 120 mm and an inner diameter of 15 mm was produced. According to the injection molding method or the like, substrates having various shapes and sizes can be easily formed. In the case of the injection molding method, the first information signal surface 2
The irregularities are formed during injection molding. Therefore, the content of that information is defined by the mold for molding. However,
The substrate 1 may be manufactured by other methods. Next, substrate 1
The reflective film 3 is formed on the first information signal surface 2 by sputtering or vacuum evaporation.

Separately from this, the second information signal surface 6 is provided on one side.
The disk-shaped substrate 5 provided with is made by an injection molding method,
The reflective film 7 is formed thereon by a sputtering method or a vacuum evaporation method. The second substrate 5 is manufactured by the same method as the method of manufacturing the first substrate 1. The shape and size of the second substrate 5 are the same as those of the first substrate 1. However, depending on the application, the first substrate 1 and the second substrate 5 may have different shapes and sizes. In the present embodiment, by setting the thicknesses of the substrates 1 and 5 to be 0.57 mm or more and 0.63 mm or less, respectively, an allowable tilt of about 0 even when using an objective lens having NA of 0.6 or more is set to about 0. It can be expanded to 0.75 degrees. In the present invention, since two substrates are bonded together to manufacture one optical information medium, there is little problem even if the strength of each substrate further decreases. Therefore, make the thickness of each substrate even thinner than about 0.6 mm,
It may also allow the use of objectives with higher NA. However, when the substrate of the present invention is manufactured from the material used for the current CD substrate, the thickness of each substrate is preferably 0.3 mm or more from the viewpoint of strength.

The injection molding process and the sputtering process for producing each substrate having the information signal surface on one side are also used in the CD manufacturing process. The cycle time required for each of these steps is only a few seconds, which is a highly productive step.

Next, as shown in FIG. 3A, the substrate 1 on which the reflective film is formed is moved at a low speed (for example, 10 to 50 rpm).
While rotating with, the ultraviolet curable resin 10 is applied in a donut shape on the reflective film. The amount of the ultraviolet curable resin 10 applied at this time is about 1 to 5 grams. As the UV curable resin 10, for example, SD1 manufactured by Dainippon Ink and Chemicals, Inc.
Use 700. Besides this, SD101 and SD301
Etc. may be used. Further, instead of the resin curable by ultraviolet rays, a resin curable by light in another wavelength band may be used, and the type of the photocurable resin is not particularly limited. However, at this point in time, UV curable resins are the most practical. A mixture of a plurality of types of resins may be used, or the resins may have a multi-layer structure.

Next, as shown in FIG. 3B, the second substrate 5 is arranged so that the second reflective film faces the ultraviolet curable resin 10, and is superposed on the first substrate 1. Instead of doing this, place the first substrate 1 on the second substrate 5,
You may superimpose them. After the ultraviolet curable resin 10 diffuses between the first and second reflective films to near the inner diameters of the substrates 1 and 5, as shown in FIG. 3C, the first substrate 1 and the second substrate 5 together with high speed (eg 1
000-5000 rpm) so that the UV curable resin has a substantially uniform thickness between the first and second reflective films. At the end of rotation, the thickness of UV curable resin is 1
It becomes about 0 to 60 μm. This thickness is optimized depending on the viscosity of the ultraviolet curable resin, the initial film pressure, the rotation speed, the rotation time, and the like.

Next, as shown in FIG. 3D, the first substrate 1 is irradiated with ultraviolet rays (wavelength: 300 to 400 nm, for example). As the ultraviolet light source, for example, a halogen lamp or a mercury lamp is used. In the case of this embodiment, 100
Irradiation of ultraviolet rays of about 200 mW / cm ² for about 10 to 40 seconds. By this ultraviolet irradiation, the ultraviolet curable resin 10 is cured and the two substrates 1 and 5 are integrally bonded to each other.
The bonding of (5) and (5) is completed.

The ultraviolet irradiation will be described in detail with reference to FIG. Ultraviolet rays (not shown in FIG. 1) applied to the second substrate 5 of FIG.
After passing through, the reflective film 7 formed on the second information signal surface 6 is irradiated. As the second substrate 5, a material that transmits the light 23 for signal reproduction with high transmittance (for example, 90% or more) is used. Such materials usually also transmit UV light with high transmittance. Most of the ultraviolet rays that have passed through the second substrate 5 are reflected by the reflective film 7, but the rest are
The light passes through the reflective film 7 and enters the ultraviolet curable resin 10.
The ultraviolet transmittance of the reflective film 7 containing aluminum as a main component is about 0.1 to 1% when the thickness of the reflective film 7 is 0.05 to 0.1 μm or less. It has been confirmed by the present inventor that even with such a relatively low transmittance, the ultraviolet curable resin 10 cures at a rate significantly higher than the expected rate.

More specifically, when the transmittance of the reflective film 7 is 1%, the amount of ultraviolet rays reaching the ultraviolet curable resin 10 is reduced to about 1/80 or less as compared with the case where the reflective film is not provided. . Normally, if a simple calculation is performed based on the data when the protective film for the CD is formed from the ultraviolet curable resin, the time required for the complete curing of the ultraviolet curable resin 10 is increased by 80 times or more,
Typically, it will be 160 seconds or more. Those skilled in the art will judge that such long-time UV irradiation makes practical optical information medium manufacturing impossible. However, according to the experiment by the present inventor, contrary to the prediction, it is 5 to 20 times (1
It was found that the ultraviolet curable resin 10 was sufficiently cured with an irradiation time of about 0 to 40 seconds). Such a result is due to the effect caused by the fact that the ultraviolet curable resin 10 is sandwiched between the two reflective films. It is considered that a slight amount of ultraviolet rays transmitted through the reflective film multiple-reflects between the two reflective films 3 and 7 and plays an important role in achieving the effect of the resin in a short time. Further, since the ultraviolet curable resin 10 is irradiated with ultraviolet light in a state where it does not come into contact with air, the adverse effect of oxygen in the air on curing is eliminated, which should greatly contribute to shortening the irradiation time. .

As the reflection film, a thin film containing aluminum as a main component is most suitable, but the reflection film is not limited thereto.
As the reflective film, another metal film may be used, or
You may use a multilayer film (for example, a dielectric multilayer film).

Instead of the above manufacturing method, a protective film is previously formed on the first reflective film 3 or the second reflective film 7, and then the UV curable resin 10 for bonding is applied and bonded. Alternatively, ultraviolet irradiation may be performed. By doing this,
It is possible to prevent deterioration of the signal information surface due to dust or the like before laminating. The protective film is preferably formed using an ultraviolet curable resin. In this case, each of the substrates 1 and 5 is manufactured by the process of molding, reflection film sputtering, and protective film formation, like the conventional CD. Alternatively, the protective film made of the ultraviolet curable resin may be cured simultaneously with the curing of the bonding ultraviolet curable resin 10.

When the ultraviolet curable resin 10 is cured by irradiation with ultraviolet rays, heat is generally generated, and the heat may cause the substrate 1 or 5 to be slightly deflected. Therefore, as shown in FIG.
At least during the irradiation of ultraviolet rays, the second substrate 5 is pressed from above by a transparent plate (for example, a glass plate) 11 so that the ultraviolet rays are exposed to the transparent plate 11, the second substrate 5, and the second reflective film (see FIG. 2).
The resin 10 may be cured by transmitting (not shown) in FIG. By doing so, it is possible to manufacture a bonded disk in which the tilt of the disk can be almost ignored without warping the substrates 1 and 5.

Next, with reference to FIG. 4, an example of an apparatus for manufacturing the above-mentioned laminated disc will be described. The first block 31 includes a first molding machine 32, a first take-out robot 33, a first sputtering apparatus 34, and a transfer machine 35 that connects them.

The substrate 1 provided with the first information signal surface 2 is manufactured by the molding machine 32 by the injection molding method, and is transferred to the point A of the transfer machine 35 by the take-out robot 33. After the transfer device 35 moves to the point B and the sputtering device 34 sputters the reflective film 3 on the information signal surface 2, the transfer device 35 moves it to the point C again.

On the other hand, the second block 36 comprises a second molding machine 37, a second take-out robot 38, a second sputtering apparatus 39 and a transfer machine 40 connecting them. The substrate 5 provided with the second information signal surface 6 is manufactured by the molding machine 37 by the injection molding method, and is transferred to the point D of the transfer machine 40 by the take-out robot 38. After moving to point E by the transfer device 40 and sputtering the reflective film 7 on the information signal surface 6 by the sputtering device 40,
The transfer machine 40 is again moved to point F.

First block 31 and second block 36
Are installed adjacent to each other, and the first block is the mobile robot 4
At 1, the second block 36 is connected to the third block 43 by the mobile robot 42. The third block 43 includes mobile robots 41 and 42, an ultraviolet irradiation device 44, a transfer machine 45 and a stocker 46 that connect them. The transfer machine 45 is also provided with an ultraviolet-curable resin application means and a disk rotation means, and executes the laminating method described with reference to FIGS. 3 (a) to 3 (c). The third block 43 is a laminating device.

The substrate 1 is moved from the first block to the point G of the transfer machine 45 by the mobile robot 41, and at that point the first substrate is rotated at a low speed to apply the ultraviolet curable resin in a donut shape. The mobile robot 42 moves the second substrate from the second block 36 to the point H of the transfer machine 45, and the transfer machine 45 moves it to the point G, so that the substrate 1 receives the first reflection film and the second reflection film. Laminate the membranes so that they face each other. Therefore, the first and second
The substrate is rotated at a high speed to integrally diffuse the ultraviolet curable resin between the first and second reflective films almost uniformly.

After that, it is moved to the point I by the transfer machine 45, guided to the ultraviolet irradiation device 44, and irradiated with ultraviolet rays from the side of the substrate 5 to be solidified. The medium thus produced is stored in the stocker 46.
Stack on.

The above is an example of the case where the ultraviolet ray is guided from point I to the ultraviolet ray irradiator and the ultraviolet ray is irradiated, but the ultraviolet ray irradiator may be moved to point I to irradiate the ultraviolet ray. When the transparent plate is pressed so that the disc does not warp when it is irradiated with ultraviolet rays, it is easier to configure the laminating device.

Although the optical disk has been described in the above embodiment, the same applies to other optical information media such as an optical card.

In the above embodiment, the present invention has been described by taking the read-only optical information medium as an example. However, if a known recording material film is provided between the substrate and the reflection film, recording / reproducing with a laser can be performed. Users will be able to freely record their own information.

(Embodiment 2) Another embodiment of the optical information medium according to the present invention will be described below with reference to FIGS. 5 and 6 (a) to (c). This embodiment relates to a "two-layer optical information medium" which enables reproduction of information from two information signal surfaces by making light incident from one direction.

First, refer to FIG. The optical information medium of the present embodiment includes a first substrate (thickness: about 0.6 mm) 51 having a first information signal surface 52, and a semitransparent film 53 formed on the first information signal surface 52. And a second substrate (thickness: about 0.6 mm) 55 having a second information signal surface 56, and a reflective film 57 formed on the second information signal surface 56, and is semitransparent. The ultraviolet curing resin layer 60 provided between the film 53 and the reflective film 57 connects the first substrate 51 and the second substrate 55.

Also in this embodiment, the information signal surfaces 52 and 56 are provided.
A plurality of pits having a size corresponding to the wavelength of the signal reproduction light are formed in the. When the substrates 51 and 55 are disc-shaped, the pits are arranged concentrically or spirally. The information signal surfaces 52 and 56 may be provided with guide grooves for tracking separately from the pits. The form of such an information signal surface is not limited to a particular one.

The semitransparent film 53 is formed of, for example, a metal such as gold or aluminum, or a dielectric such as ZnS,
When gold is used, it has a thickness of about 10 nm.

The reflection film 57 is formed of a metal whose main component is aluminum, and has a thickness of 0.05 μm in this embodiment.

The information recorded on the first information signal surface 52 is reproduced by the signal reproducing light 71 incident through the substrate 51. The light 71 incident through the substrate 51 is
The light is reflected by the semitransparent film 53 and becomes reflected light 72. The recorded information is reproduced by detecting the intensity change of the reflected light 72. On the other hand, the information recorded on the second information signal surface 56 is reproduced by the light 71 incident through the first substrate 51, the semitransparent film 53 and the ultraviolet curable resin 60. The light 71 is reflected by the reflective film 57 and becomes reflected light 72. According to this embodiment, the information recorded on the two information signal surfaces 52 and 56 can be selectively and continuously reproduced by the light 71 incident through the substrate 51. It is not necessary to inject light through the second substrate 55 in order to reproduce the information on the second information signal surface 56. Therefore, the second substrate 55 does not need to be transparent and the substrate 55
There is a great deal of freedom in the selection of materials.

Further, if, for example, one of the information surfaces of a plurality of layers can be recorded / reproduced by a laser and the other layers are exclusively used for reproduction, not only the density can be increased, but also the user can freely set his / her own information. Will also be able to record. In this case, the information surface farther from the laser incident side can be recorded and reproduced. Reduce the reflectance of the laser on the information surface near the laser incident side,
Recording and reproduction can be performed by making the laser reach the information surface far from the laser incident side. To do so, it is necessary to provide a recording material film on the second substrate. The recording material film is provided directly on the reflective film 57 or via another dielectric film or the like. Even when information is recorded on the recording material film, the second recording information surface 56 is provided with pits indicating a group for tracking, a track number, etc., and unevenness is formed. However, image data, music data, data to be processed by the information processing device, etc. are recorded on the recording material film, not on the second recorded information surface 56 itself. As the recording material film, a known recording material film such as a phase change material film, a magneto-optical material film, or an organic dye material film can be used.

Next, a method of manufacturing the optical information medium of FIG. 5 will be described with reference to FIGS.

First, as shown in FIG. 6A, a transparent substrate 51 having a first information signal surface 52 is manufactured by an injection molding method or the like. This first information signal surface 52 becomes an information surface close to the laser incident side. In the case of the injection molding method, it is preferable to use a transparent resin such as polycarbonate as the material of the substrate 51. In this embodiment, the thickness is 0.58.
A disk-shaped substrate 51 having a diameter of ± 0.03 mm, an outer diameter of 120 mm, and an inner diameter of 15 mm was manufactured. Next, the semitransparent film 53 is formed on the first information signal surface 52 of the substrate 51 by a sputtering method or a vacuum evaporation method. Sputtering target 6
As 1, a material formed of the material forming the semitransparent film is used.

Apart from this, as shown in FIG.
A disk-shaped substrate 55 having a second information signal surface 56 on one surface
Is formed by an injection molding method or the like, and the reflection film 57 is formed thereon by a sputtering method or a vacuum evaporation method. As the target 65, a metal such as aluminum is used when the optical information medium is for reproduction only, and a target made of a phase change material or a magneto-optical material is additionally used for recording and reproduction. Also in this example,
The shape and size of the second substrate 55 are the same as those of the first substrate 51. The reflection film 57 is formed from the viewpoint of reflectance and the like.
It is preferably formed from a metal containing aluminum as a main component.

Each substrate 51, 5 having an information signal surface on one side
The injection molding step and the sputtering step itself for producing No. 5 are known steps also used in the CD manufacturing process. The cycle time required for each of these steps is only a few seconds, which is a highly productive step.

Next, while rotating the transparent substrate 51, the ultraviolet curable resin 60 having a refractive index close to that of the substrate 51 is applied onto the semitransparent film 53. The refractive index of the ultraviolet curable resin 60 of this embodiment is about 1.48 to 1.55,
The refractive index of the substrate 51 is about 1.5 to 1.6.

Next, as shown in FIG. 6C, the reflection film 5
The first substrate 5 so that 7 faces the UV curable resin 60.
1 is placed and stacked on the second substrate 55. Then, the ultraviolet curable resin is irradiated with the ultraviolet rays 64 through the transparent substrate 51 and the semitransparent film 53. These resin curing steps are described in Example 1.
Although it can be performed in substantially the same steps as the steps described in, the steps of the present embodiment are different from the manufacturing method of the first embodiment in that ultraviolet rays are applied to the ultraviolet curable resin 60 through the semitransparent film 53. different. However, even in this case, the light transmitted through the semi-transparent film 53 undergoes multiple reflection between the semi-transparent film 53 and the reflective film 57 and accelerates the ultraviolet curing. The ultraviolet transmittance of the semitransparent film 53 is about 20% to 70%. Therefore, the semi-transparent film 53 functions as a kind of reflective film, and the curing mechanism similar to that described in the first embodiment completes the curing of the resin in a shorter time than expected.

For the reasons described above, it is preferable to pressurize the transparent substrate 51 with a transparent plate or the like (not shown) when irradiating with ultraviolet rays. Thus, the two information signal planes 5
The first substrate 51 and the second substrate 55 can be bonded to each other with the two and 56 facing each other with a substantially constant distance. In this example, the thickness of the ultraviolet curable resin layer was set to 30 μm or more and 60 μm or less. With this setting, the two signal information planes can be reproduced sufficiently separated. This thickness is 60
If it is thicker than μm, aberration may occur in the laser diaphragm, which is not preferable.

Also in the CD protective film forming process, the steps of coating the ultraviolet curable resin and irradiating the ultraviolet ray are used, and the productivity thereof is high. Therefore, the process of FIG.
Productivity can be high enough. Further, unlike the conventional method of forming the information signal surface with the ultraviolet curable resin, since the information signal surface 56 is formed by the injection molding method, a large dust does not adhere to the surface of the information signal surface 56 and defects are generated. Can be reduced.

FIG. 7 shows an apparatus for manufacturing a two-layer optical information medium. In FIG. 7, the first block 81 includes a first molding machine 82, a first take-out robot 83, a first sputtering apparatus 84, and a transfer machine 85 connecting them. The transparent substrate 51 on which the first information surface 52 is formed is manufactured by the molding machine 82 by the injection method, and is transferred to the point A of the transfer machine 85 by the take-out robot 83. After the transfer device 85 moves to point B and the sputtering device 84 sputters the semitransparent thin film 53 on the information surface 52, the transfer device 85 moves it to point C again.

On the other hand, the second block 86 comprises a second molding machine 87, a second take-out robot 88, a second sputtering apparatus 89 and a transfer machine 90 connecting them. The substrate 55 on which the second information surface 56 is formed is manufactured by the molding machine 87 by the injection method, and the transfer robot 9 is transferred by the take-out robot 88.
Move to point 0 of 0. The transfer device 90 moves to point E, the sputtering device 89 sputters the reflective film 57 on the information surface 56, and then the transfer device 90 moves it to point F again.

The first block 81 and the second block 86 are installed adjacent to each other, and the first block 81 is the mobile robot 91.
The second block 86 is connected to the third block 93 by the mobile robot 92. The third block 93 is
It comprises mobile robots 91 and 92, an ultraviolet irradiation device 94, a transfer machine 95 and a stocker 96 that connect them.
The transfer machine 95 also has a function of applying an ultraviolet curable resin.

The transparent substrate 51 is moved from the first block 81 to the point G of the transfer machine 95 by the mobile robot 91, the transparent substrate 51 is rotated at that point to apply the ultraviolet curable resin 60, and the transfer machine 95 is used. Move to point H. Second block 86
The substrate 55 is moved by the mobile robot 92 to the point H of the transfer machine 95, and is superposed on the transparent substrate 51. Transfer machine 9 again
At point 5, it is moved to a point I, guided to an ultraviolet irradiation device 94, and irradiated with ultraviolet rays 64 from the transparent substrate 51 side to be hardened. The media thus produced are stacked on the stocker 96.

After that, a label or the like is printed,
A printing device may be directly connected to the ultraviolet irradiation device 94.
In a normal CD, a label is printed on a protective film made of an ultraviolet curable resin, but in the two-layer optical information medium of this embodiment, the label is printed on the plane opposite to the information surface 56 of the substrate 55.

[0088]

According to the present invention, in addition to the CD manufacturing process, no special steps such as a roll coater for hot melt adhesive or a pressure machine are required, so that the laminating disk for a thin substrate does not significantly increase the cost. And its manufacturing method and manufacturing apparatus could be provided. Further, since the ultraviolet curable resin does not soften under high temperature and high humidity unlike the hot melt adhesive, it has become possible to provide a high density optical disk that can withstand in-vehicle use and the like.

As described above, according to the present invention, two information planes are produced by the injection process and the sputtering process, respectively, and these information planes are overlapped by the ultraviolet curing resin applying / curing process. It can be manufactured by applying the highly productive process used for
It is possible to provide a low-cost multilayer optical information medium.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an optical information medium according to the present invention.

FIG. 2 is an explanatory view of an example of an ultraviolet irradiation method in the method for manufacturing an optical information medium according to the present invention

3A to 3D are process diagrams in an embodiment of a method for manufacturing an optical information medium according to the present invention.

FIG. 4 is a block configuration diagram of an embodiment of an optical information medium manufacturing apparatus according to the present invention.

FIG. 5 is a sectional view showing an embodiment of another optical information medium according to the present invention.

6A to 6C are process diagrams in an embodiment of a method for manufacturing an optical information medium according to the present invention.

FIG. 7 is a block configuration diagram of an embodiment of another optical information medium manufacturing apparatus according to the present invention.

FIG. 8 is a sectional view showing a conventional example of an optical information medium.

FIG. 9 is a sectional view showing another conventional example of an optical information medium.

10A to 10C are process sectional views showing a conventional method for manufacturing an optical information medium.

[Explanation of symbols]

 1 Substrate on which the first information signal surface is formed 2, 6 Information signal surface 3, 7 Reflective film 5 Substrate on which the second information signal surface is formed 10 UV curable resin 21, 23 Incident light 22, 24 Reflected light 31 , 36, 43 Manufacturing apparatus block 32, 37 Molding machine 34, 39 Sputtering apparatus 51 Substrate on which the first information signal surface is formed 52, 56 Information signal surface 53 Semitransparent film 57 Reflective film 55 Second information signal surface Formed substrate 60 UV curable resin 61, 65 Target 64 UV ray 81, 86, 93 Manufacturing device block 82, 87 Molding machine 84, 89 Sputtering device 101 Substrate 102, 106 on which the first information signal surface is formed Information signal surface 103, 107 Reflective film 104, 108 Protective film 105 Substrate on which the second information signal surface is formed 109 Hot melt adhesive 151 First information signal Substrates 152, 180 on which signal surfaces are formed 153 Information signal surface 153 Semi-transparent film 154 UV curable resin 181 Reflective film 182 Protective film 171 Incident laser light 172 Reflected laser light

Claims (21)

[Claims] 1. A first substrate having a first information signal surface, and a first substrate formed on the first information signal surface of the first substrate.
Reflective film, a second substrate having a second information signal surface, and a second substrate formed on the second information signal surface of the second substrate.
And an optical information medium provided between the first reflective film and the second reflective film and bonding the first and second substrates. 2. The optical information medium according to claim 1, wherein the first and second reflective films are formed of a metal containing aluminum as a main component. 3. The optical information medium according to claim 1, wherein at least one of the first and second reflective films has a thickness of 0.1 μm or less. 4. The optical information medium according to claim 1, wherein the first and second substrates have substantially equal thicknesses. 5. The first and second substrates are 0.57 m
The thickness of m or more and 0.63 mm or less.
The optical information medium described in. 6. The optical information medium according to claim 1, wherein pit art is formed on at least one of the first signal information surface and the second signal information surface. 7. A recording material film is provided between at least one of the first substrate and the first reflective film and between the second substrate and the second reflective film. Claim 1
The optical information medium described in. 8. A step of forming a first substrate having a first information signal surface on one side, and a step of forming a first reflective film on the first information signal surface of the first substrate. A step of forming a second substrate having a second information signal surface on one side, a step of forming a second reflective film on the second information signal surface of the second substrate, and a photocurable resin Stacking the first substrate and the second substrate so that the first reflective film and the second reflective film face each other with a gap between them, and at least the second substrate and the second substrate. By irradiating the photocurable resin with light through the second reflective film, a part of the light is multiply reflected between the first reflective film and the second reflective film, and the photocurable resin is obtained. And a step of curing the first substrate to bond the first substrate and the second substrate together. 9. The step of superimposing the first substrate and the second substrate includes applying the photocurable resin in a donut shape while rotating the first substrate at a low speed, and the photocurable resin. The second substrate is superposed on the first substrate so that the first reflective film and the second reflective film face each other via the substrate, and the first substrate and the second substrate 9. The method for manufacturing an optical information medium according to claim 8, further comprising the step of integrally rotating and. 10. The second substrate is superposed on the first substrate, and the first substrate and the second substrate are integrally rotated at a high speed, and then transparent on the second substrate. Place the boards,
9. The method for manufacturing an optical information medium according to claim 8, further comprising a step of pressing the second substrate with the transparent plate. 11. The method for manufacturing an optical information medium according to claim 8, wherein the first reflective film and the second reflective film are formed of a metal containing aluminum as a main component. 12. A first substrate having a first reflective film formed on a first information signal surface, and a second substrate having a second reflective film formed on a second information signal surface. An apparatus for manufacturing an optical information medium by combining the above, wherein the first substrate is rotated at a low speed to apply a photo-curing resin onto the first reflective film, and the first reflective film. And a device for stacking the second substrate on the photo-curing resin so that the second reflective film and the second reflective film face each other, and the first substrate and the second substrate are integrally rotated at high speed. A manufacturing apparatus including a device and a device that emits light. 13. A first substrate having a first reflective film formed on a first information signal surface, and a second substrate having a second reflective film formed on a second information signal surface. An apparatus for manufacturing an optical information medium by combining the above, wherein the first substrate is rotated at a low speed to apply a photo-curing resin onto the first reflective film, and the first reflective film. And a device for stacking the second substrate on the photo-curing resin so that the second reflective film and the second reflective film face each other, and the first substrate and the second substrate are integrally rotated at high speed. A manufacturing apparatus comprising: an apparatus, an apparatus for pressing the second substrate with a transparent plate, and an apparatus for irradiating light. 14. A first molding machine for producing a first substrate having a first information signal surface, and forming a first reflective film on the first information signal surface of the first substrate. A first manufacturing block including a first sputtering device; a second molding machine for producing a second substrate having a second information signal surface; and a second information signal surface of the second substrate Second on top
A second sputtering device for forming a reflective film of
After the manufacturing block and the first reflective film of the first substrate and the second reflective film of the second substrate are opposed to each other via a photocurable resin layer, the second substrate and the second substrate From the third manufacturing block that irradiates the photocurable resin with light through the second reflective film, the first manufacturing block and the second manufacturing block, respectively, the first substrate and the second manufacturing block. An optical information medium manufacturing apparatus, comprising: a transfer device that moves a substrate to the third block. 15. A first substrate having a first information signal surface, a semitransparent film formed on the first information signal surface of the first substrate, and a second information signal surface. A second substrate, a reflective film formed on the second information signal surface of the second substrate, and provided between the semitransparent film and the reflective film.
An optical information medium, comprising: 16. The optical information medium according to claim 15, wherein the reflective film includes a recording material film. 17. The thickness of the first substrate is 0.55 m.
The optical information medium according to claim 15, which has a length of m or more and 0.61 mm or less. 18. The optical information medium according to claim 15, wherein the photocurable resin layer has a thickness of 30 μm or more and 60 μm or less. 19. The optical information medium according to claim 15, wherein pit art is formed on at least one of the first signal information surface and the second signal information surface. 20. A first device having a first information signal surface on one surface thereof
A step of forming a substrate, a step of forming a semitransparent film on the first information signal surface of the first substrate, and a step of forming a second substrate having a second information signal surface on one surface. And a step of forming a reflective film on the second information signal surface of the second substrate, and the first transparent film and the reflective film are opposed to each other via a photo-curing resin. The step of superimposing the substrate and the second substrate, and irradiating the photocurable resin with light through the first substrate and the semitransparent film, thereby forming the semitransparent film and the reflective film. A part of the light is multi-reflected between them, thereby curing the photo-curing resin to bond the first substrate and the second substrate, and a method for manufacturing an optical information medium, comprising: . 21. A first molding machine for producing a first substrate having a first information signal surface, and a first forming a semitransparent film on the first information signal surface of the first substrate. A first manufacturing block including a sputtering device, a second molding machine for manufacturing a second substrate having a second information signal surface, and a second molding machine for manufacturing the second substrate on the second information signal surface of the second substrate. A second manufacturing block including a second sputtering device that forms a reflective film, the semi-transparent film of the first substrate and the reflective film of the second substrate are opposed to each other with a photo-curing resin layer in between. Then, the third manufacturing block for irradiating the photocurable resin with light through the first substrate and the semitransparent film, and the first manufacturing block and the second manufacturing block, respectively, An optical information medium manufacturing apparatus including a transfer device for moving the first substrate and the second substrate to the third block. Place.