JP2001067739A - Ultraviolet filter device and production and production apparatus of two layer type optical disk using this ultraviolet filter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To bond a pair of optical disks to each other with high accuracy by controlling UV rays made incident by simple constitution. SOLUTION: This device has a UV filter 22 which is arranged on the optical path of exit light which is emitted from a UV emission light source 24 and is cast to a UV curing type adhesive 4 through the optical disks 2 and 3 and is formed of the same material as the material of disk substrates constituting the optical disks 2 and 3. The UV filter 22 absorbs and cuts the components of the exit light absorbed in the optical disks 2 and 3, allows the transmission of the other components and irradiates the optical disks 2 and 3 with this light, by which a pair of the optical disks 2 and 3 are bonded while the heat generation thereof is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet filter device suitable for use in an optical disk laminating step of a two-layer optical disk in which a pair of optical disks are bonded, and a highly accurate two-layer optical disk using this ultraviolet filter device. The present invention relates to a method and an apparatus for manufacturing a two-layer optical disk for manufacturing an optical disk.

[0002]

2. Description of the Related Art Disc-shaped optical recording media such as optical discs and magneto-optical discs (collectively referred to as optical discs in this specification) are designed to have a large storage capacity, and are capable of recording information signals at a high density. Along with the development of technologies such as compression recording, a two-layer type optical disk such as a digital video disk (DVD) formed by bonding a pair of disk substrates on which a recording section for information signals or the like is formed has also been developed. DVD has a storage capacity of about 6.4 times, from 740 Mbytes to 4.7 Gbytes, which is about 6.4 times that of a conventional 12 cm diameter music optical disc (compact disc: CD). Recording. DVDs include not only read-only DVDs but also rewritable DVDs such as information signals.
One-time rewritable DVD such as RAM and information signal
R is also provided.

For example, a single-sided reproduction type two-layer optical disk 1
As shown in FIG. 3, the first optical disk 2 on the reflection side and the second optical disk 3 on the reproduction side are bonded together with an adhesive 4. The first optical disk 2 is formed by transferring and forming pits and grooves on one main surface of a disk substrate 5 formed of a transparent synthetic resin such as a polycarbonate resin (PC) or a polymethyl methacrylate resin (PMMA). A recording layer 6 for recording signals and the like is formed. The first optical disc 2 has a reflective layer 7 formed by coating the recording layer 6 with, for example, aluminum.

The second optical disk 3 also has pits and grooves formed by transfer on one main surface of a disk substrate 8 formed of a transparent synthetic resin such as polycarbonate resin (PC) or polymethyl methacrylate resin (PMMA). Thus, a recording layer 9 for recording information signals and the like is formed.
The second optical disc 3 has a recording layer 9 covered with a translucent layer 10 made of various metals and dielectric materials. In the double-sided optical disk of the double-sided reproduction type, the first optical disk and the second optical disk have a symmetric structure.

[0005] In the two-layer type optical disk 1, for example, in a state where the first optical disk 2 is positioned and fixed on a rotary table with the reflective layer 7 side facing upward, the adhesive 4 is dropped on the surface of the reflective layer 7 and translucent. The second optical disc 3 is positioned and combined with the layer 10 as the bonding side. As the adhesive 4, for example, an epoxy-based resin adhesive, a urethane-based resin adhesive, a hot-melt-type adhesive, an ultraviolet-curable resin-based adhesive, or the like is used. In the two-layer type optical disc 1, the adhesive 4 is uniformly spread by rotating the rotary table at a high speed. The curing of the adhesive 4 causes the gap between the first optical disc 2 and the second optical disc 3 to be increased. The first optical disc 2 and the second
And the optical disk 3 are bonded together.

[0006]

However, epoxy resin adhesives and urethane resin adhesives have a problem that productivity is poor due to low curing speed. In addition, the hot-melt adhesive has a problem that its heat resistance is low and its use conditions are limited. Therefore, the dual-layer optical disc 1
In general, a UV curable resin adhesive made of a radical polymerizable acrylic UV curable resin or a cationic polymerizable epoxy UV curable resin is used as the adhesive 4.

In the two-layer type optical disk 1, for example, ultraviolet rays emitted from an ultraviolet light source such as a high-pressure mercury lamp are transmitted through the second optical disk 3 and irradiated on the ultraviolet-curable resin adhesive 4, so that the ultraviolet-curable resin adhesive 4 is cured. The first optical disk 2 and the second optical disk 3 are firmly fixed by curing the resin adhesive 4. For example, a disk substrate formed of a polycarbonate resin has light absorption characteristics as shown in FIG. 4 for incident light having a specific wavelength.

FIG. 1A is a view showing the results of actual measurement of the light absorption of a disk substrate formed of a transparent polycarbonate resin. The transparent disk substrate has a wavelength of 4
With respect to incident light in the ultraviolet region from nm to 400 nm, it has a light absorption characteristic in which the light absorption rate sharply increases with respect to incident ultraviolet light having a wavelength of about 230 nm or more. FIG. 2B is a view showing the results of actual measurement of the light absorption of a disk substrate formed of a polycarbonate resin colored with a certain kind of dye. The colored disk substrate has a wavelength of 4
For incident light in the ultraviolet region from nm to 400 nm, the wavelength controlled by the dye is from 300 nm to 400 nm.
Has a large light absorption characteristic with respect to incident ultraviolet rays.

On the other hand, as shown in FIG. 5, depending on the type of the mercury lamp, the ultraviolet light source emits ultraviolet light of many wavelengths in a short wavelength to a long wavelength region at the same time. The ultraviolet emission light source shown in FIG. 1A partially outputs a large power at a specific wavelength, but has a characteristic of outputting ultraviolet light in a short wavelength region as a whole. In the ultraviolet light source shown in FIG.
It has the property of outputting high power ultraviolet light in the range of 50 nm to 400 nm. Further, in the ultraviolet light source shown in FIG.
It has the property of outputting high power ultraviolet light in the nm range.

In the manufacturing process of the two-layer type optical disc 1, for example, when an ultraviolet light source having the characteristics shown in FIG. 5A is used, an ultraviolet curable resin adhesive having a wavelength region of 220 nm to 320 nm and high absorption sensitivity is used. Agent 4 was used. In the manufacturing process of the two-layer type optical disc 1, for example, when the ultraviolet curable resin adhesive 4 having high absorption sensitivity in the wavelength region of 350 nm to 400 nm is used, the above-described ultraviolet ray shown in FIG. An emission light source is selected. Further, in the manufacturing process of the two-layer type optical disc 1, by combining the colored disc substrate whose light absorption characteristics are controlled by the dye shown in FIG. 4B and the ultraviolet emission light source shown in FIG. Ultraviolet rays having a wavelength region of 400 nm to 450 nm are efficiently absorbed.

In the manufacturing process of the two-layer type optical disk 1, the output characteristics of the ultraviolet light source and the curing characteristics of the ultraviolet curable resin adhesive 4 are adjusted based on the material characteristics of the disk substrate as described above. The bonding of the substrates was performed. In other words, in the manufacturing process of the two-layer type optical disc 1, each selection is conventionally performed so that the curing characteristics of the ultraviolet curable resin adhesive 4 and the output characteristics of the ultraviolet light source are optimally matched. However, there is a problem that the selection range is limited.

On the other hand, in the manufacturing process of the two-layer type optical disc 1, the outgoing light emitted from the ultraviolet light source is incident on the second optical disc 3 and the ultraviolet curable resin adhesive 4 is cured. The emitted light includes a wide range of wavelengths from the short wavelength to the long wavelength emitted from the ultraviolet emission light source as described above, and a part of the emitted light is absorbed by the ultraviolet curing resin adhesive 4 to exert its curing action. . Other components of the emitted light are transmitted through the first optical disk 2, but a part of the emitted light is absorbed by the first optical disk 2 and the second optical disk 3 to generate internal heat therein.

For this reason, the two-layer type optical disk 1 may be subjected to thermal deformation such as warpage or undulation after the laminating step. For this reason, the two-layer type optical disc 1 has a problem that the C / N is lowered and the error rate is increased, so that an information signal or the like recorded at high density cannot be reproduced with high accuracy.

Therefore, according to the present invention, the first optical disc and the second
The present invention has been proposed for the purpose of providing an ultraviolet filter device that can be bonded to an optical disc with high precision. Further, the present invention provides a method and a method for manufacturing a two-layer optical disk in which a first optical disk and a second optical disk are bonded with high accuracy by providing an ultraviolet filter device having a simple configuration for controlling incident ultraviolet light. It has been proposed for the purpose of providing a device.

[0015]

According to the present invention, there is provided an ultraviolet filter apparatus comprising: a pair of optical discs bonded to each other with an ultraviolet curing adhesive;
It is used in a laminating process of a layer type optical disc. The ultraviolet filter device is disposed on the optical path of the emitted light emitted from the ultraviolet emission light source, transmitted through the optical disk and irradiated to the ultraviolet curing adhesive, and is formed of the same material as the disk substrate constituting the optical disk. It has a filter plate. In the ultraviolet filter device, a heat radiating means for radiating internal heat generated by an absorption component of the emitted light is provided on a filter plate.

According to the ultraviolet filter device of the present invention configured as described above, the component of the light emitted from the ultraviolet light source and incident on the optical disk to be absorbed by the optical disk is cut by the filter plate. Is done. Therefore, in the ultraviolet filter device, even if the ultraviolet curable resin adhesive and the ultraviolet light emitting light source are relatively freely combined, efficient ultraviolet irradiation can be performed on the ultraviolet curable resin adhesive. Also, in the UV filter device, by cutting off the absorption component from the light emitted from the UV light source, the heat generation of the optical disk is suppressed, and it is possible to manufacture a high-precision two-layer optical disk free from thermal deformation such as warpage or undulation. And Further, in the ultraviolet filter device, the filter plate, which has generated heat due to the absorption component of the emitted light, is radiated by the heat radiating means, thereby enabling continuous production of a two-layer optical disk without requiring a cooling time.

Further, a method of manufacturing a two-layer type optical disk according to the present invention, which achieves the above-mentioned object, provides a method of manufacturing a two-layer type optical disk, comprising the steps of: Then, an ultraviolet filter having a filter plate formed of the same material as the disk substrate forming the optical disk is arranged, and a pair of optical disks are bonded together. In the method of manufacturing a two-layer type optical disk, a heat radiating means is provided on the filter plate.

According to the method for manufacturing a two-layer optical disk according to the present invention described above, the light emitted from the ultraviolet light source and incident on the optical disk is formed by filtering the component to be absorbed by the optical disk with the same material. The optical disk is irradiated with the light after being cut in advance by the plate.
Therefore, according to the method for manufacturing a two-layer type optical disc, even if the ultraviolet curable resin adhesive and the ultraviolet light emitting light source are relatively freely combined, efficient ultraviolet irradiation can be performed on the ultraviolet curable resin adhesive. Become. Further, according to the method for manufacturing a two-layer optical disk, the absorption component is cut from the light emitted from the ultraviolet light source, thereby suppressing the heat generation of the optical disk and eliminating the thermal deformation such as warpage or undulation. Type optical discs are manufactured. Furthermore, according to the method for manufacturing a two-layer optical disk, the filter plate, which has generated heat by absorbing the absorption component from the emitted light, efficiently radiates the internal heat by the heat radiating means. Thus, a high-quality two-layer type optical disc can be continuously manufactured.

Further, the apparatus for manufacturing a two-layer optical disk according to the present invention, which achieves the above-mentioned object, manufactures a two-layer optical disk by bonding a pair of optical disks using an ultraviolet-curable adhesive. The apparatus for manufacturing a two-layer optical disk is arranged on the optical path of the emitted light emitted from the ultraviolet light source, transmitted through the optical disk and irradiated to the ultraviolet-curable adhesive, and has the same material as the disk substrate constituting the optical disk. And an ultraviolet filter having a filter plate formed by the method described above. Further, the apparatus for manufacturing a two-layer type optical disk has a heat radiation means attached to a filter plate of an ultraviolet filter. In the apparatus for manufacturing a two-layer type optical disc, the heat radiating means accommodates a filter plate subjected to a water-resistant treatment in a transparent container to form a cooling flow path around the filter plate, and uses the cooling flow path as a circulation flow path and filters the flow in the middle. A filter is provided.

According to the present invention configured as described above,
According to the apparatus for manufacturing a layered optical disk, the outgoing light emitted from the ultraviolet light source and incident on the optical disk is cut off by a filter plate formed of the same material to be absorbed by the optical disk, and irradiated onto the optical disk. You. Therefore, according to the manufacturing apparatus of the two-layer type optical disc, even if the ultraviolet curable resin adhesive and the ultraviolet light emitting light source are relatively freely combined, efficient ultraviolet irradiation can be performed on the ultraviolet curable resin adhesive. Become. In addition, according to the apparatus for manufacturing a two-layer type optical disk, heat generation of the optical disk itself is suppressed by cutting the absorption component from the light emitted from the ultraviolet light source in advance, and there is no thermal deformation such as warpage or undulation. A high-precision two-layer optical disk is manufactured. Further, according to the apparatus for manufacturing a two-layer type optical disc, the filter plate, which has generated heat by absorbing the absorption component from the emitted light, is efficiently radiated by the heat radiating means. Optical disks can be manufactured continuously.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings. The apparatus for manufacturing a two-layer optical disc 1 shown in FIG. 1 as an embodiment of the present invention is, specifically, a first optical disc 2 mounted on a rotary table and coated with an ultraviolet curing adhesive 4. On the other hand, when the second optical disc 3 is superposed,
Is shown in FIG. The ultraviolet irradiation device 20 irradiates ultraviolet UV from above the second optical disc 3 to cure the ultraviolet-curable adhesive 4 and to cure the first ultraviolet ray.
The optical disc 2 and the second optical disc 3 are firmly fixed to manufacture the two-layer type optical disc 1.

Of course, the present invention is not limited to the above-described apparatus for manufacturing a two-layer optical disk 1, but is also applicable to, for example, an apparatus for manufacturing a double-layer optical disk of a double-sided reproduction type. In this case, since the pair of optical discs to be bonded is symmetrical to each other, it goes without saying that any of the pair of optical discs may be placed on the rotary table.

As a whole, the two-layer type optical disk 1 has a master manufacturing process, a stamper manufacturing process, a disk substrate forming process, and the like.
A pair of optical discs manufactured through the reflective layer forming process,
It is manufactured through an optical disk laminating step including an ultraviolet irradiation step. As described above, the optical disc laminating step includes an adhesive applying step of applying an adhesive to one optical disc with a precise thickness, and an optical disc superimposing step of precisely positioning the other optical disc on the optical disc and superimposing the other optical disc. And individual steps such as an adhesive curing step of curing the adhesive. In the optical disk laminating step, a pair of optical disks is laminated in a state where the entire thickness is uniform and there is no warp or the like.

The ultraviolet irradiation device 20 includes a light source 21, an ultraviolet filter 22, and a cooling unit 23.
The ultraviolet irradiation device 20 irradiates the ultraviolet ray UV emitted from the light source unit 21 to the two-layer type optical disc 1 via the ultraviolet filter unit 22. The ultraviolet irradiation device 20 appropriately radiates the internal heat generated by absorbing a part of the ultraviolet light in the ultraviolet filter unit 22 in response to the incidence of the ultraviolet light UV by the cooling unit 23. It is possible to manufacture the layered optical disc 1 continuously.

The light source 21 includes a high-pressure mercury lamp (ultraviolet lamp) 24, a lamp housing 25, and a reflector 2.
6 and the like. As is well known, the high-pressure mercury lamp 24 has a bulb filled with mercury vapor, and emits outgoing light L containing strong ultraviolet rays UV by electric discharge in the mercury vapor ionized by application of a high voltage. As described above, the high-pressure mercury lamp 24 has an emission light L having various emission spectra as described above. However, it is necessary to select a high-pressure mercury lamp having a specification compatible with the light absorption characteristics of the ultraviolet curable adhesive 4 as in the related art. There is no. For this purpose, it is possible to select a light source unit 21 having a general purpose that emits the emission light L in a relatively wide wavelength range.

The high-pressure mercury lamp 24 is mounted in a lamp housing 25 having a predetermined side surface opened to form an emission part 25a. The lamp housing 25 is provided with, for example, a funnel-shaped reflector 26 inside the lamp housing 25 in order to efficiently emit the emitted light L emitted from the high-pressure mercury lamp 24 from the emission portion 25a.

The light source section 21 is combined with an ultraviolet filter section 22 so as to face the emission section 25a of the lamp housing 25. The ultraviolet filter unit 22 includes a filter container 27 and a filter plate 28.
The filter container 27 is made of, for example, a transparent quartz material having good light transmittance and is formed in a flat box shape sufficient to close the emission portion 25a of the lamp housing 25. The filter container 27 has a filter plate 28 to be described later sealed therein, and a cooling channel 29
Is constituted. The filter container 27 includes a pair of valves 3
Both ends of the cooling channel 29 are communicated with the cooling unit 23 via 0 and 30.

The filter plate 28 is made of the same synthetic resin material as the transparent or colored synthetic resin material for molding the disk substrate 5 of the first optical disk 2 and the disk substrate 8 of the second optical disk 3, for example, a transparent polycarbonate resin. Formed by The filter plate 28 has an outer shape enough to close the emission part 25a of the lamp housing 25 and is slightly thinner than the internal space of the filter container 27. As described above, the cooling passage 29 is formed inside the filter container 27. It is configured over the entire area on the front and back.

Since the filter plate 28 is disposed on the front surface of the light emitting portion 25a of the light source 21 as described above, the light L emitted from the light emitting portion 25a enters. The filter plate 28 has good light transmittance, but absorbs a part of the emitted light L in a wide wavelength range. In the filter plate 28, the absorption component is thermally converted inside to generate internal heat, and the temperature rises. The filter plate 28 is cooled by this internal heat being radiated by the cooling water flowing through the cooling channel 29.

Further, the filter plate 28 has a certain degree of hygroscopicity depending on the material characteristics thereof, and the characteristics may change due to water absorption when the filter plate 28 is installed in the cooling channel 29. Therefore, the filter plate 28
Is sealed in a filter container 27 with its surface subjected to a water-resistant treatment.

The cooling section 23 is connected to a cooling channel 29 of the filter container 27 through valves 30 and 30 to form a circulation channel, and a heat exchanger disposed along the channel 31. 32, a pump 33, a filtration filter 34 and the like. Cooling water flows through the inside of the conduit 31 in the cooling unit 23, and is circulated through a cooling channel 29, a heat exchanger 32, a pump 33, a filtration filter 34, and a cooling channel 29.

The heat exchanger 32 cools the heated cooling water by absorbing the internal heat of the filter plate 28 in the cooling channel 29. The pump 33 circulates the cooling water in the circulation channel. The filtration filter 34 maintains the quality of the cooling water in the circulation channel, and supplies cleaner cooling water to the filter plate 28 by being disposed immediately before the cooling channel 29.

The ultraviolet irradiation apparatus 2 configured as described above
Reference numeral 0 denotes the second optical disc in a state where the first optical disc 2 and the second optical disc 3 are superposed with the ultraviolet curable adhesive 4 applied to their opposing surfaces and positioned and placed on a rotary table (not shown). UV curable adhesive 4 from 3 side
Is irradiated with ultraviolet rays. The ultraviolet irradiation device 20 emits outgoing light L in a relatively wide wavelength range from the high-pressure mercury lamp 24 as shown in FIG. In other words, the outgoing light L depends on the curing component UV in the wavelength region for curing the ultraviolet curing adhesive 4 and the material characteristics of the disk substrate 5 of the first optical disk 2 and the disk substrate 8 of the second optical disk 3. The absorption component L1 in the wavelength region absorbed by the ultraviolet ray and the ultraviolet light curable adhesive 4 without affecting the curing of the disk substrate 5,
8 includes a transmission component L2 in a wavelength range that transmits light 8 and the like.

In the ultraviolet irradiation device 20, the light L emitted from the high-pressure mercury lamp 24 is efficiently guided by the reflector 26 to the light emitting portion 25a.
The light is made to enter the ultraviolet filter unit 22 combined with a. In the ultraviolet irradiation device 20, the disk substrate 5,
UV filter part 22 molded of the same material as 8
Has the same light absorption characteristics as the disk substrates 5 and 8 shown in FIG. Therefore, in the ultraviolet irradiation device 20, the remaining component of the outgoing light L is filtered by the filter plate 28 while the remaining component of the outgoing light L is filtered by the filter plate 28 in the wavelength region shown by hatching in FIG. To the optical disc 3.

The outgoing light L is incident on the ultraviolet filter section 22 as described above, so that only its curing component UV and the transmitting component L2 are transmitted, and is incident on the second optical disk 3. The emitted light L passes through the second optical disk 3 and reaches the ultraviolet-curable adhesive 4, and the curing component UV acts on the ultraviolet-curable adhesive 4 to cure it. The transmitted light L2 of the emitted light L is transmitted through the first optical disk 2 via the second optical disk 3 and the ultraviolet curing adhesive 4 as shown in FIG.

As described above, the ultraviolet irradiation device 20 filters the absorption component L1 of the outgoing light L to be absorbed by the disk substrates 5 and 8 by the filter plate 28 in the ultraviolet filter section 22 in advance, thereby obtaining the absorption component L1. The generation of internal heat in the first optical disk 2 and the second optical disk 3 due to the thermal change of L1 is suppressed. Therefore, the first optical disk 2 and the second optical disk 3 are firmly and precisely bonded by the ultraviolet curing adhesive 4 without causing thermal deformation.

On the other hand, in the ultraviolet irradiation device 20, the filter plate 28 absorbs the absorption component L1 so that
Heat is generated by the heat change. In the ultraviolet irradiation device 20, the cooling is efficiently performed by providing the filter plate 28 in the cooling channel 29 of the cooling unit 23. Therefore, the ultraviolet irradiation device 20 can continuously bond the first optical disk 2 and the second optical disk 3 without requiring time for cooling the filter plate 28.

In the ultraviolet irradiation device 20, the cooling unit 2 for cooling the filter plate 28 as described above is used.
Although 3 is constituted by a so-called water-cooled structure, it is needless to say that the structure is not limited to such a water-cooled structure. The ultraviolet irradiation device 20 has a cooling unit 23 having a so-called air-cooling structure in which, for example, a heat radiation fan is attached to the filter container 27 and air is blown from the heat radiation fan into the cooling channel 29 to radiate heat inside the filter plate 28. You may.
In this case, the UV irradiation device 20
It is not necessary to apply a water-resistant treatment to the filter 8, and it is preferable to provide an air filter in front of the radiating fan in order to supply clean air to the filter plate 28.

[0039]

As described above in detail, according to the ultraviolet filter device according to the present invention, on the optical path of the emitted light emitted from the ultraviolet emission light source, transmitted through the optical disk and irradiated to the ultraviolet curing adhesive. And a filter plate formed of the same material as the disk substrate that constitutes the optical disk, so that the component of the emitted light emitted from the ultraviolet emission light source and incident on the optical disk to be absorbed by the optical disk is determined in advance. The light is cut after absorption. Therefore, according to the ultraviolet filter device, even when the ultraviolet curing resin adhesive and the ultraviolet light emitting light source are relatively freely combined, efficient ultraviolet irradiation can be performed on the ultraviolet curing resin adhesive, and the High precision 2 that suppresses heat generation and eliminates thermal deformation such as warpage and swell
It is possible to manufacture a layer type optical disc.

Further, according to the method and apparatus for manufacturing a two-layer optical disk according to the present invention, the emitted light emitted from the ultraviolet light source and hardening the ultraviolet curing adhesive is the same as the disk substrate constituting the optical disk. Since the light is made incident on the optical disk via an ultraviolet filter having a filter plate formed of a material, the component of the emitted light to be absorbed by the optical disk is cut off in advance.
Therefore, according to the method and the apparatus for manufacturing a two-layer optical disk, even if the ultraviolet curable resin adhesive and the ultraviolet light source are relatively freely combined, efficient ultraviolet irradiation can be performed on the ultraviolet curable resin adhesive. Thus, a high-precision two-layer type optical disk is manufactured which suppresses heat generation of the optical disk and has no thermal deformation such as warpage or undulation.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of an ultraviolet irradiation device shown as an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an ultraviolet absorption characteristic in the ultraviolet irradiation device.

FIG. 3 is a longitudinal sectional view of an essential part for explaining a configuration of a two-layer type optical disc.

FIG. 4 is a light absorption characteristic diagram of a disk substrate molded with a polycarbonate resin, and FIG. 4A is a light absorption characteristic diagram of a disk substrate molded with a transparent polycarbonate resin; FIG. 4 is a light absorption characteristic diagram of a disk substrate formed of a colored polycarbonate resin.

FIG. 5 is a wavelength characteristic diagram of the ultraviolet light emitting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Two-layer optical disk, 2 First optical disk, 3 Second optical disk, 4 UV curable adhesive, 20 UV irradiation device, 21 Light source unit, 22 UV filter unit, 2
3 cooling unit, 24 high-pressure mercury lamp, 25 lamp housing, 26 reflector, 27 filter container, 28
Filter plate, 29 cooling channel, 30 valve, 3
1 conduit, 32 heat exchanger, 33 pump, 34 filtration filter

Claims (10)

[Claims] 1. A two-layer type optical disk bonding step in which a pair of optical disks are bonded together with an ultraviolet-curable adhesive, wherein the ultraviolet-ray bonding light is emitted from an ultraviolet light source and transmitted through the optical disk. A filter plate disposed on an optical path of emitted light irradiated to the optical disk, wherein the filter plate is formed of the same material as a disk substrate constituting the optical disk, and absorbs a component of the emitted light absorbed by the optical disk. An ultraviolet filter device which cuts and irradiates the optical disk with other components transmitted therethrough. 2. The ultraviolet filter device according to claim 1, wherein said filter plate is provided with a heat radiating means for radiating internal heat generated by an absorption component of the emitted outgoing light. 3. The filter plate is sealed in a transparent container which is subjected to a water-resistant treatment and forms a cooling channel around the filter plate. The ultraviolet filter device according to claim 1, wherein heat is radiated through a cooling medium flowing in the flow path. 4. The cooling flow path is configured such that both ends drawn out of the transparent container are connected to a circulation flow path, and cooling water is circulated therein as the cooling medium. The ultraviolet filter device according to claim 3, wherein the filter plate is cooled by being filtered and circulated by a filtration filter provided in the middle of the path. 5. A method for manufacturing a two-layer optical disk, comprising bonding a pair of optical disks using an ultraviolet-curable adhesive, wherein in the bonding step of the optical disks, the optical disk is emitted from an ultraviolet light source and transmitted through the optical disk. An ultraviolet filter having a filter plate formed of the same material as a disk substrate constituting the optical disk is disposed on an optical path of emitted light irradiated on the ultraviolet-curable adhesive; A component that absorbs components absorbed by the optical disc and transmits the other components to irradiate the optical disc, thereby suppressing heat generation of the pair of optical discs and performing bonding. Method of manufacturing optical disk. 6. The two-layer type optical disc according to claim 5, wherein in the ultraviolet filter, the filter plate radiates internal heat generated by an absorption component of the emitted light by a heat radiating means. Method. 7. A two-layer optical disk manufacturing apparatus comprising a pair of optical disks bonded together using an ultraviolet-curable adhesive, wherein the optical disk is emitted from an ultraviolet-emitting light source, passes through the optical disk, and forms the ultraviolet-curable adhesive. An ultraviolet filter having a filter plate formed of the same material as a disk substrate constituting the optical disk, the ultraviolet filter being disposed on an optical path of emitted light to be irradiated, the ultraviolet filter absorbing the emitted light to the optical disk; A two-layer type optical disc manufacturing apparatus, wherein the pair of optical discs is bonded while suppressing heat generation by irradiating the optical disc with the other components being transmitted while the other components are absorbed and cut off. . 8. The two-layer type optical disk according to claim 7, wherein said ultraviolet filter is provided with a heat radiating means for radiating internal heat generated in said filter plate by an absorption component of said emitted light. Manufacturing equipment. 9. The ultraviolet filter includes the filter plate subjected to a water-resistant treatment, and a transparent container that seals the filter plate and forms a cooling channel around the filter plate. The internal heat generated in the filter plate by the absorption component, the filter plate is cooled by radiating heat through a cooling medium flowing in the cooling flow path,
8. The apparatus for manufacturing a two-layer optical disk according to claim 7, wherein the pair of optical disks is continuously bonded. 10. The cooling flow path is configured such that both ends drawn out of the transparent container are connected to a circulation flow path, and cooling water is circulated therein as the cooling medium. 10. The two-layer type optical disc manufacturing apparatus according to claim 9, wherein the filter plate is cooled by being circulated after being filtered by a filtration filter provided in the middle of the path.