JPH05198018A - Production apparatus and production for photosetting substrate - Google Patents

Abstract

PURPOSE:To obtain the high-quality photosetting substrate having excellent transparency. CONSTITUTION:A stamper 7 and a substrate 5 to allow the passage of UV rays are superposed by holding a spacer 6 therebetween and a photosetting resin is previously injected into a space where the thickness is determined by the spacer 6. The above-mentioned substrate 5 is irradiated with UV rays from a light source through a diffusion filter 3, by which the photosetting resin is cured. The diffusion filter 3 which is visible when the distance between an evaluation diagram consisting of lines having prescribed widths and spacings and the diffusion filter is a specified value or below in the case of viewing the evaluation diagram via this diffusion filter 3 is used as the diffusion filter 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photo-curing substrate manufacturing apparatus and manufacturing method for obtaining a suitable photo-curing substrate which is used in producing a lenticular lens, a spherical / aspherical lens, an optical disk, an optical card and the like. It is about.

[0002]

2. Description of the Related Art Molding of a photocurable substrate using a photocurable resin has been widely applied in recent years in the fields of lenticular lenses, spherical / aspherical lenses, optical disks, optical cards and the like. The advantage of using a photo-curable resin is that it can easily transfer complicated shapes that are difficult to process and shapes in the sub-micron order such as information bits, can be cured in a short time, has a wide variety of materials, and has various physical characteristics. There is the point that you can freely choose one.

An apparatus for molding such a photo-curable resin (hereinafter, also simply referred to as a resin) may have a mold for injecting the resin and a light source for curing the resin. It is a very compact device even if it has an opening / closing mechanism and a resin injection mechanism, and it is attracting attention from the viewpoint of space saving and energy saving. Generally, an optical disk molding apparatus is disclosed, for example, in Japanese Patent Laid-Open Nos. 55-160338 and 57-15235.

A feature of the conventional molding apparatus of this type is that at least one surface of the mold is made of a light-transmissive material (for example, glass), and light from the light source is directly incident on the surface. is there. Here, in order to uniformly cure the resin, it is necessary to make the light illuminance uniform in the surface, and the distance between the mold and the light source is set to a position where the distribution is best, or the shape of the lamp that is the light source is the shape of the mold. I was taking countermeasures such as using the one that fits to. Further, there is also one in which a resin is cured only by indirect light by disposing a light shielding member between the light source and the mold so that the mold is not irradiated with the direct light from the light source.

[0005]

When various photo-curing substrates are manufactured by using the above-mentioned conventional molding apparatus, when the photo-curing substrate has a thin wall thickness of about 100 μm or less, the transparency is An excellent uniformly cured substrate can be obtained, but when the wall thickness becomes thicker than approximately 1 mm, streaky patterns occur on the surface of the substrate. This pattern is a shape that directly reflects the shape of the lamp that is the light source, and when a rod-shaped lamp is used, parallel streak patterns occur at positions corresponding to the installation direction of the lamp. And this pattern tends to appear more prominently as the wall thickness increases. The reason is,
This is because the light from the light source is not uniformly diffused, that is, the light cannot be made uniform, so that the resin is not uniformly cured in the substrate, and unevenness of the curing appears. Such a pattern not only impairs the appearance of the photocurable substrate but also deteriorates the optical characteristics, and thus has been a serious problem in molding various lenses and optical discs that are the photocurable substrate.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a mold for injecting a photocurable resin,
Provided is a photocurable substrate manufacturing apparatus comprising a light source for curing the injected resin, wherein the photocurable substrate manufacturing apparatus is characterized in that a diffusion filter is provided between the mold and the light source. It is a thing.

[0007]

In the photo-curing substrate manufacturing apparatus configured as described above, since the light from the light source is applied through the diffusion filter, the directions of the light are randomized and scattered and diffused to make the light uniform and It corresponds to a mold in which a curable resin is injected.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a photocurable substrate manufacturing apparatus according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a photo-curing substrate manufacturing apparatus. In the figure, 1 is a reflecting mirror, a mirror type is a semi-circular aluminum mirror plate, and a dimple type is a mirror type with a large number of 5φ dimples stamped. Is. 2 is an ultraviolet lamp as a light source,
Type A is a rod-shaped UV lamp with a maximum illuminance of 52 m on the mold surface.
W / cm, the illuminance distribution is 85%, and the B type is a spherical ultraviolet lamp with a maximum illuminance of 24 mW / cm on the mold surface and an illuminance distribution of 94%.

Reference numeral 3 is a commercially available diffusion filter, which uses, for example, frosted glass made of soda-lime glass having a thickness of 3.6 mm. In addition, 4 is a housing. In this embodiment, the distance between the ultraviolet lamp 2 and the diffusion filter 3 is set to 500 mm, and the distance between the diffusion filter 3 and the housing 4 is set to 100 mm. Reference numeral 5 is a transparent and optically homogeneous substrate, and glass such as soda glass and quartz glass is used. Reference numeral 6 denotes a spacer made of a metal plate, and in this embodiment, a photo-curing substrate having a thickness of 1.2 mm (hereinafter may be simply referred to as a disk substrate).
The thickness of 1.2 mm is used for the purpose of making. Reference numeral 7 is, for example, a nickel stamper on the surface of which a predetermined signal is formed as an uneven shape. Reference numeral 8 is a reinforcing plate lined with the nickel stamper 7 to reinforce it. Since the present invention is for producing a disk substrate having a diameter of 120 mm, for example, the nickel stamper 7, the spacer 6, and the soda lime glass that will be the substrate 5 that compose the mold have shapes that naturally conform to them. -It is formed to dimensions. Further, 9 is a space portion into which a photo-curable resin described later is injected, and 10 is a center pin.

Next, with reference to FIG. 1, a method for producing a disk substrate will be described in detail. First, the nickel stamper 7 and the substrate 5 that transmits ultraviolet rays are stacked with the spacer 6 in between.
A photo-curable resin (not shown) is injected into a space whose thickness is determined by the spacer 6 (a resin layer is injected into this space to finally form a disk substrate). Then, the center pin 10 is inserted. At this time, the photocurable resin is sufficiently defoamed,
Avoid bubbles during injection. Next, the substrate 5
Ultraviolet rays from the lamp 2 are radiated through the diffusion filter 3 to cure the photocurable resin injected into the space 9 to prepare a disk substrate. Then, the nickel stamper 7 is peeled off from the resin layer (disk substrate) to form a resin layer on the substrate 5, which serves as a photo-curing substrate having an uneven shape on the surface. The photo-curable resin is DPHA (manufactured by Nippon Kayaku Co., Ltd.)
arocur 1173 (Merck Japan Ltd.)
The one to which 3% by weight was added was used.

According to the above apparatus, the ultraviolet light from the ultraviolet lamp 2 which is the light source is reflected by the reflecting mirror 1 and the diffusion filter 3.
Since the light is radiated through, the direction of the light becomes random and the scattering and diffusion effect is further increased, and the light can be made uniform. Therefore, the disc substrate is free from unevenness in strength, has a good appearance, and has no deterioration in optical characteristics. Table 1 shows the results of evaluating the appearance of the disk substrates prepared by various methods.

[0012]

[Table 1]

As shown in Table 1, when the diffusion filter is not used, the appearance hardly changes even if the type of the lamp or the shape of the reflecting mirror is changed, but it is greatly improved by installing the diffusion filter. I understand that it will be done.

Further, the smoothness of the irradiated surface side of the disk substrate was measured by using Taristep (manufactured by Taylor and Bobson Co.), and the average roughness was evaluated. Than before
It was confirmed that the surface roughness was reduced to 1/10. In this example, a molded product having an average roughness of about 500 angstroms or less is regarded as good, and a product having an average roughness of more than about 1000 angstrom is regarded as defective.

Further, the diffusion filter 3 is a transparent substrate having fine irregularities on its surface, a transparent substrate containing fine air bubbles inside, or a transparent substrate containing fine particles having different refractive indexes therein. As long as it scatters and diffuses light. That is, it is sufficient that the surface or the inside thereof is optically non-uniform when viewed microscopically, and the effect of scattering the incident light from the light source is produced and the light is sufficiently diffused. Further, if it is transparent, the light illuminance is slightly reduced by diffusion, but there is no problem in curing the resin.

Specific substrates include glass, ceramics, plastics, etc., but glass that is generally readily available at present may be used. In particular, the transparent glass having irregularities on the surface described in the above examples, so-called frosted glass, is easily available and has a large effect. As described above, the diffusion filter 3 may be any one as long as it scatters and diffuses light.
Certain performance is required depending on the light source and photocurable resin. Therefore, the performance evaluation of the diffusion filter 3 will be described.

As shown in FIG. 2A, two black lines B having a thickness of 1 cm are drawn on the white plate W at intervals of 5 cm, and this is designated as an evaluation diagram M. The diffusion filter 3 is placed on the evaluation diagram M, and the diffusion filter is gradually separated from the evaluation diagram as shown in FIG. 2B, and the distinction between the two black lines (that is, the interval between the lines) becomes unclear. Then, the distance (distance) d between the diffusion filter and the evaluation chart is measured. The distance when the black line disappears is a predetermined value (actually, the mold used,
The above-mentioned effect can be obtained by using a diffusion filter whose value is less than or equal to the value determined by the light source and the photocurable resin.

In the apparatus of the above-mentioned embodiment, the diffusion filter 3 is made of, for example, soda-lime glass frosted glass. Table 2 shows the relationship between the number of used soda-lime glass frosted glasses having a thickness of 1.2 mm and the distance when the black line disappeared, and the molding result at that time.

[0019]

[Table 2]

From these results, it can be said that the effect will appear when one diffusion filter 3 is used in the apparatus of the embodiment, and a reliable effect can be obtained when two or more filters are used. In other words, the effect appears when using the diffusion filter that has the performance that the distance when the black line disappears is less than 10 cm.
It can be said that good results are obtained when the distance is 10 cm or less.

Therefore, consider the case where another substrate is used as the diffusion filter. As the diffusion filter 3, for example, methacrylic resin (PMMA) that does not absorb in the near ultraviolet range is used. Using a sandpaper of No. 400 on a PMMA plate with a thickness of 2 mm, scratches were formed on the surface to form a filter. Since the relationship between the number of sheets used and the distance when the black line is no longer understood is as shown in the left column of Table 3, as the diffusion filter 3 of the apparatus of the embodiment, the effect appears when one sheet is used. It is expected that a sufficient effect will be obtained if two or more sheets are used. Then, actually making a disk substrate,
As a result of measuring the number of filters and the surface roughness of the molded product, the results shown in the right column of Table 3 were obtained.

[0022]

[Table 3]

As is clear from the results shown in Table 3, the performance evaluation of the diffusion filter described above and the surface roughness of the molded product substantially correspond to each other. Therefore, it can be said that the diffusion filter can be easily and surely evaluated based on the distance between the evaluation diagram and the diffusion filter when the diffusion filter is viewed through the diffusion filter, the evaluation diagram including lines having a predetermined width and interval.

If the diffusion filter is composed of one filter, the surface processing becomes complicated and the cost tends to be high. However, as in the present embodiment, by configuring the diffusion filter with a plurality of filters so that a predetermined performance can be obtained, the processing of the filter becomes easy. However, if the number of filters increases, the light transmittance decreases and the amount of light decreases, so increasing the number of filters is not a good idea. Since the light transmittance of glass is about 90%, two or three sheets are suitable when the filter is made of glass.

[0025]

INDUSTRIAL APPLICABILITY The present invention is a photocurable substrate manufacturing apparatus comprising a mold for injecting a photocurable resin and a light source for curing the injected resin, which is diffused in a space between the mold and the light source. By providing a filter, both the direct incident light from the lamp and the reflected light from the reflecting mirror are scattered regardless, so the pattern on the surface of the cured optical substrate is significantly reduced, and a high-quality photocurable substrate with excellent transparency. Can be provided.

Further, according to the present invention, as the diffusion filter, a transparent substrate having fine irregularities on the surface, a transparent substrate containing fine air bubbles inside, and fine particles having different refractive indexes inside are contained. A transparent substrate can be used, and further, when an evaluation diagram consisting of a line having a predetermined width and spacing is viewed through the diffusion filter, the distance between the evaluation diagram and the diffusion filter is a certain value or less. At some point I tried to evaluate it by being visible, so
It is also easy to select a diffusion filter that produces an effect.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of a photocurable substrate manufacturing apparatus according to the present invention.

FIG. 2 is a diagram illustrating a method of evaluating a diffusion filter used in the photocurable substrate manufacturing apparatus according to the present invention.

[Explanation of symbols]

 2 Light source 3 Diffusion filter 5 Substrate 6 Spacer 7 Nickel stamper M Evaluation chart d Distance between evaluation chart and diffusion filter

Claims (4)

[Claims] 1. A manufacturing apparatus of a photo-curing substrate comprising a mold for injecting a photo-curable resin and a light source for curing the injected resin, wherein a diffusion filter is provided between the mold and the light source. An apparatus for manufacturing a photocurable substrate, which is provided. 2. The diffusion filter is a transparent substrate having fine irregularities on the surface, a transparent substrate containing fine bubbles inside, or a transparent substrate containing fine particles having different refractive indexes inside. The photocurable substrate manufacturing apparatus according to claim 1, wherein: 3. The diffusion filter is visible when an evaluation diagram made up of lines having a predetermined width and interval is visually observed through the diffusion filter, when the distance between the evaluation diagram and the diffusion filter is a certain value or less. It is a thing, It is characterized by the above-mentioned.
The manufacturing apparatus of the photocurable substrate described. 4. A method of manufacturing a photocurable substrate, comprising a mold for injecting a photocurable resin and a light source for curing the injected resin, wherein the photocurable resin is irradiated with scattered and diffused light. A method for producing a photo-curable substrate, characterized in that a surface-curing surface of the photo-curable substrate is reduced by curing a photosensitive resin.