JP4002354B2 - Information recording disk and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information recording disk such as a CD or two disk substrates bonded to the front and back, and a method for manufacturing the information recording disk, and a manufacturing method thereof. It has a flat shape with no uneven steps in the range up to the disc clamping area, and a convex step called stack ring is on the disc reading surface side than the disc clamping area The present invention relates to an information recording disk having a shape installed on the side and a manufacturing method thereof.
[0002]
[Prior art]
Conventionally, in such an information recording disk, generally, first, a transparent disk substrate made of polycarbonate or the like on which information pits are formed is manufactured by injection molding.
[0003]
For example, in a CD (compact disc), a reflective film such as aluminum is formed on the surface of the pit of the formed disk by a film forming means such as sputtering, and an ultraviolet curable resin is applied for the purpose of protecting the reflective film, A label is printed on this surface to make a product.
[0004]
In general, a molded CD is provided with a ring-shaped protrusion on the surface of the information reading surface so that the information reading surface does not get scratched even if it contacts a flat surface such as a player. The position where this ring-shaped protrusion is provided is approximately 35 mm in diameter, which is outside the player's clamping area and inside the information recording area. Such a ring-shaped protrusion is called a stack ring.
[0005]
[Problems to be solved by the invention]
However, when the portion where the stack ring is provided is viewed from the reflective film side, “sink marks” peculiar to injection molding can be confirmed, and there is a problem that sink marks are conspicuous and the commercial value is lowered. This sinking is caused by the shrinkage that occurs when the substrate molded at high temperature is cooled. Since the stack ring part is thick against the uniform thickness (plate thickness) of the substrate, the shrinkage amount is only in this part. It becomes larger, and only this part is conspicuously confirmed on the appearance as “sink”.
[0006]
FIG. 4 is a cross-sectional view of a main part of a conventional compact disk.
That is, as shown in FIG. 4, the information pit 11a does not exist on the opposite side surface of the disk substrate 11 corresponding to the stack ring 11d, and the surface of the stamper is a mirror surface. If the reflective film 12 is formed on the opposite side surface portion of the stack ring 11d as shown in the drawing, the sink marks 11c in this portion become conspicuous. Such an information recording disk greatly impairs the appearance of the product.
[0007]
FIG. 5 is a cross-sectional view of a main part of a conventional “single-sided single layer” type DVD.
Further, as shown in FIG. 5, similarly, in the case of a “single-sided single layer” disc of DVD, if the one-side disc substrate 21 on the dummy surface side is a transparent substrate, from the one-side disc substrate 21 side on the bonded dummy surface side, That is, sink marks 22c are observed from the opposite side of the single-sided disk substrate 22 on which the information recording area 22a of the “single-sided single-layer” disk is formed.
[0008]
FIG. 6 is a cross-sectional view of a main part of a conventional “single-sided dual-layer” type DVD.
Further, as shown in FIG. 6, in a “single-sided two-layer” disc of DVD, an ultraviolet curable resin 34 that is an adhesive is irradiated by irradiating ultraviolet rays UV from the surface on the one-side disc substrate 32 side that is a layer 0 (L0) disc. Is cured. For this reason, the stack ring 32d of the one-sided disk substrate 32 and the sink mark 32c due to the stack ring 32d act as a lens at the time of ultraviolet irradiation, resulting in uneven irradiation light quantity. Due to this non-uniformity in the amount of irradiation light, the UV curable adhesive 34 is not cured at a uniform speed, and as a result, the one-side disk that is the back layer 1 (L1) side disk as if the outline of the stack ring 32d is a shadow. There is a problem that the product value is lowered due to the surface of the substrate 31.
[0009]
As described above, the full flat disk has a problem that the appearance is greatly impaired due to the influence of sink marks 11c, 22c, and 32c due to the stack rings 11d, 22d, and 32d.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to provide an information recording disk that can prevent the appearance defect caused by the stack ring and a manufacturing method thereof.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, an information recording disk according to claim 1 is a stack ring in which an information recording area comprising information pits on one side and a ring-shaped protrusion located on the inner side of the information recording area on the other side. Is an information recording disk having a transparent disk substrate formed by injection molding and a reflective film formed on the one surface of the disk substrate, and is positioned on one surface of the disk substrate corresponding to the stack ring. It is characterized in that an irregular reflection area composed of dummy pits is formed .
[0012]
The information recording disk according to claim 2 is formed by injection molding with an information recording area consisting of information pits on one side and a ring ring having ring-shaped protrusions located on the inner side of the information recording area on the other side. A transparent single-sided disk substrate formed with a reflective film formed on the entire surface of the one surface, a reflective film formed on the entire surface of the one-sided disk substrate, and an ultraviolet curable adhesive on the reflective film. An information recording disk having a transparent dummy substrate bonded thereto is characterized in that an irregular reflection region composed of dummy pits located corresponding to the stack ring is formed on one surface of the one-side disk substrate . .
[0013]
Further, in the information recording disk of claim 3, the first information recording area composed of information pits on one surface and the stack ring composed of ring-shaped protrusions located on the inner peripheral side of the information recording area are ejected on the other surface. A transparent first one-sided disk substrate formed by molding and having a translucent reflective film formed on the entire surface, and a second information recording area composed of information pits formed on the one surface. A transparent second single-sided disk substrate having a reflective film formed on the entire surface of the first transparent disk, the first single-sided disk substrate and the second single-sided disk substrate, the semitransparent reflective film and the reflective film being In an information recording disk bonded to each other through an ultraviolet curable adhesive, the stack is bonded to the first one-side disk substrate on one surface of the second one-side disk substrate. It is characterized in that diffused reflection region consisting dummy pit located corresponding to Kling is formed.
[0015]
A method of manufacturing information recording disks according to claim 4 is a method of manufacturing a data recording disc for producing the information recording disc of claim 1, wherein, in the stamper to form the information pits of the information recording area of the disc substrate A dummy pit in the irregular reflection region is provided, and the dummy pit is formed simultaneously with the information pit .
[0016]
According to a fifth aspect of the present invention, there is provided an information recording disk manufacturing method according to the second aspect of the present invention, wherein the information recording disk manufacturing method is an information recording disk manufacturing method according to the second aspect of the invention. A dummy pit in the irregular reflection region is provided, and the dummy pit is formed simultaneously with the information pit .
[0017]
According to a sixth aspect of the present invention, there is provided an information recording disk manufacturing method according to the third aspect, wherein the information pits of the information recording area of the second one-side disk substrate are formed. The stamper is provided with dummy pits in the irregular reflection region, and the dummy pits are formed simultaneously with the information pits .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of an essential part of a compact disc showing an embodiment of the present invention.
As shown in FIG. 1, this compact disc includes a transparent disc substrate 11 having an information recording area 11a on one side and a stack ring 11d on the other side. On the surface of the disk substrate 11 facing the stack ring 11d, dummy pits 11b for irregular reflection are formed. In addition, 11f is a center hole, CA is a clamping area, and L is a laser beam for reading information.
[0020]
The dummy pit 11b which is the irregular reflection region is formed so as to cover the sink 11c generated by the stack ring 11d. That is, the dummy pit 11b is formed to the outside from the end of the slope 11e of the stack ring 11d. A reflective film 12 is formed on the entire surface of the disk substrate 11 on the information recording area 11a side. Accordingly, the information pits and dummy pits 11b of the information recording area 11a are covered with the reflective film 12.
[0021]
The dummy pits 11b can be formed by providing irregularities for forming dummy pits on a stamper (not shown). It should be noted that the information pits in the information recording area 11a and the dummy pits 11b can be formed at the same time by providing irregularities that form the dummy pits 11b in a stamper (not shown) that forms the information recording area 11a.
[0022]
In such a compact disc, the dummy pits 11b, which are irregular reflection regions, are formed in the portion where the sink marks 11c are generated by the stack ring 11d, so that the light reflected from the reflective film 12 is scattered and is formed outside the reflective film 12. It is possible to prevent sink marks and contours from forming during molding.
[0023]
FIG. 2 is a cross-sectional view of the main part of a “single-sided single layer” type DVD showing another embodiment of the present invention.
As shown in FIG. 2, this "single-sided single-layer" type DVD is bonded to a transparent one-sided disk substrate 22 having an information recording area 22a on one side and a stack ring 22d on the other side, and the one-sided disk substrate 22. And a transparent dummy substrate 21. Dummy pits 22b for irregular reflection are formed on the surface of the one-side disk substrate 22 facing the stack ring 22d. 21f is a center hole.
[0024]
The dummy pit 22b which is the irregular reflection region is formed so as to cover the sink 22c generated by the stack ring 22d. That is, the dummy pits 22b are formed from the end of the inclined surface 22e of the stack ring 22d to the outside. A reflective film 23 is formed on the entire surface of the one-side disk substrate 22 on the information recording area 22a side. Therefore, the information pits and dummy pits 22b of the information recording area 22a are covered with the reflective film 23. A transparent dummy substrate 21 is bonded onto the reflective film 23 via, for example, an ultraviolet curable adhesive 24.
[0025]
In such a “single-sided single-layer” type DVD, dummy pits 22b, which are irregular reflection regions, are formed in the portion where sink marks 22c are generated by the stack ring 22d, so that the light reflected from the reflective film 23 is scattered. It is possible to prevent sink marks 22 c and contours from appearing outside the reflective film 23.
[0026]
Instead of the above dummy pits, an array pattern that is an uneven step having an optical lens effect (hologram) that cancels against sink marks may be provided in advance. The hologram can also be used as a display area such as a watermark.
[0027]
FIG. 3 is a cross-sectional view of the main part of a “single-sided, double-layered” type DVD showing another embodiment of the present invention.
As shown in FIG. 3, this "single-sided dual-layer" type DVD has an information recording area 32a covered with a translucent reflective film 33 formed on one side and a stack ring 32d for stacking disks on the other side. The layer 1 (L1) side transparent disk substrate 32 and the information recording area 31a covered with the reflective film 35 are formed on one side and the flat surface is formed on the other side. A single-sided disk substrate 31. In addition, 31f is a center hole.
[0028]
A first dummy pit 31b for irregular reflection is formed at a position corresponding to the stack ring 32d of the one-side disk substrate 31 on the L1 side. Also, a second dummy pit 32b for diffusing the curing ultraviolet ray UV is formed in a portion corresponding to the stack ring 32d on the surface opposite to the surface on which the stack ring 32d of the L0 side disk substrate 32 is formed. ing. Although the second dummy pit 32b is provided in this embodiment, the second dummy pit 32b may be omitted.
[0029]
The first dummy pit 31b and the second dummy pit 32b for irregular reflection, which are the irregular reflection region, are formed so as to cover a range corresponding to the stack ring 32d. That is, the first dummy pit 31b and the second dummy pit 32b are formed from the end of the inclined surface 32e of the stack ring 31d to the outside.
[0030]
Since the translucent reflective film 33 is formed on the entire surface on the information recording area 32a side of the one-side disk substrate 32 on the L0 side, the information pits and second dummy pits in the information recording area 32a are formed by the translucent reflective film 33. 32b is covered.
[0031]
In addition, since the reflective film 35 is formed on the entire surface on the information recording area 31a side of the one-side disk substrate 31 on the L1 side, the information pits and the first dummy pits 31b in the information recording area 31a are covered with the reflective film 35. ing.
[0032]
The reflective film 35 side of the L1 side disk substrate 31 is bonded to the L0 side disk substrate 32 via an ultraviolet curable adhesive 34 having a predetermined thickness, for example.
[0033]
In such a “single-sided dual-layer” type DVD, the first dummy pits 31 b that are irregular reflection regions are formed in the portion where the “outline of the contour” is generated by the stack ring 32 d, so that it is reflected from the reflective film 35. It is possible to prevent light from being scattered and the contour from being raised due to uneven curing shrinkage of the ultraviolet curable adhesive 34 from being raised to the outside of the reflective film 35.
[0034]
In addition, since the second dummy pit 32b for irregular reflection is provided, when the curing ultraviolet ray is irradiated from the stack ring 32d side, after being diffused by the second dummy pit 32b, the ultraviolet curable adhesive 34 is applied. Incident light, and uneven incidence of ultraviolet rays by the stack ring 32d and sink marks 32c can be greatly reduced. Therefore, it is possible to reduce the cause of the “outline of the contour”.
[0035]
By combining the lengths of the dummy pits 11b and 22b or the first dummy pit 31b, pictures and characters can be displayed so as to be visible.
[0036]
The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the scope of the present invention.
[0037]
【The invention's effect】
As described above, according to the present invention, there is an effect that it is possible to provide an information recording disk capable of preventing appearance defects caused by stacking and a method for manufacturing the same.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a cross section of a main part of a compact disc showing an embodiment of the present invention.
FIG. 2 is a schematic view showing a cross section of the main part of a “single-sided single layer” type DVD showing another embodiment of the present invention.
FIG. 3 is a schematic view showing a cross section of a main part of a “single-sided, double-layer” type DVD showing another embodiment of the present invention.
FIG. 4 is a schematic view showing a cross section of a main part of a conventional compact disc.
FIG. 5 is a schematic view showing a cross section of a main part of a conventional “single-sided single layer” type DVD.
FIG. 6 is a schematic view showing a cross section of a main part of a conventional “single-sided, dual-layer” type DVD.
[Explanation of symbols]
11 Disc substrate 21, 22, 31, 32 One side disc substrate 11a, 22a, 31a, 32a Information recording area 11b, 22b Dummy pit (diffuse reflection area)
31b 1st dummy pit 32b 2nd dummy pit 11d, 22d, 32d Stack ring (convex part)
12, 23, 35 Reflective film 24, 34 UV curable adhesive 33 Translucent reflective film

Claims (6)

A transparent disk substrate in which an information recording area comprising information pits on one side and a stack ring comprising ring-shaped protrusions located on the inner side of the information recording area on the other side are formed by injection molding, and the disk In an information recording disk having a reflective film formed on the one surface of the substrate,
1. An information recording disk according to claim 1, wherein an irregular reflection area comprising dummy pits corresponding to the stack ring is formed on one surface of the disk substrate . An information recording area consisting of information pits on one side and a stack ring consisting of ring-shaped protrusions located on the inner side of the information recording area on the other side are formed by injection molding, respectively, and a reflective film is formed on the entire surface of the one side. A transparent single-sided disk substrate formed, a reflective film formed on the entire surface of the one-sided disk substrate, and a transparent dummy substrate bonded to the reflective film via an ultraviolet curable adhesive In an information recording disc having
2. An information recording disk according to claim 1, wherein a diffused reflection area comprising dummy pits corresponding to the stack ring is formed on one surface of the one-side disk substrate . A first information recording area consisting of information pits on one side and a stack ring consisting of ring-shaped protrusions positioned on the inner side of the information recording area on the other side are formed by injection molding, respectively, on the entire surface of the one side A transparent first disk substrate on which an anti-transparent reflective film is formed and a second information recording area consisting of information pits are formed on one surface, and a transparent film on which the reflective film is formed on the entire surface. A second one-sided disk substrate, the first one-sided disk substrate and the second one-sided disk substrate, with the anti-transparent reflective film and the reflective film facing each other, and an ultraviolet curable adhesive. In the information recording disc bonded together,
An irregular reflection area comprising dummy pits positioned corresponding to the stack ring in a state of being bonded to the first one-side disk substrate is formed on one surface of the second one-side disk substrate. Recording disc. In the manufacturing method of the information recording disc which manufactures the information recording disc of Claim 1,
A dummy pit in the irregular reflection area is provided on a stamper that forms an information pit in the information recording area of the disk substrate, and the dummy pit is formed simultaneously with the information pit.
An information recording disk manufacturing method characterized by the above . In the manufacturing method of the information recording disc which manufactures the information recording disc of Claim 2,
A method for manufacturing an information recording disk , comprising: providing a dummy pit in the irregular reflection area on a stamper for forming an information pit in the information recording area of the one-sided disk substrate; and forming the dummy pit simultaneously with the information pit . 4. The information recording disk manufacturing method for manufacturing an information recording disk according to claim 3, wherein a dummy pit of the irregular reflection area is provided in a stamper for forming an information pit of the information recording area of the second one-side disk substrate, and the dummy A method of manufacturing an information recording disk , wherein pits are formed simultaneously with the information pits .

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