JP2004227732A - Optical disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an optical disk from slipping even if a plurality of the optical disks are piled up. <P>SOLUTION: In the optical disk 1 having a recording layer provided on one surface of a disk substrate, a cover layer provided as an upper layer of the recording layer and an image printing layer 5 provided on the other surface of the disk substrate, an annular slip stopping part 6 having a friction coefficient higher than that of the part other than an outer peripheral part of the surface of the image printing layer 5 is provided at the outer peripheral part. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disk for recording / reproducing information such as CD, DVD, Blu-ray and the like.
[0002]
[Prior art]
In recent years, optical discs such as CDs and DVDs have become widespread and are used in various fields such as recording and reproduction of music and video, and data storage of computers. In addition, a standard called Blu-ray has been newly proposed as a standard for an optical disc having a recording capacity exceeding that of a DVD. In the Blu-ray disc, a recording layer is formed on at least one surface of a disc substrate, a cover layer made of a plastic sheet through which laser light is transmitted is provided on the recording layer, and the recording layer is irradiated with laser light through the cover layer. Thus, the signal recorded on the recording layer can be read.
[0003]
In an optical disc such as a CD, DVD, or Blu-ray disc, when a recording layer is provided on only one side, an image printing layer for printing characters, images, labels, etc. is generally provided on the opposite side.
[0004]
Also, in this type of optical disc, a front / back discriminating portion is provided on the outer and inner peripheral edges so that even a visually impaired person can identify the front and back surfaces, and a luminous paint or the like is used on the image print layer. In some cases, a front / back discriminating portion is provided by a discrimination mark or the like (see, for example, Patent Literature 1 and Patent Literature 2).
[0005]
[Patent Document 1]
JP-A-9-259473 [0006]
[Patent Document 2]
Japanese Patent Laid-Open No. 2002-92965 [0007]
[Problems to be solved by the invention]
By the way, when handling such an optical disk, it can be said that it is optimal to store the optical disk in a case or a bag each time. However, it is sometimes troublesome to place the optical disk in a case or a bag. It is often seen to be stacked on a desk or the like in the bare state taken out of the. Such a scene is particularly common when handling a large amount of optical disks.
[0008]
However, when the optical discs are stacked, the contact surfaces of the overlapping discs are slippery, so even if the discs are damaged due to falling or not falling down, the dust intervening between the overlapping surfaces There was a risk of scratching the surface when the disks slipped. In particular, in the case of a Blu-ray disc, when the cover layer and the image print layer are formed of a plastic sheet having the same physical characteristics, it is particularly easy to slip, so such a possibility is high. In the case of a Blu-ray disc, since the cover layer is particularly thin, about 0.1 mm, the surface scratches affect the convergence of the recording / reproducing light and deteriorate the recording / reproducing characteristics. Scratches can reach up to.
[0009]
In view of the above circumstances, an object of the present invention is to provide an optical disc that does not slide even when a plurality of sheets are stacked.
[0010]
[Means for Solving the Problems]
The optical disk of the invention of claim 1 is characterized in that a non-slip part having a higher coefficient of friction than the other surface part is provided on the outer peripheral part of at least one of the surfaces of one disk surface or the other disk surface. To do. In this case, for example, the anti-slip part is a sheet of high-friction material such as urethane rubber, or the high-friction material is printed into a thick and rough film (matte treatment), or a seal with a slit is provided. It can be configured by pasting.
[0011]
When the anti-slip portion having a higher friction coefficient is provided on the disk surface in this way, even when the disks are stacked, the contact friction resistance with the mating disk surface becomes large, so that it becomes difficult to slide on each other. Therefore, it is possible to prevent a drop due to an erroneous operation, and it is possible to prevent the occurrence of scratches due to slipping.
[0012]
Further, since the anti-slip portion has a different friction coefficient from other surface portions, for example, the presence or absence of the anti-slip portion can be confirmed simply by touching with a finger. Here, when holding the disc by hand, it is often the case that you hold your finger against the center hole of the disc and the outer periphery of the disc, so you can easily check the anti-slip part on the outer periphery of the disc surface with your finger Can do.
Therefore, when the anti-slip portion is provided only on one side, the front and back of the disc can be identified by the feel of the anti-slip portion. Further, even when anti-slip portions are provided on both the front and back surfaces, the front and back surfaces of the disk can be identified by making the anti-slip portions on the front and back surfaces distinguishable from each other. For this reason, even in a dark place (for example, in a car at night), it is possible to discriminate between the front and back surfaces of the disk simply by touching the disk surface, and the drive is not loaded in the wrong direction. The same identification is possible for visually impaired persons.
[0013]
An optical disk according to a second aspect of the present invention is the optical disk according to the first aspect, wherein a recording layer and an upper cover layer are provided on one surface side of the disk substrate, and an image printing layer is provided on the other surface side of the disk substrate. The anti-slip portion is annularly provided on the outer peripheral portion of the surface of the image printing layer.
[0014]
In the case of this optical disc, since the anti-slip portion is provided on the image printing layer side which is the non-recording surface side, there is no fear of affecting the recording surface side at all. In addition, when discs are placed on top of each other, the recording surface side and the image print layer side are usually overlapped so that they are in contact with each other. Can be raised. Moreover, since the anti-slip | skid part is provided cyclically | annularly in the surface outer peripheral part, it can confirm the presence or absence of a non-slip | skid part, regardless of which direction a finger is applied.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a Blu-ray standard optical disc will be described as an example. FIG. 1 is a perspective view of an optical disc according to the embodiment, and FIG. 2 is an enlarged cross-sectional view of one optical disc. Note that the dimensional ratios in FIG. 2 are exaggerated so that the configuration can be understood.
[0016]
This optical disc 1 has a central hole 1a, and a recording layer 3 is formed on one surface side of a disc substrate 2, and a cover layer 4 made of a transparent plastic sheet through which laser light passes is formed on the recording layer 3. An image printing layer 5 made of a plastic sheet similar to the cover layer 4 is formed on the other surface side of the disk substrate 2, and a non-slip portion 6 is annularly formed on the outer periphery of the surface of the image printing layer 5. Formed. In the Blu-ray disc, the thickness of this cover layer is set to 0.1 mm.
[0017]
The anti-slip portion 6 is a portion for increasing the contact frictional resistance with the mating disk surface when it is overlaid by increasing the friction coefficient more than other surface portions. The anti-slip portion 6 can be formed, for example, by sticking a high friction material such as urethane rubber in a sheet shape. Further, instead of attaching the high friction material, the high friction material can be formed by printing (matting) a thick and rough film. Or it can also form by sticking the seal | sticker with a fine slit.
[0018]
As described above, by providing the anti-slip portion 6 having a higher coefficient of friction than the other surface portions on the surface of the disk 1, even when the optical disk 1 is stacked as shown in FIG. The contact frictional resistance with the surface can be increased. Therefore, it becomes difficult to slide against each other, and it is possible to prevent falling due to an erroneous operation, and it is also possible to prevent the occurrence of scratches due to sliding.
[0019]
Moreover, since the anti-slip | skid part 6 has a different friction coefficient from other surface parts, the presence or absence of the non-slip | skid part 6 can be confirmed only by touching with a finger | toe, for example. Here, when holding the optical disk 1 by hand, since the finger is often held against the center hole 1a of the optical disk 1 and the outer peripheral part of the optical disk 1, the anti-slip part 6 on the outer peripheral part of the disk surface can be easily held with the finger. Can be confirmed. Therefore, when the anti-slip portion 6 is provided only on one side as in this example, the front and back of the optical disc 1 can be identified by the feel of the anti-slip portion 6. Therefore, even when used in a dark place (for example, at night in a car) or when used by a visually impaired person, the front and back surfaces of the disc 1 can be discriminated by simply touching the surface of the optical disc 1. , It will not load the drive in the wrong direction.
[0020]
Further, in the case of this optical disc 1, since the anti-slip portion 6 is provided only on the image printing layer 5 side that is the non-recording surface side, there is no fear of affecting the recording layer 3 side at all. Moreover, since the anti-slip | skid part 6 is provided cyclically | annularly in the outer peripheral part of the surface, the effect that the presence or absence of the non-slip | skid part 6 can be confirmed no matter what direction a finger is applied.
[0021]
Although the anti-slip portion 6 can be provided on the recording surface side, the recording surface side may be affected by the presence of the anti-slip portion 6 so that the recording area becomes narrow. It is desirable to provide the anti-slip portion 6 only in the case. When the discs 1 are stacked, the recording layer 3 side and the image print layer 5 side are usually overlapped so that they are in contact with each other. Therefore, the anti-slip portion 6 is provided only on the image print layer 5 side. If you do, you can achieve satisfactory results.
[0022]
It is also possible to provide the anti-slip portions 6 on both the front and back surfaces. In this case, the front and back surfaces of the disk can be identified by making the anti-slip portions on the front and back surfaces distinguishable from each other.
[0023]
In the above description, the description is based on a Blu-ray disc, but the present invention is not limited to this.
[0024]
FIG. 3 is a diagram illustrating an example in which a CD is provided with a non-slip portion. The CD 10 has a center hole 10a, and a recording layer 12 is formed on the other surface side of the transparent disk substrate 11 on which laser light is incident from one surface, and an image is recorded on the recording layer 12. An image printing layer 13 is formed, and an anti-slip portion 14 is formed annularly on the outer peripheral portion of the surface of the image printing layer 13. In the CD 10, the thickness of the substrate 11 is about 1.2 mm, and the total disc thickness is configured to be 1.2 mm like the Blu-ray disc.
[0025]
FIG. 4 is a diagram showing an example in which a non-slip portion is provided on the DVD. The DVD 20 is a single-sided DVD and has a central hole 20a. A single layer or two recording layers 22 are formed between two substrates 21 and 23, and the substrate 22 is opposite to the recording layer 23. The image forming layer 24 is formed on the surface, and the non-slip portion 25 is formed annularly on the outer peripheral portion of the surface of the image printing layer 24. In the DVD 20, the thicknesses of the substrates 21 and 23 are both about 0.6 mm, and the total disc thickness is 1.2 mm as in the case of the CD and Blu-ray disc.
[0026]
As described above, the same non-slip portion can be applied not only to the Blu-ray disc but also to an optical disc of a standard such as CD or DVD.
[0027]
【The invention's effect】
As described above, according to the first aspect of the present invention, the non-slip portion having a higher coefficient of friction than the other surface portion is provided on the outer peripheral portion of the surface of at least one of the one disk surface and the other disk surface. Since it is provided, even when a plurality of sheets are stacked, it is difficult to slip each other. Therefore, it is possible to prevent the disk from dropping due to an erroneous operation, and it is possible to prevent the occurrence of scratches due to sliding, which is particularly effective when applied to a Blu-ray disk with a thin cover layer. Further, since the friction coefficient is different only in the non-slip portion, the front and back of the disc can be identified by tactile sensation. Therefore, even when handling in a dark place or when used by a visually impaired person, it is possible to easily and reliably discriminate between the front and the back by tactile sensation. In addition, since the disc can be discriminated by the anti-slip portion in this way, it is not necessary to provide another conventional disc discriminating means as in the prior art. That is, the anti-slip part can perform both the original function as the anti-slip and the function as the front / back identification part.
[0028]
According to the second aspect of the present invention, since the non-slip portion is provided on the image printing layer side that is the non-recording surface side, there is no fear of affecting the recording surface side at all. Further, since the anti-slip portion is provided in an annular shape on the outer peripheral portion of the surface of the image printing layer, it is possible to confirm whether or not the anti-slip portion is present regardless of the direction in which the finger is applied.
[Brief description of the drawings]
FIG. 1 is a perspective view of an optical disc according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view of an optical disc (Blu-ray).
FIG. 3 is a schematic cross-sectional view of a CD.
FIG. 4 is a schematic sectional view of a DVD.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Optical disk 3 Recording layer 4 Cover layer 5 Image printing layer 6 Anti-slip part

Claims (2)

1. An optical disc characterized in that a non-slip portion having a higher coefficient of friction than other surface portions is provided on an outer peripheral portion of at least one surface of one disc surface or the other disc surface. A recording layer and an upper cover layer are provided on one surface side of the disk substrate, and an image printing layer is provided on the other surface side of the disk substrate. The optical disk according to claim 1, wherein the stop portion is provided in an annular shape.

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