JP2000011457A - Optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discriminate an identification mark such as a control No. of each substrate from one face after two substrates are stuck together. SOLUTION: An optical information recording medium in which a 1st substrate 1 having a 1st information region 2 and a 2nd substrate 6 having a 2nd second information region 7 are stuck together, is characterized in that it is provided with a 1st reflecting film 3 covering the 1st information region 2 and the 1st identification mark 4 and a 2nd reflecting film covering the 2nd information region 7 and the 2nd identification mark 9, the position where the 1st identification mark is formed and the position where the 2nd identification mark is formed are different each other in the radial direction, and so the 1st reflecting film is not formed in the region on the 1st substrate corresponding to the region where the 2nd identification mark of the 2nd substrate is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonded optical information recording medium in which two substrates having an information area in which information is recorded as a pit row are bonded.

[0002]

2. Description of the Related Art In recent years, various disc-shaped optical information recording media have been put to practical use. As playback-only ones, compact disks (Compact Disks: CDs), optical video disks, and the like are widely used. Also, as a recordable / reproducible type, a hole-type optical disk capable of recording only once by melting and sublimating a metal recording layer with a laser beam,
Phase-change optical disks between non-crystalline and single crystals, magneto-optical disks using thermomagnetic recording and magneto-optical effects, and the like have been steadily put into practical use. Among them, CD-ROM (Compact Disk-Read Only Memor
y) is expanding rapidly, mainly in the distribution of software applications for computers and game consoles. Also, with the development of image compression technology such as MPEG (Moving Picture Expert Group), video CDs that can record one-hour moving images on a single CD have been on the market.

As a next-generation medium such as a CD and a CD-ROM, there is a DVD (Digital Versatile Disk).
The DVD is a large-capacity optical disk suitable for recording data having a large amount of information such as a digitalized video signal. DVDs employ some new technologies, such as increasing the recording density of optical disks, in order to secure large capacities. For example, the thickness of the substrate is set to 0.6 mm, and the two substrates are bonded to form an optical disk having a thickness of 1.2 mm. In this case, information can be recorded on each substrate, and single-sided reproduction, double-sided reproduction, single-sided double-layer reproduction, and the like can be performed.

FIG. 3 is a schematic diagram showing a cross-sectional structure of a conventional DVD-5. In the figure, 21 is a first substrate, 22
Is a reflective film, 23 is a second substrate, 24 is an adhesive layer, and 25 is a pickup. On one surface of the first substrate 21, an information area in which information is recorded as a pit row is formed.
2 is covered. The pit train is modulated by data to be recorded. The first substrate 21 is bonded via an adhesive layer 24 to a second substrate 23 where no pit row is formed. The DVD-5 is reproduced on one side by the pickup 25.

FIG. 4 is a schematic diagram showing a cross-sectional structure of a conventional DVD-10. In the figure, the same parts as those in FIG. An information area in which information is recorded as a pit row is formed on one surface of the first substrate 21, and is covered with a reflective film 22. Second substrate 23
Similarly, an information area in which information is recorded as a pit row is formed on one surface of the second substrate 23, and the reflection film 2
2 is covered. First substrate 21 and second substrate 2
No. 3 is bonded via an adhesive layer 24 with the readout surface facing outward. DVD-10 pickup 25
, Or the optical disk is turned over, and the pickup 25 reproduces both sides from one direction.

FIG. 5 is a schematic diagram showing a cross-sectional structure of a conventional DVD-9. In the figure, the same parts as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. 26 is a translucent film, 27
Is a transparent adhesive layer. An information area in which information is recorded as a pit row is formed on one surface of the first substrate 21, and is covered with a translucent film 26. An information area in which information is recorded as a pit row is also formed on one surface of the second substrate 23,
It is covered with the reflection film 22. First substrate 21 and second substrate 21
To the substrate 23 via a transparent adhesive layer 27 with the readout surface facing outward. The information area of the first substrate 21 covered by the translucent film 26 is reproduced by the pickup 25, and the information area of the second substrate 23 covered by the reflection film 22 is reproduced by the pickup 25. That is, 2
One information area is reproduced from the same plane.

FIG. 6 is a schematic diagram showing a cross-sectional structure of a conventional DVD-18. In the figure, the same parts as those in FIGS. 3 and 5 are denoted by the same reference numerals, and description thereof will be omitted. 28 is a transparent resin layer. A pit row is formed on the upper surface of the first substrate 21 and is covered with the translucent film 26. On this translucent film 26, a transparent resin layer 28 made of an ultraviolet curable resin in which pit rows are cut by a 2P (photo polymerization) method is formed, and is covered with the reflective film 22. The same applies to the second substrate 23, in which a pit row is formed on the upper surface of the second substrate 23, covered with the translucent film 26, and a transparent resin layer made of an ultraviolet curable resin formed on the translucent film 26. A pit row is also formed on 28 by the 2P method, and is covered with the reflective film 22. The first substrate 21 and the second substrate 23 are bonded via an adhesive layer 24 with the readout surface facing outward.

The information area of the first substrate 21 covered by the semi-transparent film 26 is reproduced by the pickup 25, and the transparent resin layer 2 covered by the reflection film 22 by the pickup 25
8 information areas are reproduced. Similarly, with respect to the second substrate 23, the information area of the second substrate 23 covered with the translucent film 26 is reproduced by the pickup 25, and the information area of the transparent resin layer 28 covered with the reflection film 22 by the pickup 25. Is played. In this way, four layers on both sides are reproduced, or two layers are reproduced on one side from each side by turning the optical disk upside down.

[0009] Of the above-mentioned DVDs, the DVD shown in FIG.
-10, DVD-9 shown in FIG. 6 and DV shown in FIG.
D-18 has an information area in which information is recorded as a pit row in both the first substrate 21 and the second substrate 23. Therefore, it is necessary to manage whether the first substrate 21 and the second substrate 22 are bonded in a correct combination.

In general, in the above-mentioned bonded optical information recording medium such as a DVD, for the purpose of manufacturing control, the first substrate 21 and the second substrate 23 other than the information area on the surface on which the information area is formed are formed. Identification marks such as a title number and a serial number are formed in an area, for example, an area on the inner peripheral side of the information area. Usually, the identification mark of the first substrate 21 and the identification mark of the second substrate 23 are different. By identifying these identification marks with a video camera, laser light, visual observation, or the like, it is inspected whether the first substrate 21 and the second substrate 23 are bonded in a correct combination.

Japanese Patent Application Laid-Open No. 8-124221 discloses the first
The identification marks for identification are formed at different radial positions of the substrate and the second substrate, for example, at positions of a radius of 25 mm and a radius of 30 mm, respectively.
There is disclosed an optical information recording medium capable of identifying a first substrate or a second substrate by identifying a position where an identification mark is formed.

In the above publication, different areas, for example, a circle having a diameter of 1.5 mm and a circle having a diameter of 3 mm are marked on the first substrate and the second substrate, respectively. There is disclosed an optical information recording medium capable of identifying a first substrate or a second substrate by identifying the area of a mark formed.

[0013]

Problems to be Solved by the Invention
The optical information recording medium disclosed in Japanese Unexamined Patent Publication No. 1 is intended only to identify the first substrate or the second substrate before bonding the two substrates. The above publication discloses a configuration in which an identification mark or the like can be identified from one side of a substrate before being bonded.

However, in the actual manufacturing process, not only before laminating the two substrates but also on the optical information recording medium after laminating the two substrates, a step of printing a label or the like or a label is performed. Before the attaching step, it is necessary to check whether the contents of the label to be printed or attached correspond to the management numbers of the respective substrates of the optical information recording medium.

In the optical information recording medium disclosed in Japanese Patent Application Laid-Open No. 8-124221, the identification mark formed on each substrate is covered with a reflection film, and the reflection mark formed on each substrate is generally used. Since the positions of the inner and outer peripheries of the film are the same, both identification marks cannot be identified from one surface of the optical information recording medium bonded to the first substrate and the second substrate. Therefore, there is a problem that the optical information recording medium must be turned over one by one in the inspection process to identify each identification mark.

It is an object of the present invention to provide an optical information recording medium capable of identifying an identification mark such as a management number of each substrate from one surface even after two substrates are bonded.

[0017]

In order to solve the above-mentioned problems, the invention according to claim 1 of the present application provides a first substrate having a first information area on one side and a second information area on one side. An optical information recording medium comprising: a second substrate having the first substrate and an adhesive layer for bonding the first substrate and the second substrate.
A first information layer formed on an area other than the first information area on the same surface as the first information area for identifying the first substrate;
And a second identification mark formed in an area other than the second information area on the same surface as the second information area to identify the second substrate, and the first information area And a first reflective film covering the first identification mark, and a second reflective film covering the second information area and the second identification mark, wherein the first identification mark is formed. The radius position where the second identification mark is formed is different from the radius position where the second identification mark is formed, and the first reflection film faces the second substrate on the second substrate opposite to the radius where the second identification mark is formed. It is characterized in that it is not formed to the diameter of one substrate.

According to a second aspect of the present invention, in the optical information recording medium according to the first aspect, the first identification mark and the second identification mark are on the same side of the optical information recording medium. It is characterized in that it is formed so as to be seen from the viewpoint.

[0019]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a sectional configuration of an embodiment of the optical information recording medium of the present invention. In the figure, 1 is a first substrate, 2 is a first information area, 3 is a first reflective film, 4
Is a first identification mark, 5 is an adhesive layer, 6 is a second substrate, 7
Is a second information area, 8 is a second reflective film, 9 is a second identification mark, and 10 is a center hole.

The first substrate 1 has a thickness of 0.6 mm and an outer diameter of 1 mm.
A substrate made of polycarbonate resin, acrylic resin or the like having a diameter of 20 mm and an inner diameter (diameter of the center hole 10) of 15 mm,
On one side, there is provided a first information area 2 in which information such as a video signal and an audio signal is recorded as a pit row. In the optical information recording medium of the present embodiment, the first information area 1 is formed, for example, in a range from a diameter of 45 mm to a diameter of 116 mm.

The first substrate 1 has a first information area 2
A first identification mark 4 which is a title number, a lot number, and the like related to information recorded in the first information area 2 is provided in an area between the first information area 2 and the center hole 10. Here, the first identification mark 4 is formed as unevenness on the same surface of the first substrate 1 on which the first information area 2 is formed.
In the optical information recording medium of the present embodiment, the first identification mark 1 is formed, for example, in an area having a diameter of 38 mm to 40 mm and viewed from the reading surface of the first substrate 1 (the lower side in FIG. 1). It is formed to be true.

The area where the first information area 2 and the first identification mark 1 are formed is covered with a first reflection film 3 made of aluminum, gold or the like. In the optical information recording medium of the present embodiment, the first reflection film 3 has a diameter 3 of the first substrate 1.
It is formed on a region from 7 mm to 118 mm in diameter.

The second substrate 6 has a thickness of 0.6 mm and an outer diameter of 1 mm.
A substrate made of polycarbonate resin, acrylic resin or the like having a diameter of 20 mm and an inner diameter (diameter of the center hole 10) of 15 mm,
On one side, there is provided a second information area 7 in which information such as a video signal and an audio signal is recorded as a pit row. In the optical information recording medium of the present embodiment, the second information area 7 is formed, for example, in a range of 45 mm to 116 mm in diameter.

The second substrate 6 has a second information area 7
A second identification mark 9 such as a title number and a lot number related to the information recorded in the second information area 7 is provided in an area between the center hole 10 and the center hole 10. Here, the second identification mark 9 is formed as unevenness on the same surface of the second substrate 6 where the second information area 7 is formed,
The numbers and indications are different from those of the first identification mark 4.
In the optical information recording medium of the present embodiment, the second identification mark 9 is formed, for example, in an area having a diameter of 34 mm to 36 mm and viewed from the reading surface of the first substrate 1 (the lower side in FIG. 1). Therefore, it is preferable that they are formed so as to be true.

The area where the second information area 7 and the second identification mark 9 are formed is covered with a second reflection film 8 made of aluminum, gold or the like. In the optical information recording medium of the present embodiment, the second reflection film 8 has a diameter 3 of the second substrate 2.
It is formed on a region from 3 mm to 118 mm in diameter.
Here, since the second reflective film 8 has a small film thickness of about 50 to 100 nm, irregularities are formed on the second reflective film 8 on the second identification mark 9 along the second identification mark 9. , First
The second identification mark 9 can be recognized from the substrate 1 side.

The first substrate 1 and the second substrate 6 are bonded via a transparent adhesive layer 5 such as an ultraviolet curable resin so that the first information area 2 and the second information area 7 face each other. Have been combined.

FIG. 2 is a schematic view showing a planar structure of the optical information recording medium according to one embodiment of the present invention as viewed from the first substrate side. In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. As described above, in the optical information recording medium according to the present embodiment, the first identification mark 4 formed on the first substrate 1 is located in a region having a diameter of 38 mm to 40 mm, and the first reflective film 3 has a diameter of 40 mm. 37mm to 118mm in diameter
Area. On the other hand, the second identification mark 9 formed on the second substrate 6 has a diameter of 34 mm to 36 m.
m, and the second reflective film 8 covers an area having a diameter of 33 mm to 118 mm.

Therefore, as shown in FIG. 2, when the optical information recording medium of this embodiment is viewed from the first substrate 1,
Not only can the first identification mark 4 formed on the second substrate 6 be identified, but also the second identification mark 4 formed on the second substrate 6 can be identified.
Can be identified from the area inside the first reflection film 3 (the area inside the diameter of 37 mm). Also, as shown in FIG. 2, the second identification mark 9 is
When viewed from the first substrate 1 side, the second identification mark 9 can be more easily identified if it is formed so as to be true.

[0029]

According to the optical information recording medium of the present invention, it is possible to easily identify the identification mark such as the management number formed on each substrate from one surface even after the two substrates are bonded. it can.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a cross-sectional configuration of an embodiment of an optical information recording medium of the present invention.

FIG. 2 shows a first example of an optical information recording medium according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing a planar structure as viewed from the substrate side.

FIG. 3 is a schematic diagram showing a cross-sectional structure of a conventional DVD-5.

FIG. 4 is a schematic diagram showing a cross-sectional structure of a conventional DVD-10.

FIG. 5 is a schematic diagram showing a cross-sectional structure of a conventional DVD-9.

FIG. 6 is a schematic diagram showing a cross-sectional structure of a conventional DVD-18.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st board | substrate 2 1st information area 3 1st reflection film 4 1st identification mark 5 adhesive layer 6 2nd board | substrate 7 2nd information area 8 2nd reflection film 9 2nd identification mark 10 Central hole 21 First substrate 22 Reflective film 23 Second substrate 24 Adhesive layer 25 Pickup 26 Translucent film 27 Transparent adhesive layer 28 Transparent resin layer

Claims (2)

[Claims] 1. A first substrate having a first information area on one side, a second substrate having a second information area on one side, and bonding the first substrate and the second substrate together. An optical information recording medium comprising: a first information area formed in an area other than the first information area on the same surface as the first information area, for identifying the first substrate;
And a second mark formed in an area other than the second information area on the same surface as the second information area for identifying the second substrate.
A first mark covering the first information area and the first identification mark.
And a second film covering the second information area and the second identification mark.
Wherein the position at which the first identification mark is formed and the position at which the second identification mark is formed differ in the radial direction, and wherein the first reflection film is The second in the substrate
The optical information recording medium is not formed at the diameter of the first substrate opposite to the diameter at which the identification mark is formed. 2. The optical information recording medium according to claim 1, wherein
The optical information recording medium according to claim 1, wherein the first identification mark and the second identification mark are formed so as to be identified when viewed from the same surface side of the optical information recording medium.