JPH09106574A - Optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the visibility of display contents by providing the recording medium with >=2 reflection layers having reflection spectra varying in a visible region and displaying character information in such a manner that the information is recognizable when viewed by man. SOLUTION: Information surfaces 2 are composed of pits and are spirally recorded with the information from the center of a disk. The display contents which indicate the contents associated with the recorded information and are composed of characters or designs are so formed that the recognition by man is made possible by first reflection layers 3 on the information surface 2. The first reflection layers 3 are covered by second reflection layers 4 having the reflection spectra in the visible region different from the reflection spectra of the first reflection layers 3. Further, the second reflection layers 4 are covered by protective layers 5. An adhesive layer 6 which is a UV curing type resin, etc., is applied on the protective layer 5 of the one optical information recording medium of two sheets of the optical information recording media formed in such a manner and the protective layer is superposed and adhered on the protective layer 5 of another optical information recording medium in order to form the sticking type optical information recording medium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium for irradiating a laser beam to record / reproduce information.

[0002]

2. Description of the Related Art Conventionally, two disks are bonded together.
A laser disc (hereinafter, referred to as LD: Laser Disc) is widely used as a pasting type optical disc. In the case of the LD, the contents related to the recorded information (for example, the title of the disc, the recorded music or video title, and the manufacturer on sale) are displayed at the center of the disc with an outer diameter of 85 mm and an inner diameter of 36 mm. It was done by sticking the label paper of.

In the case of the LD, since the area of the label paper is large, it is possible to secure sufficient visibility even in the case of displaying the contents on the label paper as described above.

On the other hand, another bonded optical disk is a digital video disk (hereinafter referred to as DVD: Digital Video Disk) having a recording density increased to about 6 to 8 times that of a CD. FIG. 7 shows a schematic diagram of a sectional structure of a DVD. An information surface 32 on which information is recorded is formed on a transparent substrate 31 having a diameter of 120 mm and a thickness of 0.6 mm.

The surface of the information surface 32 is covered with a reflective layer 33 made of metal such as aluminum which reflects most of the laser light. The reflective layer 33 is further covered with a protective layer 34. The protective layer 34 plays a role of protecting the information surface 32. An adhesive layer 3 made of an ultraviolet curable resin, a hot melt adhesive, or another adhesive is formed on the protective layer 34 of one of the two disks thus manufactured.
5 is provided and the protective layer 34 of the other disc is overlapped and bonded. The recorded information is read from the DVD manufactured in this manner by the reproduction laser beam 37 emitted from the optical pickup 36.

There are various other types of DVDs. In addition to the multi-layer type in which the substrate has two layers of information surfaces, there are types in which two multi-layer type disks are adhered to increase the density.

[0007]

A DVD has a disk diameter of 120 mm, a central hole of 15 mm, and a recording area starting diameter of 46 mm, and is the same as a compact disk (hereinafter referred to as CD: Compact Disc). small. Further, since the center hole portion clamps the disc, the area of the area for displaying the recorded information is small. With the method of sticking the label paper to the center of the disc, it is not possible to secure a large area like the LD,
The visibility of the displayed contents will be poor.

Further, as mentioned above, there are some double-sided reproduction discs for DVDs to increase the recording density. In this double-sided reproduction disc, if a display relating to the information recorded on the disc is provided on the entire surface of the disc, as in the case of a CD, it becomes impossible to read. in this way,
In the case of DVD, since it is a small bonded disc,
There is a drawback in that it is difficult to display the contents related to the recorded information on the disc body.

[0009]

In order to solve the above problems, according to the invention described in claim 1 of the present invention, information is optically reproducibly recorded by transmitting a reproduction laser beam. Optical information including a substrate, a reflective layer formed on the information recording surface of the substrate and reflecting a reproduction laser beam, and an adhesive layer formed so as to cover the reflective layer, the optical information including the substrate and the reflective layer In an optical information recording medium in which two recording media are adhered by the adhesive layer, the reflective layer has two or more reflective layers having different reflection spectra in the visible region, and at least one of the reflective layers is reflected. The layer is characterized by displaying items related to the recorded information.

According to the second aspect of the present invention, a substrate on which information is optically reproducibly recorded by transmitting a reproduction laser beam, and an information recording surface of the substrate is reproduced. A semi-transparent layer that reflects the laser beam, a transparent resin layer that is formed so as to cover the semi-transparent layer, transmits the reproduction laser beam, and records information optically reproducibly, and is formed on the transparent resin layer. Optical information recording having at least a reflective layer for reflecting the reproduced laser beam and an adhesive layer formed so as to cover the reflective layer, and comprising the substrate, the semitransparent layer, the transparent resin layer and the reflective layer. An optical information recording medium comprising two mediums adhered by the adhesive layer, wherein the reflective layer has two or more reflective layers having different reflection spectra in the visible region, and at least one reflective layer among the reflective layers. Is a record It is characterized in that to display the notes relating to the broadcast.

According to the first and second aspects of the present invention, the optical information recording medium has two or more reflective layers having different reflection spectra in the visible region. When a human looks at the optical information recording medium, the two or more reflective layers are recognized as different colors. By forming at least one kind of reflective layer the characters or patterns that display the content related to the recorded information and forming the background with one kind of reflective layer, the information recorded in the recording area of the disc is related. It is possible to directly display the characters or the pattern for displaying the content to be displayed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of an embodiment of an optical information recording medium according to the present invention. The substrate 1 which is a transparent resin substrate has an information surface 2 on which information is recorded in an optically reproducible manner.
have. The information surface 2 is composed of depressions called pits, and is recorded in a spiral shape from the center of the disc. The display content, which indicates the content related to the recorded information and is composed of characters or patterns, is formed on the information surface 2 by the first reflective layer 3 so that a person can recognize it.

Then, by the second reflection layer 4 having a reflection spectrum different from that of the first reflection layer 3 in the visible region,
The first reflective layer 3 is covered. Further, the second reflective layer 4 is covered with the protective layer 5. In order to form a laminated optical information recording medium, an adhesive layer 6 which is an ultraviolet curable resin or the like is applied to the protective layer 5 of one of the two optical information recording media thus formed. Then, the protective layer 5 of the other optical information recording medium is overlaid and adhered. For the adhesive layer, in addition to the ultraviolet curable resin, a hot melt adhesive or other adhesive such as alkule resin or urethane resin can be used.

The reproducing laser beam 8 emitted from the optical pickup 7 passes through the substrate 1 and is applied to the information surface 2.
When reproducing both sides of a laminated optical information recording medium, the optical information recording medium is inverted to change the reproduction surface, or
Alternatively, the optical pickup can be illuminated from both upper and lower sides.

Here, the first reflective layer 3 and the second reflective layer 4 will be described in more detail. The material of the second reflective layer 4 which covers the whole is, for example, aluminum (Al) which is also used in the conventional CD. The reflectance of aluminum is, for example, DV
Approximately 9 for the wavelength of 650 nm of the reproducing laser used for D
0%.

Gold (Au) is an example of a metal having a reflection spectrum in the visible region different from that of aluminum. This gold is selected as the material of the first reflective layer 3. The reflectance of gold is, for example, the wavelength 650 of the reproducing laser used for DVD.
It is about 95% with respect to nm.

FIG. 2 shows an overall view of an embodiment of the optical information recording medium according to the present invention. When the laminated optical information recording medium is viewed, the first reflective layer 3 which is gold is displayed against the background of the second reflective layer 4 which is silver and the display content is “test disc 1”.
Can be recognized as In FIG. 2, the case where the display contents are recognized by the two types of reflective layers is shown. In addition to this, a third reflective layer made of a material such as copper (Cu) is formed, and the reflective layer is formed by appropriately selecting three kinds of display contents from the above materials, thereby forming gold, silver and copper. Three
Color display is possible.

Next, the manufacturing process of the reflective layer of the optical information recording medium will be described. FIG. 3 shows an embodiment of a mask used for manufacturing the display contents of the optical information recording medium according to the present invention, and FIGS. 4A and 4B show the manufacturing process of the optical information recording medium according to the present invention. An example is shown. In the present embodiment, the following description will be made on the case where gold is used for the first reflective layer 3 and aluminum is used for the second reflective layer 4. Information side 2 of board 1
The substrate 1 is placed on a sputtering device (not shown) in order to form the first reflective layer 3 having the display content shown in FIG.

Then, the mask 9 having the display content formed as a penetrating portion is arranged and fixed at an appropriate position. Then, the gold atoms jumping out from the target by the sputtering method move in the direction of arrow (a) and adhere to the substrate 1 except the portion covered with the mask 9 to form the first reflective layer 3.

Next, after removing the mask 9, aluminum is formed as the second reflective layer 4. Second reflective layer 4
Are formed so as to cover the first reflective layer 3. Thereby, two types of reflective layers as shown in FIG. 1 are formed.
Then, the optical information recording medium is manufactured by removing from the sputtering apparatus, forming a protective layer so as to cover the reflective layer, forming an adhesive layer on one of the two media, and adhering it to the other medium.

If the display contents are displayed in two or more colors,
Before the second reflective layer 4 covering the entire surface is attached by the sputtering device, another mask on which another display content is formed is fixedly arranged, and then, for example, copper (Cu) is attached by the sputtering device and other reflection is performed. A layer is formed, and then the second reflective layer 4 is formed. Accordingly, the display content is formed of two types of reflective layers, and the display content can be displayed in two colors.

FIG. 5 shows a block diagram of another embodiment of the optical information recording medium according to the present invention. This embodiment particularly shows a bonded optical information recording medium configured by bonding optical information recording media having two layers of information surfaces on one side. The substrate 11 which is a transparent resin substrate has the first information surface 12
have. The first information surface 12 has a reflectance of about 30% at a wavelength of 650 nm of a reproducing laser used for DVD, for example, and is made of an inorganic dielectric such as a silicon nitride-based compound or an aluminum nitride-based compound or a metal. It is covered with the transparent layer 13.

The semitransparent layer 13 is the transparent resin layer 14
Covered with. The transparent resin layer 14 has a second information surface 15 which is another information surface. The first reflective layer 16 is formed on the second information surface 15 so that the display content can be recognized by humans.
Then, the first reflective layer 16 is entirely covered by the second reflective layer 17 having a reflection spectrum different from that of the first reflective layer 16 in the visible range. Further, the second reflective layer 17 is
The whole is covered with the protective layer 18.

In order to bond the optical information recording medium thus formed, an adhesive layer 19 made of an ultraviolet curable resin, a hot melt adhesive or another adhesive is applied to the protective layer 18 of one optical information recording medium. Then, it is bonded to the protective layer 18 of the other optical information recording medium to form a bonded optical information recording medium. Also in this embodiment, as in the embodiment shown in FIG. 1, the display content can be recognized from the information reading surface. When performing double-sided reproduction of the bonded optical information recording medium, the optical information recording medium is inverted to change the reproduction surface, or the optical pickup is configured to be capable of irradiating the optical pickup from both upper and lower surfaces.

FIG. 6 shows a block diagram of an embodiment of the optical information recording medium. The present embodiment shows an optical information recording medium having an information surface on only one side. The first reflective layer 23 is formed on the information surface 22 of the substrate 21 which is a transparent resin substrate so that the display contents can be visually recognized by a person.

The first reflective layer 23 is entirely covered with the second reflective layer 24 having a reflection spectrum different from that of the first reflective layer 23 in the visible region. Second reflective layer 24
Is entirely covered by the protective layer 25. Protective layer 2
Reference numeral 5 protects the information surface from external impacts and dust. Also in this embodiment, it is possible to recognize the display content when viewed from the side where a person reads information.

In the optical information recording medium of this embodiment shown in FIGS. 1 and 5, the display contents of the optical information recording medium are shown, and one surface and the other surface of the two optical information recording media which are bonded together are shown. The description has been made on the assumption that the two first reflective layers respectively provided on the surfaces are the same material. However, the first information display section is formed on each of the one surface and the other surface of the optical information recording medium.
By changing the material of the reflective layer, the display content portion of the laminated optical information recording medium has the first reflective layer on one side of the optical information recording medium as gold and the first reflective layer on the other side of the optical information recording medium as gold. The reflective layer is capable of displaying information with a copper color.

Further, in the optical information recording medium of the present embodiment shown in FIGS. 1 and 5, the background of the optical information recording medium is shown, and one surface and the other surface of the two optical information recording media which are bonded to each other. The description has been made on the assumption that the two second reflective layers of the respective surfaces are the same material. However, by changing the material of the second reflective layer, which is the background formed on one surface and the other surface of the optical information recording medium, for example, the display content portion of the laminated optical information recording medium is changed to the optical information recording. The second reflective layer on one surface of the medium can be displayed as a gold background, and the second reflective layer on the other surface of the optical information recording medium can be displayed as a copper background.

In addition, in the laminated optical information recording medium in the present embodiment, a case where an adhesive layer is applied to one protective layer of two optical information recording media and the other protective layer is laminated and adhered I gave an explanation. However, it is also possible to apply an adhesive layer directly to one reflective layer and to adhere the other reflective layer in a stacked manner without providing a protective layer on the two optical information recording media. Even in such a case, the present invention can be implemented.

As described above, according to the optical information recording medium of the pasting type of the present invention, the diameter at which the recording area starts is 46 mm.
Since the character information is displayed so that a person can recognize it by using the recording area of about 120 mm where the recording area ends, the display content can be shown in a large area with good visibility. Further, unlike the LD, it is not necessary to attach the label paper to the central portion of the disc, so that the deterioration of the visibility due to the deterioration of the label paper can be prevented.

[0031]

According to the optical information recording medium of the present invention, since the character information is displayed so that it can be visually recognized by a person using the recording area, the display content can be shown with high visibility.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of an optical information recording medium according to the present invention.

FIG. 2 is an overall view of an embodiment of an optical information recording medium according to the present invention.

FIG. 3 is a mask used for producing display contents of an optical information recording medium according to the present invention.

FIG. 4 is a conceptual diagram showing an example of a manufacturing process of an optical information recording medium according to the present invention.

FIG. 5 is a configuration diagram of another embodiment of the optical information recording medium according to the present invention.

FIG. 6 is a configuration diagram of an embodiment of an optical information recording medium.

FIG. 7 is a schematic diagram of a cross-sectional structure of a DVD according to a conventional technique.

[Explanation of symbols]

 1 ... Substrate 2 ... Information surface 3 ... First reflective layer 4 ... Second reflective layer 5 ... Protective layer 6 ... Adhesive layer 7 ... Optical pickup 8 ... Playback Laser beam 9 ... Mask 11 ... First substrate 12 ... First information surface 13 ... Semi-transparent layer 14 ... Transparent resin layer 15 ... Second information surface 16 ... First reflective layer 17 ... 2 Reflective layer 18 Protective layer 19 Adhesive layer 20 Optical pickup 21 Reproduction laser beam

Claims (2)

[Claims] 1. A substrate on which information is optically reproducibly recorded by transmitting a reproduction laser beam, a reflection layer formed on an information recording surface of the substrate and reflecting the reproduction laser beam, and covering the reflection layer. An optical information recording medium having at least an adhesive layer formed as described above, wherein two optical information recording media comprising the substrate and the reflective layer are adhered by the adhesive layer, wherein the reflective layers are different in the visible range. An optical information recording medium, comprising: two or more reflective layers having a reflection spectrum, wherein at least one of the reflective layers displays a matter related to recorded information. 2. A substrate on which information is optically reproducibly recorded by transmitting a reproduction laser beam, a semitransparent layer formed on an information recording surface of the substrate and reflecting the reproduction laser beam, and the semitransparent layer. A transparent resin layer formed to cover the transparent resin layer and transmitting a reproduction laser beam to record information optically reproducibly; a reflection layer formed on the transparent resin layer to reflect the reproduction laser beam; and a reflection layer And a bonding layer formed so as to cover at least one of the optical information recording media, the optical information recording medium including the substrate, the semitransparent layer, the transparent resin layer, and the reflecting layer bonded together by the bonding layer. Type optical information recording medium, the reflective layer has two or more reflective layers having different reflection spectra in the visible region, and at least one of the reflective layers displays a matter related to recorded information. The optical information recording medium, characterized in that.