JPH1166625A - Optical information record medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a process and to enable to reduce manufacturing cost by constituting the device of a first substrate forming an information recording region on one side plane, a transparent substrate forming a dot group picture display region, and a second substrate having a reflection film and displaying a picture, and sticking a reflection film forming plane of the first substrate and a picture display region forming plane opposing each other. SOLUTION: A first transparent substrate 101 having an information recording region 102 covered by a reflection film 103 on one side and a second transparent substrate 105 in which information relating information recorded in an information recording region is displayed by a dot group and which has as picture display region 107 covered by a reflection film 103 on one side are stuck through a transparent adhesive layer 104. Density of picture such as characters, graphics or the like can be freely varied and high definition display can be performed by displaying a picture display region with a dot group consisting of a concave part and/or a convex part. Also a cutting process can be omitted.

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 having a structure in which two transparent substrates are bonded, and more particularly, to bonding a dummy substrate having no information recording area to a substrate having an information recording area. The present invention relates to an optical information recording medium having a different structure.

[0002]

2. Description of the Related Art Conventionally, CD (Compact Disk) and CD-
In a read-only single-type optical disk such as a ROM (Compact Disk-Read Only Memory), the content opposite to the surface from which the recorded signal is reproduced is printed by ink printing on the surface related to the recorded information, such as the title and the publisher. it's shown. However, recently, when the amount of recording information such as a music program is small with respect to a recording area of up to 74 minutes, an extra area on the outer peripheral side where information is not recorded is not printed by ink printing.
Optical discs with added value by displaying pictures, figures, characters, and the like that can be visually recognized by the naked eye are commercially available. This is because light scattering and diffraction occur in areas where dummy pits of random patterns are recorded, and light scattering and diffraction do not occur in areas where dummy pits are not recorded, so that contrast occurs between these areas. This is an optical disk utilizing the optical disk. Such a picture by the distribution of dummy pits,
The display of figures and characters is called pit art.

[0003] As a next-generation multimedia medium, a DVD (Di-Media) having a large storage capacity about seven times or more that of a CD has been proposed.
gital Versatile Disk) has been launched and is becoming popular in the market. In DVDs, the size of pits for recording information is increased in order to increase the recording density compared to conventional optical discs.
Compared with the CD, the radius and the circumferential direction are slightly less than half. Further, in order to reduce the influence of the deterioration of the reproduction signal quality due to the warpage or bending of the disk, the thickness of the substrate is set to 0.6.
mm and a structure in which two substrates are bonded together to increase the mechanical strength. The DVD can record information on one or both of the substrates to be bonded. Therefore, the structure of the optical disk can be a single-layer single-sided reproduction optical disk, a single-layer double-sided reproduction optical disk, a double-layer single-sided reproduction optical disk, and a double-layer double-sided double-sided reproduction optical disk.

Among them, DVD-5 which is a single-layer single-sided reproduction optical disk and DV-5 which is a double-layer single-sided reproduction optical disk
D-9 is an optical disc having a structure in which a 0.6 mm thick substrate having a recording information area and a 0.6 mm thick substrate (dummy substrate) having no recording information area are bonded together. When information related to recording information is displayed on the surface of the dummy substrate by ink printing, the DVD is bonded to the surface of the dummy substrate because the thickness of the substrate is smaller than that of the conventional CD (1.2 mm). There is a problem that warpage occurs later.
Therefore, a method (pit art) of displaying information related to the recorded information is applied to the dummy substrate according to the distribution of the area where the dummy pits of the random pattern are recorded and the area where the dummy pits are not recorded, as in the above-described CD. Discs are commercially available. In the pit art, light is scattered and diffracted in a pit-recorded area, so that a contrast is produced between the pit-recorded area and a non-pit-recorded area, and an image is displayed.

FIG. 8 is a view for explaining a cross-sectional structure of a DVD-5 in which a display is made by a conventional pit art. In the figure, reference numeral 801a denotes a substrate having no information recording area;
Denotes a substrate having an information recording area; 802, a transparent substrate;
3 is a reflective film, 804 is a protective layer, and 805 is an adhesive layer.
Here, in the transparent substrate 802, the surface facing the adhesive layer 805 will be referred to as the back surface, and the surface on the opposite side will be referred to as the front surface.

As shown in FIG. 8, a spiral or concentric pit row is formed on the back surface of a transparent substrate 802 on the side of a substrate 801b having an information recording area. This surface is covered with a reflective film 803 made of metal or the like that reflects laser light such as aluminum, and a protective layer 804. The pit row is composed of a pit pattern modulated by data to be recorded. Further, the substrate 801a having no information recording area is the substrate 801b having the information recording area.
The same structure as the side, a dummy pit row of a spiral or concentric random pattern is formed on the back surface of the transparent substrate 802, and the reflection film 80 made of metal such as aluminum is formed.
3 and further covered by a protective layer 804. However, as will be described later with reference to FIG. 10, a region where dummy pits of a random pattern are recorded and a region where such dummy pits do not exist are distributed. Since the diffraction occurs, a contrast is generated between the dummy pit and the area where the dummy pit is not recorded, and an image composed of a picture, a character, or the like is displayed so as to be visible. Also,
Some optical disks have a structure without the protective layer 804.

FIG. 9 is a view for explaining a cross-sectional structure of a DVD-9 in which a display is made by a conventional pit art. In the figure, reference numeral 901a denotes a substrate having no information recording area;
Is a substrate having an information area, 902 is a transparent substrate, 903 is a reflective film, 904 is a protective layer, 905 is an adhesive layer, 906 is a transparent resin layer, and 907 is a translucent film.

As shown in FIG. 9, a spiral or concentric pit row is formed on the upper surface of the transparent substrate 902 on the side of the substrate 901b having the information recording area. This surface is covered with a translucent film 907 made of a dielectric material or a metal, which reflects a part of the laser beam and transmits the rest.
On the translucent film 907, a transparent resin layer 906 on which a pit row is formed is laminated, and the surface on which the pit row is formed is a reflection film 903 made of metal or the like that reflects laser light such as aluminum, and further, It is covered with a protective layer 904.
The pit row formed on the transparent substrate 902 and the transparent resin layer 906 is composed of a pit pattern modulated by data to be recorded.

Further, a substrate 901 having no information recording area
The side a has the same structure as the side of the substrate 901b having the information recording area, and a spiral or concentric random pattern of dummy pits is formed on the lower surface of the transparent substrate 902,
It is covered with a reflective film 903 made of a metal such as aluminum or the like, and further with a protective layer 904. However, as will be described later with reference to FIG. 10, a region where dummy pits of a random pattern that causes light scattering and diffraction are recorded and a region where such dummy pits are not recorded are distributed. Images such as pictures and characters are displayed so as to be visually recognizable by the contrast between the two parts. Further, there is an optical disc having a structure without the protective layer 904.

FIG. 10 is an enlarged plan view of a conventional optical disk in which the numeral 1 is visually displayed as a dummy pattern of random patterns as an example. In the figure, 1001 is a pit, 1002 is a land, and 1003 is an area representing the numeral 1. In the substrates 801a and 901b having no information recording area shown in FIG. 8 and FIG.
1 is spirally or concentrically formed in a random pattern, but in an image portion such as a picture or a character, in the illustrated example,
All areas 1003 representing the numeral 1 are lands where no dummy pits exist, and contrast is obtained by changing the state of light scattering and diffraction with the area where the dummy pits exist.

That is, when the optical disk is viewed from a direction that receives specularly reflected light from the land 1002, the area 1003 representing the numeral 1 looks the brightest because it is a mirror surface, and the area where the dummy pits exist is light scattering, It looks dark due to diffraction. Conversely, when the optical disk is viewed from a direction that does not receive specularly reflected light from the land 1002, the area 1003 representing the numeral 1 looks dark, and the area where the dummy pit exists looks bright.

FIG. 11 is a view for explaining a manufacturing process for forming a conventional dummy substrate provided with pit art. In the figure, 1101 is a glass master, 1102 is a photoresist film, 1103 is a hot plate, 1104 is an exposed portion, 1105 is a pit, 1106 is a nickel conductive film,
107 is a stamper, 1108 is a dummy substrate, 1109 is a reflection film, 1110 is an adhesive layer, and 1111 is an information substrate.

As shown in step 1 of FIG. 11, a photoresist solution diluted with cellosolve acetate or the like is spin-coated at a predetermined number of revolutions on a smooth glass master 1101 by a spin coater to form a photoresist film 1102.

Next, as shown in Step 2, the glass master 1101 on which the photoresist film 1102 is formed is placed on a hot plate 1103 and heated to pre-bak the glass master 1101.

Pre-baked glass master 11
01 is mounted on a master disc cutting device and rotated as shown in Step 3, and pits having a random pattern corresponding to an arbitrary pit art are recorded by a He-Ne laser. At this time, the position of the image such as a character or a figure is determined by a coordinate calculation device installed in the cutting device.
When the laser light reaches coordinates on the glass master corresponding to images of characters, figures, etc., the output of the laser light is turned off, and the photoresist film 1102 is not exposed. Controlled.

Subsequently, the glass master 1101 is set in a developing device, a developing solution is applied while rotating, and while monitoring the diffracted light, a photo of the exposed portion 1104 exposed by the cutting device is monitored as shown in step 4. Resist film 1
Dissolve and remove 102. When the specified diffracted light intensity is obtained, the development is stopped, and the developer is washed with a washing solution.
As shown in Step 5, the glass master 1101 is heated, post-baked, and dried. At this time, pits 1105 are formed as recesses on the surface of the photoresist film 1102 of the glass master 1101.

As shown in step 6, a nickel conductive film 1106 is formed on the surface of the photoresist film 1102 on which the pits 1105 have been formed by sputtering, and as shown in step 7, nickel electroforming is performed to form the pits. 110
The stamper 1107 to which the No. 5 is transferred is obtained.

The inner and outer peripheries of the stamper 1107 are processed to a predetermined size, attached to a molding machine, and molded as shown in step 8, and a random pattern pit row corresponding to an arbitrary pit art is transferred. Also, a dummy substrate 11 of a polycarbonate resin having a diameter of 12 cm and a thickness of 0.6 mm.
08 is obtained.

Then, as shown in Step 9, a pit art formed on the dummy substrate 1108 is formed by forming a reflective film 1109 of aluminum or the like on the surface of the dummy substrate 1108 where the pits 1105 are formed by sputtering. It becomes visible.

After that, as shown in step 10, an information recording area formed in the same step as that of the dummy substrate is provided, and the information recording area is bonded via an adhesive layer 1110 to an information substrate 1111 covered with a reflective film. And the dummy substrate 1108
On the side, a bonded optical disk having a display related to recorded information formed by pit art is obtained.

[0021]

However, as described above, the conventional pit art uses the light scattering between the pit 1001 and the land 1002 and the contrast due to the difference in the diffraction state as shown in FIG. , Characters, figures, etc., it is difficult to display a halftone image.

Further, as shown in FIG. 11, in order to manufacture a dummy substrate 1108 on which pit art is formed, the glass master 1101 is rotated by a cutting device, and the glass master 1101 is formed on the glass master 1101 by a laser beam. Since a spiral or concentric pit row must be formed in the photoresist film 1102, it takes a long time. Further, there is a problem that the number of steps after the cutting step is large and the cost is increased.

[0023]

In order to solve the above problems, an optical information recording medium according to claim 1 of the present application comprises a first substrate having an information recording area formed on one side, a concave portion and / or Or a transparent substrate on which an image display area composed of a dot group composed of convex portions is formed, and a reflective film that covers the image display area, and an image is formed by the size and / or density distribution of the dots in the dot group. A second substrate to be displayed, and an adhesive layer that is bonded so that the surface of the second substrate on which the image display area is formed and the surface of the first substrate on which the reflective film is formed face each other. It is characterized by having.

According to the first aspect of the present invention, unlike a conventional pit art, an image such as a character or a graphic is displayed by a dot group composed of concave portions and / or convex portions. The density of an image such as a figure can be freely changed, and high-quality display can be performed. Further, since it can be manufactured without a cutting step of recording a spiral or concentric pit row like a conventional pit art, it can be manufactured in a short time and at a low cost.

The optical information recording medium according to claim 2 of the present application
A first substrate having an information recording area formed on one side, and a transparent substrate having an image display area formed of a dot group consisting of concave portions and / or convex portions formed on one surface and having a refractive index of n;
A second substrate on which an image is displayed according to a size and / or density distribution of dots in the dot group;
And an adhesive layer for bonding the surface of the first transparent substrate on which the image display area is formed and the surface of the first transparent substrate on which the information recording area is formed, wherein the adhesive layer is in a visible region. A colorant having an absorption other than the wavelength of the predetermined color is included, and the depth of the dots in the dot group is approximately 1/4 of the wavelength.

According to the second aspect of the present invention, unlike a conventional pit art, an image such as a character or a graphic is displayed by a dot group including concave portions and / or convex portions. The density of an image such as a figure can be freely changed, and high-quality display can be performed. Further, since it can be manufactured without a cutting step of recording a spiral or concentric pit row like a conventional pit art, it can be manufactured in a short time and at a low cost. Further, since it is not necessary to provide a reflective film for covering the image display area on the second transparent substrate, the colored adhesive layer is sufficiently irradiated with ultraviolet rays. Therefore, it is possible to provide an optical information recording medium having a high bonding strength.

The optical information recording medium according to claim 3 of the present application is
A first substrate having an information recording area formed on one side thereof, a transparent substrate having an image display area formed of a rough surface portion and a smooth surface portion formed on one surface, and a reflective film covering the image display region;
A second substrate on which an image is displayed by the distribution of the rough surface portion and the smooth surface portion of the image display region; a surface of the second substrate on which the image display region is formed; and the information recording region of the first substrate And an adhesive layer that adheres so that the surfaces on which are formed face each other.

According to the third aspect of the present invention, unlike the conventional pit art, it is possible to freely change the density of an image such as a character or a figure, and to perform a high-quality display. Further, since it can be manufactured without a cutting step of recording a spiral or concentric pit row like a conventional pit art, it can be manufactured in a short time and at a low cost.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining a cross section of a first embodiment of an optical information recording medium according to the present invention. In the figure, 101 is a first transparent substrate, 102 is an information recording area,
103 is a reflective film, 104 is an adhesive layer, 105 is a second transparent substrate, 106 is a center hole, and 107 is an image display area.
The optical information recording medium according to the present embodiment has a first transparent substrate 10 having an information recording area 102 covered with a reflective film 103 on one side.
1 and information related to the information recorded in the information recording area are displayed by a group of dots, and a second transparent substrate 105 having on one side an image display area 107 covered with a reflective film 103 is a transparent adhesive layer 104. This is an optical disk that is bonded through the optical disk. In the following description, the first transparent substrate 101
In addition, the surface on the side of the adhesive layer 104 of the second transparent substrate 105 is referred to as a back surface, and the surface on the side opposite to the adhesive layer 104 is referred to as a front surface.

FIG. 2 is a view for explaining the plane of the optical information recording medium according to the first embodiment of the present invention. In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. 201
Denotes an image, and 202 denotes a dot group. 203 is a dot. FIG. 2 shows the optical disc shown in FIG.
FIG. 3 is a plan view as viewed from the front side of FIG. Second transparent substrate 105
The image display area 107 on the back surface of the first transparent substrate 10
An image 2 composed of a dot group 202 in which information related to the information recorded in one information recording area 102, for example, a title, a publisher name, etc.
01 is recorded.

Each dot 203 is formed on the second transparent substrate 105.
Is a substantially semicircular concave portion and / or convex portion formed on the back surface of the image 201.
In the range of several μm to several tens μm according to the density of the light. The diameter of the dot 203 is determined by the resolution set. For example, when the image 201 is displayed at a resolution of 600 dpi, the diameter of the dot 203 is about 40 μm at the maximum. In this embodiment, the image 201 is a character of "DVD" displayed in three gradations. When specularly reflected light is obtained from a portion where no dots are formed and the image 201 is viewed at the brightest viewing angle, the portion that is made to be the darkest (darkest) due to light scattering and diffraction is a dot 203a having a large diameter. I do. Also, by gradually changing the diameter of the dots 203 to the dots 203b and 203c, an image having a halftone can be displayed. The depth (height) of the dot 203 in this embodiment is
Information pits such as conventional CDs, LDs (Laser Discs), and DVDs may be used. If the diameter of the dot 203 is three or more, a gradation display of a plurality of gradations of three or more gradations can be performed. In the present embodiment, the number of dots 203 per unit area is fixed, and the density of the image 201 (halftone) is displayed by the diameter of the dot 203.

As another method of expressing the density, each dot 20
A method is also possible in which the size of the dot 3 is kept constant and the distribution of the dots 203 is changed according to the density of the image 201 to be displayed. In this case, the dots 203 are formed at a high density in a portion that is to be made darkest due to light scattering and diffraction.
The dots 203 are formed at a low density in a portion desired to be bright. Of course, the method of changing the diameter of the dots 203 and the method of changing the density of the dots 203 may be used together. Furthermore, in this embodiment, the shape of each dot 203 is described as being substantially semicircular, but may be a regular polygon, an oval, a rectangle, or the like.

By forming the reflection film 103 on the back surface of the second transparent substrate 105, the image 201 can be viewed similarly to the conventional pit art, and can be displayed in three gradations. . If the diameter of the dot 203 is three or more, a gradation display of a plurality of gradations of three or more gradations can be performed.

Next, a method of manufacturing an optical information recording medium having the second transparent substrate 105 having the image 201 composed of the dot group 202 according to the present embodiment will be described. FIG. 3 is a diagram illustrating a part of the method for manufacturing the optical information recording medium according to the first embodiment of the present invention. In the figure, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. 301 is a photomask, 3
02 is a photoresist, and 303 is a glass master. First, as shown in step 11, a predetermined image 201 to be formed on the back surface of the second transparent substrate 105 is created by a personal computer or the like. The image 201 is displayed as a dot group 202 with a predetermined resolution.

As shown in step 12, the created image 20
The negative image of 1 is printed on a resin sheet by a printer or the like,
A photomask 301 is created. At this time, the ink used for printing does not transmit the light having the wavelength used in the exposure step 13. In other words, since the photomask 301 is a negative image, the dots 203 transmit light used for exposure in the exposure step 13.

Then, as shown in step 13, a photomask 301 is brought into close contact with a glass master 303 on which a photoresist film 302 has been applied and which has been subjected to a pre-baking process, and light having a wavelength to which the photoresist film 302 is exposed is applied. Irradiate. By this step, only the portion of the photoresist film 302 that corresponds to the dot group 202 displaying the predetermined image 201 is exposed. Next, the photomask 301 is separated from the glass master 303. At this time, sufficient care is taken so that the surface of the photoresist film 302 is not damaged.

After the completion of the step 13, the second transparent substrate 105 having the image 201 composed of the dot group 202 of the present embodiment is provided through the steps following the step 4 in FIG. An optical information recording medium is manufactured.

According to the optical information recording medium of the first embodiment of the present invention, unlike a conventional pit art, an image 201 such as a character or a figure is displayed by a dot group 202 composed of concave portions and / or convex portions. As a result, the density of the image 201 such as a character or a figure can be freely changed, and a high-quality display can be performed. Also, unlike conventional optical information recording media on which pit art is formed, it can be manufactured without a cutting step of recording a spiral or concentric pit row, so that characters, graphics, etc. can be manufactured at low manufacturing cost. The optical information recording medium having the image 201 can be manufactured.

Next, a second embodiment of the optical information recording medium of the present invention will be described. FIG. 4 is a diagram for explaining a cross section of the optical information recording medium according to the second embodiment of the present invention. In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. Reference numeral 401 denotes a colored adhesive layer. The optical information recording medium of the present embodiment has a first transparent substrate 101 having an information recording area 102 covered on one side with a reflective film 103 and information related to information recorded in the information recording area formed by a dot group 202. This is an optical disc in which a second transparent substrate 105 having a displayed image display area 107 on one side is bonded via a colored adhesive layer 104 colored with a predetermined coloring material.
In the following description, the surface of the first transparent substrate 101 and the second transparent substrate 105 on the side of the adhesive layer 104 is referred to as a back surface, and the surface opposite to the adhesive layer 104 is referred to as a front surface.

The optical information recording medium of the present embodiment has a dot group 2
02, an arbitrary image 201 is formed in the image display area 107 on the back surface of the second transparent substrate 105.
This is the same as the optical information recording medium of the second embodiment, except that the image display area 107 of the second transparent substrate 105 is not covered by the reflective film 103. Further, instead of the adhesive layer 104 for bonding the first transparent substrate 101 and the second transparent substrate 105, a colored adhesive layer 401 formed by adding a predetermined coloring material to an ultraviolet curable resin or the like is formed. But they are different.

Generally, in a DVD, an ultraviolet curable resin is used as the adhesive layer 104 because the film can be formed with a uniform thickness. The refractive index of the ultraviolet curable resin is about 1.5. Generally, resin substrates such as polycarbonate are used as the second transparent substrate 105, and the refractive index of these resin substrates is about 1.5. Therefore, the second
2 on the back surface of the transparent substrate 105
In the case where the second transparent substrate 105 and the adhesive layer 104 are adhered to each other without forming the reflective film 103 even if the reflective film 103 is formed, the refractive indices of the two are almost equal. The amount of reflected light is small, and the image 201 cannot be displayed visually. Therefore, in the optical information recording medium of this embodiment, the UV curable resin is colored by adding a coloring material of a desired color to the UV curable resin, the refractive index is changed, and the UV curable resin is colored and adhered to the second transparent substrate 105. The difference in refractive index from the layer 401 was set to be large. Furthermore, utilizing the diffraction effect of light,
In order to obtain the maximum contrast, the depth (height) of the dot 203 is controlled by the coloring material used.

For example, a case in which an azo dye having a red color is used as a coloring material will be described. A red azo dye is added as a coloring material to the ultraviolet curable resin to form a colored adhesive layer 401. At this time, the addition amount of the coloring material is adjusted so that the refractive index of the coloring adhesive layer 401 in the red wavelength region is different from the refractive index of the second transparent substrate 105. Here, the azo dye is used in a wavelength range of 605 nm to 700 n in the red wavelength range.
Since m has no absorption, light in this wavelength range is reflected at the interface with the second transparent substrate 105. Therefore, the dot 203
Is set to a depth (height) of 150 nm to 175 nm, which is a quarter of the wavelength in the red wavelength region, the portion of the dot 203 and the mirror surface portion other than the dot 203 Is maximized, and the image 201 becomes visible. This is because, when the depth (height) of the dot 203 is set to ４ of the wavelength of the desired light (red light in this embodiment), the light reflected from the dot 203 and the reflected light The phase with the light reflected from the mirror surface portion other than the dot 203 is 1
This is because they differ by 80 degrees. In the case of the optical information recording medium of this embodiment, since the surface on which the dots 203 are formed is the back surface of the second transparent substrate 105, the depth of the dots 203 is considered in consideration of the refractive index n of the second transparent substrate 105. The height (height) may be set to 1/4 of the wavelength in the red wavelength region. For example, when the refractive index of the second transparent substrate 105 is 1.53, the depth (height) of the dot 203 at which the maximum contrast is obtained is 99 nm to 114 nm.

When a coloring material other than red, for example, a coloring material such as a blue cyanine dye is used, the depth (height) of the dot 203 is adjusted to the blue wavelength range (435 nm to 480 nm).
Is set to 1/4 of the wavelength of the dot 203, the dot 203 part and the dot 203 are similar to the case where the red coloring material is used.
The contrast with the mirror surface portions other than the above can be maximized, and the image 201 can be viewed even in a configuration without a reflective film.

The depth (height) of the dot 203 can be adjusted by the thickness of the photoresist film 302 shown in FIG. The thickness of the photoresist film 302 is adjusted by the number of rotations of the glass master disk 303 when applying the photoresist liquid to the glass master disk 303, the concentration of the applied photoresist liquid, and the like.

According to the optical information recording medium of the second embodiment of the present invention, unlike a conventional pit art, an image 201 such as a character or a figure is displayed by a dot group 202 composed of concave portions and / or convex portions. As a result, the density of the image 201 such as a character or a figure can be freely changed, and a high-quality display can be performed. Also, unlike an optical information recording medium in which a conventional pit art is formed, since it can be manufactured without a cutting step of recording a spiral or concentric pit row, it can be manufactured in a short time. , And can be manufactured at low manufacturing cost. Further, since it is not necessary to provide a reflective film for covering the image display area 107 on the second transparent substrate 105, the colored adhesive layer 401 is sufficiently irradiated with ultraviolet rays, so that an optical information recording medium with high adhesive strength can be provided.

Next, an optical information recording medium according to a third embodiment of the present invention will be described. FIG. 5 is a diagram illustrating a cross section of a medium of the third embodiment of the optical information recording medium of the present invention.
In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

The optical information recording medium according to the present embodiment has a reflective film 10
A first transparent substrate 101 having an information recording area 102 covered on one side with an information recording area 102, and an image relating to information recorded in the information recording area are displayed by a distribution of a rough surface portion and a smooth surface portion,
This is an optical disk in which a second transparent substrate 105 having an image display area 107 covered on one side with a reflective film 103 is bonded via a transparent adhesive layer 104. In the following description, the first transparent substrate 101 and the second transparent substrate 105
The surface on the side of the adhesive layer 104 is the back surface, and the surface on the side opposite to the adhesive layer 104 is the front surface.

FIG. 6 is a view for explaining the plane of the optical information recording medium according to the third embodiment of the present invention. In the figure, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. In the figure, 601 is a rough surface portion, and 602 is a smooth surface portion.
FIG. 6 shows the optical disc shown in FIG.
5 is a plan view seen from the front side of FIG. Second transparent substrate 10
5 is provided with an image display area 107 on the back side of the first transparent substrate 1.
01 has a relationship with the information recorded in the information recording area 102, for example, a title, a release source name, and the like. The rough surface portion 601 subjected to the rough surface processing, and the smooth surface portion 602 which is a smooth mirror surface are provided. Is recorded as an image 201 consisting of:

In FIG. 6, “D” as the image 201
The character portion of “VD” is a rough surface portion 601 subjected to rough surface processing, and the portion other than the character of “DVD” is a smooth surface portion 602. The rough surface portion 601 is roughened in an uneven shape by a process described later. Therefore, when the image display region 107 is covered with the reflective film 103 and viewed from the surface of the second transparent substrate 105, light is irregularly reflected only in the rough surface portion 601 and contrast is generated between the rough surface portion 601 and the smooth surface portion 602.
Image 20 of “DVD” displayed by rough surface portion 601
1 can be visually recognized. The roughness of the rough surface portion 601 is as uneven as that of the above-described pit row or dot group, that is, several tens to
It is preferably in the range of several hundred nm. Further, if the size of the unevenness is changed in one optical disc, the density of the image 201 can be changed to a plurality of gradations.

FIG. 7 is a diagram for explaining a process of producing an image on the optical information recording medium according to the third embodiment of the present invention. In the figure, the same parts as those in FIGS. 1, 2 and 3 are denoted by the same reference numerals, and description thereof will be omitted. 701 is a mirror stamper, 70
2 is a rough surface part, 703 is a smooth surface part. First, step 14
As shown in (1), a predetermined image 201 to be formed on the back surface of the second transparent substrate 105 is created by a personal computer or the like.

As shown in step 15, the created image 20
The negative image of 1 is printed on a resin sheet by a printer or the like,
A photomask 301 is created. At this time, the ink used for printing does not transmit the light having the wavelength used in the exposure step 16. That is, since the photomask 301 is a negative image, light used for exposure in the exposure step 16 is transmitted through the image 201 (the character portion of “DVD” in this embodiment).

Then, as shown in step 16, the photomask 301 is brought into close contact with the mirror-finished stamper 701 on which the surface has been sufficiently polished, the photoresist film 302 has been applied, and the prebaking treatment has been performed.
Irradiate light of a wavelength that is sensitive to light. By this step, only the portion of the photoresist film 302 facing the predetermined image 201 is exposed. Next, the photomask 301 is separated from the mirror stamper 701. At this time, sufficient care is taken so that the surface of the photoresist film 302 is not damaged.

Subsequently, as shown in step 17, the mirror-finished stamper 701 is set in the developing device, a developing solution is applied while rotating, and the photoresist film 302 in the exposed portion exposed in step 16 is dissolved and removed. I do. In this case, since the mirror stamper 701 is not transparent, it is not possible to monitor the diffracted light. Therefore, the progress of the development is controlled by the time confirmed by experiments and the like. When a predetermined time has elapsed, the development is stopped, and the developing solution is washed with the washing solution. At this time, the image 201 is formed as a concave portion on the surface of the photoresist film 302 of the mirror surface stamper 701.

Then, as shown in step 18, the developed and cleaned mirror surface stamper 701 is immersed in a solution such as an acid or an alkali, and the image 201 is subjected to a surface roughening treatment. Only a portion of the mirror stamper 701 corresponding to the portion of the image 201 that is not covered with the photoresist film 302 is corroded by a solution such as an acid or an alkali to become a rough surface portion.

In the character "DVD" as the image 201, a solution such as an acid or an alkali is dropped into the concave portion corresponding to each character, and the concentration of the solution dropped into the concave portion corresponding to each character is changed. By changing the corrosion time, the density of the image 201 can be changed to a plurality of gradations. For example, a solution of an acid or an alkali having the highest concentration is dropped into a concave portion of a portion which is to be darkest. Then, a solution such as an acid or an alkali having a low concentration is dropped into a concave portion of a portion which is desired to look bright. The concave portion into which the solution with the highest concentration was dropped is a mirror surface stamper 70.
Corrosion of the surface of No. 1 progresses fastest, becomes the roughest surface, and the concave portion where the solution with low concentration is dropped is a mirror surface stamper 7.
01, the progress of corrosion of the surface is slowed down, and the surface roughness is also reduced. In this way, the rough surface state can be changed for each character, and the shading can be made different.

Then, as shown in step 19, a solution such as an acid or an alkali is washed with a washing solution, a mirror stamper 701 is placed on a hot plate, heated at 80 ° C. for 30 minutes, post-baked, and dried. Let it.

The mirror stamper 701 on which the image 201 is formed as a rough surface is mounted on a molding machine to obtain the second transparent substrate 105 on which the image 201 is transferred. In this embodiment, the image 201 is a rough surface portion.
May be a smooth surface portion, and a portion other than the image 201 may be a rough surface portion.

According to the fourth embodiment of the present invention, unlike a conventional optical information recording medium on which pit art is formed, it can be manufactured without a cutting step of recording a spiral or concentric pit row. Therefore, it can be manufactured in a short time and can be manufactured at a low manufacturing cost.

[0059]

According to the optical information recording medium of the first embodiment of the present invention, an image such as a character or a graphic is displayed by a dot group composed of concave portions and / or convex portions. The density of an image such as a figure can be freely changed, and high-quality display can be performed. Further, since the optical information recording medium can be manufactured without passing through a cutting step of recording a spiral or concentric pit row like a conventional pit art, an optical information recording medium can be manufactured in a short time, and the cost can be reduced. Can be manufactured.

According to the optical information recording medium of the second embodiment of the present invention, an image such as a character or a figure is displayed by a dot group composed of concave portions and / or convex portions.
The density of an image such as a character or a figure can be freely changed, and high-quality display can be performed. Further, since the optical information recording medium can be manufactured without passing through a cutting step of recording a spiral or concentric pit row like a conventional pit art, an optical information recording medium can be manufactured in a short time, and the cost can be reduced. Can be manufactured. Further, since it is not necessary to provide a reflective film for covering the image display area on the second transparent substrate, the colored adhesive layer is sufficiently irradiated with ultraviolet rays.
Therefore, it is possible to provide an optical information recording medium having a high bonding strength.

According to the optical information recording medium of the third embodiment of the present invention, the optical information recording medium can be manufactured without passing through a cutting step of recording a spiral or concentric pit row like a conventional pit art. The optical information recording medium can be manufactured in a short time, and can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a cross section of a medium according to a first embodiment of the optical information recording medium of the present invention.

FIG. 2 is a diagram illustrating a plane of the optical information recording medium according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a part of the method for manufacturing the optical information recording medium according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a cross section of a medium of an optical information recording medium according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating a cross section of the optical information recording medium according to a fourth embodiment of the present invention.

FIG. 6 is a diagram illustrating a plane of a medium of an optical information recording medium according to a fourth embodiment of the present invention.

FIG. 7 is a view for explaining a step of forming an image on an optical information recording medium according to a fourth embodiment of the present invention.

FIG. 8 shows a DVD with a conventional pit art display.
The figure explaining the sectional structure of -5.

FIG. 9 shows a DVD with a conventional pit art display.
The figure explaining the sectional structure of -9.

FIG. 10 is an enlarged plan view of a conventional optical disk in which a numeral 1 is visually displayed as a dummy pattern of random patterns as an example.

FIG. 11 is a diagram illustrating a manufacturing process for forming a conventional dummy substrate provided with pit art.

[Explanation of symbols]

 Reference Signs List 101 first transparent substrate 102 information recording area 103 reflective film 104 adhesive layer 105 second transparent substrate 106 central hole 107 image display area 201 image 202 dot group 203 dot 301 photomask 302 photoresist film 303 glass master 401 colored adhesive layer 601 Rough surface 602 Smooth surface 701 Mirror surface stamper 702 Rough surface 703 Smooth surface 801a Substrate without information recording area 801b Substrate with information recording area 802 Transparent substrate 803 Reflective film 804 Protective layer 805 Adhesive layer 901a Information recording area No substrate 901b Substrate with information area 902 Transparent substrate 903 Reflective film 904 Protective layer 905 Adhesive layer 906 Transparent resin layer 907 Translucent film 1001 Pit 1002 Land 1003 Area representing number 1 1101 Glass master 1102 photoresist film 1103 hot plate 1104 exposure part 1105 pit 1106 nickel conductive film 1107 stamper 1108 dummy substrate 1109 reflection film 1110 adhesive layer 1111 information substrate

Claims (3)

[Claims] A first substrate having an information recording area formed on one side thereof; a transparent substrate having an image display area formed of a dot group comprising concave and / or convex portions formed on one side; A second substrate, comprising: a reflective film that covers the second substrate, wherein an image is displayed according to the size and / or distribution density of the dots in the dot group; and a surface of the second substrate on which the image display area is formed. An optical information recording medium, comprising: an adhesive layer that is adhered so that a surface of the first substrate on which the reflective film is formed faces each other. 2. A first substrate having an information recording area formed on one surface thereof, and a transparent substrate having an image display area formed of a dot group comprising concave and / or convex portions formed on one surface and having a refractive index of n. A second substrate on which an image is displayed according to the size and / or distribution density of the dots in the dot group; a surface of the second substrate on which the image display area is formed; and the first transparent substrate An adhesive layer that is adhered so that the surface on which the information recording area is formed faces each other, wherein the adhesive layer includes a coloring material having an absorption other than a wavelength of a predetermined color in a visible region, and a depth of the dot. The optical information recording medium is characterized in that the length is about 1/4 of the wavelength. 3. A first substrate having an information recording area formed on one side, a transparent substrate having an image display area formed on one side having a rough surface portion and a smooth surface portion, and a reflective film covering the image display region. A second substrate on which an image is displayed by the distribution of the rough surface portion and the smooth surface portion of the image display area; and a surface of the second substrate on which the image display area is formed and the first substrate. An optical information recording medium, comprising: an adhesive layer that is adhered so that a surface on which an information recording area is formed faces each other.