JP2003099993A - Manufacturing method of optical recording medium, and sheet for optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet improving the manufacturing efficiency and excellent in size accuracy by preventing exfoliation before lamination, attachment of a foreign object, and occurrence of a film thickness abnormity and a surface abnormity by suppressing shape distortion of the sheet due to winding up and an overflow of adhesives, to efficiently and reliably manufacture an optical disk by using this sheet, and to prevent squeeze-out light transmission layer to be formed by laminating with the substrate and the exposure from the outer periphery of the light to be formed by laminating with the base material by laminating the substrate, the exfoliration of the light transmission layer and the exposure of the information signal parts. SOLUTION: Before laminating, the sheet 1 being composed of a light transmission sheet 2, an adhesion layer 3, a protector 4 having a mark, and a mold releasing film 5 is supplied for every substrate in a full punching sheet style. After the lamination, the protector 4 is exfoliated. Punching of the sheet 1 for full punching is made from a mold releasing film 2 side. The principal surface of the substrate is laminated with a sheet to be coated, and the squeezed-out part of the sheet is eliminated by trimming.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet for producing an optical recording medium and a method for producing an optical recording medium. It is suitable.

[0002]

2. Description of the Related Art In recent years, in the field of information recording, various researches and developments regarding optical information recording systems have been advanced. This optical information recording system records and / or records without contact.
Alternatively, there is an advantage that reproduction can be performed and a recording density higher than that of the magnetic recording system by one digit or more can be achieved. Further, this optical information recording system has an additional advantage that it can be applied to each memory type such as a read-only type, a write-once type, and a rewritable type. Therefore, it is considered to be applied to a wide range of applications from industrial use to consumer use as a method that can realize an inexpensive large-capacity file.

Among them, particularly, an optical disk corresponding to a read-only memory type, such as a digital audio disk (DAD) or an optical video disk, has been widely spread.

An optical disc such as a digital audio disc is formed by forming an optical disc substrate, which is a transparent substrate on which an uneven pattern such as pits and grooves indicating information signals is formed,
A reflective film made of a metal thin film such as an aluminum (Al) film, and a protective film for protecting the reflective film from moisture (H ₂ O) and oxygen (O ₂ ) in the atmosphere are provided on the reflective film. Have a configuration. When reproducing the information signal on the optical disk, reproducing light such as laser light is emitted from the optical disk substrate side toward the concave-convex pattern, and the information signal is detected by the difference in reflectance between the incident light and the returning light due to the reproducing light. To do.

When manufacturing such an optical disk, first, an optical disk substrate having an uneven pattern is formed by an injection molding method. Next, by the vacuum deposition method,
A reflective film made of a metal thin film is formed on an optical disk substrate. Next, a protective film is formed by further applying an ultraviolet curable resin on the upper layer.

Now, in the above-mentioned optical information recording system, further higher recording density is required in recent years. Therefore, in order to meet the demand for higher recording density, by increasing the numerical aperture (NA) of the objective lens used when the reproduction light of the optical pickup is irradiated,
A technique for reducing the spot diameter of the reproduction light has been proposed.
That is, while the NA of the objective lens used for reproducing the conventional digital audio disc is 0.45, the NA of the conventional digital audio disc is 6 to 6.
DVD (Digital Versatile Di) with 8 times the recording capacity
There has been proposed a technique for reducing the spot diameter by setting the NA of the objective lens used when reproducing an optical video disc such as sc) to about 0.60.

As the NA of such an objective lens is increased, in order to transmit the reproduced light emitted,
It is necessary to thin the disc substrate in the optical recording medium. This is because the allowable amount of the angle (tilt angle) deviated from the perpendicular of the disc surface with respect to the optical axis of the optical pickup is small, and this tilt angle is affected by aberration and birefringence due to the thickness of the disc substrate. This is because it is easy. Therefore, the tilt angle is made as small as possible by thinning the disc substrate. For example, in the above-mentioned digital audio disc, the thickness of the substrate is about 1.2 mm. On the other hand, DV
In an optical video disc having a recording capacity 6 to 8 times that of a digital audio disc such as D, the thickness of the substrate is about 0.6 mm.

In consideration of future demand for higher recording density, it is necessary to make the substrate thinner.
Therefore, unevenness is formed on one main surface of the substrate to form an information signal portion, and a reflective film and a light transmission layer made of a thin film capable of transmitting light are sequentially laminated on the information signal portion, and the light transmission layer side There has been proposed an optical recording medium configured to reproduce an information signal by emitting reproduction light. like this,
In an optical recording medium which reproduces an information signal by irradiating reproducing light from the light transmitting layer side, it is possible to cope with higher NA of the objective lens by making the light transmitting layer thinner.

However, if the light-transmitting layer is thinned, it becomes difficult to form the light-transmitting layer by an injection molding method using a thermoplastic resin, which is generally used for manufacturing an optical disk. That is, it is very difficult to form a light-transmitting layer of about 0.1 mm that maintains good transparency while keeping the birefringence small in the conventional technique. Therefore, a method of forming the light transmitting layer with an ultraviolet curable resin has been devised.

[0010]

However, when the light transmitting layer is made of an ultraviolet curable resin, it is very difficult to make the light transmitting layer have a uniform film thickness on the surface of the substrate. Therefore, it becomes difficult to stably reproduce the information signal.

A sheet having a thickness of 0.1 mm and a release film laminated on a light-transmitting sheet made of a thermoplastic resin, or a sheet in which the light-transmitting sheet is sandwiched between two release films, A method of forming a light-transmitting layer by using a sheet in which a pressure-sensitive adhesive layer is sandwiched between two films and sticking it to the substrate surface by roller pressure bonding has been considered.

However, in this method, deformation of the sheet at the time of pressure bonding and protrusion of the adhesive layer to the reading surface side occur, or between the light transmissive sheet and the pressure sensitive adhesive layer, or between the pressure sensitive adhesive layer and the substrate. It is easy for foreign matter to get in between.
As a result, it becomes difficult to form the light transmitting layer with a uniform film thickness and also to form a highly reliable light transmitting layer, and it becomes more difficult to stably reproduce the information signal. turn into.

Therefore, a method of laminating a planar annular laminating sheet having a three-layer structure in which a pressure-sensitive adhesive layer is provided on one surface of a light-transmitting sheet and a protector is provided on the opposite surface in advance is attached to a disk substrate. I recalled. Then, in the case of supplying the bonding sheet having the three-layer structure, a method of arranging and supplying the wide strip-shaped release sheet on one surface has been considered in consideration of transport efficiency and the like.

That is, as shown in FIG. 36, the half-cut sheet 100 is a laminating sheet 10 having a three-layer structure.
1, a pressure sensitive adhesive layer 103, a light transmissive sheet 104, and a protector 105 are sequentially laminated on one surface of a wide strip-shaped release sheet 102. Then, when the bonding sheet 101 is conveyed to the bonding position, the release sheet 102 is sent along the longitudinal direction thereof, so that each bonding sheet 10
1 moves and is sequentially supplied.

Further, such a half punched sheet 100
Is rolled into a roll when stored. Therefore, as shown in FIG. 37, in the rolled-up state, a step difference is generated between the release sheet 102 and the bonding sheet 101 having a three-layer structure and having a planar annular shape, by the amount corresponding to the bonding sheet 101. In addition, the half punched sheet 100
If the sheet is wound in the state where there is a step, the shape of the half-punched sheet 100 changes due to the influence of the pressure due to the tightening of the winding. Due to this shape change, problems such as abnormal film thickness and abnormal surface properties occur.

Furthermore, if the half-punched sheet 100 is left in a rolled-up state for a long time, it may be peeled off spontaneously due to the difference in rigidity between the release sheet 102 and the pressure-sensitive adhesive layer 103. . In particular, as shown in FIG. 38, in the half punched sheet 100 having a planar annular shape, the outer peripheral edge portion 101 of the laminating sheet 101.
In a (periphery edge portion, wavy line portion in FIG. 38A, inside circle in FIG. 38B), peeling is often caused. Then, when the interface peeling occurs at the outer peripheral edge 101a of the bonding sheet 101, the adhesive force of the pressure-sensitive adhesive layer 103 changes, the peeling pattern or the film thickness of the bonding sheet 101 changes, and foreign matter is mixed. Various problems occur.

Further, such a half punched sheet 100
Is manufactured as follows. That is, as shown in FIG. 39, first, the pressure-sensitive adhesive layer 1 is formed on the release sheet 102.
03, the light transmissive sheet 104, and the protector 105 are sequentially stacked. Next, the film thickness d of the release sheet 102
There is a step on the cutting edge by the amount of, and a predetermined part is punched out by a punching blade. Specifically, the inner peripheral punching blade 10
6, the protector 105 and the light transmitting sheet 10
4. The pressure-sensitive adhesive layer 103 and the release sheet 102 are all punched out, that is, the so-called total punching is performed, and the protector 105, the light-transmissive sheet 104 and the pressure-sensitive adhesive layer 103 are cut by the outer peripheral punching blade 107, and the release sheet 102 is removed. The so-called half removal is performed. After that, the unnecessary portion is peeled off, and the half punched sheet 1
00 is manufactured.

However, in the half-punched sheet 100 manufactured in this way, the punching dimensional accuracy may be inferior. Therefore, the present inventor has investigated the cause of the poor punching dimensional accuracy of the half-punched sheet 100, and has found the following.

That is, the blade edge of the inner peripheral punching blade 106 is projected by the thickness d of the release sheet 102 as compared with the blade edge of the outer peripheral punching blade 107. Therefore, when performing punching or cutting using these inner peripheral punching blade 106 and outer peripheral punching blade 107, first, the inner peripheral punching blade 106 is first placed at the position of the inner peripheral portion of the bonding sheet 101. Contact is made and pressure is applied there. Due to this pressure, the outer peripheral portion of the bonding sheet 101 is slightly lifted. Then, when the outer peripheral portion is slightly raised and unstable, the outer peripheral punching blade 107 contacts the protector 105. As a result, the punching dimension accuracy of the outer peripheral portion is deteriorated.

The present inventor not only deteriorates the punching dimensional accuracy in the case of half punching, but also
We also found that the following problems occur. That is, as shown in FIG. 40, since the inner peripheral punching blade 106 and the outer peripheral punching blade 107 have different edge sizes, the portion located on the outer peripheral portion of the bonding sheet 101 is unstable as described above. In this state, the outer peripheral punching blade 107 contacts. Therefore, the cutting ability in cutting the outer peripheral portion of the bonding sheet 101 by the outer peripheral punching blade 107 may decrease. If the cutting ability is reduced, the pressure-sensitive adhesive 103a of the pressure-sensitive adhesive layer 103 will protrude from the outer peripheral portion. The pressure-sensitive adhesive 103a that protrudes is
This causes problems such as abnormal surface properties of the light transmitting layer, abnormal film thickness, and adhesion to manufacturing equipment.

Further, in the case of designing an optical recording medium manufacturing apparatus, specifically, a bonding apparatus on the assumption that the half-punched sheet 100 is used, the influence of handling and front and back processes is taken into consideration in FIG. As shown
A blank space that is not used for bonding is required in four directions around the planar annular bonding sheet 101. Specifically, the outer diameter φ ₀ of the bonding sheet 101 is 120
If the mm, it is necessary to both sides of the margin d ₀ in the longitudinal direction to the sheet 101 for bonding along the direction perpendicular of the release sheet 102 to about 10 mm, the width L ₀ of the release sheet 102, 140 mm And need to. Further, the interval l ₀ between the outer peripheral ends of the two bonding sheets 101 is required to be about 30 mm, so the member pitch p ₀ of the bonding sheets 101 is about 150 mm. As described above, the bonding sheet 101 is formed into a flat circular ring shape by half-punching a plurality of layers of the original sheet while leaving the release sheet 102, and then the parts other than the bonding sheet 101 are It will be discarded. Therefore, as the area of this discarded portion becomes wider, the efficiency of manufacturing the bonding sheet 101 becomes lower.

Therefore, an object of the present invention is to prevent the peeling of sheets before bonding to prevent foreign matters from adhering to the adhesive layer, and at the same time, to change the shape of the sheet due to tightness of the winding and the pressure-sensitive adhesive forming the adhesive layer. An object of the present invention is to provide a sheet for an optical recording medium, which is capable of preventing an abnormal film thickness and an abnormal surface property of the sheet by suppressing the protrusion so as to have excellent dimensional accuracy and improve the production efficiency of the sheet.

Another object of the present invention is to provide a method of manufacturing an optical recording medium, which can be manufactured with high efficiency and high reliability, using an optical recording medium sheet. Especially.

Still another object of the present invention is to prevent the light transmitting layer produced by bonding the optical recording medium sheet and the disc substrate from sticking out from the outer periphery of the disc substrate, Another object of the present invention is to provide a method of manufacturing an optical recording medium capable of preventing peeling of the recording medium and exposure of the information signal portion.

[0025]

In order to achieve the above object, the first invention of the present invention provides a disc substrate and an information signal recordable and / or provided on one main surface of the disc substrate. An information signal section configured to be reproducible, and a light transmission layer configured to transmit a laser beam used for recording and / or reproduction of the information signal, wherein the light transmission layer is
At least a light-transmissive sheet that can transmit laser light,
An adhesive layer that can transmit laser light and that adheres a light-transmissive sheet to one main surface of the disk substrate. The light-transmissive sheet is attached to the one main surface of the disk substrate via the adhesive layer. In the method for producing an optical recording medium, the optical recording medium having at least a light-transmissive sheet, an adhesive layer, and a first protective sheet releasably laminated on the adhesive layer side in a step before bonding. The present invention is characterized in that it has a step of supplying a sheet, and the supply of the optical recording medium sheet to the disk substrate in a bonded state is carried out for each disk substrate in a fully-extracted sheet.

In the first aspect of the invention, typically, the optical recording medium sheet has a planar annular shape.

In the first aspect of the invention, typically, the sheet for optical recording medium comprises a light-transmitting sheet, an adhesive layer, and
It comprises a peelable first protective sheet provided on the adhesive layer side. Further, in the first aspect of the present invention, the identification mark is provided on the first protective sheet. Further, the first protective sheet is colored in a visible color.

In the first aspect of the invention, typically, the second surface of the light-transmissive sheet is provided on the surface opposite to the surface on which the adhesive layer is provided so as to be peelable from the light-transmissive sheet.
Protective sheet is provided. The second protective sheet is preferably made of polyethylene resin,
Other materials can also be used. Further, the second protective sheet is provided with a visually recognizable identification mark that is distinguishable from the first protective sheet. Also, the first identification mark is provided on the first protective sheet, and
A second identification mark is provided on the second protective sheet, and the first identification mark and the second identification mark can be identified from each other. Further, the second protective sheet is colored in a color that is distinguishable from the first protective sheet and is visible. Further, the first protective sheet is colored in a visible color, and the second protective sheet is colored in a visible color that is distinguishable from the color in the first protective sheet.

In the first aspect of the invention, typically, the sheet for optical recording medium comprises a light-transmitting sheet, an adhesive layer, and
The peelable third protective sheet is provided on the adhesive layer side, and the hard coat layer is provided on the surface of the light transmissive sheet opposite to the adhesive layer side. And
Preferably, the third protective sheet is provided with an identification mark, or the third protective sheet is colored in a visible color. Furthermore, more preferably, a peelable fourth protective sheet is provided on the surface of the hard coat layer, and the fourth protective sheet is made of polyethylene resin, but other materials are used. Is also possible. Further, preferably, the fourth protective sheet is provided with a visually recognizable identification mark that is distinguishable from the third protective sheet. Further, the third protective sheet is provided with the third identifying mark, the fourth protective sheet is provided with the fourth identifying mark, and the third identifying mark and the fourth identifying mark are provided. And can be distinguished from each other. As another method, the fourth protective sheet is colored in a color that is visible and distinguishable from the third protective sheet. Further, in this method, more preferably, the third protective sheet is colored in a visible color, and the fourth protective sheet is visible and distinguishable from the color in the third protective sheet. It is colored in various colors.

In the first aspect of the present invention, when the sheet for optical recording medium is used to form the light transmitting layer of the optical recording medium, scratches are prevented from being formed on the surface of the light transmitting layer of the manufactured optical disc. Therefore, a hard coat layer is typically provided on the side of the light-transmissive sheet opposite to the side on which the first adhesive layer is provided. Further, in the first invention, typically, a second protective sheet is provided on the side of the light transmissive sheet on which the hard coat layer is provided, and preferably, the second protective sheet is provided. Is made of polyethylene resin. Moreover, in this 1st invention, after peeling a protective sheet, a hard coat layer, a light-transmissive sheet, and 1st
In order to prevent the adhesive layer of No. 1 from becoming wavy, the adhesive force between the first protective sheet and the first adhesive layer is typically higher than the adhesive force between the hard coat layer and the second protective sheet. It is small, and the magnitude of the force required for peeling the second protective sheet is 0.15 N / 5c under the assumption of the magnitude relation of the adhesive force.
m or more and 2.00 N / 5 cm or less, and the magnitude of the force required for peeling the first protective sheet is 0.10 N / 5 cm or more and 1.
It is not more than 00 N / 5 cm. Also, the hard coat layer is
In order to facilitate the formation and to suppress the increase in cost by diverting commonly used equipment, specifically, it is made of UV curable resin, but it is made of diamond-like carbon (diamond-like carbon, DLC). It is also possible to configure.

According to a second aspect of the present invention, a disc substrate, an information signal section provided on one main surface of the disc substrate and configured to record and / or reproduce an information signal, and an information signal portion. A light-transmissive layer configured to transmit a laser beam used for recording and / or reproduction, the light-transmissive layer being capable of transmitting at least a laser-transmissive sheet and a laser beam. A method for manufacturing an optical recording medium comprising an adhesive layer for adhering a light-transmissive sheet to one main surface of a disk substrate, the optical recording medium having at least the light-transmissive sheet and the adhesive layer, and having an outer diameter larger than the outer diameter of the disk substrate. And a step of adhering the optical recording medium sheet to the surface of the adhesive layer and the main surface of the disc substrate so as to face each other, and a sheet for optical recording medium. It is characterized in that a step of trimming the bets on the shape of the disk substrate.

In the second invention, the optical recording medium sheet typically has a rectangular shape.

In the second invention, typically, the optical recording medium sheet is trimmed using a cutter blade, a cutting tool, a laser cutter, an ultrasonic cutter or a press die.

In the second invention, typically, the sheet for optical recording medium comprises a light-transmitting sheet, an adhesive layer, and
It comprises a peelable first protective sheet provided on the adhesive layer side. Further, preferably, the first protective sheet is provided with an identification mark. As another method, the first protective sheet is colored in a visible color. Further, in the second invention, preferably, a second protective sheet configured to be peelable from the light-transmissive sheet is provided on a surface of the light-transmissive sheet opposite to a surface on which the adhesive layer is provided. The second protective sheet is provided and is specifically made of polyethylene resin, but other materials can be used. In addition, preferably, the second protective sheet is provided with a visually recognizable identification mark that is distinguishable from the first protective sheet. Further, the first protective sheet is provided with the first identification mark, the second protective sheet is provided with the second identification mark, and the first identification mark and the second identification mark are provided. And can be distinguished from each other. Further, as another method, preferably, the second protective sheet is colored in a color that is distinguishable from the first protective sheet and is visible. Also, preferably, the first protective sheet,
The second protective sheet is colored in a visible color, and the second protective sheet is colored in a visible color that is distinguishable from the color in the first protective sheet.

In the second aspect of the invention, typically, the sheet for optical recording medium comprises a light-transmitting sheet, an adhesive layer, and
The peelable third protective sheet is provided on the adhesive layer side, and the hard coat layer is provided on the surface of the light transmissive sheet opposite to the adhesive layer side. Further, an identification mark is provided on the third protective sheet. As another method, the third protective sheet is colored in a visible color. Further, in the second invention, typically, a peelable fourth protective sheet is provided on the surface of the hard coat layer, and the fourth protective sheet is typically Although it is made of polyethylene resin, other materials can be used. In the second aspect of the invention, preferably, the fourth protective sheet is provided with a visually recognizable identification mark that is distinguishable from the third protective sheet. Further, in the second invention, more preferably, the third protective sheet is provided with a third identification mark, and the fourth protective sheet is provided with a fourth identification mark. The third identification mark and the fourth identification mark can be identified from each other. In the second aspect of the invention, as another method, the fourth protective sheet is colored in a color that is distinguishable from the third protective sheet and is visible. Further, more preferably, the third protective sheet is colored in a visible color, and
The protective sheet of (3) is also colored in a color that is visible and distinguishable from the color of the third protective sheet.

In the second aspect of the invention, when the sheet for optical recording medium is used to form the light transmitting layer of the optical recording medium, scratches are prevented from being formed on the surface of the light transmitting layer of the manufactured optical disc. Therefore, a hard coat layer is typically provided on the side of the light-transmissive sheet opposite to the side on which the first adhesive layer is provided. Further, in the first invention, typically, a second protective sheet is provided on the side of the light transmissive sheet on which the hard coat layer is provided, and preferably, the second protective sheet is provided. Is made of polyethylene resin. Further, in the second invention, after the protective sheet is peeled off, the hard coat layer, the light transmissive sheet and the first
In order to prevent the adhesive layer of No. 1 from becoming wavy, the adhesive force between the first protective sheet and the first adhesive layer is typically higher than the adhesive force between the hard coat layer and the second protective sheet. It is small, and the magnitude of the force required for peeling the second protective sheet is 0.15 N / 5c under the assumption of the magnitude relation of the adhesive force.
m or more and 2.00 N / 5 cm or less, and the magnitude of the force required for peeling the first protective sheet is 0.10 N / 5 cm or more and 1.
It is not more than 00 N / 5 cm. Also, the hard coat layer is
In order to facilitate the formation and to suppress the increase in cost by diverting commonly used equipment, specifically, it is made of UV curable resin, but it is made of diamond-like carbon (diamond-like carbon, DLC), etc. It is also possible to comprise from.

A third aspect of the present invention is a disc substrate, an information signal portion capable of recording and / or reproducing an information signal on one main surface of the disc substrate, and a laser for irradiating the information signal portion. A light-transmitting layer in an optical recording medium configured by sequentially providing a light-transmitting layer capable of transmitting at least light, a light-transmitting sheet capable of transmitting at least laser light, and a light-transmitting sheet capable of transmitting laser light. Composed of an adhesive layer for adhering the elastic sheet to one main surface of the disk substrate,
In a sheet for an optical recording medium used when forming a light transmitting layer, at least a light transmitting sheet, an adhesive layer, and a first protective sheet releasably provided on the adhesive layer side, It is characterized in that it is formed by punching from the side of the first protective sheet.

In the third aspect of the present invention, when the information signal is recorded / reproduced by rotating the optical recording medium and irradiating the laser beam, the optical recording medium is bonded in order to have a planar annular shape. In order to be able to cover the information signal section on the disc substrate,
Typically, the sheet for optical recording medium has a planar annular shape.

In the third aspect of the present invention, a typical case is used in which a disc substrate and an optical recording medium sheet larger than the disc substrate are bonded together and then the portion of the optical recording medium sheet protruding from the disc substrate is removed by cutting. Has
The sheet for optical recording medium has a rectangular shape and circular through holes.

In the third aspect of the invention, the identification mark is typically provided on the first protective sheet. As another method, the first protective sheet is colored in a visible color.

In the third aspect of the invention, typically, the second surface of the light-transmissive sheet is provided on the surface opposite to the surface on which the adhesive layer is provided so as to be peelable from the light-transmissive sheet.
Protective sheet is provided. The second protective sheet is made of polyethylene resin. The second protective sheet is provided with a visually recognizable identification mark that is distinguishable from the first protective sheet. The first protective sheet is provided with the first identification mark, the second protective sheet is provided with the second identification mark, and the first identification mark and the second identification mark are They are distinguishable from each other. As another method, the second protective sheet is colored in a color that can be distinguished from the first protective sheet and is visible. The first protective sheet is colored in a visible color, and the second protective sheet is colored in a visible color that is distinguishable from the color in the first protective sheet.

In the third aspect of the present invention, a hard coat layer is typically provided on the surface of the light transmissive sheet opposite to the side on which the adhesive layer is provided. Then, a peelable third protective sheet is provided on the surface of the hard coat layer, and the third protective sheet is made of polyethylene resin, but other materials can be used. . In addition, the third protective sheet is provided with a visually recognizable identification mark that is distinguishable from the first protective sheet. Further, the first protective sheet is provided with the third identification mark, the third protective sheet is provided with the fourth identification mark, and the third identification mark and the fourth identification mark are provided. And can be distinguished from each other. In addition, as another method, the third protective sheet is colored in a color that is distinguishable from the first protective sheet and is visible. Also, preferably,
The first protective sheet is colored in a visible color, and the third protective sheet is colored in a visible color that is distinguishable from the color in the first protective sheet.

In the present invention, typically, the disk substrate has a planar annular shape. Further, in the present invention, when it is necessary to maintain compatibility with a conventional reproducing apparatus for optical recording media or a recording / reproducing apparatus, the outer diameter of the disk substrate having a flat annular shape is 120 to 130 mm.

In the present invention, the adhesive layer is typically made of a pressure sensitive adhesive.

In the present invention, the light transmissive sheet is preferably made of the same material as the material used for the substrate in order to minimize warpage or distortion in the manufactured optical recording medium. In addition, the thickness of the light transmissive sheet is
Typically, it is configured to be smaller than the thickness of the substrate, and specifically, it is selected from 30 μm or more and 150 μm or less. In the present invention, typically, the substrate and the light-transmitting sheet are made of a light-transmitting thermoplastic resin, and specifically, a resin having a low water absorption property such as polycarbonate (PC) or cycloolefin polymer. Is used. As the material used for the substrate, for example, a substrate made of a metal such as aluminum (Al), a glass substrate, or a substrate made of a resin such as polyolefin, polyimide, polyamide, polyphenylene sulfide, or PET can be used. is there.

In the present invention, typically, the light transmissive sheet is a GaN-based semiconductor laser (emission wavelength 400 nm band, blue emission) or ZnSe-based semiconductor laser (emission wavelength) used for recording / reproducing at least information signals. 500n
m band, green), or an AlGaInP-based semiconductor laser (emission wavelength of 635 to 680 nm, red) or the like, which is made of a non-magnetic material capable of transmitting laser light.
Specifically, it is made of a light-transmitting thermoplastic resin such as polycarbonate. Further, in the present invention, the protective film is preferably made of polyethylene terephthalate (PET), and specifically, at least one surface of the PET is coated with the second adhesive. Further, a sheet to be placed on the substrate is manufactured by adhering the surface on which the second adhesive is applied to one surface of the light transmissive sheet.

The present invention is preferably configured to record information using an objective lens whose NA is increased to about 0.85 by combining two lenses in series. It is applicable to an optical recording medium having a light transmitting layer such as a digital video recording system) and a sheet used for manufacturing the optical recording medium. red, emission wavelength is 400 nm
A so-called DVR-blue using a semiconductor laser of a certain degree
It can be applied to an optical recording medium such as e.

According to the method of manufacturing an optical recording medium according to the first aspect of the present invention configured as described above, the supply of the optical recording medium sheet to the disc substrate by bonding is performed for each disc substrate. By performing the sheet-cutting process, individual sheets can be stored in a stack before the feeding.

Further, according to the method of manufacturing the optical recording medium of the second aspect of the present invention configured as described above, it is possible to cover the disc substrate and one main surface of the disc substrate on which the information signal section is provided. After adhering the sheet with another sheet, the sheet and the disk substrate can be made to have the same diameter by trimming the sheet so as to match the outer periphery of the disk substrate, and the sheet does not protrude from the outer periphery of the disk substrate. It is possible to prevent the information signal portion from being exposed.

According to the optical recording medium sheet of the third aspect of the present invention constructed as described above, at least the light transmissive sheet, the adhesive layer, and the adhesive layer side are provided so as to be peelable. And a first protective sheet provided,
By being punched from the side of the first protective sheet, it is possible to minimize the cutting thickness until the cutting tool used for punching reaches the adhesive layer. It is possible to prevent dimensional variation.

[0051]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In all the drawings of the following embodiments, the same or corresponding parts are designated by the same reference numerals.

First, the sheet for an optical recording medium according to the first embodiment of the present invention will be described. FIG. 1 shows an optical recording medium sheet according to the first embodiment, and FIG.
Another example of the sheet for an optical recording medium is shown in FIG.

As shown in FIG. 1A, the optical recording medium sheet 1 according to the first embodiment has a structure in which it is punched out into a flat annular shape, and a through hole 1a is provided in the center thereof. ing. Further, as shown in FIG. 1B, in this optical recording medium sheet 1, an adhesive layer 3 made of, for example, a pressure sensitive adhesive (PSA) is attached to one surface of the light transmissive sheet 2. Further, the protector 4 is laminated on the surface of the light transmissive sheet 2 opposite to the surface on which the adhesive layer 3 is adhered. A release film 5 is laminated on the surface of the adhesive layer 3 opposite to the light-transmitting sheet 2. Further, as shown in FIG. 2, a hard coat layer 6 is further provided on the surface of the light transmissive sheet 2 opposite to the side on which the adhesive layer 3 is provided, and the protector 4 is provided on the surface of the hard coat layer 6. It is possible to provide the optical recording medium sheet 1 by providing the sheet. Details of the hard coat layer 6 of the optical recording medium sheet 1 will be described later.

Here, in the dimensions of the optical recording medium sheet 1 according to the first embodiment, the diameter (outer diameter) of the optical recording medium sheet 1 is outside the disc substrate (not shown) of the optical disc described later. The diameter is selected to be substantially the same as or smaller than that, and specifically, for example, 120 mm. Further, the diameter (inner diameter) of the through hole 2c is equal to or larger than the opening diameter of the center hole (not shown) of the disk substrate, and the innermost peripheral diameter (for example, 23 mm diameter) of the clamp area used when clamping the optical disk. It is selected from the following range and is, for example, 23 mm.

As will be described later, the optical recording medium sheet 1 is attached to a disc substrate of an optical disc. At this time, the release film 5 and the protector 4 may be forgotten to be peeled off. That is, if the protector 4 is forgotten to be peeled off, the protector 4 will be stacked on the upper layer of the light transmitting layer, and thus recording / reproducing will be performed without focusing on the recording / reproducing laser light irradiation. I will not be able to. Further, if the release film 5 is forgotten to be peeled off, the adhesive layer 3 is not exposed, so that the bonding itself cannot be performed, and in some cases, the bonding film 3 remains as it is in the bonding device.

Therefore, in the optical recording medium sheet 1 according to the first embodiment, an identification mark is provided on the exposed surface of at least one of the protector 4 and the release film 5. That is, as shown in FIG. 3A, the exposed surface of the release film 5 of the optical recording medium sheet 1 is marked with, for example, an oil-based marker. Thereby, the release film side identification mark 5a is drawn. At this time, any visible color can be used as the color for marking. Further, as shown in FIG. 3B, it is also possible to mark the exposed surface of the protector 4 of the optical recording medium sheet 1 with, for example, an oil-based marker. As a result, the protector-side identification mark 4a is drawn, and as the color used at this time, as with the release film 5, all visible colors can be used. The marking of the protector-side identification mark 4a and the release film-side identification mark 5a is performed in the manufacturing stage of the original sheet and in the adhesive layer 3.
It may be performed either in the case of performing in the manufacturing stage or in the case of performing the punching process. Further, coloring of the protector 4 and the release film 5 itself is typically performed by using a colored protector sheet or release film sheet in the production of the original sheet, but the protector 4 of the original sheet is used. It is also possible to color the entire surface at the stage of the release film 5.

Further, as shown in FIG. 3C, the protector 4
It is also possible to mark the protector-side identification mark 4b on the exposed surface side and the release-film-side identification mark 5b on the exposed surface side of the release film 5. In this case, at least the light-transmissive sheet 2 and the adhesive layer 3 are so-called colorless and transparent that both transmit light, and their films are very thin. for that reason,
If the protector-side identification mark 4b and the release film-side identification mark 5b have the same color, the protector 4 and the release film 5 may be indistinguishable. Therefore, it is desirable that the protector-side identification mark 4b and the release film-side identification mark 5b use different colors that are distinguishable from each other.

Besides the method of drawing the identification mark on the protector 4 and the release film 5, as shown in FIG. 4A,
There is also a method of coloring the release film 5 itself with an arbitrary visually recognizable color. Also, as shown in FIG. 4B,
Similarly, the protector 4 itself may be colored with an arbitrary visible and recognizable color. At this time, in order to distinguish from the release film 5, as shown in FIG. 4C, the color of the release film 5 itself and the color of the protector 4 itself need to be distinguishable from each other. That is, as the release film 5 and the protector 4, it is possible to use sheets colored in different colors.

In the optical recording medium sheet 1 having such a structure, the light transmissive sheet 2 has a light transmissive heat satisfying at least the optical characteristics capable of transmitting the laser light used for recording / reproducing. Made of plastic resin. As the thermoplastic resin, a material whose heat resistance dimensional stability, thermal expansion coefficient, or hygroscopic expansion coefficient is close to that of the replica substrate described later is selected, and specifically, for example, polycarbonate (PC) or polymethylmethacrylate. A methacrylic resin such as (polymethylmethacrylate) is selected. The thickness of the light transmissive sheet 2 is preferably selected from the range of 60 to 100 μm, and more preferably 7
It is selected from the range of 0 to 100 μm. In the first embodiment, considering that the light-transmissive sheet 2 is bonded to one main surface of a disk substrate described later via an adhesive layer 3 made of a pressure-sensitive adhesive (PSA), the light-transmissive sheet 2 is transmitted. The thickness of the elastic sheet 2 is selected to be 70 μm, for example. The thickness of the light transmissive sheet 2 is determined by recording / recording information signals.
It is determined in consideration of the wavelength of the laser light used for reproduction and the desired film thickness of the light transmission layer of the optical disc.

The PSA forming the adhesive layer 3 is, for example, methacrylic resin. The thickness of the adhesive layer 3 is, for example, 30 μm. It is determined in consideration of the wavelength of the laser light used for recording / reproducing a signal.

The optical recording medium sheet 1 configured as described above is stacked and stored in a pole magazine. That is, as shown in FIG. 5, using a loading pole magazine 7 in which poles 7a are provided vertically, a plurality of sheets 1 for optical recording media are stacked while fitting their through holes 1a into the poles 7a. , Stored.

Next, a method of manufacturing the optical recording medium sheet 1 according to the first embodiment will be described. In Figure 5,
A punching device for this optical recording medium sheet 1 is shown, and FIG. 6 shows a raw sheet punched by using this punching device.

First, the punching device for the optical recording medium sheet 1 will be described. As shown in FIG. 5, in the punching device according to the first embodiment, the raw sheet 8
Sheet supply unit 11 around which is wound, original sheet 8
Sheet waste collecting unit 12 for collecting the surplus portion of the sheet, and the optical recording medium sheet 1 in the form of a plane ring from the original sheet 8
A sheet punching press machine 13 for punching the sheet, and an optical recording medium sheet 1 formed by punching,
The through hole 1a is used as the pole 7a of the loading pole magazine 7.
Sheet pickup 14 for fitting and stacking on the
Composed of. Further, as shown in FIG. 7, the raw sheet 8 has a laminated structure of the optical recording medium sheet 1 and is made of a strip-shaped sheet.

When the optical recording medium sheet 1 is punched from the original sheet 8 by using a punching device, first, the original sheet 8 is tensioned from the sheet supply section 11 in the state shown in FIG. 6 Send out in the direction of the middle arrow. Then, at the position of the punching blade 13a in the sheet punching press machine 13, the raw sheet 8 is partially punched into an annular shape. Thereby, the sheet 1 for an optical recording medium having a flat annular shape is formed. Here, as shown in FIG.
To give an example of respective dimensions when punching the optical recording medium sheet 1 from the raw sheet 8, the outer diameter φ _{1 of the} optical recording medium sheet ₁ is 120 mm, and the width L ₁ of the raw sheet 8 is 130 mm, between the outer periphery of the optical recording medium sheet 1 and the side portion of the original sheet 8, a so-called margin width d
₁ is 5 mm, the outer peripheral distance l ₁ between the optical recording medium sheets ₁ is 5 mm, and the member pitch p ₁ is 125 mm. The amount of the sheet 1 for an optical recording medium obtained from the original sheet 8 can be improved by 30% as compared with the case of the conventional original sheet (see FIG. 41). this is,
This is because it is a fully-extracted single-wafer type, and it is not necessary to consider the transportation of a bonding sheet or the like that has been used for bonding with a conventional disk substrate.

After punching out the optical recording medium sheet 1 as described above, the optical recording medium sheet 1 is picked up using the sheet pickup 14, and the through hole 1a formed at the time of punching is inserted into the loading pole magazine. While being fitted to the pole 7a of No. 7, they are sequentially loaded. On the other hand, a surplus portion of the original sheet 8 left after punching the optical recording medium sheet 1 from the original sheet 8, so-called sheet dust,
It is wound around the sheet residue collecting unit 12 and collected.

As described above, the desired optical recording medium sheet 1 shown in FIG. 1 is formed.

However, the present inventor has found that the following problems occur when punching out the optical recording medium sheet 1. That is, the present inventor uses the sheet punching press 13 in this punching device to punch out the pressure sensitive adhesive forming the adhesive layer 3 to the outside of the cut portion when punching the raw sheet 8. I found out that it would end up. When the pressure-sensitive adhesive is squeezed out in the punching of the sheet 1 for optical recording medium of the completely punched sheet type as described above, the following various problems occur.

That is, first of all, since the completely removed optical recording medium sheet 1 is loaded on the loading pole magazine 7, the optical recording medium sheet 1 is transferred to the disk substrate at the time of bonding. Even if only one sheet is picked up, a plurality of sheets 1 for the optical recording medium come into close contact with each other.
Secondly, if the protruding pressure-sensitive adhesive adheres to the laminating device and other devices, it may cause troubles in these devices. Thirdly, the protruding pressure-sensitive adhesive is redeposited on the surface of the optical recording medium sheet 1, so that the surface shape of the sheet is slightly deformed, and the characteristic as a light transmitting layer of the optical disc is obtained. It causes deterioration. Fourthly, the optical recording medium sheet 1 punched from the original sheet 8 is
The original sheet 8 is adhered again, and the same state as that in which it is not punched is caused.

Therefore, as a result of various studies, the present inventor has focused on the punching direction when the optical recording medium sheet 1 is punched from the original sheet 8. That is, when a laminated film made of a plurality of composite materials is punched so as to sandwich a pressure-sensitive adhesive as shown in FIG. 1, the punching direction is as shown in FIG. Then, it is performed from the side where the protector 4 is provided.
At this time, the original sheet 8 is cut in the order of the protector 4, the light-transmitting sheet 2, the adhesive layer 3, and the release film 5. At this time, the protector 4 and the light transmissive sheet 2 are cut before the punching blade 13a reaches the adhesive layer 3. As described above, as the thickness that must be cut increases before the adhesive layer 3 is cut, the punching blade 13a becomes more uneven. When the punching blades 13a vary, the pressure of the punching blades 13a against the optical recording medium sheet 1 also varies, and a phenomenon occurs in which the pressure-sensitive adhesive sticks out of the adhesive layer 3. Conceivable. Furthermore, when the inventor punches from the protector 4 side through an experiment associated with the above-described examination,
It was also found that not only the pressure-sensitive adhesive squeezes out, but also interfacial peeling occurs between the adhesive layer 3 and the release film 5. In general, in order to secure various optical properties, appearance and physical properties, peeling between the layers constituting the optical recording medium sheet 1 is not preferable. In particular, if interfacial peeling occurs between the adhesive layer 3 and the release film 5, problems such as a change in adhesive strength due to the contact of the adhesive layer 3 with air and adhesion of foreign matter to the surface of the adhesive layer 3 occur. The chances increase.

Therefore, as shown in FIG. 9, in the first embodiment, when the original sheet 8 is punched out, the cutting length until the adhesive layer 3 is cut is selected from the shorter cutting lengths. Then, specifically, the cutting by the punching blade 13a is performed from the release film 5 side toward the protector 4.

Here, the present inventor punches from the protector 4 side as shown in FIG. 8 to form 100 optical recording medium sheets 1 (first comparative example), and FIG. When 100 sheets of optical recording medium sheets 1 were formed by punching from the side of the release film 5 as shown (first example), the appearance inspection was performed on them. The comparison results are shown in Table 1 below. In addition, in Table 1, "floating" means the release film 5 and the adhesive layer 3
It is a case where inclusion of air bubbles due to peeling at the interface with and is confirmed, and "edge shape" is a case where burrs or the like are present at the cut portion after punching into a plane annular shape.

[0072]

[Table 1]

From Table 1, in the optical recording medium sheet 1 according to the first comparative example, the protrusion of the pressure-sensitive adhesive was 10
8 sheets out of 0 sheets (8%) occurred, whereas in the optical recording medium sheet 1 according to the first example, only 1 sheet out of 100 sheets (1%) of the pressure-sensitive adhesive spilled out. I know there isn't. In addition, in the optical recording medium sheet 1 according to the first comparative example, 12 out of 100 (12
%), And the edge shape is defective in 3 out of 100 sheets (3%), whereas in the sheet 1 for the optical recording medium according to the first example, none occurs. I understand. In addition, the number of non-defective products is the first
The number of non-defective products of the optical recording medium sheet 1 according to the comparative example is 10
77 out of 0 sheets (77%), whereas the number of non-defective products of the optical recording medium sheet 1 according to the first embodiment is 9 out of 100 sheets.
It can be seen that the number is 9 (99%). That is, it can be seen that the number of defective products decreased from 23 out of 100 to 1 out of 100, and the occurrence rate was 1/23 times, or about 95%. Further, according to the visual confirmation by the present inventor, when punching out from the release film 5 side, not only the protrusion of the adhesive from the edge does not occur, but also the release film 5 and the adhesive layer. It can be seen that no interfacial peeling with No. 3 occurred. On the other hand, in the case of punching out from the protector 4 side, not only the amount of sticking out of the adhesive from the edge increases, but also the sticking of the adhesive to the optical recording medium sheet 1 and the sheet feeding due to the adhesion of the sheets to each other. Defects and adhesion of pressure sensitive adhesive on the device with which this sheet came into contact were confirmed. Further, the present inventor has confirmed that minute peeling has also occurred at the interface between the release film 5 and the adhesive layer 3, and has also confirmed that minute air pockets have been generated due to this.

As described above, the punching apparatus is used to form the sheet 1 for the optical recording medium, which is completely punched out, and then the optical recording medium sheet 1 is bonded to the disc substrate. Then, an optical disc is manufactured by forming a light transmission layer of the optical disc by this bonding. The method of manufacturing this optical disc will be specifically described below.

First, the optical disk manufacturing apparatus system according to the first embodiment will be described. FIG. 10 shows a manufacturing apparatus system for this optical disk.

As shown in FIG. 10, the manufacturing apparatus system according to the first embodiment comprises a laminating apparatus 21, a substrate supply apparatus 22, a sheet supply apparatus 23 and an optical disk unloading apparatus 24. Then, the sheet supply device 23 is configured to be capable of supplying the optical recording medium sheet 1, and the substrate supply device 22 is configured to be capable of supplying the disk substrate. The optical recording medium sheet 1 and the disk substrate are bonded to each other. 21 is configured so that they can be bonded together, and an optical disk manufactured by this bonding can be carried out by an optical disk carrying-out device 24.

The laminating apparatus 21 comprises a rotating means 25, and a release film peeling portion 26, a substrate supplying portion 27, a laminating portion 28, and a protector peeling portion 29 which are sequentially arranged in the rotational direction. There is. The release film peeling section 26 is for peeling the release film 5 of the supplied optical recording medium sheet 1. The substrate supply unit 27 is for mounting the disc substrate supplied from the substrate supply device 22. Also, the bonding section 28
Is for bonding the optical recording medium sheet 1 and the disk substrate. Further, the protector peeling section 29 is for peeling the protector 4 from the optical disc manufactured by bonding.

Further, the substrate supply device 22 includes the rotating means 30.
A substrate loading pole supply unit 31 and a replenishment substrate loading pole supply unit 32 are provided on the top. The substrate loading pole supply unit 31 is for placing the disk substrate supplied to the substrate supply unit 27 of the bonding apparatus 21 by the substrate transfer arm 33. That is, at least one disk substrate among the disk substrates loaded on the substrate loading pole supply unit 31 is picked up at one end of the substrate transport arm 33, and then this arm is rotated to move the disk substrate to the substrate. It is conveyed to the supply unit 27. In addition, the replenishment substrate loading pole supply unit 32 stops when the remaining number of disk substrates in the substrate loading pole supply unit 31 becomes small, or all the disk substrates have not been conveyed to the substrate supply unit 27 of the bonding device 21. At this time, by rotating the rotating means 30, the disk substrate can be newly supplied as the substrate loading pole supply unit 31 without stopping the entire system.

Further, the sheet feeding device 23 includes the rotating means 3
4 is provided with a sheet stacking pole supply section 35 and a replenishment sheet stacking pole supply section 36. The sheet stacking pole supply unit 35 is for placing the optical recording medium sheet 1 supplied to the release film peeling unit 26 of the laminating apparatus 21 by the sheet conveying arm 37. That is, at least one optical recording medium sheet 1 among the plurality of optical recording medium sheets 1 stacked on the sheet stacking pole supply unit 35 is picked up at one end of the sheet conveying arm 37, and thereafter,
By rotating this sheet conveying arm 37,
The optical recording medium sheet 1 is conveyed to the release film peeling section 26. Further, the replenishment sheet stacking pole supply unit 36
Is lost when the remaining number of the optical recording medium sheets 1 in the sheet stacking pole supply unit 35 becomes small or when all the optical recording medium sheets 1 are not conveyed to the release film peeling unit 26 of the laminating apparatus 21. When the sheet has been stored, the rotation means 34 is rotated so that the sheet 1 for the optical recording medium can be newly supplied as the sheet stacking pole supply section 35 without stopping the entire system.

The optical disk carry-out device 24 is for carrying out manufactured optical disks to the outside, and disk discharge poles 39 are arranged side by side on the conveyor 38. Then, in the laminating device 21, from the optical recording medium sheet 1 after laminating,
The optical disc from which the protector 4 has been peeled off in the protector peeling section 29 is picked up at one end of the disc carrying arm 40 and supplied to the disc ejection pole 39. The supplied optical disk is carried out by the flow of the conveyor 38.

In the manufacturing apparatus system configured as described above, the bonding section 28 for bonding the disk substrate and the optical recording medium sheet 1 will be described in detail. FIG. 11 shows the details of the bonding section 28.

As shown in FIG. 11, in the bonding section 28 according to the first embodiment, the flat stage 41 is used.
And the movable stage 42 are installed at positions facing each other.

The flat stage 41 is used for the sheet feeding device 23.
This is for mounting the optical recording medium sheet 1 supplied from The flat stage 41 is configured so that the optical recording medium sheet 1 can be placed thereon. That is, a vertical movement pin 43 is provided at a portion of the flat stage 41 facing the movable stage 42 so as to be movable in a direction in which the flat stage 41 projects and is buried. The diameter of the vertical movement pin 43 is configured to be equal to the diameter of the through hole 1a of the optical recording medium sheet 1 described above. Then, the through hole 1 of the sheet 1 for optical recording medium
The optical recording medium sheet 1 can be placed on the flat stage 41 by fitting a in the vertical movement pin 43. Further, on the upper part of the vertical movement pin 43,
A substrate positioning pin 44 protruding in a columnar shape is provided. The diameter of the board positioning pin 44 is equal to the disk board 4
The center hole 45a of No. 5 has a diameter substantially equal to that of the center hole 45a. The substrate positioning pin 44 is configured to support the disc substrate 45 at the stepped portion with the vertical movement pin 43 while aligning the center thereof. In the flat stage 41 configured as described above, the optical recording medium sheet 1 can be placed on the flat stage 41 by fitting the vertical movement pins 43, and the disc substrate 45 can be placed at the substrate position. Output pin 44
It is configured to be able to be supported by the stepped portion with respect to the vertical movement pin 43 by being fitted to.

The plane stage 4 of the movable stage 42
A pad 46 made of an elastic material such as silicone rubber is provided on the surface of the portion opposed to 1. The pad 46 has, for example, a partial sphere shape or a conical shape formed by one portion when the sphere is divided by a predetermined plane, and a flat surface portion of the partial sphere shape or the conical shape faces the flat stage 41. Is fixed to one surface of the movable stage 42.

As described above, the bonding section 28 used for bonding the optical recording medium sheet 1 and the disk substrate in the first embodiment is constituted. The release film peeling unit 26 and the substrate supply unit 2 in the bonding device 21 of the above-described manufacturing apparatus system.
7 and the protector peeling portion 29 are configured by the portion other than the movable stage 42 and the pad 46 of the bonding portion 28. That is, the laminating device 21
On the rotating means 25, the flat stage 41 is provided side by side on the circumference.

Further, as shown in FIG. 12, the parallel maintaining means 47 composed of, for example, a plurality of columnar pins is provided in the vicinity of the mounting portion of the optical recording medium sheet 1 on the flat stage 41 of the bonding portion 28. It is also possible to provide. By providing such parallel maintaining means 47, the disc substrate 45 and the optical recording medium sheet 1 can be held in parallel with each other, and at the same time as the disc substrate 45 at an undesired stage before bonding. The contact with the optical recording medium sheet 1 can be prevented, and the blocking phenomenon can be prevented.

Next explained is an optical disc manufactured by the manufacturing method according to the first embodiment of the invention.
Here, the first optical disc and the second optical disc
The types of optical disks will be described.

That is, as shown in FIG.
In the first optical disc 50 according to the embodiment of the present invention, the disc substrate 45 is provided with unevenness on one main surface of the replica substrate 45b in which the center hole 45a is formed, and an information signal is provided on this one main surface. The portion 45c is provided. Further, in the first optical disc 50,
A light transmission layer 51 is provided on the disc substrate 45.
The light transmitting layer 51 is composed of a light transmitting sheet 2 and an adhesive layer 3 which form a main part of the optical recording medium sheet 1. Further, a through hole 1a is provided in the center thereof.

Further, a clamp region 52 is set in an annular shape around the through hole 1a on the main surface of the light transmitting layer 51 on the light transmitting sheet 2 side. On the main surface of the light transmissive layer 51 in the clamp area 52 on the light transmissive sheet 2 side,
A clamp reference surface 52a for mounting the first optical disk 50 on a spindle (not shown) of the recording / reproducing apparatus is set. Here, the light transmissive sheet 2 is configured to be adhered on the disc substrate 45 via the adhesive layer 3, and the clamp reference surface 52a is set in a portion on one main surface of the light transmissive layer 51. In consideration of the above, the diameter of the through hole 1a is selected to be equal to or larger than the diameter of the center hole 45a of the disk substrate 45, for example, 15 mm or more. The innermost circumference of the annular clamp region 52 is, for example, 23 m.
m, and the outermost diameter is, for example, 33 mm. Considering that the clamp reference surface 52a is composed of the main surface portion of the light transmitting layer 51 on the light transmitting sheet 2 side, the diameter of the through hole 1a is equal to or less than the innermost circumference of the clamp region 52, specifically, Is, for example, 22 mm or less. When it is necessary to increase the frictional force generated when clamping and rotating, the clamp reference surface 52a can be roughened. This roughening is selectively performed with respect to the clamp reference surface 52a, and specifically, the roughening is performed so that the surface roughness Ra is, for example, 30 nm or more, preferably 120 nm or more.

The first optical disc 50 according to the first embodiment is constructed as described above.

Next, the second optical disc according to the first embodiment will be described. FIG. 14 shows the second optical disc 53.

As shown in FIG. 14, in this second optical disc 53, a hard coat layer 6 is further provided on the surface of the light transmissive sheet 2 of the first optical disc 50. That is, the light transmitting layer 51 is the light transmitting sheet 2
And the adhesive layer 3 adhered to the surface of the light transmissive sheet 2 to be bonded to the disk substrate 45, and the surface of the light transmissive sheet 2 opposite to the side where the adhesive layer 3 is provided. And a hard coat layer 6. The hard coat layer 6 is made of a material having a lubricity and a high hardness, specifically, an ultraviolet curable resin (UV resin), diamond-like carbon (DLC), or the like. A clamp reference surface 52a is set on the surface of the hard coat layer 6 in the clamp area 52 set on the second optical disk 53. This clamp reference surface 52a
Is roughened, and specifically, the surface roughness Ra is, for example, 30 nm or more, preferably 120 nm.
nm or more. The configuration of the other optical discs is the same as that of the first optical disc 50, and thus the description thereof is omitted.

Next, a method of manufacturing the first optical disc 50 and the second optical disc 53 according to the first embodiment having the above-described configurations will be described.

First, as shown in FIG. 15, the disk substrate 45 is manufactured by sequentially forming the replica substrate 45b and forming a laminated film on one main surface of the replica substrate 45b. In the disc substrate 45, the center hole 45 is formed in the center of the replica substrate 45b.
a is formed, and an uneven groove track is formed on one main surface of the disk substrate 45. The uneven signal groove track and the laminated film formed on this one main surface constitute an information signal section 45c. ing.

The replica substrate 45b is manufactured by an injection molding method using a predetermined stamper. The replica substrate 45b has a thickness of, for example, 0.6 to 1.2 m.
m. Further, as the material of the replica substrate 45b,
For example, a low water-absorbing resin such as polycarbonate or cycloolefin polymer (for example, Zeonex (registered trademark)) is used. As the replica substrate 45b, for example, a substrate made of a metal such as Al, a glass substrate, or a substrate made of a resin such as polyolefin, polyimide, polyamide, polyphenylene sulfide, or PET can be used. In addition, a recording film, a reflective film, or the like is formed on the uneven portion formed on the one main surface of the replica substrate 45b, whereby the information signal unit 4 is formed.
5c is formed. The information signal section 45c is made of a reflective film, a film made of a magneto-optical material, a film made of a phase change material, an organic dye film, or the like. Among these, as the material of the reflective film, for example, an Al alloy, an Ag alloy or the like is used.

Specifically, when the final product optical disk is a read-only memory (ROM) optical disk, the information signal section 45c has a single-layer film having at least a reflective layer made of, for example, an Al alloy. Alternatively, it is composed of a laminated film. On the other hand, when the optical disc as the final product is a rewritable optical disc, the information signal section 4
5c is composed of a single layer film or a laminated film having at least a film made of a magneto-optical material or a film made of a phase change material. In the case of a write-once optical disc, it is made of a film made of an organic dye material and a phase change material. It is composed of a single layer film or a laminated film having at least a film. In addition, the replica substrate 4
As 5b, it is also possible to use a substrate configured such that the portion of the clamp region around the center hole 45a is thicker than the other portions.

Here, the disk according to the first embodiment is
Specifically, the substrate 45 is a replica substrate 45b.
For example, a disk-shaped PC board with a thickness of 1.1 mm
The diameter (outer diameter) of this PC board is, for example, 120 m
m, the opening diameter (inner diameter) of the center hole 45a
If it is 15 mm. In addition, as the information signal unit 45c,
On the region of the plica substrate 45b where the unevenness is formed, the film thickness is
Reflective layer made of 100 nm Al alloy, film thickness 18 nm
Of zinc sulfide (ZnS) and silicon oxide (SiO ₂)When
Mixture of (ZnS-SiO₂) Consisting of a first dielectric
Layer, a GeInSbTe alloy layer having a thickness of 24 nm
Phase change recording layer and ZnS-S having a thickness of 140 nm
iO₂A laminated film in which a second dielectric layer made of
Is used.

After the disk substrate 45 is manufactured as described above, a sheet preparation step is performed so that the optical recording medium sheet 1 can be bonded to one main surface of the disk substrate 45.

That is, first, the optical recording medium sheet 1
The release film side identification mark 5a formed on the
Color) or the color of the release film 5 (see FIG. 4A)
The sheet 1 for optical recording medium is conveyed to the release film peeling section 26 from the sheet stacking pole supply section 35 of the sheet supply device 23 shown in FIG. Is placed on the release film peeling section 26 so that the film is exposed. Then, the release film peeling section 26 peels the release film 5 from the optical recording medium sheet 1 to expose the adhesive layer 3.

Next, in the optical recording medium sheet 1 from which the release film 5 is peeled off, the through hole 1a has the vertical movement pin 43.
It is placed on the flat stage 41 so as to be fitted into. At this time, the optical recording medium sheet 1 has the protector 4
Are placed so as to contact the placement surface of the flat stage 41. Next, the rotating means 25 of the bonding apparatus 21 is rotated and moved to the position of the substrate supply unit 27. Next, the disc substrate 45 loaded on the substrate loading pole supply unit 31 is transported to the substrate supply unit 27 using the substrate transport arm 33. Then, the disc substrate 45 is mounted so as to be fitted to the substrate positioning pins 44 and supported by the vertical movement pins 43. At this time, the disk substrate 45 is supported and mounted by the vertical movement pins 43 so that one main surface on which the information signal section 45c is provided faces the adhesive layer 3.
16 shows the positional relationship between the disc substrate 45 and the optical recording medium sheet 1 at this time.

Next, by rotating the rotating means 25 shown in FIG. 10, the disk substrate 45 and the optical recording medium sheet 1 are moved to the position of the bonding section 28. Then, the bonding is performed in the bonding section 28 shown in FIG. 11 or 12.

That is, the movable stage 42 is moved toward the flat stage 41 (in FIG. 11 and FIG. 12,
(Below). Then, the substrate positioning pin 44 is first pressed by the pad 46, and then the vertical movement pin 43 is inserted into the flat stage 41 via the disc substrate 45. As a result, as shown in FIG. 17, the one main surface of the disc substrate 45 on the side where the information signal portion 45c is provided and the adhesive layer 3 of the optical recording medium sheet 1 are pressure-bonded. After the pressure bonding is stabilized, the movable stage 42 shown in FIGS. 11 and 12 is opened in the direction away from the flat stage 41.

As described above, as shown in FIG. 18, the information signal section 45c is provided on one main surface of the replica substrate 45b.
In a region covering the information signal portion 45c, the light transmitting layer 51 including the adhesive layer 3 and the light transmitting sheet 2 is provided, and the protector 4 is further provided. After that, FIG.
The protector peeling section 29 is moved by rotating the rotating means 25 shown in FIG.

Next, in the protector peeling section 29, with the protector-side identification mark 4a (see FIG. 3B) of the protector 4 and the mark of a predetermined color (see FIG. 4B) as marks, the protector 4 is separated from the disc substrate 45 side. An adhesive sheet (not shown) to which an adhesive having an adhesive strength greater than the adhesive strength of the slightly adhesive adhesive between the protector 4 and the light transmissive sheet 2 is adhered to the opposite surface.
Here, the adhesive force between the protector 4 and this adhesive sheet is, for example, 9.8 × 10 −1 N / 20 mm (10
0gf / 20mm) (180 ° peel strength (JIS Z-0237))
Is. Then, as shown in FIG. 19, the pressure-sensitive adhesive sheet (not shown) is 90 ° with respect to the surface of the disc substrate 45.
Pull in the direction of ~ 180 °. As a result, the protector 4 is peeled off from the light transmissive sheet 2. At this time, the protector 4 is peeled off in a state where a slightly adhesive adhesive (not shown) is attached. That is, the release surface serves as an interface between the light transmissive sheet 2 and the layer made of the slightly tacky adhesive.

As described above, the information signal section 45 is formed on the main surface of the replica substrate 45b on which the unevenness is formed, as shown in FIG.
The desired optical disc according to the first embodiment, which is provided with c and the light transmitting layer 51 including the adhesive layer 3 and the light transmitting sheet 2, is manufactured. After that, it is picked up from the flat stage 41 by the disc transfer arm 40 shown in FIG. After that, the optical recording medium as a final product is manufactured by storing it in a predetermined cartridge or the like, if necessary. Also, when manufacturing the second optical disc 53,
The optical recording medium sheet 1 used in the manufacturing process of the first optical disc 50 described above can be manufactured by using the optical recording medium sheet 1 shown in FIG.

In the method for manufacturing the optical disc according to the first embodiment as described above, the present inventor conducted an experiment on the identification mark and coloring on the protector 4 of the optical recording medium sheet 1. That is, the sheet 1 for optical recording medium (second comparative example) which is not provided with a conventional identification mark or coloring, and the sheet 1 for optical recording medium provided with the identification mark according to the first embodiment. And the colored optical recording medium sheet 1, respectively,
When manufacturing 200 optical disks,
The number of optical discs was measured when the protector 4 was not peeled and a trouble occurred in the inspection machine. The results of the experiment are shown in Table 2 below.

[0107]

[Table 2]

From Table 2, in the case of using the optical recording medium sheet 1 of the all-extracted sheet, in the second comparative example, the inspection machine trouble due to the peeling error of the protector 4 was found on 14 of 200 disks. On the other hand, it can be seen that the inspection machine trouble does not occur at all when the marked optical recording medium sheet 1 is used and when the colored optical recording medium sheet 1 is used. That is, it can be understood that, in the manufacture of the optical disc, by providing the protector 4 with the identification mark or by coloring it, it is possible to prevent the trouble of the device in the optical disc manufacturing process.

As described above, according to the first embodiment, the optical recording medium sheet 1 supplied when the light transmission layer 51 is formed in the optical disc manufacturing process is the fully-extracted sheet type. By supplying by the method described above, it is possible to avoid various problems that occur in the half punched sheet. That is, peeling at the outer peripheral edge of the optical recording medium sheet 1 can be prevented, thereby preventing adhesion and mixing of foreign matter due to change in adhesive force of the adhesive layer 3, peeling pattern, change in film thickness, and generation of static electricity. It is also possible, and it is also possible to carry out the pole magazine for loading 7
Since it is stored in the optical recording medium, it is possible to avoid a change in shape due to tightness of winding, and further, the sheet for optical recording medium 1
The release film 5 can be transported one by one.
The sheet for optical recording medium 1 obtained from the original sheet 8 can be efficiently manufactured without the need to convey the sheet for bonding according to.

Further, according to the above-described first embodiment, when the optical recording medium sheet 1 is punched out in the fully punched sheet form, the punching blade is punched from the release film 5 side. 13a can be prevented from varying and pressure variation due to this can be prevented, so that bubbles are mixed due to peeling at the interface between the release film 5 and the adhesive layer 3 and burrs are generated at the cut portion. This makes it possible to improve the dimensional accuracy and prevent the pressure-sensitive adhesive from sticking out of the adhesive layer 3.

Further, according to the optical recording medium sheet 1 according to the first embodiment of the present invention described above, the protector 4 and / or the release film 5 is provided with an identification mark, or the whole is colored. By doing so, the release film 5 and the protector 4 can be easily distinguished from each other. Therefore, a peeling error such as forgetting to peel off the release film 5 or the protector 4, and the protector 4 and the release film 5 are mutually separated. It is possible to prevent peeling errors due to misidentification. In addition, it is possible to prevent the protector 4 from being forgotten to be peeled off after the optical recording medium sheet 1 is attached to the disc substrate 45.
That is, if the protector 4 is forgotten to be peeled off, the thickness of the light transmitting layer 51 becomes the thickness having the film thickness of the protector 4, and the light transmitting layer 51 does not have a desired thickness. Since it is possible to avoid the problem that the optical disk cannot be initialized because the laser beam used is out of focus, all the items that must be evaluated in the inspection process cannot be measured because the initialization is not performed. It is possible to avoid the occurrence of trouble in the operation of the inspection machine. Therefore, it is possible to efficiently manufacture an optical disc and perform highly reliable inspection.

Here, the present inventor has a possibility that the following problems may occur in the first optical disc 50 and the second optical disc 53 manufactured by the manufacturing method according to the first embodiment. Study was carried out.

That is, when an optical disc is manufactured using the above-mentioned sheet 1 for optical recording medium having a planar annular shape, first, as shown in FIG. 20, the sheet 1 for optical recording medium is punched out from the original sheet 8. Next, as shown in FIG.
The release film 5 is peeled off from the optical recording medium sheet 1. After that, as shown in FIG. 22, the optical recording medium sheet 1 from which the release film 5 is peeled off is attached to the disc substrate 45.
23, the disk substrate 45 and the optical recording medium sheet 1 are attached to each other as shown in FIG. 23, and then the protector 4 is attached as shown in FIG. Peel off.

However, in the case of manufacturing in this way, for example, when the outer peripheral edge of the optical recording medium sheet 1 extends beyond the outer peripheral edge of the disc substrate 45 (in FIG. 24,
(Within circle a), the following problems may occur. That is, the adhesive layer 3 of the sheet 1 for the optical recording medium that protrudes
Dust or foreign matter may adhere to the portion of the optical disc, or may repeatedly be collided with the inner wall of a cartridge (not shown) in which the optical disc is housed, resulting in separation or deformation from the disc substrate 45, or protruding optical components. It is conceivable that a hand or the like touches the portion of the recording medium sheet 1, and excessive pressure is applied to the optical recording medium sheet 1 to cause peeling or deformation. If such peeling or deformation occurs, there is a possibility that information signals cannot be recorded or reproduced in the outer peripheral portion.

Further, when the outer peripheral edge of the information signal portion 45c of the disk substrate 45 is protruded from the outer peripheral edge of the optical recording medium sheet 1 (inside the circle b in FIG. 24), further trouble may occur. There is. That is, a portion of the information signal portion 45c that is not covered by the optical recording medium sheet 1 is corroded by moisture in the atmosphere, foreign matter is attached to the portion that is not covered, and a scratch is caused thereby. The possibility arises. If such corrosive foreign matter is attached or scratched, there is a possibility that the information signal cannot be recorded or reproduced in the outer peripheral portion. And
If the outer peripheral end of the information signal section 45c is designed to be closer to the inner peripheral side in order to avoid this, the recording capacity will be reduced.

In order to prevent such protrusion of the optical recording medium sheet 1 and exposure of the information signal section 45c,
It suffices if there is no eccentricity during the bonding. However, in order to eliminate the eccentricity, it is difficult to control due to various disturbances. That is, variations in the outer diameter of the replica substrate 45b to be molded (specifically, 0.1 mm
), The design dimensional tolerance of the punching blade (die) for punching the optical recording medium sheet 1 (specifically, about 0.1 mm), and the variation in the size between lots (specifically, 0.05).
mm), dimensional variations when the optical recording medium sheet 1 is continuously punched out (specifically, about 0.05 mm), and bonding position alignment accuracy in the bonding part 28 (specifically, 0. About 07 mm) and variations in the outer diameter of the film formation region of the information signal section 45c (specifically, 0.
Inevitably, variations such as about 05 mm will occur. Although various methods for minimizing these variations have been considered, these variations still occur and it is difficult to control all the variations.

Therefore, a method of manufacturing the optical disc according to the second embodiment will be described below as one method for reducing the possibility of the above-mentioned problems occurring as much as possible. In the second embodiment, the optical recording medium sheet 1 used for manufacturing and the optical disc manufactured are the same as those in the first embodiment, and therefore description thereof will be omitted.

In the method of manufacturing an optical disc according to the second embodiment, as shown in FIG. 25A, a raw fabric sheet 61 having the same laminated structure as the raw fabric sheet 8 in the first embodiment is cut. , The outer circumference is rectangular,
A rectangular sheet 62 having a circular through hole 62a is formed.
Here, to give an example of the dimensions of the rectangular sheet 62,
The width L ₂ perpendicular to the longitudinal direction of the original sheet 61 is set to, for example, 1
25 mm, the length L ₂ ′ along the longitudinal direction is, for example, 12
The rectangular sheet 62 has a square shape and the through hole 62a has a diameter of 23 mm. After that, as shown in FIG. 25B, the release film 5 is peeled from the rectangular sheet 62 as in the first embodiment.

Next, the rectangular sheet 62 is formed as shown in FIG.
The sheet is conveyed to a bonding section similar to that shown in 2 and placed on the flat stage 41. At this time, the rectangular sheet 62 is
The protector 4 is placed in contact with the placement surface of the flat stage 41. Next, the disk substrate 45 is transported and mounted so as to be fitted to the substrate positioning pins 44 and supported by the vertical movement pins 43. At this time, the disk substrate 45 is supported and mounted by the vertical movement pins 43 so that one main surface on which the information signal section 45c is provided faces the adhesive layer 3. The positional relationship between the disc substrate 45 and the rectangular sheet 62 at this time is shown in FIG. That is, as shown in FIG. 26, the rectangular sheet 62 and the disc substrate 45 are made to have the center OO ′ of the through hole 62a and the center hole 45a aligned with the adhesive layer 3 and the information signal portion 45c thereof facing each other. Position each other.

Next, the movable stage 42 shown in FIG. 11 or 12 is moved toward the flat stage 41 (see FIG. 1).
1, FIG. 12, lower part). Then, the substrate positioning pin 44 is first pressed by the pad 46, and then the vertical movement pin 43 is inserted into the flat stage 41 via the disc substrate 45. As a result, as shown in FIG. 27, the one main surface of the disc substrate 45 on which the information signal portion 45c is provided and the adhesive layer 3 of the optical recording medium sheet 1 are pressure-bonded.

After that, the disk substrate 4 of the rectangular sheet 62 is formed.
The portion protruding from 5 is trimmed (cut). Here, the trimming method according to the second embodiment will be described below.

That is, as shown in FIG. 28, first, in a state where the disc substrate 45 and the rectangular sheet 62 are bonded together, a press die 63 having a circular punching blade 63a having substantially the same diameter as the disc substrate 45 is formed. Then, it is pressed against the rectangular sheet 62 from the adhesive layer 3 side, and the rectangular sheet 62 is punched into a circular shape. As a result, in the rectangular sheet 62, the disc sheet portion 62b and the sheet extra portion 62c are separated.

As described above, the information signal section 45c is provided on one main surface of the replica substrate 45b as shown in FIG.
A planar ring-shaped light transmitting layer 51 is provided in a region covering the information signal portion 45c, and further a protector 4 is provided. Then, with the protector-side identification mark 4a (see FIG. 3B) or the mark of a predetermined color (see FIG. 4B) of the protector 4 as a mark, the protector 4 and the light on the opposite side of the protector 4 from the disk substrate 45 side are marked. A pressure-sensitive adhesive sheet (not shown) coated with a pressure-sensitive adhesive having a pressure-sensitive adhesive force greater than that of the slightly tacky adhesive agent with the permeable sheet 2.
To adhere. After that, as shown in FIG. 30, the protector 4 is peeled from the light transmissive sheet 2 by pulling this adhesive sheet (not shown) in a peeling direction.
At this time, the protector 4 is peeled off in a state where a slightly adhesive adhesive (not shown) is attached. That is, the release surface is
It serves as an interface between the light-transmissive sheet 2 and a layer made of a slightly tacky adhesive.

As described above, the information signal portion 45c and the adhesive layer 3 are formed on the one main surface of the replica substrate 45b on which the unevenness is formed.
Then, the desired first optical disc 50 provided with the light transmission layer 51 including the light transmission sheet 2 is manufactured.
After that, the optical recording medium as a final product is manufactured by storing it in a predetermined cartridge or the like, if necessary.

As the above-mentioned trimming method,
It is also possible to use the following method.

That is, as shown in FIG. 31, a contact-type cutting means (contact-type cutting means 64) for cutting by moving a tool such as a cutter blade or a cutting tool in a predetermined direction while directly contacting the tool. ) Is used,
It is also possible to cut the rectangular sheet 62 from the adhesive layer 3 side along the outer periphery of the disc substrate 45. The rectangular sheet 62 is separated into a disc sheet portion 62b and a sheet extra portion 62c by trimming using the contact-type cutting means 64, and then the protector 4 is peeled off to form a desired optical disc. To manufacture.

Further, as shown in FIG. 32, without directly contacting an instrument such as an ultrasonic cutter or a laser cutter,
A rectangular sheet 62 is adopted by adopting a method of using a so-called non-contact type cutting means (non-contact type cutting means 65) which performs cutting by irradiating ultrasonic waves or laser light and moving in a predetermined direction in the irradiation state. From the side of the adhesive layer 3 to the disk substrate 4
It is also possible to cut along the outer circumference of 5. And
By trimming using the non-contact cutting means 65, the rectangular sheet 62 is moved to the disc sheet portion 62.
b and the sheet margin 62c are separated, and then the protector 4 is peeled off to manufacture a desired optical disk.

The present inventor has adopted an optical disc in which the optical transmission layer 51 is produced by adopting the optical disc production method according to the second embodiment, and an optical disc in which a flat annular sheet is bonded to form the light transmission layer. Was manufactured, and various experiments were conducted on these optical disks. That is, five optical disks (second embodiment) in which the light transmission layer 51 is formed are manufactured by laminating the disk substrate 45 and the rectangular sheet 62, and then trimming is performed. Among the optical discs in which the substrate 45 was bonded to form the light transmitting layer, five optical discs (third comparative example) in which the planar annular sheet protruded from the outer peripheral edge of the disc substrate 45 by about 300 μm were selected. In the optical disc according to the third comparative example, the information signal section 45c is provided at the other end on the side opposite to the one end where the sheet protrudes.
Is exposed.

Then, five optical disks according to the second embodiment and five optical disks according to the third comparative example were incorporated in cartridges. After that, while keeping these cartridges horizontal,
Vibration was applied for 2 hours to collide the inner wall of the cartridge with the outer circumference of the optical disk many times. After that, the optical disc according to the second embodiment and the optical disc according to the third comparative example were taken out from the cartridge, respectively, and the outer appearance was inspected. After that, these five optical disks according to the second embodiment and five optical disks according to the third comparative example were respectively placed in a constant temperature and humidity chamber at a temperature of 85 ° C. and a humidity of 80% for 1000 hours. Then, an accelerated test was conducted to observe the state of corrosion. Table 3 below shows the results of those collision experiments and accelerated tests.

[0130]

[Table 3]

From Table 3, in the outer peripheral appearance inspection, in the optical disc according to the third comparative example, three out of five optical discs are defective, whereas in the optical disc according to the second embodiment, any of the five optical discs is defective. It has been confirmed that no problem has occurred. In the defective three optical discs among the optical discs according to the third comparative example, local peeling of the sheet was observed at the most protruding portion of the sheet. Further, from Table 3, in the corrosion test, 4 out of 5 optical disks in the optical disk according to the third comparative example are defective, whereas all 5 optical disks in the optical disk according to the second embodiment are corroded. It was confirmed that there was no occurrence. In the four defective optical discs among the optical discs according to the third comparative example, it was confirmed that corrosion occurred in the exposed portion of the information signal portion 45c.

As described above, according to the second embodiment, the disc substrate 45 and the disc substrate 45 are provided.
After laminating the rectangular sheets 62 capable of covering with each other with their centers aligned with each other, the rectangular sheet 62 is attached to the disk substrate 45 by using the press die 63, the contact type cutting means 64, or the non-contact type cutting means 65. By trimming along the outer circumference, when the light transmitting layer 51 is formed on the disc substrate 45 to form an optical disc, the light transmitting sheet 2 and the adhesive layer 3 protrude from the outer periphery of the disc substrate 45. Can be prevented. Therefore, the light transmission layer 51 in the optical disc is peeled off, and the information signal section 45 is removed.
Since it is possible to prevent the occurrence of corrosion of c, it is possible to cope with the high NA of the objective lens used at the time of recording / reproducing,
It is possible to manufacture a light transmitting layer having a small birefringence, good transparency, and a uniform film thickness while having high reliability.

The embodiments of the present invention have been specifically described above, but the present invention is not limited to the above-mentioned embodiments, and various modifications can be made based on the technical idea of the present invention.

For example, the numerical values, the sheet materials, and the laminated structure of the sheets described in the above embodiments are merely examples, and different numerical values, sheet materials, and laminated structures of sheets are used as necessary. May be.

Further, in the above-mentioned first embodiment,
As the original sheet 8 for punching out the optical recording medium sheet 1, a band-shaped sheet having a width slightly larger than the outer diameter of one sheet of the optical recording medium sheet 1 is used, but as shown in FIG. It is also possible to use a raw sheet 8 which has a large width and can punch the optical recording medium sheet 1 diagonally. In this case, the raw sheet 8 can be used.
Since it is possible to increase the density of the optical recording medium sheet 1 punched out from the optical recording medium sheet 1, the optical recording medium sheet 1 can be obtained more efficiently.

Further, in the above-mentioned second embodiment,
The raw sheet 61 is cut to form a rectangular sheet 62, and the rectangular sheet 62 is attached to the disc substrate 45. However, after the disc substrate 45 is attached to the original sheet 61 itself, trimming is performed. It is also possible to do so.

Further, in the above-described embodiment, a sheet having a four-layer structure of the light transmitting sheet 2, the adhesive layer 3, the protector 4 and the release film 5, the light transmitting sheet 2, the adhesive layer 3, the protector 4, Although the release film 5 and the sheet having a five-layer structure of the hard coat layer 6 have been described, it is also possible to use a sheet other than these laminated structures. Specifically, as shown in FIG. 34, a sheet 70 having a three-layer structure including a light-transmissive sheet 2, an adhesive layer 3 and a release film 5 and having no protector 4, or as shown in FIG. , A light-transmissive sheet 2, an adhesive layer 3, a release film 5, and a hard coat layer 6 having a four-layer structure without the protector 4 can be used. When 71 is used, the peeling process of the protector 4 becomes unnecessary in the above-described first and second embodiments, and the number of steps is reduced.

[0138]

As described above, according to the method of manufacturing the optical recording medium of the first invention of the present invention, the light transmitting sheet, the adhesive layer, and the first protective film on one surface of the adhesive layer. By using the sheet provided with, the sheet is supplied in the process of forming the light-transmitting layer by pasting in a fully-extracted sheet-fed method, so that the sheet is fed into the sheet before the step of pasting. Since it can be stored in a formula, peeling at the outer peripheral edge of the optical recording medium sheet,
As a result, it is possible to prevent foreign matter from adhering to the surface, prevent abnormalities in the surface and thickness of the light-transmitting layer, and avoid device troubles caused by the protrusion of the adhesive layer adhering to the manufacturing device. . Therefore, it is possible to deal with higher NA of the objective lens used during recording / reproduction,
An optical recording medium having a small birefringence, good transparency, and a light-transmitting layer having a uniform film thickness can be produced.

According to the method of manufacturing an optical recording medium according to the second aspect of the present invention, the disc substrate and the sheet capable of covering one main surface of the disc substrate on which the information signal portion is provided are bonded together. After that, by trimming this sheet to match the outer circumference of the disc substrate, it is possible to make the sheet and the disc substrate the same diameter, and prevent the sheet from protruding from the outer periphery of the disc substrate and exposing the information signal section. Therefore, it is possible to reduce the deformation of the light transmission layer of the optical disc and the variation in the film thickness, and at the same time, prevent the corrosion of the information signal portion and maintain the high reliability. As a result, it is possible to manufacture an optical recording medium having a small birefringence, good transparency, and a light transmitting layer having a uniform film thickness, which can cope with a higher NA of an objective lens used at the time of recording / reproducing.

According to the optical recording medium sheet of the third aspect of the present invention, at least the light transmitting sheet, the adhesive layer, and the first protective sheet releasably provided on the adhesive layer side. And having a cutout formed from the side of the first protective sheet, the cutting thickness used until the cutting tool used for punching reaches the adhesive layer can be minimized. Since it is possible to prevent variations in cutting tools and variations in dimensions, it is possible to obtain a sheet for an optical recording medium in which the dimensional accuracy of punching is improved and the protrusion of the adhesive layer is suppressed. When a recording medium sheet is used, it is possible to deal with higher NA of the objective lens used during recording / reproduction, small birefringence, good transparency, and optical recording having a light-transmitting layer of uniform thickness. It is possible to manufacture the body.

[Brief description of drawings]

FIG. 1 is a plan view and a cross-sectional view showing an optical recording medium sheet according to a first embodiment of the present invention.

FIG. 2 is a plan view and a cross-sectional view showing an example in which a hard coat layer of the optical recording medium sheet according to the first embodiment of the present invention is provided.

FIG. 3 is a plan view showing an example of identification marks provided on the release film and protector of the optical recording medium sheet according to the first embodiment of the present invention.

FIG. 4 is a plan view showing an example of coloring the release film and the protector of the optical recording medium sheet according to the first embodiment of the present invention.

FIG. 5 is a side view showing the stacking pole magazine when storing the optical recording medium sheet according to the first embodiment of the present invention.

FIG. 6 is a schematic diagram showing a punching device used for punching an optical recording medium sheet from a raw sheet according to the first embodiment of the present invention.

FIG. 7 is a plan view showing a raw sheet from which the optical recording medium sheet according to the first embodiment of the present invention is punched.

FIG. 8 is a cross-sectional view for explaining the problem of punching out the optical recording medium sheet according to the first embodiment of the present invention.

FIG. 9 is a sectional view for explaining the punching direction of the optical recording medium sheet according to the first embodiment of the present invention.

FIG. 10 is a schematic diagram showing an apparatus system used for bonding the disc substrate and the optical recording medium sheet 1 according to the first embodiment of the invention.

FIG. 11 is a schematic diagram showing a bonding portion according to the first embodiment of the present invention.

FIG. 12 is a schematic diagram showing another example of a bonding section according to the first embodiment of the present invention.

FIG. 13 is a cross-sectional view showing a first optical disc according to the first embodiment of the present invention.

FIG. 14 is a sectional view showing a second optical disc according to the first embodiment of the present invention.

FIG. 15 is a sectional view showing a disk substrate according to the first embodiment of the present invention.

FIG. 16 is a perspective view for explaining the optical disc bonding process according to the first embodiment of the present invention.

FIG. 17 is a perspective view for explaining the optical disc bonding process according to the first embodiment of the present invention.

FIG. 18 is a cross-sectional view showing a bonded state before peeling off the protector according to the first embodiment of the present invention.

FIG. 19 is a perspective view for explaining the optical disc bonding process according to the first embodiment of the present invention.

FIG. 20 is a plan view of an original sheet for explaining a method of manufacturing an optical disc for explaining a problem to be solved in the second embodiment of the present invention.

FIG. 21 is a cross-sectional view showing an optical recording medium sheet for explaining an optical disc manufacturing method for explaining the problems to be solved in the second embodiment of the present invention.

FIG. 22 is a cross-sectional view showing an optical recording medium sheet and a disk substrate for explaining an optical disk manufacturing method for explaining the problems to be solved in the second embodiment of the present invention.

FIG. 23 is a cross-sectional view showing an optical disc after being bonded to explain a problem to be solved in the second embodiment of the present invention.

FIG. 24 is a cross-sectional view showing the optical disc after the protector has been peeled off, for explaining the problem to be solved in the second embodiment of the present invention.

FIG. 25 is a plan view and a sectional view of a rectangular sheet for explaining an optical disc manufacturing method according to a second embodiment of the present invention.

26A and 26B are a cross-sectional view and a plan view of a rectangular sheet and a disc substrate for explaining the optical disc manufacturing method according to the second embodiment of the invention.

27A and 27B are a sectional view and a plan view of a rectangular sheet and a disc substrate for explaining the optical disc manufacturing method according to the second embodiment of the invention.

28A and 28B are a sectional view and a plan view for explaining a method for trimming a rectangular sheet using a press die in the method for manufacturing an optical disc according to the second embodiment of the present invention.

29A and 29B are a sectional view and a plan view of a rectangular sheet and a disc substrate for explaining the optical disc manufacturing method according to the second embodiment of the invention.

30A and 30B are a sectional view and a plan view of the optical disc and the protector at the time of peeling the protector for explaining the method for manufacturing the optical disc according to the second embodiment of the present invention.

31A and 31B are a sectional view and a plan view for explaining a method for trimming a rectangular sheet using a contact-type cutting means in a method for manufacturing an optical disc according to a second embodiment of the present invention.

32A and 32B are a sectional view and a plan view for explaining a method for trimming a rectangular sheet using a non-contact cutting means in the method for manufacturing an optical disc according to the second embodiment of the present invention.

FIG. 33 is a plan view showing another example of the method for punching the optical recording medium sheet from the original sheet according to the first embodiment of the invention.

FIG. 34 is a cross-sectional view showing a sheet for optical recording medium having a three-layer structure and a rectangular sheet according to an embodiment of the present invention.

FIG. 35 is a cross-sectional view showing a four-layer structure sheet for optical recording medium and a rectangular sheet according to the embodiment of the present invention.

FIG. 36 is a cross-sectional view for explaining a method for supplying a half-cut optical recording medium sheet according to a conventional technique.

FIG. 37 is a cross-sectional view for explaining a problem of the half-cut optical recording medium sheet according to the related art.

FIG. 38 is a cross-sectional view for explaining a problem of the half-cut optical recording medium sheet according to the related art.

FIG. 39 is a cross-sectional view for explaining a half-punching method for a sheet for an optical recording medium according to a conventional technique.

FIG. 40 is a cross-sectional view for explaining a problem of the half-drawing method of the optical recording medium sheet according to the related art.

FIG. 41 is a plan view of a sheet for explaining problems in the case of half-cutting a sheet for an optical recording medium according to a conventional technique.

[Explanation of symbols]

1 ... Sheet for optical recording medium, 1a ... Through hole, 2
... Light-transmitting sheet, 2c, 62a ... Through-hole, 3
... Adhesive layer, 4 ... Protector, 4a, 4b ...
Identification mark on the protector side, 5 ... Release film, 5
a, 5b ... Release film side identification mark, 6 ...
Hard coat layer, 7 ... Loading pole magazine, 7a
・ ・ ・ Paul, 8, 61 ・ ・ ・ Raw sheet, 11 ・ ・ ・
Sheet supply section, 12 ... Sheet debris collection section, 13 ...
-Sheet punching press machine, 13a ... punching blade, 14 ... sheet pickup, 21 ... laminating device, 22 ... substrate feeding device, 23 ... sheet feeding device, 24 ... optical disk Unloading device, 25 ...
Rotating means, 26 ... Sheet peeling section, 26 ... Release film peeling section, 27 ... Substrate supply section, 28 ... Laminating section, 29 ... Protector peeling section, 30, 34.
..Rotating means, 31 ... Substrate loading pole supply section, 32
... Replenishment substrate loading pole supply unit, 33 ... Substrate transport arm, 35 ... Sheet loading pole supply unit, 36 ...
..Replenishment sheet stacking pole supply unit, 37 ... sheet transport arm, 38 ... conveyor, 39 ... disc ejection pole, 40 ... disc transport arm, 41.
..Flat stage, 42 ... Movable stage, 43 ...
・ Pivoting pins, 44 ... Board positioning pins, 45 ...
・ Disk substrate, 45a ... Center hole, 45b
... Replica substrate, 45c ... Information signal section, 46 ...
..Pads, 47 ... Parallel maintaining means, 50 ... First
Optical disc, 51 ... Light transmitting layer, 52 ... Clamp area, 52a ... Clamp reference surface, 53 ... Second
Optical disc, 62 ... rectangular sheet, 62b ... disc sheet portion, 62c ... sheet extra portion, 63 ...
-Press die, 63a ... Punching blade, 64 ... Contact cutting means, 65 ... Non-contact cutting means, 70, 7
1 ... sheet

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mitsuhiro Abe             6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Soni             -Inside the corporation (72) Inventor Takehiko Fukushima             6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Soni             -Inside the corporation F term (reference) 5D029 LA03 LB04 RA38 TA13 TA14                 5D121 AA04 AA12 FF01 FF02 JJ05

Claims (66)

[Claims] 1. A disc substrate, an information signal section provided on one main surface of the disc substrate and configured to record and / or reproduce an information signal, and record and / or reproduce the information signal. And a light-transmitting layer configured to be able to transmit the laser light, wherein the light-transmitting layer is at least a light-transmitting sheet capable of transmitting the laser light, and capable of transmitting the laser light, An optical layer comprising an adhesive layer for adhering a light-transmissive sheet to the one main surface of the disk substrate, wherein the light-transmissive sheet is attached to the one main surface of the disk substrate via the adhesive layer. In the method for producing a recording medium, at least the light transmissive sheet, the adhesive layer, and a first protective sheet releasably laminated on the adhesive layer side are provided at a stage before the bonding. A step of supplying a sheet for an optical recording medium, and supplying the sheet for an optical recording medium with the above-mentioned bonding to the disc substrate is performed by all the punched sheets for each disc substrate. A method for manufacturing a featured optical recording medium. 2. The method of manufacturing an optical recording medium according to claim 1, wherein the disc substrate has a plane annular shape. 3. The method for producing an optical recording medium according to claim 1, wherein the sheet for optical recording medium has a planar annular shape. 4. The method for manufacturing an optical recording medium according to claim 1, wherein the optical recording medium sheet has a rectangular shape. 5. The method of manufacturing an optical recording medium according to claim 1, wherein an identification mark is provided on the first protective sheet. 6. The method for producing an optical recording medium according to claim 1, wherein the first protective sheet is colored in a visible color. 7. A second protective sheet that is peelable from the light-transmissive sheet is provided on the surface of the light-transmissive sheet opposite to the surface on which the adhesive layer is provided. The method for manufacturing an optical recording medium according to claim 1, wherein 8. The method of manufacturing an optical recording medium according to claim 7, wherein the second protective sheet is made of polyethylene resin. 9. The method for manufacturing an optical recording medium according to claim 7, wherein the second protective sheet is provided with a visually recognizable identification mark that is distinguishable from the first protective sheet. . 10. A first identification mark is provided on the first protective sheet, and a second identification mark is provided on the second protective sheet, and the first identification mark and the first identification mark are provided. The method of manufacturing an optical recording medium according to claim 7, wherein the second identification mark and the second identification mark are distinguishable from each other. 11. The method of manufacturing an optical recording medium according to claim 7, wherein the second protective sheet is colored in a color that is distinguishable from the first protective sheet and is visible. 12. The first protective sheet is colored in a visible color, and the second protective sheet is colored in a visible color that is distinguishable from the color in the first protective sheet. The method for manufacturing an optical recording medium according to claim 7, wherein the optical recording medium is manufactured. 13. The sheet for optical recording medium comprises the light-transmitting sheet, the adhesive layer, a peelable third protective sheet provided on the adhesive layer side, and the light-transmitting sheet. The method for producing an optical recording medium according to claim 1, further comprising a hard coat layer provided on a surface opposite to the side provided with the adhesive layer. 14. The method of manufacturing an optical recording medium according to claim 13, wherein an identification mark is provided on the third protective sheet. 15. The method of manufacturing an optical recording medium according to claim 13, wherein the third protective sheet is colored in a visible color. 16. The method for producing an optical recording medium according to claim 13, wherein the hard coat layer is provided on the surface thereof with a fourth protective sheet that can be peeled off. 17. The method of manufacturing an optical recording medium according to claim 16, wherein the fourth protective sheet is made of polyethylene resin. 18. The method of manufacturing an optical recording medium according to claim 16, wherein the fourth protective sheet is provided with a visually recognizable identification mark that is distinguishable from the third protective sheet. . 19. A third identification mark is provided on the third protection sheet, and a fourth identification mark is provided on the fourth protection sheet, and the third identification mark and the third identification mark are provided. The method for manufacturing an optical recording medium according to claim 16, wherein the fourth identification mark and the fourth identification mark are distinguishable from each other. 20. The method for producing an optical recording medium according to claim 16, wherein the fourth protective sheet is colored in a color that is distinguishable from the third protective sheet and is visible. 21. The third protective sheet is colored in a visible color, and the fourth protective sheet is colored in a visible color that is distinguishable from the color in the third protective sheet. 17. The method according to claim 16, wherein
A method for producing the optical recording medium described. 22. The method of manufacturing an optical recording medium according to claim 1, wherein the adhesive layer is made of a pressure sensitive adhesive. 23. A disk substrate, an information signal section provided on one main surface of the disk substrate and configured to record and / or reproduce an information signal, and record and / or reproduce the information signal. And a light-transmitting layer configured to be able to transmit the laser light, wherein the light-transmitting layer is at least a light-transmitting sheet capable of transmitting the laser light, and capable of transmitting the laser light, A method of manufacturing an optical recording medium comprising an adhesive layer for adhering a light-transmissive sheet to the one main surface of the disc substrate, the optical disc having at least the light-transmissive sheet and the adhesive layer, and having an outer diameter of the disc substrate. A step of supplying a sheet for an optical recording medium having a larger outer diameter, and the sheet for an optical recording medium is opposed to the surface of the adhesive layer and the one main surface of the disc substrate. A step of bonding, a manufacturing method of an optical recording medium characterized by a step of trimming the sheet the optical recording medium in the shape of the disk substrate. 24. The method of manufacturing an optical recording medium according to claim 23, wherein the disk substrate has a planar annular shape. 25. The method of manufacturing an optical recording medium according to claim 23, wherein the optical recording medium sheet has a rectangular shape. 26. The optical recording medium according to claim 23, wherein the sheet for optical recording medium is trimmed using a cutter blade, a cutting tool, a laser cutter, an ultrasonic cutter or a press die. Manufacturing method. 27. The optical recording medium sheet comprises the light transmissive sheet, the adhesive layer, and a peelable first protective sheet provided on the adhesive layer side. The method for manufacturing an optical recording medium according to claim 23. 28. The method of manufacturing an optical recording medium according to claim 27, wherein an identification mark is provided on the first protective sheet. 29. The method of manufacturing an optical recording medium according to claim 27, wherein the first protective sheet is colored in a visible color. 30. A second protective sheet peelable from the light-transmissive sheet is provided on the surface of the light-transmissive sheet opposite to the surface on which the adhesive layer is provided. 28. The method for manufacturing an optical recording medium according to claim 27. 31. The method for producing an optical recording medium according to claim 30, wherein the second protective sheet is made of polyethylene resin. 32. The method of manufacturing an optical recording medium according to claim 30, wherein the second protective sheet is provided with a visually recognizable identification mark that is distinguishable from the first protective sheet. . 33. A first identification mark is provided on the first protective sheet, and a second identification mark is provided on the second protective sheet, and the first identification mark and the first identification mark are provided. 31. The method of manufacturing an optical recording medium according to claim 30, wherein the second identification mark and the second identification mark are distinguishable from each other. 34. The method of manufacturing an optical recording medium according to claim 30, wherein the second protective sheet is colored in a color that is distinguishable from the first protective sheet and is visible. 35. The first protective sheet is colored in a visible color, and the second protective sheet is colored in a visible color that is distinguishable from the color in the first protective sheet. 31.
A method for producing the optical recording medium described. 36. The optical recording medium sheet comprises the light-transmitting sheet, the adhesive layer, a peelable third protective sheet provided on the adhesive layer side, and the light-transmitting sheet. 24. The method for manufacturing an optical recording medium according to claim 23, comprising a hard coat layer provided on a surface opposite to the side provided with the adhesive layer. 37. The method of manufacturing an optical recording medium according to claim 36, wherein an identification mark is provided on the third protective sheet. 38. The method of manufacturing an optical recording medium according to claim 36, wherein the third protective sheet is colored in a visible color. 39. The method for producing an optical recording medium according to claim 36, wherein a fourth protective sheet that is configured to be peelable is provided on the surface of the hard coat layer. 40. The method of manufacturing an optical recording medium according to claim 39, wherein the fourth protective sheet is made of polyethylene resin. 41. The method of manufacturing an optical recording medium according to claim 39, wherein the fourth protective sheet is provided with a visually recognizable identification mark that is distinguishable from the third protective sheet. . 42. A third identification mark is provided on the third protection sheet, and a fourth identification mark is provided on the fourth protection sheet, and the third identification mark and the third identification mark are provided. 40. The method of manufacturing an optical recording medium according to claim 39, wherein the fourth identification mark and the fourth identification mark are distinguishable from each other. 43. The method of manufacturing an optical recording medium according to claim 39, wherein the fourth protective sheet is colored in a color that is distinguishable from the third protective sheet and is visible. 44. The third protective sheet is colored in a visible color, and the fourth protective sheet is colored in a visible color, which is distinguishable from the color in the third protective sheet. 39. The method according to claim 39, wherein
A method for producing the optical recording medium described. 45. The method of manufacturing an optical recording medium according to claim 23, wherein the adhesive layer is made of a pressure sensitive adhesive. 46. A disk substrate, an information signal section capable of recording and / or reproducing an information signal on one main surface of the disk board, and at least a laser beam with which the information signal section is irradiated. A light-transmitting layer capable of transmitting at least the laser beam and the light-transmitting layer capable of transmitting the laser beam. An optical recording medium sheet, which comprises an adhesive layer for adhering a sheet to one main surface of the disc substrate, and which is used when forming the light transmitting layer, at least the light transmitting sheet and the adhesive layer, An optical recording medium, comprising: a first protective sheet releasably provided on the adhesive layer side, and being formed by punching from the first protective sheet side. Sheet. 47. The optical recording medium sheet according to claim 46, which has a plane annular shape. 48. The optical recording medium sheet according to claim 46, wherein the disc substrate has a planar annular shape. 49. The optical recording medium sheet according to claim 46, which has a rectangular shape and circular through holes. 50. The optical recording medium sheet according to claim 46, wherein the light transmissive sheet is made of a polycarbonate resin. 51. The optical recording medium sheet according to claim 46, wherein an identification mark is provided on the first protective sheet. 52. The optical recording medium sheet according to claim 46, wherein the first protective sheet is colored in a visible color. 53. A second protective sheet peelable from the light-transmissive sheet is provided on the surface of the light-transmissive sheet opposite to the surface on which the adhesive layer is provided. 47. The sheet for optical recording media according to claim 46. 54. The optical recording medium sheet according to claim 53, wherein the second protective sheet is made of a polyethylene resin. 55. The optical recording medium sheet according to claim 53, wherein the second protective sheet is provided with a visually recognizable identification mark that is distinguishable from the first protective sheet. 56. A first identification mark is provided on the first protective sheet, and a second identification mark is provided on the second protective sheet, and the first identification mark and the first identification mark are provided. 54. The optical recording medium sheet according to claim 53, wherein the second identification mark and the second identification mark are distinguishable from each other. 57. The optical recording medium sheet according to claim 53, wherein the second protective sheet is colored in a color that is distinguishable from the first protective sheet and is visible. 58. The first protective sheet is colored in a visible color, and the second protective sheet is colored in a visible color, which is distinguishable from the color in the first protective sheet. 54.
A sheet for an optical recording medium as described above. 59. The optical recording medium sheet according to claim 46, wherein a hard coat layer is provided on the surface of the light transmissive sheet opposite to the side on which the adhesive layer is provided. 60. The optical recording medium sheet according to claim 59, wherein a third protective sheet that is configured to be peelable is provided on the surface of the hard coat layer. 61. The optical recording medium sheet according to claim 60, wherein the third protective sheet is made of polyethylene resin. 62. The optical recording medium sheet according to claim 60, wherein the third protective sheet is provided with a visually recognizable identification mark that is distinguishable from the first protective sheet. 63. A third identification mark is provided on the first protective sheet, and a fourth identification mark is provided on the third protective sheet, and the third identification mark and the third identification mark are provided. 61. The method of manufacturing an optical recording medium according to claim 60, wherein the fourth identification mark and the fourth identification mark are distinguishable from each other. 64. The optical recording medium sheet according to claim 60, wherein the third protective sheet is colored in a color that is distinguishable from the first protective sheet and is visible. 65. The first protective sheet is colored in a visible color, and the third protective sheet is colored in a visible color that is distinguishable from the color in the first protective sheet. 61. The method according to claim 60, wherein
A sheet for an optical recording medium as described above. 66. The optical recording medium sheet according to claim 46, wherein the adhesive layer is made of a pressure sensitive adhesive.