JPH11162026A - Optical disk, production of optical disk and apparatus for production of optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk having a αwatermarkβ which is visible from a disk reproducing surface side and cannot be duplicated. SOLUTION: In the process for producing the optical disk A of a bonding type formed by sequentially laminating a reflection layer 2, an adhesive layer 3 and a dummy transparent substrate 4 on the signal recording surface 1a of the transparent substrate 1, the adhesive layer 3 consists of an adhesive of which the curing rate changes according to the irradiation quantity of UV rays and a light shielding mask 15 which forms the αwatermarkβ is arranged on the surface 4a side of the substrate 4. The inside of the adhesive layer 3 is irradiated with the UV rays while the irradiation quantity thereof is changed according to a state of the light shielding part agent of the light shielding 15 via the mask 15, by which the recording in the optical disk A is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonded optical disk, a method for manufacturing an optical disk, and an apparatus for manufacturing an optical disk, in which a "watermark" can be viewed from the reproduction surface side of the disk.

[0002]

2. Description of the Related Art Optical disks are widely used due to their large amount of recorded information and easy handling. By the way, recently, counterfeit products have been widely used in compact discs (CDs). In order to surely prevent the counterfeit products from being proliferated, the optical disk production and sales industry has put a great deal of effort into the development of counterfeit prevention.

Now, a high-density optical disk has appeared, in which the amount of recorded information is much larger than that of a CD, and in which countermeasures against disk forgery are taken. This high-density optical disk is called a digital versatile disk (also called a DVD or digital video disk). However, even the counterfeiting prevention measures applied to this DVD cannot be said to be for surely preventing the counterfeit products from being traversed. That is, the countermeasure for preventing forgery is as follows.
First, in the production process, a mark, a picture, a character, etc. of a size that can be visually recognized is formed on the information signal recording surface of one of the two disk-shaped single plates to be bonded with an adhesive. Form. Next, in the distribution process, such DVDs
When the information signal recording surface is viewed from the reproduction surface side (laser light incident side) of the information signal track, a spiral or concentric geometric spiral of the information signal track is formed within a certain range.
The marks, pictures, characters, and the like can be confirmed as if they were “watermarks”. Using this, DV
It is visually determined whether or not D has this "watermark". If "watermark" is present, it is determined that the disk is a genuine disk, and if "watermark" is not present, the disk is a forged disk.
As a result, counterfeit products are excluded from distribution, thereby preventing counterfeit products from escalating. Known methods for creating such a "watermark" on a disc are already known (for example, JP-A-59-177739, JP-A-2-179941, and JP-A-8-3102).
0, JP-A-8-55370, JP-A-9-631
35 gazette).

[0004]

However, the above-mentioned "watermark" is formed by directly forming a mark, a picture, a character, or the like of a size that can be visually recognized on the information signal recording surface of the disk as an uneven step. It is. As a result, there is a disadvantage that the manufacturing cost of a disk with a “watermark” is much higher than the manufacturing cost of a disk without a “watermark”. Also, when creating a fake product of such a "watermark" disc, if the information signal recording surface itself on which the "watermark" is formed is faithfully forged, both the forged disc and the genuine disc, The disc will contain the same "watermark". As a result, it is visually checked whether or not the disc has a "watermark". If there is a "watermark", it is determined that the disc is a genuine disc, and if there is no "watermark", the disc is a forged disc. There was a risk that the premise of the measures would be disrupted. Therefore, the conventional countermeasures against disc forgery using "watermarks" cannot be said to be effective for reliably preventing counterfeit discs from escalating.

In order to solve the above-mentioned problems, the present invention does not directly form a "watermark" as an uneven step on an information signal recording surface of a disk as in the prior art.
In the bonding surface of the disks (that is, in the adhesive layer where two single disks are stacked and bonded with an adhesive)
An object of the present invention is to propose an optical disk, a method of manufacturing the optical disk, and a manufacturing apparatus of the optical disk that can be enclosed in a shape such as a mark, a picture, a character, a symbol, and a number of a size that can be visually recognized as a “watermark”. It is assumed that. Accordingly, the present invention attempts to forge the disc containing the “watermark”, and peels off the two single plates bonded with the adhesive in order to forge even the “watermark”. Even if you take it out of the disk or expose it, this peeling will break the adhesive layer and, correspondingly, the "watermark" will be destroyed.
This "watermark" cannot be forged. By using the fact that the "watermark" sealed inside the disc cannot be forged as an effective means of preventing counterfeiting of the disc, during the distribution process, the reproduction side of the disc (incident side of the laser beam) ), When the information signal recording surface is visually observed, it is only necessary to visually check whether or not this “watermark” is present in a range where a spiral or concentric geometric spiral of the signal track is formed. If there is a "watermark", it can be determined that the disk is a genuine disk, and if there is no "watermark", it is a forged disk. Therefore, by preventing the forged disk from distribution, it is possible to surely prevent the counterfeit product from being proliferated. It has an effect that can be done.

[0006]

In order to solve the above-mentioned problems, the present invention provides a method and an apparatus for manufacturing an optical disk having the following constitutions (1) to (25).

(1) A manufacturing method for manufacturing an optical disk in which a reflective layer, an adhesive layer, and a second substrate are sequentially laminated on an information signal recording surface of a first substrate, wherein the adhesive layer is formed of electromagnetic radiation. A light-shielding mask provided with a light-shielding member is disposed on one surface side of the second substrate, and is made of an adhesive whose curing speed changes in accordance with the amount of irradiation. Irradiating the inside of the layer, changing the curing speed of the adhesive in accordance with the presence or absence of the light shielding member, and recording a watermark in the optical disk in accordance with the presence or absence of the light shielding member. .

(2) The method for manufacturing an optical disk according to claim 1, wherein the light-shielding mask is held by holding means, and the light-shielding mask is exchanged by exchanging the holding means. Recording a watermark corresponding to the light-shielding member of the light-shielding mask on which the optical disk has been subjected to the above-mentioned operation in the optical disk.

(3) The method for manufacturing an optical disk according to claim 2, wherein a watermark corresponding to the light shielding member is recorded at a desired position on the optical disk by adjusting the position of the holding means. Production method.

(4) The method for manufacturing an optical disk according to claim 1, wherein the plurality of light-shielding masks are mounted on a transporting means, and a desired light-shielding mask is transported by the transporting means. A method for manufacturing an optical disk, characterized in that a watermark corresponding to a light shielding member of the light shielding mask is recorded in the optical disk.

(5) The method for manufacturing an optical disk according to any one of claims 1 to 4, wherein the light shielding member has a shape including at least one of a mark, a picture, a character, a symbol, a numeral, and the like. A method for manufacturing an optical disk, comprising:

(6) The method for manufacturing an optical disk according to any one of claims 1 to 5, wherein the light-shielding mask is configured so that a part of the light-shielding mask can be replaced with another light-shielding mask member. A method for manufacturing an optical disk, comprising:

(7) The method for manufacturing an optical disk according to claim 6, wherein the watermark corresponding to the other light-shielding mask member has a shape including at least one of a mark, a picture, a character, a symbol, a numeral, and the like. A method for manufacturing an optical disk, comprising:

(8) The method for manufacturing an optical disk according to claim 8, wherein the watermark corresponding to the other light-shielding mask member is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 And when replacing one of the other light-shielding mask members with the other of the other light-shielding mask members, before and after the replacement, the watermark numbers have continuity. A method for manufacturing an optical disk, comprising:

(9) The method for manufacturing an optical disk according to claim 1, wherein the optical disk is mounted on disk mounting means, and the optical disk is rotated by rotating the disk mounting means. And a method for uniformly irradiating electromagnetic radiation onto the optical disk.

(10) The method for manufacturing an optical disc according to claim 9, wherein a watermark corresponding to a desired light shielding member is recorded at a desired position in the optical disc by adjusting a position of the disc mounting means. Manufacturing method of an optical disk.

(11) A manufacturing apparatus for manufacturing an optical disk in which a reflective layer, an adhesive layer, and a second substrate are sequentially laminated on an information signal recording surface of a first substrate, wherein the adhesive layer is provided with electromagnetic radiation. An electromagnetic radiation source that emits electromagnetic radiation and a light-shielding member are provided, which are made of an adhesive whose curing speed changes according to the irradiation amount, and the electromagnetic radiation emitted from the electromagnetic radiation source is shielded by the light-shielding member. A light-shielding mask, and a disk mounting means on which the optical disk is mounted, and which is irradiated with electromagnetic radiation passing through the light-shielding mask, and irradiates electromagnetic radiation into the optical disk adhesive layer through the light-shielding mask. An optical disk manufacturing apparatus, wherein a curing speed of the adhesive is changed according to the presence or absence of the light shielding member, and a watermark corresponding to the presence or absence of the light shielding member is recorded in the optical disk. Place.

(12) A manufacturing apparatus for manufacturing an optical disk in which a reflective layer, an adhesive layer, and a second substrate are sequentially laminated on an information signal recording surface of a first substrate, wherein the adhesive layer is provided with electromagnetic radiation. It is made of an adhesive whose curing speed changes according to the amount of irradiation, an electromagnetic radiation source that emits electromagnetic radiation, a shutter that opens and closes the optical path of the electromagnetic radiation emitted from this electromagnetic radiation source, and electromagnetic radiation that has passed through the shutter. A heat-ray cut filter that blocks emitted heat rays, a light-shielding member, and a light-shielding mask that shields the irradiation of electromagnetic radiation emitted from an electromagnetic radiation source passing through the heat-ray cut filter with the light-shielding member; And a disk mounting means for irradiating the optical disk with the electromagnetic radiation having passed through the light shielding mask. Irradiating the inside of the adhesion layer, changing the curing speed of the adhesive in accordance with the presence or absence of the light shielding member, and recording a watermark in the optical disk in accordance with the presence or absence of the light shielding member. apparatus.

(13) The optical disk manufacturing apparatus according to (11) or (12), further comprising: holding means for holding the light-shielding mask, and exchanging the light-shielding mask by exchanging the holding means. An optical disc manufacturing apparatus, wherein a watermark corresponding to the light-shielding member of the light-shielding mask that has been replaced is recorded at a desired position on the optical disc.

(14) The optical disk manufacturing apparatus according to claim 13, wherein the position of the holding means is adjusted.
An apparatus for manufacturing an optical disk, wherein a watermark corresponding to the light shielding member is recorded at a desired position on the optical disk.

(15) The optical disk manufacturing apparatus according to the above (11) or (12), further comprising a transport unit for mounting the plurality of light-shielding masks, and transporting a desired light-shielding mask by transporting the transport unit. And recording a watermark corresponding to the light-shielding member of the light-shielding mask in the optical disk.

(16) The optical disk manufacturing apparatus according to claim 15, wherein the transport means is a circular table or a linear belt conveyor.

(17) The optical disc manufacturing apparatus according to any one of claims 11 to 16, wherein the light shielding member has a shape including at least one of a mark, a picture, a character, a symbol, a numeral, and the like. An optical disk manufacturing apparatus, comprising:

(18) The apparatus for manufacturing an optical disk according to any one of claims 11 to 17, wherein the light-shielding mask is configured so that a part of the light-shielding mask can be replaced by another light-shielding mask member. An optical disk manufacturing apparatus, comprising:

(19) The optical disk manufacturing apparatus according to claim 18, wherein the plurality of other light shielding mask members are:
The light-shielding mask member is transported by the light-shielding mask member transporting means, and the desired light-shielding mask member is transported by the transporting of the light-shielding mask member transporting means, and a part of the light-shielding mask is replaced by another transported light-shielding mask member. An optical disc manufacturing apparatus characterized by recording a watermark formed on the optical disc.

(20) In the optical disk manufacturing apparatus according to the above (18) or (19), the watermark according to the other light-shielding mask member is any one of a mark, a picture, a character, a symbol, a numeral, and the like. An optical disk manufacturing apparatus characterized in that the optical disk has a shape including at least the optical disk.

(21) The optical disc manufacturing apparatus according to any one of claims 18 to 20, wherein the watermark according to the other light shielding mask member is 0, 1, 2, 3, or 2.
4, 5, 6, 7, 8, and 9, when replacing one of the other light-shielding mask members with the other of the other light-shielding mask members, An optical disk manufacturing apparatus, wherein before and after replacement, watermark numbers have continuity.

(22) The apparatus for manufacturing an optical disk according to the above (11) or (12), further comprising: a disk mounting means for mounting and rotating the optical disk, and rotating the disk mounting means. An apparatus for manufacturing an optical disk, characterized in that the optical disk is rotated to irradiate electromagnetic radiation uniformly on the optical disk.

(23) The optical disk manufacturing apparatus according to (22), wherein a watermark corresponding to a desired light shielding member is recorded at a desired position in the optical disk by adjusting a position of the disk mounting means. An optical disc manufacturing apparatus characterized by the above-mentioned.

(24) An optical disk manufactured by the method for manufacturing an optical disk according to any one of claims 1 to 10.

(25) An optical disk manufactured by the optical disk manufacturing apparatus according to any one of claims 11 to 23.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical disk, an optical disk manufacturing method, and an optical disk manufacturing apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining the structure of a "watermark" recorded on an optical disc of the present invention, and FIGS. 2 to 6, 9 and 10 are first to third embodiments of an optical disc manufacturing apparatus of the present invention, respectively. FIG. 7 is a diagram for explaining the structure of the fifth embodiment, the sixth and seventh embodiments, FIG. 7 is a diagram for explaining the structure of a light-shielding mask, and FIG. FIG. 7 is a diagram for explaining a state in which the light transmittance of ultraviolet light when transmitted through the light shielding mask changes.

The optical disk of the present invention is a laminated optical disk (eg, CD, CD-R, CD-RW, DVD-
ROM, DVD-RAM, DVD-R, DVD-RW
Etc.). The optical disk A of the present invention is manufactured by bonding two disk-shaped single plates (transparent substrate 1 and dummy transparent substrate 4) using an adhesive as shown in FIG. As this bonding method, there are several bonding methods depending on a method of applying an adhesive to a bonding surface of two single plates and then curing the adhesive.

First, the basic method is called a "hot melt coating method", in which a vinyl acetate resin or a vinyl acetate resin having a reduced viscosity at a high temperature is applied to the bonding surface of two discs to be bonded. This is a method of applying using a roll. This method is a method in which both disc single plates are immediately bonded after application of a liquid resin, and then pressure is left to stand for a while to bond the two disc single plates.

In the "spin bonding method", one of the two discs is placed on a spin table of a spinner, and is rotated and cured on the disc by electromagnetic radiation such as an ultraviolet curing resin. A liquid electromagnetic radiation curable resin to be dropped is dropped, and then another disk veneer is placed on the previous disk veneer, and the resin is allowed to spread properly between the two disk veneers. After rotating the table at high speed and spreading the resin between the two discs within the bonding surface of the discs, the resin is cured by irradiating electromagnetic radiation and the two discs are bonded. It is a method of bonding.

The "sheet laminating method" is a method of laminating two disk single plates using a double-sided pressure-sensitive adhesive sheet, in which a double-sided pressure-sensitive adhesive sheet is pasted on one disk single plate, and then another sheet is laminated. Lay the disc veneer on it,
In general, a method is used in which bonding is performed by applying pressure so that air bubbles do not enter the bonding surface of the two discs.

As a method of laminating the optical disk of the present invention, a resin that is polymerized and cured by irradiation of electromagnetic radiation such as ultraviolet rays, for example, an ultraviolet curable resin, is used as the adhesive used in the lamination. As long as the resin used is a resin that is polymerized and cured by irradiation with electromagnetic radiation, all the bonding methods (“spin bonding method”, “sheet bonding method”
Etc.) can be used. Hereinafter, a disc bonding method using an ultraviolet curable resin will be described as an example of a resin polymerized and cured by irradiation with electromagnetic radiation.

As shown in FIG. 1, the optical disk of the present invention has an optical disk A having a structure in which a disk-shaped transparent substrate 1, a reflective layer 2, an adhesive layer 3, and a disk-shaped dummy transparent substrate 4 are sequentially laminated. It is. One surface of the transparent substrate 1 is an information signal recording surface 1a, and laser light L is incident on the other surface 1b in the direction of the arrow. This information signal recording surface 1a
The information signal track is formed spirally or concentrically. This information signal track has at least one of pits, grooves (grooves), and lands. For example, the optical disk of the present invention is a DVD-RO
In the case of M, the information signal track has an information signal recorded using pits and mirrors. Also, DV
In the case of a D-RAM, this information signal track is used for recording and reproducing information signals using grooves (grooves) and lands. In the case of DVD-R and DVD-RW, information signals are recorded and reproduced using grooves (grooves). On the information signal recording surface 1a, a reflective layer 2 is formed in close contact. The adhesive used for the adhesive layer 3 is an ultraviolet curable resin. The information signal recording surface as described above is not formed on the dummy transparent substrate 4 described above.

The optical disk A of the present invention having such a structure
Is the information signal recording surface 1a described above as in the prior art.
Without directly forming a "watermark" above,
In the adhesive layer 3, a mark, picture,
This is an optical disk having a structure in which the shape of characters, symbols, numbers, and the like is used as a “watermark” and enclosed therein.

In the optical disk A, such a "watermark"
In order to make the mask, a light-shielding mask 15 is used as shown in FIG. This light-shielding mask 15 has marks, pictures, characters,
A light-shielding member 15a such as a symbol or a number is formed. Fifteen
b is a light-shielding mask portion where the light-shielding member 15a is not formed. When a reversal “watermark” is formed by inverting the above “watermark” in the optical disc A, a mark, picture, character, symbol, numeral, or the like of a size that can be visually recognized is formed on the light shielding mask portion 15b. The light shielding member 15a is formed. Such a light-shielding mask 15 is used when the liquid ultraviolet curing resin is cured after the transparent substrate 1 on which the reflective layer 2 is adhered and the dummy transparent substrate 4 are bonded using an uncured liquid ultraviolet curing resin. Used for

More specifically, as shown in FIG. 1, a light-shielding mask 15 is disposed above the dummy transparent substrate 4, and ultraviolet light is irradiated from above the light-shielding mask 15. This allows
The liquid ultraviolet curing resin in the adhesive layer 3 is transmitted through the light-shielding mask 15 and the dummy transparent substrate 4, and is irradiated with ultraviolet rays on the portion 3 </ b> B of the light-shielding mask 15 except for the projected portion 3 </ b> A corresponding to the light-shielding member 15 a. become. As a result, in the adhesive layer 3, an irradiation portion 3B irradiated with ultraviolet light and a projection portion 3A not irradiated with ultraviolet light are generated. Of course, the projected portion 3A is irradiated with the ultraviolet rays circulating from the irradiated portion 3B side. As a result, there is a difference between the curing speed of the liquid ultraviolet curable resin in the irradiated portion 3B irradiated with the ultraviolet light and the curing speed of the liquid ultraviolet curable resin in the projected portion 3A not irradiated with the ultraviolet light.

The above-mentioned “watermark” means that, as a result of the difference in the curing speed of the liquid ultraviolet curable resin in the adhesive layer 3, when the liquid ultraviolet curable resin of the projected portion 3 A to which the ultraviolet rays are not irradiated is cured, the above transparent The reflection layer 2 that has been in close contact with the substrate 1 is pulled toward the inside of the adhesion layer 3 (inside the projection portion 3A), and the adhesion state is loosened (that is, the transparent substrate 1 of the reflection layer 2).
(A minute change in the position of the adhesive layer 3 from the position where the adhesive layer 3 has been in close contact with the surface of the adhesive layer 3) causes the "watermark" to be formed in the adhesive layer 3. Incidentally, when the liquid UV-curable resin in the projection portion 3A is cured, the UV-curable resin adhered to the one surface 4b of the dummy transparent substrate 4 is adhered in addition to the looseness of the reflection layer 2 being adhered. Pulled into layer 3 (into projection 3A),
A space 6 may be formed between the surface 4b and the adhesive layer 3.

Now, the above-mentioned "watermark" is written on the optical disc A.
The following information can be inserted as a “watermark” when the information is recorded in the file. For example, in the optical disc production process, the type of the “watermark” is changed for each production lot of the optical disc (for example, one lot is in units of 100 sheets,
All “watermarks” such as marks, pictures, characters, symbols, numbers, etc. are exchanged per lot in units of 0 or 10,000. By using a relationship in which a “watermark” of a specific shape corresponds to each production lot, when a large number of optical disks manufactured through a large number of production lots are listed on a distribution / sales route, such a large number of optical disks are used. Of these, this "watermark" of only one optical disc
Can be used to accurately specify the production lot to which this optical disk belongs by simply observing. As a result, when a defect occurs in a specific production lot, and when it is desired to collect an optical disk belonging to this production lot from a distribution / sales channel, only this "watermark" is inspected (visual inspection), and a defect occurs. By simply taking out and collecting only the optical disk with the “watermark” corresponding to the production lot, there is an advantage that such a defective optical disk can be efficiently and reliably recovered.

It is also conceivable to change the type of the "watermark" for each production lot of the optical disc without changing the "watermark" itself, as described above. For example, a part of the “watermark” may have the same shape for the most part, and only a part of the “watermark” may be a “watermark” having a serial number that is progressively increased by “1” for each production lot. Conceivable. For example, the first
The “watermark” corresponding to the production lot of “No.” has a “watermark” part including “1” in a part thereof, and the “watermark” corresponding to the second production lot includes the “watermark” including “2” in part thereof ", The" watermark "corresponding to each of the third, fourth, fifth,... Production lots has a" watermark "part including" 3, 4, 5,. Attached. Also, in addition to using a “watermark” of a serial number that is progressively incremented by “1” for each production lot, a part of the “watermark” for each production lot includes alphabetical alphabetical characters and Japanese syllabary hiragana. , Katakana, etc.

As described above, the following can be achieved by sequentially changing the "watermark" portion for each production lot without changing all the types of "watermark" for each production lot of the optical disc. For example, in the optical disc production process, a part of the type of “watermark” is changed for each production lot of the optical disc (for example, 100 lots per lot, 10
The “watermark” portions such as marks, pictures, characters, symbols, and numbers are exchanged per lot in units of 00 sheets, 10,000 sheets, etc.). By using a relationship in which a “watermark” portion having a specific shape corresponds to each production lot, a large amount of optical discs manufactured through a large number of production lots can be distributed and distributed.
At the stage of being included in the sales channel, it is possible to use the visual mark of this "watermark" portion of only one optical disk from among such a large number of optical disks to accurately specify the production lot to which the optical disk belongs. As a result, when a defect occurs in a specific production lot, and when it is desired to collect an optical disk belonging to this production lot from a distribution / sales channel, only this "watermark" portion is inspected (visual inspection) and a defect occurs. By simply taking out and collecting only the optical disk having the “watermark” portion corresponding to the production lot, there is an advantage that such a defective optical disk can be efficiently and reliably recovered.

The following (1) and (2) are conceivable as a method of manufacturing the optical disk of the present invention having the above-described structure. (1) Method using a light shielding mask (2) Method not using a light shielding mask

(1) Method using a light-shielding mask In this method, as shown in FIG. 1 described above, a light-shielding mask 15 is arranged above the surface 4a of the dummy transparent substrate 4 of the optical disk A, and Irradiating the optical disc A with ultraviolet light from above the light-shielding mask 1
5, a mark of such a size as to be visible,
This is a method of forming a “watermark” in the adhesive layer 3 of the optical disc A according to shapes 15a and 15b such as pictures, characters, symbols, and numbers.

(2) Method without using a light-shielding mask This method is based on the method of using the surface 4 of the dummy transparent substrate 4 of the optical disc A.
a, 4b, which is formed on the light-shielding mask 15 and serves as a source of a "watermark";
Similar to the light-blocking members 15a and 15b such as marks, pictures, characters, symbols, and numbers, which are visible enough, the marks, pictures, characters, A light-shielding member 15aa such as a symbol or a number is provided. Also,
Reversal "watermark" inverted from the above "watermark"
Is formed, a light-shielding member 15a such as a mark, a picture, a character, a symbol, or a number is formed on the light-shielding mask portion 15b so as to be visible. Then, by irradiating the optical disc A with ultraviolet rays from above the surface 4a of the dummy transparent substrate 4, marks, pictures, characters,
This is a method of forming a “watermark” in the adhesive layer 3 of the optical disc A according to the shape of a symbol, a number, or the like. In this (2) “method without using a light-shielding mask”, the “watermark” similar to the above (1) “method using a light-shielding mask” is recorded on the optical disk A.
Can be formed in the adhesive layer 3.

By the way, the light-shielding mask 15 used in the above-mentioned (1) “method using a light-shielding mask” includes, as a light-shielding member 15a,
Write or print pictures, characters, symbols, numbers, etc. using colored inks such as black, blue, red, etc., and use light-shielding members (paper) in the shape of these marks, pictures, characters, symbols, numbers, etc. ,
A film, etc.).

The light shielding member 15a of the light shielding mask 15 described above.
Is printed using black ink, or a black member is adhered or adhered, or a black member is adhered and placed, a complete light shielding state is obtained. As a result, when ultraviolet light is irradiated from directly above the light-shielding mask 15, the shape of the light-shielding member is projected deeply into the adhesive layer 3 of the projection portion 3A immediately below the light-shielding mask 15.

On the other hand, a light-shielding member shape 15a is printed on the light-shielding mask 15 by using a colored ink other than black ink (colored ink of blue, red, green, yellow, white, or the like), or a color ink other than black is used. A light-shielding member (light-shielding member of blue, red, green, yellow, white, etc.) 15a is adhered or placed in close contact, or such a light-shielding member 15a other than black is adhered or adhered incompletely. If the light shielding member 15a is printed by using black ink, or the black light shielding member 15a is adhered or adhered to the light shielding member 15a, the light shielding member 15a is formed in the same manner as in the above-described case where the light shielding member 15a is closely mounted. A perfect light blocking state cannot be obtained.

As a result, when ultraviolet light is irradiated from directly above the light-shielding mask 15, the type and color of the light-shielding member 15 a are applied to the adhesive portion 3 A of the adhesive layer 3 of the optical disk A immediately below the light-shielding mask 15. The light-shielding member 15a is projected as a dark shadow to a light shadow with a light transmittance according to the material, the pasting state, and the mounting state. In other words, the “watermark” is projected onto the disk with ultraviolet rays having a light transmittance (shown in FIG. 8) corresponding to the density of the “watermark” corresponding to the light shielding member 15a. As shown in FIG.
When the light transmittance at a wavelength of less than nm (wavelength in the ultraviolet region) is “0”, the light blocking member 15a is black, and the light transmittance of the light blocking members 15a of other colors gradually increases.

As described above, the space 6 is generated between the adhesive layer 3 and the dummy transparent substrate 4 according to the stress distribution generated in the bonding surface of the optical disk A. The thickness of the transparent substrate 1 and the dummy transparent substrate 4 is 0.6 mm, respectively. The spectral characteristics of the light-shielding mask 15 provided with the above-described light-shielding member 15a are, for example, wavelength 4
The light transmittance of ultraviolet light of 50 nm or less is about 10%. A light-shielding member 15a for marks, pictures, characters, symbols, numerals, and the like as described above is provided on the light-shielding mask 15, and the amount of light (gradation) of the light-shielding mask 15 is changed. As described above, the transmittance changes.

Therefore, when the disc surface is viewed from the reproduction surface (the surface 1b of the transparent substrate 1) side of the optical disk A, the density (gradation)
The mark, the picture, the character, the symbol, the number, and the like having such a size as to be visible can be visually observed together with the signal track on the information signal recording surface 1a as a “watermark”. Specifically, the “watermark” whose density (gradation) has changed in this way ranges from a light level (light level) that cannot be identified by just looking at it to a dark level that can be clearly confirmed. As described above, such a “watermark” can be freely selected by changing and exchanging the light shielding member 15 a as necessary.

The next item to be considered is the optical disc A created by the above-described method.
This is a check of the focus error amount of the reproducing optical head (optical pickup) for reproducing the data.

Generally, such a “watermark” is a mark or picture which can be clearly identified on the information signal recording surface 1 a in the optical disk A when viewed from the reproduction surface (the surface 1 b of the transparent substrate 1) of the optical disk A. It is observed as optical information such as characters, symbols, and numbers that the reflection layer portion 2a of the reflection layer 2 is formed by distortion. Due to such distortion,
When the disc is reproduced, information recorded on the information signal recording surface 1a and originally to be reproduced without distortion must not be distorted by the distortion of the reflective layer 2 to cause an information defect. Therefore, it is required to add a “watermark” to the information to be reproduced so as not to give distortion.

As long as the original information signal is correctly reproduced by the reproducing optical head, the maximum density of the “watermark” can be obtained.
Clarity should be set so that it looks like a "watermark". If this "watermark" is created with priority given to the clear appearance of the "watermark", this balance will be lost, and the insertion of the "watermark" will cause a focus error in the reproducing optical head, making reproduction impossible. From the above, the optical disc of the present invention is capable of reproducing an information signal satisfactorily, and has a "watermark" whose shape can be clearly seen.
It has.

Now, with reference to one embodiment, a method of manufacturing the optical disk of the present invention for manufacturing such an optical disk of the present invention will be described in an easy-to-understand manner. A transparent substrate 1 having a pit having a track pitch of 0.74 μm and a minimum pit length of 0.4 μm in an information signal recording surface 1 a having a thickness of 0.6 mm and a diameter of 120 mm is formed using a polycarbonate resin.
Manufactured by injection molding. On the other hand, a flat dummy transparent substrate 4 having the same thickness and diameter and having no pits on its surface 4b was manufactured. On the information signal recording surface 1a having the pits, a reflective film (reflective layer) 2 having a thickness of 60 nm was formed using aluminum by vacuum film formation.

The transparent substrate 1 was mounted on a spin table with the reflection film 2 facing upward. Then, 3 ml of a liquid ultraviolet-curable resin was circumferentially dropped. After the UV-curable resin spreads to an appropriate size on the reflective film 2, the dummy transparent substrate 4 is superimposed on the UV-curable resin (adhesive layer 3) with care so as not to generate air bubbles. The spinner was rotated to obtain the desired thickness of the three adhesive layers.
The bonded transparent substrates 1 and 4 were not removed from the spinner since the ultraviolet curable resin had not been cured yet, so that the substrates 1 and 4 were not displaced from each other. The bonded optical disk A was carried to the next ultraviolet curing device. This ultraviolet curing device is a device for manufacturing the optical disk of the present invention.

An embodiment of the optical disk manufacturing apparatus according to the present invention will be described below. As shown in FIG. 2, an ultraviolet curing device B, which is a first embodiment of the optical disk manufacturing apparatus of the present invention, has an exhaust duct 10 and an exhaust fan 11 for exhausting gas inside the device B from above in the figure. UV lamp 1
2. A shutter 1 for opening and closing the optical path x of the irradiated ultraviolet light
3. A heat ray cut filter 14 for preventing heat generated from the ultraviolet lamp 12 from being transmitted downward in the figure, and a light shielding mask 1 having a light shielding member 15a for forming a "watermark".
5, a table 17 for mounting an optical disk A of two single-plate disks (transparent substrates 1 and 4) bonded with a liquid ultraviolet-ray resin, In order to place the optical disk A on the optical disk A, the optical disk A is transported from the above-mentioned bonding process, and the completed optical disk A is transported to the next process by a table transport mechanism (not shown), an outer cylinder B1 or the like. Be composed. The light-shielding mask tray 16 has a hole 16h having a diameter such that the optical disk A placed on the table 17 is sufficiently irradiated with ultraviolet rays and does not have uneven illuminance. It is attached to the outer cylinder B1 so as to be able to advance and retreat in the direction. b indicates the transfer direction of the table 17.

As described above, since the light-shielding mask 15 is removably mounted and fixed on the light-shielding mask tray 16, the light-shielding mask tray 16 is pulled out from the ultraviolet light path x, and the outer cylinder B 1 of the apparatus B is extracted. As described above, when it is desired to change the "watermark" frequently for each production lot or even within the lot as described above, the light shielding mask 15 can be easily attached and detached without disassembling the ultraviolet curing device B. can do.

By the way, many (many types) for each production lot
In order to be able to change the “watermark”, a large number of light shielding masks 1 for forming a large number of various “watermarks” are required.
A light-shielding mask tray 16 having a structure that allows replacement of the light-shielding mask 5 is required.

As shown in FIG. 3, an ultraviolet curing device C, which is a second embodiment of the optical disk manufacturing apparatus of the present invention, has a structure in which the above-described ultraviolet curing device B (shown in FIG. 2) has a light-shielding mask transport mechanism. 16a is the same as that newly added. The same parts as those described above are denoted by the same reference numerals,
The description is omitted.

As shown in FIG. 3, the ultraviolet curing device C
A light-shielding mask transport mechanism 16a capable of transporting a large number of light-shielding masks 15A, 15B, 15C,...
6 are provided above and separated from each other by a predetermined distance. The light-shielding mask transport mechanism 16a has a configuration similar to that of a so-called belt conveyor, and a large number of light-shielding masks 15A, 15B, 15C,. (1), the sheet is conveyed by the conveyance control of a control device (not shown), and stops at a predetermined position. Light shielding mask 15
A, 15B, 15C,... Are provided with light-shielding members 15Aa, 15Ba, 15 such as marks, pictures, characters, symbols, numbers, and the like, each of which is a source of “watermark”.
Ca,... Are formed.

To form a specific “watermark”,
In response to a control signal output from a control device (not shown), the light-shielding mask transport mechanism 16a transports the corresponding light-shielding mask onto the hole 16h of the light-shielding mask tray 16 and stops after accurately positioning it. Thus, the light-shielding mask is accurately placed on the hole 16h of the light-shielding mask tray 16. Thereafter, if a different light-shielding mask is desired to be used, the control device outputs a control signal in accordance with the light-shielding mask, so that the light-shielding mask transport mechanism 16a
The corresponding light-shielding mask is conveyed onto the hole 16h of the light-shielding mask tray 16, and is accurately positioned and then stopped. In this manner, the light-shielding mask is accurately placed on the hole 16h of the light-shielding mask tray 16. Thus, the required light-shielding mask can be replaced in a short time.

The ultraviolet curing device C places the light shielding masks 15A, 15A on the optical disk A placed on the table 17.
B, 15C,..., An ultraviolet ray is radiated onto the bonded disc A mounted on the turntable 17 through the transparent light-shielding mask transport mechanism 16a and the hole 16h of the light-shielding mask tray 16. It goes without saying that irradiation can be performed without unevenness or blur.

As a result, when it is desired to insert a different “watermark” for each production lot of the optical disk A using the ultraviolet curing device C, for example, the light shielding masks 15 A, 15B and 15C are linearly placed on the mask transport mechanism 16a, and as described above, the light-shielding mask corresponding to this production lot is transported using the light-shielding mask tray 16, and positioned and stopped. This can be achieved.

As shown in FIG. 4, an ultraviolet curing device D, which is a third embodiment of the optical disk manufacturing apparatus of the present invention, is different from the ultraviolet curing device C (shown in FIG. 3) in the form of a belt conveyor. The light-shielding mask transport mechanism 16a is replaced with a circular (index table) -shaped light-shielding mask transport mechanism 1.
6c. The same portions as those described above are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 4, the ultraviolet curing device D
Numerous light-shielding masks 15A, 15B, 15C, 15D, 15E, 15 for forming different "watermarks"
F, 15G,..., 15X are transmitted by a control signal (not shown) from a control device (not shown). It is provided above and separated by a predetermined distance. The light-shielding mask transport mechanism 16c includes a large number of light-shielding masks 1 mounted thereon.
5A, 15B, 15C, 15D, 1E, 15F, 15
G,..., 15X are conveyed, positioned, and stopped in a counterclockwise direction (e direction) in the figure by a control signal from a control device (not shown). Light-shielding masks Light-shielding masks 15A, 15B,
Each of 15C, 15D, 1E, 15F, 15G,..., 15X has a light-blocking member 15Aa, 15Ba, such as a mark, a picture, a character, a symbol, or a number, of a size that can be viewed, which is a source of a “watermark”. , 15Ca, 15Da, 15Ea,
, 15Xa are formed.

When a specific “watermark” is to be formed,
In response to a control signal from a control device (not shown), the light-shielding mask transport mechanism 16c transports the corresponding light-shielding mask onto the hole 16h of the light-shielding mask tray 16 and stops after accurately positioning it. Thus, the light-shielding mask is accurately placed on the hole 16h of the light-shielding mask tray 16. Thereafter, if a different light-shielding mask is desired to be used, the control device outputs a control signal corresponding to the light-shielding mask, and the light-shielding mask transport mechanism 16c causes the corresponding light-shielding mask to be placed in the light-shielding mask tray. 16 holes 1
It is transported over 6h, and after positioning accurately, it stops.
Thus, on the hole 16h of the light shielding mask tray 16,
This light-shielding mask is accurately placed. Thus, the required light-shielding mask can be replaced in a short time.

The ultraviolet curing device D places the light-shielding masks 15A, 15A on the optical disk A placed on the table 17.
B, 15C, 15D, 1E, 15F, 15G, ..., 15
X, a transparent light-shielding mask transport mechanism 16c,
Through the holes 16h of the light shielding mask tray 16, ultraviolet rays
It goes without saying that the irradiation can be performed on the bonded disc A mounted on the turntable 17 without irradiation unevenness and blur.

As a result, when it is desired to insert a different “watermark” for each production lot of the optical disc A using the ultraviolet curing device D, for example, the light-shielding masks 15A, 15B, 15C, 15
D, 1E, 15F, 15G,..., 15X are annularly mounted on the light-shielding mask transport mechanism 16c, and as described above, the light-shielding mask corresponding to this production lot is transported to the light-shielding mask transport mechanism 16c. By doing so, this can be achieved.

Generally, when the distance between the above-mentioned light-shielding mask 15 and the optical disk A placed on the table 17 increases, the ultraviolet rays which have passed around the light-shielding mask 15 reach the optical disk A and are irradiated. The “watermark” formed on top is blurred. For this reason, it is desirable that the light-shielding mask 15 be as close as possible to the optical disk A placed on the table 17. However, if it is too close, the optical disk A will come into contact with the light-shielding mask 15 due to the warp of the optical disk A. Absent.

In order to achieve this balance, the light-shielding mask tray 16 is placed in the ultraviolet curing devices B, C and D.
In the drawing, it is necessary to adjust the position in the vertical direction and adjust the positions of the optical disc A and the light shielding mask 15 in a favorable state to prevent the occurrence of blurring of the “watermark”.
Next, a specific example will be described.

As shown in FIG. 5, an ultraviolet curing device E, which is a fourth embodiment of the optical disk manufacturing apparatus of the present invention, has a light shielding mask tray 16 and a light shielding mask tray 16 having the above-described structure of the ultraviolet curing device B (shown in FIG. 2). The table 17 can be moved and adjusted vertically (arrows d and f) in the figure. The same portions as those described above are denoted by the same reference numerals, and description thereof will be omitted. The light-shielding mask tray 16 and the table 17 can be individually adjusted in the vertical direction (arrows d and f).

Thus, even if the distance between the light-shielding mask 15 placed on the light-shielding mask tray 16 and the optical disk A placed on the table 17 is large, the light-shielding mask tray 16 and the table 17 can be moved. By moving to the arrows d and f, the optical disk A and the light shielding mask 15 are moved.
With the position (1) and (2) in a good state, it is possible to reliably prevent the ultraviolet light that has passed around the light-shielding mask 15 from irradiating the disk A and blurring the “watermark” formed there.

Although not described in detail here, in the ultraviolet curing devices C and D, the optical disk A and the light shielding mask 15 are similarly moved by moving the light shielding mask tray 16 and the table 17 up and down in the drawing. By setting the position to a favorable state, it is possible to reliably prevent the ultraviolet light that has passed around the light-shielding mask 15 from being irradiated on the disk A, thereby blurring the "watermark" formed thereon.

As shown in FIG. 6, an ultraviolet curing device F, which is a fifth embodiment of the optical disk manufacturing apparatus of the present invention, has the same structure as that of the above-described ultraviolet curing device B (shown in FIG. 2) except that a light-shielding mask is partially replaced. This is the same as the one provided with the transport mechanism 18. The same parts as those described above are denoted by the same reference numerals,
The description is omitted.

As shown in FIG. 6, the light-shielding mask 15 used in the ultraviolet curing device F has a light-shielding member 15a for forming most of one "watermark", and a part of the "watermark" is replaceable. Light shielding mask portions 15aa, 15bb, 1
5cc, 15dd, 15ee, 15ff, 15gg,
.., 15xx fitting part 15A
A is provided. The light-shielding mask portion fitting portion 15AA includes the light-shielding mask portions 15aa, 15bb, and 15 fitted here.
cc, 15dd, 15ee, 15ff, 15gg, ...,
It has a concave positioning shape so that 15xx fits securely.

A large number of light shielding mask portions 15aa, 15bb, 15cc, 15
Among the dd, 15ee, 15ff, 15gg,..., 15xx, the designated light-shielding mask portion is transported and detachably fitted. Light shielding mask portions 15aa, 15
bb, 15cc, 15dd, 15ee, 15ff, 15
Each of gg,..., 15xx has a light-shielding member 15aaa, such as a mark, a picture, a character, a symbol, or a number, which is a part of the “watermark” of the light-shielding mask 15 and can be viewed.
15bbb, 15ccc, 15ddd, 15ee, 1
5fff, 15ggg,..., 15xxx are formed. For example, when it is desired to put a serial number in a part of the “watermark”, the light shielding mask portions 15aa, 15bb, 1
5cc, 15dd, 15ee, 15ff, 15gg,
…, 15xx are “1”, “2”,
A light-shielding member having a progressive number including the numbers “3”, “4”, “5”, “6”, “7”,... Is formed.

On the other hand, the light-shielding mask partial exchange transport mechanism 18
Are formed from the arm 18a and the light-shielding mask partial mounting portion 18b. The light-shielding mask portion mounting portion 18b includes a large number of light-shielding mask portions 15aa, 15bb, 15cc, 15dd, for replacing a part of the "watermark" of the light-shielding mask 15.
The 15ee, 15ff, 15gg,..., 15xx are mounted in an annular shape, and rotate in the counterclockwise direction (the direction of arrow h) in FIG. The arm 18a is arranged such that the light-shielding mask 15 placed on the light-shielding mask tray 16 around the axis 18aa.
And the light-shielding mask partial mounting portion 18b. A suction portion 18ab is provided at the tip of the arm 18a.
The suction portion 18ab is provided with a light-shielding mask portion 15aa, 15bb, 15cc, 15dd,
One of 15ee, 15ff, 15gg,..., 15xx can be easily attached and detached.

The ultraviolet curing device F operates as follows. A case where the light-shielding mask portion 15aa is fitted and mounted on the light-shielding mask portion fitting portion 15AA of the light-shielding mask 15 and then the light-shielding mask portion 15aa is replaced with another light-shielding mask portion 15bb will be described. Although not described in detail here, the light shielding mask portions 15aa, 15bb, 15cc, 15d
d, 15ee, 15ff, 15gg,..., 15xx, the light shielding mask portions 15aa, 1
Of course, it can be performed similarly to 5bb.

First, under the control of a control unit (not shown), the light-shielding mask partial mounting unit 1 rotating in the direction of arrow h
The light-shielding mask portion 15aa mounted on 8b stops the light-shielding mask portion mounting portion 18b at a position where the suction portion 18ab of the arm 18a is located above the light-shielding mask portion 15aa. Next, under the control of a control unit (not shown), the arm 18a moves the light-shielding mask portion 1 mounted on the light-shielding mask portion mounting portion 18b.
5aa is sucked by the suction portion 18ab, and thereafter, the light-shielding mask portion 15aa is lifted. Thereafter, the arm 18a that has lifted the light-shielding mask portion 15aa turns in the direction of arrow g, conveys the light-shielding mask 15 above the light-shielding mask portion fitting portion 15AA, and then stops turning. The arm 18a is configured such that the light-shielding mask portion 15aa sucked by the suction portion 18ab is moved to the light-shielding mask portion fitting portion 15A.
The suction portion 18ab is gradually lowered until it is securely fitted to the position A.

As described above, when the light-shielding mask portion 15aa is securely fitted to the light-shielding mask portion fitting portion 15AA of the light-shielding mask 15, ultraviolet light is irradiated onto the optical disc A via the light-shielding mask 15, as described above. . Thus, on the optical disk A, a light-shielding shape 15a for forming most of the "watermark" and a "watermark" corresponding to the light-shielding mask portion 15aa for forming a part of the "watermark" are formed.

When the formation of the “watermark” is completed, the arm 1
When the suction portion 18ab of 8a descends, the light shielding mask 15
The light-shielding mask portion 15aa fitted to the light-shielding mask portion fitting portion 15AA is sucked, and then the light-shielding mask portion 15aa is lifted. Thereafter, the arm 18a that has lifted the light-shielding mask portion 15aa turns in the direction of the arrow g, conveys it above the light-shielding mask portion mounting portion 18b, and stops turning. Then, the suction portion 18ab of the arm 18a descends, and the sucked light shielding mask portion 15aa is placed on the light shielding mask portion placement portion 18b.

Thereafter, under control of a control unit (not shown), the stopped light-shielding mask partial mounting portion 18b is moved by an arrow h.
Then, the light-shielding mask portion 15bb mounted on the light-shielding mask portion mounting portion 18b stops the light-shielding mask portion mounting portion 18b at a position where the suction portion 18ab of the arm 18a is located above. Next, under the control of a control unit (not shown), the arm 18a sucks the light-shielding mask portion 15bb placed on the light-shielding mask portion mounting portion 18b with the suction portion 18ab, and thereafter, the light-shielding mask portion 15ab 1
Lift 5bb. Thereafter, the light shielding mask portion 15
The arm 18a that has lifted bb pivots in the direction of arrow g, conveys it above the light-shielding mask portion fitting portion 15AA of the light-shielding mask 15, and then stops rotating. And arm 1
8a gradually lowers the suction portion 18ab until the light-shielding mask portion 15bb sucked by the suction portion 18ab is securely fitted to the light-shielding mask portion fitting portion 15AA.

As described above, when the light-shielding mask portion 15bb is securely fitted to the light-shielding mask portion fitting portion 15AA of the light-shielding mask 15, ultraviolet light is irradiated onto a new optical disk A via the light-shielding mask 15 as described above. Is done. Thus, on the optical disk A, a light-shielding shape 15a for forming most of the "watermark" and a "watermark" corresponding to the light-shielding mask portion 15bb for forming a part of the "watermark" are formed.

When the formation of the “watermark” is completed, the arm 1
When the suction portion 18ab of 8a descends, the light shielding mask 15
The light-shielding mask portion 15bb fitted to the light-shielding mask portion fitting portion 15AA is sucked, and then the light-shielding mask portion 15bb is lifted. Thereafter, the arm 18a that has lifted the light-shielding mask portion 15bb pivots in the direction of arrow g, conveys it above the light-shielding mask portion mounting portion 18b, and stops rotating. Then, the suction portion 18ab of the arm 18a descends, and the sucked light shielding mask portion 15bb is mounted on the light shielding mask portion mounting portion 18b.

As described above, the ultraviolet curing device F places the light-shielding mask portion 15aa on the light-shielding mask portion fitting portion 15AA of the light-shielding mask 15, and then moves the light-shielding mask portion 1
5aa can be replaced with a light-shielding mask portion 15bb.

The light-shielding mask portions 15aa, 15bb, 15cc, 15dd,
Supply of 15ee, 15ff, 15gg, ..., 15xx,
Alternatively, the supply to the ultraviolet curing devices B, C, and E ends before the ultraviolet shutter 13 opens, and the discharge to the outside of the ultraviolet curing device F needs to be performed after the shutter 13 closes.

In consideration of the flatness of the transparent substrate 1 and the dummy transparent substrate 4 of the optical disk A, when the transparent substrate 1 and the dummy transparent substrate 4 are formed of, for example, a glass substrate having good flatness, The light shielding mask tray 16 becomes unnecessary. The “watermark” can be created by placing the light-shielding mask 15 very close to the optical disc A. Next, this case will be described.

As shown in FIG. 9, the ultraviolet curing device G, which is the sixth embodiment of the optical disk manufacturing apparatus of the present invention, removes the light shielding mask tray 16 of the ultraviolet curing device B (shown in FIG. 2). Instead of the light-shielding mask tray 16, a tray 30 on which the light-shielding mask 15 is placed is set on the table 1.
7 is the same as that which is fixedly or detachably mounted on 7. The same portions as those described above are denoted by the same reference numerals, and description thereof will be omitted. Further, the turntable 17 rotates in the direction of arrow j during the ultraviolet exposure period so that the ultraviolet exposure unevenness does not occur on the optical disc A.

Further, as shown in FIG. 10, the ultraviolet curing device H, which is the seventh embodiment of the optical disk manufacturing apparatus of the present invention, removes the tray 30 of the ultraviolet curing device G (shown in FIG. 9). Optical disk A placed on table 17
7 is the same as the one on which the light-shielding mask 15 is directly mounted. The same portions as those described above are denoted by the same reference numerals, and description thereof will be omitted. As a result, during the UV exposure period, the UV exposure unevenness does not occur on the optical disc A.
When the turntable 17 rotates in the direction of the arrow j, the light-shielding mask 15 rotates accordingly.

Next, a method for producing the shading of the “watermark” will be described. Several types of light-shielding masks 15 were prepared as follows.

(1) Three quartz glass disks having a thickness of 1 mm and a diameter of 140 mm were prepared, one of which was made of black ink.
I wrote the word "spring". One of them was written with the word "summer" in blue ink. The third one wrote the word "autumn" with yellow ink. As described above, by changing the color of the ink to change the light transmittance of the ultraviolet light, the density of the “watermark” can be changed. In order to change the light transmittance of ultraviolet rays, one kind of ink may be used and the printing thickness of the ink may be changed. As shown in FIG. 8, as the light transmittance of ultraviolet light decreases, the “watermark” becomes darker, and conversely, as the light transmittance of ultraviolet light increases,
The “watermark” has a property of becoming thin.

Also, as the "watermark" becomes darker, the reproduced high-frequency waveform when the disk A is reproduced becomes more disturbed. If the waveform is too disturbed, normal reproduction cannot be performed. It is desirable that the light transmittance of the ultraviolet ray is set to an appropriate value while checking the reproduced waveform. As for the disc A with the “watermark” created as described above, the disc A with different “watermarks” of “spring”, “summer”, and “autumn” could be created. The light-shielding mask 15 having such a structure is shown in FIG. 7A. Reference numeral 20 denotes a quartz glass plate, and reference numerals 21 and 22 denote light-shielding members serving as a basis for a "watermark" having different shades. FIG.
The light shielding mask 15 shown in (B) uses a transparent film 23 instead of the quartz glass plate 20.

(2) The characters "ABC" were written on the ground glass 24 (FIG. 7 (C)) having fine irregularities with transparent ink or liquid ink using silicone oil on the irregular surfaces. In this case, the light-shielding mask 15. In this case, unlike the above (1), the light transmittance of the ultraviolet rays to the character portions 25 and 26 is larger than that of the quartz glass plate 20 having no minute uneven surface. As in (1) above,
A "watermark" could be formed. Although the light reproduction output was slightly disturbed, it was not at a level that would cause a great hindrance to reproduction. Further, as shown in FIG.
The recesses 28 and 29 are formed in advance, and the recesses 28 and 29 are formed.
A member forming a light-shielding member serving as a source of a “watermark” of a character or the like prepared in advance may be fitted.

Thus, FIGS. 7 (A), (B), (C),
The optical disk exposed to ultraviolet light exposure was peeled into two sheets using the light-shielding mask 15 shown in (D), and a copy thereof was taken from the information signal surface 1 a on the transparent substrate 1.
The above "watermark" had disappeared. Also, this disk A
The reproduction waveform of the optical disk was input to the optical modulator of the cutting machine, cutting was performed, and a duplicate of the optical disk was created in a normal optical disk manufacturing process.
Had disappeared.

[0099]

The optical disk, optical disk manufacturing method, and optical disk manufacturing apparatus of the present invention having the above-described configuration are as follows.
On the information signal recording surface formed on the transparent substrate of the bonded optical disk, without causing any physical unevenness directly,
Since it has a structure that disappears when a disc is forged, the fact that the "watermark" sealed inside the optical disc cannot be forged is used as an effective means of preventing counterfeiting of the optical disc, so that it can be distributed, for example. In the process, when the information signal recording surface of the optical disk is viewed from the reproduction surface side (the laser light incident side), the spiral shape or concentric geometric spiral of the signal track is formed within a certain range. Only by visually checking whether or not there is a “watermark”, it can be determined that the disk is a genuine disk if there is a “watermark” and a forged disk if there is no “watermark”. As a result, it is easy to determine whether the optical disk is a genuine optical disk, and the purchaser can confirm that the optical disk is a genuine optical disk before reproducing the optical disk. Has the effect of reliably preventing the traffic from escaping.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the structure of a “watermark” recorded on an optical disc of the present invention.

FIG. 2 is a diagram for explaining the configuration of a first embodiment of an optical disk manufacturing apparatus according to the present invention.

FIG. 3 is a diagram for explaining the configuration of a second embodiment of the optical disk manufacturing apparatus of the present invention.

FIG. 4 is a diagram for explaining a configuration of a third embodiment of the optical disk manufacturing apparatus of the present invention.

FIG. 5 is a diagram for explaining the configuration of a fourth embodiment of the optical disk manufacturing apparatus of the present invention.

FIG. 6 is a diagram for explaining the configuration of a fifth embodiment of the optical disk manufacturing apparatus of the present invention.

FIG. 7 is a diagram for explaining a structure of a light shielding mask.

FIG. 8 is a diagram for explaining a state in which the light transmittance of ultraviolet light when transmitted through the light-shielding mask changes according to the shading density of the light-shielding mask that is the basis of the “watermark”.

FIG. 9 is a diagram for explaining the configuration of a sixth embodiment of the optical disk manufacturing apparatus of the present invention.

FIG. 10 is a diagram for explaining a configuration of an optical disk manufacturing apparatus according to a seventh embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 transparent substrate (first substrate) 1a information signal recording surface 2, 2a, 2b reflective film, reflective layer portion, reflective layer 3 adhesive layer 4 dummy transparent substrate (second substrate) 4a, 4b surface 12 ultraviolet lamp (electromagnetic Radiation source) 13 Shutter 14 Heat ray cut filter 15, 15A, 15B, 15C Light shielding mask 15a, 15Aa, 15Ba, 15Ca Light shielding member 15b, 15Ab, 15Bb, 15Cb Light shielding mask portion other than light shielding member 15Aa Light shielding member mounting portion 16 Light shielding mask Tray (holding means) 16a, 16c Light-shielding mask transport mechanism (transporting means) 17 Table (disk mounting means) 20, 23, 24, 27 Transparent base A Optical disk BH UV curing device

Claims (25)

[Claims] 1. A manufacturing method for manufacturing an optical disk in which a reflective layer, an adhesive layer, and a second substrate are sequentially laminated on an information signal recording surface of a first substrate, wherein the adhesive layer is irradiated with electromagnetic radiation. A light-shielding mask provided with a light-shielding member is disposed on one surface side of the second substrate, and electromagnetic radiation is applied to the adhesive layer through the light-shielding mask. Irradiating the light into the inside of the optical disk, changing a curing speed of the adhesive in accordance with the presence or absence of the light shielding member, and recording a watermark in the optical disk in accordance with the presence or absence of the light shielding member. 2. The method for manufacturing an optical disk according to claim 1, wherein said light shielding mask is held by holding means, and said light shielding mask is replaced by replacing said holding means. A method for manufacturing an optical disc, characterized in that a watermark corresponding to the light-shielding member of the light-shielding mask is recorded in the optical disc. 3. The method for manufacturing an optical disk according to claim 2, wherein a watermark corresponding to the light shielding member is recorded at a desired position on the optical disk by adjusting the position of the holding means. Method. 4. The method for manufacturing an optical disk according to claim 1, wherein the plurality of light-shielding masks are mounted on transport means, and a desired light-shield mask is transported by transporting the transport means. A method for manufacturing an optical disk, characterized in that a watermark corresponding to a light shielding member of a light shielding mask is recorded in the optical disk. 5. The method for manufacturing an optical disk according to claim 1, wherein said light shielding member has a shape including at least one of a mark, a picture, a character, a symbol, a numeral, and the like. A method for manufacturing an optical disk, comprising: 6. The method for manufacturing an optical disk according to claim 1, wherein said light-shielding mask has a structure in which a part of said light-shielding mask can be replaced with another light-shielding mask member. A method for manufacturing an optical disk, comprising: 7. The method for manufacturing an optical disk according to claim 6, wherein the watermark according to the other light shielding mask member is a mark,
A method for manufacturing an optical disk, wherein the optical disk has a shape including at least one of a picture, a character, a symbol, a numeral, and the like. 8. The method for manufacturing an optical disk according to claim 8, wherein the watermark according to the other light shielding mask member is 0, 1, or 1.
When replacing one of the other light-shielding mask members with the other of the other light-shielding mask members, the shape is a shape including at least one of the numbers 2, 3, 4, 5, 6, 7, 8, and 9 In the method for manufacturing an optical disc, before and after the replacement, the number of the watermark has continuity. 9. The method for manufacturing an optical disk according to claim 1, wherein the optical disk is mounted on disk mounting means, and by rotating the disk mounting means, the optical disk is rotated. A method for manufacturing an optical disk, comprising: uniformly irradiating electromagnetic radiation onto the optical disk. 10. A method for manufacturing an optical disk according to claim 9, wherein a watermark corresponding to a desired light-shielding member is recorded at a desired position in the optical disk by adjusting the position of said disk mounting means. Manufacturing method of an optical disk. 11. A manufacturing apparatus for manufacturing an optical disk in which a reflective layer, an adhesive layer, and a second substrate are sequentially laminated on an information signal recording surface of a first substrate, wherein the adhesive layer is irradiated with electromagnetic radiation. An electromagnetic radiation source that emits electromagnetic radiation, and a light-shielding member are provided, and irradiation of electromagnetic radiation emitted from the electromagnetic radiation source is shielded by the light-shielding member. A light-shielding mask, comprising: a disk mounting means on which the optical disk is mounted, and which is irradiated with electromagnetic radiation passing through the light-shielding mask; and irradiating electromagnetic radiation into the optical disk adhesive layer through the light-shielding mask, An optical disc manufacturing apparatus, wherein a curing speed of the adhesive is changed in accordance with the presence or absence of the light shielding member, and a watermark corresponding to the presence or absence of the light shielding member is recorded in the optical disc. 12. A manufacturing apparatus for manufacturing an optical disk in which a reflective layer, an adhesive layer, and a second substrate are sequentially laminated on an information signal recording surface of a first substrate, wherein the adhesive layer is irradiated with electromagnetic radiation. An electromagnetic radiation source that emits electromagnetic radiation, a shutter that opens and closes an optical path of the electromagnetic radiation emitted from the electromagnetic radiation source, and an electromagnetic radiation that passes through the shutter. A heat-ray cut filter that cuts off heat rays to be applied, a light-shielding member is provided, and a light-shielding mask that shields the irradiation of electromagnetic radiation emitted from an electromagnetic radiation source that has passed through the heat-ray cut filter with the light-shielding member; And a disk mounting means for irradiating electromagnetic radiation having passed through the light-shielding mask, and bonding the electromagnetic radiation to the optical disk through the light-shielding mask. An optical disc manufacturing apparatus, comprising: irradiating the inside of a layer, changing the curing speed of the adhesive in accordance with the presence or absence of the light shielding member, and recording a watermark in the optical disc in accordance with the presence or absence of the light shielding member. . 13. The optical disk manufacturing apparatus according to claim 11, further comprising: holding means for holding said light shielding mask, wherein said light shielding mask is replaced by replacing said holding means. An optical disc manufacturing apparatus, characterized in that a watermark corresponding to the light-shielding member of the light-shielding mask that has been replaced is recorded at a desired position on the optical disc. 14. An optical disk manufacturing apparatus according to claim 13, wherein a watermark corresponding to said light shielding member is recorded at a desired position on said optical disk by adjusting the position of said holding means. apparatus. 15. The optical disk manufacturing apparatus according to claim 11, further comprising a transport unit for mounting a plurality of said light-shielding masks, wherein said transport unit transports a desired light-shielding mask. An optical disc manufacturing apparatus, wherein a watermark corresponding to a light blocking member of the light blocking mask is recorded in the optical disc. 16. An optical disk manufacturing apparatus according to claim 15, wherein said transport means is a circular table or a linear belt conveyor. 17. The optical disk manufacturing apparatus according to claim 11, wherein the light shielding member has a shape including at least one of a mark, a picture, a character, a symbol, a numeral, and the like. An optical disk manufacturing apparatus characterized by the above-mentioned. 18. The optical disk manufacturing apparatus according to claim 11, wherein said light-shielding mask has a structure in which a part of said light-shielding mask can be replaced by another light-shielding mask member. An optical disk manufacturing apparatus characterized by the above-mentioned. 19. The optical disk manufacturing apparatus according to claim 18, wherein the plurality of other light-shielding mask members are mounted on light-shielding mask member transporting means, and the plurality of other light-shielding mask member transporting means are driven by the light shielding mask member transporting means. An optical disc manufacturing apparatus, comprising: transporting another light-shielding mask member; and recording a watermark formed by replacing a part of the light-shielding mask with another transported light-shielding mask member on the optical disk. 20. The optical disk manufacturing apparatus according to claim 18, wherein the watermark according to the other light shielding mask member is a mark,
An optical disc manufacturing apparatus characterized by having a shape including at least one of a picture, a character, a symbol, a number, and the like. 21. The optical disk manufacturing apparatus according to claim 18, wherein the watermark according to the other light shielding mask member is 0, 1, or 2.
When replacing one of the other light-shielding mask members with the other of the other light-shielding mask members, the shape includes at least one of the numbers 2, 3, 4, 5, 6, 7, 8, and 9 In the optical disk manufacturing apparatus, before and after the replacement, the number of the watermark has continuity. 22. The apparatus for manufacturing an optical disk according to claim 11, further comprising: a disk mounting means on which the optical disk is mounted and rotatable, and wherein the disk mounting means is rotated to rotate the disk mounting means. An apparatus for manufacturing an optical disk, wherein the optical disk is rotated to irradiate electromagnetic radiation uniformly on the optical disk. 23. The optical disk manufacturing apparatus according to claim 22, wherein a watermark corresponding to a desired light shielding member is recorded at a desired position in the optical disk by adjusting a position of the disk mounting means. Characteristic optical disc manufacturing equipment. 24. An optical disk manufactured by the method for manufacturing an optical disk according to any one of claims 1 to 10. 25. An optical disk manufactured by the optical disk manufacturing apparatus according to any one of claims 11 to 23.