JP2009266322A - Information recording medium/manufacturing method of information recording medium and information recording and playback apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain a construction by which the outermost peripheral part of an intermediate layer is not exposed to an atmosphere with high reliability and production yield in a multilayer disk having the intermediate layer. <P>SOLUTION: The construction by which the outermost peripheral part of the intermediate layer is not exposed to an atmosphere can be easily manufactured using a present manufacturing process of the optical disk in the multilayer disk having the intermediate layer. Thereby, the optical disk capable of reducing the noise level/jitter degree of a playback signal obtained by performing playback from an optical disk to be a final product and performing stable signal playback can be manufactured at a low cost. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an information recording medium manufacturing method, an information recording medium, and an information recording / reproducing apparatus capable of easily manufacturing an information recording medium having an intermediate layer.

  A widely used optical disc (information recording medium) is usually formed by producing a glass or metal master, and performing injection molding or the like using a stamper created using the master.

By the way, in a multilayer disc having two or more recording layers on which information is recorded, a light incident side substrate (first substrate) on which a first recording layer (L ₀ layer) is formed and a non-light incident side substrate (dummy substrate). between the also) be referred to as a second substrate, the intermediate layer is a second recording layer (L ₁ layer) is formed, it is provided.

  Note that it is desirable that the end face of the intermediate layer does not protrude from the light incident side substrate (first substrate) and the non-light incident side substrate (dummy substrate) in terms of moisture absorption and appearance shape of the adhesive region and the recording layer.

Patent Document 1, a portion of the outermost periphery of the outermost peripheral portion and the L ₀ substrate of the intermediate layer, the inclined surface cutting is removed so as to form with a predetermined gradient, defective appearance due protruded adhesive An optical information recording medium for reducing the above and a manufacturing method thereof are disclosed.
JP2008-10025

However, when using the method shown in Patent Document 1, although to improve the characteristics of the external shape such as by scraping off the intermediate layer formed to the end face of the L ₀ substrate by physical methods, L ₀ By applying a force locally to the substrate, it is predicted that the substrate is distorted due to stress or a resin material piece or the like is generated when scraped off.

  In addition, it is predicted that the shaved resin material adheres to the information recording surface of the optical information recording medium, and the recording / reproducing characteristics of the optical information recording medium, particularly the recording / reproducing characteristics near the outer periphery are deteriorated. This causes a decrease in productivity, that is, yield.

Incidentally, the outermost peripheral portion of the multilayer optical disc having an intermediate layer, in order to ensure the continuity of the recording data between the L ₀ layer and the L ₁ layer (or the L ₁ layer in subsequent recording layer), stable recording and It must be reproducible. For this reason, the deterioration of the recording characteristics and the reproducing characteristics in the outermost peripheral portion of the intermediate layer includes the possibility of greatly impairing the reliability as a recording medium, and requires special attention in manufacturing.

Against this background, scraping the intermediate layer formed to the end face of the L ₀ substrate in physical means are to be avoided as much as possible.

  SUMMARY OF THE INVENTION An object of the present invention is an information recording medium having an intermediate layer and a method for manufacturing the same, without requiring a complicated manufacturing process or a manufacturing process that causes an increase in manufacturing cost in order to improve reliability and mass production efficiency. It is another object of the present invention to provide an information recording medium manufacturing method, an information recording medium and an information recording / reproducing apparatus capable of manufacturing the information recording medium.

  The present invention has been made on the basis of the above-described problems. The first substrate positioned on the light incident side, the first recording layer formed on one surface of the first substrate, A first reflective layer laminated on the first recording layer; a first adhesive layer laminated on the first reflective layer; a second substrate adhered to the first adhesive layer; A second recording layer laminated on the second substrate, a second reflective layer laminated on the second recording layer, a second adhesive layer laminated on the second reflective layer, A third substrate bonded to the second adhesive layer and facing the first substrate, wherein the second substrate is formed on the first substrate by the first adhesive layer. In the step of forming the first reflective layer, the maximum value of the outer peripheral portion is limited so that the maximum value of the outer peripheral portion is smaller than the maximum value of the outer peripheral portion of the first substrate. It is an information recording medium characterized.

  By using one embodiment of the present invention, the first recording layer provided on the light incident side substrate and the intermediate layer (second layer) prepared on the non-light incident side substrate provided opposite to the light incident side substrate are used. In an optical disc having a recording layer of 2), the maximum outer diameter portion of the intermediate layer is not exposed to the atmosphere, and the recording and reproduction characteristics are deteriorated at the outermost peripheral portion, and stress that may cause changes over time such as moisture absorption It is possible to substantially suppress the occurrence of distortion of the substrate due to the above. Moreover, since it can manufacture easily with the manufacturing apparatus used by a normal production process, it has the characteristics that a manufacturing unit price can also be restrained cheaply.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows an outline of a method for manufacturing an information storage medium to which the present invention is applied.

  First, as a master, the surface is polished to a predetermined surface roughness and a cleaned glass or metal plate is prepared (1001).

  Next, a resist material is applied to the master surface to form a resist film (1002).

  Subsequently, although not described in detail, the surface of the resist film is irradiated with a laser beam that is turned on / off based on a pulse generated through an arbitrary waveform generator or a formatter. Thereby, a latent image corresponding to information to be recorded in advance, that is, information to form a recess as a pit is recorded on the resist film. In addition, while the laser beam is being irradiated (within the period), the optical system and the objective lens not described in detail are moved in the radial direction of the base so that the latent image has a concentric shape or a rotation angle and a radial position continuous. Thus, it is formed in a spiral shape that changes. (1003).

  Next, the master on which the latent image is formed is developed to form pits (recesses) (1004).

  Subsequently, a predetermined metal material is plated on the original disk to create a stamper. In many cases, Ni (nickel) is used as a stamper (metal to be plated) (1005).

Hereinafter, a resin molded substrate (L ₀ substrate, that is, a light incident side substrate) 1 is formed by injection molding using a stamper as a mold. As the _{L 0} substrate materials, for example, PC (polycarbonate) or an acrylic resin or methacrylic resin or the like is used (1006).

The molded substrate (L ₀ substrate) 1 thus obtained is composed of an organic dye-based recording material (hereinafter simply referred to as an organic dye) used as a recording layer (L ₀ layer, ie, the first recording layer). The dye layer is formed by, for example, spin coating. As the organic dye (dye layer), for example, a metal complex containing at least azo, diazo, cyanine, phthalocyanine, styryl, anion-cation, or a mixture thereof, or a similar material is used ( 1007).

Subsequently, a reflective layer (1) 3 and an adhesive layer (1) 4 are provided on the dye layer (organic dye) 2. The reflective layer (1) 3 has a thickness of about 20 nm, and for example, Ag (silver), Al (aluminum), Au (gold), or a metal compound based on these is used. Although not described in detail, between the L ₀ dye layer 2 and the reflective layer (1) 3, preferably by RF sputtering or the like, refers to be a predetermined thickness of the dielectric layer is provided Not too long (1008).

Next, an intermediate layer (L ₁ layer, that is, a second recording layer) 5 is provided on the adhesive layer (1) 4 via the adhesive layer (1) 4. The intermediate layer 5 may also be used as the adhesive layer (1) 4 (1009).

Next, a recording material (dye layer) used as the second recording layer 6 is formed on the intermediate layer (L ₁ substrate) 5 by, for example, spin coating. The second recording layer 6 can also be made of an organic dye-based recording material, for example, a metal containing at least azo, diazo, cyanine, phthalocyanine, styryl, anion-cation, or a mixture thereof. Complexes or similar materials are used (1010).

  Next, a reflective layer (2) 7 and an adhesive layer (2) 8 are formed on the dye layer (organic dye) 6. As the reflective layer (2) 7, for example, Ag (silver), Al (aluminum), Au (gold), or a metal compound based on these is used (1011).

  Hereinafter, a dummy substrate (non-light incident side substrate) 9 is provided via the adhesive layer (2) 8 (1012).

In this way, as shown in FIG. 2, in order from the light incident surface side, the L ₀ substrate 1, the dye layer (first recording layer (L ₀ ) layer) 2, the reflective layer (1) 3, and the adhesive layer ( 1) 4, intermediate layer (L ₁ substrate) 5, dye layer (second recording layer (L ₁ ) layer) 6, reflective layer (2) 7, adhesive layer (2) 8 and dummy substrate (non-light incident side) An optical disk 10 on which a substrate is laminated is formed.

Incidentally, the adhesive layer also serving as an intermediate layer 5 or the intermediate layer 5 (1) 4, L ₀ substrate 1 i.e. when it is formed to the end face of the light incident side substrate, by physical means, secondary processing such as scraping Is often required. However, the secondary processing, topically to L ₀ substrate 1, by the force is applied, the strain due to stress in the substrate 1 and the intermediate layer 5 (or the adhesive layer (1) 4), moisture absorption, etc. It can be a cause of changes over time represented by In addition, resin material pieces (powder) and the like generated when scraped off often adhere to the second recording layer, that is, the organic dye layer 6 formed in the intermediate layer 5 due to static electricity or the like, and therefore need to be removed. In many cases.

From such a background, in the present application, as will be described below with reference to FIGS. 3 and 4, the outer peripheral region of the L ₁ substrate (intermediate layer) 5 or the adhesive layer (1) 4, radius (or diameter) becomes large radius (or diameter) than the range, i.e. subjected to easy adhesion processing 111 the predetermined range 11 of the outer peripheral portion of the stamper L ₁ substrate (intermediate layer) for 5, prepared in advance the L ₀ substrate 1 dye layer (organic dye (L ₀ layer)) 2 and the reflective layer (1) 3 are formed, to form an adhesive layer (1) 4, bonding the intermediate layer 5, or a predetermined When the adhesive layer (1) 4 having a thickness is prepared and cured, it is cured using a stamper for the L ₁ substrate 5, and the L ₁ substrate (intermediate layer) 5 and the adhesive layer (1) 4 are integrally formed. It is characterized by that.

Incidentally, adhesion facilitating treatment 111, _{L 0} substrate 1 with resin, the stamper side, that the adhesive layer (1) 4 or _{L 1} substrate (intermediate layer) as viewed from 5 side, dyes which are formed in _{L 0} substrate 1 (first By utilizing the fact that the reflective layer (1) 3 laminated on the one recording layer (L ₀ ) layer 2 is a material containing a metal or a metal compound based on these, the adhesion to the resin is low ( (Adhesion is reduced), and the adhesion with a metal or a material containing a metal compound based on these is increased (adhesion is increased). In addition, the difference in adhesiveness (adhesive strength) in the easy adhesion treatment 111 is that when the optical disc 10 is manufactured, the adhesive layer (1) 4 or the intermediate layer (L ₁ substrate) 5 and the L ₀ substrate 1 are formed. Needless to say, it is arbitrarily set based on various factors such as the process and the configuration of the manufacturing apparatus.

For example, the easy adhesion process 111 (see FIG. 3) between the adhesive layer (1) 4 and the pressure member 101 or the easy adhesion process 211 (see FIG. 4) between the stamper 201 and the adhesive layer (1) 4 is performed. Is a dielectric such as Zn—SiO ₂ , and a material having strong adhesion to the adhesive layer (1) 4, that is, an adhesive is used. In addition, the thickness of the layer (thickness of Zn—SiO ₂ or the like in the easy adhesion treatment region) is thinner than the thickness of the intermediate layer 5 (adhesive layer (1) 4), preferably about 3 to 10 μm. It is.

The easy-adhesion processing 111, by subjecting the L ₁ substrate range 11 as the (middle layer) near the outer periphery than the predetermined radius of the outer peripheral portion of the 5 for the stamper or the pressure member (or diameter), the adhesive layer (1 ) 4 to paste the 5 L ₁ substrate (intermediate layer), or after the adhesive layer (1) 4 was cured using a stamper of the intermediate layer for 5, when removing the stamper (release), L ₀ substrate (Light incident side substrate) The outer peripheral portion of the reflective layer (1) 3 on the one side, and a range (range 11) slightly larger than the range 12 having a radius (or diameter) larger than a predetermined radius (or diameter). The reflective layer (1) 3 in range 12) can be separated from the L ₀ substrate 1 (L ₀ layer 2) together with a stamper for the adhesive layer (1) 4 or L ₁ substrate (intermediate layer) 5.

By this method, the maximum outside of the intermediate layer (L ₁ substrate) 5 or the adhesive layer (1) 4 formed on the L ₀ substrate 1 subsequent to the dye film (L ₀ layer) 2 and the reflective layer (1) 3 is obtained. The diameter does not become larger than the outer diameter of the L ₀ substrate 1 (L ₀ layer 2).

Therefore, the dye film (L ₁ layer) 6, the reflective layer (2) 7 and the adhesive layer (2) 8 are formed in this order and the intermediate layer (L ₁ substrate) is formed when the optical disk 10 is formed. 5 or the adhesive layer (1) 4 does not have a maximum outer diameter larger than that of the intermediate layer (L ₁ substrate) 5 or the adhesive layer (1) 4.

As a result, there is no deterioration of the recording characteristics and reproduction characteristics at the outermost peripheral portion of the intermediate layer 5 or distortion of the substrate due to stress that may cause a change over time such as moisture absorption, and the intermediate layer (L ₁ substrate) 5 The optical disk 10 whose outer diameter does not become larger than the outer diameter of the _L0 substrate 1 can be easily manufactured. In addition, since the manufacturing process for the optical disc of the current DVD standard can be used as it is in the manufacturing process described above, the manufacturing cost of the optical disc 10 does not increase.

Although not shown, a pressure member is provided by providing a thin layer of, for example, Ag or an alloy containing Ag or Al or an alloy containing Al between the reflective layer (1) 3 and the adhesive layer (1) 4. in separating 101 or stamper 201, when separating the reflective layer (1) and the adhesive layer (1) 4 adhesion can be enhanced (pressure member 101 or the stamper 201 between the _{L 0} substrate 1 In addition, the adhesive force between the reflective layer (1) 3 and the adhesive layer (1) 4 can be maintained). In this case as well, a dielectric such as Zn—SiO ₂ can be used depending on the combination of materials of the reflective layer (1) 3 and the adhesive layer (1) 4.

  When the outermost periphery of the optical disk 10 formed by the above-described method is observed, it has been confirmed that there are no defective portions such as defective transfer of pits and air bubbles and good mechanical characteristics. Further, it was confirmed that the reproduction signal obtained by the optical disk apparatus described later with reference to FIG. 8 is stable and highly reliable.

  Furthermore, in this embodiment, an organic dye-based recording material having absorption at a wavelength of 600 to 700 nm is mixed with the above-mentioned organic dye-based recording material corresponding to a wavelength of 405 nm. A dye adjusted so as to have a recording sensitivity at the wavelength of a laser beam used as a standard is also used.

  In this embodiment, the information storage medium has a diameter of 120 mm and a thickness of 1.2 mm (bonding two polycarbonate molded substrates of 0.6 mm), and an organic dye-based recording material is used for the recording layer. Suppose that it is a write-once information storage medium.

  For the recording / reproducing light, an optical system using an objective lens having a wavelength of 405 nm and a numerical aperture NA (Numerical Apperture) of 0.65 is used. The track pitch between grooves in the data recording area is 400 nm (0.4 μm).

More specifically, in the example shown in FIG. 3, the outer peripheral region of the adhesive layer (1) 4 is a range having an outer diameter larger than the outer diameter of the intermediate layer (L ₁ substrate) 5, that is, the adhesive layer (1 The intermediate layer (L ₁ substrate) 5 bonded to the reflective layer (1) 3 laminated on the L ₀ (organic dye) layer 2 of the L ₀ substrate 1 is connected to the reflective layer (1) 3 side through 4). When the adhesive layer (1) 4 is cured, the above-mentioned easy adhesion treatment 111 is performed on a predetermined region on the outer periphery of the pressure mechanism 101 that presses the intermediate layer (L ₁ substrate) 5. When releasing the pressurizing mechanism 101 from pressing the L ₁ substrate 5 (removing the pressurizing mechanism 101), the outer periphery of the adhesive layer (1) 4 is in a range 12 having a diameter larger than the outer periphery of the intermediate layer 5. Excess adhesive on the outside can be removed.

Therefore, since the outer periphery of the intermediate layer (L ₁ substrate) 5 is within the range inside the outer diameter of the adhesive layer (1) 4, the recording characteristics and the reproduction characteristics at the outermost peripheral portion of the intermediate layer 5 are deteriorated. Alternatively, an optical disc 10 in which there is no distortion of the substrate due to stress that may cause a change over time such as moisture absorption, and the outer diameter of the intermediate layer (L ₁ substrate) 5 does not become larger than the outer diameter of the L ₀ substrate 1, It can be easily manufactured.

In the example shown in FIG. 4, the adhesive layer (1) 4 is cured to form the intermediate layer (L ₁ substrate) 5. When the adhesive layer (1) 4 is cured, the intermediate layer (L ₁ The range of the outer diameter larger than the outer diameter of the stamper 201 corresponding to the substrate 5, that is, the region of the maximum outer diameter in the region where the adhesive layer (1) 4 is cured and becomes the intermediate layer (L ₁ substrate) 5. When the adhesive layer (1) 4 is cured and then released (removed) after the adhesive layer (1) 4 is cured, the diameter 211 is larger than the outer periphery of the intermediate layer 5 by performing the above-described easy adhesion treatment in the range 211 that is outside the surface. The excess adhesive outside the large area 212 can be removed.

Therefore, since the outer periphery of the region where the adhesive layer (1) 4 is cured and becomes the intermediate layer (L ₁ substrate) 5 is substantially the outermost periphery of the adhesive layer (1) 4, the outermost peripheral portion of the intermediate layer 5 There is no substrate distortion or the like due to stress that may cause deterioration of recording characteristics and reproduction characteristics at the time of recording, or moisture change, and the outer diameter of the intermediate layer (L ₁ substrate) 5 is larger than the outer diameter of the L ₀ substrate 1. The optical disc 10 that does not increase in size can be easily manufactured.

Needless to say, the minimum diameter of the intermediate layer (L ₁ substrate) 5 is at least larger than _118.0 mm ^0.0 _/−0.04 mm, as shown in FIG.

Further, as shown in FIG. 6, in the optical disk described with reference to FIG. 3 or FIG. 4, the diameter of the reflective layer (2) 7 formed on the dummy substrate 9 side with respect to the intermediate layer (L ₁ substrate) 5 is set to the intermediate diameter. By making it larger than the diameter of the layer 5, the outermost peripheral portion of the intermediate layer 5 may be prevented from being exposed to the atmosphere by the peripheral portion of the reflective layer (2) 7.

Furthermore, as shown in FIG. 7, in the optical disk described with reference to FIG. 3 or FIG. 4, the diameter of the adhesive layer (2) 8 formed on the dummy substrate 9 side relative to the intermediate layer (L ₁ substrate) 5 is By making it larger than the diameter of the intermediate layer 5, the outermost periphery of the intermediate layer 5 may be prevented from being exposed to the atmosphere using the peripheral portion of the adhesive layer (2) 8.

  FIG. 8 shows an example of an optical disc apparatus that records information on the optical disc described with reference to FIGS. 2 to 7 or reproduces information recorded on the optical disc.

  An optical disc apparatus 501 shown in FIG. 8 records / reproduces information by condensing laser light having a predetermined wavelength emitted from a PUH (Pick Up Head, ie, optical head) 511 on an information recording layer of the optical disc 10. Yes.

  The light reflected from the optical disk 10 passes through the optical system of the PUH 511 again, and is detected as an electrical signal by a photodetector provided inside.

  The detected electrical signal is amplified by a preamplifier 514 and is output to a signal processing circuit 515 including a servo circuit, an RF signal processing circuit, an address signal processing circuit, etc. (not shown).

  In the servo circuit, servo signals such as focus, tracking, and tilt are generated, and each signal is output to a focus, tracking, and tilt actuator (not shown) of the PUH 511, respectively.

  The RF signal processing circuit (signal processing circuit 515) reproduces information such as recorded user information by mainly processing the sum signal among the detected signals. As a demodulation method at this time, there are a (level) slice method and a PRML (Pertial Response Maximum Likelyhood) method. When the PRML method is used, an error correction technique at the time of ML demodulation is usually used together. Needless to say, the RF signal reproduced by the signal processing circuit 515 is temporarily stored in the memory 517 via the control unit 516.

  The address signal processing circuit reads the physical address information indicating the recording position on the optical disk 10 by processing the detected signal and outputs it to the control unit 516.

  Based on the address information, the control unit 516 reads out information such as user information at a desired position, or records information such as user information at a desired position. At this time, the user information is modulated into data suitable for optical disc recording by a recording signal processing circuit.

  For data modulation, for example, modulation schemes such as (2,10) RLL modulation and (1,10) RLL modulation are used. In (2, 10) RLL modulation, the shortest code used for data modulation is 3T, and the longest code is 11T. In addition, a 14T code not included in the modulation rule is added for sync detection. Here, T represents a reference channel clock interval.

  The recording / reproducing waveform generation circuit 513 generates a signal for controlling the laser emission waveform based on the input code. In response to this output signal, the LD drive circuit 512 drives a laser element (not described in detail) of the PUH 511 so that the first or second wavelength laser beam having a predetermined intensity is emitted. The reproduction of information from 10 is executed.

  The control unit 516 can also execute determination of an OPC target value, calculation of signal quality information, and determination of an optimum recording waveform shape, which will be described later. The signal quality information is information such as an error rate, which is a reading rate of read data, a parity error number for which the error rate can be estimated, or jitter.

  As described above, by using one of the embodiments of the present invention, the first recording layer provided on the light incident side substrate and the non-light incident side substrate provided facing the light incident side substrate are prepared. In the optical disc having the intermediate layer (second recording layer), the maximum outer diameter portion of the intermediate layer is not exposed to the atmosphere, and the recording and reproduction characteristics are deteriorated at the outermost peripheral portion, and the moisture absorption It is possible to substantially suppress the occurrence of distortion of the substrate due to stress that may cause a change with time.

  Moreover, since it can manufacture easily with the manufacturing apparatus used by a normal production process, it has the characteristics that a manufacturing unit price can also be restrained cheaply.

  It should be noted that the content of the present invention is not limited to the form described here, and it goes without saying that various other forms can be taken without departing from the spirit of the invention. In addition, the embodiments may be implemented by appropriately combining them as much as possible, or by deleting a part thereof, and in that case, various effects resulting from the combination or deletion can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic explaining the manufacturing process of the optical disk (information recording medium) with which embodiment of this invention is applied. Schematic which shows an example of the layer structure of the optical disk shown in FIG. FIG. 3 is a schematic diagram illustrating an example of a method for manufacturing an intermediate layer (substrate on which a second recording layer is formed) in the optical disk manufacturing process illustrated in FIG. 2. FIG. 3 is a schematic diagram illustrating an example of a method for manufacturing an intermediate layer (substrate on which a second recording layer is formed) in the optical disk manufacturing process illustrated in FIG. 2. FIG. 3 is a schematic diagram for explaining a minimum outer diameter of an intermediate layer (substrate on which a second recording layer is formed) of the optical disc shown in FIG. 2. FIG. 3 is a schematic diagram illustrating an example of a method for manufacturing an intermediate layer (substrate on which a second recording layer is formed) in the optical disk manufacturing process illustrated in FIG. 2. FIG. 3 is a schematic diagram illustrating an example of a method for manufacturing an intermediate layer (substrate on which a second recording layer is formed) in the optical disk manufacturing process illustrated in FIG. 2. FIG. 2 is a schematic diagram showing an example of an optical disc apparatus (information recording / reproducing apparatus) suitable for recording information on the optical disc shown in FIG. 1 and reproducing information from the disc.

Explanation of symbols

DESCRIPTION _OF SYMBOLS 1 ... 1st board | substrate (L0 board _| substrate, light incident side board | substrate), 2 ... Organic dye-type recording material (dye layer), 3 ... Reflective layer (1), 4 ... Adhesive layer (1), 5 ... Intermediate | middle layer (L ₁ substrate), 6 organic dye recording material (dye layer), 7 reflective layer (2), 8 adhesive layer (2), 9 dummy substrate (non-light incident side substrate), 10 optical disc, 111, 211, 213 ... easy adhesion processing, 501 ... information recording / reproducing device, 511 ... optical head (PUH), 512 ... LD driving circuit, 513 ... recording / reproducing waveform generating circuit, 514 ... preamplifier, 515 ... signal processing circuit, 516 ... control Part, 517... Memory.

Claims (11)

A first substrate positioned on the light incident side;
A first recording layer formed on one surface of the first substrate;
A first reflective layer laminated on the first recording layer;
A first adhesive layer laminated on the first reflective layer;
A second substrate bonded to the first adhesive layer;
A second recording layer laminated on the second substrate;
A second reflective layer laminated on the second recording layer;
A second adhesive layer laminated on the second reflective layer;
A third substrate bonded to the second adhesive layer and facing the first substrate;
And the second substrate is formed on the first reflective layer of the first substrate by the first adhesive layer, the maximum value of the outer peripheral portion is the outer periphery of the first substrate An information recording medium, wherein the maximum value of the outer peripheral portion is limited to be smaller than the maximum value of the portion.   The second substrate is pressurized at a predetermined pressure toward the first adhesive layer, and at least a part of the outer peripheral portion is removed when the member used for pressurization is removed. The information recording medium according to claim 1, wherein the information recording medium is separated to a member used for pressurization.   3. An easy adhesion treatment is performed in advance on a region having a diameter larger than the maximum value of the outer peripheral portion of the second substrate of the member used for pressurization of the second substrate. Information recording media. A first substrate positioned on the light incident side;
A first recording layer formed on one surface of the first substrate;
A first reflective layer laminated on the first recording layer;
A first adhesive layer laminated on the first reflective layer;
A second substrate formed integrally with the first adhesive layer upon curing of the first adhesive layer;
A second recording layer laminated on the second substrate;
A second reflective layer laminated on the second recording layer;
A second adhesive layer laminated on the second reflective layer;
A third substrate bonded to the second adhesive layer and facing the first substrate;
And the second substrate has a maximum outer peripheral portion when removing a mold member used for curing the first adhesive layer laminated on the first reflective layer of the first substrate. The information recording medium, wherein the maximum value of the outer peripheral portion is limited so that the value is smaller than the maximum value of the outer peripheral portion of the first substrate.   The second substrate has a pattern prepared on a stamper used for curing the first adhesive layer transferred along with the curing of the first adhesive layer, and when the stamper is removed. 5. The information recording medium according to claim 4, wherein at least a part of the outer peripheral portion is separated on the stamper side.   6. The information recording medium according to claim 5, wherein a region having a diameter larger than a maximum value of an outer peripheral portion of the second substrate of the stamper is subjected to an easy adhesion process in advance. Forming a first recording layer on one surface of the first substrate located on the light incident side;
Forming a first reflective layer on the first recording layer;
Forming a first adhesive layer on the first reflective layer;
The first adhesive layer is pressurized with a predetermined pressure, and when the member used for pressurization is removed, at least a part of the outer peripheral portion is separated into the member side used for pressurization together with the first adhesive layer. Forming a second substrate in which the maximum value of the outer periphery is smaller than the maximum value of the outer periphery of the first substrate;
Forming a second recording layer on the second substrate;
Forming a second reflective layer on the second recording layer;
Forming a second adhesive layer on the second reflective layer;
A method of manufacturing an information recording medium, comprising forming a third substrate opposite to the first substrate on the second adhesive layer.   8. An adhesion process is applied to a region having a diameter larger than the maximum value of the outer peripheral portion of the second substrate of the member used for pressurization of the second substrate. A method for manufacturing an information recording medium. Forming a first recording layer on one surface of the first substrate located on the light incident side;
Forming a first reflective layer on the first recording layer;
While forming the first adhesive layer on the first reflective layer, the maximum value of the outer peripheral portion is limited so that the maximum value of the outer peripheral portion is smaller than the maximum value of the outer peripheral portion of the first substrate. Removing the mold member used when curing the first adhesive layer laminated on the first reflective layer of the first substrate, and integrally forming the first adhesive layer and the second substrate;
Forming a second recording layer on the second substrate;
Forming a second reflective layer on the second recording layer;
Forming a second adhesive layer on the second reflective layer;
A method of manufacturing an information recording medium, comprising forming a third substrate opposite to the first substrate on the second adhesive layer.   The region having a diameter larger than the maximum value of the outer peripheral portion of the second substrate of the stamper used for curing the first adhesive layer is preliminarily subjected to an easy adhesion treatment. Item 10. A method for manufacturing an information recording medium according to Item 9. An optical head for irradiating light of a predetermined wavelength to an arbitrary recording layer of the information recording medium according to claim 1,
A signal processing device for recording information on an arbitrary recording layer of the information recording medium by the optical head, or reproducing information from the recording layer of the information recording medium;
An information recording / reproducing apparatus comprising:

Images