JP2008130216A - Optical information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical information recording medium wherein a drawing region is expanded to an inner peripheral side and a flaw on a light incident side of a cover layer and a substrate can be prevented in the optical information recording medium performing recording and/or reproduction by being irradiated with laser light from a cover layer side. <P>SOLUTION: A surface (a lower surface) on the side opposite to the cover layer 14 of the substrate 11 having a center hole 11a has a first projecting part 11d in the vicinity of an edge part of a clamping area B on the inner peripheral side of an information recording area A and a second projecting part 11e in an area C on the outer peripheral side of the information recording area A. A reflection layer 12, a recording layer 13 and the cover layer 14 are provided in this order on the substrate 11. Thereby, a flaw of a light incident surface can be prevented and the drawing region on a label surface side can be expanded without interfering with formation of the cover layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a disc-shaped optical information recording medium, which is a light that can be printed or drawn on a label surface (a surface opposite to the light incident surface) of the optical information recording medium by screen printing, an inkjet printer, or the like. More specifically, the present invention relates to an optical information recording medium having an information recording area where information can be recorded by laser light irradiation and an area where printing, printing, or drawing can be performed.

In a conventional disc-shaped optical information recording medium such as a write-once CD (so-called CD-R), a structure in which a recording layer and a reflective layer are formed on one surface of a light-transmitting substrate provided with a pregroove or the like. The recording layer is configured to be irradiated with a laser beam having a wavelength of usually around 780 nm from the other surface side of the substrate to be recorded and / or reproduced from the recording layer. The surface of the optical information recording medium opposite to the surface irradiated with the laser light is normally used as a label surface, and characters, symbols, figures, patterns, or combinations thereof are displayed on the surface by printing or the like. Is done.
Also, a recordable digital versatile disk (so-called DVD-R) is recorded in the same manner as described above on one surface of a light-transmitting substrate provided with pregrooves at a pitch less than half that of the CD-R. And having a structure in which a layer and a reflective layer are formed, and the recording layer is irradiated with a laser beam having a wavelength of generally 630 nm to 680 nm from the other surface side of the substrate to reproduce data from and / or reproduce from the recording layer. An optical information recording medium configured as described above has also been proposed.
In the optical information recording medium such as the above-mentioned CD-R or DVD-R, when the light-transmitting substrate is injection-molded, a convex portion for preventing scratches is provided in advance. This prevents the light incident surface from being scratched by rubbing when the optical information recording medium is laminated.

On the other hand, recently, terrestrial digital high-definition TV has rapidly spread, and disk-shaped optical information that can be recorded with high density with a blue-violet laser beam having a shorter wavelength than the DVD-R. Development of recording media is in progress.
Specifically, it is called a recordable Blu-ray disc (so-called BD-R) or the like, and has a structure in which a recording layer and a cover layer are formed in this order on a substrate provided with a pre-groove, and has the cover layer. There has been proposed an optical information recording medium configured to be irradiated with a blue-violet laser beam having a wavelength of usually around 400 nm to 500 nm from the surface side to reproduce data from and / or reproduce data from the recording layer. .
Further, in the optical information recording medium such as the BD-R, for the purpose of preventing the light incident surface from being scratched, as shown in FIG. In the optical information recording medium having the cover layer 204 in this order, when the cover layer 204 is formed, convex portions 204a and 204b for preventing scratches are formed on the inner periphery and / or outer periphery of the cover layer 204 in advance. It has been proposed to prevent the light incident surface from being scratched by rubbing when the optical information recording medium is loaded. In the above figure, the right half area from the center of the optical information recording medium is shown, and the left half area is omitted.
JP 2005-174408 A

However, in the optical information recording medium described in Patent Document 1, the light incident surface side is rubbed and easily damaged when stacked before the cover layer 204 is formed.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is an optical information recording medium in which recording and / or reproduction is performed by irradiating a laser beam from the cover layer side. An object of the present invention is to provide an optical information recording medium capable of preventing scratches on the light incident surface side of the cover layer and the substrate.

In order to achieve the above object, the optical information recording medium of the present invention (1) has a recording layer and a cover layer in this order on a substrate having a hole in the center, and laser light is irradiated from the cover layer side. An optical information recording medium on which recording and / or reproduction is performed has an information recording area having a pregroove on a surface of the substrate on which the recording layer is provided, and the recording layer of the substrate A first convex portion provided in the vicinity of the inner peripheral edge of the substrate closer to the inner periphery than the information recording area, and the substrate closer to the outer periphery than the information recording area, on a surface opposite to the provided surface And a second convex portion provided in the vicinity of the outer peripheral edge. (... Hereinafter referred to as the first problem solving means of the present invention.)

One of the main forms of the optical information recording medium is that (2) the protrusion dimension h1 of the first convex portion from the surface opposite to the information recording area of the substrate is the first dimension from the surface. This is larger than the protruding dimension h2 of the second convex portion. (... Hereinafter referred to as the second problem solving means of the present invention.)

The optical information recording medium of the present invention has (3) a recording layer and a cover layer in this order on a substrate having a hole in the center, and recording is performed by irradiating laser light from the cover layer side. In the optical information recording medium to be reproduced, the first convex portion is provided in the vicinity of the inner peripheral edge of the substrate on the surface opposite to the surface on which the recording layer of the substrate is provided, An information recording area provided with a pre-groove on the surface of the substrate on which the recording layer is provided, and a second protrusion provided in the vicinity of the outer peripheral edge of the cover layer closer to the outer periphery than the information recording area; It is what has. (... Hereinafter referred to as the third problem solving means of the present invention.)

One of the main forms of the optical information recording medium is that (4) the protrusion dimension h1 of the first convex portion from the surface opposite to the information recording area of the substrate is set in the information recording area. This is larger than the projecting dimension h2 of the second convex portion from the surface of the cover layer. (... Hereinafter referred to as the fourth problem solving means of the present invention.)

In another embodiment of the optical information recording medium, an ink receiving layer is provided on the surface of the substrate opposite to the surface on which the recording layer is provided. (... Hereinafter referred to as the fifth problem solving means of the present invention.)

The operation of the first problem solving means is as follows. That is, the information recording area having a pregroove on the surface of the substrate on which the recording layer is provided, and the information recording area on the surface opposite to the surface of the substrate on which the recording layer is provided. A first convex portion provided in the vicinity of the inner peripheral edge of the substrate closer to the inner periphery than the area, and a second convex portion provided in the vicinity of the outer peripheral edge of the substrate closer to the outer periphery than the information recording area. Therefore, even when the height dimension of the convex portion of the clamping area of the substrate is reduced, it is possible to prevent damage during loading.

The operation of the second problem solving means is as follows. That is, since the protrusion dimension h1 of the first protrusion from the surface opposite to the information recording area of the substrate is larger than the protrusion dimension h2 of the second protrusion from the surface, the substrate or optical information When the recording medium is individually taken out from the loaded state, a pressure-reduced air chamber is provided between the lower substrate or the optical information recording medium, and it is possible to prevent a peeling error from occurring.

The operation of the third problem solving means is as follows. That is, the surface of the substrate on the side on which the recording layer is provided, having a first convex portion in the vicinity of the inner peripheral edge of the substrate on the surface opposite to the surface on which the recording layer is provided. And the second convex portion provided in the vicinity of the outer peripheral edge of the cover layer closer to the outer periphery than the information recording region, and the convex portion on the inner peripheral side of the substrate. Even when the height dimension of the portion is reduced, it is possible to prevent scratches during loading.

The operation of the fourth problem solving means is as follows. That is, the protrusion dimension h1 of the first protrusion from the surface opposite to the information recording area of the substrate is greater than the protrusion dimension h2 of the second protrusion from the surface of the cover layer of the information recording area. When the substrate or optical information recording medium is individually taken out from the loaded state, a decompressed air chamber is provided between the lower substrate or the optical information recording medium and a peeling error occurs. Can be prevented.

The operation of the fifth problem solving means is as follows. In other words, since the ink receiving layer is provided on the surface opposite to the surface on which the recording layer is provided on the substrate, drawing can be performed over the entire area of the label surface using an ink jet printer or the like.

According to the optical information recording medium of the present invention, it is possible to provide an optical information recording medium having a drawing area on the label surface side, preventing the light incident surface from being damaged and preventing the formation of the cover layer. The above object and other objects, structural features, and operational effects of the present invention will become apparent from the following description and the accompanying drawings.

  Hereinafter, a first embodiment of the optical information recording medium of the present invention will be described with reference to FIG. FIG. 1 is a partially enlarged sectional view showing an outline of the internal structure of the optical information recording medium 10 of the first embodiment. FIG. 1 shows the right half area from the center of the optical information recording medium 10 and omits the left half area.

  As shown in FIG. 1, a recording layer 13 and a cover layer 14 are provided in this order on a substrate 11 having a hole 11a in the center, and recording and / or reproduction is performed by irradiating a laser beam from the cover layer 14 side. Is a disk-shaped optical information recording medium 10 in which

Specifically, an information recording area A having a pregroove 11b is provided on the surface of the disc-like substrate 11 having a hole 11a at the center where the recording layer 13 is provided. Further, a first protrusion provided on the surface of the substrate 11 opposite to the surface on which the recording layer 13 is provided, in the vicinity of the inner peripheral edge of the substrate 11 closer to the inner periphery than the information recording area A. 11 d and a second convex portion 11 e provided in the vicinity of the outer peripheral edge of the substrate 11 closer to the outer periphery than the information recording area A. On the substrate 11, a reflective layer 12, a recording layer 13, and a cover layer 14 are provided in this order. The first convex portion 11 d near the inner peripheral edge of the substrate 11 and the second convex portion 11 e near the outer peripheral edge of the substrate 11 are provided simultaneously with the molding of the substrate 11.
Here, the information recording area A is within the range where the tracking guide pregroove 11b is provided on the upper surface of the substrate 11, and is usually provided in the range of 46 mm to 117 mm in diameter. In addition, a so-called clamping area B, which is a flat area for stably holding the information recording medium 10 during recording and / or reproduction, is usually provided near the inner periphery of the information recording area A. The clamping area B is usually in the range of 23 mm to 33 mm in diameter. In the present embodiment, the vicinity of the inner periphery of the substrate 11 refers to a region closer to the inner periphery than the clamping area B. Further, the area closer to the outer periphery than the information recording area A refers to an area from a diameter of 117 mm to the outermost peripheral edge of the disk (usually a diameter of 120 mm).

In the present embodiment, the protrusion dimension h1 (eg, 50 μm) of the first protrusion 11d from the surface 11c of the substrate 11 opposite to the information recording area A is set to the second distance from the surface 11c. This is larger than the protrusion dimension h2 (for example, 20 μm) of the convex portion 11e.

Next, a preferred embodiment of the substrate 11 is as follows. That is, as the substrate 11, various materials used as substrate materials for conventional optical information recording media can be arbitrarily selected and used. Specific examples include acrylic resins such as polycarbonate and polymethyl methacrylate, vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers, epoxy resins, amorphous polyolefins, polyester resins, metals such as aluminum, and glass. These may be used together if necessary. Among the above materials, a thermoplastic resin is preferable from the viewpoint of moldability, moisture resistance, dimensional stability, and low price, and polycarbonate is particularly preferable.
When these resins are used, the substrate 11 can be formed using an injection molding method. The thickness of the substrate 11 is preferably in the range of 0.9 to 1.6 mm.

A tracking guide pre-groove 11b is formed on the surface of the substrate 11 on which the recording layer 13 is provided. Moreover, it is preferable that the pitch of the said pregroove 11b is 500 nm or less normally.

Next, a preferred embodiment of the recording layer 13 is as follows. That is, the recording layer 13 is preferably a dye type containing a dye as a recording substance, but is not limited thereto, and may be an inorganic write once type (write-once type) or the like. Among these, a dye-type recording layer in which pits are formed by laser beam irradiation and data is recorded is preferable. As the dye, a phthalocyanine dye, a cyanine dye, an azo dye, and the like are preferable. Data information such as music, images, and computer programs can be recorded and / or reproduced on the recording layer 13 by irradiation with the laser light. The recording layer 13 is prepared by dissolving the dye in a suitable solvent together with a binder or the like to prepare a coating solution, and then applying the coating solution directly on the substrate 11 or via another layer by a spin coating method. It is formed by applying a film by a screen printing method or the like to form a coating film and then drying. The other layer includes a light reflecting layer 12 described later.

Next, a preferred embodiment of the cover layer 14 is as follows. That is, as the cover layer 14, a transparent ultraviolet curable resin is dissolved in a suitable solvent to prepare a coating solution, and then the coating solution is removed from the clamping area B closer to the inner periphery than the information recording area A. A coating film is formed by spin coating, screen printing, or the like so as to cover the recording layer 13 over the outer peripheral portion C closer to the outer periphery than the information recording area A, and then dried and irradiated with ultraviolet rays. Is formed. The thickness of the cover layer 14 is usually 0 because the recording layer is configured to be irradiated with a blue-violet laser beam having a wavelength in the vicinity of 400 nm to 500 nm to be recorded / reproduced from the recording layer. .1 mm is preferred.
It should be noted that a layer may be formed between the recording layer 13 and the cover layer 14 for the purpose of adjusting recording characteristics and the like, improving adhesion, or protecting the recording layer. In this case, the total thickness of these layers, the recording layer 13 and the cover layer 14 is preferably about 0.1 mm.

Next, a preferred embodiment of the first convex portion 11d of the substrate 11 is as follows. That is, as the first protrusion 11d, the surface of the substrate 11 opposite to the surface on which the recording layer 13 is provided is closer to the inner periphery than the information recording area A and the clamping area B. It is preferable that the substrate 11 is formed in the vicinity of the inner peripheral edge of the substrate 11 simultaneously with the molding of the substrate 11. The projecting dimension of the first convex portion 11d from the surface of the substrate 11 opposite to the information recording area A is preferably 300 μm or less, and more preferably 50 μm or less. The projecting dimension of the first convex portion 11d is preferably 10 μm or more. The first convex portion 11d is preferably formed in a ring shape with the hole of the substrate 11 as the center.

Next, preferable implementation of the second convex portion 11e of the substrate 11 is as follows. That is, as the second convex portion 11e, the information recording area A has a surface opposite to the surface on which the recording layer 13 is provided of the substrate 11 like the first convex portion 11d. It is preferably provided in the vicinity of the outer periphery of the substrate 11 in the region C near the outer periphery, and is preferably formed simultaneously with the molding of the substrate 11 in the same manner as the first convex portion 11d. The projecting dimension of the second convex portion 11e from the surface of the substrate 11 opposite to the information recording area A is preferably 200 μm or less, and more preferably 20 μm or less. The projecting dimension of the second convex portion 11e is preferably 5 μm or more. In addition, the second convex portion 11e is preferably formed in a ring shape around the hole of the substrate 11 like the first convex portion 11d. Further, the difference between the projecting dimension of the first projecting portion 11d and the projecting dimension of the second projecting portion 11e is preferably 5 μm or more.
In the optical information recording medium described in the background art, since the convex portions having the same thickness are provided on the inner periphery and the outer periphery of the cover layer 204, the medium positioned on the upper side is located between the overlapping media. A space surrounded by the lower surface of the substrate, the surface of the cover layer 204 in the information recording area A of the medium located on the lower side, the convex portion 204a on the inner peripheral side of the cover layer 204, and the convex portion 204b on the outer peripheral side. Arise. For this reason, if an uppermost medium is peeled off from a state in which a plurality of media are loaded, a decompressed air chamber is generated between the lower optical information recording medium and a damage due to a peeling error occurs. And it was easy to fall. On the other hand, in the present embodiment, as described above, the protrusion dimension h1 of the first protrusion 11d from the surface 11c on the opposite side of the information recording area A of the substrate 11 is set to the first dimension from the surface 11c. It is larger than the protruding dimension h2 of the second convex portion 11e. For this reason, even if some bending occurs in the information recording medium 10, the upper and lower media have the same bending, so that the first protrusion 11 d and the second protrusion 11 d on the lower surface of the upper medium substrate. Since the contact between the convex portion 11e and the lower medium cover layer is suppressed and the closed space as in the background art is prevented, it is possible to prevent the occurrence of a peeling error.

Next, a preferred embodiment of the light reflecting layer 12 is as follows. The light reflecting layer 12 reflects laser light for recording and / or reproducing data. In the present invention, the light reflecting layer 12 is provided with a function of increasing the reflectance with respect to the laser light or improving the recording / reproducing characteristics. It is preferable to provide between the substrate 11 and the recording layer 13 as necessary. The light reflecting layer 12 is preferably a metal film such as Au, Al, Ag, Cu, or Pd, an alloy film of these metals, or an alloy film in which a trace component is added to these metals, or the like, such as sputtering or vacuum deposition. Is formed on the surface of the substrate 11 where the pregroove 11b is formed.

Next, a second embodiment of the optical information recording medium of the present invention will be described with reference to FIG. FIG. 2 is a partially enlarged cross-sectional view showing an outline of the internal structure of the optical information recording medium 20 of the second embodiment. 2 shows the right half region from the center of the optical information recording medium 20, and the left half region is omitted.

    As shown in FIG. 2, a recording layer 23 and a cover layer 24 are provided in this order on a substrate 21 having a hole 21a in the center, and recording and / or reproduction is performed by irradiating a laser beam from the cover layer 24 side. This is a disk-shaped optical information recording medium 20 in which the recording is performed.

Specifically, an information recording area A having a pre-groove 21b is provided on the surface of the disc-like substrate 21 having a hole 21a at the center where the recording layer 23 is provided. Further, provided on the surface (lower surface) opposite to the surface on which the recording layer 23 of the substrate 21 is provided, in the vicinity of the inner peripheral edge of the substrate 21 closer to the inner periphery than the information recording area A. The first convex portion 21d and the second convex portion 21e provided in the vicinity of the outer peripheral edge of the substrate 21 closer to the outer periphery than the information recording area A are provided. On the substrate 21, a reflective layer 22, a recording layer 23, and a cover layer 24 are provided in this order. Further, the first convex portion 21 d in the vicinity of the inner peripheral edge of the substrate 21 and the second convex portion 21 e in the vicinity of the outer peripheral edge of the substrate 21 are provided simultaneously with the molding of the substrate 21.

In the present embodiment, the protrusion dimension h1 of the first protrusion 21d from the surface 21c of the information recording area A of the substrate 21 opposite to the cover layer 24 of the substrate 21 (eg, 50 μm). Is larger than the protruding dimension h2 (for example, 20 μm) of the second convex portion 21e from the surface 21c.

Further, the optical information recording medium 20 of the present embodiment is different from the first embodiment in that the ink receiving layer 26 is provided on the surface of the substrate 21 opposite to the surface on which the recording layer 23 is provided. Is different. Specifically, the optical information recording medium 20 of the present embodiment has an ink receiving layer 26 via a base layer 25 on the surface opposite to the surface of the substrate 21 on which the recording layer 23 is provided. is there.
Other configurations and operational effects are the same as in the first embodiment, and a description thereof will be omitted.

Next, a preferred embodiment of the base layer 25 is as follows. That is, the base layer 25 is preferably composed mainly of an ultraviolet curable resin and a pigment. For example, an ultraviolet curable ink containing an ultraviolet curable resin and a pigment is screen-printed or spin-coated. The substrate 21 can be formed by printing on the surface of the substrate 21 opposite to the surface on which the recording layer 23 is provided, and curing the printed film with ultraviolet light. The base layer 25 is preferably provided to prevent the metallic glossy surface of the reflective layer 22 from being exposed when the substrate 21 and the ink receiving layer 26 described later are transparent.

Next, a preferred embodiment of the ink receiving layer 26 is as follows. That is, the ink receiving layer 26 preferably includes an ultraviolet curable resin as a main component, for example, the ultraviolet curable resin, other binder components, a viscosity modifier, a pigment, and other components are mixed. The ultraviolet curable ink thus obtained is printed by means such as a screen printing method or a spin coating method, and then cured by irradiating with ultraviolet rays, and is formed directly on the substrate 21 or through the above-described underlayer 25. Is done.
Examples of the pigment include organic and inorganic coloring pigments, inorganic fillers such as silica, alumina, aluminum hydroxide, and clay, or organic fillers such as acrylic beads, nylon beads, and rubber fine particles. You may use together single type or arbitrary multiple types.

  Next, a third embodiment of the optical information recording medium of the present invention will be described with reference to FIG. FIG. 3 is a partially enlarged sectional view showing an outline of the internal structure of the optical information recording medium 30 of the third embodiment. In the above figure, the right half region from the center of the optical information recording medium 30 is shown, and the left half region is omitted.

  As shown in FIG. 3, a recording layer 33 and a cover layer 34 are provided in this order on a substrate 31 having a hole 31a in the center, and recording and / or reproduction is performed by irradiating a laser beam from the cover layer 34 side. This is a disk-shaped optical information recording medium 30 in which recording is performed.

Specifically, the first convex portion 31d is formed in the vicinity of the inner peripheral edge of the substrate 31 on the surface opposite to the surface on which the recording layer 33 is provided of the disc-shaped substrate 31 having the hole 31a in the center. Have In addition, an information recording area A having a pregroove 31b is provided on the surface of the substrate 31 on which the recording layer 33 is provided. On the substrate 31, a reflective layer 32, a recording layer 33, and a cover layer 34 are provided in this order. A second convex portion 34 b is provided in the vicinity of the outer peripheral edge of the cover layer 34 in the region C closer to the outer periphery than the information recording region A. The first convex portion 31 d in the vicinity of the inner peripheral edge of the substrate 31 is provided simultaneously with the molding of the substrate 31. The second convex portion 34b in the vicinity of the outer peripheral edge of the cover layer 34 is formed integrally when the cover layer 34 is formed by the spin coat method.

In the present embodiment, the projection dimension h1 (eg, 50 μm) of the first protrusion 31d from the surface 31c on the opposite side of the information recording area A of the substrate 31 is the cover of the information recording area A. The protrusion dimension h2 of the second protrusion 34b from the surface 34a of the layer 34 is larger than the protrusion dimension h2 (example: 20 μm).
For this reason, even when the medium is slightly bent, the upper and lower media have the same bending, so that the second lower surface of the upper medium substrate and the lower medium cover layer 34 are provided. Since contact with the convex part 34b is suppressed and a closed space as in the background art is prevented from occurring, it is possible to prevent a peeling error from occurring.
This embodiment is different from the first embodiment in that the second convex portion of the first embodiment is a surface opposite to the surface of the substrate 11 on which the recording layer is provided. In the present embodiment, the cover layer 34 is provided on the surface of the substrate 31 on the side where the recording layer is provided, in the vicinity of the outer peripheral edge of the cover layer 34. It differs in that it is provided integrally. Other configurations and operational effects are the same as in the first embodiment, and a description thereof will be omitted.

Next, a fourth embodiment of the optical information recording medium of the present invention will be described with reference to FIG. FIG. 4 is a partially enlarged sectional view showing an outline of the internal structure of the optical information recording medium 40 of the fourth embodiment. 4 shows the right half area from the center of the optical information recording medium 40, and the left half area is omitted.

  As shown in FIG. 4, a recording layer 43 and a cover layer 44 are provided in this order on a substrate 41 having a hole 41a in the center, and recording and / or reproduction is performed by irradiating a laser beam from the cover layer 44 side. This is a disk-shaped optical information recording medium 40 in which recording is performed.

Specifically, the convex portion 41d at the first position is formed in the vicinity of the inner peripheral edge of the substrate on the surface opposite to the surface on which the recording layer 43 is provided of the disk-shaped substrate 41 having the hole 41a in the center. Have. Further, an information recording area A having a pregroove 41b is provided on the surface of the substrate 41 on the side where the recording layer 43 is provided. On the substrate 41, a reflective layer 42, a recording layer 43, and a cover layer 44 are provided in this order. And it has the 2nd convex part 44b provided in the vicinity of the outer periphery of the said cover layer 44 of the area | region C near the outer periphery from this information recording area A. As shown in FIG. The first convex portion 41 d in the vicinity of the inner peripheral edge of the substrate 41 is provided simultaneously with the molding of the substrate 41. Further, the second convex portion 44b near the outer peripheral edge of the cover layer 44 is formed integrally when the cover layer 44 is formed by the spin coat method.

In the present embodiment, the protrusion dimension h1 (eg, 50 μm) of the first convex portion 41d from the surface 41c of the substrate 41 opposite to the information recording area A is the cover of the information recording area A. The protrusion dimension h2 (for example, 20 μm) of the second convex portion 44b from the surface 44a of the layer 44 is made larger.
For this reason, even if the medium is slightly bent, the upper and lower media have the same bending, so that the second lower surface of the upper medium substrate and the lower medium cover layer 44 are provided. Since the contact with the convex portion 44b is suppressed and a closed space as in the background art is prevented, it is possible to prevent a peeling error from occurring.

Further, the optical information recording medium 40 of this embodiment is different from the third embodiment in that an ink receiving layer 46 is provided on the surface of the substrate 41 opposite to the surface on which the recording layer 43 is provided. Is different. Specifically, the optical information recording medium 40 of the present embodiment has an ink receiving layer 46 via a base layer 45 on the surface opposite to the surface of the substrate 41 on which the recording layer 43 is provided. is there. Other configurations and operational effects are the same as in the first embodiment, and a description thereof will be omitted.

It is a partial expanded sectional view which shows the outline | summary of the internal structure of 1st Embodiment of the optical information recording medium of this invention. It is a partial expanded sectional view which shows the outline | summary of the internal structure of 2nd Embodiment of the optical information recording medium of this invention. It is a partial expanded sectional view which shows the outline | summary of the internal structure of 3rd Embodiment of the optical information recording medium of this invention. It is a partial expanded sectional view which shows the outline | summary of the internal structure of 4th Embodiment of the optical information recording medium of this invention. It is a partial expanded sectional view which shows background art.

Explanation of symbols

10: Optical information recording medium 11: Substrate 11a: Hole 11b: Pregroove 11c: Surface of substrate (lower surface)
11d: 1st convex part 11e: 2nd convex part 12: Reflective layer 13: Recording layer 14: Cover layer 14a: Surface of cover layer 20: Optical information recording medium 21: Substrate 21a: Hole 21b: Pregroove 21c: Board surface (bottom)
21d: 1st convex part 21e: 2nd convex part 22: Reflective layer 23: Recording layer 24: Cover layer 24a: Cover layer surface 25: Underlayer 26: Ink receiving layer 30: Optical information recording medium 31: Substrate 31a: Hole 31b: Pregroove 31c: Surface (bottom surface) of substrate
31d: First convex portion 32: Reflective layer 33: Recording layer 34: Cover layer 34a: Cover layer surface 34b: Second convex portion 40: Optical information recording medium 41: Substrate 41a: Hole 41b: Pregroove 41c: Board surface (bottom)
41d: 1st convex part 42: Reflective layer 43: Recording layer 44: Cover layer 44a: Cover layer surface 44b: 2nd convex part 45: Underlayer 46: Ink receiving layer A: Information recording area B: Clamping Area C: Area h1: Projection dimension h2: Projection dimension

Claims (5)

  In an optical information recording medium having a recording layer and a cover layer in this order on a substrate having a hole in the center, and recording and / or reproduction is performed by irradiating a laser beam from the cover layer side. An information recording area having a pregroove is provided on a surface of the substrate on which the recording layer is provided, and an inner surface of the substrate on the side opposite to the surface on which the recording layer is provided is within the information recording area. A first convex portion provided in the vicinity of the inner peripheral edge of the substrate closer to the periphery, and a second convex portion provided in the vicinity of the outer peripheral edge of the substrate closer to the outer periphery than the information recording area. A characteristic optical information recording medium. 2. The protrusion dimension h1 of the first protrusion from the surface opposite to the information recording area of the substrate is made larger than the protrusion dimension h2 of the second protrusion from the surface. The optical information recording medium described. In an optical information recording medium having a recording layer and a cover layer in this order on a substrate having a hole in the center, and recording and / or reproduction is performed by irradiating a laser beam from the cover layer side. A first convex portion is provided in the vicinity of the inner peripheral edge of the substrate on the surface opposite to the surface on which the recording layer is provided on the substrate, and the surface on the side on which the recording layer is provided on the substrate. An optical information recording medium comprising: an information recording area provided with a groove; and a second protrusion provided in the vicinity of the outer peripheral edge of the cover layer closer to the outer periphery than the information recording area. The protrusion dimension h1 of the first protrusion from the surface opposite to the information recording area of the substrate is made larger than the protrusion dimension h2 of the second protrusion from the surface of the cover layer of the information recording area. The optical information recording medium according to claim 3. 5. The optical information recording medium according to claim 1, further comprising an ink receiving layer on a surface opposite to a surface on which the recording layer is provided of the substrate.

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