JP2007035181A - Optical disk cartridge housing body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk cartridge housing body with high light resistance. <P>SOLUTION: The optical disk cartridge housing body in which an optical disk having a recording layer on a base having a center hole is housed in a cartridge with an opening of a diameter equal to or smaller than an outer circumferential diameter of the optical disk formed so as to expose a face opposite from the recording layer to the outside from the opening is provided with a light shielding layer at an opposite side from the recording layer of the base of the optical disk and satisfying at least either the following condition A or condition B. The condition A: the inner circumferential diameter of the light shielding layer is smaller than the inner circumferential diameter of the recording layer by over 13mm, and at least partially larger than the inner circumferential diameter of the optical disk by over 0.1mm. The condition B: at least a portion of the outer circumferential diameter of the light shielding layer is equal to or larger than the outer circumferential diameter of the recording layer, and the diameter of the opening of the cartridge is at least partially equal to or smaller than the outer circumferential diameter of the light shielding layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical disk cartridge housing in which an optical disk is housed in a cartridge.

Conventionally, an optical disk called a write-once digital versatile disk (so-called DVD-R) is known as an optical disk having a higher recording density.
This DVD-R is a transparent disk-shaped substrate in which guide grooves (grooves) for tracking irradiated laser light are formed with a narrow groove width that is half or less (0.74 to 0.8 μm) of CD-R. On top of this, usually a disc in which two recording layers containing an organic dye, a light reflecting layer, and a protective layer are laminated in this order are laminated with the recording layer inside, or a disc shape having the same shape as this disc It has a structure in which a protective substrate is bonded with the recording layer inside. Recording and reproduction of information on this DVD-R is performed by irradiating with visible laser light (usually laser light having a wavelength of 630 nm to 680 nm), and recording with higher density than CD-R is possible. Is possible.

On the other hand, recently, networks such as the Internet and high-definition TVs are rapidly spreading. Also, HDTV (High Definition Television) has started to be broadcast.
Under such circumstances, there is a need for a larger-capacity optical disc capable of recording image information inexpensively and easily. Although DVD-R plays a role as a large-capacity optical disk at present, there is an increasing demand for larger capacity and higher density, and development of an optical disk that can meet these demands is also necessary. For this reason, development of a larger-capacity optical disk capable of performing high-density recording with light having a shorter wavelength than that of DVD-R is underway.

When such an optical disk is used or stored with the disk main body exposed, the optical disk is defenseless against scratches and light and has poor storability. Therefore, in order to improve resistance to scratches in particular, a form is known that is used in a state of being housed in a cartridge (see, for example, Patent Document 1). In such a cartridge, an example in which an opening that exposes the surface opposite to the recording layer of the optical disk to the outside is known. However, stray light that has accumulated from the opening of the cartridge may reach the recording layer, which may deteriorate the light resistance of the optical disc. In particular, this deterioration in light resistance is significant when a dye is used in the recording layer.
JP 2003-242740 A

The present invention has been made in view of the above-described conventional problems, and an object thereof is to achieve the following object. That is,
An object of the present invention is to provide an optical disk cartridge housing having high light resistance.

Means for solving the above-mentioned problems are as follows. That is,
The optical disk cartridge housing body of the present invention is a surface opposite to the recording layer in an optical disk having a recording layer on a substrate having a center hole, in which an opening having a diameter equal to or smaller than the outer peripheral diameter of the optical disk is formed. Is an optical disc cartridge housing that is exposed so as to be exposed to the outside from the opening, and has a light shielding layer on the side opposite to the recording layer of the substrate of the optical disc, and among the following conditions A and B It is characterized by satisfying at least one of the following.
Condition A: The inner peripheral diameter of the light shielding layer is 13 mm or more smaller than the inner peripheral diameter of the recording layer, and at least a part is 0.1 mm or more larger than the inner peripheral diameter of the optical disc.
Condition B: At least part of the outer diameter of the light shielding layer is equal to or larger than the outer diameter of the recording layer, and at least part of the diameter of the opening of the cartridge is equal to or smaller than the outer diameter of the light shielding layer.

  According to the optical disk cartridge housing of the present invention, the light shielding layer formed on the optical disk shields stray light from the outside that enters from the opening of the cartridge, so that stray light reaching the recording layer can be reduced.

  In addition to the opening, the cartridge may be provided with an inlet / outlet for inserting / removing the optical disc.

  According to the present invention, it is possible to provide an optical disk cartridge housing having high light resistance.

The optical disk cartridge housing body of the present invention is a surface opposite to the recording layer in an optical disk having a recording layer on a substrate having a center hole, in which an opening having a diameter equal to or smaller than the outer peripheral diameter of the optical disk is formed. Is an optical disc cartridge housing that is exposed so as to be exposed to the outside from the opening, and has a light shielding layer on the side opposite to the recording layer of the substrate of the optical disc, and among the following conditions A and B It is characterized by satisfying at least one of the following.
Condition A: The inner peripheral diameter of the light shielding layer is 13 mm or more smaller than the inner peripheral diameter of the recording layer, and at least a part is 0.1 mm or more larger than the inner peripheral diameter of the optical disc.
Condition B: At least part of the outer diameter of the light shielding layer is equal to or larger than the outer diameter of the recording layer, and at least part of the diameter of the opening of the cartridge is equal to or smaller than the outer diameter of the light shielding layer.
Embodiments of the optical disk cartridge housing according to the present invention will be described below.

  FIG. 1 is a top view of an optical disk cartridge housing 10 to which the present invention is applied. The optical disk cartridge housing 10 is generally composed of a cartridge 12 having an opening 12 a and an optical disk 14 housed in the cartridge 12. In FIG. 1, a circle drawn with a broken line indicates the outer periphery of the optical disk 14, and a circle drawn with a dashed line (the inside of the circle drawn with a broken line) indicates the outer periphery of the light shielding layer of the optical disk 14. As shown in FIG. 1, the diameter of the opening 12a of the cartridge 12 is smaller than the outer diameter of the optical disk 14, and the optical disk 14 cannot be taken out from the opening 12a.

  FIG. 2 is a view schematically showing a cross section taken along the line AA of the cartridge housing type disk 10 shown in FIG. In FIG. 2, for the sake of simplicity of explanation, the optical disk 14 shows a form in which a recording layer 18 is formed on a substrate 16 and a light shielding layer 20 is formed on the opposite side of the recording layer 18 of the substrate 16. Yes. As shown in FIG. 2, in the optical disk 14, the surface of the substrate 16 opposite to the recording layer 18, that is, the light shielding layer 20 is exposed to the outside from the opening 12 a of the cartridge 12.

In the optical disk cartridge housing of the present invention, at least one of the following conditions A and B is satisfied. That is,
Condition A: The inner peripheral diameter of the light shielding layer is 13 mm or more smaller than the inner peripheral diameter of the recording layer, and at least a part is 0.1 mm or more larger than the inner peripheral diameter of the optical disc.
Condition B: At least part of the outer diameter of the light shielding layer is equal to or larger than the outer diameter of the recording layer, and at least part of the diameter of the opening of the cartridge is equal to or smaller than the outer diameter of the light shielding layer.

That is, the condition A, in FIG. 2, the inner circumferential diameter d ₂ of the light-shielding layer, 13 mm or more smaller than the inner circumferential diameter d ₃ of the recording layer, and at least a part of the inner peripheral diameter d ₁ of the optical disk 0 .1mm or larger. Incidentally, the inner peripheral diameter d ₁ of the optical disc is usually 15 mm.

  In the optical disk cartridge housing of the present invention, by setting so as to satisfy the condition A, the inner periphery of the light shielding layer is positioned inside the inner periphery of the recording layer. Can be prevented from adversely affecting the recording layer.

  In the present invention, as described above, in the condition A, the inner diameter of the light shielding layer is at least partially larger than the inner diameter of the optical disk by 0.1 mm or more, but when the difference is less than 0.1 mm, Formation of a light shielding layer becomes difficult. The inner peripheral diameter of the light shielding layer is preferably 1 mm or more larger than the inner peripheral diameter of the optical disc, more preferably 3 mm or more, and even more preferably 5 mm or more. The inner diameter of the light shielding layer is 13 mm or more smaller than the inner diameter of the recording layer. However, if the difference is less than 13 mm, the light shielding property is insufficient and the light resistance effect cannot be exhibited. The inner diameter of the light shielding layer is preferably 18 mm or more smaller than the inner diameter of the recording layer, and more preferably 23 mm or more.

Similarly, by setting so as to satisfy the condition B, the outer periphery of the light shielding layer is positioned outside the outer periphery of the recording layer, and the periphery of the opening of the cartridge is positioned inside the outer periphery of the light shielding layer. Therefore, stray light from the outside can be prevented from adversely affecting the recording layer.
The outer diameter of the light shielding layer is preferably larger than the outer diameter of the recording layer by 0.1 mm or more, more preferably 1 mm or more, and further preferably 2 mm or more.

  In the present invention, if any one of the conditions A and B is satisfied, the effect of improving the light resistance can be exhibited. However, the present invention further satisfies both the conditions A and B. It is preferable that the above effects can be exhibited.

  The diameter of the opening of the cartridge is equal to or smaller than the outer peripheral diameter of the light shielding layer. If the area where the cartridge and the light shielding layer overlap is large, the visibility is lowered. Therefore, the average value of the difference between the diameter of the opening of the cartridge and the outer diameter of the light shielding layer is preferably 50 mm or less, more preferably 30 mm or less. Preferably, it is 10 mm or less.

  In the present invention, it is essential that the diameter of the opening of the cartridge is smaller than the outer diameter of the optical disk. Specifically, it is preferably 1 mm or more smaller than the outer diameter of the optical disk, preferably 3 mm or smaller. Is more preferable, and it is still more preferable that it is 5 mm or more smaller. More specifically, in the case of a cartridge that accommodates an optical disc having an outer diameter of 120 mm, the diameter of the opening is preferably 119 mm or less, more preferably 118 mm or less, still more preferably 117 mm or less, and particularly preferably 116 mm or less.

  The material of the cartridge is preferably a material having a transmittance of light of a predetermined wavelength of 50% or less, more preferably 30% or less, and more preferably 10% in order to exert the effect of the present invention. The following materials are more preferable. The predetermined wavelength indicates the absorption peak wavelength of the dye in the recording layer. The absorption peak wavelength is determined in the wavelength range of 350 to 800 nm.

  In the optical disk cartridge housing of the present invention, it is preferable to provide another opening for allowing recording and / or reproducing laser light to enter the recording layer on the side opposite to the opening of the cartridge. When recording and / or reproducing, recording and / or reproducing can be performed by bringing the recording / reproducing head closer to the separately provided opening (or by bringing the optical disc closer) on the recording and / or reproducing system side. it can.

  Examples of the method of storing the optical disk in the cartridge include 1) a method of loading with the opening widened, 2) a method of separately providing an inlet / outlet and loading from the inlet / outlet, and 3) a method of storing at the time of cartridge production. In the present invention, 2) is preferable from the viewpoints of being able to be taken out, being able to simplify the mechanism, and light shielding properties. As 1), at least a part of the opening may be movable or deformed so that the optical disk can be taken out.

  The entrance / exit provided in the cartridge in 2) will be described with a specific example. FIG. 3 is a perspective view showing only the cartridge 30 provided with the entrance 30a. The entrance / exit 30a is provided with a notch 30b so that the optical disc can be easily received from the entrance / exit 30a in a state where the optical disc is gripped. In FIG. 3, one notch is provided at the center of the inlet / outlet of the cartridge. However, the number, position and shape of the notch are not limited as long as the effects of the present invention are not impaired. Examples of the shape of the notch include a semicircular shape, a semi-elliptical shape, a rectangular shape, a trapezoidal shape, and a triangular shape. Examples of the position of the notch include the center, the edge, or the middle thereof. Moreover, you may provide so that it may become left-right symmetric in the shape and number of notches. Furthermore, it is good also as a notch part in both upper and lower sides of an entrance / exit, and having a different number and shape in upper and lower sides.

  In the optical disk cartridge housing of the present invention, it is preferable that the gap between the cartridge and the optical disk surface is narrow during storage in order to improve the light shielding property. The recording and / or reproducing system side preferably has a mechanism for widening the gap between the cartridge and the optical disk surface in order to avoid sliding between the optical disk and the cartridge when the optical disk rotates.

Next, the light shielding layer will be described. The light shielding layer preferably has a symmetrical shape (for example, a circle, an ellipse, a rectangle, a square, or a star) with respect to the rotation center of the optical disk. Moreover, it is preferable that there is little eccentricity.
The material of the light shielding layer is not particularly limited as long as it has a light shielding property, but it is preferable to use a radiation curable resin and a color material (dye or pigment) that absorbs light of a predetermined wavelength. Alternatively, it is preferable to form a layer containing the coloring material on the surface or inside of the radiation curable resin layer. The radiation curable resin is a resin that is cured by electromagnetic waves such as ultraviolet rays, electron beams, X-rays, γ-rays, and infrared rays. Among them, ultraviolet rays and electron beams are preferable. The method for forming the light shielding layer is not limited, but it is preferably formed by silk printing, letterpress printing, gravure printing or the like. Printing may be performed once or a plurality of times, and is preferably performed 1 to 20 times. In particular, 10 times is preferable and 6 times is more preferable.

  The lower limit of the thickness of the light shielding layer is preferably 2 μm, more preferably 5 μm, and even more preferably 7 μm. The upper limit is preferably 90 μm, more preferably 70 μm, still more preferably 50 μm, and particularly preferably 30 μm.

The optical disk according to the present invention will be described in detail below.
The optical disc according to the present invention has at least a recording layer on a substrate having a center hole, and has other layers such as a light reflection layer and a barrier layer as necessary, and is opposite to the recording layer of the substrate. Has a light shielding layer.
Hereinafter, the substrate and each layer will be described.

〔substrate〕
As the substrate in the present invention, various materials used as substrate materials for conventional optical disks can be arbitrarily selected and used. From the viewpoints of moisture resistance, dimensional stability, and low price, thermoplastic resins such as amorphous polyolefin and polycarbonate are preferable, and polycarbonate is particularly preferable.
When these resins are used, the substrate can be manufactured by injection molding.
The thickness of the substrate is more preferably 1.0 to 1.3 mm.

  Further, the substrate is provided with an unevenness (pre-groove) representing information such as a guide groove for tracking or an address signal on the surface on which the recording layer is provided. In order to achieve a higher recording density, a pre-groove having a narrower track pitch is required as compared with CD-R and DVD-R. For example, when the optical disk according to the present invention is used as a suitable medium corresponding to a blue-violet laser, the pregroove formed is preferably in the following range.

The track pitch of the pregroove is preferably in the range of 260 to 330 nm.
The pregroove width (half width) is preferably in the range of 100 to 150 nm.

The (groove) depth of the pregroove is preferably in the range of 28 to 50 nm.
The pregroove angle is preferably 40 to 50 °.

These pregroove values can be measured by an AFM (atomic force microscope). The angle of the pre-groove means that the groove depth of the groove is D, the surface of the substrate before the groove is formed as a reference, the inclined portion having a depth of D / 10 from the surface, and the deepest groove. This is an angle formed by a straight line connecting the inclined portion having a height of D / 10 from the portion and the substrate surface (groove bottom surface).
When the optical disc of the present invention is a read-only optical disc, pits indicating predetermined information are formed simultaneously with the formation of the pregroove.

  In order to produce a substrate having pregrooves (and pits) having such a groove shape, a stamper used at the time of injection molding needs to be formed by high-precision mastering. In order to achieve the above-mentioned groove shape, it is preferable to use DUV (wavelength 330 nm or less, deep ultraviolet) laser or EB (electron beam) cutting for this mastering.

  An undercoat layer such as a polymer substance; a silane coupling agent may be formed on the surface of the substrate on the side where the light reflecting layer described later is provided in order to improve planarity and adhesion.

[Recording layer]
The recording layer in the present invention is preferably a dye type containing a dye as a recording material, but is not limited to this, and is not limited to this, and an inorganic write-once type (write-once type), a phase change type, a magneto-optical type, a read-only type, etc. It can also be.
Accordingly, examples of the recording material contained in the recording layer include organic compounds such as dyes and phase change metal compounds.
Among these, a dye-type recording layer capable of recording information only once with a laser beam is preferable. Such a dye-type recording layer preferably contains a dye having absorption in the recording wavelength region. Examples of the dye include a cyanine dye, an oxonol dye, a metal complex dye, an azo dye, and a phthalocyanine dye.

Such a recording layer is prepared by dissolving a dye in a suitable solvent to prepare a coating solution, and then coating the coating solution on a substrate or a light reflecting layer described later to form a coating film, followed by drying. It is formed by doing.
The concentration of the pigment in the coating solution is preferably in the range of 0.5 to 3% by mass.

The thickness of the recording layer formed in this manner is preferably in the range of 90 to 180 nm on the groove (projection on the substrate).
Further, the thickness of the recording layer is preferably in the range of 110 to 250 nm on the land (the concave portion in the substrate).
Further, the ratio of the thickness of the recording layer on the groove / the thickness of the recording layer on the land is preferably 0.7 to 0.8.

  In the case of an optical disc having a diameter of 120 mm, the recording layer is preferably formed in a region having a diameter of 40 to 119 mm, more preferably in a region of 42 to 118 mm, and in a region of 44 to 117 mm. It is more preferable.

The recording layer can contain various anti-fading agents in order to improve the light resistance of the recording layer.
As the antifading agent, a singlet oxygen quencher is generally used. As the singlet oxygen quencher, those described in publications such as known patent specifications can be used.
The use amount of the antifading agent such as the singlet oxygen quencher is preferably in the range of 5 to 25% by mass with respect to the amount of the pigment.

Although the solvent coating method in the case where the recording layer is a dye-type recording layer has been described above, the recording layer can also be formed by a film forming method such as vapor deposition, sputtering, or CVD in accordance with the physical properties of the recording material.
For example, when a phase change metal compound is used as the recording material, it is preferable to form the recording layer using such a film forming method. Here, any of SbTe, AgSbTe, InAgSbTe, or the like may be used as the phase change metal compound.

[Cover layer]
The cover layer in the present invention is bonded to the above-described recording layer or a barrier layer described later via an adhesive or a pressure-sensitive adhesive.
The cover layer used in the present invention is not particularly limited as long as it is a transparent material film. Among them, it is preferable to use polycarbonate or cellulose triacetate.
Note that “transparent” means that the transmittance is 80% or more with respect to light used for recording and reproduction.

Further, the cover layer may contain various additives as long as the effects of the present invention are not hindered. For example, a UV absorber for cutting light having a wavelength of 400 nm or less and / or a pigment for cutting light having a wavelength of 500 nm or more may be contained.
Further, as the surface physical properties of the cover layer, it is preferable that both the two-dimensional roughness parameter and the three-dimensional roughness parameter have a surface roughness of 5 nm or less.
Further, from the viewpoint of the concentration of light used for recording and reproduction, the birefringence of the cover layer is preferably 10 nm or less.

The thickness of the cover layer is appropriately determined depending on the wavelength and NA of the laser beam irradiated for recording and reproduction, but in the present invention, it is preferably in the range of 0.05 to 0.12 mm. .
Moreover, it is preferable that the total thickness which match | combined the cover layer and the layer which consists of an adhesive agent or an adhesive is 0.095-0.105 mm.
The light incident surface of the cover layer may be provided with a protective layer (hard coat layer) for preventing the light incident surface from being damaged when the optical disc is manufactured.

  For example, a UV curable resin, an EB curable resin, a thermosetting resin, or the like is preferably used as the adhesive used to bond the cover layer, and it is particularly preferable to use a UV curable resin. Moreover, you may use an adhesive for bonding a cover layer. Specifically, acrylic, rubber and silicon adhesives can be used, but acrylic adhesives are preferred from the viewpoint of transparency and durability. As a crosslinking agent used together with the said adhesive, an isocyanate type crosslinking agent is mentioned, for example.

  When a UV curable resin is used as an adhesive, the UV curable resin may be used as it is or dissolved in an appropriate solvent such as methyl ethyl ketone or ethyl acetate to prepare a coating solution, which may be supplied from the dispenser to the barrier layer surface. . Further, in order to prevent warpage of the manufactured optical disk, it is preferable that the UV curable resin constituting the adhesive layer has a low curing shrinkage rate. Examples of such UV curable resins include UV curable resins such as “SD-640” manufactured by Dainippon Ink and Chemicals, Inc.

  The thickness of the adhesive layer or the pressure-sensitive adhesive layer is preferably in the range of 10 to 30 μm.

  As the pressure-sensitive adhesive used for laminating the cover layer, acrylic, rubber-based, and silicon-based pressure-sensitive adhesives can be used. From the viewpoint of transparency and durability, acrylic pressure-sensitive adhesive is used. preferable. As such an acrylic pressure-sensitive adhesive, 2-ethylhexyl acrylate, n-butyl acrylate and the like are the main components, and in order to improve cohesion, short-chain alkyl acrylates and methacrylates such as methyl acrylate, ethyl acrylate, and methyl methacrylate are used. And acrylic acid, methacrylic acid, acrylamide derivatives, maleic acid, hydroxylethyl acrylate, glycidyl acrylate, and the like, which can be crosslinking points with the crosslinking agent, are preferably used. The glass transition temperature (Tg) and the crosslinking density can be changed by appropriately adjusting the mixing ratio and type of the main component, the short chain component, and the component for adding a crosslinking point.

  As a crosslinking agent used together with the said adhesive, an isocyanate type crosslinking agent is mentioned, for example.

[Other layers]
The optical disk according to the present invention may have other arbitrary layers in addition to the above essential layers as long as the effects of the present invention are not impaired. Examples of such other optional layers include a light reflecting layer (described later) provided between the substrate and the recording layer, a barrier layer (described later) provided between the recording layer and the cover layer, and the light reflecting layer and recording. Examples thereof include an interface layer provided between the layers.
Each of these essential and optional layers may be a single layer or may have a multilayer structure.

(Light reflection layer)
In the present invention, it is preferable to form a light reflection layer between the substrate and the recording layer in order to increase the reflectance with respect to the laser beam or to provide the function of improving the recording / reproducing characteristics.
The light reflecting layer can be formed on the substrate by vacuum-depositing, sputtering, or ion plating a light-reflecting material having a high reflectance with respect to laser light.
The thickness of the light reflecting layer is generally in the range of 10 to 300 nm, and preferably in the range of 50 to 200 nm.
The reflectance is preferably 70% or more.

  As the light reflective material having a high reflectance, Au, Ag, or an alloy thereof is particularly preferable.

  As a light reflective material having a high reflectance, Mg, Se, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Co, Ni, Ru, Rh, Pd , Ir, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Si, Ge, Te, Pb, Po, Sn, Bi, and other metals and semi-metals or stainless steel. These light reflecting materials may be used alone or in combination of two or more or as an alloy. Among these, Cr, Ni, Pt, Cu, Ag, Au, Al, and stainless steel are preferable. Particularly preferred are Au, Ag, Al or alloys thereof, and most preferred are Au, Ag or alloys thereof.

[Formation of barrier layer (intermediate layer)]
In the present invention, it is preferable to form a barrier layer between the recording layer and the cover layer.
The barrier layer is provided for improving the storage stability of the recording layer, improving the adhesion between the recording layer and the cover layer, adjusting the reflectance, adjusting the thermal conductivity, and the like.
The material used for the barrier layer is not particularly limited as long as it is a material that transmits light used for recording and reproduction, and can express the above functions. Is a material with low gas and moisture permeability and is preferably a dielectric.
Specifically, ZnS—SiO ₂ , SnO ₂ , and ZnO—Ga ₂ O ₃ are preferable.

The barrier layer is preferably formed using RF sputtering.
The thickness of the barrier layer in the present invention is preferably in the range of 3 to 50 nm.

  As described above, the optical disc according to the present invention has an ink-absorbing resin layer having a predetermined thickness and a predetermined covering area ratio on the surface opposite to the light incident surface in addition to the substrate, the recording layer, and the cover layer. is doing. As described above, the optical disk according to the present invention has an effect that the amount of change in warpage is suppressed and the recording / reproduction characteristics are also improved by the presence of the ink-absorbing resin layer.

  When recording the information on the optical disc according to the present invention, when the optical disc according to the present invention has a recording layer, the recording layer is physically or chemically irradiated by irradiating laser light with a wavelength of 100 to 600 nm from the cover layer side. The recording can be performed with a change. By recording in this way, good and stable recording / reproducing characteristics can be imparted by performing recording by irradiating the optical disk having the above-described configuration with laser light having an appropriate wavelength.

More preferably, the lower limit of the recording wavelength (laser light wavelength) is 200 nm or more, more preferably 300 nm or more, and particularly preferably 350 nm or more. Moreover, as an upper limit, it is more preferable that it is 500 nm or less, It is further more preferable that it is 450 nm or less, It is especially preferable that it is 420 nm or less.
Each of the upper limit value and the lower limit value can be arbitrarily combined.
Information may be recorded on the groove of the optical disk according to the present invention or on the land, but the groove is preferable.
Furthermore, information is also reproduced by the laser beam in the above wavelength region.

More specifically, information recording and reproduction using the optical disc (recordable type) according to the present invention and the optical information recording method according to the present invention are performed, for example, as follows.
First, while rotating the optical disk at a predetermined linear velocity (0.5 to 10 m / sec) or a predetermined constant angular velocity, a blue-violet laser (for example, wavelength 405 nm) is passed through the objective lens from the cover layer side. Irradiate recording light. By this irradiation light, the recording layer absorbs the light and the temperature rises locally. For example, information is recorded by generating pits and changing their optical characteristics. Information recorded as described above can be reproduced by irradiating a blue-violet laser beam from the cover layer side while rotating the optical disc at a predetermined constant linear velocity and detecting the reflected light.

Examples of the laser light source having an oscillation wavelength of 500 nm or less as described above include a blue-violet semiconductor laser having an oscillation wavelength in the range of 390 to 415 nm, a blue-violet SHG laser having a central oscillation wavelength of 425 nm, and the like.
In order to increase the recording density, the NA of the objective lens used for the pickup is preferably 0.7 or more, and more preferably 0.85 or more.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

[Example 1]
<Production of optical disc>
(substrate)
An injection-molded substrate made of polycarbonate resin having a thickness of 1.1 mm, an outer diameter of 120 mm, an inner diameter of 15 mm (center hole diameter) and a spiral pre-groove (track pitch of 320 nm, groove width of 107 nm, groove depth of 37 nm) was used. . The groove depth was measured by measuring the distance between the deepest part and the shallowest part. The groove width was measured at a half depth of the groove depth. The angle of the inclined portion of the groove was measured by measuring the angle of a straight line connecting the shallower portion of the groove depth 10% and the deeper portion 10%.

(Formation of light reflection layer)
An APC light reflecting layer (Ag: 98.1% by mass, Pd: 0.9% by mass, Cu%) having a film thickness of 100 nm was formed by DC sputtering in an Ar atmosphere on a pregroove of the substrate. : 1.0% by mass). The film thickness of the light reflecting layer was adjusted by the sputtering time.

(Formation of recording layer)
Dye A represented by the following chemical formula: 2 g was added and dissolved in 100 ml of 2,2,3,3-tetrafluoropropanol to prepare a dye-containing coating solution. And the prepared pigment | dye containing coating liquid was apply | coated by the spin coat method on the light reflection layer. Thereafter, the film was stored at 23 ° C. and 50% RH for 1 hour to form a recording layer (thickness on the groove 135 nm, thickness on the land 180 nm). The recording layer was formed from an inner peripheral portion of 48 mm (diameter) to an outer peripheral portion of 116 mm (diameter).

  After forming the recording layer, annealing was performed in a clean oven. The annealing process was performed by supporting the substrate on a vertical stack pole while keeping a space with a spacer, and holding at 80 ° C. for 1 hour.

(Formation of barrier layer)
Thereafter, a thickness of ZnO—Ga ₂ O ₃ (ZnO: Ga ₂ O ₃ = 7: 3 (mass ratio)) is formed on the recording layer by RF sputtering in an Ar atmosphere using a Cube manufactured by Unaxis. A 5 nm barrier layer was formed.

(Covering the cover layer)
As the cover layer, a polycarbonate film (Teijin Pure Ace, thickness: 80 μm) having an inner diameter of 15 mm and an outer diameter of 120 mm and coated with an adhesive on one side, the thickness of the adhesive layer and the polycarbonate film is used. The total thickness was set to 100 μm.
Then, the cover layer was placed on the barrier layer so that the barrier layer and the pressure-sensitive adhesive layer were in contact with each other, and the cover layer was pressed and pressed with a pressing member.

(Formation of light shielding layer)
Ultraviolet curable ink (White No. 3, manufactured by Teikoku Mfg. Co., Ltd., local maximum) in the region from the inner peripheral part 22 mm (diameter) to the outer peripheral part 117 mm (diameter) on the back surface (opposite side of the light reflecting layer) Absorbing 350 nm, transmittance 1%) was printed by screen printing, and after printing, a light shielding layer having a layer thickness of 8 μm was formed by irradiating with 80 W / cm ultraviolet rays from a metal halide lamp. As the screen, a Tetron screen having 300 lines / inch mesh, a yarn diameter of 31 μm, and an opening of 38 μm was used.
An optical disc was produced through the above steps.

(Storage of optical disk in cartridge)
The optical disk produced as described above was inserted into a BD cartridge (described in detail below) so that the recording layer was on the inside, and the optical disk cartridge housing of Example 1 was produced.
Detailed cartridge material for BD: Shading resin (ABS mixed with blue pigment)
Diameter of opening: 115mm
Size: 135 x 135 x 13mm
Entrance: Yes

  The inner diameter of the light shielding layer in the optical disk cartridge housing of Example 1 is 26 mm smaller than the inner diameter of the recording layer and 7 mm larger than the inner diameter (center hole diameter) of the optical disk. Further, the outer diameter of the light shielding layer is 1 mm larger than the outer diameter of the recording layer, and the diameter of the opening of the cartridge is 2 mm smaller than the outer diameter of the light shielding layer.

[Example 2]
The optical disc of Example 2 was the same as Example 1 except that the formation region of the light shielding layer was changed from the inner peripheral part 24 mm (diameter) to the outer peripheral part 116 mm (diameter) in “Formation of light shielding layer” in Example 1. A cartridge housing was produced.
The inner diameter of the light shielding layer in the optical disk cartridge housing of Example 2 is 24 mm smaller than the inner diameter of the recording layer and 9 mm larger than the inner diameter (center hole diameter) of the optical disk. The outer diameter of the light shielding layer is the same as the outer diameter of the recording layer, and the diameter of the opening of the cartridge is 1 mm smaller than the outer diameter of the light shielding layer.

[Example 3]
The optical disc of Example 3 was the same as Example 1 except that the formation region of the light shielding layer was changed from the inner peripheral part 16 mm (diameter) to the outer peripheral part 118 mm (diameter) in “Formation of light shielding layer” in Example 1. A cartridge housing was produced.
In the optical disk cartridge housing of Example 3, the inner diameter of the light shielding layer is 32 mm smaller than the inner diameter of the recording layer and 1 mm larger than the inner diameter (center hole diameter) of the optical disk. Further, the outer diameter of the light shielding layer is 2 mm larger than the outer diameter of the recording layer, and the diameter of the opening of the cartridge is 3 mm smaller than the outer diameter of the light shielding layer.

[Comparative Example 1]
The optical disc of Comparative Example 1 was the same as Example 1 except that the formation region of the light shielding layer was changed from the inner peripheral part 40 mm (diameter) to the outer peripheral part 114 mm (diameter) in “Formation of light shielding layer” in Example 1. A cartridge housing was produced.
The inner diameter of the light shielding layer in the optical disk cartridge housing of Comparative Example 1 is 4 mm smaller than the inner diameter of the recording layer and 25 mm larger than the inner diameter (center hole diameter) of the optical disk. Further, the outer diameter of the light shielding layer is 2 mm smaller than the outer diameter of the recording layer, and the diameter of the opening of the cartridge is 1 mm larger than the outer diameter of the light shielding layer.

[Evaluation]
Light Resistance Test Recording / reproduction and jitter measurement were performed using a disk drive device (DDU1000, NA: 8.5, laser wavelength: 403 nm, Pulse Tech Industry Co., Ltd.). The recording signal was recorded or reproduced using Pulse Tech MSG2, with a clock frequency of 66 MHz, a linear velocity of 5.28 m / s, a recording power of 5.4 mW, and a reproducing power of 0.3 mW. Note that the recording was performed in the groove.
First, the optical disk was taken out from the entrance / exit of the BD cartridge, and the jitter at the inner peripheral portion (diameter 48 mm) was measured. After the measurement, the optical disk was stored in a BD cartridge, and irradiated with 80 klux light from the opening of the BD cartridge for 32 hours with a fade tester (manufactured by Suga Test Instruments Co., Ltd.). Jitter at the outer periphery (diameter 115 mm) was measured. The results are shown in Table 1.

  From Table 1, it can be seen that the optical disk cartridge housings of Examples 1 to 3 have sufficient light resistance with little change in jitter before and after light irradiation. In contrast, the optical disk cartridge housing of Comparative Example 1 had a large change in jitter before and after light irradiation and was inferior in light resistance.

It is a top view which shows one Embodiment of the optical disk cartridge accommodating body of this invention. It is a fragmentary sectional view along the AA line of FIG. It is a perspective view which shows the cartridge which concerns on this invention.

Explanation of symbols

10 optical disc cartridge housing 12 cartridge 12a opening 14 optical disc 16 substrate 18 recording layer 20 light shielding layer 30 cartridge

Claims (2)

An optical disk having a recording layer on a substrate having a center hole is exposed to the outside from the opening on a cartridge in which an opening having a diameter equal to or smaller than the outer diameter of the optical disk is formed. An optical disk cartridge housing body stored as follows,
An optical disk cartridge housing comprising a light shielding layer on a side opposite to a recording layer of a substrate of the optical disk and satisfying at least one of the following conditions A and B:
Condition A: The inner peripheral diameter of the light shielding layer is 13 mm or more smaller than the inner peripheral diameter of the recording layer, and at least a part is 0.1 mm or more larger than the inner peripheral diameter of the optical disc.
Condition B: At least part of the outer diameter of the light shielding layer is equal to or larger than the outer diameter of the recording layer, and at least part of the diameter of the opening of the cartridge is equal to or smaller than the outer diameter of the light shielding layer.   2. The optical disk cartridge housing according to claim 1, wherein the cartridge is provided with an inlet / outlet through which the optical disk is taken in and out.

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