WO2013190626A1 - Support d'enregistrement et appareil d'enregistrement/reproduction - Google Patents

Support d'enregistrement et appareil d'enregistrement/reproduction Download PDF

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Publication number
WO2013190626A1
WO2013190626A1 PCT/JP2012/065543 JP2012065543W WO2013190626A1 WO 2013190626 A1 WO2013190626 A1 WO 2013190626A1 JP 2012065543 W JP2012065543 W JP 2012065543W WO 2013190626 A1 WO2013190626 A1 WO 2013190626A1
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WIPO (PCT)
Prior art keywords
recording
laser beam
dielectric film
film
reproducing
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Application number
PCT/JP2012/065543
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English (en)
Japanese (ja)
Inventor
松川　真
信彦 加藤
智施 神野
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パイオニア株式会社
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Priority to PCT/JP2012/065543 priority Critical patent/WO2013190626A1/fr
Priority to PCT/JP2013/064391 priority patent/WO2013190949A1/fr
Publication of WO2013190626A1 publication Critical patent/WO2013190626A1/fr

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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/2403—Layers; Shape, structure or physical properties thereof
    • G11B7/24047—Substrates
    • G11B7/2405—Substrates being also used as track layers of pre-formatted layers
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/257—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
    • G11B7/0045—Recording
    • G11B2007/00457—Two photon recording
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/242—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
    • G11B7/244—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising organic materials only
    • G11B7/246—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising organic materials only containing dyes
    • G11B2007/24624—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising organic materials only containing dyes fluorescent dyes
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/257—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
    • G11B2007/25705—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials
    • G11B2007/25706—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials containing transition metal elements (Zn, Fe, Co, Ni, Pt)
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/257—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
    • G11B2007/25705—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials
    • G11B2007/2571—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials containing group 14 elements except carbon (Si, Ge, Sn, Pb)
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/257—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
    • G11B2007/25705—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials
    • G11B2007/25715—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials containing oxygen

Definitions

  • the present invention relates to a technical field of a recording medium such as an optical disc having a large number of recording layers, and a recording / reproducing apparatus that performs at least one of a recording operation and a reproducing operation on such a recording medium.
  • a recording medium including a large number of recording layers for example, a recording medium having a plurality of recording layers that are actually targets of at least one of a recording operation and a reproducing operation, and a guide layer on which a tracking guide track is formed (for example, A so-called guide layer separation type optical disc) is known (see Patent Document 1).
  • a recording / reproducing apparatus that performs at least one of a recording operation and a reproducing operation with respect to such a recording medium has a guide laser beam for reading the guide track of the guide layer, and at least one of the recording operation and the reproducing operation with respect to the recording layer.
  • the recording / reproducing laser beam is irradiated.
  • the recording / reproducing apparatus performs at least one of the recording operation and the reproducing operation by irradiating the recording layer with the recording / reproducing laser beam while performing tracking control based on the push-pull signal obtained from the return light of the guide laser beam.
  • Patent Document 2 is cited as a prior art document related to the present invention, although it is not a prior art document disclosing a guide layer separation type optical disc.
  • the guide layer is located on the back side of the plurality of recording layers when viewed from the guide laser light emission side. For this reason, the guide laser beam passes through the plurality of recording layers before reaching the guide layer. For this reason, in order for the guide layer to be suitably irradiated with the guide laser beam, the transmittance of the guide laser beam in each of the plurality of recording layers is ensured (for example, the transmittance is a predetermined value (for example, 85%) or more). It is desirable to set On the other hand, a part of the guide laser beam is reflected by each of the plurality of recording layers. A part of the guide laser light reflected by each of the plurality of recording layers becomes so-called stray light.
  • the noise component resulting from stray light will be superimposed on the tracking error signal generated based on the return light of the guide laser light.
  • the signal quality of the tracking error signal is relatively deteriorated.
  • the reflectance of the guide laser light in each of the plurality of recording layers is suppressed (for example, the reflectance is set to a predetermined value (for example, 10%) or less). ) Is desired.
  • each of the plurality of recording layers at least one of a recording operation and a reproducing operation is performed by a recording / reproducing laser beam having a wavelength different from the wavelength of the guide laser beam.
  • the transmittance of the recording / reproducing laser beam in each of the plurality of recording layers is ensured (for example, the transmittance is set to a predetermined value ( For example, it is desirable to set it to 80%) or higher.
  • each of the plurality of recording layers is suppressed. It is desirable to suppress the reflectance of the recording / reproducing laser beam in (for example, set the reflectance to a predetermined value (eg, 3%) or less).
  • the plurality of recording layers satisfy the condition that the guide laser light transmittance and the recording / reproducing laser light transmittance are ensured while the guide laser light reflectance and the recording / reproducing laser light reflectance are suppressed. It is desirable to satisfy.
  • a recording / reproducing apparatus that performs at least one of a recording operation and a reproducing operation for a recording medium having a plurality of recording layers performs recording control using the return light of the guide laser light, and performs recording / reproducing laser light. At least one of the recording operation and the reproducing operation with respect to the plurality of recording layers used can be suitably performed (in other words, with high quality).
  • the reflectance of the guide laser light and the reflectance of the recording / reproducing laser light are similarly suppressed.
  • the present invention provides, for example, a recording medium including a recording layer that enables at least one of a recording operation and a reproducing operation to be suitably performed, and performs at least one of a recording operation and a reproducing operation on such a recording medium. It is an object to provide a recording / reproducing apparatus.
  • a recording medium includes a guide layer on which a guide track irradiated with guide laser light having a wavelength included in the range of 630 nm to 680 nm is formed, and a wavelength included in the range of 400 nm to 410 nm.
  • a recording layer that is irradiated with a recording / reproducing laser beam comprising: (i) a recording film whose optical characteristics change by irradiation of the recording / reproducing laser beam; and (ii) a dielectric film.
  • the dielectric film has a refractive index of 2.2 or less with respect to the guide laser beam, and the refractive index of the dielectric film with respect to the recording / reproducing laser beam is 1.85. That's it.
  • the recording / reproducing apparatus performs at least one of a recording operation and a reproducing operation with respect to the recording medium described above.
  • the characteristics of the recording layer of the first specific example, the characteristics of the recording layer of the second specific example and the characteristics of the recording layer of the third specific example, and the characteristics of the recording layer of the first comparative example and the recording layer of the second comparative example It is a table
  • the recording medium of the present embodiment has a guide layer on which a guide track is irradiated with a guide laser beam having a wavelength included in the range of 630 nm to 680 nm, and a recording / reproduction having a wavelength included in the range of 400 nm to 410 nm.
  • a recording layer that is irradiated with a laser beam, and the recording layer is formed by stacking (i) a recording film whose optical characteristics are changed by irradiation of the recording / reproducing laser beam, and (ii) a dielectric film.
  • the dielectric film has a refractive index of 2.2 or less with respect to the guide laser beam, and the refractive index of the dielectric film with respect to the recording / reproducing laser beam is 1.85 or more.
  • the recording medium of this embodiment includes a guide layer and a recording layer.
  • the guide layer is formed with a tracking guide track. Therefore, a recording / reproducing apparatus that performs at least one of a recording operation and a reproducing operation with respect to the recording medium (more specifically, with respect to a recording layer included in the recording medium)
  • a push-pull signal corresponding to the positional relationship between the guide track and the beam spot of the guide laser light can be acquired based on the return light of the light (that is, the guide laser light reflected by the guide layer).
  • the recording / reproducing apparatus can perform tracking control based on the push-pull signal.
  • the recording layer has a laminated structure in which a recording film and a dielectric film are laminated. Note that the recording film and the dielectric film may be laminated in this order when viewed from the laser beam emission side. Alternatively, the dielectric film and the recording film may be laminated in this order when viewed from the laser beam emission side.
  • the recording film is a film whose surface or internal optical characteristics change when irradiated with a recording / reproducing laser beam (for example, irradiated with a recording / reproducing laser beam focused on the recording film).
  • a place where the optical characteristic change occurs is treated as one of the so-called “mark part” and “space part”, and a part where the optical characteristic change does not occur is any of the so-called “mark part” or “space part”. By treating it as the other, data is recorded on the recording layer.
  • the dielectric film is a film for improving reliability with respect to power fluctuations in the recording film (that is, fluctuations in the power of the recording / reproducing laser beam irradiated on the recording film).
  • the dielectric film may be used to protect the recording film in addition to or instead of improving the reliability against power fluctuations in the recording film.
  • the wavelength of the guide laser light mainly used for tracking control is in the range of 630 nm to 680 nm.
  • the wavelength ⁇ 1 of the guide laser light satisfies the condition of 630 nm ⁇ ⁇ 1 ⁇ 680 nm. That is, the guide laser beam may be substantially equivalent to the red laser beam.
  • the wavelength of the recording / reproducing laser beam used mainly for at least one of the recording operation and the reproducing operation with respect to the recording layer is in the range of 400 nm to 410 nm.
  • the wavelength ⁇ 2 of the recording / reproducing laser beam satisfies the condition of 400 nm ⁇ ⁇ 2 ⁇ 410 nm. That is, the recording / reproducing laser beam may be substantially equivalent to the blue laser beam.
  • the recording medium of this embodiment is particularly designed so that the refractive index of the dielectric film constituting the recording layer satisfies the following conditions. Specifically, the refractive index of the dielectric film with respect to the guide laser beam is designed to be 2.2 or less. In addition, the refractive index of the dielectric film with respect to the recording / reproducing laser beam is designed to be 1.85 or more.
  • the recording layer (i-1) suppresses the reflectance of the guide laser beam (for example, the reflectance is a predetermined value (for example, 10 And (i-2) suppressing the reflectance of the recording / reproducing laser beam (for example, setting the reflectance to a predetermined value (for example, 3%) or less), while (ii-1)
  • the transmittance of the guide laser beam is ensured (for example, the transmittance is set to a predetermined value (for example, 85%) or more), and (ii-2) the transmittance of the recording / reproducing laser beam is secured (for example, the transmittance is The condition of setting to a predetermined value (for example, 80% or more) can be satisfied.
  • the recording / reproducing apparatus that performs at least one of the recording operation and the reproducing operation on the recording medium having such a recording layer uses the recording / reproducing laser beam while performing the tracking control using the return light of the guide laser beam. At least one of the recording operation and the reproducing operation with respect to the plurality of recording layers can be suitably performed (in other words, with high quality).
  • the dielectric film includes at least one of an inorganic compound and a mixture of inorganic compounds.
  • the dielectric film having the refractive index described above can be realized relatively easily by at least one of the inorganic compound and the mixture of inorganic compounds. Therefore, the various effects described above are suitably realized.
  • the dielectric film includes at least one of an inorganic compound and a mixture of inorganic compounds as described above, includes (i) an oxide of Zn, an oxide of Ti, an oxide of Zr, or Sn. (Ii) Al nitride, or (iii) Zn sulfide.
  • the dielectric film having the above-described refractive index can be realized relatively easily by the material, (ii) Al nitride (ie, AlN), or (iii) Zn sulfide (ie, ZnS). Therefore, the various effects described above are suitably realized.
  • the dielectric film includes at least one of an inorganic compound and a mixture of inorganic compounds as described above, includes (i) Zn oxide, Ti oxide, Zr oxide, Si And a mixture of at least two of (ii) Al nitride, and (iii) Zn sulfide.
  • Zn oxide ie, ZnO
  • Ti oxide ie, TiO 2
  • Zr oxide ie, ZrO 2
  • Si oxide ie, SiO 2
  • Sn ie, SnO 2
  • Al nitride ie, AlN
  • Zn sulfide ie, ZnS
  • the dielectric film includes at least one of an inorganic compound and a mixture of inorganic compounds as described above, the dielectric film includes a mixture of TiO 2 and SiO 2 .
  • the dielectric film having the above-described refractive index can be realized relatively easily by the mixture of TiO 2 and SiO 2 . Therefore, the various effects described above are suitably realized.
  • the dielectric film includes a mixture of TiO 2 and SiO 2 as described above, the dielectric film includes 15 mol% or more and 59 mol% or less of SiO 2 .
  • the dielectric film having the above-described refractive index can be relatively easily made by the mixture of TiO 2 and SiO 2 (however, the mixture having a SiO 2 content of 15 mol% or more and 59 mol% or less). Can be realized. Therefore, the various effects described above are suitably realized.
  • the extinction coefficient of the dielectric film with respect to the guide laser beam is 0.05 or less, and the extinction coefficient of the dielectric film with respect to the recording / reproducing laser beam is 0. 05 or less.
  • the absorption of the guide laser beam and the recording / reproducing laser beam in the dielectric film (in other words, the absorption of the guide laser beam and the recording / reproducing laser beam in the recording layer composed of the dielectric film) can be suppressed. it can.
  • the recording layer can satisfy the conditions of ensuring the transmittance of the guide laser beam and the recording / reproducing laser beam while suppressing the reflectance of the guide laser beam and the recording / reproducing laser beam.
  • the various effects described above are suitably realized.
  • the modulation degree of the data recorded on the recording layer is 40% or more by changing the optical characteristics of the recording film by the irradiation of the recording / reproducing laser beam.
  • the recording / reproducing apparatus that performs at least one of the recording operation and the reproducing operation with respect to the recording medium having such a recording layer performs the tracking control using the return light of the guide laser light, and performs the recording / reproducing laser beam.
  • At least one of the recording operation and the reproducing operation with respect to a plurality of recording layers using can be performed suitably (in other words, with high quality).
  • the thickness of the dielectric film in the stacking direction is 20 nm or more and 110 nm or less.
  • the dielectric film having the above-described refractive index can be realized relatively easily by the dielectric film having such a thickness (that is, the film thickness). Therefore, the various effects described above are suitably realized.
  • the recording layer further includes another dielectric film disposed so as to sandwich the recording film between the recording film and the dielectric film.
  • the recording layer further includes another dielectric film, the above-described various effects are suitably realized.
  • the other dielectric films like the above-described dielectric film, improve reliability with respect to power fluctuations in the recording film (that is, fluctuations in the power of the recording / reproducing laser beam applied to the recording film). It may be a membrane. Alternatively, the other dielectric film may be a film for protecting the recording film.
  • the recording layer further includes another dielectric film
  • the other dielectric film is designed so as to satisfy the above-described conditions (that is, have the above-described characteristics).
  • other dielectric films may be designed so as not to satisfy the above conditions.
  • the recording layer further includes a light absorption film that forms the laminated structure together with the recording film and the dielectric film.
  • the light absorbing film is a film mainly for absorbing recording / reproducing laser light and supplying necessary energy to the recording layer.
  • the light absorption film is mainly composed of an oxide of Fe.
  • the above-described light absorption film can be realized relatively easily by the oxide of Fe. Therefore, the various effects described above are suitably realized.
  • the recording film contains Bi and O.
  • the recording film described above can be realized relatively easily by Bi and O. Therefore, the various effects described above are suitably realized.
  • ⁇ 14> In another aspect of the recording medium of the present embodiment, a plurality of the recording layers are provided.
  • the various effects described above are preferably realized.
  • the dielectric film constituting each of the plurality of recording layers is designed so as to satisfy the above conditions (that is, have the above characteristics). It is preferable. However, while the dielectric film constituting a part of the plurality of recording layers satisfies the above conditions, the dielectric film constituting the other part of the plurality of recording layers You may design so that the above-mentioned conditions may not be satisfied.
  • the recording / reproducing apparatus of the present embodiment performs at least one of a recording operation and a reproducing operation on the recording medium of the present embodiment described above (including various aspects thereof).
  • the recording / reproducing apparatus of this embodiment suppresses the reflectance of the guide laser beam (for example, sets the reflectance to a predetermined value (for example, 10%) or less) and (i-2) records / reproduces While suppressing the reflectance of the laser beam (for example, setting the reflectance to a predetermined value (for example, 3%) or less), (ii-1) ensuring the transmittance of the guide laser beam (for example, reducing the transmittance) (Ii-2) Conditions for ensuring the transmittance of the recording / reproducing laser beam (for example, setting the transmittance to a predetermined value (for example, 80%) or more) At least one of a recording operation and a reproducing operation can be performed on the recording layer that satisfies the above.
  • the recording / reproducing apparatus of this embodiment preferably performs at least one of the recording operation and the reproducing operation with respect to the plurality of recording layers using the recording / reproducing laser beam while performing the tracking control using the return light of the guide laser beam. (In other words, high quality). Therefore, the various effects described above are suitably realized.
  • the recording / reproducing apparatus of the present embodiment may also adopt various aspects.
  • the recording medium of the present embodiment includes a guide layer and a recording layer, and the dielectric film constituting the recording layer has a refractive index with respect to the guide laser beam of 2.2 or less and a recording / reproducing laser beam.
  • the condition that the refractive index with respect to is 1.85 or more is satisfied.
  • the recording / reproducing apparatus of this embodiment performs at least one of a recording operation and a reproducing operation with respect to the recording medium of this embodiment. Therefore, at least one of the recording operation and the reproducing operation with respect to the plurality of recording layers using the recording / reproducing laser beam is preferably performed (in other words, with high quality) while performing the tracking control using the return light of the guide laser beam. Can do.
  • FIG. 1 is a schematic perspective view in which a plurality of layers constituting one optical disk 11 are disassembled at intervals in the stacking direction (vertical direction in FIG. 1) to make each layer easy to see.
  • FIG. FIG. 2 is a cross-sectional view showing a cross section of the optical disc 11 together with the irradiation modes of the guide laser beam LB1 and the recording / reproducing laser beam LB2.
  • the optical disc 11 includes a single guide layer 12 and a plurality of (that is, two or more) recording layers 13. That is, the optical disk 11 is a so-called guide layer separation type optical disk.
  • the optical disc 11 may include a single recording layer 13 instead of the plurality of recording layers 13.
  • the tracking guide laser beam LB1 focused on the guide layer 12 and the plurality of recording layers 13 are collected.
  • the recording / reproducing laser beam LB2 emitted is simultaneously irradiated from the recording / reproducing apparatus 100.
  • the guide laser beam LB1 and the recording / reproducing laser beam LB2 are simultaneously irradiated from the recording / reproducing apparatus 100.
  • the recording / reproducing laser beam LB2 may be used for tracking (that is, the guide laser beam LB1 may not be used).
  • the wavelength of the guide laser beam LB1 mainly used for tracking control is in the range of 630 nm to 680 nm.
  • the wavelength ⁇ 1 of the guide laser beam LB1 satisfies the condition of 630 nm ⁇ ⁇ 1 ⁇ 680 nm. That is, the guide laser beam LB1 may be substantially equivalent to the red laser beam.
  • the lower limit value of the wavelength ⁇ 1 of the guide laser beam LB1 is set in consideration of a predetermined margin (that is, an error that can be substantially regarded as 630 nm) ⁇ 1 with respect to the above-described numerical value of “630 nm”. It may be set.
  • the upper limit value of the wavelength ⁇ 1 of the guide laser beam LB1 is set in consideration of a predetermined margin (substantially an error that can be regarded as 680 nm) ⁇ 1 with respect to the numerical value of “680 nm” described above. May be. Therefore, the wavelength ⁇ 1 of the guide laser beam LB1 may satisfy the condition of 630 ⁇ ⁇ 1 nm ⁇ ⁇ 1 ⁇ 680 ⁇ ⁇ 1 nm.
  • the wavelength of the recording / reproducing laser beam LB2 mainly used for at least one of the recording operation and the reproducing operation with respect to each of the plurality of recording layers 13 is in the range of 400 nm to 410 nm.
  • the wavelength ⁇ 2 of the recording / reproducing laser beam LB2 satisfies the condition of 400 nm ⁇ ⁇ 2 ⁇ 410 nm. That is, the recording / reproducing laser beam LB2 may be substantially equivalent to the blue laser beam.
  • the lower limit value of the wavelength ⁇ 2 of the recording / reproducing laser beam LB2 takes into account a predetermined margin (that is, an error that can be substantially regarded as 400 nm) ⁇ 2 with respect to the numerical value of “400 nm” described above. May be set.
  • the upper limit value of the wavelength ⁇ 2 of the recording / reproducing laser beam LB2 is set in consideration of a predetermined margin (substantially an error that can be regarded as 410 nm) ⁇ 2 with respect to the above-described numerical value of “410 nm”. It may be set. Therefore, the wavelength ⁇ 2 of the recording / reproducing laser beam LB2 may satisfy the condition of 400 ⁇ ⁇ 2 nm ⁇ ⁇ 2 ⁇ 410 ⁇ ⁇ 2 nm.
  • the optical disk 11 preferably adopts the CLV method.
  • preformat information for example, clock information, address information, recording start, etc.
  • timing information, etc. is recorded in advance.
  • the guide track TR formed on the guide layer 12 may be a single spiral.
  • the groove track GT is preferably switched to the land track LT in a predetermined region of the guide layer 12.
  • the land track LT is preferably switched to the groove track GT in a predetermined region of the guide layer 12.
  • the guide track TR may be a double spiral in which the groove track GT and the land track LT are separated.
  • the recording / reproducing laser beam LB2 is focused on one desired recording layer 13 to be recorded or reproduced among the plurality of recording layers 13 stacked on the guide layer 12.
  • the recording / reproducing laser beam LB2 is a blue laser beam having a relatively short wavelength as in, for example, BD (Blu-ray Disc: Blu-ray Disc).
  • the guide laser beam LB1 is a red laser beam having a relatively long wavelength, for example, like DVD.
  • the diameter of the beam spot formed on the guide layer 12 by the guide laser beam LB1 is, for example, about several times the diameter of the beam spot formed on the recording layer 13 by the recording / reproducing laser beam LB2.
  • Each of the plurality of recording layers 13 is a recording layer capable of optically recording and reproducing recording information independently. More specifically, each of the plurality of recording layers 13 is composed of, for example, a translucent thin film containing a two-photon absorption material.
  • a two-photon absorption material a fluorescent type using a fluorescent material in which the fluorescence intensity in a region where two-photon absorption occurs is changed, a refractive index changing type using a photorefractive material in which the refractive index is changed by electron localization, etc.
  • photochromic compounds, bis (aralkylidene) cycloalkanone compounds, etc. is promising as refractive index changing type two-photon absorption materials.
  • the optical disk structure using a two-photon absorption material includes (i) a bulk type in which the entire optical disk 11 is made of a two-photon absorption material, and (ii) a recording layer 13 of a two-photon absorption material and a spacer layer 15 of another transparent material.
  • the layer structure type has an advantage that focus control can be performed using light reflected at the interface between the recording layer 13 and the spacer layer 15.
  • the bulk type has an advantage that the manufacturing cost can be suppressed because there are few multilayer film forming steps.
  • Each of the plurality of recording layers 13 may be, for example, a dye material in addition to the above-described two-photon absorption material, phase change material using an inorganic material, alloying type, and punching type.
  • the guide track TR is not formed in advance in an unrecorded state, and for example, the entire region is a mirror surface or a flat surface without unevenness.
  • FIG. 3 is a cross-sectional view showing a detailed configuration of each of the plurality of recording layers 13 provided in the optical disc 11 of the present embodiment.
  • the optical disc 11 includes a cover layer 14, a plurality of recording layers 13, a plurality of spacer layers 15, a guide layer 12, a 2P (Photo Polymer) layer 16, and a substrate 17. Yes.
  • the plurality of recording layers 13 and the plurality of spacer layers 15 are arranged such that two adjacent recording layers 13 sandwich one spacer layer 15 therebetween.
  • the upper side of FIG. 3 is the emission side of the guide laser beam LB1 and the recording / reproducing laser beam LB2.
  • the cover layer 14 is a layer located on the outermost surface side of the optical disc 11 and is used to protect each layer formed on the lower layer side of the cover layer 14.
  • the cover layer 14 has a thickness of 54 ⁇ m, for example.
  • the spacer layer 15 is a member positioned between two adjacent recording layers 13 (in other words, a member for bonding the two adjacent recording layers 13 together).
  • the total thickness of one recording layer 13 and one spacer layer 15 adjacent to each other is, for example, 12 ⁇ m or 16 ⁇ m.
  • a general spacer layer may be used as the spacer layer 15.
  • the 2P layer 16 is a member positioned between the plurality of recording layers 13 and the guide layer 12.
  • the 2P layer 16 has a thickness of 146 ⁇ m, for example.
  • the substrate 17 is a member that is the basis of the optical disk 11.
  • the material of the substrate 15 may be various materials such as glass, ceramics, and resin.
  • resin constituting the substrate 15 polycarbonate resin, olefin resin, acrylic resin, epoxy resin, polystyrene resin, polyethylene resin, polypropylene resin, silicone resin, fluorine resin, ABS resin, Urethane resin or the like may be used.
  • polycarbonate resin and olefin resin are preferable from the viewpoint of ease of processing and molding. In this embodiment, polycarbonate resin is used.
  • Each of the plurality of recording layers 13 includes a dielectric film 131, a recording film 132, a light absorption film 133, and a dielectric film 134 as viewed from the emission side of the guide laser beam LB1 and the recording / reproducing laser beam LB2.
  • each of the plurality of recording layers 13 may not include any one of the dielectric film 131 and the dielectric film 134.
  • each of the plurality of recording layers 13 may not include the light absorption film 133.
  • the dielectric film 131 functions as a film that improves the reliability against power fluctuations in the recording film 132 (that is, the power of the recording / reproducing laser beam LB2 when the recording film 132 is irradiated). Further, the dielectric film 131 may have a function of making it difficult for moisture in the substrate 17 or external moisture to reach the recording film 132 (that is, a function of suppressing alteration of the recording film 132). The characteristics of the dielectric film 131 will be described in detail later.
  • the recording film 132 functions as an inorganic reaction film, and is melted and mixed by the heat of the recording / reproducing laser beam LB2. As a result, the reflectance of the recording film 132 changes depending on whether or not the recording / reproducing laser beam LB2 is irradiated.
  • Bi—O or Bi—MO As a main component of the recording film 132, Bi—O or Bi—MO (where M is Mg, Ca, Y, Dy, Ce, Tb, Ti, Zr, V, Nb, Ta, Mo, W, Mn, Fe, Zn, Al, In, Si, Ge, Sn, Sb, Li, Na, K, Sr, Ba, Sc, La, Nd, Sm, Gd, Ho, Cr, Co, Ni, Cu, Ga, Pb It is preferable that the main component is at least one element selected from among them. In this embodiment, for the sake of convenience of explanation, the description will be made using an example in which Bi—Ge—O is used as the main component of the recording film 132.
  • the film thickness of the recording film 132 is 10 nm, for example. However, the film thickness of the recording film 133 may be any value other than 10 nm.
  • the light absorption film 133 has a function of supplying the necessary energy to the recording film 132 by absorbing the recording / reproducing laser beam LB2.
  • Fe 3 O 4 is preferably used as a main component of the light absorption film 133.
  • Fe 2 O 3 , FeO, CrO, Cr 2 O 3 , MnO, Mn 2 O 3 , MnO 2 , V and 2 O 3, VO 2 and, and V 2 O 5, NiO and may be Nd 2 O 3 and the like are used.
  • the film thickness of the light absorption film 133 is 2 nm, for example. However, the film thickness of the light absorption film 133 may be any value other than 2 nm.
  • a Bi-MO peroxide is used as the material of the recording film 132.
  • the recording film 132 is formed by reactive sputtering. Since the light absorption film 133 may be oxidized during the formation of the recording film 132, it is preferable to use a material having light absorption characteristics in the oxide state as the material of the light absorption film 133.
  • the dielectric film 134 functions as a film that improves the reliability against the power fluctuation in the recording film 132 (that is, the power of the recording / reproducing laser beam LB2 when the recording film 132 is irradiated).
  • the dielectric film 134 may have a function of making it difficult for moisture in the substrate 17 or external moisture to reach the recording film 132 (that is, a function of suppressing alteration of the recording film 132). The characteristics of the dielectric film 134 will be described later in detail.
  • the description will be focused on the characteristics of the dielectric film 131 in order to simplify the description.
  • the characteristics of the dielectric film 134 may match the characteristics of the dielectric film 131.
  • some of the characteristics of the dielectric film 134 coincide with some of the characteristics of the dielectric film 131, while the other part of the characteristics of the dielectric film 134 is the other part of the characteristics of the dielectric film 131. Does not have to match.
  • not all the characteristics of the dielectric film 134 need to match the characteristics of the dielectric film 131.
  • the dielectric film 131 constituting each of the plurality of recording layers 13 preferably has the following characteristics. That is, it is preferable that all the dielectric films 131 included in the optical disc 11 have the following characteristics. However, the dielectric film 131 that constitutes a part of the plurality of recording layers 13 has at least a part of the following characteristics, while the other part of the plurality of recording layers 13. The dielectric film 131 constituting the recording layer 13 may not have the following characteristics.
  • the dielectric film 131 has a characteristic that the refractive index with respect to the guide laser beam LB1 is 2.2 or less.
  • the numerical value “2.2” corresponds to the upper limit value of the refractive index of the dielectric film 131 with respect to the guide laser beam LB1.
  • a lower limit value of the refractive index of the dielectric film 131 with respect to the guide laser beam LB1 may be set.
  • the dielectric film 131 may have a characteristic that the refractive index with respect to the guide laser beam LB1 is 1.35 or more.
  • the dielectric film 131 has a characteristic that the refractive index with respect to the recording / reproducing laser beam LB2 is 1.85 or more.
  • the numerical value “1.85” corresponds to the lower limit value of the refractive index of the dielectric film 131 with respect to the recording / reproducing laser beam LB2.
  • an upper limit value of the refractive index of the dielectric film 131 with respect to the recording / reproducing laser beam LB2 may be set.
  • the dielectric film 131 may have a characteristic that the refractive index with respect to the recording / reproducing laser beam LB1 is 2.8 or less.
  • the dielectric film 131 As a material of the dielectric film 131 having such a refractive index, Zn oxide (that is, ZnO), Ti oxide (that is, TiO 2 ), Zr oxide (that is, ZrO 2 ), Sn (that is, that is) , SnO 2 ) oxide, Al nitride (ie, AlN), or Zn sulfide (ie, ZnS).
  • the dielectric film 131 may be ZnO, TiO 2 , ZrO 2 , SnO 2 , AlN or ZnS.
  • the dielectric film 131 may be a mixture of at least two of ZnO, TiO 2 , ZrO 2 , SiO 2 , SnO 2 , AlN, and ZnS.
  • the dielectric film 131 made of ZnO has a refractive index with respect to the guide laser beam LB1 of 1.93 (that is, 2.2 or less) and a refractive index with respect to the recording / reproducing laser beam LB2. Is 2.06 (that is, 1.85 or more).
  • the dielectric film 131 made of AlN has a refractive index with respect to the guide laser beam LB1 of 1.85 (that is, 2.2 or less) and a refractive index with respect to the recording / reproducing laser beam LB2. 95 (that is, 1.85 or more).
  • the dielectric film 131 made of ZrO 2 —Y 2 O 3 (where the weight percentage of Y 2 O 3 is 5 wt%) has a refractive index of 2.06 with respect to the guide laser beam LB1 (that is, And a refractive index with respect to the recording / reproducing laser beam LB2 is 2.11 (that is, 1.85 or more).
  • the dielectric film 131 made of a mixture of TiO 2 and SiO 2 has a refractive index of 1.95 with respect to the guide laser beam LB1 (that is, And the refractive index with respect to the recording / reproducing laser beam LB2 is 2.08 (that is, 1.85 or more).
  • the dielectric film 131 made of a mixture of TiO 2 and Al 2 O 3 has a refractive index of 1.87 with respect to the guide laser beam LB1.
  • the dielectric film 131 made of a mixture of ZnS and SiO 2 (however, the content of SiO 2 is 20 mol%) has a refractive index of 2.14 with respect to the guide laser beam LB1 (that is, 2 And a refractive index with respect to the recording / reproducing laser beam LB2 is 2.36 (that is, 1.85 or more).
  • the dielectric film 131 made of a mixture of ZnO and SnO 2 (however, the content of SnO 2 is 30 mol%) has a refractive index of 2.01 with respect to the guide laser beam LB1 (that is, 2 And a refractive index with respect to the recording / reproducing laser beam LB2 is 2.195 (that is, 1.85 or more).
  • a mixture of TiO 2 and SiO 2 is preferably used as the material of the dielectric film 131. That is, the dielectric film 131 is preferably a mixture of TiO 2 and SiO 2 .
  • the content of SiO 2 is preferably 15 mol% or more and 59 mol% or less. In other words, it is preferable that the lower limit of the SiO 2 content is 15 mol% and the upper limit of the SiO 2 content is 59 mol%.
  • FIG. 4 shows the refractive index of the dielectric film 131 composed of a mixture of TiO 2 and SiO 2 (that is, the refractive index with respect to the guide laser beam LB1 and the refractive index with respect to the recording / reproducing laser beam LB2) and the SiO 2 content rate. It is a graph which shows the correlation between.
  • both the refractive index of the dielectric film 131 with respect to the guide laser beam LB1 and the refractive index of the dielectric film 131 with respect to the recording / reproducing laser beam LB2 increase the content of SiO 2 in the dielectric film 131. Decreases as you go.
  • the content of SiO 2 is preferably 15 mol% or more.
  • the SiO 2 content is preferably 59 mol% or less.
  • FIG. 4 is a graph obtained by connecting the sample values of the refractive index obtained through experiments by the inventors of the present application with an approximate curve.
  • the accuracy of the sample value of the refractive index and the accuracy of the approximate curve may be affected.
  • the lower limit value of the content of SiO 2 takes into account a predetermined margin (that is, an error that can be substantially regarded as 15 mol%) ⁇ 1 with respect to the numerical value of “15 mol%” described above. May be set.
  • the upper limit of the content rate of SiO 2 is set in consideration of a predetermined margin (that is, an error that can be equated with 59 mol%) ⁇ 2 with respect to the numerical value of “59 mol%” described above. Also good. Accordingly, the content of SiO 2 may be met 15 ⁇ ⁇ 1mol% ⁇ SiO 2 content ratio ⁇ 59 ⁇ ⁇ 2mol% conditions.
  • the dielectric film 131 has a characteristic that the extinction coefficient with respect to the guide laser beam LB1 is 0.05 or less.
  • the upper limit value of the extinction coefficient of the dielectric film 131 with respect to the guide laser beam LB1 is preferably 0.05.
  • the dielectric film 131 has a characteristic that the extinction coefficient with respect to the recording / reproducing laser beam LB2 is 0.05 or less. Is preferred.
  • the upper limit value of the extinction coefficient of the dielectric film 131 with respect to the recording / reproducing laser beam LB2 is preferably 0.05.
  • the upper limit value of the extinction coefficient is based on the above-described numerical value of “0.05” after taking into account a predetermined margin (that is, an error that can be substantially regarded as 0.05) ⁇ . It may be set. That is, the upper limit value of the extinction coefficient may be 0.05 ⁇ ⁇ .
  • the thickness of the dielectric film 131 is preferably 20 nm or more and 110 nm.
  • the lower limit value of the film thickness of the dielectric film 131 is 20 nm and the upper limit value of the film thickness of the dielectric film 131 is 110 nm.
  • the lower limit value of the film thickness of the dielectric film 131 takes into account a predetermined margin (that is, an error that can be substantially regarded as 20 nm) ⁇ 1 with respect to the numerical value of “20 nm” described above. It may be set.
  • the upper limit value of the thickness of the dielectric film takes into account a predetermined margin (that is, an error that can be substantially regarded as 110 nm) ⁇ 2 with respect to the numerical value of “110 nm” described above. It may be set. Therefore, the dielectric film may satisfy the condition of 20 ⁇ ⁇ 1 nm ⁇ dielectric film thickness ⁇ 110 nm ⁇ ⁇ 2 nm.
  • the dielectric film 131 has a modulation degree of the recording layer 13 (that is, a modulation degree when data is recorded on the recording layer 13 by irradiation with the recording / reproducing laser beam LB2) of 40% or more.
  • the lower limit value of the modulation degree of the recording layer 13 is preferably 40%.
  • the lower limit value of the modulation degree is set in consideration of a predetermined margin (that is, an error that can be substantially regarded as 40%) ⁇ with respect to the numerical value of “40%” described above. Also good. That is, the lower limit value of the modulation degree may be 40 ⁇ ⁇ %.
  • FIG. 5 is a graph showing the correlation among the refractive index of the dielectric film 131, the degree of modulation, and the modulation with respect to the recording / reproducing laser beam LB2.
  • the degree of modulation As shown in FIG. 5, as the refractive index of the dielectric film 131 with respect to the recording / reproducing laser beam LB2 increases, the degree of modulation also increases.
  • the modulation degree becomes 40%. Therefore, when the refractive index of the dielectric film 131 with respect to the recording / reproducing laser beam LB2 is 1.85 or more, the modulation degree is often 40% or more.
  • Each of the plurality of recording layers 13 having the dielectric film 131 having the characteristics described above suppresses the reflectance of the (i-1) guide laser beam LB1 (for example, the reflectance is a predetermined value (for example, 10%)). And (i-2) suppressing the reflectance of the recording / reproducing laser beam LB2 (for example, setting the reflectance to a predetermined value (for example, 3%) or less), while (ii-1) the guide The transmittance of the laser beam LB1 is secured (for example, the transmittance is set to a predetermined value (for example, 85%) or more) and (ii-2) the transmittance of the recording / reproducing laser beam LB2 is secured (for example, the transmittance) Is set to a predetermined value (for example, 80% or more)).
  • the “reflectance” and “transmittance” here mean the reflectivity and transmittance in a state where the recording film 132 is not melted by the irradiation of the recording / reproducing laser beam LB2.
  • the recording / reproducing apparatus 101 that performs at least one of the recording operation and the reproducing operation with respect to the optical disc 11 including the recording layer 13 performs the tracking control using the return light of the guide laser beam LB1, and performs the recording / reproducing laser beam. At least one of the recording operation and the reproducing operation with respect to the plurality of recording layers 13 using LB2 can be suitably performed (in other words, with high quality).
  • FIG. 6 is a cross-sectional view showing the recording layer 13a of the first specific example.
  • FIG. 7 is a cross-sectional view showing the recording layer 13b of the second specific example.
  • FIG. 8 is a cross-sectional view showing the recording layer 13c of the third specific example.
  • FIG. 9 is a cross-sectional view showing the recording layer 13d of the fourth specific example.
  • FIG. 10 is a cross-sectional view showing the recording layer 13e of the first comparative example.
  • FIG. 11 is a cross-sectional view showing the recording layer 13f of the second comparative example.
  • FIG. 12 shows the characteristics of the recording layer 13a of the first specific example, the characteristics of the recording layer 13b of the second specific example, the characteristics of the recording layer 13c of the third specific example, the characteristics of the recording layer 13d of the fourth specific example, It is a table
  • each recording layer 13 can realize the characteristics shown in FIG. 12 even when the optical disc 11 includes a plurality of recording layers 13.
  • the recording layer 13a of the first specific example is composed of a dielectric film 131 made of ZnO and having a film thickness of 40 nm, and a film made of BiGeO and having a film thickness.
  • the recording layer 13a of the first specific example was formed on the substrate 17 having a track pitch of 0.64 ⁇ m under the following conditions.
  • Each of the dielectric films 131 and 134 uses a mixed gas having a gas pressure of 0.63 Pa composed of argon gas supplied at 85 sccm and oxygen gas supplied at 5 sccm as a sputtering gas, and has a high frequency input power of 500 W. It was formed by the RF sputtering method set to.
  • the recording film 132 is formed by RF sputtering in which a high frequency input power is set to 150 W while using a mixed gas having a gas pressure of 0.58 Pa composed of argon gas supplied at 75 sccm and oxygen gas supplied at 15 sccm as a sputtering gas. Formed by law.
  • the light absorbing film 133 is an RF in which a high frequency input power is set to 500 W while using a mixed gas having a gas pressure of 0.65 Pa composed of argon gas supplied at 90 sccm and oxygen gas supplied at 1 sccm as a sputtering gas. It was formed by sputtering.
  • each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13a of the first specific example has a refractive index of 1.93 with respect to the guide laser beam LB1 (that is, 2.2 or less). And the refractive index with respect to the recording / reproducing laser beam LB2 is 2.06 (that is, 1.85 or more). Further, each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13a of the first specific example has an extinction coefficient of 0 (that is, 0.05 or less) with respect to the guide laser beam LB1, and recording / reproduction. The extinction coefficient with respect to the laser beam LB2 is 0.001 (that is, 0.05 or less).
  • the reflectance, transmittance, and degree of modulation were measured when a recording operation was performed on the recording layer 13a of the first specific example.
  • the recording operation was performed using a recording / reproducing laser LB2 having a wavelength of 405 nm that is irradiated onto the recording layer 13a through an optical system having an aperture ratio NA of 0.85.
  • the recording operation was performed while performing tracking control based on the return light of the guide laser LB1 having a wavelength of 655 nm, which is irradiated to the guide layer 12 through an optical system having an aperture ratio NA of 0.60.
  • the recording operation was performed under the conditions that the linear velocity was 7.68 m / s, the recording linear density was 115 nm / bit, and the modulation method was 1-7 modulation.
  • the recording layer 13a of the first specific example has (i-1) a reflectance of the guide laser beam LB1 of 6.1% (that is, 10% or less) and (i-2) a recording / reproducing laser. While the reflectance of the light LB2 is 1% (that is, 3% or less), (ii-1) the transmittance of the guide laser beam LB1 is 93.4% (that is, 85% or more). In addition, the condition that (ii-2) the transmittance of the recording / reproducing laser beam LB2 is 87.1% (that is, 80% or more) is satisfied. In addition, the modulation degree of the recording layer 13a of the first specific example satisfies the condition that it becomes 74.4% (that is, 40% or more).
  • the recording layer 13b of the second specific example is composed of a mixture of TiO 2 and SiO 2 (however, the content of SiO 2 is 35 mol%) and A dielectric film 131 having a thickness of 45 nm, a recording film 132 made of BiGeO and having a thickness of 10 nm, a light absorption film 133 made of Fe 3 O 4 and having a thickness of 2 nm, and TiO 2 And a dielectric film 134 composed of a mixture of SiO 2 and SiO 2 (however, the content of SiO 2 is 35 mol%) and having a film thickness of 35 nm.
  • the recording layer 13b of the second specific example was formed on the substrate 17 having a track pitch of 0.64 ⁇ m under the following conditions.
  • Each of the dielectric films 131 and 134 is formed by an RF sputtering method in which a high frequency input power is set to 750 W while using a mixed gas of argon gas supplied at 90 sccm and a gas pressure of 0.63 Pa as a sputtering gas. It was done.
  • the recording film 132 and the light absorption film 133 were formed in the same manner as in the first specific example.
  • each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13b of the second specific example has a refractive index of 1.95 with respect to the guide laser beam LB1 (that is, 2.2 or less). And the refractive index with respect to the recording / reproducing laser beam LB2 is 2.08 (that is, 1.85 or more).
  • each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13b of the second specific example has an extinction coefficient of 0.001 (that is, 0.05 or less) with respect to the guide laser beam LB1.
  • the extinction coefficient with respect to the recording / reproducing laser beam LB2 is 0.002 (that is, 0.05 or less).
  • the reflectance, transmittance, and degree of modulation when the recording operation was performed on the recording layer 13b of the second specific example were measured.
  • the recording layer 13b of the second specific example has (i-1) a reflectivity of the guide laser beam LB1 of 6.6% (that is, 10% or less) and (i-2) a recording / reproducing laser. While the reflectance of the light LB2 is 1.1% (that is, 3% or less), (ii-1) the transmittance of the guide laser beam LB1 is 92.4% (that is, 85% or more). And (ii-2) the condition that the transmittance of the recording / reproducing laser beam LB2 is 88.6% (that is, 80% or more). In addition, the modulation degree of the recording layer 13b of the second specific example satisfies the condition that it becomes 65.5% (that is, 40% or more).
  • the recording layer 13c of the third specific example is a mixture of TiO 2 and Al 2 O 3 (however, the content of Al 2 O 3 is 50 mol%).
  • the recording layer 13c of the third specific example was formed on the substrate 17 having a track pitch of 0.64 ⁇ m under the following conditions.
  • Each of the dielectric films 131 and 134 was formed in the same manner as in the second specific example.
  • the recording film 132 and the light absorption film 133 were formed in the same manner as in the first specific example.
  • each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13c of the third specific example has a refractive index of 1.87 with respect to the guide laser beam LB1 (that is, 2.2 or less). And a refractive index with respect to the recording / reproducing laser beam LB2 is 1.91 (that is, 1.85 or more). Further, each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13c of the third specific example has an extinction coefficient with respect to the guide laser beam LB1 of 0.0028 (that is, 0.05 or less) and The extinction coefficient with respect to the recording / reproducing laser beam LB2 is 0.006 (that is, 0.05 or less).
  • the reflectance, transmittance, and degree of modulation were measured when a recording operation was performed on the recording layer 13c of the third specific example.
  • the recording operation was performed under the same conditions as in the first specific example.
  • the reflectivity of the guide laser beam LB1 is 5.3% (that is, 10% or less), and (i-2) the recording / reproducing laser. While the reflectance of the light LB2 is 1.1% (that is, 3% or less), (ii-1) the transmittance of the guide laser beam LB1 is 93% (that is, 85% or more). And (ii-2) the condition that the transmittance of the recording / reproducing laser beam LB2 is 88.3% (that is, 80% or more) is satisfied. In addition, the modulation degree of the recording layer 13c of the third specific example satisfies the condition that it is 50.5% (that is, 40% or more).
  • the recording layer 13d of the fourth specific example is composed of a mixture of ZnO and SnO 2 (provided that the content of SnO 2 is 30 mol%) and is a film.
  • the recording layer 13d of the fourth specific example was formed on the substrate 17 having a track pitch of 0.64 ⁇ m under the following conditions.
  • Each of the dielectric films 131 and 134 has a high frequency input power of 500 W while using a mixed gas having a gas pressure of 0.63 Pa composed of argon gas supplied at 89 sccm and oxygen gas supplied at 1 sccm as the sputtering gas. It was formed by the RF sputtering method set to.
  • the recording film 132 and the light absorption film 133 were formed in the same manner as in the first specific example.
  • each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13d of the fourth specific example has a refractive index of 2.01 with respect to the guide laser beam LB1 (that is, 2.2 or less). And the refractive index with respect to the recording / reproducing laser beam LB2 is 2.195 (that is, 1.85 or more). Further, each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13d of the fourth specific example has an extinction coefficient of 0.0049 (that is, 0.05 or less) with respect to the guide laser beam LB1. The extinction coefficient with respect to the recording / reproducing laser beam LB2 is 0.0016 (that is, 0.05 or less).
  • the reflectance, transmittance, and degree of modulation when the recording operation was performed on the recording layer 13d of the fourth specific example were measured.
  • the recording layer 13d of the fourth specific example has (i-1) the reflectance of the guide laser beam LB1 is 8% (that is, 10% or less) and (i-2) the recording / reproducing laser beam LB2.
  • the transmittance of the guide laser beam LB1 is 91.1% (that is, 85% or more).
  • (ii-2) the condition that the transmittance of the recording / reproducing laser beam LB2 is 83.6% (that is, 80% or more) is satisfied.
  • the degree of modulation of the recording layer 13c of the third specific example satisfies the condition that it is 73.2% (that is, 40% or more).
  • the recording layer 13e of the first comparative example is composed of a dielectric film 131 made of SiN and having a thickness of 53 nm, and BiGeO.
  • the recording layer 13e of the first comparative example was formed on the substrate 17 having a track pitch of 0.64 ⁇ m under the following conditions.
  • Each of the dielectric films 131 and 134 uses a mixed gas having a gas pressure of 0.65 Pa composed of argon gas supplied at 85 sccm and nitrogen gas supplied at 5 sccm as a sputtering gas, and a high frequency input power of 400 W. It was formed by the RF sputtering method set to.
  • the recording film 132 and the light absorption film 133 were formed in the same manner as in the first specific example.
  • each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13e of the first comparative example has a refractive index with respect to the guide laser beam LB1 of 1.71 (that is, 2.2 or less). ).
  • each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13e of the first comparative example has a refractive index of 1.81 with respect to the recording / reproducing laser beam LB2. That is, each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13e of the first comparative example does not have a characteristic that the refractive index with respect to the recording / reproducing laser beam LB2 is 1.85 or more.
  • each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13e of the first comparative example has an extinction coefficient of 0 (that is, 0.05 or less) with respect to the guide laser beam LB1, and recording / reproduction.
  • the extinction coefficient with respect to the laser beam LB2 is 0 (that is, 0.05 or less).
  • the reflectance, transmittance, and degree of modulation when the recording operation was performed on the recording layer 13e of the first comparative example were measured.
  • the recording operation was performed under the same conditions as in the first specific example.
  • the recording layer 13e of the first comparative example has (i-1) the reflectance of the guide laser beam LB1 is 3.9% (that is, 10% or less) and (i-2) the recording / reproducing laser. While the reflectance of the light LB2 is 1% (that is, 3% or less), (ii-1) the transmittance of the guide laser beam LB1 is 95.6% (that is, 85% or more). In addition, (ii-2) the condition that the transmittance of the recording / reproducing laser beam LB2 is 87.8% (that is, 80% or more) is satisfied. However, the modulation degree of the recording layer 13e of the first comparative example is 36.6%.
  • the condition that the modulation degree of the recording layer 13e of the first comparative example is 40% or more is not satisfied. Therefore, for the recording layer 13e of the first comparative example, at least one of the recording operation and the reproducing operation using the recording / reproducing laser beam LB2 is preferably performed while performing the tracking control using the return light of the guide laser beam LB1. (In other words, high quality) is not always possible.
  • the recording layer 13f of the second comparative example is composed of a dielectric film 131 made of TiO 2 and a film thickness of 41 nm, and a film made of BiGeO.
  • the recording layer 13f of the second comparative example was formed on the substrate 17 having a track pitch of 0.64 ⁇ m under the following conditions.
  • Each of the dielectric films 131 and 134 uses a mixed gas having a gas pressure of 0.63 Pa composed of argon gas supplied at 90 sccm and oxygen gas supplied at 1 sccm as a sputtering gas, and a high frequency input power of 500 W. It was formed by the RF sputtering method set to.
  • the recording film 132 and the light absorption film 133 were formed in the same manner as in the first specific example.
  • each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13f of the second comparative example has a refractive index of 2.52 with respect to the recording / reproducing laser beam LB2 (that is, 1.85). It has the characteristics of However, each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13f of the second comparative example has a refractive index of 2.35 with respect to the guide laser beam LB1. That is, each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13f of the second comparative example does not have a characteristic that the refractive index with respect to the guide laser beam LB1 is 2.2 or less.
  • each of the dielectric film 131 and the dielectric film 134 included in the recording layer 13f of the second comparative example has an extinction coefficient of 0 (that is, 0.05 or less) with respect to the guide laser beam LB1, and recording / reproduction.
  • the extinction coefficient with respect to the laser beam LB2 is 0 (that is, 0.05 or less).
  • the reflectance, transmittance, and degree of modulation were measured when the recording operation was performed on the recording layer 13f of the second comparative example.
  • the recording operation was performed under the same conditions as in the first specific example except that the linear velocity was 3.84 m / s.
  • the recording layer 13f of the second comparative example has (i-2) the reflectance of the recording / reproducing laser beam LB2 is 1.2% (that is, 3% or less), while (ii-2) The condition that the transmittance of the recording / reproducing laser beam LB2 is 89.1% (that is, 80% or more) is satisfied.
  • the modulation degree of the recording layer 13e of the second comparative example satisfies the condition of 72.9% (that is, 40% or more).
  • (i-1) the reflectance of the guide laser beam LB1 is 15.1%
  • (ii-1) the transmittance of the guide laser beam LB1 is 84.1. %become.
  • the reflectance of the guide laser beam LB1 is 10% or less, while (ii-1) the transmittance of the guide laser beam LB1 is 85% or more. Does not satisfy the condition of becoming. Accordingly, for the recording layer 13f of the second comparative example, at least one of the recording operation and the reproducing operation using the recording / reproducing laser beam LB2 is preferably performed while performing the tracking control using the return light of the guide laser beam LB1. (In other words, high quality) is not always possible.
  • FIG. 13 is a block diagram showing a basic configuration of the recording / reproducing apparatus 101.
  • the recording / reproducing apparatus 101 is configured as a disk drive.
  • the recording / reproducing apparatus 101 is connected to the host computer 201.
  • the recording / reproducing apparatus 101 includes an optical pickup (PU: Pick Up) 102, a signal recording / reproducing unit 103, a spindle motor 104, a bus 106, a CPU (drive control unit) 111, a memory 112, and a data input / output unit 113.
  • FIG. 14 is a block diagram showing a configuration of the optical pickup 102.
  • the optical pickup 102 includes a light source LD1 that is a red laser diode and a light source LD2 that is a blue laser diode.
  • a guide laser beam LB1 is emitted from the light source LD1, and a recording / reproducing laser beam LB2 is emitted from the light source LD2.
  • the guide laser beam LB1 emitted from the light source LD1 is condensed on the guide layer 12 of the optical disc 11 through a deflection beam splitter (PBS), a quarter-wave plate (1/4 WP), an objective lens 102L, and the like.
  • PBS deflection beam splitter
  • the return light from the guide layer 12 of the guide laser beam LB1 is incident on the light receiving element PD1 through the objective lens 102L, the quarter-wave plate, the deflecting beam splitter, and the like.
  • the recording / reproducing laser beam LB2 emitted from the light source LD2 is recorded or reproduced from a plurality of recording layers 13 of the optical disc 11 through a deflection beam splitter (PBS), a quarter-wave plate, an objective lens 102L, and the like.
  • the light is focused on a desired recording layer 13 as a target.
  • the return light of the recording / reproducing laser beam LB2 is incident on the light receiving element PD2 via the objective lens 102L, a quarter-wave plate, a deflection beam splitter, and the like.
  • the light receiving elements PD1 and PD2 are typically light receiving elements such as a two-part or four-part CCD.
  • the host computer 201 includes an operation / display control unit 202, an operation button 203, a display panel 204, a bus 206, a CPU 211, a memory 212, and a data input / output control unit 213.
  • recording data to be recorded is input from the data input / output control unit 213 to the recording / reproducing apparatus 101.
  • the recording data reproduced from the recording / reproducing apparatus 101 is output via the data input / output control unit 213.
  • the memory 112 and the memory 212 are (i) a computer program for controlling each element such as the CPU 111 in the recording / reproducing apparatus 101 and each element such as the CPU 211 in the host computer 201 so that a recording / reproducing operation described later is performed, And (ii) various data such as control data, in-process data, and processed data necessary for the recording / reproducing operation are appropriately used for temporarily or permanently storing the data via the bus 106, the bus 206, and the like.
  • the present invention can be appropriately changed without departing from the gist or the idea of the invention that can be read from the claims and the entire specification, and a recording medium and a recording / reproducing apparatus accompanying such a change are also included in the present invention. Included in technical thought.

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  • Optical Record Carriers And Manufacture Thereof (AREA)

Abstract

La présente invention porte sur un support d'enregistrement (11) qui a stratifiées dans celui-ci une couche de guidage (12) à irradier avec un faisceau laser de guidage (LB1) ayant une longueur d'onde dans une plage de 630-680 nm, et une couche d'enregistrement (13) à irradier avec un faisceau laser d'enregistrement/reproduction (LB2) ayant une longueur d'onde dans une plage de 400-410 nm. La couche d'enregistrement a une structure stratifiée ayant un film d'enregistrement (132) et des films de matière diélectrique (131, 134) stratifiés dans celle-ci, l'indice de réfraction du film de matière diélectrique par rapport au faisceau laser de guidage est de 2,2 au maximum, et l'indice de réfraction du film de matière diélectrique par rapport au faisceau laser d'enregistrement/reproduction est d'au moins 1,85.
PCT/JP2012/065543 2012-06-18 2012-06-18 Support d'enregistrement et appareil d'enregistrement/reproduction WO2013190626A1 (fr)

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PCT/JP2012/065543 WO2013190626A1 (fr) 2012-06-18 2012-06-18 Support d'enregistrement et appareil d'enregistrement/reproduction
PCT/JP2013/064391 WO2013190949A1 (fr) 2012-06-18 2013-05-23 Support d'enregistrement et dispositif d'enregistrement/lecture

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016129237A1 (fr) * 2015-02-10 2016-08-18 パナソニックＩｐマネジメント株式会社 Support d'enregistrement d'informations et procédé de fabrication associé

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002260276A (ja) * 2000-08-01 2002-09-13 Tdk Corp 光情報媒体
JP2004241103A (ja) * 2002-10-22 2004-08-26 Tdk Corp 光記録媒体およびその製造方法
JP2004355743A (ja) * 2003-05-30 2004-12-16 Tdk Corp 光情報記録媒体
JP2011034611A (ja) * 2009-07-30 2011-02-17 Tdk Corp 光記録媒体
JP2011170936A (ja) * 2010-02-22 2011-09-01 Tdk Corp 光記録媒体、光記録再生方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002260276A (ja) * 2000-08-01 2002-09-13 Tdk Corp 光情報媒体
JP2004241103A (ja) * 2002-10-22 2004-08-26 Tdk Corp 光記録媒体およびその製造方法
JP2004355743A (ja) * 2003-05-30 2004-12-16 Tdk Corp 光情報記録媒体
JP2011034611A (ja) * 2009-07-30 2011-02-17 Tdk Corp 光記録媒体
JP2011170936A (ja) * 2010-02-22 2011-09-01 Tdk Corp 光記録媒体、光記録再生方法

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016129237A1 (fr) * 2015-02-10 2016-08-18 パナソニックＩｐマネジメント株式会社 Support d'enregistrement d'informations et procédé de fabrication associé
JPWO2016129237A1 (ja) * 2015-02-10 2017-11-24 パナソニックＩｐマネジメント株式会社 情報記録媒体、並びに情報記録媒体の製造方法
US10438627B2 (en) 2015-02-10 2019-10-08 Panasonic Intellectual Property Management Co., Ltd. Information recording medium and method for manufacturing information recording medium

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