Classifications

• • 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
  • G11B7/2407—Tracks or pits; Shape, structure or physical properties thereof
  • G11B7/24073—Tracks
• • 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
• • 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
  • G11B7/24035—Recording layers
  • G11B7/24038—Multiple laminated 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
  • G11B7/24—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
  • G11B7/258—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 reflective 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
  • G11B7/26—Apparatus or processes specially adapted for the manufacture of record carriers
• • 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
  • G11B7/253—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 substrates
  • G11B7/2533—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 substrates comprising resins
  • G11B7/2534—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 substrates comprising resins polycarbonates [PC]

Definitions

• Multilayer optical recording medium and method of manufacturing the same
• the present invention relates to a multilayer optical recording medium having a plurality of information recording layers and a method of manufacturing the same, and more particularly to a multilayer optical recording medium as a single recording medium by superposing two information recording layers. .
• a pit pattern consisting of minute unevenness corresponding to an information signal to be recorded is formed on one surface of a transparent substrate having light transmittance, and the light substrate is irradiated with a light beam by transmitting through the transparent substrate.
• the compact disc (CD: Compact Disc) is widely used as an optical recording medium that enables the reproduction of the recorded information signal by detecting the reflected light beam reflected by the pit pattern force with a light detector. It! /.
• CDs digital data such as music and video are formed by forming pit rows with a shortest pit length of 0.9 ⁇ m at a track pitch of 1.6 m on a transparent substrate with a thickness of 1.2 mm. It is recorded.
• the recording capacity of this CD is about 650 Mbytes.
• As a format conforming to this CD standard there are CD-ROM, Video-CD and the like.
• DVDs digital versatile discs
• the size of pits for recording information to improve the recording density over conventionally used optical disks such as CDs is half or less in the radial direction and the circumferential direction as compared with CDs.
• the thickness of the substrate is set to 0.6 mm to reduce the influence of the degradation of the reproduction signal quality due to the warpage and the stagnation of the disc, and on the other hand, the two substrates are bonded to improve the mechanical strength.
• Adopt a configuration. This DVD has a track pitch of 0., and a pit row with a shortest pit length of 0.4 m to form digital data such as music and video. Is recorded.
• the recording capacity of this DVD is about 5 Gbytes.
• DVDs can record information on one or both of the substrates being bonded together.
• a plurality of information recording layers can be provided on one or both of the substrates to be bonded. That is, there are various types of optical disc structures, such as single-layer single-sided reproduction optical discs, single-layer double-sided reproduction optical discs, multilayer single-sided reproduction optical discs and multilayer double-sided reproduction optical discs.
• this SACD there is a single layer disc composed of only a single HD (High Definition) layer provided with a high-density information area compatible with SACD.
• the information recorded in the HD layer is not limited to music information, and may be digital data such as video based on the above-mentioned DVD standard, for example!
• a dual layer disc in which an HD layer is laminated over two layers, and a hybrid disc in which an HD layer and a CD layer conforming to the above-described CD standard are laminated one by one. is there.
• the CD layer is set to a normal numerical aperture (NA) of 0.45, and reproduction is performed using a laser beam with a wavelength of 780 nm by a pickup for CD.
• NA numerical aperture
• the HD pickup is used to reproduce using a laser beam with a wavelength of 650 nm.
• the hybrid disc of SACD described above is configured by sequentially laminating a first transparent substrate, an HD layer, a second transparent substrate, and a CD layer, and the HD layer is covered with a semitransparent film of high refractive index and It is common to However, for semitransparent films that are actually used, they are required when recording or reproducing digital data based on the DVD standard. There were many cases where it was difficult to meet the standard of reflectance and it was difficult to perform stable recording and reproduction of DVD data.
• the present invention has been proposed in view of the above-mentioned problems, and the object of the present invention is to provide a reflection disk required for recording and reproducing digital data based on the standards of CD and DVD in a hybrid disc in SACD. It is an object of the present invention to provide a multilayer optical recording medium satisfying the specification of the rate and a method of manufacturing the same.
• the multilayer optical recording medium to which the present invention is applied is a multilayer optical recording medium in which at least a first transparent substrate, a first information recording layer, a second transparent substrate, and a second information recording layer are sequentially laminated.
• the first information recording layer has a reflection characteristic to the wavelength of the first reproduction signal, and has a transmission characteristic to the wavelength of the second reproduction signal, and the first transparent substrate
• a semitransparent film having a higher refractive index is formed over one or more layers, and in the second information recording layer, a reflective film having a reflection characteristic with respect to the wavelength of the second reproduction signal is formed.
• the total thickness of the transparent film is represented by ⁇ X m X ⁇ ⁇ ⁇ where n is the wavelength of the second reproduction signal and n is the refractive index of the first transparent substrate. However, 1. 0 ⁇ ⁇ 3 1. 3, and m is an integer of 1 or more.
• Another multilayer optical recording medium to which the present invention is applied is a multilayer optical recording medium in which at least a first transparent substrate, a first information recording layer, a second transparent substrate, and a second information recording layer are sequentially laminated.
• the first information recording layer has a reflection characteristic with respect to the wavelength of the first reproduction signal, and a transmission characteristic with respect to the wavelength of the second reproduction signal, and the first transparent substrate
• a semitransparent film having a higher refractive index is formed over one or more layers, and in the second information recording layer, a reflective film having a reflection characteristic to the wavelength of the second reproduction signal is formed, and the semitransparent film is formed.
• the film is formed by sequentially laminating a Si-H compound layer, an SiO layer, and an Si-H compound layer, and the SiO layer has a thickness of 5 nm.
• It is comprised by film thickness of -20 nm.
• the present invention is a method of manufacturing a multilayer optical recording medium, in which at least a first transparent substrate, a first information recording layer, a second transparent substrate, and a second information recording layer are sequentially laminated.
• a first transparent substrate provided with the second information recording layer and a second transparent substrate provided with the second information A transparent substrate is formed, and then, on the first information recording layer provided on the first transparent substrate, the first reproduction signal has a reflection characteristic with respect to the wavelength of the first reproduction signal, and the second reproduction signal has a wavelength
• the film thickness of the second transparent signal having transmission characteristics and a refractive index higher than that of the first transparent substrate indicates the wavelength of the second reproduction signal, and the refractive index of the first transparent substrate indicates n, a X m X ⁇ ⁇ ⁇ ⁇ (where 1.
• a second semitransparent film is formed and provided on a second transparent substrate
• a reflective film having a reflective characteristic with respect to the wavelength of the second reproduction signal is formed on the information recording layer, and the surface on which the semitransparent film is formed of the first transparent substrate is used as a superimposed surface.
• the transparent substrate on the side opposite to the side on which the second information recording layer is formed, and the overlapping surfaces of the first and second transparent
• the thickness of the semitransparent film is reduced to Xm X ⁇ ⁇ ⁇ (However, 1. 0 ⁇ ⁇ ⁇ 1. 3, m is an integer of 1 or more.)
• FIG. 1 is an exploded perspective view showing a multilayer optical recording medium to which the present invention is applied.
• FIG. 2 is a cross-sectional view of a multilayer optical recording medium to which the present invention is applied.
• Figure 3 shows the reflectance R of the HD layer with respect to the thickness Th of the semitransparent film of the multilayer optical recording medium
• FIG. 4 is a cross-sectional view showing another configuration of a multilayer optical recording medium to which the present invention is applied.
• FIG. 5 shows the HD layer relative to the thickness Th of the semitransparent film of the multilayer optical recording medium provided with the SiO layer.
• FIG. 6 is a characteristic diagram showing the relationship between the reflectance R of and the reflectance R of the CD layer.
• FIG. 6 shows the HD layer relative to the thickness Th of the semitransparent film of the multilayer optical recording medium provided with the SiO layer.
• FIG. 6 is a characteristic diagram showing the relationship between the reflectance R of and the reflectance R of the CD layer.
• FIG. 7 shows the HD layer relative to the thickness Th of the semitransparent film of the multilayer optical recording medium provided with the SiO layer.
• FIG. 6 is a characteristic diagram showing the relationship between the reflectance R of and the reflectance R of the CD layer.
• FIG. 8 is a perspective view showing the first and Z or second transparent substrates coated with UV curable resin.
• FIG. 9 is a side view showing a process of bonding the first and second transparent substrates.
• this multilayer optical recording medium 1 has an HD (High Definition) layer 11 provided with a high-density information area compatible with SACD, and a CD layer 21 conforming to the CD (Compact Disc) standard. It is a so-called hybrid disc, which is configured as a single disc by superimposing both layers one by one.
• HD High Definition
• CD Compact Disc
• the HD layer 11 is configured to be able to be reproduced by a DSD (Direct Stream Digital) signal.
• This DSD signal has a high sampling frequency such as 64 times the sampling frequency (44.1 kHz) of the digital audio signal of the PCM signal system applied to the CD layer 21 and is a signal exceeding the audio frequency. Reproduction can be realized.
• the information recorded in the HD layer 11 is not limited to music information, but may be digital data such as video according to the above-mentioned DVD standard.
• information is recorded as a pit string in a recording format conforming to the CD standard.
• a reproduction signal for reproducing information recorded in the HD layer 11 is referred to as a first reproduction signal
• a reproduction signal for reproducing information recorded in the CD layer 21 is referred to as a second reproduction signal. It is said.
• FIG. 2 shows a cross section of the multilayer optical recording medium 1 shown in FIG.
• the multilayer optical recording medium 1 is configured by sequentially laminating an HD layer 11, a semitransparent film 31, a second transparent substrate 22, a CD layer 21, and a metal film 23 in order from the first transparent substrate 12. It is done.
• the first transparent substrate 12 and the second transparent substrate 22 are made of, for example, a polycarbonate resin. It is a transparent disk-shaped substrate made of fat, acrylic resin, and glass resin.
• the metal film 23 is a metallic thin film exhibiting reflection characteristics with respect to the wavelength of the second reproduction signal.
• the semitransparent film 31 is formed on the surface of the HD layer 11 and has reflection characteristics for the wavelength of the first reproduction signal and has transmission characteristics for the wavelength of the second reproduction signal.
• the refractive index of the translucent film 31 is set higher than the refractive index of the first transparent substrate 12. This refractive index is preferably composed of a refractive index of 3.0 or more, and the absorption coefficient is preferably composed of not more than 0.55.
• the semitransparent film 31 may be made of, for example, a Si-H compound. This Si-H compound can be generated by mixing hydrogen gas into Si during film formation.
• the semitransparent film 31 is generally formed to have a film thickness of 20 nm or less.
• the CD reflectance standard ⁇ 70%: hereinafter referred to as the CD reflectance standard
• digital data based on the DVD standard By satisfying the reflectance standard (18 to 30%: hereinafter referred to as the DVD reflectance standard) required for playback, a stable playback operation is realized.
• the periodicity of the film thickness simultaneously satisfying both the CD reflectance standard and the DVD reflectance standard can be defined as follows.
• the total W of the film thickness of the semitransparent film 31 is represented by a x m x ⁇ ⁇ ⁇ , where n is the wavelength of the second reproduction signal and n is the refractive index of the transparent substrate 12. However, 1. 0 ⁇ 1.3, and m is an integer of 1 or more.
• the multilayer optical recording medium 1 to which the present invention is applied is based on the standards of both the CD and the DVD by setting the film thickness W of the semitransparent film 31 to be ⁇ X m X ⁇ ⁇ ⁇ .
• the specification of reflectance when playing back data will be satisfied, and stable playback operation will be realized for both CD and DVD.
• the tolerance of the film thickness Th simultaneously satisfying both the CD reflectance standard and the DVD reflectance standard becomes larger. Larger effects can be expected.
• the multi-layered optical recording medium 1 to which the present invention is applied may be applied to the multi-layered optical recording medium 2 in which the semitransparent film 41 which is not limited to the embodiment described above is formed of a plurality of layers.
• An example of this multilayer optical recording medium 2 is shown in FIG. In FIG. 4, the same components and members as those of the multilayer optical recording medium 1 described above are indicated by the same reference numerals and detailed description will be omitted.
• the multilayer optical recording medium 2 shown in FIG. 4 includes, in order from the first transparent substrate 12, an HD layer 11, a semitransparent film 41, an SiO layer 52, a semitransparent film 41, a second transparent substrate 22, a CD layer 21, a metal film.
• Stack 23
• the semitransparent film 41 is made of a Si—H compound, and the SiO layer 52 is sandwiched between
• the film thickness Th of the semitransparent film 41 can be obtained by adding the thickness of the film composed of the two-layered Si—H compound.
• the film thickness Th of the semitransparent film 41 is divided into two equal parts and divided into two layers will be described as an example, it is not limited to such a case. Two layers may be formed at any film thickness ratio.
• the SiO layer 52 has a thickness of about 5 nm to 20 nm between the semitransparent films 41 composed of these two layers. Composed of film thickness.
• the film thickness of the SiO layer 52 is set to 5 nm, as shown in FIG.
• the tolerance range becomes relatively wide when the film thickness Th is in the range of 120 to 130 nm. . That is, when the film thickness of the Si02 layer 52 is 10 nm, the tolerance range of the film thickness Th satisfying both the CD reflectance standard and the DVD reflectance standard simultaneously becomes larger, and the film thickness of the SiO layer 52 When the thickness is increased beyond 10 nm, the tolerance of the critical thickness Th decreases.
• this SiO layer 52 is approximately in the range of about 5 nm to 20 nm.
• the film thickness Th satisfying both the CD reflectance standard and the DVD reflectance standard simultaneously appears with a period of approximately m ⁇ n ⁇ x.
• the CD reflectance standard and the DVD can be obtained by configuring the film thickness of the S iO layer 52 laminated between the semitransparent films 41 to about 5 nm to 20 nm.
• the first transparent substrate 12 and the second transparent substrate can be produced by injection molding a transparent polycarbonate resin having light transmittance using, for example, a molding apparatus for molding. Form 22 respectively.
• one of the first transparent substrates 12 is The surface is provided with an HD layer 11 in which a pit pattern corresponding to digital data such as video is formed in compliance with the DVD standard.
• the pit pattern constituting the HD layer 11 is formed by transferring the pit pattern formed on a stamper disposed in a molding die.
• a semitransparent film 31 made of, for example, a Si—H compound is formed on the HD layer 11.
• a CD layer 21 is provided on which a pit pattern corresponding to digital data such as music information is formed in compliance with the standard of the CD.
• the pit pattern constituting the CD layer 21 is formed by transferring the pit pattern formed on the stamper disposed in the molding die. Then, on the CD layer 21, a metal film 23 made of aluminum is formed.
• UV light ultraviolet light
• the multilayer optical recording medium 1 by laminating the first and second transparent substrates 12 and 22 will be described.
• the semitransparent film 31 of the first transparent substrate 12 and A photocurable resin 35 is applied to at least one of the surfaces of the second transparent substrate 22 on which the metal film 23 is formed.
• the photocurable resin 35 is applied using an appropriate application method such as spin coating.
• the first transparent substrate 12 and the second transparent substrate 22 are superimposed. At this time, the first and second transparent substrates 12 and 22 are overlapped with the semitransparent film 31 positioned on the surface of the second transparent substrate 12 or 22 opposite to the surface on which the metal film 23 is formed. It is adjusted.
• the first and second transparent substrates 12 and 22 superimposed on each other are integrated by irradiating the ultraviolet light from the ultraviolet light source 38 while being crimped by the pressure roller 36 and curing the photocurable resin 35.
• the first and second transparent substrates 12 and 22 integrated through the photocurable resin 35 form a multilayer optical recording medium 1 provided with multilayer information recording layers.
• the bonding of the first and second transparent substrates 12 and 22 is not limited to the above example. Various methods used when manufacturing a multilayer optical recording medium formed by bonding a plurality of substrates can be appropriately adopted.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Optical Record Carriers And Manufacture Thereof (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=35785126

Family Applications (1)

Country Status (8)

Families Citing this family (1)

Citations (4)

Family Cites Families (2)

• 2004
  • 2004-07-16 JP JP2004210346A patent/JP2006031841A/ja active Pending
• 2005
  • 2005-07-12 MX MXPA06014364A patent/MXPA06014364A/es not_active Application Discontinuation
  • 2005-07-12 WO PCT/JP2005/012841 patent/WO2006009010A1/ja not_active Ceased
  • 2005-07-12 CN CNA200580021859XA patent/CN1977326A/zh active Pending
  • 2005-07-12 EP EP05765676A patent/EP1770695A4/en not_active Withdrawn
  • 2005-07-12 KR KR1020077000475A patent/KR20070034050A/ko not_active Withdrawn
  • 2005-07-12 US US11/596,354 patent/US20080259760A1/en not_active Abandoned
  • 2005-07-15 TW TW094124190A patent/TW200615940A/zh not_active IP Right Cessation

Patent Citations (4)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events