JP2008310956A - Recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording medium wherein it can be detected whether data are rewritten. <P>SOLUTION: In a magnetic tape 10C (a recording medium) provided with a supporting body 14A, a rewritable magnetic layer 11A and a write-once type back coat layer 15B (an optical recording layer) with a dyestuff both of which are formed on the supporting body 14A, the magnetic layer 11A, the supporting body 14A and the back coat layer 15B are layered in this order. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a recording medium having a rewritable magnetic layer (first recording layer) and a non-rewritable write-once type optical recording layer (second recording layer).

One type of high-speed, large-capacity storage medium is magnetic tape. In recent years, proposals for WORM (Write Only read many) have been made on this magnetic tape because of the importance of security. For example, information indicating whether or not the WORM is recorded in a cartridge memory mounted on a magnetic tape cartridge (see Patent Document 1, Patent Document 2, and Patent Document 3), a write once area, and a write many area are stored in the cartridge memory. It is to be recorded (see Patent Document 4).
JP 2000-268443 A (paragraph numbers 0013 to 0128, FIG. 1) Japanese Patent Laid-Open No. 2002-150741 (paragraph numbers 0028 to 0094, FIG. 3) JP2003-123342A (paragraph numbers 0010 to 0018, FIG. 1) JP 2004-86971 A (paragraph numbers 0012 to 0028, FIG. 4)

  However, the conventional magnetic tape ignores the information on whether or not the WORM is recorded in the cartridge memory, and records “following data” including erasure in the magnetic layer in which “previous data” is recorded. It was physically possible to do. That is, for example, when the information about the WORM is ignored and the “previous data” is recorded after all the “previous data” is erased, it is not possible to detect whether the data has been rewritten.

  Therefore, an object of the present invention is to provide a recording medium that can detect whether or not data has been rewritten.

  As means for solving the above problems, the present invention comprises a support, a rewritable magnetic layer and a write-once optical recording layer provided on the support, the magnetic layer, A recording medium comprising a support and an optical recording layer laminated in this order.

  According to such a recording medium, as will be described later in the embodiment, for example, (1) all data is recorded on the magnetic layer (first recording layer), and part of the data is recorded on the optical recording layer ( Data recorded on the magnetic layer after recording was rewritten by adopting a method of recording redundantly on the second recording layer and (2) a method of dividing the data and recording on the magnetic layer and the optical recording layer In the case of data reproduction, the data read from the magnetic layer and the data read from the optical recording layer are collated or combined according to the recording method to detect whether the data in the magnetic layer has been rewritten. can do.

  Further, since the magnetic layer, the support, and the optical recording layer are laminated in this order, and the optical recording layer is disposed (positioned) on the outside, for example, noise during recording and reproduction can be reduced. it can.

  According to the present invention, it is possible to provide a recording medium that can detect whether or not data has been rewritten.

  Hereinafter, each embodiment of the present invention will be described with reference to the accompanying drawings. In the description of each embodiment, the same constituent elements are denoted by the same reference numerals, and redundant descriptions are omitted.

≪First Reference Example≫
First, a magnetic tape (recording medium) and a recording / reproducing system (recording system and reproducing system) according to a first reference example will be described with reference to FIGS.
In the drawings to be referred to, FIG. 1 is a cross-sectional view schematically showing a configuration of a magnetic tape and a recording / reproducing system according to a first reference example. FIG. 2 is a block diagram schematically showing the configuration of the control device shown in FIG. FIG. 3 is a conceptual diagram of a data recording method in the first reference example.

<Configuration of magnetic tape>
First, the configuration of the magnetic tape according to the first reference example will be described. As shown in FIG. 1, the magnetic tape 10A has a five-layer structure, and guides from the head side in sliding contact with the recording head 21 and the reproducing head 23. The magnetic layer 11A (first recording layer), the reflective layer 12A, the optical recording layer 13A (second recording layer), the support 14A, and the backcoat layer 15A are laminated in this order toward the back side in sliding contact with a roller or the like. Has been. That is, in the magnetic tape 10A, the optical recording layer 13A, the reflective layer 12A, and the magnetic layer 11A are laminated in this order on one surface side (head side) of the support 14A, and the other surface side (back) of the support 14A. The back coat layer 15A is laminated on the side).

[Magnetic layer]
The magnetic layer 11A has a thickness of 10 to 300 nm (preferably 10 to 300 nm, more preferably 10 to 200 nm, most preferably 10 to 100 nm), and data can be magnetically written and rewritten. Is a layer.
Such a magnetic layer 11A is formed of a ferromagnetic powder and a binder. Further, the magnetic layer 11A usually contains conductive powder (eg, carbon black), an abrasive, and a lubricant.

(Ferromagnetic powder)
Examples of the ferromagnetic powder include magnetic iron oxide FeO _x (x = 1.33 to 1.5), Co-modified FeO _x (x = 1.33 to 1.5), Fe, Ni, or Co as a main component ( Known ferromagnetic powders such as ferromagnetic alloy powders (ferromagnetic metal powders) and plate-shaped hexagonal ferrite powders can be used. In particular, it is preferable to use a ferromagnetic alloy powder. In addition to predetermined atoms, the ferromagnetic powder includes Al, Si, S, Sc, Ti, V, Cr, Cu, Y, Mo, Rh, Pd, Ag, Sn, Sb, Te, Ba, Ta, W, It may contain at least one atom of Re, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, P, Co, Mn, Zn, Ni, Sr and B.

  The ferromagnetic powder may be treated in advance with a dispersant, lubricant, surfactant, antistatic agent or the like before dispersion. Specifically, Japanese Patent Publication No. 44-14090, Japanese Patent Publication No. 45-18372, Japanese Patent Publication No. 47-22062, Japanese Patent Publication No. 47-22513, Japanese Patent Publication No. Sho 46-28466, Japanese Patent Publication No. Sho 46-38755, Japanese Patent Publication No. 47 No. 4286, JP-B 47-12422, JP-B 47-17284, JP-B 47-18509, JP-B 47-18573, JP-B 39-10307, and JP-B 48-39639, Processing methods described in the specifications of U.S. Pat. Nos. 3,026,215, 3,031,341, 3,100,194, 3,342,005, and 3,389,014 can be used. The ferromagnetic alloy powder may contain a small amount of hydroxide or oxide.

(Ferromagnetic powder-ferromagnetic alloy powder)
The specific surface area of the ferromagnetic alloy powder is preferably 30 to 70 m ² / g, and the crystallite size obtained from the X-ray diffraction method is 5 to 30 nm. If the specific surface area is too small, it will not be sufficient for high-density recording, and if it is too large, it will not be possible to disperse sufficiently, so that it will not be possible to form a magnetic layer 11A with a smooth surface, so that it will be compatible with high-density recording as well. Disappear.

The ferromagnetic alloy powder contains, for example, Fe. Specifically, it is a metal alloy mainly composed of Fe—Co, Fe—Ni, Fe—Zn—Ni, or Fe—Ni—Co. Fe alone may be used. These ferromagnetic alloy powders preferably have a saturation magnetization (saturated magnetic flux density) (σs) of 110 A · m ² / kg or more, more preferably 120 A · m ² / kg, in order to achieve a high recording density. kg or more and 170 A · m ² / kg or less. The coercive force (Hc) is 1500 to 2500 oersted (Oe) (119 to 199 kA / m) (preferably 1700 to 2200 oersted (135 to 175 kA / m), particularly preferably 1800 to 2100 oersted (143 to 167 kA / m). )).
The average major axis length of the ferromagnetic alloy powder obtained by a transmission electron microscope is 0.15 μm or less, preferably 0.01 to 0.12 μm, and the acicular ratio (the arithmetic average value of the major axis length / minor axis length). ) Is 3-12, preferably 4-10. In order to further improve the characteristics, non-metals such as B, C, Al, Si and P, or salts and oxides thereof may be added during the composition. Usually, an oxide layer is formed on the particle surface of the ferromagnetic alloy powder in order to be chemically stabilized.

(Ferromagnetic powder-plate hexagonal ferrite powder)
Plate-shaped hexagonal ferrite powder is a ferromagnetic material having a flat plate shape and an easy axis of magnetization in a direction perpendicular to the flat plate surface. Specific examples of the plate-shaped hexagonal ferrite powder include barium ferrite (magnet brambite type and magnetobranbite type partially containing spinel phase) and strontium ferrite (magnet brambitite type and partly containing spinel phase) Magnetobranbitite type), lead ferrite, calcium ferrite, and cobalt-substituted products thereof. Of these, cobalt substitutes of barium ferrite and cobalt substitutes of strontium ferrite are particularly preferable. The plate-shaped hexagonal ferrite powder used in the present invention includes Co—Ti, Co—Ti—Zr, Co—Ti—Zn, Ni—Ti—Zn, or Ir— as necessary to control the coercive force. What added elements, such as Zn, can be used.

In the plate-like hexagonal ferrite powder, the plate diameter means the plate width of hexagonal plate-like particles and can be measured with an electron microscope. The plate-shaped hexagonal ferrite powder used in the present invention preferably has a particle size (average plate diameter) in the range of 0.001 to 0.05 μm, and a plate-like ratio (arithmetic average value of plate diameter / plate thickness). It is preferable that it exists in the range of 2-10, and it is preferable that the specific surface area exists in the range of 20-80 m < ² > / g. The plate-shaped hexagonal ferrite powder is difficult to record at high density if the particle size is too large or too small for the same reason as the ferromagnetic metal powder. These plate-shaped hexagonal ferrite powders have a saturation magnetization (σs) of at least 50 A · m ² / kg or more (more preferably 53 A · m ² / kg or more) in order to achieve a high recording density. Is preferred. The coercive force (Hc) is 1500 to 2500 oersted (Oe) (119 to 199 kA / m) (preferably 1700 to 2200 oersted (135 to 175 kA / m), particularly preferably 1800 to 2100 oersted (143 to 167 kA / m). m)).

(Water content of ferromagnetic powder)
The moisture content of the ferromagnetic powder is preferably 0.01 to 2% by weight. Further, it is preferable to optimize the moisture content depending on the kind of the binder (resin). The pH of the ferromagnetic powder is preferably optimized depending on the combination with the binder used, and the pH is usually in the range of 4 to 12, preferably in the range of 5 to 10. The ferromagnetic powder is preferably coated with at least a part of its surface with Al, Si, P, Y, or an oxide thereof as required. The amount used in the surface treatment is usually 0.1 to 10% by weight with respect to the ferromagnetic powder. Since the ferromagnetic powder coated in this manner can suppress the adsorption of a lubricant such as fatty acid to 100 mg / m ² or less, the desired effect can be achieved even if the amount of lubricant added to the magnetic layer 11A is reduced. it can. The ferromagnetic powder may contain soluble inorganic ions such as Na, Ca, Fe, Ni, and Sr, but the content is preferably as small as possible. Usually, if it is 5000 ppm or less, it does not affect the characteristics. The ferromagnetic powder and the manufacturing method thereof are described in, for example, Japanese Patent Application Laid-Open No. 7-22224.

(Conductive powder-carbon black)
The carbon black of the magnetic layer 11A reduces the surface electrical resistance (RS) of the magnetic layer 11A, reduces the dynamic friction coefficient (μK value), improves running durability, and ensures the smooth surface properties of the magnetic layer 11A. It is added for various purposes. The carbon black preferably has an average particle size in the range of 5 to 350 nm (more preferably 10 to 300 nm). The specific surface area is preferably 5 to 500 m ² / g (more preferably 50 to 300 m ² / g). The DBP oil absorption is preferably in the range of 10 to 1000 ml / 100 g (more preferably 50 to 300 ml / 100 g). The pH is preferably 2 to 10, the water content is 0.1 to 10%, and the tap density is preferably 0.1 to 1 g / ml.

  Carbon black obtained by various manufacturing methods can be used. Examples of carbon black that can be used include furnace black, thermal black, acetylene black, channel black and lamp black. Specific examples of carbon black products include BLACKPEARLS 2000, 1300, 1000, 900, 800, 700, VULCAN XC-72 (above, manufactured by Cabot Corporation), # 35, # 50, # 55, # 60 and # 80 (above, manufactured by Asahi Carbon Co., Ltd.), # 3950B, # 3750B, # 3250B, # 2400B, # 2300B, # 1000, # 900, # 40, # 30, and # 10B (above, Mitsubishi Chemical) Manufactured by Co., Ltd.), CONDUCTEX SC, RAVEN, 150, 50, 40, 15 (above, Columbia Carbon Co., Ltd.), Ketjen Black EC, Ketjen Black ECDJ-500 and Ketjen Black ECDJ-600 (above, Lion Azo Co., Ltd.). The normal addition amount of carbon black is in the range of 0.1 to 30 parts by mass (preferably 0.2 to 15 parts by mass) with respect to 100 parts by mass of the ferromagnetic powder.

(Abrasive)
Examples of the abrasive for the magnetic layer 11A include fused alumina, α-alumina, silicon carbide, chromium oxide (Cr ₂ O ₃ ), corundum, artificial corundum, diamond, artificial diamond, garnet, emery (main component: corundum and Magnetite). These abrasives have a Mohs hardness of 5 or more (preferably 6 or more, particularly preferably 8 or more), and an average particle size of 0.05 to 1 μm (more preferably 0.2 to 0.8 μm). That is preferred. The addition amount of the abrasive is usually in the range of 3 to 25 parts by mass (preferably 3 to 20 parts by mass) with respect to 100 parts by mass of the ferromagnetic powder.

(lubricant)
The lubricant of the magnetic layer 11A is added to ooze out on the surface of the magnetic layer 11A, thereby reducing the friction between the surface of the magnetic layer 11A and the recording head 21 and maintaining the sliding contact state smoothly. Examples of the lubricant include fatty acids and fatty acid esters.

(Lubricant-Fatty acid)
Examples of fatty acids include acetic acid, propionic acid, 2-ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, arachidic acid, oleic acid, elaidic acid, linoleic acid, linolenic acid, and palmitoleic acid And aliphatic carboxylic acids such as these or mixtures thereof.

(Lubricant-fatty acid ester)
Examples of fatty acid esters include butyl stearate, sec-butyl stearate, isopropyl stearate, butyl oleate, amyl stearate, 3-methylbutyl stearate, 2-ethylhexyl stearate, 2-hexyl decyl stearate. , Butyl palmitate, 2-ethylhexyl myristate, a mixture of butyl stearate and butyl palmitate, oleyl oleate, butoxyethyl stearate, 2-butoxy-1-propyl stearate, dipropylene glycol monobutyl ether with stearic acid Various ester compounds such as acylated compounds, diethylene glycol dipalmitate, hexamethylenediol acylated with myristic acid to form diols, and glycerol oleate It can be mentioned.

  The aforementioned fatty acids and fatty acid esters can be used alone or in combination of two or more compounds. The normal content of the lubricant is in the range of 0.2 to 20 parts by mass (preferably 0.5 to 10 parts by mass) with respect to 100 parts by mass of the ferromagnetic powder.

(Binder)
Examples of the binder for the magnetic layer 11A include a thermoplastic resin, a thermosetting resin, a reactive resin, and a mixture thereof.

(Binder-Thermoplastic resin)
Examples of thermoplastic resins include vinyl chloride, vinyl acetate, vinyl alcohol, maleic acid, acrylic acid, acrylic ester, vinylidene chloride, acrylonitrile, methacrylic acid, methacrylic ester, styrene, butadiene, ethylene, vinyl butyral, vinyl A polymer or a copolymer containing acetal and vinyl ether as structural units can be given.
Examples of the copolymer include vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, acrylate ester-acrylonitrile copolymer, acrylate ester- Vinylidene chloride copolymer, acrylic ester-styrene copolymer, methacrylic ester-acrylonitrile copolymer, methacrylic ester-vinylidene chloride copolymer, methacrylic ester-styrene copolymer, vinylidene chloride Examples thereof include an acrylonitrile copolymer, a butadiene-acrylonitrile copolymer, a styrene-butadiene copolymer, and a chlorovinyl ether-acrylic ester copolymer.
Other thermoplastic resins include polyamide resins, fiber-based resins (cellulose acetate butyrate, cellulose diacetate, cellulose propionate, nitrocellulose, etc.), polyvinyl fluoride, polyester resins, polyurethane resins, various rubber-based resins. Resins can also be used.

(Binder-thermosetting resin, reactive resin)
Examples of thermosetting resins or reactive resins include phenolic resins, epoxy resins, polyurethane curable resins, urea resins, melamine resins, alkyd resins, acrylic reactive resins, formaldehyde resins, silicone resins, epoxy-polyamide resins, Mention may be made of a mixture of polyester resin and polyisocyanate prepolymer, a mixture of polyester polyol and polyisocyanate, and a mixture of polyurethane and polyisocyanate.

  Examples of the polyisocyanate include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, naphthylene-1,5-diisocyanate, o-toluidine diisocyanate, isophorone diisocyanate, triphenylmethane triisocyanate, and the like. Mention may be made of isocyanates, products of these isocyanates with polyalcohols, and polyisocyanates produced by condensation of isocyanates.

  As the polyurethane (resin), known materials having a structure such as polyester polyurethane, polyether polyurethane, polyether polyester polyurethane, polycarbonate polyurethane, polyester polycarbonate polyurethane, and polycaprolactone polyurethane can be used.

  That is, in the present invention, the binder of the magnetic layer 11A is vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer. It is preferably composed of a combination of at least one resin selected from coalescence and nitrocellulose and a polyurethane resin, or a combination obtained by further adding a polyisocyanate as a curing agent.

The binder may be —COOM, —SO ₃ M, —OSO ₃ M, —P═O (OM) ₂ , —O— as needed to obtain better dispersibility and durability of the resulting layer. P = O (OM) ₂ (M represents a hydrogen atom or an alkali metal), —OH, —NR ₂ , —N ⁺ R ₃ (R represents a hydrocarbon group), an epoxy group, —SH, — It is preferable to use at least one polar group selected from CN or the like by copolymerization or addition reaction. Such a polar group is preferably introduced into the binder in an amount of 10 ⁻¹ to 10 ⁻⁸ mol / g (more preferably 10 ⁻² to 10 ⁻⁶ mol / g).

  The binder in the magnetic layer 11A is usually used in the range of 5 to 50 parts by mass (preferably 10 to 30 parts by mass) with respect to 100 parts by mass of the ferromagnetic powder. When the vinyl layer resin, the polyurethane resin, and the polyisocyanate are used in combination as the binder for the magnetic layer 11A, the vinyl chloride resin is 5 to 70% by weight and the polyurethane resin is 2 to 50% in the total binder. It is preferred to use such that the polyisocyanate is included in an amount ranging from 2% to 50% by weight.

  A dispersing agent can be added to the coating liquid for forming the magnetic layer 11A in order to satisfactorily disperse powders such as ferromagnetic powder and carbon black in the binder. Further, if necessary, conductive particles (antistatic agents) other than plasticizer, carbon black, antifungal agents and the like can be added. Examples of the dispersant include 12 to 18 carbon atoms such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, elaidic acid, linoleic acid, linolenic acid, and stearic acid. A fatty acid (RCOOH, R is an alkyl group having 11 to 17 carbon atoms, or an alkenyl group), a metal soap composed of an alkali metal or an alkaline earth metal of the fatty acid, a compound containing fluorine of the fatty acid ester, Fatty acid amide, polyalkylene oxide alkyl phosphate ester, lecithin, trialkyl polyolefinoxy quaternary ammonium salt (alkyl is 1 to 5 carbon atoms, olefin is ethylene, propylene, etc.), sulfate, copper phthalocyanine, etc. Can be used. These may be used alone or in combination. A dispersing agent is added in 0.5-20 mass parts with respect to 100 mass parts of binders.

[Reflective layer]
The reflective layer 12A has a thickness of 10 to 800 nm (preferably 20 to 500 nm, more preferably 50 to 300 nm), and reflects the reading laser irradiated from the back side at the time of reproduction with high reflectance. Is a layer. The reflectance is preferably 70% or more.

As a material for forming the reflective layer 12A, that is, a light reflective material having a high reflectance to the laser, Mg, Se, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Co, Ni, Ru, Rh, Pd, Ir, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Si, Ge, Te, Pb, Po, Sn, Bi, etc. And metals and semi-metals or stainless steel. These light reflecting materials may be used alone, or may be used in combination of two or more kinds or as an alloy. Among these, Cr, Ni, Pt, Cu, Ag, Au, Al, and stainless steel are preferable. Particularly preferred is Au, Ag, Al or an alloy thereof, and most preferred is Au, Ag or an alloy thereof.
The reflective layer 12A can be formed by vacuum deposition, sputtering or ion plating of these light reflective materials.

[Optical recording layer]
The optical recording layer 13A is a write-once (write-once) recording layer, and once data is written, the data cannot be physically rewritten (including data erasure).
More specifically, the optical recording layer 13A contains an organic dye whose chemical structure changes due to heat generated by laser (light) irradiation or photons (photons) and whose optical characteristics such as reflection, transmission, refraction, and degree of deflection change. can do.

  Organic dyes contained in the optical recording layer 13A include cyanine, phthalocyanine, naphthalocyanine, azo, anthraquinone, naphthoquinone, pyrylium, azurenium, squarilium, indophenol, indoaniline, triaryl. Known organic pigments such as methane can be used.

Next, a method for forming the optical recording layer 13A will be briefly described.
The optical recording layer 13A is formed, for example, by coating the support 14A with an optical recording layer coating liquid in which the organic dye is mixed with a solvent, a resin, and a nonmagnetic pigment. In this case, a substituent for increasing the compatibility between the organic dye and the solvent / resin, and a polar group for increasing the adsorptivity to the non-magnetic pigment are added to the molecules constituting the organic dye within a range that does not impair the optical properties. It may be introduced.

  Nonmagnetic pigments include, for example, nonmagnetic inorganic compounds such as metal oxides, metal carbonates, metal sulfates, metal nitrides, metal carbides, metal sulfides, melamine resins, and pegzoquaminamine resins. it can.

Examples of nonmagnetic inorganic compounds include α-alumina, β-alumina, γ-alumina, θ-alumina, silicon carbide, chromium oxide, cerium oxide, α-iron oxide, hematite having an alpha (α) conversion rate of 90% or more. Goethite, corundum, silicon nitride, titanium oxide, silicon dioxide, tin oxide, magnesium oxide, tungsten oxide, zirconium oxide, boron nitride, zinc oxide, calcium carbonate, calcium sulfate, barium sulfate, molybdenum disulfide, zinc oxide, indium oxide, ITO (tin oxide-indium oxide) or the like can be used alone or in combination.
Among these, preferred are white or colorless and chemically stable oxides such as titanium dioxide, zinc oxide, tin oxide, indium oxide, ITO, zirconium oxide, tungsten oxide, and silicon dioxide. Particularly preferable are tin oxide, indium oxide, zinc oxide and ITO having high conductivity. Further, these oxides may be doped with antimony to enhance conductivity.
In addition, as nonmagnetic inorganic compounds, black particles such as powdered carbon black and titanium carbide are not suitable because they absorb and block light.

[Support]
The support 14A is a base also called a base film. The support 14A has a thickness of, for example, 2.0 to 4.7 μm, and is a wide film made of polyethylene terephthalate, wholly aromatic polyamide, wholly aromatic polyamideimide, wholly aromatic polyimide, or the like.

[Back coat layer]
The backcoat layer 15A is a layer for ensuring the slidability of the magnetic tape 10A with respect to a guide roller (not shown). The backcoat layer 15A has a thickness of 0.1 to 1.0 μm, for example, and is formed by applying a slurry of carbon black, calcium carbonate, inorganic powder, and the like and a binder to the support 14A. As a binder, what added the polyisocyanate type compound as a hardening | curing agent to at least 1 type selected from the nitrocellulose resin, the polyurethane resin, and the polyester resin can be used, for example.

<Configuration of recording / playback system>
Next, the configuration of the recording / reproducing system S1 will be described.
As shown in FIG. 1, the recording / reproducing system S1 mainly includes data writing means 30 for writing data to the recording head 21 and the optical recording layer 13A on the recording side, and data of the reproducing head 23 and the optical recording layer 13A on the reproduction side. Data reading means 40 for reading and a control device 100A electrically connected to these are provided.
In the first reference example, the recording head 21 and the reproducing head 23 are arranged on the magnetic layer 11A side of the magnetic tape 10A, and the data writing means 30 and the data reading means 40 are arranged on the back coat layer 15A side of the magnetic tape 10A. ing.

[Recording head]
The recording head 21 is a magnetic head for magnetically writing data to the magnetic layer 11A, and a known recording head can be used.

[Data writing means]
The data writing means 30 is means for optically writing data to the optical recording layer 13A in a write-once type (write-once type). The data writing means 30 mainly includes a laser generator 31 that generates a writing laser (also referred to as a writing laser), a beam splitter, a lens, a tracking mechanism including a tracking motor, a screw, and the like (all not shown). ).

[Playhead]
The reproducing head 23 is a magnetic head for reading data magnetically written on the magnetic layer 11A, and a known reproducing head such as an MR head can be used.

[Data reading means]
The data reading means 40 is a means for optically reading data written in a write-once type on the optical recording layer 13A. The data reading means 40 mainly includes a laser generator 41 that generates a reading laser (also referred to as a reading laser), a beam splitter, a lens, a tracking mechanism (all not shown), and an optical sensor 42 ( Photosensor).
Note that the laser generator 41, the beam splitter, the lens, and the tracking mechanism that constitute the data reading means 40 generally share corresponding devices that constitute the data writing means 30.

[Control device]
As shown in FIG. 2 in addition to FIG. 1, the control device 100A includes a write control means 110A for controlling the recording head 21 and the data writing means 30 and data from the magnetic tape 10A when data is recorded on the magnetic tape 10A. Read control means 120A for controlling the reproduction head 23 and the data reading means 40 during reproduction.

(Write control means)
The write control unit 110A writes all of the data to be written on the magnetic tape 10A to the magnetic layer 11A by the recording head 21, and at least a part of the written data is written to the optical recording layer 13A by the data writing unit 30. Means.

  More specifically, the write control unit 110A includes an input unit 111 to which data is input from the data input side to the recording head 21 side, and a modulation unit on the recording head 21 side for all the input data. 113, a selection unit 112 that selects a part of the data and also sends it to the modulation unit 116 on the laser generator 31 side, a modulation unit 113 that modulates the transmitted data to form a data signal, and this data signal And an amplifier 114 that amplifies the signal and sends it to the recording head 21, and these are electrically connected.

  Further, the write control means 110A modulates the data selected by the selection unit 112 from the selection unit 112 toward the laser generator 31 to obtain a data signal, and amplifies the data signal to amplify the data signal. And an amplifier 117 which is electrically connected to each other.

The selection unit 112 selects the selected data so that it can be understood that “which part of the data is selected, this selected part is sent to the laser generator 31 side, and is recorded on the magnetic layer 11A and the optical recording layer 13A”. Is to be processed. As shown in FIG. 3, the selection unit 112 according to the first reference example selects (1) data to be recorded sent from the input unit 111, (2) selects part of the data (in FIG. , “Address A01”, “address A02”... Are added as head information of the selected data, and the selected partial data and corresponding head information such as “address A01” are set. Thus, it also has a function of sending to the modulation unit 116 on the laser generator 31 side.
(3) As a result, the modulation unit 116 modulates a part of the selected data and the corresponding head information such as “address A01” as a set, and further amplifies by the amplifier 117, and then the laser generator. 31. Therefore, the head information of “address A01” is written in the optical recording layer 13A together with the selected data (see FIG. 3).
On the other hand, since all of the data attached with head information such as “address A01” is sent to the modulation unit 113 on the recording head 21 side, the data is modulated by the modulation unit 113 and amplified by the amplifier 114, and then the recording head. As shown in FIG. 3, all data with head information such as address A01 "is written in the magnetic layer 11A.
Therefore, by referring to head information such as “address A01”, it is possible to identify the leading position of data recorded in duplicate on the magnetic layer 11A and the optical recording layer 13A.

(Reading control means)
The reading control means 120A outputs the data read by the reproducing head 23, and the data read by the reproducing head 23 and the data reading means 40 corresponding to the recording method (selection method by the selection unit 112) by the writing control means 110A. Is a means for collating the data read and determining whether or not the data recorded in the magnetic layer 11A has been rewritten.

  More specifically, the read control unit 120A includes an amplifier 121 that amplifies the data signal from the reproduction head 23 from the reproduction head 23 side toward the data output side, and a demodulation unit that demodulates the amplified data signal. 122 and an output unit 124 that outputs the demodulated data signal as data, and these are electrically connected.

  The read control unit 120A also includes an amplifier 125 that amplifies a data signal from the optical sensor 42 that reads data on the optical recording layer 13A, a demodulator 126 that demodulates the amplified data signal, and a recording method of the write control unit 110A. Corresponding to the data of the optical recording layer 13A and the data of the magnetic layer 11A are provided, and these are electrically connected.

  The collating unit 127 collates the data of the magnetic layer 11A read by the reproducing head 23 with the data of the optical recording layer 13A read by the optical sensor 42 in accordance with the recording method by the writing control unit 110A, and magnetically This is a part for detecting whether or not the data of the layer 11A has been rewritten.

One collation method by the collation unit 127 will be described in correspondence with the selection method by the selection unit 112.
The collating unit 127 detects (1) head information such as “address A01” from the magnetic layer 11A and head information such as “address A01” from the optical recording layer 13A. In this detection, when the corresponding head information is not detected from the magnetic layer 11A side, the collation unit 127 determines that the data of the magnetic layer 11A has been rewritten.
When the head information from the magnetic layer 11A matches the head information from the optical recording layer 13A, the collating unit 127 (2) collates data following the head information. Next, when the data matches, the reproduction is continued as it is. On the other hand, if the data do not match, the collation unit 127 determines that the data in the magnetic layer 11A has been rewritten.
When the collating unit 127 determines that the data of the magnetic layer 11A has been rewritten, in the first reference example, a warning is displayed on a monitor (not shown).

<Operation of recording and playback system>
Next, the operation of the recording / reproducing system S1 will be described with reference to FIGS. Description will be made in the order of data recording and data reproduction.

[When recording data]
As shown in FIG. 2, data (= data to be recorded) input to the input unit 111 of the control device 100 </ b> A is sent to the selection unit 112.
As shown in FIG. 3, the selection unit 112 selects at least a part of this data (selects two parts in FIG. 3), and sends “address A01” and “address” as head information to the head of the selected part. Address A02 "is attached. The data to which the head information is attached is sent to the modulation unit 113. Then, after being modulated by the modulator 113 and amplified by the amplifier 114, it is written to the magnetic layer 11 </ b> A by the recording head 21.
The selection unit 112 also sends the selected data and the corresponding head information as a set to the modulation unit 116. The set of the selected data and head information is modulated by the modulator 116, amplified by the amplifier 117, and then written to the optical recording layer 13A in a write-once manner by the laser generator 31 (see FIG. 3). .
In this way, all of the data is recorded on the magnetic layer 11A, and at least a part of the data is recorded on the optical recording layer 13A in an overlapping manner.

[When playing back data]
The data read from the magnetic layer 11 </ b> A by the reproducing head 23 is amplified by the amplifier 121, demodulated by the demodulator 122, and then output from the output unit 124.
On the other hand, data read from the optical recording layer 13 </ b> A by the optical sensor 42 is amplified by the amplifier 125, demodulated by the demodulator 126, and then sent to the collator 127.

  The collating unit 127 collates the data of the magnetic layer 11A from the demodulating unit 122 and the data of the optical recording layer 13A from the demodulating unit 126 based on the head information of the “address A01. To do. Then, when the data match, the collating unit 127 determines that the data of the magnetic layer 11A has not been rewritten, and the reproduction is continued as it is. On the other hand, when the data does not match or when there is no head information in the magnetic layer 11A, the collating unit 127 determines that the data in the magnetic layer 11A has been rewritten, and displays a warning.

  Thus, according to the magnetic tape (recording medium) and the recording / reproducing system S1 according to the first reference example, it is possible to easily detect whether or not the data recorded on the magnetic layer 11A has been rewritten.

  Further, all the data is written in the magnetic layer 11A having a high recording density and a high recording speed / reading speed, and a part of the data is written in the optical recording layer 13A, thereby ensuring a large recording capacity and a high recording speed. Can do.

≪Second reference example≫
Next, a recording / reproducing system according to the second reference example will be described with reference to FIGS. In the drawings to be referred to, FIG. 4 is a block diagram of a control device according to a second reference example. FIG. 5 is a conceptual diagram of a data recording method in the second reference example.
The recording / reproducing system according to the second reference example differs from the recording / reproducing system S1 according to the first reference example in the configuration of the control device 100B and in the recording method on the magnetic tape 10A.

[Control device]
As shown in FIG. 4, the control device 100B according to the second reference example includes a write control unit 110B and a read control unit 120B, like the control device 100A according to the first reference example.

(Write control means)
The write control unit 110B is different from the write control unit 110A according to the first reference example in that the recording head 21 and the data writing unit 30 divide and record data into the magnetic layer 11A and the optical recording layer 13A. . More specifically, the write control unit 110B according to the second reference example includes a dividing unit 115 instead of the selection unit 112 according to the first reference example.

As shown in FIG. 5, the dividing unit 115 (1) divides the data to be recorded sent from the input unit 111 (2) is divided under a predetermined condition (four divisions in FIG. 5), and the divided data To the head, as head information, “address A11”, “address A12”, “address A13”, “address A14” are sequentially attached, and each divided data and corresponding head information are set as a set. The signal is alternately distributed to the modulation unit 113 and the modulation unit 116. The modulation unit 113 is connected to the recording head 21 through an amplifier 114, and the modulation unit 116 is connected to the laser generator 31 through an amplifier 117.
In the example illustrated in FIG. 5, data with “address A11” and “address A13” is distributed to the modulation unit 113, and data with “address A12” and “address A14” is distributed to the modulation unit 116. It has become so.

The data to which “address A11” and “address A13” are attached is modulated by the modulation unit 113, amplified by the amplifier 114, and then (3) written to the magnetic layer 11A by the recording head 21. ing.
On the other hand, data to which “address A12” and “address A14” are attached is modulated by the modulation unit 116, amplified by the amplifier 117, and then written to the optical recording layer 13A by the laser generator 31. Yes.

(Reading control means)
The read control means 120B differs from the read control means 120A according to the first reference example in a method for determining whether or not the data of the magnetic layer 11A has been rewritten. More specifically, the reading control unit 120B according to the second reference example includes a combining unit 123 instead of the collating unit 127 according to the first reference example.

  The combining unit 123 is connected to the downstream side of the demodulating unit 122 and the demodulating unit 126, and (1) the divided data read by the reproducing head 23 and the optical sensor 42 is used as head information such as “address A11”. And (2) a function for displaying a warning when the combination is not possible.

  Therefore, according to the recording / reproducing system according to the second reference example, at the time of data recording, the data is divided by the dividing unit 115 under a predetermined condition and written separately into the magnetic layer 11A and the optical recording layer 13A, and at the time of data reproduction By combining the data corresponding to this recording method (division method), it is possible to easily detect whether or not the data recorded on the magnetic layer 11A has been rewritten.

≪Third reference example≫
Next, a magnetic tape and a recording / reproducing system according to a third reference example will be described with reference to FIG. FIG. 6 is a diagram schematically showing a configuration of a magnetic tape and a recording / reproducing system according to a third reference example.

<Magnetic tape>
As shown in FIG. 6, the magnetic tape 10B according to the third reference example has a five-layer structure like the magnetic tape 10A according to the first reference example, but the stacking order of the reflective layer 12A and the optical recording layer 13A is different. Is different. That is, the magnetic tape 10B becomes a magnetic layer 11A, an optical recording layer 13A, a reflective layer 12A, a support 14A, and a backcoat layer 15A from the head side slidingly contacting the recording head 21 and the reproducing head 23 toward the back side. Yes.

<Recording and playback system>
The recording / reproducing system S2 according to the third reference example includes the same equipment as the recording / reproducing system S1 according to the first reference example, but the data writing means 30 for writing data to the optical recording layer 13A on the recording side, and the reproducing side The difference is that the data reading means 40 for reading data from the optical recording layer 13A is arranged on the magnetic layer 11A side.

  Therefore, according to the magnetic tape 13B and the recording / reproducing system S2, the recording head 21, the data writing unit 30, the reproducing head 23, and the data reading unit 40 are arranged on one side (the magnetic layer 11A side) of the magnetic tape 10B. be able to. That is, the recording / reproducing system S2 can be configured even when there is no space on the backcoat layer 15A side of the traveling magnetic tape 10B.

<< First Embodiment >>
Next, the magnetic tape according to the first embodiment will be described with reference to FIG. FIG. 7 is a diagram showing the configuration of the magnetic tape according to the first embodiment. FIG. 7 depicts the recording / reproducing system S1 according to the first reference example in order to clarify the arrangement of the reproducing head 23, the data writing means 30, and the like with respect to the magnetic tape according to the first embodiment. .

<Magnetic tape>
As shown in FIG. 7, the magnetic tape 10C according to the first embodiment has a four-layer structure. More specifically, the magnetic tape 10C has a magnetic layer 11A (first recording layer), a support 14A, and a dye-containing back coat from the head side that is in sliding contact with the recording head 21 and the like toward the back side that is in sliding contact with a guide roller and the like. The layers 15B are stacked in this order. That is, the magnetic tape 10C does not include the single optical recording layer 13A according to the first reference example, but the dyed backcoat layer 15B functions as a write-once type optical recording layer.

The dye-containing backcoat layer 15B contains an organic dye that forms the optical recording layer 13A in addition to the composition that forms the backcoat layer 15A described in the first reference example. Such a dye-containing backcoat layer 15B is formed by applying a coating agent containing carbon black or the like, an organic dye, and a binder.
Therefore, according to such a magnetic tape 10C, the same function as that of the magnetic tape 10A can be maintained, and the thickness can be reduced to the extent that the optical recording layer 13A is not provided.

<< Second Embodiment >>
Next, a magnetic tape according to the second embodiment will be described with reference to FIG. FIG. 8 is a diagram schematically showing the configuration of the magnetic tape according to the second embodiment.

<Magnetic tape>
As shown in FIG. 8, the magnetic tape 10D according to the second embodiment includes a lower layer 16 in addition to the configuration of the magnetic tape 10C according to the first embodiment. The lower layer 16 includes the magnetic layer 11A and the support 14A. Is intervening between.

[Underlayer]
The lower layer 16 is a substantially nonmagnetic layer, and is also referred to as a nonmagnetic layer or an underlayer. The lower layer 16 is a layer for increasing the magnetic recording density by regularly arranging ferromagnetic powder and the like with high accuracy when forming the magnetic layer 11A. Such a lower layer 16 includes a nonmagnetic powder, a binder, and a lubricant.

(Non-magnetic powder)
Examples of the nonmagnetic powder include nonmagnetic inorganic powder and carbon black. The non-magnetic inorganic powder is preferably relatively hard, and preferably has a Mohs hardness of 5 or more (more preferably 6 or more).

  Specific examples of the nonmagnetic inorganic powder include α-alumina, β-alumina, γ-alumina, silicon carbide, chromium oxide, cerium oxide, α-iron oxide, corundum, silicon nitride, titanium carbide, titanium dioxide, silicon dioxide. , Boron nitride, zinc oxide, calcium carbonate, calcium sulfate, and barium sulfate. These can be used alone or in combination. Of these, titanium dioxide, α-alumina, α-iron oxide or chromium oxide is preferred. The average particle size of the nonmagnetic inorganic powder is preferably in the range of 0.01 to 1.0 μm (preferably 0.01 to 0.5 μm, particularly 0.02 to 0.1 μm).

  Carbon black is added for the purpose of imparting electrical conductivity to the magnetic layer 11A to prevent charging, and ensuring the smooth surface properties of the magnetic layer 11A formed on the lower layer 16. The carbon black contained in the lower layer 16 preferably has an average particle size of 35 nm or less (more preferably 10 to 35 nm). The amount of carbon black added is 3 to 20 parts by mass, preferably 4 to 18 parts by mass, and more preferably 5 to 15 parts by mass with respect to 100 parts by mass of the total nonmagnetic inorganic powder.

(Binder)
As the binder of the lower layer 16, the binder described in the magnetic layer 11A according to the first reference example can be used. The binder is usually in the range of 5 to 50 parts by mass (preferably 10 to 30 parts by mass) with respect to 100 parts by mass of the nonmagnetic powder of the lower layer 16. In the case of using a combination of vinyl chloride resin, polyurethane resin, and polyisocyanate as binders in the lower layer, vinyl chloride resin is 5 to 70% by weight and polyurethane resin is 2 to 50% by weight in all binders. And polyisocyanates are preferably used in amounts ranging from 2 to 50% by weight. In the lower layer 16, a dispersant and other additives that can be added to the magnetic layer 11 </ b> A described above can also be added.

(lubricant)
As the lubricant, for example, fatty acid or fatty acid ester can be used. The addition amount of the lubricant is preferably in the range of 0.2 to 20 parts by mass with respect to 100 parts by mass of the total nonmagnetic powder.

≪Fourth reference example≫
Next, a magnetic tape according to a fourth reference example will be described with reference to FIG. FIG. 9 is a perspective view showing a configuration of a magnetic tape according to a fourth reference example.

<Magnetic tape>
As shown in FIG. 9, the magnetic tape 10E according to the fourth reference example has a two-layer structure in the thickness direction. However, the magnetic layer 11E and the optical recording layer 13E provided on one side of the support 14A are provided. , Arranged in two rows along the running direction. That is, since the magnetic layer 11E and the optical recording layer 13E are not laminated in the thickness direction, the magnetic tape 10E becomes thin. Note that a reflective layer 12A, a backcoat layer 15A, and the like may be appropriately provided on the magnetic tape 10E.

<< Third Embodiment >>
Next, a magnetic disk according to the third embodiment will be described with reference to FIG. FIG. 10 is a perspective view showing the configuration of the magnetic disk according to the third embodiment.

  As shown in FIG. 10, the magnetic disk 10F according to the third embodiment has a disk shape (disc shape) unlike the belt-like magnetic tape 10A according to the first reference example. The magnetic disk 10F mainly includes a support 14F also called a substrate, a magnetic layer 11F provided on the upper surface (one surface), and an optical recording layer 13F provided on the lower surface (the other surface). ing. Note that a reflective layer or the like may be provided as appropriate.

According to such a magnetic disk 10F, the magnetic disk 10F is rotated by a spindle motor or the like, and magnetic tape traveling means such as a feed reel, a winding reel, and a guide roller are not required for traveling the magnetic tape 10A.
In the case of such a magnetic disk 10F, a recording head for writing data to the rotating magnetic layer 11F, a reproducing head for reading data, a data writing means for writing data in a write-once type to the optical recording layer 13F, and data for reading data The reading means is moved in a substantially radial direction of the magnetic disk 10F by a tracking mechanism, a swing arm (swing arm) or the like.

≪Fifth Reference Example≫
Next, a magnetic disk according to the fifth reference example will be described with reference to FIG. FIG. 11 is a perspective view showing a configuration of a magnetic disk according to a fifth reference example.

<Magnetic disk>
As shown in FIG. 11, the magnetic disk 10G according to the fifth reference example has a disk shape like the magnetic disk 10F according to the third embodiment, but the magnetic layer 11G and the optical recording layer 13G are supported. It is provided on the upper surface (one surface) of the body 14F. More specifically, the magnetic layer 11G is disposed on the inner side, and the optical recording layer 13G is disposed on the outer side.
Therefore, according to such a magnetic disk 10G, it is thinner than the magnetic disk 10F according to the third embodiment.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and the constituent elements described in the embodiments may be appropriately combined without departing from the spirit of the present invention. In addition, for example, the following appropriate changes are possible.

  In the first reference example, the case where the rewritable first recording layer is the magnetic layer 11A and the non-rewritable write-once second recording layer is the optical recording layer 13A has been described. The type of the two recording layers is not limited to this. For example, the first recording layer may be an optical recording layer rewritable by phase change used for CD-RW, DVD-RW, or the like, or a magneto-optical recording layer used for MO or the like.

It is a figure which shows typically the structure of the magnetic tape and recording / reproducing system which concern on a 1st reference example. It is a block diagram which shows the structure of the control apparatus shown in FIG. It is a conceptual diagram of the data recording system in the first reference example. It is a block diagram which shows the structure of the control apparatus which concerns on a 2nd reference example. It is a conceptual diagram of the data recording system in the second reference example. It is a figure which shows typically the structure of the magnetic tape and recording / reproducing system which concern on a 3rd reference example. It is a figure which shows the structure of the magnetic tape which concerns on 1st Embodiment. It is a figure which shows the structure of the magnetic tape which concerns on 2nd Embodiment. It is a perspective view which shows the structure of the magnetic tape which concerns on a 4th reference example. It is a perspective view which shows the structure of the magnetic disc which concerns on 3rd Embodiment. It is a perspective view which shows the structure of the magnetic disc which concerns on a 5th reference example.

Explanation of symbols

S1, S2 Recording / reproducing system 10A, 10B, 10C, 10D, 10E Magnetic tape (recording medium)
10F, 10G magnetic disk (recording medium)
11A, 11E, 11F, 11G Magnetic layer (first recording layer)
12A Reflective layer 13A, 13E, 11F, 11G Optical recording layer (second recording layer)
14A, 14F Support 15A Backcoat layer 15B Dye-containing backcoat layer (optical recording layer, second recording layer)
16 Lower layer (nonmagnetic layer)
DESCRIPTION OF SYMBOLS 21 Recording head 23 Playback head 30 Data writing means 31 Laser generator 40 Data reading means 41 Laser generator 42 Optical sensor 100A, 100B Control apparatus 110A, 110B Write control means 112 Selection part 115 Dividing part 120A, 120B Reading control means 123 Coupling Part 127 Verification part A01, A02 ..., A11, A12 ... Address

Claims (1)

A support, and a rewritable magnetic layer and a write-once optical recording layer provided on the support,
The magnetic layer, the support, and the optical recording layer are laminated in this order.

Images