CN100501849C

CN100501849C - Optical recording medium and optical recording method

Info

Publication number: CN100501849C
Application number: CNB2006100927840A
Authority: CN
Inventors: 松本郁夫; 德井健二; 田田浩
Original assignee: Victor Company of Japan Ltd
Current assignee: Victor Company of Japan Ltd
Priority date: 2005-06-14
Filing date: 2006-06-14
Publication date: 2009-06-17
Anticipated expiration: 2026-06-14
Also published as: CN1881439A

Abstract

A method of recording data in an optical storage medium comprising the steps of: recording data in the optical storage medium having a substrate, a first laminated layer structure formed on the substrate and having at least a first reflective film and a first recording filn, and a second laminated layer structure formed over the first laminated layer structure and having at least a second reflective film and a second recording film, the data being recorded in at least one of a plurality of specific sections of the first recording film of the first laminated layer structure, with a beam having a wavelength in a 650-nm band and a beam spot having a specific area, and recording data in the second recording film of the second laminated layer structure through the substrate and the data-recorded specific section of the first recording film of the first laminated layer structure, the second laminated layer structure exhibiting a reflectivity of 5% or higher but 10% or lower when the beam is focused onto the second recording film.

Description

Optical recording media and optic recording method

Technical field

The present invention relates to utilize the irradiation of light (for example laser) to carry out the optical recording media of recording of information, deletion, reproduction and the optic recording method of recorded information in this optical recording media.Especially, the invention provides a kind of optical recording media and optic recording method, is being that purpose has in the double-deck phase-change optical storage medium of two-layer rewritable recording film to increase memory capacity, can obtain good recording characteristic and good repeating rewrites characteristic.

Background technology

Phase-change optical recording medium is meant, utilizing the medium that the reversible variation phenomenon of crystalline phase and amorphous phase can rewrite information, for example is CD-RW (repeatable recording type compact-disc), DVD-RW (repeatable recording type digital multi-purpose disk) or the DVD-RAM (the random access digital multi-purpose disk of repeatable recording) of development in this year.Wherein DVD-RW and DVD-RAM mainly are used in record that contains much information and the rewriting as image information.

And, in the phase-change optical recording medium of popularizing rapidly at the recording medium of using as in recent years video recorder and personal computer, except good recording characteristic and the requirement of rewriting characteristic, from the viewpoint of long-time video recording and Large Volume Data keeping, the enhancing of recording capacity and the requirement of densification record are increased.

As one of recording capacity method that increases above-mentioned phase-change optical recording medium, there is the signal that reduces to write down to improve the method for the density of unit area.Reduce tracer signal, known have shorten the optical maser wavelength be used in record, perhaps increase the method for the numerical aperture (NA) of object lens.For example, indigo plant (Blu-Ray) CD is arranged as the practical example of the method.

In DVD dish, from the recording capacity of 4.7GB/ face, by improving the density of tracer signal, become the recording capacity of 23GB/ face in Blu-ray disc, realized the increase of recording capacity.And, in Blu-ray disc, replacing the laser of the wavelength 650nm that uses at DVD and use the laser of 405nm, the NA of object lens also 0.60 increases to 0.85 from what use at DVD, has improved the density of tracer signal.

As another method of the recording capacity that increases phase-change optical recording medium, also proposed to overlap the recording layer in a plurality of optical recording medias and the multiple stratification that forms, having popularized recording layer in market is two-layer DVD-ROM (Read Only Memory).In the optical recording media of such multiple stratification, can utilize two-layer recording layer that recording capacity is increased to twice, utilize four layers recording layer to increase to four times.In recent years, overlapped the double-layer optical recording medium of additional record type of the recording film of organic pigment, for example the bilayer of DVD ± R (DL) dish has been realized commercialization.In this wise recording film is being made 2 layers when having increased recording capacity, the optical maser wavelength of use and the NA of lens are with equally getting final product in the past, so have the advantage of the system that can realize at an easy rate.

Studying the method that identical therewith method is applied to phase-change optical recording medium.Under the situation of DVD-ROM,,, still, in phase-change optical recording medium, be to overlap recording film (recording layer) so coiling coincident reflection film on the cross-wise direction owing to be to reproduce special use.

The structure and the recording method of phase-change optical storage medium with 1 layer of rewritable recording film is as described below.

The structure of phase-change optical storage medium is, irradiation is had record, reproduce and the substrate of face as the bottom surface of the laser of each power of deletion usefulness on, stack gradually deielectric-coating, recording film, deielectric-coating, reflectance coating at least.In the phase-change optical storage medium that constitutes like this, when record, recording impulse is applied (irradiation) to recording film with the laser of recording power, fuse recording film, and pass through chilling, form amorphous record mark.The reflectivity of the recording film of the luminance factor crystalline state of record mark is low, therefore, can utilize optical mode that record mark is read as recorded information.When the deletion record mark, by the laser of the irradiation power (deletion power) littler, make recording layer reach the temperature that Tc is above, fusing point is following than recording power, become crystalline state from non-crystalline state, thereby the erasing record mark can rewrite.In a laser radiation, carry out in the light beam rewriting of this record and deletion, because it is short to rewrite the required time, so wish.

Phase-change optical recording medium with two-layer recording film is the structure identical with above-mentioned phase-change optical storage medium, forms the two-layer unit record layer that is made of deielectric-coating, recording film, deielectric-coating, reflectance coating at least on substrate.

In TOHKEMY 2003-338079 communique (patent documentation 1), following problem has been proposed: constitute the crystalline state of seeing the recording film of the Information Level (L0 layer) that is positioned at the front side from the laser light incident side, be recorded or do not write down and different with recording film, this exerts an influence to information record or the information regeneration of seeing Information Level (L1 layer) farthest from the laser light incident side.Disclose following technology in patent documentation 1: the appointing of the non-crystalline state of information or Unrecorded crystalline state ,-state is irrelevant with recording for the crystalline state of the recording film of L0 layer, can carry out correct record-playback to the L1 layer, therefore, recording film can be designed so that the crystalline state in the recording film of L0 layer and the transmission rate variance and the absorbance difference of non-crystalline state diminish without restriction.Crystalline state and non-crystalline state can detect by optical mode.

Research according to the present inventor, in the time of will being used in recording film in the chalcogenide material of patent documentation 1 disclosed TeGeSb, InSe etc., though can confirm effect in patent documentation 1 explanation, but,, be difficult to the design film is designed so that the transmission rate variance of crystalline state and non-crystalline state is as far as possible little when being used in recording film at high speed crystalline growth materials such as the AgInSbTe that crystallization rate is fast, InGeSb, GaSb (below be labeled as " FGM ").

And, if use FGM, then need to form the recording film of chilling structure, therefore, the thickness of each film of constituting optical recording media is set with a lot of restrictions, be difficult to the membrane structure that realizes obtaining good recording characteristic and rewrite characteristic.

In TOHKEMY 2003-303420 communique (patent documentation 2), not explanation of transmissivity extent relation to aforesaid recording film, and provided a kind of recording method, promptly, in the optical information recording medium that possesses the recording layer more than two-layer, from light incident side recording layer opening entry farthest, record method from vertical direction successively, perhaps the method that writes down with its reverse order from the near recording layer of light incident side.

Research according to the present inventor, in the recording method according to the record order that is documented in patent documentation 2, under the situation of phase-change optical storage medium, confirmed material and thickness (design conditions of medium) according to recording film, the transmissivity before and after the record and the magnitude relationship of reflectivity change.Therefore, even the setting recording order, according to the design conditions of medium, recording characteristic can worsen sometimes.

Moreover, if change in proper order, just there is the invalid problem of interchangeability for its record of each optical recording media.For this reason, the characteristic of regulation optical recording media determines that based on this recording method is very important.

In having the phase-change optical storage medium of two-layer recording film, from when farthest the L1 layer opening entry of laser light incident side, record sees through the recording film of the L0 layer that is in Unrecorded crystalline state with laser according to the recording method of patent documentation 2.On the other hand, if from the L0 layer opening entry of laser light incident side, in order to record on the L1 layer, record will see through the recording film that has write down the L0 layer that becomes non-crystalline state of information with laser.The recording status of the recording film of L0 layer at this moment and when the transmissivity of recording status is not variant, according to the record order, can produce big difference in the transmissivity of L0 layer, therefore, because the variation of recording laser power and the minimizing of reproducing signal can not obtain good recording characteristic.Therefore, need to design the method for the recording film of being put down in writing as patent documentation 1 simultaneously.

Patent documentation 1: TOHKEMY 2003-338079 communique

Patent documentation 2: TOHKEMY 2003-303420 communique

Summary of the invention

Therefore, the objective of the invention is to, a kind of optical recording media and optic recording method are provided, in having the phase-change optical storage medium of two-layer recording film, can both obtain good recording characteristic and rewrite characteristic at arbitrary recording film.

For solving above-mentioned problem, the invention provides optical recording media and optic recording method with (a)～(c) structure.

(a) a kind of optical recording media utilizes the light of the wavelength with 650nm frequency band to write down or information reproduction, and it has: substrate; The 1st unit record layer that has first recording film and first reflectance coating at least that on aforesaid substrate, forms successively and have second recording film at least and the 2nd unit record layer of second reflectance coating; In above-mentioned first recording film, write down under the recording status of information, after above-mentioned light is by aforesaid substrate and the 1st unit record layer, focus on above-mentioned second recording film, when shining as the focal point with regulation area, the reflectivity of above-mentioned the 2nd unit record layer is more than or equal to 5% and smaller or equal to 10%.

(b) optical recording media in (a) record is, in above-mentioned the 1st unit record layer, when above-mentioned light shines above-mentioned the 1st unit record layer as directional light, wherein above-mentioned directional light has the big area of sectional area ratio afore mentioned rules area with the direction of the direct of travel quadrature of above-mentioned light, if the transmissivity when establishing the not recording status that is in the information that do not record in above-mentioned first recording film is Tc, reflectivity is Rc, if the transmissivity when being in the recording status of the information that write down in above-mentioned first recording film is Tr, reflectivity is Rr, then Tc ≦ Tr ≦ 60%, and 9% ≦ Rr ≦ Rc ≦ 15%.

(c) a kind of recording method of optical recording media, this optical recording media has: substrate; The 1st unit record layer and the 2nd unit record layer that on aforesaid substrate, form successively, above-mentioned the 1st unit record layer has first recording film and first reflectance coating of the light recording information of the wavelength that utilizes the 650nm frequency band at least, and above-mentioned the 2nd unit record layer has second recording film and second reflectance coating that utilizes above-mentioned light recording information at least; In above-mentioned first recording film, write down under the recording status of information, after above-mentioned light is by aforesaid substrate and the 1st unit record layer, focus on above-mentioned second recording film, when shining as the focal point with regulation area, the reflectivity of above-mentioned the 2nd unit record layer is more than or equal to 5% and smaller or equal to 10%; In above-mentioned the 1st unit record layer, when above-mentioned light shines above-mentioned the 1st unit record layer as directional light, wherein above-mentioned directional light has the big area of sectional area ratio afore mentioned rules area with the direction of the direct of travel quadrature of above-mentioned light, if the transmissivity when establishing the not recording status that is in the information that do not record in above-mentioned first recording film is Tc, reflectivity is Rc, if the transmissivity when being in the recording status of the information that write down in above-mentioned first recording film is that Tr, reflectivity are Rr, then Tc ≦ Tr ≦ 60% and 9% ≦ Rr ≦ Rc ≦ 15%; Method for recording information comprises in above-mentioned optical recording media: in the 1st step of the regional record information with regulation area of above-mentioned first recording film; The zone of the information that records by above-mentioned first recording film is to the 2nd step of the above-mentioned second recording film recorded information.

According to the present invention, in having the phase-change optical storage medium of two-layer recording film, arbitrary recording film can both obtain good recording characteristic and rewrite characteristic.Further, even recording film uses FGM to form, arbitrary recording film can both obtain good recording characteristic and rewrite characteristic.

Description of drawings

Fig. 1 is the longitudinal section of stepped construction of the optical recording media A of expression one embodiment of the present invention.

Fig. 2 (a) represents that as parameter the figure that concerns between the thickness of the transmissivity Tc of L0 layer and first recording film 3, Fig. 2 (b) represent the figure that concerns between the thickness of the transmissivity Tr of L0 layer and first recording film 3 with the thickness of first reflectance coating 5 as parameter with the thickness of first reflectance coating 5.

Fig. 3 is expression with the thickness of first recording film 3 figure as relation between the number of rewrites of parameter and the shake.

Fig. 4 is the figure of relation of the C/N of expression L1 layer reflectivity R1 and 3T signal.

Fig. 5 is that the expression reflectivity R11 that the L1 layer is independent is the figure that parameter is represented the simulation result that concerns between the transmissivity Tr of L0 layer and the L1 layer reflectivity R1.

Fig. 6 is the figure of the recording impulse string of expression one embodiment of the present invention.

Fig. 7 is the figure of an embodiment of expression optical recorder of the present invention.

Fig. 8 is the planimetric map of optical recording media A.

Fig. 9 be pattern be illustrated in the figure of 3 log file systems that use in the record to optical recording media A.

Embodiment

As possessing two-layer two-layer phase-change optical storage medium, enumerated the medium that phase transition optical disk such as DVD-RW, DVD-RAM or light-card etc. can rewrite duplicate message with unit record layer of recording film.And, in the following description, two stratotype phase change discs have been described as an embodiment of optical recording media of the present invention, still, have optical recording media with spline structure in addition light-card etc., also can be suitable for the present invention, this is mathematical.

Two stratotype phase-change optical storage medium A of present embodiment are, with incident record, reproduce and deletion is on first substrate 1 of bottom surface with the plane of incidence 1A of laser L, across as the L0 layer middle layer (hyaline layer) 13 of the 1st unit record layer stacked as the L1 layer and second substrate 11 of the 2nd unit record layer.Constituting unit record layer in the unit record layer of optical recording media A, that be positioned at the front when seeing from the laser light incident side (plane of incidence 1A) of optical recording media A is the 1st unit record layer (L0 layer), sees that from the laser light incident side unit record layer that is positioned at inboard the darkest side is the 2nd unit record layer (a L1 layer).

The L0 layer is formed in unit record layer on first substrate 1, that stacked gradually first deielectric-coating 2, first recording film 3, second deielectric-coating 4, first reflectance coating the 5, the 1st diaphragm 6.The L1 layer is formed in unit record layer on second substrate that label surface 11B with second substrate 11 is the bottom surface, that stacked gradually second reflectance coating 10, the 3rd deielectric-coating 9, second recording film 8, the 4th deielectric-coating the 7, the 2nd diaphragm 12.The 1st diaphragm 6 of L0 layer and the 2nd diaphragm 12 of L1 layer are become mutually opposed across middle layer 13 by bonding.

Hyaline layer 13 can use ultraviolet ray (UV) gel-type resin, also can use two sides binding type thin slice.

As the material of first substrate 1 and second substrate 11, can use transparent various synthetic resin, transparent glass etc.For fear of the influence with the scar of first substrate 1 etc. of adhering to of dust, wish to use the first transparent substrate 1, with the laser of optically focused from first substrate, 1 side opening entry.As the first such substrate 1 and the material of second substrate 11, can exemplify out glass, polycarbonate, polymethyl methacrylate, polyene resin, epoxy resin, polyimide resin etc.Especially,, moulding little from optical birefringence, hydroscopicity considers that easily hope is polycarbonate resin.

The thickness of first substrate 1 and second substrate 11 is particular determination not, but considers with full depth to be the interchangeability of the digital multi-purpose disk (below be labeled as " DVD ") of 1.2mm, and hope is 0.58mm～0.6mm.First substrate 1 and second substrate 11 also can be flexible, also can be rigidity, still, under flexible situation, use with banded, laminar, card shape.Under the situation of rigidity, use with card shape or plate-like.

First deielectric-coating 2 and second deielectric-coating 4 are in order to prevent that first substrate 1, first recording film 3 etc. are provided with because of thermal deformation causes the recording characteristic deterioration when writing down; have from pining for protecting the effect of first substrate 1, first recording film 3, also have the effect of improving the C/N (Crrier to Noise Ratio) of reproducing signal by the interference effect of optics.The 3rd deielectric-coating 9 and the 4th deielectric-coating 7 also have identical effect for second substrate 11, second recording film 8.

First deielectric-coating 2, second deielectric-coating 4, the 3rd deielectric-coating 9 and the 4th deielectric-coating 7 (first deielectric-coating～the 4th deielectric-coating) laser to record-playback respectively are transparent, and refractive index n is in the scope of 1.9 ≦ n ≦ 2.3.Moreover as the material of first deielectric-coating～the 4th deielectric-coating, from the viewpoint of thermal characteristics, hope is SiO ₂, SiO, ZnO, TiO ₂, Ta ₂O ₅, Nb ₂O ₅, ZrO ₂, oxide such as MgO, ZnS, In ₂S ₃, TaS ₄Sulfides, the monomer of carbonide such as SiC, TaC, WC, TiC, the perhaps potpourri of these monomers.

And first deielectric-coating～the 4th deielectric-coating can not be identical materials, composition, also can make up different respectively materials and constitute.And, ZnS and SiO ₂The situation of hybrid films under, even repeat record, deletion, also be not easy to cause the deterioration of recording sensitivity, C/N, deletion rate etc., therefore especially wish.

The thickness of first deielectric-coating 2 and the 3rd deielectric-coating 9, probably the scope at 5nm～500nm gets final product.Moreover, consider to be difficult to peel off, and be difficult to take place defective such as fracture from first substrate 1 and first recording film 3, second substrate 11 and second recording film 8 separately, therefore hope is the scope of 40nm～300nm.If thinner than 40nm, be not easy to guarantee the optical characteristics of coiling so, if thicker than 300nm, productivity is poor so.And, more wish scope at 50nm～80nm.

Second deielectric-coating 4 and the 4th deielectric-coating 7 wish it is the scope of 5nm～40nm, so that have the recording characteristic of good C/N, deletion rate etc., can stably repeatedly rewrite.If thinner than 5nm, the heat of recording film is guaranteed to be not easy so, so the optimal recording power rising, if thicker than 40nm, can cause rewriteeing the deterioration of characteristic so.More wish it is the scope of 10nm～20nm.

First recording film 3, second recording film 8 be Ag-In-Sb-Te alloys, comprise Ag or Si, Al in Ge-In-Sb-Te alloy or Ge-In-Sb-Te alloy, the alloy film of at least a composition among Ti, Bi, the Ga.The thickness of first recording film 3, from the light transmissive viewpoint of L1 layer being seen wishing is below the 10nm, the thickness of second recording film 8 wishes it is 10nm～25nm.

And, also can interfacial film be set on the single face or the two sides at the interface of first deielectric-coating～the 4th deielectric-coating that joins with first recording film 3, second recording film 8.As the material of interfacial film, it is very important not comprise the sulphur thing.Be used for interfacial film if will comprise the material of sulphur thing, the rewriting by repeating so, the sulphur in the interfacial film is diffused in first recording film 3, second recording film 8, and therefore recording characteristic meeting deterioration does not wish.And, from the bad viewpoint of deletion characteristic, do not wish yet.

The material of interfacial film, hope are to comprise at least a material in nitride, oxide, the carbonide, and specifically, hope is to comprise material at least a in germanium nitride, silicon nitride, aluminium nitride, aluminium oxide, zirconia, chromium oxide, silit, the carbon.And, in these materials, also can comprise oxygen, nitrogen, hydrogen etc.Above-mentioned nitride, oxide, carbonide can not be stoichiometric compositions also, and nitrogen, oxygen, carbon surplus or deficiency also can.Therefore, interfacial film is not easy to peel off, and raisings such as preservation permanance etc. can improve all characteristic of unit record layer.

Material as translucent first reflectance coating 5 and second reflectance coating 10, can exemplify out metals such as Al, Au with light reflective, Ag, with be major component with these and comprise by more than one the metal or the alloy of the interpolation element that constitutes of semiconductor, in metals such as Al, Au, Ag, mixed the material etc. of the metallic compound such as metal nitride, metal oxide, metal germanide of Al, Si etc.At this, as major component, the proportion that refers to constitute metals such as Al, Au, Ag in all material of first reflectance coating 5 and second reflectance coating 10 surpasses 50% situation of all material, and hope is the situation more than 90%.

Wherein, metals such as Al, Au, Ag, and be the alloy of major component with these metals, therefore reflectivity height and temperature conductivity height wish.Example as alloy, the material that normally in Al, has added at least a elements such as Si, Mg, Cu, Pd, Ti, Cr, Hf, Ta, Nb, Mn, Zr, or in Au or Ag, added material of at least a elements such as Cr, Ag, Cu, Pd, Pt, Ni, Nd, In, Ca etc.But, when considering high-speed record,, wish that especially being is the metal or alloy of major component with the high Ag of pyroconductivity from the viewpoint of recording characteristic.

The thickness of translucent first reflectance coating 5 is if consider that hope is below the 10nm to the seeing through of the light of L1 layer.The thickness of second reflectance coating 10 changes with the pyroconductivity size of the material that forms second reflectance coating 10, and hope is below 50nm～300nm.If second reflectance coating 10 is more than the 50nm, do not change on the optical property so, the value of reflectivity is not impacted, the influence of cooling velocity is become big.And during fabrication, forming the above thickness of 300nm then needs the time.Therefore,, can guarantee performance by using the high material of pyroconductivity, simultaneously with film thickness monitoring at above-mentioned optimum range.

Moreover, in order to improve reflectivity and pyroconductivity, first reflectance coating 5 and second reflectance coating 10 are become at transparent high electricity lead the multimembrane structure that clips metallic reflective coating between the deielectric-coating.

" measurement of transmissivity "

In the optical recording media of present embodiment, when the L1 layer is carried out record-playback, need make laser see through the L0 layer.For this reason, under the situation of two-layer phase-change optical storage medium, at the transmissivity T0 of the laser in the near L0 layer of incident laser, according to emulation needs 40% at least.And the L1 layer of dark side need not see through laser for one deck down, therefore, constitutes the recording film of L1 layer and reflectance coating and can form and guarantees characteristic institute thickness fully.

At this, the L1 layer separately the reflectivity of the light of reflection be made as " the reflectivity R11 that the L1 layer is independent ".The L1 layer is meant separately, utilizes tack coat 13 bonding first substrates 1 (or false substrate) and structure that the L1 layer that forms on second substrate 11 forms, and it is mutually opposed that the 2nd diaphragm 12 and first substrate 1 clip tack coat 13.The independent reflectivity R11 of L1 layer is, from the plane of incidence 1A of first substrate 1 laser focusing is become the focal point with regulation area to second recording film 8, shine second recording film 8 (the L1 layer is all), and the value estimated of the disc drives tester (DDU1000 is hereinafter referred to as estimating instrument) that uses pulse work (パ Le ステ Star Network) company to make.And each film that constitutes the L1 layer in the present embodiment is extremely thin, and therefore the laser by shining behind the whole L1 layer has and the roughly the same area of regulation area that laser had that focuses on second recording film 8.Also identical in whole L0 layer.

The evaluation of the reflectivity that utilization evaluation instrument carries out is carried out according to the DVD-RW standard is following.At first, use has the laser based on the wavelength of DVD-RW standard, will be with top condition by the tracer signal write optical recording media A of 8-16 modulation system modulation, and, with suitable reproducing power (in the present embodiment, be 1.4mW) reproduce, observe reproducing signal with oscillograph, the maximum level of obtaining reproducing signal is the voltage levvl of I14H.According to the voltage levvl of obtaining,, estimate reflectivity based on the standard plate that can obtain the voltage levvl of corresponding reflectivity in advance.

The laser of Shi Yonging in the present embodiment has the wavelength that comprises based on the 650nm frequency band of the 650nm ± 10nm of DVD-RW standard.And to have carried NA be 0.65 optical lens and the laser diode with 658nm wavelength to the evaluation instrument of Shi Yonging in the present embodiment, still, if the wavelength of 650nm frequency band obtains reflectivity much at one so.

And, if the reflectivity that will see through the L0 layer from the laser that first substrate, 1 side (plane of incidence 1A) of optical recording media A shown in Figure 1 is shone and reflect at the L1 layer is made as " L1 layer emissivity R1 ", so, laser sees through the L0 layer and in the reflection of L1 layer, sees through the L0 layer once more.Therefore, the L1 layer reflectivity R1 in two stratotype phase-change optical storage mediums as the optical recording media A of present embodiment becomes the independent reflectivity R11 multiplied result of the transmissivity T0 of L0 layer and L1 layer (R1=T0 * R11 * T0).In the present embodiment, laser has the wavelength of 650nm frequency band.

In the present embodiment, the transmissivity T0 of L0 layer refers to, in the L0 layer that forms on first substrate 1, from the optical transmission rate of first substrate, 1 side irradiation.The transmissivity T0 of L0 layer is, as the ETA-RT that analytical equipment uses Steag ETA-Optik GmbH company to make, obtain and to have the laser of wavelength of 650nm frequency band as having illumination such as the big area (the 2nd area) of preceding described regulation area (the 1st area) transmissivity when being mapped to the L0 layer.At this, the 2nd area is the sectional area with the L0 layer of the direction of the direct of travel quadrature of laser, is to make to have the size that laser that the 2nd area shines the L0 layer becomes almost parallel.Therefore, in the present embodiment, having the laser that the 2nd area shines is directional light.

And in the present embodiment, transmissivity of supposing first substrate 1 etc. does not exert an influence to the transmissivity T0 of L0 layer, the reflectivity R1 and the independent reflectivity R11 of L1 layer of L1 layer.

For example, suppose the independent reflectivity R11 of L1 layer be general phase-change optical storage medium reflectivity 20%, the transmissivity T0 of L0 layer is 40%, L1 layer reflectivity R1 becomes 40% * 20% * 40%=3.2% so.Equally, if the transmissivity T0 of L0 layer is 45%, L1 layer reflectivity R1 becomes 4% so; If the transmissivity T0 of L0 layer is 50%, L1 layer reflectivity R1 becomes 5% so.

In order to obtain 10% L1 layer reflectivity R1 with the same terms, the transmissivity T0 of L0 layer must be 72%.And even the reflectivity R11 that the L1 layer is independent is increased to 25%, in order to obtain 10% L1 layer reflectivity R1, the transmissivity T0 of L0 layer must be 66%.

As mentioned above, L1 layer reflectivity R1 depends on the transmissivity T0 of L0 layer and the independent reflectivity R11 of L1 layer and changes.If improve the transmissivity T0 of L0 layer, in the increase of the reflectivity R1 of L1 layer, also can obtain effect so.

Therefore, be necessary that the thickness setting that the L0 layer is all becomes, make the L0 layer can guarantee the transmissivity T0 that wishes, the cooling velocity of first recording film 3 when making record becomes the best.Especially, first recording film 3 that laser absorption is big, the reduced thickness of first reflectance coating 5 are effective to increasing transmissivity T0.

And, need not see through incident light from the L1 layer of the inboard that light incident side is seen, therefore can preferentially guarantee good recording characteristic, with the thickness optimization of second recording film 8 and second reflectance coating 10.

Fig. 2 (a) represents that as parameter first recording film 3 is in the figure of relation of the thickness of the transmissivity Tc of L0 layer of crystalline state (not recording status) and first recording film 3 with the thickness of first reflectance coating 5, and Fig. 2 (b) represents that as parameter first recording film 3 is in the figure of relation of the thickness of the transmissivity Tr of L0 layer of crystallization, amorphous admixture (recording status) and first recording film 3 with the thickness of first reflectance coating 5.Record to first recording film 3 is to use the recording power and the laser rule (light strategy) that can obtain good shake in each combination of first recording film 3 and first reflectance coating 5 to carry out once.

First recording film 3 is in the L0 layer transmissivity Tr in the L0 layer that the L0 layer transmissivity Tc in the L0 layer of recording status not and first recording film 3 be in recording status, is generically and collectively referred to as the transmissivity T0 of L0 layer.

Shown in Fig. 2 (a), thick at the film that has made up first recording film 3 and first reflectance coating 5, promptly the thickness of first recording film 3 is the thickness of the 4nm and first reflectance coating 5 when being the combination of 4nm, and the L0 layer can obtain the transmissivity Tc more than 60%.

Shown in Fig. 2 (b), if first recording film 3 is in recording status, when the thickness of first recording film 3 was 4nm and 5nm, the L0 layer can obtain the transmissivity Tr more than 60% so, and the thickness of first reflectance coating 5 also can become 4nm or 5nm.If form the thickness of first reflectance coating 5 with 4nm, the thickness of first recording film 3 also can be formed by 4nm so, can make all thickness of L0 layer the thinnest.And if first recording film 3 is in recording status, several % rise when the light transmission of first recording film 3 is than recording status not so.

Represent that at Fig. 3 thickness with first recording film 3 is as the number of rewrites of parameter and the relation of shake (DOW (Direct Over Write) jittering characteristic).At this.Described rewriting is meant that a light beam rewrites, and, eliminates the record mark that formed in the past with a laser scanning that is, forms new record mark.Then, DOW0 is the first record that forms record mark to the not recording portion of initialized optical recording media A, and DOW1 is further to rewriteeing its first time that forms record mark.

According to Fig. 3, when forming the thickness of first recording film 3 with 4nm among the optical recording media A in present embodiment, can distinguish to can not get the good jitter value below 10% of jittering characteristic.Further, if thickness is 5nm, rise when number of rewrites surpasses 100 times so, shake surpasses 10%, and therefore, the thickness of judging first recording film 3 that can access good jittering characteristic is more than the 5nm.

This is because if form first recording film 3 with FGM as present embodiment, so along with the thickness attenuation, descend rapidly by the interfacial effect crystallization rate, so can not delete the information that has write down.As shown in Figure 3, in the optical recording media A of present embodiment, if form first recording film 3 with the thickness of 4nm, crystallization rate reduces so, the deletion difficulty.The thickness limit that can delete is 5nm.

According to above Fig. 2 (a) and Fig. 3, when using first recording film 3 of recording status not, be that the thickness of 5nm, first reflectance coating 5 is 4nm if establish the thickness of first recording film 3, just become the thick combination of film of the necessary characteristic that can access optical recording media A.But the transmissivity Tc of L0 layer of this moment is 56%, shown in Fig. 2 (b), than first recording film 3 that uses recording status and the transmissivity Tr (T0) of the L0 layer when having adopted the combination of identical thickness little.

Therefore, if use first recording film 3 of recording status, the transmissivity Tr (T0) of big L0 layer in the time of obtaining than first recording film 3 that uses recording status not so is so wish.

Further, shown in Fig. 2 (b), with the thickness of first recording film 3 is that the thickness of 4nm, first reflectance coating 5 is that 4nm is when forming, the transmissivity Tr of L0 layer becomes 66%, therefore, if adopt the membrane structure make the independent reflectivity R11 of L1 layer become 25% L1 layer, can infer to obtain aforesaid 10% L1 layer reflectivity R1.But as shown in Figure 3, the thickness 5nm of first recording film 3 is the limit that can access sufficient crystallization rate and shake, so the transmissivity Tr of L0 layer is difficult to reach 66%.Therefore, improve the transmissivity Tr of L0 layer, be difficult to obtain 10% L1 layer reflectivity R1.

Therefore, according to Fig. 2 (a), Fig. 2 (b) and Fig. 3, distinguished that the higher limit of the transmissivity Tr of L0 layer in the optical recording media A of present embodiment is 60%.

Fig. 4 represent first recording film 3 and second recording film 8 be among the optical recording media A of recording status, L1 layer reflectivity R1 and use the relation of the C/N (CNR) of the 3T signal that the 1mW reproduction laser power according to dvd standard reproduces.Optical recording media A is writing down the tracer signal of 8-16 modulated random pattern.

According to Fig. 4, distinguished that the reflectivity R1 of the L1 layer that obtains the above CNR of 50dB that can fully satisfy when optical recording media A practical is more than 5%.The CNR of discontented 50db might cause problems such as error rate reduction.Therefore, according to Fig. 4, find that the lower limit of the reflectivity R1 of L1 layer is 5%.

The thickness of the first suitable recording film 3 when satisfying the recording characteristic of L0 layer, from the crystallization rate that the interfacial effect of aforesaid first recording film 3 causes, also have can attenuation the limit.Therefore, shown in above-mentioned method, be difficult to the thickness attenuation of first recording film 3 is increased the transmissivity T0 of L0 layer, the limit is arranged.

Therefore,, not only to improve the transmissivity T0 of L0 layer, also need to consider to improve the method for the independent reflectivity R11 of L1 layer as far as possible in order to improve L1 layer reflectivity R1.As described above, the L1 layer does not need to consider seeing through of light, therefore membrane structure can be designed so that the independent reflectivity R11 of L1 layer obtains appropriate value.

Represent at Fig. 5, the reflectivity R11 that the L1 layer is independent is as parameter, obtains the transmissivity Tr and second recording film 8 that use can obtain the recording power of good shake and the laser rule has write down primary information on first recording film 3 L0 layer with emulation and is in the not relation of the L1 layer reflectivity R1 of recording status.The independent reflectivity R11 of L1 layer for example can control by the thickness that changes the 4th deielectric-coating 7.But if the tendency that the thickness that increases the 4th deielectric-coating 7 to obtain the independent reflectivity R11 of higher L1 layer, has degree of modulation to reduce so, the reflectivity R11 independent from the L1 layer surpasses at 25% o'clock, is difficult to guarantee the degree of modulation more than 50%.

According to Fig. 5, distinguished if improve the independent reflectivity R11 of L1 layer, so, even the transmissivity Tr of L0 layer is the low reflectivity R1 that also can obtain necessary L1 layer.Therefore, by the L1 layer that formation uprises the independent reflectivity R11 of L1 layer, can set the transmissivity Tr of L0 layer than the lowland, the thickness of first recording film 3 is not the thinnest thickness, but can guarantee thickness sufficient.

" optical recording device "

Below, represent to be used for to have embodiment laser, optical recorder of the present invention of the recording impulse string of one embodiment of the present invention as shown in Figure 6 to the optical recording media A of present embodiment irradiation at Fig. 7.

The recording impulse string comprises as shown in Figure 6: beginning pulse Ttop, and e rises from the deletion power P, applies laser with recording power Pw at first on recording film; Multiple-pulse Tmp is the pulse that is connected on beginning pulse Ttop back, alternately applies recording power Pw and lowest power Pb; Cooling pulse Tc1 makes laser rise to from lowest power Pb and eliminates power P e.Cooling pulse Tc1 becomes the terminal of the recording impulse string of corresponding each mark.Beginning pulse Ttop and multiple-pulse Tmp become and form the heating pulse (recording impulse) that record mark is used on recording films.And, the situation that does not have multiple-pulse Tmp and only form the recording impulse string with beginning pulse Ttop is also arranged.

At first, Spindle Motor 31 rotation optical recording media A.The rotating speed of Spin Control portion 32 control Spindle Motors 31 is so that become the line speed record corresponding with the purpose writing speed.And, have the record, reproduction or the deletion that are used in optical recording media A semiconductor laser (LD) 33, make the object lens (not shown) and four shaven heads 34 of cutting apart photo detector (not shown) for example of the laser focusing irradiation of LD33, be set to and can on the radial direction of optical recording media A, move.

And as the record light source of the optical recorder that is used in present embodiment, hope is the high-intensity light source as laser, strobe light.Wherein, because semiconductor laser can be realized the miniaturization of light source, power consumption is little, and therefore modulation is easily wished.

Four of shaven head 34 is cut apart photo detector and is received the reflected light that shines the laser on the optical recording media A from LD 33.Cut apart the light that photo detector receives based on four, signal generating unit 57 generates push-pull signals, outputs to swing detection portion 36.And, cut apart the light that photo detector receives based on four, signal generating unit 57 is to driving governor 44 output focus error signal and trail-and-error signals.Moreover signal generating unit 57 generates the reproducing signal (RF signal) of cutting apart the composite signal of photo detector as four, outputs to reflectivity test section 46 and driving governor 44.

Driving governor 44 is controlled actuator control part 35 according to focus error signal and the trail-and-error signal supplied with from signal generating unit 57.The focusing and the tracking of actuator control part 35 control shaven heads 34.

Driving governor 44 is also controlled Spin Control portion 32, swing detection portion 36, address demodulator circuit 37, recording clock generating unit 38.

System controller 45 controlling and driving controller 44 and each several parts.

Swing detection portion 36 possesses bandpass filter able to programme (BPF) 361, to the detected swinging signal of address demodulator circuit 37 outputs.Address demodulator circuit 37 is according to detected Wobble signal demodulating address information, and output.Input is had PLL condensating synthesizering circuit 381 by the recording clock generating unit 38 of the address information of demodulation, generates the recording channel clock, outputs to recording impulse generating unit 39 and umber of pulse control portion 40.

At this, be described in detail the reproducing movement of the optical recording media A of record reproducing device.

The planimetric map of representing optical recording media A at Fig. 8.Optical recording media A has center pit 21 and is positioned at the pinch zones 22 of its periphery.Periphery in pinch zones 22 is provided with block of information (Lead-In Area) 23 and best power control zone (OPC district) 25 with one heart circularly, and further, its outer regions becomes the recording areas 24 of real data such as being used for recording image information, acoustic information.At this, Lead-In Area 23 can be the free position of rom state or RAM state.In addition, also have by forming swing in high frequency and hole at the laser aiming groove that is used for obtaining tracking signal, with identifying information as the method for reproducing special-purpose recorded information storage.

Write down at Lead-In Area 23 and to be used for so that optical recording media A obtains the record condition that the mode of superperformance writes down, as identifying information.Identifying information is the following stated for example, they be the recording impulse string information that expression changes the recording impulse string that uses when record mark based on recorded information forms, or the expression record is with the laser intensity (recording power Pw and deletion power P e etc.) of laser and the recording parameters (record condition) of its application time (pulse is wide) etc.Moreover, can also be with the transmissivity Tr of manufacturer's information of the kind of optical recording media A, optical recording media A, the unit record number of plies that optical recording media A has, constituent parts recording layer as the identifying information record.

When the installation portion 58 of record reproducing device has been installed when recording areas 24 has write down the optical recording media A of information, so by the rotating speed of Spin Control portion 32 control Spindle Motors 31, make the rotation of optical recording media A become the line speed record of corresponding purpose writing speed.The LD33 of shaven head 34 is to faint the reading of Lead-In Area 23 irradiations (reproduce and use) laser, and shaven head 34 is supplied with by four to signal generating unit 57 and cut apart the reflected light that photo detector receives.LD33, shaven head 34 and signal generating unit 57 are as the recapiulation work of reproducing recorded information from optical recording media A.

Signal generating unit 57 generates reproducing signal based on reflected light, supplies to reflectivity test section 46.Reflectivity test section 46 is judged gradient positive and negative of its reflectance varies, and identification is L0 layer, or L1 layer.Moreover, shaven head 34 or optical recording media A are moved up and down, focus is focused on the purpose recording film.Actuator control part 35 as 34 pairs on control shaven head constitute each recording film of optical recording media A focusing, and the focus of the tracking that is formed on the track in each recording film and tracking control section worked.

Then, shaven head 34 is to the be subjected to light signal of signal generating unit 57 outputs from recording areas 24, and signal generating unit 57 generates and the output reproducing signal.Reproducing signal is exported after by not shown demodulation section demodulation.Simultaneously, swing detection portion 36 is according to the radial push-pull signal of supplying with from signal generating unit 57, and wobble detection signal and LPP signal output to address demodulator circuit 37.

Demodulator circuit 37 demodulation LPP signals in address are obtained address information, output to driving governor 44.

Below, illustrate with record reproducing device in relevant structure and the work of record of optical recording media A.

When the optical recording media A that has recording portion not in recording areas 24 has been installed at the installation portion 58 of record reproducing device, the LD33 of shaven head 34 is to faint the reading of Lead-In Area 23 irradiations (reproduce and use) laser, and shaven head 34 is supplied with by four to signal generating unit 57 and cut apart the reflected light that photo detector receives.Signal generating unit 57 generates reproducing signal based on reflected light, to system controller 45 identifying information of reproducing signal of having supplied with demodulation.Identification signal comprises the information of recording impulse string information, expression recording parameters etc.

System controller 45 is written to storer 451 with identifying information, based on this identifying information controlling and driving controller 44.Driving governor 44 is controlled actuator control part 35, swing detection portion 36, address demodulator circuit 37 based on the control from system controller 45.

When the record of optical recording media A, system controller 45 is written to recorded information as indication the instruction unit work of which the unit record layer in L0 layer, the L1 layer.Then, reflectivity test section 46 is judged gradient positive and negative of the reflectance varies of unit record layers, and identification is L0 layer, or L1 layer, and actuator control part 35 34 pairs on control shaven heads have accepted to write the focusing and the tracking of the unit record layer of indication.

The system controller 45 of present embodiment has been stored 3 following log file systems in storer 451.System controller 45 is indicated based on the log file system.In Fig. 9 (A)～(C), be illustrated in to pattern 3 log file systems that use in the record to optical recording media A.

Log file system shown in Fig. 9 (A) is, at first at the whole records of interior thoughtful periphery of first recording film 3 that constitutes the L0 layer, and then opposite types from the periphery of second recording film 8 that constitutes the L1 layer towards interior Zhou Jinhang record.

Log file system shown in Fig. 9 (B) is at first at the whole records of the interior thoughtful periphery of first recording film 3 that constitutes the L0 layer and after finishing, to follow from the parallel type that writes down towards periphery in interior week of second recording film 8 that constitutes the L1 layer.

Log file system shown in Fig. 9 (C) is, at first from interior all opening entries of first recording film 3 that constitutes the L0 layer after any position, recording film 8 begin towards interior all sides the optional position of radius much at one from constituting second of L1 layer, record in second recording film 8 of area of radius same radius of the area that uses in the record that has with first recording film 3 with above-mentioned optional position.At this moment, adopt opposite types.And, at the non-recorded part of the recording section of following the L0 layer and the non-recorded part of the recording section of following the L1 layer, with identical method duplicate record action.

In 3 above log file systems, if rewrite liking the recording section of L0 layer, L1 layer, any recording film of L0 layer, L1 layer can so.

Shaven head 34 shines recording laser to optical recording media A.The swinging signal that driving governor 44 is supplied with by swing detection portion 36 to 38 outputs of recording clock generating unit.And, to the address information of system controller 45 outputs by 37 supplies of address demodulator circuit.

Import the recording clock generating unit 38 of demodulated address information, have PLL condensating synthesizering circuit 381, generate the recording channel clock, output to recording impulse generating unit 39 and umber of pulse control portion 40.

System controller 45 is controlled EFM+ scramblers 42, mark lengths counter 41, is reached umber of pulse control portion 40.Moreover system controller 45 is controlling recording train of impulses control part 39 and LD drive division 43 also.

The recorded information of 42 pairs of inputs of EFM+ scrambler is carried out the 8-16 demodulation, and outputs to recording impulse string generating unit 39 and mark lengths counter 41 as demodulating data.Mark lengths counter 41 outputs to recording impulse string generating unit 39 and umber of pulse control portion 40 as the mark lengths generating unit work of counting the regulation mark lengths based on demodulating data with its count value.Umber of pulse control portion 40 comes controlling recording train of impulses generating unit 39 based on count value that is supplied to and recording channel clock, so that recording impulse becomes the pulse of regulation.

Recording impulse string generating unit 39 possesses beginning pulse control signal generating unit 39t, multiple-pulse control signal generating unit 39m and cooling pulse control signal generating unit 39c.

Beginning pulse control signal generating unit 39t generates the beginning pulse control signal, and multiple-pulse control signal generating unit 39m generates the multiple-pulse control signal, and cooling pulse control signal generating unit 39c generates the cooling pulse control signal.

Each control signal supplies to LD drive division 43, switching part 431 is according to the control signal that is supplied to, the drive current source 431w of recording power P, drive current source 431e, the drive current source 431b of lowest power Pb of deletion power P e are switched, generate the recording impulse string.

Pw drive current source 431w, Pe drive current source 431e and Pb drive current source 431b, according to the recording power Pw in the storer 451 that is stored in system controller 45, deletion power P e and lowest power Pb to bare headed 34 supplying electric currents.These three values are the good optimum values of recording characteristic that are used to make optical recording media A, represent that the identifying information of this optimum value is stored in the storer 451 in advance, perhaps by the storage of more newly arriving.And storer 451 is for example ROM (Read Only Memory) or recordable RAM (Random Access Memory).

, the high linear speed (high power speed) that the optical recorder of present embodiment can corresponding optical recording media A is changed select the setting recording linear velocity from a plurality of line speed record.When having imported when being used to select the indicator signal of line speed record (times fast mode), system controller 45 is controlled Pw drive current source 431w, Pe drive current source 431e and Pb drive current source 431b as described above based on the identifying information of the line speed record that is instructed to that is stored in storer 451.In storer 451, stored the identifying information of a plurality of line speed records as described above.

The recording impulse string that generates is imported into shaven head 34.Shaven head 34 control LD33 make the LD luminescent waveform of its output device recording impulse string likely and power, and recorded information is recorded in optical recording media A.

Recording impulse string generating unit 39, LD drive division 43 and shaven head 34 are as recording portion 400 work, this recording portion 400 is according to the mark lengths that is generated by mark lengths counter 41, generate the recording impulse string, shine recording light to recording film accordingly by LD33 and recording impulse string, the record mark of record expression recorded information.

" structure of optical recording media "

In the basic structure of two stratotype phase-change optical storage medium A of one embodiment of the present invention shown in Figure 1, change first recording film 3 that constitutes the L0 layer, the thickness of first reflectance coating 5, the characteristic of investigation transmissivity T0, reflectivity R0 etc.

(embodiment 1)

On first substrate 1 of the polycarbonate resin of diameter 120mm, thickness of slab 0.6mm, each film that formation is narrated below.Track space with 0.74 μ m on substrate 1 forms dead slot.This groove depth is 25nm, the ratio of groove (groove) width and bank ground (land) width, and the chances are 40: 60.And from the incident direction of laser, groove becomes convex.

At first, with vacuum tank exhaust gas inside to 3 * 10 ^-4Behind the Pa, use 2 * 10 ^-1Added the SiO of 20mol% in the argon atmosphere gas of Pa ₂The ZnS target and utilize the high frequency magnetron sputtering method, on first substrate 1, form first deielectric-coating 2 of thickness 70nm.

Then, following each film that stacks gradually: with the plain single alloys target of the quaternary of Ge-In-Sb-Te, first recording film 3 of stacked thickness 5nm; Then, use and first deielectric-coating, 2 identical materials second deielectric-coating 4 of stacked 9nm; Use the Ag alloys target, translucent first reflectance coating 5 of stacked thickness 4nm.After taking out substrate 1 in the vacuum tank; the spin coated propylene is ultraviolet curable resin (SK5110 that Sony Chemical goods Co., Ltd. makes) on translucent first reflectance coating 5; shine by ultraviolet ray and to solidify; forming thickness is the 1st diaphragm 6 of 3 μ m, thereby forms the L0 layer as the 1st unit record layer.

As the L1 layer of the 2nd unit record layer, be with same second substrate 11 that forms of first substrate 1 on, by with the sputter of L0 layer the same terms, stack gradually each film as follows: use the Ag alloys target, second reflectance coating 10 of stacked 120nm; With with first deielectric-coating, 2 identical materials, the 3rd deielectric-coating 9 of stacked 16nm; With the plain single alloys target of the quaternary of Ge-In-Sb-Te, second recording film 8 of stacked thickness 16nm; The 4th deielectric-coating 7 of stacked 80nm.In this thickness structure, measure the independent reflectivity R11 of L1 layer as previously mentioned, can guarantee that so the independent reflectivity R11 of L1 layer is 25%.

After taking out second substrate 11 in the vacuum tank; the spin coated propylene is ultraviolet curable resin (SK5110 that Sony Chemical goods Co., Ltd. makes) on the 4th deielectric-coating 7; solidify by the ultraviolet ray irradiation, forming thickness is the 2nd diaphragm 12 of 3 μ m, becomes the L1 layer.

The POP120 type apparatus for initializing that utilizes CP computer machine company of Hitachi to make carries out the initialization of L0 layer, L1 layer.After L0 layer, L1 layer recording layer separately carried out initialization, use two sides adhesive type thin slice 13 (adhesive linkages 13) that the 1st diaphragm 6 is bonding opposed to each other mutually with the 2nd diaphragm 12, made two stratotype phase-change optical storage medium A.

And in the present embodiment, the transmissivity Tc of the not recording status (after the initialization) of L0 layer and reflectivity Rc and the transmissivity Tr of recording status and the measurement of reflectivity Rr were carried out at independent state before bonding with the L1 layer.Independent L0 layer is meant, first substrate 1 and the L0 layer that forms on first substrate 1.At this, first recording film 3 is in the reflectivity Rr of the L0 layer in the L0 layer that the reflectivity Rc of the L0 layer in the L0 layer of recording status not and first recording film 3 be in recording status, be generically and collectively referred to as the reflectivity R0 of L0 layer.

The reflectivity R0 of L0 layer and the measurement of transmissivity T0 are, the laser that will have the wavelength of 650nm frequency band from the plane of incidence 1A of first substrate 1 shines on the L0 layer as the directional light with the 2nd area, and the EETA-RT that analytical equipment uses Steag ETA-Optik GmbH company to make measures.

Record to first recording film 3 carries out once, the laser rule of in record, using be as shown in Figure 6 based on 8-16 modulated random pattern according to the recording impulse string of DVD-RW Versionl.1 standard.When if the mark lengths of record mark is nT, the quantity that apply the pulse of recording power Pw, promptly starts pulse Ttop and multiple-pulse Tmp is (n-1).Line speed record is 7.7m/s (the twice speed that is equivalent to the two-layer standard of DVD-Video), and unit clock T is 19.2ns (a DVD twice speed), and bit length is 0.293 μ m/ bit.Carry out the record with the DVD-Video equal densities, two-layer recording capacity is equivalent to the 8.5G byte.

In the present embodiment, the absorptivity A0 of L0 layer obtains with A0 (%)=100%-transmissivity T0 (%)-reflectivity R0 (%).To be in the transmissivity Tc of recording status not and absorptivity Ac that reflectivity Rc obtains and be in the transmissivity Tr of recording status and the absorptivity Ar that reflectivity Rr obtains based on first recording film 3, be generically and collectively referred to as the absorptivity A0 of L0 layer based on first recording film 3.

Then, as described above the L1 layer is pasted on the L0 layer, carry out first recording film 3 (L0 layer) and be in not that the L1 layer reflectivity Rc1 and first recording film 3 of recording status are in the measurement of the L1 layer reflectivity Rr1 of recording status.Be in first recording film 3 not that the L1 layer reflectivity Rc1 and first recording film 3 of recording status are in the L1 layer reflectivity Rr1 of recording status, be generically and collectively referred to as L1 layer reflectivity R1.

At first, with the condition identical with first recording film 3, second recording film 8 that constitutes the L1 layer being carried out record 10 times, then, is the 1st area to second recording film 8 of recording status with laser focusing, and the in-service evaluation instrument is measured L1 layer emissivity R1.Carry out when record 10 times, to second recording film 8 of the bonding L1 layer of the L0 layer that is in recording status with first recording film 3, the zone of the information that records by first recording film 3, recorded information.Further, use 8-16 modulated random pattern according to the algorithm of stipulating in the DVD-RW standard (114/114H), is carried out the measurement of degree of modulation after second recording film 8 has been carried out writing down for 10 times.

Moreover, laser focusing on first recording film 3, is estimated recording characteristic and jittering characteristic.Under these conditions, comprise that contiguous track carries out 10 records (DOW9) afterwards, cut apart, measure two data shakes of clock at the amplitude center of its reproducing signal.The reproducing power of this moment is constant to be 1.4mW.

And rewriteeing characteristic is to measure (DOW999) shake afterwards of 1000 records.

And, in the present embodiment, 10 records (DOW9) be dithered as 9% when following, for well.Further, about the higher limit of the rewriting shake of 1000 records (DOW999), establishing when error rate begins to worsen is 12%, if 12% with next good.

The results are shown in table 1.

[table 1]

As shown in table 1, first recording film 3 of L0 layer is in not that the transmissivity Tc of recording status is 56%, and reflectivity Rc is 11%, and the transmissivity Tr of recording status is 60%, and reflectivity Rr is 9%.

Initial characteristic and regenerative recording characteristic be, DOW9 is dithered as 8.9%, though be the state near 9%, belongs in the good standard.Though transmissivity Tr is 60% very high, the rewriting shake of DOW999 is in 12.0%.

First recording film 3 of L0 layer is in that the reflectivity Rr1 of the L1 layer of recording status is 9.0%, has fully surpassed the lower limit 5% of the reflectivity R1 of above-mentioned L1 layer, and is very good.And though not record in table 1, the degree of modulation of L1 layer guarantees 53%, has surpassed 50%.

(embodiment 2)

With first recording film 3 that forms thickness 6nm except that the plain single alloys target of the quaternary of using Ge-In-Sb-Te, use the Ag alloys target to form translucent first reflectance coating 5 of 7nm, other condition identical with embodiment 1 has been made optical recording media.

With the result that embodiment 1 estimates in the same manner, as shown in table 1, the reflectivity Rr1 of L1 layer is 5.0% to be lower limit, the DOW9 shake of L0 layer is 8.0%,, the shake of DOW999 is 10.0%, obtains very good recording characteristic.

(embodiment 3)

With first recording film 3 that forms thickness 6nm except that the plain single alloys target of the quaternary of using Ge-In-Sb-Te, use the Ag alloys target to form translucent first reflectance coating 5 of 4nm, other condition identical with embodiment 1 has been manufactured optical recording media.

With the result that embodiment 1 estimates in the same manner, as shown in table 1, the reflectivity Rr1 of L1 layer is 7.8%, and the D0W9 shake of L0 layer is 8.5%, and the shake of DOW999 is 11.8%, obtains good recording characteristic.

(embodiment 4)

With first recording film 3 that forms thickness 6nm except that the plain single alloys target of the quaternary of using Ge-In-Sb-Te, use the Ag alloys target to form translucent first reflectance coating 5 of 5nm, other condition identical with embodiment 1 has been manufactured optical recording media.

With the result that embodiment 1 estimates in the same manner, as shown in table 1, the reflectivity Rr1 of L1 layer is 6.5%, and the DOW9 of L0 layer shake is 8.8%, the shake of DOW999 is 11.5%, obtains good recording characteristic.

(comparative example 1)

With first recording film 3 that forms thickness 4nm except that the plain single alloys target of the quaternary of using Ge-In-Sb-Te, use the Ag alloys target to form translucent first reflectance coating 5 of 4nm, other condition identical with embodiment 1 has been manufactured optical recording media.

With the result that embodiment 1 estimates in the same manner, as shown in table 1, the reflectivity Rr1 of L1 layer is 10.9%, and for well, (Tr Tc) has surpassed 60% to the transmissivity T0 of L0 layer.But the shake of the DOW9 of L0 layer is 15.1%, and the shake of DOW999 becomes 20.0%, the non-constant of recording characteristic.

(comparative example 2)

With first recording film 3 that forms thickness 7nm except that the plain single alloys target of the quaternary of using Ge-In-Sb-Te, use the Ag alloys target to form translucent first reflectance coating 5 of 7nm, other condition identical with embodiment 1 has been manufactured optical recording media.

With the result that embodiment 1 estimates in the same manner, as shown in table 1, the reflectivity Rr1 of L1 layer is 4.2%, reduces a lot.Therefore, as shown in Figure 2, the CNR of 3T signal is not enough 50dB, and the DOW9 of L0 layer shake is 7.8% for this reason, and the DOW999 shake is 9.8%, and recording characteristic is very good, but can not be used for practicality.

(comparative example 3)

Make the L0 layer with embodiment 1 identically, use the 3rd deielectric-coating 9 that forms the L1 layer of 16nm with the 1st diaphragm 2 identical materials; Form second recording film 8 of thickness 16nm with the plain single alloys target of the quaternary of Ge-In-Sb-Te; And the 4th deielectric-coating 7 of 110nm.For other films that constitute the L1 layer, be the structure identical with embodiment 1.By forming such thickness structure, reflectivity R11 that can the L1 layer is independent guarantees to be 28%.

With the result that embodiment 1 estimates in the same manner, the reflectivity Rr1 of L1 layer is 10.1%, has surpassed 10%.This is because the independent reflectivity R11 of L1 layer is 28%, has improved a lot of effects.But in this comparative example, the characteristic of L0 layer is identical good with embodiment 1, but in the characteristic of L1 layer, especially degree of modulation drops to 46% significantly.Should guarantee minimum 50% the scheduling of separating, be inadequate according to the membrane structure that is purpose with the independent reflectivity R11 of raising L1 layer.Therefore, the optical recording media of the membrane structure of comparative example 3 can not be provided in practicality.

According to above embodiment 1～4 and comparative example 1～3, studied the L0 layer and be in the proper range of the reflectivity Rr1 of the L1 layer of recording status.According to embodiment 1～4, L1 layer reflectivity Rr1 can obtain the good recording characteristic of L0 layer between 5% to 10%.

In order as comparative example 1, the reflectivity Rr1 of L1 layer to be increased to more than 10%, if form first recording film 3 of L0 layer and the thickness of first reflectance coating 5 thinner, to improve the transmissivity Tr of L0 layer, interfacial effect crystallization rate by first recording film 3 reduces the recording characteristic rapid deterioration of L0 layer so.And as comparative example 2, if the reflectivity Rr1 less than 5% of L1 layer, then the CNR deficiency can not be provided in practicality, and this also can understand from the Fig. 2 that has represented.

And, shown in comparative example 3, improve the method that the independent reflectivity R11 of L1 layer improves L1 layer reflectivity Rr1, can worsen the recording characteristic of L1 layer, especially degree of modulation largely.Therefore, when improving the independent reflectivity R11 of L1 layer, can obtain good recording characteristic, and, be difficult to realize that L1 layer reflectivity Rr1 surpasses the membrane structure of 10% optical recording media.

As mentioned above, the scope of reflectivity Rr1 that optical recording media A can obtain the L1 layer of good record characteristic is, when the L0 layer of the laser light incident side that is positioned at the wavelength with 650nm frequency band is in recording status, is more than 5% and below 10%.

Moreover, according to the result who obtains by embodiment 1～4 and comparative example 1～3, carried out first recording film 3 be in recording status not or the transmissivity T0 of the L0 layer during recording status (Tc, Tr), reflectivity R0 (Rc, Rr) and absorptivity A0 (Ac, the research of proper range Ar).

As shown in table 1, the transmissivity Tr that first recording film 3 is in recording status is greater than (the Tc ≦ Tr), and the reflectivity Rr that first recording film 3 is in recording status is less than (the Rr ≦ Rc) of the reflectivity Rc of recording status not of the transmissivity Tc of recording status not.Moreover the absorptivity Ac that first recording film 3 is in recording status not is than the big (Ar＜Ac) of the absorptivity Ar of recording status.As Tc ≦ Tr, keep the high state of transmissivity Tc by the transmissivity Tr that makes recording status than initialization (record) state, can guarantee that the record of two stratotype phase-change optical storage mediums exchanges.

According to table 1, in order in the optical recording media A of present embodiment, to obtain good recording characteristic, wish that transmissivity T0, reflectivity R0 and the absorptivity A0 of L0 layer satisfies above-mentioned relation, also wish it is the scope of Tc ≦ Tr ≦ 60% and 9% ≦ Rr ≦ Rc ≦ 15%.These values all are that irradiation has the 2nd area and has the laser (directional light) of the wavelength of 650nm frequency band and the value having carried out estimating.

Be in not still recording status of recording status according to first recording film 3, be speculated as the characteristic of L0 layer, especially transmissivity are exerted an influence and used such directional light, in the optical recording media A of present embodiment, not to be used for illustrating the not difference of the transmissivity of the part of recorded information (crystalline state) and the mark part (non-crystalline state) that forms for recorded information of the recording film put down in writing as patent documentation 1.

In the design as the recording film in past of patent documentation 1 record, purpose is to reduce in the recording film part of recorded information (crystalline state) not and the transmissivity of the mark part (non-crystalline state) that forms for recorded information poor.For this reason, if the absorptivity of the crystalline state of establishing (not recording status) is the absorptivity of A1, non-crystalline state (recording status) is that the reflectivity of A2, crystalline state is that R1, amorphous reflectivity are R2, must be the membrane structure that satisfies the relation of A1＜A2 and R2＜R1 so, perhaps satisfy A1 A2 and R2 in the membrane structure of relation of R1 any.

Necessary relation in the optical recording media in above-mentioned past, with the relation of Rr ≦ Rc and Ar＜Ac necessary in the optical recording media A of present embodiment (if imitation above-mentioned be R2 ≦ R1, A2＜A1) different.

And, according to table 1, if the thickness of first recording film 3 can be known the scope that can obtain superperformance according to various combinations in the thickness of 5nm～6nm, first reflectance coating 5 scope at 4nm～6nm.

, among the embodiment 2, the L0 layer is in that the L1 layer reflectivity Rr1 of recording status is more than 5%, and the L0 layer is in not that the L1 layer reflectivity Rc1 of recording status is 4.2%, therefore can not obtain sufficient CNR.Therefore, compare with the L0 layer being write down before the L1 layer is write down, hope is the method that again the L1 layer is write down after the L0 layer is write down.

Use optical recording media A with embodiment 1, the 2 same present embodiments that form, carried out the 1st method that (the L0 layer is recording status) after L0 layer (the first recording film 3) record write down L1 layer (second recording film 8) and the L0 layer write down before (the L0 layer is recording status not) record the comparison of the 2nd method of L1 layer.In the 1st method, to the regional service recorder with regulation area of first recording film 3 with laser log after the information, laser is used to second recording film, 8 irradiation records in the zone of the information by having write down first recording film 3, comes recorded information.

Utilize the method identical to estimate the reflectivity R1 of L1 layer, use the condition identical, with the jittering characteristic of laser focusing evaluation L1 layer to second recording film 8 with the L0 layer with

embodiment

1,2.

It the results are shown in table 2.

[table 2]

The optical recording media identical with embodiment 1, the characteristic when utilizing the 1st method to write down are used in embodiment 5 expression.The optical recording media identical with embodiment 2, the characteristic when utilizing the 1st method to write down are used in embodiment 6 expression.

The optical recording media identical with embodiment 1, the characteristic when utilizing the 2nd method to write down are used in comparative example 4 expression.The optical recording media identical with embodiment 2, the characteristic when utilizing the 2nd method to write down are used in comparative example 5 expression.

Embodiment

5,6 shows the good value of jittering characteristic of L1 layer reflectivity R1 (Rr1) and L1 layer.On the other hand, in comparative example 4, the jittering characteristic of L1 layer has problem, and in the comparative example 5, though realized record-playback, L1 layer reflectivity R1 (Rc1) does not satisfy making CNR become the above standard of 50dB less than 5%.And, also see the deterioration of the characteristic of L1 layer, especially DOW999.

Therefore, at first seeing that to constituting first recording film 3 of the L0 layer that is positioned at the front shines the record laser from light incident side, has the regional record information of regulation area, then make record constitute second recording film 8 of L1 layer by back, zone (posting field) irradiation of the information that records of 1 recording film 3 with laser, come the optic recording method of the one embodiment of the present invention of recorded information to be, the expanded range of the optical recording media A of present embodiment with superperformance, and the allowed band when enlarging the thickness design is resultful.

Form the method for the optical recording media A of present embodiment, be not limited to above-mentioned method, it also can be following method, promptly on first substrate 1, stack gradually first deielectric-coating 2, first recording film 3, second deielectric-coating 4, first reflectance coating 5 at least, thereon, the resin that coating is solidified through the UV irradiation, push the transparent stamper that is used for the transfer printing track, irradiation UV is cured under this state, then, peel off transparent stamper, stack gradually the 4th deielectric-coating 7, second recording film 8, the 3rd deielectric-coating 9, second reflectance coating 10 afterwards.

And, as this structure, also can be on semitransparent reflecting film 5, to form the transparent dielectric film of the transmissivity that can improve the L0 layer.

Claims

1. an optical recording media utilizes the light of the wavelength with 650nm ± 10nm to write down or information reproduction, it is characterized in that having:

Substrate;

The 1st unit record layer that has the 1st recording film and the 1st reflectance coating at least that on aforesaid substrate, forms successively and have the 2nd recording film at least and the 2nd unit record layer of the 2nd reflectance coating;

Above-mentioned the 1st recording film is Ag-In-Sb-Te alloy or Ge-In-Sb-Te alloy or the alloy film that comprises at least a composition among Ag, Si, Al, Ti, Bi, the Ga in the Ge-In-Sb-Te alloy, forms with the thickness below the 10nm;

Above-mentioned the 1st reflectance coating is Al, Au, Ag or is major component and comprises by more than one the metal or the alloy of the interpolation element that forms of semiconductor with these Al or Au or Ag, forms with the thickness below the 10nm;

Above-mentioned the 2nd recording film be Ag-In-Sb-Te alloy or Ge-In-Sb-Te alloy or in the Ge-In-Sb-Te alloy, comprise Ag or Si, Al, Ti, Bi, Ga in the alloy film of at least a composition;

Above-mentioned the 2nd reflectance coating is Al, Au, Ag or is major component and comprises by more than one the metal or the alloy of the interpolation element that forms of semiconductor with these Al or Au or Ag;

In above-mentioned the 1st recording film, write down under the recording status of information, after above-mentioned light is by aforesaid substrate and the 1st unit record layer, focus on above-mentioned the 2nd recording film, when shining with the form of focal point with regulation area, the reflectivity of above-mentioned the 2nd unit record layer is more than or equal to 5% and smaller or equal to 10%.

2. optical recording media as claimed in claim 1 is characterized in that,

In above-mentioned the 1st unit record layer, when above-mentioned light with the direction of the direct of travel quadrature of this light on the form of the big directional light of sectional area ratio afore mentioned rules area when shining above-mentioned the 1st unit record layer, if the transmissivity when establishing the not recording status that is in the information that do not record in above-mentioned the 1st recording film is Tc, reflectivity is Rc, if the transmissivity when being in the recording status of the information that write down in above-mentioned the 1st recording film is that Tr, reflectivity are Rr, then

Tc ≦ Tr ≦ 60% and 9% ≦ Rr ≦ Rc ≦ 15%.

3. the recording method of an optical recording media is characterized in that, this optical recording media has:

Substrate;

The 1st unit record layer and the 2nd unit record layer that on aforesaid substrate, form successively, above-mentioned the 1st unit record layer has the 1st recording film and the 1st reflectance coating of the light recording information of the wavelength that utilizes 650nm ± 10nm at least, and above-mentioned the 2nd unit record layer has the 2nd recording film and the 2nd reflectance coating that utilizes above-mentioned light recording information at least;

In above-mentioned the 1st recording film, write down under the recording status of information, after above-mentioned light is by aforesaid substrate and the 1st unit record layer, focus on above-mentioned the 2nd recording film, when shining with the form of focal point with regulation area, the reflectivity of above-mentioned the 2nd unit record layer is more than or equal to 5% and smaller or equal to 10%;

In above-mentioned the 1st unit record layer, when above-mentioned light with the direction of the direct of travel quadrature of this light on the form of the big directional light of sectional area ratio afore mentioned rules area when shining above-mentioned the 1st unit record layer, if the transmissivity when establishing the not recording status that is in the information that do not record in above-mentioned the 1st recording film is Tc, reflectivity is Rc, if the transmissivity when being in the recording status of the information that write down in above-mentioned the 1st recording film is that Tr, reflectivity are Rr, then Tc ≦ Tr ≦ 60% and 9% ≦ Rr ≦ Rc ≦ 15%;

Method for recording information comprises in above-mentioned optical recording media:

The 1st step in the regional record information with regulation area of above-mentioned the 1st recording film;

The zone of the information that records by above-mentioned the 1st recording film is to the 2nd step of above-mentioned the 2nd recording film recorded information.