JPH10269575A - Multilayer optical information recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform recording without reducing a reproducing signal intensity by starting information recording from a second information recording body in a side opposite that of light incidence and, after finishing all recording of the second information recording body, recording information in the first recording body of the light incidence side. SOLUTION: A multilayer optical information recording medium has a structure where a first substrate 1, a first information recording body 2, a transparent adhesive layer 5, a second information recording body 4 and a second substrate 3 are stacked sequentially. For recording information in the first and second information recording bodies 2 and 4 by a light beam made incident through the first substrate 1, in the same position of the multilayer light information recording medium where the light beam is made incident, information is recorded in the second information recording body 4 before information is recorded in the first information recording medium 2. Thus, information is recorded in the information recording bodies 2 and 4 included in the multilayer optical information recording medium capable of recording information three- dimensionally with low jitters without reducing a reproducing signal intensity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recording information on an optical information recording medium such as an optical disk, an optical tape, an optical card, etc., and more particularly to an optical information recording method for high recording density. Things.

[0002]

2. Description of the Related Art Hitherto, a method for increasing the recording density of an optical information recording medium has been to improve the surface recording density on a two-dimensional optical information recording medium plane. However, the size of information media such as media is limited due to the demand for miniaturization of the device, and the size of the mark that can be recorded is also limited by the diffraction limit of light. Has limitations. Therefore, as a method for further increasing the density, a three-dimensional recording / reproducing method including the depth direction is required. As such a technique, for example, as described in JP-A-3-219440 and JP-A-5-101398, two-dimensional plane information is recorded and reproduced three-dimensionally with a multilayer structure. It is known that an optical information recording medium is provided, a light beam is focused on each layer, and information is recorded and reproduced.

[0003]

However, a multilayer optical information recording medium disclosed in the above-mentioned prior art, capable of recording information in a depth direction in addition to a plane direction, and capable of recording information three-dimensionally. No consideration was given to the recording method for each layer. Therefore, the intensity of the reproduced signal is greatly reduced by the recording method as compared with the recording on the two-dimensional optical information recording medium, and the signal intensity necessary for reproducing the information cannot be obtained.

If information is recorded on a shallow layer first, the recorded information on the shallow layer may affect the recording on the deep layer.

An object of the present invention is to disclose, as a method for recording information on a multilayer optical information recording medium capable of recording information three-dimensionally, a technique capable of recording without reducing the intensity of a reproduction signal. It is in.

[0006]

In order to achieve the above object of the present invention, the present invention is configured as described below.

That is, between the first and second substrates,
The first information recording structure provided on the first substrate and the second information recording structure provided on the second substrate are arranged such that the first and second substrates are respectively located outside. Recording information on a multilayer optical information recording medium having a structure arranged so as to be positioned and recording information on the first and second information recording structures by a light beam incident through the first substrate; As a method, information recording is started from the second information recording structure on the side opposite to the light incident side, and after all the second information recording structures have been recorded, the information is stored in the first information recording structure on the light incident side. Shall be recorded.

In other words, it has a structure in which a first substrate, a first information recording structure, a second information recording structure, and a second substrate are stacked in this order, and the light is incident through the first substrate. In the multi-layer optical information recording medium for recording information on the first and second information recording structures by the light beam thus applied, the first information recording structure is recorded on the medium at the same position where the light beam is incident. It can also be said that information is recorded in the second information recording structure before information is recorded.

This case is particularly effective when the first and second information recording structures are all composed of an information recording structure that can be recorded only once or an information recording structure that is used only for one-time recording.

[0010] A first information recording structure having two to four information recording structures on at least one of the first and second substrates.
And the second optical information recording medium has a structure in which the first and the second substrates are arranged so as to be located on the outside, respectively, and each of the information recording structures in the first optical information recording medium has Records information by a light beam incident through the first substrate, and stores information in each information recording structure in the second optical information recording medium by a light beam incident through the second substrate. As a method of recording information on a multilayer optical information recording medium for recording information, in the first and second optical information recording media, information is sequentially recorded from the information recording structure on the side opposite to the light incidence, and After all the information recording structures on the opposite side have been recorded, recording is performed on the adjacent information recording structure on the light incident side.

Also in this case, when the information recording structures in the first and second optical information recording media are all composed of an information recording structure that can be recorded only once or an information recording structure that is used only for one time recording. Especially effective.

When information is recorded on the information recording structure on the side opposite to the light incident side, if information has already been recorded on the information recording structure on the light incident side of the information recording structure to be recorded, The light beam transmitted through the information recording structure is distorted, and information cannot be accurately recorded on the opposite information recording structure.

[0013] In the above-mentioned multilayer optical information recording method, the recording layer in the information recording structure is selected from the group consisting of a phase change type recording layer, a magneto-optical type recording layer, a heat deformation type recording layer and an organic dye type recording layer. The present invention can be applied to any one selected recording layer.

In the above-described multi-layer optical information recording method, the recording layer in the information recording structure is made of a SnSbSe-based Se or the like.
Chalcogenide-based material, Te-O-based, T
e-O-Co system, Te-O-Pd system, GeSbTe system,
Chalcogenide-based materials containing Te as a main component, such as InSbTe-based and AgInSbTe-based materials; chalcogenide-based materials containing both Se and Te as a main component, such as GeTeSe;
Any phase change recording layer using a multilayer alloy type chalcogenide material such as b2Se3 / Bi2Te3 / Sb2Se3 is applicable.

In the above-described multilayer optical information recording method, the recording layer in the information recording structure may include at least one of a cyanine dye, a phthalocyanine dye, a polymethine dye, a naphthoquinone dye, a rhodamine dye, an azulhenium dye, and a macrocyclic azaannulene dye. Any organic dye type recording layer using a dye material containing one as a main component is applicable.

[0016]

Embodiments of the present invention will be described below in more detail.

Embodiment 1 FIG. 1 shows an example of a cross-sectional structure of a multilayer optical information recording medium used in the multilayer optical information recording method of the present invention exemplified in this embodiment. First, the diameter 120
A first substrate 1 having a guide groove for tracking formed on the surface of a disc-shaped polycarbonate plate having a thickness of 0.58 mm and a thickness of 0.58 mm by an injection molding method was prepared. The groove shape of the substrate 1 was a spiral U-shaped groove having a land width and a groove width of 0.74 μm and a groove depth of 70 nm. On the guide groove of the first substrate 1, by a high-frequency magnetron sputtering method using an argon gas, (Zn
S) The lower optical interference layer having a composition of 80 (SiO2) 20 is 55 nm
, A phase change recording layer having a composition of Sn2Sb2Se7 in atomic ratio to a thickness of 45 nm, a light absorbing layer having a composition of Sb80Bi20 in atomic% to a thickness of 5 nm, and (ZnS) 80 in atomic%.
An optical information recording medium A was manufactured by forming a first information recording structure 2 comprising four layers of thin films in which an upper optical interference layer having a composition of (SiO2) 20 was formed to have a thickness of 100 nm.
Next, a second substrate 3 having a guide groove for tracking formed on the surface of a disc-shaped polycarbonate plate having a diameter of 120 mm and a thickness of 0.58 mm by an injection molding method was prepared. The groove shape of the substrate 3 is a spiral U-shaped groove having a land width and a groove width of 0.74 μm and a groove depth of 70 n.
m. A light reflecting layer having a composition of Sb80Bi20 in atomic% of 50 nm was formed on the guide groove of the second substrate 3 by a high-frequency magnetron sputtering method using argon gas.
The phase change recording layer having a composition of Sn2Sb2Se7 in atomic ratio to a thickness of 55 nm and an atomic percentage of (ZnS) 80 (S
An optical information recording medium B was produced by forming a second information recording structure 4 comprising three layers of thin films of an optical interference layer having a composition of iO2) 20 and having a thickness of 55 nm. The optical information recording media A and B produced in this manner were bonded together with the transparent adhesive layer 5 made of an ultraviolet curable resin so that the substrates 1 and 3 were outside, to produce a multilayer optical information recording medium α. Here, a delayed curing type was used as the ultraviolet curing resin. After hanging the delay-curing type ultraviolet curable resin on the optical information recording medium A or B, and then irradiating with ultraviolet rays in advance,
Place the other optical information recording medium 45
After bonding to a thickness of μm, the mixture was left to cure for 1 hour.

The multilayer optical information recording medium α produced as described above was irradiated with a laser wavelength of 650 nm and an objective lens numerical aperture (N
A) Recording / reproducing characteristics were evaluated using an optical disk drive A having an optical head of 0.6. The multi-layer optical information recording medium α is rotated at a constant linear velocity or angular velocity, and continuous light from a semiconductor laser is passed to the arbitrary radial position through the substrate 1 by the objective lens in the optical head, and the first information of the optical information recording medium A is The light was focused on the recording structure 2 or the second information recording structure 4 of the optical information recording medium B, and the recording and reproduction characteristics were evaluated by performing auto-focusing so as to focus on each information recording structure while performing tracking. The reproduction characteristics were evaluated by detecting the intensity of the reflected light for reproduction.

The multilayer optical information recording medium α is rotated at a constant linear velocity of 6 m / s using the optical disk drive, and reproduced light (continuous light) is focused on each of the information recording structures. Light) power level is 1.5 mW, recording light power (multi-pulse light of 50% duty) level is 12 mW, and the shortest mark length is 0.62 μm 8-.
After recording a 16-modulation (EFM +) random pattern (corresponding to a data detection window width of 0.207 μm), the jitter of the reproduced signal was measured. Here, the jitter is the recorded 8-
After performing a waveform equalization process on a 16-modulation random pattern with three taps and a transversal filter, a DC slice signal is set at the center of the eye of the read eye pattern using a tracking slice, and a cross signal between the reproduction signal and the slice signal is set. A point was detected as an edge position and measured. PLL (pha
se lock loop) and SYNC (synchronous cod
The time interval between the clock signal and the data signal from (e) was taken into a jitter meter (Time Interval Analyzer) by 10,000, and the standard deviation (σ) at this time was normalized by the data detection window width to define the jitter. Here, the maximum jitter level at which information can be reproduced without error even when the disc is tilted is 10%.

Two multilayer optical information recording media α were prepared. On one multilayer optical information recording medium α1, after recording the entire surface on the first information recording structure 2 of the optical information recording medium A on the light incident side, the entire surface is recorded on the second information recording structure 4 of the optical information recording medium B. did. On the other multilayer optical information recording medium α2, after the entire surface is recorded on the second information recording structure 4 of the optical information recording medium B on the side opposite to the light incident side, the first information recording structure 2 of the optical information recording medium A is Was recorded in full. The above multilayer optical information recording medium α1,
The jitter of the reproduction signal of each information recording structure was measured by focusing on each information recording structure in α2. The results are shown in Tables 1 and 2, respectively.

[0021]

[Table 1]

[0022]

[Table 2]

Here, first, the optical information recording medium A on the light incident side
In the multilayer optical information recording medium α1 recorded on the first information recording structure 2, the jitter of the second information recording structure is 12%, which exceeds 10% of the maximum jitter level, and stable information cannot be reproduced. Was. On the other hand, in the multilayer optical information recording medium α2 previously recorded on the second information recording structure 4 of the optical information recording medium B on the side opposite to the light incidence, the jitter of the second information recording structure is 8%, which is sufficiently stable. Information can be reproduced.

In the above-mentioned multilayer optical information recording medium α, in addition to the chalcogenide-based material mainly composed of SnSbSe-based Se used in the present embodiment, Te-O-based, Te-O-Co
System, Te-O-Pd system, GeSbTe system, InSbTe
, Chalcogenide-based materials such as AgInSbTe based on Te, chalcogenide-based materials based on both Se and Te such as GeTeSe, Sb2Se3 / B
Even when a multi-layer alloy type chalcogenide-based material such as i2Te3 / Sb2Se3 was used, the same result as in the present embodiment was obtained.

In the above-mentioned multilayer optical information recording medium α, as a recording layer used in each information recording structure, in addition to the phase change recording layer used in the present embodiment, a magneto-optical recording layer, a thermally deformable recording layer Even when the layer and the organic dye type recording layer were used, the same results as in the present embodiment were obtained.

In the above-mentioned multilayer optical information recording medium α, a silicon-based reactive adhesive or an epoxy-based reactive adhesive is used as the transparent adhesive layer 5 in addition to the ultraviolet curable resin used in the present embodiment. Also, the same result as in the present embodiment was obtained.

As the substrate used in the present embodiment, in addition to a polycarbonate substrate manufactured by an injection molding method, a polyolefin substrate or a PMM manufactured by an injection molding method is used.
The same result as that of the present example was obtained using the A substrate or the substrate in which an ultraviolet curable resin layer having an information surface was formed on the surface of a glass or resin substrate by a photopolymerization method. .

<Embodiment 2> FIG. 2 shows an example of a sectional structure of a multilayer optical information recording medium used in the multilayer optical information recording method of the present invention exemplified in the present embodiment. First, the diameter 120
A first substrate 6 having a guide groove for tracking formed on a surface of a disc-shaped polycarbonate plate having a thickness of 0.58 mm and a thickness of 0.58 mm by an injection molding method was prepared. The groove shape of the substrate 6 was a spiral U-shaped groove having a land width and a groove width of 0.74 μm and a groove depth of 70 nm. On the guide groove of the first substrate 6, a high-frequency magnetron sputtering method using an argon gas is used to obtain a Te atomic ratio.
The phase change recording layer having a composition of 1O (oxygen) 1.1Co0.1 is 45 n
Thus, a first information recording structure 7 composed of a single thin film having a thickness of m was formed. Next, an ultraviolet curable resin layer 8 having the same groove shape as that of the substrate 6 was formed to a thickness of 45 μm by a photopolymerization method (2P method) of transferring an information surface from a stamper using an ultraviolet curable resin. As the stamper used here, either a mold made of Ni or a transparent mold made of plastic can be used. On this, a cyanine dye recording layer was formed to a thickness of 70 nm by a spin coating method, and an Au reflection layer was formed to a thickness of 50 nm by a high-frequency magnetron sputtering method using an argon gas. A second information recording structure 9 was formed. Further, an ultraviolet curable resin was spin-coated thereon at a thickness of 10 μm, and then cured by irradiating ultraviolet rays to form a protective layer 10, thereby producing an optical information recording medium C. Next, an optical information recording medium C ′ was produced in exactly the same manner as described above. The optical information recording media C and C ′ produced in this manner were bonded together with the adhesive layer 11 so that the respective substrates faced outward, thereby producing a multilayer optical information recording medium β. In the adhesive layer 11, after a silicon-based reactive adhesive is spin-coated on the protective layer 10 of the information storage medium C to a thickness of 50 μm, the information storage medium C ′ is evacuated in a vacuum to prevent air bubbles from entering. Stuck together.

The multilayer optical information recording medium β is rotated at a constant linear velocity of 6 m / s by using the optical disk drive, and reproduced light (continuous light) is focused on each of the information recording structures. Light) power level is 1.5 mW, recording light power (multi-pulse light of 50% duty) level is 12 mW, and the shortest mark length is 0.62 μm 8-.
After recording a 16-modulation (EFM +) random pattern (corresponding to a data detection window width of 0.207 μm), the jitter of the reproduced signal was measured. Here, the jitter is the recorded 8-
After performing a waveform equalization process on a 16-modulation random pattern with three taps and a transversal filter, a DC slice signal is set at the center of the eye of the read eye pattern using a tracking slice, and a cross signal between the reproduction signal and the slice signal is set. A point was detected as an edge position and measured. PLL (pha
se lock loop) and SYNC (synchronous cod
The time interval between the clock signal and the data signal from (e) was taken into a jitter meter (Time Interval Analyzer) by 10,000, and the standard deviation (σ) at this time was normalized by the data detection window width to define the jitter. Here, the maximum jitter level at which information can be reproduced without error even when the disc is tilted is 10%.

Two multilayer optical information recording media β were prepared. On one multilayer optical information recording medium β1, the entire surface was recorded on the first information recording structure 7 on the light incident side of the optical information recording medium C, and then the entire surface was recorded on the second information recording structure 9. On the other multilayer optical information recording medium β2, the entire surface was recorded on the second information recording structure 9 on the side opposite to the light incident side of the optical information recording medium C, and then the entire surface was recorded on the first information recording structure 7. Each information recording structure in the multilayer optical information recording media β1 and β2 was focused on, and the jitter of the reproduction signal of each information recording structure was measured. The results are shown in Tables 3 and 4, respectively.

[0031]

[Table 3]

[0032]

[Table 4]

Here, in the multilayer optical information recording medium β1 previously recorded on the first information recording structure 7 on the light incident side of the optical information recording medium C, the jitter of the second information recording structure is 12%, and the maximum jitter is The level exceeded 10%, and stable information could not be reproduced. On the other hand, in the multilayer optical information recording medium β2 previously recorded on the second information recording structure 9 on the side opposite to the light incidence of the optical information recording medium C, the jitter of the second information recording structure is 8%, which is sufficiently stable. Information can be reproduced.

In the above-mentioned multilayer optical information recording medium β, instead of the cyanine dye of the recording layer used in the information recording structure 9, other dyes such as phthalocyanine dye, polymethine dye, naphthoquinone dye, rhodamine dye, azurenium dye The same result as in the present embodiment was obtained by using a dye material containing at least one of a dye, a macrocyclic azaannulene dye, and a cyanine dye used in the information recording structure 9 as a main component.

A multilayer optical information recording medium γ bonded by using the optical information recording media D having three information recording structures in the optical information recording medium C and an optical information recording device having four information recording structures. Recording / reproduction in each information recording structure was examined using the multilayer optical information recording medium δ bonded between the recording media E. Multilayer optical information recording medium γ or multilayer optical information recording medium δ
When recording is performed on the information recording structure on the light incident side when recording on the information recording structure in the middle, the jitter of the reproduction signal in the recorded information recording structure shows a large value of 12% or more, and the maximum jitter Over 10% of the level, stable information could not be reproduced. On the other hand, information is sequentially recorded from the information recording structure on the side opposite to the light incident side, that is, the light is recorded after all the information recording structures on the side opposite to the light incident side, far from the light incident side, have been recorded. When the information was recorded on the information recording structure closer to the incident side, after the information was recorded on all the information recording structures, each information recording structure was reproduced. %, A sufficiently stable reproduction of information was possible.

[0036]

As described above, according to the present invention, the above 3
It is possible to record information with low jitter on all information recording structures in a multilayer optical information recording medium on which information can be dimensionally recorded, without reducing the intensity of the reproduction signal.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a cross-sectional structure of a multilayer optical information recording medium α exemplified in Embodiment 1 of the present invention.

FIG. 2 is a schematic diagram showing a cross-sectional structure of a multilayer optical information recording medium β exemplified in Embodiment 2 of the present invention.

[Explanation of symbols]

 1, 3, 6, ... substrate 2, 4, 7, 9 ... information structure 5 ... transparent adhesive layer 8 ... ultraviolet curable resin layer 10 ... protective layer 11 ... adhesive layer.

Claims (7)

[Claims] 1. A first information recording structure provided on a first substrate between a first substrate and a second substrate, and a second information recording structure provided on a second substrate. Have a structure in which the first and second substrates are respectively located outside, and the first and the second information recording are performed by a light beam incident through the first substrate. In a multilayer optical information recording medium for recording information on a structure, information recording is started from a second information recording structure on the side opposite to the light incidence, and after all the second information recording structures have been recorded, the light incidence is started. Recording information on the first information recording structure on the side of the optical disc. 2. The multi-layer optical information recording method according to claim 1, wherein said first and second information recording structures are all recordable only once, or are used only once. A multilayer optical information recording method, comprising: 3. A first and a second optical information recording medium having two to four information recording structures on at least one of the first and second substrates, the first and the second substrates. Are arranged so as to be located on the outside, respectively, and the information recording structure in each of the first optical information recording media is provided with the first
A multi-layer optical disc that records information by a light beam incident through the second substrate, on which information is recorded by a light beam incident through the substrate. In the information recording medium, in the first and second optical information recording media, information is sequentially recorded from the information recording structure on the side opposite to the light incidence, and all the information recording structures on the side opposite to the light incidence end. Recording on an adjacent information recording structure on the light incident side after the recording. 4. The multi-layer optical information recording method according to claim 3, wherein all of the information recording structures in the first and second optical information recording media can be recorded only once or only once. A multi-layer optical information recording method comprising an information recording structure used for: 5. The multi-layer optical information recording method according to claim 1, wherein the recording layer in the information recording structure is a phase change type recording layer, a magneto-optical type recording layer, a heat deformation type recording layer. A multi-layer optical information recording method, comprising one kind of recording layer selected from the group consisting of a recording layer and an organic dye type recording layer. 6. A structure in which a first substrate, a first information recording structure, a second information recording structure, and a second substrate are stacked in this order, and a light beam incident through the first substrate is used. ,
In a multilayer optical information recording medium for recording information on the first and second information recording structures, at the same position of the medium where a light beam is incident, before recording information on the first information recording structure, A multi-layer optical information recording method, wherein information is recorded on the second information recording structure. 7. The multi-layer optical information recording method according to claim 6, wherein, after all the information has been recorded on the second information recording structure, information is recorded on the first information recording structure. Multilayer optical information recording method.