JPH0477968B2 - - Google Patents
Info
- Publication number
- JPH0477968B2 JPH0477968B2 JP59019909A JP1990984A JPH0477968B2 JP H0477968 B2 JPH0477968 B2 JP H0477968B2 JP 59019909 A JP59019909 A JP 59019909A JP 1990984 A JP1990984 A JP 1990984A JP H0477968 B2 JPH0477968 B2 JP H0477968B2
- Authority
- JP
- Japan
- Prior art keywords
- layer
- reflectance
- thickness
- film
- phase change
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000031700 light absorption Effects 0.000 claims description 19
- 230000003287 optical effect Effects 0.000 claims description 13
- 239000000758 substrate Substances 0.000 claims description 8
- 229910052711 selenium Inorganic materials 0.000 claims description 6
- 230000001681 protective effect Effects 0.000 claims description 4
- 239000000956 alloy Substances 0.000 claims description 3
- 229910052714 tellurium Inorganic materials 0.000 claims description 3
- 229910052797 bismuth Inorganic materials 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 claims description 2
- 239000010410 layer Substances 0.000 description 78
- 239000010408 film Substances 0.000 description 30
- 239000011669 selenium Substances 0.000 description 22
- 230000000694 effects Effects 0.000 description 12
- 239000011241 protective layer Substances 0.000 description 10
- 230000035945 sensitivity Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 9
- 238000010521 absorption reaction Methods 0.000 description 5
- 239000011347 resin Substances 0.000 description 5
- 229920005989 resin Polymers 0.000 description 5
- 239000004065 semiconductor Substances 0.000 description 4
- 238000002834 transmittance Methods 0.000 description 3
- 239000004925 Acrylic resin Substances 0.000 description 2
- 229920000178 Acrylic resin Polymers 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- 239000012790 adhesive layer Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 230000001678 irradiating effect Effects 0.000 description 2
- -1 For example Substances 0.000 description 1
- 229910001370 Se alloy Inorganic materials 0.000 description 1
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- UHYPYGJEEGLRJD-UHFFFAOYSA-N cadmium(2+);selenium(2-) Chemical compound [Se-2].[Cd+2] UHYPYGJEEGLRJD-UHFFFAOYSA-N 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920003217 poly(methylsilsesquioxane) Polymers 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
- G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
- G11B7/257—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
- G11B7/2578—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
- G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
- G11B7/257—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
- G11B2007/25705—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials
- G11B2007/25708—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials containing group 13 elements (B, Al, Ga)
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
- G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
- G11B7/257—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
- G11B2007/25705—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials
- G11B2007/2571—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials containing group 14 elements except carbon (Si, Ge, Sn, Pb)
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
- G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
- G11B7/257—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers
- G11B2007/25705—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials
- G11B2007/25715—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of layers having properties involved in recording or reproduction, e.g. optical interference layers or sensitising layers or dielectric layers, which are protecting the recording layers consisting essentially of inorganic materials containing oxygen
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
- G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
- G11B7/253—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates
- G11B7/2531—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates comprising glass
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
- G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
- G11B7/253—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates
- G11B7/2533—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates comprising resins
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Thermal Transfer Or Thermal Recording In General (AREA)
- Optical Record Carriers And Manufacture Thereof (AREA)
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は光学式の反射型あるいは透過型ビデオ
デイスク、デジタルオーデイオデイスク等に係
り、特に、任意の情報をデイスクに書き込むのに
好適な情報記録媒体に関する。[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to optical reflective or transmissive video discs, digital audio discs, etc., and particularly to an information recording medium suitable for writing arbitrary information onto the disc. Regarding.
レーザ光の照射により情報の書き込み、および
読み出しが可能な情報記録媒体として、情報記録
を光学的特性、例えば反射率、透過率、屈折率等
の変化として記録する方法が提案されている。そ
の中でも、レーザ光に対して光吸収性が良く光を
熱に変換する効果を有する光吸収層と加熱により
光学的特性が変化する相変化層の2層膜により記
録膜を構成した情報記録媒体は感度が高く高密度
記録が可能である。このような記録膜としては、
例えば、相変化層としてセレンSe、あるいはSe
化合物等が用いられ、また、光吸収層としてビス
マスBi、テルルTe、あるいはこれらの化合物等
が用いられ、その厚さはそれぞれ50〜1500Åであ
る。この記録膜を有する情報記録媒体を実用に供
する際には、上述した薄い記録膜の保護が必須で
ある。
2. Description of the Related Art As an information recording medium on which information can be written and read by irradiation with laser light, a method has been proposed in which information is recorded as a change in optical characteristics, such as reflectance, transmittance, refractive index, etc. Among them, information recording media in which the recording film is composed of two layers: a light absorption layer that has good light absorption properties for laser light and has the effect of converting light into heat, and a phase change layer whose optical properties change when heated. has high sensitivity and enables high-density recording. As such a recording film,
For example, selenium Se or Se as a phase change layer.
Bismuth Bi, tellurium Te, or a compound thereof is used as the light absorption layer, each having a thickness of 50 to 1500 Å. When putting an information recording medium having this recording film into practical use, it is essential to protect the thin recording film as described above.
従来、第1図に示すごとく、ガラスまたはアク
リル樹脂等の透明基板3上に相変化層1を形成
し、その上に光吸収層2、更にSiO2、Al2O3ある
いは樹脂等の保護層4を形成して、基板側よりレ
ーザ光を照射して情報記録を行うことにより情報
記録膜の安定性・信頼性を高めている。しかし、
保護層4を形成することにより、記録感度が半分
以下に低下し、情報の書き込みには保護層なしの
場合の2倍以上のレーザパワーが必要となつてい
る。通常レーザ光源として用いられている半導体
レーザの出力には限度があり、記録感度の低下に
より情報の書き込みが不可能となる。以上のごと
く、従来技術では、記録感度を大幅に低下させる
ことなく有効な保護層を形成することが出来ない
という欠点があつた。 Conventionally, as shown in FIG. 1, a phase change layer 1 is formed on a transparent substrate 3 made of glass or acrylic resin, a light absorption layer 2 is formed on the phase change layer 1, and a protective layer made of SiO 2 , Al 2 O 3 or resin is formed on the phase change layer 1. 4 is formed and information is recorded by irradiating laser light from the substrate side, thereby increasing the stability and reliability of the information recording film. but,
By forming the protective layer 4, the recording sensitivity is reduced to less than half, and writing information requires more than twice the laser power as in the case without the protective layer. There is a limit to the output of a semiconductor laser, which is normally used as a laser light source, and the recording sensitivity decreases, making it impossible to write information. As described above, the conventional technology has the disadvantage that it is not possible to form an effective protective layer without significantly reducing recording sensitivity.
〔発明の目的〕
本発明の目的は、上述した従来技術の欠点を改
善し、記録感度が高く安定性の良い情報記録媒体
を提供することにある。[Object of the Invention] An object of the present invention is to improve the above-mentioned drawbacks of the prior art and to provide an information recording medium with high recording sensitivity and good stability.
本発明は、従来の情報記録膜では光吸収層から
の熱利用が相変化層に接した側だけであり、保護
膜に接した反対側から逃げる熱を有効に利用して
いなことに着目し、基板上に第1の相変化層、光
吸収層、および第2の相変化層を順次形成し、そ
の上に保護層を形成することにより、光吸収層か
らの熱利用率を倍増し、記録感度を向上させたこ
とを特徴とする。
The present invention focuses on the fact that in conventional information recording films, heat from the light absorption layer is used only on the side in contact with the phase change layer, and the heat escaping from the opposite side in contact with the protective film is effectively used. , by sequentially forming a first phase change layer, a light absorption layer, and a second phase change layer on a substrate, and forming a protective layer thereon, the heat utilization rate from the light absorption layer is doubled; It is characterized by improved recording sensitivity.
以下、本発明の一実施例を図面を用いて詳細に
説明する。
Hereinafter, one embodiment of the present invention will be described in detail using the drawings.
本発明における記録膜の構成を第2図に示す。
光透過性のガラス基板あるいはアクリル樹脂等の
樹脂基板3上に、書き込み光、例えば波長830nm
の半導体レーザ光に対してその光吸収率が小さ
く、主として熱によつてその反射率、透過率、屈
折率等の光学的特性が10%以上変化する第1の相
変層1を設け、その上に上記レーザ光に対する光
吸収率が大きく、その吸収によつてその光を熱に
変換する効果を有する光吸収層2を設け、更にそ
の上に、第1と同様の第2の相変化層5を設け、
3層構造の記録膜とする。この記録膜をSiO2、
Al2O3あるいは樹脂等の保護層4によつて保護し
ている。第1および第2の相変化層としては、加
熱によつて上述した光学的特性が変化する材料、
例えばSe、あるいはSb2Se3、TeSe2、TnSe、
CdSe等のSe化合物やSe合金を使用し、光吸収層
としては、第1および第2の相変化層の光学的特
性を変化させ得る温度(例えば200℃)において
溶融ないしは軟化などの望ましくない物理化、化
学変化が生じることのないBi、Teあるいはこれ
らの合金等を用いる。 FIG. 2 shows the structure of the recording film in the present invention.
Write light, for example, at a wavelength of 830 nm, is applied onto a light-transmissive glass substrate or a resin substrate 3 made of acrylic resin.
A first phase change layer 1 is provided, which has a small optical absorption rate with respect to the semiconductor laser light and whose optical properties such as reflectance, transmittance, and refractive index change by 10% or more mainly due to heat. A light absorption layer 2 having a high light absorption rate for the laser beam and having the effect of converting the light into heat by absorption is provided on top of the light absorption layer 2, and a second phase change layer similar to the first layer is provided on top of the light absorption layer 2. 5,
The recording film has a three-layer structure. This recording film is made of SiO 2 ,
It is protected by a protective layer 4 made of Al 2 O 3 or resin. The first and second phase change layers include materials whose optical properties change upon heating;
For example, Se, or Sb 2 Se 3 , TeSe 2 , TnSe,
Se compounds such as CdSe or Se alloys are used as the light absorption layer, and undesirable physical properties such as melting or softening at temperatures (e.g. 200°C) that can change the optical properties of the first and second phase change layers are required. Bi, Te, or their alloys, etc., which do not undergo any chemical changes are used.
この様な情報記録媒体に対してその情報を書き
込むには、透明基板3側より、出力約10mWの半
導体レーザ(波長830nm)光をその記録パターン
に応じて相対的に走査する。このときレーザ光は
ほとんど第の相変化層を透過して光吸収層2に到
達するが、ここにおける吸収率が大であるために
光が吸収されて熱に変換され、レーザ光の照射部
において光吸収層が200℃程度に上昇し、この部
分に接した第1および第2の相変化層を局部的に
加熱する。加熱された第1および第2の相変化変
層は、その光学的特性例えばその反射率が変化す
るのでレーザ光が照射された部分とされない部分
で反射率の差が生じ、光学的情報記録がなされ
る。これを読み出すには、書き込み同様、半導体
レーザによつて行う。この場合の読み出しパワー
は書き込み時のパワーに比べ十分小さいパワー例
えば1mWによつて行うものであり、この低いパ
ワーによる読み出しによれば、再書き込みがなさ
れることがない。 To write information on such an information recording medium, semiconductor laser light (wavelength: 830 nm) with an output of about 10 mW is scanned relatively from the transparent substrate 3 side according to the recording pattern. At this time, most of the laser light passes through the first phase change layer and reaches the light absorption layer 2, but since the absorption rate here is high, the light is absorbed and converted into heat, and the laser light irradiation area The temperature of the light absorption layer rises to about 200° C., and the first and second phase change layers in contact with this portion are locally heated. The heated first and second phase change layers change their optical properties, such as their reflectance, so that a difference in reflectance occurs between the portions that are irradiated with the laser beam and the portions that are not irradiated with the laser beam, resulting in optical information recording. It will be done. To read this, like writing, a semiconductor laser is used. In this case, the reading power is sufficiently lower than the writing power, for example, 1 mW, and reading with this low power prevents rewriting.
本発明においては、上述した第1および第2の
相変化層、吸収層の膜厚は重要である。即ち、薄
膜の干渉効果を用いて第1および第2の相変化層
における光学的特性変化を効率よく読み出すには
各層の膜厚を適当な値にしておく必要がある。相
変化層にSb2Se3を、光吸収層にBiを用いた場合
の各層の厚さと情報書き込み前の反射率10およ
び書き込み後の反射率20を第3〜第5図に示
す。第3図は、Bi層を200Å、第2のSb2Se3層を
400Å、および保護層として厚さ30μmの樹脂層
を設けた時の第1のSb2Se3層の厚さに対する反
射率の変化を示すものである。第1のSb2Se3層
の膜厚により反射率が変化しているのは膜の干渉
効果によるものであり、膜厚500Å近傍では書き
込み前の反射率が5%で、書き込み後には30%に
増大しており、この膜厚を選定すれば極めて良好
な記録情報の読み出しが可能となる。また、第1
および第2のSb2Se3層の厚さをそれぞれ500Å、
400Åにした時のBi層の厚さ変化に対する反射率
の変化を第4図に示す。Bi層の厚さが400Å以上
になると光吸収が大きいため、Bi層は膜として
の干渉効果をもたず、反射率に対する膜厚依存性
をもたなくなる。本発明では、第2のSb2Se3層
からの干渉効果を利用するため、Bi層の厚さを
400Å以下、例えば200〜300Åに選んでいる。更
に、第1のSb2Se3層およびBi層の厚さそれぞれ
500Å、200Åにした時の第2のSb2Se3層の厚さ
変化に対する反射率の変化を第5図に示す。第2
のSb2Se3層の厚さが100〜800Åのとき書き込み
後の反射率20が書き込み前の反射率10に対し
て2倍以上となり、良好な情報書き込み、読み出
しができる。以上のごとく、透明基板上に、第1
のSb2Se3層400〜700Å、Bi層100〜400Å、およ
び第2のSb2Se3層100〜800Åの3層記録膜を形
成し、これを樹脂層により保護した情報記録媒体
は、良好な反射率変化を得られ、レーザ光による
書き込みに適することがわかる。 In the present invention, the film thicknesses of the first and second phase change layers and absorption layer described above are important. That is, in order to efficiently read out optical property changes in the first and second phase change layers using the thin film interference effect, it is necessary to set the film thickness of each layer to an appropriate value. When Sb 2 Se 3 is used for the phase change layer and Bi is used for the light absorption layer, the thickness of each layer and the reflectance 10 before information writing and the reflectance 20 after writing are shown in FIGS. 3 to 5. Figure 3 shows a Bi layer of 200 Å and a second Sb 2 Se 3 layer.
400 Å and a change in reflectance with respect to the thickness of the first Sb 2 Se 3 layer when a resin layer with a thickness of 30 μm is provided as a protective layer. The reflectance changes with the film thickness of the first Sb 2 Se 3 layer due to the interference effect of the film, and when the film thickness is around 500 Å, the reflectance before writing is 5% and after writing it is 30%. If this film thickness is selected, extremely good readout of recorded information becomes possible. Also, the first
and the thickness of the second Sb 2 Se 3 layer is 500 Å, respectively.
Figure 4 shows the change in reflectance with respect to the change in the thickness of the Bi layer when the thickness was set to 400 Å. When the Bi layer has a thickness of 400 Å or more, light absorption is large, so the Bi layer does not have an interference effect as a film, and the reflectance does not depend on the film thickness. In the present invention, in order to utilize the interference effect from the second three Sb 2 Se layers, the thickness of the Bi layer is
The thickness is selected to be 400 Å or less, for example 200 to 300 Å. Furthermore, the thickness of the first Sb 2 Se 3 layer and Bi layer is
FIG. 5 shows the change in reflectance with respect to the thickness change of the second Sb 2 Se 3 layer when the thickness is 500 Å and 200 Å. Second
When the thickness of the Sb 2 Se 3 layer is 100 to 800 Å, the reflectance 20 after writing is more than twice the reflectance 10 before writing, and good information can be written and read. As described above, the first
An information recording medium in which a three-layer recording film is formed with three Sb 2 Se layers of 400 to 700 Å, a Bi layer of 100 to 400 Å, and a second Sb 2 Se three layer of 100 to 800 Å, and this is protected by a resin layer, has good performance. It can be seen that a change in reflectance can be obtained, making it suitable for writing with laser light.
一方、第6図に、上記の3層記録膜40と従来
の2層記録膜30のレーザパワーに対する反射率
比(書き込み後/書き込み前)の関係を示す。第
6図は、上記記録媒体をデイスク状に作成し、こ
れを1800rpmで回転させ、半径130mmの位置で一
定レベルの信号を書き込んだ時のレーザパワーに
対する反射率比であり、各層の厚さは第1の
Sb2Se3500Å、Bi200Å、および第2のSb2Se3400
Åである。第6図に示すごとく、本発明による3
層記録膜は従来の2層記録膜に比べ小さいレーザ
パワーで一定の反射率比が得られ、即ち、記録感
度が高いことがわかる。 On the other hand, FIG. 6 shows the relationship between the reflectance ratio (after writing/before writing) with respect to the laser power of the above three-layer recording film 40 and the conventional two-layer recording film 30. Figure 6 shows the reflectance ratio to the laser power when the above recording medium was made into a disk shape, rotated at 1800 rpm, and a signal of a constant level was written at a radius of 130 mm, and the thickness of each layer was first
Sb 2 Se 3 500 Å, Bi 200 Å, and a second Sb 2 Se 3 400
It is Å. As shown in FIG. 6, 3 according to the present invention
It can be seen that the layered recording film can obtain a constant reflectance ratio with a smaller laser power than the conventional two-layered recording film, that is, has a high recording sensitivity.
以上に述べた様に、本発明による3層記録膜は
保護膜を形成しても書き込み時の記録感度が高
く、大きな反射率比が得られるので、光学式のビ
デオデイスクあるいはデジタルオーデイオデイス
ク等の性能向上および信頼性の向上に多大の効果
を有する。 As described above, the three-layer recording film according to the present invention has high recording sensitivity during writing even with the formation of a protective film, and a large reflectance ratio can be obtained, so it can be used for optical video discs, digital audio discs, etc. It has a great effect on improving performance and reliability.
以上の実施例では、反射型情報記録媒体につい
て説明したが、本発明の構成は透過型としてもそ
のまま用いることが出来ることは容易に理解でき
よう。 In the above embodiments, a reflective type information recording medium has been described, but it is easy to understand that the configuration of the present invention can be used as is for a transmissive type.
また、本発明の効果として、上述の記録感度の
向上の外に、第7図のごとく反射型両面貼合わせ
デイスクにおいて、裏面反射によるノイズ低減に
も多大の効果を有する。即ち、第1図に示す従来
の2層記録膜、例えば相変化層としてSb2Se3、
光吸収層としてBiの用いた場合、Bi層の厚さを
400Å程度にしても記録膜の透過率が10%以上で
あり、しかもBi層の表面反射率が高い(50〜60
%)ため、レーザ光を照射して情報を読み出す際
に、読み出し光の一部が反射側デイスクのBi層
に反射されて戻ることによりノイズとなつてデイ
スクの性能を劣化させていた。しかし、本発明に
よる3層記録膜では、光吸収層を中心としてほぼ
光学的に対象であり、第3図から類推できる様
に、第2のSb2Se3側の反射率を10%以下にする
ことは容易である。従つて、反対側デイスクから
の戻り光を大幅に低減することが可能となり、ノ
イズ低減に多大な効果を有する。 Furthermore, as an effect of the present invention, in addition to the above-mentioned improvement in recording sensitivity, in a reflective type double-sided laminated disk as shown in FIG. 7, it has a great effect in reducing noise due to backside reflection. That is, in the conventional two-layer recording film shown in FIG. 1, for example, Sb 2 Se 3 as the phase change layer,
When Bi is used as the light absorption layer, the thickness of the Bi layer is
Even at a thickness of about 400 Å, the transmittance of the recording film is more than 10%, and the surface reflectance of the Bi layer is high (50 to 60 Å).
%), when reading information by irradiating laser light, a portion of the read light was reflected back by the Bi layer of the reflective disk, becoming noise and degrading the performance of the disk. However, in the three-layer recording film according to the present invention, the optical absorption layer is almost optically symmetrical, and as can be inferred from Fig. 3, the reflectance on the second Sb 2 Se 3 side is kept below 10%. It's easy to do. Therefore, it is possible to significantly reduce the return light from the opposite disk, which has a great effect on noise reduction.
上記実施例では、保護層とデイスク接着層兼用
したが、それぞれ独立の保護層と接着層を用いて
も、それぞれ透明な場合には本発明が適用できる
ことは明らかであろう。 In the above embodiments, the protective layer and disk adhesive layer were used as both, but it is clear that the present invention can be applied even if an independent protective layer and adhesive layer are used as long as each layer is transparent.
本発明によれば、保護膜を形成した情報記録媒
体の感度を大幅に向上できるので、情報記録媒体
の性能向上および信頼性向上に多大の効果があ
る。
According to the present invention, it is possible to significantly improve the sensitivity of an information recording medium on which a protective film is formed, which has a great effect on improving the performance and reliability of the information recording medium.
第1図は従来の情報記録媒体の断面を示す模式
図、第2図は本発明による情報記録媒体の断面を
示す模式図、第3図は第1のSb2Se3層の膜厚と
反射率の関係を示す図、第4図はBi層の膜厚と
反射率の関係を示す図、第5図は第2のSb2Se3
層の膜厚と反射率の関係を示す図、第6図はレー
ザパワーと反射率比の関係を示す図、第7図は本
発明による両面貼合わせデイスクの断面を示す模
式図である。
1……第1の相変化層、2……光吸収層、3…
…透明基板、4……保護層、5……第2の相変化
層
Fig. 1 is a schematic diagram showing a cross section of a conventional information recording medium, Fig. 2 is a schematic diagram showing a cross section of an information recording medium according to the present invention, and Fig. 3 is a diagram showing the film thickness and reflection of the first Sb 2 Se 3 layer. Figure 4 is a diagram showing the relationship between Bi layer thickness and reflectance, Figure 5 is a diagram showing the relationship between Bi layer thickness and reflectance, and Figure 5 is a diagram showing the relationship between Bi layer thickness and reflectance .
FIG. 6 is a diagram showing the relationship between layer thickness and reflectance ratio, FIG. 6 is a diagram showing the relationship between laser power and reflectance ratio, and FIG. 7 is a schematic diagram showing a cross section of a double-sided laminated disk according to the present invention. DESCRIPTION OF SYMBOLS 1...First phase change layer, 2...Light absorption layer, 3...
...Transparent substrate, 4...Protective layer, 5...Second phase change layer
Claims (1)
なる情報記録媒体において情報記録膜が第1、第
2および第3層からなり、第1及び、第3の層は
加熱により光学的特性が変化するSeあるいはSe
合金材料からなり、上記第2の層は書き込み光に
対して光吸収性を有するBi、Teあるいはこれら
の合金材料よりなることを特徴とする情報記録媒
体。1. In an information recording medium formed by forming an information recording film and its protective film on a substrate, the information recording film consists of a first, second, and third layer, and the first and third layers have optical properties by heating. Se or Se where changes
An information recording medium characterized in that the second layer is made of an alloy material, and the second layer is made of Bi, Te, or an alloy material thereof, which has light absorption property for writing light.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP59019909A JPS60164937A (en) | 1984-02-08 | 1984-02-08 | Information recording medium |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP59019909A JPS60164937A (en) | 1984-02-08 | 1984-02-08 | Information recording medium |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS60164937A JPS60164937A (en) | 1985-08-28 |
JPH0477968B2 true JPH0477968B2 (en) | 1992-12-09 |
Family
ID=12012338
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP59019909A Granted JPS60164937A (en) | 1984-02-08 | 1984-02-08 | Information recording medium |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS60164937A (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4653024A (en) * | 1984-11-21 | 1987-03-24 | Energy Conversion Devices, Inc. | Data storage device including a phase changeable material |
JPH0694230B2 (en) * | 1985-12-25 | 1994-11-24 | 旭化成工業株式会社 | Information recording material |
JPH03275382A (en) * | 1990-03-27 | 1991-12-06 | Fuji Photo Film Co Ltd | Optical recording medium and recording regeneration method |
WO1999030908A1 (en) * | 1997-12-17 | 1999-06-24 | Asahi Kasei Kogyo Kabushiki Kaisha | Write once optical information recording medium |
US6809401B2 (en) * | 2000-10-27 | 2004-10-26 | Matsushita Electric Industrial Co., Ltd. | Memory, writing apparatus, reading apparatus, writing method, and reading method |
US6507061B1 (en) * | 2001-08-31 | 2003-01-14 | Intel Corporation | Multiple layer phase-change memory |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5837853A (en) * | 1981-08-01 | 1983-03-05 | Ricoh Co Ltd | Optical information recording medium |
-
1984
- 1984-02-08 JP JP59019909A patent/JPS60164937A/en active Granted
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5837853A (en) * | 1981-08-01 | 1983-03-05 | Ricoh Co Ltd | Optical information recording medium |
Also Published As
Publication number | Publication date |
---|---|
JPS60164937A (en) | 1985-08-28 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CA1220552A (en) | Information recording medium | |
EP0038499B1 (en) | Optical recording and reproducing system | |
JPH0666093B2 (en) | recoding media | |
JPS60160036A (en) | Optical disk | |
US4525412A (en) | Information recording medium | |
JP2001023259A (en) | Magneto-optical recording medium and its production | |
KR20050010809A (en) | Recording medium having high melting point recording layer, information recording method thereof, and information reproducing apparatus and method therefor | |
JPH0477968B2 (en) | ||
JPH0221060B2 (en) | ||
JPH0222453B2 (en) | ||
JP4221450B2 (en) | Super-resolution near-field high-density recording medium using a refractory metal oxide or silicon oxide mask layer | |
JPH0263262B2 (en) | ||
JPH0373937B2 (en) | ||
US5419937A (en) | Optical record carrier | |
JPH0416355B2 (en) | ||
JPH0376237B2 (en) | ||
JPS61110349A (en) | Information recording medium | |
JP3153393B2 (en) | Recordable optical disc | |
WO1982004159A1 (en) | An information recording medium | |
JPH0114039B2 (en) | ||
JPH0462140B2 (en) | ||
JPH0562248A (en) | Optical disk medium using two wavelengths | |
JP2506868B2 (en) | optical disk | |
JPS5987634A (en) | Information recording medium | |
JPS62139155A (en) | Optical magnetic memory medium |