JPS639310B2 - - Google Patents
Info
- Publication number
- JPS639310B2 JPS639310B2 JP56193920A JP19392081A JPS639310B2 JP S639310 B2 JPS639310 B2 JP S639310B2 JP 56193920 A JP56193920 A JP 56193920A JP 19392081 A JP19392081 A JP 19392081A JP S639310 B2 JPS639310 B2 JP S639310B2
- Authority
- JP
- Japan
- Prior art keywords
- melting point
- layer
- thin film
- low melting
- point alloy
- 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
Links
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
-
- 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
- G11B2007/25706—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 transition metal elements (Zn, Fe, Co, Ni, Pt)
-
- 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
- G11B7/258—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of reflective layers
- G11B7/2585—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of reflective layers based on aluminium
Landscapes
- Thermal Transfer Or Thermal Recording In General (AREA)
- Read Only Memory (AREA)
- Optical Record Carriers And Manufacture Thereof (AREA)
Description
【発明の詳細な説明】
本発明は光学的に情報を記録、再生する高密度
の光学的メモリ装置に適用し得る高感度の光学的
メモリ媒体に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a highly sensitive optical memory medium that can be applied to high-density optical memory devices that optically record and reproduce information.
従来、この種の光学的メモリ媒体としては、ガ
ラスまたはプラスチツク基体上に記録層として例
えばBi、Teなどの金属薄膜層を形成し、集束レ
ーザ光による溶融蒸発を原理とした凹部（ビツ
ト）を形成して情報を記憶する方式のものが使用
されてきた。しかしながら、このような金属薄膜
記録層は一般に反射率が高く、例えばBiの場合
可視光では約65％に達すること、および溶融点が
比較的高く、例えばBiで271℃、Teで450℃であ
ることが原因となり、記録感度が低、そのため記
録するのに大出力のレーザ装置が必要であつた。
一方有機色素薄膜記録層は一般に反射率が低く、
低熱伝導率であり溶融点が比較的低いため、相対
的に高感度となり、したがつて低い出力レーザに
より記録しうる特長を有しているが、多くの金属
薄膜の場合と同様にレーザビーム照射で生成され
た凹部の周辺部の形状がぎざぎざ形または擂鉢形
になり易く、情報再生時における信号対雑音比
（Ｓ／Ｎ比）を低下させるという欠点があつた。 Conventionally, this type of optical memory medium has been produced by forming a thin film layer of metal such as Bi or Te as a recording layer on a glass or plastic substrate, and forming recesses (bits) using the principle of melting and evaporation using a focused laser beam. A method of storing information using a computer has been used. However, such metal thin film recording layers generally have a high reflectance, for example reaching about 65% in visible light for Bi, and a relatively high melting point, for example 271 °C for Bi and 450 °C for Te. This resulted in low recording sensitivity, which required a high-output laser device for recording.
On the other hand, organic dye thin film recording layers generally have low reflectance;
Its low thermal conductivity and relatively low melting point make it relatively sensitive and therefore recordable with low power lasers; however, as with many metal thin films, laser beam irradiation is The shape of the periphery of the concave portion generated in this method tends to be jagged or mortar-shaped, which has the disadvantage of lowering the signal-to-noise ratio (S/N ratio) during information reproduction.
本発明はこのような現状に鑑みて為されたもの
であり、その目的は従来技術の欠点をを解消し、
反射率が低く比較的低融点の色素薄膜記録層およ
び低融点合金層からなる高感度の光学的メモリ媒
体を提供することである。本発明の光学的メモリ
媒体はガラスまたはプラスチツク基体およびその
上に形成された表面張力の大きい低融点合金層さ
らにその上に形成された色素薄膜記録層とからな
り、レーザビームを照射することによりこの色素
薄膜記録層および低融点合金層に同時に凹部を形
成することにより情報を記録し、かつ情報を再生
し得るものであり、本発明の特長は低いエネルギ
ー密度のレーザビームで高いＳ／Ｎ比の情報記録
再生が得られることである。すなわち、レーザビ
ーム照射で上記低融点合金層が溶融蒸発した際、
この溶融部は表面張力により凝集、収縮し、凹部
の周辺部が円形状になり易い性質を利用すること
により、同時に溶融蒸発した色素薄膜記録層の凹
部の形状がたとえぎざぎざ形や擂鉢形の不完全な
形状であつてもこの低融点合金層の上記性質によ
つて完全な円形状に修正されるために高いＳ／Ｎ
比が得られるものである。本発明における低融点
合金層の融点は使用される色素薄膜記録層の融点
と同程度またはそれ以下であることが必要であ
り、例えばこの関係が逆であると低いエネルギー
密度のレーザビームで色素薄膜記録層に凹部が形
成されても低融点合金層が変化しないため本発明
の目的が達成されないことになる。また本発明に
おける低融点合金層の組成はSn、Bi、Pb、Cdの
内の２種類以上の組合せからなる表面張力の大き
い合金からなり、必要溶融温度により成分、組成
を適宜選択することができ、例えば12.5％Sn−
50.0％Bi−25.0％Pb−12.5％Cd合金は溶融温度が
60〜72℃、16.0％Sn−52.0％Bi−32.0％Pb合金は
溶融温度が95℃、45.0％Sn−5.0％Bi−32.0％Pb
−18.0％Cd合金は溶融温度が132〜139℃、43.0％
Sn−14.0％Bi−43.0％Pb合金は溶融温度が143〜
168℃である。これらの低融点合金はアルミニウ
ム薄膜などを反射膜として真空蒸着させた基板上
に真空蒸着またはスパツタリングなどにより容易
に形成することができ、通常その膜厚は50〜
500nｍで効果を発揮することができる。なおこ
の低融点合金はアルミニウム反射膜と融点が著じ
るしく異なるため合金化することはない。色素薄
膜記録層の色素は特に限定されず、オキサジン系
色素、アニリン系色素、ナフトール系色素などが
適用され、基板上に形成された低融点合金層の上
に真空蒸着法により、あるいは適当な溶剤を用い
てスピナー法などで塗布、乾燥することにより容
易に形成することができ、通常その膜厚は100〜
200nｍ程度である。 The present invention has been made in view of the current situation, and its purpose is to eliminate the drawbacks of the prior art,
The object of the present invention is to provide a highly sensitive optical memory medium comprising a dye thin film recording layer with low reflectance and a relatively low melting point and a low melting point alloy layer. The optical memory medium of the present invention consists of a glass or plastic substrate, a low melting point alloy layer with a high surface tension formed on the substrate, and a dye thin film recording layer formed thereon. Information can be recorded and reproduced by forming recesses in the dye thin film recording layer and the low melting point alloy layer at the same time.The feature of the present invention is that it is possible to record and reproduce information by simultaneously forming recesses in the dye thin film recording layer and the low melting point alloy layer. It is possible to record and reproduce information. That is, when the low melting point alloy layer is melted and evaporated by laser beam irradiation,
This molten area coagulates and contracts due to surface tension, and by taking advantage of the property that the periphery of the recess tends to have a circular shape, the shape of the recess in the dye thin film recording layer that is melted and evaporated at the same time can be changed to a jagged or mortar-shaped irregularity. Even if the shape is perfect, it is corrected to a perfect circular shape by the above properties of this low melting point alloy layer, resulting in a high S/N.
The ratio can be obtained. The melting point of the low melting point alloy layer in the present invention needs to be on the same level as or lower than the melting point of the dye thin film recording layer used. For example, if this relationship is reversed, a dye thin film can be formed by a laser beam with a low energy density. Even if recesses are formed in the recording layer, the low melting point alloy layer does not change, so the object of the present invention cannot be achieved. In addition, the composition of the low melting point alloy layer in the present invention is an alloy with a high surface tension consisting of a combination of two or more of Sn, Bi, Pb, and Cd, and the components and composition can be selected as appropriate depending on the required melting temperature. , e.g. 12.5% Sn−
The melting temperature of the 50.0%Bi−25.0%Pb−12.5%Cd alloy is
60~72℃, 16.0%Sn-52.0%Bi-32.0%Pb alloy has a melting temperature of 95℃, 45.0%Sn-5.0%Bi-32.0%Pb
-18.0%Cd alloy has a melting temperature of 132~139℃, 43.0%
Sn-14.0%Bi-43.0%Pb alloy has a melting temperature of 143~
It is 168℃. These low-melting point alloys can be easily formed by vacuum evaporation or sputtering on a substrate on which a thin aluminum film or the like is vacuum-deposited as a reflective film, and the film thickness is usually 50~50 mm.
It can be effective at 500nm. Note that this low melting point alloy is not alloyed with the aluminum reflective film because its melting point is significantly different. The dye for the dye thin film recording layer is not particularly limited, and oxazine dyes, aniline dyes, naphthol dyes, etc. are applied, and the dye is deposited on a low melting point alloy layer formed on a substrate by vacuum evaporation or using an appropriate solvent. It can be easily formed by coating and drying using a spinner method, etc., and the film thickness is usually 100~
It is about 200nm.
次に本発明の実施の一例における光学的メモリ
媒体の構成およびそれによる情報の記録、再生操
作を図面により説明する。第１図は本発明の光学
的メモリ媒体を用いた記録、再生工程の一具体例
を示した系統図であり、第２図は第１図における
記録後の光学的メモリ媒体の一部を示した拡大断
面図である。図において１は基体、２は反射膜、
３は表面張力のきわめて大きい低融点合金層、４
は色素薄膜記録層、５は回転装置、６はレーザ、
７は光変調器、８は偏光ビームスプリツタ、９は
対物レンズ、１０は光検出器、１１は記録部とな
る凹部、１２は未記録部を示す。前記基体１はガ
ラスまたはポリメチルメタアクリレートのような
プラスチツク製の直径約30cmの円板であり、その
片面に反射膜２として膜厚約100nｍのアルミニ
ウム薄膜を真空蒸着により形成し、その上に膜厚
50〜300nｍの低融点合金層３をスパツタリング
し、さらにその上に膜厚約100nｍの色素薄膜よ
りなる記録層４を真空蒸着法により形成する。こ
のようにして作製した光学的メモリリ媒体を回転
装置５に装着して回転させながら記録、再生が行
なわれる。記録は先ずレーザ６からのレーザ光を
光変調器７により変調して情報を持つた光とし、
偏光ビームスプリツタ８および対物レンズ９によ
り集束されたレーザ光のビーム径は約1μｍであ
り、その熱作用により記録層４の色素薄膜は溶融
蒸発し、その結果第２図に示すような凹部１１が
形成され情報が記録される。記録された情報の再
生はレーザ６におけるレーザ光の出力を記録時の
約1/10程度にし、すなわち記録層４の未記録部１
２を溶融蒸発させない程度の出力に下げ凹部１１
と未記録部１２の反射率の違いにより光検出器１
０で電気信号に変換して情報が再生される。 Next, the configuration of an optical memory medium and information recording and reproducing operations thereof in an embodiment of the present invention will be explained with reference to the drawings. FIG. 1 is a system diagram showing a specific example of the recording and reproducing process using the optical memory medium of the present invention, and FIG. 2 shows a part of the optical memory medium after recording in FIG. FIG. In the figure, 1 is the base, 2 is the reflective film,
3 is a low melting point alloy layer with extremely high surface tension; 4
is a dye thin film recording layer, 5 is a rotating device, 6 is a laser,
7 is a light modulator, 8 is a polarizing beam splitter, 9 is an objective lens, 10 is a photodetector, 11 is a concave portion serving as a recording portion, and 12 is an unrecorded portion. The substrate 1 is a circular plate made of glass or plastic such as polymethyl methacrylate and has a diameter of about 30 cm.A thin aluminum film with a thickness of about 100 nm is formed on one side of the substrate as a reflective film 2 by vacuum evaporation, and a film is formed on it. thickness
A low melting point alloy layer 3 with a thickness of 50 to 300 nm is sputtered, and a recording layer 4 made of a thin dye film with a thickness of about 100 nm is further formed thereon by vacuum evaporation. The optical memory medium thus produced is mounted on the rotating device 5 and recorded and reproduced while being rotated. For recording, first, the laser beam from the laser 6 is modulated by the optical modulator 7 to become light carrying information.
The beam diameter of the laser beam focused by the polarizing beam splitter 8 and the objective lens 9 is approximately 1 μm, and the dye thin film of the recording layer 4 is melted and evaporated by its thermal action, resulting in the formation of a recess 11 as shown in FIG. is formed and information is recorded. To reproduce the recorded information, the output of the laser beam in the laser 6 is reduced to about 1/10 of that of recording, that is, the unrecorded part 1 of the recording layer 4 is
2 to a level that does not melt and evaporate the concave part 11.
Due to the difference in the reflectance of the unrecorded area 12 and the
0, the information is converted into an electrical signal and reproduced.
次に本発明の具体実施例を説明する。 Next, specific embodiments of the present invention will be described.
実施例 １
色素薄膜記録層４として分子式C14H15N3で示
されるデメチルアニリン色素（溶融温度115℃）
を用い、低融点合金層３として16.0％Sn−52.0％
Bi−32.0％Pb合金（溶融温度95℃）を用いて第
１図で説明した方法により光学的メモリ媒体を作
製し、出力10ｍＷのHe−Neレーザ光を使用して
カラービデオ信号の記録、再生を行なつた結果、
Ｓ／Ｎ比45dB以上の良好な再生画像品質が得ら
れた。Example 1 Demethylaniline dye represented by the molecular formula C 14 H 15 N 3 as the dye thin film recording layer 4 (melting temperature 115°C)
16.0%Sn-52.0% as low melting point alloy layer 3
An optical memory medium was fabricated using a Bi-32.0%Pb alloy (melting temperature 95°C) by the method explained in Figure 1, and a color video signal was recorded and played back using a He-Ne laser beam with an output of 10 mW. As a result,
Good reproduced image quality with an S/N ratio of 45 dB or more was obtained.
実施例 ２
色素薄膜記録層４として分子式C18H16ON2で
示されるナフトール系色素（溶融温度133℃）を
用い、低融点合金層３として55.5％Bi−44.5％Pb
合金（溶融温度124℃）を用いた以外は実施例１
と同様の操作により光学的メモリ媒体の作製およ
び記録、再生実験を行なつたところ、実施例１と
略同等の結果を得ることができた。Example 2 A naphthol dye (melting temperature 133°C) having the molecular formula C 18 H 16 ON 2 was used as the dye thin film recording layer 4, and 55.5% Bi-44.5% Pb was used as the low melting point alloy layer 3.
Example 1 except that alloy (melting temperature 124°C) was used.
When an optical memory medium was manufactured and recording and playback experiments were performed using the same operations as in Example 1, substantially the same results as in Example 1 were obtained.
実施例 ３
色素薄膜記録層４として分子式C24H20N4Oで
示されるベータナフトール系色素（溶融温度184
〜185℃）を用い、低融点合金層３として51.2％
Sn−30.6％Pb−18.2％Cd（溶融温度143℃）を用
いた以外は実施例１と同様の操作により光学的メ
モリ媒体の作製および記録、再生実験を行なつた
ところ、実施例１と略同等の結果を得ることがで
きた。Example 3 As the dye thin film recording layer 4 , a beta -naphthol dye (melting temperature 184
~185℃), 51.2% as low melting point alloy layer 3
An optical memory medium was fabricated, and recording and playback experiments were conducted in the same manner as in Example 1 except that Sn-30.6%Pb-18.2%Cd (melting temperature 143°C) was used. We were able to obtain equivalent results.
以上説明したように本発明の光学的メモリ媒体
は、レーザ光照射により溶融蒸発した色素薄膜記
録層の凹部の形状がたとえぎざぎざ形や擂鉢形の
不完全な形状であつても、低融点合金の溶融部は
表面張力により凝集・収縮し、凹部の周辺部が完
全な円形状に修正されるため、かつ色素薄膜記録
層およびこの色素薄膜記録層の溶融温度と同等か
またはそれ以下の溶融温度を持つ低融点合金層と
の複合膜にすることにより、低いレーザ出力で情
報の記録、再生時のＳ／Ｎ比を著じるしく向上さ
せ、高感度にし得、その結果各種メモリ装置の価
格を廉価にし得る利点を有するものである。 As explained above, in the optical memory medium of the present invention, even if the shape of the concave portion of the dye thin film recording layer melted and vaporized by laser beam irradiation is an imperfect shape such as a jagged shape or a mortar shape, the optical memory medium of the present invention is made of a low melting point alloy. The melted area coagulates and contracts due to surface tension, and the peripheral part of the recess is corrected into a perfect circular shape. By creating a composite film with a low melting point alloy layer, it is possible to significantly improve the S/N ratio during information recording and reproduction with low laser output, making it possible to achieve high sensitivity.As a result, the price of various memory devices can be reduced. It has the advantage of being inexpensive.
図面は本発明の実施の一例を示すもので、第１
図は光学的メモリ媒体を用いた記録、再生工程の
系統図、第２図は第１図における記録後の光学的
メモリ媒体の一部を示した拡大断面図である。
１……基体、２……反射膜、３……低融点合金
層、４……色素薄膜記録層、１１……凹部、１２
……未記録部。
The drawings show an example of the implementation of the present invention.
The figure is a system diagram of a recording and reproducing process using an optical memory medium, and FIG. 2 is an enlarged sectional view showing a part of the optical memory medium after recording in FIG. 1. DESCRIPTION OF SYMBOLS 1...Substrate, 2...Reflection film, 3...Low melting point alloy layer, 4...Dye thin film recording layer, 11...Recessed part, 12
...Unrecorded section.
Claims (1)
Pb、Cdの内の少なくとも２種類以上を組合せた
合金よりなる低融点合金層と、さらにその上に形
成された色素薄膜記録層とを備え、前記低融点合
金層の溶融温度は前記色素薄膜記録層の溶融蒸発
温度と同程度またはそれ以下で構成され、レーザ
光を照射することにより前記色素薄膜記録層およ
び低融点合金層に同時に凹部を形成し情報を記録
するようにした光学的メモリ媒体。1 Substrate and Sn, Bi, formed on the substrate
A low melting point alloy layer made of an alloy that is a combination of at least two of Pb and Cd, and a dye thin film recording layer formed thereon, the melting temperature of the low melting point alloy layer being the same as the dye thin film recording layer. An optical memory medium having a melting and evaporating temperature of the same layer or less, and recording information by simultaneously forming recesses in the dye thin film recording layer and the low melting point alloy layer by irradiating the layer with laser light.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56193920A JPS5894146A (en) | 1981-12-01 | 1981-12-01 | Optical memory medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56193920A JPS5894146A (en) | 1981-12-01 | 1981-12-01 | Optical memory medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5894146A JPS5894146A (en) | 1983-06-04 |
| JPS639310B2 true JPS639310B2 (en) | 1988-02-26 |
Family
ID=16315933
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56193920A Granted JPS5894146A (en) | 1981-12-01 | 1981-12-01 | Optical memory medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5894146A (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5452518A (en) * | 1977-10-04 | 1979-04-25 | Canon Inc | Recording medium |
-
1981
- 1981-12-01 JP JP56193920A patent/JPS5894146A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5894146A (en) | 1983-06-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4023185A (en) | Ablative optical recording medium | |
| US4219826A (en) | Optical recording medium | |
| JPS61171389A (en) | Thin film for information recording | |
| JP2002133712A (en) | Optical information recording medium, manufacturing method thereof, recording / reproducing method, and recording / reproducing apparatus | |
| JPH0528535A (en) | Optical recording medium | |
| JPS639310B2 (en) | ||
| JPS6130329B2 (en) | ||
| US5728441A (en) | Recordable/replayable optical recording medium and optical recording method therefor | |
| JPS61130089A (en) | Optical recording medium | |
| JPS5916156A (en) | optical memory medium | |
| JP2664207B2 (en) | Thin film for information recording | |
| JP2512044B2 (en) | Optical recording medium and optical recording method | |
| JPS5894147A (en) | optical memory medium | |
| CA1131774A (en) | Optical recording medium | |
| JP2811603B2 (en) | Optical information recording medium | |
| JPH01298545A (en) | Disk-shaped optical information recording medium and its production | |
| JP2001202657A (en) | optical disk | |
| JP2512045B2 (en) | Optical recording medium and optical recording method | |
| JPS5916157A (en) | optical memory medium | |
| JPH01151026A (en) | Optical recording medium and optical recording method | |
| JPH0438632A (en) | Optical recording medium and production thereof | |
| JPS60226037A (en) | Information recording medium | |
| JP2979620B2 (en) | Optical information recording medium and optical information recording / reproducing method | |
| JPH03292630A (en) | How to record information | |
| JPS58146043A (en) | magneto-optical recording medium |