JPH05159360A - Phase shift type optical disk - Google Patents
Phase shift type optical diskInfo
- Publication number
- JPH05159360A JPH05159360A JP3324912A JP32491291A JPH05159360A JP H05159360 A JPH05159360 A JP H05159360A JP 3324912 A JP3324912 A JP 3324912A JP 32491291 A JP32491291 A JP 32491291A JP H05159360 A JPH05159360 A JP H05159360A
- Authority
- JP
- Japan
- Prior art keywords
- difference
- recording
- film
- absorption layer
- overwriting
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、レーザ光照射により可
逆的な相変化を用いて情報を記録する光ディスクに関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc for recording information using a reversible phase change upon irradiation with laser light.
【０００２】[0002]
【従来の技術】レーザ光を用いた光ディスク記録方式は
大容量記録が可能であり、非接触で高速アクセスできる
ことから、大容量メモリとして実用化が始まっている。
光ディスクはコンパクトディスクやレーザディスクとし
て知られている再生専用型、ユーザ自身で記録できる追
記型、及びユーザ側で繰り返し記録消去ができる書き替
え型に分類される。追記型・書き替え型の光ディスクは
コンピュータの外部メモリ、あるいは文書・画像ファイ
ルとして使用されようとしている。2. Description of the Related Art An optical disk recording system using laser light is capable of large-capacity recording and can be accessed at high speed in a non-contact manner.
Optical discs are classified into read-only types known as compact discs and laser discs, write-once types that can be recorded by the user himself, and rewritable types that can be repeatedly recorded and erased by the user. The write-once / rewritable optical disc is about to be used as an external memory of a computer or as a document / image file.
【０００３】書き替え型光ディスクには、記録膜の相変
化を利用した相変化型光ディスクと垂直磁化膜の磁化方
向の変化を利用した光磁気ディスクがある。このうち、
相変化光ディスクは、外部磁場が不要で、かつ、オーバ
ライトが容易にできることから、今後、書き替え型光デ
ィスクの主流になることが期待されている。Rewritable optical disks include phase-change optical disks that utilize the phase change of the recording film and magneto-optical disks that utilize the change of the magnetization direction of the perpendicular magnetization film. this house,
Since the phase change optical disk does not require an external magnetic field and can be easily overwritten, it is expected to become the mainstream of rewritable optical disks in the future.
【０００４】従来よりレーザ光照射により結晶−非晶質
間の相変化を起こす記録膜を用いた書き替え可能な、い
わゆる相変化型光ディスクが知られている。相変化型光
ディスクでは記録膜に記録すべき情報に応じた高パワの
レーザ光スポットを照射し、記録膜温度を局部的に上昇
させることにより、結晶−非晶質間の相変化を起こさせ
て記録し、これに伴う光学定数の変化を低パワのレーザ
光によって反射光強度差として読み取ることにより再生
を行っている。例えば、結晶化時間が比較的遅い記録膜
を用いた相変化光ディスクでは、ディスクを回転させ、
このディスクに形成された記録膜にレーザ光を照射し、
この記録膜の温度を融点以上に上昇させ、レーザ光が通
過した後、急冷することによりその部分を非晶質状態と
し、記録する。消去時には、記録膜温度を結晶化温度以
上、融点以下の結晶化可能温度範囲で結晶化を進行させ
るために十分な時間保持し、記録膜を結晶化させる。こ
のための方法としては、レーザ光進行方向に長い長円レ
ーザ光を照射する方法が知られている。既に記録したデ
ータを消去しながら新しい情報を記録する２ビームによ
る疑似的なオーバライトを行う場合には、消去用の長円
レーザ光を記録用円形レーザ光に先行させて照射するよ
うに配置する。Conventionally, a so-called phase change type optical disk is known, which is rewritable using a recording film which causes a phase change between a crystal and an amorphous state by irradiation with a laser beam. In a phase change type optical disk, a high power laser beam spot corresponding to the information to be recorded is irradiated on the recording film to locally raise the temperature of the recording film to cause a phase change between crystalline and amorphous. Reproduction is performed by recording and reading the change in the optical constants accompanying this as a reflected light intensity difference with a low power laser beam. For example, in a phase change optical disc using a recording film with a relatively slow crystallization time, the disc is rotated,
The recording film formed on this disc is irradiated with laser light,
The temperature of this recording film is raised above the melting point, and after the laser beam has passed, it is rapidly cooled to make that portion amorphous and then recorded. At the time of erasing, the recording film is crystallized by holding the temperature of the recording film within a temperature range which is equal to or higher than the crystallization temperature and is equal to or lower than the melting point, which is sufficient for crystallization. As a method for this purpose, there is known a method of irradiating a long elliptical laser beam in the laser beam traveling direction. When performing pseudo overwrite by two beams for recording new information while erasing already recorded data, it is arranged so that the elliptic laser light for erasing is irradiated prior to the circular laser light for recording. ..
【０００５】一方、高速結晶化が可能な情報記録膜を用
いたディスクでは、円形に集光した１本のレーザ光を使
う。従来より知られている方法は、レーザ光のパワを２
つのレベル間で変化させることにより、結晶化あるいは
非晶質化を行う。すなわち、記録膜の温度を融点以上に
上昇させることが可能なパワのレーザ光を記録膜に照射
することにより、そのほとんどの部分は冷却時に非晶質
状態となり、一方、記録膜温度が結晶化温度以上、融点
以下の温度に達するようなパワのレーザ光が照射された
部分は結晶状態になる。相変化型光ディスクの記録膜に
は、カルコゲナイド系材料であるＧｅＳｂＴｅ系、Ｉｎ
ＳｂＴｅ系、ＩｎＳｅ系、ＩｎＴｅ系、ＡｓＴｅＧｅ
系、ＴｅＯｘ−ＧｅＳｎ系、ＴｅＳｅＳｎ系、ＳｂＳｅ
Ｂｉ系、ＢｉＳｅＧｅ系などが用いられるが、いずれも
抵抗加熱真空蒸着法、電子ビーム真空蒸着法、スパッタ
リング法などの成膜法で成膜される。成膜直後の記録膜
の状態は一種の非晶質状態であり、この記録膜に記録を
行って非晶質の記録部を形成するために、記録膜全体を
結晶質にしておく初期化処理が行われる。記録はこの結
晶化された状態の中に非晶質部分を形成することにより
達成される。On the other hand, a disk using an information recording film capable of high-speed crystallization uses a single laser beam focused in a circular shape. The conventionally known method is to increase the power of laser light to 2
Crystallization or amorphization is performed by changing between two levels. That is, by irradiating the recording film with a laser beam of a power capable of raising the temperature of the recording film to the melting point or more, most of the part becomes an amorphous state during cooling, while the recording film temperature is crystallized. A portion of the power irradiated with the laser light that reaches a temperature equal to or higher than the melting point and equal to or lower than the melting point becomes a crystalline state. The recording film of the phase-change optical disk is composed of a chalcogenide-based material such as GeSbTe-based or In-based.
SbTe system, InSe system, InTe system, AsTeGe
System, TeOx-GeSn system, TeSeSn system, SbSe
Bi-based material, BiSeGe-based material, or the like is used, and both are formed by a film-forming method such as a resistance heating vacuum evaporation method, an electron beam vacuum evaporation method, or a sputtering method. The state of the recording film immediately after film formation is a kind of amorphous state, and an initialization process in which the entire recording film is made crystalline in order to perform recording on this recording film to form an amorphous recording portion. Is done. Recording is accomplished by forming an amorphous portion within this crystallized state.
【０００６】[0006]
【発明が解決しようとする課題】従来、相変化型光ディ
スクの構成は、図２に示すように基板１上に第一保護膜
２，記録膜３，第二保護膜４，反射膜７を順次積層し
た、いわゆる４層反射膜構成であった。この構成では、
記録膜の相変化に伴う光学定数の変化を反射率変化に効
率良く変換でき、良好な再生信号が確保できるという長
所を持つ反面、反射膜７においてほとんどの光が反射さ
れてしまうため、記録膜の光学定数変化に伴う反射率差
を大きく確保しようとすると、記録膜での吸収率にも大
きな差が生じるという欠点があった。記録膜の吸収率の
差があると、オーバライト時に記録膜が結晶か、非晶質
かによって記録膜昇温状態に差が生じることになり、オ
ーバライト信号がオーバライト前の信号成分によって変
調され、これがオーバライト消去率を制限する一因にな
っていた。Conventionally, the structure of a phase-change type optical disk has a structure in which a first protective film 2, a recording film 3, a second protective film 4, and a reflective film 7 are sequentially formed on a substrate 1 as shown in FIG. It was a so-called four-layer reflective film structure in which the layers were laminated. In this configuration,
The advantage of being able to efficiently convert the change of the optical constant due to the phase change of the recording film into the change of the reflectance and ensuring a good reproduction signal, on the other hand, most of the light is reflected by the reflecting film 7, so that the recording film If a large difference in reflectance due to the change in the optical constant is to be secured, there is a drawback that a large difference occurs in the absorptance of the recording film. If there is a difference in the absorptance of the recording film, there will be a difference in the recording film temperature rise state depending on whether the recording film is crystalline or amorphous at the time of overwriting, and the overwrite signal is modulated by the signal component before overwriting. This has been one of the causes of limiting the overwrite erase rate.
【０００７】本発明の目的は上記の欠点を解決し、相変
化型光ディスクのオーバライト消去率を改善し、高密度
記録を可能にする新規な相変化型光ディスクを提供する
ことにある。An object of the present invention is to solve the above-mentioned drawbacks, to improve the overwrite erasure rate of a phase change type optical disk, and to provide a novel phase change type optical disk which enables high density recording.
【０００８】[0008]
【課題を解決するための手段】本発明は、結晶と非晶質
間の可逆的な相変化を用い、レーザ光照射による情報記
録膜の相状態変化によって情報の記録再生消去を行う相
変化型光ディスクであって、透明基板と、前記透明基板
上に形成された第一の保護膜と、前記第一保護膜上に形
成された相変化型情報記録膜と、前記記録膜上に形成さ
れた第二の保護膜と、前記第二保護膜上に形成された吸
収層と、前記吸収層上に形成された放熱層を有すること
を特徴とする。The present invention uses a reversible phase change between a crystal and an amorphous phase to perform information recording / reproducing / erasing by changing the phase state of an information recording film by laser light irradiation. An optical disc, comprising a transparent substrate, a first protective film formed on the transparent substrate, a phase change type information recording film formed on the first protective film, and formed on the recording film. A second protective film, an absorption layer formed on the second protective film, and a heat dissipation layer formed on the absorption layer.
【０００９】[0009]
【実施例】次に、本発明の実施例について図面を参照し
て説明する。図１は本発明にかかる光ディスクの構成を
示した図である。基板１上に第一保護膜２、記録膜３、
第二保護膜４、吸収層５、放熱層６が順次形成されたも
のである。基板１には、円盤状のガラスもしくはプラス
チックが用いられる。第一保護膜２と、第二保護膜４に
は、ＳｉＯ2 、Ｓｉ3 Ｎ4 、ＡｌＮ、ＴｉＯ2 、ＺｎＳ
などの誘電体材料が用いられる。記録膜３としては、カ
ルゴゲナイド系材料であるＧｅＳｂＴｅ系、ＩｎＳｂＴ
ｅ系、ＩｎＳｅ系、ＩｎＴｅ系、ＡｓＴｅＧｅ系、Ｔｅ
Ｏｘ−ＧｅＳｎ系、ＴｅＳｅＳｎ系、ＳｂＳｅＢｉ系、
ＢｉＳｅＧｅ系などが用いられる。吸収層５には、使用
されるレーザ波長において、吸収特性を持つ材料、特に
は、Ｔｉ、Ｎｉ、Ｗ、Ｍｏ、Ｖ、Ｎｂ、Ｃｒ、Ｆｅなど
の金属が使用される。放熱層６には、熱伝導率が大きい
材料、特には、Ａｌ、Ａｕ、Ｃｕ、Ａｇなどの金属が用
いられる。Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a diagram showing the configuration of an optical disc according to the present invention. On the substrate 1, the first protective film 2, the recording film 3,
The second protective film 4, the absorption layer 5, and the heat dissipation layer 6 are sequentially formed. A disk-shaped glass or plastic is used for the substrate 1. SiO 2 , Si 3 N 4 , AlN, TiO 2 , ZnS are used for the first protective film 2 and the second protective film 4.
A dielectric material such as As the recording film 3, a GeSbTe-based material, which is a chalcogenide-based material, or InSbT-based material, is used.
e-based, InSe-based, InTe-based, AsTeGe-based, Te
Ox-GeSn system, TeSeSn system, SbSeBi system,
BiSeGe system or the like is used. For the absorption layer 5, a material having absorption characteristics at a laser wavelength used, particularly a metal such as Ti, Ni, W, Mo, V, Nb, Cr or Fe is used. For the heat dissipation layer 6, a material having a high thermal conductivity, particularly a metal such as Al, Au, Cu, Ag is used.
【００１０】本発明の特徴はこのディスクの構成にあ
り、特に第二保護膜４上に形成した吸収層５と放熱層６
に特徴がある。前述した従来の４層反射膜構成では、反
射膜７でほとんどの光が反射されてしまうため、ディス
クの反射率差がそのまま記録膜の吸収率差となってしま
い、十分な再生信号を確保しようとすると吸収率差が大
きくなりオーバライト消去率不十分となる欠点があった
が、本発明に係るディスクにおいては、記録膜３を透過
した光が、吸収層５において、かなり吸収されるので、
ディスクとしてある程度の反射率差がある場合でも、記
録膜３での吸収率差を小さく抑えることができる。この
場合、吸収層５での光吸収に伴う昇温があり、吸収層５
への熱的な負担が大きくなる恐れがあるが、それに対し
ては吸収層５に隣接して形成した放熱層６が有効に作用
する。すなわち、放熱層６は吸収層５で発生した熱を効
率良く逃がす役割をするので、吸収層５への熱的負担は
大幅に軽減される。The feature of the present invention resides in the structure of this disc, and particularly, the absorption layer 5 and the heat dissipation layer 6 formed on the second protective film 4.
It is characterized by In the above-described conventional four-layer reflective film structure, most of the light is reflected by the reflective film 7, so that the difference in reflectance of the disk becomes the difference in absorptance of the recording film as it is, so that a sufficient reproduced signal can be secured. Then, there is a drawback that the difference in absorption rate becomes large and the overwrite erasure rate becomes insufficient. However, in the disc according to the present invention, the light transmitted through the recording film 3 is considerably absorbed in the absorption layer 5,
Even if the disc has a certain difference in reflectance, the difference in absorptance in the recording film 3 can be suppressed to a small value. In this case, there is a temperature rise due to light absorption in the absorption layer 5,
There is a risk that the heat load on the heat dissipation layer 6 will increase, but the heat dissipation layer 6 formed adjacent to the absorption layer 5 effectively acts on this. That is, since the heat dissipation layer 6 plays a role of efficiently releasing the heat generated in the absorption layer 5, the thermal load on the absorption layer 5 is significantly reduced.
【００１１】次に、使用するレーザ波長を８３０ｎｍに
設定し、結晶と非晶質間の吸収率差ができるだけ小さ
く、かつ、両相間での反射率差が大きくなるようにディ
スク構成を決定し、ディスクを作成した。基板１には直
径１３０ｍｍ、厚さ１．２ｍｍのプリグルーブ付きポリ
カーボネート基板を用いた。第一保護膜２及び第二保護
膜４にはＺｎＳ＋ＳｉＯ2 混合膜を、記録膜３にはＧｅ
ＳｂＴｅを、吸収層５にはＴｉを、放熱層６にはＡｌを
用い、マグネトロンスパッタ法により連続成膜した。各
層の膜厚は、第一保護膜１４０ｎｍ、記録膜２０ｎｍ、
第二保護膜２２０ｎｍ、吸収層５０ｎｍ、放熱層５０ｎ
ｍとした。このディスクでは、波長８３０ｎｍにおける
吸収率は結晶に対して６３％、非晶質に対しても６３％
であり、反射率は結晶に対して２４％、非晶質に対して
１％であった。Next, the laser wavelength to be used is set to 830 nm, and the disc structure is determined so that the difference in the absorptance between the crystal and the amorphous is as small as possible and the difference in the reflectivity between the two phases is large. I made a disc. As the substrate 1, a polycarbonate substrate with a pregroove having a diameter of 130 mm and a thickness of 1.2 mm was used. A ZnS + SiO 2 mixed film is used for the first protective film 2 and the second protective film 4, and Ge is used for the recording film 3.
SbTe was used, Ti was used for the absorption layer 5, and Al was used for the heat dissipation layer 6 to continuously form a film by a magnetron sputtering method. The film thickness of each layer is 140 nm for the first protective film, 20 nm for the recording film,
Second protective film 220 nm, absorption layer 50 nm, heat dissipation layer 50 n
m. With this disc, the absorption rate at a wavelength of 830 nm is 63% for crystals and 63% for amorphous materials.
The reflectance was 24% for crystals and 1% for amorphous.
【００１２】次に、前記ディスクにオーバライトを行
い、特性を評価した。記録消去再生には、波長８３０ｎ
ｍの半導体レーザを搭載した光ヘッドを用いた。初期化
処理後のディスクを回転数３６００ｒｐｍにて回転さ
せ、半径３０ｍｍのトラックに８．４ＭＨｚ（Ｄｕｔｙ
５０％）信号と２．２ＭＨｚ（Ｄｕｔｙ５０％）信号を
交互にオーバライトした。再生信号の二次高調波歪が最
小となるように、記録パワと消去パワをそれぞれ１３ｍ
Ｗ、７ｍＷに設定した。この時の両周波数に対する消去
率はそれぞれ３０ｄＢ、２９ｄＢであった。次に、同一
回転数で半径６０ｍｍのトラックに両周波数を交互にオ
ーバライトし、特性を測定した。記録パワは１８ｍＷ、
消去パワは１０ｍＷに設定した。この時のオーバライト
消去率は８．４ＭＨｚに対して３２ｄＢ、２．２ＭＨｚ
に対しては３０ｄＢであった。従来の４層反射膜構成で
は、ここで示した記録周波数のオーバライトにおいて
は、十分な消去率が確保できなかったが、本発明に係る
ディスク構成を採用することによって、消去率を大幅に
改善できた。また、半径３０ｍｍ及び６０ｍｍにおいて
測定した繰り返しオーバライト特性は良好であり、吸収
層５に隣接して形成した放熱層６の有効性が確認でき
た。Next, the disk was overwritten and the characteristics were evaluated. 830n wavelength for recording / erasing
An optical head equipped with a m semiconductor laser was used. The disk after the initialization processing is rotated at a rotation speed of 3600 rpm, and a track with a radius of 30 mm is 8.4 MHz (Duty).
The 50%) signal and the 2.2 MHz (Duty 50%) signal were alternately overwritten. The recording power and the erasing power are 13 m each to minimize the second harmonic distortion of the reproduced signal.
W was set to 7 mW. At this time, the erasing rates for both frequencies were 30 dB and 29 dB, respectively. Next, the two frequencies were alternately overwritten on a track having a radius of 60 mm at the same number of revolutions, and the characteristics were measured. Recording power is 18mW,
The erasing power was set to 10 mW. The overwrite erase rate at this time is 32 dB against 2.2 MHz at 8.4 MHz.
Was 30 dB. With the conventional four-layer reflective film structure, a sufficient erasing rate could not be secured in the overwrite of the recording frequency shown here, but by adopting the disk structure according to the present invention, the erasing rate is significantly improved. did it. Further, the repeated overwrite characteristics measured at radii of 30 mm and 60 mm were good, and the effectiveness of the heat dissipation layer 6 formed adjacent to the absorption layer 5 was confirmed.
【００１３】[0013]
【発明の効果】以上説明したように、本発明では、使用
するレーザ波長に対して記録膜の吸収率を一定にできる
ため、オーバライト時の消去率として十分な値が確保で
き、さらにオーバライト時のビット形状歪を抑える効果
もある。これにより、オーバライト時の再生信号のジッ
タ増加を小さく抑えることができるという効果がある。As described above, according to the present invention, since the absorptance of the recording film can be made constant with respect to the laser wavelength to be used, a sufficient value can be secured as the erasing rate at the time of overwriting, and further the overwriting can be achieved. It also has the effect of suppressing bit shape distortion. As a result, there is an effect that it is possible to suppress an increase in the jitter of the reproduction signal at the time of overwrite.
【図１】本発明にかかる相変化型光ディスクの構成を示
す図である。FIG. 1 is a diagram showing a configuration of a phase change type optical disc according to the present invention.
【図２】従来の相変化型光ディスクの構成を示す図であ
る。FIG. 2 is a diagram showing a configuration of a conventional phase change optical disc.
１ 基板 ２ 第一保護膜 ３ 記録膜 ４ 第二保護膜 ５ 吸収層 ６ 放熱層 ７ 反射膜 1 substrate 2 first protective film 3 recording film 4 second protective film 5 absorption layer 6 heat dissipation layer 7 reflection film
Claims (1)
レーザ光照射による情報記録膜の相状態変化によって情
報の記録再生消去を行う相変化型光ディスクであって、
透明基板と、前記透明基板上に形成された第一の保護膜
と、前記第一保護膜上に形成された相変化型情報記録膜
と、前記記録膜上に形成された第二の保護膜と、前記第
二保護膜上に形成された吸収層と、前記吸収層上に形成
された放熱層を有することを特徴とする相変化型光ディ
スク。1. Using a reversible phase change between crystalline and amorphous,
A phase change type optical disc that records / reproduces / erases information by changing a phase state of an information recording film by laser light irradiation,
Transparent substrate, first protective film formed on the transparent substrate, phase change type information recording film formed on the first protective film, and second protective film formed on the recording film A phase-change optical disc comprising: an absorption layer formed on the second protective film; and a heat dissipation layer formed on the absorption layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3324912A JP2830557B2 (en) | 1991-12-10 | 1991-12-10 | Phase change optical disk |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3324912A JP2830557B2 (en) | 1991-12-10 | 1991-12-10 | Phase change optical disk |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05159360A true JPH05159360A (en) | 1993-06-25 |
| JP2830557B2 JP2830557B2 (en) | 1998-12-02 |
Family
ID=18171012
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3324912A Expired - Fee Related JP2830557B2 (en) | 1991-12-10 | 1991-12-10 | Phase change optical disk |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2830557B2 (en) |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0706177A1 (en) * | 1994-03-25 | 1996-04-10 | Toray Industries, Inc. | Optical recording medium |
| EP0737967A2 (en) * | 1995-03-28 | 1996-10-16 | Toray Industries, Inc. | Optical recording media and a method for recording on the optical recording media |
| US5840466A (en) * | 1994-03-25 | 1998-11-24 | Toray Industries, Inc. | Optical recording media and their production methods |
| EP0887791A1 (en) * | 1996-02-28 | 1998-12-30 | Asahi Kasei Kogyo Kabushiki Kaisha | Method of designing a phase-change optical recording medium, and a phase-change optical recording medium |
| US6268034B1 (en) | 1998-08-05 | 2001-07-31 | Matsushita Electric Industrial Co., Ltd. | Optical information recording medium and method for producing the same, method for recording and reproducing information thereon and recording/reproducing apparatus |
| US6300039B1 (en) * | 1994-03-25 | 2001-10-09 | Toray Industries, Inc. | Optical recording medium |
| US6343062B1 (en) | 1997-09-26 | 2002-01-29 | Matsushita Electric Industrial Co., Ltd | Optical disk device and optical disk for recording and reproducing high-density signals |
| US6388984B2 (en) | 1997-08-28 | 2002-05-14 | Matsushita Electric Industrial Co., Ltd. | Optical information recording medium and its recording and reproducing method |
| US6503690B1 (en) | 1997-08-12 | 2003-01-07 | Matsushita Electric Industrial Co., Ltd. | Optical information recording medium, method for producing the same, and method for recording and reproducing optical information |
| US6740382B2 (en) | 1997-09-09 | 2004-05-25 | Hitachi, Ltd. | Information recording medium |
| US6806030B2 (en) * | 2000-03-30 | 2004-10-19 | Hitachi, Ltd. | Information recording medium and method for manufacturing information recording medium |
| US6821707B2 (en) | 1996-03-11 | 2004-11-23 | Matsushita Electric Industrial Co., Ltd. | Optical information recording medium, producing method thereof and method of recording/erasing/reproducing information |
| KR100517466B1 (en) * | 1998-06-27 | 2005-11-25 | 엘지전자 주식회사 | Disc With Heat Radiating Layer |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60264293A (en) * | 1984-06-14 | 1985-12-27 | Matsushita Electric Ind Co Ltd | Optical recording member |
| JPH02240842A (en) * | 1989-03-15 | 1990-09-25 | Hitachi Ltd | Phase transition type optical disk which allows melting erasing |
-
1991
- 1991-12-10 JP JP3324912A patent/JP2830557B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60264293A (en) * | 1984-06-14 | 1985-12-27 | Matsushita Electric Ind Co Ltd | Optical recording member |
| JPH02240842A (en) * | 1989-03-15 | 1990-09-25 | Hitachi Ltd | Phase transition type optical disk which allows melting erasing |
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0706177A1 (en) * | 1994-03-25 | 1996-04-10 | Toray Industries, Inc. | Optical recording medium |
| EP0706177A4 (en) * | 1994-03-25 | 1998-09-02 | Toray Industries | Optical recording medium |
| US5840466A (en) * | 1994-03-25 | 1998-11-24 | Toray Industries, Inc. | Optical recording media and their production methods |
| US6300039B1 (en) * | 1994-03-25 | 2001-10-09 | Toray Industries, Inc. | Optical recording medium |
| EP0737967A2 (en) * | 1995-03-28 | 1996-10-16 | Toray Industries, Inc. | Optical recording media and a method for recording on the optical recording media |
| EP0737967A3 (en) * | 1995-03-28 | 1997-09-24 | Toray Industries | Optical recording media and a method for recording on the optical recording media |
| EP0887791A1 (en) * | 1996-02-28 | 1998-12-30 | Asahi Kasei Kogyo Kabushiki Kaisha | Method of designing a phase-change optical recording medium, and a phase-change optical recording medium |
| EP0887791A4 (en) * | 1996-02-28 | 1999-10-06 | Asahi Chemical Ind | Method of designing a phase-change optical recording medium, and a phase-change optical recording medium |
| US6149999A (en) * | 1996-02-28 | 2000-11-21 | Asahi Kasei Kogyo Kabushiki Kaisha | Method of designing a phase-change optical recording medium, and a phase-change optical recording medium |
| US7037413B1 (en) | 1996-03-11 | 2006-05-02 | Matsushita Electric Industrial Co., Ltd. | Optical information recording medium, producing method thereof and method of recording/erasing/reproducing information |
| US6821707B2 (en) | 1996-03-11 | 2004-11-23 | Matsushita Electric Industrial Co., Ltd. | Optical information recording medium, producing method thereof and method of recording/erasing/reproducing information |
| US6503690B1 (en) | 1997-08-12 | 2003-01-07 | Matsushita Electric Industrial Co., Ltd. | Optical information recording medium, method for producing the same, and method for recording and reproducing optical information |
| US6388984B2 (en) | 1997-08-28 | 2002-05-14 | Matsushita Electric Industrial Co., Ltd. | Optical information recording medium and its recording and reproducing method |
| US6740382B2 (en) | 1997-09-09 | 2004-05-25 | Hitachi, Ltd. | Information recording medium |
| US6343062B1 (en) | 1997-09-26 | 2002-01-29 | Matsushita Electric Industrial Co., Ltd | Optical disk device and optical disk for recording and reproducing high-density signals |
| KR100517466B1 (en) * | 1998-06-27 | 2005-11-25 | 엘지전자 주식회사 | Disc With Heat Radiating Layer |
| US6268034B1 (en) | 1998-08-05 | 2001-07-31 | Matsushita Electric Industrial Co., Ltd. | Optical information recording medium and method for producing the same, method for recording and reproducing information thereon and recording/reproducing apparatus |
| US6806030B2 (en) * | 2000-03-30 | 2004-10-19 | Hitachi, Ltd. | Information recording medium and method for manufacturing information recording medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2830557B2 (en) | 1998-12-02 |
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