JPH0675302B2 - optical disk - Google Patents
optical diskInfo
- Publication number
- JPH0675302B2 JPH0675302B2 JP58147197A JP14719783A JPH0675302B2 JP H0675302 B2 JPH0675302 B2 JP H0675302B2 JP 58147197 A JP58147197 A JP 58147197A JP 14719783 A JP14719783 A JP 14719783A JP H0675302 B2 JPH0675302 B2 JP H0675302B2
- Authority
- JP
- Japan
- Prior art keywords
- heat
- resistant inorganic
- inorganic material
- material layer
- recording film
- 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
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
-
- 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
Landscapes
- Optical Record Carriers And Manufacture Thereof (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は、オーディオディスク、ビデオディスク、ある
いは文書・画像ファイル用ディスク等として利用される
情報信号を記録・再生・消去可能な光ディスクに関す
る。Description: TECHNICAL FIELD The present invention relates to an optical disc capable of recording / reproducing / erasing an information signal used as an audio disc, a video disc, a disc for document / image files, or the like.
従来例の構成とその問題点 ユーザーにより情報信号の記録・再生が可能な光ディス
クにおいて、記録時におけるトラッキング方式として
は、機械精度による方式、あるいはディスク基板上に形
成したトラック案内溝を利用する方式が知られている。Configuration of conventional example and its problems In an optical disc in which an information signal can be recorded / reproduced by a user, a mechanical precision method or a method using a track guide groove formed on a disc substrate is used as a tracking method at the time of recording. Are known.
前者は、精度が不十分であるため、トラック間隔が大き
くなり、高密度に情報信号を記録するには不適当であ
る。また後者の場合は、トラック案内溝を加工する必要
から、ディスク基板の材料は、比較的安価で、製造工程
の容易なプラスチック材料が主に利用されている。The former is insufficient in precision, and thus the track interval becomes large, and is not suitable for recording information signals at high density. In the latter case, since the track guide groove needs to be processed, a plastic material which is relatively inexpensive and easy to manufacture is mainly used as the material of the disk substrate.
ところで、一旦記録された情報信号の消却も可能な光デ
ィスクとしては、トラック案内溝を形成したプラスチッ
ク基板上に可逆性記録膜を直接形成したものが従来から
知られているが、情報信号の記録・消去時に膜温度が摂
氏100〜300度程度に上昇するために、プラスチック基板
に熱的な形状変化を生じさせ、その形状変化が情報信号
の品質を悪化させる原因となり、繰り返し記録・消去を
行なう時に問題があった。By the way, as an optical disc capable of erasing an information signal once recorded, a reversible recording film is directly formed on a plastic substrate having a track guide groove is conventionally known. When erasing, the film temperature rises to about 100 to 300 degrees Celsius, which causes a thermal shape change on the plastic substrate, which causes deterioration of the quality of the information signal. There was a problem.
そこで、この問題を解決するために、一層の耐熱性無機
物層をプラスチック基板と可逆性記録膜との間に介在さ
せて、これによりプラスチック基板の熱的形状変化を阻
止する方法も考え出されたが、プラスチック基板と無機
物層の線膨張率の差に起因して、温度変化により内部応
力が発生し、その結果、耐熱性無機物層やプラスチック
にひび割れやしわが発生するという問題があった。Therefore, in order to solve this problem, a method of interposing a heat-resistant inorganic material layer between the plastic substrate and the reversible recording film to prevent thermal shape change of the plastic substrate has been devised. However, due to the difference in linear expansion coefficient between the plastic substrate and the inorganic layer, internal stress is generated due to temperature change, and as a result, cracks and wrinkles occur in the heat resistant inorganic layer and plastic.
また、可逆性記録膜を構成する物質は、比較的酸化し易
いものが多いため、記録膜近傍に余剰の酸素が存在する
と、記録膜の特性が劣化してくるという問題があった。Further, since many of the substances constituting the reversible recording film are relatively easily oxidized, there is a problem that the characteristics of the recording film are deteriorated when excess oxygen exists in the vicinity of the recording film.
発明の目的 本発明は、上記従来の欠点を解消するもので、情報信号
の記録・消却時におけるレーザ照射により、プラスチッ
ク基板に熱的形状変化が発生するのを防止すると共に、
温度変化があってもディスク構成要素にひび割れやしわ
等機械的変形が発生することを防止することができ、さ
らに可逆性記録膜の酸化による性能の劣化を防止するこ
とができる光ディスクを提供することを目的とする。An object of the present invention is to eliminate the above-mentioned conventional drawbacks, and to prevent the thermal shape change from occurring in the plastic substrate due to the laser irradiation at the time of recording / erasing the information signal,
To provide an optical disc capable of preventing mechanical deformation such as cracks and wrinkles from occurring in a disc constituent element even when temperature changes, and further preventing deterioration of performance due to oxidation of a reversible recording film. With the goal.
発明の構成 本発明は、上記目的を達成するために、プラスチック基
板と可逆性記録膜との間に、プラスチック基板に隣接す
る第１の耐熱性無機物層および可逆性記録膜と第１の耐
熱性無機物層との双方に隣接する第２の耐熱性無機物層
を介在させ、第２の耐熱性無機物層を還元性のある物質
とし、かつ第１の耐熱性無機物層の線膨張率をプラチッ
ク基板の線膨張率よりも小さく、第２の耐熱性無機物層
の線膨張率よりも大きくした構成とする。In order to achieve the above object, the present invention provides a first heat-resistant inorganic material layer and a reversible recording film and a first heat-resistant layer between a plastic substrate and a reversible recording film, which are adjacent to the plastic substrate. A second heat-resistant inorganic material layer adjacent to both the inorganic material layer and the second heat-resistant inorganic material layer is used as a reducing substance, and the linear expansion coefficient of the first heat-resistant inorganic material layer is set to that of the plastic substrate. The linear expansion coefficient is smaller than the linear expansion coefficient and larger than the linear expansion coefficient of the second heat-resistant inorganic layer.
なお、可逆性記録膜は、光磁気記録膜、あるいは結晶と
非晶質問の遷移を利用した相変化記録膜などが考えられ
る。The reversible recording film may be a magneto-optical recording film or a phase change recording film utilizing the transition between crystal and amorphous.
実施例の説明 以下、本発明の実施例について、図面を参照しながら説
明する。第１図は本発明の一実施例にかかる光ディスク
を示す縦断面図である。Description of Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a vertical sectional view showing an optical disc according to an embodiment of the present invention.
第１図において、１は表面にトラック案内溝２が形成さ
れたプラスチック基板で、このプラスチック基板１と可
逆性記録膜５との間に第１の耐熱性無機物層３と第２の
耐熱性無機物層４とを介在させてある。In FIG. 1, reference numeral 1 denotes a plastic substrate having a track guide groove 2 formed on the surface thereof. A first heat-resistant inorganic material layer 3 and a second heat-resistant inorganic material are provided between the plastic substrate 1 and the reversible recording film 5. And layer 4 is interposed.
第１の耐熱性無機物層３の線膨張率は、プラスチック基
板１および第２の耐熱性無機物層４のそれぞれの線膨張
率の中間値になるようにしてある。また、第２の耐熱性
無機物層４は還元性のある一酸化珪素から構成してあ
る。The linear expansion coefficient of the first heat-resistant inorganic material layer 3 is set to an intermediate value between the linear expansion coefficients of the plastic substrate 1 and the second heat-resistant inorganic material layer 4. The second heat-resistant inorganic material layer 4 is made of reductive silicon monoxide.
より具体的に構成を説明すると、トラック案内溝２を形
成した線膨張率８×10-51/℃のポリメタルメタクリレー
ト製基板１上に、線膨張率約1.6×10-51/℃で厚さ500Å
の酸化ホウ素（B2O3）層３を形成し、さらに、線膨張率
８×10-61/℃以下で厚さ500Åの一酸化珪素層４を形成
する。その上に、光磁気記録材料であるガドリウム鉄
（GdFe）で厚さ500Åの可逆性記録膜５を形成し、図示
していないが、さらに必要に応じて、反射膜としてAl薄
膜及び保護膜としてSiO薄膜を設ける。More specifically, the structure will be described with reference to a linear expansion coefficient of about 1.6 × 10 -5 1 / ° C. on a polymetal methacrylate substrate 1 having a track guide groove 2 and a linear expansion coefficient of 8 × 10 -5 1 / ° C. Thickness 500Å
A boron oxide (B 2 O 3 ) layer 3 is formed, and a silicon monoxide layer 4 having a linear expansion coefficient of 8 × 10 −6 1 / ° C. or less and a thickness of 500 Å is formed. On top of that, a reversible recording film 5 having a thickness of 500Å is formed of gadolinium iron (GdFe) which is a magneto-optical recording material, and although not shown, an Al thin film and a protective film may be used as a reflective film if necessary. An SiO thin film is provided.
以上のように構成した光ディスクは、基板１側からレー
ザ光を入射させて情報信号の記録・再生・消去を1000万
回以上繰り返して行なった後も、基板１と可逆性記録膜
５との間に、耐熱材料として酸化ホウ素層３及び一酸化
珪素層４を介在させたことにより、レーザ照射による記
録膜５の温度上昇にもかかわらずポリメタルメタクリレ
ート製基板１の熱的形状変化は認められず、その結果、
再生された情報信号に品質の低下は見られなかった。The optical disc having the above-described structure is arranged between the substrate 1 and the reversible recording film 5 even after the laser light is incident from the substrate 1 side to record / reproduce / erase information signals repeatedly for 10 million times or more. In addition, since the boron oxide layer 3 and the silicon monoxide layer 4 are interposed as the heat-resistant material, the thermal shape change of the polymetal methacrylate substrate 1 is not recognized despite the temperature rise of the recording film 5 due to the laser irradiation. ,as a result,
No deterioration in quality was found in the reproduced information signal.
また、比較的線膨張率の差が大きい基板１と一酸化珪素
層４との間に、それらの中間の線膨張率を有する酸化ホ
ウ素層３を介在させてあるので、温度変化によって生ず
る内部応力の分散緩和が段階的にでき、ディスク構成要
素にひび割れや、しわ等の欠陥が生じることはなかっ
た。Further, since the boron oxide layer 3 having a linear expansion coefficient between those of the substrate 1 and the silicon monoxide layer 4 having a relatively large difference in linear expansion coefficient is interposed, the internal stress caused by the temperature change is increased. The dispersion was gradually relaxed, and cracks and wrinkles did not occur on the disk components.
さらに、第２の耐熱性無機物層４を還元性のある一酸化
珪素としたことで、第２図に示したように可逆性記録膜
５の保磁力が劣化することなく、信号の記録再生特性も
変わらなかった。Furthermore, since the second heat-resistant inorganic layer 4 is made of reductive silicon monoxide, the coercive force of the reversible recording film 5 is not deteriorated as shown in FIG. Did not change.
第２図は、第２の耐熱性無機物層を一酸化珪素層４とし
た場合の光ディスクの場合と、一酸化珪素層４の代わり
に二酸化珪素層を用いた場合とについて、可逆性記録膜
５の保持力の45℃放置特性を示しており、Ａは一酸化珪
素層４の場合、Ｂは二酸化珪素層の場合を示している。FIG. 2 shows the reversible recording film 5 in the case of an optical disc in which the second heat-resistant inorganic layer is the silicon monoxide layer 4 and in the case of using a silicon dioxide layer instead of the silicon monoxide layer 4. 4 shows the holding power of 45 ° C., and A shows the case of the silicon monoxide layer 4, and B shows the case of the silicon dioxide layer.
第２図に示すように、二酸化珪素層の場合Ｂでは可逆性
記録膜５が酸化して、その保持力に経時的な劣化がみら
れるものの、一酸化珪素層の場合Ａでは、還元性のある
一酸化珪素層４を可逆性記録膜５に隣接させて、可逆性
記録膜５の酸化防止をしていることから、その保持力の
経時的劣化は全く認められないものである。As shown in FIG. 2, in the case of the silicon dioxide layer B, the reversible recording film 5 oxidizes, and its holding power deteriorates with time. Since a certain silicon monoxide layer 4 is adjacent to the reversible recording film 5 to prevent the reversible recording film 5 from being oxidized, deterioration of its holding power with time is not observed at all.
なお、本実施例においては、断面矩形状のトラック案内
溝２を基板１表面に形成したが、他の断面形状のもの、
例えばＶ字状またはＵ字状のトラック案内溝を形成して
もよい。In this embodiment, the track guide groove 2 having a rectangular cross section is formed on the surface of the substrate 1, but the track guide groove 2 having another cross section is used.
For example, a V-shaped or U-shaped track guide groove may be formed.
また本発明は、トラック案内溝を形成していない基板に
ついても適用可能であるのはいうまでもない。Needless to say, the present invention can be applied to a substrate having no track guide groove.
発明の効果 以上説明したように、本発明にかかる光ディスクでは、
可逆性記録膜に還元性を持つ第２の耐熱性無機物層を隣
接させ、第２の耐熱性無機物層とプラスチック基板との
間にそれらの中間値の線膨張率を有する第１の耐熱性無
機物層を介在させたので、可逆性記録膜の加熱によるプ
ラスチック基板の熱的形状変化を防止できると共に、温
度変化による内部応力の分散緩和をして、ディスク構成
要素のひび割れやしわの発生等を防止することができ
る。さらに、可逆性記録膜は酸化が防止され、性能の劣
化を防止することができる。従って、この光ディスクに
繰り返し記録・再生・消去を行っても、記録・再生・消
去条件は変化することなく、再生信号の品質低下は皆無
であるという優れた効果が得られる。EFFECTS OF THE INVENTION As described above, in the optical disc according to the present invention,
A second heat-resistant inorganic material layer having a reducing property adjacent to the reversible recording film, and a first heat-resistant inorganic material having a linear expansion coefficient between the second heat-resistant inorganic material layer and the plastic substrate, which is an intermediate value therebetween. Since the layer is interposed, it is possible to prevent the thermal shape change of the plastic substrate due to the heating of the reversible recording film, and to alleviate the dispersion of internal stress due to the temperature change and prevent the formation of cracks and wrinkles of the disk components. can do. Furthermore, the reversible recording film is prevented from being oxidized and can be prevented from deteriorating in performance. Therefore, even if the recording / reproducing / erasing is repeatedly performed on this optical disc, the recording / reproducing / erasing conditions do not change, and the excellent effect that the quality of the reproduced signal is not deteriorated is obtained.
第１図は本発明の一実施例にかかる光ディスクを示す縦
断面図、第２図は同光ディスクにおける可逆性記録膜の
保磁力に関する放置特性を示すグラフである。 １……プラスチック基板、２……トラック案内溝、３…
…第１の耐熱性無機物層、４……第２の耐熱性無機物
層、５……可逆性記録膜。FIG. 1 is a vertical cross-sectional view showing an optical disc according to an embodiment of the present invention, and FIG. 2 is a graph showing a leaving characteristic with respect to coercive force of a reversible recording film in the optical disc. 1 ... Plastic substrate, 2 ... Track guide groove, 3 ...
... 1st heat-resistant inorganic material layer, 4 ... 2nd heat-resistant inorganic material layer, 5 ... Reversible recording film.
Claims (2)
に、前記プラスチック基板に隣接する第１の耐熱性無機
物層および前記可逆性記録膜と前記第１の耐熱性無機物
層との双方に隣接する第２の耐熱性無機物層を介在さ
せ、前記第２の耐熱性無機物層を還元性物質とし、かつ
前記第１の耐熱性無機物層の線膨張率を前記プラスチッ
ク基板の線膨張率よりも小さく、前記第２の耐熱性無機
物層の線膨張率よりも大きい物質としたことを特徴とす
る光ディスク。1. A first heat-resistant inorganic material layer adjacent to the plastic substrate between the plastic substrate and the reversible recording film, and adjacent to both the reversible recording film and the first heat-resistant inorganic material layer. The second heat-resistant inorganic material layer is interposed, the second heat-resistant inorganic material layer is used as a reducing substance, and the linear expansion coefficient of the first heat-resistant inorganic material layer is smaller than that of the plastic substrate. An optical disc comprising a material having a coefficient of linear expansion larger than that of the second heat-resistant inorganic layer.
ことを特徴とする特許請求の範囲第１項記載の光ディス
ク。2. The optical disk according to claim 1, wherein the second heat-resistant inorganic material layer is made of silicon monoxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58147197A JPH0675302B2 (en) | 1983-08-10 | 1983-08-10 | optical disk |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58147197A JPH0675302B2 (en) | 1983-08-10 | 1983-08-10 | optical disk |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6038746A JPS6038746A (en) | 1985-02-28 |
| JPH0675302B2 true JPH0675302B2 (en) | 1994-09-21 |
Family
ID=15424748
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58147197A Expired - Lifetime JPH0675302B2 (en) | 1983-08-10 | 1983-08-10 | optical disk |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0675302B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6192448A (en) * | 1984-10-11 | 1986-05-10 | Nippon Columbia Co Ltd | Optical information recording medium |
| US4719594A (en) * | 1984-11-01 | 1988-01-12 | Energy Conversion Devices, Inc. | Grooved optical data storage device including a chalcogenide memory layer |
| JPH07114032B2 (en) * | 1986-01-14 | 1995-12-06 | ソニー株式会社 | Optical recording medium |
| JPH07111788B2 (en) * | 1987-01-23 | 1995-11-29 | 株式会社日立製作所 | Optical information recording medium |
| US4872172A (en) * | 1987-11-30 | 1989-10-03 | Tandem Computers Incorporated | Parity regeneration self-checking |
| JPH0827984B2 (en) * | 1989-07-28 | 1996-03-21 | 松下電器産業株式会社 | Optical information recording medium |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5817037B2 (en) * | 1979-03-26 | 1983-04-04 | 株式会社日立製作所 | Recording parts |
-
1983
- 1983-08-10 JP JP58147197A patent/JPH0675302B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6038746A (en) | 1985-02-28 |
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