JPH04319531A - Optical information reproducing method and optical information recording medium - Google Patents
Optical information reproducing method and optical information recording mediumInfo
- Publication number
- JPH04319531A JPH04319531A JP3088847A JP8884791A JPH04319531A JP H04319531 A JPH04319531 A JP H04319531A JP 3088847 A JP3088847 A JP 3088847A JP 8884791 A JP8884791 A JP 8884791A JP H04319531 A JPH04319531 A JP H04319531A
- Authority
- JP
- Japan
- Prior art keywords
- recording
- layer
- light
- recording layer
- optical information
- 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.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 15
- 230000003287 optical effect Effects 0.000 title claims description 24
- 230000031700 light absorption Effects 0.000 claims description 6
- 230000001678 irradiating effect Effects 0.000 claims description 4
- 239000010410 layer Substances 0.000 description 53
- 239000000463 material Substances 0.000 description 7
- 239000011241 protective layer Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000010287 polarization Effects 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- BQCIDUSAKPWEOX-UHFFFAOYSA-N 1,1-Difluoroethene Chemical compound FC(F)=C BQCIDUSAKPWEOX-UHFFFAOYSA-N 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- UBOXGVDOUJQMTN-UHFFFAOYSA-N trichloroethylene Natural products ClCC(Cl)Cl UBOXGVDOUJQMTN-UHFFFAOYSA-N 0.000 description 1
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は、光ディスク等の光記憶
媒体に高い面記録密度をもってデータの書き込み／読み
出しを行うことができる再生方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing method that allows data to be written to and read from an optical storage medium such as an optical disk at a high areal recording density.
【０００２】0002
【従来の技術】従来この種の光情報再生方法、例えば光
ディスク装置の再生方法としては特開平１−２４５４３
３号公報に開示されたものがある。この方法では半導体
レーザの光ビームを光学系を用いて絞り込み、光記録媒
体の一点にスポット照射し、その光スポットからの反射
光を前記光学系を介して受光素子に導き、該受光素子の
出力から反射光の光強度、偏光方向等の変化、即ち前記
光記録媒体上の一点に記録された情報を再生していた。2. Description of the Related Art Conventionally, this type of optical information reproducing method, for example, a reproducing method for an optical disk device, is disclosed in Japanese Patent Application Laid-Open No. 1-24543.
There is one disclosed in Publication No. 3. In this method, a light beam from a semiconductor laser is focused using an optical system, a spot is irradiated onto a single point on an optical recording medium, and the reflected light from the light spot is guided to a light receiving element through the optical system, and the output of the light receiving element is In other words, the information recorded at one point on the optical recording medium is reproduced by changes in the light intensity, polarization direction, etc. of the reflected light.
【０００３】0003
【発明が解決しようとする課題】しかしながら、従来の
光情報再生方法では、光スポットからの反射光の光量変
化を検出していたため、光スポット内に同時に複数の記
録マークが入った場合に記録マークが判別できない。そ
のため、１つの情報を記録するに必要な面積は光スポッ
トの大きさで制限され、線記録密度、トラツク密度とも
高くすることができなかった。[Problems to be Solved by the Invention] However, in the conventional optical information reproducing method, changes in the amount of light reflected from the optical spot are detected, so when multiple recording marks are simultaneously included in the optical spot, the recording mark cannot be determined. Therefore, the area required to record one piece of information is limited by the size of the light spot, and it has been impossible to increase both the linear recording density and the track density.
【０００４】本発明は、上記に鑑みてなされたもので、
その目的とするところは、光スポットの大きさに制限さ
れずに高密度な記録を実現できる再生方法を提供するこ
とにある。The present invention has been made in view of the above, and
The purpose is to provide a reproduction method that can realize high-density recording without being limited by the size of a light spot.
【０００５】[0005]
【課題を解決するための手段】上記目的を達成するため
に本発明では、請求項１として、レーザ光を情報記録媒
体に照射して形成する光スポットからの反射光を利用し
て情報を再生する方法において、前記情報記録媒体に温
度によって複素屈折率が変化するエンハンス層を形成し
、前記光スポットの照射により記録層の光吸収率の高い
部分の温度が上昇し、それにともなってエンハンス層の
複素屈折率が記録層高温部に接した領域のみ変化するこ
とを利用して記録層に書き込まれた情報を再生する光情
報再生方法、また、請求項２として、レーザ光を照射し
て形成する光スポットからの反射光を利用して情報を再
生する情報記録媒体において、光スポットによって複素
屈折率が変化する層を記録層に接して形成した光情報記
録媒体を要旨とする。[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for reproducing information using reflected light from a light spot formed by irradiating a laser beam onto an information recording medium. In the method, an enhancement layer whose complex refractive index changes depending on the temperature is formed on the information recording medium, and the temperature of the portion of the recording layer with high light absorption increases by irradiation with the light spot, and the enhancement layer changes accordingly. An optical information reproducing method for reproducing information written in a recording layer by utilizing the fact that the complex refractive index changes only in a region in contact with a high-temperature portion of the recording layer. In an information recording medium that reproduces information using reflected light from a light spot, the gist is an optical information recording medium in which a layer whose complex refractive index changes depending on the light spot is formed in contact with a recording layer.
【０００６】[0006]
【作用】本発明の請求項１によれば、光スポット照射さ
れたことにより記録層の光吸収率のよい記録マーク部の
みが温度上昇し、記録マーク部に接したエンハンス層の
み複素屈折率が変化してその部分の記録層に書かれた記
録マークが選択的に再生できる。[Function] According to claim 1 of the present invention, only the recording mark portion of the recording layer with good light absorption rate increases in temperature by being irradiated with a light spot, and only the complex refractive index of the enhancement layer in contact with the recording mark portion increases. The recording marks written on the recording layer in that area can be selectively reproduced.
【０００７】本発明の請求項２によれば、記録層に光ス
ポット照射それることで、光スポットのうち光吸収率の
高い記録マーク部のみ複素屈折率が変化してその部分の
記録層に書かれた記録マークを選択的に再生できる媒体
を供給できる。According to claim 2 of the present invention, by irradiating a light spot onto the recording layer, the complex refractive index of only the recording mark portion of the light spot having a high light absorption rate changes, and the recording layer in that portion changes. It is possible to provide a medium on which written recording marks can be selectively reproduced.
【０００８】[0008]
【実施例】図１は本発明の光情報再生方法の原理を説明
する図である。図中、１はレーザ等の光源、２は入射光
と出射光とを分離するビームスプリッタ、３は対物レン
ズ、４は光情報を記録する媒体、５は温度により複素屈
折率が変化するエンハンス層、６は媒体４に形成されて
いる記録層、７は検出器である。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram illustrating the principle of the optical information reproducing method of the present invention. In the figure, 1 is a light source such as a laser, 2 is a beam splitter that separates incident light and output light, 3 is an objective lens, 4 is a medium for recording optical information, and 5 is an enhancement layer whose complex refractive index changes depending on temperature. , 6 is a recording layer formed on the medium 4, and 7 is a detector.
【０００９】媒体４の記録層６には記録情報を表す記録
マーク（図示せず）が同心円又はスパイラル状のトラッ
ク上に形成されている。また、媒体４は図示しない駆動
系により一定の回転数で回転している。光源１より出射
された光はビームスプリッタ２、１／４波長板８を透過
し、対物レンズ３により媒体４の記録層６に集光される
。ここで媒体４の記録層６を光が通過する時に光スポッ
ト中の記録マーク部のみ光吸収率が高くなることから、
記録層の記録マーク部に接したエンハンス層５のみで複
素屈折率が変り、記録マークのコントラストが強調され
る。記録層６で反射された光は対物レンズ３、１／４波
長板８を通って、ビームスプリッタ２で入射光と分離さ
れ、検出器７において電気信号に変換される。Recording marks (not shown) representing recorded information are formed on the recording layer 6 of the medium 4 on concentric or spiral tracks. Further, the medium 4 is rotated at a constant rotational speed by a drive system (not shown). Light emitted from a light source 1 passes through a beam splitter 2 and a quarter-wave plate 8, and is focused onto a recording layer 6 of a medium 4 by an objective lens 3. Here, when the light passes through the recording layer 6 of the medium 4, only the recording mark portion in the light spot has a high light absorption rate.
The complex refractive index changes only in the enhancement layer 5 in contact with the recording mark portion of the recording layer, and the contrast of the recording mark is emphasized. The light reflected by the recording layer 6 passes through the objective lens 3 and the quarter-wave plate 8, is separated from the incident light by the beam splitter 2, and is converted into an electrical signal by the detector 7.
【００１０】次に、エンハンス層５を設けたことによる
効果を図２、図３に従って詳細に説明する。図３（ａ）
にエンハンス層無しの場合の記録マークの出力分布を示
す。各記録マークの出力は同一（高さａ）である。しか
し、図２に示すように、光束２０が媒体４の記録層２２
に入射すると、記録層２２では光吸収率の高い記録マー
クの温度が上昇し、記録マークの出力分布が図３（ｂ）
の出力分布（高さｂ）となる。そこで、ｂ＞ａであるか
ら、媒体に入射した光束２０の光スポット２６はエンハ
ンス層２１により高温となった記録マーク２８のみ強調
される。したがって、記録層２２に形成された記録マー
ク２８はエンハンス部２７のみ再生されることとなり、
トラック方向、トラック幅方向に近接して記録マークが
形成されていても、近接した記録マークの影響を十分小
さくしてエンハンス部２７のみ信号を再生できる。した
がって、線密度、トラック密度を大幅に向上した信号を
検出できることとなる。Next, the effects of providing the enhancement layer 5 will be explained in detail with reference to FIGS. 2 and 3. Figure 3(a)
shows the output distribution of recording marks without an enhancement layer. The output of each recording mark is the same (height a). However, as shown in FIG.
When the light is incident on the recording layer 22, the temperature of the recording marks with high light absorption increases, and the output distribution of the recording marks changes as shown in FIG. 3(b).
The output distribution (height b) is as follows. Since b>a, the light spot 26 of the light beam 20 incident on the medium only emphasizes the recording mark 28 that has become hot due to the enhancement layer 21. Therefore, only the enhanced portion 27 of the recording mark 28 formed on the recording layer 22 is reproduced.
Even if recording marks are formed close to each other in the track direction and track width direction, only the enhancement section 27 can reproduce the signal by sufficiently reducing the influence of the close recording marks. Therefore, it is possible to detect a signal with significantly improved linear density and track density.
【００１１】保護層２１、記録層２２、保護層２４、反
射層２５の多層構造を用いて、再生出力のコントラスト
をあげた例を示したが、この構成以外の反射層の無いも
の等の媒体構成でよいことは言うまでもない。また保護
層２４とエンハンス層を共用してもよい。Although an example has been shown in which the contrast of the reproduced output is increased by using a multilayer structure of the protective layer 21, the recording layer 22, the protective layer 24, and the reflective layer 25, it is possible to use media other than this configuration such as those without a reflective layer. Needless to say, the configuration is fine. Further, the protective layer 24 and the enhancement layer may be used in common.
【００１２】また、保護層２１が直接あるいは他の層を
挟んで媒体基板に取り付けられていても、反射層２５が
直接あるいは他の層を挟んで媒体基板に取り付けられて
いてもよい。また、ここでは追記媒体および相変化媒体
等の反射率の変わる媒体に対する光学系を用いて説明し
たが、光磁気媒体等偏光角の変わる媒体でも従来から知
られている光磁気用の光学系を用いれば良いことは言う
までもない。Further, the protective layer 21 may be attached to the medium substrate directly or with another layer in between, and the reflective layer 25 may be attached to the medium substrate directly or with another layer in between. In addition, although the optical system for media with variable reflectance such as write-once media and phase change media has been explained here, conventionally known optical systems for magneto-optical media can also be used for media with variable polarization angles such as magneto-optical media. Needless to say, it is good to use it.
【００１３】エンハンス層としては、温度によって複素
屈折率の変化する材料が用いられる。この材料としては
、フッ化ビニリデン・トリクロロエチレン共重合体など
のフッ素系の高分子材料、サーモクロミツク材料等が上
げられる。さらに、エンハンス層の膜厚としては、１０
ｎｍから１０００ｎｍ形成したもの、特に１００ｎｍか
ら５００ｎｍ形成したものが好例である。[0013] As the enhancement layer, a material whose complex refractive index changes depending on temperature is used. Examples of this material include fluorine-based polymer materials such as vinylidene fluoride/trichloroethylene copolymer, thermochromic materials, and the like. Furthermore, the thickness of the enhancement layer is 10
A good example is one formed with a thickness of 100 nm to 1000 nm, especially one formed with a thickness of 100 nm to 500 nm.
【００１４】前記材料の内には光を当てたことで安定状
態に変わってしまうものもあるが、紫外線を照射する等
してもとの状態に戻る材料であれば使用できる。再生後
に紫外線を照射する等の操作を行ってやればよい。Some of the above-mentioned materials change to a stable state when exposed to light, but any material that returns to its original state when exposed to ultraviolet rays can be used. After regeneration, operations such as irradiation with ultraviolet rays may be performed.
【００１５】図４に別の実施例を示す。図４においては
、エンハンス層４２が記録層４３と保護層４１の間に形
成されている。この様にすると、光束４０がエンハンス
層４２を通って記録層４３に入射すると、記録層４３で
は光束４０の強度分布の強い部分の記録マーク部のみ温
度が上昇し、記録層の記録マークに接したエンハンス層
の複素屈折率が変化する。そこで、媒体に入射した光束
４０の光スポットはエンハンス層４２によりエンハンス
部のみで記録層の記録マークよりの信号エンハンスする
こととなる。したがって、記録層４３に形成された記録
マークはエンハンス部のみが強く再生されることとなり
、トラツク方向、トラツク幅方向に近接して記録マーク
が形成されていても、近接した記録マークの影響を受け
ることなくエンハンス部のみ信号を再生でき、線密度、
トラツク密度を大幅に向上した信号を検出できることと
なる。FIG. 4 shows another embodiment. In FIG. 4, an enhancement layer 42 is formed between a recording layer 43 and a protective layer 41. In this way, when the light beam 40 passes through the enhancement layer 42 and enters the recording layer 43, the temperature of only the recording mark portion of the recording layer 43 where the intensity distribution of the light beam 40 is strong rises, and the temperature rises, causing the temperature to rise when the light beam 40 comes into contact with the recording mark on the recording layer. The complex refractive index of the enhanced layer changes. Therefore, the light spot of the light flux 40 incident on the medium is enhanced by the enhancement layer 42, which enhances the signal from the recording mark on the recording layer only at the enhancement portion. Therefore, only the enhanced part of the recorded marks formed on the recording layer 43 is strongly reproduced, and even if the recorded marks are formed close to each other in the track direction and the track width direction, they are affected by the close recorded marks. The signal can be reproduced only in the enhanced part without
This makes it possible to detect signals with significantly improved track density.
【００１６】図４に示した実施例でも前の実施例と同様
に各種の変形ができることは言うまでもない。また、前
の実施例では光の干渉効果を変化させるため、熱により
複素屈折率の実数部が可逆的に変化する性質を持つ材料
が好例であるのに対し、この実施例では透過光量を変化
させるため、熱により複素屈折率の虚数部が可逆的に変
化する性質を持つ材料が好例で有る。It goes without saying that the embodiment shown in FIG. 4 can be modified in various ways, just like the previous embodiment. In addition, in the previous example, a material with the property of reversibly changing the real part of the complex refractive index due to heat was used as a good example in order to change the light interference effect, whereas in this example, the amount of transmitted light is changed. A good example of this is a material that has the property that the imaginary part of the complex refractive index changes reversibly with heat.
【００１７】[0017]
【発明の効果】以上説明したように、本発明の請求項１
によれば、光スポットのうち強力に照射された記録マー
ク部のみエンハンス層の複素屈折率が変化してその部分
の記録層に書かれた記録マークが選択的に再生でき、高
密度に記録された信号を回りの影響を受けないので、記
録密度を大幅に向上できる。[Effect of the invention] As explained above, claim 1 of the present invention
According to , the complex refractive index of the enhancement layer changes only in the recording mark part that is strongly irradiated with the light spot, and the recording mark written on the recording layer in that part can be selectively reproduced, and the recording mark can be recorded with high density. Since the recorded signal is not affected by the surroundings, recording density can be greatly improved.
【００１８】本発明の請求項２によれば、高密度な記録
再生を可能とする媒体ができる。According to claim 2 of the present invention, a medium that enables high-density recording and reproduction can be obtained.
【図１】図１は本発明の光情報再生方法の原理を説明す
る図である。FIG. 1 is a diagram illustrating the principle of the optical information reproducing method of the present invention.
【図２】図２（ａ）及び（ｂ）は本発明の一実施例に係
わる光情報記録媒体の構成図であって、（ａ）はその断
面図、（ｂ）はその平面図である。FIGS. 2(a) and 2(b) are configuration diagrams of an optical information recording medium according to an embodiment of the present invention, in which (a) is a cross-sectional view thereof, and (b) is a plan view thereof. .
【図３】図３（ａ）及び（ｂ）は本発明の一実施例に係
わるエンハンス層による記録マークの出力強度分布を説
明するグラフである。FIGS. 3A and 3B are graphs illustrating the output intensity distribution of recording marks by an enhancement layer according to an embodiment of the present invention.
【図４】図４は本発明の別の実施例に係わる光情報記録
媒体の構成を示す断面図である。FIG. 4 is a sectional view showing the structure of an optical information recording medium according to another embodiment of the present invention.
１ 光源 ２ ビームスプリッタ ３ 対物レンズ ４ 媒体 ５ エンハンス層 ６ 記録層 ７ 検出器 ２２ 記録層 ２３ エンハンス層 ４２ エンハンス層 ４３ 記録層 1. Light source 2 Beam splitter 3 Objective lens 4 Medium 5 Enhancement layer 6 Recording layer 7 Detector 22 Recording layer 23 Enhancement layer 42 Enhancement layer 43 Recording layer
Claims (2)
成する光スポットからの反射光を利用して情報を再生す
る方法において、前記情報記録媒体に温度によって複素
屈折率が変化するエンハンス層を記録層に接して形成し
、前記光スポットの照射により記録層の光吸収率の高い
部分の温度が上昇し、それにともなってエンハンス層の
複素屈折率が記録層高温部に接した領域のみ変化するこ
とを利用して、記録層に書き込まれた情報を選択して再
生することを特徴とする光情報再生方法。1. A method for reproducing information using reflected light from a light spot formed by irradiating an information recording medium with a laser beam, the information recording medium comprising an enhancement layer whose complex refractive index changes depending on temperature. Formed in contact with the recording layer, the temperature of the portion of the recording layer with high light absorption increases by irradiation with the light spot, and accordingly, the complex refractive index of the enhancement layer changes only in the region in contact with the high temperature portion of the recording layer. An optical information reproducing method characterized in that information written in a recording layer is selectively reproduced by utilizing this fact.
トからの反射光を利用して情報を再生する情報記録媒体
において、温度によって複素屈折率が変化する層を記録
層に接して形成したことを特徴とする光情報記録媒体。2. In an information recording medium that reproduces information using reflected light from a light spot formed by irradiating a laser beam, a layer whose complex refractive index changes depending on temperature is formed in contact with the recording layer. An optical information recording medium characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3088847A JPH04319531A (en) | 1991-04-19 | 1991-04-19 | Optical information reproducing method and optical information recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3088847A JPH04319531A (en) | 1991-04-19 | 1991-04-19 | Optical information reproducing method and optical information recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04319531A true JPH04319531A (en) | 1992-11-10 |
Family
ID=13954372
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3088847A Pending JPH04319531A (en) | 1991-04-19 | 1991-04-19 | Optical information reproducing method and optical information recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04319531A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0512673A (en) * | 1991-07-03 | 1993-01-22 | Mitsubishi Electric Corp | High density recording and reproducing system for optical disk device |
| JPH06215416A (en) * | 1993-01-14 | 1994-08-05 | Nec Corp | Optical disk medium and optical disk cartridge and optical disk reproducing device |
| US5576084A (en) * | 1993-11-11 | 1996-11-19 | Victor Company Of Japan, Ltd. | Optical recording medium and the producing method of the optical recording medium |
-
1991
- 1991-04-19 JP JP3088847A patent/JPH04319531A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0512673A (en) * | 1991-07-03 | 1993-01-22 | Mitsubishi Electric Corp | High density recording and reproducing system for optical disk device |
| JPH06215416A (en) * | 1993-01-14 | 1994-08-05 | Nec Corp | Optical disk medium and optical disk cartridge and optical disk reproducing device |
| US5576084A (en) * | 1993-11-11 | 1996-11-19 | Victor Company Of Japan, Ltd. | Optical recording medium and the producing method of the optical recording medium |
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