JPH03292632A - Signal reproducing method for optical disk - Google Patents
Signal reproducing method for optical diskInfo
- Publication number
- JPH03292632A JPH03292632A JP2094452A JP9445290A JPH03292632A JP H03292632 A JPH03292632 A JP H03292632A JP 2094452 A JP2094452 A JP 2094452A JP 9445290 A JP9445290 A JP 9445290A JP H03292632 A JPH03292632 A JP H03292632A
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- reflectance
- reflection factor
- scanning spot
- optical disk
- 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
- 230000003287 optical effect Effects 0.000 title claims abstract description 26
- 238000000034 method Methods 0.000 title claims description 8
- 239000004065 semiconductor Substances 0.000 abstract description 4
- 238000001514 detection method Methods 0.000 abstract description 3
- 230000001678 irradiating effect Effects 0.000 abstract 1
- 239000000463 material Substances 0.000 description 11
- 230000003595 spectral effect Effects 0.000 description 7
- 230000008018 melting Effects 0.000 description 6
- 238000002844 melting Methods 0.000 description 6
- 229910052798 chalcogen Inorganic materials 0.000 description 4
- 150000001787 chalcogens Chemical class 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910052581 Si3N4 Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 238000009835 boiling Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
Landscapes
- Optical Recording Or Reproduction (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、情報信号に応じて位相ピットが形成されてな
る光ディスクの信号再生方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a signal reproducing method for an optical disc in which phase pits are formed in accordance with an information signal.
本発明は、信号に応じて位相ピントが形成されてなる光
ディスクの反射率（分光特性）が温度によって変化する
ようになし、読み出し光の走査スポット内で反射率を部
分的に変化させることにより、高密度情報の再生を可能
とするものである。The present invention allows the reflectance (spectral characteristics) of an optical disk on which a phase focus is formed according to a signal to change depending on the temperature, and partially changes the reflectance within the scanning spot of the readout light. This makes it possible to reproduce high-density information.
〔従来の技術］
例えばデジタルオーディオディスク（いわゆるコンパク
トディスク）やビデオディスク等の光ディスクにおいて
は、予め情報記録面上に信号に応じて位相ピントを形成
しておき、読み出し光の走査スポットが位相ピントに照
射されたときに回折により反射光量が大幅に減少するこ
とを利用し、この反射光量の減少を光検出器で検出する
ことによって信号が再生される。[Prior Art] For example, in optical discs such as digital audio discs (so-called compact discs) and video discs, a phase focus is formed in advance on the information recording surface according to a signal, and the scanning spot of the readout light is aligned with the phase focus. Taking advantage of the fact that the amount of reflected light decreases significantly due to diffraction when irradiated, a signal is reproduced by detecting this decrease in the amount of reflected light with a photodetector.
ところで、光ディスクにおける信号再生分解能は、はと
んど再生光学系の光源の波長λと対物レンズの開口数Ｎ
Ａで決まり、空間周波数２Ｎ＾／λが読み取り限界とな
る。By the way, the signal reproduction resolution on an optical disk is basically determined by the wavelength λ of the light source of the reproduction optical system and the numerical aperture N of the objective lens.
A, and the spatial frequency 2N^/λ becomes the reading limit.
したがって、光ディスクにおいて高密度化を実現するた
めには、再生光学系の光源（例えば半導体レーザ）の波
長λを短くし、対物レンズの開口数ＮＡを大きくする必
要がある。Therefore, in order to achieve high density in an optical disc, it is necessary to shorten the wavelength λ of the light source (for example, a semiconductor laser) of the reproduction optical system and increase the numerical aperture NA of the objective lens.
位相ピットを読み取ることを特徴とするものである。It is characterized by reading phase pits.
しかしながら、光源の波長や対物レンズの開口数の改善
には自ずと限度があり、これによって記録密度を飛躍的
に高めることは難しいのが実情である。However, there are limits to the improvement of the wavelength of the light source and the numerical aperture of the objective lens, and the reality is that it is difficult to dramatically increase the recording density.
そこで本発明は、このような従来の実情に鑑みて提案さ
れたものであって、光源の波長や対物レンズの開口数に
よる読み取り限界以上の高密度位相ピット情報の再生を
可能とする光ディスクの信号再生方法を提供することを
目的とする。The present invention has been proposed in view of the above-mentioned conventional circumstances, and is an optical disk signal that enables reproduction of high-density phase pit information that exceeds the reading limit due to the wavelength of the light source and the numerical aperture of the objective lens. The purpose is to provide a reproduction method.
上述の目的を達成するために、本発明の信号再生方法は
、信号に応じて位相ピットが形成されるとともに温度に
よって反射率が変化する光ディスクに対して読み出し光
を照射し、読み出し光の走査スポット内で反射率を部分
的に変化させながら〔作用〕
信号に応じて位相ピットが形成されるとともに温度によ
って反射率が変化する光ディスクに対して読み出し光を
照射すると、読み出し光の走査スポット内で温度分布が
生じ、例えばある温度以上となった部分の反射率が向上
する。In order to achieve the above object, the signal reproducing method of the present invention irradiates readout light onto an optical disk in which phase pits are formed according to the signal and whose reflectance changes depending on temperature, and the scanning spot of the readout light is [Operation] When a readout light is irradiated onto an optical disk where phase pits are formed depending on the signal and the reflectance changes depending on the temperature, the temperature changes within the scanning spot of the readout light. A distribution occurs, and for example, the reflectance of a portion where the temperature exceeds a certain level improves.
その結果、走査スポットの残りの部分がいわばマスクさ
れた形となり、前記反射率が向上した部分の位相ピット
のみが読み取られる。As a result, the remaining part of the scanning spot becomes a so-called masked shape, and only the phase pits in the part where the reflectance has been improved are read.
すなわち、第１図に示すように、信号に応じて形成され
た位相ピット（２）のうちの複数の位相ピッ） （２ａ
） 、 （２ｂ）が読み出し光の走査スポット（１）内
に入った場合に、温度上昇によって反射率が向上した高
反射率領域（３）内の位相ピッ） （２ａ）のみが検出
される。これに対して、前記高反射率領域（３）以外の
領域（図中斜線領域）では、位相ピット（２）の有無に
かかわらず反射率が低く、たとえ位相ピット（２ｂ）が
走査スポット（１）内に入ったとしても、これによる走
査スポット（１）内の反射率変化は僅かであり、信号と
して検出されることはない。That is, as shown in FIG. 1, a plurality of phase pits (2a
), (2b) enters the scanning spot (1) of the readout light, only the phase peak (2a) in the high reflectance region (3) whose reflectance has improved due to temperature rise is detected. On the other hand, in areas other than the high reflectance area (3) (shaded area in the figure), the reflectance is low regardless of the presence or absence of the phase pit (2), and even if the phase pit (2b) is the scanning spot (1 ), the change in reflectance within the scanning spot (1) due to this is slight and will not be detected as a signal.
〔実施例］
以下、本発明を適用した具体的な実施例についで説明す
る。[Example] Hereinafter, specific examples to which the present invention is applied will be described.
１鳥１
本実施例は、相変化により反射率が変わる光ディスクを
用いた例である。ONE BIRD ONE This example uses an optical disk whose reflectance changes due to phase change.
第２図は、本実施例で用いた光ディスクの構成を示すも
のであり、この光ディスクは、情報信号に応じて位相ピ
ットが形成された透明基板（１１）上に第１の窒化シリ
コン膜（１２）＋ ＳｂｇＳｅｓ膜（１３）、第２の窒
化シリコン膜（１４）、 Ａｎ！膜（１５）が順次積層
形成されてなるものである。FIG. 2 shows the configuration of the optical disc used in this example. This optical disc consists of a first silicon nitride film (12) on a transparent substrate (11) on which phase pits are formed according to information signals. ) + SbgSes film (13), second silicon nitride film (14), An! The film (15) is formed by sequentially stacking layers.
上記ｓｂオＳｅ３膜（１３）は、カルコゲン系のアモル
ファス材料であって、アモルファス状態と結晶状態で反
射率が大きく異なる０例えば、前記第１の窒化シリコン
１！（１２）の膜厚を１０００人、第２の窒化シリコン
膜（１４）の膜厚を５００人とし、５ｂｌＳｅｓ膜（１
３）の膜厚を変えてアモルファス状態と結晶状態におけ
る反射率（半導体レーザ波長における反射率）を測定す
ると、第３図に示すようにアモルファス状態の方が反射
率が高く、特に５ｂｔＳｅｓ膜（１３）の膜厚を９００
人としたときには、アモルファス状態で反射率約６０％
、結晶状態で反射率１％以下となる。The sb-Se3 film (13) is a chalcogen-based amorphous material, and has a reflectance that differs greatly between the amorphous state and the crystalline state. (12) has a thickness of 1000 layers, the second silicon nitride film (14) has a thickness of 500 layers, and the 5blSes film (1
When the reflectance (reflectance at the semiconductor laser wavelength) in the amorphous state and the crystalline state is measured by changing the film thickness of 3), as shown in Figure 3, the reflectance is higher in the amorphous state, especially for the 5btSes film (13 ) film thickness to 900
When used as a human, the reflectance is approximately 60% in an amorphous state.
, the reflectance is 1% or less in the crystalline state.
そこで本実施例では、このアモルファス状態と結晶状態
の反射率の差を利用して高密度再生を行う、以下、本実
施例の再生方法について説明する。Therefore, in this embodiment, high-density reproduction is performed using the difference in reflectance between the amorphous state and the crystalline state.The reproduction method of this embodiment will be described below.
前述の光ディスクは、５ｂｌＳｅ、膜（１３）を全面結
晶状態としておき、これを初期化状態とする。In the optical disc described above, the 5blSe film (13) is entirely in a crystalline state, and this is set as an initialized state.
この初期化状態の光ディスクに対して読み出し光として
レーザビームを照射すると、レーザスポット内の一部が
アモルファス化して反射率が上がる。この様子を第４図
に示す。When the optical disk in this initialized state is irradiated with a laser beam as read light, a portion of the laser spot becomes amorphous and the reflectance increases. This situation is shown in FIG.
光ディスクにレーザスポット（２１）が照射されると、
レーザパワー） （２１）内の光強度は図中破線Ａで示
す如き分布を示し、５ｂｌＳｅ、膜（１３）の温度分布
は、レーザスポット（２１）の走査速度に対応してわず
かに遅れたものとなる。（第４図中曲線Ｂ）ここで、レ
ーザスポット（２１）が第４図中矢印Ｘ方向に走査され
ているとすると、レーザスポット（２１）の走行方向先
端側から次第に温度が上昇し、遂にはＳｂｇＳｅ、膜（
１３）の融点Ｔ以上の温度となる。When the optical disc is irradiated with a laser spot (21),
Laser power) The light intensity in (21) shows a distribution as shown by the broken line A in the figure, and the temperature distribution of the 5blSe film (13) is slightly delayed in accordance with the scanning speed of the laser spot (21). becomes. (Curve B in Fig. 4) Here, if the laser spot (21) is scanned in the direction of the arrow X in Fig. 4, the temperature gradually rises from the tip side of the laser spot (21) in the traveling direction, and finally is SbgSe, film (
13) becomes a temperature higher than the melting point T.
この段階で、Ｓｂ！Ｓｅ、膜（１３）は結晶状態から液
体状態へと移行する。そして、レーザスポット（２１）
が通過すると、Ａｌ膜（１５）による冷却効果により上
記Ｓｂ、Ｓｅｚ膜（１３）の温度が急激に下がり、融点
Ｔを超えた部分のみが液体状態からアモルファス状態へ
と移行して反射率が大幅に上昇する０以上によってアモ
ルファス化した領域を図中領域Ｐで示す。At this stage, Sb! Se, the film (13) transitions from a crystalline state to a liquid state. And laser spot (21)
When passing through, the temperature of the Sb and Sez films (13) decreases rapidly due to the cooling effect of the Al film (15), and only the portion that exceeds the melting point T transitions from a liquid state to an amorphous state, resulting in a significant increase in reflectance. The region which becomes amorphous due to the increase in the value of 0 or more is indicated by region P in the figure.
また、第４図中線Ｃは、レーザスポット（２１）の中心
点の軌跡に沿ったＳｂ、Ｓｅ、膜（１３）の反射率を示
すものである。Moreover, line C in FIG. 4 shows the reflectance of Sb, Se, and the film (13) along the locus of the center point of the laser spot (21).
レーザスポット（２１）の照射により融点Ｔまで加熱さ
れる前のＳｂ！Ｓｅ＝膜（１３）は、結晶状態であるた
めに反射率が極めて低く、この領域に位相ピット（２２
）が存在したとしても、その有無による反射率変化は僅
かであり、信号として取り出されることはない、一方、
レーザスポット（２１）の照射により融点Ｔまで加熱さ
れアモルファス化した領域Ｐでは、Ｓｂ、Ｓｅ３膜（１
３）は高い反射率を示し、位相ピット（２２）の有無に
よる反射率変化が信号として取り出される。Sb before being heated to the melting point T by irradiation with the laser spot (21)! Since the Se = film (13) is in a crystalline state, its reflectance is extremely low, and phase pits (22
) exists, the change in reflectance due to its presence or absence is slight and is not extracted as a signal.On the other hand,
In the region P heated to the melting point T by the irradiation of the laser spot (21) and made amorphous, Sb and Se3 films (1
3) shows a high reflectance, and the change in reflectance due to the presence or absence of the phase pit (22) is extracted as a signal.
すなわち、レーザスポット（２１）内で見たときには、
融点Ｔまで加熱される前の部分は実質的に信号の再生に
は関与しなくなり、図中斜線領域で示すアモルファス化
した領域Ｐ、においてのみ位相ピッ） （２２）が検出
される。したがって、レーザスポット（２１）の一部が
マスクされ、レーザスポット（２１）内にいわば窓が開
けられレーザスポット（２１）径が等価的に縮小した形
となって、対物レンズの開口数や半導体レーザの波長に
よって決まる検出限界を大きく上回る高密度再往が可能
となる。That is, when viewed within the laser spot (21),
The portion before being heated to the melting point T substantially does not participate in signal reproduction, and phase peaks (22) are detected only in the amorphous region P shown by the hatched region in the figure. Therefore, a part of the laser spot (21) is masked, a so-called window is opened in the laser spot (21), and the diameter of the laser spot (21) is equivalently reduced. High-density recursion that far exceeds the detection limit determined by the laser wavelength becomes possible.
なお、実際に位相ピット（２２）による信号を読み出す
領域（アモルファス化した領域）Ｐｘの太きさは、レー
ザパワーの上下〔すなわち５ｂｚＳｅｘ膜（１３）の温
度の上下〕によって適宜コントロールすることが可能で
ある。In addition, the thickness of the region (amorphous region) Px from which signals are actually read by the phase pit (22) can be controlled as appropriate by increasing and decreasing the laser power (i.e., increasing and decreasing the temperature of the 5bzSex film (13)). It is.
また、以上の方法によった場合、アモルファス状態が安
定状態として光デイスク上に残存することになるので、
なんらかの手法によってエネルギーを与え、再生後には
このアモルファス状態を元の結晶状態に戻す消去操作を
行うことが好ましい。Furthermore, when the above method is used, the amorphous state remains on the optical disk as a stable state, so
It is preferable to apply energy by some method and perform an erasing operation to return the amorphous state to the original crystalline state after regeneration.
例えば、再生のためのレーザスポットの後に長円形のス
ポットを照射し、５ｂｔＳｅｓ膜（１３）を融点Ｔ以下
且つ結晶化温度以上に加熱してやれば、５ｂｘＳｅｚ膜
（１３）はアモルファス状態から結晶状態へと移行する
。For example, if an elliptical spot is irradiated after the laser spot for reproduction and the 5btSes film (13) is heated to below the melting point T and above the crystallization temperature, the 5bxSez film (13) changes from an amorphous state to a crystalline state. Transition.
以上、カルコゲン系アモルファス材料を用い、相変化に
よる反射率変化を利用して高密度再生を行う実施例につ
いて説明したが、カルコゲン系アモルファス材料として
は前記５ｂｚＳｅｓに限られるものではなく、例えばＴ
ｅ−Ｇｅ−３ｎ−０系アモルファス材料やＩｎ−５ｅ系
アモルファス材料、Ｉｎ−５ｂ系アモルファス材料等も
使用可能であり、さらにはカルコゲン系以外のアモルフ
ァス材料であうでも良い。Above, an embodiment has been described in which high-density reproduction is performed using a chalcogen-based amorphous material by utilizing reflectance change due to phase change. However, the chalcogen-based amorphous material is not limited to the above-mentioned 5bzSes, and for example, T
e-Ge-3n-0 type amorphous materials, In-5e type amorphous materials, In-5b type amorphous materials, etc. can also be used, and furthermore, amorphous materials other than chalcogen type may be used.
１差」ｌ工
本実施例は、干渉フィルターにおける水分咬着による分
光特性の変化を利用したものである。1 Difference This embodiment utilizes the change in spectral characteristics due to water occlusion in an interference filter.
本実施例で使用した光ディスクの構造は、第５図に示す
ようなもので、位相ピットが形成された透明基板（３１
）上に、屈折率の大きく異なる材料をそれぞれ厚さが再
生光の波長の１７４となるように繰り返し成膜すること
により、干渉フィルターが形成されてなるものである。The structure of the optical disk used in this example is as shown in FIG. 5, with a transparent substrate (31
), an interference filter is formed by repeatedly forming films of materials having greatly different refractive indexes so that each film has a thickness of 174 mm, which is the wavelength of the reproduction light.
本例では、屈折率の大きく異なる材料として、ＭｇＦ層
（３２） ［屈折率１．３８］とＺｎＳ層（３３） ［
屈折率２．３５３を採用した。勿論、これに限らず屈折
率の大きく異なる材料の組み合わせであれば如何なるも
のであってもよく、例えば屈折率の小さな材料としては
ＳｉＯ〔屈折率１．５〕等が挙げられ、また屈折率の大
きな材料としてはＴｉ１ｔ （屈折率２．７３）やＣｅ
ｎｔ Ｃ屈折率２．３５）等が挙げられる。In this example, the MgF layer (32) [refractive index 1.38] and the ZnS layer (33) [
A refractive index of 2.353 was adopted. Of course, the combination is not limited to this, and any combination of materials with significantly different refractive indexes may be used. For example, an example of a material with a small refractive index is SiO [refractive index 1.5]; Large materials include Ti1t (refractive index 2.73) and Ce.
nt C refractive index 2.35).
上述のＭｇＦ層（３２）やＺｎＳ層（３３）は蒸着形成
されるが、これらを蒸着形成する際に到達真空度を例え
ば１０−’Ｔｏｒｒ程度と通常よりも低（設定すると、
膜構造がいわゆるポーラスなものとなり、そこに水分が
残留する。そして、この水分が残留した膜からなる干渉
フィルターにおいては、室温と水の沸点近くまで温度を
上げた時とで、例えば第６図に示すように、反射率分光
特性が大きく異なる。The above-mentioned MgF layer (32) and ZnS layer (33) are formed by vapor deposition, but when forming these by vapor deposition, the ultimate vacuum is set to be lower than usual (for example, about 10-' Torr).
The membrane structure becomes so-called porous, and moisture remains there. In an interference filter made of a film in which moisture remains, the reflectance spectral characteristics differ greatly between room temperature and when the temperature is raised to near the boiling point of water, as shown in FIG. 6, for example.
すなわち、室温では図中曲線ｉで示すように波長７次に
変曲点とする特性を示すのに対して、沸点近くまで温度
を上げると図中曲線ｉで示すように波長λ９を特徴とす
る特性になり、温度が下がると再び曲線ｉで示す特性に
戻るというように、急峻な波長シフトが観察される。こ
の現象は、水分が気化することにより屈折率が大きく変
わり、この影響で分光特性が変化することによるものと
考えられる。That is, at room temperature, as shown by curve i in the figure, it exhibits characteristics with an inflection point of wavelength 7, whereas when the temperature is raised to near the boiling point, it exhibits a characteristic of wavelength λ9, as shown by curve i in the figure. A sharp wavelength shift is observed, such that when the temperature decreases, the characteristic returns to the characteristic shown by curve i. This phenomenon is thought to be due to the fact that the refractive index changes significantly due to the vaporization of water, and the spectral characteristics change due to this effect.
したがって、再生光の光源の波長をこれら変曲点λ６．
λ９の中間の波長λ。に選べば、室温時と加熱時でダイ
ナミックに反射率が変化することになる。Therefore, the wavelength of the light source of the reproduction light is set at these inflection points λ6.
The intermediate wavelength λ of λ9. If selected, the reflectance will change dynamically between room temperature and heating.
本実施例では、この反射率変化を利用して高密度再生を
行う、高密度再生が可能となる原理は、先の第１図に示
す通りで、この場合には水分が気化して波長シフトが起
こった領域が高反射率領域（３）に相当し、温度が上昇
していない部分がマスクされた形となる。ただし、本例
では温度が下がると反射率特性が元の状態に戻るので、
特別な消去操作は必要ない。In this example, high-density reproduction is performed using this change in reflectance. The principle that enables high-density reproduction is as shown in Figure 1 above. In this case, water vaporizes and the wavelength shifts. The area where this occurs corresponds to the high reflectance area (3), and the area where the temperature has not increased is masked. However, in this example, the reflectance characteristics return to their original state when the temperature drops, so
No special erasing operation is required.
以上、本発明の具体的な実施例について説明したが、本
発明がこれら実施例に限定されるものではなく、反射率
変化は如何なる現象を利用したものであってもよい、ま
た、再生に際しては、パルス光源を利用すれば鋭い温度
変化を与えることができ、反射率が変化する部分をより
シャープなものとすることができる。Although specific embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and any phenomenon may be used to change the reflectance. By using a pulsed light source, it is possible to give a sharp temperature change, and the portion where the reflectance changes can be made even sharper.
以上の説明からも明らかなように、本発明においては、
光ディスクの反射率（分光特性）が温度によって変化す
るようになし、読み出し光の走査スポット内で反射率を
部分的に変化させているので、走査スポットの一部をマ
スクして走査スポット径を等価的に縮小した形とするこ
とができ、対物レンズの開口数や半導体レーザの波長に
よって決まる検出限界を大きく上回る高密度再生が可能
となる。As is clear from the above description, in the present invention,
The reflectance (spectral characteristics) of the optical disk is made to change depending on the temperature, and the reflectance is partially changed within the scanning spot of the readout light, so a part of the scanning spot is masked to make the scanning spot diameter equivalent. This enables high-density reproduction that far exceeds the detection limit determined by the numerical aperture of the objective lens and the wavelength of the semiconductor laser.
第１図は本発明における再生原理を説明する模式図であ
る。
第２図は相変化による反射率変化を利用した光ディスク
の構成例を示す要部概略断面図であり、第３図はＳｂ、
Ｓｅ３のアモルファス状態と結晶状態での反射率の膜厚
依存性を示す特性図、第４図はレーザスポットの走査に
よる相変化並びに反射率変化の様子をレーザスポットの
温度分布と共に示す模式図である。
第５図は水分を含んだ干渉フィルターにおける反射率分
光特性の変化を利用した光ディスクの構成例を示す要部
概略断面図であり、第６図は干渉フィルターにおける温
度による反射率分光特性の変化の様子を示す特性図であ
る。FIG. 1 is a schematic diagram illustrating the reproduction principle in the present invention. FIG. 2 is a schematic cross-sectional view of a main part showing an example of the configuration of an optical disk that utilizes reflectance changes due to phase change, and FIG. 3 shows Sb, Sb,
A characteristic diagram showing the film thickness dependence of the reflectance of Se3 in the amorphous state and the crystalline state. Figure 4 is a schematic diagram showing the state of phase change and reflectance change due to scanning of the laser spot, together with the temperature distribution of the laser spot. . Fig. 5 is a schematic cross-sectional view of the main part showing an example of the configuration of an optical disk that utilizes changes in reflectance spectral characteristics in an interference filter containing moisture, and Fig. 6 shows changes in reflectance spectral characteristics due to temperature in an interference filter. It is a characteristic diagram showing the situation.
Claims (1)
って反射率が変化する光ディスクに対して読み出し光を
照射し、読み出し光の走査スポット内で反射率を部分的
に変化させながら位相ピットを読み取ることを特徴とす
る光ディスクの信号再生方法。A readout light is irradiated onto an optical disk where phase pits are formed according to the signal and the reflectance changes depending on the temperature, and the phase pits are read while partially changing the reflectance within the scanning spot of the readout light. Characteristic optical disc signal reproduction method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2094452A JP2844824B2 (en) | 1990-04-10 | 1990-04-10 | Optical disk signal reproduction method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2094452A JP2844824B2 (en) | 1990-04-10 | 1990-04-10 | Optical disk signal reproduction method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03292632A true JPH03292632A (en) | 1991-12-24 |
| JP2844824B2 JP2844824B2 (en) | 1999-01-13 |
Family
ID=14110659
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2094452A Expired - Fee Related JP2844824B2 (en) | 1990-04-10 | 1990-04-10 | Optical disk signal reproduction method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2844824B2 (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0596501A2 (en) * | 1992-11-04 | 1994-05-11 | Pioneer Electronic Corporation | Tracking method for an optical disk |
| US5353277A (en) * | 1991-10-14 | 1994-10-04 | Sony Corporation | Optical disk having intertrack heat conduction suppression |
| US5450387A (en) * | 1991-10-07 | 1995-09-12 | Sony Corporation | Optical pickup apparatus for phase changing optical disk |
| US5541909A (en) * | 1992-10-19 | 1996-07-30 | Hitachi, Ltd. | Optical disc with phase pits and a reproducing apparatus for data recorded on the optical disc |
| 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 |
| US5610879A (en) * | 1993-03-05 | 1997-03-11 | Matsushita Electric Industrial Co. Ltd. | Optical reproducing device, optical reproducing method using the same, and optical record medium used in the same |
| US5709978A (en) * | 1993-06-18 | 1998-01-20 | Hitachi, Ltd. | Supperresolution readout thin film and information recording medium |
| US5867455A (en) * | 1993-12-07 | 1999-02-02 | Hitachi, Ltd. | Optical method and device for irradiating domains at predetermined positions |
| FR2912539A1 (en) * | 2007-02-09 | 2008-08-15 | Commissariat Energie Atomique | HIGH RESOLUTION OPTICAL INFORMATION STORAGE MEDIUM |
| EP1978517A1 (en) * | 2007-04-06 | 2008-10-08 | Commissariat à l'Energie Atomique | Super-resolution optical recording medium |
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| JP3866016B2 (en) | 1999-07-02 | 2007-01-10 | Ｔｄｋ株式会社 | Optical information medium and reproducing method thereof |
| JP4287580B2 (en) | 1999-11-30 | 2009-07-01 | Ｔｄｋ株式会社 | Reproduction method of optical information medium |
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Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5450387A (en) * | 1991-10-07 | 1995-09-12 | Sony Corporation | Optical pickup apparatus for phase changing optical disk |
| US5353277A (en) * | 1991-10-14 | 1994-10-04 | Sony Corporation | Optical disk having intertrack heat conduction suppression |
| US5541909A (en) * | 1992-10-19 | 1996-07-30 | Hitachi, Ltd. | Optical disc with phase pits and a reproducing apparatus for data recorded on the optical disc |
| EP0596501A3 (en) * | 1992-11-04 | 1995-01-04 | Pioneer Electronic Corp | Tracking method for an optical disk. |
| EP0596501A2 (en) * | 1992-11-04 | 1994-05-11 | Pioneer Electronic Corporation | Tracking method for an optical disk |
| US5610879A (en) * | 1993-03-05 | 1997-03-11 | Matsushita Electric Industrial Co. Ltd. | Optical reproducing device, optical reproducing method using the same, and optical record medium used in the same |
| US5912104A (en) * | 1993-06-18 | 1999-06-15 | Hitachi, Ltd. | Information recording medium |
| US5709978A (en) * | 1993-06-18 | 1998-01-20 | Hitachi, Ltd. | Supperresolution readout thin film and information recording medium |
| 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 |
| US5867455A (en) * | 1993-12-07 | 1999-02-02 | Hitachi, Ltd. | Optical method and device for irradiating domains at predetermined positions |
| US5946275A (en) * | 1993-12-07 | 1999-08-31 | Hitachi, Ltd. And Hitachi Maxell, Ltd. | Optical readout method with a direction of a magnetic field applied to a recording medium changed with a signal, and a system therefor |
| FR2912539A1 (en) * | 2007-02-09 | 2008-08-15 | Commissariat Energie Atomique | HIGH RESOLUTION OPTICAL INFORMATION STORAGE MEDIUM |
| WO2008101801A1 (en) * | 2007-02-09 | 2008-08-28 | Commissariat A L'energie Atomique | High resolution optical information storage medium |
| EP1978517A1 (en) * | 2007-04-06 | 2008-10-08 | Commissariat à l'Energie Atomique | Super-resolution optical recording medium |
| FR2914775A1 (en) * | 2007-04-06 | 2008-10-10 | Commissariat Energie Atomique | SUPER-RESOLUTION OPTICAL RECORDING MEDIUM |
| US8092887B2 (en) | 2007-04-06 | 2012-01-10 | Commissariat A L'energie Atomique | Super-resolution optical recording medium |
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