JPH02236823A - Optical recording and reproducing system - Google Patents
Optical recording and reproducing systemInfo
- Publication number
- JPH02236823A JPH02236823A JP5727189A JP5727189A JPH02236823A JP H02236823 A JPH02236823 A JP H02236823A JP 5727189 A JP5727189 A JP 5727189A JP 5727189 A JP5727189 A JP 5727189A JP H02236823 A JPH02236823 A JP H02236823A
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- Prior art keywords
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- reproducing
- data
- reproduction
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- 230000003287 optical effect Effects 0.000 title claims description 23
- 238000000034 method Methods 0.000 claims abstract description 20
- 239000004065 semiconductor Substances 0.000 claims abstract description 7
- 230000005540 biological transmission Effects 0.000 claims description 6
- 230000001172 regenerating effect Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 8
- 238000007796 conventional method Methods 0.000 description 7
- 230000005415 magnetization Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 230000010287 polarization Effects 0.000 description 3
- 230000005374 Kerr effect Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
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- Signal Processing For Digital Recording And Reproducing (AREA)
- 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、光ディスク装置における高記録密度方式に係
る光記録再生方式に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical recording/reproducing method related to a high recording density method in an optical disc device.
光記録再生のうち特にイレーザブルなディスクを代表す
る光磁気ディスクの光記録再生方式では、磁性薄膜から
なる記録媒体にレーザ光を集光照射し、記録媒体上の磁
化の変化として情報を記録する熱磁気記録により行われ
る。In the optical recording and reproducing method of magneto-optical disks, which represent particularly erasable disks among optical recording and reproducing, a recording medium made of a magnetic thin film is irradiated with focused laser light, and information is recorded as a change in magnetization on the recording medium. This is done by magnetic recording.
すなわち、あらかじめ記録層の膜面全体に垂直に外部磁
界をかけ、上向き磁化になるように記録層を磁化させて
“0”を書き込んだ後、“1”を書き込む部分にレーザ
ビームをスポット的に照射して加熱する。加熱された微
小部分は保磁力H,が小さくなり、レーザビーム照射の
際微弱な外部バイアス磁界を下向き磁化となる方向に与
えておくと、磁化反転して“1゜゛が記録される。レー
ザビームを照射するかしないか、すなわち記録層に照射
された微小スポットの温度を上昇させるかさせないかに
より、磁気記録パターンを形成する方式がとられている
。That is, in advance, an external magnetic field is applied perpendicularly to the entire film surface of the recording layer to magnetize the recording layer so that it is magnetized upward to write "0", and then a laser beam is spot-wise applied to the part where "1" is to be written. Irradiate and heat. The coercive force H, of the heated minute part becomes smaller, and if a weak external bias magnetic field is applied in the direction of downward magnetization during laser beam irradiation, the magnetization is reversed and "1°" is recorded. Laser beam A method is adopted in which a magnetic recording pattern is formed depending on whether or not to irradiate the recording layer, that is, whether or not to raise the temperature of the minute spot irradiated onto the recording layer.
一方、情報の読み出しの方式は;例えば直線偏光したレ
ーザビームを磁気記録パターンに照射した場合、その反
射光または透過光の偏光面を回転させる効果(それぞれ
磁気カー効果,磁気ファラデー効果と呼ばれる)を記録
層は有しているので、例えば磁気カー効果を利用する場
合には、反射光の偏光面の回転角θ3が記録磁化の方向
によって異なることを利用して、反射光が光検出器に入
る前に検光子を通し、磁化の向きに対応した情報を光量
変化として読み出している。On the other hand, the method of reading information is; for example, when a magnetic recording pattern is irradiated with a linearly polarized laser beam, the effect of rotating the plane of polarization of the reflected or transmitted light (called the magnetic Kerr effect and magnetic Faraday effect, respectively) is used. For example, when using the magnetic Kerr effect, the reflected light enters the photodetector by utilizing the fact that the rotation angle θ3 of the polarization plane of the reflected light differs depending on the direction of recording magnetization. Before passing it through an analyzer, information corresponding to the direction of magnetization is read out as changes in the amount of light.
すなわち、従来のこのような光磁気ディスク装置におけ
る情報の読み出し方法では、記録媒体面上の磁化の変化
した領域が明または暗の領域(以降記録ピットと称する
)となる。これは反射率変化型の光ディスク装置で記録
ピットでの反射光全体の光量変化を検出することで再生
信号が読み出される方式と基本的に等価である。この様
な検出方法には、単一の光検出器を用いたものや、偏光
ビームスプリンタにより2つに偏光分割された光束をそ
れぞれ2つの光検出器で受光し、その出力の差をとる差
動検出法等がある。That is, in the conventional method for reading information in such a magneto-optical disk device, the areas on the surface of the recording medium where the magnetization has changed become bright or dark areas (hereinafter referred to as recording pits). This is basically equivalent to a method in which a reproduced signal is read out by detecting a change in the amount of light reflected from a recording pit in a reflectance change type optical disk device. Such detection methods include those that use a single photodetector, and those that use a polarization beam splitter to split the beam into two, which are each received by two photodetectors, and the difference between the outputs is calculated. There are motion detection methods, etc.
このとき、ディジタル情報の再生識別には読み出し信号
振幅の中点付近にスライスレベルを設けて記録ピット列
から記録ピット情報のパルス化を行う。同時に読み出し
波形の゜“0”1 ゜゛1′′に対応してピーク値を検
出して、ピット情報と各種変調方式で決まる再生クロッ
クとのタイミング関係から“0”“1”のパターンを判
定し源データの情報再生を行っている。At this time, to identify the reproduction of digital information, a slice level is provided near the midpoint of the read signal amplitude, and the recorded pit information is pulsed from the recorded pit string. At the same time, the peak values corresponding to ゜“0” 1 ゜゛1'' of the readout waveform are detected, and the pattern of “0” and “1” is determined from the timing relationship between the pit information and the reproduced clock determined by various modulation methods. The information of the source data is being reproduced.
上述した従来の光磁気ディスク装置における情報の記録
再生方式において、記録媒体面上に集光される読み出し
用のレーザスポットの強度分布は広がり(ガウシアンビ
ーム)を持つため、反射光の強度変化は急峻なものとは
ならない。従って、記録密度が大きくなると、読み出し
時には記録ピット間の干渉(以下、符号間干渉と称する
)が大きくなり、SN比の低下を起こしピット誤り率の
悪化を招く。すなわち、例えば第6図の上側の図に示す
ように記録媒体面上に記録された記録ピット61同士が
再生用のレーザスポット62の径付近まで接近して高密
度記録されると、第6図の下側の図に示すように記録ピ
ット間の読み出し信号は実線から点線の状態になる。こ
の時の再生分解能はB/Aで表される。実際の情報の識
別には位相マージンを考えて読み出し信号振幅の中点付
近にスライスレベルを設けて情報の再生を行うため、再
生分解能が0.5より小さくなると再生ノイズや再生光
パワー変動、記録媒体の反射率変動などが影響して安定
に情報の再生ができなくなるといった欠点を有している
。In the information recording and reproducing method of the conventional magneto-optical disk device described above, the intensity distribution of the reading laser spot focused on the recording medium surface has a spread (Gaussian beam), so the intensity change of the reflected light is steep. It doesn't become something. Therefore, as the recording density increases, interference between recorded pits (hereinafter referred to as inter-symbol interference) increases during reading, causing a decrease in the S/N ratio and worsening of the pit error rate. That is, for example, as shown in the upper diagram of FIG. 6, when the recording pits 61 recorded on the recording medium surface approach each other to the vicinity of the diameter of the laser spot 62 for reproduction and are recorded at high density, as shown in FIG. As shown in the lower figure, the read signal between recording pits changes from a solid line to a dotted line. The reproduction resolution at this time is expressed as B/A. In order to actually identify information, information is reproduced by setting a slice level near the midpoint of the read signal amplitude in consideration of the phase margin, so if the reproduction resolution is less than 0.5, reproduction noise, reproduction optical power fluctuations, and recording This method has the disadvantage that information cannot be stably reproduced due to changes in the reflectance of the medium.
また、同時に読み出し波形が歪むため記録情報の再生タ
イミングを乱し、光磁気ディスク装置の位相マージンを
低下させピット誤り率を低下させることになる。Furthermore, since the read waveform is distorted at the same time, the reproduction timing of recorded information is disturbed, the phase margin of the magneto-optical disk device is reduced, and the pit error rate is reduced.
従来の光記録再生方式は、上述の様な欠点を有している
ため、記録密度を高くすることに制約が大きく光磁気デ
ィスク装置の応用を狭めることになる。これは、反射率
変化型の光ディスク装置についても同様である。Conventional optical recording and reproducing systems have the above-mentioned drawbacks, and therefore are severely restricted in increasing the recording density, which limits the applications of magneto-optical disk devices. This also applies to reflectance change type optical disc devices.
本発明の目的は、上記のごとき欠点を改善して、再生信
号が安定でかつ品質良好で、記録密度を従来の2倍以上
に向上させることのできる光記録再生方式を提供するこ
とにある。It is an object of the present invention to provide an optical recording and reproducing system that can improve the above-mentioned drawbacks, provide stable and good quality reproduced signals, and increase the recording density to more than twice that of the conventional method.
本発明は、レーザを光源とし、ピット列を用いて記録再
生される光ディスク系であって、記録系と再生系を含め
たシステムをパーシャルレスポンス型ディジタル伝送路
とみなせる記録再生系の光記録再生方式において、
記録側には、源データを2値データに変調する変調符号
器と、記録再生系でのエラー伝搬を抑えるため2値の中
間系列データを作る記録側等化回路と、半導体レーザ駆
動回路とを備え、再生側には、読み出しアンプと、前記
記録側等化回路に対抗し読み出された多値の信号から前
記2値の中間系列データを識別する再生側等化回路と、
識別された中間系列データから前記源データを再生する
復調符号器とを備え、
多値の信号の記録再生を行うことを特徴とする。The present invention relates to an optical disc system that uses a laser as a light source and performs recording and playback using a pit train, and is an optical recording and playback system for the recording and playback system in which the system including the recording system and playback system can be regarded as a partial response type digital transmission path. On the recording side, there is a modulation encoder that modulates source data into binary data, a recording side equalization circuit that creates binary intermediate series data to suppress error propagation in the recording/reproduction system, and a semiconductor laser drive circuit. and on the reproduction side, a readout amplifier, and a reproduction side equalization circuit that opposes the recording side equalization circuit and identifies the binary intermediate series data from the read multi-level signal;
The apparatus is characterized in that it includes a demodulation encoder that reproduces the source data from the identified intermediate sequence data, and performs recording and reproduction of multilevel signals.
本発明では、記録側等化回路は、モジュロ加算回路から
構成することができる。In the present invention, the recording side equalization circuit can be constructed from a modulo addition circuit.
また、再生側等化回路は、多値レベル判定系とモジュロ
加算回路から構成することができる。Further, the reproduction side equalization circuit can be constructed from a multilevel level determination system and a modulo addition circuit.
また、再生側等化回路の多値レベル判定系は、読み出し
波形の等化フィルタと多値レベル識別器とから構成する
ことができる。Further, the multi-value level determination system of the reproduction-side equalization circuit can be composed of a read waveform equalization filter and a multi-value level discriminator.
本発明によれば、高い記録密度になると発生する再生時
の符号間干渉を積極的に利用することで、記録密度を従
来の2倍以上に向上させることができるばかりでなく、
記録再生時に生じる誤り伝搬についても抑えることが可
能である.
〔実施例〕
第1図は本発明の第1の実施例を示すブロック図である
.本実施例では、半導体レーザを光源とし、ピット列を
用いて記録再生される光ディスク系であり、記録系と再
生系を含めたシステムをパーシャルレスポンス型ディジ
タル伝送路の一種であるデュオバイナリ伝送路とみなせ
る記録再生系を例に説明する。According to the present invention, by actively utilizing the intersymbol interference during reproduction that occurs when recording density is high, it is not only possible to increase the recording density to more than twice that of the conventional method, but also to
It is also possible to suppress error propagation that occurs during recording and playback. [Embodiment] FIG. 1 is a block diagram showing a first embodiment of the present invention. In this example, the optical disc system uses a semiconductor laser as a light source and records and plays back using a pit train, and the system including the recording system and playback system is a duobinary transmission line, which is a type of partial response digital transmission line. An example of a recording/reproducing system will be explained.
光磁気記録側においては、例えば源データを2値データ
に変調する変調符号器1と、記録再生系でのエラー伝搬
を抑えるため2値の中間系列データを作るモジュロ2加
算回路2から構成される記録側等化回路と、LD(半導
体レーザ)駆動回路3とを備えている。すなわち記録過
程においては、源データを変調符号器1に通し符号化し
た記録データを記録側等化回路であるモジュロ2加算回
路2を介して中間系列データに変換し、半導体レーザを
光源とする記録再生ヘッドで情報を記録ピット列の形で
記録媒体上に記録する。なお、半導体レーザ,記録再生
ヘッドおよび記録媒体を含む系を、記録再生アナログ系
4で示している。On the magneto-optical recording side, it is composed of, for example, a modulation encoder 1 that modulates source data into binary data, and a modulo-2 addition circuit 2 that creates binary intermediate series data to suppress error propagation in the recording/reproducing system. It includes a recording side equalization circuit and an LD (semiconductor laser) drive circuit 3. That is, in the recording process, source data is passed through a modulation encoder 1 and encoded recording data is converted to intermediate series data via a modulo 2 addition circuit 2, which is a recording side equalization circuit, and recording is performed using a semiconductor laser as a light source. A playback head records information on a recording medium in the form of a recording pit train. Note that a system including a semiconductor laser, a recording/reproducing head, and a recording medium is shown as a recording/reproducing analog system 4.
第3図(a)には記録側等化回路無し、第3図(b)に
は記録側等化回路有りの場合のデータの変換例を示す。FIG. 3(a) shows an example of data conversion without the recording-side equalization circuit, and FIG. 3(b) shows an example of data conversion with the recording-side equalization circuit.
第3図(a)で示すように、再生データが記録再生時の
ノイズ等によって誤って再生されると、復調後にはデー
タの誤り伝搬が生じる。これに対し、第3図(b)で示
すように、記録側等化回路で記録データである情報系列
を中間系列データに変換することで、記録再生系でのノ
イズなどによるピットの読み誤りの伝lm(エラー伝搬
と呼ぶ)を大幅に改善できる。このとき、記録媒体面上
に記録される記録ピット列はもちろん2値のディジタル
情報列であるが、読み出しの時に前述したように符号間
の干渉が読み出し信号波形の歪や分解能の低下を生じさ
せる。本発明では、この符号間干渉を積極的に使うこと
で3値の記録再生系を構成することになる。As shown in FIG. 3(a), if reproduced data is erroneously reproduced due to noise during recording and reproduction, error propagation of the data occurs after demodulation. In contrast, as shown in Figure 3(b), by converting the information series, which is recorded data, into intermediate series data in the recording side equalization circuit, errors in pit reading due to noise in the recording/reproducing system can be avoided. The transmission lm (referred to as error propagation) can be significantly improved. At this time, the recording pit string recorded on the surface of the recording medium is of course a binary digital information string, but during readout, as mentioned above, interference between symbols causes distortion of the readout signal waveform and a decrease in resolution. . In the present invention, a ternary recording and reproducing system is constructed by actively using this intersymbol interference.
一方、再生側には、読み出しアンプ5と、記録側等化回
路に対抗し、読み出された3値の信号から前記2値の中
間系列データを識別する3値レベル識別器6およびモジ
ュロ2加算回路8から構成される再生側等化回路と、源
データ系列を再生する復調符号器9と、クロック再生系
7とを備えている。On the other hand, on the playback side, there is a readout amplifier 5, a ternary level discriminator 6 that opposes the recording side equalization circuit, and identifies the binary intermediate series data from the readout ternary signal, and a modulo-2 addition. It includes a reproduction side equalization circuit constituted by a circuit 8, a demodulation encoder 9 for reproducing the source data sequence, and a clock reproduction system 7.
第4図は本発明に係る読み出しの原理を説明するだめの
図である.ここで、2値情報で記録された記録ピット列
が符号間干渉によって3値化されて読み出される。読み
出し信号の情報識別には従来の方式とは異なり第4図(
d)に示すようにスライスレベルを81およびS2のよ
うに2段階に設定しておく。このとき、各スライスレベ
ルでの識別は各々“1”O”1”に対応することになる
。同時にクロック再生系7で、読み出し波形の″1”O
” ”1”に対応してピーク値を検出して、ピット
情報と再生クロックとのタイミング関係をとる。各スラ
イスレベルでパルス化された情報系列は、第4図(e)
.(f).(g)に示すように、データ識別窓としてサ
ンプリングクロックとのタイミングにより元の2値のデ
ータ系列に変換されることになる。この復調データ系列
から復調符号器9を通して源データ系列が再生されるこ
とになる。FIG. 4 is a diagram for explaining the principle of reading according to the present invention. Here, the recorded pit string recorded as binary information is ternarized by intersymbol interference and read out. Unlike the conventional method, the information identification of the read signal is performed using the method shown in Fig. 4 (
As shown in d), the slice level is set to two levels, 81 and S2. At this time, the identification at each slice level corresponds to "1", "O", and "1", respectively. At the same time, the clock regeneration system 7 outputs "1" O of the read waveform.
The peak value corresponding to "1" is detected and the timing relationship between the pit information and the reproduced clock is determined.The information sequence pulsed at each slice level is shown in Fig. 4(e).
.. (f). As shown in (g), the data is converted into the original binary data series based on the timing with the sampling clock as the data identification window. A source data sequence is reproduced from this demodulated data sequence through a demodulation encoder 9.
第5図に本実施例のパーシャルレスポンス方式の電力ス
ペクトルを示す。図に示すように、従来2値で記録した
データを2値データとして読み出す方式に比べ半分の帯
域で達成できる。このため従来の方式に比べ2倍の情報
を記録再生できる。FIG. 5 shows the power spectrum of the partial response method of this embodiment. As shown in the figure, this can be achieved with half the bandwidth compared to the conventional method of reading data recorded in binary format as binary data. Therefore, twice as much information can be recorded and reproduced compared to conventional methods.
第2図には本発明の光記録再生方式に係る第2の実施例
を示す。本発明に係る第1の実施例と異なる点は、再生
側に、読み出したアナログレベルの等化フィルタ10を
挿入し、記録再生アナログ系における波形歪をデュオバ
イナリ型伝送路に補正する役割を持たせた構成である。FIG. 2 shows a second embodiment of the optical recording/reproducing system of the present invention. The difference from the first embodiment of the present invention is that an equalization filter 10 for the read analog level is inserted on the playback side, and has the role of correcting waveform distortion in the recording/playback analog system to the duobinary transmission line. The configuration is
これは、記録再生系での記録パワー依存による波形歪や
再生アンプ系での波形歪などの補正を容易にし、パーシ
ャルレスポンス型等化フィルタを実現する構成である。This is a configuration that facilitates correction of waveform distortion due to recording power dependence in the recording/reproduction system and waveform distortion in the reproduction amplifier system, and realizes a partial response type equalization filter.
以上の各実施例では、パーシャルレスポンス方式を用い
た基本的な光磁気ディスクにおける多値信号検出系の例
をデュオバイナリ符号を用いて示したが、種々のパーシ
ャルレスポンス符号を用いてもよい。そのときには、記
録側等化回路並びに再生側等化回路はN元のモジュロ加
算回路を用いることで対処可能である。なお、記録側等
化回路では記録再生アナログ系での記録ピット形状の熱
磁気的な特性を予め考慮して記録タイミングなどを予め
等化する補償回路を追加挿入してもよい。In each of the above embodiments, an example of a basic multilevel signal detection system in a magneto-optical disk using a partial response method is shown using a duobinary code, but various partial response codes may be used. In this case, the recording side equalization circuit and the reproduction side equalization circuit can be handled by using an N-element modulo addition circuit. Note that in the recording-side equalization circuit, a compensation circuit may be additionally inserted to take into account the thermomagnetic characteristics of the recording pit shape in the recording/reproduction analog system and equalize the recording timing in advance.
なお本発明では、光磁気記録を例に述べたが、もちろん
追記型などの反射率変化型記録媒体を用いた光ディスク
系でも同様にパーシャルレスポンス型の方式を利用する
ことが可能である。Although the present invention has been described using magneto-optical recording as an example, it is of course possible to similarly utilize the partial response type system in an optical disk system using a reflectance change type recording medium such as a write-once type.
以上説明したように本発明の光記録再生方式は、符号間
干渉を積極的に利用することによって情報の記録密度を
従来の2倍以上に増加できると共に情報の転送レートを
向上させることができ、光ディスクの応用範囲を拡大で
きるものである。また、ピット誤りの伝搬が抑えられる
ため光ディスク系のアナログレベルで生じるピット落ち
など不安定な要素が排除され総合的なピット誤り率の軽
減ができるといった効果がある。As explained above, the optical recording and reproducing method of the present invention can increase the recording density of information to more than twice that of the conventional method and improve the information transfer rate by actively utilizing intersymbol interference. This allows the range of applications of optical discs to be expanded. Furthermore, since the propagation of pit errors is suppressed, unstable factors such as dropped pits that occur at the analog level of optical disc systems are eliminated, and the overall pit error rate can be reduced.
第1図は本発明の光記録再生方式の第1の実施例を示す
ブロック図、
第2図は本発明の光記録再生方式の第2の実施例を示す
ブロック図、
第3図は本発明の光記録再生方式に係るデータの変換例
を説明するための図、
第4図は本発明に係る読み出しの原理を説明するための
図、
第5図は本発明に係るパーシャルレスポンス方式の電力
スペクトルを示す図、
第6図は本発明に係る符号間干渉の説明をするための図
である。
1・・・・・変調符号器
2・・・・・モジュロ2加算回路
3・・・・・LD駆動回路
4・・・・・記録再生アナログ系
5・・・・・読み出しアンプ
6・・・・・3値レベル識別器
7・・・・・クロック再生系
8・・・・・モジュロ2加算回路
9・・・・・変調符号器
10・・・・・等化フィルタ
第2図
二甜デーク
+10
記録データ
+10
+00
中闇系列
10α1101000
再生データ
再生テタ
+00
復調データ
復調データ
(○)記録テ′一タ
(b)中間系列
o 0
0 o O
鵬
図
8!闇tFIG. 1 is a block diagram showing a first embodiment of the optical recording/reproducing method of the present invention, FIG. 2 is a block diagram showing a second embodiment of the optical recording/reproducing method of the present invention, and FIG. 3 is a block diagram showing the second embodiment of the optical recording/reproducing method of the present invention. Figure 4 is a diagram for explaining the principle of readout according to the present invention. Figure 5 is a power spectrum of the partial response method according to the present invention. FIG. 6 is a diagram for explaining intersymbol interference according to the present invention. 1... Modulation encoder 2... Modulo 2 addition circuit 3... LD drive circuit 4... Recording/playback analog system 5... Readout amplifier 6... ... Three-level level discriminator 7 ... Clock recovery system 8 ... Modulo 2 addition circuit 9 ... Modulation encoder 10 ... Equalization filter Figure 2 +10 Recorded data +10 +00 Middle series 10α1101000 Reproduction data Reproduction data +00 Demodulated data Demodulated data (○) Recorded data (b) Intermediate series o 0 0 o O Peng Figure 8! darkness
Claims (1)
れる光ディスク系であって、記録系と再生系を含めたシ
ステムをパーシャルレスポンス型ディジタル伝送路とみ
なせる記録再生系の光記録再生方式において、 記録側には、源データを2値データに変調する変調符号
器と、記録再生系でのエラー伝搬を抑えるため2値の中
間系列データを作る記録側等化回路と、半導体レーザ駆
動回路とを備え、 再生側には、読み出しアンプと、前記記録側等化回路に
対抗し読み出された多値の信号から前記2値の中間系列
データを識別する再生側等化回路と、識別された中間系
列データから前記源データを再生する復調符号器とを備
え、 多値の信号の記録再生を行うことを特徴とする光記録再
生方式。(1) In an optical recording and reproducing system that uses a laser as a light source and performs recording and reproducing using a pit train, the system including the recording system and reproducing system can be regarded as a partial response type digital transmission path. On the recording side, there is a modulation encoder that modulates source data into binary data, a recording side equalization circuit that creates binary intermediate series data to suppress error propagation in the recording/reproduction system, and a semiconductor laser drive circuit. The reproduction side includes a readout amplifier, a reproduction side equalization circuit that opposes the recording side equalization circuit and identifies the binary intermediate series data from the read multi-level signal, and an identified reproduction side equalization circuit. An optical recording and reproducing method, comprising: a demodulating encoder for reproducing the source data from intermediate sequence data, and recording and reproducing multilevel signals.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5727189A JPH02236823A (en) | 1989-03-09 | 1989-03-09 | Optical recording and reproducing system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5727189A JPH02236823A (en) | 1989-03-09 | 1989-03-09 | Optical recording and reproducing system |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH02236823A true JPH02236823A (en) | 1990-09-19 |
Family
ID=13050866
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP5727189A Pending JPH02236823A (en) | 1989-03-09 | 1989-03-09 | Optical recording and reproducing system |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH02236823A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5790482A (en) * | 1994-07-20 | 1998-08-04 | Hitachi, Ltd. | Optical disk apparatus for recording information using a light intensity modulation method with a partial response detector |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5562517A (en) * | 1978-10-31 | 1980-05-12 | Fujitsu Ltd | Reproducing system of magnetic storage device |
JPS5658121A (en) * | 1979-10-17 | 1981-05-21 | Hitachi Denshi Ltd | Magnetic record/reproduction system for digital signal |
JPS5812110A (en) * | 1981-07-10 | 1983-01-24 | Victor Co Of Japan Ltd | Magnetic reproducer |
JPS5845605A (en) * | 1981-09-12 | 1983-03-16 | Canon Inc | Magnetic recording and reproducing system |
JPS5954011A (en) * | 1982-09-21 | 1984-03-28 | Sony Corp | Recording circuit |
JPS62269444A (en) * | 1986-05-16 | 1987-11-21 | Matsushita Electric Ind Co Ltd | Digital information transmission equipment |
-
1989
- 1989-03-09 JP JP5727189A patent/JPH02236823A/en active Pending
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5562517A (en) * | 1978-10-31 | 1980-05-12 | Fujitsu Ltd | Reproducing system of magnetic storage device |
JPS5658121A (en) * | 1979-10-17 | 1981-05-21 | Hitachi Denshi Ltd | Magnetic record/reproduction system for digital signal |
JPS5812110A (en) * | 1981-07-10 | 1983-01-24 | Victor Co Of Japan Ltd | Magnetic reproducer |
JPS5845605A (en) * | 1981-09-12 | 1983-03-16 | Canon Inc | Magnetic recording and reproducing system |
JPS5954011A (en) * | 1982-09-21 | 1984-03-28 | Sony Corp | Recording circuit |
JPS62269444A (en) * | 1986-05-16 | 1987-11-21 | Matsushita Electric Ind Co Ltd | Digital information transmission equipment |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5790482A (en) * | 1994-07-20 | 1998-08-04 | Hitachi, Ltd. | Optical disk apparatus for recording information using a light intensity modulation method with a partial response detector |
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