JPH0210544A - Optical magnetic memory - Google Patents
Optical magnetic memoryInfo
- Publication number
- JPH0210544A JPH0210544A JP15930588A JP15930588A JPH0210544A JP H0210544 A JPH0210544 A JP H0210544A JP 15930588 A JP15930588 A JP 15930588A JP 15930588 A JP15930588 A JP 15930588A JP H0210544 A JPH0210544 A JP H0210544A
- Authority
- JP
- Japan
- Prior art keywords
- group
- erasing
- recording
- beam spot
- executed
- 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
- 230000003287 optical effect Effects 0.000 title abstract description 5
- 230000001678 irradiating effect Effects 0.000 claims description 2
- 230000005415 magnetization Effects 0.000 abstract description 8
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 239000000203 mixture Substances 0.000 abstract 1
- 230000001172 regenerating effect Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 7
- 238000012217 deletion Methods 0.000 description 6
- 230000037430 deletion Effects 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 238000004364 calculation method Methods 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 201000009310 astigmatism Diseases 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/1055—Disposition or mounting of transducers relative to record carriers
- G11B11/10576—Disposition or mounting of transducers relative to record carriers with provision for moving the transducers for maintaining alignment or spacing relative to the carrier
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10502—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing characterised by the transducing operation to be executed
- G11B11/10526—Bulk initialisation or erasing, e.g. at least one whole information track with a single action
Abstract
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は消去ＬＩｆ能な光磁気記憶装置に関する。[Detailed description of the invention] (Industrial application field) The present invention relates to a magneto-optical storage device capable of erasing LIf.
（従来の技術） 従来、光磁気記憶装置で使用される媒体は。(Conventional technology) Traditionally, the media used in magneto-optical storage devices are:
第４図で示される様な構成を有する。It has a configuration as shown in FIG.
第４図において、２２は基体であり、該基体の表面には
磁性膜２３が形成されている６図示される様に、媒体に
は情報の記録される記録部（以下「ランド」と称する）
２１が凸部としてトラック状に形成されており、該記録
部２１に隣接して２つの非記録部（以下ｒグループ」と
称する。）２０が凹部（溝）として形成されている。情
報の記録はバイアス磁界を印加しながら、レーザービー
ムＬＢをＥ記うンド２１にスポット状に照射することに
より１行われる。In FIG. 4, 22 is a base, and a magnetic film 23 is formed on the surface of the base. As shown in Figure 6, the medium has a recording section (hereinafter referred to as "land") where information is recorded.
21 is formed in a track shape as a convex portion, and two non-recording portions (hereinafter referred to as r group) 20 are formed as recesses (grooves) adjacent to the recording portion 21. Recording of information is performed by irradiating the laser beam LB in a spot shape onto the E recording pad 21 while applying a bias magnetic field.
ところで、媒体製造時に形成された磁性膜２３は磁化の
向きがランダムであるため、情報の記録に先立ち、消去
動作が行われる。By the way, since the magnetic film 23 formed at the time of manufacturing the medium has a random magnetization direction, an erasing operation is performed before information is recorded.
該消去動作は上記記録時のバイアス磁界の向きと逆の向
きにバイアス磁界を印加しながら、消去パワーのレーザ
ービームＬＢをラッド２１に照射して、ビームスポット
を形成し、該ビームスポットでランド２１を走査する。In the erasing operation, a laser beam LB of erasing power is applied to the rad 21 while applying a bias magnetic field in the opposite direction to the direction of the bias magnetic field during recording to form a beam spot, and the beam spot forms a beam spot on the land 21. scan.
この走査の際には、ビームスポットを適当な大きさでラ
ンド上に位置させ、常にスポラ）ＳＰＩの様な状態が得
られる様に、オートフォーカシング（ＡＦ）、オートト
ラッキング（ＡＴ）がなされる。During this scanning, autofocusing (AF) and autotracking (AT) are performed so that the beam spot is positioned on the land with an appropriate size and a state similar to sporadic SPI is always obtained.
従って、理想的には、消去動作ではランド２１の磁化の
みが一定の向きに揃えられる。Therefore, ideally, in the erase operation, only the magnetization of the land 21 is aligned in a certain direction.
ただし、実際には、ＡＦおよびＡＴを行ってもスポラ）
ＳＦ３の様にグループ２０へと部分的にはみ出すことも
ある。また、ＡＴのための手段としてプッシュプル方式
を採用した場合には、記録／再生／消去用のレーザービ
ームがＡＴ用のビームとしても使用されるため、ビーム
スポットはＳＦ３の様に常にグループ２０へと部分的に
はみ出す程度の広がりを持っている。However, in reality, even if AF and AT are performed, sporadic
It may partially protrude into group 20 as in SF3. In addition, when a push-pull method is adopted as a means for AT, the laser beam for recording/playback/erasing is also used as a beam for AT, so the beam spot is always directed to group 20 like SF3. It has such an extent that it partially protrudes.
以上の様なＳＦ３ 、ＳＦ３の様な場合にはグループ２
０の一部にもレーザービーム照射がなされるのであるが
、グループに照射されるビームのパワーは小さいので、
該グループに対しては磁化を一定に揃える消去動作は実
質状なされず、ランダムな磁化が残ったままとなる。SF3 as above, group 2 in cases like SF3
A part of 0 is also irradiated with a laser beam, but the power of the beam irradiated to the group is small, so
An erasing operation to uniformly align the magnetization is not substantially performed on the group, and random magnetization remains.
情報の記録時には１．Ｌ−、記消去時とは逆向きのバイ
アス磁界を印加しながら、記録パワーのレーザービーム
ＬＢをランド２１に照射して、ビームスポットを形成し
、該ビームスポットでランド２１を走査しながら、記録
情報に従ってレーザービームを０Ｎ−ＯＦＦさせる。こ
の記録の場合も図示されるスポットＳＰ２ 、ＳＦ３の
状態が実現されるが、消去時と同様にグループ２０に照
射されるビームのパワーは小さいので該グ
ループに対しては記録動作は実質上なされず、ランダム
な磁化が残ったままとなる。When recording information, 1. L-, while applying a bias magnetic field in the opposite direction to that used during recording and erasing, a laser beam LB of recording power is irradiated onto the land 21 to form a beam spot, and while the land 21 is scanned with the beam spot, recording is performed. Turn the laser beam ON-OFF according to the information. In the case of this recording as well, the states of spots SP2 and SF3 shown in the figure are realized, but as in the case of erasing, the power of the beam irradiated to group 20 is small, so no recording operation is actually performed for this group. , random magnetization remains.
（発明が解決しようとする課題）
媒体に記録されている情報の再生はスポットからの反射
光を検出することによりなされる。しかし、スポットを
ランド２１上からはみ出さないように形成することは実
際には不可能であるため、媒体からの反射光にはランド
２１の部分による反射光とグループ２０の部分による反
射光とが含まれることになる。(Problem to be Solved by the Invention) Information recorded on a medium is reproduced by detecting reflected light from a spot. However, since it is actually impossible to form a spot so that it does not protrude from above the land 21, the light reflected from the medium includes the light reflected by the land 21 and the light reflected by the group 20. will be included.
また、前述した様にグループ２０の磁化の向きはランダ
ムのままであるため、この部分からの反射光による信号
成分はランド２１の部分からの反射光による正規の信号
に対しノイズとなる。Further, as described above, since the magnetization direction of the group 20 remains random, the signal component due to the reflected light from this portion becomes noise compared to the normal signal due to the reflected light from the land 21 portion.
このため、従来の光磁気記憶装置においては。For this reason, in conventional magneto-optical storage devices.
再生エラーレートが高くなりがちであるという問題点が
あった。There was a problem that the playback error rate tended to be high.
（課題を解決するための手段）
本発明は上記の様な問題点を解決し、光磁気記憶装置の
再生時におけるグループからの反射光に基づく再生信号
のノイズを除去することを目的としてなされたものであ
り、非記録部に対し消去動差を行う手段を備え、該手段
により非記録部の磁化の向きを揃える＊ｔｂを持たせた
ことを特徴としている。(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems and removing noise in the reproduced signal based on reflected light from the group during reproduction of a magneto-optical storage device. It is characterized in that it is equipped with a means for performing an erase motion on the non-recording portion, and that the means provides *tb for aligning the direction of magnetization of the non-recording portion.
（実施例） 本発明の実施例を以下に示す。(Example) Examples of the present invention are shown below.
第１図は、本発明による光磁気記憶装置の概略図である
。ｌは消去可能な光磁気媒体であり、第４図に示される
様な構成を有する。光磁気媒体１はスピンドルモーター
２によって矢印方向（Ｒ）に３００Ｏｒｐｍの速さで回
転する。４は光学ヘッドであり、リニアモーター（不図
示）によって媒体ｌの半径方向（Ｓ）に移動可能である
。光学へ・、ド４の中には、図には示されてｌ／％ない
が、半導体レーザー、光学系、ＡＦ／ＡＴ用ボイスツボ
イスコイルＡＴ用サーボセンサー、再生信号を検知する
フォトセンサーが配置されてｌ、Ｘる。３は電磁石であ
り、記Ｒ／消去時のＩくイアス磁界を発生し、その磁界
は、媒体上の記録／消去領域に一様にあたる、５は電磁
石３を駆動する駆動回路であり、コントローラ６からの
制御信号によって、電磁石３の磁界方向を消去、記録の
動作に従って切り換える機能を持っている。７はグルー
プ消去を指示するスイ２・チである。FIG. 1 is a schematic diagram of a magneto-optical storage device according to the present invention. 1 is an erasable magneto-optical medium and has a configuration as shown in FIG. The magneto-optical medium 1 is rotated by a spindle motor 2 in the direction of the arrow (R) at a speed of 300 rpm. 4 is an optical head, which can be moved in the radial direction (S) of the medium l by a linear motor (not shown). To the optics, although not shown in the figure, there are semiconductor lasers, optical systems, voice coil AT servo sensors for AF/AT, and photosensors for detecting playback signals. It is placed l,X. 3 is an electromagnet, which generates a magnetic field during recording/erasing, and the magnetic field uniformly hits the recording/erasing area on the medium; 5 is a drive circuit that drives the electromagnet 3; a controller 6; It has a function of switching the direction of the magnetic field of the electromagnet 3 according to the erasing and recording operations using a control signal from the electromagnet 3. 7 is a switch 2-1 for instructing group deletion.
第２図は本実施例装置におけるフォーカスサーボ系及び
トラッキングサーボ系を示すブロック図である０本実施
例ではＡＦ動作は非点収差方式、ＡＴ動作はプッシュプ
ル方式を用いている。FIG. 2 is a block diagram showing a focus servo system and a tracking servo system in the apparatus of this embodiment. In this embodiment, the AF operation uses an astigmatism method, and the AT operation uses a push-pull method.
第２図において、ｌＯは４分割センサーであり、その受
光量がそれぞれ３１〜Ｓ４であるとする。該センサー１
０は上記光学へラド４に内蔵されている。In FIG. 2, it is assumed that lO is a four-divided sensor, and the amount of received light is 31 to S4, respectively. The sensor 1
0 is built into the optical helad 4.
フォーカスサーボはオペアンプ１１．１２゜１３によっ
て（Ｓｌ＋３３）−（Ｓ２＋３４）の演算を行い、該演
算結果をフォーカス駆動回路１４に入力し、ここで、位
相補償、電力増幅を行い、アクチュエーターのフォーカ
スコイルを駆動することによりなされる。The focus servo calculates (Sl + 33) - (S2 + 34) using an operational amplifier 11.12゜13, and inputs the calculation result to the focus drive circuit 14, which performs phase compensation and power amplification to drive the focus coil of the actuator. This is done by driving.
トラッキングサーボは、オペアンプ１５゜１６．１８、
ｖ′Ｊ＃！スイッチ１７及びトラッキング駆動回路１９
を用いてなされる。前記コントローラ６から切換スイッ
チ１７に入力されるＡＴ極極性ジノ上信号従って、ラン
ドトラッキングの場合は（Ｓ１＋３４）−（Ｓ２＋３３
）の演算結果が駆動回路１９に入力され、グループトラ
ッキングの場合には（Ｓ２＋３３）−（Ｓ１＋３４）の
演算結果が駆動回路１９に入力される。Tracking servo is operational amplifier 15°16.18,
v′J#! Switch 17 and tracking drive circuit 19
It is done using Accordingly, in the case of land tracking, the AT polarity signal input from the controller 6 to the changeover switch 17 is (S1+34)-(S2+33
) is input to the drive circuit 19, and in the case of group tracking, the calculation result of (S2+33)-(S1+34) is input to the drive circuit 19.
駆動回路１９では位相補償、電力増−が行われ、アクチ
ュエーターのトラッキングコイルが駆動される。The drive circuit 19 performs phase compensation and power increase to drive the tracking coil of the actuator.
第３図は本実施例におけるグループ消去時の動作シーケ
ンスを示すフロー図である。FIG. 3 is a flow diagram showing the operation sequence during group deletion in this embodiment.
以下上記第１図及び第２図を参照しながら第３図に従っ
てグループ消去の動作を説明する。The operation of group deletion will be described below with reference to FIG. 3 while referring to FIGS. 1 and 2 above.
グループ消去動作は、外部からスイッチ７を閉じること
により開始される。即ち、先ず、コントローラ６は切換
スイッチ７が閉じているかいないかを判定する（ステッ
プ３１）、ここで該スイッチが開いていると判定された
場合には、そのまま終了し、グループ消去を行わない。The group erase operation is initiated by closing switch 7 from the outside. That is, first, the controller 6 determines whether the changeover switch 7 is closed or not (step 31). If it is determined that the switch is open, the process ends without performing group deletion.
該ステップ３１においてスイッチ７が閉じていると判定
された場合には続いて″ｆ１．ｉａ石３を消去磁界が発
生するように駆動する（ステップ３２）。If it is determined in step 31 that the switch 7 is closed, then the "f1.ia" stone 3 is driven so as to generate an erasing magnetic field (step 32).
そして、コントローラ６の内部にあるＡＴササ−回路内
の切換スイッチ１７に対しＡＴＴ性切換信号を送る（ス
テップ３３）、これにより、ランド２１に照射されてい
たレーザービームスポットがグループ２０へと移動せし
められる。Then, an ATT switching signal is sent to the switching switch 17 in the AT sustainer circuit inside the controller 6 (step 33), thereby causing the laser beam spot irradiated on the land 21 to move to the group 20. It will be done.
続いて、上記ビームスポット移動が適正に行われてグル
ープトラッキングがＯＫの状態となったか否かが判定さ
れ（ステップ３４）、ＯＫとなるまで待機する。Next, it is determined whether the beam spot movement has been properly performed and group tracking is OK (step 34), and the process waits until it is OK.
グループトラッキングがＯＫとなった後に、レーザーパ
ワーを消去パワーにセットする動作がなされ（ステップ
３５）、以後グループトラッキングを行いながらグルー
プ消去がなされる。この消去はスイッチ７が開くまで行
われる。After group tracking is OK, the laser power is set to erasing power (step 35), and group erasing is then performed while group tracking is being performed. This erasure continues until switch 7 is opened.
ステップ３６でスイッチ７が開いていると判定された場
合には、続いてレーザーパワーを再生パワーにセットし
くステップ３７）、電磁石３をＯＦＦとしくステップ３
８）、スイッチ１７に対しＡＴＴ性切換信号を出しくス
テップ３９）、これにより、レーザービームスポットを
グループ２０からランド２１へと移動させる。If it is determined in step 36 that the switch 7 is open, then the laser power is set to the reproduction power (step 37), and the electromagnet 3 is turned off (step 3).
8), step 39) of issuing an ATT switching signal to the switch 17, thereby moving the laser beam spot from the group 20 to the land 21;
以上により、グループ消去動作を終了する。With the above steps, the group deletion operation is completed.
（発明の効果）
以上詳細に説明したように、本発明によれば、非記Ｑ部
の消去動作をも行うので、再生時において光ビームスポ
ットが部分的に非記録部にはみ出しても、再生信号への
ノイズ混入の原因とはならず、このため、再生エラーレ
ートを大幅に低下させることが出来る。(Effects of the Invention) As explained in detail above, according to the present invention, since the erasing operation of the non-recorded Q portion is also performed, even if the light beam spot partially protrudes into the non-recorded portion during reproduction, the reproduction This does not cause noise to be mixed into the signal, and therefore the reproduction error rate can be significantly reduced.
第１図は本発明の一実施例の概略図。 第２図は本発明のＡＴ極性の切換動作の説明図。 第３図はグループ消去動作のフロー説明図。 第４図は光磁気記録媒体の構造図。 、光磁気記録媒体 、スピンドルモーター 、電磁石 、光ヘー、ド 、電磁石駆動回路 、コントローラ 、グループ消去スイッチ 、４分割サーボセンサー １２．１３．ＡＦ用オペアンプ フォーカスコイル駆動回路 １６、ｌ ８ 、 ＡＴ用オペアンプ 、ＡＴ極性切換スイッチ 、トラッキングコイル駆動回路 、グループ 、ランド 、基体 、磁性膜 ■ １ ｌ、 １４゜ ｌ−“５、 FIG. 1 is a schematic diagram of an embodiment of the present invention. FIG. 2 is an explanatory diagram of the AT polarity switching operation of the present invention. FIG. 3 is a flow explanatory diagram of group deletion operation. FIG. 4 is a structural diagram of a magneto-optical recording medium. , magneto-optical recording medium , spindle motor ,electromagnet , light he, de , electromagnet drive circuit ,controller , group erase switch , 4-part servo sensor 12.13. AF operational amplifier Focus coil drive circuit 16, l 8 , AT operational amplifier , AT polarity switch , tracking coil drive circuit ,group ,land , substrate , magnetic film ■ 1 l, 14° l-“5,
Claims (1)
部とを持つ消去可能な光磁気記録媒体を用い、該媒体に
対しバイアス磁界を印加しながら、光ビームをスポット
状に照射して情報の記録、再生及び消去を行う光磁気記
憶装置において、前記記録媒体に対する光ビームスポッ
トのトラッキング動作を記録部と非記録部とに切り換え
る手段と、 前記非記録部に対するバイアス磁界の向きを切り替える
手段と、 前記非記録部に対し消去レーザーパワーを照射する手段
とを有し、 前記非記録部を一方向に磁化する機能を有する事を特徴
とする、光磁気記憶装置。(1) Using an erasable magneto-optical recording medium having a track-shaped recording part and a non-recording part adjacent to the recording part, a light beam is irradiated in a spot shape while applying a bias magnetic field to the medium. A magneto-optical storage device that records, reproduces, and erases information using a magneto-optical storage device, comprising means for switching a tracking operation of a light beam spot on the recording medium between a recording portion and a non-recording portion, and switching a direction of a bias magnetic field for the non-recording portion. A magneto-optical storage device, comprising: means for irradiating the non-recording portion with erasing laser power, and having a function of magnetizing the non-recording portion in one direction.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15930588A JPH0210544A (en) | 1988-06-29 | 1988-06-29 | Optical magnetic memory |
| EP19890303971 EP0339875B1 (en) | 1988-04-26 | 1989-04-21 | Method and apparatus for initializing intermediate region between tracks on magnetooptical recording medium |
| DE1989612390 DE68912390T2 (en) | 1988-04-26 | 1989-04-21 | Method and device for initializing an area lying between the tracks of a magneto-optical recording medium. |
| US08/082,507 US5309416A (en) | 1988-04-26 | 1993-06-25 | Method and apparatus for initializing intermediate region between tracks on magnetooptical recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15930588A JPH0210544A (en) | 1988-06-29 | 1988-06-29 | Optical magnetic memory |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0210544A true JPH0210544A (en) | 1990-01-16 |
Family
ID=15690899
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15930588A Pending JPH0210544A (en) | 1988-04-26 | 1988-06-29 | Optical magnetic memory |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0210544A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7055935B2 (en) | 1997-07-15 | 2006-06-06 | Silverbrook Research Pty Ltd | Ink ejection devices within an inkjet printer |
-
1988
- 1988-06-29 JP JP15930588A patent/JPH0210544A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7055935B2 (en) | 1997-07-15 | 2006-06-06 | Silverbrook Research Pty Ltd | Ink ejection devices within an inkjet printer |
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