JPS63276731A - Method for writing to magneto-optical recording medium - Google Patents
Method for writing to magneto-optical recording mediumInfo
- Publication number
- JPS63276731A JPS63276731A JP62110864A JP11086487A JPS63276731A JP S63276731 A JPS63276731 A JP S63276731A JP 62110864 A JP62110864 A JP 62110864A JP 11086487 A JP11086487 A JP 11086487A JP S63276731 A JPS63276731 A JP S63276731A
- Authority
- JP
- Japan
- Prior art keywords
- medium
- thin film
- information
- recording
- magnetic field
- 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
- 238000000034 method Methods 0.000 title claims abstract description 20
- 230000005415 magnetization Effects 0.000 claims abstract description 16
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 4
- 239000000956 alloy Substances 0.000 claims abstract description 4
- 238000010438 heat treatment Methods 0.000 claims abstract 3
- 229910052723 transition metal Inorganic materials 0.000 claims abstract 3
- 239000010409 thin film Substances 0.000 claims description 47
- 229910052771 Terbium Inorganic materials 0.000 claims description 4
- 229910000599 Cr alloy Inorganic materials 0.000 claims description 3
- 229910052692 Dysprosium Inorganic materials 0.000 claims 2
- 229910052688 Gadolinium Inorganic materials 0.000 claims 2
- 229910052779 Neodymium Inorganic materials 0.000 claims 2
- 229910052761 rare earth metal Inorganic materials 0.000 claims 2
- 150000003624 transition metals Chemical class 0.000 claims 2
- 229910052742 iron Inorganic materials 0.000 claims 1
- 229910052759 nickel Inorganic materials 0.000 claims 1
- 150000002910 rare earth metals Chemical class 0.000 claims 1
- 239000000758 substrate Substances 0.000 abstract description 7
- 229910000684 Cobalt-chrome Inorganic materials 0.000 abstract 1
- 238000003491 array Methods 0.000 abstract 1
- 239000010952 cobalt-chrome Substances 0.000 abstract 1
- 239000010408 film Substances 0.000 description 7
- 230000003287 optical effect Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 230000005284 excitation Effects 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 230000005374 Kerr effect Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- AJCDFVKYMIUXCR-UHFFFAOYSA-N oxobarium;oxo(oxoferriooxy)iron Chemical compound [Ba]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O AJCDFVKYMIUXCR-UHFFFAOYSA-N 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は光磁気ディスクなどの光磁気記録媒体に高速の
重ね書きの機能を持たせるようにした書き込み方法に関
するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a writing method in which a magneto-optical recording medium such as a magneto-optical disk is provided with a high-speed overwriting function.
（従来の技術）
従来、光磁気ディスクへの記録（情報の書き込み）は、
一様に磁化した光記録媒体（Ｔｂ−Ｆｅ薄膜等の垂直磁
化薄膜）に対し異方性磁界以下のバイアス磁場を磁化と
□逆向きに加えつつレーザービームを照射して照射領域
の温度をキュリー温度以上に上げた後、媒体が冷却する
過程でバイアス磁場の方向に磁化が反転することを利用
しており、レーザービームをオン・オフする事で磁化反
転の列として情報を記録していた。(Conventional technology) Conventionally, recording (writing information) on a magneto-optical disk was done by
A bias magnetic field less than the anisotropic magnetic field is applied to a uniformly magnetized optical recording medium (perpendicularly magnetized thin film such as a Tb-Fe thin film) in the opposite direction to the magnetization, and a laser beam is irradiated to cure the temperature of the irradiated area. This method takes advantage of the fact that the magnetization reverses in the direction of the bias magnetic field as the medium cools after being raised above the temperature, and by turning the laser beam on and off, information is recorded as a sequence of magnetization reversals.
（発明が解決しようとする問題点）
この方式では一旦記録された領域に再度新しい情報を記
録する場合には逆向きのバイアス磁場中で連続レーザー
ビームを照射して媒体を加熱し磁化を全て一様な方向に
そろえる事（これを消去過程という）が必要であった。(Problem to be solved by the invention) In this method, when new information is to be recorded in an area that has been previously recorded, a continuous laser beam is irradiated in a bias magnetic field in the opposite direction to heat the medium and unify all the magnetization. It was necessary to align them in different directions (this is called the elimination process).
即ち、消去した後に再度記録を行なう必要があり、通常
の磁気記録における情報の書き込みのように予め記録さ
れていた領域の上に別の情報を記録することで前の情報
は自動的に消える事はなく、アクセス速度の高速化上の
障害となっていた。In other words, it is necessary to record again after erasing the data, and just like writing information in normal magnetic recording, recording new information over the previously recorded area automatically erases the previous information. This was an obstacle to increasing access speed.
本発明の目的は、光磁気ディスクのような光磁気記録媒
体において磁気記録と同等のアクセス速度を持ち、しか
も消去過程を経ずに新しい情報を書き加えられる、光磁
気記録媒体への書き込み方法を提供することにある。An object of the present invention is to provide a method for writing to a magneto-optical recording medium such as a magneto-optical disk, which has an access speed equivalent to that of magnetic recording and also allows new information to be written without going through an erasing process. It is about providing.
（問題点を解決するための手段）
本発明は上記目的を達成するため、キュリー温度が高い
垂直磁化薄膜（第１媒体）とこの薄膜の異方性磁場より
も大きい異方性磁場を持ちしかもキュリー温度は前記薄
膜よりも低い垂直磁化薄膜（第２媒体）との２層構造を
有する光磁気記録媒体を使用し、磁気記録用ヘッドを用
いて磁化反転の列として情報を第１媒体へ記録した後、
該記録領域を光ビームで第２媒体のキュリー温度以上に
加熱し、第２媒体が冷却する過程で第１媒体の磁化反転
情報を第２媒体へ転写するようにした。(Means for Solving the Problems) In order to achieve the above object, the present invention has a perpendicularly magnetized thin film (first medium) with a high Curie temperature and an anisotropic magnetic field larger than the anisotropic magnetic field of this thin film. A magneto-optical recording medium having a two-layer structure with a perpendicularly magnetized thin film (second medium) whose Curie temperature is lower than that of the thin film is used, and a magnetic recording head is used to record information on the first medium as an array of magnetization reversals. After that,
The recording area is heated with a light beam to a temperature higher than the Curie temperature of the second medium, and in the process of cooling the second medium, the magnetization reversal information of the first medium is transferred to the second medium.
（作用）
本発明によれば、磁気記録と同等のアクセス速度を持ち
、しかも消去過程を経ずに新しい情報を書き加えられる
。(Function) According to the present invention, the access speed is equivalent to that of magnetic recording, and new information can be added without going through an erasing process.
（実施例）
第１図には、本発明方法に用いる光磁気ディスクの概略
を示す。図中１１は光磁気ディスク用基板で、ガラス円
板上に紫外線硬化樹脂である２ｐ剤を塗布後、ホトリソ
グラフ技術を用いて同心円状のトラック溝を形成したも
のである。この基板１１上にスパッタリング法を用いて
７７％Ｐｅ−２３％Ｔｂ薄膜（第２媒体）１２を６０Ｏ
Ａ厚形成後、引き続きその上に８０％Ｃｏ−２０％Ｃｒ
薄膜（第１媒体）１３を１００ＯＡ厚形成し光磁気ディ
スク媒体１０とした。(Example) FIG. 1 schematically shows a magneto-optical disk used in the method of the present invention. In the figure, reference numeral 11 denotes a magneto-optical disk substrate, in which a 2P agent, which is an ultraviolet curing resin, is applied onto a glass disk, and then concentric track grooves are formed using photolithography. On this substrate 11, a 77% Pe-23% Tb thin film (second medium) 12 was deposited at 60O
After forming A thickness, 80%Co-20%Cr is applied on top of it.
A thin film (first medium) 13 was formed to a thickness of 100 OA to obtain a magneto-optical disk medium 10.
即ち、第１媒体１３はキュリー温度が高い垂直磁化薄膜
よりなり、第２媒体１２は第１媒体１３の異方性磁場よ
りも大きい異方性磁場を持ちしかもキュリー温度は第１
媒体１３よりも低い垂直磁化薄膜よりなる。１４は光ヘ
ッドで、ガラス基板１１を通してレーザー光よりなる光
ビーム１５を光デイスク媒体１０上に集光し、その反射
光のカー効果による偏光の傾きを検出している。１６は
磁気記録用ヘッドである。本実施例では磁気記録用ヘッ
ド１６は、垂直磁化記録を目的にしているので主磁極励
磁型の構造となっているが、原理的にはリング型でもあ
るいは補助磁極励磁型でも垂直磁化記録は可能である。That is, the first medium 13 is made of a perpendicularly magnetized thin film with a high Curie temperature, and the second medium 12 has an anisotropic magnetic field larger than that of the first medium 13 and has a Curie temperature higher than that of the first medium 13.
It is made of a thin film with perpendicular magnetization lower than that of the medium 13. Reference numeral 14 denotes an optical head that focuses a light beam 15 made of laser light onto the optical disk medium 10 through the glass substrate 11, and detects the polarization inclination of the reflected light due to the Kerr effect. 16 is a magnetic recording head. In this embodiment, the magnetic recording head 16 is intended for perpendicular magnetization recording, so it has a main pole excitation type structure, but in principle, perpendicular magnetization recording is also possible with a ring type or an auxiliary pole excitation type. It is.
主磁極の幅は３００μｍであり基板の溝幅（１，６μｍ
）にくらべて、非常に大きい。しかし、この寸法の差異
は本発明の方式を用いることで原則的には問題とならな
い。以下に本発明による書き込みの動作メカニズムを述
べる。The width of the main pole is 300 μm, and the groove width of the substrate (1.6 μm
) is very large compared to However, this difference in size does not pose a problem in principle when the method of the present invention is used. The writing operation mechanism according to the present invention will be described below.
光磁気ディスク媒体１０が矢印方向へと回転している時
、先ずＣｏ−Ｃｒ薄膜１３に対してヘッド１６の主磁極
から発生する磁場で情報を記録する。When the magneto-optical disk medium 10 rotates in the direction of the arrow, information is first recorded on the Co--Cr thin film 13 using a magnetic field generated from the main pole of the head 16.
この過程は従来の磁気記録における書き込みプロセスと
同一である。この時の記録磁界は約４００００ｅであり
、Ｃｏ−Ｃｒ薄膜１３の保磁力（Ｈｅ−７００００ｅ）
より充分大きいためＣｏ−Ｃｒ薄膜１３は完全に磁化さ
れるが、Ｔｂ−Ｐｅ薄膜１２のＨｃ （１５Ｋ Ｏｅ
）よりは小さいためＴｂ−Ｐｅ薄膜１２は磁化されない
。This process is the same as the writing process in conventional magnetic recording. The recording magnetic field at this time is about 40,000e, and the coercive force of the Co-Cr thin film 13 (He-70,000e)
The Co-Cr thin film 13 is completely magnetized because it is sufficiently larger than the Hc (15K Oe) of the Tb-Pe thin film 12.
), the Tb--Pe thin film 12 is not magnetized.
情報の記録は次の過程を経て完結する。引続き、この媒
体１０は光ヘッド１４の下に移動して光ビーム１５で加
熱される。光ビーム１５のパワーは１０ａ＋Ｗであり、
照射部分の最高温度は１５０℃と推定される。Ｔｂ−Ｆ
ｅ薄膜１２はキュリー温度が約１２５℃なので容易に非
磁性になるのに対し、Ｃｏ−Ｃｒ薄膜１３のキュリー温
度は約６００℃と高いため、磁化情報は破壊されずに残
っておりそのビットからは漏れ磁界が発生している。次
に、媒体が移動して光ビーム１５で照射された領域の温
度が低下してきた場合には、Ｔｂ−Ｆｅ薄膜１２の磁化
はＣｏ−Ｃｒ薄膜１３から発生する磁場方向に揃うため
、Ｃｏ−Ｃｒ薄膜１３に書き込まれた磁化情報はＴｂ−
Ｐｅ薄膜１２に転写される。即ち、光・ビーム１５の幅
のトラックでＴｂ−Ｆｅ薄膜１２上には磁気情報が記録
される。Information recording is completed through the following process. Subsequently, this medium 10 is moved under the optical head 14 and heated by the light beam 15. The power of the light beam 15 is 10a+W,
The maximum temperature of the irradiated part is estimated to be 150°C. Tb-F
The e-thin film 12 has a Curie temperature of about 125°C, so it easily becomes non-magnetic, whereas the Co-Cr thin film 13 has a high Curie temperature of about 600°C, so the magnetization information remains undestructed and can be transferred from the bit. A leakage magnetic field is generated. Next, when the medium moves and the temperature of the area irradiated with the light beam 15 decreases, the magnetization of the Tb--Fe thin film 12 aligns in the direction of the magnetic field generated from the Co--Cr thin film 13. The magnetization information written in the Cr thin film 13 is Tb-
It is transferred to the Pe thin film 12. That is, magnetic information is recorded on the Tb--Fe thin film 12 with a track having the width of the light beam 15.
書き込まれた情報の再生は光ビーム１５の反射光の偏光
面の傾きの差として読み出すことができる。この時のレ
ーザーパワーは、通常媒体温度がＴｂ−Ｆｅ薄膜１２の
キュリー温度よりも充分低い温度になるように設定する
必要がある。本実施例では読みだし時のパワーは２ｍＷ
である。この媒体１０への重ね書きは、Ｃｏ−Ｃｒ薄膜
１３上へ磁気ヘッド１６で新しい情報を書き加えて行け
ば達成できる。Ｃｏ−Ｃｒ薄膜１３への重ね書きは通常
−４０ｄＢ程度の消し残り成分を伴うが、この値は極め
て小さいといえる。この時、両媒体１２．１３のＨｅは
Ｔｂ−Ｆｅ＞ ＞ Ｃｏ−Ｃｒなので重ね書きのための
磁場はＣｏ−Ｃｒ薄膜１３のみを磁化しＴｂ−Ｆｅ薄膜
１２には影響を及ぼさない。次に具体例を述べる。The written information can be read out as a difference in the inclination of the polarization plane of the reflected light of the light beam 15. The laser power at this time usually needs to be set so that the medium temperature is sufficiently lower than the Curie temperature of the Tb--Fe thin film 12. In this example, the power at the time of reading is 2mW.
It is. This overwriting on the medium 10 can be accomplished by writing new information onto the Co--Cr thin film 13 using the magnetic head 16. Overwriting on the Co--Cr thin film 13 usually involves an unerased component of about -40 dB, but this value can be said to be extremely small. At this time, since He in both media 12 and 13 is Tb-Fe>>Co-Cr, the magnetic field for overwriting magnetizes only the Co-Cr thin film 13 and does not affect the Tb-Fe thin film 12. Next, a specific example will be described.
最初に回転しているディスク媒体１０の第１媒体（Ｃｏ
−Ｃｒ薄膜）１３に対し１０μｍのビットを書き込み、
しかるのちに光ビーム（１ｈＷ）を１μｍ径に集光して
記録領域を１５０℃に加熱した所、Ｃｏ−Ｃｒ薄膜１３
の記録ビットは第２媒体（Ｔｂ−Ｆｅ薄膜）１２に転写
された。この記録ビットの再生信号のＳＮ比は５５ｄＢ
であった。次に、同一領域に対し磁気ヘッド１６を用い
てビット長１５μｍのビットを書き込み、しかるのちに
光ビーム１５で加熱し磁気情報を転写の後に、この信号
を再生した所ＳＮ比は４５ｄＢが得られた。The first medium (Co
- Cr thin film) Write a 10 μm bit to 13,
After that, a light beam (1 hW) was focused to a diameter of 1 μm and the recording area was heated to 150° C., and the Co-Cr thin film 13
The recorded bits were transferred to the second medium (Tb-Fe thin film) 12. The SN ratio of the reproduced signal of this recorded bit is 55 dB
Met. Next, a bit with a bit length of 15 μm is written in the same area using the magnetic head 16, and then heated with the light beam 15 to transfer the magnetic information. When this signal is reproduced, an S/N ratio of 45 dB is obtained. Ta.
即ち、本発明に依れば記録情報をＣｏ−Ｃｒ薄膜１３上
に連続して書き加えることが出来るので消去過程を経な
くても重ね書きができる。また、磁気ヘッド１６による
Ｃｏ−Ｃｒ薄膜１３上への書き込み過程は熱の拡散等、
低速のメカニズムを経ないので原理的には磁気記録と同
等の高速書き込み（数十Ｍ Ｈｚ ）を実現できる。一
方、磁気記録と比較した場合には、磁気転写過程と読み
だし過程に光ビームを用いているために、μｍオーダー
の狭トラツク記録とそのサーボが実現できるという長所
がある。書き込み用磁気ヘッドのトラックサーボは特に
必要ではなく広い幅のヘッドで書き込みが出来るという
利点もある。記録情報はガラス基板側から光を照射して
検出するため媒体上のごみや欠陥の影響が少ないという
長所もある。That is, according to the present invention, since recorded information can be continuously written on the Co--Cr thin film 13, overwriting can be performed without going through an erasing process. In addition, the process of writing onto the Co-Cr thin film 13 by the magnetic head 16 involves heat diffusion, etc.
Since it does not go through a low-speed mechanism, it is theoretically possible to achieve high-speed writing (several tens of MHz) equivalent to magnetic recording. On the other hand, when compared with magnetic recording, it has the advantage that narrow track recording on the order of .mu.m and its servo can be realized because a light beam is used in the magnetic transfer process and the read process. Track servo for the write magnetic head is not particularly necessary, and there is an advantage that writing can be performed with a wide head. Recorded information is detected by irradiating light from the glass substrate side, so it also has the advantage of being less affected by dust and defects on the medium.
なお、本実施例における第１及び第２媒体は各々高キュ
リー温度、及び低キユリ一温度高異方性磁場の垂直膜の
例であり、この他にも第１媒体としては垂直磁気記録用
媒体として検討されているバリウムフェライト膜、Ｇｏ
−Ｃｒ合金に種々の添加元素を加えた膜等が、第２媒体
としては光磁気記録用媒体であるＭｎ−Ｂ１合金膜、Ｙ
ＩＧ膜、ＣＯフェライト膜等が適用出来ると考えられる
。Note that the first and second media in this example are examples of perpendicular films with a high Curie temperature and a low Curie temperature and high anisotropy magnetic field, respectively, and the first medium may also include a perpendicular magnetic recording medium Barium ferrite film, Go
The second medium is a Mn-B1 alloy film, which is a magneto-optical recording medium, and a Y-Cr alloy film with various additive elements.
It is considered that IG film, CO ferrite film, etc. can be applied.
（発明の効果）
以上説明した如く、本発明によれば重ね書き可能な光磁
気記録媒体としてＣｏ−Ｃｒ合金等の垂直磁化薄膜上に
Ｔｂ−Ｆｅ薄膜のような磁気光学効果の大きい膜を積層
して形成し、磁気記録用ヘッドで情報をＣｏ−Ｃｒ薄膜
上に書き込み、レーザービームでＴｂ−Ｆｅ薄膜を加熱
し、Ｇｏ−Ｃｒ薄膜の磁化情報をＴｂ−Ｐｅ薄膜へ転写
するようにしたので、高速度の重ね書きが達成できる。(Effects of the Invention) As explained above, according to the present invention, a film with a large magneto-optic effect such as a Tb-Fe thin film is laminated on a perpendicularly magnetized thin film such as a Co-Cr alloy as an overwritable magneto-optical recording medium. The information was written on the Co--Cr thin film using a magnetic recording head, the Tb--Fe thin film was heated with a laser beam, and the magnetization information of the Go--Cr thin film was transferred to the Tb--Pe thin film. , high-speed overwriting can be achieved.
即ち、磁気記録用ヘッドの駆動周波数は数十ＭＨｚまで
充分に追従するので、従来、光ビームで記録していた書
き込みスピードの上限（数Ｍ Ｈｚ ）よりも格段の高
速が図れると同時に、Ｃｏ−Ｃｒ薄膜への書き込み時に
書き込みトラックをサーボしなくても良いという利点が
ある。光磁気記録用ディスクのトラック幅は１〜２μｍ
であり、−刃用用の磁気記録用ヘッドのトラックサーボ
誤差は１μｍ程度なので、単に、磁気記録用ヘッドを用
いて光磁気記録用媒体へ信号を書き込もうとした場合に
は、トラックサーボの問題は極めて重大な阻害要因とな
るが、本発明でこのような技術上の困難は無いという顕
著な効果がある。In other words, since the driving frequency of the magnetic recording head sufficiently follows up to several tens of MHz, it is possible to achieve a much higher writing speed than the upper limit (several MHz) of conventional recording using a light beam, and at the same time, it is possible to There is an advantage that there is no need to servo the write track when writing to the Cr thin film. The track width of magneto-optical recording disks is 1 to 2 μm.
The track servo error of the magnetic recording head for blades is about 1 μm, so if you simply try to write a signal to a magneto-optical recording medium using a magnetic recording head, the track servo problem will not be solved. However, the present invention has the remarkable effect of not having such technical difficulties.
第１図は本発明による光磁気ディスクへの書き込み方法
の説明図である。図中、１１は光磁気ディスク用基板、
１２は第２媒体（８０％Ｆｅ−２０％Ｔｂ薄膜）、１３
は第１媒体（８０％Ｃｏ−２０％Ｃｒ薄膜）、１４は光
ヘッド、１５は光ビーム、１６は磁気記録用ヘッドであ
る。FIG. 1 is an explanatory diagram of a method of writing to a magneto-optical disk according to the present invention. In the figure, 11 is a magneto-optical disk substrate;
12 is the second medium (80% Fe-20% Tb thin film), 13
1 is a first medium (80% Co-20% Cr thin film), 14 is an optical head, 15 is a light beam, and 16 is a magnetic recording head.
Claims (2)
この薄膜の異方性磁場よりも大きい異方性磁場を持ちし
かもキュリー温度は前記薄膜よりも低い垂直磁化薄膜（
第２媒体）との２層構造を有する光磁気記録媒体を使用
し、磁気記録用ヘッドを用いて磁化反転の列として情報
を第１媒体へ記録した後、該記録領域を光ビームで第２
媒体のキュリー温度以上に加熱し、第２媒体が冷却する
過程で第１媒体の磁化反転情報を第２媒体へ転写するこ
とを特徴とする光磁気記録媒体への書き込み方法。(1) A perpendicularly magnetized thin film (first medium) with a high Curie temperature and a perpendicularly magnetized thin film (first medium) which has an anisotropic magnetic field larger than that of this thin film and whose Curie temperature is lower than that of the thin film.
A magneto-optical recording medium having a two-layer structure with a second medium) is used, and after information is recorded on the first medium as an array of magnetization reversals using a magnetic recording head, the recording area is exposed to a second medium using a light beam.
A method for writing to a magneto-optical recording medium, which comprises heating the medium to a temperature higher than its Curie temperature, and transferring magnetization reversal information of a first medium to a second medium while the second medium cools.
た第２媒体としては希土類・遷移金属合金薄膜（希土類
元素はＴｂ、Ｇｄ、Ｎｄ、Ｄｙの内少なくとも１種類以
上、遷移金属としては、Ｆｅ、Ｃｏ、Ｎｉの内少なくと
も１種類以上を含む）を使用する事を特徴とする特許請
求の範囲第１項記載の光磁気記録媒体への書き込み方法
。(2) The first medium is a Co-Cr alloy thin film, and the second medium is a rare earth/transition metal alloy thin film (the rare earth element is at least one of Tb, Gd, Nd, and Dy, and the transition metal is at least one of Tb, Gd, Nd, and Dy). , Fe, Co, and Ni).
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62110864A JPH0814900B2 (en) | 1987-05-08 | 1987-05-08 | Writing method to magneto-optical recording medium |
| US07/188,876 US5051970A (en) | 1987-05-08 | 1988-05-02 | Magneto-optic recording system with overwrite capability |
| KR1019880005262A KR910003935B1 (en) | 1987-05-08 | 1988-05-06 | Magneto-opticla recording system |
| DE8888304128T DE3876133T2 (en) | 1987-05-08 | 1988-05-06 | DEVICE AND RECORD CARRIER FOR MAGNETO-OPTICAL RECORDING. |
| EP88304128A EP0291248B1 (en) | 1987-05-08 | 1988-05-06 | A magneto-optic medium and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62110864A JPH0814900B2 (en) | 1987-05-08 | 1987-05-08 | Writing method to magneto-optical recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63276731A true JPS63276731A (en) | 1988-11-15 |
| JPH0814900B2 JPH0814900B2 (en) | 1996-02-14 |
Family
ID=14546614
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62110864A Expired - Fee Related JPH0814900B2 (en) | 1987-05-08 | 1987-05-08 | Writing method to magneto-optical recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0814900B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6435745A (en) * | 1987-07-23 | 1989-02-06 | Kerdix Inc | Recording structure composed of magneto-optical recording layer and magnetic recording layer and apparatus and method for recording and reading data |
| JPH02177148A (en) * | 1988-12-28 | 1990-07-10 | Canon Inc | Information recording method and information recording and reproducing method |
| JPH02189751A (en) * | 1989-01-19 | 1990-07-25 | Canon Inc | Magneto-optical recorder |
| US5233578A (en) * | 1988-12-28 | 1993-08-03 | Canon Kabushiki Kaisha | Method of recording information on a recording medium having at least two magnetic layers |
| EP0478786B1 (en) * | 1990-03-24 | 1996-09-18 | Seiko Epson Corporation | Magnetooptic recording medium, and method of magnetooptic recording and reproduction |
| JP2002512725A (en) * | 1998-04-09 | 2002-04-23 | シーゲイト テクノロジー エルエルシー | Limitation of track width and radial control by laser assist in magnetic recording |
| US7274626B2 (en) | 2004-01-23 | 2007-09-25 | Hitachi, Ltd. | Magneto-optical recording using a heating element |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5850639A (en) * | 1981-09-18 | 1983-03-25 | Ricoh Co Ltd | Vertically magnetized recording medium |
| JPS5857645A (en) * | 1981-10-01 | 1983-04-05 | Akai Electric Co Ltd | Disk medium for vertical magnetic recording |
-
1987
- 1987-05-08 JP JP62110864A patent/JPH0814900B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5850639A (en) * | 1981-09-18 | 1983-03-25 | Ricoh Co Ltd | Vertically magnetized recording medium |
| JPS5857645A (en) * | 1981-10-01 | 1983-04-05 | Akai Electric Co Ltd | Disk medium for vertical magnetic recording |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6435745A (en) * | 1987-07-23 | 1989-02-06 | Kerdix Inc | Recording structure composed of magneto-optical recording layer and magnetic recording layer and apparatus and method for recording and reading data |
| JPH02177148A (en) * | 1988-12-28 | 1990-07-10 | Canon Inc | Information recording method and information recording and reproducing method |
| US5233578A (en) * | 1988-12-28 | 1993-08-03 | Canon Kabushiki Kaisha | Method of recording information on a recording medium having at least two magnetic layers |
| JPH02189751A (en) * | 1989-01-19 | 1990-07-25 | Canon Inc | Magneto-optical recorder |
| EP0478786B1 (en) * | 1990-03-24 | 1996-09-18 | Seiko Epson Corporation | Magnetooptic recording medium, and method of magnetooptic recording and reproduction |
| JP2002512725A (en) * | 1998-04-09 | 2002-04-23 | シーゲイト テクノロジー エルエルシー | Limitation of track width and radial control by laser assist in magnetic recording |
| US7274626B2 (en) | 2004-01-23 | 2007-09-25 | Hitachi, Ltd. | Magneto-optical recording using a heating element |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0814900B2 (en) | 1996-02-14 |
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| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |