JPS60160001A - Thin metallic film having its surface protected by carbide - Google Patents
Thin metallic film having its surface protected by carbideInfo
- Publication number
- JPS60160001A JPS60160001A JP1550684A JP1550684A JPS60160001A JP S60160001 A JPS60160001 A JP S60160001A JP 1550684 A JP1550684 A JP 1550684A JP 1550684 A JP1550684 A JP 1550684A JP S60160001 A JPS60160001 A JP S60160001A
- Authority
- JP
- Japan
- Prior art keywords
- laser beam
- erasing
- recording
- intensity
- magnetization
- 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
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
Landscapes
- Optical Elements Other Than Lenses (AREA)
- Recording Or Reproducing By Magnetic Means (AREA)
Abstract
Description
【発明の詳細な説明】
（発明の技術分野）
本発明は、磁％カー効果又は磁気ファラデー効果を利用
して記録再生される、元磁気記偉媒体に対して記録する
か又は記録を消去するための光磁気記録又は消去装置に
関するものであ・る。Detailed Description of the Invention (Technical Field of the Invention) The present invention relates to recording or erasing information on a former magnetic recording medium that is recorded and reproduced using the magnetic Kerr effect or the magnetic Faraday effect. This relates to magneto-optical recording or erasing devices.
（発明の背景）
近年の情報化社会の進展は目覚ましく、それに伴ない大
容量の記録媒体並びに記録再生方式の必要性が急速に高
まっており、既にレーザービデオディスク、デジタルオ
ーディオディスク等が実用化されている。しかしながら
、実用化された記録媒体は書換えが出来ない欠点があり
、゛書換え可能な記録媒体並びに記録再生方式が望まれ
ている。(Background of the Invention) In recent years, the information society has progressed at a remarkable pace, and the need for large-capacity recording media and recording/playback methods is rapidly increasing. Laser video discs, digital audio discs, etc. have already been put into practical use. ing. However, the recording media that have been put into practical use have the drawback of not being rewritable, and a rewritable recording medium and recording/reproducing system are desired.
そして、書換え可能な記録再生方式の１つとして光磁気
記録再生方式が提案されミ試作品も発表されている。こ
の光磁気記録再生方式というのは、例えばＧｄＣｏ、Ｇ
ｄＴｂＦｅのような磁性材料の垂直磁化膜を主体とする
光磁気記録媒体に強力な外部磁場を印加して、この垂直
磁化膜の磁化の向きを一旦上向きか下向きかのいずれか
に揃えておき、例えば断面半径１ミクロンのレーザービ
ームを照射して、局部的に垂直磁化膜を磁性材料のキー
リ一点：（Ｔｃ ）以上又はその近くに加熱し、加熱部
分の保磁力をゼロ又は極めて小さくし、同時に弱い反転
磁場を印加することにより磁化の向きを反転させ、そし
て今媒体は高速で移動させているのでレーザービームの
照射位置は刻々と移動し、その結果、長円：ロ＝コ状の
ビットが形成される。A magneto-optical recording and reproducing method has been proposed as one of the rewritable recording and reproducing methods, and a prototype has also been announced. This magneto-optical recording and reproducing method is, for example, GdCo, G
Applying a strong external magnetic field to a magneto-optical recording medium mainly consisting of a perpendicularly magnetized film made of a magnetic material such as dTbFe, and once aligning the direction of magnetization of this perpendicularly magnetized film either upward or downward, For example, by irradiating a laser beam with a cross-sectional radius of 1 micron, the perpendicularly magnetized film is locally heated to a temperature above or near one point (Tc) of the magnetic material, and the coercive force of the heated area is reduced to zero or extremely small, and at the same time By applying a weak reversal magnetic field, the direction of magnetization is reversed, and since the medium is now moving at high speed, the irradiation position of the laser beam moves every moment, and as a result, an elliptical (ro-co-shaped) bit is formed. It is formed.
ビットの長さは最低でも巾を１ミクロンとすれば２ミク
ロン位になる。The length of the bit is at least 2 microns, assuming a width of 1 micron.
そして、情報はこのビットの有無及びビットａの形で記
録される。Information is then recorded in the form of the presence or absence of this bit and bit a.
他方、記録された情報はビット部分の磁化の向きが膜の
それと反対に向いていることがら、直線偏光を照射する
と磁化の同さく上又は下）によって反射光又は透過光の
偏光面の回転状況が相違する現象（磁気カー効果又は磁
気ファラデー効果）を利用して再生される。On the other hand, since the direction of magnetization of the bit part of the recorded information is opposite to that of the film, when linearly polarized light is irradiated, the polarization plane of the reflected or transmitted light changes depending on whether the magnetization is above or below the same direction. are reproduced using different phenomena (magnetic Kerr effect or magnetic Faraday effect).
つまり、入射光に対して磁化の向きが上向きのとき、反
射光又は透過光の偏光面が入射光の偏光面に対してθに
度回転したとすると、入射光に対して磁化の向きが下向
きのと＠は一θに度回転する。In other words, when the direction of magnetization is upward with respect to the incident light, if the polarization plane of reflected or transmitted light is rotated by θ degrees with respect to the polarization plane of the incident light, then the direction of magnetization is downward with respect to the incident light. No and @ rotate by one θ degree.
従って、反射光又は透過光の先に偏光子（アナライザー
とも呼ばれる）の主軸を−１１に度面にほぼ直焚するよ
うに置いておくと、下向き磁化の部分からの光はアナラ
イザーをほとんど透過せず、上向きの磁化の部分からの
元はｓｉｎ ２σＫを乗じた分だけ透過するので、アナ
ライザーの先にディテクター（光電変換素子）を設置し
ておけば、記録媒体を高速でスキャンニングして行くと
、記録されたビットの有無及びビット長に応じて電流の
強弱信号として再生されることになる。Therefore, if a polarizer (also called an analyzer) is placed in front of the reflected or transmitted light so that its main axis is set at -11 degrees, the light from the downwardly magnetized part will hardly pass through the analyzer. First, the source from the upwardly magnetized part will be transmitted by the amount multiplied by sin 2σK, so if you install a detector (photoelectric conversion element) at the end of the analyzer, you can scan the recording medium at high speed. , and is reproduced as a current strength signal depending on the presence or absence of recorded bits and the bit length.
そして、記録を消去するには、記録さ九たビットに対し
て記録時と同じようにレーザービームを照射して加熱し
、それにより保磁力をゼロ又は極めて低い値とし、同時
に反転磁場を印加することにより、そのビットの磁化の
向きを元に戻し、その上でレーザービームの照射を止め
て、元の磁化の向きに固定する。これにより、記録され
たビットは消去され、その結果記録が消去され、媒体は
記轡前の状態に戻る。従って、再記録が可能になるので
、上述の如く記録を行なえば書換えが完了する。To erase the record, the nine recorded bits are heated with a laser beam in the same way as during recording, thereby reducing the coercive force to zero or an extremely low value, and at the same time applying a reversal magnetic field. By doing so, the magnetization direction of the bit is returned to its original direction, and then the laser beam irradiation is stopped to fix the magnetization direction to the original direction. This erases the recorded bits, thereby erasing the recording and returning the medium to its pre-recording state. Therefore, since re-recording becomes possible, rewriting is completed by performing recording as described above.
ところで従来の光磁気記録又は消去装置は、レーザービ
ームを同一強度レベルでビット長に応じて成る時間照射
してビットを形成するので、レーザービームの強度レベ
ルの変化と形成されるビット形状との関係を示すと、第
１図（１）、（２）に示す如くなる。By the way, in conventional magneto-optical recording or erasing devices, bits are formed by irradiating a laser beam at the same intensity level for a period of time depending on the bit length, so the relationship between changes in the intensity level of the laser beam and the shape of the formed bit is When shown, it becomes as shown in FIG. 1 (1) and (2).
他方、θにの大きい磁性材料例えばＴｂＦｅＣｏ、Ｄ７
ＦｅＣＯ１’Ｇ’ｄＴｂＦ’ｅＣＯなどはキュリ一点（
Ｔｅ）が高く、そのため記録及び消去のときに高強度の
レーサービームを必要としている。On the other hand, magnetic materials with large θ such as TbFeCo, D7
For FeCO1'G'dTbF'eCO, etc., one cucumber (
Te) is high, so a high-intensity laser beam is required for recording and erasing.
しかしながら上述の＃Ｋが太き（Ｔｃの昼い磁性材料は
結晶化温度がＴｃより高いものの比較的接近しており、
そのため加熱され過ぎると、垂直磁化を示す非晶質状態
から垂直磁化を示さない結晶状態へと転相する傾向が出
てくる。そのため、記録又は消去したつもりでも、完全
に反転した磁化は “１００％ではなくなり、Ｓ／Ｎ比
又は消去精度が低下する欠点があった。However, the above-mentioned #K is thick (the daytime magnetic material of Tc has a crystallization temperature higher than Tc, but it is relatively close to
Therefore, when heated too much, there is a tendency for the phase to change from an amorphous state exhibiting perpendicular magnetization to a crystalline state exhibiting no perpendicular magnetization. Therefore, even when recording or erasing is intended, the completely reversed magnetization is no longer 100%, which has the drawback of lowering the S/N ratio or erasing accuracy.
（発明の目的）
従って、本発明の目的は、上述の如き欠点を解決し、Ｔ
ｃの高い磁性材料を用いた記録媒体であっても、記録及
び消去時に非晶質磁性材料の結晶化の危険を減少させる
光磁気記録又は消去装置を提供することにある。(Object of the invention) Therefore, the object of the present invention is to solve the above-mentioned drawbacks and to
An object of the present invention is to provide a magneto-optical recording or erasing device that reduces the risk of crystallization of an amorphous magnetic material during recording and erasing even in a recording medium using a magnetic material with a high c.
（発明の概要）
本発明者は鋭意研究の結果、偶然にも、当初加熱してそ
の微少部分の磁化の反転に成功したならば、その後はレ
ーザービームの強度を弱めても（つまり、余り加熱せす
とも）反転が将棋倒しのように継続し、そのため形成さ
れるビット部分の結晶化の危険が軽減されることを見い
出し、本発明を成すに至′−）声。(Summary of the Invention) As a result of intensive research, the inventor of the present invention discovered that, by chance, if the magnetization of a minute portion was successfully reversed by heating initially, then even if the intensity of the laser beam was weakened (in other words, if the laser beam was not heated too much) The inventors discovered that the reversal continues like a chess game, thereby reducing the risk of crystallization of the formed bit part, and thus achieved the present invention'-) Voice.
何故、磁化の反転に成功したならば、その後はレーザー
ビームの強度を弱めてもよいのが、その原因を十分に解
明していないが、おそらく、反転した磁気モーメントか
らの交換相互作用が外部磁場と共に隣接の未反転磁気モ
ーメントに作用するので、温度が十分に高くなく保磁力
が相当に残っている状態でも反転するものと本発明者は
考えている。The reason why the intensity of the laser beam can be weakened after the magnetization is successfully reversed is not fully understood, but it is likely that the exchange interaction from the reversed magnetic moment is caused by the external magnetic field. The present inventor believes that since the magnetic flux acts on the adjacent unreversed magnetic moment, the reversal occurs even when the temperature is not high enough and a considerable amount of coercive force remains.
従って、本発明は、光磁気記録又は消去装置に於いて、
レーザービームの強度を磁化の反転が開始されたならば
その後は下げて磁化の反転を継続させることにより必要
なピットを形成又は消去することを特徴とする光磁気記
録又は消去装置ｆ：提供する。Therefore, the present invention provides a magneto-optical recording or erasing device that:
Magneto-optical recording or erasing device f: Provided is a magneto-optical recording or erasing device, characterized in that the intensity of the laser beam is lowered after the start of magnetization reversal to continue magnetization reversal to form or erase necessary pits.
以下、実施例により本発明を説明するが、本発叩はこれ
らの実施例に限定される訳ではない。The present invention will be explained below with reference to examples, but the present invention is not limited to these examples.
（実施例１）
第２′図は＝、本１実施・例の光磁気記録又は消去装置
の全体的な構成を示す概略図である。図中ｆｌ）は光源
の駆動回路、（２）はレーザーダイオード光源、（３）
ハコリメーターレンズ、（４）はビームスプリンター、
（５）は対物レンズ、（６）はディスク状の記録媒体（
Ｄｉｓｋ）ｋ回転させるためのスピンドルモーター、（
７）は集光レンズ、（８）はアナライザー、（９）はデ
ィテクターである。記録及び消去のためだけならば（７
）、（８）、（９）は不用であるが、多くの場合再生も
同じ装置で兼用させるので、ここでは再生兼用型の装置
で説明する。（Ｄｉｓｋ）は本発明の構成要件には含ま
れないディスク状の記録媒体である。(Embodiment 1) Figure 2' is a schematic diagram showing the overall configuration of a magneto-optical recording or erasing device according to the first embodiment. In the figure, fl) is a light source drive circuit, (2) is a laser diode light source, and (3)
Ha collimator lens, (4) is a beam splinter,
(5) is an objective lens, (6) is a disk-shaped recording medium (
Spindle motor for rotating Disk)k, (
7) is a condenser lens, (8) is an analyzer, and (9) is a detector. If it is only for recording and erasing (7
), (8), and (9) are unnecessary, but since in many cases the same device is used for both reproduction and reproduction, an explanation will be given here using a device that can also be used for reproduction. (Disk) is a disk-shaped recording medium that is not included in the constituent elements of the present invention.
第３図は第２図に示す駆動回路（１）の更に詳しい内容
を示すブロック図でるり、図中に示す記号（カ）社レー
ザーダイオード光源（２）を表わす。FIG. 3 is a block diagram showing more detailed contents of the drive circuit (1) shown in FIG. 2, and represents a laser diode light source (2) shown in the figure.
本実施例の装置を用い、ＧｄＴｂＦｅＣｏ系垂直磁化膜
を記録層とすゐ光磁気記録媒体（ディスク状）を等連線
速度１３．２ｍ席で回転させながら、この媒体にレーザ
ービームを照射しながら、３０００ｅの外部磁場を印加
して、今０１０】０１・・・の情報を記録した。Using the apparatus of this example, a magneto-optical recording medium (disc-shaped) with a GdTbFeCo perpendicularly magnetized film as a recording layer was rotated at a continuous linear velocity of 13.2 m while irradiating the medium with a laser beam. , 3000e of external magnetic field was applied, and the information 010]01... was recorded.
そのため、レーザービームの強度を第４図ｆｉ＋の如く
変化させた。第４図（１）に於いて、記録時レーザービ
ーム初期強＃：Ｐｗ ＝ １５．６ ｍＷ、記録時に低
下させたレーザービーム強度ＰＬ ＝ ８．３ ｍＷ、
記録時パルス巾ｔｗ −；、、５ Ｘ １０−’秒、非
記録時パルス間隔日＝ ５ Ｘ １０−’ 秒、記録時
の初期レーザービーム強度照射時間ｔｐ ＝２ Ｘ ３
０−’秒である。Therefore, the intensity of the laser beam was changed as shown in FIG. 4 fi+. In FIG. 4 (1), the initial laser beam intensity during recording #: Pw = 15.6 mW, the reduced laser beam intensity during recording PL = 8.3 mW,
Pulse width during recording tw -;, 5 x 10-' seconds, pulse interval day during non-recording = 5 x 10-' seconds, initial laser beam intensity irradiation time during recording tp = 2 x 3
0-' seconds.
（実施例２）
装装置の構成は実施例】（第２図）とほぼ同じであるが
、ここでは（Ｄｉ’ｆｋＡ）からの反射光を集光レンズ
（７）で集めてディテクター（９）で受光して、変換さ
れる電気信号をフォーカシング及びトラッキング用の信
号として利用する例について説明する。(Example 2) The configuration of the mounting device is almost the same as in Example (Figure 2), but here the reflected light from (Di'fkA) is collected by a condenser lens (7) and sent to a detector (9). An example will be described in which the electrical signals received and converted are used as signals for focusing and tracking.
フォーカシング及びトラッキング用の信号は、トラッキ
ング中原則として常時必要であり、そのためビットの記
録時又は消去時以外もレーザービームを照射する必要が
おる。しかしながら、レーザービームの強度は記録又は
消去に必要なほどに。Focusing and tracking signals are, in principle, always required during tracking, and therefore it is necessary to irradiate a laser beam even when recording or erasing bits. However, the intensity of the laser beam is high enough for recording or erasing.
高くする必要はない。There's no need to make it expensive.
従って、ここではレーザービームの強度を第５図の如く
変化させ、ビットの形成を行なうと同時に形成時以外も
低強度（ＰＤＣ）のビームを照射し続け、その反射光を
フォーカシング及びトラッキング用信号として利用する
。Therefore, here, the intensity of the laser beam is changed as shown in Figure 5, and at the same time as the bit is formed, a low intensity (PDC) beam is continued to be irradiated even when not forming the bit, and the reflected light is used as a focusing and tracking signal. Make use of it.
一方、消去装置は原理的には反転させる外部磁場の方向
が異なるだけで記録装置と同じであるが、ある一定範囲
内の記録を消去しようとする場合、形成されたピッ゛ト
だけを拾って消去するのは面倒なので、その範囲内では
ピットの有無にかかわらず、第６図（１）に示すように
レーザービームを−１−ｒ消去強度Ｐｇレベルで照射し
た後、反転が開始されたならば、本発明に従いＰＬレベ
ルに下けて照射し続は反転を継続させて行き、消去を完
了させる。この場合、ＰＬレベルで照射し続けたとき、
反転が継続するか否か信頼性に欠けるときには、第６図
（２）に示すように時々レーザーの照射強度を元の消去
強度ＰＫレベルまで戻してもよい。On the other hand, an erasing device is in principle the same as a recording device, except that the direction of the external magnetic field is reversed, but when attempting to erase records within a certain range, it picks up only the formed pits. Since it is troublesome to erase, within that range, regardless of the presence or absence of pits, after irradiating the laser beam with the -1-r erasing intensity Pg level as shown in Figure 6 (1), if the reversal starts. For example, according to the present invention, the irradiation is performed at a lower level than the PL level, and then the inversion is continued to complete erasing. In this case, when continuing to irradiate at the PL level,
If it is not reliable whether the reversal continues or not, the laser irradiation intensity may be returned to the original erase intensity PK level from time to time as shown in FIG. 6(2).
（発明の効果）
本発明によれば、記録（ピット形成）時に高強度（Ｐｗ
）のレーザービームに媒体がさらされる時間が短かくな
るので、それだけ媒体の非晶買嵩直磁化膜が結晶化する
危険が減少し、その結果再生の際のＳ／Ｎ比の低下が避
けられ、また媒体の記録・消去の繰り返しによる媒体寿
命の短縮が避けられる。(Effects of the Invention) According to the present invention, high strength (Pw
) The time the medium is exposed to the laser beam is shortened, so the risk of crystallization of the amorphous directly magnetized film of the medium is reduced, and as a result, a decrease in the S/N ratio during playback can be avoided. Furthermore, shortening of the life of the medium due to repeated recording and erasing of the medium can be avoided.
そのほか、本発明によれば記録又は消去時に必要な高い
レーザービーム強度は短時間でよいので、安価な低パワ
ーの半導体レーザー光源（一時的ならば高強度のビーム
を出せるので）を使用でき、従って装置が安価に作製で
きる。In addition, according to the present invention, the high laser beam intensity required for recording or erasing is required for a short time, so an inexpensive low-power semiconductor laser light source (which can emit a high-intensity beam temporarily) can be used. The device can be manufactured at low cost.
第１図（１）は、レーザービームの照射強度の変化を示
すグラフであり、同（２）はレーザービームの照射によ
って記録媒体上に形成されるビットの平面図でおる。（
従来例）。
第２図は、本発明の実施例１にかかる光磁気記録又は消
去装置の全体的構成を示す概略図でめる。
第３歯は、第２図中の駆動回路（１）の更に詳しい内容
を示すブロック図である。
第４図（１）は、実施例１の装置でのレーザービームの
照射強度の変化を示すグラフであり、同（２）は照射に
よって記録媒体上に形成されるピットの平面図であり、
同（３）は対応する０、１情報を示す数列である。
第５図（１）は、実施例２の装置でのレーザービームの
照射強度の変化を示すグラフであり、同（２）は面図で
あり、同（３）は対応する０、１ 情報を示す数列であ
る。
第６図（１）、（２）は消去時のレーザービームの照射
強度の経時変化を示すグラフである。
出願人 日本光学工業株式会社
代理人 渡 辺 隆 男FIG. 1 (1) is a graph showing changes in laser beam irradiation intensity, and FIG. 1 (2) is a plan view of a bit formed on a recording medium by laser beam irradiation. (
conventional example). FIG. 2 is a schematic diagram showing the overall configuration of a magneto-optical recording or erasing device according to Embodiment 1 of the present invention. The third tooth is a block diagram showing more detailed contents of the drive circuit (1) in FIG. 2. FIG. 4 (1) is a graph showing changes in the irradiation intensity of the laser beam in the apparatus of Example 1, and FIG. 4 (2) is a plan view of pits formed on the recording medium by the irradiation.
(3) is a sequence of numbers indicating corresponding 0 and 1 information. FIG. 5 (1) is a graph showing changes in the irradiation intensity of the laser beam in the apparatus of Example 2, FIG. 5 (2) is a top view, and FIG. This is the sequence of numbers shown. FIGS. 6(1) and 6(2) are graphs showing changes over time in the irradiation intensity of the laser beam during erasing. Applicant: Nippon Kogaku Kogyo Co., Ltd. Agent: Takashi Watanabe
Claims (1)
該媒体を局部的に加熱して、加熱部分の保磁力を低下さ
せ、同時に反転磁場を印加して、加熱部分の磁化の向き
を反転させることによりピッ）１−形成又は消去する光
磁気記録又は消去装置に於いて、該レーザービームの強
度を磁化の反転が開始されたならば、その後は下げて磁
化の反転を継続させることによりビットを形成又は消去
することを特徴とする光磁気記録又は消去装置。 ２ 前記レーザーピームラ、フォーカシング又はトラッ
キング信号を得るために、記録又は消去時以外にも低強
度で、前記媒体に照射し続けることを特徴とする特許請
求の範囲第１項記載の光磁気記録又は消去装置。[Claims] 1. A magneto-optical recording medium is irradiated with a laser beam to locally heat the medium to lower the coercive force of the heated portion, and at the same time a reversal magnetic field is applied to increase the coercive force of the heated portion. 1) In a magneto-optical recording or erasing device that performs recording or erasing by reversing the direction of magnetization, once the intensity of the laser beam has started to be reversed, the intensity of the laser beam is then lowered to prevent reversal of magnetization. A magneto-optical recording or erasing device characterized by forming or erasing bits by continuous operation. 2. The magneto-optical recording according to claim 1, characterized in that the medium is continuously irradiated with low intensity even during recording or erasing in order to obtain the laser beam unevenness, focusing, or tracking signal. erasing device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1550684A JPS60160001A (en) | 1984-01-31 | 1984-01-31 | Thin metallic film having its surface protected by carbide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1550684A JPS60160001A (en) | 1984-01-31 | 1984-01-31 | Thin metallic film having its surface protected by carbide |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4097790A Division JPH0743848B2 (en) | 1992-04-17 | 1992-04-17 | Recordable optical disc |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60160001A true JPS60160001A (en) | 1985-08-21 |
| JPH0565583B2 JPH0565583B2 (en) | 1993-09-20 |
Family
ID=11890687
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1550684A Granted JPS60160001A (en) | 1984-01-31 | 1984-01-31 | Thin metallic film having its surface protected by carbide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60160001A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01119942A (en) * | 1987-11-02 | 1989-05-12 | Fujitsu Ltd | Magneto-optical recording method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS495836A (en) * | 1973-03-20 | 1974-01-19 | ||
| JPS4920081A (en) * | 1972-04-15 | 1974-02-22 | ||
| JPS5466384A (en) * | 1977-11-08 | 1979-05-28 | Seiko Epson Corp | Outer parts for pocket watch |
| JPS54139891A (en) * | 1978-04-24 | 1979-10-30 | Nagaoka Kk | Specific work metal material and its manufacturing method |
| JPS5722998A (en) * | 1980-07-14 | 1982-02-06 | Kaiken:Kk | Remote controller of bowthruster and method of automatically steering ship to fixed direction |
| JPS5779171A (en) * | 1980-09-09 | 1982-05-18 | Westinghouse Electric Corp | Product equipped with protective coating and production thereof |
-
1984
- 1984-01-31 JP JP1550684A patent/JPS60160001A/en active Granted
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4920081A (en) * | 1972-04-15 | 1974-02-22 | ||
| JPS495836A (en) * | 1973-03-20 | 1974-01-19 | ||
| JPS5466384A (en) * | 1977-11-08 | 1979-05-28 | Seiko Epson Corp | Outer parts for pocket watch |
| JPS54139891A (en) * | 1978-04-24 | 1979-10-30 | Nagaoka Kk | Specific work metal material and its manufacturing method |
| JPS5722998A (en) * | 1980-07-14 | 1982-02-06 | Kaiken:Kk | Remote controller of bowthruster and method of automatically steering ship to fixed direction |
| JPS5779171A (en) * | 1980-09-09 | 1982-05-18 | Westinghouse Electric Corp | Product equipped with protective coating and production thereof |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01119942A (en) * | 1987-11-02 | 1989-05-12 | Fujitsu Ltd | Magneto-optical recording method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0565583B2 (en) | 1993-09-20 |
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