JPH0756709B2 - Magneto-optical storage device - Google Patents
Magneto-optical storage deviceInfo
- Publication number
- JPH0756709B2 JPH0756709B2 JP56173976A JP17397681A JPH0756709B2 JP H0756709 B2 JPH0756709 B2 JP H0756709B2 JP 56173976 A JP56173976 A JP 56173976A JP 17397681 A JP17397681 A JP 17397681A JP H0756709 B2 JPH0756709 B2 JP H0756709B2
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- laser beam
- magneto
- beam splitter
- analyzer
- 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.)
- Expired - Lifetime
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/21—Intermediate information storage
- H04N1/2166—Intermediate information storage for mass storage, e.g. in document filing systems
- H04N1/2195—Intermediate information storage for mass storage, e.g. in document filing systems with temporary storage before final recording or on play-back, e.g. in a frame buffer
-
- 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
- G11B11/10532—Heads
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N2201/00—Indexing scheme relating to scanning, transmission or reproduction of documents or the like, and to details thereof
- H04N2201/0077—Types of the still picture apparatus
- H04N2201/0084—Digital still camera
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N2201/00—Indexing scheme relating to scanning, transmission or reproduction of documents or the like, and to details thereof
- H04N2201/0077—Types of the still picture apparatus
- H04N2201/0089—Image display device
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
Description
【発明の詳細な説明】 本発明は、膜面に垂直な方向に磁化容易軸をもつ磁気記
録媒体にレーザビーム等の光ビームを照射して部分的に
記録媒体を昇温させ、照射部分での保磁力を減少させる
ことによって、該領域に作用する磁界の方向に対応して
磁区を配列させて情報の記録と消去を行い、一方磁気光
学効果により記録情報の再生を行う光磁気記憶装置に関
する。The present invention irradiates a magnetic recording medium having an easy axis of magnetization in a direction perpendicular to a film surface with a light beam such as a laser beam to partially raise the temperature of the recording medium and A magneto-optical storage device for recording and erasing information by arranging magnetic domains corresponding to the direction of a magnetic field acting on the area by reducing the coercive force of the magnetic field and reproducing the recorded information by the magneto-optical effect. .
近年、光記憶装置は高密度化、大容量化、及び高速アク
セス化が可能なメモリ装置として広く研究されており、
このうち記憶ディスクに微細ピット列を形成し、該ピッ
ト部における光ビームの回折現象を利用して再生する装
置、及び記憶媒体の反射率変化を利用して再生する装置
について一部実用化の域に達している。しかしながら上
記装置は再生専用あるいは情報の追加記録が可能である
という機能をもつに留まっており、メモリ装置の一大特
徴である情報の消去機能をも有する光記憶装置について
は未だ研究開発段階にある。In recent years, optical storage devices have been widely studied as memory devices capable of high density, large capacity, and high speed access.
Of these, a device in which a fine pit row is formed on a storage disk and is reproduced by utilizing a diffraction phenomenon of a light beam in the pit portion, and a device which is reproduced by utilizing a change in reflectance of a storage medium are partially put into practical use. Has reached. However, the above-mentioned device has only the function of being read-only or capable of additionally recording information, and the optical storage device having the information erasing function, which is one of the major features of the memory device, is still in the research and development stage. .
本発明は情報の記録・再生・消去が可能な光磁気記憶装
置に関するものであり、次にこの光磁気記憶装置の問題
点について説明する。The present invention relates to a magneto-optical storage device capable of recording / reproducing / erasing information. Next, problems of this magneto-optical storage device will be described.
光磁気記憶装置の基本構成を第２図に示す。１は記録及
び再生に必要な所定の光エネルギーを射出できるレーザ
光源、２は所定の偏光ビームを透過する偏光子、３は反
射光を検出器側に導くための、２個のプリズムを斜面に
おいて組み合わせたビームスプリッタ、４はレーザ光源
１より射出されたレーザビームを記憶媒体５上に集光す
る絞りレンズ、６は基板、７は反射情報光を偏光面につ
いて検波し情報信号を得るための検光子、８は光検出器
である。The basic configuration of the magneto-optical storage device is shown in FIG. Reference numeral 1 is a laser light source capable of emitting predetermined light energy required for recording and reproduction, 2 is a polarizer for transmitting a predetermined polarized beam, and 3 is a prism having two prisms for guiding reflected light to a detector side. A combined beam splitter, 4 is a diaphragm lens for condensing the laser beam emitted from the laser light source 1 on the storage medium 5, 6 is a substrate, and 7 is a detector for detecting reflected information light on a polarization plane to obtain an information signal. Photons, 8 are photodetectors.
上記の基本構成をもつ光磁気記憶装置を用いて行う情報
の記録・再生は公知の手法により容易に達成できるもの
の、装置の小型化を計る上でレーザ光源１は小出力のレ
ーザ装置、例えば半導体レーザを使わざるを得ない。従
って記憶媒体５には記録感度の低いMnBi、MnBiAl、MnBi
Cu等の結晶性磁性材料よりも記録感度の高いGd、Tb、D
y、Sm等の希土類金属とFe、Co、Ni等の遷移金属とを組
み合わせて生成されるTbDyFe、GdTbFe、GdDyFe、TbFe等
の非晶質磁性体が利用されることになる。しかしながら
上記非晶質磁性材料による磁気光学効果は前記結晶性磁
性材料に比べて弱く、いわゆるカー回転角は0.1゜〜0.2
゜に留り、再生信号のS/Nが低く、さらに前記検光子７
の方位角設定が困難であった。そのため第３図に示すよ
うな記憶素子構造の改善により、光学的に反射光のカー
回転角を増大させる手法によりカー回転角の増大を計る
努力がなされている。第３図において９はガラスあるい
はアクリル樹脂等により作製される基板、10はAl、Au、
Cu等の金属薄膜にてなる反射膜、11は希土類・遷移金属
の非晶質磁性材料の薄膜、12はSiO2、SiO等の透明誘電
体にてなる薄膜であり、いずれも蒸着法、スパッタ法等
により順に積層されている。それぞれの薄膜の厚みは薄
膜の干渉効果によりカー回転角が増大するよう適宜設定
されている。Although recording / reproducing of information performed by using the magneto-optical storage device having the above-mentioned basic structure can be easily achieved by a known method, the laser light source 1 is a low-power laser device such as a semiconductor in order to downsize the device. I have no choice but to use a laser. Therefore, the storage medium 5 has MnBi, MnBiAl, and MnBi with low recording sensitivity.
Higher recording sensitivity than crystalline magnetic materials such as Cu Gd, Tb, D
Amorphous magnetic materials such as TbDyFe, GdTbFe, GdDyFe, and TbFe produced by combining rare earth metals such as y and Sm and transition metals such as Fe, Co, and Ni will be used. However, the magneto-optical effect of the amorphous magnetic material is weaker than that of the crystalline magnetic material, and the so-called Kerr rotation angle is 0.1 ° to 0.2.
The S / N of the reproduced signal is low, and the analyzer 7
It was difficult to set the azimuth angle. Therefore, efforts have been made to increase the Kerr rotation angle by a method of optically increasing the Kerr rotation angle of reflected light by improving the memory element structure as shown in FIG. In FIG. 3, 9 is a substrate made of glass or acrylic resin, 10 is Al, Au,
A reflective film made of a metal thin film such as Cu, 11 is a thin film of an amorphous magnetic material of a rare earth / transition metal, and 12 is a thin film made of a transparent dielectric material such as SiO 2 or SiO. It is laminated in order by a method or the like. The thickness of each thin film is appropriately set so that the Kerr rotation angle increases due to the interference effect of the thin films.
本発明は上記現状に鑑み、光磁気記憶装置に不可欠なビ
ームスプリッタの偏光特性を利用し、さらに磁気光学効
果を強調して再生信号のS/N向上並びに検波用検光子の
方位設定を容易にすべくなされたものである。In view of the above-mentioned present situation, the present invention utilizes the polarization characteristics of a beam splitter which is indispensable for a magneto-optical storage device, and further enhances the magneto-optical effect to improve the S / N of a reproduced signal and easily set the orientation of a detection analyzer. It was done to do so.
以下に本発明に係わる光磁気記憶装置の構成を説明す
る。The configuration of the magneto-optical storage device according to the present invention will be described below.
第１図は本発明に係る光磁気記憶装置の基本構成を示す
説明図である。尚、第２図に記載の光学素子と同一のも
のについては同一の符号を記した。また、本発明による
効果は再生の場合に特に有効であるので再生手法をもっ
て説明する。FIG. 1 is an explanatory diagram showing the basic configuration of a magneto-optical storage device according to the present invention. The same elements as those of the optical element shown in FIG. 2 are designated by the same reference numerals. Further, the effect of the present invention is particularly effective in the case of reproduction, so that a reproduction method will be described.
半導体レーザ13よい射出されたレーザビームは集光レン
ズ14によりコリメートされて所定の方位に設定された偏
光子２を通って図中の矢印にて示したように紙面内で矢
印の方向に振動する直線偏光ビーム（Ｐ波）となる。該
直線偏光ビームはRS＞RP（RS:S波エネルギー反射率、
RP:P波エネルギー反射率）の偏光特性を効果的にもつよ
うに、２個のプリズムを斜面において組み合わせそのプ
リズム斜面に誘電体薄膜が多層コートされたビームスプ
リッタ15を通過する。前述した様に入射偏光はＰ波であ
るので偏光状態は保存されて透過エネルギーのみTP倍と
なる（TP:ビームスプリッタ15のＰ波エネルギー透過
率）。次に該偏光レーザビームは絞りレンズ４により既
に磁気記録された第３図に示す構成の記憶媒体５上をス
ポット状に照射する。そして、上記照射点に当った偏光
レーザビームは当該照射点の磁化状態に応じて、いわゆ
るカー効果で知られる磁気光学効果を受けて増大したカ
ー回転角αだけ回転した偏光レーザビームとなって反射
される。即ち第４図に示すように入射偏光Ｐに対して記
録されて磁化反転を受けた領域では−α、それ以外の初
期磁区のままの領域では＋αだけ偏光面が回転した反射
レーザビームQ1とQ2が得られることになる。再び該反射
レーザビームはビームスプリッタ15に入射するのが前述
の偏光特性の効果により光検出器側に反射されるレーザ
ビームはR1、R2となり、その偏光面回転角βはαより増
大されることになる。この場合、第４図に示されている
ように、ビームスプリッタ15のＰ波振幅反射率 はほぼ半分（0.5）であり、Ｓ波反射率 は１に近いというようにされている。従ってその透過軸
が第４図においてＴとなる様に検光子７を設定すること
により、集光レンズ16を介して検出器８には前記記録領
域がパルス状に配列した部分を走査した場合、第５図の
様にパルス状情報信号が得られる。但し、実際には反射
レーザビームQ1,Q2は記録媒体５の光磁気特性による偏
光解消並びにビームスプリッタ15において反射されるＳ
波とＰ波の間に一般に位相差が生じるため検光子７に到
達する偏光は若干の楕円偏光となるため、その信号出力
は第６図の様になる。The laser beam emitted from the semiconductor laser 13 is collimated by the condenser lens 14, passes through the polarizer 2 set in a predetermined direction, and oscillates in the direction of the arrow in the plane of the paper as shown by the arrow in the figure. It becomes a linearly polarized beam (P wave). The linearly polarized beam is R S > R P (R S : S wave energy reflectance,
R P: the polarization characteristics of the P-wave energy reflectance) as effectively with a dielectric thin film of two prisms in combination thereof prism slopes in the slope passes a beam splitter 15 which is multi-layer coated. As described above, since the incident polarized light is P-wave, the polarization state is preserved and only the transmitted energy becomes T P times (T P : P-wave energy transmittance of the beam splitter 15). Next, the polarized laser beam is applied in spots on the storage medium 5 having the structure shown in FIG. Then, the polarized laser beam that hits the irradiation point is reflected as a polarized laser beam that is rotated by the Kerr rotation angle α increased by receiving the magneto-optical effect known as the so-called Kerr effect according to the magnetization state of the irradiation point. To be done. That is, as shown in FIG. 4, the reflected laser beam Q 1 whose polarization plane is rotated by −α in the region recorded with respect to the incident polarized light P and subjected to the magnetization reversal and in the region other than the initial magnetic domain remains + α. Q 2 will be obtained. The reflected laser beam enters the beam splitter 15 again, and the laser beam reflected to the photodetector side is R 1 and R 2 due to the effect of the above-mentioned polarization characteristic, and the polarization plane rotation angle β is increased from α. Will be. In this case, as shown in FIG. 4, the P-wave amplitude reflectance of the beam splitter 15 is Is almost half (0.5), and S wave reflectance Is said to be close to 1. Therefore, when the analyzer 7 is set so that its transmission axis is T in FIG. 4, when the detector 8 scans the portion where the recording areas are arranged in a pulse pattern through the condenser lens 16, A pulse-shaped information signal is obtained as shown in FIG. However, in reality, the reflected laser beams Q 1 and Q 2 are depolarized by the magneto-optical characteristics of the recording medium 5 and reflected by the beam splitter 15 by S.
Since a phase difference generally occurs between the P wave and the P wave, the polarized light reaching the analyzer 7 becomes a little elliptically polarized light, and the signal output is as shown in FIG.
以上説明した様に、プリズム斜面に誘電体薄膜を多層コ
ートしたビームスプリッタ15の反射偏光特性を前述の様
に設定すると、カー回転角を効果的に増大させることが
できるため、検光子７の設定が容易にる。さらに磁気光
学再生においては （P:検光子に到達する光エネルギー、θK:カー回転角）
の関係があるため、 が増大されるようにビームスプリッタのＰ波エネルギー
反射率RP、Ｓ波エネルギー反射率RSを設定した場合には
S/Nの向上も計れることになる。As described above, when the reflective polarization characteristics of the beam splitter 15 in which the dielectric thin film is multilayer-coated on the prism slopes are set as described above, the Kerr rotation angle can be effectively increased, so that the analyzer 7 is set. Is easy. Furthermore, in magneto-optical reproduction (P: Light energy reaching the analyzer, θ K : Kerr rotation angle)
Because of the relationship If the P-wave energy reflectance R P and the S-wave energy reflectance R S of the beam splitter are set so that
S / N can also be improved.
第１図は本発明に係る光磁気記憶装置の基本構成を示す
図、第２図は従来の光磁気記憶装置の基本構成を示す
図、第３図は記憶素子の構成を示す側面図、第４図は本
発明に係る光磁気記憶装置における再生原理を示す説明
図、第５図，第６図は磁気光学効果による情報の再生信
号の一例を示す波形図である。 １……レーザ光源、２……偏光子、３……ビームスプリ
ッタ、４……絞りレンズ、５……記憶媒体、６、９……
基板、７……検光子、８……光検出器、10……反射膜、
11……希土類・遷移金属の非晶質磁性材料の薄膜、12…
…誘電体薄膜、13……半導体レーザ、14……集光レン
ズ、15……ビームスプリッタ、16……集光レンズ。1 is a diagram showing a basic configuration of a magneto-optical storage device according to the present invention, FIG. 2 is a diagram showing a basic configuration of a conventional magneto-optical storage device, FIG. 3 is a side view showing a configuration of a storage element, FIG. FIG. 4 is an explanatory diagram showing a reproducing principle in the magneto-optical storage device according to the present invention, and FIGS. 5 and 6 are waveform diagrams showing an example of a reproduced signal of information by the magneto-optical effect. 1 ... Laser light source, 2 ... Polarizer, 3 ... Beam splitter, 4 ... Aperture lens, 5 ... Storage medium, 6, 9 ...
Substrate, 7 ... Analyzer, 8 ... Photodetector, 10 ... Reflective film,
11 …… Thin film of amorphous magnetic material of rare earth / transition metal, 12…
… Dielectric thin film, 13… Semiconductor laser, 14… Condenser lens, 15… Beam splitter, 16… Condenser lens.
フロントページの続き (72)発明者 高橋 明 大阪府大阪市阿倍野区長池町22番22号 シ ヤ−プ株式会社内 (72)発明者 山岡 秀嘉 大阪府大阪市阿倍野区長池町22番22号 シ ヤ−プ株式会社内 (56)参考文献 特開 昭57−44241（ＪＰ，Ａ) 特開 昭57−200958（ＪＰ，Ａ) 米国特許3625617（ＵＳ，Ａ) ＴＨＩＮ−ＦＩＬＭ ＯＰＴＩＣＡＬ ＦＩＬＴＥＲＳ（Ｈ．Ａ．Ｍａｃｌｅｏｄ 著．ＡＤＡＭ ＨＩＬＧＥＲ社）第301〜 304頁 電子通信学会 磁気記録研究会資料（資 料番号ＭＲ74−14）「磁気−光記憶用材 料」Front Page Continuation (72) Inventor Akira Takahashi 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Hideka Yamaoka 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka (56) References JP-A-57-44241 (JP, A) JP-A-57-200958 (JP, A) US Pat. No. 3625617 (US, A) THIN-FILM OPTICAL FILTERS (HA. Macleod, ADAM HILGER, pp. 301-304 Material of the Institute of Electronics and Communication, Magnetic Recording Research Group (material number MR74-14) "Magnetic-optical memory material"
Claims (1)
希土類・遷移金属の非晶質磁性薄膜を具備し、該非晶質
磁性薄膜の干渉作用によりカー効果が増大するようにさ
れた記憶媒体と、半導体レーザ光源と、該半導体レーザ
光源からのレーザビームを通過させるプリズム斜面に誘
電体薄膜の多層コートが施されたビームスプリッタと、
該ビームスプリッタを通過したＰ波を該記憶媒体にスポ
ット状に照射する絞りレンズと、該照射点における該磁
性薄膜の磁化状態に応じて偏光面が回転して反射された
レーザビームであって、該絞りレンズを経てビームスプ
リッタに入射し、該プリズム斜面にて反射されて出射す
るレーザビームが入射する検光子と、該検光子によって
検光された光を受光する光検出器とを具備し、該ビーム
スプリッタの偏光特性は、そのプリズム斜面の誘電体薄
膜の多層コートにより反射され、該検光子に向けて出射
されるレーザビームについてのエネルギー反射率が、Ｓ
波エネルギー反射率をRSとし、Ｐ波エネルギー反射率を
RPとしたとき、RS＞RPにされて、レーザビームの偏光面
の回転角が増大するようにされているとを特徴とする光
磁気記憶装置。1. A memory comprising a metal reflection film and an amorphous magnetic thin film of a rare earth / transition metal having perpendicular magnetic anisotropy, and the Kerr effect is increased by the interference action of the amorphous magnetic thin film. A medium, a semiconductor laser light source, and a beam splitter in which a multilayer coating of a dielectric thin film is applied to a prism slant surface for passing a laser beam from the semiconductor laser light source,
A stop lens for irradiating the storage medium with the P-wave that has passed through the beam splitter in a spot shape, and a laser beam whose polarization plane is rotated and reflected according to the magnetization state of the magnetic thin film at the irradiation point, The light beam is incident on a beam splitter through the diaphragm lens, and an analyzer on which a laser beam emitted by being reflected by the prism slope is incident, and a photodetector for receiving the light analyzed by the analyzer, The polarization characteristic of the beam splitter is such that the energy reflectance of the laser beam emitted toward the analyzer is reflected by the multilayer coating of the dielectric thin film on the prism slant surface,
The wave energy reflectance is R S , and the P wave energy reflectance is
A magneto-optical storage device characterized in that, when R P , R S > R P , and the rotation angle of the polarization plane of the laser beam is increased.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56173976A JPH0756709B2 (en) | 1981-10-29 | 1981-10-29 | Magneto-optical storage device |
| CA000414156A CA1190321A (en) | 1981-10-29 | 1982-10-26 | Magneto-optical head assembly |
| US06/437,504 US4573149A (en) | 1981-10-29 | 1982-10-28 | Magneto-optical head assembly with improved detection means |
| DE8282305749T DE3280063D1 (en) | 1981-10-29 | 1982-10-28 | MAGNETO-OPTICAL HEAD DEVICE. |
| EP82305749A EP0078673B1 (en) | 1981-10-29 | 1982-10-28 | Magneto-optical head assembly |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56173976A JPH0756709B2 (en) | 1981-10-29 | 1981-10-29 | Magneto-optical storage device |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6184990A Division JP2510131B2 (en) | 1994-08-05 | 1994-08-05 | Magneto-optical storage device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5877047A JPS5877047A (en) | 1983-05-10 |
| JPH0756709B2 true JPH0756709B2 (en) | 1995-06-14 |
Family
ID=15970502
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56173976A Expired - Lifetime JPH0756709B2 (en) | 1981-10-29 | 1981-10-29 | Magneto-optical storage device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0756709B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2504734B2 (en) * | 1983-11-08 | 1996-06-05 | シャープ株式会社 | Optical device of magneto-optical storage device |
| JPS62167643A (en) * | 1986-01-20 | 1987-07-24 | Sanyo Electric Co Ltd | Optical head |
| EP0256685A3 (en) * | 1986-08-14 | 1988-11-30 | Optical Coating Laboratory, Inc. | Optical system and components for optical disk reader optical system and components for optical disk reader |
| JP3554844B2 (en) | 1998-03-19 | 2004-08-18 | 富士通株式会社 | Magneto-optical head device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3625617A (en) | 1970-07-15 | 1971-12-07 | Honeywell Inc | Kerr effect read-out system for an optical memory |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5744241A (en) * | 1980-08-27 | 1982-03-12 | Matsushita Electric Ind Co Ltd | Magnetooptic reproducer |
-
1981
- 1981-10-29 JP JP56173976A patent/JPH0756709B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3625617A (en) | 1970-07-15 | 1971-12-07 | Honeywell Inc | Kerr effect read-out system for an optical memory |
Non-Patent Citations (2)
| Title |
|---|
| ＴＨＩＮ−ＦＩＬＭＯＰＴＩＣＡＬＦＩＬＴＥＲＳ（Ｈ．Ａ．Ｍａｃｌｅｏｄ著．ＡＤＡＭＨＩＬＧＥＲ社）第３０１〜３０４頁 |
| 電子通信学会磁気記録研究会資料（資料番号ＭＲ７４−１４）「磁気−光記憶用材料」 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5877047A (en) | 1983-05-10 |
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