JPH0427617B2 - - Google Patents
Info
- Publication number
- JPH0427617B2 JPH0427617B2 JP62124722A JP12472287A JPH0427617B2 JP H0427617 B2 JPH0427617 B2 JP H0427617B2 JP 62124722 A JP62124722 A JP 62124722A JP 12472287 A JP12472287 A JP 12472287A JP H0427617 B2 JPH0427617 B2 JP H0427617B2
- Authority
- JP
- Japan
- Prior art keywords
- film
- magneto
- recording
- magnetic
- servo
- 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
- 230000005291 magnetic effect Effects 0.000 claims description 13
- 239000000758 substrate Substances 0.000 claims description 11
- 230000015654 memory Effects 0.000 claims description 4
- 239000011347 resin Substances 0.000 claims description 3
- 229920005989 resin Polymers 0.000 claims description 3
- 230000005415 magnetization Effects 0.000 claims description 2
- 239000005357 flat glass Substances 0.000 claims 1
- 239000010408 film Substances 0.000 description 27
- 230000000694 effects Effects 0.000 description 6
- 238000000034 method Methods 0.000 description 4
- 230000005374 Kerr effect Effects 0.000 description 3
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- 239000012790 adhesive layer Substances 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 239000000696 magnetic material Substances 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000002223 garnet Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 229910016629 MnBi Inorganic materials 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- -1 etc. is formed Inorganic materials 0.000 description 1
- 239000002902 ferrimagnetic material Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 239000011232 storage material Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 229910052725 zinc Inorganic materials 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
- G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
- G11B11/10586—Record carriers characterised by the selection of the material or by the structure or form characterised by the selection of the material
- G11B11/10589—Details
-
- 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
- G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
- G11B11/10584—Record carriers characterised by the selection of the material or by the structure or form characterised by the form, e.g. comprising mechanical protection elements
Description
【発明の詳細な説明】
＜技術分野＞
本発明はレーザ光により情報の記録、再生、消
去を行う磁気光学記憶素子に関する。DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a magneto-optical storage element that records, reproduces, and erases information using laser light.
＜従来技術＞
近年、高密度・大容量・高速アクセス等の種々
の要求を満足し得る光メモリ装置の研究開発が活
発に推進されている。各種光メモリ装置のうちで
も特に記憶材料として垂直磁化膜を用いた磁気光
学記憶装置は、不要になつた情報を消去しその上
に新しい情報を再記録できるという特長があり注
目を受けている。<Prior Art> In recent years, research and development of optical memory devices that can satisfy various demands such as high density, large capacity, and high speed access have been actively promoted. Among various optical memory devices, magneto-optical memory devices that use a perpendicularly magnetized film as a storage material are attracting attention because of their ability to erase information that is no longer needed and re-record new information thereon.
しかし上記の利点を有する一方で磁気光学記憶
装置は再生信号が少いという欠点があり、特に磁
気光学記憶素子からの反射光を利用して情報の再
生を行う、所謂カー効果再生方式においては磁性
体のカー回転角が小さいため信号雑音比（Ｓ／
Ｎ）を高める事が困難であつた。そのため従来で
は記録媒体である磁性材料を改良したり或いは記
録媒体上にSiOやSiO2の誘電体膜を形成したりし
てカー回転角を高める工夫がなされていた。後者
の例として例えばMnBi磁性体膜上にSiO膜を形
成する事によつてカー回転角が0.7度から3.6度に
増大した例が報告されている（J.Appl.Phys.
Vo145.No.8.August1974）。しかしながこのような
磁性体膜上への誘電体膜の形成ではカー回転角の
増大に伴つて反射光量が減退し実質的なＳ／Ｎは
約２倍程度にしか増大していない。 However, while having the above-mentioned advantages, magneto-optical storage devices have the disadvantage that the reproduction signal is small, and in particular, in the so-called Kerr effect reproduction method, which reproduces information using reflected light from the magneto-optic storage element, magnetic Since the Kerr rotation angle of the body is small, the signal-to-noise ratio (S/
It was difficult to increase N). Therefore, in the past, efforts have been made to increase the Kerr rotation angle by improving the magnetic material of the recording medium or by forming a dielectric film of SiO or SiO 2 on the recording medium. As an example of the latter, it has been reported that the Kerr rotation angle increased from 0.7 degrees to 3.6 degrees by forming a SiO film on a MnBi magnetic film (J. Appl. Phys.
Vo145.No.8.August1974). However, in forming a dielectric film on such a magnetic film, the amount of reflected light decreases as the Kerr rotation angle increases, and the actual S/N only increases by about twice.
又SiOやSiO2等の誘電体薄膜を形成しただけで
は、磁性体に腐蝕の恐れのある場合はその腐蝕の
実質的な防御とはなり得ない事や、記録ビツト径
が1μｍ程度であるため1μｍ程度の小さなほこり
やゴミが該誘電体膜に付着した場合は該ビツト検
出が不可能になる事等のため、実質的な記録素子
とするためには厚さ0.5〜２mm程度のガラス又は
透明樹脂を使用する事が望ましい。しかしそうる
事によりカー回転角の増大は期待できず、従つて
誘電体膜の形成によるＳ／Ｎの増大の効果も理論
値程の期待はできなくなつた。 Furthermore, simply forming a dielectric thin film such as SiO or SiO 2 cannot provide substantial protection against corrosion if there is a risk of corrosion in the magnetic material, and the recording bit diameter is approximately 1 μm. If dust or dirt as small as about 1 μm adheres to the dielectric film, it will become impossible to detect the bit, so a glass or transparent film with a thickness of about 0.5 to 2 mm should be used as a practical recording element. It is preferable to use resin. However, by doing so, the Kerr rotation angle could not be expected to increase, and therefore, the effect of increasing the S/N ratio by forming the dielectric film could not be expected to be as great as the theoretical value.
一方最近ではガーネツト基板の上にDyFe等の
アモルフアス磁性体を付けDyFeに記録された情
報をＳ／Ｎの良いガーネツトに転写し読み出す方
式等も提案されている（第４回日本応用磁気学会
学術講演会5aB−４）。しかしその方式では大面
積の記憶素子にはなり得ず大容量メモリには適さ
ない。 On the other hand, recently, a method has been proposed in which an amorphous magnetic material such as DyFe is placed on a garnet substrate and information recorded on DyFe is transferred to and read out from a garnet with a good S/N ratio (4th Academic Conference of the Japan Society of Applied Magnetics). Meeting 5aB-4). However, this method cannot be used as a large-area storage element and is not suitable for large-capacity memories.
又以上の問題とは別に光メモリ装置は高密度記
録が基本的な条件であるためその記録ビツト径は
上述したごとく1μｍ程度であり、従つて記録、
再生、消去の過程でフオーカスサーボ、トラツク
サーボ等のサーボ技術が不可欠となる。さもない
と記録装置は複雑でかつ精巧なものが必要となり
実用には適さなくなる。そして特にトラツクサー
ボをかける場合にはフイリツプス・MCA方式の
ビデオデイスク装置の様にあらかじめ記録されて
いる情報を再生するだけの装置とは異なり磁気光
学記憶装置では何等の情報のない場所に新たに信
号を記録していく必要があり、そのためには信号
の記録トラツクと平行してサーボ用のガイドトラ
ツクがある事が望ましい。 In addition to the above-mentioned problems, the basic condition of optical memory devices is high-density recording, so the recording bit diameter is about 1 μm as mentioned above, and therefore recording,
Servo technologies such as focus servo and track servo are essential in the reproduction and erasing process. Otherwise, the recording device would need to be complicated and sophisticated, making it unsuitable for practical use. In particular, when applying track servo, unlike a device such as a Philips MCA video disk device that only plays back pre-recorded information, a magneto-optical storage device generates a new signal where there is no information. It is necessary to record the signal, and for this purpose, it is desirable to have a servo guide track in parallel with the signal recording track.
＜目的＞
本発明は以上の点に鑑みなされたものであつて
反射光量を減らす事なく磁気光学効果を増大させ
しかもサーボ用のガイドトラツクをも形成するこ
とを目的とする。<Objective> The present invention has been made in view of the above points, and it is an object of the present invention to increase the magneto-optic effect without reducing the amount of reflected light, and to also form a guide track for a servo.
＜実施例＞
次に本発明の具体的な実施例を図面を参照しな
がら詳説する。<Examples> Next, specific examples of the present invention will be described in detail with reference to the drawings.
第１図は本発明の磁気光学記憶素子の一実施例
の一部拡大側面断面図である。平担なガラス基板
９上に帯状の溝を有する樹脂基板１０を重ねてな
る基板１上にGdTbFe、GdTbDyFe、SmTbFe、
TbCo等の希土類と遷移金属よりなるアモルフア
スフエリ磁性体の垂直磁化膜２をスパツタリング
や蒸着法で形成する。更にその上からSiO2，
SiO，MgF，TiO2等の透明な誘電体膜３を形成
し、該誘電体膜３の上からAl，Ag，Au，Cu，
Zn，Sn等の反射膜４を形成する。更に反射膜４
は支持基板６に接着層５で接着される。この素子
構成において情報の記録、再生、消去は基板１を
通して行われる。その時記録トラツクとして帯状
の溝の部分７を用いても土手の部分８を用いても
良い。ガイドトラツクについても同じ事が言え
る。即ち溝の部分７でも土手の部分８でも良いし
又サーボ信号の取り方によつて溝の部分７と土手
の部分８を半々に用いてガイドトラツクとしても
良い。換言すれば基板１に段差を設ける事によつ
てトラツクサーボ用の信号を得ようとするもので
ある。この帯状の溝７はたとえば磁気光学素子が
円板である場合は同心円状もしくはらせん状をな
す。磁性膜２は充分に薄く、従つて磁性体層に入
射した再生光は磁性体面からの反射によるカー効
果と磁性体膜を通り抜け反射層４で反射され再び
磁性体膜を通り抜けることで起こるフアラデイ効
果が合わせる事によつて、単なるカー効果のみに
比べて数倍回転角が増大し、かつ返り光量はほと
んど減少しないためＳ／Ｎが大きく増大するもの
である。 FIG. 1 is a partially enlarged side cross-sectional view of an embodiment of the magneto-optic storage element of the present invention. GdTbFe, GdTbDyFe, SmTbFe,
A perpendicular magnetization film 2 of an amorphous ferrimagnetic material made of a rare earth element such as TbCo and a transition metal is formed by sputtering or vapor deposition. Furthermore, from above, SiO 2 ,
A transparent dielectric film 3 made of SiO, MgF, TiO 2 , etc. is formed, and Al, Ag, Au, Cu, etc.
A reflective film 4 of Zn, Sn, etc. is formed. Furthermore, reflective film 4
is adhered to the support substrate 6 with an adhesive layer 5. In this element configuration, information is recorded, reproduced, and erased through the substrate 1. At this time, the band-shaped groove portion 7 or the bank portion 8 may be used as the recording track. The same can be said about guide tracks. That is, either the groove portion 7 or the bank portion 8 may be used, or depending on how the servo signal is obtained, the groove portion 7 and the bank portion 8 may be used half and half to form a guide track. In other words, by providing a step on the substrate 1, a track servo signal is obtained. For example, when the magneto-optical element is a disk, the band-shaped groove 7 has a concentric or spiral shape. The magnetic film 2 is sufficiently thin, so that the reproduction light incident on the magnetic layer undergoes both the Kerr effect due to reflection from the magnetic surface and the Faraday effect caused by passing through the magnetic film, being reflected by the reflective layer 4, and passing through the magnetic film again. By combining these, the rotation angle increases several times compared to the mere Kerr effect alone, and the amount of reflected light hardly decreases, so the S/N ratio increases greatly.
ここで本発明の主旨は溝を形成した基板と磁気
光学効果を増大させるための反射膜とにある。従
つて本発明の主旨の範囲で種々の構成をとること
が出来る。例えば誘電体膜３は無くても良いし、
又誘電体膜３と磁性体膜２の間に極めて薄いAl，
Cr，Ti等の金属薄膜を形成しても良い。更に支
持板６の代わりに基板１、磁性膜２、誘電膜３、
反射膜４からなる素子を接着層５で張り合せ両面
使用可能な磁気光学記憶素子とする事も出来る。 Here, the gist of the present invention resides in a substrate having grooves formed therein and a reflective film for increasing the magneto-optic effect. Therefore, various configurations can be adopted within the scope of the spirit of the present invention. For example, the dielectric film 3 may be omitted,
Also, between the dielectric film 3 and the magnetic film 2, an extremely thin layer of Al,
A thin metal film of Cr, Ti, etc. may also be formed. Furthermore, instead of the support plate 6, a substrate 1, a magnetic film 2, a dielectric film 3,
It is also possible to make a magneto-optical memory element that can be used on both sides by bonding the element made of the reflective film 4 with an adhesive layer 5.
尚、記録トラツクやガイドトラツクは必ずしも
平行な帯状である必要がなくトラツク番号や、ト
ラツクをセクターごとに分ける場合の情報を入れ
ても良い。 Note that the recording tracks and guide tracks do not necessarily have to be in the form of parallel strips, and may include track numbers or information for dividing the tracks into sectors.
＜効果＞
以上説明した如く、本発明によれば磁気光学効
果が良好であつて、しかもサーボ用のガイドトラ
ツクを有する磁気光学記憶素子を提供できるもの
である。<Effects> As explained above, according to the present invention, it is possible to provide a magneto-optic memory element which has a good magneto-optic effect and also has a guide track for servo.
第１図は本発明に係わる磁気光学記憶素子の一
実施例の一部拡大側面断面図を示す。
図中、１……基板、２……アモルフアス磁性体
膜、３……誘電体膜、４……反射膜、５……接着
層、６……支持基板、７……溝部、８……土手
部、９……ガラス基板、１０……樹脂。
FIG. 1 shows a partially enlarged side cross-sectional view of an embodiment of a magneto-optic storage element according to the present invention. In the figure, 1...Substrate, 2...Amorphous magnetic film, 3...Dielectric film, 4...Reflection film, 5...Adhesive layer, 6...Support substrate, 7...Groove, 8...Bank Part, 9...Glass substrate, 10...Resin.
Claims (1)
基板を重ねてなる基板上に、膜面に垂直な磁化容
易軸を有する磁性体薄膜を形成するとともに該膜
の上部に反射膜を形成したことを特徴とする磁気
光学記憶素子。1. A thin magnetic film having an axis of easy magnetization perpendicular to the film surface was formed on a flat glass substrate overlaid with a resin substrate having band-shaped grooves, and a reflective film was formed on top of the film. A magneto-optical memory element characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12472287A JPS62295238A (en) | 1987-05-20 | 1987-05-20 | Magneto-optical memory element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12472287A JPS62295238A (en) | 1987-05-20 | 1987-05-20 | Magneto-optical memory element |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP409081A Division JPS57120253A (en) | 1981-01-14 | 1981-01-14 | Magnetooptical storage elemen |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62295238A JPS62295238A (en) | 1987-12-22 |
| JPH0427617B2 true JPH0427617B2 (en) | 1992-05-12 |
Family
ID=14892484
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12472287A Granted JPS62295238A (en) | 1987-05-20 | 1987-05-20 | Magneto-optical memory element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62295238A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0368194B1 (en) * | 1988-11-07 | 1998-06-17 | Hitachi, Ltd. | Magneto-optical recording medium |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5231503A (en) * | 1975-09-03 | 1977-03-10 | Yasunaga Riken Co Ltd | Fabric form for civil engineering work |
| JPS54130103A (en) * | 1978-03-16 | 1979-10-09 | Philips Nv | Device for writing and reading information on recording carrier body and recording carrier body |
| JPS554793A (en) * | 1978-05-24 | 1980-01-14 | Philips Nv | Information recording element and producing same |
-
1987
- 1987-05-20 JP JP12472287A patent/JPS62295238A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5231503A (en) * | 1975-09-03 | 1977-03-10 | Yasunaga Riken Co Ltd | Fabric form for civil engineering work |
| JPS54130103A (en) * | 1978-03-16 | 1979-10-09 | Philips Nv | Device for writing and reading information on recording carrier body and recording carrier body |
| JPS554793A (en) * | 1978-05-24 | 1980-01-14 | Philips Nv | Information recording element and producing same |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62295238A (en) | 1987-12-22 |
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