JPH08235657A - Magnetooptical recording medium - Google Patents
Magnetooptical recording mediumInfo
- Publication number
- JPH08235657A JPH08235657A JP9618895A JP9618895A JPH08235657A JP H08235657 A JPH08235657 A JP H08235657A JP 9618895 A JP9618895 A JP 9618895A JP 9618895 A JP9618895 A JP 9618895A JP H08235657 A JPH08235657 A JP H08235657A
- Authority
- JP
- Japan
- Prior art keywords
- layer
- magneto
- dielectric layer
- recording medium
- thickness
- 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
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、マークエッジ記録方式
に好適な光磁気記録媒体に関し、さらに詳細には、トラ
ック方向に対称性の高い記録マークを得ることができる
光磁気記録媒体に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical recording medium suitable for a mark edge recording system, and more particularly to a magneto-optical recording medium capable of obtaining a recording mark having high symmetry in the track direction.
【０００２】[0002]
【従来の技術】近年、情報化技術の発達及び情報量の増
大に伴い、高記録密度を有する光メモリが注目されてい
る。光メモリのうち、記録された情報の書換えが可能な
光磁気ディスクの開発が急速に行われている。光磁気デ
ィスクへの記録は、レーザ光を光磁気記録媒体に照射す
ることによって磁性層を加熱して磁区の保磁力を低下さ
せるとともに、バイアス磁界を印加して磁区を反転させ
ることによって行なわれる。2. Description of the Related Art In recent years, with the development of information technology and the increase in the amount of information, an optical memory having a high recording density has been receiving attention. Among optical memories, a magneto-optical disk capable of rewriting recorded information is being rapidly developed. Recording on the magneto-optical disk is performed by irradiating the magneto-optical recording medium with laser light to heat the magnetic layer to lower the coercive force of the magnetic domain and to apply a bias magnetic field to reverse the magnetic domain.
【０００３】光記録媒体の記録方式としては、記録マー
クの中心位置で信号の記録・再生を行うマークポジショ
ン方式と、記録マークの端部位置で信号の記録再生を行
うマークエッジ方式が知られている。このうち、マーク
エッジ方式は、マークポジション方式に比べて記録密度
が高い点で優れている。As a recording system for an optical recording medium, a mark position system for recording / reproducing a signal at the center position of a recording mark and a mark edge system for recording / reproducing a signal at an end position of a recording mark are known. There is. Among them, the mark edge method is superior to the mark position method in that the recording density is high.
【０００４】かかるマークエッジ方式で光磁気ディスク
に記録が行われる場合、情報は記録されたマーク長に応
じて記録される。記録の際に、光磁気ディスクの磁性層
に吸収される熱は、磁性層のレーザービームの進行方向
の後方部分、すなわち記録マーク（記録された磁区）の
後端部側により多く蓄積され易い。このため、記録マー
クの長さ方向には温度分布が生じ、記録マークは、図１
に示すように、一般にビームの進行方向に沿って非対称
の形状になる。さらに、記録マークの端部位置が本来の
信号位置からづれ、ピット長を変動させることによって
ジッタを増し、結果としてエラー信号を引き起こす可能
性がある。When recording is performed on a magneto-optical disk by the mark edge method, information is recorded according to the recorded mark length. During recording, a large amount of heat absorbed by the magnetic layer of the magneto-optical disk is likely to be accumulated in the rear portion of the magnetic layer in the traveling direction of the laser beam, that is, the rear end side of the recording mark (recorded magnetic domain). Therefore, a temperature distribution occurs in the length direction of the recording mark, and the recording mark is
As shown in, the shape is generally asymmetric along the beam traveling direction. Further, the end position of the recording mark is deviated from the original signal position, and the pit length is changed to increase jitter, which may result in an error signal.
【０００５】このような非対称形状が顕著になる理由
は、以下のように考えられる。光磁気ディスクは一般に
見かけ上のカー回転角を増大させる目的で磁性層の後方
に第２誘電体層を挟んで反射層を設けている。光照射に
より最初に記録マークの前端部を形成すべき位置の磁性
層が加熱されるが、その熱は下層の第２誘電体層を通じ
て反射層に逃げる。その熱が反射層をレーザービームの
進行方向に伝わって反射層全体を加熱する。記録マーク
の後端部になるべき磁性層の位置に光が照射された時点
でその下層の第２誘電体層及び反射層は予熱されている
ために磁性層からは熱が逃げにくくマーク後端部近傍の
温度が上昇し易い。このため、記録マークの前端部では
磁性層と第２誘電体層との間の温度差により熱が下層に
逃げて磁性層の反転磁区が充分に成長できないのに対し
て、後端部では磁性層内で熱が拡散して反転磁区が充分
に成長するために、記録マークが非対称形となる。The reason why such an asymmetrical shape becomes remarkable is considered as follows. In a magneto-optical disk, a reflective layer is generally provided behind a magnetic layer with a second dielectric layer interposed for the purpose of increasing the apparent Kerr rotation angle. The light irradiation first heats the magnetic layer at the position where the front end of the recording mark is to be formed, but the heat escapes to the reflective layer through the second dielectric layer below. The heat is transmitted through the reflective layer in the traveling direction of the laser beam to heat the entire reflective layer. At the time when the position of the magnetic layer, which should be the rear end of the recording mark, is irradiated with light, the second dielectric layer and the reflective layer therebelow are preheated, so that heat cannot escape easily from the magnetic layer. The temperature near the part easily rises. Therefore, at the front end of the recording mark, the heat escapes to the lower layer due to the temperature difference between the magnetic layer and the second dielectric layer, and the reversed magnetic domain of the magnetic layer cannot grow sufficiently. Since the heat is diffused in the layer and the reversed magnetic domain is sufficiently grown, the recording mark becomes asymmetric.
【０００６】[0006]
【発明が解決しようとする課題】本発明の目的は、上記
従来のマークエッジ記録方式が有していた欠点を解消
し、トラック方向に沿って対称性の高い記録マークを形
成してジッタの小さい光磁気記録媒体を提供することに
ある。SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the above-mentioned conventional mark edge recording method and form recording marks with high symmetry along the track direction to reduce jitter. It is to provide a magneto-optical recording medium.
【０００７】[0007]
【課題を解決するための手段】本発明に従えば、基板上
に第１誘電体層、磁性層、第２誘電体層、反射膜層を順
次積層してなる光磁気記録媒体において、第２誘電体層
の厚みＬ2 が、５ｎｍ≦Ｌ2 ≦１８ｎｍであることを特
徴とする上記光磁気記録媒体が提供される。ここで、第
２誘電体層の厚みＬ2 が５ｎｍ未満であると、初期のＣ
／Ｎ比が低く且つ耐腐食性が低下するために媒体寿命が
短くなり、Ｌ2 が１８ｎｍを超えると熱を反射層に意図
的に逃がす本発明の効果が消滅するため好ましくない。
第２誘電体層の厚みＬ2 は、一層好ましくは、７ｎｍ≦
Ｌ2 ≦１３ｎｍである。According to the present invention, there is provided a magneto-optical recording medium comprising a substrate, on which a first dielectric layer, a magnetic layer, a second dielectric layer and a reflective film layer are sequentially laminated. There is provided the magneto-optical recording medium, wherein the dielectric layer has a thickness L 2 of 5 nm ≦ L 2 ≦ 18 nm. Here, when the thickness L 2 of the second dielectric layer is less than 5 nm, the initial C
Since the / N ratio is low and the corrosion resistance is low, the life of the medium is shortened, and when L 2 exceeds 18 nm, the effect of the present invention in which heat is intentionally released to the reflective layer disappears, which is not preferable.
The thickness L 2 of the second dielectric layer is more preferably 7 nm ≦
L 2 ≦ 13 nm.
【０００８】本発明の光磁気記録媒体において、磁性層
の厚みをＬ3 、磁性層の屈折率をｎ3 、再生光の波長を
λとしたときに、必要な記録・再生・消去特性を確保し
且つ吸収した熱を意図的に反射層に逃がすために、磁性
層の厚みは、 ０．０６λ≦ｎ3 Ｌ3 ≦０．１２λ を満足することが好ましい。In the magneto-optical recording medium of the present invention, when the thickness of the magnetic layer is L 3 , the refractive index of the magnetic layer is n 3 , and the wavelength of the reproducing light is λ, necessary recording / reproducing / erasing characteristics are secured. In order to allow the absorbed heat to escape to the reflective layer intentionally, the thickness of the magnetic layer preferably satisfies 0.06λ ≦ n 3 L 3 ≦ 0.12λ.
【０００９】本発明の光磁気記録媒体において、第１誘
電体層の厚みをＬ1 、第１誘電体層の屈折率をｎ1 、再
生光の波長をλとしたときに、エンハンス条件を回避す
ることにより再生光として検出される反射光強度を充分
にし且つ生産性を低下させない程度の厚さを維持する等
の理由から、第１誘電体層の厚みが、 ０．２５λ≦ｎ1 Ｌ1 ≦０．３６ λ あるいは、 ０．０７λ≦ｎ1 Ｌ1 ≦０．１６ λ を満足することが好ましい。光磁気記録媒体の再生に使
用される再生光の波長λは、一般に６８０ｎｍである
が、エンハンス効果との関係から使用される再生光の波
長λに応じて、前記のような条件を満足する磁性層厚さ
及び第１誘電体層厚さを採用するのが好ましい。λ＝６
８０ｎｍの場合、第１誘電体層は生産性を考慮して１０
０ｎｍ以下が好ましい。In the magneto-optical recording medium of the present invention, when the thickness of the first dielectric layer is L 1 , the refractive index of the first dielectric layer is n 1 , and the wavelength of the reproducing light is λ, the enhancing condition is avoided. The thickness of the first dielectric layer is 0.25λ ≦ n 1 L 1 for the reason that the intensity of the reflected light detected as the reproduction light is sufficient and the thickness is maintained so as not to reduce the productivity. It is preferable that ≦ 0.36 λ or 0.07 λ ≦ n 1 L 1 ≦ 0.16 λ is satisfied. The wavelength λ of the reproducing light used for reproducing the magneto-optical recording medium is generally 680 nm, but the magnetic properties satisfying the above-mentioned conditions depending on the wavelength λ of the reproducing light used in relation to the enhancement effect. The layer thickness and the first dielectric layer thickness are preferably adopted. λ = 6
In the case of 80 nm, the first dielectric layer has a productivity of 10
It is preferably 0 nm or less.
【００１０】本発明の光磁気記録媒体を構成する第１及
び第２誘電体層は、独立に、ＳｉＮ，ＳｉＯ2 ，ＴａＯ
5 ，ＳｉＡｌＮ，ＺｒＯ2 ，ＳｉＣからなる群から選ば
れる材料から構成されていることが好ましい。また、反
射層としては、磁性層から伝播された熱を溜めて熱源と
して機能させる点からＡｌ，Ａｌ−Ｔｉ，ＡｌＣｒ等の
材料から構成するのが好ましい。The first and second dielectric layers constituting the magneto-optical recording medium of the present invention are independently SiN, SiO 2 , TaO.
It is preferably composed of a material selected from the group consisting of 5 , SiAlN, ZrO 2 , and SiC. Further, the reflective layer is preferably made of a material such as Al, Al-Ti, AlCr or the like from the viewpoint that the heat propagated from the magnetic layer is stored and it functions as a heat source.
【００１１】本発明の光磁気記録媒体は、マークエッジ
方式で再生・記録が行われるのが好適である。本発明に
よると、マークエッジ方式で検出されるマーク前端及び
後端の位置精度が従来より向上し、ジッタを低減するこ
とができる。The magneto-optical recording medium of the present invention is preferably subjected to reproduction / recording by the mark edge method. According to the present invention, the positional accuracy of the mark front end and the mark rear end detected by the mark edge method is improved as compared with the prior art, and the jitter can be reduced.
【００１２】本発明の光磁気記録媒体の一例として、基
板上に第１誘電体層、磁性層、第２誘電体層及び反射層
の４層を積層して構成され且つλ＝６８０ｎｍの再生光
で再生される光磁気ディスクにおいて、磁性層の膜厚を
１５〜２３ｎｍ、第１誘電体層の膜厚を８５〜１００ｎ
ｍ、第２誘電体層の膜厚を１０〜１８ｎｍとして構成す
ることが好ましい。この場合、第１誘電体層の膜厚を２
５〜４５ｎｍにしてもよい。As an example of the magneto-optical recording medium of the present invention, a reproducing light having a wavelength of λ = 680 nm is formed by laminating four layers of a first dielectric layer, a magnetic layer, a second dielectric layer and a reflecting layer on a substrate. In the magneto-optical disk to be reproduced by, the thickness of the magnetic layer is 15 to 23 nm and the thickness of the first dielectric layer is 85 to 100 n.
m, and the film thickness of the second dielectric layer is preferably 10 to 18 nm. In this case, the film thickness of the first dielectric layer is 2
It may be 5 to 45 nm.
【００１３】[0013]
【作用】図３に光磁気ディスクのトラック２上に記録さ
れた記録マーク１と、レーザ光照射時における記録マー
クに対応したトラック位置における磁性層の温度分布を
示す。点線４は従来の光磁気ディスクの磁性層の温度分
布であり、実線３は本発明の光磁気ディスクの磁性層の
温度分布である。本発明では、光磁気記録媒体を構成す
る第２誘電体層の厚みを従来よりも薄くすることによ
り、レーザ光照射により磁性層に発生した熱は、その下
層の第２誘電体を通じて反射層に素早く伝播し、第２誘
電体層または反射層自体を熱源として機能させる。かか
る熱源の存在により、記録マークの前端部に相当する位
置では磁性層と第２誘電体層及び反射層との温度差が少
なくなり、そこから熱が急速に奪われることはなく、磁
区の反転が充分に行われる。記録マークの後端部に相当
する位置でも同様のことが起こるために、図３に示した
ように、レーザビーム進行方向における記録マークの温
度分布はほぼ一定となる。従って、記録マークはマーク
長さ方向に渡って対称になる。FIG. 3 shows the recording mark 1 recorded on the track 2 of the magneto-optical disk and the temperature distribution of the magnetic layer at the track position corresponding to the recording mark at the time of laser light irradiation. The dotted line 4 is the temperature distribution of the magnetic layer of the conventional magneto-optical disk, and the solid line 3 is the temperature distribution of the magnetic layer of the magneto-optical disk of the present invention. In the present invention, by making the thickness of the second dielectric layer constituting the magneto-optical recording medium thinner than before, heat generated in the magnetic layer by laser light irradiation is transferred to the reflective layer through the second dielectric layer thereunder. Propagates quickly and causes the second dielectric layer or the reflective layer itself to function as a heat source. Due to the presence of such a heat source, the temperature difference between the magnetic layer and the second dielectric layer and the reflective layer at the position corresponding to the front end of the recording mark is reduced, and heat is not rapidly taken away from the magnetic layer and the magnetic domain is reversed. Is fully done. Since the same thing occurs at the position corresponding to the rear end of the recording mark, the temperature distribution of the recording mark in the laser beam traveling direction becomes almost constant as shown in FIG. Therefore, the recording mark is symmetrical in the mark length direction.
【００１４】[0014]
実施例１ ４つの成膜室を備える連続スパッタ装置を用いて本発明
の光磁気記録ディスクを作製した。スタンパを用いてプ
リフォーマット信号に対応するピットが形成されたポリ
カーボネート基板を用意した。ポリカーボネート基板を
第１成膜室に設置し、スパッタターゲットとしてＳｉＮ
を用い、スパッタガスとしてＮ2 分圧５％のＡｒ＋Ｎ2
混合ガスを０．２Ｐａの圧力で用いることよって、第１
誘電体層として屈折率２．１のＳｉＮを基板上に膜厚８
７ｎｍで成膜した。次いで、基板を第２成膜室に搬送し
て、ＴｂＦｅＣｏＮｂをターゲットとしてＡｒガス圧
０．２Ｐａ下で組成Ｔｂ24.5Ｆｅ63.5Ｃｏ18Ｎｂ2 の磁
性層を膜厚１９ｎｍで成膜した。次いで、第３成膜室に
基板を移し、ＳｉＮを第１誘電体層成膜時と同じスパッ
タ条件にて成膜して、磁性層上に膜厚１１ｎｍのＳｉＮ
第２誘電体層を得た。次いで、第４成膜室中で、Ａｌ97
Ｔｉ3 層をＡｒガス圧０．２Ｐａ下で成膜し、第２誘電
体層上に膜厚５０ｎｍの反射層を形成した。積層された
ポリカーボネート基板をスパッタ装置から取り出し、最
上層にＵＶ系保護樹脂をスピンコートして保護膜を形成
した。こうして、ポリカーボネート基板上にＳｉＮ第１
誘電体層／Ｔｂ24.5Ｆｅ63.5Ｃｏ10Ｎｂ2 磁性層／Ｓｉ
Ｎ第２誘電体層／Ａｌ97Ｔｉ3 反射層／ＵＶ系保護樹脂
を積層した光磁気ディスクを得た。Example 1 A magneto-optical recording disk of the present invention was produced by using a continuous sputtering apparatus equipped with four film forming chambers. A polycarbonate substrate having pits corresponding to preformatted signals was prepared using a stamper. A polycarbonate substrate is installed in the first film forming chamber and SiN is used as a sputter target.
Ar + N 2 with a N 2 partial pressure of 5% as a sputtering gas
By using the mixed gas at a pressure of 0.2 Pa, the first
SiN having a refractive index of 2.1 as the dielectric layer is formed on the substrate to a film thickness of 8
The film was formed at 7 nm. Next, the substrate was transported to the second film forming chamber, and a magnetic layer having a composition of Tb 24.5 Fe 63.5 Co 18 Nb 2 was formed to a film thickness of 19 nm with TbFeCoNb as a target under Ar gas pressure of 0.2 Pa. Then, the substrate is transferred to a third film forming chamber, SiN is formed under the same sputtering conditions as those for forming the first dielectric layer, and SiN having a film thickness of 11 nm is formed on the magnetic layer.
A second dielectric layer was obtained. Then, in the fourth film forming chamber, Al 97
A Ti 3 layer was formed under Ar gas pressure of 0.2 Pa, and a reflective layer having a film thickness of 50 nm was formed on the second dielectric layer. The laminated polycarbonate substrate was taken out from the sputtering apparatus, and UV protective resin was spin-coated on the uppermost layer to form a protective film. Thus, the SiN first layer on the polycarbonate substrate
Dielectric layer / Tb 24.5 Fe 63.5 Co 10 Nb 2 magnetic layer / Si
A magneto-optical disk in which N second dielectric layer / Al 97 Ti 3 reflective layer / UV protective resin was laminated was obtained.
【００１５】実施例２ ＳｉＮ第１誘電体層の膜厚を９８ｎｍとし、磁性層の膜
厚を１５ｎｍとし、ＳｉＮ第２誘電体層の膜厚を１５ｎ
ｍとした以外は、実施例１と同様にして、ポリカーボネ
ート基板上にＳｉＮ第１誘電体層／Ｔｂ24.5Ｆｅ63.5Ｃ
ｏ10Ｎｂ2 磁性層／ＳｉＮ第２誘電体層／Ａｌ97Ｔｉ3
反射層／ＵＶ系保護樹脂を積層した光磁気ディスクを得
た。EXAMPLE 2 The SiN first dielectric layer has a thickness of 98 nm, the magnetic layer has a thickness of 15 nm, and the SiN second dielectric layer has a thickness of 15 n.
SiN first dielectric layer / Tb 24.5 Fe 63.5 C was formed on a polycarbonate substrate in the same manner as in Example 1 except that m was set.
o 10 Nb 2 magnetic layer / SiN second dielectric layer / Al 97 Ti 3
A magneto-optical disk having a reflective layer / UV protective resin laminated was obtained.
【００１６】比較例１ ＳｉＮ第１誘電体層の膜厚を８０ｎｍとし、磁性層の膜
厚を２５ｎｍとし、ＳｉＮ第２誘電体層の膜厚を２５ｎ
ｍとした以外は、実施例１と同様にして、ポリカーボネ
ート基板上にＳｉＮ第１誘電体層／Ｔｂ24.5Ｆｅ63.5Ｃ
ｏ10Ｎｂ2 磁性層／ＳｉＮ第２誘電体層／Ａｌ97Ｔｉ3
反射層／ＵＶ系保護樹脂を積層した光磁気ディスクを得
た。Comparative Example 1 The SiN first dielectric layer has a thickness of 80 nm, the magnetic layer has a thickness of 25 nm, and the SiN second dielectric layer has a thickness of 25 n.
SiN first dielectric layer / Tb 24.5 Fe 63.5 C was formed on a polycarbonate substrate in the same manner as in Example 1 except that m was set.
o 10 Nb 2 magnetic layer / SiN second dielectric layer / Al 97 Ti 3
A magneto-optical disk having a reflective layer / UV protective resin laminated was obtained.
【００１７】比較例２ ＳｉＮ第１誘電体層の膜厚を７５ｎｍとし、磁性層の膜
厚を１０ｎｍとし、ＳｉＮ第２誘電体層の膜厚を４ｎｍ
とした以外は、実施例１と同様にして、ポリカーボネー
ト基板上にＳｉＮ第１誘電体層／Ｔｂ24.5Ｆｅ63.5Ｃｏ
10Ｎｂ2 磁性層／ＳｉＮ第２誘電体層／Ａｌ97Ｔｉ3 反
射層／ＵＶ系保護樹脂を積層した光磁気ディスクを得
た。Comparative Example 2 The thickness of the SiN first dielectric layer was 75 nm, the thickness of the magnetic layer was 10 nm, and the thickness of the SiN second dielectric layer was 4 nm.
The same procedure as in Example 1 except that the SiN first dielectric layer / Tb 24.5 Fe 63.5 Co was formed on the polycarbonate substrate.
A magneto-optical disk in which 10 Nb 2 magnetic layer / SiN second dielectric layer / Al 97 Ti 3 reflective layer / UV protective resin was laminated was obtained.
【００１８】上記実施例１、２及び比較例１、２で得ら
れた光磁気ディスクに、マークエッジ記録方式で図２に
示すような波形の信号を記録した。記録用レーザ波長を
λ＝６８０ｎｍとし、線速９．４２ｍ／ｓにて、ディス
ク最内周のトラック（ｒ＝３０mm）に信号を記録した。
記録パワーを、図２に示すような櫛形波形で、Ｐａ＝
５．２ｍＷ、Ｐｗ＝８．４ｍＷ、Ｐｗ2 ＝９．０ｍＷと
した。これらのパワーは上記例で得られた光磁気ディス
クにおけるマークエッジ記録に好適なパワーであること
を確認できたため、これらのパワーを標準パワーとし
た。標準パワーに対して±１５％のパワー変動を与えた
場合についても上記櫛形信号を記録した。次いで、標準
パワー及び±１５％変動パワーで記録した場合の再生信
号のジッタを測定した。ジッタは、記録されたマークか
らの再生信号のゼロクロス点で求め、再生信号の前端部
から次の（マークからの）再生信号の前端部の間隔（Ｌ
−Ｌ）及び後端部から次の（マークからの）再生信号の
後端部の間隔（Ｔ−Ｔ）と記録信号のそれらに相当する
間隔との差を求め、全ての信号のジッタの平均値を算出
した。さらに、実施例１，２及び比較例１，２で得られ
た光磁気ディスクに上記信号を１０6 回消去及び書き込
み操作を繰り返した後、標準＋１５％パワーで記録した
信号のジッタを観測した。Signals having the waveforms shown in FIG. 2 were recorded on the magneto-optical disks obtained in Examples 1 and 2 and Comparative Examples 1 and 2 by the mark edge recording method. A recording laser wavelength was set to λ = 680 nm, and a signal was recorded on the innermost track (r = 30 mm) of the disc at a linear velocity of 9.42 m / s.
The recording power is a comb waveform as shown in FIG.
5.2mW, Pw = 8.4mW, was Pw 2 = 9.0mW. Since it was confirmed that these powers were suitable for mark edge recording on the magneto-optical disk obtained in the above example, these powers were set as standard powers. The comb signal was recorded even when a power fluctuation of ± 15% was applied to the standard power. Next, the jitter of the reproduced signal when recording was performed with the standard power and the fluctuation power of ± 15% was measured. Jitter is obtained at the zero-cross point of the reproduction signal from the recorded mark, and the distance (L from the front end of the reproduction signal to the front end of the next reproduction signal (from the mark) (L
-L) and the difference between the interval (T-T) at the rear end of the next reproduction signal (from the mark) from the rear end and the interval corresponding to those of the recording signal, and average the jitter of all signals. The value was calculated. Furthermore, after repeating the above-mentioned signal erasing and writing operations 10 6 times on the magneto-optical disks obtained in Examples 1 and 2 and Comparative Examples 1 and 2, the jitter of the signal recorded at the standard + 15% power was observed.
【００１９】[0019]
【表１】 [Table 1]
【００２０】表１からわかるように、実施例の光磁気デ
ィスクは比較例の光磁気ディスクに対してジッタが約１
／２まで低下している。１０6 回消去及び書き込みを繰
り返した後も同様の結果が得られた。また、標準パワー
からパワーが±１５％変動した場合でも本発明に従う光
磁気ディスクはジッタが殆ど変わらない。As can be seen from Table 1, the magneto-optical disk of the example has a jitter of about 1 as compared with the magneto-optical disk of the comparative example.
It has fallen to / 2. Similar results were obtained after erasing and writing were repeated 10 6 times. Further, even if the power fluctuates ± 15% from the standard power, the magneto-optical disk according to the present invention hardly changes the jitter.
【００２１】ジッタ測定時の記録パターンは、２チャン
ネルビットから８チャンネルビット（１チャンネルビッ
トはこの場合４０ｎｓ）の記録表のくし形パルスをラン
ダム記録した。この際、記録するビット長によってＰｗ
2 の分割パルス数を増減させ、ＰａとＰｗの部分は一定
にして記録パターンの長さを調節した。The recording pattern at the time of measuring the jitter was random recording of comb-shaped pulses in a recording table of 2 channel bits to 8 channel bits (1 channel bit is 40 ns in this case). At this time, depending on the bit length to be recorded, Pw
The length of the recording pattern was adjusted by increasing or decreasing the number of divided pulses of 2 and keeping the Pa and Pw portions constant.
【００２２】[0022]
【発明の効果】本発明の光磁気記録媒体は、トラック方
向に沿って記録マークの対称性が高く、記録マーク端部
位置の精度が高い。また、本発明の光磁気記録媒体は、
記録パワーが変動してもジッタ特性に殆ど変化がなく、
しかも繰り返し使用後もジッタ特性に変動がない。従っ
て、光磁気記録媒体はマークエッジ記録方式に好適であ
る。The magneto-optical recording medium of the present invention has a high symmetry of the recording marks along the track direction and a high accuracy of the recording mark end position. Further, the magneto-optical recording medium of the present invention,
Even if the recording power changes, the jitter characteristics hardly change,
Moreover, the jitter characteristics do not change even after repeated use. Therefore, the magneto-optical recording medium is suitable for the mark edge recording method.
【図１】ビーム進行方向に対して非対称形である記録マ
ーク（反転磁区）を示す概念図である。FIG. 1 is a conceptual diagram showing recording marks (reversed magnetic domains) that are asymmetric with respect to a beam traveling direction.
【図２】実施例及び比較例で記録した櫛形波形の信号を
示す図である。FIG. 2 is a diagram showing comb-shaped waveform signals recorded in Examples and Comparative Examples.
【図３】レーザ光照射によって記録マークが記録される
際の光磁気ディスクのトラック方向の温度分布を示す概
念図である。FIG. 3 is a conceptual diagram showing a temperature distribution in a track direction of a magneto-optical disk when a recording mark is recorded by laser light irradiation.
１ 記録マーク ２ トラック ３ 温度分布曲線（本発明） ４ 温度分布曲線（従来技術） 1 recording mark 2 track 3 temperature distribution curve (present invention) 4 temperature distribution curve (prior art)
Claims (8)
電体層、反射膜層を順次積層してなる光磁気記録媒体に
おいて、 第２誘電体層の厚みＬ2 が、５ｎｍ≦Ｌ2 ≦１８ｎｍで
あることを特徴とする上記光磁気記録媒体。1. A magneto-optical recording medium in which a first dielectric layer, a magnetic layer, a second dielectric layer and a reflective film layer are sequentially laminated on a substrate, and the thickness L 2 of the second dielectric layer is 5 nm. The above-mentioned magneto-optical recording medium, wherein ≦ L 2 ≦ 18 nm.
2 ≦１３ｎｍであることを特徴とする請求項１の光磁気
記録媒体。2. The thickness L 2 of the second dielectric layer is 7 nm ≦ L
2. The magneto-optical recording medium according to claim 1, wherein 2 ≦ 13 nm.
ｎ3 、再生光の波長をλとしたときに、磁性層の厚みＬ
3 が、 ０．０６λ≦ｎ3 Ｌ3 ≦０．１２λ を満足することを特徴とする請求項１または２の光磁気
記録媒体。3. The thickness L of the magnetic layer, where L 3 is the thickness of the magnetic layer, n 3 is the refractive index of the magnetic layer, and λ is the wavelength of the reproduction light.
3. The magneto-optical recording medium according to claim 1, wherein 3 satisfies 0.06λ ≦ n 3 L 3 ≦ 0.12λ.
層の屈折率をｎ1 、再生光の波長をλとしたときに、第
１誘電体層の厚みＬ1 が、 ０．２５λ≦ｎ1 Ｌ1 ≦０．３６λ を満足することを特徴とする請求項１〜３のいずれか一
項の光磁気記録媒体。4. When the thickness of the first dielectric layer is L 1 , the refractive index of the first dielectric layer is n 1 , and the wavelength of the reproduction light is λ, the thickness L 1 of the first dielectric layer is 4. The magneto-optical recording medium according to claim 1, which satisfies 0.25λ ≦ n 1 L 1 ≦ 0.36λ.
層の屈折率をｎ1 、再生光の波長をλとしたときに、第
１誘電体層の厚みＬ1 が、 ０．０７λ≦ｎ1 Ｌ1 ≦０．１６λ を満足することを特徴とする請求項１〜３のいずれか一
項の光磁気記録媒体。5. When the thickness of the first dielectric layer is L 1 , the refractive index of the first dielectric layer is n 1 , and the wavelength of the reproduction light is λ, the thickness L 1 of the first dielectric layer is 4. The magneto-optical recording medium according to claim 1, wherein 0.07λ ≦ n 1 L 1 ≦ 0.16λ is satisfied.
Ｎ，ＳｉＯ2 ，ＴａＯ5 ，ＳｉＡｌＮ，ＺｒＯ2 ，Ｓｉ
Ｃからなる群から選ばれる材料から構成されていること
を特徴とする請求項１〜５のいずれか一項の光磁気記録
媒体。6. The first and second dielectric layers are independently Si.
N, SiO 2 , TaO 5 , SiAlN, ZrO 2 , Si
6. The magneto-optical recording medium according to claim 1, wherein the magneto-optical recording medium is made of a material selected from the group consisting of C.
ｍであることを特徴とする請求項１〜６のいずれか一項
の光記録媒体。7. The wavelength λ of the reproduction light of the optical recording medium is 680n.
The optical recording medium according to any one of claims 1 to 6, wherein m is m.
る請求項１〜７のいずれか一項の光磁気記録媒体。8. The magneto-optical recording medium according to claim 1, wherein recording / reproducing is performed by a mark edge method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9618895A JPH08235657A (en) | 1994-12-28 | 1995-03-29 | Magnetooptical recording medium |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33949094 | 1994-12-28 | ||
| JP6-339490 | 1994-12-28 | ||
| JP9618895A JPH08235657A (en) | 1994-12-28 | 1995-03-29 | Magnetooptical recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08235657A true JPH08235657A (en) | 1996-09-13 |
Family
ID=26437397
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9618895A Pending JPH08235657A (en) | 1994-12-28 | 1995-03-29 | Magnetooptical recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08235657A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPWO2019065200A1 (en) * | 2017-09-29 | 2020-10-15 | 富士フイルム株式会社 | Magnetic tape and magnetic recording / playback device |
| JPWO2019065199A1 (en) * | 2017-09-29 | 2020-10-22 | 富士フイルム株式会社 | Magnetic tape and magnetic recording / playback device |
-
1995
- 1995-03-29 JP JP9618895A patent/JPH08235657A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPWO2019065200A1 (en) * | 2017-09-29 | 2020-10-15 | 富士フイルム株式会社 | Magnetic tape and magnetic recording / playback device |
| JPWO2019065199A1 (en) * | 2017-09-29 | 2020-10-22 | 富士フイルム株式会社 | Magnetic tape and magnetic recording / playback device |
| JP2021120915A (en) * | 2017-09-29 | 2021-08-19 | 富士フイルム株式会社 | Magnetic tape and magnetic recording/reproducing device |
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