JPH064926A - Magneto-optical disk device - Google Patents

Abstract

PURPOSE:To miniaturize and lighten a device by eliminating a recording magnet related to a recording magnetic layer and making a magnet for optical head drive magnetic field share its function. CONSTITUTION:This device is constituted so that a part of magnetic flux 5a of a driving magnet 5 traverses a driving coil 4 to straight drive an optical head 1 and the other magnetic flux 5b passes through the position of the laser beam spot 2 of a disk 3 at right angles to the surface, and the driving magnet serves also as the recording magnet 10 in a usual example functionally. Further, respective driving magnets 5 of a pair of left and right are arranged symmetrically to the moving plane of the optical path of the optical head 1 and since the directions of respective generative magnetic field are opposed to each other, the strength of the magnetic field in the laser beam spot 2 is doubled. Further, since an initialization magnet 9 is arranged on the same side as the optical head 1 to the disk 3, the size of the optical head in the direction of the optical axis is reduceable and the device is miniaturized.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】この発明は、初期化層，記録層の
２磁性層を有する光磁気ディスクに情報が消去動作なし
に再記録される光強度変調方式の装置であって、記録磁
性層に係る記録用磁石を、光ヘッドの駆動磁界用磁石に
機能的に兼ねさせることによって削除し、小形化，軽量
化を図る光磁気ディスク装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light intensity modulation type apparatus in which information is re-recorded on a magneto-optical disk having two magnetic layers, an initializing layer and a recording layer, without a erasing operation. The present invention relates to a magneto-optical disk device in which the recording magnet according to (1) is deleted by making the magnet for the driving magnetic field of the optical head also serve as a function, thereby reducing the size and weight.

【０００２】[0002]

【従来の技術】従来例は、初期化層，記録層の２磁性層
を有する光磁気ディスクに、情報が消去動作なしに再記
録される光強度変調方式の光磁気ディスク装置である。
図２は従来例の斜視図で、後述する発明に係る実施例と
共通である。図２において、光ヘッド１が、その一対の
軸受1aと、対応して平行に配設されたガイド軸８との滑
動嵌合に基づき、ガイド軸８に沿って直進可能に案内さ
れる。光ヘッド１の上面から出射されるレーザ光が、ス
ポット状に絞られて、一点鎖線表示の光磁気ディスク
（以下、ディスクという）３の記録媒体を照射し、その
照射箇所は、光ヘッド１の直進とともにディスク３の半
径に沿って移動可能である。光ヘッド１は、一対のボイ
スコイル・モータによって直進駆動される。すなわち、
ボイスコイル・モータは、光ヘッド1 の左右各側面に付
設されたコイル４と、永久磁石６およびヨーク７からな
る磁気回路とによって構成される。コイル４を流れる電
流が、磁気回路の磁界内で受ける電磁力によって、光ヘ
ッド1 は駆動される。2. Description of the Related Art A conventional example is an optical intensity modulation type magneto-optical disk device in which information is re-recorded on a magneto-optical disk having two magnetic layers, an initialization layer and a recording layer, without erasing operation.
FIG. 2 is a perspective view of a conventional example, which is common to an embodiment according to the invention described later. In FIG. 2, the optical head 1 is guided so as to be able to move straight along the guide shaft 8 based on the sliding fitting between the pair of bearings 1a and the corresponding guide shaft 8 arranged in parallel. The laser light emitted from the upper surface of the optical head 1 is focused into a spot shape and irradiates a recording medium of a magneto-optical disk (hereinafter referred to as a disk) 3 indicated by a chain line, and the irradiation location is the position of the optical head 1. It can move along the radius of the disk 3 as it goes straight. The optical head 1 is driven straight by a pair of voice coil motors. That is,
The voice coil motor is composed of a coil 4 attached to each of the left and right side surfaces of the optical head 1, and a magnetic circuit including a permanent magnet 6 and a yoke 7. The optical head 1 is driven by the electromagnetic force that the current flowing through the coil 4 receives in the magnetic field of the magnetic circuit.

【０００３】図３は従来例の側面図である。図３におい
て、光ヘッド１からの、記録信号に基づき光強度変調さ
れて出射され、直径約１μｍのレーザ光スポット２に絞
られたレーザ光の照射によって、ディスク３の照射箇所
の温度が局所的に上昇する。その箇所は同時に外部磁界
の影響を受け、詳しく後述するように、情報が消去動作
なしに再記録される。なお、情報再生のときには、光強
度の弱いレーザ光スポットの照射による反射光の偏光面
の回転方向を検出することで、ディスクの磁化方向つま
り情報を得ることができる。FIG. 3 is a side view of a conventional example. In FIG. 3, the temperature of the irradiated portion of the disk 3 is locally changed by the irradiation of the laser light emitted from the optical head 1 with its light intensity modulated on the basis of the recording signal and focused on the laser light spot 2 having a diameter of about 1 μm. Rise to. At the same time, that portion is affected by an external magnetic field, and information is re-recorded without an erasing operation, as described later in detail. During information reproduction, the magnetization direction of the disk, that is, information can be obtained by detecting the rotation direction of the polarization plane of the reflected light due to the irradiation of the laser light spot having a weak light intensity.

【０００４】図４はディスクの２磁性層構造と再記録動
作を示す模式図である。ディスクは記録層３ｍと初期化
層３ｉを備える。初期化層３ｉは、保持力が小さく、キ
ュリー温度が高い。逆に、記録層３ｍは、保持力が大き
く、キュリー温度が低い。まず、回転するディスクで、
レーザ光の照射箇所つまり記録をおこなう位置から右側
に外れた位置で、初期化磁石９によって保持力の小さい
初期化層３ｉの磁化を下向き矢印の方向に配向させる。
このとき、記録層３ｍの磁化は、保持力が初期化磁石９
の磁界Ｈo より大きいため、その磁界Ｈo の方向には反
転しない。その状態で、レーザ光照射箇所までくると、
常時そこでは磁界Ｈo と逆方向でこれより弱い記録用磁
石10による磁界Ｈm がかけられている。ここで、照射レ
ーザ光の光強度が弱いときには、キュリー温度の高い初
期化層３ｉの磁化はそのまま保存され、キュリー温度の
低い記録層３ｍだけが保持力が小さくなり反転しやすく
なる。したがって、記録層３ｍの磁化は、冷却過程で交
換結合によって、初期化層３ｉの磁化方向に配向する。
一方、照射レーザ光の光強度が強いときには、初期化層
３ｉ, 記録層３ｍいずれもキュリー温度に達するから、
全体が記録用磁石10による磁界Ｈm の方向に向くことに
なる。すなわち、照射レーザ光の光強度の違いだけで磁
化の方向が決まるから、旧データを消去する過程をへず
に新データの記録( オーバライト) が可能となる。FIG. 4 is a schematic diagram showing the two-magnetic layer structure of the disk and the re-recording operation. The disc includes a recording layer 3m and an initialization layer 3i. The initialization layer 3i has a low holding power and a high Curie temperature. On the contrary, the recording layer 3m has a large holding power and a low Curie temperature. First, with the spinning disc,
At the position irradiated with the laser beam, that is, at the position deviated to the right from the position where recording is performed, the initialization magnet 9 orients the magnetization of the initialization layer 3i having a small coercive force in the direction of the downward arrow.
At this time, the magnetization of the recording layer 3m has a coercive force of the initialization magnet 9
Since it is larger than the magnetic field Ho of the magnetic field Ho, it does not reverse in the direction of the magnetic field Ho. In that state, when it reaches the laser light irradiation point,
A magnetic field Hm generated by a recording magnet 10 weaker than the magnetic field Ho is always applied thereto. Here, when the light intensity of the irradiation laser light is weak, the magnetization of the initialization layer 3i having a high Curie temperature is preserved as it is, and only the recording layer 3m having a low Curie temperature has a low coercive force and is easily inverted. Therefore, the magnetization of the recording layer 3m is oriented in the magnetization direction of the initialization layer 3i by exchange coupling in the cooling process.
On the other hand, when the intensity of the irradiation laser light is high, both the initialization layer 3i and the recording layer 3m reach the Curie temperature,
The whole is oriented in the direction of the magnetic field Hm generated by the recording magnet 10. That is, since the direction of magnetization is determined only by the difference in the light intensity of the irradiation laser light, new data can be recorded (overwrite) without the process of erasing old data.

【０００５】[0005]

【発明が解決しようとする課題】従来例では、外部磁石
として初期化磁石９と、記録用磁石10との二つが必要で
あり、それだけ部品点数が増し、ひいては重量も増すと
いう欠点が生じる。さらに、記録用磁石10は、構造上ど
うしてもディスク3 の光ヘッド1 とは逆側に配置しなけ
ればならないから、装置のディスク3 と直角方向の寸法
が大きくなるという問題も起こる。In the conventional example, the initialization magnet 9 and the recording magnet 10 are required as two external magnets, which causes a drawback that the number of parts increases and the weight also increases. Further, since the recording magnet 10 must be arranged on the side of the disk 3 opposite to the optical head 1 due to the structure, there is a problem that the size of the device in the direction perpendicular to the disk 3 becomes large.

【０００６】この発明の課題は、従来の技術がもつ以上
の問題点を解消し、記録磁性層に係る記録用磁石を、光
ヘッドの駆動磁界用磁石に機能的に兼ねさせることによ
って削除し、小形化，軽量化を図る光磁気ディスク装置
を提供することにある。The object of the present invention is to eliminate the above-mentioned problems of the prior art and to eliminate the recording magnet relating to the recording magnetic layer by making it function as a driving magnetic field magnet of the optical head. An object of the present invention is to provide a magneto-optical disk device that is compact and lightweight.

【０００７】[0007]

【課題を解決するための手段】請求項１に係る光磁気デ
ィスク装置は、初期化層，記録層の２磁性層を有する光
磁気ディスクに情報が消去動作なしに再記録される光強
度変調方式の装置において、前記光磁気ディスクの半径
方向に沿って光ヘッドを駆動するための駆動磁界発生手
段が、その発生磁束の一部を前記光磁気ディスクのレー
ザ光照射箇所でその光磁気ディスクの面と直角に通過さ
せることによって、その光磁気ディスクの記録磁性層に
係る記録磁界発生手段を機能的に兼ねる構成にする。A magneto-optical disk apparatus according to a first aspect of the present invention is a light intensity modulation system in which information is re-recorded on a magneto-optical disk having two magnetic layers, an initialization layer and a recording layer, without erasing operation. In the above device, the driving magnetic field generating means for driving the optical head along the radial direction of the magneto-optical disk, a part of the generated magnetic flux is a surface of the magneto-optical disk at a laser light irradiation position of the magneto-optical disk. By passing the magnetic field at a right angle to the recording magnetic field generating means for the recording magnetic layer of the magneto-optical disk, the function is also provided.

【０００８】請求項２に係る光磁気ディスク装置は、請
求項１に記載の装置において、駆動磁界発生手段が、光
ヘッドの光軸の移動平面に関して対称に配置される一対
であり、その各発生磁界の方向が対向する。請求項３に
係る光磁気ディスク装置は、請求項１または２に記載の
装置において、光磁気ディスクの初期化磁性層に係る初
期化磁界発生手段が、光磁気ディスクに対し光ヘッドと
同じ側に配置される。According to a second aspect of the present invention, there is provided a magneto-optical disk device according to the first aspect, wherein the drive magnetic field generating means is a pair arranged symmetrically with respect to a moving plane of an optical axis of the optical head, and each of them is generated. The directions of the magnetic fields are opposite. A magneto-optical disk device according to a third aspect is the device according to the first or second aspect, wherein the initialization magnetic field generating means associated with the initialization magnetic layer of the magneto-optical disc is located on the same side of the magneto-optical disc as the optical head. Will be placed.

【０００９】[0009]

【作用】請求項１ないし３のいずれかの項に係る光磁気
ディスク装置では、光ヘッド駆動用の駆動磁界発生手段
の発生磁束の一部が、光磁気ディスクのレーザ光照射箇
所でその面と直角に通過することで、光磁気ディスクの
記録磁性層に係る記録磁界発生手段の機能が代替され
る。In the magneto-optical disk device according to any one of claims 1 to 3, a part of the magnetic flux generated by the drive magnetic field generating means for driving the optical head is brought into contact with the surface of the magneto-optical disk at the laser light irradiation position. By passing at a right angle, the function of the recording magnetic field generating means relating to the recording magnetic layer of the magneto-optical disk is replaced.

【００１０】とくに請求項３に係る光磁気ディスク装置
では、一対の駆動磁界発生手段が、その各発生磁界の方
向が対向するように、光ヘッドの光軸の移動平面に関し
て対称に配置される。とくに請求項２に係る光磁気ディ
スク装置では、光磁気ディスクの初期化磁性層に係る初
期化磁界発生手段が、光磁気ディスクに対して光ヘッド
と同じ側に配置される。Particularly, in the magneto-optical disk device according to the third aspect, the pair of driving magnetic field generating means are arranged symmetrically with respect to the moving plane of the optical axis of the optical head so that the directions of the respective magnetic fields generated are opposed to each other. Particularly, in the magneto-optical disk device according to the second aspect, the initialization magnetic field generating means for the initialization magnetic layer of the magneto-optical disk is arranged on the same side of the magneto-optical disk as the optical head.

【００１１】[0011]

【実施例】この発明に係る光磁気ディスク装置の実施例
について、以下に図を参照しながら説明する。図１は実
施例の側面図、図２は実施例の斜視図で、既に述べた従
来例と共通である。この実施例が従来例と異なる点は、
駆動用磁石を変更し、その磁束の一部がディスクのレー
ザ光照射箇所でその面と直角に通過するようにすること
によって、従来例における記録用磁石の機能を代替させ
たことである。すなわち、図１において、駆動用磁石５
の一部の磁束５ａが、駆動用コイル４を横切って光ヘッ
ド１を直進駆動させ、他の磁束５ｂが、ディスク３のレ
ーザ光スポット２の箇所で、その面と直角に通過するよ
うにし、従来例における記録磁石10を機能的に兼ねる構
成にする。そのため、駆動用磁石５は、従来例における
より縦方向寸法が大きくとられるとともに、起磁力が増
強される。また、ヨーク７の駆動用コイル４を貫通する
部分の縦方向寸法を、磁束５ｂが通過しやすいように小
さくし、その部分を含むヨーク７の材質の飽和磁束密度
を、磁束５ｂが取り込まれないように低く抑える。しか
も、左右一対の各駆動用磁石５が、光ヘッド１の光軸の
移動平面（光軸を含み紙面と直角な平面）に関して対称
に配置され、その各発生磁界の方向が対向するから、レ
ーザ光スポット２における磁界の強さは倍増される、言
いかえれば駆動用磁石５をそれだけ小形化することがで
きる。さらに、初期化磁石９の配置は、ディスク３に対
し光ヘッド１と同じ側にすることができるから、その分
だけ光ヘッド１の光軸方向の寸法を短縮可能で、装置の
小形化を支援する。DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a magneto-optical disk device according to the present invention will be described below with reference to the drawings. FIG. 1 is a side view of the embodiment and FIG. 2 is a perspective view of the embodiment, which is common to the conventional example already described. The difference between this embodiment and the conventional example is that
This is to replace the function of the recording magnet in the conventional example by changing the driving magnet so that a part of its magnetic flux passes through the disk at the laser light irradiation position at right angles to its surface. That is, in FIG. 1, the driving magnet 5
Part of the magnetic flux 5a drives the optical head 1 straightly across the drive coil 4, and the other magnetic flux 5b passes at the laser light spot 2 of the disk 3 at a right angle to its surface, The recording magnet 10 in the conventional example is configured to have a function also. Therefore, the driving magnet 5 has a larger vertical dimension than that in the conventional example, and the magnetomotive force is enhanced. Further, the vertical dimension of the portion of the yoke 7 penetrating the driving coil 4 is reduced so that the magnetic flux 5b can easily pass therethrough, and the saturation magnetic flux density of the material of the yoke 7 including the portion is not taken in by the magnetic flux 5b. To keep it low. Moreover, the pair of left and right driving magnets 5 are arranged symmetrically with respect to the moving plane of the optical axis of the optical head 1 (the plane including the optical axis and perpendicular to the paper surface), and the directions of the respective magnetic fields generated are opposed to each other. The strength of the magnetic field at the light spot 2 is doubled, in other words, the drive magnet 5 can be made smaller accordingly. Further, since the initialization magnet 9 can be arranged on the same side as the optical head 1 with respect to the disk 3, the dimension of the optical head 1 in the optical axis direction can be shortened by that amount, and the miniaturization of the device is supported. To do.

【００１２】[0012]

【発明の効果】請求項１ないし３のいずれかの項に係る
光磁気ディスク装置では、光ヘッド駆動用の駆動磁界発
生手段の発生磁束の一部が、光磁気ディスクのレーザ光
照射箇所でその面と直角に通過することで、光磁気ディ
スクの記録磁性層に係る記録磁界発生手段の機能が代替
される。したがって、記録磁界発生手段が削除され、そ
の分だけ装置の小形化，軽量化が図れる。In the magneto-optical disk device according to any one of claims 1 to 3, a part of the magnetic flux generated by the driving magnetic field generating means for driving the optical head is generated at the laser light irradiation portion of the magneto-optical disk. By passing at right angles to the surface, the function of the recording magnetic field generating means relating to the recording magnetic layer of the magneto-optical disk is replaced. Therefore, the recording magnetic field generating means is eliminated, and the size and weight of the device can be reduced accordingly.

【００１３】とくに請求項２に係る光磁気ディスク装置
では、一対の駆動磁界発生手段が、その各発生磁界の方
向が対向するように、光ヘッドの光軸の移動平面に関し
て対称に配置されるから、記録磁界発生手段の機能が強
化され、言いかえれば駆動磁界発生手段の小形化が図
れ、ひいては装置の小形化，軽量化が支援される。とく
に請求項２に係る光磁気ディスク装置では、光磁気ディ
スクの初期化磁性層に係る初期化磁界発生手段が、光磁
気ディスクに対して光ヘッドと同じ側に配置されるか
ら、その逆側に配置される部材はなく、したがって装置
の小形化が支援される。Particularly, in the magneto-optical disk device according to the second aspect, the pair of driving magnetic field generating means are arranged symmetrically with respect to the moving plane of the optical axis of the optical head so that the directions of the respective magnetic fields generated are opposed to each other. The function of the recording magnetic field generating means is enhanced, in other words, the driving magnetic field generating means can be downsized, which in turn supports the downsizing and weight reduction of the device. Particularly, in the magneto-optical disk device according to the second aspect, the initialization magnetic field generating means relating to the initialization magnetic layer of the magneto-optical disk is arranged on the same side as the optical head with respect to the magneto-optical disk. There are no components to be placed, thus helping miniaturization of the device.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明に係る実施例の側面図FIG. 1 is a side view of an embodiment according to the present invention.

【図２】実施例と従来例との共通な斜視図FIG. 2 is a perspective view common to an embodiment and a conventional example.

【図３】従来例の側面図FIG. 3 is a side view of a conventional example.

【図４】ディスクの２磁性層構造と再記録動作を示す模
式図FIG. 4 is a schematic diagram showing a two-magnetic layer structure of a disc and a re-recording operation.

【符号の説明】[Explanation of symbols]

１ 光ヘッド ２ レーザ光スポット ３ ディスク（光磁気ディスク） ３ｉ 初期化層 ３ｍ 記録層 ４ 駆動用コイル ５ 駆動用磁石 ５ａ 磁束 ５ｂ 磁束 ７ ヨーク ８ ガイド軸 ９ 初期化磁石 1 optical head 2 laser light spot 3 disk (magneto-optical disk) 3i initialization layer 3m recording layer 4 drive coil 5 drive magnet 5a magnetic flux 5b magnetic flux 7 yoke 8 guide axis 9 initialization magnet

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】初期化層，記録層の２磁性層を有する光磁
気ディスクに情報が消去動作なしに再記録される光強度
変調方式の装置において、前記光磁気ディスクの半径方
向に沿って光ヘッドを駆動するための駆動磁界発生手段
が、その発生磁束の一部を前記光磁気ディスクのレーザ
光照射箇所でその光磁気ディスクの面と直角に通過させ
ることによって、その光磁気ディスクの記録磁性層に係
る記録磁界発生手段を機能的に兼ねる構成にしたことを
特徴とする光磁気ディスク装置。1. A device of a light intensity modulation type in which information is re-recorded on a magneto-optical disk having two magnetic layers of an initializing layer and a recording layer without an erasing operation, in which light is read along the radial direction of the magneto-optical disk. The drive magnetic field generating means for driving the head passes a part of the generated magnetic flux at a laser light irradiation position of the magneto-optical disk at a right angle to the surface of the magneto-optical disk, thereby recording magnetic field of the magneto-optical disk. A magneto-optical disk device having a structure which also functions as a recording magnetic field generating means relating to the layers. 【請求項２】請求項１に記載の装置において、駆動磁界
発生手段は、光ヘッドの光軸の移動平面に関して対称に
配置される一対であり、その各発生磁界の方向が対向す
ることを特徴とする光磁気ディスク装置。2. The apparatus according to claim 1, wherein the driving magnetic field generating means are a pair arranged symmetrically with respect to the moving plane of the optical axis of the optical head, and the directions of the respective generated magnetic fields are opposed to each other. Magneto-optical disk device. 【請求項３】請求項１または２に記載の装置において、
光磁気ディスクの初期化磁性層に係る初期化磁界発生手
段が、光磁気ディスクに対して光ヘッドと同じ側に配置
されることを特徴とする光磁気ディスク装置。3. The apparatus according to claim 1 or 2, wherein
A magneto-optical disk device, wherein an initialization magnetic field generating means for the initialization magnetic layer of the magneto-optical disk is arranged on the same side as the optical head with respect to the magneto-optical disk.