JPH0646215B2 - Coercive force measuring device - Google Patents
Coercive force measuring deviceInfo
- Publication number
- JPH0646215B2 JPH0646215B2 JP4332484A JP4332484A JPH0646215B2 JP H0646215 B2 JPH0646215 B2 JP H0646215B2 JP 4332484 A JP4332484 A JP 4332484A JP 4332484 A JP4332484 A JP 4332484A JP H0646215 B2 JPH0646215 B2 JP H0646215B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- magnetic field
- coercive force
- medium
- magneto
- 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
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/12—Measuring magnetic properties of articles or specimens of solids or fluids
- G01R33/14—Measuring or plotting hysteresis curves
Landscapes
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Measuring Magnetic Variables (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は磁気光学効果を利用した保磁力測定装置に関す
るものである。TECHNICAL FIELD The present invention relates to a coercive force measuring device utilizing a magneto-optical effect.
従来例の構成とその問題点 近年、光磁気ディスクは書き換え可能な大容量記録媒体
として注目され、精力的に研究・開発が行われてきてい
る。光磁気記録媒体（以下媒体と略す）の保持力は媒体
の特性の中で最も重要なパラメータの一つであり、媒体
の記録領域上の微少部分の保磁力を広範囲にわたって測
定する必要がある。Structure of Conventional Example and Problems Thereof In recent years, a magneto-optical disk has attracted attention as a rewritable large-capacity recording medium, and research and development have been vigorously carried out. The coercive force of a magneto-optical recording medium (hereinafter abbreviated as medium) is one of the most important parameters in the characteristics of the medium, and it is necessary to measure the coercive force of a minute portion on the recording area of the medium over a wide range.
第１図は、光磁気光学効果を利用した、従来の保磁力測
定装置の構成図である。FIG. 1 is a block diagram of a conventional coercive force measuring device utilizing the magneto-optical effect.
第１図において、１はガスレーザー、半導体レーザ等の
光源、２は偏光子、３はフォトダイオード、光電子増倍
管等の光電変換素子等で構成される受光器、４は検光
子、５はハーフミラー、６は対物レンズ、７はマグネッ
トコイル、８はホール素子等の磁界検出素子、９は光磁
気記録媒体、１０は検光子４と同じ動作、作用効果を持
つ検光子、１１は受光器３と同じ動作、作用効果を持つ
受光器、１２，１３はそれぞれ受光器３，１１の出力を
Ｙ軸に、磁界検出素子８の出力をＸ軸に表示できる表示
装置である。In FIG. 1, 1 is a light source such as a gas laser or semiconductor laser, 2 is a polarizer, 3 is a photodetector composed of a photodiode, a photoelectric conversion element such as a photomultiplier tube, 4 is an analyzer, and 5 is Half mirror, 6 is an objective lens, 7 is a magnet coil, 8 is a magnetic field detecting element such as a Hall element, 9 is a magneto-optical recording medium, 10 is an analyzer having the same operation and effect as the analyzer 4, 11 is a light receiver Optical receivers having the same operations and effects as those of 3, and display devices 12 and 13 capable of displaying the outputs of the optical receivers 3 and 11 on the Y axis and the output of the magnetic field detecting element 8 on the X axis, respectively.
以下に第１図で示した構成で媒体の保磁力を測定する方
法を述べる。The method for measuring the coercive force of the medium with the configuration shown in FIG. 1 will be described below.
光源１を出た光は偏光子２を通過後、直線偏光面を有す
る光となる。この光はハーフミラー５によって、媒体９
の方向に反射される。The light emitted from the light source 1 becomes a light having a linear polarization plane after passing through the polarizer 2. This light is transmitted by the half mirror 5 to the medium 9
Is reflected in the direction of.
媒体９がこの光に対して反射性を有する場合には、光は
光磁気記録媒体９で反射され、検光子４を通過し、受光
器３に達する。受光器３は光の量に対応した信号を表示
装置１２に送る。When the medium 9 has reflectivity for this light, the light is reflected by the magneto-optical recording medium 9, passes through the analyzer 4, and reaches the light receiver 3. The light receiver 3 sends a signal corresponding to the amount of light to the display device 12.
また、媒体９がこの光に対して透過性を有する場合に
は、光は光磁気記録媒体９を透過し、検光子１０を介し
て、受光器１１に達する。受光器11は光の量に対応した
信号を表示装置１３に送る。When the medium 9 is transparent to this light, the light passes through the magneto-optical recording medium 9 and reaches the light receiver 11 via the analyzer 10. The light receiver 11 sends a signal corresponding to the amount of light to the display device 13.
マグネットコイル７により媒体９の受光面に交番磁界を
印加することにより、検光子４又は１０を通過する光量
が変化する。磁界の変化を磁界検出素子８により、又光
量の変化を受光素子３又は１１によって検出し、表示装
置１２又は１３に、カーヒステリシス曲線、又はファラ
デーヒステリシス曲線を描いて、保磁力を表示する。By applying an alternating magnetic field to the light receiving surface of the medium 9 by the magnet coil 7, the amount of light passing through the analyzer 4 or 10 changes. A change in the magnetic field is detected by the magnetic field detecting element 8 and a change in the light amount is detected by the light receiving element 3 or 11, and a Kerr hysteresis curve or a Faraday hysteresis curve is drawn on the display device 12 or 13 to display the coercive force.
さて、第１図に示した従来例の構成を利用して保磁力を
測定する場合、ヒステリシス曲線を描くためには、媒体
９を静止してきわめて低い周波数の交番磁界を印加する
必要がある。直径１２〜30cmの光磁気ディスクの保磁力
を数十平方ミクロンの微少面積について測定し、光磁気
ディスクの全記録領域にわたって保磁力分布を求める必
要がある場合には、上記従来例の構成では、短時間に測
定することができないという問題点を有していた。When measuring the coercive force using the configuration of the conventional example shown in FIG. 1, it is necessary to stop the medium 9 and apply an alternating magnetic field having an extremely low frequency in order to draw a hysteresis curve. When it is necessary to measure the coercive force of a magneto-optical disk having a diameter of 12 to 30 cm for a small area of several tens of square microns and obtain the coercive force distribution over the entire recording area of the magneto-optical disk, It has a problem that it cannot measure in a short time.
発明の目的 本発明は上記従来の問題点を解消するもので、光磁気記
録媒体の保磁力分布測定を短時間に行い得る保磁力測定
装置を提供することを目的とする。An object of the present invention is to solve the above conventional problems, and an object of the present invention is to provide a coercive force measuring device capable of measuring coercive force distribution of a magneto-optical recording medium in a short time.
発明の構成 本発明は、光源からの光を長楕円形の光に変換しさらに
集光する光学系と、前記光学系からの光を透過又は反射
してなる光磁気記録媒体と、前記光磁気記録媒体の光照
射部を挟んで設けられ、かつ前記長楕円光の長手方向に
磁界強度が正から負へ連続して変化するように設けられ
た複数個の磁界印加素子と、前記光磁気記録媒体からの
透過光又は反射光を受光する複数個の受光素子を前記長
手方向に略直線状に設置した受光器とを備えた構成とな
っており、これにより保磁力分布を短時間に測定するこ
とができる。The present invention relates to an optical system that converts light from a light source into oblong-shaped light and further collects the light, a magneto-optical recording medium that transmits or reflects the light from the optical system, and the magneto-optical recording medium. A plurality of magnetic field applying elements provided so as to sandwich a light irradiation part of a recording medium and provided so that the magnetic field strength continuously changes from positive to negative in the longitudinal direction of the oblong light; It is configured to include a plurality of light receiving elements for receiving transmitted light or reflected light from the medium and a light receiver in which the light receiving elements are installed in a substantially straight line in the longitudinal direction, thereby measuring the coercive force distribution in a short time. be able to.
実施例の説明 本発明の実施例について図面にもとづいて説明する。第
２図は本発明の一実施例における透過型の保磁力測定装
置の概略構成図である。第２図において第１図と同一部
材には同一番号を付し説明を省略する。１４は光を長楕
円形に集光するシリンドリカルレンズ、１５，１６は磁
界印加素子であって、光が透過できる部分を有してお
り、さらに同一磁極面が向き合った状態で、かつ完全に
重ならないように配置されている。１７はシリンドリカ
ルレンズ１４が形成する長楕円光の長手方向に一直線に
並んだ受光素子群を有する受光器、１８は受光器１７か
らの信号を表示する表示装置である。Description of Embodiments Embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a schematic configuration diagram of a transmission type coercive force measuring device according to an embodiment of the present invention. In FIG. 2, the same members as those in FIG. Reference numeral 14 is a cylindrical lens for condensing light into an elliptical shape, and 15 and 16 are magnetic field applying elements, each of which has a portion through which light can be transmitted. It is arranged not to become. Reference numeral 17 is a light receiver having a light receiving element group aligned in the longitudinal direction of the oblong light formed by the cylindrical lens 14, and 18 is a display device for displaying a signal from the light receiver 17.
まず、光源１を出た光は偏光子２で直線偏光となり、シ
リンドリカルレンズ１４を通過し、長楕円形の断面を有
する光となる。シリンドリカルレンズ１４の位置は光が
光磁気記録媒体９上で焦点を結ぶように調整する。ま
た、磁界印加素子１５，１６の位置はその切り欠き部を
光が通過するように調整する。光磁気記録媒体９を透過
した光は磁界印加素子１６の切り欠き部を通過し、検光
子４を通過する際に光の偏光面の角度に応じて強度変調
を受け、受光器１７の受光素子に入射する。First, the light emitted from the light source 1 is linearly polarized by the polarizer 2, passes through the cylindrical lens 14, and becomes light having an oblong cross section. The position of the cylindrical lens 14 is adjusted so that the light is focused on the magneto-optical recording medium 9. Further, the positions of the magnetic field applying elements 15 and 16 are adjusted so that light passes through the cutout portions. The light transmitted through the magneto-optical recording medium 9 passes through the cutout portion of the magnetic field applying element 16, and when passing through the analyzer 4, undergoes intensity modulation according to the angle of the polarization plane of the light, and the light receiving element of the light receiver 17 is received. Incident on.
第２図において、磁界印加素子１５は磁力線が下方向に
出るように、また磁界印加素子１６は磁力線が上方向に
出るように、磁界が印加されており、長楕円形の光の長
手方向、すなわち受光素子の並びの方向に、磁界の大き
さと方向が第３図（ａ）に示すように正から負へ連続し
て変化するように構成されている。In FIG. 2, the magnetic field is applied to the magnetic field applying element 15 so that the lines of magnetic force are directed downward, and the magnetic field applying element 16 is applied such that the lines of magnetic force are directed upward, and in the longitudinal direction of the oblong light, That is, the magnitude and direction of the magnetic field are continuously changed from positive to negative in the direction of arrangement of the light receiving elements, as shown in FIG.
なお、第２図に示した構成は媒体の透過光を用いたファ
ラデー効果を利用したものであるが、反射光を用いたカ
ー効果を利用した測定でも利用できる。The configuration shown in FIG. 2 uses the Faraday effect using the transmitted light of the medium, but it can also be used in the measurement using the Kerr effect using the reflected light.
ここで、第３図（ａ）に示した磁界分布の発生の原理に
ついて説明する。Here, the principle of generation of the magnetic field distribution shown in FIG. 3A will be described.
第３図（ｂ）に示した曲線（イ）は、磁界印加素子１５
に矢印で示した方向に磁力線Ｃが発生するように、即ち
磁界印加素子１５の下面がＮ極、上面がＳ極とした場合
における、磁界印加素子１５の下部面に平行で下方に距
離Ｒ１離れた直線Ｌ１上の磁界の強度を表している。The curve (a) shown in FIG. 3 (b) is the magnetic field applying element 15
So that the magnetic force lines C are generated in the direction indicated by the arrow, that is, when the lower surface of the magnetic field applying element 15 is the N pole and the upper surface is the S pole, the distance R1 is parallel to the lower surface of the magnetic field applying element 15 and is downward. The intensity of the magnetic field on the straight line L1 is shown.
また第３図（ｃ）に示した曲線（ロ）は、磁界印加素子
１６に矢印で示した方向に磁力線Ｄが発生するように、
即ち磁界印加素子１６の上面がＮ極、下面がＳ極とした
場合における、磁界印加素子１６の上部面に平行で上方
に距離Ｒ２離れた直線Ｌ２上の磁界の強度を表してい
る。Further, the curve (b) shown in FIG. 3 (c) indicates that the magnetic field lines D are generated in the magnetic field applying element 16 in the direction indicated by the arrow.
That is, when the upper surface of the magnetic field applying element 16 is the N pole and the lower surface is the S pole, the magnetic field strength is shown on the straight line L2 parallel to the upper surface of the magnetic field applying element 16 and separated by the distance R2 upward.
ここで直線Ｌ１とＬ２を一致させ、磁界印加素子１５，
１６を左右に平行移動して位置調整をする。即ち磁界印
加素子１５，１６によって第３図（ａ）に示す磁界強度
分布を得ることができるようにずらして配置する。Here, the straight lines L1 and L2 are made to coincide with each other, and the magnetic field applying elements 15,
Move 16 in parallel to the left and right to adjust the position. That is, the magnetic field applying elements 15 and 16 are arranged so as to be displaced so that the magnetic field strength distribution shown in FIG.
この時、磁界印加素子１５と１６は同一磁極面が向き合
った状態で、かつ完全に重ならないずれた配置状態とな
る。At this time, the magnetic field applying elements 15 and 16 are in a state where the same magnetic pole surfaces face each other and are arranged so that they do not completely overlap.
次に、保磁力測定の方法を以下に説明する。媒体を磁界
印加素子１５と１６の間の空間に第３図（ｂ）及び
（ｃ）の直線Ｌ１，Ｌ２に沿って配し、楕円光の長手方
向に移動させる。媒体上の任意の点に注目すると、この
点は磁界印加素子１５と１６の間の空間を通過する際
に、第３図に示した磁界を破る。媒体上のこの点の保持
力がＨc(Ｈc＜Ｈmax)であるとすると、この点は最初上
向きの磁界Ｈmaxを受け、移動に伴って連続的に小さく
なる磁界を受ける。そして、ある場所で下向きの磁界を
受けるようになり、移動に伴って連続的に大きくなり下
向きの磁界Ｈmaxまで達する磁界を受ける。この点の磁
化は大きさＨｃの下向きの磁界を受けた時に反転する。
磁化の反転により、媒体のファラデー回転角の方向が逆
転するため検光子４を通過する光量が変化する。Next, the method of measuring the coercive force will be described below. The medium is placed in the space between the magnetic field applying elements 15 and 16 along the straight lines L1 and L2 in FIGS. 3B and 3C, and moved in the longitudinal direction of the elliptical light. Focusing on an arbitrary point on the medium, this point breaks the magnetic field shown in FIG. 3 when passing through the space between the magnetic field applying elements 15 and 16. If the coercive force at this point on the medium is H c (H c <H max ), then this point is first subjected to an upward magnetic field H max and then to a continuously decreasing magnetic field as it moves. Then, a downward magnetic field is received at a certain place, and the magnetic field is continuously increased with the movement and reaches a downward magnetic field H max . The magnetization at this point is reversed when it receives a downward magnetic field of magnitude H c .
By reversing the magnetization, the direction of the Faraday rotation angle of the medium is reversed, so that the amount of light passing through the analyzer 4 changes.
媒体に照射した楕円光の長手方向の磁界分布が既知であ
れば、受光器１７の各受光素子に入る入射光の量が、ど
の受光素子を境にして変化しているかが判明すれば、磁
界印加素子１５と１６の間を通過する媒体の保磁力を知
ることができる。If the magnetic field distribution in the longitudinal direction of the elliptical light with which the medium is irradiated is known, if it is known which light receiving element the incident light amount entering each light receiving element of the light receiving unit 17 changes, the magnetic field The coercive force of the medium passing between the application elements 15 and 16 can be known.
第４図は本発明の一実施例における保磁力測定装置の構
成図である。FIG. 4 is a block diagram of a coercive force measuring device in one embodiment of the present invention.
第４図において、第１図，第２図と同一部材には同一番
号を付し説明を省略する。第４図において、１９は円板
形状の光磁気記録媒体で、例えば光磁気ディスクが用い
られる。（以下単にこれを媒体という。）２０は受光器
１７からの信号を表示する表示装置、２１は媒体１９を
回転するための回転機、２２は受光器１７と同じ動作、
作用効果を有する受光器２３からの信号を表示するため
の表示装置である。4, the same members as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 4, reference numeral 19 denotes a disk-shaped magneto-optical recording medium, for example, a magneto-optical disk is used. (Hereinafter, this is simply referred to as a medium.) 20 is a display device for displaying a signal from the light receiver 17, 21 is a rotating machine for rotating the medium 19, 22 is the same operation as the light receiver 17,
It is a display device for displaying a signal from the light receiver 23 having an action effect.
尚、上記構成の保磁力測定装置は、媒体１９が光透過型
の光磁気記録媒体でも反射型の光磁気記録媒体でも測定
できるように受光器等を２ケ所に設けているが、媒体１
９の種類に応じて一方のみの構成にしてもよいことは言
うまでもない。In the coercive force measuring device having the above-described configuration, the light receivers and the like are provided at two locations so that the medium 19 can be measured whether it is a light transmission type magneto-optical recording medium or a reflection type magneto-optical recording medium.
It goes without saying that only one of the configurations may be adopted depending on the nine types.
以上のように構成された本実施例の保磁力測定装置につ
いて、以下にその動作を説明する。The operation of the coercive force measuring device of the present embodiment configured as described above will be described below.
光源１を出た光は偏光子２によって直線偏光面を有する
光となる。この光はシリンドリカルレンズ４を通過後、
長楕円形の断面を有する光となる。この光はハーフミラ
ー５によって媒体１９の方向に反射される。The light emitted from the light source 1 becomes light having a linear polarization plane by the polarizer 2. After this light passes through the cylindrical lens 4,
The light has an oblong cross section. This light is reflected by the half mirror 5 toward the medium 19.
媒体１９がこの光に対して反射性を有する場合には、光
は媒体１９で反射される。この光は検光子４を通過し、
受光器１７に達する。受光器１７はその受光素子群に入
射した光量に応じた信号を表示装置２０に送る。If the medium 19 is reflective to this light, the light is reflected by the medium 19. This light passes through the analyzer 4,
Reach the light receiver 17. The light receiver 17 sends a signal according to the amount of light incident on the light receiving element group to the display device 20.
また、媒体１９がこの光に対して透過性を有する場合に
は、光は媒体１９を通過し、検光子１０を通過して、受
光器２２に達する。受光器２２はその受光素子群に入射
した光量に応じた信号を表示装置２２に送る。If the medium 19 is transparent to this light, the light passes through the medium 19, passes through the analyzer 10, and reaches the light receiver 22. The light receiver 22 sends a signal according to the amount of light incident on the light receiving element group to the display device 22.
一方媒体１９は回転機２１により自転し保磁力が測定さ
れる。On the other hand, the medium 19 is rotated by the rotating machine 21 and the coercive force is measured.
本実施例の構成により、まず媒体１９を回転機２１で回
転させながら、一磁区の保磁力を次々に測定していき、
媒体１９に入射する光、並びに磁界印加素子１５，１６
を媒体１９の径方向に動かして、媒体１９の全記録領域
に対して保磁力分布を測定しているので、従来の方法と
同程度の測定精度を確保し、しかもより短時間の測定を
可能としている。With the configuration of this embodiment, the coercive force of one magnetic domain is sequentially measured while rotating the medium 19 by the rotating machine 21,
Light incident on medium 19 and magnetic field applying elements 15, 16
Is moved in the radial direction of the medium 19 to measure the coercive force distribution over the entire recording area of the medium 19, so the measurement accuracy is as high as that of the conventional method, and a shorter measurement time is possible. I am trying.
尚、媒体１９の全記録領域を測定する場合、光学系又は
磁界印加素子１５，１６を静止させ、媒体１９を径方向
に動かしてもよい。When measuring the entire recording area of the medium 19, the optical system or the magnetic field applying elements 15 and 16 may be stationary and the medium 19 may be moved in the radial direction.
例えば、半径５０mmから半径１８０mmまでの記録領域を
有する媒体１９の保磁力を半径１mm毎に、各測定半径に
対して３０゜づつ隔った１２個の測定点、合計１５６０
個の測定点に対して測定した結果、従来例の構成による
測定では、全ての測定点に対する測定所要時間は約１５
時間であったが、本実施例による保磁力測定では、同数
の測定点について、約６分４０秒で測定が完了した。For example, the coercive force of the medium 19 having a recording area from a radius of 50 mm to a radius of 180 mm is divided into 1 mm radii and 12 measurement points separated by 30 ° for each measurement radius, for a total of 1560.
As a result of measuring the individual measurement points, the measurement time required for all the measurement points is about 15 in the conventional configuration.
Although it was time, in the coercive force measurement according to this example, the measurement was completed in about 6 minutes and 40 seconds at the same number of measurement points.
以上のように本実施例によれば、媒体１９の移動中の保
磁力測定でき、従来の百分の一以下という極めて短時間
に媒体１９の保磁力分布を測定することができる。As described above, according to the present embodiment, the coercive force of the medium 19 can be measured while the medium 19 is moving, and the coercive force distribution of the medium 19 can be measured in an extremely short time of 1/100 or less of the conventional one.
なお、本実施例の構成による保磁力測定装置は光磁気デ
ィスクの磁性媒体製造装置と組み合わせることにより、
磁性媒体製造時の保磁力モニタとして利用することがで
きる。また、本実施例の構成による保持力測定装置は光
磁気ディスクの記録再生機と組み合わせることにより、
保磁力の大小に応じて記録又は消去条件を制御すること
できる。The coercive force measuring device having the configuration of the present embodiment is combined with a magnetic medium manufacturing device for a magneto-optical disk,
It can be used as a coercive force monitor when manufacturing a magnetic medium. Further, the coercive force measuring device according to the configuration of this embodiment is combined with a magneto-optical disk recording / reproducing device,
Recording or erasing conditions can be controlled according to the magnitude of the coercive force.
発明の効果 本発明は、光磁気記録媒体の移動中に保磁力測定ができ
るとともに、保磁力測定時間を大幅に短縮できる保磁力
測定装置を実現でき、その効果は大なるものがある。EFFECTS OF THE INVENTION The present invention can realize a coercive force measuring device capable of measuring coercive force during movement of a magneto-optical recording medium and significantly shortening the coercive force measuring time, and the effect thereof is great.
第１図は従来の保磁力測定装置の構成図、第２図は本発
明の一実施例における保磁力測定装置の概略構成図、第
３図は同磁界引加素子が作る磁界分布図、第４図は同保
磁力測定装置の構成図である。 １……光源、１４……シリンドリカルレンズ、１５，１
６……磁界印加素子、１７，２３……受光器、１９……
光磁気記録媒体、２１……回転機。FIG. 1 is a configuration diagram of a conventional coercive force measuring device, FIG. 2 is a schematic configuration diagram of a coercive force measuring device in one embodiment of the present invention, and FIG. 3 is a magnetic field distribution diagram created by the magnetic field adding element. FIG. 4 is a block diagram of the coercive force measuring device. 1 ... Light source, 14 ... Cylindrical lens, 15, 1
6 ... Magnetic field applying element, 17, 23 ... Photo receiver, 19 ...
Magneto-optical recording medium, 21 ... Rotating machine.
Claims (3)
に集光する光学系と、前記光学系からの光を透過又は反
射してなる光磁気記録媒体と、前記光磁気記録媒体の光
照射部を挟んで設けられ、かつ前記長楕円光の長手方向
に磁界強度が正から負へ連続して変化するように設けら
れた複数個の磁界印加素子と、前記光磁気記録媒体から
の透過光又は反射光を受光する複数個の受光素子を前記
長手方向に略直線状に設置した受光器を備えたことを特
徴とする保磁力測定装置。1. An optical system for converting light from a light source into oblong-shaped light and further condensing it, a magneto-optical recording medium for transmitting or reflecting the light from the optical system, and the magneto-optical recording medium. From the magneto-optical recording medium, and a plurality of magnetic field applying elements that are provided so as to sandwich the light irradiating section and that are provided so that the magnetic field strength continuously changes from positive to negative in the longitudinal direction of the oblong light. 2. A coercive force measuring device comprising a light receiver in which a plurality of light receiving elements for receiving the transmitted light or the reflected light are installed in a substantially linear shape in the longitudinal direction.
った状態で、かつ完全に重ならないように配置したこと
を特徴とする特許請求の範囲第１項記載の保磁力測定装
置。2. The coercive force measuring device according to claim 1, wherein the two magnetic field applying elements are arranged so that the same magnetic pole faces face each other and do not completely overlap each other.
素子を備えたことを特徴とする特許請求の範囲第１項記
載の保磁力測定装置。3. The coercive force measuring device according to claim 1, further comprising a magnetic field applying element having a portion that does not prevent passage of light.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4332484A JPH0646215B2 (en) | 1984-03-06 | 1984-03-06 | Coercive force measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4332484A JPH0646215B2 (en) | 1984-03-06 | 1984-03-06 | Coercive force measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60186768A JPS60186768A (en) | 1985-09-24 |
| JPH0646215B2 true JPH0646215B2 (en) | 1994-06-15 |
Family
ID=12660631
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4332484A Expired - Lifetime JPH0646215B2 (en) | 1984-03-06 | 1984-03-06 | Coercive force measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0646215B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2605042B2 (en) * | 1987-06-03 | 1997-04-30 | 株式会社日立製作所 | Magnetic defect inspection device |
-
1984
- 1984-03-06 JP JP4332484A patent/JPH0646215B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60186768A (en) | 1985-09-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100474038C (en) | Optical device | |
| US5131744A (en) | Mirror rotation angle detection mechanism | |
| US7106683B2 (en) | Optical pickup device and recording/reproducing device | |
| US5119361A (en) | Optical information readout apparatus | |
| CA2004377A1 (en) | Optical output controlling method and apparatus therefor | |
| JPH0646215B2 (en) | Coercive force measuring device | |
| US5119352A (en) | Magneto optic data storage read out apparatus and method | |
| US6741528B1 (en) | Magneto-optical head device | |
| JPH10500524A (en) | Optical focusing adjustment device | |
| US5101393A (en) | Optical position error detection using complementary steep angle reflections/transmissions | |
| US6246657B1 (en) | Fiber bundle switch | |
| JPH0478029A (en) | Optical information recording and reproducing device | |
| JPH11250484A (en) | Monitor optical system and optical recording and reproducing device | |
| JPH10269614A (en) | Polarization proximity field light detecting head and optical information recording and reproducing device using the same | |
| CN1732519A (en) | Disc drive for an optical scanning device | |
| JPH07334887A (en) | Positioning method for magnetic head | |
| JPS61237241A (en) | Photomagnetic recording and reproducing device | |
| JPS639305B2 (en) | ||
| JPH0673202B2 (en) | Magneto-optical reproducing device | |
| JPS6361936A (en) | Double reflection measuring instrument | |
| JPH02165077A (en) | Optical measurement of magnetic field and detector | |
| JPH02168180A (en) | Method for optically measuring magnetic field and detection element | |
| JPH0746440B2 (en) | Optical recording / reproducing device | |
| JPH02123530A (en) | Optical recording medium driving device | |
| KR20060003283A (en) | Apparatus of optical pick-up |