公开(公告)号：US5637394A

公开(公告)日：1997-06-10

申请号：US356857

申请日：1994-12-15

申请人： Junsaku Nakajima ,  Naoyasu Iketani ,  Yoshiteru Murakami ,  Akira Takahashi ,  Hiroyuki Katayama ,  Kenji Ohta

发明人： Junsaku Nakajima ,  Naoyasu Iketani ,  Yoshiteru Murakami ,  Akira Takahashi ,  Hiroyuki Katayama ,  Kenji Ohta

IPC分类号： G11B11/105 ,  G11B5/66

CPC分类号： G11B11/10586 ,  G11B11/10515 ,  G11B11/10584 ,  Y10S428/90 ,  Y10T428/26 ,  Y10T428/265

摘要： A magneto-optical recording medium comprising a readout layer and a recording layer has a relationship that an external magnetic field H1 is smaller than an external magnetic field H4, where the H1 is a minimum external magnetic field necessary to make a magnetization direction of the readout layer direct to the direction reverse to a magnetization direction of the recording layer substantially at the room temperature, and the H4 is a maximum external magnetic field necessary to make the magnetization direction of the readout layer direct to the direction same as the magnetization direction of the recording layer at an high temperature not lower than a predetermined temperature. Moreover, the magneto-optical disk is provided, between the readout layer and the recording layer, with an intermediate layer which inhibits an effective bias magnetic field from the recording layer to the readout layer at the room temperature. Since it is possible to reproduce only the information in the high-temperature area close to the center of the laser beam irradiated during reproducing, recording density is improved. Furthermore, since an initializing magnetic field at reproducing is not necessary and the reproducing magnetic field can be made smaller, the apparatus can be made smaller and the electric power consumption can be decreased.

摘要翻译： 包括读出层和记录层的磁光记录介质具有外部磁场H1小于外部磁场H4的关系，其中H1是使读出磁化方向发生所需的最小外部磁场 层直接与基本上在室温下的记录层的磁化方向相反的方向，并且H4是使读出层的磁化方向直到与磁化方向相同的方向所需的最大外部磁场 记录层在不低于预定温度的高温下进行。 此外，在读出层和记录层之间设置磁光盘，其中间层在室温下抑制从记录层到读出层的有效偏置磁场。 由于只能再现靠近在再现期间照射的激光束的中心的高温区域的信息，所以记录密度提高。 此外，由于不需要再现时的初始化磁场并且可以使再现磁场更小，所以可以使装置更小，并且可以降低电力消耗。

公开(公告)号：US06665235B2

公开(公告)日：2003-12-16

申请号：US10214881

申请日：2002-08-08

申请人： Yoshiteru Murakami ,  Junji Hirokane ,  Junichiro Nakayama ,  Junsaku Nakajima ,  Akira Takahashi ,  Kenji Ohta ,  Naoyasu Iketani

发明人： Yoshiteru Murakami ,  Junji Hirokane ,  Junichiro Nakayama ,  Junsaku Nakajima ,  Akira Takahashi ,  Kenji Ohta ,  Naoyasu Iketani

IPC分类号： G11B1100

CPC分类号： G11B11/10586 ,  B60T1/005 ,  F16D63/00 ,  G11B7/00718 ,  G11B7/126 ,  G11B11/10506 ,  G11B11/10515 ,  G11B11/10517 ,  G11B11/10543 ,  G11B11/10595

摘要： Featured is a recording and reproducing method of a magneto-optical recording medium including a recording layer for recording thereon information magneto-optically and a readout layer which has in-plane magnetization at room temperature and where a transition occurs from in-plane magnetization to perpendicular magnetization as temperature raises. The method includes projecting a light beam onto such a magneto-optical recording medium so as to form a perpendicularly magnetized area in the readout layer by duplication of the magnetization of said recording layer to the area. In further embodiments, the recording medium further includes an intermediate layer made of non-magnetic film formed between the readout and recording layers and the readout and recording layers are composed of rare-earth transition metal alloys such as TbFeCo (recoding layer) readout layer, made of GdFeCo (readout layer).

摘要翻译： 特别是磁光记录介质的记录和再现方法，其包括用于在其上记录磁光信息的记录层和在室温下具有面内磁化的读出层，并且其中从面内磁化转变为垂直 磁化随温度升高。 该方法包括将光束投影到这种磁光记录介质上，以便通过将所述记录层的磁化复制到该区域而在读出层中形成垂直磁化区域。 在另外的实施例中，记录介质还包括由读出和记录层之间形成的非磁性膜制成的中间层，并且读出和记录层由稀土过渡金属合金如TbFeCo（记录层）读出层， 由GdFeCo（读出层）制成。

公开(公告)号：US06483785B1

公开(公告)日：2002-11-19

申请号：US09685829

申请日：2000-10-10

申请人： Yoshiteru Murakami ,  Junji Hirokane ,  Junichiro Nakayama ,  Junsaku Nakajima ,  Akira Takahashi ,  Kenji Ohta ,  Naoyasu Iketani

发明人： Yoshiteru Murakami ,  Junji Hirokane ,  Junichiro Nakayama ,  Junsaku Nakajima ,  Akira Takahashi ,  Kenji Ohta ,  Naoyasu Iketani

IPC分类号： G11B1100

CPC分类号： G11B7/126 ,  G11B7/00718 ,  G11B11/10506 ,  G11B11/10515 ,  G11B11/10517 ,  G11B11/10543 ,  G11B11/10584 ,  G11B11/10586 ,  G11B11/10595 ,  Y10S428/90

摘要： Featured is a recording and reproducing method for recording and reproducing information on and from a recording medium. The medium includes a base having a property that a light can be transmitted therethrough, a readout layer formed on the base, which has an in-plane magnetization at room temperature, whereas, a transition occurs from in-plane magnetization to perpendicular magnetization as temperature rises and a recording layer formed on said readout layer for recording thereon information magneto-optically. A groove for guiding a light beam is formed on a readout layer side of the base and a groove width is set substantially equal to a land width formed between grooves. The recording layer on the grooves and the recording layer on lands are used in recording and reproducing information. Further a light beam is incident on a converging lens of an optical head, the light beam having a larger diameter &ohgr; than an aperture &agr; of the converging lens for converging the light beam on a predetermined position of the magneto-optical recording medium.

摘要翻译： 特色是用于在记录介质上记录和再现信息的记录和再现方法。 该介质包括具有光可以透射的性质的基底，形成在基底上的读出层，其在室温下具有面内磁化强度，而从平面内磁化转变为垂直磁化转变为温度 并且在所述读出层上形成用于在其上记录光学信息的记录层。 在基板的读出层侧形成用于引导光束的槽，并且将槽宽度设定为与槽之间形成的焊盘宽度大致相等。 凹槽上的记录层和焊盘上的记录层用于记录和再现信息。 此外，光束入射到光学头的会聚透镜上，所述光束具有比会聚透镜的孔径α更大的直径Ω，用于将光束会聚在磁光记录介质的预定位置。

公开(公告)号：US06261707B1

公开(公告)日：2001-07-17

申请号：US08147373

申请日：1993-11-03

申请人： Yoshiteru Murakami ,  Junji Hirokane ,  Junichiro Nakayama ,  Junsaku Nakajima ,  Akira Takahashi ,  Kenji Ohta ,  Naoyasu Iketani

发明人： Yoshiteru Murakami ,  Junji Hirokane ,  Junichiro Nakayama ,  Junsaku Nakajima ,  Akira Takahashi ,  Kenji Ohta ,  Naoyasu Iketani

IPC分类号： G11B566

CPC分类号： G11B7/126 ,  G11B7/00718 ,  G11B11/10506 ,  G11B11/10515 ,  G11B11/10517 ,  G11B11/10543 ,  G11B11/10584 ,  G11B11/10586 ,  G11B11/10595 ,  Y10S428/90

摘要： A magneto-optical recording medium is composed of a base which has a property that a light can be transmitted therethrough, a readout layer formed on the base, which has in-plane magnetization at room temperature, whereas, a transition occurs from in-plane magnetization to perpendicular magnetization as the temperature thereof is raised and a recording layer formed on the readout layer for recording information magneto-optically. A recording and reproducing method and the optical head are designed for the magneto-optical recording medium. By the recording and reproducing method using the optical head, information recorded at high density can be reproduced.

摘要翻译： 磁光记录介质由具有光透射性的基底组成，形成在基底上的读出层，其在室温下具有面内磁化，而从平面内发生转变 随着其温度升高，磁化至垂直磁化，以及形成在读出层上用于磁光记录信息的记录层。 记录和再现方法和光学头被设计用于磁光记录介质。 通过使用光学头的记录和再现方法，可以再现以高密度记录的信息。

公开(公告)号：US5707727A

公开(公告)日：1998-01-13

申请号：US395165

申请日：1995-02-27

申请人： Akira Takahashi ,  Yoshiteru Murakami ,  Junsaku Nakajima ,  Kenji Ohta ,  Junichiro Nakayama ,  Hiroyuki Katayama ,  Michinobu Mieda

发明人： Akira Takahashi ,  Yoshiteru Murakami ,  Junsaku Nakajima ,  Kenji Ohta ,  Junichiro Nakayama ,  Hiroyuki Katayama ,  Michinobu Mieda

IPC分类号： G11B11/10 ,  G11B11/105 ,  G11B5/66 ,  B32B5/16 ,  G11B5/02 ,  G11B11/00

CPC分类号： G11B11/10593 ,  G11B11/10506 ,  G11B11/10515 ,  G11B11/10517 ,  G11B11/10586 ,  Y10S428/90 ,  Y10T428/26 ,  Y10T428/265

摘要： A magneto-optical recording medium has a recording layer whereon information is magneto-optically recorded. A readout layer is provided on the recording layer. The readout layer has a compensating temperature that is located between room temperature and the Curie temperature. In the readout layer, upon an application of a light beam, the in-plane magnetization occurs at room temperature and a transition from the in-plane magnetization to vertical magnetization occurs as the temperature of the irradiated area of the readout layer rises above a predetermined temperature. By employing this magneto-optical recording medium, with an application of a light beam that is intensity modulated into two levels, only a spot having a temperature not less than a predetermined temperature is involved in the reproduction; therefore, a recorded bit with a size smaller than the diameter of the light beam can be reproduced, thereby greatly increasing the recording density. Further, the level of the reproduced signals is increased, and crosstalk from the adjoining tracks is reduced; thus, information recording and overwriting can be conducted more easily.

摘要翻译： 磁光记录介质具有磁信息记录信息的记录层。 读出层设置在记录层上。 读出层具有位于室温和居里温度之间的补偿温度。 在读出层中，在施加光束时，在室温下发生平面内磁化，并且随着读出层的照射区域的温度上升到预定值以上，从面内磁化向垂直磁化的转变发生 温度。 通过采用该磁光记录介质，通过施加强度调制为两个级别的光束，只有具有不低于预定温度的温度的点参与再现; 因此，可以再现具有小于光束直径的尺寸的记录位，从而大大提高记录密度。 此外，再现信号的电平增加，并且来自相邻轨道的串扰减小; 因此，可以更容易地进行信息记录和重写。

公开(公告)号：US5563852A

公开(公告)日：1996-10-08

申请号：US350317

申请日：1994-12-05

申请人： Yoshiteru Murakami ,  Naoyasu Iketani ,  Akira Takahashi ,  Kenji Ohta

发明人： Yoshiteru Murakami ,  Naoyasu Iketani ,  Akira Takahashi ,  Kenji Ohta

IPC分类号： C23C14/18 ,  C23C14/34 ,  C23C14/56 ,  G11B11/105 ,  G11B5/66

CPC分类号： C23C14/3414 ,  C23C14/185 ,  C23C14/568 ,  G11B11/10582 ,  G11B11/10586 ,  G11B11/10589

摘要： A magneto-optical recording medium includes a readout layer has in-plane magnetization at room temperature and in which a transition occurs from in-plane magnetization to perpendicular magnetization when temperature thereof is raised, and a recording layer for recording thereon information. The composition of the readout layer varies in a direction perpendicular to the surface thereof, and in the readout layer, the Co density on the light incident side is higher than the Co density on the interface between the readout layer and the recording layer. Therefore, the Curie temperature on the reproducing light incident side of the readout layer is high and the the polar Kerr rotation angle in reproducing increases, thereby achieving improvements in a reproducing signal quality. On the other hand, since the Curie temperature on the interface is low, the shift of the threshold temperature at which a transition occurs from in-plane to perpendicular by the magnetic interaction between the layers can be suppressed, thereby achieving a high quality reproducing signal without changing the laser power required for reproduction very much.

摘要翻译： 磁光记录介质包括读出层，其在室温下具有面内磁化，并且其温度升高时从面内磁化转变为垂直磁化，并且在其上记录信息的记录层。 读出层的组成在垂直于其表面的方向上变化，在读出层中，光入射侧的Co密度高于读出层与记录层之间的界面上的Co密度。 因此，读出层的再现光入射侧的居里温度高，再现时的极性克尔旋转角度增加，从而实现再现信号质量的改善。 另一方面，由于界面的居里温度低，所以可以抑制通过层之间的磁相互作用从平面到垂直发生的阈值温度的偏移，从而实现高质量再现信号 而不需要更改再生所需的激光功率。

公开(公告)号：US5824426A

公开(公告)日：1998-10-20

申请号：US535967

申请日：1995-09-28

申请人： Naoyasu Iketani ,  Yoshiteru Murakami ,  Akira Takahashi ,  Kenji Ohta

发明人： Naoyasu Iketani ,  Yoshiteru Murakami ,  Akira Takahashi ,  Kenji Ohta

IPC分类号： C23C14/18 ,  C23C14/34 ,  G11B7/26 ,  G11B11/105 ,  G11B5/716 ,  G11B5/66 ,  G11B11/00

CPC分类号： C23C14/3407 ,  C23C14/185 ,  G11B11/10582 ,  G11B11/10586 ,  G11B7/26

摘要： A magneto-optical recording medium includes a readout layer having in-plane magnetization at room temperature and in which a transition occurs from in-plane magnetization to a perpendicular magnetization when temperature rises, and a recording layer for storing information thereon magneto-optically. In the readout layer made of GdFeCo by adding Nd thereto, an amount of Nd to be added changes in a direction perpendicular to its film surface, and an amount of Nd is larger on a light incidence side than on the other side. As a result, even when a laser with a short wavelength is used, high density recording can be achieved as undesirable recording and reproducing operations due to a change in a magnetic interaction is prevented and also deterioration in quality of a reproducing signal is prevented.

摘要翻译： 磁光记录介质包括在室温下具有面内磁化的读出层，并且其中当温度升高时从面内磁化转变为垂直磁化的过渡;以及用于在磁光上存储信息的记录层。 在通过添加Nd而由GdFeCo制成的读出层中，要添加的Nd的量在垂直于其膜表面的方向上变化，并且Nd的量在光入射侧比在另一侧更大。 结果，即使使用具有短波长的激光器，由于防止了磁相互作用的变化而导致由于不期望的记录和再现操作而导致高密度记录，并且也防止再现信号的质量劣化。

公开(公告)号：US5764601A

公开(公告)日：1998-06-09

申请号：US685115

申请日：1996-07-23

申请人： Yoshiteru Murakami ,  Naoyasu Iketani ,  Akira Takahashi ,  Kenji Ohta

发明人： Yoshiteru Murakami ,  Naoyasu Iketani ,  Akira Takahashi ,  Kenji Ohta

IPC分类号： C23C14/18 ,  C23C14/34 ,  C23C14/56 ,  G11B11/105 ,  G11B11/00 ,  G11B5/66

CPC分类号： C23C14/3414 ,  C23C14/185 ,  C23C14/568 ,  G11B11/10582 ,  G11B11/10586 ,  G11B11/10589

摘要： A magneto-optical recording medium includes a readout layer has in-plane magnetization at room temperature and in which a transition occurs from in-plane magnetization to perpendicular magnetization when temperature thereof is raised, and a recording layer for recording thereon information. The composition of the readout layer varies in a direction perpendicular to the surface thereof, and in the readout layer, the Co density on the light incident side is higher than the Co density on the interface between the readout layer and the recording layer. Therefore, the Curie temperature on the reproducing light incident side of the readout layer is high and the the polar Kerr rotation angle in reproducing increases, thereby achieving improvements in a reproducing signal quality. On the other hand, since the Curie temperature on the interface is low, the shift of the threshold temperature at which a transition occurs from in-plane to perpendicular by the magnetic interaction between the layers can be suppressed, thereby achieving a high quality reproducing signal without changing the laser power required for reproduction very much.

摘要翻译： 磁光记录介质包括读出层，其在室温下具有面内磁化，并且其温度升高时从面内磁化转变为垂直磁化，并且在其上记录信息的记录层。 读出层的组成在垂直于其表面的方向上变化，在读出层中，光入射侧的Co密度高于读出层与记录层之间的界面上的Co密度。 因此，读出层的再现光入射侧的居里温度高，再现时的极性克尔旋转角度增加，从而实现再现信号质量的改善。 另一方面，由于界面的居里温度低，所以可以抑制通过层之间的磁相互作用从平面到垂直发生的阈值温度的偏移，从而实现高质量再现信号 而不需要更改再生所需的激光功率。

公开(公告)号：US5486395A

公开(公告)日：1996-01-23

申请号：US984350

申请日：1992-12-02

申请人： Yoshiteru Murakami ,  Naoyasu Iketani ,  Akira Takahashi ,  Kenji Ohta

发明人： Yoshiteru Murakami ,  Naoyasu Iketani ,  Akira Takahashi ,  Kenji Ohta

IPC分类号： G11B11/10 ,  G11B11/105 ,  B32B3/02 ,  G11B5/66

CPC分类号： G11B11/10504 ,  G11B11/10515 ,  G11B11/10582 ,  G11B11/10586 ,  Y10S428/90

摘要： A magneto optical disk comprising: a circular substrate; a recording layer, formed on the substrate, for magneto-optical recording of information; a readout layer, formed between the substrate and the recording layer, for the reproduction of information recorded on the recording layer, wherein the readout layer has a Curie temperature which is higher than the Curie temperature of the recording layer, and exhibits in-plane magnetization at room temperature and a change from in-plane magnetization to perpendicular magnetization when its temperature rises over a certain temperature as a result of the application of a light beam, and wherein the magnetic compensation temperature is set such that it increases from the peripheral edge of the magneto-optical disk toward the center thereof. When the magneto-optical disk is used with a magneto-optical recording and reproducing device using a CAV system, it achieves high-density recording and the reproduction of signals with reduced noise, without causing the light beam control system to be complicated.

摘要翻译： 一种磁光盘，包括：圆形衬底; 记录层，形成在基板上，用于磁光记录信息; 形成在基板和记录层之间的用于再现记录在记录层上的信息的读出层，其中读出层的居里温度高于记录层的居里温度，并且表现出面内磁化 在室温下由于施加光束而在其温度上升超过一定温度时从面内磁化变化到垂直磁化的变化，并且其中磁补偿温度被设定为使得其从外周边缘 磁光盘朝向其中心。 当磁光盘与使用CAV系统的磁光记录和再现装置一起使用时，可以实现高密度记录和降低噪声的信号的再现，而不会使光束控制系统复杂化。

公开(公告)号：US5922177A

公开(公告)日：1999-07-13

申请号：US112930

申请日：1998-07-09

申请人： Naoyasu Iketani ,  Yoshiteru Murakami ,  Akira Takahashi ,  Kenji Ohta

发明人： Naoyasu Iketani ,  Yoshiteru Murakami ,  Akira Takahashi ,  Kenji Ohta

IPC分类号： C23C14/18 ,  C23C14/34 ,  G11B7/26 ,  G11B11/105 ,  C23C14/00 ,  C23C14/32

CPC分类号： C23C14/3407 ,  C23C14/185 ,  G11B11/10582 ,  G11B11/10586 ,  G11B7/26

摘要： A method to produce a magneto-optical recording medium which includes a readout layer having in-plane magnetization at room temperature and in which a transition occurs from in-plane magnetization to a perpendicular magnetization when temperature rises, and a recording layer for storing information thereon magneto-optically. In the readout layer made of GdFeCo by adding Nd thereto, an amount of Nd to be added changes in a direction perpendicular to its film surface, and an amount of Nd is larger on a light incidence side than on the other side. As a result, even when a laser with a short wavelength is used, high density recording can be achieved as undesirable recording and reproducing operations due to a change in a magnetic interaction is prevented and also deterioration in quality of a reproducing signal is prevented.

摘要翻译： 一种制造磁光记录介质的方法，其包括在室温下具有面内磁化的读出层，并且其中当温度升高时从面内磁化转变为垂直磁化，并且在其上存储信息的记录层 磁光学。 在通过添加Nd而由GdFeCo制成的读出层中，要添加的Nd的量在垂直于其膜表面的方向上变化，并且Nd的量在光入射侧比在另一侧更大。 结果，即使使用具有短波长的激光器，由于防止了磁相互作用的变化而导致由于不期望的记录和再现操作而导致高密度记录，并且也防止再现信号的质量劣化。