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：US5317555A

公开(公告)日：1994-05-31

申请号：US910837

申请日：1992-07-08

申请人： Akira Takahashi ,  Yoshiteru Murakami ,  Junsaku Nakajima ,  Kenji Ohta

发明人： Akira Takahashi ,  Yoshiteru Murakami ,  Junsaku Nakajima ,  Kenji Ohta

IPC分类号： G11B11/10 ,  G11B11/105 ,  G11B13/04

CPC分类号： G11B11/10545 ,  G11B11/10515

摘要： A magneto-optical disk has a recording layer whereon recorded bits are formed by the magnetic field modulation method and a readout layer whose axis of easy magnetization is parallel to the recording layer at room temperature, and varies to be perpendicular to the recording layer within a predetermined temperature range between room temperature and the Curie temperature. During reproduction of the recorded bits the first semiconductor laser emits a heating-use light beam to form the first light spot on the readout layer Thus, a ring-shaped region corresponding to the predetermined temperature range exhibits perpendicular magnetic anisotropy and the recorded bits are copied from the recording layer onto the ring-shaped region. As the first light spot is shifted, the ring-shaped region as a readout window of recorded bits is also shifted. Further, the second semiconductor laser emits a reproduction-use light beam such that the second light spot is formed on the readout layer to overlap the first light spot at a rear portion thereof. Consequently, only one recorded bit copied onto the rear portion of the ring-shaped region can be reproduced; therefore, high-quality reproduced signals can be obtained from the magneto-optical disk having information recorded with high density.

摘要翻译： 磁光盘具有通过磁场调制方法形成记录位的记录层和容易磁化的轴在室温下与记录层平行的读出层，并且在其内变化为垂直于记录层 室温和居里温度之间的预定温度范围。 在再现记录位期间，第一半导体激光器发出加热用光束，以在读出层上形成第一光点。因此，对应于预定温度范围的环形区域呈现垂直的磁各向异性，并且记录的位被复制 从记录层到环形区域。 当第一个光点移动时，作为记录位的读出窗口的环形区域也被移位。 此外，第二半导体激光器发射再现用光束，使得第二光点形成在读出层上，以在其后部与第一光点重叠。 因此，只能再现复制到环形区域后部的一个记录位; 因此，可以从具有以高密度记录的信息的磁光盘获得高质量的再现信号。

公开(公告)号：US5305300A

公开(公告)日：1994-04-19

申请号：US888548

申请日：1992-05-22

申请人： Kenji Ohta ,  Akira Takahashi ,  Junsaku Nakajima ,  Yoshiteru Murakami

发明人： Kenji Ohta ,  Akira Takahashi ,  Junsaku Nakajima ,  Yoshiteru Murakami

IPC分类号： G11B11/105 ,  G11B7/24

CPC分类号： G11B11/10582 ,  G11B11/10593 ,  Y10S428/90

摘要： A magneto-optical storage device having a configuration wherein a first AlN film, a Pt/co multi-layer film formed by alternately depositing Pt and Co, a second AlN film, and an Al reflective film are successively laminated on a substrate in this order. Assuming that respectively the thickness of the first AlN film is .delta.AlN (1); that of the second AlN film is .delta.AlN (2); that of the Pt single layer is .delta.Pt; that of the Co single layer is .delta.Co; and the total thickness of the Pt/Co multi-layer film is .delta.Pt/Co, each thickness of those layers is set to range within: 50 nm .ltoreq..delta.AlN (1).ltoreq.200 nm; 120 nm.ltoreq..delta.AlN (2).ltoreq.140 nm; 0.6 nm.ltoreq..delta.Pt.ltoreq.1.0 nm; 0.3 nm.ltoreq..delta.Co.ltoreq.0.6 nm; and 15 nm.ltoreq..delta.Pt/Co.ltoreq.20 nm. In accordance with the above arrangement, it is possible to greatly widen the tolerances of the film thicknesses of the first and second dielectric layers for obtaining a predetermined reflective index as well as a maximum Kerr rotation angle. Consequently, without strictly controlling the film thicknesses of the first and second AlN films, a magneto-optical storage device with stable performance suitable for practical use can be produced easily.

摘要翻译： 具有这样一种结构的磁光存储装置，其中第一AlN膜，通过交替沉积Pt和Co形成的Pt / co多层膜，第二AlN膜和Al反射膜依次层叠在基板上 。 假设第一AlN膜的厚度分别为（Δ）AlN（1）; 第二AlN膜的厚度为（Δ）AlN（2）; Pt单层为（delta）Pt; Co单层为（delta）Co; 并且Pt / Co多层膜的总厚度为（delta）Pt / Co，这些层的每个厚度设定在：50nm <=（delta）AlN（1）<= 200nm的范围内; 120nm <=（delta）AlN（2）<= 140nm; 0.6nm <=（delta）Pt <= 1.0nm; 0.3nm <=（delta）Co <= 0.6nm; 和15nm <=（delta）Pt / Co <= 20nm。 根据上述结构，可以大大拓宽第一和第二介质层的膜厚的公差，以获得预定的反射率以及最大的克尔旋转角。 因此，在不严格控制第一和第二AlN膜的膜厚的情况下，可以容易地制造出具有适合于实际应用的稳定性能的磁光存储装置。

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：US6143436A

公开(公告)日：2000-11-07

申请号：US909194

申请日：1997-08-11

申请人： Junsaku Nakajima ,  Akira Takahashi ,  Junji Hirokane ,  Yoshiteru Murakami ,  Kenji Ohta

发明人： Junsaku Nakajima ,  Akira Takahashi ,  Junji Hirokane ,  Yoshiteru Murakami ,  Kenji Ohta

IPC分类号： G11B11/10 ,  G03G5/16 ,  G11B5/00 ,  G11B5/02 ,  G11B5/64 ,  G11B5/65 ,  G11B5/66 ,  G11B5/74 ,  G11B11/105 ,  G11B13/04 ,  G11B19/02

CPC分类号： G03G5/16 ,  G11B11/10589 ,  G11B13/045 ,  G11B5/00 ,  G11B5/656 ,  G11B11/10504 ,  G11B11/10515 ,  G11B11/10532 ,  G11B19/02 ,  G11B2005/0002 ,  G11B2005/0021 ,  G11B5/74 ,  Y10S428/90

摘要： A magnetic recording medium having a recording layer made up of a ferrimagnetic material whose compensation temperature is included within room temperatures and an information recording-reproduction method using the magnetic recording medium. During recording, while a light beam is projected on the recording layer so as to raise the temperature of a recording portion, information is recorded by applying a signal magnetic field from a magnetic head. During reproduction, while a light beam is projected on a reproducing portion of the recording layer so as to raise the temperature thereof, information is reproduced by detecting leakage flux from the reproducing portion by the magnetic head. Thus, during reproduction, no magnetic flux is generated from other portions of the recording layer not irradiated by the light beam. With the arrangement, crosstalk due to leakage flux from adjoining tracks not irradiated by the optical beam can be eliminated. Therefore, track pitches can be made narrower so as to increase recording density of the magnetic recording medium. Further, since crosstalk from adjoining tracks is eliminated, a high S/N can be achieved.

摘要翻译： 一种磁记录介质，其具有由补偿温度包括在室温内的铁氧体材料制成的记录层和使用该磁记录介质的信息记录再现方法。 在记录期间，当光束投射在记录层上以提高记录部分的温度时，通过施加来自磁头的信号磁场来记录信息。 在再现期间，当光束投射在记录层的再现部分上以升高其温度时，通过由磁头检测来自再现部分的漏磁通来再现信息。 因此，在再现期间，不会由不被光束照射的记录层的其它部分产生磁通量。 利用该布置，可以消除由于未被光束照射的相邻轨道的漏磁通引起的串扰。 因此，可以使轨道间距更窄，以提高磁记录介质的记录密度。 此外，由于消除了来自相邻轨道的串扰，可以实现高S / N。

公开(公告)号：US5477528A

公开(公告)日：1995-12-19

申请号：US346586

申请日：1994-11-16

申请人： Yoshiteru Murakami ,  Junsaku Nakajima ,  Akira Takahashi ,  Junichiro Nakayama ,  Kenji Ohta

发明人： Yoshiteru Murakami ,  Junsaku Nakajima ,  Akira Takahashi ,  Junichiro Nakayama ,  Kenji Ohta

IPC分类号： G11B11/10 ,  G11B11/105 ,  G11B7/00

CPC分类号： G11B11/10515 ,  G11B11/10595

摘要： A magneto-optical disk, which possesses a disc-shaped substrate and a recording layer composed of a perpendicular magnetization film that is formed on the substrate, characterized in having: an area wherein magnetic domains having an upward magnetization and magnetic domains having a downward magnetization are alternately aligned along at least one circuit of the disk, the area being formed on the recording layer, the length of the magnetic domains having the upward magnetization being virtually equal to the length of the magnetic domains having the downward magnetization. This invention also has a reproducing method which is characterized in that, when information is reproduced by projecting a light beam onto the magneto-optical recording disk, the intensity of the light beam is adjusted so as to maximize the amplitude of a reproduced signal that is obtained from the area. With the above arrangement, a high-quality reproduced signal can be obtained independent of the characteristics of individual magneto-optical disks.

摘要翻译： 一种磁光盘，其具有盘形基板和由形成在基板上的垂直磁化膜构成的记录层，其特征在于具有：具有向上磁化的磁畴和具有向下磁化的磁畴的区域 沿着盘的至少一个电路交替排列，所述区域形成在记录层上，具有向上磁化的磁畴的长度实质上等于具有向下磁化的磁畴的长度。 本发明还具有一种再现方法，其特征在于，当通过将光束投射到磁光记录盘上来再现信息时，调整光束的强度，以使得再现信号的幅度最大化 从该地区获得。 通过上述配置，可以独立于各个磁光盘的特性来获得高质量的再生信号。

公开(公告)号：US5452272A

公开(公告)日：1995-09-19

申请号：US175748

申请日：1993-12-30

申请人： Yoshiteru Murakami ,  Junsaku Nakajima ,  Akira Takahashi ,  Kenji Ohta

发明人： Yoshiteru Murakami ,  Junsaku Nakajima ,  Akira Takahashi ,  Kenji Ohta

IPC分类号： G11B7/135 ,  G11B11/10 ,  G11B11/105 ,  G11B11/00

CPC分类号： G11B11/10586 ,  G11B11/10515 ,  G11B11/10543

摘要： A magneto-optical recording and reproducing device is provided with a magneto-optical disk for reproducing recorded information using light, a semiconductor laser, an objective lens for converging a light beam emitted from the semiconductor laser onto the magneto-optical disk and a light interrupting member for interrupting a portion of a light beam before it is incident on the objective lens. The magneto-optical disk is composed of a readout layer which is predominant in in-plane magnetization, and in which a transition occurs to be predominant in perpendicular magnetization as temperature thereof is raised and a recording layer for recording thereon information using a perpendicular magnetization. In this arrangement, since the light interrupting member is provided, a light spot can be made smaller, thereby improving a recording density. Moreover, even when temperature of the readout layer is raised due to a side robe generated by the light interrupting member, in-plane magnetization is maintained in the readout layer. Thus, interference by unwanted reproducing signals due to the side robe can be prevented, thereby improving a reproducing signal quality.

摘要翻译： 磁光记录和再现装置设置有用于使用光再现记录信息的磁光盘，半导体激光器，用于将从半导体激光器发射的光束会聚到磁光盘上的物镜和光中断 用于在光束入射到物镜之前中断光束的一部分。 磁光盘由在平面磁化中占主要地位的读出层组成，其中随着温度的升高而在垂直磁化中发生转移，而在其中利用垂直磁化记录信息的记录层。 在这种布置中，由于设置了遮光构件，可以使光点更小，从而提高记录密度。 此外，即使由于由遮光构件产生的侧蓬而导致读出层的温度上升，在读出层中也保持平面内的磁化。 因此，可以防止由于侧灯引起的不必要的再现信号的干扰，从而提高再现信号质量。