Magneto-optical recording medium having a readout layer with varying
composition and curie temperature
    61.
    发明授权
    Magneto-optical recording medium having a readout layer with varying composition and curie temperature 失效
    磁光记录介质具有不同组成和居里温度的读出层

    公开(公告)号:US5563852A

    公开(公告)日:1996-10-08

    申请号:US350317

    申请日:1994-12-05

    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。

    Magneto-optical recording medium and method for processing the surface
    63.
    发明授权
    Magneto-optical recording medium and method for processing the surface 失效
    磁光记录介质及表面处理方法

    公开(公告)号:US5427833A

    公开(公告)日:1995-06-27

    申请号:US175957

    申请日:1993-12-30

    摘要: A surface of a magneto-optical recording medium of the present invention is textured with fine and physical protrusions and recessions. The shapes of physical protrusions and recessions vary at each radial locations on the medium such that, for example, rough protrusions and recessions are formed in inner parts of the recording medium and fine protrusions and recessions are formed in outer parts thereof. Therefore, floating force given to a floating head from the medium being rotated based on the constant angular velocity method through an air layer in the outer parts equals floating force in the inner parts. Consequently, since the floating height of the floating head becomes constant irrespective of radial locations on the medium, information can be recorded under constant recording conditions, permitting the accuracy of the recording to improve. Regarding a method for processing the surface of a magneto-optical recording medium relating to the present invention, for example, a texture tape whose roughness is large is used in inner parts of the medium while a texture tape whose roughness is small is used in outer parts thereof. As a result, a magneto-optical recording medium having the above characteristics is produced.

    摘要翻译: 本发明的磁光记录介质的表面具有精细和物理的突出和凹陷的纹理。 物理突起和凹陷的形状在介质上的每个径向位置处变化,使得例如在记录介质的内部形成粗糙的突起和凹陷,并且在其外部形成微小的突起和凹陷。 因此,通过外部部分中的空气层,基于恒定的角速度法,从介质旋转的浮动浮动力等于内部部分的浮力。 因此,由于浮动头的浮动高度与介质上的径向位置无关地变得恒定,所以可以在恒定的记录条件下记录信息,从而可以提高记录的准确性。 关于本发明的磁光记录介质的表面的处理方法,例如,在粗糙度小的纹理带用于外部的粗糙度较小的纹理带时,粗糙度大的纹理带用于介质的内部, 其部分。 结果,产生具有上述特性的磁光记录介质。

    Magneto-optical disk and method of manufacturing the same
    64.
    发明授权
    Magneto-optical disk and method of manufacturing the same 失效
    磁光盘及其制造方法

    公开(公告)号:US5353278A

    公开(公告)日:1994-10-04

    申请号:US694990

    申请日:1991-05-02

    IPC分类号: G11B11/105 G11B23/00 G11B5/54

    摘要: A magneto-optical disk comprising a substrate whereon a recording medium is formed, and a depression is formed on the substrate on the inside of the recording medium of the substrate. A center hub is installed on the depression such that the center hub is substantially level with a protective resin layer covering the recording medium. On the center hub, a flying head performs CSS (Contact Start and Stop). This configuration of the disk eliminates the occurrence of dust due to the abrasion and head crash, and achieves stable CSS. A method of manufacturing the magneto-optical disk, wherein the protective resin layer is formed after installing the center hub on the depression. In this method, since a space is not produced between the center hub and the protective resin layer, the stable flying characteristics is obtained. And a magneto-optical disk whereon small physical bumps and pits are formed on the substrate on the inside of the recording medium, which prevents the flying head from sticking to the disk. A method of manufacturing the magneto-optical disk by using a stamper, which permits the disk to be mass produced.

    摘要翻译: 一种磁光盘,包括形成记录介质的基板,并且在基板的记录介质的内侧上的基板上形成凹陷。 中心毂安装在凹陷处,使得中心毂基本上与覆盖记录介质的保护树脂层水平。 在中心枢纽上,飞头执行CSS(联系人启动和停止)。 盘的这种配置消除了由于磨损和头部碰撞引起的灰尘的发生,并且实现了稳定的CSS。 一种制造磁光盘的方法,其中在将中心毂安装在凹陷部之后形成保护树脂层。 在该方法中,由于在中心轮毂和保护树脂层之间不产生空间,因此获得了稳定的飞行特性。 另外,在记录介质的内侧的基板上形成小的物理凸点和凹坑的磁光盘,防止飞头粘附到盘上。 通过使用压模来制造磁光盘的方法,该压模允许大量生产盘。

    Magneto-optic reproducing device using right and left circularly
polarized light
    65.
    发明授权
    Magneto-optic reproducing device using right and left circularly polarized light 失效
    使用右侧和左侧圆形偏振光的磁光复制装置

    公开(公告)号:US5202860A

    公开(公告)日:1993-04-13

    申请号:US664183

    申请日:1991-03-04

    IPC分类号: G11B11/105

    CPC分类号: G11B11/10545

    摘要: A reproducing optical device for a magneto-optical recording medium related to the present invention having light sources that emit linearly polarized lights towards a magneto-optical recording medium, polarization directions of the linearly polarized lights being mutually orthogonal. A quarter wavelength plate disposed between the recording medium and the light sources converts each of the linearly polarized lights into right and left circularly polarized lights respectively. Corresponding to recorded information, the recording medium has magnetized sections that are magnetized in a perpendicularly upward and downward direction with respect to a medium surface. Moreover, the recording medium displays the property of circular dichroism. When the right circularly polarized light and the left circularly polarized light are reflected off the recording medium, a first and a second photodetector generate a first and a second reproduced signal respectively, based on variation in reflected light intensity of each of the circularly polarized lights. This variation corresponds to the upward and the downward magnetization directions of the magnetized sections and is due to the circular dichroism effect. There is a phase difference of half a cycle between the first and the second reproduced signal and the signals vary inversely with respect to each other. Consequently, disk noise is cancelled by differentially amplifying the first and the second reproduced signal, and an SN ratio of a reproduced signal thereby can be improved.