公开(公告)号：US10607647B2

公开(公告)日：2020-03-31

申请号：US15611243

申请日：2017-06-01

Applicant: HOYA CORPORATION ,  HOYA LAMPHUN LTD.

Inventor： Toshio Takizawa ,  Kraisorn Phandon ,  Kenichi Nishimori

IPC: G11B5/73 ,  G11B5/82

Abstract: A magnetic disk substrate having a flat main surface, an end face, and a chamfered face formed between the main surface and the end face. The substrate has an offset portion, present on the main surface within a range of 92.0 to 97.0% in a radial direction from a center of the substrate. A distance from the center of the substrate to the end face of the substrate in a radial direction is 100%, the offset portion being raised or lowered with respect to a virtual straight line connecting two points on the main surface, set at positions of 92.0% and 97.0%. A maximum distance from the virtual straight line to the offset portion in a direction perpendicular to the virtual straight line is a “maximum offset value.”

公开(公告)号：US09183866B2

公开(公告)日：2015-11-10

申请号：US14551675

申请日：2014-11-24

Applicant: HOYA CORPORATION ,  HOYA GLASS DISK (Thailand) LTD.

Inventor： Toshio Takizawa ,  Kraisorn Phandon ,  Kenichi Nishimori

IPC: G11B5/73 ,  G11B5/82

CPC classification number: G11B5/7315 ,  G11B5/82

Abstract: A magnetic disk substrate having a flat main surface, an end face, and a chamfered face formed between the main surface and the end face. The substrate has an offset portion, present on the main surface within a range of 92.0 to 97.0% in a radial direction from a center of the substrate. A distance from the center of the substrate to the end face of the substrate in a radial direction is 100%, the offset portion being raised or lowered with respect to a virtual straight line connecting two points on the main surface, set at positions of 92.0% and 97.0%. A maximum distance from the virtual straight line to the offset portion in a direction perpendicular to the virtual straight line is a “maximum offset value.”

Abstract translation: 一种磁盘基板，其具有平坦的主表面，端面和形成在主表面和端面之间的倒角面。 该基板具有偏离部分，该主体表面在距离基板中心的径向方向上在92.0至97.0％的范围内。 从基板的中心到基板的端面的径向方向的距离为100％，偏移部相对于连接主面上的两点的虚拟直线上升或下降，设定在92.0的位置 ％和97.0％。 在与虚拟直线垂直的方向上从虚拟直线到偏移部分的最大距离为“最大偏移值”。

公开(公告)号：US09697861B2

公开(公告)日：2017-07-04

申请号：US14818796

申请日：2015-08-05

Applicant: HOYA CORPORATION ,  HOYA GLASS DISK (Thailand) LTD.

Inventor： Toshio Takizawa ,  Kraisorn Phandon ,  Kenichi Nishimori

IPC: G11B5/73 ,  G11B5/82

CPC classification number: G11B5/7315 ,  G11B5/82

Abstract: A magnetic disk substrate having a flat main surface, an end face, and a chamfered face formed between the main surface and the end face. The substrate has an offset portion, present on the main surface within a range of 92.0 to 97.0% in a radial direction from a center of the substrate. A distance from the center of the substrate to the end face of the substrate in a radial direction is 100%, the offset portion being raised or lowered with respect to a virtual straight line connecting two points on the main surface, set at positions of 92.0% and 97.0%. A maximum distance from the virtual straight line to the offset portion in a direction perpendicular to the virtual straight line is a “maximum offset value.”