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公开(公告)号：US10431252B2
公开(公告)日：2019-10-01
申请号：US15441931
申请日：2017-02-24
Applicant: HOYA CORPORATION
Inventor： Masanori Tamaki , Takeyoshi Takahashi , Masaaki Ueda
Abstract: A magnetic-disk glass substrate has a circular hole at a center, and includes a pair of main surfaces and a side wall surface orthogonal to the main surfaces. A roundness of the circular hole is 1.5 μm or less. A difference between a maximum value and a minimum value of radii of three inscribed circles that are respectively derived from outlines in the circumferential direction at three positions spaced apart by 200 μm in a substrate thickness direction on the side wall surface of the circular hole is 3.5 μm or less.
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Patent Agency Ranking
公开(公告)号：US09595286B2
公开(公告)日：2017-03-14
申请号：US14770025
申请日：2014-02-28
Applicant: HOYA CORPORATION
Inventor： Masanori Tamaki , Takeyoshi Takahashi , Masaaki Ueda
CPC classification number: G11B5/82 , G11B5/73 , G11B5/7315 , G11B5/8404
Abstract: A magnetic-disk glass substrate has a circular center hole, a pair of main surfaces and an edge surface. The edge surface has a side wall surface and chamfered surfaces interposed between the side wall surface and the main surfaces, and a roundness of an edge surface on an outer circumferential side is 1.5 μm or less. Also, a midpoint A between centers of two least square circle respectively derived from outlines in a circumferential direction respectively obtained at two positions spaced apart by 200 μm in a substrate thickness direction on the side wall surface on the outer circumferential side, and centers B and C respectively derived from a respective one of two chamfered surfaces on the outer circumferential side in the substrate thickness direction, are located such that a sum of respective distances between A and B, and A and C, is 1 μm or less.
Abstract translation: 磁盘玻璃基板具有圆形中心孔，一对主表面和边缘表面。 边缘表面具有插入在侧壁表面和主表面之间的侧壁表面和倒角表面，并且外周侧上的边缘表面的圆度为1.5μm以下。 此外，分别从外周侧的侧壁面上的基板厚度方向上隔开200μm的两个位置以及中心B和 分别从基板厚度方向的外周侧的两个倒角面的相应一个中分别导出，以使得A和B之间的距离之和以及A和C之间的总和为1μm以下。
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公开(公告)号：US09595284B2
公开(公告)日：2017-03-14
申请号：US14767515
申请日：2014-02-24
Applicant: HOYA CORPORATION
Inventor： Masanori Tamaki , Takeyoshi Takahashi , Masaaki Ueda
CPC classification number: G11B5/82 , G11B5/7315 , G11B5/8404
Abstract: A magnetic-disk glass substrate has a circular hole at a center, and includes a pair of main surfaces and a side wall surface orthogonal to the main surfaces. A roundness of the circular hole is 1.5 μm or less. A difference between a maximum value and a minimum value of radii of three inscribed circles that are respectively derived from outlines in the circumferential direction at three positions spaced apart by 200 μm in a substrate thickness direction on the side wall surface of the circular hole is 3.5 μm or less.
Abstract translation: 磁盘玻璃基板在中心具有圆形孔，并且包括一对主表面和与主表面正交的侧壁表面。 圆孔的圆度为1.5μm以下。 圆孔的侧壁面的基板厚度方向间隔开200μm的三个位置的圆周方向的轮廓的最大值和最小值的最小值与最小值之间的差为3.5 μm以下。
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公开(公告)号：US10553243B2
公开(公告)日：2020-02-04
申请号：US15444911
申请日：2017-02-28
Applicant: HOYA CORPORATION
Inventor： Masanori Tamaki
Abstract: A magnetic-disk glass substrate capable of suppressing turbulence of air flow in a vicinity of an outer circumferential side edge portion of the magnetic disk and suppressing disk flutter is provided. This magnetic-disk glass substrate includes a pair of main surfaces, a side wall surface formed on an outer circumferential side edge surface, and chamfered surfaces interposed between the side wall surface and the main surfaces, respectively. The side wall surface has a roundness of 1.5 μm or less. A difference in radius between an inscribed circle and a circumcircle of a plurality of outlines of the side wall surface at a plurality of positions that include a central position of the magnetic-disk glass substrate in a thickness direction and are different from each other in the thickness direction is 5 μm or less.
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公开(公告)号：US10535366B2
公开(公告)日：2020-01-14
申请号：US15442051
申请日：2017-02-24
Applicant: HOYA CORPORATION
Inventor： Masanori Tamaki , Takeyoshi Takahashi , Masaaki Ueda
Abstract: A magnetic-disk glass substrate has a circular center hole a pair of main surfaces and an edge surface. The edge surface has a side wall surface and chamfered surfaces interposed between the side wall surface and the main surfaces, and a roundness of an edge surface on an outer circumferential side is 1.5 μm or less. Also, a midpoint A between centers of two least square circle respectively derived from outlines in a circumferential direction respectively obtained at two positions spaced apart by 200 μm in a substrate thickness direction on the side wall surface on the outer circumferential side, and centers B and C respectively derived from a respective one of two chamfered surfaces on the outer circumferential side in the substrate thickness direction, are located such that a sum of respective distances between A and B, and A and C, is 1 μm or less.
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6.发明授权Manufacturing method of glass substrate for magnetic disk, magnetic disk, and magnetic recording / reproducing device 有权用于磁盘，磁盘和磁记录/再现装置的玻璃基板的制造方法公开(公告)号：US08974561B2
公开(公告)日：2015-03-10
申请号：US13627057
申请日：2012-09-26
Applicant: Hoya Corporation
Inventor： Masanori Tamaki , Hiroki Nakagawa , Yoshihiro Tawara
CPC classification number: B24B37/044 , A61C17/00 , B24D3/005 , C03C19/00 , C03C21/002 , C03C21/008 , C09G1/02 , G11B5/73 , G11B5/8404
Abstract: A manufacturing method of a glass substrate for a magnetic disk is provided whereby nano pits and/or nano scratches cannot be easily produced in polishing a principal face of a glass substrate using a slurry containing zirconium oxide as an abrasive. The manufacturing method of a glass substrate for a magnetic disk includes, for instance, a polishing step of polishing a principal face of a glass substrate using a slurry containing, as an abrasive, zirconium oxide abrasive grains having monoclinic crystalline structures (M) and tetragonal crystalline structures (T).
Abstract translation: 提供了一种用于磁盘的玻璃基板的制造方法，其中使用含有氧化锆作为研磨剂的浆料在玻璃基板的主面研磨时不容易产生纳米凹坑和/或纳米划痕。 用于磁盘的玻璃基板的制造方法包括例如使用包含作为磨料的含有单斜晶体结构（M）和四方晶系的氧化锆磨粒的浆料研磨玻璃基板的主面的抛光步骤 晶体结构（T）。
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