Patents Assigned to HOYA GLASS DISK VIETNAM II LTD.
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Publication number: 20230197111Abstract: A magnetic-disk substrate has an average value of squares of inclinations that is 0.0025 or less, and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm. The main surface is configured to receive at least a magnetic recording layer thereon. The magnetic-disk substrate includes an outer circumferential end portion and an inner circumferential end portion, and the outer circumferential end portion and the inner circumferential end portion have chamfered portions.Type: ApplicationFiled: February 6, 2023Publication date: June 22, 2023Applicants: HOYA CORPORATION, HOYA GLASS DISK VIETNAM II LTD.Inventors: Masanobu ITAYA, Kinobu OSAKABE, Toshio TAKIZAWA
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Patent number: 11587585Abstract: A magnetic-disk substrate has an average value of squares of inclinations that is 0.0025 or less, and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm. The main surface is configured to receive at least a magnetic recording layer thereon. The magnetic-disk substrate includes an outer circumferential end portion and an inner circumferential end portion, and the outer circumferential end portion and the inner circumferential end portion have chamfered portions.Type: GrantFiled: June 30, 2021Date of Patent: February 21, 2023Assignees: HOYA CORPORATION, HOYA GLASS DISK VIETNAM II LTD.Inventors: Masanobu Itaya, Kinobu Osakabe, Toshio Takizawa
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Publication number: 20210327464Abstract: A magnetic-disk substrate has an average value of squares of inclinations that is 0.0025 or less, and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm. The main surface is configured to receive at least a magnetic recording layer thereon. The magnetic-disk substrate includes an outer circumferential end portion and an inner circumferential end portion, and the outer circumferential end portion and the inner circumferential end portion have chamfered portions.Type: ApplicationFiled: June 30, 2021Publication date: October 21, 2021Applicants: HOYA CORPORATION, HOYA GLASS DISK VIETNAM II LTD.Inventors: Masanobu ITAYA, Kinobu OSAKABE, Toshio TAKIZAWA
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Patent number: 11081134Abstract: A hard disk drive includes a magnetic-disk substrate in which an average value of squares of inclinations is 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.Type: GrantFiled: March 28, 2019Date of Patent: August 3, 2021Assignees: HOYA CORPORATION, HOYA GLASS DISK VIETNAM II LTD.Inventors: Masanobu Itaya, Kinobu Osakabe, Toshio Takizawa
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Patent number: 10283156Abstract: A magnetic-disk glass substrate of the present invention has an average value of squares of inclinations of 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more of 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.Type: GrantFiled: January 9, 2017Date of Patent: May 7, 2019Assignees: HOYA CORPORATION, HOYA GLASS DISK VIETNAM II LTD.Inventors: Masanobu Itaya, Kinobu Osakabe, Toshio Takizawa
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Patent number: 9728217Abstract: A glass substrate for use as a magnetic disk for heat assisted magnetic recording can restrain the occurrence of scratches when a magnetic head is in operation. The glass substrate for the magnetic disk includes a principal face on which an arithmetic average waviness Wa of a wavelength band of 1 to 3 mm is 2.15 ? or less.Type: GrantFiled: October 31, 2013Date of Patent: August 8, 2017Assignees: HOYA GLASS DISK VIETNAM II LTD., HOYA CORPORATIONInventors: Masayoshi Yoshida, Masahiro Katagiri
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Publication number: 20170186459Abstract: A magnetic-disk glass substrate of the present invention has an average value of squares of inclinations of 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more of 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.Type: ApplicationFiled: January 9, 2017Publication date: June 29, 2017Applicants: HOYA CORPORATION, HOYA GLASS DISK VIETNAM II LTD.Inventors: Masanobu ITAYA, Kinobu OSAKABE, Toshio TAKIZAWA
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Patent number: 9564166Abstract: A magnetic-disk glass substrate of the present invention has an average value of squares of inclinations of 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more of 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.Type: GrantFiled: June 28, 2013Date of Patent: February 7, 2017Assignees: HOYA CORPORATION, HOYA GLASS DISK VIETNAM II LTD.Inventors: Masanobu Itaya, Kinobu Osakabe, Toshio Takizawa
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Publication number: 20160254018Abstract: It is to provide a glass substrate for a magnetic disk to be a source of a magnetic disk for heat assisted magnetic recording and a magnetic disk for heat assisted magnetic recording which can restrain the occurrence of scratches when a magnetic head is in operation. A glass substrate for a magnetic disk to be a source of a magnetic disk for heat assisted magnetic recording includes a principal face on which an arithmetic average waviness Wa of a wavelength band of 1 to 3 mm is 2.15 ? or less.Type: ApplicationFiled: October 31, 2013Publication date: September 1, 2016Applicants: HOYA GLASS DISK VIETNAM II LTD., HOYA CORPORATIONInventors: Masayoshi YOSHIDA, Masahiro KATAGIRI
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Publication number: 20150213826Abstract: A magnetic-disk glass substrate of the present invention has an average value of squares of inclinations of 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more of 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.Type: ApplicationFiled: June 28, 2013Publication date: July 30, 2015Applicants: HOYA GLASS DISK VIETNAM II LTD., HOYA CORPORATIONInventors: Masanobu Itaya, Kinobu Osakabe, Toshio Takizawa