Invention Grant
- Patent Title: Magnetic-disk substrate, magnetic disk, and magnetic-disk drive device
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Application No.: US17385787Application Date: 2021-07-26
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Publication No.: US11682424B2Publication Date: 2023-06-20
- Inventor: Masanobu Itaya , Kinobu Osakabe
- Applicant: HOYA CORPORATION
- Applicant Address: JP Tokyo
- Assignee: HOYA CORPORATION
- Current Assignee: HOYA CORPORATION
- Current Assignee Address: JP Tokyo
- Agency: Global IP Counselors, LLP
- Main IPC: G11B5/82
- IPC: G11B5/82 ; G11B5/73 ; G11B5/84 ; B82Y10/00 ; B82Y40/00
Abstract:
A magnetic-disk substrate has a pair of main surfaces, and an arithmetic average roughness Ra of each of the main surfaces is 0.11 nm or less. The arithmetic average roughness Ra is a value obtained through measurement using an atomic force microscope provided with a probe having a probe tip provided with a carbon nanofiber rod-shaped member. The magnetic-disk substrate is made of glass or aluminum alloy.
Public/Granted literature
- US20210375313A1 MAGNETIC-DISK SUBSTRATE, MAGNETIC DISK, AND MAGNETIC-DISK DRIVE DEVICE Public/Granted day:2021-12-02
Information query
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