The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 10, 2026
Filed:
Mar. 06, 2023
Furukawa Electric Co., Ltd., Tokyo, JP;
Uacj Corporation, Tokyo, JP;
Wataru Kumagai, Tokyo, JP;
Hideyuki Hatakeyama, Tokyo, JP;
Ryo Sakamoto, Tokyo, JP;
Naoki Kitamura, Tokyo, JP;
Kotaro Kitawaki, Tokyo, JP;
FURKAWA ELECTRIC CO., LTD., Tokyo, JP;
UACJ Corporation, Tokyo, JP;
Abstract
The present invention intends to provide a magnetic disk that is flat while being thin and hardly causes physical errors. The present invention provides a magnetic disk having a hole in the center, a thickness of 0.60 mm or less, TIRs on circles having different radial distances r1 (mm) and r2 (mm) denoted by TIR1 (μm) and TIR2 (μm), and an amount of radial variation ΔTIR for TIRs of 0.50 μm/mm or less in an outer circumferential region of the magnetic disk with r/R=0.70 to 0.99, where “R” is a disk radius (mm), “r” is a radial distance (mm) measured from the disk center, and the ΔTIR is represented by an absolute value |(TIR1−TIR2)/(r1−r2)| of the ratio of the difference (TIR1−TIR2) between the TIR1 and the TIR2 to the difference (r1−r2) between r1 and r2 of the magnetic disk.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile