Hoya Assigned Patent

Hoya Corporation, Tokyo, Japan, has been assigned a patent (12020735) developed by Eda; Shinji, Hung Yen Province, Vietnam, for “substrate for magnetic disk and magnetic disk.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A substrate for a magnetic disk has a disk shape. The substrate has a diameter D of 85 mm or more and a thickness T of 0.6 mm or less. When an impact is applied to the substrate under conditions of 70 (G) and 2 (msec) in a normal direction of main surfaces of the substrate in a state in which an inner circumferential end portion of the substrate is fixed, the maximum amplitude of vibration in a thickness direction of an outer circumferential end portion of the substrate is 0.25 mm or less, the substrate is a non-magnetic metal substrate, and regarding the Young’s modulus E and the thickness T of the substrate, a value of E.Math.T.sup.3 is 3 to 18 (GPa.Math.mm.sup.3).”

The patent application was filed on 2023-04-01 (18/194619).