Hoya Assigned Patent

Hoya Corporation, Tokyo, Japan, has been assigned a patent (12266389) developed by Azuma; Shuhei, Hung Yen Province, Vietnam, and Takizawa; Toshio, Akishima, Japan, for “magnetic disk substrate, magnetic disk, annular-shaped substrate, and method for manufacturing magnetic disk substrate.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A magnetic-disk substrate according to an embodiment includes two main surfaces and an outer circumferential edge surface. In the magnetic-disk substrate, the outer circumferential edge surface includes two chamfered surfaces that are respectively connected to the main surfaces, and a side wall surface that is curved and extends to protrude outward between the two chamfered surfaces. The side wall surface has a radius of curvature of 1100 μm or more on a cross-section of the magnetic-disk substrate extending along a plate thickness direction of the magnetic-disk substrate.”

The patent application was filed on 2022-02-24 (18/547572).