Hoya and Hoya Glass Disk Vietnam II Assigned Patent

Hoya Corp., Tokyo, Japan, and Hoya Glass Disk Vietnam II Ltd., Yen Province, Vietnam, has been assigned a patent (11587585) developed by Itaya, Masanobu, Minami-Alps, Japan, Osakabe, Kinobu, Tokorozawa, Japan, and Takizawa, Toshio, Kai, Japan, for “magnetic-disk substrate and magnetic disk.”

The abstract of the patent published by the U.S. Patent and Trademark Office states: “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.”

The patent application was filed on 2021-06-30 (17/364730).