US 12,406,694 B2
Magnetic disk-use glass substrate manufacturing method, discoidal glass substrate, glass substrate, and magnetic disk-use glass substrate
Shuhei Azuma, Hung Yen (VN); and Toshio Takizawa, Yamanashi (JP)
Assigned to HOYA CORPORATION, Tokyo (JP)
Appl. No. 18/845,828
Filed by HOYA CORPORATION, Tokyo (JP)
PCT Filed Mar. 13, 2023, PCT No. PCT/JP2023/009666
§ 371(c)(1), (2) Date Sep. 10, 2024,
PCT Pub. No. WO2023/171824, PCT Pub. Date Sep. 14, 2023.
Claims priority of application No. 2022-037807 (JP), filed on Mar. 11, 2022.
Prior Publication US 2025/0201272 A1, Jun. 19, 2025
Int. Cl. B32B 3/00 (2006.01); C03C 23/00 (2006.01); G11B 5/73 (2006.01); G11B 5/84 (2006.01)
CPC G11B 5/73921 (2019.05) [B32B 3/00 (2013.01); C03C 23/0025 (2013.01); G11B 5/8404 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A disk-shaped glass substrate comprising:
a main surface; and
an outer circumferential end face,
wherein the outer circumferential end face has at least two regions with different roughnesses in a circumferential direction of the outer circumferential end face.