US 11,854,585 B2
Magnetic recording medium and cartridge
Noboru Sekiguchi, Tokyo (JP); Yuuko Kamoshita, Tokyo (JP); and Minoru Yamaga, Tokyo (JP)
Assigned to Sony Group Corporation, Tokyo (JP)
Appl. No. 17/790,298
Filed by Sony Group Corporation, Tokyo (JP)
PCT Filed Jan. 19, 2021, PCT No. PCT/JP2021/001664
§ 371(c)(1), (2) Date Jun. 30, 2022,
PCT Pub. No. WO2021/149680, PCT Pub. Date Jul. 29, 2021.
Claims priority of application No. 2020-007936 (JP), filed on Jan. 21, 2020.
Prior Publication US 2023/0042175 A1, Feb. 9, 2023
Int. Cl. G11B 5/71 (2006.01); G11B 5/592 (2006.01); G11B 5/78 (2006.01); G11B 5/706 (2006.01)
CPC G11B 5/71 (2013.01) [G11B 5/5928 (2013.01); G11B 5/70678 (2013.01); G11B 5/78 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A magnetic recording medium with a tape shape comprising:
a substrate;
an underlayer provided on the substrate; and
a magnetic layer provided on the underlayer,
wherein the magnetic layer has a surface having an uneven shape,
a height range ΔH obtained from statistical information of a height of the uneven shape is in a range of 4.00 nm≤ΔH≤10.00 nm, and
a gradient range ΔA obtained from statistical information of a gradient of the uneven shape is in a range of 2.50 degrees ≤ΔA.