公开(公告)号：JP2001093262A

公开(公告)日：2001-04-06

申请号：JP26674199

申请日：1999-09-21

Applicant: IBM

Inventor： MATSUZAKI SHINICHI ,  SASAKI MASAKAZU ,  OTA MUTSURO ,  SUZUKI TAKAHISA

IPC: G11B33/12 ,  G11B17/038 ,  G11B19/20 ,  G11B25/04

Abstract: PROBLEM TO BE SOLVED: To provide a low-cost dummy disk, wherein disk slipping or the deformation of the dummy disk is prevented even when a heating/cooling process is repeated, and the increase of a load on a bearing by a weight increase is prevented. SOLUTION: A dummy disk 24 made of stainless steel is loaded instead of the magnetic disk of a hard disk drive. Rigidity is reduced by forming a circumferential groove 241 in the dummy disk 24, and a resonance frequency is matched with magnetic disks (0, 1). Thus, even when the dummy disk 24 is loaded, a pitching frequency equal to that when only the magnetic disk is loaded.