Patent ID: 7549340

Claim:
An apparatus for measuring a vibration characteristic of a head gimbal assembly, comprising: a shaker configured to shake the head gimbal assembly; a fixture configured to fix the head gimbal assembly to the shaker; a first laser Doppler vibrometer configured to detect a first vibration velocity of the shaker; a second laser Doppler vibrometer configured to detect a second vibration velocity of a head of the head gimbal assembly; the apparatus being configured to find the vibration characteristic of the head gimbal assembly according to the detected first and second vibration velocities; wherein the fixture comprises: a base block fixed to the shaker and having an external thread; a mount block having a through hole and joined to the base block with the external thread of the base block being passed through the through hole, the mount block supporting the head gimbal assembly; and a nut fastened to the external thread tat protrudes from the mount block, to fix the mount block and the base block together.