Apparatus for measuring vibration characteristic of head gimbal assembly

• US 7,549,340 B2
• Filed: 01/18/2007
• Issued: 06/23/2009
• Est. Priority Date: 01/20/2006
• Status: Active Grant

• Current Assignee: NHK Spring Company Limited
• Original Assignee: NHK Spring Company Limited
• Inventors: Nishida, Tatsuhiko, Ando, Toshiki, Hanya, Masao
• Primary Examiner(s): Williams; Hezron
• Assistant Examiner(s): SAINT SURIN, JACQUES M
• Application Number:
  US11/654,749
• Publication Number:
  US 20070169556A1
• Time in Patent Office: 887 Days
• Field of Search: 736/62, 73/18.2, 735/93, 735/97, 736/49, 736/59, 73/1, 73/82
• US Class Current: 73/662
• CPC Class Codes: G01M 7/025 Measuring arrangements

Abstract

An apparatus surely measures the vibration characteristic of a head gimbal assembly and has a wide range of resonance frequencies to be set, the apparatus has a first laser Doppler vibrometer to detect a vibration velocity of a shaker, a second laser Doppler vibrometer to detect a vibration velocity of a head of the head gimbal assembly fixed to a fixture, and a reflection mirror to orthogonally reflect a laser beam emitted from the first laser Doppler vibrometer toward the fixture fixed to the shaker, and the apparatus finds the vibration characteristic of the head gimbal assembly according to the detected vibration velocities.

Claims

1. 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.

2. The apparatus of claim 1, wherein the base block has one of a rectangular parallelepiped shape and a cylindrical shape.

3. The apparatus of claim 1, wherein the mount block has a rectangular sectional shape to reduce the total length of the fixture.

4. The apparatus of claim 1, wherein at least one of the base block and mount block is made of one of light metal and light alloy.

5. 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 internal thread;

a mount block having a through hole and joined to the base block so that the through hole agrees with the internal thread, the mount block supporting the head gimbal assembly; and

a bolt passed through the through hole of the mount block and fastened to the internal thread of the base block, to fix the mount block and the base block together.

6. The apparatus of claim 5, wherein the base block has one of a rectangular parallelepiped shape and a cylindrical shape.

7. The apparatus of claim 5, wherein the mount block has a rectangular sectional shape to reduce the total length of the fixture.

8. The apparatus of claim 5, wherein one of the base block, the mount block, or the bolt is made of one of light metal or light alloy.