Patents Examined by Varsha A. Kapadla
  • Patent number: 6667840
    Abstract: The present invention provides a method to screen tracks on a magnetic disc in a disc drive for harmonic resonance. There are several algorithms in the method performing different functions at various stages of the method. At any point in time, only one track is subjected to test by the method. The first stage of the method has one algorithm performing the function of obtaining a summation of all the absolute Position Error Signal (PES) velocities on a single track. Another algorithm performs the function of obtaining the average PES velocity with the summation of the absolute PES velocities. At the subsequent stage, another algorithm performs the function of obtaining the average PES velocity of a number of revolutions. An algorithm at the final stage performs the function of comparing the average PES velocity to a preset standard criterion, which is determined empirically in a separate algorithm. The track would be failed if the average PES velocity exceeds the preset standard criterion value.
    Type: Grant
    Filed: April 19, 2000
    Date of Patent: December 23, 2003
    Assignee: Seagate Technology LLC
    Inventors: Kok Hiang Cheong, Kian Keong Ooi, Wing Kong Chiang, Ricky Wei Watt Yeo