Patent ID: 6349079
Filing Date: 2002-02-19
Classification: G11B

Abstract:
A method of detecting a head positioning error in a computer storage device, comprising the steps of:providing a rotating storage medium having a plurality of generally concentric tracks, each one of the tracks having a first and a second set of optically-detectable position marks disposed along the track, the first and second sets of position marks being radially offset in opposite directions from a centerline of the track; directing an incident beam of radiation onto a selected track; sensing a reflected beam of radiation from the selected track and responsively generating an electrical reflection signal, the reflection signal having a first and a second set of reflection pulses respectively corresponding to the first and second sets of position marks; differentiating the reflection signal to thereby produce a first and a second set of differentiated pulses respectively corresponding to the first and second sets of position marks; determining a first area of the first set of differentiated pulses and a second area of the second set of differentiated pulses; and comparing the first area to the second area.