Patent ID: 7616535

Claim:
A method of determining a track searching direction, suitable for determining the track searching direction of an optical pick-up head, the optical pick-up head includes a top left photo-sensor, a top right photo-sensor, a bottom right photo-sensor and a bottom left photo-sensor for reading the light intensities of a reflected main beam, comprising the steps of: calculating a seeking error (SE) to obtain a seeking error signal, wherein SE=(A−B)−(D−C), and A, B, C, D respectively represent the light intensities of the reflected main beam measured by the top left photo-sensor, the top right photo-sensor, the bottom right photo-sensor and the bottom left photo-sensor; calculating a tracking error (TE) to obtain a tracking error signal, wherein TE=(A+D)−(B+C); and contrasting the phase of the seeking error signal with that of the tracking error signal, wherein, when the phase of the seeking error signal leads that of the tracking error signal by 90°, the track searching direction is determined to be forward, and when the phase of the seeking error signal lags that of the tracking error signal by 90°, the track searching direction is determined to be backward.