Track accessing control apparatus having a high-pass filter for extracting a tracking signal

Claim 1

A track accessing apparatus for a light beam for an optical disk having an information recording track, comprising: means for directing the light beam onto the optical disk, said directing means including an objective lens driving coil having an inherent vibrating frequency; means for detecting a reflection of the light beam from the optical disk and for generating a tracking signal including a track detection alternating signal and a low frequency component having a frequency lower than that of the track detection alternating signal, the alternations of said track detection alternating signal being representative of the frequency at which tracks are traversed by the light beam; high-pass filter means for removing the low frequency component of the tracking signal, said high-pass filter means having a cut-off frequency than said inherent vibrating frequency and lower than a frequency at which tracks are traversed by the light beam; means for counting a number of alternation of the track detection alternating signal; and means for moving the light beam directing means across the tracks according to the number of alternations counted by said counting means.