Patent ID: 7298676

Claim:
An optical pickup apparatus, comprising: light emitting means for emitting a single beam that will be focused onto a track of optical disks having different track pitches; optical means for diffracting the single beam, focusing the optical spot of the diffracted beam having a specific diffraction coefficient on the track, and transmitting the diffracted beam, which is reflected by the track, to an outside; and optical detection means comprising a first optical detection unit on which a central beam having a 0-order diffraction coefficient is focused, and second and third optical detection units on which side beams having ±1 diffraction coefficients are focused, respectively, each of the optical detection units being segmented into a specific number of optical detection areas, at least one of the optical detection units being provided with an optical detection area, on which a tracking error signal is not formed, to compensate for tracking error offset attributable to optical axis shift of an objective lens.