PURPOSE: An optical pickup device is provided to detect tracking error signals having a low offset. CONSTITUTION: An LD(Laser Diode,20) emits laser beams. The laser beams are converted into parallel beams by a collimating lens(25). A beam splitter(30) changes the traveling path of the incident beams. An objective lens(40) focuses the incident beams on the recording face of the disk via the beam splitter to form optical spots. A hologram element(60) diffracts the incident beams reflected from the disk. A photodetector(70) receives the incident beams. The photodetector adopts a focusing lens(69) for changing the incident beams into focusing beams. A tracking error signal detector(80) detects tracking error signals having no offset when the objective lens is moved. An optical pickup device traces the right track position of a disk by correcting offset of tracking error signals when the objective lens is moved.
