| 摘要 |
<p>There is disclosed a tracking error detecting apparatus for an optical head, which includes a semiconductor laser apparatus, a diffraction grating, a beam splitter, an objective lens and a photo-detector, in which a laser beam from the semiconductor laser apparatus is divided into a main beam and two side beams at both sides of the main beam by the diffraction grating, the three beams are introduced through the beam splitter and the objective lens to an optical recording medium, beams reflected on the optical recording medium are introduced through the objective lens to the beam splitter and reflected thereon, the reflected beams are made incident on the photo-detector and detected outputs of at least two beams of the three beams from the photo-detector are used to produce a tracking error signal corresponding to the tracking state of the main beam on the optical recording medium. In this case, the reflection of the side beam of the reflected beams on the optical recording medium which passes through the objective lens, the beam splitter and the diffraction grating and returns to the semiconductor laser apparatus is suppressed at a laser beam emission end face to thereby reduce the influence by the skew of the optical disc on the tracking error signal.</p> |
