Patent ID: 7145844

Claim:
An optical head comprising: a shaping element for shaping a beam emitted from a light source; a converging element for converging the beam that has been shaped by the shaping element on an optical recoding medium; a first detector for detecting an electric signal based on a zeroth-order diffracted beam and a first-order diffracted beam contained in the beam that has been reflected by the optical recoding medium; a second detector for detecting the distance between the spot position of the zeroth-order diffracted beam and the spot position of the first-order diffracted beam; driving means for swinging the shaping element; and controlling means for controlling the driving means so that the shaping element is swung based on the distance, which has been detected by the second detector, between the spot position of the zeroth-order diffracted beam and the spot position of the first-order diffracted beam. wherein the shaping element is provided in a swingable manner so that a distance between a spot position at which the zeroth-order diffracted beam is incident on the detector and a spot position at which the first-order diffracted beam is incident on the detector can be adjusted.