| 摘要 |
PURPOSE:To facilitate regulation of an optical axis and to access to an elastic surface wave at a high speed by placing an optical system formed of an optical integrated circuit on a swing arm rotatable in a track (radial) direction. CONSTITUTION:A reflected light from an optical disk 11 is diffracted by a polarization separate type hologram 12 through the same passage, and condensed to penta-divisional detectors 8, 8' to detect an information signal, a focus error signal and a tracking error signal from the disk 11. In the case of track accessing, a driving coil 13 is energized to rotate a swing arm 1 at a shaft 15 as a center to be roughly tracked. In the case of precise tracking, it is executed by a high speed optical polarizer by an elastic surface wave excited by a pectinated electrode 5. In the case of controlling a focus of an objective lens, part of the arm 1 is formed of an electrostrictive converter plate 17, the plate is deflected by applying a driving voltage based on the error signal to displace the lens in a predetermined direction. |
