| 摘要 |
PURPOSE:To quickly adjust an optical information recorder and reproducing device with a simple mechanism, by providing a transmission type optical wedge which is rotatable in a plane vertical to the advancing direction of an optical beam in the optical path of another optical beams for tracking control. CONSTITUTION:Lights emitting out from a semiconductor laser 1 are changed to parallel lights by a collimator lens 3 and the advancing direction of the parallel lights is slightly changed by a transmission type optical wedge 15. The wedge 15 is rotated in a plane vertical to the incident lights of the optical beam and can rotate the direction of the optical beam. That is to say, in regard to light beam spots image-forming on a photomagnetic disk 9 through an objective lens 8, the spots 22a and 22c of both side tracking beams move in circles. (The dotted line represents a recorded bit string). The transmission type optical wedge 15 is adjusted and fixed so that the light spot 22b is superposed upon the recorded bit string and the spots 22a and 22c are respectively put of the right side and left side of the recorded bit string about a half. |
