| 摘要 |
PURPOSE:To attain parallel reading of plural tracks and to sharply improve a data transfer speed by successively switching the optical path of optical beams from a light source by a deflecting means. CONSTITUTION:When an optical beam L2 passed through a half mirror is passed through a polarized light converting element 14 consisting of opto-electrical crystal and a deflecting means consisting of a wedge-shaped double refraction crystal 15, the polarizing direction of the optical beams L2 is alternately switched between two rectangular directions in accordance with a phase difference. When one polarizing direction of the optical beams L3 is set up so as to coincide with the optical crystal axis of the crystal 15, the polarized light in the direction goes an abnormal optical component and a linear polarized light rectangular to the abnormal optical component goes a normal optical component. When the optical beams L3 whose polarizing directions are alternately switched is passed through the crystal 15, respective optical beams L4, L5 refracted at respectively different angles are alternately obtained in accordance with the polarizing directions. Consequently, parallel reading can be attained and the data transfer speed can be improved. |
