| 摘要 |
PURPOSE:To prevent the increase of jitter by making the spot shape of a recording laser beam longwise in the radial direction and decrease the curvature of a curved side edge. CONSTITUTION:The beam from a semiconductor laser 12 for reproduction is made to be parallel beam by means of a collimator 22 and a light spot for reproduction is made to be almost circular by means of a built-in cylindrical lens 23. On the other hand, the beam from a semiconductor laser 11 for recording reaches a magnetic layer 3 as it is without using a cylindrical lens in its optical system. Consequently, the spot is circular while the light spot for recording remains an ellipsoid. The major axis of the recording spot faces the radial direction of the magneto-optical disk 1 and the minor axis faces the extending direction of a track. Consequently, a reproducing signal becomes a symmetrical shape and the jitter is reduced. |
