| 摘要 |
PURPOSE:To rewrite records many times with high quality by making a difference between the maximum inclination of light intensity of a light spot in the direction of a recording track with which a recording medium is first irradiated and the maximum inclination of light intensity of the light spot in the direction of a recording track with which the recording medium is next irradiated. CONSTITUTION:Light spots of which intensity inclination is different in before- and-after in the direction of a recording track are used. The same result is obtained by an optical system in which a shape of a condenser lens is asymmetric or by a semiconductor laser 1 in which light radiation is asymmetric. Asymmetric degree of intensity distribution of light may be changed in accordance with linear velocity of a recording medium by changing angle of a flat panel in an optical system provided with an light transmission panel which is not parallel to a disk plane, moving a cylindrical lens perpendicular to the axis in an optical system using an asymmetric cylindrical lens 14, or taking out it from the optical system completely. In this case, since temperature distribution in rewriting records is symmetric for before-and-after, shape distortion of recording spots is few, and drift of a recording film can be prevented. |
