| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high recording density and a large capacity of an optical disk by reducing occurrence quantity of spherical aberration by increasing the numerical apertures NA of objective lenses loaded on an optical head. <P>SOLUTION: An actuator 14 for collimator lens is provided in an optical head 1 used when recording/reproducing are performed for an optical disk 2 on which a light transmitting layer 4 is formed on a recording layer. Then, a collimator lens 13 arranged between a light source 10 and an object lens 16 is moved by this actuator 14 for collimator lens 13 so that spherical aberration caused by a thickness error of the light transmitting layer 4 is canceled, and that spherical aberration caused by thickness error of the light transmitting layer is canceled. <P>COPYRIGHT: (C)2010,JPO&INPIT |
