| 摘要 |
<P>PROBLEM TO BE SOLVED: To conduct focus control without moving an objective lens toward a focusing direction, by utilizing the properties characteristics of a liquid crystal element. <P>SOLUTION: An optical pickup is provided with a focus control means, with which focusing position of light beams passed through an objective lens 4 is varied toward a focusing direction of the objective lens 4. The optical pickup has an optical system, in which light beams emitted from a light emitting element 5 with a prescribed radiating angle are made into parallel light beams by a collimating lens 9. The focus control means is formed by the liquid crystal element 10, which is arranged in the mutual optical path between a disk recording surface D and the objective lens 4 which faces the disk recording surface D. The liquid crystal element 10 has the characteristics, where the refractive index of the passed light beams that are made incident on the liquid crystal element 10, in a tilted manner, are changed according to the level of an applied voltage. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
