| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a liquid crystal optical element in which going and returning diffractive lenses are provided to correct a spherical aberration caused by a temperature change of a two-layer optical disk and a plastic objective lens, and nonetheless optical axis deviation of each diffractive lens is small and is easily manufactured; and to provide an optical pickup device using the liquid crystal optical element. <P>SOLUTION: The liquid crystal display element 5 is located in an optical path through which a laser beam goes and returns, and includes a going correction part 1 having a diffractive lens function and a spherical aberration correction function, and a returning correction part 2 having at least a diffractive lens function. Diffractive lens electrodes of the going correction part 1 and the returning correction part 2 are integrally formed on both sides of a transparent substrate 20. <P>COPYRIGHT: (C)2011,JPO&INPIT |
