| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain an optical pickup with simple structure capable of obtaining satisfactory optical properties by reducing the quantity of astigmatism occurring at a mirror at a low temperature. <P>SOLUTION: By generating astigmatism in a direction nearly perpendicular to the astigmation occurring at the mirror at a low temperature by an objective lens or a collimator lens, the astigmation occurring at the mirror is reduced to obtain the satisfactory optical properties by the simple constitution. <P>COPYRIGHT: (C)2009,JPO&INPIT |
