| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an objective lens for an optical pickup device that is able to make optical disks of three types, BD, DVD and CD, compatible by a common objective lens, restricts occurrence of high order spherical aberration even in wavelength change in temperature or light, and is able to satisfactorily obtain a balance between a wavelength characteristic and a temperature characteristic, and to provide an optical pickup device using the objective lens. <P>SOLUTION: In the objective lens for the optical pickup device, the optical disks of the three types, BD, DVD and CD, can be made compatible by the common objective lens. In a basis structure overlapping the central area and intermediate area of the objective lens, flare can be provided by imparting an over-spherical aberration during the use of a third optical disk, based on the magnitude relation between a central area side pitch and an intermediate area side pitch with a boundary between them and the relation between the step directions. <P>COPYRIGHT: (C)2013,JPO&INPIT |
