Focal point adjusting method, and optical pickup device

Abstract

A focus control process (S), a spherical aberration correcting process (S), and a focus offset adjusting process (Sto S) are performed in this order. In the focus control process, an output of a focus error signal obtained by detecting focal point displacement that occurs in a direction of an optical axis of a light beam focused through a two-element object lens is controlled so that the output becomes close to zero. In the spherical aberration correcting process, spherical aberration that occurs with respect to the light beam is corrected. In the focus offset adjusting process, offset of the focus error signal is adjusted. In this way, it is possible to provide a focal point adjusting method and an optical pickup device in which focus control can be performed stably by eliminating the offset.