Optical pickup having optical path length correction function

摘要

An optical pickup configured so as to reproduce signals recorded in optical disks of plural standards by means of a single laser beam. The optical pickup has an objective lens for gathering a laser beam emitted from a semiconductor laser-which emits a laser beam of single wavelength-onto a signal recording layer provided in each of optical disks of first and second standards whose cover layers differ from each other in terms of a thicknesses. The first standard is; for example, a CD, and the second standard is; for example, a DVD. An optical path length correction member-in which there is formed an optical path length correction section for making a correction to an optical path length falling within a range smaller than the diameter of a light beam passing through the objective lens-is provided in an optical path between the semiconductor laser and the objective lens. The optical path length correction section may also be formed on a lens plane of the objective lens facing the semiconductor laser.