Optical element and optical head device using it and optical information device using this optical head device, and computer, optical disk player car navigation system, optical disk recorder and optical disk server using this optical information device

摘要

Providing an objective lens with a large numerical aperture (NA), the present invention records or plays conventional optical disks such as CDs and DVDs using an optical head capable of recording or reproducing high-density optical disks. An optical element ( 8 ) is provided between a first and second laser light source and an objective lens ( 18 ) for the purpose of converting a wave front of a second optical beam 32 . Furthermore, the optical element ( 8 ) and the objective lens ( 18 ) are fixed to move as a single piece.