Patent ID: 9013965
Filing Date: 2015-04-21
Classification: G11B

Abstract:
1. An optical pickup device comprising: a light source configured to generate a beam for recording and/or reproducing information to/from a medium; an objective lens configured to receive the beam from the medium; a quarter-wave plate (QWP) disposed parallel to the objective lens such that a surface of the QWP through which the beam passes is oriented parallel to a surface of the objective lens through which the beam passes; a reflection mirror configured to reflect the beam onto the QWP after the beam passes through the QWP; and a polarization minor disposed between the objective lens and the QWP, and configured to reflect the beam generated from the light source onto the QWP, and allow the beam reflected by the reflection minor to pass to the objective lens, wherein the beam changes into a circularly-polarized beam element in response to passing through the QWP and changes into a straight beam in response to being reflected by the reflection mirror.