OPTICAL PICKUP DEVICE WITH DIFFRACTION ELEMENT AND OPTICAL RECORDING AND REPRODUCING DEVICE WITH THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an optical pickup device, using a diffraction element, which prevents noise due to diffracted light of other order which is not used to record and reproduce information.

SOLUTION: There is provided an optical pickup device for reproducing information recorded on an optical recording medium and for recording information on the optical recording medium. The optical pickup device includes a light source unit which emits light, the diffraction element which diffracts the light emitted by the light source unit, and an objective which focuses a (p)th-order diffracted light used to record and reproduce information among a plurality of pieces of diffracted light diffracted by the diffraction element on any one of a plurality of information reording layers formed in the optical recording medium. Pieces of (p±1)th-order diffracted light which are not used to record and reproduce the information are focused on a position off the plurality of information recording layers and a surface of the optical recording medium.

COPYRIGHT: (C)2012,JPO&INPIT