| 摘要 |
PURPOSE: An optical pickup device and an optical disk drive thereof are provided to effectively control coherent light which is generated from a multi-layered medium. CONSTITUTION: An optical pickup device comprises an optical transmission unit (10), a light source unit (20), a light receiving unit (30), a light control unit (14), and a supplementary light-receiving cell. The optical transmission unit includes an object lens which is faced with a medium including a multi-recording layer for recording data. The light source unit provides a single beam which is used to record and replay the information of the multi-recording layer for the optical transmission unit. The light receiving unit is provided on a progress route of a reflected beam which is generated from the media to which a single beam is sent. The light control unit diffracts a part of stray light, which is included in the reflected beam and generated from the medium, not to be sent in a main light-receiving cell. The supplementary light-receiving cell compensates the reduction of RF signals in the main light-receiving cell, where the reduction of the RF signals is generated by effective light which is diffracted by the light control unit. |
