| 摘要 |
PROBLEM TO BE SOLVED: To reduce the thickness and the number of parts of a condensing system. SOLUTION: The optical pickup is equipped with a condensing element 4 having an objective lens 6 and an immersion lens 7, a hologram 3 for bisecting a reflecting optical flux, a plurality of light receiving elements 9, 10 which are arranged on both sides of an incident optical path 8 and receive two reflecting optical fluxes bisected by the hologram 3 and deflected by a deflecting element 2, while each light-receiving position is made different before and after the convergence. The optical pickup outputs detection signals for focusing and tracking by the output of the light receiving elements 9, 10. In this case, the incident beam and the reflecting optical flux from a medium 1 are deflected nearly at right angles through the deflecting element 2, thereby reducing an optical path length in the direction orthogonal to the medium 1 for reducing the thickness, and also reducing the number of parts and the assembly man-hour of the condensing system. |
