| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical recording/reproducing device having a high utilization rate of light from a light source and having a constitution of being minimized in an optical recording/reproducing device utilizing a triple beams method as a tracking error detecting method. SOLUTION: A dittraction grating is formed on a surface 14a on the one side, a surface 14b on the other side is formed in a convex spherical face, and an optical element of multiple functions to make diverging light from the light source pass through is provided. Spherical aberration generated in the forward passage from the light source 1 just prior to a objective lens 6 is corrected by a combination of the convex spherical face of the optical device 14 of multiple functions and a curved surface formed on a lens 4A provided between a beam splittor 3 and the objective lens 6. |
