| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical pickup device which is furnished with a single optical system for optical pickup being is a combination of a fixed part including a light source part provided with a plurality of light sources having different wavelengths and of a movable part including an objective lens movable with respect to the fixed part and which performs an excellent write-in/read-out of information even if any one of light sources is used, and to provide an optical system for optical pickup used for the optical pickup device. SOLUTION: A luminous flux emitted from a first semiconductor laser 11A on the short wavelength side is made incident on an objective lens 15 of the optical system for optical pickup as a converged light and a luminous flux emitted from a second semiconductor laser 11B on the long wavelength side is made incident on the objective lens as a divergent light, thus a spherical aberration caused by a relative motion of the light source part and the optical system for optical pickup is decreased. |
