| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical head which deals with two kinds of optical recording media varying in the thicknesses of light transparent layers and is capable of easily correcting the respective spherical aberrations generated during the recording and reproducing of the respective optical recording media. SOLUTION: In recording and reproducing of the one optical recording medium, the zero order light which is a first laser beam L1 emitted from a light emitting and receiving element 11 and is transmitted as it is through a hologram element 13 is condensed by an objective lens 14 onto the optical recording medium. In recording and reproducing of the other optical recording medium, the first order light which is a second laser beam L2 emitted from the light emitting and receiving element 11 and is diffracted by the hologram element 13 is condensed by the objective lens 14 onto the optical recording medium. |
