| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device capable of recording/reproducing information on/from different types of optical information recording media by using lights of at least two wavelengths different from each other. <P>SOLUTION: This optical pickup device is provided with a first light source 12, a second light source 11 and a third light source 13 for emitting luminous fluxes whose wavelengths are λ1, λ2 and λ3 respectively (λ1 < λ2 < λ3) in order to record/reproduce information on/from first and second optical information recording media having transparent substrates and a third information recording medium having a transparent substrate thicker than those of the first and second optical information recording media, and an objective lens 1 for converging the luminous flux from each of the light sources on each of the optical information recording media. In recording/reproducing the information on/from each of the optical information recording media, the luminous flux emitted from the first light source to the second optical information recording medium, the luminous flux emitted from the second light source to the first optical information recording medium and the luminous flux emitted from the third light source to the third optical information recording medium are made incident as parallel light on the objective lens 1, respectively. They are converged on their corresponding optical information recording media. <P>COPYRIGHT: (C)2004,JPO |
