| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device which can stably and satisfactorily reproduce signals recorded in a plurality of types of optical recording mediums different in thickness of protection layers and recording density of information and different in wavelengths of laser beams used for reproduction. <P>SOLUTION: The optical pickup device is provided with a two-wavelength semiconductor laser 11, a phase difference plate 12, diffraction gratings 13 and 13b arranged from a side of the two-wavelength semiconductor laser 11 in order, a beam splitter 14, a collimator lens 15, an objective lens 16, a sensor lens 17 and a photodetector 18. A second light emitting part 11e of the two-wavelength semiconductor laser 11 is arranged near a focus of the collimator lens 15. The objective lens 16 is constituted to satisfy a sine condition with respect to light from a first light emitting part 11d of the two-wavelength semiconductor laser 11. <P>COPYRIGHT: (C)2004,JPO |
