OPTICAL ELEMENT, ADJUSTING METHOD THEREFOR, OPTICAL PICKUP DEVICE USING THE SAME AND OPTICAL REPRODUCING DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce the number of parts in an optical element constituting diffraction gratings and to reduce the time required for adjusting the fitting positions of the diffraction gratings by forming the diffraction gratings on both faces of the optical element.

SOLUTION: An optical pickup device 10 has a two wavelength semiconductor laser 11 where a light source 11e of a wavelength suitable for recording/playing-back of a CD and a light source 11d of a wavelength suitable for recording/playing-back of a DVD are light-emitted from the same package. The optical element 13 where one diffraction grating 13b on a surface or a rear face generates a sub-beam for tracking control in a CD system disk, and the other diffraction grating 13a generates a sub-beam for tracking control in a DVD system disk is arranged in an optical path.

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