COMPATIBLE OPTICAL PICKUP

摘要

PROBLEM TO BE SOLVED: To provide a compatible optical pickup in which defocus of a short wavelength light source due to mode hopping is reduced and sufficient working distance is secured so that collision between an objective lens and a low density optical disk is not caused to light emitted by a long wavelength light source by providing the compatible optical pickup with a divergent lens.

SOLUTION: The compatible optical pickup includes an optical unit for emitting short wavelength light suitable for high density optical disk and at least one long wavelength light suitable for at least one kind of low density optical disk, receiving and detecting the light reflected from the high density optical disk and the low density optical disk, the objective lens for forming a light spot on the high density optical disk and the low density optical disk by focusing incident short wavelength and long wavelength light beams, a diffractive device for correcting chromatism according to a change in wavelength of the short wavelength light beam by refracting the short wavelength light beam incident from the side of the optical unit and the divergent lens for increasing a working distance with respect to the at least one kind of low density optical disks by refracting the long wavelength light beam proceeding toward the objective lens.

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