Patent ID: 6895593
Filing Date: 2005-05-17
Classification: G11B

Abstract:
1. An actuator used with an optical pickup, the actuator comprising: a base on which a holder is fixed; a lens holder in which a plurality of installation holes are formed such that a plurality of objective lenses to record and/or reproduce optical discs having different recording densities are installed at different heights; a support member, which movably supports the lens holder, having one end coupled to the lens holder and the other end coupled to the holder; and a magnetic circuit which drives the lens holder in focusing and tracking directions, the plurality of installation holes include a first installation hole in which a first objective lens for at least one type of low density optical disc is installed, and a second installation hole in which a second objective lens for a high density optical disc is installed, wherein when a working distance of the first objective lens for the low density optical disc installed in the first installation hole is represented as WD separation distance with respect to optical disc of second objective lens=WD where, and contact between the second objective lens, having a shorter working distance, and the optical disc is prevented when the optical disc is installed and the first objective lens has a longer working distance operates.