Patent ID: 6438090
Filing Date: 2002-08-20
Classification: G11B

Abstract:
An optical pickup device for recording/reproducing information on/from at least one optical medium having a plurality of recording surfaces or a plurality of optical media each having at least one recording surface, comprising:a light source for emitting a beam of light for information recording/reproduction; a plurality of optical heads for focusing the beam on a plurality of different recording surfaces; an optical path switching device, positioned between the light source and the optical heads, for changing an optical path for guiding the beam alternatively to one of the optical heads; a first relay lens, positioned between the light source and the optical path switching device, for changing the beam into a convergent beam; second relay lenses, positioned individually between the optical path switching device and the optical heads, for changing a divergent beam, obtained after the convergent beam from the first relay lens is temporarily converged, back into a parallel beam; and a lens drive unit for driving the first relay lens along the optical axis thereof so as to adjust the respective lengths of optical paths between the first relay lens and the second relay lenses.