| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical-system driving device which is constituted in such a way that two objective lenses are mounted so as to deal with recording mediums having two kinds of cover-glass thicknesses and which can be made small and lightweight as a whole. SOLUTION: An optical-system driving device is constituted so as to be provided at least with two objective lenses 1a, 1b, with a holder 2 which holds the two objective lenses 1a, 1b, with a carriage 6 which supports the holder 2 so as to be movable in nearly the radial direction of a recording medium and/or to nearly the vertical direction of the recording medium, with a mechanism which drives the carriage 6 to nearly the radial direction of the recording medium, with an optical system which radiates a laser beam in nearly the radial direction of the recording medium from the outside of the carriage 6 and with a reflection optical element which changes the optical path of the laser beam in directions of the optical axes of the objective lenses 1a, 1b. In this case, the two objective lenses 1a, 1b are arranged so as not to be parallel to the radial direction and the tangent-line direction of the recording medium. By this constitution, the holder 2 which holds the objective lenses 1a, 1b can be made small and lightweight. |
