Patent ID: 6160768
Filing Date: 2000-12-12
Classification: B82Y,G11B

Abstract:
An optical pickup comprising:a light source for emitting a light beam;an objective lens for condensing the emitted light beam onto an information record medium, which comprises an information record surface for recording information thereon, from one external surface of said information record medium;an immersion lens disposed on an optical path of the condensed light beam between said objective lens and said information record medium for increasing a numerical aperture for the condensed light beam; anda floating device for floating said immersion lens from said one external surface, such that a distance between a center of curvature of said immersion lens and said information record surface is within a predetermined tolerable range;wherein said floating device comprises:a first magnet opposed to another external surface of said information record medium;a second magnet opposed to said one external surface and movable in one body with said immersion lens; andan elastic body for holding said immersion lens and said second magnet with respect to said objective lens;said floating device floating said immersion lens such that the distance between the center of curvature of said immersion lens and said information record surface is within the predetermined tolerable range, by balancing an elastic force of said elastic body and an attraction or repulsion force between said first and second magnets.