3d actuator for otpical disc system

Abstract

An optical pick-up actuator ( 1 ) has a lens holder ( 2 ). The lens holder has tracking ( 5 r ) and focusing ( 5 f ) coils which substantially extend in two parallel planes at a side of the lens holder ( 2 ). A magnet system ( 7 ) is arranged separately from the lens holder and extends beyond said planes, said magnet system cooperating with the tracking and focusing coils, the coil systems being arranged for effecting tilt through cooperation with the magnet system. Preferably, a coil system is provided at each of two opposite sides of the lens holder.

1 . Optical pick-up actuator comprising a lens holder suspended by suspension means and having tracking and focusing coils an objective lens, means for tilting the optical lens holder, a coil system at a side of the lens holder, said coil system comprising a focusing coil system substantially extending in a first plane and a tracking coil system substantially extending in a second plane parallel to the first plane, the actuator having a magnet system separate from the lens holder and extending substantially beyond the first and the second plane, seen from the lens holder, said magnet system cooperating with the tracking and focusing coils, the focusing and/or tracking coil systems being arranged for effecting tilt through cooperation with the magnet system. 
     
     
         2 . Optical pick-up actuator as claimed in  claim 1 , characterized in that the lens holder comprises a magnet system separate from the lens holder beyond the first and the second plane at each of two mutually opposed sides of the lens holder comprising a focusing coil system substantially extending in a first plane and a tracking coil system substantially extending in a second plane, so as to be parallel to the first plane and associated with each of said coil systems. 
     
     
         3 . Optical pick-up actuator as claimed in  claim 1 , characterized in that the first and the second plane substantially coincide. 
     
     
         4 . Optical pick-up actuator as claimed in  claim 1 , characterized in that the magnet system  7  comprises an arrangement of sub-magnets, the magnetic axes of at least some of said sub-magnets having a non-perpendicular orientation relative to the first and/or the second plane of the coils. 
     
     
         5 . Optical pick-up actuator as claimed in  claim 4 , characterized in that at least some of the sub-magnets have a diagonal orientation relative to the first and/or the second plane. 
     
     
         6 . Optical pick-up actuator as claimed in  claim 1 , characterized in that at least one of said coil focusing and/or tracking coil systems comprises one or more pairs of coils at each opposite side, wherein said pair or pairs of coils forms or form a means for tilting the lens holder. 
     
     
         7 . Optical pick-up actuator as claimed in  claim 6 , characterized in that the pair of the coils forming a means for tilting the lens holder is arranged substantially mirror-symmetrically with respect to a mirror plane, said mirror plane extending through and parallel to an optical axis of the lens holder and substantially perpendicular to the planes of the planar coil arrangements. 
     
     
         8 . Optical pick-up actuator as claimed in  claim 6 , characterized in that both focus and tracking coil systems are mirror-symmetrically arranged with respect to said mirror plane, wherein the pair of coils forming the means for tilting is arranged at opposite sides of said plane at some distance from the mirror plane, and the other coil system is arranged adjacent the mirror plane. 
     
     
         9 . Optical pick-up actuator as claimed in  claim 6 , characterized in that the center of gravity of the coil system not comprising the means for tilting the lens holder is arranged closer to the center of gravity than the coils comprised in the means for tilting the lens holder. 
     
     
         10 . Optical pick-up actuator as claimed in  claim 7 , characterized in that the center of gravity of the coil system not comprising the means for tilting the lens holder is arranged substantially adjacent the center of gravity of the lens holder. 
     
     
         11 . Optical pick-up actuator as claimed in  claim 1 , characterized in that the pair of the coils forming a means for tilting the lens holder forms part of the focus coil system. 
     
     
         12 . Optical pick-up actuator as claimed in  claim 1 , characterized in that the lens holder comprises a magnetic yoke. 
     
     
         13 . Optical pick-up actuator as claimed in  claim 1 , characterized in that the tracking and focus coil systems share a common electrical line. 
     
     
         14 . Optical read and/or write system comprising an optical pick-up actuator according to  claim 1 .