An objective lens driving device of a sliding shaft type is mounted on an optical information recording and reproducing apparatus. The objective lens driving device includes an armature unit having a magnet magnetized in a plurality of pairs of magnetic poles, and a stator unit having a yoke, and control...http://www.google.com.au/patents/US5105405?utm_source=gb-gplus-sharePatent US5105405 - Objective lens driving device
