Objective lens driving device and optical disc apparatus

An objective lens driving device comprising:

• an objective lens;
• a lens holder which holds the objective lens;
• two magnets which are disposed facing each other to sandwich the lens holder;
• focusing coils which are fixed on the lens holder to generate driving force in focusing direction by electromagnetic force action with the magnets;
• tracking coils which are fixed on the lens holder to generate driving force in tracking direction by electromagnetic force action with the magnets;
• and
• an elastic supporting member which supports the lens holder in movable manner, wherein
• on a surface of the lens holder which faces to the magnet, one of the focusing coils and two of the tracking coils are set up to align in a direction that is parallel to the tracking direction with the focusing coil being as a center,
• the magnets are magnetized as multipole magnets such that two effective portions which are sides of the focusing coil that face each other to generate the driving force, act with different direction magnetic fields respectively, and such that two effective portions which are sides of the tracking coils that face each other to generate the driving force, act with different direction magnetic fields respectively, and
• the two magnets are disposed such that N-S polarity of them becomes inverse at a part of the surfaces which face each other.