Patent ID: 7325243

Claim:
An electromagnetic driving device for an object lens of an optical pickup comprising: an object lens having an optical axis; a lens-bearing seat having a lens frame for carrying said object lens and defining said object lens' optical axis, said lens-bearing seat having a hollow rectangular section next to said lens frame; a base as a bottommost part to said electromagnetic driving device, wherein said base has a plurality of erect sections; an auxiliary magnetic device comprising a plurality of magnets having at least two pairs of magnets, wherein said magnets are fixed to said erect sections of said base and form a closed magnetic space therein; a focusing coil whose axis is parallel to said object lens' optical axis, wherein said focusing coil is placed within said closed magnetic space and fixed to said lens bearing seat; a tracking coil whose axis is perpendicular to said object lens' optical axis, wherein said tracking coil is placed within said closed magnetic space perpendicular to said focusing coil and fixed to said lens bearing seat; a plurality of elastomers, wherein each of said elastomers is attached to said lens bearing seat and has an end fixed to said base; and a top cover as a topmost part to said electromagnetic driving device, wherein said top cover is made of a material with permeance and provides protection to said focusing coil, said tracking coil, and said auxiliary magnetic device; wherein said auxiliary magnetic device, said focusing coil and said tracking coil are positioned entirely in said hollow rectangular section of said lens-bearing seat.