Voice coil motor apparatus

Abstract

The present invention discloses a voice coil motor apparatus, especially one applied to an auto-focus or variable-focus lens module of a miniaturized camera. The voice coil motor apparatus of the present invention comprises: a voice coil motor, a plurality of steel guidance shafts, a lens holder, and a base. The voice coil motor includes a magnetic part, which further comprises magnets and yokes, and an electrical part, which further comprises a coil winding. The magnetic part is rigidly coupled to the lens holder to form the moving member of the apparatus. The electrical part and the steel guidance shafts are fixed on the base to form the non-moving member. The voice coil motor apparatus of the present invention is characterized in that the pre-loaded force due to the interaction between the leakage flux of the magnetic part and the steel guidance shafts eliminates the free-play resulting from the tolerance gap between the moving and the non-moving members in order to achieve a high repeatability of motion performance, and that the magnets and the yokes form a non-circular magnetic structure having a rectangular contour in order to minimize the overall dimension of the voice coil motor apparatus.

Dependencies are inferred from the claim text.