Patent ID: 7706088

Claim:
A voice coil type lens drive assembly for adjusting the focus of a lens by utilizing a repulsive magnetic force which a magnetic field created upon energization of coils of a movable unit loaded with the lens induces between the coils and fixed magnets opposed to the coils, the lens drive assembly comprising: a lower base; an electrically conductive spring disposed on the base; a metallic yoke disposed on the electrically conductive spring; magnets mounted within the yoke; a movable unit inserted into the yoke in opposition to the magnets; a leaf spring disposed on the yoke; and an upper cover frame coupled to the base while being superimposed on the leaf spring, the electrically conductive spring comprising an outer spring body, a thin spring piece formed inside the spring body, and a spring wire, the spring wire comprising a curvilinear portion connected at one end to the inner spring piece and repeating U-turn and another curvilinear portion connected at an opposite end to the outer spring body and repeating U-turn, respectively at plural positions of a circumference direction in a sole plane, the two curvilinear portions being disposed at a mutually intersecting angle, the leaf spring comprising a thin quadrangular spring frame located on an outer edge side, a thin circular spring ring located on an inner edge side, and a spring wire, the spring wire comprising a curvilinear portion connected at one end to the spring ring and repeating U-turn and another curvilinear portion connected at an opposite end to the spring frame and repeating U-turn, respectively at plural positions of a circumference direction in a sole plane.