Patent ID: 7990463

Claim:
A multi-stage lens driving device which defines a central axis, comprising: a front cover, which is a hollow annular cover having a plurality of recesses formed on an inner periphery thereof and a plurality of holders on an outer periphery thereof; a rear cover, which can be combined with the front cover, thereby forming a receiving space therebetween; a plurality of yokes, disposed respectively in the recesses formed on the inner periphery of the front cover; a plurality of driving coils, disposed respectively on the holders of the front cover and corresponding respectively to the yokes disposed in the recesses; a lens seat, which is a hollow housing disposed in the receiving space; and a plurality of permanent magnets, surrounding and embedded in an outer periphery of the lens seat, disposed in correspondence to the yokes and spaced therefrom by a predetermined distance; wherein, when predetermined impulse currents of different directions are applied to the driving coils respectively, polarities of corresponding yokes are thereby reversed; magnetic attraction and repulsion between the respective permanent magnets; and the yokes result in a rotational translation of the lens seat in the receiving space along the central axis; and when no impulse current is applied to the driving coils, the lens seat is held at a predetermined location by an attraction between the permanent magnets and the yokes, so that the lens seat does not wobble.