Optimal Design of Magnetic Zooming Mechanism Used in Cameras of Mobile Phones via Genetic Algorithm

One of the important features for the cameras in cell phones today is the optical zooming. This paper presents design and optimization of a zooming mechanism via genetic algorithm (GA). The goal is to maximize voice coil motor (VCM) sensitivity in the zooming mechanism and, simultaneously, to keep various dimensions under physical limitation. The optimization first chooses key independent dimensions as design variables, and then establishes the computation procedure for the VCM sensitivity via equivalent circuitry. The correctness of the expression is validated by finite element analysis (FEA). Optimization results lead to that dimensions of the yokes and magnets reach optima at their extremes in preset constraints, and in result, high uniformity of the magnetic flux intensity along guide ways of the VCM is achieved