Five-axis stabilization system for a 2-DOF translational OIS

This study proposes a novel 5-axis stabilization system for a new two degree-of-freedom (DOF) translational optical image stabilizer (OIS) of cell cameras installed on the mobile phone. The OIS can improves the blurring image caused by the hand shakings when shooting a picture because the OIS stabilize the movements of the lens holder to efficiently reduce the misalignment of the optical path between the focusing lens and center of the image sensor. Unlikely Other OIS designs, this OIS stabilizes the lens holder by a two-DOF translational mechanism actuated by voice coil motors (VCM) and compensates for up to five directions of camera motion. The work can be divided into three main parts: (1) mechanism designs, (2) establishments of the dynamic equation of motions (EOM) of a two-DOF translational structure, and (3) realizations of a lead and lag controller with high-precision. In the first part, mechanism designs of the OIS are focused on that the four-parallel-wire suspension structure of the lens holder provides the translational movements in vertical and lateral axes and magnets offer optimal magnetic field for actuation. The second part shows the dynamic characteristics of the translational OIS system has been analyzed and the EOM has been derived. Based on the Newton's laws, the motions of the OIS have been modeled through considering the moment of inertia and the mass. Finally, a lead and lag controller is applied and the associated simulations are conducted. Based on the simulation results, the lead and lag controller is forged with the assistances from MATLAB pre-simulation and tested by a FPGA module. The controller would be built up which contains the drive system for anti-shake mechanism. After a series of experiments and verifications, the prototype of the novel OIS is finally accomplished with satisfactory performance of vibration reduction. The designed OIS module can reach a control translational range of ±1 mm in the required 0.1 second.