Low-Power High-Speed Electromagnetic Flapping Shutters Using Trapezoidal Shutter Blades Suspended by H-Type Torsional Springs

We present small-size, low-power, and high-speed electromagnetic flapping shutters composed of trapezoidal twin blades suspended by H-type torsional springs for phone camera applications. The previous electrostatic rolling and flapping shutters need high input voltage, while the previous electromagnetic rotating shutters are too large to use in phone cameras. For low-power and high-speed angle motion in the small size available on phone cameras, the present electromagnetic flapping shutters are designed to use the low-inertia trapezoidal twin blades, each suspended by the low-stiffness H-type torsional springs. The size of the only shutter device is , and the total size of the shutter system, including two permanent magnets (NdFeB), is . In the experimental study, the electromagnetic flapping shutters generate the steady-state rotational angles of and in the magnetic fields of 0.15 and 0.30 T, respectively, for the input current of 60 mA, while achieving the maximum overshoot angles of and in the magnetic fields of 0.15 and 0.30 T, respectively. The electromagnetic flapping shutters show the rising/settling times of 1.0 ms/20.0 ms for opening and 1.7 ms/10.3 ms for closing. The life time and light-blocking rate of the shutters are measured to be cycles and 80.7%, respectively. Therefore, we experimentally demonstrated that the small-size , low-power (≤ 60 mA), and high-speed (~1/370 s) electromagnetic flapping shutters are suitable for phone camera applications.