METHOD AND APPARATUS FOR CONTROLLING A MEMS MICRO-MIRROR DEVICE

摘要

The present invention concerns a method and an apparatus for controlling a MEMS micro-mirror device. The invention enables the control of the micro-mirror deflection angle and of the micro-mirror scanning frequency, essential for the projection as it relates directly to the size of the projected image. The MEMS micro-mirror device has a fixed part (102) and a micro-mirror (100) that can oscillate along at least one oscillation axis, a magnet (200) either placed next to said fixed part (102) or on the said movable part (100) and a sensing coil (202) placed on said moving part (100) or on said fixed part (102). A detecting circuit detects at least one value (U?nd) of the inducted voltage in said sensing coil (202) for each period and for each oscillation axis, and a calculating circuit (404) calculates the amplitude of the movement of said micro-mirror (100) by means of said value (Umd)- Another independent electrical drive coil can be used in order to have two independent electrical coils respectively for driving the micro- mirror and for sensing its positions. The invention can prevent an unexpected default of the projection system.