本文介紹微投影三種主要技術發展概況，並針對雷射掃描投影技術與微機電掃描晶片 (MEMS scanning mirror) 的投影原理與技術特性做說明介紹。由於微機電掃描晶片以類比方式將混成單一光束的紅、藍、綠光雷射掃描成一二維畫面，畫面中每一畫素色彩則透過同步高速調變紅、藍、綠光雷射輸出功率合成，具備高光學效率、低功耗、色域廣以及無需對焦等特性，加上反射鏡面簡諧運動掃描導致的亮度均勻性、雷射入射導致的影像幾何變形均可透過韌體運算補償修正，因此投影光機所需零件最簡化，具備體積縮小、低成本等優勢，符合內建式微投影應用的要求。

In this article, we introduce the three primary pico-projector technologies and focus on discussing the working principle and features of laser scan projection display with MEMS scanning mirror. The MEMS scanning mirror scans RGB laser beams aligned into a single spot into a two-dimensional image area to form an image. Each pixel color is formed by modulating the RGB lasers simultaneously that leads to high optical efficiency, lower power consumption, wide color gamut and focus free operation. The geometrical distortion and brightness uniformity due to laser incident angle and sinusoidal motion of the scanning mirror may be compensated and corrected through fi rmware computation without additional optical components. Therefore, the light engine requires the least components and is inherently small and low cost, and is best suited for embedded projection application.