Laser scanning displays offer the possibility of creating bright, high-resolution images from compact projection devices. The requirements of the optical systems that produce quality images using scanned laser illumination differ significantly from traditional incoherent projection systems. In scanning systems, the laser beam size and quality determines the resolution of the scanned line. The geometrical orientation of the scanning mirrors has a significant impact on distortions that appear over the entire scanned image. In addition to the influence of Gaussian beam characteristics and geometrical factors on scanned image quality and system design, we also discuss optical, mechanical and electronic features of MEMS based scanning systems that keep manufacturing costs low.