Actuated polysilicon micromirrors for raster-scanning displays

Abstract

We have designed and fabricated polysilicon microscanners using surface micromachining technologies. The scanners have electrostatic-comb actuators to drive 300/spl times/400 /spl mu/m/sup 2/ micromirrors mounted on stationary frames by torsion bars. Torsion-bar mounting improves scanning precision from what is achievable using hinge mounting with journal bearings. The scans are accurate to 0.19 mrad; that is a scan jitter of 0.1% of the full scale, or 9% of a pixel. A 7/spl times/10-pixel laser-scanning display built with a 7-element, fan-diode-laser array and a scanning polysilicon micromirror is presented. A dual axis, raster-scanning system based on similar resonant microscanners can be integrated on a chip with the light sources to produce compact microdisplay modules.