POLYSILICON OPTICAL MICROSCANNERS FOR LASER-SCANNING DISPLAYS

We have designed and fabricated polysilicon microscanners using surfac e micromachining technologies. The scanners have electrostatic-comb ac tuators to drive 300 x 400 mu m(2) micromirrors mounted on stationary frames by torsion bars. Torsion-bar mounting improves scanning precisi on from what is achievable using hinge mounting with journal bearings. The scans are accurate to 0.19 mad; that is a scan jitter of 0.1% of the full scale, or 9% of a pixel. A 7 x 10-pixel laser-scanning displa y built with a seven-element, fan-diode-laser array and a scanning pol ysilicon micromirror is presented. A dual-axis, raster-scanning system based on similar resonant microscanners can be integrated on a chip w ith the Light sources to produce compact microdisplay modules. (C) 199 8 Published by Elsevier Science S.A. All rights reserved.