Optical raster-scanning displays based on surface-micromachined polysilicon mirrors

We demonstrate high-resolution, raster-scanning display systems based on pairs of orthogonally scanning, surface-micromachined mirrors. The first mirror of the raster-scanning pair determines the line-scan rate of the display and is driven at its resonant frequency which is on the order of 4.7 kHz, The second mirror, driven at a frequency below its resonance and scanning orthogonally to the first mirror, determines the image refresh rate. Both mirrors have a maximum optical scanning angle of 15 degrees, Single chip and two chip scanners are demonstrated. The resolution of the single-chip display, based on average pixel size, is 102 x 119 pixels. The curvature of the mirror surfaces are characterized and optically compensated to achieve this resolution.