A method and apparatus are disclosed for increasing contrast in micromirror-based
image display devices. As a result the displayed image is a more faithful reproduction
of the original and is more pleasing to human perception than is possible with
a low contrast display. The method and apparatus comprise a micromirror design
and a modulation scheme for driving micromirrors with a combination of analog and
digital techniques to achieve partial and full micromirror deflection. The analog
techniques permit the mirrors to be deflected to positions intermediate between
the resting position and the position of maximum deflection. These intermediate
deflections appear as intermediate light levels in an image. Compared to digital
modulation, the analog techniques provide an increase in the number of light levels
that can be displayed by a system that is limited by its incoming data rate and
maximum micromirror speed.