Analog pulse width modulation cell for digital micromechanical device

Abstract

A frame-addressed bistable micromirror array and method of operation. An analog input signal representing the desired intensity of an image pixel is applied to input 302. An address signal synchronized to the analog input signal is applied to input 304 of a given micromirror cell to store the pixel intensity information on input capacitor 306. After intensity information for each pixel in the video frame or field, or a portion of the frame of field, is stored on the input capacitor 306 of the appropriate micromirror cell, a frame signal is applied to input 308 to enable the transfer of charge between capacitors 306 and 310 and to turn on transistor 314 allowing a voltage applied to input 316 to charge capacitor 318. The pre-charge voltage is chosen to ensure the biased micromirrors are fully deflected to a first state. A ramp voltage is applied to input 322. A ramp voltage is applied to input 322. When the difference between the voltage across capacitor 310, which is applied to the gate of transistor 324, and the ramp voltage, which is applied to the drain of transistor 324, exceeds the threshold voltage required to turn on transistor 324, transistor 324 is turned on, and the voltage across capacitor 318 follows the ramp voltage applied to 322. The range of the ramp voltage is chosen so that, when any ramp voltage in the range is applied to the deflectable element of the micromirror, the deflectable element will assume the second state.

Dependencies are inferred from the claim text.