8.1 Overview

DLP5500 is a 0.55 inch diagonal spatial light modulator which consists of an array of highly reflective aluminum micromirrors. Pixel array size and square grid pixel arrangement are shown in Figure 11.

The DMD is an electrical input, optical output micro-electrical-mechanical system (MEMS). The electrical interface is Low Voltage Differential Signaling (LVDS), Double Data Rate (DDR).

DLP5500 DMD consists of a two-dimensional array of 1-bit CMOS memory cells. The array is organized in a grid of M memory cell columns by N memory cell rows. Refer to the Functional Block Diagram.

The positive or negative deflection angle of the micromirrors can be individually controlled by changing the address voltage of underlying CMOS addressing circuitry and micromirror reset signals (MBRST).

Each cell of the M × N memory array drives its true and complement (‘Q’ and ‘QB’) data to two electrodes underlying one micromirror, one electrode on each side of the diagonal axis of rotation. Refer to Figure 15. The micromirrors are electrically tied to the micromirror reset signals (MBRST) and the micromirror array is divided into reset groups.

Electrostatic potentials between a micromirror and its memory data electrodes cause the micromirror to tilt toward the illumination source in a DLP projection system or away from it, thus reflecting its incident light into or out of an optical collection aperture. The positive (+) tilt angle state corresponds to an 'on' pixel, and the negative (–) tilt angle state corresponds to an 'off' pixel.

Refer to Micromirror Array Optical Characteristics for the ± tilt angle specifications. Refer to the Pin Configuration and Functions for more information on micromirror clocking pulse (reset) control.