Compared with CRT projection and LCD

displaying system based on digital micromirror device (DMD) has its own advantage. The performance

gray-level modulation and color controlling method of the video displaying system based on DMD are analyzed in detail. At first

the principle of DLP Discovery4100 DMD module was given. Also

the spatial and temporal gray-level modulation was introduced. Considering the feature of those two methods

one color controlling method of chromatic video based on temporal gray-level modulation was proposed. In this method

frame period was equally divided to be the R

G

B section. In each of the R

G

B section

status of the micromirror in the DMD was controlled according to the gray-level of corresponding color. Considering the DLP Discovery4100 DMD module

the relationship between gray-level

video frame frequency and DMD type was given. Analyzing result shows that

when same gray-level is selected

the maximal frame frequency of three DMD chromatic video displaying system equals to that of gray video displaying system

while the maximal frame frequency of single and double DMD chromatic video displaying system is just 1/2 and 1/3 of that level. Analyzing result could provide academic basis for designing of video displaying system.