Most microdisplays use a silicon chip as the substrate material. The chip also houses the addressing electronics (at least an active matrix with integrated drivers), usually implemented in standard CMOS technology. This mature technology generates very reliable and stable circuits (better than TFT technology) and allows very small pixel pitches (down to 10 �m or even somewhat smaller) and high display resolutions.
Microdisplays can be used in projectors or in "near to the eye" (NTE) applications, such as in head-mounted displays and camera view-finders.
Several electro-optical effects can be used to generate the image: Electroluminescence (EL), OLED, vacuum fluorescence (VF), reflective Liquid Crystal effects and tilting or deforming of micro-mirrors (requires micro-machining). The most popular combinations today are Liquid Crystal On Silicon (LCOS), OLED on silicon and tilted mirrors (DMD or DLP).