A DLP projector using Texas Instruments DLP technology. This example uses one, two or three microfabricated light valves called digital micromirror devices (DMDs). The use of versions of single - and double-DMD of the wheels of color in time with the updates to mirror to modulate the color. The most common problem with the single - or two-DMD varieties is a 'Rainbow' visible that some people perceive when moving their eyes. More recent projectors with higher speed (2 x or 4 x) and otherwise optimised color wheels decreased this artifact. Systems with 3 DMDs never have this problem, because they display each primary color at the same time.