During a given period of time, the landed duty cycle of a given micromirror follows from the image content being displayed by that micromirror.

For example, in the simplest case, when displaying pure-white on a given micromirror for a given time period, that micromirror experiences a 100/0 landed duty cycle during that time period. Likewise, when displaying pure-black, the micromirror experiences a 0/100 landed duty cycle.

Between the two extremes (ignoring for the moment color and any image processing that may be applied to an incoming image), the landed duty cycle tracks one-to-one with the linear gray scale value, as shown in Table 8-2.

Accounting for color rendition (but still ignoring image processing) requires knowing both the color intensity (from 0% to 100%) for each constituent primary color (red, green, and/or blue) for the given micromirror as well as the color cycle time for each primary color, where “color cycle time” is the total percentage of the frame time that a given primary must be displayed in order to achieve the desired white point.

During a given period of time, the landed duty cycle of a given micromirror can be calculated as follows:

where

• Red_Cycle_%, Green_Cycle_%, and Blue_Cycle_%, represent the percentage of the frame time that Red, Green, and Blue are displayed (respectively) to achieve the desired white point.

For example, assume that the red, green and blue color cycle times are 50%, 20%, and 30% respectively (in order to achieve the desired white point), then the landed duty cycle for various combinations of red, green, blue color intensities would be as shown in Table 8-3.

When used with a single near-IR LED, the landed duty cycle of the DLP4500NIR device depends on the single LED cycle time and the scale value.

For example, assume the LED cycle time is 100% and the scale value is 80%, then the landed duty cycle is 80/20.