How infrared is displayed

In night vision mode with 2 separate inputs, the projector displays the two inputs alternating every other frame. The output is displayed a double speed of the inputs, i.e. at 120Hz in case of 60Hz input. The DMD is illuminated with visible RGB light every other frame, while the IR “light” is illuminating the DMD all the time.

The display device (DMD) itself do not know whether it is displaying IR or VL. And this is causing problems when the actual image content is not carrying all 3 color components (full RGB). As an example, only the red color component is active on the input. The DMD is attempting to display this as an RGB image even if it is illuminated with IR. The result is that the DMD is active only approximately one third of the frame, thereby “wasting” a lot of the IR output power.

In Pulse release 2.1 and onwards, there is an option to create a Color Component mapping per connector input. This gives the flexibility on individual connector to connect DMD “colors” to input color channel.