A display includes a light source. The display also includes a filter positioned to receive light from the light source. The filter is a dye-based filter and attenuates light in the infrared range. The filter can be configured to have a very sharp spectral cutoff. The filter can be an NVIS filter. The...http://www.google.es/patents/US7081991?utm_source=gb-gplus-sharePatente US7081991 - Dye-based filter
