Internal filtering for LCDs
Display appearance unaffected externally
Need to partially disassemble display
Full MIL-STD-3009 and RTCA/DO-275 compliance
NVG upgrading of displays by internal filtering is best suited to LCD displays using edge illumination of a light plate.
There must be a space available for the filter as a thin filter strip is positioned between the light sources (LED or CCFL) and the edge of the light plate. Sometimes the light plate can be machined to accommodate the filter.
The advantages of this approach is that the display external appearance and behaviour is unaffected, and the filter area is relatively small, keeping material costs down.
The disadvantages are that some disassembly is needed, and this could affect the equipment warranty. However, we frequently work with the display OEM to get around the latter issue.
We maintain extensive stocks of different thin filter materials suited to this type of upgrade, and for the different light sources that are commonly encountered.
Following the upgrade we can test in our dark room facility if required to certify compliance with MIL-STD-3009/RTCA/DO-275 or other relevant standards.