Secondary filtering operations such as EMI/RFI shielding, antiglare/antireflective coatings or contrast enhancement can be added to the night vision filters. By significantly reducing NIR radiation, night vision goggles (NVG) can be used along with electronic display and lighting systems without affecting the nighttime sensitivity of the NVIS. Often the chromaticity of the display of lighting systems must be adjusted, which can be easily accomplished along with the near IR filtering. These filters are designed to absorb or reflect in the deep red and NIR.
The filtering of commercial light sources and displays is accomplished using near infrared (NIR) absorbing glass, thermoplastic substrates which absorb NIR radiation, or thin film coatings that simultaneously reflect NIR radiation and allow visible light to pass. By contrast, by reducing the near IR transmittance to 5% of the total visible component will often meet the minimum necessary requirements for ground based vehicles and equipment. To achieve NVC for a cockpit environment, there can be little to no overlap between the emissions spectrum of the display or light source and the spectral response of the NVIS. The NVIS are not used to read the cockpit displays (except the original AN/PVS-5), therefore the filtered displays must be visible to the unaided eye.Īvionic NVIS (ANVIS) filtering requirements are more demanding than ground based systems. If displays or light sources in the cockpit are not properly filtered, the AGC will activate and the NVIS will become proportionally less sensitive to nighttime objects outside of the cockpit. To protect the image intensifier assembly, the systems are equipped with an automatic gain control (AGC) which will aperture down the NVIS when exposed to bright lights in the region of approximately 600nm to 930nm. The NVIS will amplify the nighttime scene approximately 2000 times. The NVIS work by converting photons from the outside night scene onto a micro-displayed visible image.
NVIS are passive systems, typically helmet mounted binocular image intensification devices that have a very high sensitivity to radiation in the approximate region of 600nm to 930nm (orange to near infrared). Specific NVIS colored filters can be selected based on light source (LED or incandescent), transmission and NIR rejection requirements.
Nighttime screen filter pc full#
Full color NIR reflecting filters can only be used in the backlighting system due to photopic and off-angle reflections. Night vision filters can be incorporated in front of any display or light source, or into the backlight assembly or light guides of an LCD.
Glass NVIS White or Full Color (NIR Absorbing).Plastic NVIS White or Full Color (for white LED’s and full-color LCD’s).Dontech’s filters for night vision compatibility include: Furthermore, night vision compatibility (NVC) is only achieved when the design of the lighting equipment allows for proper use with and without the NVIS, at night or during the day.ĭontech provides filters for use in Classes A, B and C NVIS requirements and in Type I Direct View Image NVIS and Type II Projected Image NVIS (e.g., Cats Eyes) environments. Night vision goggles (NVG) or night vision imaging systems (NVIS) must be used in an environment that will not have near infrared (NIR) noise, which would interfere with the nighttime sensitivity of the NVGs. Dontech’s night vision filters are primarily used in military electronic display and lighting applications.