All solid state electrochromic device for helmet-mounted displays

Helmet-Mounted Displays (HMDs) do not allow the pilot to change transmission level of a visor transitioning from high to low light levels. A variable-transmittance visor (VTV) is a possible solution. The Eclipse Variable Electrochromic Device (EclipseECDTM) is well suited for these light modulation applications. The EclipseECTM modulates light intensity by changing the transmission level under an applied electric field. The optical density may be continuously changed by varying voltage. EclipseECDTM is comprised of vacuum deposited layers of a transparent bottom electrode, an active element, and a transparent top electrode, incorporating an all, solid-state electrolyte. The solid-state electrolyte eliminates possible complications associated with gel-based technologies, the need for lamination, and any additional visor modifications. The low-temperature deposition process enables direct application onto HMD flight visors. Additionally, the coating is easily manufactured; can be trimmed, has near spectral neutrality and fails in the clear (bleached) condition. Before introducing VTV technology to the warfighter, there are numerous human factors issues that must be assessed. Considerations include optical characteristics such as transmissive range, haze, irising, internal reflections, multiple imaging, user controllability, ease of fit, and field of view. Advanced materials tailoring coupled with meeting critical criteria will help ensure successful integration of VTV technology.