SBIR-STTR Award

Continuous attenuation of ambient light without image distortionis of great importance in helmet mounted displays. To accomplishthis, wepropose a device based on liquid crystal-dichroic dyemixture. The system is electrically controllable, light weight,with full grey scalecapability for all light conditions. Itaddresses all of the requirements and restrictions of visorbased helmet mounted displays. It canbe made to be fullyautomatic to maintain an essentially constant ambient lightintensity or manually adjustable by the operator. Therequirements for producing such devices are compatible withexisting stateof the art visor and goggle manufacturingtechnology. The scope of the proposed work is to identify themost suitable materials and systemconfigurations, and todemonstrate the principle of operation. A prototype will beconstructed for a goggle-based system to demonstrate theapplication and to address manufacturing issues. In addition tomilitary use, the system can be utilized by private sector foravionics and possibly other industries to control amient light.

Continuous attenuation of ambient light without image distortion is of vital importance for helmet mounted displays. In Phase I of thie project, we designed, developed and demonstrated an electrically controllable, lightweight Variable Attenuation Liquid Crystal Device (VALiD) with full gray scale capability for all relevant lighting conditions. It addressed all of the requirements and restrictions of a visor based helmet mounted display. In addition, we have designed, developed and demonstrated a "fail to clear" version of the device, FCVALiD, which can be implemented on plastic substates. The system can be made fully automatic to maintain constant ambient light intensity, or manually adjustable by the operator. The aim of the work proposed under Phase II is to - identify and develop materials and system configurations which optimize device performance,- determine drive electronics for manual and automatic control with full gray scale operation,- identify and address processing issues of plastic substrates,- implement FC-VALiD on a GENTEX supplied, cylindrical goggle or visor,- attempt to produce a flight-test worthy HGU-gg/p or HGU-86 type visor with FC-VALiD. This effort will be in co-operation with GENTEX and HONEYWELL

Keywords:
dichroic dye liquid crystal electrooptic plastic substrate ambient light attenuator curved substrat