Ambient Light Control Using Guest Host Liquid Crystal-Dye Systems

Continuous attenuation of ambient light without image distortion is of great importance in helmet mounted displays. To accomplish this, we propose a device based on liquid crystal-dichroic dye mixture. The system is electrically controllable, light weight, with full grey scale capability for all light conditions. It addresses all of the requirements and restrictions of visor based helmet mounted displays. It can be made to be fully automatic to maintain an essentially constant ambient light intensity or manually adjustable by the operator. The requirements for producing such devices are compatible with existing state of the art visor and goggle manufacturing technology. The scope of the proposed work is to identify the most suitable materials and system configurations, and to demonstrate the principle of operation. A prototype will be constructed for a goggle-based system to demonstrate the application and to address manufacturing issues. In addition to military use, the system can be utilized by private sector for avionics and possibly other industries to control amient light.