Flat Head-Mounted Displays

A number of military situations require individual soldiers and pilots to instantaneously respond to complex visual scenes and make rapid decisions regarding potential threats. Text and graphics overlaid on the scene provide a means to aid the soldier in the decision making process. Helmet mounted displays that simultaneously allow the direct view of the natural scene with text and graphic overlays are referred to as augmented vision or see-through displays. Examples of graphics include maps, targeting coordinates and instant access to instruction manuals. The challenge of adding text and graphics to the vision channel has been addressed by a number of organizations for both commercial and military applications. Demonstrations for the Land Warrior program, the Commanche Helicopter and the European Eurofighter Typhoon have met with encouraging results, but systems are plagued by high cost and excessive weight and volume. The traditional solution has been to form images of expensive microdisplays on the retina. The required specifications for the image delivery system have resulted in expensive and complex optical systems. We propose to eliminate the requirement for expensive imaging optics by encoding the far field pattern of the desired information onto a computer generated hologram (CGH). The CGH will reside near the pupil of the eye, and the lens of the eye will perform the necessary transformation to present the desired overlay image data to the retina. We propose to apply our considerable expertise in CGH design and fabrication to demonstrating the feasibility of this revolutionary approach to near-eye see-through microdisplays. We will explore a variety of optical microsystem architectures to evaluate the requirements on beam delivery. While the initial demonstration system will provide a fixed overlay, we will enable future dynamic overlays by developing architectures and fast hardware accelerated algorithms for computing far field information in real-time.