Ultrabright head-mounted displays using LED-illuminated LCOS

We report design and test of a high brightness laboratory-breadboard LED/LCOS HMD system employing a 0.78-inchdiagonal 1280× 768 ferroelectric liquid-crystal-on-silicon microdisplay and a red-green-blue LED. With an 8× viewing optic giving a 35°-diagonal field of view, the system yielded brightnesses greater 40,000 cd/m2 (12,000 fL) in colorsequential mode and greater than 100,000 cd/m2 (30,000 fL) in monochrome mode, at LED power consumptions of 1.1 W and 3.3 W, respectively. The illumination optics employed a rectangular light pipe and tailored diffuser to efficiently fill the microdisplay panel aperture and exit pupil. The high efficiency of such image generators facilitates display readability in see-through HMDs operating in high-ambient-light environments, as well as enabling ultra-low power HMDs (less than 100 mW total) for dismounted users of battery-powered systems.