1000:1 Contrast Ratio Transmissive Electrowetting Displays

Transmissive electrowetting display pixels are reported with ~1000:1 contrast ratio and >; 50% optical transmission. This high performance is enabled by improved optical density of a black oil layer, and through use of an integrated metal reflector. The integrated metal reflector is placed such that black-oil motion self-aligns with the reflector, ensuring optimal operation of the pixel structure. The integrated reflector can also serve as a storage capacitor during active-matrix addressing. The pixels utilize new black SU-8 for the hydrophilic grid, which allows high contrast ratio in bright lighting. These high contrast electrowetting display pixels are increasingly compelling for high efficiency transmissive displays, and it is theoretically predicted that >; 80% transmission, <; 20 ms switching speed, and >; 1000:1 contrast ratio can be simultaneously achieved with optimized design.