Ultra-High Transmission Electrowetting Displays Enabled by Integrated Reflectors

A reflector technique for increasing the transmission performance of a back-lit electrowetting display is presented. The electrowetting display pixel structure consists of an opaque oil film that blocks light transmission. Electrowetting with 5-10 V breaks up the oil film and creates a transmissive area for the pixel. With real-world electrowetting materials and device constraints, the transmissive area typically reaches 60% to 80% of the pixel area. By integrating a simple thin-film reflector between the backlight and the remaining oil film area, the effective transmission can be boosted to >90%. This high efficiency is promising for battery-powered applications and for high-brightness sunlight-legible displays.