Investigation of oil-motion non-uniformity in a reflective display based on electrowetting

A novel reflective display based on electrowetting technology has gained much attention because of its readability in sunlight. This technology can provide high-efficiency control of the display pixel reflectivity. In the on-state, the oil droplet is expected to move to the same corner regularly. To realize uniform motion of the oil, it is possible to provide a symmetry-breaking mechanism in the pixel. However, depending on the uniformity of the processing and the size of the built-in symmetry breaking, it is possible that the oil actually moves to a different position. The visibility of defects, by the representation of oil-motion non-uniformity, depending on different notch pattern, notch size, and defect type, has been investigated in the perception experiments. Results indicate that the influence of the defects is more obvious for the more preferred pattern. The larger the notch sizes, the easier the defects can be observed. The best notch pattern is pointed out. When designing an electrowetting display, these results need to be considered to eliminate the influence of oil-motion non-uniformity on the image quality by making the droplet as small as possible or by adding optical layers such as diffusers films.