Parameters for Lowering the Driving Voltage of Twisting Ball Electronic Paper

We report the theoretical study and the model experiment on twisting ball displays for lowering their driving voltage toward the application of digital signage. A motion equation was theoretically derived for describing the rotation of a cylinder type display element. The motion equation suggests that there are two ways to lower the driving voltage. One is to increase the σ which represents the di ff erence in the surface electric charge densities of the black and white regions of the display elements. Another is to increase the sin θ . The θ is the angle between the boundary of the black and white regions and the perpendicular to the electric field. The rotations of display elements were also characterized experimentally, with particular emphasis on the threshold voltage and the response time, as a function of σ and θ . We found theoretically and experimentally that both σ and θ are important parameters to lower the driving voltage of twisting ball displays.