Patent ID: 8547324

Claim:
An electrophoretic display sheet comprising: a display layer having one surface and an other surface opposite to the one surface, a dispersion liquid in which first particles and second particles are dispersed, and a plurality of reservoir portions provided between the one surface and the other surface, the plurality of reservoir portions being filled with the dispersion liquid in which the first particles and the second particles are dispersed, and the reservoir portions having predetermined positions and a bottom surface, wherein the first particles exhibit an electrorheological effect and have at least one color, and the second particles have a color that is different from the at least one color of the first particles; a first electrode provided on the one surface of the display layer; and second electrodes provided on the other surface of the display layer; wherein when a primary electric field is generated in the display layer by applying a primary voltage between the first electrode and the second electrodes, the second particles dispersed in the dispersion liquid constitute a colored part on the bottom surface of the reservoir portions by being fixed to the bottom surface of the reservoir portions impeding movement of the second particles in the dispersion liquid, and when an electric field having a direction is generated in the display layer by applying a voltage between the first electrode and the second electrodes, the first particles dispersed in the dispersion liquid are locally gathered to the predetermined positions of the reservoir portions so as to make rows of the first particles along the direction of the electric field in the dispersion liquid due to the electrorheological effect, so that the colored part constituted of the second particles is visible through gaps between the rows of the first particles, and a color in the reservoir portions visibly observed through the rows of the first particles is the color of the second particles, while the second particles remain fixed to the bottom surface of the reservoir portions impeding the movement of the second particles in the dispersion liquid.