A dispersion medium is filled in a display section and is dispersed with charged particles that migrates in accordance with a direction of an electric field. An image forming section applies, upon receiving an image forming request, an electric voltage between a first electrode and a second electrode to generate the electric field in the dispersion medium, thereby performing an image forming operation. A refresh controlling section switches, before the image forming section performs the image forming operation, the direction of the electric field alternately at predetermined timing to uniformly disperse the charged particles in the dispersion medium, thereby performing a refresh operation. An image-formation-elapsed-time measuring section measures a first elapsed time from a previous image forming operation performed by the image forming section until the image forming request. A refresh determining section determines whether the refresh controlling section performs the refresh operation based on the first elapsed time.