Patent ID: 8144117

Claim:
An image display device comprising: a display unit that has electrophoretic particles between a rear-surface electrode on a rear-surface substrate and a transparent electrode on a transparent substrate provided for each of plural display pixels constituting a display image and that generates a driving electric field for moving the electrophoretic particles to the rear-surface electrode or the transparent electrode between the rear-surface electrode and the transparent electrode for each of the plural display pixels, a display status of each of the plural display pixels being changed when the electrophoretic particles are moved; and a driving unit that applies, after receiving a display driving instruction, a display driving voltage for controlling the driving electric field of each of the plural display pixels to at least one of the rear-surface electrode and the transparent electrode for each of the plural display pixels, an arrangement of the electrophoretic particles corresponding to the display driving voltage being maintained even after the driving unit completes the application of the display driving voltage, which results in maintaining the display status of the display image, wherein, when not applying a next display driving voltage even after a predetermined time elapses from starting or completion of applying a previous display driving voltage, the driving unit applies, to at least one of the rear-surface electrode and the transparent electrode, a preparatory driving voltage for generating a preparatory electric field capable of improving a response of the electrophoretic particles to the driving electric field to an extent so as not to change the arrangement of the electrophoretic particles for a predetermined preparatory driving time, the predetermined time is adjusted based on whether a power source of the image display is a battery or an electric power supply.