Patent ID: 7230604

Claim:
A drive method for displaying an image on a display medium comprising first and second substrates, at least one of which is transparent, disposed with a gap therebetween, and two types of particles sealed between the first and second substrates, each type of particle having different color and charge characteristics than the other type of particle, comprising: applying a first voltage pulse to at least one of the first and second substrates to urge particles that, according to the image, are to move to the first substrate to move towards the first substrate when changing an image displayed on the medium; and applying a second voltage pulse to urge particles that, according to the image, are to move to the second substrate, opposite to the first substrate, to move towards the second substrate, thereby changing the image displayed on the medium; wherein the first substrate comprises a first electrode and the second substrate comprises a second electrode, the first and second voltage pulses are applied between the first electrode and the second electrode, and at least the first and second voltage pulses are applied to produce the image, and wherein the display medium is free of liquid.